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Sample records for neutron quality factor

  1. Neutron quality factor

    SciTech Connect

    1995-06-01

    Both the International Commission on Radiological Protection (ICRP) and the National Council on Radiation Protection and Measurements (NCRP) have recommended that the radiation quality weighting factor for neutrons (Q{sub n}, or the corresponding new modifying factor, w{sub R}) be increased by a value of two for most radiation protection practices. This means an increase in the recommended value for Q{sub n} from a nominal value of 10 to a nominal value of 20. This increase may be interpreted to mean that the biological effectiveness of neutrons is two times greater than previously thought. A decision to increase the value of Q{sub n} will have a major impact on the regulations and radiation protection programs of Federal agencies responsible for the protection of radiation workers. Therefore, the purposes of this report are: (1) to examine the general concept of {open_quotes}quality factor{close_quotes} (Q) in radiation protection and the rationale for the selection of specific values of Q{sub n}; and (2) to make such recommendations to the Federal agencies, as appropriate. This report is not intended to be an exhaustive review of the scientific literature on the biological effects of neutrons, with the aim of defending a particular value for Q{sub n}. Rather, the working group examined the technical issues surrounding the current recommendations of scientific advisory bodies on this matter, with the aim of determining if these recommendations should be adopted by the Federal agencies. Ultimately, the group concluded that there was no compelling basis for a change in Q{sub n}. The report was prepared by Federal scientists working under the auspices of the Science Panel of the Committee on Interagency Radiation Research and Policy Coordination (CIRRPC).

  2. Photon and neutron dose contributions and mean quality factors phantoms of different size irradiated by monoenergetic neutrons.

    PubMed

    Dietze, G; Siebert, B R

    1994-10-01

    The International Commission on Radiological Protection (ICRP) in its Publication 60 introduced important changes in the concept of risk-related quantities. For external neutron radiation in particular the introduction of the equivalent dose with the radiation weighting factor wR instead of the dose equivalent concept with the quality factor Q(L) has many consequences. The value of wR is defined by the external neutron radiation field, while the radiation quality in the phantom depends on the radiation field at the position of interest and hence on the size of and the position in the phantom. It has been investigated to what extent the size of the phantom influences the mean radiation quality in the phantoms. For incident monoenergetic neutrons, mean photon dose contributions and mean quality factors have been calculated. Results are presented for various phantoms which characterize the conditions for a mouse, a rat, the ICRU sphere and a human body.

  3. Neutrons in proton pencil beam scanning: parameterization of energy, quality factors and RBE

    NASA Astrophysics Data System (ADS)

    Schneider, Uwe; Hälg, Roger A.; Baiocco, Giorgio; Lomax, Tony

    2016-08-01

    The biological effectiveness of neutrons produced during proton therapy in inducing cancer is unknown, but potentially large. In particular, since neutron biological effectiveness is energy dependent, it is necessary to estimate, besides the dose, also the energy spectra, in order to obtain quantities which could be a measure of the biological effectiveness and test current models and new approaches against epidemiological studies on cancer induction after proton therapy. For patients treated with proton pencil beam scanning, this work aims to predict the spatially localized neutron energies, the effective quality factor, the weighting factor according to ICRP, and two RBE values, the first obtained from the saturation corrected dose mean lineal energy and the second from DSB cluster induction. A proton pencil beam was Monte Carlo simulated using GEANT. Based on the simulated neutron spectra for three different proton beam energies a parameterization of energy, quality factors and RBE was calculated. The pencil beam algorithm used for treatment planning at PSI has been extended using the developed parameterizations in order to calculate the spatially localized neutron energy, quality factors and RBE for each treated patient. The parameterization represents the simple quantification of neutron energy in two energy bins and the quality factors and RBE with a satisfying precision up to 85 cm away from the proton pencil beam when compared to the results based on 3D Monte Carlo simulations. The root mean square error of the energy estimate between Monte Carlo simulation based results and the parameterization is 3.9%. For the quality factors and RBE estimates it is smaller than 0.9%. The model was successfully integrated into the PSI treatment planning system. It was found that the parameterizations for neutron energy, quality factors and RBE were independent of proton energy in the investigated energy range of interest for proton therapy. The pencil beam algorithm has

  4. Effective quality factors for neutrons based on the revised ICRP/ICRU recommendations.

    PubMed

    Veinot, K G; Hertel, N E

    2005-01-01

    The quality factor (Q) is intended to relate the biological effectiveness of a radiation to the absorbed dose delivered in tissue. Quality factors are defined as a function of the unrestricted linear energy transfer (L) relationship in water and are used with operational quantities. Radiation weighting factors (wR) are used in protection quantities to take into account total radiation detriment. While the International Commission on Radiological Protection (ICRP) defines the Q(L) relationship, the International Commission on Radiation Units and Measurements (ICRU) recommends the charged particle stopping power and range data. If either of these data recommendations change, the quality factors must be recomputed. The latest guidance from both organisations applicable to neutron quality factors are the ICRP Publication 60 (Q(L) relationship) and the ICRU Report 49 (stopping power and range data). In the present study, absorbed dose conversion coefficients (pGy cm2) were calculated for two operational quantities defined by the ICRU--the ambient absorbed dose and the personal absorbed dose. Dose-equivalent (pSv cm2) conversion coefficients were also computed using mean quality factors based on ICRP 60 and ICRU 49 recommendations. Effective quality factors were then calculated from the ratio of the dose-equivalent to the absorbed dose conversion coefficients for both the personal dose-equivalent and ambient dose-equivalent and compared to values reported in the literature.

  5. Analysis of linear energy transfers and quality factors of charged particles produced by spontaneous fission neutrons from 252Cf and 244Pu in the human body.

    PubMed

    Endo, Akira; Sato, Tatsuhiko

    2013-04-01

    Absorbed doses, linear energy transfers (LETs) and quality factors of secondary charged particles in organs and tissues, generated via the interactions of the spontaneous fission neutrons from (252)Cf and (244)Pu within the human body, were studied using the Particle and Heavy Ion Transport Code System (PHITS) coupled with the ICRP Reference Phantom. Both the absorbed doses and the quality factors in target organs generally decrease with increasing distance from the source organ. The analysis of LET distributions of secondary charged particles led to the identification of the relationship between LET spectra and target-source organ locations. A comparison between human body-averaged mean quality factors and fluence-averaged radiation weighting factors showed that the current numerical conventions for the radiation weighting factors of neutrons, updated in ICRP103, and the quality factors for internal exposure are valid.

  6. Neutron charge radius and the neutron electric form factor

    SciTech Connect

    Gentile, T. R.; Crawford, C. B.

    2011-05-15

    For nearly forty years, the Galster parametrization has been employed to fit existing data for the neutron electric form factor, G{sub E}{sup n}, vs the square of the four-momentum transfer, Q{sup 2}. Typically this parametrization is constrained to be consistent with experimental data for the neutron charge radius. However, we find that the Galster form does not have sufficient freedom to accommodate reasonable values of the radius without constraining or compromising the fit. In addition, the G{sub E}{sup n} data are now at sufficient precision to motivate a two-parameter fit (or three parameters if we include thermal neutron data). Here we present a modified form of a two-dipole parametrization that allows this freedom and fits both G{sub E}{sup n} (including recent data at both low and high four-momentum transfer) and the charge radius well with simple, well-defined parameters. Analysis reveals that the Galster form is essentially a two-parameter approximation to the two-dipole form but becomes degenerate if we try to extend it naturally to three parameters.

  7. Neutron Detector Signal Processing to Calculate the Effective Neutron Multiplication Factor of Subcritical Assemblies

    SciTech Connect

    Talamo, Alberto; Gohar, Yousry

    2016-06-01

    This report describes different methodologies to calculate the effective neutron multiplication factor of subcritical assemblies by processing the neutron detector signals using MATLAB scripts. The subcritical assembly can be driven either by a spontaneous fission neutron source (e.g. californium) or by a neutron source generated from the interactions of accelerated particles with target materials. In the latter case, when the particle accelerator operates in a pulsed mode, the signals are typically stored into two files. One file contains the time when neutron reactions occur and the other contains the times when the neutron pulses start. In both files, the time is given by an integer representing the number of time bins since the start of the counting. These signal files are used to construct the neutron count distribution from a single neutron pulse. The built-in functions of MATLAB are used to calculate the effective neutron multiplication factor through the application of the prompt decay fitting or the area method to the neutron count distribution. If the subcritical assembly is driven by a spontaneous fission neutron source, then the effective multiplication factor can be evaluated either using the prompt neutron decay constant obtained from Rossi or Feynman distributions or the Modified Source Multiplication (MSM) method.

  8. Variance Reduction Factor of Nuclear Data for Integral Neutronics Parameters

    SciTech Connect

    Chiba, G. Tsuji, M.; Narabayashi, T.

    2015-01-15

    We propose a new quantity, a variance reduction factor, to identify nuclear data for which further improvements are required to reduce uncertainties of target integral neutronics parameters. Important energy ranges can be also identified with this variance reduction factor. Variance reduction factors are calculated for several integral neutronics parameters. The usefulness of the variance reduction factors is demonstrated.

  9. Neutron electric form factor via recoil polarimetry

    SciTech Connect

    Madey, Richard; Semenov, Andrei; Taylor, Simon; Aghalaryan, Aram; Crouse, Erick; MacLachlan, Glen; Plaster, Bradley; Tajima, Shigeyuki; Tireman, William; Yan, Chenyu; Ahmidouch, Abdellah; Anderson, Brian; Asaturyan, Razmik; Baker, O; Baldwin, Alan; Breuer, Herbert; Carlini, Roger; Christy, Michael; Churchwell, Steve; Cole, Leon; Danagoulian, Samuel; Day, Donal; Elaasar, Mostafa; Ent, Rolf; Farkhondeh, Manouchehr; Fenker, Howard; Finn, John; Gan, Liping; Garrow, Kenneth; Gueye, Paul; Howell, Calvin; Hu, Bitao; Jones, Mark; Kelly, James; Keppel, Cynthia; Khandaker, Mahbubul; Kim, Wooyoung; Kowalski, Stanley; Lung, Allison; Mack, David; Manley, D; Markowitz, Pete; Mitchell, Joseph; Mkrtchyan, Hamlet; Opper, Allena; Perdrisat, Charles; Punjabi, Vina; Raue, Brian; Reichelt, Tilmann; Reinhold, Joerg; Roche, Julie; Sato, Yoshinori; Seo, Wonick; Simicevic, Neven; Smith, Gregory; Stepanyan, Samuel; Tadevosyan, Vardan; Tang, Liguang; Ulmer, Paul; Vulcan, William; Watson, John; Wells, Steven; Wesselmann, Frank; Wood, Stephen; Yan, Chen; Yang, Seunghoon; Yuan, Lulin; Zhang, Wei-Ming; Zhu, Hong Guo; Zhu, Xiaofeng

    2003-05-01

    The ratio of the electric to the magnetic form factor of the neutron, G_En/G_Mn, was measured via recoil polarimetry from the quasielastic d({pol-e},e'{pol-n)p reaction at three values of Q^2 [viz., 0.45, 1.15 and 1.47 (GeV/c)^2] in Hall C of the Thomas Jefferson National Accelerator Facility. Preliminary data indicate that G_En follows the Galster parameterization up to Q^2 = 1.15 (GeV/c)^2 and appears to rise above the Galster parameterization at Q^2 = 1.47 (GeV/c)^2.

  10. Kerma factors for use in 37-group neutron spectrum calculations

    NASA Astrophysics Data System (ADS)

    Zeman, G. H.; Bice, W. S., Jr.

    1983-12-01

    Neutron kerma factors have been regrouped from the format of the International Commission on Radiation Units and Measurements Report 26 (ICRU-26) to supplement those available in the 37-group format of the Oak Ridge Data Library Collection 31 (DLC-31). Lists of regrouped neutron kerma factors are presented for eight elements and for seven compounds and mixtures. For several elements, disagreements in excess of 15% were observed between those neutron kerma factors available in DLC-31 and the regrouped neutron kerma factors of ICRU-26.

  11. Kerma Factors for Use in 37-Group Neutron Spectrum Calculations

    DTIC Science & Technology

    1983-12-01

    PFPPI TECHNICAL REPORT Kerma factors for use in 37-group neutron spectrum calculations en en CO G. H. Zeman W. S. Bice, Jr. DEFENSE NUCLEAR...AGENCY ARMED FORCES RADIOBIOLOGY RESEARCH INSTITUTE BETHESDA, MARYLAND 20814 APPRCVED FOR PUBLIC RELEASE; DISTRIBUTION UNLIMITED REVIEWED AND...FACTORS FOR USE IN 37-GROUP NEUTRON SPECTRUM CALCULATIONS 7. AUTHORfs; G. H. Zeman and W. S. Bice, Jr. 9. PERFORMING

  12. Thermal neutron self-shielding correction factors for large sample instrumental neutron activation analysis using the MCNP code

    NASA Astrophysics Data System (ADS)

    Tzika, F.; Stamatelatos, I. E.

    2004-01-01

    Thermal neutron self-shielding within large samples was studied using the Monte Carlo neutron transport code MCNP. The code enabled a three-dimensional modeling of the actual source and geometry configuration including reactor core, graphite pile and sample. Neutron flux self-shielding correction factors derived for a set of materials of interest for large sample neutron activation analysis are presented and evaluated. Simulations were experimentally verified by measurements performed using activation foils. The results of this study can be applied in order to determine neutron self-shielding factors of unknown samples from the thermal neutron fluxes measured at the surface of the sample.

  13. Experimental setup for the determination of the correction factors of the neutron doseratemeters in fast neutron fields

    SciTech Connect

    Iliescu, Elena; Bercea, Sorin; Dudu, Dorin; Celarel, Aurelia

    2013-12-16

    The use of the U-120 Cyclotron of the IFIN-HH allowed to perform a testing bench with fast neutrons in order to determine the correction factors of the doseratemeters dedicated to neutron measurement. This paper deals with researchers performed in order to develop the irradiation facility testing the fast neutrons flux generated at the Cyclotron. This facility is presented, together with the results obtain in determining the correction factor for a doseratemeter dedicated to the neutron dose equivalent rate measurement.

  14. A study of neutron radiation quality with a tissue-equivalent proportional counter for a low-energy accelerator-based in vivo neutron activation facility.

    PubMed

    Aslam; Waker, A J

    2011-02-01

    The accelerator-based in vivo neutron activation facility at McMaster University has been used successfully for the measurement of several minor and trace elements in human hand bones due to their importance to health. Most of these in vivo measurements have been conducted at a proton beam energy (E(p)) of 2.00 MeV to optimise the activation of the selected element of interest with an effective dose of the same order as that received in chest X rays. However, measurement of other elements at the same facility requires beam energies other than 2.00 MeV. The range of energy of neutrons produced at these proton beam energies comes under the region where tissue-equivalent proportional counters (TEPCs) are known to experience difficulty in assessing the quality factor and dose equivalent. In this study, the response of TEPCs was investigated to determine the quality factor of neutron fields generated via the (7)Li(p, n)(7)Be reaction as a function of E(p) in the range 1.884-2.56 MeV at the position of hand irradiation in the facility. An interesting trend has been observed in the quality factor based on ICRP 60, Q(ICRP60), such that the maximum value was observed at E(p)=1.884 MeV (E(n)=33±16 keV) and then continued to decline with increasing E(p) until achieving a minimum value at E(p)=2.0 MeV despite a continuous increase in the mean neutron energy with E(p). This observation is contrary to what has been observed with direct fast neutrons where the quality factor was found to increase continuously with an increase in E(p) (i.e. increasing E(n)). The series of measurements conducted with thermal and fast neutron fields demonstrate that the (14)N(n, p)(14)C produced 580 keV protons in the detector play an important role in the response of the counter under 2.0 MeV proton energy (E(n) ≤ 250 keV). In contrast to the lower response of TEPCs to low-energy neutrons, the quality factor is overestimated in the range 1-2 depending on beam energy <2.0 MeV. This study provides

  15. Factors Affecting Medical Service Quality

    PubMed Central

    MOSADEGHRAD, Ali Mohammad

    2014-01-01

    Abstract Background A better understanding of factors influencing quality of medical service can pinpoint better strategies for quality assurance in medical services. This study aimed to identify factors affecting the quality of medical services provided by Iranian physicians. Methods Exploratory in-depth individual interviews were conducted with sixty-four physicians working in various medical institutions in Iran. Results Individual, organizational and environmental factors enhance or inhibit the quality of medical services. Quality of medical services depends on the personal factors of the physician and patient, and factors pertaining to the healthcare setting and the broader environment. Conclusion Differences in internal and external factors such as availability of resources, patient cooperation and collaboration among providers affect the quality of medical services and patient outcomes. Supportive leadership, proper planning, education and training and effective management of resources and processes improve the quality of medical services. This article contributes to healthcare theory and practice by developing a conceptual framework for understanding factors that influence medical services quality. PMID:26060745

  16. Factors influencing healthcare service quality

    PubMed Central

    Mosadeghrad, Ali Mohammad

    2014-01-01

    Background: The main purpose of this study was to identify factors that influence healthcare quality in the Iranian context. Methods: Exploratory in-depth individual and focus group interviews were conducted with 222 healthcare stakeholders including healthcare providers, managers, policy-makers, and payers to identify factors affecting the quality of healthcare services provided in Iranian healthcare organisations. Results: Quality in healthcare is a production of cooperation between the patient and the healthcare provider in a supportive environment. Personal factors of the provider and the patient, and factors pertaining to the healthcare organisation, healthcare system, and the broader environment affect healthcare service quality. Healthcare quality can be improved by supportive visionary leadership, proper planning, education and training, availability of resources, effective management of resources, employees and processes, and collaboration and cooperation among providers. Conclusion: This article contributes to healthcare theory and practice by developing a conceptual framework that provides policy-makers and managers a practical understanding of factors that affect healthcare service quality. PMID:25114946

  17. The Magnetic Form Factor of the Neutron, G

    NASA Astrophysics Data System (ADS)

    Markowitz, Pete Edward Christopher

    We measured the d(e,e^' n)p cross-section at three values of Q^2 : 0.255, 0.176 and 0.109 (GeV/c)^2 . The electrons were detected with the OHIPS magnetic spectrometer, and the neutrons were detected in a liquid mineral oil scintillator array. The measurement were made at a fixed neutron angle of theta_ {n} = 57^circ; the Q^2 values were obtained by varying the incident electron energy and the scattering angle. These cross sections are sensitive primarily to the neutron magnetic form factor at these quasifree kinematics. The efficiency of the neutron detector was determined by the associated particle technique with the d(gamma ,pn) reaction for each of the three neutron kinetic energies. The value of G_sp{M} {n} extracted from the cross sections are consistent with the dipole parametrization at the two higher momentum transfers; at the lowest momentum transfer the value of G_sp{M}{n} is 10% higher than the dipole model. This enhancement at low momentum transfer is consistent with previous measurements.

  18. Neutron-Proton Asymmetry Dependence of Spectroscopic Factors in Ar Isotopes

    SciTech Connect

    Lee, Jenny; Tsang, Betty; Shapira, Dan

    2010-01-01

    Spectroscopic factors have been extracted for proton-rich 34Ar and neutron-rich 46Ar using the (p, d) neutron transfer reaction. The experimental results show little reduction of the ground state neutron spectroscopic factor of the proton-rich nucleus 34Ar compared to that of 46Ar. The results suggest that correlations, which generally reduce such spectroscopic factors, do not depend strongly on the neutron-proton asymmetry of the nucleus in this isotopic region as was reported in knockout reactions. The present results are consistent with results from systematic studies of transfer reactions but inconsistent with the trends observed in knockout reaction measurements.

  19. Prospects for using coherent elastic neutrino-nucleus scattering to measure the nuclear neutron form factor

    NASA Astrophysics Data System (ADS)

    Patton, Kelly; McLaughlin, Gail; Scholberg, Kate; Engel, Jon; Schunck, Nicolas

    2017-01-01

    Coherent elastic neutrino-nucleus scattering is a potential probe of nuclear neutron form factors. We show that the neutron root-mean-square (RMS) radius can be measured with tonne-scale detectors of argon, germanium, or xenon. In addition, the fourth moment of the neutron distribution can be studied experimentally using this method. The impacts of both detector size and detector shape uncertainty on such a measurement were considered. The important limiting factor was found to be the detector shape uncertainty. In order to measure the neutron RMS radius to 5%, comparable to current experimental uncertainties, the detector shape uncertainty needs to be known to 1% or better.

  20. The neutron electric form factor to Q² = 1.45 (GeV/c)²

    SciTech Connect

    Plaster, Bradley

    2004-02-01

    The nucleon elastic electromagnetic form factors are fundamental quantities needed for an understanding of nucleon and nuclear electromagnetic structure. The evolution of the Sachs electric and magnetic form factors with Q2, the square of the four-momentum transfer, is related to the distribution of charge and magnetization within the nucleon. High precision measurements of the nucleon form factors are essential for stringent tests of our current theoretical understanding of confinement within the nucleon. Measurements of the neutron form factors, in particular, those of the neutron electric form factor, have been notoriously difficult due to the lack of a free neutron target and the vanishing integral charge of the neutron. Indeed, a precise measurement of the neutron electric form factor has eluded experimentalists for decades; however, with the advent of high duty-factor polarized electron beam facilities, experiments employing polarization degrees of freedom have finally yielded the first precise measurements of this fundamental quantity. Following a general overview of the experimental and theoretical status of the nucleon form factors, a detailed description of an experiment designed to extract the neutron electric form factor from measurements of the neutron's recoil polarization in quasielastic 2H(e, e')1H scattering is presented. The experiment described here employed the Thomas Jefferson National Accelerator Facility's longitudinally polarized electron beam, a magnetic spectrometer for detection of the scattered electron, and a neutron polarimeter designed specifically for this experiment. Measurements were conducted at three Q2 values of 0.45, 1.13, and 1.45 (GeV/c)2, and the final results extracted from an analysis of the data acquired in this experiment are reported and compared with recent theoretical predictions for the nucleon form factors.

  1. Charge form factors of two-neutron halo nuclei in halo EFT

    NASA Astrophysics Data System (ADS)

    Hagen, P.; Hammer, H.-W.; Platter, L.

    2013-09-01

    We set up a formalism to calculate the charge form factors of two-neutron halo nuclei with S -wave neutron-core interactions in the framework of the halo effective field theory. The method is applied to some known and suspected halo nuclei. In particular, we calculate the form factors and charge radii relative to the core to leading order in the halo EFT and compare to experiments where they are available. Moreover, we investigate the general dependence of the charge radius on the core mass and the one- and two-neutron separation energies.

  2. Calculation of self-shielding factor for neutron activation experiments using GEANT4 and MCNP

    NASA Astrophysics Data System (ADS)

    Romero-Barrientos, Jaime; Molina, F.; Aguilera, Pablo; Arellano, H. F.

    2016-07-01

    The neutron self-shielding factor G as a function of the neutron energy was obtained for 14 pure metallic samples in 1000 isolethargic energy bins from 1.10-5eV to 2.107eV using Monte Carlo simulations in GEANT4 and MCNP6. The comparison of these two Monte Carlo codes shows small differences in the final self-shielding factor mostly due to the different cross section databases that each program uses.

  3. Interpreting the neutron's electric form factor: Rest frame charge distribution or foldy term?

    SciTech Connect

    Nathan Isgur

    1998-12-01

    The neutron's electric form factor contains vital information on nucleon structure, but its interpretation within many models has been obscured by relativistic effects. The author demonstrates that, to leading order in the relativistic expansion of a constituent quark model, the Foldy term cancels exactly against a contribution to the Dirac form factor F{sub 1} to leave intact the naive interpretation of G{sup n}{sub E} as arising from the neutron's rest frame charge distribution.

  4. Neutron dose per fluence and weighting factors for use at high energy accelerators.

    PubMed

    Cossairt, J Donald; Vaziri, Kamran

    2009-06-01

    In June 2007, the United States Department of Energy incorporated revised values of neutron weighting factors into its occupational radiation protection regulation Title 10, Code of Federal Regulations Part 835, as part of updating its radiation dosimetry system. This has led to a reassessment of neutron radiation fields at high energy accelerators such as those at the Fermi National Accelerator Laboratory (Fermilab) in the context of the amended regulation and contemporary guidance of the International Commission on Radiological Protection (ICRP). Values of dose per fluence factors appropriate for accelerator radiation fields calculated elsewhere are collated and radiation weighting factors compared. The results of this revision to the dosimetric system are applied to americium-beryllium neutron energy spectra commonly used for instrument calibrations. Also, a set of typical accelerator neutron energy spectra previously measured at Fermilab are reassessed in light of the new dosimetry system. The implications of this revision and of recent ICRP publications are found to be of moderate significance.

  5. Neutron dose per fluence and weighting factors for use at high energy accelerators

    SciTech Connect

    Cossairt, J.Donald; Vaziri, Kamran; /Fermilab

    2008-07-01

    In June 2007, the United States Department of Energy incorporated revised values of neutron weighting factors into its occupational radiation protection Regulation 10 CFR Part 835 as part of updating its radiation dosimetry system. This has led to a reassessment of neutron radiation fields at high energy proton accelerators such as those at the Fermi National Accelerator Laboratory (Fermilab). Values of dose per fluence factors appropriate for accelerator radiation fields calculated elsewhere are collated and radiation weighting factors compared. The results of this revision to the dosimetric system are applied to americium-beryllium neutron energy spectra commonly used for instrument calibrations. A set of typical accelerator neutron energy spectra previously measured at Fermilab are reassessed in light of the new dosimetry system. The implications of this revision are found to be of moderate significance.

  6. 7 CFR 52.782 - Allowances for quality factors.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 2 2011-01-01 2011-01-01 false Allowances for quality factors. 52.782 Section 52.782... for Quality Factors § 52.782 Allowances for quality factors. Table IV—Allowances for Quality Factors Factor Sample unit size Maximum number permissible for the respective grade A A B B C C Pits 20 ozs...

  7. Factors Affecting School Quality in Florida

    ERIC Educational Resources Information Center

    Thornton, Barry; Arbogast, Gordon

    2014-01-01

    This paper examines the factors that are theorized to be determinants of school quality in the 67 counties of Florida from 2000 to 2011. The model constructed for this purpose is comprised of a mix of independent variables that include county educational attainment (number of high school graduates and State University System enrollees) and…

  8. Factors that Predict Quality Classroom Technology Use

    ERIC Educational Resources Information Center

    Hastings, Tricia A.

    2009-01-01

    Despite technological advancements intended to enhance teaching and learning in the 21st century, numerous teacher and school factors continue to impede quality classroom technology use. Determining the effectiveness of educational technology is challenging and requires a detailed understanding of multifaceted, complex, contextual relationships.…

  9. Microscopic structure factor of liquid hydrogen by neutron-diffraction measurements

    SciTech Connect

    Celli, M.; Bafile, U.; Zoppi, M.; Cuello, G.J.; Formisano, F.; Magli, R.; Neumann, M.

    2005-01-01

    The center-of-mass structure factor of liquid para hydrogen has been measured, using neutron diffraction, in four thermodynamic states close to the triple point. Path integral Monte Carlo simulations have been carried out at the same temperatures and densities. The present experimental data are in reasonable quantitative agreement with the simulations and closer to these results than previous neutron determinations available in the literature. The thermodynamic derivatives of the structure factor, from both experiment and simulation, have been compared to previous measurements obtaining a quantitative consistency.

  10. 7 CFR 52.810 - Allowances for quality factors.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... PROCESSED FOOD PRODUCTS 1 United States Standards for Grades of Frozen Red Tart Pitted Cherries Allowances for Quality Factors § 52.810 Allowances for quality factors. Table I—Allowances for Quality Factors... 7 Agriculture 2 2011-01-01 2011-01-01 false Allowances for quality factors. 52.810 Section...

  11. 7 CFR 52.810 - Allowances for quality factors.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... PROCESSED FOOD PRODUCTS 1 United States Standards for Grades of Frozen Red Tart Pitted Cherries Allowances for Quality Factors § 52.810 Allowances for quality factors. Table I—Allowances for Quality Factors... 7 Agriculture 2 2010-01-01 2010-01-01 false Allowances for quality factors. 52.810 Section...

  12. Wedge factor dependence with depth and field size for fast neutron beams.

    PubMed

    Popescu, Alina; Risler, Ruedi

    2003-07-21

    The dependence of the wedge factors (WFs) on field size (FS) and depth for a fast neutron beam has been investigated. In a previous study (Popescu et al 1999 Med. Phys. 26 541), a method was presented that allows a simple and accurate way of calculating the wedge-factor dependence on FS and depth in the case of a photon beam. The validity of a similar approach is tested in the present study for neutron beam dosimetry. The clinical neutron therapy system at the University of Washington (UW) has a flattening filter assembly consisting of two filters: a small field filter and a large field filter. Despite this complication, the approach presented in Popescu et al (1999 Med. Phys. 26 541) can be used to describe the WF dependence on FS and depth (d).

  13. Monte-Carlo investigation of radiation beam quality of the CRNA neutron irradiator for calibration purposes.

    PubMed

    Mazrou, Hakim; Sidahmed, Tassadit; Allab, Malika

    2010-10-01

    An irradiation system has been acquired by the Nuclear Research Center of Algiers (CRNA) to provide neutron references for metrology and dosimetry purposes. It consists of an (241)Am-Be radionuclide source of 185 GBq (5Ci) activity inside a cylindrical steel-enveloped polyethylene container with radially positioned beam channel. Because of its composition, filled with hydrogenous material, which is not recommended by ISO standards, we expect large changes in the physical quantities of primary importance of the source compared to a free-field situation. Thus, the main goal of the present work is to fully characterize neutron field of such special delivered set-up. This was conducted by both extensive Monte-Carlo calculations and experimental measurements obtained by using BF(3) and (3)He based neutron area dosimeters. Effects of each component present in the bunker facility of the Algerian Secondary Standard Dosimetry Laboratory (SSDL) on the energy neutron spectrum have been investigated by simulating four irradiation configurations and comparison to the ISO spectrum has been performed. The ambient dose equivalent rate was determined based upon a correct estimate of the mean fluence to ambient dose equivalent conversion factors at different irradiations positions by means of a 3-D transport code MCNP5. Finally, according to practical requirements established for calibration purposes an optimal irradiation position has been suggested to the SSDL staff to perform, in appropriate manner, their routine calibrations.

  14. Measurements of the neutron dose equivalent for various radiation qualities, treatment machines and delivery techniques in radiation therapy

    NASA Astrophysics Data System (ADS)

    Hälg, R. A.; Besserer, J.; Boschung, M.; Mayer, S.; Lomax, A. J.; Schneider, U.

    2014-05-01

    In radiation therapy, high energy photon and proton beams cause the production of secondary neutrons. This leads to an unwanted dose contribution, which can be considerable for tissues outside of the target volume regarding the long term health of cancer patients. Due to the high biological effectiveness of neutrons in regards to cancer induction, small neutron doses can be important. This study quantified the neutron doses for different radiation therapy modalities. Most of the reports in the literature used neutron dose measurements free in air or on the surface of phantoms to estimate the amount of neutron dose to the patient. In this study, dose measurements were performed in terms of neutron dose equivalent inside an anthropomorphic phantom. The neutron dose equivalent was determined using track etch detectors as a function of the distance to the isocenter, as well as for radiation sensitive organs. The dose distributions were compared with respect to treatment techniques (3D-conformal, volumetric modulated arc therapy and intensity-modulated radiation therapy for photons; spot scanning and passive scattering for protons), therapy machines (Varian, Elekta and Siemens linear accelerators) and radiation quality (photons and protons). The neutron dose equivalent varied between 0.002 and 3 mSv per treatment gray over all measurements. Only small differences were found when comparing treatment techniques, but substantial differences were observed between the linear accelerator models. The neutron dose equivalent for proton therapy was higher than for photons in general and in particular for double-scattered protons. The overall neutron dose equivalent measured in this study was an order of magnitude lower than the stray dose of a treatment using 6 MV photons, suggesting that the contribution of the secondary neutron dose equivalent to the integral dose of a radiotherapy patient is small.

  15. Measurements of the neutron dose equivalent for various radiation qualities, treatment machines and delivery techniques in radiation therapy.

    PubMed

    Hälg, R A; Besserer, J; Boschung, M; Mayer, S; Lomax, A J; Schneider, U

    2014-05-21

    In radiation therapy, high energy photon and proton beams cause the production of secondary neutrons. This leads to an unwanted dose contribution, which can be considerable for tissues outside of the target volume regarding the long term health of cancer patients. Due to the high biological effectiveness of neutrons in regards to cancer induction, small neutron doses can be important. This study quantified the neutron doses for different radiation therapy modalities. Most of the reports in the literature used neutron dose measurements free in air or on the surface of phantoms to estimate the amount of neutron dose to the patient. In this study, dose measurements were performed in terms of neutron dose equivalent inside an anthropomorphic phantom. The neutron dose equivalent was determined using track etch detectors as a function of the distance to the isocenter, as well as for radiation sensitive organs. The dose distributions were compared with respect to treatment techniques (3D-conformal, volumetric modulated arc therapy and intensity-modulated radiation therapy for photons; spot scanning and passive scattering for protons), therapy machines (Varian, Elekta and Siemens linear accelerators) and radiation quality (photons and protons). The neutron dose equivalent varied between 0.002 and 3 mSv per treatment gray over all measurements. Only small differences were found when comparing treatment techniques, but substantial differences were observed between the linear accelerator models. The neutron dose equivalent for proton therapy was higher than for photons in general and in particular for double-scattered protons. The overall neutron dose equivalent measured in this study was an order of magnitude lower than the stray dose of a treatment using 6 MV photons, suggesting that the contribution of the secondary neutron dose equivalent to the integral dose of a radiotherapy patient is small.

  16. High quality factor indium oxide mechanical microresonators

    SciTech Connect

    Bartolomé, Javier Cremades, Ana; Piqueras, Javier

    2015-11-09

    The mechanical resonance behavior of as-grown In{sub 2}O{sub 3} microrods has been studied in this work by in-situ scanning electron microscopy (SEM) electrically induced mechanical oscillations. Indium oxide microrods grown by a vapor–solid method are naturally clamped to an aluminum oxide ceramic substrate, showing a high quality factor due to reduced energy losses during mechanical vibrations. Quality factors of more than 10{sup 5} and minimum detectable forces of the order of 10{sup −16} N/Hz{sup 1/2} demonstrate their potential as mechanical microresonators for real applications. Measurements at low-vacuum using the SEM environmental operation mode were performed to study the effect of extrinsic damping on the resonators behavior. The damping coefficient has been determined as a function of pressure.

  17. Coupling and quality factors in RFID

    NASA Astrophysics Data System (ADS)

    Cole, Peter H.

    2001-11-01

    The performance of a wide variety of RFID systems depends critically on: how efficiently energy is coupled to and from an electronically coded label; on how effectively it is used within the label; and sometimes on how effectively it is transformed from one form to another within the label. The paper considers the definition of appropriate coupling factors and quality factors which describe these processes, and their role in regulating system performance in the near and far fields of both linear and non-linear process based technologies. Calculations allowing feasibility estimates of some new process combinations on which some RFID systems may be based are presented.

  18. Factors affecting the quality of cryoprecipitate

    PubMed Central

    Subramaniyan, Rajeswari; Marwaha, Neelam; Jain, Ashish; Ahluwalia, Jasmina

    2017-01-01

    BACKGROUND: Many variables affect the quality of cryoprecipitate (CRYO). We investigated the effect of freezing techniques and ABO blood groups on the quality of CRYO with respect to factor VIII: C and fibrinogen levels. MATERIALS AND METHODS: Ninety-six whole blood units each collected from in-house (Group I) and blood donation camps outside the hospital premises (Group II) were processed for CRYO preparation. Within each group, half the number of plasma units was frozen using blast freezer and another half using the conventional freezer. The CRYOs from blood groups A, B, and O were equally distributed, i.e. 32 within each of the Groups I and II. The fibrinogen and factor VIII: C levels in CRYO were analyzed using single-stage clotting assay. RESULTS: In Group I, the mean ± standard deviation percentage recovery of factor VIII levels in CRYO prepared using the conventional freezer and blast freezer were 58.5% ±16.2% and 66.7% ±16.4%, respectively, and in Group II, it was 55.3% ±17.6% and 70.4% ±13.4%, respectively. Recovery of factor VIII was higher in CRYO prepared using blast freezer than that of CRYO prepared using conventional freezer (P < 0.000). In Group II, CRYOs prepared using blast freezer had higher percent recovery of fibrinogen than that of Group I. In both the groups, the mean factor VIII levels in blood group A were higher than that of factor VIII levels in the blood group O CRYO. CONCLUSION: The factor VIII recovery in CRYO improves significantly with higher baseline factor VIII: C levels, blood group A donor, and rapid freezing using blast freezer. Rapid freezing also increases the fibrinogen yield. PMID:28316438

  19. Precise Determination of the Neutron Magnetic Form Factor to Higher Q{sup 2}

    SciTech Connect

    William K. Brooks; Jeffery D. Lachniet

    2004-10-01

    The neutron elastic magnetic form factor G{sub M}{sup n} has been extracted from quasielastic scattering from deuterium in the CEBAF Large Acceptance Spectrometer, CLAS. The kinematic coverage of the measurement is continuous over a broad range, extending from below 1 GeV{sup 2} to nearly 5 GeV{sup 2} in four-momentum transfer squared. High precision is achieved by employing a ratio technique in which most uncertainties cancel, and by a simultaneous in-situ calibration of the neutron detection efficiency, the largest correction to the data. Preliminary results are shown with statistical errors only.

  20. [Factors that affect inpatients' quality of sleep].

    PubMed

    da Costa, Shíntia Viana; Ceolim, Maria Filomena

    2013-02-01

    The aim of this study was to identify factors that interfere with the sleep quality of patients admitted to a university hospital in a city in the state of São Paulo, Brazil. This was an exploratory, cross sectional study using non-probability sampling. Participants were 117 patients (59% men, mean age 48.0 years, standard deviation 16.9) hospitalized for at least 72 hours in stable clinical condition. The data were collected with an identification questionnaire and the Factors Affecting Sleep Quality (FASQ) questionnaire. Data processing was performed with descriptive statistics; each item of the FASQ underwent a test and a retest. The factors most often reported were waking up early (55.6%), disrupted sleep (52.1%), excessive lighting (34.2%), receipt of care by nursing staff (33.3%) and organic disorders such as pain and fatigue (26.5%). It is suggested that nurses should plan interventions to modify factors that require intense noise and lighting at night in order to reduce disruption and, consequently, sleep deprivation among patients.

  1. 7 CFR 52.782 - Allowances for quality factors.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 2 2012-01-01 2012-01-01 false Allowances for quality factors. 52.782 Section 52.782 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards... for Quality Factors § 52.782 Allowances for quality factors. Table IV—Allowances for Quality...

  2. 7 CFR 52.782 - Allowances for quality factors.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Allowances for quality factors. 52.782 Section 52.782 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards... for Quality Factors § 52.782 Allowances for quality factors. Table IV—Allowances for Quality...

  3. 7 CFR 52.810 - Allowances for quality factors.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 2 2012-01-01 2012-01-01 false Allowances for quality factors. 52.810 Section 52.810 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards... for Quality Factors § 52.810 Allowances for quality factors. Table I—Allowances for Quality...

  4. Conversion factors from counts to chemical ratios for the EURITRACK tagged neutron inspection system

    NASA Astrophysics Data System (ADS)

    El Kanawati, W.; Perot, B.; Carasco, C.; Eleon, C.; Valkovic, V.; Sudac, D.; Obhodas, J.

    2011-10-01

    The EURopean Illicit TRAfficking Countermeasures Kit (EURITRACK) uses 14 MeV neutrons produced by the 3H(d,n) 4H fusion reaction to detect explosives and narcotics in cargo containers. Reactions induced by fast neutrons produce gamma rays, which are detected in coincidence with the associated alpha particle to determine the neutron direction. In addition, the neutron path length is obtained from a time-of-flight measurement, thus allowing the origin of the gamma rays inside the container to be determined. Information concerning the chemical composition of the target material is obtained from the analysis of the energy spectrum. The carbon, oxygen, and nitrogen relative count contributions must be converted to chemical proportions to distinguish illicit and benign organic materials. An extensive set of conversion factors based on Monte Carlo numerical simulations has been calculated, taking into account neutron slowing down and photon attenuation in the cargo materials. An experimental validation of the method is presented by comparing the measured chemical fractions of known materials, in the form of bare samples or hidden in a cargo container, to their real chemical composition. Examples of application to real cargo containers are also reported, as well as simulated data with explosives and illicit drugs.

  5. Precise measurement of the neutron magnetic form factor G(M)n in the few-GeV2 region.

    PubMed

    Lachniet, J; Afanasev, A; Arenhövel, H; Brooks, W K; Gilfoyle, G P; Higinbotham, D; Jeschonnek, S; Quinn, B; Vineyard, M F; Adams, G; Adhikari, K P; Amaryan, M J; Anghinolfi, M; Asavapibhop, B; Asryan, G; Avakian, H; Bagdasaryan, H; Baillie, N; Ball, J P; Baltzell, N A; Barrow, S; Batourine, V; Battaglieri, M; Beard, K; Bedlinskiy, I; Bektasoglu, M; Bellis, M; Benmouna, N; Berman, B L; Biselli, A S; Bonner, B E; Bookwalter, C; Bouchigny, S; Boiarinov, S; Bradford, R; Branford, D; Briscoe, W J; Bültmann, S; Burkert, V D; Calarco, J R; Careccia, S L; Carman, D S; Casey, L; Cheng, L; Cole, P L; Coleman, A; Collins, P; Cords, D; Corvisiero, P; Crabb, D; Crede, V; Cummings, J P; Dale, D; Daniel, A; Dashyan, N; De Masi, R; De Vita, R; De Sanctis, E; Degtyarenko, P V; Denizli, H; Dennis, L; Deur, A; Dhamija, S; Dharmawardane, K V; Dhuga, K S; Dickson, R; Djalali, C; Dodge, G E; Doughty, D; Dragovitsch, P; Dugger, M; Dytman, S; Dzyubak, O P; Egiyan, H; Egiyan, K S; El Fassi, L; Elouadrhiri, L; Empl, A; Eugenio, P; Fatemi, R; Fedotov, G; Fersch, R; Feuerbach, R J; Forest, T A; Fradi, A; Gabrielyan, M Y; Garçon, M; Gavalian, G; Gevorgyan, N; Giovanetti, K L; Girod, F X; Goetz, J T; Gohn, W; Golovatch, E; Gothe, R W; Graham, L; Griffioen, K A; Guidal, M; Guillo, M; Guler, N; Guo, L; Gyurjyan, V; Hadjidakis, C; Hafidi, K; Hakobyan, H; Hanretty, C; Hardie, J; Hassall, N; Heddle, D; Hersman, F W; Hicks, K; Hleiqawi, I; Holtrop, M; Hu, J; Huertas, M; Hyde-Wright, C E; Ilieva, Y; Ireland, D G; Ishkhanov, B S; Isupov, E L; Ito, M M; Jenkins, D; Jo, H S; Johnstone, J R; Joo, K; Juengst, H G; Kageya, T; Kalantarians, N; Keller, D; Kellie, J D; Khandaker, M; Khetarpal, P; Kim, K Y; Kim, K; Kim, W; Klein, A; Klein, F J; Klusman, M; Konczykowski, P; Kossov, M; Kramer, L H; Kubarovsky, V; Kuhn, J; Kuhn, S E; Kuleshov, S V; Kuznetsov, V; Laget, J M; Langheinrich, J; Lawrence, D; Lima, A C S; Livingston, K; Lowry, M; Lu, H Y; Lukashin, K; Maccormick, M; Malace, S; Manak, J J; Markov, N; Mattione, P; McAleer, S; McCracken, M E; McKinnon, B; McNabb, J W C; Mecking, B A; Mestayer, M D; Meyer, C A; Mibe, T; Mikhailov, K; Mineeva, T; Minehart, R; Mirazita, M; Miskimen, R; Mokeev, V; Moreno, B; Moriya, K; Morrow, S A; Moteabbed, M; Mueller, J; Munevar, E; Mutchler, G S; Nadel-Turonski, P; Nasseripour, R; Niccolai, S; Niculescu, G; Niculescu, I; Niczyporuk, B B; Niroula, M R; Niyazov, R A; Nozar, M; O'Rielly, G V; Osipenko, M; Ostrovidov, A I; Park, K; Park, S; Pasyuk, E; Paterson, C; Pereira, S Anefalos; Philips, S A; Pierce, J; Pivnyuk, N; Pocanic, D; Pogorelko, O; Polli, E; Popa, I; Pozdniakov, S; Preedom, B M; Price, J W; Prok, Y; Protopopescu, D; Qin, L M; Raue, B A; Riccardi, G; Ricco, G; Ripani, M; Ritchie, B G; Rosner, G; Rossi, P; Rowntree, D; Rubin, P D; Sabatié, F; Saini, M S; Salamanca, J; Salgado, C; Sandorfi, A; Santoro, J P; Sapunenko, V; Schott, D; Schumacher, R A; Serov, V S; Sharabian, Y G; Sharov, D; Shaw, J; Shvedunov, N V; Skabelin, A V; Smith, E S; Smith, L C; Sober, D I; Sokhan, D; Starostin, A; Stavinsky, A; Stepanyan, S; Stepanyan, S S; Stokes, B E; Stoler, P; Stopani, K A; Strakovsky, I I; Strauch, S; Suleiman, R; Taiuti, M; Taylor, S; Tedeschi, D J; Thompson, R; Tkabladze, A; Tkachenko, S; Ungaro, M; Vlassov, A V; Watts, D P; Wei, X; Weinstein, L B; Weygand, D P; Williams, M; Wolin, E; Wood, M H; Yegneswaran, A; Yun, J; Yurov, M; Zana, L; Zhang, J; Zhao, B; Zhao, Z W

    2009-05-15

    The neutron elastic magnetic form factor was extracted from quasielastic electron scattering on deuterium over the range Q;{2}=1.0-4.8 GeV2 with the CLAS detector at Jefferson Lab. High precision was achieved with a ratio technique and a simultaneous in situ calibration of the neutron detection efficiency. Neutrons were detected with electromagnetic calorimeters and time-of-flight scintillators at two beam energies. The dipole parametrization gives a good description of the data.

  6. Weighting factors for radiation quality: how to unite the two current concepts.

    PubMed

    Kellerer, Albrecht M

    2004-01-01

    The quality factor, Q(L), used to be the universal weighting factor to account for radiation quality, until--in its 1991 Recommendations--the ICRP established a dichotomy between 'computable' and 'measurable' quantities. The new concept of the radiation weighting factor, w(R), was introduced for use with the 'computable' quantities, such as the effective dose, E. At the same time, the application of Q(L) was restricted to 'measurable' quantities, such as the operational quantities ambient dose equivalent or personal dose equivalent. The result has been a dual system of incoherent dosimetric quantities. The most conspicuous inconsistency resulted for neutrons, for which the new concept of wR had been primarily designed. While its definition requires an accounting for the gamma rays produced by neutron capture in the human body, this effect is not adequately reflected in the numerical values of wR, which are now suitable for mice, but are--at energies of the incident neutrons below 1 MeV--conspicuously too large for man. A recent Report 92 to ICRP has developed a proposal to correct the current imbalance and to define a linkage between the concepts Q(L) and wR. The proposal is here considered within a broader assessment of the rationale that led to the current dual system of dosimetric quantities.

  7. The use of neutron radiography in agriculture to improve the food quality.

    PubMed

    de Jesus, Selma P; Crispim, Verginia R; Brandão, Luís E B

    2002-11-01

    The report presented in the 7th ONU's Conference (USA, 2001) about climatic changes that took place at the end of 2001 informs that, in less than 50 years, more than 45% of the world population will be suffering from lack of water. This fact occurs by the absence of management on water resources, mainly, in agriculture. As the excess as the lack of humidity in soil can change the harvest quality, causing physiologic anomalies in food and promoting soil diseases incidence caused by bacteria and fungus. In order to establish a larger control in the food quality, a study has been performed, through the neutron radiographic technique, that proposes the optimization of agricultural harvests in relation to the minimum quantity of water necessary for the plant to develop and, also, of the soil compactness. Thus, neutron radiographic images of the system root-soil can be produced so that each root will be evaluated for its ability to penetrate in the soil layers, having the advantage of not interfering in this system what it is not possible through the usual techniques yet. The initial tests using bean roots showed that the soil thickness, which involved the roots, resulted in low contrast images, what impeded their visualization with enough clearness so that their grow could not be observed. For this reason, it was opted to the gadolinium as a contrast agent so that we have been studying its transport through the roots.

  8. 7 CFR 52.782 - Allowances for quality factors.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... Red Tart Pitted Cherries 1 Allowances for Quality Factors § 52.782 Allowances for quality factors... 1 per 20 ozs. Defects: 100 cherries Total—multilated, plus minor blemished plus blemished. 10 15...

  9. 7 CFR 52.810 - Allowances for quality factors.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... PRODUCTS THEREOF, AND CERTAIN OTHER PROCESSED FOOD PRODUCTS 1 United States Standards for Grades of Frozen Red Tart Pitted Cherries Allowances for Quality Factors § 52.810 Allowances for quality factors. Table... 7 Agriculture 2 2013-01-01 2013-01-01 false Allowances for quality factors. 52.810 Section...

  10. 7 CFR 52.810 - Allowances for quality factors.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... PRODUCTS THEREOF, AND CERTAIN OTHER PROCESSED FOOD PRODUCTS 1 United States Standards for Grades of Frozen Red Tart Pitted Cherries Allowances for Quality Factors § 52.810 Allowances for quality factors. Table... 7 Agriculture 2 2014-01-01 2014-01-01 false Allowances for quality factors. 52.810 Section...

  11. Density analysis of the neutron structure factor and the determination of the pair potential of krypton

    NASA Astrophysics Data System (ADS)

    Barocchi, F.; Zoppi, M.; Egelstaff, P. A.

    1985-04-01

    We propose a method of analysis of the density behavior of the experimental neutron scattering structure factor which permits us to derive directly from the experimental results an ``experimental'' pair potential. We apply the method to the recent results of Teitsma and Egelstaff in krypton gas and derive a pair potential which is in good agreement with the empirical potential of Barker et al. Some discrepancies in the range 4

  12. Measurement of the neutron electric form factor GEn in quasielastic scattering

    SciTech Connect

    Donal Day

    2003-07-15

    We have measured the electric form factor of the neutron, GEn, at two momentum transfers (Q2= 0.5 and Q2= 1.0 GeV/c2) through quasielastic scattering in Jefferson Lab's Hall C. Longitudinally polarized electrons scattered from polarized deuterated ammonia and GEn was extracted from the beam-target asymmetry AVed which, in quasielastic kinematics, is particularly sensitive to GEn and insensitive to MEC and FSI.

  13. Boron carbide coatings for neutron detection probed by x-rays, ions, and neutrons to determine thin film quality

    SciTech Connect

    Nowak, G. Störmer, M.; Horstmann, C.; Kampmann, R.; Höche, D.; Lorenz, U.; Müller, M.; Schreyer, A.; Becker, H.-W.; Haese-Seiller, M.; Moulin, J.-F.; Pomm, M.; Randau, C.; Hall-Wilton, R.

    2015-01-21

    Due to the present shortage of {sup 3}He and the associated tremendous increase of its price, the supply of large neutron detection systems with {sup 3}He becomes unaffordable. Alternative neutron detection concepts, therefore, have been invented based on solid {sup 10}B converters. These concepts require development in thin film deposition technique regarding high adhesion, thickness uniformity and chemical purity of the converter coating on large area substrates. We report on the sputter deposition of highly uniform large-area {sup 10}B{sub 4}C coatings of up to 2 μm thickness with a thickness deviation below 4% using the Helmholtz-Zentrum Geesthacht large area sputtering system. The {sup 10}B{sub 4}C coatings are x-ray amorphous and highly adhesive to the substrate. Material analysis by means of X-ray-Photoelectron Spectroscopy, Secondary-Ion-Mass-Spectrometry, and Rutherford-Back-Scattering (RBS) revealed low impurities concentration in the coatings. The isotope composition determined by Secondary-Ion-Mass-Spectrometry, RBS, and inelastic nuclear reaction analysis of the converter coatings evidences almost identical {sup 10}B isotope contents in the sputter target and in the deposited coating. Neutron conversion and detection test measurements with variable irradiation geometry of the converter coating demonstrate an average relative quantum efficiency ranging from 65% to 90% for cold neutrons as compared to a black {sup 3}He-monitor. Thus, these converter coatings contribute to the development of {sup 3}He-free prototype detectors based on neutron grazing incidence. Transferring the developed coating process to an industrial scale sputtering system can make alternative {sup 3}He-free converter elements available for large area neutron detection systems.

  14. Boron carbide coatings for neutron detection probed by x-rays, ions, and neutrons to determine thin film quality

    NASA Astrophysics Data System (ADS)

    Nowak, G.; Störmer, M.; Becker, H.-W.; Horstmann, C.; Kampmann, R.; Höche, D.; Haese-Seiller, M.; Moulin, J.-F.; Pomm, M.; Randau, C.; Lorenz, U.; Hall-Wilton, R.; Müller, M.; Schreyer, A.

    2015-01-01

    Due to the present shortage of 3He and the associated tremendous increase of its price, the supply of large neutron detection systems with 3He becomes unaffordable. Alternative neutron detection concepts, therefore, have been invented based on solid 10B converters. These concepts require development in thin film deposition technique regarding high adhesion, thickness uniformity and chemical purity of the converter coating on large area substrates. We report on the sputter deposition of highly uniform large-area 10B4C coatings of up to 2 μm thickness with a thickness deviation below 4% using the Helmholtz-Zentrum Geesthacht large area sputtering system. The 10B4C coatings are x-ray amorphous and highly adhesive to the substrate. Material analysis by means of X-ray-Photoelectron Spectroscopy, Secondary-Ion-Mass-Spectrometry, and Rutherford-Back-Scattering (RBS) revealed low impurities concentration in the coatings. The isotope composition determined by Secondary-Ion-Mass-Spectrometry, RBS, and inelastic nuclear reaction analysis of the converter coatings evidences almost identical 10B isotope contents in the sputter target and in the deposited coating. Neutron conversion and detection test measurements with variable irradiation geometry of the converter coating demonstrate an average relative quantum efficiency ranging from 65% to 90% for cold neutrons as compared to a black 3He-monitor. Thus, these converter coatings contribute to the development of 3He-free prototype detectors based on neutron grazing incidence. Transferring the developed coating process to an industrial scale sputtering system can make alternative 3He-free converter elements available for large area neutron detection systems.

  15. Biophysics of NASA radiation quality factors.

    PubMed

    Cucinotta, Francis A

    2015-09-01

    NASA has implemented new radiation quality factors (QFs) for projecting cancer risks from space radiation exposures to astronauts. The NASA QFs are based on particle track structure concepts with parameters derived from available radiobiology data, and NASA introduces distinct QFs for solid cancer and leukaemia risk estimates. The NASA model was reviewed by the US National Research Council and approved for use by NASA for risk assessment for International Space Station missions and trade studies of future exploration missions to Mars and other destinations. A key feature of the NASA QFs is to represent the uncertainty in the QF assessments and evaluate the importance of the QF uncertainty to overall uncertainties in cancer risk projections. In this article, the biophysical basis for the probability distribution functions representing QF uncertainties was reviewed, and approaches needed to reduce uncertainties were discussed.

  16. Boron Neutron Capture Therapy (BNCT) Dose Calculation using Geometrical Factors Spherical Interface for Glioblastoma Multiforme

    SciTech Connect

    Zasneda, Sabriani; Widita, Rena

    2010-06-22

    Boron Neutron Capture Therapy (BNCT) is a cancer therapy by utilizing thermal neutron to produce alpha particles and lithium nuclei. The superiority of BNCT is that the radiation effects could be limited only for the tumor cells. BNCT radiation dose depends on the distribution of boron in the tumor. Absorbed dose to the cells from the reaction 10B (n, {alpha}) 7Li was calculated near interface medium containing boron and boron-free region. The method considers the contribution of the alpha particle and recoiled lithium particle to the absorbed dose and the variation of Linear Energy Transfer (LET) charged particles energy. Geometrical factor data of boron distribution for the spherical surface is used to calculate the energy absorbed in the tumor cells, brain and scalp for case Glioblastoma Multiforme. The result shows that the optimal dose in tumor is obtained for boron concentrations of 22.1 mg {sup 10}B/g blood.

  17. Personnel neutron dosimetry at Department of Energy facilities

    SciTech Connect

    Brackenbush, L.W.; Endres, G.W.R.; Selby, J.M.; Vallario, E.J.

    1980-08-01

    This study assesses the state of personnel neutron dosimetry at DOE facilities. A survey of the personnel dosimetry systems in use at major DOE facilities was conducted, a literature search was made to determine recent advances in neutron dosimetry, and several dosimetry experts were interviewed. It was concluded that personnel neutron dosimeters do not meet current needs and that serious problems exist now and will increase in the future if neutron quality factors are increased and/or dose limits are lowered.

  18. Survey of Excited State Neutron Spectroscopic Factors for Z=8-28 Nuclei

    NASA Astrophysics Data System (ADS)

    Tsang, M. B.; Lee, Jenny; Su, S. C.; Dai, J. Y.; Horoi, M.; Liu, H.; Lynch, W. G.; Warren, S.

    2009-02-01

    We have extracted 565 neutron spectroscopic factors of sd and fp shell nuclei by systematically analyzing more than 2000 measured (d, p) angular distributions. We are able to compare 125 of the extracted spectroscopic factors to values predicted by large-basis shell-model calculations and evaluate the accuracies of spectroscopic factors predicted by different shell-model interactions in these regions. We find that the spectroscopic factors predicted for most excited states of sd-shell nuclei using the latest USDA or USDB interactions agree with the experimental values. For fp shell nuclei, the inability of the current models to account for the core excitation and fragmentation of the states leads to considerable discrepancies. In particular, the agreement between data and shell-model predictions for Ni isotopes is not better than a factor of 2 using either the GXPF1A or the XT interaction.

  19. Preliminary ANS (Advanced Neutron Source) reactor cold source gain factor calculations for liquid deuterium and liquid nitrogen-15

    SciTech Connect

    Henderson, D.L.

    1988-11-01

    Individual energy group gain factors are computed for liquid nitrogen-15 and liquid deuterium cold source moderators using simple one-dimensional slab and spherical geometry calculational models. The energy spectrum of the neutron source is assumed to be that of a thermalized Maxwellian flux at 20/degree/C. The slab geometry calculations indicate that the optimum thickness for neutron transmission through a slab given an isotropic incident flux is for wavelengths above .6 nm, approximately .20 m for liquid deuterium and between .28 and .32 m for liquid nitrogen-15. The gain factors at .8 nm corresponding to these thicknesses are 15.5 for liquid deuterium and 3.50 for liquid nitrogen-15. The spherical geometry analysis showed that the cold neutron current below 10 MeV of 1.36 n/m/sup 2/-s for the neutron component entering the cavity of a .16 m thick liquid deuterium spherical shell exceeds the neutron leakage current of 1.08 n/cm/sup 2/-s from a .38 m diameter liquid deuterium solid sphere. However, the cold neutron factors for the neutron entering the void region are considerably lower than for the solid sphere case. 15 refs., 24 figs., 7 tabs.

  20. Quality factors for alpha particles emitted in tissue

    NASA Technical Reports Server (NTRS)

    Borak, Thomas B.; Chatterjee, A. (Principal Investigator)

    2002-01-01

    A concept of a mean or dose averaged quality factor was defined in ICRP Publication 26 using relationships for quality factor as a function of LET. The concept of radiation weighting factors, wR, was introduced in ICRP Publication 60 in 1990. These are meant to be generalized factors that modify absorbed dose to reflect the risk of stochastic effects as a function of the quality of the radiation incident on the body or emitted by radioactivity within the body. The values of wr are equal to 20 for all alpha particles externally or internally emitted. This note compares the dose averaged quality factor for alpha particles originating in tissue using the old and revised recommendations for quality factor as a function of LET. The dose averaged quality factor never exceeds 20 using the old recommendations and is never less than 20 with the revised recommendations.

  1. Evaluation of gamma-ray exposure buildup factors and neutron shielding for bismuth borosilicate glasses

    NASA Astrophysics Data System (ADS)

    Singh, Vishwanath P.; Badiger, N. M.; Chanthima, N.; Kaewkhao, J.

    2014-05-01

    Gamma-ray exposure buildup factor (EBF) values and neutron shielding effectiveness of bismuth borosilicate (BBS) glass systems in composition (50-x)SiO2:15B2O3:2Al2O3:10CaO:23Na2O:xBi2O3 (where x=0, 5, 10, 15 and 20 mol%) were calculated. The EBF values were computed for photon energy 0.015-15 MeV up to penetration depths of 40 mfp (mean free path) by the geometrical progression (G-P) method. The EBF values were found dependent upon incident photon energy, penetration and bismuth molar concentration. In low- and high-energy photon regions, the EBF values were minimum whereas maximum in the intermediate-energy region. The fast neutron removal cross sections for energy 2-12 MeV were calculated by the partial density method. The BBS glass with 20 mol% Bi2O3 is found to be superior gamma-ray and neutron transparent shielding. The EBF values of the BBS glasses were compared with steel-magnetite concrete and lead. The investigation was carried out to explore the advantages of the BBS glasses in different radiation shielding applications.

  2. Determination of canine dose conversion factors in mixed neutron and gamma radiation fields. Technical report

    SciTech Connect

    Torres, B.A.; Bhatt, R.C.; Myska, J.C.; Holland, B.K.

    1996-07-01

    The primary objective of mixed-field neutron/gamma radiation dosimetry in canine irradiation experiments conducted at the Armed Forces Radiobiology Research Institute (AFRRI) is to determine the absorbed midline tissue dose (MLT) at the region of interest in the canine. A dose conversion factor (DCF) can be applied to free-in-air (FIA) dose measurements to estimate the MLT doses to canines. This report is a summary of the measured DCFs that were used to determine the MLT doses in canines at AFRRI from 1979 to 1992.

  3. A quality assessment of the effects of a hydrogenous filter on a p(66)Be(40) neutron beam.

    PubMed

    Slabbert, J P; Binns, P J; Jones, H L; Hough, J H

    1989-11-01

    Recent measurements in a p(62)Be(36) neutron therapy beam have shown that the quality of the in-phantom beam changes with depth. This variation can be ascribed to the presence of a relatively large low-energy neutron component emanating from the neutron source. As part of the pre-clinical calibration programme at a newly commissioned neutron therapy facility, radiobiological and microdosimetric observations were made to determine the magnitude of this effect on a p(66)Be(40) beam and to evaluate the hardening effect of a hydrogenous filter. The reported data identify a correlation between the two assays and quantify a linear relationship between y* and filter thicknesses less than or equal to 6 cm. Using the data obtained in the study, a filter thickness was selected to comply with clinical requirements. By employing lineal energy spectra, it is demonstrated that subtle changes in beam quality may be quantified in a reproducible manner without resorting to time-consuming radiobiological studies.

  4. Factor selection for service quality evaluation: a hospital case study.

    PubMed

    Ameryoun, Ahmad; Najafi, Seyedvahid; Nejati-Zarnaqi, Bayram; Khalilifar, Seyed Omid; Ajam, Mahdi; Ansarimoghadam, Ahmad

    2017-02-13

    Purpose The purpose of this paper is to develop a systematic approach to predict service quality dimension's influence on service quality using a novel analysis based on data envelopment and SERVQUAL. Design/methodology/approach To assess hospital service quality in Tehran, expectation and perception of those who received the services were evaluated using SERVQUAL. The hospital service quality dimensions were found by exploratory factor analysis (EFA). To compare customer expectation and perception, perceived service quality index (PSQI) was measured using a new method based on common weights. A novel sensitivity approach was used to test the service quality factor's impact on the PSQI. Findings A new service quality dimension named "trust in services" was found using EFA, which is not an original SERVQUAL factor. The approach was applied to assess the hospital's service quality. Since the PSQI value was 0.76 it showed that improvements are needed to meet customer expectations. The results showed the factor order that affect PSQI. "Trust in services" has the strongest influence on PSQI followed by "tangibles," "assurance," "empathy," and "responsiveness," respectively. Practical implications This work gives managers insight into service quality by following a systematic method; i.e., measuring perceived service quality from the customer viewpoint and service factors' impact on customer perception. Originality/value The procedure helps managers to select the required service quality dimensions which need improvement and predict their effects on customer perception.

  5. Clean measurements of the nucleon axial-vector and free-neutron magnetic form factors

    SciTech Connect

    Deur, A.

    2013-11-07

    We discuss the feasibility of a weak charged current experiment using a low energy electron beam. A first goal is to measure the Q{sup 2} dependence of the axial-vector form factor g{sub a}(Q{sup 2}). It can be measured model-independently and as robustly as for electromagnetic form factors from typical electron scattering experiments, in contrast to the methods used so far to measure g{sub a}(Q{sup 2}). If g{sub a}(Q{sup 2}) follows a dipole form, the axial mass can be extracted with a better accuracy than the world data altogether. The most important detection equipment would be a segmented neutron detector with good momentum and angular resolution that is symmetric about the beam direction, and covers a moderate angular range. A high intensity beam (100 uA) is necessary. Beam polarization is highly desirable as it provides a clean measurement of the backgrounds. Beam energies between 70 and 110 MeV are ideal. This range would provide a Q{sup 2} mapping of g{sub a} between 0.01 neutron magnetic form factor G{sub M}{sup n}. The experiment employs the usual techniques of electron-nucleon scattering and presents no special difficulty. Higher energy extensions are possible. They could yield measurements of g{sub a}(Q{sup 2}) up to Q{sup 2}=3 GeV{sup 2} and the possibility to access other form factors, such as the almost unknown pseudoscalar form factor g{sub P}. However, the experiments become much more challenging as soon as beam energies pass the pion production threshold.

  6. Understanding the Institutional-Level Factors of Urban School Quality

    ERIC Educational Resources Information Center

    Gottfried, Michael A.

    2012-01-01

    Background/Context: This article addresses which school-level factors contribute to school quality. Previous research has focused on assessing the effects of school-level variables on student-level quality (e.g., achievement). However, the field has been limited in not evaluating the effects of school-level factors directly on measured…

  7. Neutron distribution, electric dipole polarizability and weak form factor of 48Ca from chiral effective field theory

    NASA Astrophysics Data System (ADS)

    Wendt, Kyle

    2016-03-01

    How large is the 48Ca nucleus? While the electric charge distribution of this nucleus was accurately measured decades ago, both experimental and ab initio descriptions of the neutron distribution are deficient. We address this question using ab initio calculations of the electric charge, neutron, and weak distributions of 48Ca based on chiral effective field theory. Historically, chiral effective field theory calculations of systems larger than 4 nucleons have been plagued by strong systematic errors which result in theoretical descriptions that are too dense and over bound. We address these errors using a novel approach that permits us to accurately reproduce binding energy and charge radius of 48Ca, and to constrain electroweak observables such as the neutron radius, electric dipole polarizability, and the weak form factor. For a full list of contributors to this work, please see ``Neutron and weak-charge distributions of the 48Ca nucleus,'' Nature Physics (2015) doi:10.1038/nphys3529.

  8. Quality control and performance evaluation of k0-based neutron activation analysis at the Portuguese research reactor

    NASA Astrophysics Data System (ADS)

    Dung, H. M.; Freitas, M. C.; Blaauw, M.; Almeida, S. M.; Dionisio, I.; Canha, N. H.

    2010-10-01

    The quality control (QC) and performance evaluation for the k0-based neutron activation analysis ( k0-NAA) at the Portuguese research reactor (RPI) has been developed with the intention of using the method to meet the demands of trace element analysis for the applications in environmental, epidemiological and nutritional studies amongst others. The QC and performance evaluation include the following aspects: (1) estimation of the overall/combined standard uncertainty from the primary uncertainty sources; (2) validation of the method using a synthetic multi-element standard (SMELS); and (3) analysis of the certified reference materials from the National Institute of Standards and Technology (USA): NIST-SRM-1633a and NIST-SRM-1648 and the reference material from the International Atomic Energy Agency: IAEA-RM-336, for the purpose of controlling the overall accuracy and precision of the analytical results. The obtained results revealed that the k0-NAA method established at the RPI was fit for the purpose. The overall/combined standard uncertainty was estimated for elements of interest in the intended applications. The laboratory's analytical results as compared to the assigned values with the bias were less than 12% for most elements, except for a few elements which biased within 13-18%. The u-score values for most elements were less than |1.64|, except for Co, La and Ti within |1.64|-|1.96| and Sc, Cr, K and Sb within |1.96|-|2.58|. The NIST-1633a was also analyzed over 14 months for the purpose of evaluating the reproducibility of the method. The quality factors of k0-NAA established at RPI were evaluated, proving that the method meets the requirements of trace element analysis, which is also considering the method's performance for which the k0-NAA affords a specific, rapid and convenient capability for the intended applications.

  9. Neutron spectroscopic factors of 55Ni hole-states from (p,d) transfer reactions

    NASA Astrophysics Data System (ADS)

    Sanetullaev, A.; Tsang, M. B.; Lynch, W. G.; Lee, Jenny; Bazin, D.; Chan, K. P.; Coupland, D.; Henzl, V.; Henzlova, D.; Kilburn, M.; Rogers, A. M.; Sun, Z. Y.; Youngs, M.; Charity, R. J.; Sobotka, L. G.; Famiano, M.; Hudan, S.; Shapira, D.; Peters, W. A.; Barbieri, C.; Hjorth-Jensen, M.; Horoi, M.; Otsuka, T.; Suzuki, T.; Utsuno, Y.

    2014-09-01

    Spectroscopic information has been extracted on the hole-states of 55Ni, the least known of the quartet of nuclei (55Ni, 57Ni, 55Co and 57Cu), one nucleon away from 56Ni, the N=Z=28 double magic nucleus. Using the H1(Ni56,d)Ni55 transfer reaction in inverse kinematics, neutron spectroscopic factors, spins and parities have been extracted for the f7/2, p3/2 and the s1/2 hole-states of 55Ni. These new data provide a benchmark for large basis calculations that include nucleonic orbits in both the sd and pf shells. State of the art calculations have been performed to describe the excitation energies and spectroscopic factors of the s1/2 hole-state below Fermi energy.

  10. Factors affecting enhanced video quality preferences

    PubMed Central

    Satgunam, PremNandhini; Woods, Russell L; Bronstad, P Matthew; Peli, Eli

    2013-01-01

    The development of video quality metrics requires methods for measuring perceived video quality. Most such metrics are designed and tested using databases of images degraded by compression and scored using opinion ratings. We studied video quality preferences for enhanced images of normally-sighted participants using the method of paired comparisons with a thorough statistical analysis. Participants (n=40) made pair-wise comparisons of high definition (HD) video clips enhanced at four different levels using a commercially available enhancement device. Perceptual scales were computed with binary logistic regression to estimate preferences for each level and to provide statistical inference of the differences among levels and the impact of other variables. While moderate preference for enhanced videos was found, two unexpected effects were also uncovered: (1) Participants could be broadly classified into two groups: those who preferred enhancement ("Sharp") and those who disliked enhancement ("Smooth"). (2) Enhancement preferences depended on video content, particularly for human faces to be enhanced less. The results suggest that algorithms to evaluate image quality (at least for enhancement) may need to be adjusted or applied differentially based on video content and viewer preferences. The possible impact of similar effects on image quality of compressed video needs to be evaluated. PMID:24107400

  11. Quality assurance program for the determination of selenium in foods and diets by instrumental neutron activation

    SciTech Connect

    Zhang, W.H.; Chatt, A.

    1996-12-31

    The biological essentially of selenium for animals was first evidenced in 1957. However, it was not until 1973 that an enzyme called glutathione peroxidase was proven to be a selenoenzyme. At present, selenium is known to be a normal component of several enzymes, proteins, and some aminoacryl transfer nucleic acids. A few selenium compounds have been reported to possess anticarcinogenic properties. There is an increasing interest in understanding the role of selenium in human nutrition and metabolism. Analytical methods are being developed in several laboratories for the determination of total and species-specific selenium in whole blood, serum, urine, soft and hard tissues, food, water, proteins, etc. We have developed several instrumental neutron activation analysis (INAA) methods using the, Dalhousie University SLOWPOKE-2 reactor facility for the determination of parts-per-billion levels of selenium. These methods include cyclic INAA (CINAA) and pseudocyclic INAA (PCINAA) using both conventional and anticoincidence gamma-ray spectrometry. Considering the immense health significance, it is imperative that the selenium levels in foods and diets be measured under an extensive quality assurance program for routine monitoring purposes.

  12. Factors associated with sleep quality among operating engineers.

    PubMed

    Choi, Seung Hee; Terrell, Jeffrey E; Pohl, Joanne M; Redman, Richard W; Duffy, Sonia A

    2013-06-01

    Blue collar workers generally report high job stress and are exposed to loud noises at work and engage in many of risky health behavioral factors, all of which have been associated with poor sleep quality. However, sleep quality of blue collar workers has not been studied extensively, and no studies have focused Operating Engineers (heavy equipment operators) among whom daytime fatigue would place them at high risk for accidents. Therefore, the purpose of this study was to determine variables associated with sleep quality among Operating Engineers. This was a cross-sectional survey design with a dependent variable of sleep quality and independent variables of personal and related health behavioral factors. A convenience sample of 498 Operating Engineers was recruited from approximately 16,000 Operating Engineers from entire State of Michigan in 2008. Linear regression was used to determine personal and related health behavior factors associated with sleep quality. Multivariate analyses showed that personal factors related to poor sleep quality were younger age, female sex, higher pain, more medical comorbidities and depressive symptoms and behavioral factors related to poor sleep quality were nicotine dependence. While sleep scores were similar to population norms, approximately 34 % (n = 143) showed interest in health services for sleep problems. While many personal factors are not changeable, interventions to improve sleep hygiene as well as interventions to treat pain, depression and smoking may improve sleep quality resulting in less absenteeism, fatal work accidents, use of sick leave, work disability, medical comorbidities, as well as subsequent mortality.

  13. Conflict Resolution (CORE) for Software Quality Factors

    DTIC Science & Technology

    1993-05-01

    gnals until an achievable solution is identified. In a session, there may be several candidato solu- tions. 14. SUBJECT TERMS 15 NUMBER OF PAGES...determining software quality requirements. This activity can also be carried out manually , although the complexity of the task is considerable. Information...the ASQS User’s Manual [14]. The rationale which lead to the development of the ASQS was that system acquisition managers are typically unfamiliar

  14. Training, Quality Assurance Factors, and Tools Investigation: a Work Report and Suggestions on Software Quality Assurance

    NASA Technical Reports Server (NTRS)

    Lee, Pen-Nan

    1991-01-01

    Previously, several research tasks have been conducted, some observations were obtained, and several possible suggestions have been contemplated involving software quality assurance engineering at NASA Johnson. These research tasks are briefly described. Also, a brief discussion is given on the role of software quality assurance in software engineering along with some observations and suggestions. A brief discussion on a training program for software quality assurance engineers is provided. A list of assurance factors as well as quality factors are also included. Finally, a process model which can be used for searching and collecting software quality assurance tools is presented.

  15. Replica neutron guides for experiments with ultracold neutrons

    NASA Astrophysics Data System (ADS)

    Serebrov, A. P.; Vasil'ev, A. V.; Lasakov, M. S.; Siber, E. V.; Murashkin, A. N.; Egorov, A. I.; Fomin, A. K.; Sbitnev, S. V.; Geltenbort, P.; Zimmer, O.

    2017-01-01

    The method for producing neutron guides for ultracold neutrons based on the replica method has been described. A comparative analysis of the quality of replica neutron guides, neutron guides made from polished anode-mechanical steel tubes, and neutron guides from electropolished tubes has been given.

  16. g-Factors of Isomeric States in the Neutron-Rich Nuclei

    SciTech Connect

    Georgiev, G.; Neyens, G.; Hass, M.; Balabanski, Dimiter Loukanov; Bingham, Carrol R; Borcea, C.; Coulier, N.; Coussenment, R.; Daugas, J. M.; De France, Gilles M; Gorska, M.; Grawe, Hubert H; Grzywacz, Robert Kazimierz; Lewitowicz, Marek; Mach, Henryk A; Matea, I.; de Oliveira Santos, F.; Page, R. D.; Pfutzner, Marek; Penionzhkevich, Yu. E.; Podolyak, Zsolt F; Regan, Patrick H; Rykaczewski, Krzysztof Piotr; Sawicka, M.; Smirnova, N. A.; Sobolev, Yu.; Stanoiu, M.; Teughels, S.; Vyvey, K.

    2004-02-01

    We report the results from the first experiment to measure gyromagnetic factors of {micro}s isomers in neutron-rich nuclei produced by intermediate-energy projectile-fragmentation reactions. The Time Dependent Perturbed Angular Distribution (TDPAD) method was applied in combination with the heavy-ion-gamma correlation technique. The nuclides in the vicinity of {sup 68}Ni were produced and spin-oriented following the fragmentation of a {sup 76}Ge, 61.4 MeV/ u beam at GANIL. The results obtained, |g|({sup 69 m}Cu) = 0.225(25) and |g|({sup 67 m}Ni) = 0.125(6) provide another indication of the importance of proton excitation across the Z = 28 shell gap for the description of these states.

  17. Calculation of thermal neutron self-shielding correction factors for aqueous bulk sample prompt gamma neutron activation analysis using the MCNP code

    NASA Astrophysics Data System (ADS)

    Nasrabadi, M. N.; Jalali, M.; Mohammadi, A.

    2007-10-01

    In this work thermal neutron self-shielding in aqueous bulk samples containing neutron absorbing materials is studied using bulk sample prompt gamma neutron activation analysis (BSPGNAA) with the MCNP code. The code was used to perform three dimensional simulations of a neutron source, neutron detector and sample of various material compositions. The MCNP model was validated against experimental measurements of the neutron flux performed using a BF 3 detector. Simulations were performed to predict thermal neutron self-shielding in aqueous bulk samples containing neutron absorbing solutes. In practice, the MCNP calculations are combined with experimental measurements of the relative thermal neutron flux over the sample's surface, with respect to a reference water sample, to derive the thermal neutron self-shielding within the sample. The proposed methodology can be used for the determination of the elemental concentration of unknown aqueous samples by BSPGNAA where knowledge of the average thermal neutron flux within the sample volume is required.

  18. Quality assurance of temporal variability of natural decay chain and neutron induced background for low-level NORM analysis

    SciTech Connect

    Yoho, Michael; Porterfield, Donivan R.; Landsberger, Sheldon

    2015-09-22

    In this study, twenty-one high purity germanium (HPGe) background spectra were collected over 2 years at Los Alamos National Laboratory. A quality assurance methodology was developed to monitor spectral background levels from thermal and fast neutron flux levels and naturally occurring radioactive material decay series radionuclides. 238U decay products above 222Rn demonstrated minimal temporal variability beyond that expected from counting statistics. 238U and 232Th progeny below Rn gas displayed at most twice the expected variability. Further, an analysis of the 139 keV 74Ge(n, γ) and 691 keV 72Ge(n, n') spectral features demonstrated temporal stability for both thermal and fast neutron fluxes.

  19. Coincidence gate utilization factors for neutron correlation counters with up to three components in the die-away profile

    SciTech Connect

    Croft, S.; McElroy, R.D.; Kane, S.C.

    2007-07-01

    We present analytical expressions for the gate utilization factors (GUFs), up to fourth order, for both signal triggered and random triggered histograms based on a three-component capture time profile. These are useful for refined design performance calculations of passive neutron multiplicity counters using shift register correlation analysis. To our knowledge, these expressions are new. (authors)

  20. Neutron measurements

    SciTech Connect

    McCall, R.C.

    1981-01-01

    Methods of neutron detection and measurement are discussed. Topics include sources of neutrons, neutrons in medicine, interactions of neutrons with matter, neutron shielding, neutron measurement units, measurement methods, and neutron spectroscopy. (ACR)

  1. Broken symmetry dielectric resonators for high quality factor Fano metasurfaces

    SciTech Connect

    Campione, Salvatore; Liu, Sheng; Basilio, Lorena I.; Warne, Larry K.; Langston, William L.; Luk, Ting S.; Wendt, Joel R.; Reno, John L.; Keeler, Gordon A.; Brener, Igal; Sinclair, Michael B.

    2016-10-25

    We present a new approach to dielectric metasurface design that relies on a single resonator per unit cell and produces robust, high quality factor Fano resonances. Our approach utilizes symmetry breaking of highly symmetric resonator geometries, such as cubes, to induce couplings between the otherwise orthogonal resonator modes. In particular, we design perturbations that couple “bright” dipole modes to “dark” dipole modes whose radiative decay is suppressed by local field effects in the array. Our approach is widely scalable from the near-infrared to radio frequencies. We first unravel the Fano resonance behavior through numerical simulations of a germanium resonator-based metasurface that achieves a quality factor of ~1300 at ~10.8 μm. Then, we present two experimental demonstrations operating in the near-infrared (~1 μm): a silicon-based implementation that achieves a quality factor of ~350; and a gallium arsenide-based structure that achieves a quality factor of ~600, the highest near-infrared quality factor experimentally demonstrated to date with this kind of metasurface. Importantly, large electromagnetic field enhancements appear within the resonators at the Fano resonant frequencies. Here, we envision that combining high quality factor, high field enhancement resonances with nonlinear and active/gain materials such as gallium arsenide will lead to new classes of active optical devices.

  2. Broken symmetry dielectric resonators for high quality factor Fano metasurfaces

    DOE PAGES

    Campione, Salvatore; Liu, Sheng; Basilio, Lorena I.; ...

    2016-10-25

    We present a new approach to dielectric metasurface design that relies on a single resonator per unit cell and produces robust, high quality factor Fano resonances. Our approach utilizes symmetry breaking of highly symmetric resonator geometries, such as cubes, to induce couplings between the otherwise orthogonal resonator modes. In particular, we design perturbations that couple “bright” dipole modes to “dark” dipole modes whose radiative decay is suppressed by local field effects in the array. Our approach is widely scalable from the near-infrared to radio frequencies. We first unravel the Fano resonance behavior through numerical simulations of a germanium resonator-based metasurfacemore » that achieves a quality factor of ~1300 at ~10.8 μm. Then, we present two experimental demonstrations operating in the near-infrared (~1 μm): a silicon-based implementation that achieves a quality factor of ~350; and a gallium arsenide-based structure that achieves a quality factor of ~600, the highest near-infrared quality factor experimentally demonstrated to date with this kind of metasurface. Importantly, large electromagnetic field enhancements appear within the resonators at the Fano resonant frequencies. Here, we envision that combining high quality factor, high field enhancement resonances with nonlinear and active/gain materials such as gallium arsenide will lead to new classes of active optical devices.« less

  3. First Evaluation of the Biologic Effectiveness Factors of Boron Neutron Capture Therapy (BNCT) in a Human Colon Carcinoma Cell Line

    SciTech Connect

    Dagrosa, Maria Alejandra; Crivello, Martin; Perona, Marina; Thorp, Silvia; Santa Cruz, Gustavo Alberto; Pozzi, Emiliano; Casal, Mariana; Thomasz, Lisa; Cabrini, Romulo; Kahl, Steven; Juvenal, Guillermo Juan; Pisarev, Mario Alberto

    2011-01-01

    Purpose: DNA lesions produced by boron neutron capture therapy (BNCT) and those produced by gamma radiation in a colon carcinoma cell line were analyzed. We have also derived the relative biologic effectiveness factor (RBE) of the neutron beam of the RA-3- Argentine nuclear reactor, and the compound biologic effectiveness (CBE) values for p-boronophenylalanine ({sup 10}BPA) and for 2,4-bis ({alpha},{beta}-dihydroxyethyl)-deutero-porphyrin IX ({sup 10}BOPP). Methods and Materials: Exponentially growing human colon carcinoma cells (ARO81-1) were distributed into the following groups: (1) BPA (10 ppm {sup 10}B) + neutrons, (2) BOPP (10 ppm {sup 10}B) + neutrons, (3) neutrons alone, and (4) gamma rays ({sup 60}Co source at 1 Gy/min dose-rate). Different irradiation times were used to obtain total absorbed doses between 0.3 and 5 Gy ({+-}10%) (thermal neutrons flux = 7.5 10{sup 9} n/cm{sup 2} sec). Results: The frequency of micronucleated binucleated cells and the number of micronuclei per micronucleated binucleated cells showed a dose-dependent increase until approximately 2 Gy. The response to gamma rays was significantly lower than the response to the other treatments (p < 0.05). The irradiations with neutrons alone and neutrons + BOPP showed curves that did not differ significantly from, and showed less DNA damage than, irradiation with neutrons + BPA. A decrease in the surviving fraction measured by 3-(4,5-dimetiltiazol-2-il)-2,5-difeniltetrazolium bromide (MTT) assay as a function of the absorbed dose was observed for all the treatments. The RBE and CBE factors calculated from cytokinesis block micronucleus (CBMN) and MTT assays were, respectively, the following: beam RBE: 4.4 {+-} 1.1 and 2.4 {+-} 0.6; CBE for BOPP: 8.0 {+-} 2.2 and 2.0 {+-} 1; CBE for BPA: 19.6 {+-} 3.7 and 3.5 {+-} 1.3. Conclusions: BNCT and gamma irradiations showed different genotoxic patterns. To our knowledge, these values represent the first experimental ones obtained for the RA-3 in a

  4. A Precise Measurement of the Neutron Magnetic Form Factor GMn in the Few-GeV2 Region

    SciTech Connect

    Lachniet, Jeff; Afanaciev, Andrei; Afanasev, Andrei; Afanaciev, Andrei; Afanasev, Andrei; Afanaciev, Andrei; Afanasev, Andrei; Afanaciev, Andrei; Afanasev, Andrei; Arenhovel, Hartmuth; Brooks, William; Gilfoyle, Gerard; Jeschonnek, Sabine; Quinn, Brian; Vineyard, Michael

    2009-01-01

    The neutron elastic magnetic form factor GMn has been extracted from quasielastic electron scattering data on deuterium with the CEBAF Large Acceptance Spectrometer (CLAS) at Jefferson Lab. The kinematic coverage of the measurement is continuous from Q2=1 GeV2 to 4.8 GeV2. High precision was achieved by employing a ratio technique in which many uncertainties cancel, and by a simultaneous in-situ calibration of the neutron detection efficiency, the largest correction to the data. Neutrons were detected using the CLAS electromagnetic calorimeters and the time-of-flight scintillators. Data were taken at two different electron beam energies, allowing up to four semi-independent measurements of GMn to be made at each value of Q2. The dipole parameterization is found to provide a good description of the data over the measured Q2 range.

  5. Approaching Safety through Quality: Factors Influencing College Student Perceptions.

    PubMed

    Ramaswamy, S K; Mosher, G A

    2016-04-01

    Quality management practices have been identified by previous literature as a factor that could potentially reduce the level of safety incidents and hazards in agricultural work environments. The present study used multivariate analysis to examine the effect of independent variables such as quality and safety awareness, work experience, safety and quality management experience, and the perceived importance of safety and quality on the role of quality management practices as a mitigating factor for safety hazards and incidents in agriculture. Variables were measured on a five-point scale using a survey questionnaire. Data were collected from approximately 900 undergraduates enrolled in the College of Agriculture and Life Sciences at a large land grant university in the U.S. The level of student work experience and student perceptions of the importance of quality explained a significant amount of the variance in student views of quality management practices as a mitigating factor for safety hazards and incidents. The findings of this study provide further evidence for using quality management practices as a basis for safety interventions targeted at the agricultural workforce.

  6. Preslaughter factors affecting poultry meat quality chapter 2.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Poultry meat quality is affected by numerous antemortem factors, in particular those occurring during the last 24 hours that the bird is alive. These short term factors influence carcass yield (live shrink), carcass defects (bruising, broken/dislocated bones), carcass microbiological contamination, ...

  7. Precise Measurement of the Neutron Magnetic Form Factor G{sub M}{sup n} in the Few-GeV{sup 2} Region

    SciTech Connect

    Lachniet, J.; Afanasev, A.; Arenhoevel, H.; Brooks, W. K.; Gilfoyle, G. P.; Higinbotham, D.; Burkert, V. D.; Carman, D. S.; Cords, D.; Degtyarenko, P. V.; Deur, A.; Gyurjyan, V.; Ito, M. M.; Kageya, T.; Kubarovsky, V.; Lowry, M.; Manak, J. J.; Mecking, B. A.; Mestayer, M. D.; Niczyporuk, B. B.

    2009-05-15

    The neutron elastic magnetic form factor was extracted from quasielastic electron scattering on deuterium over the range Q{sup 2}=1.0-4.8 GeV{sup 2} with the CLAS detector at Jefferson Lab. High precision was achieved with a ratio technique and a simultaneous in situ calibration of the neutron detection efficiency. Neutrons were detected with electromagnetic calorimeters and time-of-flight scintillators at two beam energies. The dipole parametrization gives a good description of the data.

  8. Clean measurements of the nucleon axial-vector and free-neutron magnetic form factors

    SciTech Connect

    Deur, Alexandre P.

    2013-11-01

    We discuss the feasibility of a weak charged current experiment using a low energy electron beam. A first goal is to measure the Q^2 dependence of the axial-vector form factor g_a(Q^2). It can be measured model-independently and as robustly as for electromagnetic form factors from typical electron scattering experiments, in contrast to the methods used so far to measure g_a(Q^2). If g_a(Q^2) follows a dipole form, the axial mass can be extracted with a better accuracy than the world data altogether. The most important detection equipment would be a segmented neutron detector with good momentum and angular resolution that is symmetric about the beam direction, and covers a moderate angular range. A high intensity beam (100 uA) is necessary. Beam polarization is highly desirable as it provides a clean measurement of the backgrounds. Beam energies between 70 and 110 MeV are ideal. This range would provide a Q^2 mapping of g_a between 0.01

  9. Behavioral Factors Related to Sleep Quality and Duration in Adults

    PubMed Central

    Shim, Joohee; Kang, Seung Wan

    2017-01-01

    Background The purpose of this study was to measure the sleep quality and duration in healthy adults and to identify any influencing factors. Methods This study was a descriptive research investigation that evaluated 240 healthy adults at least 19 years of age. The data were assessed using the following self-administered questionnaires: the Pittsburgh Sleep Quality Index (PSQI), the Beck Depression Inventory, the State-Trait Anxiety Inventory-Korean YZ, and the Fatigue Severity Scale. Results The PSQI global score was 5.69 ± 3.23, and 59.6% of the participants were classified as having poor quality sleep (PSQI score > 5). The significant risk factors for poor sleep quality were female gender (p = 0.021), number of comorbid conditions (p = 0.003), depression (p < 0.001), fatigue (p < 0.001), and anxiety (p < 0.001). Stepwise multiple regression analyses showed that significant predictors of poor sleep quality were depression (p < 0.001) and fatigue (p < 0.001). Participants slept an average of 6.16 ± 1.36 hours a night. A shorter sleep duration was correlated with older age (p = 0.010), a higher body mass index (BMI) (p = 0.026), a greater depression score (p = 0.002), a higher fatigue score (p = 0.028), and lower sleep quality (p < 0.001). In addition, stepwise multiple regression analyses revealed that factors significantly associated with sleep duration were depression (p = 0.002) and BMI (p = 0.034). Conclusion The number of comorbid conditions and the presence of depression and fatigue were risk factors for both low sleep quality and short sleep duration. Therefore, to improve sleep quality, there is a need for comprehensive interventional programs to manage these and any other factors that disturb sleep. PMID:28261557

  10. Factors Affecting the Application of a Simple Ratio Technique for Spectral Correction of a Neutron Personnel Albedo Dosimeter.

    NASA Astrophysics Data System (ADS)

    Nelson, Robert Clifton

    To accurately assess the dose equivalent indicated by the albedo response of a neutron personnel dosimeter, additional knowledge is generally required in order to apply the needed spectral specific correction factors. This work was designed to evaluate the capability of the USAF Personnel Neutron Dosimeter to "self-calibrate" for moderated fission neutron spectra. The boron/bare ratio technique is compared with a simple theoretical model of the dosimeter and with the 23 cm (9 in) to 7.6 cm (3 in) Hankins' remmeter calibration technique. The overall goal was to provide dose-equivalent estimates comparable to those provided by the remmeter technique without the necessity of special on-site measurements. Although the boron/bare technique with the present dosimeter design fails to provide calibration factors needed for moderated fission neutron spectra, theoretical predictions based upon the model and the measured dosimeter responses are used to propose a dosimeter design which might fulfill the desired goal. Ancillary data gathered during the study are also presented.

  11. Animal factors affecting the meat quality of Australian lamb meat.

    PubMed

    Jacob, R H; Pethick, D W

    2014-02-01

    This paper integrates the key industry findings from the twelve preceding papers in this special edition of Meat science. In so doing, various animal factors important for the quality of Australian lamb meat are highlighted for sensory, visual appeal and human health attributes. Intramuscular fat concentration (IMF) was found to be a key element of eating quality that interacts both positively and negatively with a range of other factors. Shear force, IMF, colour stability and docosahexaenoic acid (DHA) will likely respond to genetic selection whilst other omega-3 fatty acids require nutritional intervention. Australian lamb meat can generally be regarded as a good source of the minerals iron and zinc; and a source of omega 3 fatty acids when finished on green pasture. Breeding priorities for meat quality will likely depend on breed type with improvement of meat colour stability more important for the wool focused Merino breed and improvement of sensory quality for the terminal sire breeds.

  12. Organisational factors affecting the quality of hospital clinical coding.

    PubMed

    Santos, Suong; Murphy, Gregory; Baxter, Kathryn; Robinson, Kerin M

    2008-01-01

    The influence of organisational factors on the quality of hospital coding using the International Statistical Classification of Diseases and Health Related Problems, 10th Revision, Australian Modification (ICD-10-AM) was investigated using a mixed quantitative-qualitative approach. The organisational variables studied were: hospital specialty; geographical locality; structural characteristics of the coding unit; education, training and resource supports for Clinical Coders; and quality control mechanisms. Baseline data on the hospitals' coding quality, measured by the Performance Indicators for Coding Quality tool, were used as an independent index measure. No differences were found in error rates between rural and metropolitan hospitals, or general and specialist hospitals. Clinical Coder allocation to "general" rather than "specialist" unit coding resulted in fewer errors. Coding Managers reported that coding quality can be improved by: Coders engaging in a variety of role behaviours; improved Coder career opportunities; higher staffing levels; reduced throughput; fewer time constraints on coding outputs and associated work; and increased Coder interactions with medical staff.

  13. Quality factors for space radiation: A new approach.

    PubMed

    Borak, Thomas B; Heilbronn, Lawrence H; Townsend, Lawrence W; McBeth, Rafe A; de Wet, Wouter

    2014-04-01

    NASA has derived new models for radiological risk assessment based on epidemiological data and radiation biology including differences in Relative Biological Effectiveness for leukemia and solid tumors. Comprehensive approaches were used to develop new risk cross sections and the extension of these into recommendations for risk assessment during space missions. The methodology relies on published data generated and the extensive research initiative managed by the NASA Human Research Program (HRP) and reviewed by the National Academy of Sciences. This resulted in recommendations for revised specifications of quality factors, QNASA(Z,β) in terms of track structure concepts that extend beyond LET alone. The new paradigm for quality factors placed demands on radiation monitoring procedures that are not satisfied by existing dosimetry systems or particle spectrometers that are practical for space exploration where mass, volume, band width and power consumption are highly constrained. We have proposed a new definition of quality factors that relaxes the requirements for identifying charge, Z, and velocity, β, of the incident radiation while still preserving the functional form of the inherent risk functions. The departure from the exact description of QNASA(Z,β) is that the revised values are new functions of LET for solid cancers and leukemia. We present the motivation and process for developing the revised quality factors. We describe results of extensive simulations using GCR distributions in free space as well as the resulting spectra of primary and secondary particles behind aluminum shields and penetration through water. In all cases the revised dose averaged quality factors agreed with those based on the values obtained using QNASA(Z,β). This provides confidence that emerging technologies for space radiation dosimetry can provide real time measurements of dose and dose equivalent while satisfying constraints on size, mass, power and bandwidth. The revised

  14. Quality factors for space radiation: A new approach

    NASA Astrophysics Data System (ADS)

    Borak, Thomas B.; Heilbronn, Lawrence H.; Townsend, Lawrence W.; McBeth, Rafe A.; de Wet, Wouter

    2014-04-01

    NASA has derived new models for radiological risk assessment based on epidemiological data and radiation biology including differences in Relative Biological Effectiveness for leukemia and solid tumors. Comprehensive approaches were used to develop new risk cross sections and the extension of these into recommendations for risk assessment during space missions. The methodology relies on published data generated and the extensive research initiative managed by the NASA Human Research Program (HRP) and reviewed by the National Academy of Sciences. This resulted in recommendations for revised specifications of quality factors, QNASA (Z , β) in terms of track structure concepts that extend beyond LET alone. The new paradigm for quality factors placed demands on radiation monitoring procedures that are not satisfied by existing dosimetry systems or particle spectrometers that are practical for space exploration where mass, volume, band width and power consumption are highly constrained. We have proposed a new definition of quality factors that relaxes the requirements for identifying charge, Z, and velocity, β, of the incident radiation while still preserving the functional form of the inherent risk functions. The departure from the exact description of QNASA (Z , β) is that the revised values are new functions of LET for solid cancers and leukemia. We present the motivation and process for developing the revised quality factors. We describe results of extensive simulations using GCR distributions in free space as well as the resulting spectra of primary and secondary particles behind aluminum shields and penetration through water. In all cases the revised dose averaged quality factors agreed with those based on the values obtained using QNASA (Z , β). This provides confidence that emerging technologies for space radiation dosimetry can provide real time measurements of dose and dose equivalent while satisfying constraints on size, mass, power and bandwidth. The

  15. The gamma-ray and neutron shielding factors of fly-ash brick materials.

    PubMed

    Singh, Vishwanath P; Badiger, N M

    2014-03-01

    A comprehensive study of gamma-ray exposure build-up factors (EBFs) of fly-ash brick materials has been carried out for photon energies of 0.015-15 MeV up to a penetration depth of 40 mfp (mean free path) by a geometrical progression (GP) fitting method. The EBF values of the fly-ash brick materials were found to be dependent upon the photon energy, penetration depth and chemical composition, and were found to be higher than the values for mud bricks and common bricks. Above a photon energy of 3 MeV for large penetration depths (>10 mfp), the EBF becomes directly proportional to Zeq. EBFs of fly-ashes were found to be less than or equal to those of concrete for low penetration depths (<10 mfp) for intermediate photon energies up to 1.5 MeV. The EBF values of fly-ash materials were found to be almost independent of Si concentration. The fast neutron removal cross sections of the fly-ash brick materials, mud bricks and common bricks were also calculated to understand their shielding effectiveness. The shielding effectiveness of the fly-ash materials against gamma-ray radiation was lower than that of common and mud bricks.

  16. High quality factor etchless silicon photonic ring resonators.

    PubMed

    Luo, Lian-Wee; Wiederhecker, Gustavo S; Cardenas, Jaime; Poitras, Carl; Lipson, Michal

    2011-03-28

    We demonstrate high quality factor etchless silicon photonic ring resonators fabricated by selective thermal oxidation of silicon without the silicon layer being exposed to any plasma etching throughout the fabrication process. We achieve a high intrinsic quality factor of 510,000 in 50 µm-radius ring resonators, corresponding to a ring loss of 0.8 dB/cm. The device has a total chip insertion loss of 2.5 dB, achieved by designing etchless silicon inverse nanotapers at both the input and output of the chip.

  17. Human factors systems approach to healthcare quality and patient safety

    PubMed Central

    Carayon, Pascale; Wetterneck, Tosha B.; Rivera-Rodriguez, A. Joy; Hundt, Ann Schoofs; Hoonakker, Peter; Holden, Richard; Gurses, Ayse P.

    2013-01-01

    Human factors systems approaches are critical for improving healthcare quality and patient safety. The SEIPS (Systems Engineering Initiative for Patient Safety) model of work system and patient safety is a human factors systems approach that has been successfully applied in healthcare research and practice. Several research and practical applications of the SEIPS model are described. Important implications of the SEIPS model for healthcare system and process redesign are highlighted. Principles for redesigning healthcare systems using the SEIPS model are described. Balancing the work system and encouraging the active and adaptive role of workers are key principles for improving healthcare quality and patient safety. PMID:23845724

  18. High Quality Factor Mechanical Resonators Based on WSe2 Monolayers

    PubMed Central

    2016-01-01

    Suspended monolayer transition metal dichalcogenides (TMD) are membranes that combine ultralow mass and exceptional optical properties, making them intriguing materials for opto-mechanical applications. However, the low measured quality factor of TMD resonators has been a roadblock so far. Here, we report an ultrasensitive optical readout of monolayer TMD resonators that allows us to reveal their mechanical properties at cryogenic temperatures. We find that the quality factor of monolayer WSe2 resonators greatly increases below room temperature, reaching values as high as 1.6 × 104 at liquid nitrogen temperature and 4.7 × 104 at liquid helium temperature. This surpasses the quality factor of monolayer graphene resonators with similar surface areas. Upon cooling the resonator, the resonant frequency increases significantly due to the thermal contraction of the WSe2 lattice. These measurements allow us to experimentally study the thermal expansion coefficient of WSe2 monolayers for the first time. High Q-factors are also found in resonators based on MoS2 and MoSe2 monolayers. The high quality-factor found in this work opens new possibilities for coupling mechanical vibrational states to two-dimensional excitons, valley pseudospins, and single quantum emitters and for quantum opto-mechanical experiments based on the Casimir interaction. PMID:27459399

  19. Realization of high quality production schedules: Structuring quality factors via iteration of user specification processes

    NASA Technical Reports Server (NTRS)

    Hamazaki, Takashi

    1992-01-01

    This paper describes an architecture for realizing high quality production schedules. Although quality is one of the most important aspects of production scheduling, it is difficult, even for a user, to specify precisely. However, it is also true that the decision as to whether a scheduler is good or bad can only be made by the user. This paper proposes the following: (1) the quality of a schedule can be represented in the form of quality factors, i.e. constraints and objectives of the domain, and their structure; (2) quality factors and their structure can be used for decision making at local decision points during the scheduling process; and (3) that they can be defined via iteration of user specification processes.

  20. The Average Quality Factors by TEPC for Charged Particles

    NASA Technical Reports Server (NTRS)

    Kim, Myung-Hee Y.; Nikjoo, Hooshang; Cucinotta, Francis A.

    2004-01-01

    The quality factor used in radiation protection is defined as a function of LET, Q(sub ave)(LET). However, tissue equivalent proportional counters (TEPC) measure the average quality factors as a function of lineal energy (y), Q(sub ave)(Y). A model of the TEPC response for charged particles considers energy deposition as a function of impact parameter from the ion s path to the volume, and describes the escape of energy out of sensitive volume by delta-rays and the entry of delta rays from the high-density wall into the low-density gas-volume. A common goal for operational detectors is to measure the average radiation quality to within accuracy of 25%. Using our TEPC response model and the NASA space radiation transport model we show that this accuracy is obtained by a properly calibrated TEPC. However, when the individual contributions from trapped protons and galactic cosmic rays (GCR) are considered; the average quality factor obtained by TEPC is overestimated for trapped protons and underestimated for GCR by about 30%, i.e., a compensating error. Using TEPC's values for trapped protons for Q(sub ave)(y), we obtained average quality factors in the 2.07-2.32 range. However, Q(sub ave)(LET) ranges from 1.5-1.65 as spacecraft shielding depth increases. The average quality factors for trapped protons on STS-89 demonstrate that the model of the TEPC response is in good agreement with flight TEPC data for Q(sub ave)(y), and thus Q(sub ave)(LET) for trapped protons is overestimated by TEPC. Preliminary comparisons for the complete GCR spectra show that Q(sub ave)(LET) for GCR is approximately 3.2-4.1, while TEPC measures 2.9-3.4 for QQ(sub ave)(y), indicating that QQ(sub ave)(LET) for GCR is underestimated by TEPC.

  1. Precise Measurement of the Transverse Asymmetry in Quasielastic 3He(e,e') and the Neutron Magnetic Form Factor

    SciTech Connect

    Jens-Ole Hansen for the Jefferson Lab E95-001 Collaboration

    2000-01-01

    We have measured the transverse asymmetry At' in 3He(e, e') quasielastic scattering with high statistical precision for Q{sup 2}-values from 0.1 to 0.6 (GeV/c){sup 2}. The data are expected to allow extraction of the neutron magnetic form factor GnM with an uncertainty similar to that of recent experiments on deuterium. Data analysis is currently in progress.

  2. Transverse asymmetry AT' from the quasielastic 3He(e,e') process and the neutron magnetic form factor.

    PubMed

    Xu, W; Dutta, D; Xiong, F; Anderson, B; Auberbach, L; Averett, T; Bertozzi, W; Black, T; Calarco, J; Cardman, L; Cates, G D; Chai, Z W; Chen, J P; Choi, S; Chudakov, E; Churchwell, S; Corrado, G S; Crawford, C; Dale, D; Deur, A; Djawotho, P; Filippone, B W; Finn, J M; Gao, H; Gilman, R; Glamazdin, A V; Glashausser, C; Glöckle, W; Golak, J; Gomez, J; Gorbenko, V G; Hansen, J O; Hersman, F W; Higinbotham, D W; Holmes, R; Howell, C R; Hughes, E; Humensky, B; Incerti, S; de Jager, C W; Jensen, J S; Jiang, X; Jones, C E; Jones, M; Kahl, R; Kamada, H; Kievsky, A; Kominis, I; Korsch, W; Kramer, K; Kumbartzki, G; Kuss, M; Lakuriqi, E; Liang, M; Liyanage, N; LeRose, J; Malov, S; Margaziotis, D J; Martin, J W; McCormick, K; McKeown, R D; McIlhany, K; Meziani, Z E; Michaels, R; Miller, G W; Pace, E; Pavlin, T; Petratos, G G; Pomatsalyuk, R I; Pripstein, D; Prout, D; Ransome, R D; Roblin, Y; Rvachev, M; Saha, A; Salmè, G; Schnee, M; Shin, T; Slifer, K; Souder, P A; Strauch, S; Suleiman, R; Sutter, M; Tipton, B; Todor, L; Viviani, M; Vlahovic, B; Watson, J; Williamson, C F; Witała, H; Wojtsekhowski, B; Yeh, J; Zołnierczuk, P

    2000-10-02

    We have measured the transverse asymmetry A(T') in 3He(e,e(')) quasielastic scattering in Hall A at Jefferson Laboratory with high precision for Q2 values from 0.1 to 0.6 (GeV/c)(2). The neutron magnetic form factor G(n)(M) was extracted based on Faddeev calculations for Q2 = 0.1 and 0.2 (GeV/c)(2) with an experimental uncertainty of less than 2%.

  3. Identifying Key Hospital Service Quality Factors in Online Health Communities

    PubMed Central

    Jung, Yuchul; Hur, Cinyoung; Jung, Dain

    2015-01-01

    Background The volume of health-related user-created content, especially hospital-related questions and answers in online health communities, has rapidly increased. Patients and caregivers participate in online community activities to share their experiences, exchange information, and ask about recommended or discredited hospitals. However, there is little research on how to identify hospital service quality automatically from the online communities. In the past, in-depth analysis of hospitals has used random sampling surveys. However, such surveys are becoming impractical owing to the rapidly increasing volume of online data and the diverse analysis requirements of related stakeholders. Objective As a solution for utilizing large-scale health-related information, we propose a novel approach to identify hospital service quality factors and overtime trends automatically from online health communities, especially hospital-related questions and answers. Methods We defined social media–based key quality factors for hospitals. In addition, we developed text mining techniques to detect such factors that frequently occur in online health communities. After detecting these factors that represent qualitative aspects of hospitals, we applied a sentiment analysis to recognize the types of recommendations in messages posted within online health communities. Korea’s two biggest online portals were used to test the effectiveness of detection of social media–based key quality factors for hospitals. Results To evaluate the proposed text mining techniques, we performed manual evaluations on the extraction and classification results, such as hospital name, service quality factors, and recommendation types using a random sample of messages (ie, 5.44% (9450/173,748) of the total messages). Service quality factor detection and hospital name extraction achieved average F1 scores of 91% and 78%, respectively. In terms of recommendation classification, performance (ie, precision) is

  4. Validation of neutron flux redistribution factors in JSI TRIGA reactor due to control rod movements.

    PubMed

    Kaiba, Tanja; Žerovnik, Gašper; Jazbec, Anže; Štancar, Žiga; Barbot, Loïc; Fourmentel, Damien; Snoj, Luka

    2015-10-01

    For efficient utilization of research reactors, such as TRIGA Mark II reactor in Ljubljana, it is important to know neutron flux distribution in the reactor as accurately as possible. The focus of this study is on the neutron flux redistributions due to control rod movements. For analyzing neutron flux redistributions, Monte Carlo calculations of fission rate distributions with the JSI TRIGA reactor model at different control rod configurations have been performed. Sensitivity of the detector response due to control rod movement have been studied. Optimal radial and axial positions of the detector have been determined. Measurements of the axial neutron flux distribution using the CEA manufactured fission chambers have been performed. The experiments at different control rod positions were conducted and compared with the MCNP calculations for a fixed detector axial position. In the future, simultaneous on-line measurements with multiple fission chambers will be performed inside the reactor core for a more accurate on-line power monitoring system.

  5. Leadership and management quality: key factors in effective health systems.

    PubMed

    Pfeffermann, Guy

    2012-01-01

    The effectiveness of health care systems in the developing world is related to the quality of their leadership and management, yet that factor has been neglected by academics and funders. Based on replicable existing models, the article proposes an approach to strengthening local management training institutions.

  6. Factors Influencing Practical Training Quality in Iranian Agricultural Higher Education

    ERIC Educational Resources Information Center

    Mojarradi, Gholamreza; Karamidehkordi, Esmail

    2016-01-01

    This paper presents an analysis of the factors influencing the practical training quality of agricultural higher education programmes from the senior students' perspective. The study was conducted in two public universities located in the north-west of Iran using a cross-sectional survey and structured interviews with a randomised sample of 254…

  7. The Use of a Multichannel Analyzer to Investigate Effects of Experimental Factors on Gross-Counting Gamma and Neutron Detectors

    SciTech Connect

    Volz, Heather M.; Rennie, John A.; Lovejoy, Christopher M.; Martinez, Diana E. R; Dempsey, Michael A.; Livesay, Jake; Lousteau, Angela

    2012-07-12

    Radiation detection technology is invaluable to many fields of study in identifying nuclear materials. However, many detectors use gross-counting methods that give only a relative count rate. Without a spectrum (information on counts over time vs energy), it can be more difficult to discern if an alarm is false, innocent, or real. In particular, we would like to understand better the effect of experimental factors (i.e., external conditions and equipment parameters) on detector data, with possible implications for false alarms. To more thoroughly characterize detector technology, a multichannel analyzer (MCA) was used to record spectra from neutron (helium-3 tubes) and gamma (photomultiplier tubes) gross-counting detectors. Several factors could affect the signal-to-noise ratio of sources. For example, we examined the effects of neutron detector high voltage setting on the appearance of a californium-252 spectrum, the effect of discriminator values on integrated counts in neutron detection, and the effect of gain changes on the gamma spectra from several sources. Possible implications of ambient temperature of the experiment on the data collected will be discussed. The input impedance of the MCA must be considered to ensure that data are not affected by the measurement itself. Moreover, a calibration on the MCA was performed to verify the conversion of a MCA channel number to a voltage. In summary, the series of source spectra collected on an MCA with a variety of experimental conditions allow us to understand factors that affect data better, and assure us that gross-counting neutron and gamma detectors will have minimal false alarms.

  8. Advantage and limitations of weighting factors and weighted dose quantities and their units in boron neutron capture therapy.

    PubMed

    Rassow, J; Sauerwein, W; Wittig, A; Bourhis-Martin, E; Hideghéty, K; Moss, R

    2004-05-01

    ICRU/IAEA made proposals, which should be followed by all BNCT groups, to report always the four absorbed dose components, boron dose DB, proton dose Dp, gamma-ray dose Dgamma, and neutron dose Dn, as well as the sum DT of all components, as total absorbed dose, together with the total weighted dose Dw (to be used only for internal purposes, indicating the used weighting factors) at all points of interest and the treatment conditions.

  9. Status of Bates experiment 85-05: The electric form factor of the neutron from the d(e↘,e'n↘)p reaction

    NASA Astrophysics Data System (ADS)

    Madey, R.; Eden, T.; Zhang, W. M.; Anderson, B. D.; Baldwin, A. R.; Keane, D.; Manley, D. M.; Watson, J. W.; Kowalski, S.; Bertozzi, W.; Dodson, G.; Dow, K.; Farkhondeh, M.; Korsch, W.; Tieger, D.; Turchinetz, W.; Weinstein, L.; Reichelt, T.; Finn, J. M.; Beard, K. B.; Markowitz, P.; McIntyre, J.; Rutt, P.; Lourie, R.; Barkhuff, D.; Van Verst, S.; Chang, C. C.; Kelly, J. J.; Payerle, T.; Cameron, J. M.; Ni, B.; Spraker, M.; Mougey, J.; Ulmer, P.; Whitney, R.; Flanders, B. S.; Pella, P. J.; Hyde-Wright, C. E.; Jiang, W.

    1992-01-01

    The Bates E85-05 Collaboration measured the polarization of the neutron in the d(e↘,en↘)p reaction in the quasifree region with the objective of extracting the electric form factor of the neutron. Electron-neutron coincidence spectra were obtained during 567 μA-hours of integrated beam. We succeeded in operating a Mo/ller scattering polarimeter in the coincidence mode with a low-duty factor accelerator in order to measure the polarization of the electron beam.

  10. Factors affecting quality and safety of fresh-cut produce.

    PubMed

    Francis, G A; Gallone, A; Nychas, G J; Sofos, J N; Colelli, G; Amodio, M L; Spano, G

    2012-01-01

    The quality of fresh-cut fruit and vegetable products includes a combination of attributes, such as appearance, texture, and flavor, as well as nutritional and safety aspects that determine their value to the consumer. Nutritionally, fruit and vegetables represent a good source of vitamins, minerals, and dietary fiber, and fresh-cut produce satisfies consumer demand for freshly prepared, convenient, healthy food. However, fresh-cut produce deteriorates faster than corresponding intact produce, as a result of damage caused by minimal processing, which accelerates many physiological changes that lead to a reduction in produce quality and shelf-life. The symptoms of produce deterioration include discoloration, increased oxidative browning at cut surfaces, flaccidity as a result of loss of water, and decreased nutritional value. Damaged plant tissues also represent a better substrate for growth of microorganisms, including spoilage microorganisms and foodborne pathogens. The risk of pathogen contamination and growth is one of the main safety concerns associated with fresh-cut produce, as highlighted by the increasing number of produce-linked foodborne outbreaks in recent years. The pathogens of major concern in fresh-cut produce are Listeria monocytogenes, pathogenic Escherichia coli mainly O157:H7, and Salmonella spp. This article describes the quality of fresh-cut produce, factors affecting quality, and various techniques for evaluating quality. In addition, the microbiological safety of fresh-cut produce and factors affecting pathogen survival and growth on fresh-cut produce are discussed in detail.

  11. The impact of gate width setting and gate utilization factors on plutonium assay in passive correlated neutron counting

    NASA Astrophysics Data System (ADS)

    Henzlova, D.; Menlove, H. O.; Croft, S.; Favalli, A.; Santi, P.

    2015-10-01

    In the field of nuclear safeguards, passive neutron multiplicity counting (PNMC) is a method typically employed in non-destructive assay (NDA) of special nuclear material (SNM) for nonproliferation, verification and accountability purposes. PNMC is generally performed using a well-type thermal neutron counter and relies on the detection of correlated pairs or higher order multiplets of neutrons emitted by an assayed item. To assay SNM, a set of parameters for a given well-counter is required to link the measured multiplicity rates to the assayed item properties. Detection efficiency, die-away time, gate utilization factors (tightly connected to die-away time) as well as optimum gate width setting are among the key parameters. These parameters along with the underlying model assumptions directly affect the accuracy of the SNM assay. In this paper we examine the role of gate utilization factors and the single exponential die-away time assumption and their impact on the measurements for a range of plutonium materials. In addition, we examine the importance of item-optimized coincidence gate width setting as opposed to using a universal gate width value. Finally, the traditional PNMC based on multiplicity shift register electronics is extended to Feynman-type analysis and application of this approach to Pu mass assay is demonstrated.

  12. The Impact of Gate Width Setting and Gate Utilization Factors on Plutonium Assay in Passive Correlated Neutron Counting

    SciTech Connect

    Henzlova, Daniela; Menlove, Howard Olsen; Croft, Stephen; Favalli, Andrea; Santi, Peter Angelo

    2015-06-15

    In the field of nuclear safeguards, passive neutron multiplicity counting (PNMC) is a method typically employed in non-destructive assay (NDA) of special nuclear material (SNM) for nonproliferation, verification and accountability purposes. PNMC is generally performed using a well-type thermal neutron counter and relies on the detection of correlated pairs or higher order multiplets of neutrons emitted by an assayed item. To assay SNM, a set of parameters for a given well-counter is required to link the measured multiplicity rates to the assayed item properties. Detection efficiency, die-away time, gate utilization factors (tightly connected to die-away time) as well as optimum gate width setting are among the key parameters. These parameters along with the underlying model assumptions directly affect the accuracy of the SNM assay. In this paper we examine the role of gate utilization factors and the single exponential die-away time assumption and their impact on the measurements for a range of plutonium materials. In addition, we examine the importance of item-optimized coincidence gate width setting as opposed to using a universal gate width value. Finally, the traditional PNMC based on multiplicity shift register electronics is extended to Feynman-type analysis and application of this approach to Pu mass assay is demonstrated.

  13. The Impact of Gate Width Setting and Gate Utilization Factors on Plutonium Assay in Passive Correlated Neutron Counting

    DOE PAGES

    Henzlova, Daniela; Menlove, Howard Olsen; Croft, Stephen; ...

    2015-06-15

    In the field of nuclear safeguards, passive neutron multiplicity counting (PNMC) is a method typically employed in non-destructive assay (NDA) of special nuclear material (SNM) for nonproliferation, verification and accountability purposes. PNMC is generally performed using a well-type thermal neutron counter and relies on the detection of correlated pairs or higher order multiplets of neutrons emitted by an assayed item. To assay SNM, a set of parameters for a given well-counter is required to link the measured multiplicity rates to the assayed item properties. Detection efficiency, die-away time, gate utilization factors (tightly connected to die-away time) as well as optimummore » gate width setting are among the key parameters. These parameters along with the underlying model assumptions directly affect the accuracy of the SNM assay. In this paper we examine the role of gate utilization factors and the single exponential die-away time assumption and their impact on the measurements for a range of plutonium materials. In addition, we examine the importance of item-optimized coincidence gate width setting as opposed to using a universal gate width value. Finally, the traditional PNMC based on multiplicity shift register electronics is extended to Feynman-type analysis and application of this approach to Pu mass assay is demonstrated.« less

  14. Preliminary Study for a Tetrahedron Formation: Quality Factors and Visualization

    NASA Technical Reports Server (NTRS)

    Guzman, Jose J.; Schiff, Conrad; Bauer, Frank (Technical Monitor)

    2002-01-01

    Spacecraft flying in tetrahedron formations are excellent for electromagnetic and plasma studies. The quality of the science recorded is strongly affected by the tetrahedron evolution. This paper is a preliminary study on the computation of quality factors and visualization for a formation of four or five satellites. Four of the satellites are arranged geometrically in a tetrahedron shape. If a fifth satellite is present, it is arbitrarily initialized at the geometric center of the tetrahedron. The fifth satellite could act as a collector or as a spare spacecraft. Tetrahedron natural coordinates are employed for the initialization. The natural orbit evolution is visualized in geocentric equatorial inertial and in geocentric solar magnetospheric coordinates.

  15. The study of surgical image quality evaluation system by subjective quality factor method

    NASA Astrophysics Data System (ADS)

    Zhang, Jian J.; Xuan, Jason R.; Yang, Xirong; Yu, Honggang; Koullick, Edouard

    2016-03-01

    GreenLightTM procedure is an effective and economical way of treatment of benign prostate hyperplasia (BPH); there are almost a million of patients treated with GreenLightTM worldwide. During the surgical procedure, the surgeon or physician will rely on the monitoring video system to survey and confirm the surgical progress. There are a few obstructions that could greatly affect the image quality of the monitoring video, like laser glare by the tissue and body fluid, air bubbles and debris generated by tissue evaporation, and bleeding, just to name a few. In order to improve the physician's visual experience of a laser surgical procedure, the system performance parameter related to image quality needs to be well defined. However, since image quality is the integrated set of perceptions of the overall degree of excellence of an image, or in other words, image quality is the perceptually weighted combination of significant attributes (contrast, graininess …) of an image when considered in its marketplace or application, there is no standard definition on overall image or video quality especially for the no-reference case (without a standard chart as reference). In this study, Subjective Quality Factor (SQF) and acutance are used for no-reference image quality evaluation. Basic image quality parameters, like sharpness, color accuracy, size of obstruction and transmission of obstruction, are used as subparameter to define the rating scale for image quality evaluation or comparison. Sample image groups were evaluated by human observers according to the rating scale. Surveys of physician groups were also conducted with lab generated sample videos. The study shows that human subjective perception is a trustworthy way of image quality evaluation. More systematic investigation on the relationship between video quality and image quality of each frame will be conducted as a future study.

  16. Measurement of the Electric Form Factor of the Neutron through d-vector(e-vector, e'n)p

    SciTech Connect

    Hongguo Zhu; Abdellah Ahmidouch; H. Anklin; H. Arenhoevel; Chris Armstrong; C. Bernet; Werner Boeglin; Herbert Breuer; Paul Brindza; D. Brown; S. Bueltmann; Roger Carlini; Nicholas Chant; Anthony Cowley; Donald Crabb; Samuel Danagoulian; D. B. Day; Tom Eden; Rolf Ent; Yusuf Farah; Renee Fatimi; Kenneth Garrow; Chris Harris; Markus Hauger; A. Honegger; J. Jourdan; M. Kaufmann; Mahbub Khandaker; Gunther Kubon; Jechiel Lichtenstadt; Richard Lindgren; Robert Lourie; Allison Lung; David Mack; Sudhir Malik; Pete Markowitz; Kenneth McFarlane; Paul McKee; Dustin McNulty; Geoffrey Milanovich; Joseph Mitchell; Hamlet Mkrtchyan; M. Muehlbauer; Thomas Petitjean; Yelena Prok; Daniela Rohe; Emmanuel Rollinde; Oscar Rondon-Aramayo; Philip Roos; Reyad Sawafta; Ingo Sick; C. Smith; Tim Southern; Michael Steinacher; Stepan Stepanyan; Vardan Tadevosyan; Raphael Tieulent; Al Tobias; Bill Vulcan; Glen Warren; H. Woehrle; Stephen Wood; Chen Yan; Marko Zeier; Jianguo Zhao; Beni Zihlmann

    2001-08-20

    We report the first measurement using a solid polarized target of the neutron electric form factor G{sup n}{sub E} via d-vector(e-vector, e'n)p. G{sup n}{sub E} was determined from the beam-target asymmetry in the scattering of longitudinally polarized electrons from polarized deuterated ammonia ({sup 15}ND{sub 3}). The measurement was performed in Hall C at Thomas Jefferson National Accelerator Facility in quasifree kinematics with the target polarization perpendicular to the momentum transfer. The electrons were detected in a magnetic spectrometer in coincidence with neutrons in a large solid angle segmented detector. We find G{sup n}{sub E} = 0.04632{+-}0.00616(stat){+-}0.00341(syst) at Q{sup 2} = 0.495 (GeV/c){sup 2}.

  17. [Factors associated with the quality of life of elderly men].

    PubMed

    Tavares, Darlene Mara dos Santos; Dias, Flavia Aparecida; de Freitas Santos, Nilce Maria; Haas, Vanderlei José; de Miranzi, Sybelle Castro Sousa

    2013-06-01

    This was an analytical, cross-sectional household survey study aimed at describing the sociodemographic characteristics, health and quality of life of elderly men, and to verify the socioeconomic and health factors related to quality of life. Participants in this study included 804 elderly men. Data were collected using the following instruments: Older Americans Resources and Services scale (OARS), the World Health Organization Quality of Life-BREF (WHOQOL-BREF), and the World Health Organization Quality of Life Assessment for Older Adults (WHOQOL-OLD). Descriptive analysis, student's t-test, Pearson correlation and multiple linear regression (p<0.05) were used. The prevalent characteristics were: individuals 60-70 years old, married, 4-8 years of education, and a minimum wage income. The lowest quality of life scores were in the physical domain and autonomy facet, and were associated with: the absence of a companion, education, low income, higher number of comorbidities, and functional disability. Functional disability had the strongest influence on the quality of life, except for the physical domain and intimacy facet.

  18. Quality assurance of temporal variability of natural decay chain and neutron induced background for low-level NORM analysis

    DOE PAGES

    Yoho, Michael; Porterfield, Donivan R.; Landsberger, Sheldon

    2015-09-22

    In this study, twenty-one high purity germanium (HPGe) background spectra were collected over 2 years at Los Alamos National Laboratory. A quality assurance methodology was developed to monitor spectral background levels from thermal and fast neutron flux levels and naturally occurring radioactive material decay series radionuclides. 238U decay products above 222Rn demonstrated minimal temporal variability beyond that expected from counting statistics. 238U and 232Th progeny below Rn gas displayed at most twice the expected variability. Further, an analysis of the 139 keV 74Ge(n, γ) and 691 keV 72Ge(n, n') spectral features demonstrated temporal stability for both thermal and fast neutronmore » fluxes.« less

  19. Optimized Quality Factor of Graphene Oxide-Reinforced PVC Nanocomposite

    NASA Astrophysics Data System (ADS)

    Joshi, Girish M.; Deshmukh, Kalim

    2014-04-01

    Graphene oxide (GO)-reinforced polyvinyl chloride (PVC) composite films were prepared by solution blending. The homogeneity of GO dispersion with PVC was confirmed by an optical microscope. Quality factor ( Q-factor) as a function of temperature (40-150 °C) was measured within a broadband frequency range of 50-35 MHz. The controlled GO loading demonstrates a crucial impact on the optimization of the Q-factor, resonance frequency ( f 0) and wide bandwidth. This nanocomposite may be well suited for electronic applications. The further development of GO-reinforced polymer nanocomposites based on an optimized Q-factor may result in a material for electromagnetic frequency radiation shields for radar and communication towers/devices.

  20. Quality factor of secondary cosmic radiation at flight altitudes.

    PubMed

    Burda, O; Sato, T; Wissmann, F

    2013-06-01

    Dosimetry at aviation altitudes requires instruments that are able to measure the dose contributions of all field components. Tissue-equivalent proportional counters (TEPCs) are well suited for this task. From the measured lineal energy distribution, the absorbed dose and the dose equivalent can be obtained. The ratio of both quantities is named the quality factor, which is a measure of the biological effectiveness of the radiation field. The results of this work show that the mean quality factors obtained by using a TEPC are independent of the altitude, at least at altitudes between flight level (FL) 300 and FL 400, but show a significant dependence on the vertical cutoff rigidity. From a numerical simulation of the radiation field inside an aircraft, the influence of the aircraft structure can be shown.

  1. Method for determining formation quality factor from seismic data

    DOEpatents

    Taner, M. Turhan; Treitel, Sven

    2005-08-16

    A method is disclosed for calculating the quality factor Q from a seismic data trace. The method includes calculating a first and a second minimum phase inverse wavelet at a first and a second time interval along the seismic data trace, synthetically dividing the first wavelet by the second wavelet, Fourier transforming the result of the synthetic division, calculating the logarithm of this quotient of Fourier transforms and determining the slope of a best fit line to the logarithm of the quotient.

  2. Improving the Optical Quality Factor of the WGM Resonator

    NASA Technical Reports Server (NTRS)

    Savchenkov, Anatoliy; Matsko, Andrey; Iltchenko, Vladimir

    2008-01-01

    Resonators usually are characterized with two partially dependent values: finesse (F) and quality factor (Q). The finesse of an empty Fabry-Perot (FP) resonator is defined solely by the quality of its mirrors and is calculated as F=piR(exp 1/2)/(1-R). The maximum up-to-date value of reflectivity R approximately equal to 1 - 1.6 x 10(exp -6) is achieved with dielectric mirrors. An FP resonator made with the mirrors has finesse F=1.9 x 10(exp 6). Further practical increase of the finesse of FP resonators is problematic because of the absorption and the scattering of light in the mirror material through fundamental limit on the reflection losses given by the internal material losses and by thermodynamic density fluctuations on the order of parts in 109. The quality factor of a resonator depends on both its finesse and its geometrical size. A one-dimensional FP resonator has Q=2 F L/lambda, where L is the distance between the mirrors and lambda is the wavelength. It is easy to see that the quality factor of the resonator is unlimited because L is unlimited. F and Q are equally important. In some cases, finesse is technically more valuable than the quality factor. For instance, buildup of the optical power inside the resonator, as well as the Purcell factor, is proportional to finesse. Sometimes, however, the quality factor is more valuable. For example, inverse threshold power of intracavity hyperparametric oscillation is proportional to Q(exp 2) and efficiency of parametric frequency mixing is proportional to Q(exp 3). Therefore, it is important to know both the maximally achievable finesse and quality factor values of a resonator. Whispering gallery mode (WGM) resonators are capable of achieving larger finesse compared to FP resonators. For instance, fused silica resonators with finesse 2.3 x 10(exp 6) and 2.8 x 10(exp 6) have been demonstrated. Crystalline WGM resonators reveal even larger finesse values, F=6.3 x 10(exp 6), because of low attenuation of light in the

  3. Relationship factors and quality among mixed-orientation couples.

    PubMed

    Kays, Jill L; Yarhouse, Mark A; Ripley, Jennifer S

    2014-01-01

    Mixed-orientation couples are defined as a heterosexual couple in which 1 partner experiences same-sex attraction and the other does not. Despite the fact that there is a sizable number of mixed-orientation couples in the U.S. adult population, few researchers have studied this population, and thus, there is limited understanding of these relationships. The authors examined the degree to which relationship commitment, partner-focused forgivingness, and marital values were associated with relationship quality, and how these variables predicted relationship quality. The total sample (N = 265) consisted of 2 independent samples-105 sexual minorities (i.e., the spouse who experiences same-sex attraction) and 160 heterosexual spouses. The data were not dyadic. Together, commitment, partner-focused forgivingness, and marital values accounted for roughly 43% of the variance in relationship quality. Relationship commitment was found to be the largest single predictor of relationship quality, followed by partner-focused forgivingness. Research and clinical implications are discussed. This study significantly adds to the current research base by quantitatively measuring various variables in these relationships, as well as expanding our understanding of relationship quality in mixed-orientation couples and factors that may play a role.

  4. Redundancy in neutron activation analysis: A valuable tool in assuring analytical quality

    SciTech Connect

    Greenberg, R.R.

    1996-12-31

    Neutron activation analysis (NAA) has become widely used and is extremely valuable for the certification of standard reference materials (SRMs) at the National Institute of Standards and Technology (NIST). This is due to a number of reasons. First, NAA has essentially no significant sources of error in common with the other analytical techniques used at NIST to measure inorganic concentrations. This is important because most certified elemental concentrations are derived from the data determined by two (and occasionally more) independent analytical techniques. Two or more techniques are used for SRM certification because, although each technique has previously been evaluated and shown to be accurate, unexpected problems can arise, especially when analyzing new matrices. Another reason for the use of NAA for SRM certification is the potential of this technique for accuracy. The SRM measurements with estimated accuracies of 1 to 2% (at essentially 95% confidence intervals) are routinely made at NIST using NAA.

  5. Measurement of coherent Debye-Waller factor in in vivo deuterated C-phycocyanin by inelastic neutron scattering.

    PubMed

    Bellissent-Funel, M C; Filabozzi, A; Chen, S H

    1997-04-01

    Quasielastic neutron scattering measurements of dry and 35% D2O hydrated amorphous protein powder of C-phycocyanin were made as a function of temperature ranging from 313K down to 100K. The protein is grown from blue-green algae cultured in D2O and is deuterated up to 99%. The scattering is thus dominated by coherent scattering. Within the best energy resolution of the time-of-flight instrument, which is 28 mueV FWHM, the scattering appears entirely elastic. For this reason we are able to extract a coherent Debye-Waller factor by making an independent measurement of the static structure factor. We observe a considerable difference in the q dependence of the Debye-Waller factor between the dry and hydrated proteins; furthermore, there is an interesting temperature dependence of the Debye-Waller factor that is quite different from that predicted for dense hard-sphere liquids.

  6. Determination of the neutron electric form factor from the reaction 3He(e,e'n) at medium momentum transfer

    NASA Astrophysics Data System (ADS)

    Becker, J.; Andresen, H. G.; Annand, J. R. M.; Aulenbacher, K.; Beuchel, K.; Blume-Werry, J.; Dombo, Th.; Drescher, P.; Ebert, M.; Eyl, D.; Frey, A.; Grabmayr, P.; Großmann, T.; Hartmann, P.; Hehl, T.; Heil, W.; Herberg, C.; Hoffmann, J.; Kellie, J. D.; Klein, F.; Livingston, K.; Leduc, M.; Meyerhoff, M.; Möller, H.; Nachtigall, Ch.; Natter, A.; Ostrick, M.; Otten, E. W.; Owens, R. O.; Plützer, S.; Reichert, E.; Rohe, D.; Schäfer, M.; Schmieden, H.; Sprengard, R.; Steigerwald, M.; Steffens, K.-H.; Surkau, R.; Walcher, Th.; Watson, R.; Wilms, E.

    The electric form factor of the neutron GEn has been determined in double polarized exclusive 3He(e,e'n) scattering in quasi-elastic kinematics by measuring asymmetries A⊥, A∥ of the cross section with respect to helicity reversal of the electron, with the nuclear spin being oriented perpendicular to the momentum transfer q in case of A⊥ and parallel in case of A∥. The experiment was performed at the 855 MeV c. w. microtron MAMI at Mainz. The degree of polarization of the electron beam and of the gaseous 3He target were each about 50%. Scattered electrons and neutrons were detected in coincidence by detector arrays covering large solid angles. Quasi-elastic scattering events were reconstructed from the measured electron scattering angles ϑe, φe and the neutron momentum vector pn' in the plane wave impulse approximation. We obtain the result (0.27 < Q2c2/GeV2 < 0.5)= 0.0334 +/- 0.0033stat+/- 0.0028syst which is averaged over the indicated range of Q2, the squared momentum transfer. This GEn value is significantly smaller than measured from the D(e,e'n) reaction under similar kinematical conditions. To what extent final state interactions in 3He quench the GEn result is subject of calculations currently in progress elsewhere.

  7. Assessment of the neutron emission anisotropy factor of a sealed AmBe source by means of measurements and Monte Carlo simulations

    NASA Astrophysics Data System (ADS)

    Loreti, S.; Pietropaolo, A.

    2015-10-01

    The neutron emission anisotropy factor of a sealed Americium-Beryllium source is experimentally determined and compared to Monte Carlo simulations. The measurements were done at the Italian Institute for Metrology of Ionizing Radiations using a long counter neutron detector and a "X.3" type AmBe sealed neutron source. Experimental data are compared to simulations performed with the MCNP code where the precise structure of the source is taken into account starting from its technical design. The contributions of the single structural parts are described to point out the effective sources of the emission anisotropy.

  8. Factors influencing quality of chest compression depth in nursing students.

    PubMed

    Roh, Young Sook; Lim, Eun Ju

    2013-12-01

    The purpose of the study was to identify factors influencing quality of chest compression depth in nursing students. A convenience sample of 102 female nursing students enrolled in a cardiopulmonary resuscitation skills training session. Each student performed 3 min of chest compression skills on a Resusci Anne SkillReporter manikin for measurements of both depth and rate. Nursing students with correct compression depth (50-60 mm) had higher body weight (t = -2.02, P = 0.046) and body mass index (t = -2.19, P = 0.031) compared with students in the incorrect depth group. Mean chest compression depth was shallower in underweight nursing students compared with normal weight or overweight students (F = 8.89, P < 0.001). Body weight was a significant factor influencing quality of chest compression depth (F = 4.25, P = 0.003). Educational intervention targeting underweight nursing students might need to enhance the quality of chest compression skills.

  9. Personnel neutron dose assessment upgrade: Volume 2, Field neutron spectrometer for health physics applications

    SciTech Connect

    Brackenbush, L.W.; Reece, W.D.; Miller, S.D.; Endres, G.W.R.; Durham, J.S.; Scherpelz, R.I.; Tomeraasen, P.L.; Stroud, C.M.; Faust, L.G.; Vallario, E.J.

    1988-07-01

    Both the (ICRP) and the (NCPR) have recommended an increase in neutron quality factors and the adoption of effective dose equivalent methods. The series of reports entitled Personnel Neutron Dose Assessment Upgrade (PNL-6620) addresses these changes. Volume 1 in this series of reports (Personnel Neutron Dosimetry Assessment) provided guidance on the characteristics, use, and calibration of personnel neutron dosimeters in order to meet the new recommendations. This report, Volume 2: Field Neutron Spectrometer for Health Physics Applications describes the development of a portable field spectrometer which can be set up for use in a few minutes by a single person. The field spectrometer described herein represents a significant advance in improving the accuracy of neutron dose assessment. It permits an immediate analysis of the energy spectral distribution associated with the radiation from which neutron quality factor can be determined. It is now possible to depart from the use of maximum Q by determining and realistically applying a lower Q based on spectral data. The field spectrometer is made up of two modules: a detector module with built-in electronics and an analysis module with a IBM PC/reg sign/-compatible computer to control the data acquisition and analysis of data in the field. The unit is simple enough to allow the operator to perform spectral measurements with minimal training. The instrument is intended for use in steady-state radiation fields with neutrons energies covering the fission spectrum range. The prototype field spectrometer has been field tested in plutonium processing facilities, and has been proven to operate satisfactorily. The prototype field spectrometer uses a /sup 3/He proportional counter to measure the neutron energy spectrum between 50 keV and 5 MeV and a tissue equivalent proportional counter (TEPC) to measure absorbed neutron dose.

  10. Accelerator-based epithermal neutron sources for boron neutron capture therapy of brain tumors.

    PubMed

    Blue, Thomas E; Yanch, Jacquelyn C

    2003-01-01

    the use of microchannels have emerged as viable target cooling options. Neutron fields for reactor-based neutron sources provide an obvious basis of comparison for ABNS field quality. This paper compares Monte Carlo calculations of neutron field quality for an ABNS and an idealized standard reactor neutron field (ISRNF). The comparison shows that with lithium as a target, an ABNS can create a neutron field with a field quality that is significantly better (by a factor of approximately 1.2, as judged by the relative biological effectiveness (RBE)-dose that can be delivered to a tumor at a depth of 6cm) than that for the ISRNF. Also, for a beam current of 10 mA, the treatment time is calculated to be reasonable (approximately 30 min) for the boron concentrations that have been assumed.

  11. Neutron measurements onboard the space shuttle.

    PubMed

    Badhwar, G D; Keith, J E; Cleghorn, T F

    2001-06-01

    The radiation environment inside a shielded volume is highly complex, consisting of both charged and neutral particles. Since the inception of human space flights, the charged particle component has received virtually all of the attention. There is however, a significant production of secondary neutrons, particularly from the aluminum structure in low earth orbiting spacecrafts. The interactions of galactic cosmic rays (GCR), and solar energetic particles with the earth's atmosphere produce a non-isotropic distribution of albedo neutrons. Inside any reasonable habitable module, the average radiation quality factor of neutrons is about 4-5 times larger than the corresponding average quality factor of charged particles. The measurement of neutrons and their energy spectra is a difficult problem due the intense sources of charged particles. This paper reviews the results of Shuttle flight experiments (made during both solar maximum and solar minimum) to measure the contribution of neutrons to the dose equivalent, as well as theoretical calculations to estimate the appropriate range of neutron energies that contribute most to the dose equivalent.

  12. Neutron effects in humans: protection considerations

    SciTech Connect

    Fry, R.J.M.

    1985-01-01

    Committee I of the International Commission on Radiological Protection has recommended that the Quality Factor for neutrons should be changed from 10 to 20. This article is an interesting recount of the tale of Q from the viewpoint of an observer which illustrates many of the problems that the selection of protection standards pose. 32 refs., 5 tabs.

  13. Measurements of the electric form factor of the neutron at JLab via recoil polarimetry in the reaction: d(e, e-prime n)p

    SciTech Connect

    J.M. Finn

    2004-11-01

    Preliminary results are reported for measurements of the ratio of the electric form factor to the magnetic form factor of the neutron, GEn/GMn, obtained via recoil polarimetry from the quasielastic 2H(e, e?n) 1H reaction at Q2 values of 0.45, 1.13, and 1.45 (GeV/c)2. The measurements, conducted in Hall C of the Thomas Jefferson National Accelerator Facility, together with other recent polarization measurements, are the result of a decade long effort to establish a firm experimental database for the important, but elusive, electric form factor of the neutron.

  14. Definition of a quality factor for single site location estimates

    NASA Astrophysics Data System (ADS)

    Coetzee, Petrus J.; Plessis, Warren P.

    2016-06-01

    A technique to estimate the performance of single site location (SSL) based on high-frequency direction finding for reigning ionospheric propagation conditions is described. This technique is based on classic propagation information (maximum useable frequency, frequency for optimum traffic, optimum working frequency, highest possible frequency, lowest possible frequency, etc.) which can be deduced by ray tracing through an ionospheric model such as the International Reference Ionosphere. The correlation between the elevation angle measured by an interferometric direction finder and the angles corresponding to the propagation conditions is used to assign a quality factor to the calculated SSL ground range result.

  15. Stored electromagnetic energy and quality factor of radiating structures

    PubMed Central

    Jelinek, Lukas; Vandenbosch, Guy A. E.

    2016-01-01

    This paper deals with the old yet unsolved problem of defining and evaluating the stored electromagnetic energy—a quantity essential for calculating the quality factor, which reflects the intrinsic bandwidth of the considered electromagnetic system. A novel paradigm is proposed to determine the stored energy in the time domain leading to the method, which exhibits positive semi-definiteness and coordinate independence, i.e. two key properties actually not met by the contemporary approaches. The proposed technique is compared with an up-to-date frequency domain method that is extensively used in practice. Both concepts are discussed and compared on the basis of examples of varying complexity. PMID:27274693

  16. Lifestyle and semen quality: role of modifiable risk factors.

    PubMed

    Jurewicz, Joanna; Radwan, Michał; Sobala, Wojciech; Ligocka, Danuta; Radwan, Paweł; Bochenek, Michał; Hanke, Wojciech

    2014-02-01

    The relationship between exposure to lifestyle factors and adverse effects on human reproductive health is debated in the scientific literature and these controversies have increased public and regulatory attention. The aim of the study was to examine the association between modifiable lifestyle factors and main semen parameters, sperm morphology, and sperm chromatin structure. The study population consisted of 344 men who were attending an infertility clinic for diagnostic purposes with normal semen concentration of 20-300 M/ml or with slight oligozoospermia (semen total concentration of 15-20 M/ml) [WHO 1999]. Participants were interviewed and provided semen samples. The interview included questions about demographics, socio-economic status, medical history, lifestyle factors (consumption of alcohol, tobacco, coffee intake, cell phone and sauna usage), and physical activity. The results of the study suggest that lifestyle factors may affect semen quality. A negative association was found between increased body mass index (BMI) and semen volume (p = 0.03). Leisure time activity was positively associated with sperm concentration (p = 0.04) and coffee drinking with the percentage of motile sperm cells, and the percentage of sperm head and neck abnormalities (p = 0.01, p = 0.05, and p = 0.03, respectively). Drinking red wine 1-3 times per week was negatively related to sperm neck abnormalities (p = 0.01). Additionally, using a cell phone more than 10 years decreased the percentage of motile sperm cells (p = 0.02). Men who wore boxer shorts had a lower percentage of sperm neck abnormalities (p = 0.002) and percentage of sperm with DNA damage (p = 0.02). These findings may have important implications for semen quality and lifestyle.

  17. Charge and matter form factors of two-neutron halo nuclei in halo effective field theory at next-to-leading order

    NASA Astrophysics Data System (ADS)

    Vanasse, Jared

    2017-02-01

    By using halo effective field theory (EFT), an expansion in Rcore/Rhalo , where Rcore is the radius of the core and Rhalo the radius of the halo nucleus, the charge and neutron form factors of the two-neutron halo nuclei 11Li, 14Be, and 22C are calculated to next-to-leading order (NLO) by treating them as an effective three-body system. From the form factors, the point-charge and point-matter radii, inter-neutron distances, and neutron opening angles are extracted. Agreement is found with existing experimental extractions. Results are given for the point-charge and point-matter radii for arbitrary neutron core scattering effective range ρc n, which can be used for predictions once ρc n is measured. Estimates for ρc n are also used to make NLO predictions. Finally, the point-charge radii of this work are compared with other halo-EFT predictions, and setting the core mass equal to the neutron mass the point-charge radius is found to agree with an analytical prediction in the unitary limit.

  18. Tunable high quality factor in two multimode plasmonic stubs waveguide

    PubMed Central

    Chen, Zhiquan; Li, Hongjian; Zhan, Shiping; Li, Boxun; He, Zhihui; Xu, Hui; Zheng, Mingfei

    2016-01-01

    We numerically investigate the optical characteristics of a metal-dielectric-metal (MDM) waveguide side-coupled with two identical multimode stub resonators. Double plasmon-induced transparency (PIT) peaks with narrow full width at half maximum (FWHM) and high quality factor (Q-factor) can be observed in this structure. The Q-factors of PIT peaks in two stub resonators system are larger than those in single stub resonator system. A multimode coupled-radiation oscillator theory (MC-ROT), which is derived from ROT, is proposed to analyze the spectral response in the multimode system for the first time. The analytical results are confirmed by the finite-difference time-domain (FDTD) simulation results. We can also find that the Q-factors of the two PIT peaks have an opposite evolution tendency with the change of the stubs parameters and the maximum can reach to 427. These results may provide some applications for ultrasensitive sensors, switches and efficient filters. PMID:27075935

  19. Neutron scatter camera

    DOEpatents

    Mascarenhas, Nicholas; Marleau, Peter; Brennan, James S.; Krenz, Kevin D.

    2010-06-22

    An instrument that will directly image the fast fission neutrons from a special nuclear material source has been described. This instrument can improve the signal to background compared to non imaging neutron detection techniques by a factor given by ratio of the angular resolution window to 4.pi.. In addition to being a neutron imager, this instrument will also be an excellent neutron spectrometer, and will be able to differentiate between different types of neutron sources (e.g. fission, alpha-n, cosmic ray, and D-D or D-T fusion). Moreover, the instrument is able to pinpoint the source location.

  20. Optical Quality and Related Factors in Ocular Hypertension: Preliminary Study.

    PubMed

    Wang, Yu-Jing; Yang, Yan-Ning; Huang, Lin-Ying; Wang, Bo; Han, Yu-Can; Yan, Jiang-Bo

    2016-01-01

    Background. To evaluate the optical quality and related factors in patients with ocular hypertension (OHT). Methods. This was a prospective case-control study. A total of 12 eyes with OHT and 20 control eyes underwent testing with Optical Quality Analysis System II (OQAS II) to evaluate the modulation transfer function cut off frequency (MTF cutoff), the Strehl 2D ratio (SR), objective scatter index (OSI), tear-film mean OSI (TFOSI), and the OQAS values (OV100%,OV20%, and OV9%). Results. The optical quality of patients with OHT declined, with lower MTF cutoff (OHT 36.86 ± 7.11 cpd , controls 48.50 ± 4.04 cpd, t = -4.60, P < 0.05), lower SR (OHT 0.22 ± 0.04, controls 0.27 ± 0.05, t = -2.72, P < 0.05), lower OV100% (OHT 1.26 ± 0.25, controls 1.61 ± 0.14, t = -4.03, P < 0.05), lower OV20% (OHT 1.27 ± 0.27, controls 1.72 ± 0.20, t = -4.00, P < 0.05), and lower OV9% (OHT 1.30 ± 0.25, controls 1.69 ± 0.32, t = -2.28, P < 0.05). There were not any statistically significant differences in OSI and TFOSI. The MTF cutoff in patients with OHT was correlated significantly with age (r = -0.59, P < 0.05). Conclusions. Optical quality of patients with OHT is reduced, with lower MTF cutoff, SR, OV100%, OV20%, and OV9%. MTF cutoff is negatively related to age.

  1. Operator role definition: An initial step in the human factors engineering design of the advanced neutron source (ANS)

    SciTech Connect

    Knee, H.E.; Spelt, P.F.; Houser, M.M.; Hill, W.E.

    1994-12-31

    The Advanced Neutron Source (ANS) is a new basic and applied research facility sponsored by the U.S. Department of Energy that is proposed for construction. It will provide neutron beams for measurements and experiments in the fields of materials science and engineering, biology, chemistry, materials analysis, and nuclear science. The facility will provide a useful neutron beam flux that is at least five times more than is available at the world`s best existing facilities. It will also provide world-class facilities for isotopes production, materials irradiation testing, materials analysis, and the production of positrons. ANS will be unique in the United States in the extent to which human factors engineering (HFE) principles will be included in its design and construction. Initial HFE accomplishments include the development of a functional analysis, an operating philosophy, and a program plan. In fiscal year 1994, HFE activities are focusing on the role of the ANS control room reactor operator (RO). An operator-centered control room model was used in conjunction with information gathered from existing ANS system design descriptions and other literature to define RO responsibilities. From this list, a survey instrument was developed and administered to ANS design engineers, operations management personnel at Oak Ridge National Laboratory`s High Flux Isotope Reactor (HFIR), and HFIR ROs to detail the nature of the RO position. Initial results indicated that the RO should function as a high-level system supervisor with considerable monitoring, verification, and communication responsibilities. The relatively high level of control automation has resulted in a reshaping of the RO`s traditional safety and investment protection roles.

  2. Impact of solvent quality on the density profiles of looped triblock copolymer brushes by neutron reflectivity measurements

    SciTech Connect

    Huang, Zhenyu; Alonzo, Jose; Liu, Ming; Ji, Haining; Yin, Fang; Smith, Grant; Mays, Jimmy; Kilbey, II, S Michael; Dadmun, Mark D

    2008-01-01

    Preferential adsorption of poly(2-vinylpyridine)-deuterated polystyrene-poly(2-vinylpyridine) (PVP-dPS-PVP) triblock copolymers from toluene onto silicon leads to the formation of dPS loops tethered by the PVP end blocks. Using neutron reflectometry, we have determined the segment density profiles of these looped polymer brushes in toluene, a good solvent for the dPS block, and in cyclohexane at 20 C (poor solvent), 32 C, (near- solvent), and 50 C (marginal solvent). While the swelling behavior qualitatively agrees with that observed for singly grafted brushes, there are interesting differences in the local structural details: In a good solvent, the segment density profiles are composed of an inner parabolic region and a long, extended tail. In cyclohexane, the profiles are described by exponential decays. We ascribe these features to a novel polydispersity effect that arises due to tethering the PS loops by both ends. The results also show that the less dense layers undergo more significant changes in swollen height as solvent quality is changed and that the looped brushes of different molecular weight, asymmetry, and tethering density adhere to scaling relationships derived for lightly cross-linked polymer gels.

  3. Examining the Factor Structure and Hierarchical Nature of the Quality of Life Construct

    ERIC Educational Resources Information Center

    Wang, Mian; Schalock, Robert L.; Verdugo, Miguel A.; Jenaro, Christina

    2010-01-01

    There is considerable debate in the area of individual quality of life research regarding the factor structure and hierarchical nature of the quality of life construct. Our purpose in this study was to test via structural equation modeling an a priori quality of life model consisting of eight first-order factors and one second-order factor. Data…

  4. Perforated diode neutron sensors

    NASA Astrophysics Data System (ADS)

    McNeil, Walter J.

    A novel design of neutron sensor was investigated and developed. The perforated, or micro-structured, diode neutron sensor is a concept that has the potential to enhance neutron sensitivity of a common solid-state sensor configuration. The common thin-film coated diode neutron sensor is the only semiconductor-based neutron sensor that has proven feasible for commercial use. However, the thin-film coating restricts neutron counting efficiency and severely limits the usefulness of the sensor. This research has shown that the perforated design, when properly implemented, can increase the neutron counting efficiency by greater than a factor of 4. Methods developed in this work enable detectors to be fabricated to meet needs such as miniaturization, portability, ruggedness, and adaptability. The new detectors may be used for unique applications such as neutron imaging or the search for special nuclear materials. The research and developments described in the work include the successful fabrication of variant perforated diode neutron detector designs, general explanations of fundamental radiation detector design (with added focus on neutron detection and compactness), as well as descriptive theory and sensor design modeling useful in predicting performance of these unique solid-state radiation sensors. Several aspects in design, fabrication, and operational performance have been considered and tested including neutron counting efficiency, gamma-ray response, perforation shapes and depths, and silicon processing variations. Finally, the successfully proven technology was applied to a 1-dimensional neutron sensor array system.

  5. Monte Carlo simulations of neutron spectral fluence, radiation weighting factor and ambient dose equivalent for a passively scattered proton therapy unit

    NASA Astrophysics Data System (ADS)

    Zheng, Yuanshui; Fontenot, Jonas; Taddei, Phil; Mirkovic, Dragan; Newhauser, Wayne

    2008-01-01

    Stray neutron exposures pose a potential risk for the development of secondary cancer in patients receiving proton therapy. However, the behavior of the ambient dose equivalent is not fully understood, including dependences on neutron spectral fluence, radiation weighting factor and proton treatment beam characteristics. The objective of this work, therefore, was to estimate neutron exposures resulting from the use of a passively scattered proton treatment unit. In particular, we studied the characteristics of the neutron spectral fluence, radiation weighting factor and ambient dose equivalent with Monte Carlo simulations. The neutron spectral fluence contained two pronounced peaks, one a low-energy peak with a mode around 1 MeV and one a high-energy peak that ranged from about 10 MeV up to the proton energy. The mean radiation weighting factors varied only slightly, from 8.8 to 10.3, with proton energy and location for a closed-aperture configuration. For unmodulated proton beams stopped in a closed aperture, the ambient dose equivalent from neutrons per therapeutic absorbed dose (H*(10)/D) calculated free-in-air ranged from about 0.3 mSv/Gy for a small scattered field of 100 MeV proton energy to 19 mSv/Gy for a large scattered field of 250 MeV proton energy, revealing strong dependences on proton energy and field size. Comparisons of in-air calculations with in-phantom calculations indicated that the in-air method yielded a conservative estimation of stray neutron radiation exposure for a prostate cancer patient.

  6. Road construction: Emissions Factors and Air Quality Impacts

    NASA Astrophysics Data System (ADS)

    Font Font, Anna M.; Baker, Timothy; Mudway, Ian; Fuller, Gary W.

    2014-05-01

    Very few studies have investigated the air pollution impacts of road construction. Over a 17 month period a congested main road in south east London was widened from two lanes to four. Emissions factors for road construction were determined and a notable deterioration in residential air quality was found with the final expanded road layout. Air quality monitoring sites measuring PM10, PM2.5, NOX, NO2 and meteorological variables were deployed on both sides of the road construction to quantify ambient air quality before, during and after the completion of the road works, with additional measurements from a nearby background site. PM10 samples were collected for oxidative potential measurements. PM10 was the only pollutant to increase during the construction; mean PM10 from the road increased by 15 µg m-3 during working hours; weekdays between 6 am and 5 pm; and on Saturdays between 6 am and 12 pm, compared to concentrations before the road works. During the construction the number of days with daily mean PM10 concentrations greater than 50 µg m-3 was more than 35 for both sides of the road, breaching the European Union Limit Value (LV). Downwind-upwind differences were used to calculate real-world PM10 emissions associated to the construction activity by means of box modelling. The quantity of PM10 emitted per area and month of construction was 0.0009 kg PM10 m-2 month-1 for the construction period. This emission factor was similar to the one used in the UK National Atmospheric Emissions Inventory (NAEI). Worst case construction emissions factors were 0.0105 kg PM10 m-2 month-1, compared to 0.0448 kg PM10 m-2 month-1 and 0.1038 kg PM10 m-2 month-1 used in current European and US inventories, respectively. After the completion of the road widening an increase in all pollutants was measured during rush hour peaks: 2-4 µg m-3 for PM10; 1 µg m-3 for PM2.5; 20 and 4 ppbv (40 and 8 µg m-3) for NOX and NO2, respectively, leading to a breach of the NO2 annual mean LV

  7. Study on γ-ray exposure buildup factors and fast neutron-shielding properties of some building materials

    NASA Astrophysics Data System (ADS)

    Singh, Vishwanath P.; Badiger, N. M.; El-Khayatt, A. M.

    2014-06-01

    We have computed γ-ray exposure buildup factors (EBF) of some building materials; glass, marble, flyash, cement, limestone, brick, plaster of paris (POP) and gypsum for energy 0.015-15 MeV up to 40 mfp (mfp, mean free path) penetration depth. Also, the macroscopic effective removal cross-sections (ΣR) for fast neutron were calculated. We discussed the dependency of EBF values on photon energy, penetration depth and chemical elements. The half-value layer and kinetic energy per unit mass relative to air of building materials were calculated for assessment of shielding effectiveness. Shielding thicknesses for glass, marble, flyash, cement, limestone and gypsum plaster (or Plaster of Paris, POP) were found comparable with ordinary concrete. Among the studied materials limestone and POP showed superior shielding properties for γ-ray and neutron, respectively. Radiation safety inside houses, schools and primary health centers for sheltering and annual dose can be assessed by the determination of shielding parameters of common building materials.

  8. Measurement of the Neutron electric form factor at Q2=0.8 (GeV/c)2

    SciTech Connect

    Glazier, Derek

    2003-01-01

    Nucleon form factors allow a sensitive test for models of the nucleon. Recent experiments utilising polarisation observables have resulted, for the first time, in a model-independent determination of the neutron electric form factor G$n\\atop{E}$. This method employed an 80% longitudinally polarised, high intensity (10 uA) electon beam (883 MeV) that was quasi-elastically scattered off a liquid deuterium target in the reaction D ($\\vec{e}$, e$\\vec{n}$)p. A neutron polarimeter was designed and installed to measure the ratio of transverse-to-longitudinal polarisation using neutron scattering asymmetries. This ratio allowed a determination of the neutron elastic form factor, G$n\\atop{E}$, free of the previous large systematic uncertainties associated with the deuterium wave function. The experiment took place in the A1 experimental hall at MAMI taking advantage of a high resolution magnetic spectrometer. A detailed investigation was carried out into the performance of the neutron polarimeter.

  9. A Perfect Electromagnetic Cavity: High Quality Factor in Subwavelength Dimensions

    NASA Astrophysics Data System (ADS)

    Ginis, Vincent; Tassin, Philippe; Soukoulis, Costas M.; Veretennicoff, Irina

    2010-03-01

    Transformation optics has recently provided a new way to look at the interaction between light and matter. It uses the analogy between the macroscopic Maxwell's equations in complex dielectrics and the free-space Maxwell's equations on the background of an arbitrary metric to exploit the full potential of metamaterials, of which the most exciting examples are invisibility cloaks. In this contribution, we want to show how transformation optics can be applied to design a cavity with extraordinary properties. We have demonstrated theoretically the existence of eigenmodes whose wavelength is much larger than the characteristic dimensions of the cavity. Furthermore, our design avoids the bending losses observed in traditional microcavities, so that the quality factor is only limited by intrinsic absorption of the materials. Such a ``perfect cavity'' may be interesting for applications involving optical data storage or quantum optics, where it can be used to control the rate of spontaneous emission through the Purcell effect.

  10. Anomalous Behavior of High Quality Factor Planar Superconducting Resonators

    NASA Astrophysics Data System (ADS)

    Megrant, Anthony; Chen, Zijun; Chiaro, Ben; Dunsworth, Andrew; Quintana, Chris; Campbell, Brooks; Kelly, Julian; Barends, Rami; Chen, Yu; Jeffrey, Evan; Mutus, Josh; Neill, Charles; O'Malley, Peter; Sank, Daniel; Vainsencher, Amit; Wenner, Jim; White, Ted; Bochmann, Jorg; Hoi, Iochun; Palmstrom, Christopher; Martinis, John; Cleland, Andrew

    2014-03-01

    Superconducting coplanar waveguide resonators have proven to be invaluable tools in studying some of the decoherence mechanisms found in superconducting qubits. Surface two-level states tend to dominate decoherence at temperatures below Tc/10 and at very low microwave powers, assuming loss through other channels (e.g. quasiparticles, vortices, and radiation loss) has been mitigated through proper shielding and design. I will present recent measurements of resonators whose behavior diverges significantly from the standard two-level state model at low temperatures and low excitation energies, resulting in startling behavior of the internal quality factor. This research was funded by the Office of the Director of National Intelligence (ODNI), Intelligence Advanced Research Projects Activity (IARPA), through the Army Research Office grant W911NF-09-1-0375.

  11. Factors facilitating a national quality registry to aid clinical quality improvement: findings of a national survey

    PubMed Central

    Eldh, Ann Catrine; Wallin, Lars; Fredriksson, Mio; Vengberg, Sofie; Winblad, Ulrika; Halford, Christina; Dahlström, Tobias

    2016-01-01

    Objectives While national quality registries (NQRs) are suggested to provide opportunities for systematic follow-up and learning opportunities, and thus clinical improvements, features in registries and contexts triggering such processes are not fully known. This study focuses on one of the world's largest stroke registries, the Swedish NQR Riksstroke, investigating what aspects of the registry and healthcare organisations facilitate or hinder the use of registry data in clinical quality improvement. Methods Following particular qualitative studies, we performed a quantitative survey in an exploratory sequential design. The survey, including 50 items on context, processes and the registry, was sent to managers, physicians and nurses engaged in Riksstroke in all 72 Swedish stroke units. Altogether, 242 individuals were presented with the survey; 163 responded, representing all but two units. Data were analysed descriptively and through multiple linear regression. Results A majority (88%) considered Riksstroke data to facilitate detection of stroke care improvement needs and acknowledged that their data motivated quality improvements (78%). The use of Riksstroke for quality improvement initiatives was associated (R2=0.76) with ‘Colleagues’ call for local results’ (p=<0.001), ‘Management Request of Registry data’ (p=<0.001), and it was said to be ‘Simple to explain the results to colleagues’ (p=0.02). Using stepwise regression, ‘Colleagues’ call for local results’ was identified as the most influential factor. Yet, while 73% reported that managers request registry data, only 39% reported that their colleagues call for the unit's Riksstroke results. Conclusions While an NQR like Riksstroke demonstrates improvement needs and motivates stakeholders to make progress, local stroke care staff and managers need to engage to keep the momentum going in terms of applying registry data when planning, performing and evaluating quality initiatives. PMID

  12. Cross sections and partial kerma factors for elastic and inelastic neutron scattering from nitrogen, oxygen and calcium at En = 21.6 MeV.

    PubMed

    Olsson, N; Ramström, E; Trostell, B

    1990-09-01

    The Studsvik high-resolution, low-background time-of-flight facility has been used to measure differential neutron scattering cross sections for nitrogen, oxygen and calcium at a neutron energy of 21.6 MeV. Angular distributions in the range 10 degrees-160 degrees have been measured for both elastic and inelastic scattering from some low-lying levels in the three nuclei. Angle-integrated cross sections have been determined by fitting Legendre polynomial expansions to the differential data. Partial kerma factors for elastic and inelastic scattering have been deduced from these fits. Analyses in terms of the spherical optical model and the distorted-wave Born approximation have provided information on potential parameters and deformations, which have been used to calculate cross sections and partial kerma factors. Comparisons have been made with other recent data sets and model predictions, as well as with the evaluated neutron data file ENDF/B-V.

  13. Neutron electric form factor up to Q{sup 2} = 1.47 GeV/c{sup 2}

    SciTech Connect

    Richard Madey; Andrei Semenov; S. Taylor; Aram Aghalaryan; Erick Crouse; Glen MacLachlan; Bradley Plaster; Shigeyuki Tajima; William Tireman; Chenyu Yan; Abdellah Ahmidouch; Brian Anderson; Hartmuth Arenhovel; Razmik Asaturyan; O. Baker; Alan Baldwin; Herbert Breuer; Roger Carlini; E Christy; Steve Churchwell; Leon Cole; Areg Danagoulian; Donal Day; Mostafa Elaasar; Rolf Ent; Manouchehr Farkhondeh; Howard Fenker; John Finn; Liping Gan; Kenneth Garrow; Paul Gueye; Calvin Howell; Bitao Hu; Mark Jones; James Kelly; Cynthia Keppel; Mahbubul Khandaker; Wooyoung Kim; Stanley Kowalski; Allison Lung; David Mack; D. Manley; Pete Markowitz; Joseph Mitchell; Hamlet Mkrtchyan; Allena Opper; Charles Perdrisat; Vina Punjabi; Brian Raue; Tilmann Reichelt; Joerg Reinhold; Julie Roche; Yoshinori Sato; Irina Semenova; Wonick Seo; Neven Simicevic; G. Smith; Samuel Stepanyan; Vardan Tadevosyan; Liguang Tang; Paul Ulmer; William Vulcan; J. W. Watson; Steven Wells; Frank Wesselmann; Stephen Wood; Chen Yan; Seunghoon Yang; Lulin Yuan; Wei-Ming Zhang; Hong Guo Zhu; Xiaofeng Zhu

    2003-07-15

    The ratio of the electric to the magnetic form factor of the neutron, g /equiv G{sub En}/G{sub Mn} , was measured via recoil polarimetry (R.G. Arnold, C.E. Carlson, F. Gross, Phys. Rev. C 23, 363 (1981)) from the quasielastic {sup 2}H (/mathop(e)/limitse' /mathop(n)/limits) 1H reaction at three values of Q{sup 2} (viz, 0.45, 1.15, and 1.47 (GeV/c){sup 2}) in Hall C of the Thomas Jefferson National Accelerator Facility. The data reveal that GEn continues to follow the Galster parameterization up to Q{sup 2} = 1.15 (GeV/c){sup 2} and rises above the Galster parameterization at Q{sup 2} = 1.47 (GeV/c){sup 2}.

  14. Transcription factor motif quality assessment requires systematic comparative analysis

    PubMed Central

    Kibet, Caleb Kipkurui; Machanick, Philip

    2016-01-01

    Transcription factor (TF) binding site prediction remains a challenge in gene regulatory research due to degeneracy and potential variability in binding sites in the genome. Dozens of algorithms designed to learn binding models (motifs) have generated many motifs available in research papers with a subset making it to databases like JASPAR, UniPROBE and Transfac. The presence of many versions of motifs from the various databases for a single TF and the lack of a standardized assessment technique makes it difficult for biologists to make an appropriate choice of binding model and for algorithm developers to benchmark, test and improve on their models. In this study, we review and evaluate the approaches in use, highlight differences and demonstrate the difficulty of defining a standardized motif assessment approach. We review scoring functions, motif length, test data and the type of performance metrics used in prior studies as some of the factors that influence the outcome of a motif assessment. We show that the scoring functions and statistics used in motif assessment influence ranking of motifs in a TF-specific manner. We also show that TF binding specificity can vary by source of genomic binding data. We also demonstrate that information content of a motif is not in isolation a measure of motif quality but is influenced by TF binding behaviour. We conclude that there is a need for an easy-to-use tool that presents all available evidence for a comparative analysis. PMID:27092243

  15. Factors Influencing the Quality of Encapsulation in Rock Bolting

    NASA Astrophysics Data System (ADS)

    Aziz, Naj; Craig, Peter; Mirzaghorbanali, Ali; Nemcik, Jan

    2016-08-01

    Bolt installation quality is influenced by various factors, some are well known and others are less recognised. A programme of field and laboratory studies was undertaken to examine various factors of relevance to the load transfer mechanism between the bolt, resin and rock to ensure test methods truly represent field performance. Short encapsulation tests were undertaken as part of the Australian Coal Association Research Program (ACARP) funded project (C21011) with the ultimate aim of developing standard test methods for assessing bolt encapsulation with chemical resin anchor installations. The field study consisted of a series of Short Encapsulation Pull Tests (SEPT) carried out in three mines with different geological conditions to determine the most representative and practical method of SEPT. Additional field work included installation of bolts into threaded steel tubes for subsequent removal and laboratory evaluation. A series of pull tests was carried out by installing bolts in overhead rig mounted sandstone block, cast in concrete with controlled encapsulation length. Factors of importance considered included; borehole diameter, resin annulus thickness, installation time (including bolt spin to the back and "spin at back"), the effect of gloving and hole over drill. It was found that the borehole diameter had a detrimental effect on the encapsulation bonding strength. Bolt installation time of approximately 10 s constituted an acceptable time for effective bolt installation and within the resin manufacturers recommended time of 14 s. Maintaining constant length of encapsulation was paramount for obtaining consistency and repeatability of the test results. Finally, a numerical simulation study was carried out to assess the capabilities of FLAC 2D software in simulating the pull testing of rock bolts.

  16. Epithermal Neutrons, Illumination, Spatial Scale and Topography: A Correlative Analysis of Factors Influencing the Detection of Slope Hydration Using LRO's Lunar Exploration Neutron Detector

    NASA Astrophysics Data System (ADS)

    McClanahan, T. P.; Mitrofanov, I. G.; Boynton, W. V.; Chin, G.; Evans, L. G.; Starr, R. D.; Livengood, T.; Sagdeev, R.; Parsons, A. M.; Su, J. J.; Murray, J.; Sanin, A.; Litvak, M.; Harshman, K.; Hamara, D.; Bodnarik, J.

    2014-10-01

    This research correlates the Moon’s south polar epithermal neutron flux, topography and a visible illumination model and shows that there is a widespread hydration of polward-facing (PF) slopes that is occurring at a continuum of spatial scales.

  17. Biological effectiveness of neutron irradiation on animals and man

    SciTech Connect

    Straume, T.

    1982-11-01

    Neutron experiments on a highly radiosensitive in vivo system - oocytes in mice - provide new insight into the nature of the radiosensitive targets of these important cells. With the radiobiological literature as background, neutron data from animals and humans are integrated, and the controversial question of radiation protection standards for neutrons is addressed. Oocyte killing in juvenile mice by 0.43-MeV, /sup 252/Cf-fission, and 15 MeV neutrons, compared with that by /sup 60/Co gamma rays, yields unusually low neutron RBEs (relative biological effectiveness). At 0.1 rad of 0.43-MeV neutrons the RBE is only 1.8, contrasting greatly with values of 100 or more reported at low-doses for other endpoints. In mice just prior to birth, however, when oocytes are less radiosensitive, the neutron RBE is much higher, similar to values for most other mammalian endpoints. This dramatic change in neutron RBE with mouse age (occurring within 2 to 3 days) can be explained as the result of a shift from a less radiosensitive target (presumably nuclear DNA) to a much more radiosensitive one (probably the oocyte plasma membrane). Using various approaches, a value for the neutron Quality Factor (Q, a radiation protection standard) is estimated as 17 (+-100%), much lower than 100 which has been suggested. With the large uncertainty, 17 is not markedly different from the value of 10 presently in general use.

  18. The Transverse Asymmetry A{sub T}, from Quasi-elastic {sup 3}{ovr He}({rvec e}, e{prime}) Process and the Neutron Magnetic Form Factor

    SciTech Connect

    Wang Xu; Dipangkar Dutta; Feng Xiong; Brian Anderson; Leonard Auerbach; Todd Averett; William Bertozzi; Tim Black; John Calarco; Lawrence Cardman; Gordon Cates; Zhengwei Chai; Jian-ping Chen; Seonho Choi; Eugene Chudakov; Steve Churchwell; G.S. Corrado; C. Crawford; Daniel Dale; Alexandre Deur; Pibero Djawotho; Bradley Filippone; John Finn; Haiyan Gao; Ronald Gilman; Oleksandr Glamazdin; Charles Glashausser; Walter Gloeckle; J. Golak; Javier Gomez; Viktor Gorbenko; Jens-ole Hansen; F. Hersman; Douglas Higinbotham; Richard Holmes; Calvin Howell; Emlyn Hughes; Thomas Humensky; Sebastien Incerti; Cornelis De Jager; John Jensen; Xiaodong Jiang; C.E. Jones; Mark Jones; R. Kahl; H. Kamada; A. Kievsky; Ioannis Kominis; Wolfgang Korsch; Kevin Kramer; Gerfried Kumbartzki; Michael Kuss; Enkeleida Lakuriqi; Meihua Liang; Nilanga Liyanage; John Lerose; Sergey Malov; Demetrius Margaziotis; J.W. Martin; Kathy Mccormick; Robert Mckeown; Kevin Mcilhany; Zein-eddine Meziani; Robert Michaels; G.W. Miller; Joseph Mitchell; Sirish Nanda; E. Pace; Tina Pavlin; Gerassimos Petratos; Roman Pomatsalyuk; D. Pripstein; David Prout; Ronald Ransome; Yves Roblin; Marat Rvachev; Arunava Saha; G. Salme; Michael Schnee; Taeksu Shin; Karl Slifer; Paul Souder; Steffen Strauch; Riad Suleiman; Mark Sutter; Bryan Tipton; Luminita Todor; Michele Viviani; Branislav Vlahovic; J. Watson; Claude Williamson; H. Witala; Bogdan Wojtsekhowski; Jen-chuan Yeh; Piotr Zolnierczuk

    2000-10-01

    We have measured the transverse asymmetry from inclusive scattering of longitudinally polarized electrons from polarized {sup 3}He nuclei at quasi-elastic kinematics in Hall A at Jefferson Lab with high statistical and systematic precision. The neutron magnetic form factor was extracted based on Faddeev calculations with an experimental uncertainty of less than 2%.

  19. Benchmarking Potential Factors Leading to Education Quality: A Study of Cambodian Higher Education

    ERIC Educational Resources Information Center

    Chen, Ching-Yaw; Sok, Phyra; Sok, Keomony

    2007-01-01

    Purpose: To study the quality in higher education in Cambodia and explore the potential factors leading to quality in Cambodian higher education. Design/methodology/approach: Five main factors that were deemed relevant in providing quality in Cambodian higher education were proposed: academic curriculum and extra-curricular activities, teachers'…

  20. Quality of Life Factor as Breast Cancer Risks

    PubMed Central

    Gledo, Ibrahim; Pranjic, Nurka; Parsko, Subhija

    2012-01-01

    Background: Numerous studies have observed risk factors for breast cancer. We investigated the association between quality life factors as breast cancer risks in a case-control study in industrial Zenica- Doboj Canton in Bosnia and Herzegovina. Methods: The case-control study was included 200 women, 100 without (control subjects) and 100 women with diagnosed breast cancer. We used questionnaires about breast cancer risks“ as study tool. Logistic regression was used to compute odds ratios (ORs) and 95% confidence intervals (CI) and a full assessment of confounding was included in analysis. Results: Breast cancer was positive associated with increasing age of life (from 45 years and more; OR= 1.25); further relative breast cancer history (OR= 4.42; 95%CI, 0.483-4.043); exposure to CT (OR=2.02; 95%CI, 1,254-3.261); never birth child (OR= 1.394; 95%CI, 0.808-2,407); used replacement hormonal therapy (OR= 1.826; 95%CI, 1.637-10.590); arrival time of menstruation (OR=2.651; 95%CI, 1.303-1.571); length of smoking status (OR=1.534; 95%CI, 0.756-3.098), alcohol consumption (OR=1.728; 95% CI, 0.396-7.533); exposure to CT per year (p=0.009), routine physical inactivity (p=0.009) and replacement hormones treatment (p=0.036). Conclusion: Inverse associations of breast cancer and poverty, arival time of menopause were observed. The link between breast cancer and a distant-cousin- degree family history of breast cancer was inverse association with breast cancer too. These results provide further evidence that, for most women, physical activity may reduce the risk of invasive breast cancer. PMID:23922526

  1. High quality factor platinum silicide microwave kinetic inductance detectors

    NASA Astrophysics Data System (ADS)

    Szypryt, P.; Mazin, B. A.; Ulbricht, G.; Bumble, B.; Meeker, S. R.; Bockstiegel, C.; Walter, A. B.

    2016-10-01

    We report on the development of microwave kinetic inductance detectors (MKIDs) using platinum silicide as the sensor material. MKIDs are an emerging superconducting detector technology, capable of measuring the arrival times of single photons to better than two microseconds and their energies to around ten percent. Previously, MKIDs have been fabricated using either sub-stoichiometric titanium nitride or aluminum, but TiN suffers from the spatial inhomogeneities in the superconducting critical temperature and Al has a low kinetic inductance fraction, causing low detector sensitivity. To address these issues, we have instead fabricated the PtSi microresonators with the superconducting critical temperatures of 944 ± 12 mK and high internal quality factors ( Q i ≳ 10 6 ). These devices show typical quasiparticle lifetimes of τ q p ≈ 30 - 40 μ s and spectral resolution, R = λ / Δ λ , of 8 at 406.6 nm. We compare PtSi MKIDs to those fabricated with TiN and detail the substantial advantages that PtSi MKIDs have to offer.

  2. Prototype Stilbene Neutron Collar

    SciTech Connect

    Prasad, M. K.; Shumaker, D.; Snyderman, N.; Verbeke, J.; Wong, J.

    2016-10-26

    A neutron collar using stilbene organic scintillator cells for fast neutron counting is described for the assay of fresh low enriched uranium (LEU) fuel assemblies. The prototype stilbene collar has a form factor similar to standard He-3 based collars and uses an AmLi interrogation neutron source. This report describes the simulation of list mode neutron correlation data on various fuel assemblies including some with neutron absorbers (burnable Gd poisons). Calibration curves (doubles vs 235U linear mass density) are presented for both thermal and fast (with Cd lining) modes of operation. It is shown that the stilbene collar meets or exceeds the current capabilities of He-3 based neutron collars. A self-consistent assay methodology, uniquely suited to the stilbene collar, using triples is described which complements traditional assay based on doubles calibration curves.

  3. Factors Affecting the Application of a Simple Ratio Technique for Spectral Correction of a Neutron Personnel Albedo Dosimeter.

    DTIC Science & Technology

    1983-11-01

    nY reaction (Ha79). The effect pof the Boron-lO pouch can be theoretically calculated for known spectra by using the Boron-lO neutron absorption cross section curve...14 MeV the 6LiF response curve can be appropriately approximated by utilizing the Lithium-6 neutron absorption cross section curve (Ga76,GI83

  4. Ultracold neutron detector for neutron lifetime measurements

    NASA Astrophysics Data System (ADS)

    Andreev, V.; Vassiljev, A.; Ivanov, E.; Ilyin, D.; Krivshich, A.; Serebrov, A.

    2017-02-01

    The gas-filled detector of ultracold neutrons has been designed and constructed for the spectrometer of the neutron lifetime measurements at the ILL, Grenoble, France. The detector has been successfully tested and is currently being used at this spectrometer. We could show that minimization of the ;wall; effect is a key factor to ensure efficient background suppression and to maximize the detection efficiency. This effect is primarily related to the composition of the gas mixture, which crucially depends on the neutron velocity spectrum.

  5. Factors Influencing Perceptions of Service Quality in Cooperative Extension Workers

    ERIC Educational Resources Information Center

    Anaza, Nwamaka A.; Rutherford, Brian N.; Widdows, Richard

    2012-01-01

    The authors examined the direct and indirect impact of empowerment on service quality as perceived by Extension staff. Using a sample 283 respondents, the results revealed that along with empowerment, constructs such as job satisfaction and organizational identification positively affected service quality. Undoubtedly, each of these variables…

  6. The Impact Factor: Implications of Open Access on Quality

    ERIC Educational Resources Information Center

    Grozanick, Sara E.

    2010-01-01

    There has been debate about the extent to which open access affects the quality of scholarly work. At the same time, researchers have begun to look for ways to evaluate the quality of open access publications. Dating back to the growth of citation indexes during the 1960s and 1970s, citation analysis--examining citation statistics--has since been…

  7. DOE personnel neutron dosimetry evaluation and upgrade program

    SciTech Connect

    Faust, L.G.; Stroud, C.M.; Vallario, E.J.

    1988-10-01

    The US Department of Energy (DOE) sponsors an extensive research program to improve the methods, dosimeters, and instruments available to DOE facilities for measuring neutron dose and assessing its effects on the work force. The Total Dose Meter was recently developed for measuring in real time the adsorbed dose of mixed neutron and gamma radiation and for calculating the dose equivalent. The Field Neutron Spectrometer was developed to provide a portable instrument for determining neutron spectra in the workplace for flux-to-dose equivalent conversion and quality factor calculation. The Combination Thermoluminescence/Track Etch Dosimeter (TLD/TED) was developed to extend the effective neutron energy range of the conventional TLDs to improve detection of fast-energy neutrons. An Optically Stimulated Luminescence Dosimeter is presently being developed for application to gamma, neutron, and beta radiation. An Effective Dose Equivalent System is being developed to provide guidance in implementing the January 1987 Presidential Directive to determine effective dose equivalent. Superheated Drop Detectors are being investigated for their potential as real time neutron dosimeters. This paper includes discussions of these improvements brought about by the DOE research program. 3 refs.

  8. Compact D-D/D-T neutron generators and their applications

    SciTech Connect

    Lou, Tak Pui

    2003-01-01

    Boron Neutron Capture Therapy (BNCT). The neutron flux required for positron production could not be provided with a single D-T neutron generator. Therefore, a subcritical fission multiplier was designed to increase the neutron yield. The neutron flux was increased by a factor of 25. A D-D driven fission multiplier was also studied for BNCT and a gain of 17 was obtained. The fission multiplier system gain was shown to be limited by the neutron absorption in the fuel and the reduction of source brightness. A brief discussion was also given regarding the neutron generator applications for fast neutron brachytherapy and neutron interrogation systems. It was concluded that new designs of compact D-D/D-T neutron generators are feasible and that superior quality neutron beams could be produced and used for various applications.

  9. A Measurement of the neutron electric form factor at very large momentum transfer using polaried electrions scattering from a polarized helium-3 target

    SciTech Connect

    Kelleher, Aidan

    2010-02-01

    Knowledge of the electric and magnetic elastic form factors of the nucleon is essential for an understanding of nucleon structure. Of the form factors, the electric form factor of the neutron has been measured over the smallest range in Q2 and with the lowest precision. Jefferson Lab experiment 02-013 used a novel new polarized 3 He target to nearly double the range of momentum transfer in which the neutron form factor has been studied and to measure it with much higher precision. Polarized electrons were scattered off this target, and both the scattered electron and neutron were detected. Gn E was measured to be 0.0242 ± 0.0020(stat) ± 0.0061(sys) and 0.0247 ± 0.0029(stat) ± 0.0031(sys) at Q2 = 1.7 and 2.5 GeV2 , respectively.

  10. Advantages of passive detectors for the determination of the cosmic ray induced neutron environment.

    PubMed

    Hajek, M; Berger, T; Schöner, W; Vana, N

    2002-01-01

    Due to the pronounced energy dependence of the neutron quality factor, accurate assessment of the biologically relevant dose requires knowledge of the spectral neutron fluence rate. Bonner sphere spectrometers (BSSs) are the only instruments which provide a sufficient response over practically the whole energy range of the cosmic ray induced neutron component. Measurements in a 62 MeV proton beam at Paul Scherrer Institute, Switzerland, and in the CERN-EU high-energy reference field led to the assumption that conventional active devices for the detection of thermal neutrons inside the BSS, e.g. 6Lil(Eu) scintillators, also respond to charged particles when used in high-energy mixed radiation fields. The effects of these particles cannot be suppressed by amplitude discrimination and are subsequently misinterpreted as neutron radiation. In contrast, paired TLD-600 and TLD-700 thermoluminescence dosemeters allow the determination of a net thermal neutron signal.

  11. Nuclear Reprogramming by Defined Factors: Quantity Versus Quality.

    PubMed

    Sebban, Shulamit; Buganim, Yosef

    2016-01-01

    The generation of induced pluripotent stem cells (iPSCs) and directly converted cells holds great promise in regenerative medicine. However, after in-depth studies of the murine system, we know that the current methodologies to produce these cells are not ideal and mostly yield cells of poor quality that might hold a risk in therapeutic applications. In this review we address the duality found in the literature regarding the use of 'quality' as a criterion for the clinic. We discuss the elements that influence reprogramming quality, and provide evidence that safety and functionality are directly linked to cell quality. Finally, because most of the available data come from murine systems, we speculate about what aspects can be applied to human cells.

  12. Analysis Supporting Factors and Constraints LPMP Performance in Improving the Quality of Education in Jambi Province

    ERIC Educational Resources Information Center

    Rosadi, Kemas Imron

    2015-01-01

    Development of education in Indonesia is based on three aspects, namely equity and expansion, quality and relevance, as well as good governance. Quality education is influenced by several factors related to quality education managerial leaders, limited funds, facilities, educational facilities, media, learning resources, tools and training…

  13. The human factors of quality and QA in R D environments

    SciTech Connect

    Hill, S.G.

    1990-01-01

    Achieving quality is a human activity. It is therefore important to consider the human in the design, development and evaluation of work processes and environments in an effort to enhance human performance and minimize error. It is also important to allow for individual differences when considering human factors issues. Human Factors is the field of study which can provide information on integrating the human into the system. Human factors and quality are related for the customer of R D work, R D personnel who perform the work, and the quality professional who overviews the process of quality in the work. 18 refs., 1 fig.

  14. High quality 99mTc obtained from 99Mo produced by 100Mo(n,2 n) using accelerator neutrons

    NASA Astrophysics Data System (ADS)

    Nagai, Yasuki; Kawabata, Masako; Sato, Nozomi; Hashimoto, Kazuyuki; Saeki, Hideya; Motoishi, Shoji; Hatsukawa, Yuichi; Ohta, Akio; Shiina, Takayuki; Kawauchi, Yukimasa; Special GroupGeneration Technology using Accelerator Neutrons Collaboration

    2014-09-01

    99m Tc, the daughter nuclide of 99Mo, is widely used for medical diagnosis. In Japan, about 0.9 million diagnostic procedures are carried out using 99mTc. 99Mo has been mostly produced using 235U in research reactors. Because of recent shortages of 99Mo, a variety of alternative production methods of 99Mo or 99mTc were proposed. We proposed to produce 99Mo by 100Mo(n,2 n) using neutrons from an accelerator. The route is characterized to produce a large quantity of high-quality 99Mo with a minimum level of radioactive wastes, since the cross section of the 100Mo(n,2n)99Mo reaction at 11 < En < 18 MeV is large, and the cross sections of the (nα) , (nn ' p) , and (np) reactions on 100Mo are quite small. Intense neutrons are available because of recent progresses of accelerator and target technologies. In the talk, we show our recent experimental results to obtain 99mTc with high-quality using 99Mo produced by 100Mo(n,2 n) .

  15. Neutron capture therapies

    SciTech Connect

    Yanch, Jacquelyn C.; Shefer, Ruth E.; Klinkowstein, Robert E.

    1999-01-01

    In one embodiment there is provided an application of the .sup.10 B(n,.alpha.).sup.7 Li nuclear reaction or other neutron capture reactions for the treatment of rheumatoid arthritis. This application, called Boron Neutron Capture Synovectomy (BNCS), requires substantially altered demands on neutron beam design than for instance treatment of deep seated tumors. Considerations for neutron beam design for the treatment of arthritic joints via BNCS are provided for, and comparisons with the design requirements for Boron Neutron Capture Therapy (BNCT) of tumors are made. In addition, exemplary moderator/reflector assemblies are provided which produce intense, high-quality neutron beams based on (p,n) accelerator-based reactions. In another embodiment there is provided the use of deuteron-based charged particle reactions to be used as sources for epithermal or thermal neutron beams for neutron capture therapies. Many d,n reactions (e.g. using deuterium, tritium or beryllium targets) are very prolific at relatively low deuteron energies.

  16. Neutron capture therapies

    SciTech Connect

    Yanch, J.C.; Shefer, R.E.; Klinkowstein, R.E.

    1999-11-02

    In one embodiment there is provided an application of the {sup 10}B(n,{alpha}){sup 7}Li nuclear reaction or other neutron capture reactions for the treatment of rheumatoid arthritis. This application, called Boron Neutron Capture Synovectomy (BNCS), requires substantially altered demands on neutron beam design than for instance treatment of deep seated tumors. Considerations for neutron beam design for the treatment of arthritic joints via BNCS are provided for, and comparisons with the design requirements for Boron Neutron Capture Therapy (BNCT) of tumors are made. In addition, exemplary moderator/reflector assemblies are provided which produce intense, high-quality neutron beams based on (p,n) accelerator-based reactions. In another embodiment there is provided the use of deuteron-based charged particle reactions to be used as sources for epithermal or thermal neutron beams for neutron capture therapies. Many d,n reactions (e.g. using deuterium, tritium or beryllium targets) are very prolific at relatively low deuteron energies.

  17. Fruits of neutron research

    SciTech Connect

    Krause, C.

    1994-12-31

    Car windshields that don`t break during accidents and jets that fly longer without making a refueling stop. Compact discs, credit cards, and pocket calculators. Refrigerator magnets and automatic car window openers. Beach shoes, food packaging, and bulletproof vests made of tough plastics. The quality and range of consumer products have improved steadily since the 1970s. One of the reasons: neutron research. Industries, employing neutron scattering techniques, to study materials properties, to act as diagnostics in tracing system performance, or as sources for radioactive isotopes used in medical fields for diagnostics or treatment, have all benefited from the fruits of advanced work with neutron sources.

  18. Quality of life and cost factors in panic disorder.

    PubMed

    Davidson, J R

    1996-01-01

    Quality of life encompasses domains of personal happiness, role fulfillment, and health status. Increasing attention has been paid to the relationship between quality of life and panic disorder, with accumulating evidence now available to suggest impairment in several domains among subjects with panic disorder. This review summarizes the results of community-based and treatment-seeking populations of subjects with panic disorder. Impaired personal happiness, restricted role functioning, and increased use of health services are all described. Evidence suggests that accurate diagnosis and effective treatment can significantly lessen health service utilization, resulting in substantial cost offset and also leading to increased work productivity and personal effectiveness.

  19. Current good manufacturing practices, quality control procedures, quality factors, notification requirements, and records and reports, for infant formula. Final rule.

    PubMed

    2014-06-10

    The Food and Drug Administration (FDA or we) is issuing a final rule that adopts, with some modifications, the interim final rule (IFR) entitled "Current Good Manufacturing Practices, Quality Control Procedures, Quality Factors, Notification Requirements, and Records and Reports, for Infant Formula'' (February 10, 2014). This final rule affirms the IFR's changes to FDA's regulations and provides additional modifications and clarifications. The final rule also responds to certain comments submitted in response to the request for comments in the IFR.

  20. Neutron radiography using neutron imaging plate.

    PubMed

    Chankow, Nares; Punnachaiya, Suvit; Wonglee, Sarinrat

    2010-01-01

    The aims of this research are to study properties of a neutron imaging plate (NIP) and to test it for use in nondestructive testing (NDT) of materials. The experiments were carried out by using a BAS-ND 2040 Fuji NIP and a neutron beam from the Thai Research Reactor TRR-1/M1. The neutron intensity and Cd ratio at the specimen position were approximately 9x10(5) ns/cm(2) s and 100 respectively. It was found that the photostimulated luminescence (PSL) readout of the imaging plate was directly proportional to the exposure time and approximately 40 times faster than the conventional NR using Gd converter screen/X-ray film technique. The sensitivities of the imaging plate to slow neutron and to Ir-192 gamma-rays were found to be approximately 4.2x10(-3) PSL/mm(2) per neutron and 6.7x10(-5) PSL/mm(2) per gamma-ray photon respectively. Finally, some specimens containing light elements were selected to be radiographed with neutrons using the NIP and the Gd converter screen/X-ray film technique. The image quality obtained from the two recording media was found to be comparable.

  1. Do Non-Economic Quality of Life Factors Drive Immigration?

    ERIC Educational Resources Information Center

    Pacheco, Gail Anne; Rossouw, Stephanie; Lewer, Joshua

    2013-01-01

    This paper contributes to the immigration literature by generating two unique non-economic quality of life (QOL) indices and testing their role on recent migration patterns. Applying the generated QOL indices in conjunction with four independent welfare measures to an augmented gravity model of immigration, this paper finds an insignificant…

  2. Assessing factors influencing the postharvest quality of California mandarins

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Mandarins are becoming increasingly popular with consumers but sometimes suffer from the development of off-flavor during storage. To investigate this problem the influence of fruit maturity, storage time and holding temperature on flavor quality were investigated. Mandarins were obtained once in Fe...

  3. Style and Quality in Research Supervision: The Supervisor Dependency Factor.

    ERIC Educational Resources Information Center

    Kam, Booi Hon

    1997-01-01

    A survey of 250 graduate research students examined the extent of dependency on supervisors in a range of research-related tasks, and how that dependency affected the research supervision process. Results suggest appropriate research supervision has no set prescription, but interactions among quality and style of supervision, role expectations of…

  4. STREAM NETWORK EXPANSION: A RIPARIAN WATER QUALITY FACTOR

    EPA Science Inventory

    Little is known about how active stream network expansion during rainstorms influences the ability of riparian buffers to improve water quality. We used aerial photographs to quantify stream network expansion during the wet winter season in five agricultural watersheds in western...

  5. Factors Influencing Assessment Quality in Higher Vocational Education

    ERIC Educational Resources Information Center

    Baartman, Liesbeth; Gulikers, Judith; Dijkstra, Asha

    2013-01-01

    The development of assessments that are fit to assess professional competence in higher vocational education requires a reconsideration of assessment methods, quality criteria and (self)evaluation. This article examines the self-evaluations of nine courses of a large higher vocational education institute. Per course, 4-11 teachers and 3-10…

  6. Investigation of factors affecting the quality of americium electroplating.

    PubMed

    Trdin, M; Benedik, L; Samardžija, Z; Pihlar, B

    2012-09-01

    Four different electrolyte solutions were used in the electrodeposition of americium and their influences on the quality of the thin layer of deposited americium isotopes in combination with three different cathode disc materials were investigated. The relations between alpha spectral resolution and disc surface properties were established.

  7. Neutron dosimetry in low-earth orbit using passive detectors

    NASA Technical Reports Server (NTRS)

    Benton, E. R.; Benton, E. V.; Frank, A. L.

    2001-01-01

    This paper summarizes neutron dosimetry measurements made by the USF Physics Research Laboratory aboard US and Russian LEO spacecraft over the past 20 years using two types of passive detector. Thermal/resonance neutron detectors exploiting the 6Li(n,T) alpha reaction were used to measure neutrons of energies <1 MeV. Fission foil neutron detectors were used to measure neutrons of energies above 1 MeV. While originally analysed in terms of dose equivalent using the NCRP-38 definition of quality factor, for the purposes of this paper the measured neutron data have been reanalyzed and are presented in terms of ambient dose equivalent. Dose equivalent rate for neutrons <1 MeV ranged from 0.80 microSv/d on the low altitude, low inclination STS-41B mission to 22.0 microSv/d measured in the Shuttle's cargo bay on the highly inclined STS-51F Spacelab-2 mission. In one particular instance a detector embedded within a large hydrogenous mass on STS-61 (in the ECT experiment) measured 34.6 microSv/d. Dose equivalent rate measurements of neutrons >1 MeV ranged from 4.5 microSv/d on the low altitude STS-3 mission to 172 microSv/d on the 6 year LDEF mission. Thermal neutrons (<0.3 eV) were observed to make a negligible contribution to neutron dose equivalent in all cases. The major fraction of neutron dose equivalent was found to be from neutrons >1 MeV and, on LDEF, neutrons >1 MeV are responsible for over 98% of the total neutron dose equivalent. Estimates of the neutron contribution to the total dose equivalent are somewhat lower than model estimates, ranging from 5.7% at a location under low shielding on LDEF to 18.4% on the highly inclined (82.3 degrees) Biocosmos-2044 mission. c2001 Elsevier Science Ltd. All rights reserved.

  8. Modulation of high quality factors in rolled-up microcavities

    NASA Astrophysics Data System (ADS)

    Fang, Yangfu; Li, Shilong; Mei, Yongfeng

    2016-09-01

    We systematically investigate the evolution of resonant modes in a rolled-up microcavity as the overlap length between structural notches increases, which presents a modulation behavior for high Q factors. The resonant modes in the rolled-up microcavity display a deterministic mode chirality, which is well correlated to the Q factor. We derive a two-mode non-Hermitian Hamiltonian to clarify these unusual findings. It reveals that strong resonant interactions of scattered waves between the structural notches are responsible for the high mode chirality (thus high Q factor) and its modulation behavior in rolled-up microcavities.

  9. The determination of beam quality correction factors: Monte Carlo simulations and measurements.

    PubMed

    González-Castaño, D M; Hartmann, G H; Sánchez-Doblado, F; Gómez, F; Kapsch, R-P; Pena, J; Capote, R

    2009-08-07

    Modern dosimetry protocols are based on the use of ionization chambers provided with a calibration factor in terms of absorbed dose to water. The basic formula to determine the absorbed dose at a user's beam contains the well-known beam quality correction factor that is required whenever the quality of radiation used at calibration differs from that of the user's radiation. The dosimetry protocols describe the whole ionization chamber calibration procedure and include tabulated beam quality correction factors which refer to 60Co gamma radiation used as calibration quality. They have been calculated for a series of ionization chambers and radiation qualities based on formulae, which are also described in the protocols. In the case of high-energy photon beams, the relative standard uncertainty of the beam quality correction factor is estimated to amount to 1%. In the present work, two alternative methods to determine beam quality correction factors are prescribed-Monte Carlo simulation using the EGSnrc system and an experimental method based on a comparison with a reference chamber. Both Monte Carlo calculations and ratio measurements were carried out for nine chambers at several radiation beams. Four chamber types are not included in the current dosimetry protocols. Beam quality corrections for the reference chamber at two beam qualities were also measured using a calorimeter at a PTB Primary Standards Dosimetry Laboratory. Good agreement between the Monte Carlo calculated (1% uncertainty) and measured (0.5% uncertainty) beam quality correction factors was obtained. Based on these results we propose that beam quality correction factors can be generated both by measurements and by the Monte Carlo simulations with an uncertainty at least comparable to that given in current dosimetry protocols.

  10. Water quality: a factor in Arkansas River development

    USGS Publications Warehouse

    Dover, T.B.

    1957-01-01

    One of the first requisites for intelligent planning of the utilization and control of water and for the administration of laws relating to its use, is data on the quantity, quality, and mode of occurence of water supplies. The collections, evaluation, interpretation, and publication of such data constitute the primary function of the Water Resources Division of the United States Geological Survey. Since 1895 the Congress has made appropriations to this agency for investigations of the water resources of the Nation. In 1929 the Congress adopted the policy of dollar-for-dollar cooperation with State and local governmental agencies for water-resources investigations. The Geological Survey's Federal-State cooperative program of quality-of-water investigations in Oklahoma was started in 1944 in cooperation with the Oklahoma Planning and Resources Board. Since July of this year the program has been carried on cooperatively with the newly created Oklahoma Water Resources Board.

  11. Feedstock Quality Factor Calibration and Data Model Development

    SciTech Connect

    Richard D. Boardman; Tyler L. Westover; Garold L. Gresham

    2010-05-01

    The goal of the feedstock assembly operation is to deliver uniform, quality-assured feedstock materials that will enhance downstream system performance by avoiding problems in the conversion equipment. In order to achieve this goal, there is a need for rapid screening tools and methodologies for assessing the thermochemical quality characteristics of biomass feedstock through the assembly process. Laser-induced breakdown spectroscopy (LIBS) has been identified as potential technique that could allow rapid elemental analyses of the inorganic content of biomass feedstocks; and consequently, would complement the carbohydrate data provided by near-infrared spectrometry (NIRS). These constituents, including Si, K, Ca, Na, S, P, Cl, Mg, Fe and Al, create a number of downstream problems in thermochemical processes. In particular, they reduce the energy content of the feedstock, influence reaction pathways, contribute to fouling and corrosion within systems, poison catalysts, and impact waste streams.

  12. Modelling of the serine-proteinase fold by X-ray and neutron scattering and sedimentation analyses: occurrence of the fold in factor D of the complement system.

    PubMed Central

    Perkins, S J; Smith, K F; Kilpatrick, J M; Volanakis, J E; Sim, R B

    1993-01-01

    Solution scattering is a powerful means of determining the overall arrangement of domains in the multidomain proteins of complement. the serine-proteinase domain is central to all proteolytic events during complement activation. As models of this domain, bovine beta-trypsin, trypsinogen, alpha-chymotrypsin and chymotrypsinogen A were studied by neutron and X-ray synchrotron solution scattering. At pH 7, all the X-ray and neutron M(r) values corresponded to monomeric proteins. The X-ray radii of gyration, RG, of beta-trypsin, trypsinogen, alpha-chymotrypsin and chymotrypsinogen A (measured in positive solute-solvent contrasts) were 1.59 nm, 1.78 nm, 1.71 nm and 1.76 nm (+/- 0.05-0.11 nm) in that order. Neutron contrast variation showed that the RG at infinite contrast, RC, for these four proteins were 1.57 nm, 1.70 nm, 1.67 nm and 1.78 nm (+/- 0.03 nm) in that same order. The radial inhomogeneity of neutron-scattering density, alpha, was positive at (5-13) x 10(-5), and corresponds to the preponderance of hydrophilic residues near the protein surface. On trypsinogen activation, a small reduction in the RG value of 0.13 +/- 0.07 nm was just detectable, while the RG of chymotrypsinogen A was unchanged after activation. The RC and alpha values of the four proteins can be calculated by using crystallographic co-ordinates. The reduced RG of beta-trypsin relative to trypsinogen was explained in terms of the removal of the extended N-terminal hexapeptide of trypsinogen. The full X-ray and neutron-scattering curves in positive and negative contrasts agreed well with scattering curves calculated from crystallographic coordinates to a nominal structural resolution of 4.5 nm, provided that the internal structure was considered in neutron modelling, and that the hydration was considered in X-ray modelling. Sedimentation-coefficient data also provide information on the disposition of domains in multidomain proteins. It was found that the hydrated X-ray sphere model could be

  13. On the determination of series resistance and diode quality factor of solar cells

    NASA Technical Reports Server (NTRS)

    Anderson, R. L.

    1976-01-01

    The series resistance and diode quality factor are used for evaluation of solar cell performance. These parameters are normally deduced from the terminal I-V characteristics under forward bias. The method produces a smaller series resistance and a larger value for diode quality factor than appropriate for the device when operating as a solar cell. It is suggested that the diode quality factor be determined from measured saturated photocurrent, open circuit voltage characteristics and the series resistance be measured with an r-f bridge or calculated from a measurement of the surface sheet resistance.

  14. Pediatric Coccidioidomycosis Patients: Perceptions, Quality of Life and Psychosocial Factors

    PubMed Central

    Gaab, Erin Mary; Naeem, Fouzia

    2015-01-01

    Research investigating the effects of coccidioidomycosis (valley fever) on children and the psychosocial implications of this disease in general is lacking. This study reviews what is known about pediatric coccidioidomycosis patients. It documents the psychological functioning, quality of life, and illness perceptions of a sample of coccidioidomycosis patient families. Primary caregivers of pediatric patients and patients from a major hospital in the San Joaquin Valley of California were interviewed regarding their perceptions of disease detection, access to care and the patient/family experience. PMID:27417796

  15. Atmospheric neutrons

    NASA Technical Reports Server (NTRS)

    Korff, S. A.; Mendell, R. B.; Merker, M.; Light, E. S.; Verschell, H. J.; Sandie, W. S.

    1979-01-01

    Contributions to fast neutron measurements in the atmosphere are outlined. The results of a calculation to determine the production, distribution and final disappearance of atmospheric neutrons over the entire spectrum are presented. An attempt is made to answer questions that relate to processes such as neutron escape from the atmosphere and C-14 production. In addition, since variations of secondary neutrons can be related to variations in the primary radiation, comment on the modulation of both radiation components is made.

  16. Neutron dosimetry

    DOEpatents

    Quinby, Thomas C.

    1976-07-27

    A method of measuring neutron radiation within a nuclear reactor is provided. A sintered oxide wire is disposed within the reactor and exposed to neutron radiation. The induced radioactivity is measured to provide an indication of the neutron energy and flux within the reactor.

  17. Neutron guide

    DOEpatents

    Greene, Geoffrey L.

    1999-01-01

    A neutron guide in which lengths of cylindrical glass tubing have rectangular glass plates properly dimensioned to allow insertion into the cylindrical glass tubing so that a sealed geometrically precise polygonal cross-section is formed in the cylindrical glass tubing. The neutron guide provides easier alignment between adjacent sections than do the neutron guides of the prior art.

  18. Prediction of In-Phantom Dose Distribution Using In-Air Neutron Beam Characteristics for Boron Neutron Capture Synovectomy

    SciTech Connect

    Verbeke, Jerome M.; Chen, Allen S.; Vujic, Jasmina L.; Leung, Ka-Ngo

    2000-08-15

    A monoenergetic neutron beam simulation study was carried out to determine the optimal neutron energy range for treatment of rheumatoid arthritis using radiation synovectomy. The goal of the treatment is the ablation of diseased synovial membranes in joints such as knees and fingers. This study focuses on human knee joints. Two figures of merit are used to measure the neutron beam quality, the ratio of the synovium-absorbed dose to the skin-absorbed dose, and the ratio of the synovium-absorbed dose to the bone-absorbed dose. It was found that (a) thermal neutron beams are optimal for treatment and that (b) similar absorbed dose rates and therapeutic ratios are obtained with monodirectional and isotropic neutron beams. Computation of the dose distribution in a human knee requires the simulation of particle transport from the neutron source to the knee phantom through the moderator. A method was developed to predict the dose distribution in a knee phantom from any neutron and photon beam spectra incident on the knee. This method was revealed to be reasonably accurate and enabled one to reduce the particle transport simulation time by a factor of 10 by modeling the moderator only.

  19. Characteristics of double-plasmonic-racetrack resonator to increase quality factor

    NASA Astrophysics Data System (ADS)

    Okamoto, Hiroyuki; Onishi, Sei; Kataoka, Mai; Yamaguchi, Kenzo; Haraguchi, Masanobu; Okamoto, Toshihiro

    2013-01-01

    We have numerically evaluated wavelength characteristics at telecommunication wavelengths by means of a doubleplasmonic-racetrack resonator using the finite-difference time domain method. We investigated the effect of the space between the two plasmonic racetracks of the resonator on the quality factor. The quality factor of the proposed structure is 57 when the space between two racetracks is 600 nm. The quality factor of a double-plasmonic-racetrack resonator of a dielectric-filled trench is 1.5 times greater than that of a single-plasmonic-racetrack resonator of an air-filled trench. The phase mismatch of the trench channel plasmon polaritons contributes to the quality factor of the double-plasmonicracetrack resonator.

  20. The disruptive physician. A quality of professional life factor.

    PubMed

    Pfifferling, J H

    1999-01-01

    Medical leaders need to understand that attending to quality of professional life issues includes dealing with the insidious costs and stress associated with disruptive physician behavior. The disruptive physician or professional undermines practice morale, heightens turnover in the organization, steals from productive activities, increases the risks for ineffective or substandard practice, and causes distress among colleagues. Physician executives need to help reduce or prevent this behavior and develop accepted systems in which to manage, confront, and rehabilitate the person labeled "disruptive." Suggested strategies to consider in developing a system include: (1) Defining reasonable and competent interpersonal behavior; (2) educating in interpersonal skills; (3) evaluating interpersonal skills; (4) developing disruptive policy; and (5) assessing, confronting, and rehabilitating.

  1. Exploratory and Confirmatory Factor Analysis of the PROMIS Pain Quality Item Bank

    PubMed Central

    Revicki, Dennis A.; Cook, Karon F.; Amtmann, Dagmar; Harnam, Neesha; Chen, Wen-Hung; Keefe, Francis J.

    2013-01-01

    Purpose The assessment of pain sensation and quality is a key component in understanding the experience of individuals with chronic pain. This study evaluated the factor structure of the Patient-reported Outcome Measurement Information System (PROMIS) pain quality item bank. Methods As part of the PROMIS project, we developed a pool of 37 pain quality items, based on a review of existing pain questionnaires and development of new items. A Web-based survey was designed and completed by 845 members of the general population and 967 individuals with different types of chronic pain. Exploratory factor analysis (EFA) was conducted on a random split-half sample of the data to examine the factor structure of the 37 PROMIS pain quality items in the general population and in a chronic pain sample. A confirmatory factor analysis was conducted in the holdout sample. Results The EFA of the pain quality items resulted in comparable six-factor solutions for the general and chronic pain samples: (1) pulling/tugging pain; (2) tingling/numbness pain; (3) sharp/stabbing pain; (4) dull/aching pain; (5) pounding/pulsing pain; and (6) affective pain. The confirmatory factor analysis in the holdout sample supported this factor structure. Conclusions Further research is needed to evaluate the psychometric characteristics of the derived scales based on their factor scores. PMID:23836435

  2. Factors Associated with the Utilization and Quality of Prenatal Care in Western Rural Regions of China

    ERIC Educational Resources Information Center

    Dongxu, Wang; Yuhui, Shi; Stewart, Donald; Chun, Chang; Chaoyang, Li

    2012-01-01

    Purpose: The paper seeks to identify key features of prenatal care utilization and quality in western regions of China and to determine the factors affecting the quality of prenatal care. Design/methodology/approach: A descriptive, cross-sectional study was conducted. The instrument for the study was a 10-stem respondent-administered, structured…

  3. Change in Quality of Life after Rehabilitation: Prognostic Factors for Visually Impaired Adults

    ERIC Educational Resources Information Center

    Langelaan, Maaike; de Boer, Michiel R.; van Nispen, Ruth M. A.; Wouters, Bill; Moll, Annette C.; van Rens, Ger H. M. B.

    2009-01-01

    The overall aim of rehabilitation for visually impaired adults is to improve the quality of life and (societal) participation. The objectives of this study were to obtain the short-term and long-term outcome of a comprehensive rehabilitation programme on quality of life for visually impaired adults, and prognostic baseline factors responsible for…

  4. Factors that Impact Quality of E-Teaching/Learning Technologies in Higher Education

    ERIC Educational Resources Information Center

    Daukilas, Sigitas; Kaciniene, Irma; Vaisnoriene, Daiva; Vascila, Vytautas

    2008-01-01

    The article analyzes and assesses factors that have impact upon the quality of eTeaching/learning technologies in higher education; it is on their basis that the concept of eTeaching/learning quality is denied. Research data about the students' motives in choosing various teaching/learning technologies for the development of their competence are…

  5. Diet quality is inversely related to cardiovascular risk factors in adults

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The goal of the study was to determine if there was an association between diet quality and cardiovascular risk factors in adults. National Health and Nutrition Examination Survey 2001–2008 data were used to compare diet quality, as determined by using 2005 Healthy Eating Index-2005 scores, and card...

  6. On the potential impact of the newly proposed quality factors on space radiation protection

    NASA Technical Reports Server (NTRS)

    Wilson, John W.; Townsend, Lawrence W.; Cucinotta, Francis A.

    1987-01-01

    The recently proposed changes in the defined quality factor hold great potential for easing some of the protection requirements from electrons and protons in the near-Earth environment. At the same time, the high Linear Energy Transfer (LET) components play an even more important role which must be further evaluated. Several recommendations are made which need to be addressed before these new quality factors can be implemented into space radiation potection practice.

  7. Analysis of the Neutron Electric Form Factor at Q2 = 1.4 GeV2 using the reaction 3 H->e (e-> ,e' n) pp

    NASA Astrophysics Data System (ADS)

    Obrecht, Richard; Super Bigbite Collaboration

    2016-09-01

    The Jefferson Lab Hall A experiment E02-013 extracted the neutron electric form factor GEn by measuring the beam-target asymmetry in quasi-elastically scattering of longitudinally polarized electrons from a polarized 3He target via the semi-exclusive reaction3 H->e (e-> ,e' n) pp . The experiment measured the electric form factor at a spacelike four-momentum transfer squared Q2 = 1.4, 1.7, 2.7, and 3.4 GeV2, but only the latter three points were published by S. Riordan et al. (Phys. Rev. Lett. 105, 262302). The goal of this talk is to present the analysis chain necessary to extract the form factor from a neutron asymmetry that arises by periodically changing the sign of the beam helicity. The analysis includes selecting quasi-elastic events in a high noise environment, and correcting for various factors that dilute the signal such as false proton asymmetries and final state interactions within the target. Jefferson Lab Hall A.

  8. Improvement of the quality factor of single crystal diamond mechanical resonators

    NASA Astrophysics Data System (ADS)

    Liao, Meiyong; Toda, Masaya; Sang, Liwen; Teraji, Tokuyuki; Imura, Masataka; Koide, Yasuo

    2017-02-01

    Single-crystal diamond (SCD) has the potential to boost microelectromechanical system (MEMS) with unprecedented performance in terms of its intrinsic mechanical, chemical, and electronic properties, especially in the applications under extreme conditions. On the basis of the analysis of the energy dissipation in diamond mechanical resonators, the authors report on the marked improvement of the quality factor of SCD-MEMS resonators. Ion implantation assisted lift-off technique (IAL) is utilized to fabricate the SCD resonators. The quality factor of the resonator fabricated from the ion-damaged SCD layer alone is as low as 100-300 owing to the bulk or surface defects. The growth of homoepitaxial layers on the ion-implanted SCD substrates significantly improves the quality factor by more than 100 times. Cantilevers made of SCD epilayers of different thicknesses are examined. It is found that the quality factor increases with increasing the epilayer thickness. The maximum quality factor of the SCD cantilevers fabricated by the IAL technique reaches 3.9 × 104. A bilayer model is proposed to describe the variation of the quality factor.

  9. Identifying Items to Assess Methodological Quality in Physical Therapy Trials: A Factor Analysis

    PubMed Central

    Cummings, Greta G.; Fuentes, Jorge; Saltaji, Humam; Ha, Christine; Chisholm, Annabritt; Pasichnyk, Dion; Rogers, Todd

    2014-01-01

    Background Numerous tools and individual items have been proposed to assess the methodological quality of randomized controlled trials (RCTs). The frequency of use of these items varies according to health area, which suggests a lack of agreement regarding their relevance to trial quality or risk of bias. Objective The objectives of this study were: (1) to identify the underlying component structure of items and (2) to determine relevant items to evaluate the quality and risk of bias of trials in physical therapy by using an exploratory factor analysis (EFA). Design A methodological research design was used, and an EFA was performed. Methods Randomized controlled trials used for this study were randomly selected from searches of the Cochrane Database of Systematic Reviews. Two reviewers used 45 items gathered from 7 different quality tools to assess the methodological quality of the RCTs. An exploratory factor analysis was conducted using the principal axis factoring (PAF) method followed by varimax rotation. Results Principal axis factoring identified 34 items loaded on 9 common factors: (1) selection bias; (2) performance and detection bias; (3) eligibility, intervention details, and description of outcome measures; (4) psychometric properties of the main outcome; (5) contamination and adherence to treatment; (6) attrition bias; (7) data analysis; (8) sample size; and (9) control and placebo adequacy. Limitation Because of the exploratory nature of the results, a confirmatory factor analysis is needed to validate this model. Conclusions To the authors' knowledge, this is the first factor analysis to explore the underlying component items used to evaluate the methodological quality or risk of bias of RCTs in physical therapy. The items and factors represent a starting point for evaluating the methodological quality and risk of bias in physical therapy trials. Empirical evidence of the association among these items with treatment effects and a confirmatory factor

  10. Factors influencing the quality of life perception in patients with type 2 diabetes mellitus

    PubMed Central

    Timar, Romulus; Velea, Iulian; Timar, Bogdan; Lungeanu, Diana; Oancea, Cristian; Roman, Deiana; Mazilu, Octavian

    2016-01-01

    Purpose To evaluate the impact of several factors on the patient’s perception on quality of life in a group of patients with type 2 diabetes mellitus (T2DM). Patients and methods In this cross-sectional study, 198 patients with T2DM were enrolled according to a consecutive-case population-based study design. In all participants, the perception on the quality of life was measured using the quality of life index – diabetes version III proposed by Ferrans and Powers. We evaluated the impact of several anthropometric and diabetes-related (ie, diabetes history and quality of glycemic control) factors on the patient’s perception on the quality of life. Results The presence of diabetes complications was associated with a decreased quality of life: retinopathy (1 vs 5 points; P<0.001), chronic kidney disease (−1 vs 5 points; P<0.001), and neuropathy (−1 vs 5 points; P<0.001). A significant reverse correlation was found between the patient’s quality of life and depression’s severity (Spearman’s r=−0.345; P<0.001) and body mass index (Spearman’s r=−0.158; P=0.026). A positive association between the quality of life and the quality of diabetes-related self-care activities was found (Spearman’s r=0.338; P<0.001). No significant association was found between the patient’s quality of life and the quality of glycemic control, diabetes duration, age, gender, or smoking status. Conclusion To improve the patient’s quality of life, special care should be given to the modifiable diabetes-related factors: the prevention and treatment of diabetes complications, treatment of depression, and weight loss in obese and overweight patients. PMID:28003741

  11. A Secreted Factor Coordinates Environmental Quality with Bacillus Development

    PubMed Central

    Ababneh, Qutaiba O.; Tindall, Amanda J.; Herman, Jennifer K.

    2015-01-01

    Entry into sporulation is governed by the master regulator Spo0A. Spo0A accumulates in its active form, Spo0A-P, as cells enter stationary phase. Prior reports have shown that the acute induction of constitutively active Spo0A during exponential growth does not result in sporulation. However, a subsequent study also found that a gradual increase in Spo0A-P, mediated through artificial expression of the kinase, KinA, during exponential growth, is sufficient to trigger sporulation. We report here that sporulation via KinA induction depends on the presence of an extracellular factor or factors (FacX) that only accumulates to active levels during post-exponential growth. FacX is retained by dialysis with a cutoff smaller than 500 Dalton, can be concentrated, and is susceptible to proteinase K digestion, similar to described quorum-sensing peptides shown to be involved in promoting sporulation. However, unlike previously characterized peptides, FacX activity does not require the Opp or App oligopeptide transporter systems. In addition, FacX activity does not depend on SigH, Spo0A, or ComX. Importantly, we find that in the presence of FacX, B. subtilis can be induced to sporulate following the artificial induction of constitutively active Spo0A. These results indicate that there is no formal requirement for gradual Spo0A-P accumulation and instead support the idea that sporulation requires both sufficient levels of active Spo0A and at least one other signal or condition. PMID:26657919

  12. Risk factors and monitoring for water quality to determine best management practices for splash parks.

    PubMed

    de Man, H; Leenen, E J T M; van Knapen, F; de Roda Husman, A M

    2014-09-01

    Splash parks have been associated with infectious disease outbreaks as a result of exposure to poor water quality. To be able to protect public health, risk factors were identified that determine poor water quality. Samples were taken at seven splash parks where operators were willing to participate in the study. Higher concentrations of Escherichia coli were measured in water of splash parks filled with rainwater or surface water as compared with sites filled with tap water, independent of routine inspection intervals and employed disinfection. Management practices to prevent fecal contamination and guarantee maintaining good water quality at splash parks should include selection of source water of acceptable quality.

  13. Nanotube mechanical resonators with quality factors of up to 5 million.

    PubMed

    Moser, J; Eichler, A; Güttinger, J; Dykman, M I; Bachtold, A

    2014-12-01

    Carbon nanotube mechanical resonators have attracted considerable interest because of their small mass, the high quality of their surfaces, and the pristine electronic states they host. However, their small dimensions result in fragile vibrational states that are difficult to measure. Here, we observe quality factors Q as high as 5 × 10(6) in ultra-clean nanotube resonators at a cryostat temperature of 30 mK, where we define Q as the ratio of the resonant frequency over the linewidth. Measuring such high quality factors requires the use of an ultra-low-noise method to rapidly detect minuscule vibrations, as well as careful reduction of the noise of the electrostatic environment. We observe that the measured quality factors fluctuate because of fluctuations of the resonant frequency. We measure record-high quality factors, which are comparable to the highest Q values reported in mechanical resonators of much larger size, a remarkable result considering that reducing the size of resonators is usually concomitant with decreasing quality factors. The combination of ultra-low mass and very large Q offers new opportunities for ultra-sensitive detection schemes and quantum optomechanical experiments.

  14. Nanotube mechanical resonators with quality factors of up to 5 million

    NASA Astrophysics Data System (ADS)

    Moser, J.; Eichler, A.; Güttinger, J.; Dykman, M. I.; Bachtold, A.

    2014-12-01

    Carbon nanotube mechanical resonators have attracted considerable interest because of their small mass, the high quality of their surfaces, and the pristine electronic states they host. However, their small dimensions result in fragile vibrational states that are difficult to measure. Here, we observe quality factors Q as high as 5 × 106 in ultra-clean nanotube resonators at a cryostat temperature of 30 mK, where we define Q as the ratio of the resonant frequency over the linewidth. Measuring such high quality factors requires the use of an ultra-low-noise method to rapidly detect minuscule vibrations, as well as careful reduction of the noise of the electrostatic environment. We observe that the measured quality factors fluctuate because of fluctuations of the resonant frequency. We measure record-high quality factors, which are comparable to the highest Q values reported in mechanical resonators of much larger size, a remarkable result considering that reducing the size of resonators is usually concomitant with decreasing quality factors. The combination of ultra-low mass and very large Q offers new opportunities for ultra-sensitive detection schemes and quantum optomechanical experiments.

  15. Beam quality M 2 factor matrix for non-circular symmetric laser beams

    NASA Astrophysics Data System (ADS)

    Du, Yongzhao; Fu, Yuqing; Zheng, Chaoying

    2017-02-01

    It is standard to use Mx2 and My2 to characterize the beam quality of a non-circular symmetrical beam on its x-axis and y-axis orientation. However, we knew that the values of Mx2 and My2 are inconsistent if one selects a different coordinate system or measures beam quality with different experimental conditionals, even when analyzing the same beam. To overcome this, a new beam quality characterization method, the M 2 factor matrix, is developed. It not only contains the beam quality terms, Mx2 and My2 , to characterize the beam quality along x-axis and y-axis orientation for the non-symmetric beam, but also introduces two additional cross terms, M xy and M yx , which are used to characterize the location relationship between the principal axis of the test beam and coordinate system in experiment. Moreover, M 2 factor matrix can be measured with a similar procedure to the traditional M 2 factor whose measurement instructions are described in ISO11146 by adding some additional image and signal processing procedure. The measurement principle and method is present and the experiment system for beam quality M 2 factor matrix is built to demonstrate the performance of M 2 factor matrix with real experiments.

  16. Factors controlling air quality in different European subway systems.

    PubMed

    Martins, Vânia; Moreno, Teresa; Mendes, Luís; Eleftheriadis, Konstantinos; Diapouli, Evangelia; Alves, Célia A; Duarte, Márcio; de Miguel, Eladio; Capdevila, Marta; Querol, Xavier; Minguillón, María Cruz

    2016-04-01

    Sampling campaigns using the same equipment and methodology were conducted to assess and compare the air quality at three South European subway systems (Barcelona, Athens and Oporto), focusing on concentrations and chemical composition of PM2.5 on subway platforms, as well as PM2.5 concentrations inside trains. Experimental results showed that the mean PM2.5 concentrations widely varied among the European subway systems, and even among different platforms within the same underground system, which might be associated to distinct station and tunnel designs and ventilation systems. In all cases PM2.5 concentrations on the platforms were higher than those in the urban ambient air, evidencing that there is generation of PM2.5 associated with the subway systems operation. Subway PM2.5 consisted of elemental iron, total carbon, crustal matter, secondary inorganic compounds, insoluble sulphate, halite and trace elements. Of all metals, Fe was the most abundant, accounting for 29-43% of the total PM2.5 mass (41-61% if Fe2O3 is considered), indicating the existence of an Fe source in the subway system, which could have its origin in mechanical friction and wear processes between rails, wheels and brakes. The trace elements with the highest enrichment in the subway PM2.5 were Ba, Cu, Mn, Zn, Cr, Sb, Sr, Ni, Sn, Co, Zr and Mo. Similar PM2.5 diurnal trends were observed on platforms from different subway systems, with higher concentrations during subway operating hours than during the transport service interruption, and lower levels on weekends than on weekdays. PM2.5 concentrations depended largely on the operation and frequency of the trains and the ventilation system, and were lower inside the trains, when air conditioning system was operating properly, than on the platforms. However, the PM2.5 concentrations increased considerably when the train windows were open. The PM2.5 levels inside the trains decreased with the trains passage in aboveground sections.

  17. Factors Affecting Perceived Learning, Satisfaction, and Quality in the Online MBA: A Structural Equation Modeling Approach

    ERIC Educational Resources Information Center

    Sebastianelli, Rose; Swift, Caroline; Tamimi, Nabil

    2015-01-01

    The authors examined how six factors related to content and interaction affect students' perceptions of learning, satisfaction, and quality in online master of business administration (MBA) courses. They developed three scale items to measure each factor. Using survey data from MBA students at a private university, the authors estimated structural…

  18. Confirming the Three-Factor Structure of the Quality of Relationships Inventory within Couples

    ERIC Educational Resources Information Center

    Verhofstadt, Lesley L.; Buysse, Ann; Rosseel, Yves; Peene, Olivier J.

    2006-01-01

    The current study further validates the Quality of Relationships Inventory (QRI; G. R. Pierce, I. G. Sarason, & B. R. Sarason, 1991) by evaluating its factor structure in a sample of 572 partners from 286 couples. Confirmatory factor analysis was used to compare 3 different models of the QRI and to investigate the invariance of the factor…

  19. Not So Fast: Inflation in Impact Factors Contributes to Apparent Improvements in Journal Quality

    ERIC Educational Resources Information Center

    Neff, Bryan D.; Olden, Julian D.

    2010-01-01

    The Institute for Scientific Information (ISI) impact factor has become an important standard for assessing journal quality. Here we propose that impact factors may be subject to inflation analogous to changes in monetary prices in economics. The possibility of inflation came to light as a result of the observation that papers published today tend…

  20. Complex seismic amplitude inversion for P-wave and S-wave quality factors

    NASA Astrophysics Data System (ADS)

    Zong, Zhaoyun; Yin, Xingyao; Wu, Guochen

    2015-07-01

    Stratum quality factors (P-wave and S-wave quality factors, Qp and Qs) have gradually been utilized in the study of physical state of crust and uppermost mantle, tectonic evolution, hydrogeololgy, gas hydrates, petroleum exploration, etc. Different opinions of the seismic attenuation mechanism result in various approaches to estimate the P-wave and S-wave quality factors. Considering the viscoelasticity of the underground medium, the constitutive matrix of the Earth medium is written as the superposition of homogeneous background medium, elastic perturbation medium and viscoelastic perturbation medium. Under the hypothesis of Born integral and stationary phase approximation, the seismic reflectivity is initially raised in terms of P-wave and S-wave moduli, density, P-wave and S-wave quality factors. Furthermore, incorporating the complex seismic traces with the seismic wavelets at different offsets, a two-step inversion approach is proposed to estimate the P-wave and S-wave quality factors. The AVO/AVA Bayesian inversion approach is suggested to estimate the P-wave modulus and S-wave modulus with the real component of the pre-stack seismic data initially. Taking the estimated P-wave and S-wave moduli as prior information, the P-wave and S-wave quality factors are further estimated with the imaginary component of the complex pre-stack seismic data, which is the quadrature of the original data. Finally, synthetic examples demonstrate that the proposed approach is able to estimate P-wave and S-wave quality factors stably and properly, and two field data examples demonstrate that the proposed approach may work as an efficient approach to fluid identification.

  1. Boron neutron capture therapy (BNCT): implications of neutron beam and boron compound characteristics.

    PubMed

    Wheeler, F J; Nigg, D W; Capala, J; Watkins, P R; Vroegindeweij, C; Auterinen, I; Seppälä, T; Bleuel, D

    1999-07-01

    The potential efficacy of boron neutron capture therapy (BNCT) for malignant glioma is a significant function of epithermal-neutron beam biophysical characteristics as well as boron compound biodistribution characteristics. Monte Carlo analyses were performed to evaluate the relative significance of these factors on theoretical tumor control using a standard model. The existing, well-characterized epithermal-neutron sources at the Brookhaven Medical Research Reactor (BMRR), the Petten High Flux Reactor (HFR), and the Finnish Research Reactor (FiR-1) were compared. Results for a realistic accelerator design by the E. O. Lawrence Berkeley National Laboratory (LBL) are also compared. Also the characteristics of the compound p-Boronophenylaline Fructose (BPA-F) and a hypothetical next-generation compound were used in a comparison of the BMRR and a hypothetical improved reactor. All components of dose induced by an external epithermal-neutron beam fall off quite rapidly with depth in tissue. Delivery of dose to greater depths is limited by the healthy-tissue tolerance and a reduction in the hydrogen-recoil and incident gamma dose allow for longer irradiation and greater dose at a depth. Dose at depth can also be increased with a beam that has higher neutron energy (without too high a recoil dose) and a more forward peaked angular distribution. Of the existing facilities, the FiR-1 beam has the better quality (lower hydrogen-recoil and incident gamma dose) and a penetrating neutron spectrum and was found to deliver a higher value of Tumor Control Probability (TCP) than other existing beams at shallow depth. The greater forwardness and penetration of the HFR the FiR-1 at greater depths. The hypothetical reactor and accelerator beams outperform at both shallow and greater depths. In all cases, the hypothetical compound provides a significant improvement in efficacy but it is shown that the full benefit of improved compound is not realized until the neutron beam is fully

  2. Optimization study for an epithermal neutron beam for boron neutron capture therapy at the University of Virginia Research Reactor

    SciTech Connect

    Burns, Jr., Thomas Dean

    1995-05-01

    The non-surgical brain cancer treatment modality, Boron Neutron Capture Therapy (BNCT), requires the use of an epithermal neutron beam. This purpose of this thesis was to design an epithermal neutron beam at the University of Virginia Research Reactor (UVAR) suitable for BNCT applications. A suitable epithermal neutron beam for BNCT must have minimal fast neutron and gamma radiation contamination, and yet retain an appreciable intensity. The low power of the UVAR core makes reaching a balance between beam quality and intensity a very challenging design endeavor. The MCNP monte carlo neutron transport code was used to develop an equivalent core radiation source, and to perform the subsequent neutron transport calculations necessary for beam model analysis and development. The code accuracy was validated by benchmarking output against experimental criticality measurements. An epithermal beam was designed for the UVAR, with performance characteristics comparable to beams at facilities with cores of higher power. The epithermal neutron intensity of this beam is 2.2 x 108 n/cm2 • s. The fast neutron and gamma radiation KERMA factors are 10 x 10-11cGy•cm2/nepi and 20 x 10-11 cGy•cm2/nepi , respectively, and the current-to-flux ratio is 0.85. This thesis has shown that the UVAR has the capability to provide BNCT treatments, however the performance characteristics of the final beam of this study were limited by the low core power.

  3. Neutron Transport Characteristics of a Nuclear Reactor Based Dynamic Neutron Imaging System

    SciTech Connect

    Khaial, Anas M.; Harvel, Glenn D.; Chang, Jen-Shih

    2006-07-01

    An advanced dynamic neutron imaging system has been constructed in the McMaster Nuclear Reactor (MNR) for nondestructive testing and multi-phase flow studies in energy and environmental applications. A high quality neutron beam is required with a thermal neutron flux greater than 5.0 x 10{sup 6} n/cm{sup 2}-s and a collimation ratio of 120 at image plane to promote high-speed neutron imaging up to 2000 frames per second. Neutron source strength and neutron transport have been experimentally and numerically investigated. Neutron source strength at the beam tube entrance was evaluated experimentally by measuring the thermal and fast neutron fluxes, and simple analytical neutron transport calculations were performed based upon these measured neutron fluxes to predict facility components in accordance with high-speed dynamic neutron imaging and operation safety requirements. Monte-Carlo simulations (using MCNP-4B code) with multiple neutron energy groups have also been used to validate neutron beam parameters and to ensure shielding capabilities of facility shutter and cave walls. Neutron flux distributions at the image plane and the neutron beam characteristics were experimentally measured by irradiating a two-dimensional array of Copper foils and using a real-time neutron radiography system. The neutron image characteristics -- such as neutron flux, image size, beam quality -- measured experimentally and predicted numerically for beam tube, beam shutter and radiography cave are compared and discussed in detail in this paper. The experimental results show that thermal neutron flux at image plane is nearly uniform over an imaging area of 20.0-cm diameter and its magnitude ranges from 8.0 x 10{sup 6} - 1.0 x 10{sup 7} n/cm{sup 2}-sec while the neutron-to-gamma ratio is 6.0 x 10{sup 5} n/cm{sup 2}-{mu}Sv. (authors)

  4. Neutron detector

    DOEpatents

    Stephan, Andrew C.; Jardret; Vincent D.

    2011-04-05

    A neutron detector has a volume of neutron moderating material and a plurality of individual neutron sensing elements dispersed at selected locations throughout the moderator, and particularly arranged so that some of the detecting elements are closer to the surface of the moderator assembly and others are more deeply embedded. The arrangement captures some thermalized neutrons that might otherwise be scattered away from a single, centrally located detector element. Different geometrical arrangements may be used while preserving its fundamental characteristics. Different types of neutron sensing elements may be used, which may operate on any of a number of physical principles to perform the function of sensing a neutron, either by a capture or a scattering reaction, and converting that reaction to a detectable signal. High detection efficiency, an ability to acquire spectral information, and directional sensitivity may be obtained.

  5. Factors Affecting Quality of Emergency Service in Iran’s Military Hospitals: A Qualitative Study

    PubMed Central

    Zaboli, Rouhollah; Shokri, Mohamad; Javadi, Maryam Seyed; Teymourzadeh, Ehsan; Ameryoun, Ahmad

    2016-01-01

    Introduction Quality is a key factor for the success of any organization. Moreover, accessing quality in the emergency department is highly significant due to the sensitive and complex role of this department in hospitals as well as the healthcare and medical treatment system. This study aimed to identify, from the perspective of medical experts and nurses serving in the military health and medical treatment system, the factors that affect the quality of emergency service provided in selected military hospitals in Iran. Methods This qualitative research was performed in Valiaser Hospital of Tehran (Iran) in 2015, using the framework analysis method. The purposive sampling technique was used for data collection. A total of 14 participants included two emergency medicine specialists, four general physicians, two senior nurses (holding M.Sc. degrees), and six nurses (holding B.Sc. degree). Data were collected through semistructured interviews. Sampling continued until data saturation occurred. The Atlas/Ti software was employed for data analysis. Results Four basic themes emerged as the effective factors on the quality of emergency services, namely, structural themes, process/performance themes, outcome themes, and environmental/contextual themes. Moreover, through a framework analysis, 47 subthemes were specified and summarized as indicators of the different aspects of the main themes. Conclusion The factors affecting the quality of emergency services in Iran’s selected military hospitals are especially complicated due to the diversity of the missions involved; thus, different factors can influence this quality. Therefore, an effort should be made to tackle the existing obstacles, facilitate the identification of these effective factors, and promotion of the quality of healthcare services. PMID:27790355

  6. Neutron spectra and dose equivalents calculated in tissue for high-energy radiation therapy

    PubMed Central

    Kry, Stephen F.; Howell, Rebecca M.; Salehpour, Mohammad; Followill, David S.

    2009-01-01

    Neutrons are by-products of high-energy radiation therapy and a source of dose to normal tissues. Thus, the presence of neutrons increases a patient’s risk of radiation-induced secondary cancer. Although neutrons have been thoroughly studied in air, little research has been focused on neutrons at depths in the patient where radiosensitive structures may exist, resulting in wide variations in neutron dose equivalents between studies. In this study, we characterized properties of neutrons produced during high-energy radiation therapy as a function of their depth in tissue and for different field sizes and different source-to-surface distances (SSD). We used a previously developed Monte Carlo model of an accelerator operated at 18 MV to calculate the neutron fluences, energy spectra, quality factors, and dose equivalents in air and in tissue at depths ranging from 0.1 to 25 cm. In conjunction with the sharply decreasing dose equivalent with increased depth in tissue, the authors found that the neutron energy spectrum changed drastically as a function of depth in tissue. The neutron fluence decreased gradually as the depth increased, while the average neutron energy decreased sharply with increasing depth until a depth of approximately 7.5 cm in tissue, after which it remained nearly constant. There was minimal variation in the quality factor as a function of depth. At a given depth in tissue, the neutron dose equivalent increased slightly with increasing field size and decreasing SSD; however, the percentage depth-dose equivalent curve remained constant outside the primary photon field. Because the neutron dose equivalent, fluence, and energy spectrum changed substantially with depth in tissue, we concluded that when the neutron dose equivalent is being determined at a depth within a patient, the spectrum and quality factor used should be appropriate for depth rather than for in-air conditions. Alternately, an appropriate percent depth-dose equivalent curve should

  7. Atmospheric neutrons

    NASA Technical Reports Server (NTRS)

    Preszler, A. M.; Moon, S.; White, R. S.

    1976-01-01

    Additional calibrations of the University of California double-scatter neutron detector and additional analysis corrections lead to slightly changed neutron fluxes. The theoretical angular distributions of Merker (1975) are in general agreement with the reported experimental fluxes but do not give the peaks for vertical upward and downward moving neutrons. The theoretical neutron escape current is in agreement with the experimental values from 10 to 100 MeV. The experimental fluxes obtained agree with those of Kanbach et al. (1974) in the overlap region from 70 to 100 MeV.

  8. A summary of ammonia emission factors and quality criteria for commercial poultry production in North America

    NASA Astrophysics Data System (ADS)

    Wood, David; Cowherd, Savannah; Van Heyst, Bill

    2015-08-01

    Efforts to quantify emissions of ammonia to the atmosphere from poultry housing in North America have been underway for the past two decades. In order to accurately estimate emissions from facilities in each poultry sector, emission factors used to derive the average must be of sufficiently high quality. However, it has become evident that current methods are inadequate and emission factors do not accurately reflect North American poultry production. Using an initial screening, based on measurement methods for ammonia and ventilation rates as well as study duration, a collection of studies have been identified that report the highest quality emission factors currently available. Each study was rated for data quality and then an average emission factor was developed for each sector of poultry production and rated based its ability to represent that sector. The laying hen sector, using deep pit manure storage, received a C (average) emission factor quality rating, which is the highest of all the poultry sectors evaluated. Laying hen with manure belts, broiler chicken, and turkey sectors received quality ratings considered to be below average or poor. This study highlights the need for additional research that needs to be conducted in order to accurately quantify ammonia releases from housing in most poultry sectors in North America.

  9. High quality factor resonance at room temperature with nanostrings under high tensile stress

    NASA Astrophysics Data System (ADS)

    Verbridge, Scott S.; Parpia, Jeevak M.; Reichenbach, Robert B.; Bellan, Leon M.; Craighead, H. G.

    2006-06-01

    Quality factors as high as 207 000 are demonstrated at room temperature for radio-frequency silicon nitride string resonators with cross sectional dimensions on the scale of 100 nm, made with a nonlithographic technique. A product of quality factor and surface to volume ratio greater than 6000 nm-1 is presented, the highest yet reported. Doubly clamped nanostring resonators are fabricated in high tensile-stress silicon nitride using a nonlithographic electrospinning process. We fabricate devices with an electron beam process, and demonstrate frequency and quality factor results identical to those obtained with the nonlithographic technique. We also compare high tensile-stress doubly clamped beams with doubly clamped and cantilever resonators made of a lower stress material, as well as cantilever beams made of the high stress material. In all cases, the doubly clamped high stress beams have the highest quality factors. We therefore attribute the high quality factors to high tensile stress. Potential dominant loss mechanisms are discussed, including surface and clamping losses, and thermoelastic dissipation. Some practical advantages offered by these nanostrings for mass sensing are discussed.

  10. Identification and assessment of potential water quality impact factors for drinking-water reservoirs.

    PubMed

    Gu, Qing; Deng, Jinsong; Wang, Ke; Lin, Yi; Li, Jun; Gan, Muye; Ma, Ligang; Hong, Yang

    2014-06-10

    Various reservoirs have been serving as the most important drinking water sources in Zhejiang Province, China, due to the uneven distribution of precipitation and severe river pollution. Unfortunately, rapid urbanization and industrialization have been continuously challenging the water quality of the drinking-water reservoirs. The identification and assessment of potential impacts is indispensable in water resource management and protection. This study investigates the drinking water reservoirs in Zhejiang Province to better understand the potential impact on water quality. Altogether seventy-three typical drinking reservoirs in Zhejiang Province encompassing various water storage levels were selected and evaluated. Using fifty-two reservoirs as training samples, the classification and regression tree (CART) method and sixteen comprehensive variables, including six sub-sets (land use, population, socio-economy, geographical features, inherent characteristics, and climate), were adopted to establish a decision-making model for identifying and assessing their potential impacts on drinking-water quality. The water quality class of the remaining twenty-one reservoirs was then predicted and tested based on the decision-making model, resulting in a water quality class attribution accuracy of 81.0%. Based on the decision rules and quantitative importance of the independent variables, industrial emissions was identified as the most important factor influencing the water quality of reservoirs; land use and human habitation also had a substantial impact on water quality. The results of this study provide insights into the factors impacting the water quality of reservoirs as well as basic information for protecting reservoir water resources.

  11. Analyzing the Dimensions of the Quality of Life in Hepatitis B Patientsusing Confirmatory Factor Analysis

    PubMed Central

    Abedi, Ghassem; Rostami, Farideh; Nadi, Aliasghar

    2015-01-01

    Background and Objectives: The scope of the quality of life assessment is not widespread in any time like today. Economists, social scientists and politicians look at this topic from the particular approach. The life quality in hepatitis B patients regarding the degree of its progress is considered a major concern in these patients. Thus, the aim of the study was analyzing the dimensions of the life quality of a group of people suffering from hepatitis B in Mazandaran province in 2012. Methods: This study was done by descriptive, cross-sectional method on 210 (118 women and 92 men) hepatitis B patients that six month have passed from their diagnosis and formation of follow-up form in health centers, using access sampling method atsix regions of Mazandaran province. The instruments of the study were the questionnaire of World Health Organization questionnaire (WHOQOL-BREF) and the chronic liver disease questionnaire (CLDQ). For analyzing the data from descriptive statistics and Kolmogrov-Smirnov test, one sample t-test, two stage Confirmatoryfactor analysis, Spss and Lisrel software has been used. Results: Findings showed that the social relationship dimension with factor loading of 0.81 has the most amount of coefficient of effectiveness; physical health with factor loading of 0.72, mental health with factor loading of 0.63 and environmental health with factor loading of 0.55 have the least amount of coefficient of effectiveness in creating the generallife quality of hepatitis B patients. In the quality of life in hepatitis patients, the emotional function with factor loading of 0.76 has the most coefficient of effectiveness, activity dimension with factor loading of 0.67, fatigue withfactor loading of 0.47, abdominal syptoms with factor loading of 0.42 and worry with factor loading of 0.32 have the least coeficient of effectivness in making CLDQ domains of hepatit B patients. Conclusions: The general quality of life in patients had been below average and social

  12. Psychosocial Factors Associated with Diet Quality in a Working Adult Population

    PubMed Central

    Dunbar, Sandra B.; Higgins, Melinda; Dai, Jun; Ziegler, Thomas R.; Frediani, Jennifer K.; Reilly, Carolyn; Brigham, Kenneth L.

    2014-01-01

    The associations between specific intra- and inter-personal psychosocial factors and dietary patterns were explored in a healthy, working adult population. Participants (N= 640) were enrolled in a prospective predictive health study and characterized by a mean age of 48(SD = 11) years, 67% women, and 30% minority. Baseline psychosocial measures of perceived stress, depressive symptoms, social support, and family functioning were examined for their relationships with three diet quality indices - AHEI, DASH, and the Mediterranean. Dietary intake was of moderate quality in this high income, well-educated, psychosocially healthy population. Social support was positively associated with better diet quality for all three indices (p< .01). Further research should focus on socio-environmental factors associated with diet quality. PMID:23408456

  13. Resident attractiveness: an influential factor in the quality of care in nursing homes.

    PubMed

    Campbell, Sara L

    2005-08-01

    Studying the characteristics considered attractive in residents in long-term care can provide an innovative picture of how nursing staff may perceive and inadvertently respond to residents based on those characteristics. It may be difficult to believe that attractiveness can affect the quality of residents' care. However, being open to the discovery of all factors that may influence the quality of care is important to promote positive changes in resident outcomes in nursing homes.

  14. Reaching the theoretical resonance quality factor limit in coaxial plasmonic nanoresonators fabricated by helium ion lithography.

    PubMed

    Melli, M; Polyakov, A; Gargas, D; Huynh, C; Scipioni, L; Bao, W; Ogletree, D F; Schuck, P J; Cabrini, S; Weber-Bargioni, A

    2013-06-12

    Optical antenna structures have revolutionized the field of nano-optics by confining light to deep subwavelength dimensions for spectroscopy and sensing. In this work, we fabricated coaxial optical antennae with sub-10-nanometer critical dimensions using helium ion lithography (HIL). Wavelength dependent transmission measurements were used to determine the wavelength-dependent optical response. The quality factor of 11 achieved with our HIL fabricated structures matched the theoretically predicted quality factor for the idealized flawless gold resonators calculated by finite-difference time-domain (FDTD). For comparison, coaxial antennae with 30 nm critical dimensions were fabricated using both HIL and the more common Ga focus ion beam lithography (Ga-FIB). The quality factor of the Ga-FIB resonators was 60% of the ideal HIL results for the same design geometry due to limitations in the Ga-FIB fabrication process.

  15. Factors Affecting Parent's Perception on Air Quality-From the Individual to the Community Level.

    PubMed

    Guo, Yulin; Liu, Fengfeng; Lu, Yuanan; Mao, Zongfu; Lu, Hanson; Wu, Yanyan; Chu, Yuanyuan; Yu, Lichen; Liu, Yisi; Ren, Meng; Li, Na; Chen, Xi; Xiang, Hao

    2016-05-12

    The perception of air quality significantly affects the acceptance of the public of the government's environmental policies. The aim of this research is to explore the relationship between the perception of the air quality of parents and scientific monitoring data and to analyze the factors that affect parents' perceptions. Scientific data of air quality were obtained from Wuhan's environmental condition reports. One thousand parents were investigated for their knowledge and perception of air quality. Scientific data show that the air quality of Wuhan follows an improving trend in general, while most participants believed that the air quality of Wuhan has deteriorated, which indicates a significant difference between public perception and reality. On the individual level, respondents with an age of 40 or above (40 or above: OR = 3.252; 95% CI: 1.170-9.040), a higher educational level (college and above: OR = 7.598; 95% CI: 2.244-25.732) or children with poor healthy conditions (poor: OR = 6.864; 95% CI: 2.212-21.302) have much more negative perception of air quality. On the community level, industrial facilities, vehicles and city construction have major effects on parents' perception of air quality. Our investigation provides baseline information for environmental policy researchers and makers regarding the public's perception and expectation of air quality and the benefits to the environmental policy completing and enforcing.

  16. ASVCP quality assurance guidelines: control of general analytical factors in veterinary laboratories.

    PubMed

    Flatland, Bente; Freeman, Kathy P; Friedrichs, Kristen R; Vap, Linda M; Getzy, Karen M; Evans, Ellen W; Harr, Kendal E

    2010-09-01

    Owing to lack of governmental regulation of veterinary laboratory performance, veterinarians ideally should demonstrate a commitment to self-monitoring and regulation of laboratory performance from within the profession. In response to member concerns about quality management in veterinary laboratories, the American Society for Veterinary Clinical Pathology (ASVCP) formed a Quality Assurance and Laboratory Standards (QAS) committee in 1996. This committee recently published updated and peer-reviewed Quality Assurance Guidelines on the ASVCP website. The Quality Assurance Guidelines are intended for use by veterinary diagnostic laboratories and veterinary research laboratories that are not covered by the US Food and Drug Administration Good Laboratory Practice standards (Code of Federal Regulations Title 21, Chapter 58). The guidelines have been divided into 3 reports on 1) general analytic factors for veterinary laboratory performance and comparisons, 2) hematology and hemostasis, and 3) clinical chemistry, endocrine assessment, and urinalysis. This report documents recommendations for control of general analytical factors within veterinary clinical laboratories and is based on section 2.1 (Analytical Factors Important In Veterinary Clinical Pathology, General) of the newly revised ASVCP QAS Guidelines. These guidelines are not intended to be all-inclusive; rather, they provide minimum guidelines for quality assurance and quality control for veterinary laboratory testing. It is hoped that these guidelines will provide a basis for laboratories to assess their current practices, determine areas for improvement, and guide continuing professional development and education efforts.

  17. Quality of life in chronic haemodialysis and peritoneal dialysis patients in Turkey and related factors.

    PubMed

    Oren, Besey; Enç, Nuray

    2013-12-01

    Turkey is the fifth country in Europe with regard to the number of patients receiving haemodialysis (HD). However, only a limited number of studies have comparatively investigated the factors that affect quality of life in haemodialysis and peritoneal dialysis (PD) patients in Turkey. The purpose of the study was to investigate the factors that affect quality of life in haemodialysis and peritoneal dialysis patients, as well as providing a comparison of quality of life between these groups. In this cross-sectional study, Quality of Life Scale and a data form was completed by 300 dialysis patients who received treatment at five hospital-based dialysis units in Istanbul, Turkey. The data were evaluated using arithmetic mean values, standard deviations, minimums, maximums, percentages, independent groups t-tests, Spearman correlation analyses and one-way variance analyses. The quality of life values in peritoneal dialysis patients were found to be higher than those of haemodialysis patients (P < 0.05). It was concluded that the quality of life in chronic dialysis patients was affected by various factors.

  18. Sleep Quality and Factors Influencing Self-Reported Sleep Duration and Quality in the General Internal Medicine Inpatient Population

    PubMed Central

    Dobing, Selina; Frolova, Natalia; McAlister, Finlay

    2016-01-01

    Background Sleep quality in hospitalized Canadian General Internal Medicine patients is not well characterized. Our goals were to characterize hospital sleep quality in this population and identify potentially modifiable barriers to good sleep. Methods GIM inpatients at a quaternary centre in Edmonton, Canada completed a survey, including the Verran-Snyder Halpern (VSH) questionnaire, to characterize the previous night’s sleep within 48 hours prior to discharge. A chart review was also completed to assess comorbidities, discharge diagnoses, and pharmaceutical sleep aid use. Results Patients reported significantly worse nighttime sleep duration in hospital compared with home (mean 5.5 versus 7.0 hours per night, p < 0.0001). Sleep quality was poor, as measured by the VSH disturbance (mean 371), effectiveness (190), and supplementation (115) subscales. Variables independently associated with poorer sleep duration in multivariable regression include prior diagnosis of sleep disorder and multi-patient occupancy rooms. Age, sex, admitting diagnosis, length of stay, frequency of vital checks, and use of sleep pharmaceuticals during the index hospitalization were not associated with sleep duration. The most frequently reported reasons for poor sleep included noise (59%), nursing interruptions (30%), uncomfortable beds (18%), bright lights (16%), unfamiliar surroundings (14%), and pain (9%). Conclusions Sleep quality for GIM inpatients is significantly worse in hospital than at home. There is a need to test non-pharmacologic interventions to address the most frequently identified factors causing poor sleep hygiene for GIM inpatients. PMID:27280292

  19. [Influence of socioeconomic factors on the quality of life of elderly hypertensive individuals].

    PubMed

    Andrade, João Marcus Oliveira; Rios, Lorena Roseli; Teixeira, Larissa Silva; Vieira, Fernanda Silva; Mendes, Danilo Cangussu; Vieira, Maria Aparecida; Silveira, Marise Fagundes

    2014-08-01

    This study sought to evaluate the association between socioeconomic variables and the quality of life of elderly hypertensive patients treated under the Family Health Program in the city of Montes Claros, Minas Gerais, Brazil. An analytical cross study was conducted in a representative sample of 294 elderly hypertensive patients. Data were collected using a questionnaire on socioeconomic characteristics and quality of life (MINICHAL). The data were analyzed using the nonparametric Mann-Whitney and Kuskall-Wallis tests. The results showed that marital status, religion and education affect the quality of life of elderly hypertensive patients in a statistically significant way. Elderly hypertensive patients who were single/divorced/widowed, evangelical, spiritualist and belonging to other religious bodies, illiterate achieved lower scores in terms of quality of life. For the remaining variables, there was no statistical association. The conclusion, drawn is that socioeconomic factors such as marital status, education and religion influence the quality of life of elderly hypertensive patients.

  20. Estimation of near-surface quality factors by constrained inversion of Rayleigh-wave attenuation coefficients

    NASA Astrophysics Data System (ADS)

    Xia, Jianghai; Xu, Yixian; Miller, Richard D.; Ivanov, Julian

    2012-07-01

    Quality factors (Q) of near-surface materials are as important as velocities of the materials in many applications. Only phase information of surface-wave data is utilized when high-frequency (≥ 2 Hz) surface-wave data are routinely inverted to determine near-surface shear (S)-wave velocities. Amplitude information of high-frequency surface-wave data can be used to determine quality factors of near-surface materials. Given S-wave velocity, compressional (P)-wave velocity, and Rayleigh-wave phase velocities, it is feasible to solve for S-wave quality factor QS and P-wave quality factor QP (for some specific velocity models) down to 30 m below the ground surface in many settings by inverting high-frequency Rayleigh-wave attenuation coefficients in a layered earth model. Amplitude of seismic data is an exponential function of attenuation coefficients. When calculating attenuation coefficients from changes in amplitude, this nonlinear nature would result in that small variations in amplitude cause huge changes in attenuation coefficients. This result suggests data (attenuation coefficients) that normally possess large errors could eventually transfer to a model (quality factors); therefore, constraints (or a priori information) on models are necessary. Because an inversion system to solve this problem is unstable, a regularization parameter must be introduced into an inversion algorithm to stabilize the inversion. These characteristics of the inversion problem allow us to solve the problem as a constrained and regularized linear system. Usually, a set of models that meet the defined constraints can be obtained by solving the system. Based on the linear nature of the inversion system, a smooth model can be selected from the set of models as a solution of the inversion using the L-curve method. This approach is a trade-off solution between data misfit and model length. Several real-world examples demonstrate the importance of constraints in finding acceptable realistic

  1. Deconstructing Racial Differences: The Effects of Quality of Education and Cerebrovascular Risk Factors

    PubMed Central

    Carvalho, Janessa O.; Tommet, Doug; Crane, Paul K.; Thomas, Michael L.; Claxton, Amy; Habeck, Christian; Manly, Jennifer J.

    2015-01-01

    Objectives. To evaluate the effects of vascular conditions and education quality on cognition over time in White and African American (AA) older adults. Method. We investigated cross-sectional and longitudinal racial differences in executive functioning (EF) and memory composites among Whites (n = 461) and AAs (n = 118) enrolled in a cohort study. We examined whether cerebrovascular risk factors and Shipley Vocabulary scores (a proxy for education quality) accounted for racial differences. Results. On average, AAs had lower quality of education and more cerebrovascular risk factors including hypertension, diabetes, and obesity. AAs had lower mean EF and memory at baseline, but there were no group differences in rates of decline. Cross-sectional racial differences in EF and memory persisted after controlling for vascular disease, but disappeared when controlling for Shipley Vocabulary. Discussion. Quality of education appears to be more important than cerebrovascular risk factors in explaining cross-sectional differences in memory and EF performance between White and AA older adults. Further investigation is needed regarding the relative contribution of education quality and cerebrovascular risk factors to cognitive decline among ethnically/racially diverse older adults. PMID:25098527

  2. Psychosocial factors as predictors of quality of life in chronic portuguese patients

    PubMed Central

    2014-01-01

    Background Chronic illnesses are diseases of long duration and generally of slow progression. They cause significant quality of life impairment. The aim of this study was to analyse psychosocial predictors of quality of life and of subjective well-being in chronic Portuguese patients. Methods Chronic disease patients (n = 774) were recruited from central Portuguese Hospitals. Participants completed self-reported questionnaires assessing socio-demographic, clinical, psychosocial and outcome variables: quality of life (HRQL) and subjective well-being (SWB). MANCOVA analyses were used to test psychosocial factors as determinants of HRQL and SWB. Results After controlling for socio-demographic and clinical variables, results showed that dispositional optimism, positive affect, spirituality, social support and treatment adherence are significant predictors of HRQL and SWB. Similar predictors of quality of life, such as positive affect, treatment adherence and spirituality, were found for subgroups of disease classified by medical condition. Conclusions The work identifies psychosocial factors associated with quality of life. The predictors for the entire group of different chronic diseases are similar to the ones found in different chronic disease subgroups: positive affect, social support, treatment adherence and spirituality. Patients with more positive affect, additional social support, an adequate treatment adherence and a feel-good spirituality, felt better with the disease conditions and consequently had a better quality of life. This study contributes to understanding and improving the processes associated with quality of life, which is relevant for health care providers and chronic diseases support. PMID:24405802

  3. Neutronic reactor

    DOEpatents

    Wende, Charles W. J.

    1976-08-17

    A safety rod for a nuclear reactor has an inner end portion having a gamma absorption coefficient and neutron capture cross section approximately equal to those of the adjacent shield, a central portion containing materials of high neutron capture cross section and an outer end portion having a gamma absorption coefficient at least equal to that of the adjacent shield.

  4. NEUTRONIC REACTOR

    DOEpatents

    Fermi, E.; Zinn, W.H.; Anderson, H.L.

    1958-09-16

    Means are presenied for increasing the reproduction ratio of a gaphite- moderated neutronic reactor by diminishing the neutron loss due to absorption or capture by gaseous impurities within the reactor. This means comprised of a fluid-tight casing or envelope completely enclosing the reactor and provided with a valve through which the casing, and thereby the reactor, may be evacuated of atmospheric air.

  5. Enhancement in Quality Factor of SRF Niobium Cavities by Material Diffusion

    SciTech Connect

    Dhakal, Pashupati; Ciovati, Gianluigi; Kneisel, Peter K.; Myneni, Ganapati Rao

    2015-06-01

    An increase in the quality factor of superconducting radiofrequency cavities is achieved by minimizing the surface resistance during processing steps. The surface resistance is the sum of temperature independent residual resistance and temperature/material dependent Bardeen-Cooper-Schrieffer (BCS) resistance. High temperature heat treatment usually reduces the impurities concentration from the bulk niobium, lowering the residual resistance. The BCS part can be reduced by selectively doping non-magnetic impurities. The increase in quality factor, termed as Q-rise, was observed in cavities when titanium or nitrogen thermally diffused in the inner cavity surface.

  6. Bioaccumulation factor portions of the proposed water quality guidance for the Great Lakes system

    SciTech Connect

    Not Available

    1993-08-01

    Bioaccumulation factors are being proposed to be used in the derivation of human health and wildlife criteria specific for the Great Lakes Water Quality Initiative (GLWQI). Adopting the use of bioaccumulation factors instead of bioconcentration factors presents a significant change from current Agency guidance. Because there is not an established procedure for determining bioaccumulation factors, national guidance may be eventually modeled on the proposed GLWQI Guidance. The document was produced to facilitate review of and comment on the proposed procedure for determining bioaccumulation factors by persons who may not keep abreast of Federal Register notices, including the larger scientific community. The document is composed of two chapters and one appendix. Chapter 1 describes the development of the proposed procedure for determining bioaccumulation factors; Chapter 2 presents the proposed methodology for development of bioaccumulation factors.

  7. Neutron tubes

    DOEpatents

    Leung, Ka-Ngo; Lou, Tak Pui; Reijonen, Jani

    2008-03-11

    A neutron tube or generator is based on a RF driven plasma ion source having a quartz or other chamber surrounded by an external RF antenna. A deuterium or mixed deuterium/tritium (or even just a tritium) plasma is generated in the chamber and D or D/T (or T) ions are extracted from the plasma. A neutron generating target is positioned so that the ion beam is incident thereon and loads the target. Incident ions cause D-D or D-T (or T-T) reactions which generate neutrons. Various embodiments differ primarily in size of the chamber and position and shape of the neutron generating target. Some neutron generators are small enough for implantation in the body. The target may be at the end of a catheter-like drift tube. The target may have a tapered or conical surface to increase target surface area.

  8. Neutron source

    DOEpatents

    Cason, J.L. Jr.; Shaw, C.B.

    1975-10-21

    A neutron source which is particularly useful for neutron radiography consists of a vessel containing a moderating media of relatively low moderating ratio, a flux trap including a moderating media of relatively high moderating ratio at the center of the vessel, a shell of depleted uranium dioxide surrounding the moderating media of relatively high moderating ratio, a plurality of guide tubes each containing a movable source of neutrons surrounding the flux trap, a neutron shield surrounding one part of each guide tube, and at least one collimator extending from the flux trap to the exterior of the neutron source. The shell of depleted uranium dioxide has a window provided with depleted uranium dioxide shutters for each collimator. Reflectors are provided above and below the flux trap and on the guide tubes away from the flux trap.

  9. Characterization of neutron calibration fields at the TINT's 50 Ci americium-241/beryllium neutron irradiator

    NASA Astrophysics Data System (ADS)

    Liamsuwan, T.; Channuie, J.; Ratanatongchai, W.

    2015-05-01

    Reliable measurement of neutron radiation is important for monitoring and protection in workplace where neutrons are present. Although Thailand has been familiar with applications of neutron sources and neutron beams for many decades, there is no calibration facility dedicated to neutron measuring devices available in the country. Recently, Thailand Institute of Nuclear Technology (TINT) has set up a multi-purpose irradiation facility equipped with a 50 Ci americium-241/beryllium neutron irradiator. The facility is planned to be used for research, nuclear analytical techniques and, among other applications, calibration of neutron measuring devices. In this work, the neutron calibration fields were investigated in terms of neutron energy spectra and dose equivalent rates using Monte Carlo simulations, an in-house developed neutron spectrometer and commercial survey meters. The characterized neutron fields can generate neutron dose equivalent rates ranging from 156 μSv/h to 3.5 mSv/h with nearly 100% of dose contributed by neutrons of energies larger than 0.01 MeV. The gamma contamination was less than 4.2-7.5% depending on the irradiation configuration. It is possible to use the described neutron fields for calibration test and routine quality assurance of neutron dose rate meters and passive dosemeters commonly used in radiation protection dosimetry.

  10. Radii of neutron drops probed via the neutron skin thickness of nuclei

    DOE PAGES

    Zhao, P. W.; Gandolfi, S.

    2016-10-10

    Multineutron systems are crucial to understanding the physics of neutron-rich nuclei and neutron stars. Neutron drops, neutrons confined in an external field, are investigated systematically in both nonrelativistic and relativistic density functional theories and with ab initio calculations. Here, we demonstrate a new strong linear correlation, which is universal in the realm of mean-field models, between the rms radii of neutron drops and the neutron skin thickness of 208 Pb and 48 Ca , i.e., the difference between the neutron and proton rms radii of a nucleus. This correlation can be used to deduce the radii of neutron drops frommore » the measured neutron skin thickness in a model-independent way, and the radii obtained for neutron drops can provide a useful constraint for realistic three-neutron forces, due to its high quality. Furthermore, we present a new correlation between the slope L of the symmetry energy and the radii of neutron drops, and provide the first validation of such a correlation by using density-functional models and ab initio calculations. These newly established correlations, together with more precise measurements of the neutron skin thicknesses of 208 Pb and 48 Ca and/or accurate determinations of L , will have an enduring impact on the understanding of multineutron interactions, neutron-rich nuclei, neutron stars, etc.« less

  11. Radii of neutron drops probed via the neutron skin thickness of nuclei

    SciTech Connect

    Zhao, P. W.; Gandolfi, S.

    2016-10-10

    Multineutron systems are crucial to understanding the physics of neutron-rich nuclei and neutron stars. Neutron drops, neutrons confined in an external field, are investigated systematically in both nonrelativistic and relativistic density functional theories and with ab initio calculations. Here, we demonstrate a new strong linear correlation, which is universal in the realm of mean-field models, between the rms radii of neutron drops and the neutron skin thickness of 208 Pb and 48 Ca , i.e., the difference between the neutron and proton rms radii of a nucleus. This correlation can be used to deduce the radii of neutron drops from the measured neutron skin thickness in a model-independent way, and the radii obtained for neutron drops can provide a useful constraint for realistic three-neutron forces, due to its high quality. Furthermore, we present a new correlation between the slope L of the symmetry energy and the radii of neutron drops, and provide the first validation of such a correlation by using density-functional models and ab initio calculations. These newly established correlations, together with more precise measurements of the neutron skin thicknesses of 208 Pb and 48 Ca and/or accurate determinations of L , will have an enduring impact on the understanding of multineutron interactions, neutron-rich nuclei, neutron stars, etc.

  12. Factors affecting the quality of life of homebound elderly hemiparetic stroke patients with cognitive impairment

    PubMed Central

    Takemasa, Seiichi; Nakagoshi, Ryoma; Uesugi, Masayuki; Inoue, Yuri; Gotou, Makoto; Koeda, Hideki; Naruse, Susumu

    2016-01-01

    [Purpose] This study examined the quality of life of homebound elderly hemiparetic stroke patients with cognitive impairment and the factors affecting their quality of life. [Subjects and Methods] The subjects of the study were 17 home-based elderly hemiparetic stroke patients with cognitive impairment (8 males and 9 females, average age: 76.3 ± 10.5 years old). Their physical and psychological conditions, quality of life and other items were investigated. Nishimura’s Mental State Scale for the Elderly was used for the cognitive impairment assessment. The Functional Independence Measure was used to assess activities of daily living, and the Japanese Quality of Life Inventory for the Elderly with Dementia was used to assess quality of life. [Results] The subjects’ quality of life was affected by their cognitive impairment level and independence of activities of daily living. However, no correlations were observed between the quality of life of the homebound elderly hemiparetic stroke patients with cognitive impairment, age, gender or care-need level. [Conclusion] In order to improve the quality of life of homebound elderly hemiparetic stroke patients with cognitive impairment, assistance helping them to maintain their cognitive abilities and on-going rehabilitation for improving activities of daily living independence are required. PMID:28174455

  13. Risk factors for equine laminitis: a systematic review with quality appraisal of published evidence.

    PubMed

    Wylie, Claire E; Collins, Simon N; Verheyen, Kristien L P; Newton, J Richard

    2012-07-01

    Epidemiological studies into the risk factors for naturally-occurring equine laminitis are limited. There are a small number of such studies, although the results are inconsistent and remain disputed. The reasons for the conflicting results remain unclear. The aim of this review was to critically evaluate previous research in order to identify publications which provide the best evidence of risk factors for naturally-occurring equine laminitis. A systematic review of English language publications was conducted using MEDLINE (1950-2010), CAB Direct (1910-2010) and IVIS (1997-2010). Additional publications were included by searching bibliographies. Search terms included laminitis, equine, risk factors and epidemiology. Publications which compared a case population to a control population and made inferences about parameters as risk factors for naturally-occurring equine laminitis were included. Information was extracted using predefined data fields, including 18 study quality indicators. In total, 17 publications were fully appraised. Six were considered to provide the most reliable information about risk factors for naturally-occurring laminitis. Information on signalment was well researched and there was good evidence for an association with chronic laminitis and increasing age. There remain inconsistent results for many other horse-level risk factors including gender, breed and bodyweight. Previous publications estimating risk factors for equine laminitis were of reasonable quality, although they were limited in the number and scope of the risk factors studied. High-quality, evidence-based studies are needed to identify further risk factors and to establish consensus over previously identified risk factors for different equine populations.

  14. Factors controlling reservoir quality in tertiary sandstones and their significance to geopressured geothermal production

    SciTech Connect

    Loucks, R.G.; Richmann, D.L.; Milliken, K.L.

    1981-01-01

    Variable intensity of diagenesis is the factor primarily responsible for contrasting regional reservoir quality of Tertiary sandstones from the upper and lower Texas coast. Detailed comparison of Frio sandstone from the Chocolate Bayou/Danbury Dome area, Brazoria County, and Vicksburg sandstones from the McAllen Ranch Field area, Hidalgo County, reveals that extent of diagenetic modification is most strongly influenced by (1) detrital mineralogy and (2) regional geothermal gradients. The regional reservoir quality of Frio sandstones from Brazoria County is far better than that characterizing Vicksburg sandstones from Hidalgo County, especially at depths suitable for geopressured geothermal energy production. However, in predicting reservoir quality on a site-specific basis, locally variable factors such as relative proportions for porosity types, pore geometry as related to permeability, and local depositional environment must also be considered. Even in an area of regionally favorable reservoir quality, such local factors can significantly affect reservoir quality and, hence, the geothermal production potential of a specific sandstone unit.

  15. Use of fast neutrons for assessing sarcopenia by measuring body phosphorus: relevance to health and quality of life of the elderly

    NASA Astrophysics Data System (ADS)

    Kehayias, Joseph J.; Zhuang, Hong; Doherty, Patricia L.

    1997-02-01

    Sarcopenia, defined as the loss of skeletal muscle with age, may lead to frailty, fractures due to falls, and reduced immunity to disease. By understanding the causes of muscle loss with age we will be able to develop ways of maintaining functional capacity and quality of life for the elderly. Elemental Partition Analysis (EPA) is a new approach to body composition assessment. A major element of the body is measured and then, by means of other measurements, is partitioned to the contributing body compartments. We developed a model for measuring total body muscle by applying the EPA method to total body phosphorus (TBP). We measure TBP by in vivo fast neutron activation analysis using the reaction 31P(n,(alpha) )28Al. The main contributors to TBP are bone and skeletal muscle. Adipose tissue and the liver contribute less than 3 percent. We use dual-energy x-ray absorptiometry (DXA) to evaluate the contribution of bone to TBP. COrrections are applied for the small contributions of the liver and adipose tissue to TBP to derive muscle phosphorus. The technique requires high precision measurements for both TBP and DXA. The total body radiation exposure for measuring human subjects is 0.30 mSv.

  16. Chromosome aberrations in human fibroblasts induced by monoenergetic neutrons. I. Relative biological effectiveness.

    PubMed

    Pandita, T K; Geard, C R

    1996-06-01

    The relative biological effectiveness (RBE) of neutrons for many biological end points varies with neutron energy. To test the hypothesis that the RBE of neutrons varies with respect to their energy for chromosome aberrations in a cell system that does not face interphase death, we studied the yield of chromosome aberrations induced by monoenergetic neutrons in normal human fibroblasts at the first mitosis postirradiation. Monoenergetic neutrons at 0.22, 0.34, 0.43, 1, 5.9 and 13.6 MeV were generated at the Accelerator Facility of the Center for Radiological Research, Columbia University, and were used to irradiate plateau-phase fibroblasts at low absorbed doses from 0.3 to 1.2 Gy at a low dose rate. The reference low-LET, low-dose-rate radiation was 137Cs-gamma rays (0.66 MeV). A linear dose response (Y = alphaD) for chromosome aberrations was obtained for all monoenergetic neutrons and for the gamma rays. The yield of chromosome aberrations per unit dose was high at low neutron energies (0.22, 0.34 and 0.43 MeV) with a gradual decline with the increase in neutron energy. Maximum RBE (RBEm) values varied for the different types of chromosome aberrations. The highest RBE (24.3) for 0.22 and 0.43 MeV neutrons was observed for intrachromosomal deletions, a category of chromosomal change common in solid tumors. Even for the 13.6 MeV neutrons the RBEm (11.1) exceeded 10. These results show that the RBE of neutrons varies with neutron energy and that RBEs are dissimilar between different types of asymmetric chromosome aberrations and suggest that the radiation weighting factors applicable to low-energy neutrons need firmer delineation. This latter may best be attained with neutrons of well-defined energies. This would enable integrations of appropriate quality factors with measured radiation fields, such as those in high-altitude Earth atmosphere. The introduction of commercial flights at high altitude could result in many more individuals being exposed to neutrons than

  17. Factors Influencing Learners' Perceptions of the Quality of Computer Based Learning Materials.

    ERIC Educational Resources Information Center

    Sambrook, Sally

    2001-01-01

    Online and paper instruments were used by 159 learners to evaluate 5 computer-based learning materials requiring information technology skills. Top factors influencing perceptions of quality were as follows: user friendliness, presentation, graphics, engagement, information, knowledge, understanding, level, learning mode, and language. (SK)

  18. Evaluating Journal Quality: Is the H-Index a Better Measure than Impact Factors?

    ERIC Educational Resources Information Center

    Hodge, David R.; Lacasse, Jeffrey R.

    2011-01-01

    Objectives: This study evaluates the utility of a new measure--the h-index--that may provide a more valid approach to evaluating journal quality in the social work profession. Method: H-index values are compared with Thomson ISI 5-year impact factors and expert opinion. Results: As hypothesized, the h-index correlates highly with ISI 5-year impact…

  19. Exploring Factors Influencing Collaborative Knowledge Construction in Online Discussions: Student Facilitation and Quality of Initial Postings

    ERIC Educational Resources Information Center

    Ioannou, Andri; Demetriou, Skevi; Mama, Maria

    2014-01-01

    Although lots of studies have investigated collaborative knowledge construction in online courses, the factors influencing this process are yet to be fully determined. This study provides quantitative and qualitative types of evidence on how (naturally emerged) student facilitation and quality of initial postings influence collaborative knowledge…

  20. Quality of Drawing as a Factor in the Interpretation of Figure Drawings.

    ERIC Educational Resources Information Center

    Johnson, Frank A.; Greenberg, Roger P.

    1978-01-01

    The drawings of 32 poliomyelitis patients and their matched controls were examined to see whether figure drawings primarily reflect the subject's projection of psychological state, ability to draw, or some combination of these two factors. Quality of drawing may at times be the overwhelming determinant of clinical and research findings.…

  1. Microcrystalline diamond cylindrical resonators with quality-factor up to 0.5 million

    SciTech Connect

    Saito, Daisuke; Yang, Chen; Lin, Liwei; Heidari, Amir; Najar, Hadi; Horsley, David A.

    2016-02-01

    We demonstrate high quality-factor 1.5 mm diameter batch-fabricated microcrystalline diamond cylindrical resonators (CR) with quality-factors limited by thermoelastic damping (TED) and surface loss. Resonators were fabricated 2.6 and 5.3 μm thick in-situ boron-doped microcrystalline diamond films deposited using hot filament chemical vapor deposition. The quality-factor (Q) of as-fabricated CR's was found to increase with the resonator diameter and diamond thickness. Annealing the CRs at 700 °C in a nitrogen atmosphere led to a three-fold increase in Q, a result we attribute to thinning of the diamond layer via reaction with residual O{sub 2} in the annealing furnace. Post-anneal Q exceeding 0.5 million (528 000) was measured at the 19 kHz elliptical wineglass modes, producing a ring-down time of 8.9 s. A model for Q versus diamond thickness and resonance frequency is developed including the effects of TED and surface loss. Measured quality factors are shown to agree with the predictions of this model.

  2. The Effects of Psychosocial Factors on Quality of Life among Individuals with Chronic Pain

    ERIC Educational Resources Information Center

    Lee, Gloria K.; Chronister, Julie; Bishop, Malachy

    2008-01-01

    This study investigated the psychosocial factors affecting the quality of life (QOL) of 171 individuals with chronic pain. Participants completed a battery of self-rated inventories measuring three sets of predictor variables--demographic (age, gender, income, marital status), pain-specific (chronicity, severity, duration, frequency, pain…

  3. Factors Contributing to Employment and Enhancement in Quality of Life of Adult Education Students.

    ERIC Educational Resources Information Center

    Fraser, Jane

    A statistical analysis of an adult high school was conducted to determine factors for achievement and enhancement of quality of life of adult learners. Participants were 206 adult students studying English as a Second Language or enrolled in upgrading and business courses at a metropolitan Toronto (Ontario, Canada) secondary school. Variables…

  4. Factors Influencing Older Worker Quality of Life and Intent to Continue to Work

    ERIC Educational Resources Information Center

    Spokus, Diane

    2008-01-01

    High turnover has been a major problem in healthcare organizations. The purpose of this study was to examine the relationship among job characteristics, social support, and organizational characteristics on quality of the working life. Subsequently, the intent was to examine how those factors collectively influence turnover intention. A…

  5. Testing the Factor Structure of the Family Quality of Life Survey--2006

    ERIC Educational Resources Information Center

    Isaacs, B.; Wang, M.; Samuel, P.; Ajuwon, P.; Baum, N.; Edwards, M.; Rillotta, F.

    2012-01-01

    Background: Although the Family Quality of Life Survey--2006 (FQOLS-2006) is being used in research, there is little evidence to support its hypothesised domain structure. The purpose of this study was to test the domain structure of the survey using confirmatory factor analysis. Method: Samples from Australia, Canada, Nigeria and the USA were…

  6. Factors Influencing Quality of Life of Hungarian Postmenopausal Women Screened by Osteodensitometry

    ERIC Educational Resources Information Center

    Maroti-Nagy, Agnes; Paulik, Edit

    2011-01-01

    The aim of our study was to evaluate factors influencing health related quality of life in Hungarian postmenopausal women who underwent osteodensitometry. A questionnaire-based cross-sectional study was carried out; 359 women aged over 40 years were involved, attending the outpatient Bone Densitometry Centre of Szeged. Two kinds of tools were…

  7. Factors Influencing Health-Related Quality of Life of Overweight and Obese Children in South Korea

    ERIC Educational Resources Information Center

    Kim, Hee Soon; Park, Jiyoung; Ma, Yumi; Ham, Ok Kyung

    2013-01-01

    The purpose of this study was to identify factors influencing health-related quality of life (HRQoL) of overweight and obese children in Korea. This study employed a cross-sectional descriptive study design. A total of 132 overweight and obese children participated in the study. Anthropometric measurements included body mass index, percent body…

  8. Real-time measurement of laser beam quality factor by the Fresnel phase-retrieval method

    NASA Astrophysics Data System (ADS)

    Yang, Pao-Keng; Liu, Jian-You; Chen, Yung-Chieh; Hsu, Chia-En

    2016-09-01

    Conventionally, it is a tedious work to measure the beam quality factor for a laser beam because one needs to move a camera-based beam profiler from one location to another for many times to record intensity profiles at different positions around the beam waist. We present a simple method for determining the laser beam quality factor from only two laser intensity profiles at different cross sections around the waist. We first used an iterative phase-retrieval algorithm, based on the Huygens-Fresnel principle, to reconstruct the phase profiles at the two cross sections where the intensity profiles had been measured. Once the optical field amplitude (the square root of intensity) and phase distribution functions at certain cross section of a laser beam had been determined, we can propagate the light wave at this cross section by using the Fresnel diffraction formula to obtain the intensity profiles at different positions, from which the beam quality factor can be determined. Using a HeNe laser for test, we had experimentally demonstrated the feasibility of our idea by showing that the result from our proposed method is in good agreement with that obtained from the conventional method. Our setup is capable of executing a real-time measurement of the beam quality factor because the two intensity profiles can be simultaneously recorded by using a beam splitter and two beam-profilers controlled by the same computer.

  9. Students' College Preparation Level Based on Quality Factors of the High School Attended

    ERIC Educational Resources Information Center

    Richmond, Lori M.

    2011-01-01

    The present qualitative study examined the views and perspectives of five Executive Directors of Admissions of Midwestern colleges and universities to seek data on high school students' college preparation level based on the quality factors of the high school they attended. Interviews were conducted using multiple open-ended questions on various…

  10. Determinants of judgment and decision making quality: the interplay between information processing style and situational factors.

    PubMed

    Ayal, Shahar; Rusou, Zohar; Zakay, Dan; Hochman, Guy

    2015-01-01

    A framework is presented to better characterize the role of individual differences in information processing style and their interplay with contextual factors in determining decision making quality. In Experiment 1, we show that individual differences in information processing style are flexible and can be modified by situational factors. Specifically, a situational manipulation that induced an analytical mode of thought improved decision quality. In Experiment 2, we show that this improvement in decision quality is highly contingent on the compatibility between the dominant thinking mode and the nature of the task. That is, encouraging an intuitive mode of thought led to better performance on an intuitive task but hampered performance on an analytical task. The reverse pattern was obtained when an analytical mode of thought was encouraged. We discuss the implications of these results for the assessment of decision making competence, and suggest practical directions to help individuals better adjust their information processing style to the situation at hand and make optimal decisions.

  11. Electrostatic levitation facility optimized for neutron diffraction studies of high temperature liquids at a spallation neutron source

    SciTech Connect

    Mauro, N. A.; Vogt, A. J.; Derendorf, K. S.; Johnson, M. L.; Kelton, K. F.; Rustan, G. E.; Quirinale, D. G.; Goldman, A. I.; Kreyssig, A.; Lokshin, K. A.; Neuefeind, J. C.; An, Ke; Wang, Xun-Li; Egami, T.

    2016-01-15

    Neutron diffraction studies of metallic liquids provide valuable information about inherent topological and chemical ordering on multiple length scales as well as insight into dynamical processes at the level of a few atoms. However, there exist very few facilities in the world that allow such studies to be made of reactive metallic liquids in a containerless environment, and these are designed for use at reactor-based neutron sources. We present an electrostatic levitation facility, NESL (for Neutron ElectroStatic Levitator), which takes advantage of the enhanced capabilities and increased neutron flux available at spallation neutron sources (SNSs). NESL enables high quality elastic and inelastic neutron scattering experiments to be made of reactive metallic and other liquids in the equilibrium and supercooled temperature regime. The apparatus is comprised of a high vacuum chamber, external and internal neutron collimation optics, and a sample exchange mechanism that allows up to 30 samples to be processed between chamber openings. Two heating lasers allow excellent sample temperature homogeneity, even for samples approaching 500 mg, and an automated temperature control system allows isothermal measurements to be conducted for times approaching 2 h in the liquid state, with variations in the average sample temperature of less than 0.5%. To demonstrate the capabilities of the facility for elastic scattering studies of liquids, a high quality total structure factor for Zr{sub 64}Ni{sub 36} measured slightly above the liquidus temperature is presented from experiments conducted on the nanoscale-ordered materials diffractometer (NOMAD) beam line at the SNS after only 30 min of acquisition time for a small sample (∼100 mg)

  12. Electrostatic levitation facility optimized for neutron diffraction studies of high temperature liquids at a spallation neutron source.

    PubMed

    Mauro, N A; Vogt, A J; Derendorf, K S; Johnson, M L; Rustan, G E; Quirinale, D G; Kreyssig, A; Lokshin, K A; Neuefeind, J C; An, Ke; Wang, Xun-Li; Goldman, A I; Egami, T; Kelton, K F

    2016-01-01

    Neutron diffraction studies of metallic liquids provide valuable information about inherent topological and chemical ordering on multiple length scales as well as insight into dynamical processes at the level of a few atoms. However, there exist very few facilities in the world that allow such studies to be made of reactive metallic liquids in a containerless environment, and these are designed for use at reactor-based neutron sources. We present an electrostatic levitation facility, NESL (for Neutron ElectroStatic Levitator), which takes advantage of the enhanced capabilities and increased neutron flux available at spallation neutron sources (SNSs). NESL enables high quality elastic and inelastic neutron scattering experiments to be made of reactive metallic and other liquids in the equilibrium and supercooled temperature regime. The apparatus is comprised of a high vacuum chamber, external and internal neutron collimation optics, and a sample exchange mechanism that allows up to 30 samples to be processed between chamber openings. Two heating lasers allow excellent sample temperature homogeneity, even for samples approaching 500 mg, and an automated temperature control system allows isothermal measurements to be conducted for times approaching 2 h in the liquid state, with variations in the average sample temperature of less than 0.5%. To demonstrate the capabilities of the facility for elastic scattering studies of liquids, a high quality total structure factor for Zr64Ni36 measured slightly above the liquidus temperature is presented from experiments conducted on the nanoscale-ordered materials diffractometer (NOMAD) beam line at the SNS after only 30 min of acquisition time for a small sample (∼100 mg).

  13. Electrostatic levitation facility optimized for neutron diffraction studies of high temperature liquids at a spallation neutron source

    DOE PAGES

    Mauro, N. A.; Vogt, A. J.; Derendorf, K. S.; ...

    2016-01-01

    Neutron diffraction studies of metallic liquids provide valuable information about inherent topological and chemical ordering on multiple length scales as well as insight into dynamical processes at the level of a few atoms. But, there exist very few facilities in the world that allow such studies to be made of reactive metallic liquids in a containerless environment, and these are designed for use at reactor-based neutron sources. We present an electrostatic levitation facility, NESL (for Neutron ElectroStatic Levitator), which takes advantage of the enhanced capabilities and increased neutron flux available at spallation neutron sources (SNSs). NESL enables high quality elasticmore » and inelastic neutron scattering experiments to be made of reactive metallic and other liquids in the equilibrium and supercooled temperature regime. The apparatus is comprised of a high vacuum chamber, external and internal neutron collimation optics, and a sample exchange mechanism that allows up to 30 samples to be processed between chamber openings. Two heating lasers allow excellent sample temperature homogeneity, even for samples approaching 500 mg, and an automated temperature control system allows isothermal measurements to be conducted for times approaching 2 h in the liquid state, with variations in the average sample temperature of less than 0.5%. Furthermore, to demonstrate the capabilities of the facility for elastic scattering studies of liquids, a high quality total structure factor for Zr64Ni36 measured slightly above the liquidus temperature is presented from experiments conducted on the nanoscale-ordered materials diffractometer (NOMAD) beam line at the SNS after only 30 min of acquisition time for a small sample ( 100 mg).« less

  14. Electrostatic levitation facility optimized for neutron diffraction studies of high temperature liquids at a spallation neutron source

    SciTech Connect

    Mauro, N. A.; Vogt, A. J.; Derendorf, K. S.; Johnson, M. L.; Rustan, G. E.; Quirinale, D. G.; Kreyssig, A.; Lokshin, K. A.; Neuefeind, J. C.; An, Ke; Wang, Xun-Li; Goldman, A. I.; Egami, T.; Kelton, K. F.

    2016-01-01

    Neutron diffraction studies of metallic liquids provide valuable information about inherent topological and chemical ordering on multiple length scales as well as insight into dynamical processes at the level of a few atoms. But, there exist very few facilities in the world that allow such studies to be made of reactive metallic liquids in a containerless environment, and these are designed for use at reactor-based neutron sources. We present an electrostatic levitation facility, NESL (for Neutron ElectroStatic Levitator), which takes advantage of the enhanced capabilities and increased neutron flux available at spallation neutron sources (SNSs). NESL enables high quality elastic and inelastic neutron scattering experiments to be made of reactive metallic and other liquids in the equilibrium and supercooled temperature regime. The apparatus is comprised of a high vacuum chamber, external and internal neutron collimation optics, and a sample exchange mechanism that allows up to 30 samples to be processed between chamber openings. Two heating lasers allow excellent sample temperature homogeneity, even for samples approaching 500 mg, and an automated temperature control system allows isothermal measurements to be conducted for times approaching 2 h in the liquid state, with variations in the average sample temperature of less than 0.5%. Furthermore, to demonstrate the capabilities of the facility for elastic scattering studies of liquids, a high quality total structure factor for Zr64Ni36 measured slightly above the liquidus temperature is presented from experiments conducted on the nanoscale-ordered materials diffractometer (NOMAD) beam line at the SNS after only 30 min of acquisition time for a small sample ( 100 mg).

  15. Identification af explosive power factors as predictors of player quality in young female volleyball players.

    PubMed

    Grgantov, Zoran; Milić, Mirjana; Katić, Ratko

    2013-05-01

    With the purpose of determining the factor structure of explosive power, as well as the influence of each factor on situational efficiency, 56 young female volleyball players were tested using 14 tests for assessing nonspecific and specific explosive power. By factor analysis, 4 significant factors were isolated which explained the total of over 80% of the common variability in young female volleyball players. The first factor was defined as volleyball-specific jumping, the second factor as nonspecific jumping and sprinting, the third factor as throwing explosive power, while the fourth factor was interpreted as volleyball-specific throwing and spiking speed from the ground. Results obtained by regression analysis in the latent space of explosive power indicate that the identified factors are good predictors of player quality in young female volleyball players. The fourth factor defined as throwing and spiking speed from the ground had the largest influence on player quality, followed by volleyball-specific jumping and nonspecific jumping and sprinting, and to a much lesser extent, by throwing explosive power The results obtained in this age group bring to the fore the ability of spiking and serving a ball of high speed, which hinders the opponents from playing those balls in serve reception and field defence. This ability, combined with a high standing vertical jump reach and spike approach vertical jump reach (which is the basis of the 1st varimax factor) enables successful performance of all volleyball elements by which points are won in complex 1 (spike) and complex 2 (serve and block). Even though the 2nd factor (nonspecific jumping and sprinting) has a slightly smaller impact on situational efficiency in young players, this ability provides preconditions i.e. preparation for successful realisation of all volleyball elements, so greater attention must be paid to perfecting it in young female volleyball players.

  16. Dehydration process of fish analyzed by neutron beam imaging

    NASA Astrophysics Data System (ADS)

    Tanoi, K.; Hamada, Y.; Seyama, S.; Saito, T.; Iikura, H.; Nakanishi, T. M.

    2009-06-01

    Since regulation of water content of the dried fish is an important factor for the quality of the fish, water-losing process during drying (squid and Japanese horse mackerel) was analyzed through neutron beam imaging. The neutron image showed that around the shoulder of mackerel, there was a part where water content was liable to maintain high during drying. To analyze water-losing process more in detail, spatial image was produced. From the images, it was clearly indicated that the decrease of water content was regulated around the shoulder part. It was suggested that to prevent deterioration around the shoulder part of the dried fish is an important factor to keep quality of the dried fish in the storage.

  17. High quality factor trapezoidal subwavelength grating waveguide micro-ring resonator

    NASA Astrophysics Data System (ADS)

    Wang, Zheng; Xu, Xiaochuan; Fan, D. L.; Wang, Yaguo; Chen, Ray T.

    2016-03-01

    In recent decades, silicon photonics has attracted intensive research interest in optical communications due to its advantageous compact dimensions and high-volume manufacturability. Particularly, micro-ring resonators on silicon-oninsulator (SOI) platform have been widely exploited as a basic building block for a vast range of applications such as switches, modulators, and sensors. A majority of these applications involve light-matter interaction, which can be substantially enhanced by the high quality factor micro-ring resonators. However, conventional strip waveguide based micro-ring resonators suffer from the intrinsic dilemma in achieving high light confinement and strong light-matter interaction simultaneously. Subwavelength grating (SWG) waveguides, comprised of periodically interleaved high and low refractive index materials with a pitch less than one wavelength, have been demonstrated as a promising alternative. For SWG waveguides built on SOI wafers, the ratio of silicon and cladding materials can be engineered microscopically to achieve desired macroscopic properties. The control of these properties could potentially lead to significant performance improvements compared with conventional micro-ring resonators based photonic devices, such as filters and sensors. However, SWG waveguide based micro-ring resonators (SWGMRs) that have been demonstrated so far can only provide a moderate quality factor (~5600) with a large radius (e.g. 15 μm), which greatly jeopardize the wide spread research efforts in this area. In this paper, we propose to use trapezoidal silicon pillars to reduce the bend loss of SWGMRs to improve the quality factor. For the first time, we experimentally demonstrate the smallest SWGMR (the micro-ring radius equals to 5 μm) with an applicable quality factor as high as 11,500. This approach also can be applied to SWGMRs with larger radii for higher quality factors. We also experimentally demonstrated a 10 μm radius SWGMR that can provide

  18. NEUTRON SOURCE

    DOEpatents

    Bernander, N.K. et al.

    1960-10-18

    An apparatus is described for producing neutrons through target bombardment with deuterons. Deuterium gas is ionized by electron bombardment and the deuteron ions are accelerated through a magnetic field to collimate them into a continuous high intensity beam. The ion beam is directed against a deuteron pervious metal target of substantially the same nnaterial throughout to embed the deuterous therein and react them to produce neutrons. A large quantity of neutrons is produced in this manner due to the increased energy and quantity of ions bombarding the target.

  19. Thermal neutron detection system

    DOEpatents

    Peurrung, Anthony J.; Stromswold, David C.

    2000-01-01

    According to the present invention, a system for measuring a thermal neutron emission from a neutron source, has a reflector/moderator proximate the neutron source that reflects and moderates neutrons from the neutron source. The reflector/moderator further directs thermal neutrons toward an unmoderated thermal neutron detector.

  20. NEUTRONIC REACTOR STRUCTURE

    DOEpatents

    Weinberg, A.M.; Vernon, H.C.

    1961-05-30

    A neutronic reactor is described. It has a core consisting of natural uranium and heavy water and having a K-factor greater than unity which is surrounded by a reflector consisting of natural uranium and ordinary water having a Kfactor less than unity.

  1. Neutronic Reactor Structure

    DOEpatents

    Vernon, H. C.; Weinberg, A. M.

    1961-05-30

    The neutronic reactor is comprised of a core consisting of natural uranium and heavy water with a K-factor greater than unity. The core is surrounded by a reflector consisting of natural uranium and ordinary water with a Kfactor less than unity. (AEC)

  2. Use of watershed factors to predict consumer surfactant risk, water quality, and habitat quality in the upper Trinity River, Texas.

    PubMed

    Atkinson, S F; Johnson, D R; Venables, B J; Slye, J L; Kennedy, J R; Dyer, S D; Price, B B; Ciarlo, M; Stanton, K; Sanderson, H; Nielsen, A

    2009-06-15

    Surfactants are high production volume chemicals that are used in a wide assortment of "down-the-drain" consumer products. Wastewater treatment plants (WWTPs) generally remove 85 to more than 99% of all surfactants from influents, but residual concentrations are discharged into receiving waters via wastewater treatment plant effluents. The Trinity River that flows through the Dallas-Fort Worth metropolitan area, Texas, is an ideal study site for surfactants due to the high ratio of wastewater treatment plant effluent to river flow (>95%) during late summer months, providing an interesting scenario for surfactant loading into the environment. The objective of this project was to determine whether surfactant concentrations, expressed as toxic units, in-stream water quality, and aquatic habitat in the upper Trinity River could be predicted based on easily accessible watershed characteristics. Surface water and pore water samples were collected in late summer 2005 at 11 sites on the Trinity River in and around the Dallas-Fort Worth metropolitan area. Effluents of 4 major waste water treatment plants that discharge effluents into the Trinity River were also sampled. General chemistries and individual surfactant concentrations were determined, and total surfactant toxic units were calculated. GIS models of geospatial, anthropogenic factors (e.g., population density) and natural factors (e.g., soil organic matter) were collected and analyzed according to subwatersheds. Multiple regression analyses using the stepwise maximum R(2) improvement method were performed to develop prediction models of surfactant risk, water quality, and aquatic habitat (dependent variables) using the geospatial parameters (independent variables) that characterized the upper Trinity River watershed. We show that GIS modeling has the potential to be a reliable and inexpensive method of predicting water and habitat quality in the upper Trinity River watershed and perhaps other highly urbanized

  3. High quality factor silica microspheres functionalized with self-assembled nanomaterials.

    PubMed

    Kandas, Ishac; Zhang, Baigang; Daengngam, Chalongrat; Ashry, Islam; Jao, Chih-Yu; Peng, Bo; Ozdemir, Sahin K; Robinson, Hans D; Heflin, James R; Yang, Lan; Xu, Yong

    2013-09-09

    With extremely low material absorption and exceptional surface smoothness, silica-based optical resonators can achieve extremely high cavity quality (Q) factors. However, the intrinsic material limitations of silica (e.g., lack of second order nonlinearity) may limit the potential applications of silica-based high Q resonators. Here we report some results in utilizing layer-by-layer self-assembly to functionalize silica microspheres with nonlinear and plasmonic nanomaterials while maintaining Q factors as high as 10(7). We compare experimentally measured Q factors with theoretical estimates, and find good agreement.

  4. Hydrological factors behind the water quality changes due to restoration in boreal peatlands

    NASA Astrophysics Data System (ADS)

    Ronkanen, Anna-Kaisa; Marttila, Hannu; Walle Menberu, Meseret; Irannezhad, Masoud; Tahvanainen, Teemu; Penttinen, Jouni; Hokkanen, Reijo; Klöve, Björn

    2016-04-01

    Recovery of hydrological conditions after restoration in previously drained peatlands is typically faster process compared to changes in runoff water quality. Often nutrient load from restored sites increase remarkably during restoration operation and reduce over time when conditions stabilize. However, in some sites nutrient load can remain high for long periods of time which increase negative effects of restoration on downstream water bodies. The factors and challenges behind these processes are poorly understood in practical catchment restoration planning. This study aims to understand factors affecting water quality changes after peatland restoration. Totally 43 peatlands areas of which 24 sites were previously drained and restored during the study and 19 sites at their pristine stage (control sites) were included to the study. The control pristine sites had as little anthropogenic disturbances as possible and the sites were chosen so that the paired study sites closely share similar peatland type, nutrient status and weather conditions. Pore water quality (total phosphorus, total nitrogen, dissolved organic carbon, pH, electric conductivity and colour) was measured from all sites and runoff quality and amount from 7 sites in the years 2008-2014. Measured parameters, different peatland types and nutrient loads were studied together with numerous hydrological parameters (variation in water table fluctuations, peat pore water recharge coefficient, physical parameters of peat e.g. specific yield, degree of humification) by statistical methods. Differences in water table dependent hydrological conditions indicate e.g. flow paths and residence time of water that is known to have effect on runoff water quality. As a result, water table related hydrological changes following restoration are as well assumed to explain alterations in water quality in different peatland types. In addition, using water table related hydrological processes as a proxy for water quality

  5. Hearing the patient's voice? Factors affecting the use of patient survey data in quality improvement

    PubMed Central

    Davies, E; Cleary, P

    2005-01-01

    Objective: To develop a framework for understanding factors affecting the use of patient survey data in quality improvement. Design: Qualitative interviews with senior health professionals and managers and a review of the literature. Setting: A quality improvement collaborative in Minnesota, USA involving teams from eight medical groups, focusing on how to use patient survey data to improve patient centred care. Participants: Eight team leaders (medical, clinical improvement or service quality directors) and six team members (clinical improvement coordinators and managers). Results: Respondents reported three types of barriers before the collaborative: organisational, professional and data related. Organisational barriers included lack of supporting values for patient centred care, competing priorities, and lack of an effective quality improvement infrastructure. Professional barriers included clinicians and staff not being used to focusing on patient interaction as a quality issue, individuals not necessarily having been selected, trained or supported to provide patient centred care, and scepticism, defensiveness or resistance to change following feedback. Data related barriers included lack of expertise with survey data, lack of timely and specific results, uncertainty over the effective interventions or time frames for improvement, and consequent risk of perceived low cost effectiveness of data collection. Factors that appeared to have promoted data use included board led strategies to change culture and create quality improvement forums, leadership from senior physicians and managers, and the persistence of quality improvement staff over several years in demonstrating change in other areas. Conclusion: Using patient survey data may require a more concerted effort than for other clinical data. Organisations may need to develop cultures that support patient centred care, quality improvement capacity, and to align professional receptiveness and leadership with

  6. Importance of a quality assurance scheme for factor VIII assays in quality monitoring of human plasma destined for fractionation into factor VIII concentrate.

    PubMed

    Gabra, G S; Prowse, C V; Boulton, F E

    1989-01-01

    A national quality assurance scheme has been established to monitor the validity of factor VIII assays performed by the various laboratories of the Scottish National Blood Transfusion Service engaged in collection and processing of donor plasma destined for fractionation. The results over the first 3-year period show that comparable assay values can be obtained by participating centres using a common standard, despite differences in equipment, methods or substrate chosen for the one-stage assay. The results also showed that chromogenic factor VIII assays correlated well with the one-stage method. Random factor VIII assays performed on plasma, harvested and frozen within 18 h from collection, were analysed to validate recently proposed Scottish specifications which stipulate that 70% of plasma donations destined for fractionation should contain at least 0.7 IU/ml. Plasma harvested and frozen between 8 and 18 h from collection did not meet the specified level in any of the regional centres. This nationally specified level was also not met by plasma harvested and frozen within 8 h from collection in spite of being achieved individually by three regional centres. Assays performed on large plasma pools at the Fractionation Centre suggested loss of some factor VIII during storage, transportation and thawing of plasma prior to bulk processing.

  7. Piloting Vertical Flight Aircraft: A Conference on Flying Qualities and Human Factors

    NASA Technical Reports Server (NTRS)

    Blanken, Christopher L. (Editor); Whalley, Matthew S. (Editor)

    1993-01-01

    This document contains papers from a specialists' meeting entitled 'Piloting Vertical Flight Aircraft: A Conference on Flying Qualities and Human Factors.' Vertical flight aircraft, including helicopters and a variety of Vertical Takeoff and Landing (VTOL) concepts, place unique requirements on human perception, control, and performance for the conduct of their design missions. The intent of this conference was to examine, for these vehicles, advances in: (1) design of flight control systems for ADS-33C standards; (2) assessment of human factors influences of cockpit displays and operational procedures; (3) development of VTOL design and operational criteria; and (4) development of theoretical methods or models for predicting pilot/vehicle performance and mission suitability. A secondary goal of the conference was to provide an initial venue for enhanced interaction between human factors and handling qualities specialists.

  8. Effect of boron and gadolinium concentration on the calculated neutron multiplication factor of U(3)O/sub 2/ fuel pins in optimum geometries

    SciTech Connect

    Thomas, J.T.

    1984-10-01

    The KENO-Va improved Monte Carlo criticality program is used to calculate the neutron multiplication factor for TMI-U2 fuel compositions in a variety of configurations and to display parametric regions giving rise to maximum reactivity contributions. The lattice pitch of UO/sub 2/ fuel pins producing a maximum k/sub eff/ is determined as a function of boron concentrations in the coolant for infinite and finite systems. The characteristics of U/sub 3/O/sub 8/-coolant mixtures of interest to modeling the rubble region of the core are presented. Several disrupted core configurations are calculated and comparisons made. The results should be useful to proposed defueling of the TMI-U2 reactor.

  9. Fast neutron dosimetry

    SciTech Connect

    DeLuca, P.M. Jr.; Pearson, D.W.

    1992-01-01

    This progress report concentrates on two major areas of dosimetry research: measurement of fast neutron kerma factors for several elements for monochromatic and white spectrum neutron fields and determination of the response of thermoluminescent phosphors to various ultra-soft X-ray energies and beta-rays. Dr. Zhixin Zhou from the Shanghai Institute of Radiation Medicine, People's Republic of China brought with him special expertise in the fabrication and use of ultra-thin TLD materials. Such materials are not available in the USA. The rather unique properties of these materials were investigated during this grant period.

  10. NEUTRONIC REACTOR

    DOEpatents

    Wade, E.J.

    1958-09-16

    This patent relates to a reflector means for a neutronic reactor. A reflector comprised of a plurality of vertically movable beryllium control members is provided surrounding the sides of the reactor core. An absorber of fast neutrons comprised of natural uramum surrounds the reflector. An absorber of slow neutrons surrounds the absorber of fast neutrons and is formed of a plurality of beryllium blocks having natural uranium members distributcd therethrough. in addition, a movable body is positioned directly below the core and is comprised of a beryllium reflector and an absorbing member attached to the botiom thereof, the absorbing member containing a substance selected from the goup consisting of natural urantum and Th/sup 232/.

  11. Neutron reflectivity

    NASA Astrophysics Data System (ADS)

    Cousin, Fabrice; Menelle, Alain

    2015-10-01

    The specular neutron reflectivity is a technique enabling the measurement of neutron scattering length density profile perpendicular to the plane of a surface or an interface, and thereby the profile of chemical composition. The characteristic sizes that are probed range from around 5 Å up 5000 Å. It is a scattering technique that averages information on the entire surface and it is therefore not possible to obtain information within the plane of the interface. The specific properties of neutrons (possibility of tuning the contrast by isotopic substitution, sensitivity to magnetism, negligible absorption, low energy of the incident neutrons) makes it particularly interesting in the fields of soft matter, biophysics and magnetic thin films. This course is a basic introduction to the technique and does not address the magnetic reflectivity. It is composed of three parts describing respectively its principle and its formalism, the experimental aspects of the method (spectrometers, samples) and two examples related to the materials for energy.

  12. NEUTRONIC REACTORS

    DOEpatents

    Wigner, E.P.

    1960-11-22

    A nuclear reactor is described wherein horizontal rods of thermal- neutron-fissionable material are disposed in a body of heavy water and extend through and are supported by spaced parallel walls of graphite.

  13. Risk factors for bacteriological quality of bulk tank milk in Prince Edward Island dairy herds. Part 1: overall risk factors.

    PubMed

    Elmoslemany, A M; Keefe, G P; Dohoo, I R; Jayarao, B M

    2009-06-01

    The objective of this study was to determine on-farm risk factors for bacteriological quality of bulk tank milk. Bulk tank raw milk quality was evaluated on all Prince Edward Island dairy herds (n = 235) over a 2-yr period (March 2005 to March 2007). Biweekly total bacterial, preliminary incubation, laboratory pasteurization, and coliform counts were conducted using a Petrifilm culture system. For the assessment of risk factors, a case-control study was conducted from January 2006 to May 2007. Case and control herds were defined based on the last 6 analyses of bulk tank bacterial counts before on-farm evaluation. Cases were herds that had multiple elevated counts for any of the parameters measured. A total of 69 herds (39 cases and 30 control herds) were evaluated. Data collection included 1) observation and questionnaire on basic hygiene and farm management practices; 2) complete wash analysis of the milking equipment, monitoring the presence of bacterial films on equipment and evaluation of cooling system function; and 3) environmental and cow hygiene scoring. Data were analyzed using multivariable logistic regression. The results of the final model indicated that high alkalinity in the wash water and poor teat-end cleanliness were associated with high bacterial counts in bulk tank milk (odds ratios = 12 and 5.3, respectively). It was also observed that high water temperature of detergent wash and the use of a water softener were associated with low bacterial counts in bulk tank milk (odds ratios = 0.87 and 0.11, respectively). A significant association between udder hair clipping and teat-end cleanliness was also observed. In conclusion, this study highlights the importance of udder hygiene and milking system washing factors on hygienic quality of bulk tank milk.

  14. Factors determining yield and quality of illicit indoor cannabis (Cannabis spp.) production.

    PubMed

    Vanhove, Wouter; Van Damme, Patrick; Meert, Natalie

    2011-10-10

    Judiciary currently faces difficulties in adequately estimating the yield of illicit indoor cannabis plantations. The latter data is required in penalization which is based on the profits gained. A full factorial experiment in which two overhead light intensities, two plant densities and four varieties were combined in the indoor cultivation of cannabis (Cannabis spp.) was used to reveal cannabis drug yield and quality under each of the factor combinations. Highest yield was found for the Super Skunk and Big Bud varieties which also exhibited the highest concentrations of Δ(9)-tetrahydrocannabinol (THC). Results show that plant density and light intensity are additive factors whereas the variety factor significantly interacts with both plant density and light intensity factors. Adequate estimations of yield of illicit, indoor cannabis plantations can only be made if upon seizure all factors considered in this study are accounted for.

  15. NEUTRON SOURCES

    DOEpatents

    Richmond, J.L.; Wells, C.E.

    1963-01-15

    A neutron source is obtained without employing any separate beryllia receptacle, as was formerly required. The new method is safer and faster, and affords a source with both improved yield and symmetry of neutron emission. A Be container is used to hold and react with Pu. This container has a thin isolating layer that does not obstruct the desired Pu--Be reaction and obviates procedures previously employed to disassemble and remove a beryllia receptacle. (AEC)

  16. NEUTRONIC REACTOR

    DOEpatents

    Fraas, A.P.; Mills, C.B.

    1961-11-21

    A neutronic reactor in which neutron moderation is achieved primarily in its reflector is described. The reactor structure consists of a cylindrical central "island" of moderator and a spherical moderating reflector spaced therefrom, thereby providing an annular space. An essentially unmoderated liquid fuel is continuously passed through the annular space and undergoes fission while contained therein. The reactor, because of its small size, is particularly adapted for propulsion uses, including the propulsion of aircraft. (AEC)

  17. Understanding critical factors for the quality and shelf-life of MAP fresh meat: a review.

    PubMed

    Singh, Preeti; Wani, Ali Abas; Saengerlaub, Sven; Langowski, Horst-Christian

    2011-02-01

    Due to increased demands for greater stringency in relation to hygiene and safety issues associated with fresh food products, coupled with ever-increasing demands by retailers for cost-effective extensions to product shelf-lives and the requirement to meet consumer expectations in relation to convenience and quality, the food packaging industry has rapidly developed to meet and satisfy expectations. One of the areas of research that has shown promise, and had success, is modified atmosphere packaging (MAP). The success of MAP-fresh meat depends on many factors including good initial product quality, good hygiene from the source plants, correct packaging material selection, the appropriate gas mix for the product, reliable packaging equipment, and maintenance of controlled temperatures and humidity levels. Advances in plastic materials and equipment have propelled advances in MAP, but other technological and logistical considerations are needed for successful MAP systems for raw chilled meat. Although several parameters critical for the quality of MA packed meat have been studied and each found to be crucial, understanding of the interactions between the parameters is needed. This review was undertaken to present the most comprehensive and current overview of the widely available, scattered information about the various integrated critical factors responsible for the quality and shelf life of MA packed meat with an interest to stimulate further research to optimize different quality parameters.

  18. Hamilton study: distribution of factors confounding the relationship between air quality and respiratory health

    SciTech Connect

    Pengelly, L.D.; Kerigan, A.T.; Goldsmith, C.H.; Inman, E.M.

    1984-10-01

    Hamilton, Ontario is an industrial city with a population of 300,000 which is situated at the western end of Lake Ontario. Canada's two largest iron and steel mills are located here; the city historically has had relatively poor air quality, which has improved markedly in the last 25 years. Concern about the health effects of current air quality recently led us to carry out an epidemiological study of the effects of air pollution on the respiratory health of over 3500 school children. Respiratory health was measured by pulmonary function testing of each child, and by an assessment of each child's respiratory symptoms via a questionnaire administered to the parents. Previous studies had shown that other environmental factors (e.g. parental smoking, parental cough, socioeconomic level, housing, and gas cooking) might also affect respiratory health, and thus confound any potential relationships between health and air pollution. The questionnaire also collected information on many of these confounding factors. For the purposes of initial analysis, the city was divided into five areas in which differences in air quality were expected. In general, factors which have been associated with poor respiratory health were observed to be more prevalent in areas of poorer air quality.

  19. Social factors related to quality of life among HIV infected children in ubon Ratchathani Province, Thailand.

    PubMed

    Kuntawee, Chalermkwan; Fungladda, Wijitr; Kaewkungwal, Jaranit; Chanthavanich, Pornthep; Chotpittayasunon, Tawee

    2010-09-01

    A cross-sectional study was conducted to determine the social factors and quality of life of HIV infected children attending the Pediatric Infectious Disease Clinic, Sappasithiprasong Hospital, Ubon Ratchathani Province, Thailand. Data were collected during October-November 2008, by interviewing caretakers and their children using a structured questionnaire. The children's families were in need of improved social support (84.5%), since community resources provided limited support, such as clothes, food, financial support, consultation, and information. The HIV infected children's quality of life needed improvement (78.7%). The factors associated with quality of life included having others as main caretakers (OR 4.64, 95% CI 1.45-14.78), parental death (OR 4.19, 95% CI 1.55-11.31), age of caregivers above 45 years old (OR 9.52, 95% CI 2.62-34.53), and family income less than THB 5,000 per month (OR 5.25, 95% CI 1.14-23.39). However, on multivariate analysis, only age of caregiver was a significant predictor for quality of life of the child. Children who were cared for by caregivers aged 45 years or above had a better quality of life than those whose caregivers were 20-45 years old (OR 6.32, 95% CI 1.12-35.62). Therefore, to improve quality of life among HIV infected children, age of caregiver is an important factor to be considered. Government and non-government organizations should focus on supporting caregivers in terms of food, financial, and emotional support based on resources available in the community.

  20. NEUTRONIC REACTOR

    DOEpatents

    Wigner, E.P.

    1958-04-22

    A nuclear reactor for isotope production is described. This reactor is designed to provide a maximum thermal neutron flux in a region adjacent to the periphery of the reactor rather than in the center of the reactor. The core of the reactor is generally centrally located with respect tn a surrounding first reflector, constructed of beryllium. The beryllium reflector is surrounded by a second reflector, constructed of graphite, which, in tune, is surrounded by a conventional thermal shield. Water is circulated through the core and the reflector and functions both as a moderator and a coolant. In order to produce a greatsr maximum thermal neutron flux adjacent to the periphery of the reactor rather than in the core, the reactor is designed so tbat the ratio of neutron scattering cross section to neutron absorption cross section averaged over all of the materials in the reflector is approximately twice the ratio of neutron scattering cross section to neutron absorption cross section averaged over all of the material of the core of the reactor.

  1. Factors Affecting Cirrus-HD OCT Optic Disc Scan Quality: A Review with Case Examples

    PubMed Central

    Hardin, Joshua S.; Taibbi, Giovanni; Nelson, Seth C.; Chao, Diana; Vizzeri, Gianmarco

    2015-01-01

    Spectral-domain OCT is an established tool to assist clinicians in detecting glaucoma and monitor disease progression. The widespread use of this imaging modality is due, at least in part, to continuous hardware and software advancements. However, recent evidence indicates that OCT scan artifacts are frequently encountered in clinical practice. Poor image quality invariably challenges the interpretation of test results, with potential implications for the care of glaucoma patients. Therefore, adequate knowledge of various imaging artifacts is necessary. In this work, we describe several factors affecting Cirrus HD-OCT optic disc scan quality and their effects on measurement variability. PMID:26351574

  2. Factors Affecting Cirrus-HD OCT Optic Disc Scan Quality: A Review with Case Examples.

    PubMed

    Hardin, Joshua S; Taibbi, Giovanni; Nelson, Seth C; Chao, Diana; Vizzeri, Gianmarco

    2015-01-01

    Spectral-domain OCT is an established tool to assist clinicians in detecting glaucoma and monitor disease progression. The widespread use of this imaging modality is due, at least in part, to continuous hardware and software advancements. However, recent evidence indicates that OCT scan artifacts are frequently encountered in clinical practice. Poor image quality invariably challenges the interpretation of test results, with potential implications for the care of glaucoma patients. Therefore, adequate knowledge of various imaging artifacts is necessary. In this work, we describe several factors affecting Cirrus HD-OCT optic disc scan quality and their effects on measurement variability.

  3. FOREWORD: Neutron metrology Neutron metrology

    NASA Astrophysics Data System (ADS)

    Thomas, David J.; Nolte, Ralf; Gressier, Vincent

    2011-12-01

    The International Committee for Weights and Measures (CIPM) has consultative committees covering various areas of metrology. The Consultative Committee for Ionizing Radiation (CCRI) differs from the others in having three sections: Section (I) deals with radiation dosimetry, Section (II) with radionuclide metrology and Section (III) with neutron metrology. In 2003 a proposal was made to publish special issues of Metrologia covering the work of the three Sections. Section (II) was the first to complete their task, and their special issue was published in 2007, volume 44(4). This was followed in 2009 by the special issue on radiation dosimetry, volume 46(2). The present issue, volume 48(6), completes the trilogy and attempts to explain neutron metrology, the youngest of the three disciplines, the neutron only having been discovered in 1932, to a wider audience and to highlight the relevance and importance of this field. When originally approached with the idea of this special issue, Section (III) immediately saw the value of a publication specifically on neutron metrology. It is a topic area where papers tend to be scattered throughout the literature in journals covering, for example, nuclear instrumentation, radiation protection or radiation measurements in general. Review articles tend to be few. People new to the field often ask for an introduction to the various topics. There are some excellent older textbooks, but these are now becoming obsolete. More experienced workers in specific areas of neutron metrology can find it difficult to know the latest position in related areas. The papers in this issue attempt, without presenting a purely historical outline, to describe the field in a sufficiently logical way to provide the novice with a clear introduction, while being sufficiently up-to-date to provide the more experienced reader with the latest scientific developments in the different topic areas. Neutron radiation fields obviously occur throughout the nuclear

  4. Factors associated with poor sleep quality in women with cancer 1

    PubMed Central

    Mansano-Schlosser, Thalyta Cristina; Ceolim, Maria Filomena

    2017-01-01

    ABSTRACT Objectives: to analyze the factors associated with poor sleep quality, its characteristics and components in women with breast cancer prior to surgery for removing the tumor and throughout the follow-up. Method: longitudinal study in a teaching hospital, with a sample of 102 women. The following were used: a questionnaire for sociodemographic and clinical characterization, the Pittsburgh Sleep Quality Index; the Beck Depression Inventory; and the Herth Hope Scale. Data collection covered from prior to the surgery for removal of the tumor (T0) to T1, on average 3.2 months; T2, on average 6.1 months; and T3, on average 12.4 months. Descriptive statistics and the Generalized Estimating Equations model were used. Results: depression and pain contributed to the increase in the score of the Pittsburgh Sleep Quality Index, and hope, to the reduction of the score - independently - throughout follow-up. Sleep disturbances were the component with the highest score throughout follow-up. Conclusion: the presence of depression and pain, prior to the surgery, contributed to the increase in the global score of the Pittsburgh Sleep Quality Index, which indicates worse quality of sleep throughout follow-up; greater hope, in its turn, influenced the reduction of the score of the Pittsburgh Sleep Quality Index. PMID:28301036

  5. Evaluation of variations and affecting factors of eco-environmental quality during urbanization.

    PubMed

    Cui, Erqian; Ren, Lijun; Sun, Haoyu

    2015-03-01

    Regional eco-environmental quality is the foundation of economic sustainable development and rational utilization of resources. It is necessary to understand and evaluate the regional eco-environmental quality correctly. Based on national remote sensing land use data, normalized difference vegetation index (NDVI) data and some other statistical data, this paper established an eco-environmental quality index (EQI) model to evaluate the ecological status of Jinan from 2000 to 2011. The results of eco-environmental quality showed little variation, with EQI values ranged from 62.00 to 69.01. EQI of each region in Jinan firstly decreased sharply and then increased slowly with the development of local economy. Besides the spatial and temporal variations analysis, affecting factors of eco-environmental quality was also discussed in this article. According to the results of correlation and regression analysis, meteorological conditions (rainfall and sunshine duration) and industrial structure (the proportion of primary industry) had relatively high correlations with eco-environmental quality. To summarize, a better eco-environmental status is associated with increasing rainfall, shorter sunshine duration, and lower proportion of primary industry. This article aims to giving supporting data and decision-making bases to restore the ecological environment and promote the sustainable development of Jinan.

  6. Factors Influencing Quality of Life and Predictors of Low Quality of Life Scores in Patients on Treatment for Pulmonary Tuberculosis: A Cross Sectional Study

    PubMed Central

    Adeyeye, Olufunke O.; Coker, Ayodele; Kuyinu, Yetunde; Bamisile, Raymond T.; Ekrikpo, Udeme; Onadeko, Babatunde

    2014-01-01

    There is paucity of information on the quality of life of patients with pulmonary tuberculosis in Nigeria. This study assessed the factors influencing their quality of life and the independent predictors of low quality of life scores. Two hundred and sixty consecutive patients with pulmonary tuberculosis seen at the Lagos University Teaching Hospital were evaluated for health related quality of life using the World Health Organization Quality of life instrument (WHOQoL-BREF). Sociodemographic characteristics of the patients were related to the various domains of quality of life and a multivariate logistic regression analysis was performed to identify the independent predictors of low quality of life scores in the patients. The mean age of the patients was 36.7±12 years. Sex, age and marital status of patients were found to influence quality of life scores. The independent predictors of low quality of life scores were low monthly income, duration of the illness, concomitant illnesses, unemployment, advancing age and male gender. Several socio demographic and economic factors influenced the quality of life of patients with tuberculosis and are predictive of poor scores. It is important to consider these factors when treating patients with tuberculosis to optimise outcome of care. PMID:28299129

  7. The quality of our Nation's waters: factors affecting public-supply-well vulnerability to contamination: understanding observed water quality and anticipating future water quality

    USGS Publications Warehouse

    Eberts, Sandra M.; Thomas, Mary Ann; Jagucki, Martha L.

    2013-01-01

    As part of the U.S. Geological Survey National Water-Quality Assessment (NAWQA) Program, a study was conducted from 2001 to 2011 to shed light on factors that affect the vulnerability of water from public-supply wells to contamination (referred to hereafter as “public-supply-well vulnerability”). The study was designed as a follow-up to earlier NAWQA studies that found mixtures of contaminants at low concentrations in groundwater near the water table in urban areas across the Nation and, less frequently, in deeper groundwater typically used for public supply. Beside the factors affecting public-supply-well vulnerability to contamination, this circular describes measures that can be used to determine which factor (or factors) plays a dominant role at an individual public-supply well. Case-study examples are used throughout to show how such information can be used to improve water quality. In general, the vulnerability of the water from public-supply wells to contamination is a function of contaminant input within the area that contributes water to a well, the mobility and persistence of a contaminant once released to the groundwater, and the ease of groundwater and contaminant movement from the point of recharge to the open interval of a well. The following measures described in this circular are particularly useful for indicating which contaminants in an aquifer might reach an individual public-supply well and when, how, and at what concentration they might arrive: * Sources of recharge—Information on the sources of recharge for a well provides insight into contaminants that might enter the aquifer with the recharge water and potentially reach the well. * Geochemical conditions—Information on the geochemical conditions encountered by groundwater traveling to a well provides insight into contaminants that might persist in the water all the way to the well. * Groundwater-age mixtures—Information on the ages of the different waters that mix in a well

  8. Geographic factors as determinants of food security: a Western Australian food pricing and quality study.

    PubMed

    Pollard, Christina Mary; Landrigan, Timothy John; Ellies, Pernilla Laila; Kerr, Deborah Anne; Lester, Matthew Langdon Underwood; Goodchild, Stanley Edward

    2014-01-01

    Food affordability and quality can influence food choice. This research explores the impact of geographic factors on food pricing and quality in Western Australia (WA). A Healthy Food Access Basket (HFAB) was cost and a visual and descriptive quality assessment of 13 commonly consumed fresh produce items was conducted in-store on a representative sample of 144 food grocery stores. The WA retail environment in 2010 had 447 grocery stores servicing 2.9 million people: 38% of stores the two major chains (Coles® Supermarkets Australia and Woolworths ® Limited) in population dense areas, 50% were smaller independently owned stores (Independent Grocers Association®) in regional areas as well, and 12% Indigenous community stores in very remote areas. The HFAB cost 24% (p<0.0001) more in very remote areas than the major city with fruit (32%, p<0.0001), vegetables (26.1%, p<0.0005) and dairy (40%, p<0.0001) higher. Higher price did not correlate with higher quality with only 80% of very remote stores meeting all criteria for fresh produce compared with 93% in Perth. About 30% of very remote stores did not meet quality criteria for bananas, green beans, lettuce, and tomatoes. With increasing geographic isolation, most foods cost more and the quality of fresh produce was lower. Food affordability and quality may deter healthier food choice in geographically isolated communities. Improving affordability and quality of nutritious foods in remote communities may positively impact food choices, improve food security and prevent diet-sensitive chronic disease. Policy makers should consider influencing agriculture, trade, commerce, transport, freight, and modifying local food economies.

  9. Neutron anatomy

    SciTech Connect

    Bacon, G.E.

    1994-12-31

    The familiar extremes of crystalline material are single-crystals and random powders. In between these two extremes are polycrystalline aggregates, not randomly arranged but possessing some preferred orientation and this is the form taken by constructional materials, be they steel girders or the bones of a human or animal skeleton. The details of the preferred orientation determine the ability of the material to withstand stress in any direction. In the case of bone the crucial factor is the orientation of the c-axes of the mineral content - the crystals of the hexagonal hydroxyapatite - and this can readily be determined by neutron diffraction. In particular it can be measured over the volume of a piece of bone, utilizing distances ranging from 1mm to 10mm. The major practical problem is to avoid the intense incoherent scattering from the hydrogen in the accompanying collagen; this can best be achieved by heat-treatment and it is demonstrated that this does not affect the underlying apatite. These studies of bone give leading anatomical information on the life and activities of humans and animals - including, for example, the life history of the human femur, the locomotion of sheep, the fracture of the legs of racehorses and the life-styles of Neolithic tribes. We conclude that the material is placed economically in the bone to withstand the expected stresses of life and the environment. The experimental results are presented in terms of the magnitude of the 0002 apatite reflection. It so happens that for a random powder the 0002, 1121 reflections, which are neighboring lines in the powder pattern, are approximately equal in intensity. The latter reflection, being of manifold multiplicity, is scarcely affected by preferred orientation so that the numerical value of the 0002/1121 ratio serves quite accurately as a quantitative measure of the degree of orientation of the c-axes in any chosen direction for a sample of bone.

  10. Effect of photometric detector spectral response quality on white LED spectral mismatch correction factors.

    PubMed

    Rosas, E; Estrada-Hernández, A

    2016-07-01

    Light-emitting-diode (LED)-based solid-state lighting has become a real option for private and public lighting after achieving high total luminous flux (TLF) and luminous efficacy levels, thus promoting the development of energy efficient use regulation to be fulfilled by LED lamps and LED luminaires. Here, we propose a photometer-quality-based fast-checking criterion. This allows photometric technicians to perform a quick evaluation of the photometric head spectral response quality effect on the LED source spectral mismatch correction factor-when determining the TLF and luminous efficacy minimum approved levels-performance parameters subject to mandatory verification by the conformity assessment procedures technically supporting the corresponding regulation. The proposed criterion applies for a wide range of photometric detector heads' qualities (2.6%≤f1'≤36.4%).

  11. Olive (Olea europaea L.) tree nitrogen status is a key factor for olive oil quality.

    PubMed

    Erel, Ran; Kerem, Zohar; Ben-Gal, Alon; Dag, Arnon; Schwartz, Amnon; Zipori, Isaac; Basheer, Loai; Yermiyahu, Uri

    2013-11-27

    The influence of macronutrient status on olive oil properties was studied for three years. Data were analyzed by a multivariate model considering N, P, K, and fruiting year as explanatory factors. Oil quality parameters were primarily associated with N concentration in leaves and fruits which increased with N in irrigation solution. The effect of P on oil quality was mainly indirect since increased P availability increased N accumulation. The potassium level had negligible effects. The oil phenolic content decreased linearly as a function of increased leaf N, indicating protein-phenol competition in leaves. The overall saturation level of the fatty acids decreased with fruit N, resulting in increased polyunsaturated fatty acids. Free fatty acids increased with increased levels of fruit N. High fruit load tended to reduce fruit N and subsequently improve oil quality. The effect of N on oil properties depended solely on its concentration in leaves or fruits, regardless of the cause.

  12. Multi-purpose neutron radiography system

    SciTech Connect

    Barton, J.P.; Bryant, L.E.; Berry, P.

    1996-07-01

    A conceptual design is given for a low cost, multipurpose radiography system suited for the needs of the Los Alamos National Laboratory (LANL). The proposed neutron source is californium-252. One purpose is to provide an in-house capability for occasional, reactor quality, neutron radiography thus replacing the recently closed Omega-West Reactor. A second purpose is to provide a highly reliable standby transportable neutron radiography system. A third purpose is to provide for transportable neutron probe gamma spectroscopy techniques. The cost is minimized by shared use of an existing x-ray facility, and by use of an existing transport cask. The achievable neutron radiography and radioscopy performance characteristics have been verified. The demonstrated image qualities range from high resolution gadolinium - SR film, with L:D = 100:1, to radioscopy using a LIXI image with L:D = 30:1 and neutron fluence 3.4 x 10{sup 5} n/cm{sup 2}.

  13. Modeling and analysis of mechanical Quality factor of the resonator for cylinder vibratory gyroscope

    NASA Astrophysics Data System (ADS)

    Xi, Xiang; Wu, Xuezhong; Wu, Yulie; Zhang, Yongmeng

    2017-01-01

    Mechanical Quality factor( Q factor) of the resonator is an important parameter for the cylinder vibratory gyroscope(CVG). Traditional analytical methods mainly focus on a partial energy loss during the vibration process of the CVG resonator, thus are not accurate for the mechanical Q factor prediction. Therefore an integrated model including air damping loss, surface defect loss, support loss, thermoelastic damping loss and internal friction loss is proposed to obtain the mechanical Q factor of the CVG resonator. Based on structural dynamics and energy dissipation analysis, the contribution of each energy loss to the total mechanical Q factor is quantificationally analyzed. For the resonator with radius ranging from 10 mm to 20 mm, its mechanical Q factor is mainly related to the support loss, thermoelastic damping loss and internal friction loss, which are fundamentally determined by the geometric sizes and material properties of the resonator. In addition, resonators made of alloy 3J53 (Ni42CrTiAl), with different sizes, were experimentally fabricated to test the mechanical Q factor. The theoretical model is well verified by the experimental data, thus provides an effective theoretical method to design and predict the mechanical Q factor of the CVG resonator.

  14. Measurement of mechanical quality factors of polymers in flexural vibration for high-power ultrasonic application.

    PubMed

    Wu, Jiang; Mizuno, Yosuke; Tabaru, Marie; Nakamura, Kentaro

    2016-07-01

    A method for measuring the mechanical quality factor (Q factor) of materials in large-amplitude flexural vibrations was devised on the basis of the original definition of the Q factor. The Q factor, the ratio of the reactive energy to the dissipated energy, was calculated from the vibration velocity distribution. The bar thickness was selected considering the effect of the thickness on the estimation error. In the experimental setup, a 1-mm-thick polymer-based bar was used as a sample and fixed on the top of a longitudinal transducer. Using transducers of different lengths, flexural waves in the frequency range of 20-90kHz were generated on the bar. The vibration strain in the experiment reached 0.06%. According to the Bernoulli-Euler model, the reactive energy and dissipated energy were estimated from the vertical velocity distribution on the bar, and the Q factors were measured as the driving frequency and strain were varied. The experimental results showed that the Q factors decrease as the driving frequencies and strains increase. At a frequency of 28.30kHz, the Q factor of poly(phenylene sulfide) (PPS) reached approximately 460 when the strain was smaller than 0.005%. PPS exhibited a much higher Q factor than the other tested polymers, which implies that it is a potentially applicable material as the elastomer for high-power ultrasonic devices.

  15. Improving the quality factor of microwave cavities for axion search experiments

    NASA Astrophysics Data System (ADS)

    Ahn, Saebyeok; Jung, Junu; Youn, Sungwoo; Semertzidis, Yannis

    2017-01-01

    In cavity-based axion search experiments, the quality factor (Q) of microwave resonant cavities is an important parameter to be sensitive to faint signal from the axion-to-photon conversion. One of the R&D efforts conducted at the Center for Axion and Precision Physics Research (CAPP) of the Institute for Basic Science (IBS) is to improve the quality factor of resonant cavities by employing two approaches - pure material and heat treatment. Using a 4K cryocooler and liquid helium, we measure the temperature dependence of Q value to find the effect of material purity and an optimal condition of heat treatment. The measurements are performed on Cu and Al cavities and the results are shown in this presentation.

  16. Measurement of a high electrical quality factor in a niobium resonator for a gravitational radiation detector

    NASA Technical Reports Server (NTRS)

    Folkner, W. M.; Moody, M. V.; Richard, J.-P.

    1989-01-01

    The mechanical and electrical quality factors of a 10-g niobium resonator were measured at 4.4 K and were found to be 8.1 x 10 to the 6th, and 3.8 x 10 to the 6th, respectively. The value for the electrical quality factor is high enough for a system operating at 50 mK at a sensitivity level of one phonon. The resonator's low damping properties make it suitable for use as a transducer for a cryogenic three-mode gravitational radiation detector. A practical design is given for the mounting of the resonator on a 2400-kg aluminum-bar detector. Projections are made for the sensitivity of a 2400-kg bar instrumented as a three-mode system with this resonator inductively coupled to a SQUID.

  17. (Ba,Sr)TiO3 tunable capacitors with RF commutation quality factors exceeding 6000

    NASA Astrophysics Data System (ADS)

    Meyers, Cedric J. G.; Freeze, Christopher R.; Stemmer, Susanne; York, Robert A.

    2016-09-01

    The fabrication, measurement, and modeling of radio-frequency (RF), tunable interdigital capacitors (IDCs) are described. High quality factors of 200 in the S/L-bands combined with a 47% tunability are achieved by utilizing epitaxial (Ba,Sr)TiO3 films grown by hybrid molecular beam epitaxy on LaAlO3 substrates. The fabricated devices consisted of one-port and two-port IDCs embedded in ground-signal-ground, coplanar waveguide transmission lines to enable RF probing. Wideband RF scattering parameters under bias were measured from 100 MHz to 40 GHz. A commutation quality factor averaging 6000 across the L band is achieved. These are the highest reported values in this band.

  18. Quality limiting factors of imaging endoscopes based on optical fiber bundles

    NASA Astrophysics Data System (ADS)

    Ortega-Quijano, N.; Arce-Diego, J. L.; Fanjul-Vélez, F.

    2008-04-01

    Nowadays, imaging endoscopes have a key role in medicine, for diagnostic, treatment and surgical applications. Coherent optical fiber bundles used for medical imaging show flexibility and a high active area, but they entail two main quality-limiting factors: leaky modes and crosstalk or interference between the optical fibers of the bundle. The former provokes a worsening of lateral resolution, while the latter causes a decrease in the contrast of the final image. In this work, both factors are studied in detail. We analyse the main characteristics of these effects, showing the limitations they impose to the endoscopic system. Finally, some solutions are proposed, and a method for determining optical fibers with the appropriate opto-geometrical parameters is presented in order to achieve an optimum design and improve the image quality of the endoscope.

  19. Chip Mount Design as a Dissipation-Limiting Factor in High Quality Superconducting Resonators

    NASA Astrophysics Data System (ADS)

    Campbell, Brooks; Barends, R.; Bochmann, J.; Chen, Yu; Chen, Z.; Chiaro, B.; Dunsworth, A.; Hoi, I.; Jeffrey, E.; Kelly, J.; Megrant, A.; Mutus, J.; Neil, C.; O'Malley, P.; Quintana, C.; Roushan, P.; Sank, D.; Vainsencher, A.; Wenner, J.; White, T.; Cleland, A. N.; Martinis, J. M.

    2014-03-01

    Superconducting quantum computing technology continues to make progress with regards to both materials quality and circuit complexity. We have found that chip mount design can become a coherence-limiting factor for superconducting coplanar resonators with an internal quality factor above 1 million. Understanding the impact of chip-to-mount coupling will aid in both proper mount design for higher density circuits as well as the further improvement of coherence times. These coplanar resonators provide an ideal test circuit as they are sensitive to a variety of loss mechanisms including radiation, infrared light, and magnetic fields which also affect more complex superconducting circuits. I will present results relating the coherence and performance of resonators to box design, box material, and chip layout.

  20. Evaluation of a PIN Photodiode Detector in Neutron-Gamma Fields

    NASA Astrophysics Data System (ADS)

    Cárdenas, José Patricio N.; Campos, Letícia L.; Filho, Tufic Madi

    2011-08-01

    Semiconductor detectors are suitable for applications in radiation dosimetry in nuclear research reactors and for radiation protection purposes. The performance of these detectors depends on the quality of their semiconductor. The aim of this work was to evaluate a commercial PIN Photodiode in the neutron-gamma fields of the IEA-R1 nuclear research reactor and from an AmBe neutron source. This semiconductor was studied as a neutron detector using some types of converters to determine a dose-to-counts conversion factor to dose equivalent. The results have shown that this component may be implemented for assessing the neutron spectra in some radiation fields and in dose equivalent in radiation protection routines.

  1. Argon/propane ionization-chamber dosimetry for mixed x-ray/neutron fields.

    PubMed

    Schulz, R J

    1978-01-01

    The photoneutrons produced by high-energy x-ray machines can diffuse through the mazes usually employed at the treatment-room entrance and readily penetrate the lead-lined doors used for x-ray shielding. The measurement of these neutrons in the presence of x-rays and the determination of dose equivalent poses a problem for which there is currently no standard method of solution. In order to separate x-ray dose from neutron dose, the author employed an ionization chamber alternately filled with argon or propane. The response characteristics of this chamber to x-ray and neutrons are described. Quality factors were determined from a calculated neutron spectrum. As a result of these measurements, a 10-in. polyethylene door was added to the entranceway of a 25-MV linear accelerator.

  2. Predictors and Effective Factors on Quality of Life Among Iranian Patients with Rheumatoid Arthritis

    PubMed Central

    Karimi, Saied; Yarmohammadian, Mohammad Hossein; Shokri, Azad; Mottaghi, Payman; Qolipour, Kamal; Kordi, Ayan; Bahman Ziari, Najmeh

    2013-01-01

    Introduction: Rheumatoid arthritis is a chronic autoimmune disorder that leads to joint swelling, stiffness, pain and progressive joint destruction. It is a common disease with prevalence of 1% worldwide that affecting all aspects of patients’ lives. Therefore, this study was conducted to summarize and provide a clear view of quality of life among the patients in Iran through a literature review. Methods: This study was conducted as a literature review over article published between 2000 to 2013, by using data bases comprise of Google scholar, Science Direct, Pubmed, IRANDOC, SID, Medlib, Magiran and by key words: “quality of life”, “rheumatoid arthritis”, “Iran” and their Persian equivalents. Finally 2065 articles assessed and according to the aim of the study are 11 studies synthesized. Extracted results first were summarized in Extraction Table, and then analyzed manually. Results: In reviewed articles rheumatoid arthritis patients’ quality of life was measured by using five different tools, the most important one of them was SF36 questionnaire. Among eight dimensions of SF36 questionnaire, the highest mean according included articles result was social functioning with average score of 63.4 and the lowest for physical limitation (physical role functioning) with score of 43. Overall, mean of eight dimensions was 52.47. The most important factors affecting quality of life were disease severity and pain, depression, income, educational, occupational status, married status, sign of disease, fatigue, anxiety and disease activity scores. Conclusion: The results of the study showed relatively low quality of life of rheumatoid arthritis patients in Iran. Empowering patients by participating them in service delivery process and decision making can improves quality of life and in this regard health care provider must be focused on patient self-care abilities and reinforcing this factor by training them. PMID:24167426

  3. A Network and Visual Quality Aware N-Screen Content Recommender System Using Joint Matrix Factorization

    PubMed Central

    Ullah, Farman; Sarwar, Ghulam; Lee, Sungchang

    2014-01-01

    We propose a network and visual quality aware N-Screen content recommender system. N-Screen provides more ways than ever before to access multimedia content through multiple devices and heterogeneous access networks. The heterogeneity of devices and access networks present new questions of QoS (quality of service) in the realm of user experience with content. We propose, a recommender system that ensures a better visual quality on user's N-screen devices and the efficient utilization of available access network bandwidth with user preferences. The proposed system estimates the available bandwidth and visual quality on users N-Screen devices and integrates it with users preferences and contents genre information to personalize his N-Screen content. The objective is to recommend content that the user's N-Screen device and access network are capable of displaying and streaming with the user preferences that have not been supported in existing systems. Furthermore, we suggest a joint matrix factorization approach to jointly factorize the users rating matrix with the users N-Screen device similarity and program genres similarity. Finally, the experimental results show that we also enhance the prediction and recommendation accuracy, sparsity, and cold start issues. PMID:24982999

  4. A Power Factor Corrected SMPS with Improved Power Quality for Welding Applications

    NASA Astrophysics Data System (ADS)

    Narula, Swati; Singh, Bhim; Bhuvaneswari, G.; Pandey, Rahul

    2015-04-01

    This paper presents the analysis, design and implementation of a power factor corrected Arc Welding Power Supply (AWPS) with a boost converter at the front end and three full-bridge (FB) converters connected in parallel at the load end. The modular arrangement of the FB converters offers several meritorious features like usage of power devices with comparatively lower voltage and current ratings, ease of power expandability, easy maintenance, etc. The boost converter operates in continuous conduction mode minimizing the input current ripple and leading to the lowest RMS current thereby improving the input power quality. Individual control loops are designed for each power stage. A dual loop control scheme is employed to incorporate over-current limit on the proposed AWPS which ensures excellent weld bead quality. The proposed AWPS is implemented to validate its performance over a wide range of line/load variations. Test results confirm its fast parametrical response to load and source voltage variations and over-current protection leading to improved welding performance and weld bead quality. The system is found to perform extremely well with very low input current THD and unity power factor, adhering to international power quality norms.

  5. Modeling water quality in an urban river using hydrological factors--data driven approaches.

    PubMed

    Chang, Fi-John; Tsai, Yu-Hsuan; Chen, Pin-An; Coynel, Alexandra; Vachaud, Georges

    2015-03-15

    Contrasting seasonal variations occur in river flow and water quality as a result of short duration, severe intensity storms and typhoons in Taiwan. Sudden changes in river flow caused by impending extreme events may impose serious degradation on river water quality and fateful impacts on ecosystems. Water quality is measured in a monthly/quarterly scale, and therefore an estimation of water quality in a daily scale would be of good help for timely river pollution management. This study proposes a systematic analysis scheme (SAS) to assess the spatio-temporal interrelation of water quality in an urban river and construct water quality estimation models using two static and one dynamic artificial neural networks (ANNs) coupled with the Gamma test (GT) based on water quality, hydrological and economic data. The Dahan River basin in Taiwan is the study area. Ammonia nitrogen (NH3-N) is considered as the representative parameter, a correlative indicator in judging the contamination level over the study. Key factors the most closely related to the representative parameter (NH3-N) are extracted by the Gamma test for modeling NH3-N concentration, and as a result, four hydrological factors (discharge, days w/o discharge, water temperature and rainfall) are identified as model inputs. The modeling results demonstrate that the nonlinear autoregressive with exogenous input (NARX) network furnished with recurrent connections can accurately estimate NH3-N concentration with a very high coefficient of efficiency value (0.926) and a low RMSE value (0.386 mg/l). Besides, the NARX network can suitably catch peak values that mainly occur in dry periods (September-April in the study area), which is particularly important to water pollution treatment. The proposed SAS suggests a promising approach to reliably modeling the spatio-temporal NH3-N concentration based solely on hydrological data, without using water quality sampling data. It is worth noticing that such estimation can be

  6. A Control Based System of Mechanical Loss Measurement for High Quality Factor Oscillators

    NASA Astrophysics Data System (ADS)

    Louis Gitelman, Louis; Smith, Nicolas; Jafar, Isaac; Harry, Gregory; Newport, Jonathan; Abernathy, Matt; LIGO Collaboration

    In this poster we will present the control system being developed to measure the quality factor of optics used in the Advanced LIGO gravitational wave detectors to predict thermal noise levels. It works by locking the phase between the optic's exciter and normal mode to pi/2 and locking the optics's amplitude allowing one to equate the energy output of the exciter to the mechanical loss of the optic. To do this the amplitude of the normal mode is detected using a birefringence meter and lockin amplifier, which is then fedback to an electrostatic exciter to control the mode's amplitude and phase with a PID controller written on a python script. The poster will discuss the components and assembly of this system and the theoretical control structure behind it. It will also discuss the speed, accuracy and general feasibility of this method of quality factor measurement relative to other methods, and steps to improve and develop this method of quality factor measurement and the possible applications for LIGO and in general.

  7. Analytical optimization of active bandwidth and quality factor for TOCSY experiments in NMR spectroscopy

    PubMed Central

    Coote, Paul; Bermel, Wolfgang; Wagner, Gerhard; Arthanari, Haribabu

    2016-01-01

    Active bandwidth and global quality factor are the two main metrics used to quantitatively compare the performance of TOCSY mixing sequences. Active bandwidth refers to the spectral region over which at least 50% of the magnetization is transferred via a coupling. Global quality factor scores mixing sequences according to the worst-case transfer over a range of possible mixing times and chemical shifts. Both metrics reward high transfer efficiency away from the main diagonal of a two-dimensional spectrum. They can therefore be used to design mixing sequences that will function favorably in experiments. Here, we develop optimization methods tailored to these two metrics, including precise control of off-diagonal cross peak buildup rates. These methods produce square shaped transfer efficiency profiles, directly matching the desirable properties that the metrics are intended to measure. The optimization methods are analytical, rather than numerical. The two resultant shaped pulses have significantly higher active bandwidth and quality factor, respectively, than all other known sequences. They are therefore highly suitable for use in NMR spectroscopy. We include experimental verification of these improved waveforms on small molecule and protein samples. PMID:27515670

  8. Physics and material science of ultra-high quality factor superconducting resonator

    NASA Astrophysics Data System (ADS)

    Vostrikov, Alexander

    The nitrogen doping into niobium superconducting radio frequency cavity walls aiming to improve the fundamental mode quality factor is the subject of the research in the given work. Quantitative nitrogen diffusion into niobium model calculating the concentration profile was developed. The model estimations were confirmed with secondary ion mass spectrometry technique measurements. The model made controlled nitrogen doping recipe optimization possible. As a result the robust reproducible recipe for SRF cavity walls treatment with nitrogen doping was developed. The cavities produced with optimized recipe met LCLS--II requirements on quality factor of 2. · 10 10 at acceleration field of 16~MV/m. The microscopic effects of nitrogen doping on superconducting niobium properties were studied with low energy muon spin rotation technique and magnetometer measurements. No significant effect of nitrogen on the following features was found: electron mean free path, magnetic field penetration depth, and upper and surface critical magnetic fields. It was detected that for nitrogen doped niobium samples magnetic flux starts to penetrate inside the superconductor at lower external magnetic field value compared to the low temperature baked niobium ones. This explains lower quench field of SRF cavities treated with nitrogen. Quality factor improvement of fundamental mode forced to analyze the high order mode (HOM) impact on the particle beam dynamics. Both resonant and cumulative effects caused by monopole and dipole HOMs respectively are found to be negligible within the requirements for LCLS--II.

  9. Effect of non-uniform surface resistance on the quality factor of superconducting niobium cavity

    NASA Astrophysics Data System (ADS)

    Tan, Weiwei; Lu, Xiangyang; Yang, Ziqin; Zhao, Jifei; Yang, Deyu; Yang, Yujia

    2016-08-01

    The formula Rs = G /Q0 is commonly used in the calculation of the surface resistance of radio frequency niobium superconducting cavities. The applying of such equation is under the assumption that surface resistance is consistent over the cavity. However, the distribution of the magnetic field varies over the cavity. The magnetic field in the equator is much higher than that in the iris. According to Thermal Feedback Theory, it leads non-uniform distribution of the density of heat flux, which results in a different temperature distribution along the cavity inter surface. The BCS surface resistance, which depends largely on the temperature, is different in each local inner surface. In this paper, the effect of surface non-uniform resistance on the quality factor has been studied, through the calculation of Q0 in the original definition of it. The results show that it is necessary to consider the non-uniform distribution of magnetic field when the accelerating field is above 20 MV/m for TESLA cavities. Also, the effect of inhomogeneity of residual resistance on the quality factor is discussed. Its distribution barely affects the quality factor.

  10. Physics and material science of ultra-high quality factor superconducting resonator

    SciTech Connect

    Vostrikov, Alexander

    2015-08-01

    The nitrogen doping into niobium superconducting radio frequency cavity walls aiming to improve the fundamental mode quality factor is the subject of the research in the given work. Quantitative nitrogen diffusion into niobium model calculating the concentration profile was developed. The model estimations were confirmed with secondary ion mass spectrometry technique measurements. The model made controlled nitrogen doping recipe optimization possible. As a result the robust reproducible recipe for SRF cavity walls treatment with nitrogen doping was developed. The cavities produced with optimized recipe met LCLS–II requirements on quality factor of 2.7 ∙ 1010 at acceleration field of 16 MV/m. The microscopic effects of nitrogen doping on superconducting niobium properties were studied with low energy muon spin rotation technique and magnetometer measurements. No significant effect of nitrogen on the following features was found: electron mean free path, magnetic field penetration depth, and upper and surface critical magnetic fields. It was detected that for nitrogen doped niobium samples magnetic flux starts to penetrate inside the superconductor at lower external magnetic field value compared to the low temperature baked niobium ones. This explains lower quench field of SRF cavities treated with nitrogen. Quality factor improvement of fundamental mode forced to analyze the high order mode (HOM) impact on the particle beam dynamics. Both resonant and cumulative effects caused by monopole and dipole HOMs respectively are found to be negligible within the requirements for LCLS–II.

  11. Neutron therapy of cancer

    NASA Technical Reports Server (NTRS)

    Frigerio, N. A.; Nellans, H. N.; Shaw, M. J.

    1969-01-01

    Reports relate applications of neutrons to the problem of cancer therapy. The biochemical and biophysical aspects of fast-neutron therapy, neutron-capture and neutron-conversion therapy with intermediate-range neutrons are presented. Also included is a computer program for neutron-gamma radiobiology.

  12. Analysis of River Water Quality and its influencing factors for the Effective Management of Water Environment

    NASA Astrophysics Data System (ADS)

    Shrestha, G.; Sadohara, S.; Yoshida, S.; Yuichi, S.

    2011-12-01

    In Japan, remarkable improvements in water quality have been observed over recent years because of regulations imposed on industrial wastewater and development of sewerage system. However, pollution loads from agricultural lands are still high and coverage ratio of sewerage system is still low in small and medium cities. In present context, nonpoint source pollution such as runoff from unsewered developments, urban and agricultural runoffs could be main water quality impacting factors. Further, atmospheric nitrogen (N) is the complex nonpoint source than can seriously affect river water environment. This study was undertaken to spatially investigate the present status of river water quality of Hadano Basin located in Kanagawa Prefecture, Japan. Water quality of six rivers was investigated and its relationship with nonpoint pollution sources was analyzed. This study, with inclusion of ground water circulation and atmospheric N, can be effectively employed for water quality management of other watersheds also, both with and without influence of ground water circulation. Hence, as a research area of this study, it is significant in terms of water quality management. Total nitrogen (TN) was found consistently higher in urbanized basins indicating that atmospheric N might be influencing TN of river water. Ground water circulation influenced both water quality and quantity. In downstream basins of Muro and Kuzuha rivers, Chemical oxygen demand (COD) and total phosphorus (TP) were diluted by ground water inflow. In Mizunashi River and the upstream of Kuzuha River, surface water infiltrated to the subsurface due to higher river bed permeability. Influencing factors considered in the analysis were unsewered population, agricultural land, urban area, forest and atmospheric N. COD and TP showed good correlation with unsewered population and agricultural land. While TN had good correlation with atmospheric N deposition. Multiple regression analysis between water quality

  13. Socio-economical factors that influence the perception of quality of life in patients with osteoporosis.

    PubMed

    Abobului, M; Berghea, F; Vlad, V; Balanescu, A; Opris, D; Bojinca, V; Predeteanu, D; Ionescu, R

    2015-01-01

    The appearance of osteoporosis in elders and the growth of the frequency which it is diagnosed with as we approach patients who are older and older, makes this health problem very important in the societies in which a high number of persons reach old age. These societies, usually belonging to economically advanced jurisdictions, are the first interested in the way health expenses can balance the benefits of the quality of life acquired in these groups of population. The evaluation of the quality of life has become a very important process, which still raises methodological problems to the researchers. The aim of this study was to analyze to what extent the factors involved in defining the quality of life by the patients modified according to the existence of osteoporosis as a defined but also as a perceived disease, as far as it is considered a serious or less serious affection by each patient. 210 female patients participated in the study. The statistical analysis was done by using SPSS 22.0 (IBM Corp. - U.S.A.). p < 0,05 was used as a limit for the statistical significance. Descriptive and analytical analyses were made by following Pearson correlation index in cases of normal distributions, the comparison between groups was made by using t-Student test, respectively chi square test in the cases which required its use. The current study highlights a direct relationship between the quality of life, as it is perceived by the patients, and the quality of the health status, which is more important than the relationship between the quality of life and the other objectives measured by WHOQOL scale. This study also shows that for the Romanian patient diagnosed with osteoporosis, who is enclosed in the age limits of this study, the health status represents the main driver of monitoring the quality of life.

  14. Does strabismus surgery improve quality and mood, and what factors influence this?

    PubMed

    McBain, H B; MacKenzie, K A; Hancox, J; Ezra, D G; Adams, G G W; Newman, S P

    2016-05-01

    AimsTo establish the impact of adult strabismus surgery on clinical and psychosocial well-being and determine who experiences the greatest benefit from surgery and how one could intervene to improve quality of life post-surgery.MethodsA longitudinal study, with measurements taken pre-surgery and at 3 and 6 months post-surgery. All participants completed the AS-20 a disease specific quality of life scale, along with measures of mood, strabismus and appearance-related beliefs and cognitions and perceived social support. Participants also underwent a full orthoptic assessment at their preoperative visit and again 3 months postoperatively. Clinical outcomes of surgery were classified as success, partial success or failure, using the largest angle of deviation, diplopia and requirement for further therapy.Results210 participants took part in the study. Strabismus surgery led to statistically significant improvements in psychosocial and functional quality of life. Those whose surgery was deemed a partial success did however experience a deterioration in quality of life. A combination of clinical variables, high expectations, and negative beliefs about the illness and appearance pre-surgery were significant predictors of change in quality of life from pre- to post-surgery.ConclusionsStrabismus surgery leads to significant improvements in quality of life up to 6 months postoperatively. There are however a group of patients who do not experience these benefits. A series of clinical and psychosocial factors have now been identified, which will enable clinicians to identify patients who may be vulnerable to poorer outcomes post-surgery and allow for the development of interventions to improve quality of life after surgery.

  15. DOSIMETRIC response of a REM-500 in low energy neutron fields typical of nuclear power plants.

    PubMed

    Aslam; Matysiak, W; Atanackovic, J; Waker, A J

    2012-06-01

    This study investigates the response of a REM-500 to assess neutron quality factor and dose equivalent in low energy neutron fields, which are commonly encountered in the workplace environment of nuclear power stations. The McMaster University 3 MV Van de Graaff accelerator facility was used to measure the response of the instrument in monoenergetic neutron fields in the energy range 51 to 727 keV by bombarding a thin LiF target with 1.93-2.50 MeV protons. The energy distribution of the neutron fields produced in the facility was measured by a (3)He filled gas ionization chamber. The MCA mode of the REM-500 instrument was used to collect lineal energy distributions at varying neutron energies and to calculate the frequency and dose-mean lineal energies. The effective quality factor, Q-, was also calculated using the values of Q(y)listed in the REM-500 operation manual and compared with those of ICRP 60. The authors observed a continuously increasing trend in y - F, y-D, and Q-with an increase in neutron energy. It is interesting to note that standard tissue equivalent proportional counters (TEPCs) filled with tissue equivalent(TE) gas give rise to a similar trend for these microdosimetric quantities of interest in the same energy range; however, the averages calculated in this study are larger by about 15%compared to a TEPC filled with propane-based TE gas probably because of the larger stopping power of protons in propane compared to TE gas. These somewhat larger event sizes did not result in any significant increase in the Q-compared to those obtained from a TEPC filled with TE gas and were found to be in good agreement with other measurements reported earlier at corresponding neutron energies. The instrument quality factor response, R(Q), defined as the ratio of measured quality factor to the calculated quality factor in an ICRU tissue sphere,was found to vary with neutron energy. The instrument response,R(Q), was ~0.6 at 727 keV, which deteriorates further to

  16. NEUTRONIC REACTOR

    DOEpatents

    Hurwitz, H. Jr.; Brooks, H.; Mannal, C.; Payne, J.H.; Luebke, E.A.

    1959-03-24

    A reactor of the heterogeneous, liquid cooled type is described. This reactor is comprised of a central region of a plurality of vertically disposed elongated tubes surrounded by a region of moderator material. The central region is comprised of a central core surrounded by a reflector region which is surrounded by a fast neutron absorber region, which in turn is surrounded by a slow neutron absorber region. Liquid sodium is used as the primary coolant and circulates through the core which contains the fuel elements. Control of the reactor is accomplished by varying the ability of the reflector region to reflect neutrons back into the core of the reactor. For this purpose the reflector is comprised of moderator and control elements having varying effects on reactivity, the control elements being arranged and actuated by groups to give regulation, shim, and safety control.

  17. Neutron multiplicity ,easurements With 3He alternative: Straw neutron detectors

    DOE PAGES

    Mukhopadhyay, Sanjoy; Wolff, Ronald S.; Meade, John A.; ...

    2015-01-27

    Counting neutrons emitted by special nuclear material (SNM) and differentiating them from the background neutrons of various origins is the most effective passive means of detecting SNM. Unfortunately, neutron detection, counting, and partitioning in a maritime environment are complex due to the presence of high-multiplicity spallation neutrons (commonly known as “ship effect”) and to the complicated nature of the neutron scattering in that environment. In this study, a prototype neutron detector was built using 10B as the converter in a special form factor called “straws” that would address the above problems by looking into the details of multiplicity distributions ofmore » neutrons originating from a fissioning source. This paper describes the straw neutron multiplicity counter (NMC) and assesses the performance with those of a commercially available fission meter. The prototype straw neutron detector provides a large-area, efficient, lightweight, more granular (than fission meter) neutron-responsive detection surface (to facilitate imaging) to enhance the ease of application of fission meters. Presented here are the results of preliminary investigations, modeling, and engineering considerations leading to the construction of this prototype. This design is capable of multiplicity and Feynman variance measurements. This prototype may lead to a near-term solution to the crisis that has arisen from the global scarcity of 3He by offering a viable alternative to fission meters. This paper describes the work performed during a 2-year site-directed research and development (SDRD) project that incorporated straw detectors for neutron multiplicity counting. The NMC is a two-panel detector system. We used 10B (in the form of enriched boron carbide: 10B4C) for neutron detection instead of 3He. In the first year, the project worked with a panel of straw neutron detectors, investigated its characteristics, and developed a data acquisition (DAQ) system to collect

  18. Prediction of in-phantom dose distribution using in-air neutron beam characteristics for BNCS

    SciTech Connect

    Verbeke, Jerome M.

    1999-12-14

    A monoenergetic neutron beam simulation study is carried out to determine the optimal neutron energy range for treatment of rheumatoid arthritis using radiation synovectomy. The goal of the treatment is the ablation of diseased synovial membranes in joints, such as knees and fingers. This study focuses on human knee joints. Two figures-of-merit are used to measure the neutron beam quality, the ratio of the synovium absorbed dose to the skin absorbed dose, and the ratio of the synovium absorbed dose to the bone absorbed dose. It was found that (a) thermal neutron beams are optimal for treatment, (b) similar absorbed dose rates and therapeutic ratios are obtained with monodirectional and isotropic neutron beams. Computation of the dose distribution in a human knee requires the simulation of particle transport from the neutron source to the knee phantom through the moderator. A method was developed to predict the dose distribution in a knee phantom from any neutron and photon beam spectra incident on the knee. This method was revealed to be reasonably accurate and enabled one to reduce by a factor of 10 the particle transport simulation time by modeling the moderator only.

  19. Factors Associated with Quality of Life among Hemodialysis Patients in Malaysia

    PubMed Central

    Md. Yusop, Nor Baizura; Yoke Mun, Chan; Shariff, Zalilah Mohd; Beng Huat, Choo

    2013-01-01

    Although hemodialysis treatment has greatly increased the life expectancy of end stage renal disease patients, low quality of life among hemodialysis patients is frequently reported. This cross-sectional study aimed to determine the relationship between medical history, hemodialysis treatment and nutritional status with the mental and physical components of quality of life in hemodialysis patients. Respondents (n=90) were recruited from Hospital Kuala Lumpur and dialysis centres of the National Kidney Foundation of Malaysia. Data obtained included socio-demography, medical history, hemodialysis treatment and nutritional status. Mental and physical quality of life were measured using the Mental Composite Summary (MCS) and Physical Composite Summary (PCS) of the Short-Form Health Survey 36-items, a generic core of the Kidney Disease Quality of Life Short Form. Two summary measures and total SF-36 was scored as 0–100, with a higher score indicating better quality of life. Approximately 26 (30%) of respondents achieved the body mass index (24 kg/m2) and more than 80% (n=77) achieved serum albumin level (>35.0 mg/dL) recommended for hemodialysis patients. The majority of respondents did not meet the energy (n=72, 80%) and protein (n=68,75%) recommendations. The total score of SF-36 was 54.1±19.2, while the score for the mental and physical components were 45.0±8.6 and 39.6±8.6, respectively. Factors associated with a higher MCS score were absence of diabetes mellitus (p=0.000) and lower serum calcium (p=0.004), while higher blood flow (p=0.000), higher serum creatinine (p=0.000) and lower protein intake (p=0.006) were associated with a higher PCS score. To improve the overall quality of life of hemodialysis patients, a multidisciplinary intervention that includes medical, dietetic and psychosocial strategies that address factors associated with mental and physical quality of life are warranted to reduce further health complications and to improve quality of life

  20. Photon and neutron fluence-to-kerma conversion factors for ICRP-1975 reference man using improved elemental compositions for bone and marrow of the skeleton

    SciTech Connect

    Kerr, G.D.

    1982-11-01

    A twelve-element approximation of the total-body, soft-tissue and skeletal components of ICRP-1975 Reference Man is used to investigate particle fluence-to-kerma conversion factors for photons with energies between 1 keV and 20 MeV and neutrons with energies between 0.0253 eV and 20 MeV. Several recent ICRP revisions to the elemental composition of Reference Man, which have not been included in other kerma-factor calculations, are taken into account. This work suggests some additional revisions to the major-element content (i.e., H, C, N, and O) and to the mineral and trace-element content (i.e., Na, Mg, P, S, Cl, K, Ca, and Fe) of various total-body, soft-tissue, and skeletal components of Reference Man. The revisions to the bone and red marrow of the skeleton offer significant new refinements in red-bone-marrow dosimetry.

  1. Measurements of the Electric Form Factor of the Neutron at Q2=0.45 and 1.13 (GeV/c)2

    SciTech Connect

    Tajima, Shigeyuki

    2003-01-01

    Precise measurements of the electric form factor of the neutron, Gn E, over a wide range of the square of the four-momentum transfer, Q2, are important for understanding nucleon and nuclear electromagnetic structure. In the non-relativistic limit, the electric and magnetic form factors are related to the charge and magnetization distribution inside a nucleon, respectively. The measured values of the form factors also serve as an important test for nucleon models. Among the four nucleon form factors, the electric form factor of the neutron, Gn E, is the most difficult one to measure and therefore has been very poorly known especially in the region Q2 > 1 (GeV/c)2 due to the lack of a free neutron target and the small value of Gn E. The Jefferson Laboratory E93-038 collaboration measured the ratio of the electric to magnetic form factor of the neutron, g = Gn E/Gn M, at three acceptance-averaged Q2 values of 0.45, 1.13 and 1.45 (GeV/c)2 using the quasi-elastic 2H(~e, e0~n)1H reaction. In our experiment, an electron was scattered quasielastically from a neutron in a liquid-deuterium target, and the electron was detected in an electron spectrometer in coincidence with the neutron which was detected in a neutron polarimeter. The polarimeter was used to analyze the polarization of the recoil neutrons by measuring the np elastic scattering asymmetry. The experiment was performed in Hall-C at Thomas Jefferson National Accelerator Facility during the period from September 2000 to April 2001. The value of g was determined from the measured ratio of the sideways and longitudinal components of the neutron polarization vector. The values for Gn E were computed from our measured values of g = Gn E/Gn M using the Gn M values obtained from a fit to the world data. The E93-038 collaboration reported the first measurements of Gn E using polarization techniques at Q2 greater than 1 (GeV/c)2. Furthermore, our

  2. NEUTRONIC REACTOR

    DOEpatents

    Fermi, E.; Szilard, L.

    1957-09-24

    Reactors of the type employing plates of natural uranium in a moderator are discussed wherein the plates are um-formly disposed in parallel relationship to each other thereby separating the moderator material into distinct and individual layers. Each plate has an uninterrupted sunface area substantially equal to the cross-sectional area of the active portion of the reactor, the particular size of the plates and the volume ratio of moderator to uranium required to sustain a chain reaction being determinable from the known purity of these materials and other characteristics such as the predictable neutron losses due to the formation of radioactive elements of extremely high neutron capture cross section.

  3. NEUTRONIC REACTOR

    DOEpatents

    Wigner, E.P.; Weinberg, A.W.; Young, G.J.

    1958-04-15

    A nuclear reactor which uses uranium in the form of elongated tubes as fuel elements and liquid as a coolant is described. Elongated tubular uranium bodies are vertically disposed in an efficient neutron slowing agent, such as graphite, for example, to form a lattice structure which is disposed between upper and lower coolant tanks. Fluid coolant tubes extend through the uranium bodies and communicate with the upper and lower tanks and serve to convey the coolant through the uranium body. The reactor is also provided with means for circulating the cooling fluid through the coolant tanks and coolant tubes, suitable neutron and gnmma ray shields, and control means.

  4. The dynamics of narrative writing in primary grade children: writing process factors predict story quality.

    PubMed

    von Koss Torkildsen, Janne; Morken, Frøydis; Helland, Wenche A; Helland, Turid

    In this study of third grade school children, we investigated the association between writing process measures recorded with key stroke logging and the final written product. Moreover, we examined the cognitive predictors of writing process and product measures. Analyses of key strokes showed that while most children spontaneously made local online revisions while writing, few revised previously written text. Children with good reading and spelling abilities made more online revisions than their peers. Two process factors, transcription fluency and online revision activity, contributed to explaining variance in narrative macrostructural quality and story length. As for cognitive predictors, spelling was the only factor that gave a unique contribution to explaining variance in writing process factors. Better spelling was associated with more revisions and faster transcription. The results show that developing writers' ability to make online revisions in creative writing tasks is related to both the quality of the final written product and to individual literacy skills. More generally, the findings indicate that investigations of the dynamics of the writing process may provide insights into the factors that contribute to creative writing during early stages of literacy.

  5. Risk factors affecting chemical and bacteriological quality of bulk tank milk in Kerman, Iran.

    PubMed

    Mansouri-Najand, Ladan; Rezaii, Zeinab

    2015-01-01

    Milk is often described as a complete food because it contains protein, sugar, fat, vitamins, and minerals. This study was performed to investigate risk factors affecting chemical and bacteriological quality of bulk tank milk. According to the following conducted experiments, the milk was divided into two standard and non-standard groups. Then, effect of risk factors on making the samples non-standard was studied. Risk factors such as type of milk delivery unit, distance of cattle farm from plant, size of herd, education level of stockbreeders, capacity of milk transport tank, capacity of cooler device, and number of workers employed in cattle farms were evaluated in this study. Microbial and chemical evaluations were performed. Beta-lactam antibiotic residues and somatic cell count were specified. At the same time, the stockbreeders who referred to the plant were given some questionnaires and the mentioned primary questions were asked. After collecting the data, logistic regression model was used. According to the obtained results and comparison with Iran's national standard, 26 out of 109 samples were determined to be at standard level and 83 ones had at least one out-of-standard factor. The results obtained from the model demonstrated significant effect of education of stockbreeders and capacity of cooler devices on the milk quality. Education of stockbreeders could greatly affect management of a cattle farm unit.

  6. Water quality in turkey farms in Khemisset (Morocco) and potential risk factors.

    PubMed

    El Allaoui, A; Rhazi Filali, F; Derouich, A

    2016-12-01

    The objectives of this study were to assess the microbiological and physical/chemical quality of water in broiler turkey farms in the province of Khemisset (north-western Morocco) and, based on a questionnaire, to ascertain potential risk factors for contamination of drinking water with faecal coliforms. A total of 80 samples were collected and analysed in 20 farms (four from each farm). At the main inlet to the water line at the entrance to each turkey house, 100% of the samples were of unacceptable quality in terms of faecal coliforms, Escherichia coli, faecal streptococci, sulphitereducing anaerobes and enterococci. A significant reduction in microbiological contamination of the water line (p < 0.05) was observed on Day 60. While more than 90% of the samples were of satisfactory quality in terms of pH, nitrites, conductivity, nitrates and iron, only 35% were satisfactory in terms of total hardness and only 20% met quality standards for ammonium content. The factors affecting levels of contamination with faecal coliforms were water chlorination (p = 0.065; odds ratio = 14; 90% confidence interval [CI] = 1.14-71), cleaning and disinfection (p = 0.028; odds ratio = 14; 95% CI = 1.25-156.6) and antibiotic treatment (p = 0.001; odds ratio = 6; 95% CI = 2.1-35.2). To improve water quality in poultry farms, farmers are advised to protect wells from contamination and to install water purification units (pre-oxidation, coagulation, flocculation, disinfection). In addition, turkey houses and rearing equipment should be rigorously cleaned and disinfected between each batch of birds.

  7. Effects of various factors on sleep disorders and quality of life in Parkinson's disease.

    PubMed

    Telarovic, Srdjana; Mijatovic, Dragana; Telarovic, Irma

    2015-12-01

    In Parkinson's disease (PD), sleep disorders (SD) occur as a result of the neurochemical changes in sleep centres, neurodegenerative changes in dopaminergic neurons, and other factors. The most common SD include excessive daytime sleepiness, insomnia, restless legs syndrome and nocturia. The aim of the study was to compare quality of sleep, as a factor that greatly impacts quality of life (QoL), between PD patients and a control group and to further examine SD in the PD group with focus on incidence and SD types as well as on effects various factors (age, sex, PD characteristics, medication usage) have on these disorders. The study included 110 patients who met the criteria for the diagnosis of PD and 110 age-matched healthy controls. We used the Pittsburgh Sleep Quality Index, PD Sleep Scale, Epworth Sleepiness Scale, PD QoL Questionnaire-8 and PD Questionnaire-39 (items 30 and 33). In the group with PD, we considered the duration of the disease, the stage of disease according to the Hoehn and Yahr scale, medications and their impact on the SD. The average duration of the disease was 6 years and the mean stage was 2.44. The result showed significant differences in the sleep quality between groups. In the PD group, SD differences were also found according to gender, duration of the disease and medication usage. The most common SD were fragmented sleep, insomnia and nocturia. To improve the QoL of PD patients, it is necessary to pay more attention to detecting and solving SD.

  8. Amorphous Silicon Based Neutron Detector

    SciTech Connect

    Xu, Liwei

    2004-12-12

    Various large-scale neutron sources already build or to be constructed, are important for materials research and life science research. For all these neutron sources, neutron detectors are very important aspect. However, there is a lack of a high-performance and low-cost neutron beam monitor that provides time and temporal resolution. The objective of this SBIR Phase I research, collaboratively performed by Midwest Optoelectronics, LLC (MWOE), the University of Toledo (UT) and Oak Ridge National Laboratory (ORNL), is to demonstrate the feasibility for amorphous silicon based neutron beam monitors that are pixilated, reliable, durable, fully packaged, and fabricated with high yield using low-cost method. During the Phase I effort, work as been focused in the following areas: 1) Deposition of high quality, low-defect-density, low-stress a-Si films using very high frequency plasma enhanced chemical vapor deposition (VHF PECVD) at high deposition rate and with low device shunting; 2) Fabrication of Si/SiO2/metal/p/i/n/metal/n/i/p/metal/SiO2/ device for the detection of alpha particles which are daughter particles of neutrons through appropriate nuclear reactions; and 3) Testing of various devices fabricated for alpha and neutron detection; As the main results: · High quality, low-defect-density, low-stress a-Si films have been successfully deposited using VHF PECVD on various low-cost substrates; · Various single-junction and double junction detector devices have been fabricated; · The detector devices fabricated have been systematically tested and analyzed. · Some of the fabricated devices are found to successfully detect alpha particles. Further research is required to bring this Phase I work beyond the feasibility demonstration toward the final prototype devices. The success of this project will lead to a high-performance, low-cost, X-Y pixilated neutron beam monitor that could be used in all of the neutron facilities worldwide. In addition, the technologies

  9. The endocrine interface of environmental and egg factors affecting chick quality.

    PubMed

    Decuypere, E; Bruggeman, V

    2007-05-01

    Day-old chicks are the endproduct of the hatchery industry and form important starting material for the broiler farms. The major objective is to obtain a high hatchability of marketable chicks and a low spread of hatch. For the farmers, these chicks have to perform well, which is translated in high viability, high growth rate, high breast meat yield, and low feed conversion. A good-quality 1-d-old chick is hence a crucial hinge between the hatchery and the broiler farm. Moreover, maximal hatchability is not always synonymous with maximal posthatch viability and growth potential of the chick. Quantitative and qualitative scoring of chick quality is assessed. We will briefly discuss some recently developed scoring systems, which will convert differences in qualitative parameters into a quantitative score. Preincubation factors such as egg storage duration and age of broiler breeders, as well as incubation conditions, affect day-old chick quality and subsequent broiler performance. Heat production and metabolism, hormonal balances of thyroid hormones and corticosterone, and gas exchange (O(2), CO(2)) are of fundamental importance for embryonic development and survival during incubation. Results from our studies indicated that embryos with higher pCO(2) levels in the air cell and higher triiodothyronine-thyroxine ratios at internal pipping or in the newly hatched chicks had higher hatchability, chick quality, and posthatch chick growth until 7 d of age. Incubation factors such as temperature, turning conditions, or gaseous environment also affect development, change concentrations of hormones related to metabolism and growth of the embryo, and in this way affect 1-d-old chick quality. Moreover, the spread of the hatch process is affected by incubation conditions as well as by the aforementioned preincubation factors. Depending on the spread of the hatching curve together with the place in the sequence of hatching (early or late) and in interaction with quality of the

  10. Analysis of ecological quality of the environment and influencing factors in China during 2005-2010.

    PubMed

    Wang, Shi-Xin; Yao, Yao; Zhou, Yi

    2014-01-30

    Since the twentieth century, China has been facing various kinds of environmental problems. It is necessary to evaluate and analyze the ecological status of the environment over China, which is of great importance for environmental protection measures. In this article, an Eco-environmental Quality Index (EQI) model is established using national remote sensing land-use data, NDVI data from MODIS and other statistical data. The model is used to evaluate the ecological status over China during 2005, 2008 and 2010, and spatial and temporal variations in EQI are analyzed during the period 2005-2010. We also discuss important factors affecting ecological quality, with special emphasis on meteorological conditions (including rainfall and sunshine duration) and anthropogenic factors (including normalized population and gross domestic product densities). The results show that, EQIs in northwestern China are generally lower than those in the southeast of the country, presenting a ladder-like distribution. There is significant correlation between EQI, rainfall and sunshine duration. Population density and GDP also have some relation to EQI. On the whole, the environmental quality results showed little variation during 2005-2010, with national average EQIs of 54.86, 55.07 and 54.43 in 2005, 2008 and 2010, respectively. During 2005-2010, differences in EQI were observed at the local level, but those at the provincial level were small.

  11. Health-related quality of life and related factors of military police officers

    PubMed Central

    2014-01-01

    Purpose The present study aimed to determine the effect of demographic characteristics, occupation, anthropometric indices, and leisure-time physical activity levels on coronary risk and health-related quality of life among military police officers from the State of Santa Catarina, Brazil. Methods The sample included 165 military police officers who fulfilled the study’s inclusion criteria. The International Physical Activity Questionnaire and the Short Form Health Survey were used, in addition to a spreadsheet of socio-demographic, occupational and anthropometric data. Statistical analyses were performed using descriptive analysis followed by Spearman Correlation and multiple linear regression analysis using the backward method. Results The waist-to-height ratio was identified as a risk factor low health-related quality of life. In addition, the conicity index, fat percentage, years of service in the military police, minutes of work per day and leisure-time physical activity levels were identified as risk factors for coronary disease among police officers. Conclusions These findings suggest that the Military Police Department should adopt an institutional policy that allows police officers to practice regular physical activity in order to maintain and improve their physical fitness, health, job performance, and quality of life. PMID:24766910

  12. A time-domain Discontinuous Galerkin method for mechanical resonator quality factor computations

    NASA Astrophysics Data System (ADS)

    Govindjee, Sanjay; Persson, Per-Olof

    2012-08-01

    Numerical simulations are becoming increasingly important in the design of micromechanical resonators, in particular for the prediction of complex frequency response in high quality devices where damping is controlled by anchor losses. Frequency based approaches have been shown to predict these accurately, however, they require the solution of eigenvalue problems or the inversion of Helmholtz-type operators which are known to be very difficult for large-scale iterative solvers. We propose using a time-domain approach instead, where a broadband input signal is propagated through the system with a local explicit time-stepper. This is achieved using a new high-order Discontinuous Galerkin (DG) discretization for the linear elasticity equations, in particular a second-order formulation with Compact DG fluxes and a Runge-Kutta time integrator, where the block-diagonal mass matrices allow for efficient, stable, and accurate time stepping. Our solver scales well on distributed parallel computers, even in three spatial dimension and for large problem sizes. The resulting output signal is analyzed using a well-known filter diagonalization method, which is capable of finding accurate frequencies and quality factors for as little as a hundred periods of data. We validate the properties of our scheme on model problems, and demonstrate the feasibility of our proposed analysis process on two high quality factor disk resonators, using an axisymmetric formulation as well as full three dimensional simulations which is shown to scale well.

  13. Neutronic reactor

    DOEpatents

    Carleton, John T.

    1977-01-25

    A graphite-moderated nuclear reactor includes channels between blocks of graphite and also includes spacer blocks between adjacent channeled blocks with an axis of extension normal to that of the axis of elongation of the channeled blocks to minimize changes in the physical properties of the graphite as a result of prolonged neutron bombardment.

  14. NEUTRONIC REACTORS

    DOEpatents

    Anderson, H.L.

    1958-10-01

    The design of control rods for nuclear reactors are described. In this design the control rod consists essentially of an elongated member constructed in part of a neutron absorbing material and having tube means extending therethrough for conducting a liquid to cool the rod when in use.

  15. Ambient air quality trends and driving factor analysis in Beijing, 1983-2007.

    PubMed

    Zhang, Ju; Ouyang, Zhiyun; Miao, Hong; Wang, Xiaoke

    2011-01-01

    The rapid development in Beijing, the capital of China, has resulted in serious air pollution problems. Meanwhile great efforts have been made to improve the air quality, especially since 1998. The variation in air quality under the interaction of pollution and control in this mega city has attracted much attention. We analyzed the changes in ambient air quality in Beijing since the 1980's using the Daniel trend test based on data from long-term monitoring stations. The results showed that different pollutants displayed three trends: a decreasing trend, an increasing trend and a flat trend. SO2, dustfall, B[a]P, NO2 and PM10 fit decreasing trend pattern, while NOx showed an increasing trend, and CO, ozone pollution, total suspended particulate (TSP), as well as Pb fit the flat trend. The cause of the general air pollution in Beijing has changed from being predominantly related to coal burning to mixed traffic exhaust and coal burning related pollution. Seasonally, the pollution level is typically higher during the heating season from November to the following March. The interaction between pollution sources change and implementation of air pollution control measures was the main driving factor that caused the variation in air quality. Changes of industrial structure and improved energy efficiency, the use of clean energy and preferred use of clean coal, reduction in pollution sources, and implementation of advanced environmental standards have all contributed to the reduction in air pollution, particularly since 1998.

  16. Diet quality is inversely related to cardiovascular risk factors in adults.

    PubMed

    Nicklas, Theresa A; O'Neil, Carol E; Fulgoni, Victor L

    2012-12-01

    The goal of the study was to determine if there was an association between diet quality and cardiovascular risk factors (CVRF) in adults. NHANES 2001-2008 data were used to compare diet quality, as determined by using 2005 Healthy Eating Index (HEI-2005) scores, and CVRF in adults aged ≥19 y (n = 18,988; 51% men, 50% white, 21% African American, 25% Hispanic American, 4% other). HEI-2005 scores were calculated by using one 24-h dietary recall collected from the participants. Weight and adiposity, blood pressure, and CVRF were measured. Regression analyses were conducted to assess the linear relationship of CVRF and HEI-2005 scores by using appropriate covariates accounting for sample weights and the complex sample design of NHANES. OR were calculated for HEI quartiles and CVRF. BMI (P < 0.0001), waist circumference (WC) (P < 0.0001), diastolic blood pressure (P = 0.0002), C-reactive protein (P = 0.0016), total cholesterol (P = 0.0006), LDL cholesterol (P = 0.0039), and metabolic syndrome (P = 0.0035) were inversely associated with HEI-2005. HDL cholesterol significantly (P = 0.0048) increased across HEI-2005 quartiles. Compared with the lowest HEI-2005 quartile, individuals with the highest diet quality (HEI-2005 quartile 4) were less likely to be overweight or obese (34%) or have elevated WC (35%), elevated blood pressure (26%), metabolic syndrome (35%), and decreased HDL-cholesterol concentrations (21%). Data suggest that diet quality is inversely associated with several CVRF.

  17. Local quality functions for graph clustering with non-negative matrix factorization

    NASA Astrophysics Data System (ADS)

    van Laarhoven, Twan; Marchiori, Elena

    2014-12-01

    Many graph clustering quality functions suffer from a resolution limit, namely the inability to find small clusters in large graphs. So-called resolution-limit-free quality functions do not have this limit. This property was previously introduced for hard clustering, that is, graph partitioning. We investigate the resolution-limit-free property in the context of non-negative matrix factorization (NMF) for hard and soft graph clustering. To use NMF in the hard clustering setting, a common approach is to assign each node to its highest membership cluster. We show that in this case symmetric NMF is not resolution-limit free, but that it becomes so when hardness constraints are used as part of the optimization. The resulting function is strongly linked to the constant Potts model. In soft clustering, nodes can belong to more than one cluster, with varying degrees of membership. In this setting resolution-limit free turns out to be too strong a property. Therefore we introduce locality, which roughly states that changing one part of the graph does not affect the clustering of other parts of the graph. We argue that this is a desirable property, provide conditions under which NMF quality functions are local, and propose a novel class of local probabilistic NMF quality functions for soft graph clustering.

  18. BEAM QUALITY CORRECTION FACTORS FOR KAP METERS FOR LIGHTLY AND HEAVILY FILTERED X-RAY BEAMS.

    PubMed

    Herrnsdorf, L; Petersson, H

    2016-06-01

    Kerma-area product (KAP) meters have a pronounced energy dependence when measuring air KAP for lightly filtered X-ray beams (RQR). Today, it is also common with more heavily filtered beams. In this work, the energy dependence for lightly as well as heavily filtered beams (RQC) was investigated for several KAP meter models. The relative energy dependence of the readings of an external and an internal KAP meter was determined relative to an ionisation chamber, which had been calibrated at the primary standards laboratory. As a complement to the measurements, the sensitivity of a KAP meter for various X-ray beam qualities was modelled using Monte Carlo simulations of photon transport and absorption. The result showed a variation in relative energy dependence of up to 30 % for KAP meters for RQC beam qualities compared with RQR qualities. A reduced sensitivity of KAP meters for heavily filtered beams in comparison with lightly filtered ones was found, and it is important that the beam-specific radiation quality correction factors are applied to correct the registered KAP values.

  19. Factors dominating stratification cycle and seasonal water quality variation in a Korean estuarine reservoir.

    PubMed

    Lee, Young Geun; Kang, Joo-Hyon; Ki, Seo Jin; Cha, Sung Min; Cho, Kyung Hwa; Lee, Yun Seok; Park, Yongeun; Lee, Seung Won; Kim, Joon Ha

    2010-05-01

    A comprehensive monitoring program was conducted during 2005-2007 to investigate seasonal variations of hydrologic stability and water quality in the Yeongsan Reservoir (YSR), located at the downstream end of the Yeongsan River, Korea. A principal component analysis (PCA) was performed to identify factors dominating the seasonal water quality variation from a large suite of measured data--11 physico-chemical parameters from 48 sampling sites. The results showed that three principal components explained approximately 62% of spatio-seasonal water quality variation, which are related to stratifications, pollutant loadings and resultant eutrophication, and the advective mixing process during the episodic rainfall-runoff events. A comparison was then made between YSR and an upstream freshwater reservoir (Damyang Reservoir, DYR) in the same river basin during an autumn season. It was found that the saline stratification and pollutant input from the upstream contributed to greater concentrations of nutrients and organic matter in YSR compared to DYR. In YSR, saline stratification in combination with thermal stratification was a dominant cause of the longer period (for two consecutive seasons) of hypoxic conditions at the reservoir bottom. The results presented here will help better understand the season- and geography-dependent characteristics of reservoir water quality in Asian Monsoon climate regions such as Korea.

  20. Direct measurement of electron beam quality conversion factors using water calorimetry

    SciTech Connect

    Renaud, James Seuntjens, Jan; Sarfehnia, Arman; Marchant, Kristin; McEwen, Malcolm; Ross, Carl

    2015-11-15

    Purpose: In this work, the authors describe an electron sealed water calorimeter (ESWcal) designed to directly measure absorbed dose to water in clinical electron beams and its use to derive electron beam quality conversion factors for two ionization chamber types. Methods: A functioning calorimeter prototype was constructed in-house and used to obtain reproducible measurements in clinical accelerator-based 6, 9, 12, 16, and 20 MeV electron beams. Corrections for the radiation field perturbation due to the presence of the glass calorimeter vessel were calculated using Monte Carlo (MC) simulations. The conductive heat transfer due to dose gradients and nonwater materials was also accounted for using a commercial finite element method software package. Results: The relative combined standard uncertainty on the ESWcal dose was estimated to be 0.50% for the 9–20 MeV beams and 1.00% for the 6 MeV beam, demonstrating that the development of a water calorimeter-based standard for electron beams over such a wide range of clinically relevant energies is feasible. The largest contributor to the uncertainty was the positioning (Type A, 0.10%–0.40%) and its influence on the perturbation correction (Type B, 0.10%–0.60%). As a preliminary validation, measurements performed with the ESWcal in a 6 MV photon beam were directly compared to results derived from the National Research Council of Canada (NRC) photon beam standard water calorimeter. These two independent devices were shown to agree well within the 0.43% combined relative uncertainty of the ESWcal for this beam type and quality. Absorbed dose electron beam quality conversion factors were measured using the ESWcal for the Exradin A12 and PTW Roos ionization chambers. The photon-electron conversion factor, k{sub ecal}, for the A12 was also experimentally determined. Nonstatistically significant differences of up to 0.7% were found when compared to the calculation-based factors listed in the AAPM’s TG-51 protocol

  1. Sleep quality and associated factors in ankylosing spondylitis: relationship with disease parameters, psychological status and quality of life.

    PubMed

    Batmaz, İbrahim; Sarıyıldız, Mustafa Akif; Dilek, Banu; Bez, Yasin; Karakoç, Mehmet; Çevik, Remzi

    2013-04-01

    The aim of this study is to investigate sleep quality in patients with ankylosing spondylitis (AS) and to evaluate the relationship of the disease parameters with sleep disturbance. Eighty AS patients (60 males and 20 females) fulfilling the modified New York criteria, and 52 age- and gender-matched controls (33 males and 19 females) were enrolled in the study. Sleep quality was assessed using the Pittsburgh Sleep Quality Index (PSQI). Pain was measured by visual analogue scale. The disease activity and functional status were assessed by the Bath AS disease Activity Index and the Bath AS Functional Index. The Bath AS Metrology Index was used to evaluate mobility restrictions, and the Bath AS Radiology Index was employed to evaluate the radiological damage. The psychological status and quality of life were assessed with the hospital anxiety-depression scale and AS quality of life scale. The patients with AS had significantly more unfavourable scores in the subjective sleep quality, habitual sleep efficiency domains (p < 0.001) and the total PSQI score (p < 0.05). Poor sleep quality (total PSQI score) was positively correlated with increased pain, poor quality of life, higher depressed mood, higher disease activity and mobility restrictions. Pain was also an independent contributor to poorer sleep quality (p = 0.002). The sleep quality is disturbed in patients with AS. The lower quality of sleep is greatly associated with the pain, disease activity, depression, quality of life and increased limitation of mobility.

  2. Methods for absorbing neutrons

    DOEpatents

    Guillen, Donna P [Idaho Falls, ID; Longhurst, Glen R [Idaho Falls, ID; Porter, Douglas L [Idaho Falls, ID; Parry, James R [Idaho Falls, ID

    2012-07-24

    A conduction cooled neutron absorber may include a metal matrix composite that comprises a metal having a thermal neutron cross-section of at least about 50 barns and a metal having a thermal conductivity of at least about 1 W/cmK. Apparatus for providing a neutron flux having a high fast-to-thermal neutron ratio may include a source of neutrons that produces fast neutrons and thermal neutrons. A neutron absorber positioned adjacent the neutron source absorbs at least some of the thermal neutrons so that a region adjacent the neutron absorber has a fast-to-thermal neutron ratio of at least about 15. A coolant in thermal contact with the neutron absorber removes heat from the neutron absorber.

  3. Recent Advances in Neutron Physics

    ERIC Educational Resources Information Center

    Feshbach, Herman; Sheldon, Eric

    1977-01-01

    Discusses new studies in neutron physics within the last decade, such as ultracold neutrons, neutron bottles, resonance behavior, subthreshold fission, doubly radiative capture, and neutron stars. (MLH)

  4. Studies on kinetics of water quality factors to establish water transparency model in Neijiang River, China.

    PubMed

    Li, Ronghui; Pan, Wei; Guo, Jinchuan; Pang, Yong; Wu, Jianqiang; Li, Yiping; Pan, Baozhu; Ji, Yong; Ding, Ling

    2014-05-01

    The basis for submerged plant restoration in surface water is to research the complicated dynamic mechanism of water transparency. In this paper, through the impact factor analysis of water transparency, the suspended sediment, dissolved organic matter, algae were determined as three main impactfactors for water transparency of Neijiang River in Eastern China. And the multiple regression equation of water transparency and sediment concentration, permanganate index, chlorophyll-a concentration was developed. Considering the complicated transport and transformation of suspended sediment, dissolved organic matter and algae, numerical model of them were developed respectively for simulating the dynamic process. Water transparency numerical model was finally developed by coupling the sediment, water quality, and algae model. These results showed that suspended sediment was a key factor influencing water transparency of Neijiang River, the influence of water quality indicated by chemical oxygen demand and algal concentration indicated by chlorophyll a were indeterminate when their concentrations were lower, the influence was more obvious when high concentrations are available, such three factors showed direct influence on water transparency.

  5. Association between lifestyle factors and quality-adjusted life years in the EPIC-NL cohort.

    PubMed

    Fransen, Heidi P; May, Anne M; Beulens, Joline W J; Struijk, Ellen A; de Wit, G Ardine; Boer, Jolanda M A; Onland-Moret, N Charlotte; Hoekstra, Jeljer; van der Schouw, Yvonne T; Bueno-de-Mesquita, H Bas; Peeters, Petra H M

    2014-01-01

    The aim of our study was to relate four modifiable lifestyle factors (smoking status, body mass index, physical activity and diet) to health expectancy, using quality-adjusted life years (QALYs) in a prospective cohort study. Data of the prospective EPIC-NL study were used, including 33,066 healthy men and women aged 20-70 years at baseline (1993-7), followed until 31-12-2007 for occurrence of disease and death. Smoking status, body mass index, physical activity and adherence to a Mediterranean-style diet (excluding alcohol) were investigated separately and combined into a healthy lifestyle score, ranging from 0 to 4. QALYs were used as summary measure of healthy life expectancy, combining a person's life expectancy with a weight for quality of life when having a chronic disease. For lifestyle factors analyzed separately the number of years living longer in good health varied from 0.12 year to 0.84 year, after adjusting for covariates. A combination of the four lifestyle factors was positively associated with higher QALYs (P-trend <0.0001). A healthy lifestyle score of 4 compared to a score of 0 was associated with almost a 2 years longer life in good health (1.75 QALYs [95% CI 1.37, 2.14]).

  6. Academic mobility as a key factor of quality assurance in tertiary education

    NASA Astrophysics Data System (ADS)

    Voroshilova, Anna A.

    2015-01-01

    Academic mobility of both faculty and students forms a critical element of the international dimension of higher education and is one of the most important factors of quality assurance of higher education institutions worldwide. Internationalization and globalization of Russian higher education system is having one of the major impacts on the quality management and assurance. Faculty and student mobility figures are now one of the core factors for obtaining state accreditation for Russian universities as well as an important indicator showing the university success and prestige. The aim of the paper is a closer look at the perspectives and results of the academic mobility, the factors stimulating and discouraging mobility, and the outcomes of the mobility influencing the education in Russian universities. Siberian State Aerospace University has had more than 10 years experience in organizing student mobility. Most of the problems in carrying out international activities are common for the whole Russia but still there are some peculiarities featuring technical universities situated in the centre of Russia.

  7. Neutron sources based on medical Linac

    NASA Astrophysics Data System (ADS)

    Costa, M.; Durisi, E.; Monti, V.; Visca, L.; Zanini, A.; Giannini, G.

    2016-11-01

    The paper proposes the study of a novel photo-neutron source based on a medical high-energy electron Linac. Previous studies by the authors already demonstrated the possibility to obtain with this technique a thermal neutron flux of the order of 107 cm-2 s-1 . This paper shows possible Linac's setup and a new photo-converter design to reach a thermal neutron flux around 6×107 cm-2 s-1 , keeping a reasonable high quality of the beam with respect to fast neutron and gamma contaminations.

  8. Neutron reflecting supermirror structure

    DOEpatents

    Wood, James L.

    1992-01-01

    An improved neutron reflecting supermirror structure comprising a plurality of stacked sets of bilayers of neutron reflecting materials. The improved neutron reflecting supermirror structure is adapted to provide extremely good performance at high incidence angles, i.e. up to four time the critical angle of standard neutron mirror structures. The reflection of neutrons striking the supermirror structure at a high critical angle provides enhanced neutron throughput, and hence more efficient and economical use of neutron sources.

  9. Neutron reflecting supermirror structure

    DOEpatents

    Wood, J.L.

    1992-12-01

    An improved neutron reflecting supermirror structure comprising a plurality of stacked sets of bilayers of neutron reflecting materials. The improved neutron reflecting supermirror structure is adapted to provide extremely good performance at high incidence angles, i.e. up to four time the critical angle of standard neutron mirror structures. The reflection of neutrons striking the supermirror structure at a high critical angle provides enhanced neutron throughput, and hence more efficient and economical use of neutron sources. 2 figs.

  10. Unravel biophysical factors on river water quality response in Chilean Central-Southern watersheds.

    PubMed

    Yevenes, Mariela A; Arumí, José L; Farías, Laura

    2016-05-01

    Identifying the key anthropogenic (land uses) and natural (topography and climate) biophysical drivers affecting river water quality is essential for efficient management of water resources. We tested the hypothesis that water quality can be predicted by different biophysical factors. Multivariate statistics based on a geographical information system (GIS) were used to explore the influence of factors (i.e., precipitation, topography, and land uses) on water quality (i.e., nitrate (NO 3 (-)), phosphate (PO 4 (3-)), silicate (Si(OH)4), dissolved oxygen (DO), suspended solids (TSS), biological oxygen demand (DO), temperature (T), conductivity (EC), and pH) for two consecutive years in the Itata and Biobío river watersheds, Central Chile (36° 00' and 38° 30'). The results showed that (NO 3 (-)), (PO 4 (3-)), Si(OH)4, TSS, EC, and DO were higher during rainy season (austral fall, winter, and spring), whereas BOD and temperature were higher during dry season. The spatial variation of these parameters in both watersheds was related to land use, topography (e.g., soil moisture, soil hydrological group, and erodability), and precipitation. Soil hydrological group and soil moisture were the strongest explanatory predictors for PO 4 (3-) , Si(OH)4 and EC in the river, followed by land use such as agriculture for NO 3 (-) and DO and silviculture for TSS and Si(OH)4. High-resolution water leaching and runoff maps allowed us to identify agriculture areas with major probability of water leaching and higher probability of runoff in silviculture areas. Moreover, redundancy analysis (RDA) revealed that land uses (agriculture and silviculture) explained in 60 % the river water quality variation. Our finding highlights the vulnerability of Chilean river waters to different biophysical drivers, rather than climate conditions alone, which is amplified by human-induced degradation.

  11. Gallium nitride L3 photonic crystal cavities with an average quality factor of 16 900 in the near infrared

    NASA Astrophysics Data System (ADS)

    Vico Triviño, Noelia; Minkov, Momchil; Urbinati, Giulia; Galli, Matteo; Carlin, Jean-François; Butté, Raphaël; Savona, Vincenzo; Grandjean, Nicolas

    2014-12-01

    Photonic crystal point-defect cavities were fabricated in a GaN free-standing photonic crystal slab. The cavities are based on the popular L3 design, which was optimized using an automated process based on a genetic algorithm, in order to maximize the quality factor. Optical characterization of several individual cavity replicas resulted in an average unloaded quality factor Q = 16 900 at the resonant wavelength λ˜1.3 μm , with a maximal measured Q value of 22 500. The statistics of both the quality factor and the resonant wavelength are well explained by first-principles simulations including fabrication disorder and background optical absorption.

  12. Transmission factors for the penetration of neutron and photon fluence into wood-frame dwellings, 1990 (TF90)

    SciTech Connect

    Rhoades, W.A.; Lillie, R.A.; Emmett, M.B.

    1992-05-01

    An earlier study at Oak Ridge calculated radiation doses to persons inside reinforced concrete buildings during the exposure at Nagasaki. The ``DS86`` study conducted at several laboratories in the United States and Japan concentrated on persons inside wood-frame dwellings at both Nagasaki and Hiroshima. The present study is directed toward applying the general technical approach of the DS86. Numerous simplifications were indicated as a result of the earlier research, and the numerical results are represented as ``transmission factors`` relating radiation outside the dwellings to doses received by individuals within. An advantage of this method is that the transmission factors can be presented in tables that can be reviewed, inspected, and applied in a very tangible and straightforward manner.

  13. Transmission factors for the penetration of neutron and photon fluence into wood-frame dwellings, 1990 (TF90)

    SciTech Connect

    Rhoades, W.A.; Lillie, R.A.; Emmett, M.B.

    1992-05-01

    An earlier study at Oak Ridge calculated radiation doses to persons inside reinforced concrete buildings during the exposure at Nagasaki. The DS86'' study conducted at several laboratories in the United States and Japan concentrated on persons inside wood-frame dwellings at both Nagasaki and Hiroshima. The present study is directed toward applying the general technical approach of the DS86. Numerous simplifications were indicated as a result of the earlier research, and the numerical results are represented as transmission factors'' relating radiation outside the dwellings to doses received by individuals within. An advantage of this method is that the transmission factors can be presented in tables that can be reviewed, inspected, and applied in a very tangible and straightforward manner.

  14. Quality factor of luminescent solar concentrators and practical concentration limits attainable with semiconductor quantum dots

    DOE PAGES

    Klimov, Victor I.; Baker, Thomas A.; Lim, Jaehoon; ...

    2016-05-09

    In this study, luminescent solar concentrators (LSCs) can be utilized as both large-area collectors of solar radiation supplementing traditional photovoltaic cells as well as semitransparent “solar windows” that provide a desired degree of shading and simultaneously serve as power-generation units. An important characteristic of an LSC is a concentration factor (C) that can be thought of as a coefficient of effective enlargement (or contraction) of the area of a solar cell when it is coupled to the LSC. Here we use analytical and numerical Monte Carlo modeling in addition to experimental studies of quantum-dot-based LSCs to analyze the factors thatmore » influence optical concentration in practical devices. Our theoretical model indicates that the maximum value of C achievable with a given fluorophore is directly linked to the LSC quality factor (QLSC) defined as the ratio of absorption coefficients at the wavelengths of incident and reemitted light. In fact, we demonstrate that the ultimate concentration limit (C0) realized in large-area devices scales linearly with the LSC quality factor and in the case of perfect emitters and devices without back reflectors is approximately equal to QLSC. To test the predictions of this model, we conduct experimental studies of LSCs based on visible-light emitting II–VI core/shell quantum dots with two distinct LSC quality factors. We also investigate devices based on near-infrared emitting CuInSexS2–x quantum dots for which the large emission bandwidth allows us to assess the impact of varied QLSC on the concentration factor by simply varying the detection wavelength. In all cases, we find an excellent agreement between the model and the experimental observations, suggesting that the developed formalism can be utilized for express evaluation of prospective LSC performance based on the optical spectra of LSC fluorophores, which should facilitate future efforts on the development of high-performance devices based on

  15. Quality factor of luminescent solar concentrators and practical concentration limits attainable with semiconductor quantum dots

    SciTech Connect

    Klimov, Victor I.; Baker, Thomas A.; Lim, Jaehoon; Velizhanin, Kirill A.; McDaniel, Hunter

    2016-05-09

    In this study, luminescent solar concentrators (LSCs) can be utilized as both large-area collectors of solar radiation supplementing traditional photovoltaic cells as well as semitransparent “solar windows” that provide a desired degree of shading and simultaneously serve as power-generation units. An important characteristic of an LSC is a concentration factor (C) that can be thought of as a coefficient of effective enlargement (or contraction) of the area of a solar cell when it is coupled to the LSC. Here we use analytical and numerical Monte Carlo modeling in addition to experimental studies of quantum-dot-based LSCs to analyze the factors that influence optical concentration in practical devices. Our theoretical model indicates that the maximum value of C achievable with a given fluorophore is directly linked to the LSC quality factor (QLSC) defined as the ratio of absorption coefficients at the wavelengths of incident and reemitted light. In fact, we demonstrate that the ultimate concentration limit (C0) realized in large-area devices scales linearly with the LSC quality factor and in the case of perfect emitters and devices without back reflectors is approximately equal to QLSC. To test the predictions of this model, we conduct experimental studies of LSCs based on visible-light emitting II–VI core/shell quantum dots with two distinct LSC quality factors. We also investigate devices based on near-infrared emitting CuInSexS2–x quantum dots for which the large emission bandwidth allows us to assess the impact of varied QLSC on the concentration factor by simply varying the detection wavelength. In all cases, we find an excellent agreement between the model and the experimental observations, suggesting that the developed formalism can be utilized for express evaluation of prospective LSC performance based on the optical spectra of LSC fluorophores, which should facilitate future efforts

  16. Differential absorbed dose distributions in lineal energy for neutrons and gamma rays at the mono-energetic neutron calibration facility.

    PubMed

    Takada, M; Baba, M; Yamaguchi, H; Fujitaka, K

    2005-01-01

    Absorbed dose distributions in lineal energy for neutrons and gamma rays of mono-energetic neutron sources from 140 keV to 15 MeV were measured in the Fast Neutron Laboratory at Tohoku University. By using both a tissue-equivalent plastic walled counter and a graphite-walled low-pressure proportional counter, absorbed dose distributions in lineal energy for neutrons were obtained separately from those for gamma rays. This method needs no knowledge of energy spectra and dose distributions for gamma rays. The gamma-ray contribution in this neutron calibration field >1 MeV neutron was <3%, while for <550 keV it was >40%. The measured neutron absolute absorbed doses per unit neutron fluence agreed with the LA150 evaluated kerma factors. By using this method, absorbed dose distributions in lineal energy for neutrons and gamma rays in an unknown neutron field can be obtained separately.

  17. Beam characterization at the Neutron Radiography Reactor

    SciTech Connect

    Sarah W. Morgan; Jeffrey C. King; Chad L. Pope

    2013-12-01

    The quality of a neutron-imaging beam directly impacts the quality of radiographic images produced using that beam. Fully characterizing a neutron beam, including determination of the beam's effective length-to-diameter ratio, neutron flux profile, energy spectrum, potential image quality, and beam divergence, is vital for producing quality radiographic images. This paper provides a characterization of the east neutron imaging beamline at the Idaho National Laboratory Neutron Radiography Reactor (NRAD). The experiments which measured the beam's effective length-to-diameter ratio and potential image quality are based on American Society for Testing and Materials (ASTM) standards. An analysis of the image produced by a calibrated phantom measured the beam divergence. The energy spectrum measurements consist of a series of foil irradiations using a selection of activation foils, compared to the results produced by a Monte Carlo n-Particle (MCNP) model of the beamline. The NRAD has an effective collimation ratio greater than 125, a beam divergence of 0.3 +_ 0.1 degrees, and a gold foil cadmium ratio of 2.7. The flux profile has been quantified and the facility is an ASTM Category 1 radiographic facility. Based on bare and cadmium covered foil activation results, the neutron energy spectrum used in the current MCNP model of the radiography beamline over-samples the thermal region of the neutron energy spectrum.

  18. Factors affecting the quality of anticoagulation with warfarin: experience of one cardiac centre

    PubMed Central

    Ciurus, Tomasz; Cichocka-Radwan, Anna

    2015-01-01

    Introduction The risk of complications in anticoagulation therapy can be reduced by maximising the percentage of time spent by the patient in the optimal therapeutic range (TTR). However, little is known about the predictors of anticoagulation control. The aim of this paper was to assess the quality of anticoagulant therapy in patients on warfarin and to identify the factors affecting its deterioration. Material and methods We studied 149 patients who required anticoagulant therapy with warfarin due to non-valvular atrial fibrillation and/or venous thromboembolism. Each patient underwent proper training regarding the implemented treatment and remained under constant medical care. Results The mean age of the patients was 68.8 ± 12.6 years, and 59% were male. A total of 2460 international normalised ratio (INR) measurements were collected during the 18-month period. The mean TTR in the studied cohort was 76 ± 21%, and the median was 80%. The level at which high-quality anticoagulation was recorded for this study was based on TTR values above 80%. Seventy-five patients with TTR ≥ 80% were included in the stable anticoagulation group (TTR ≥ 80%); the remaining 74 patients constituted the unstable anticoagulation group (TTR < 80%). According to multivariate stepwise regression analysis, the independent variables increasing the risk of deterioration of anticoagulation quality were: arterial hypertension (OR 2.74 [CI 95%: 1.06-7.10]; p = 0.038), amiodarone therapy (OR 4.22 [CI 95%: 1.30-13.70]; p = 0.017), and obesity (OR 1.11 [CI 95%: 1.02-1.21]; p = 0.013). Conclusions The presence of obesity, hypertension, or amiodarone therapy decreases the quality of anticoagulation with warfarin. High quality of anticoagulation can be achieved through proper monitoring and education of patients. PMID:26855650

  19. Factors Contributing to the Quality of Sibling Relationships for Adults With Schizophrenia

    PubMed Central

    Smith, Matthew J.; Greenberg, Jan S.

    2008-01-01

    Objectives Research suggests that the quality of sibling relationships has a significant impact on the lives of adults with schizophrenia. A life course perspective was used to guide an investigation of the predictors of the quality of the relationship between adults with schizophrenia and their siblings. Methods The data come from a longitudinal study of families of adults with schizophrenia. This study is based on a survey of 136 siblings of adults with schizophrenia. Multiple regression was used to estimate the predictors of sibling relationship quality. Results Siblings reported a better relationship when they grew up in a more cohesive family environment (beta=.16, p<.05) and when they experienced more personal gains from coping with the challenges of a brother’s or sister’s mental illness (beta=.37, p<.001). Siblings reported a worse relationship when they perceived their brother or sister with schizophrenia as having control over his or her symptoms (beta=−.18, p<.05), expressed greater fear of their brother’s or sister’s behavior (beta=−.17, p<.05), and indicated that their brother or sister had struck or threatened them at some point in their lives (beta=−.18, p<.05). Conclusions The quality of the sibling relationship is a major contributor to sibling involvement in the future and to the quality of life of adults with schizophrenia. By identifying the factors associated with positive sibling relationships, mental health providers will be better prepared to engage siblings in the treatment process and help promote stronger bonds of affection between adults with schizophrenia and their siblings. PMID:18182540

  20. Symmetric reflection line resonator and its quality factor modulation by a two-dimensional electron gas

    SciTech Connect

    Zhang, Miao-Lei; Deng, Guang-Wei; Li, Shu-Xiao; Li, Hai-Ou; Cao, Gang; Tu, Tao; Xiao, Ming; Guo, Guang-Can; Guo, Guo-Ping; Jiang, Hong-Wen; Siddiqi, Irfan

    2014-02-24

    We have designed and fabricated a half-wavelength reflection line resonator that consists of a pair of coupled microstrip lines on a GaAs/AlGaAs heterostructure. By changing the top gate voltage on a small square with a two-dimensional electron gas under the resonator, the quality factor was tuned over a large range from 2700 to below 600. Apart from being of fundamental interest, this gate modulation technique has the potential for use in on-chip resonator applications.

  1. Large quality factor in sheet metamaterials made from dark dielectric meta-atoms.

    PubMed

    Jain, Aditya; Tassin, Philippe; Koschny, Thomas; Soukoulis, Costas M

    2014-03-21

    Metamaterials--or artificial electromagnetic materials--can create media with properties unattainable in nature, but mitigating dissipation is a key challenge for their further development. Here, we demonstrate a low-loss metamaterial by exploiting dark bound states in dielectric inclusions coupled to the external waves by small nonresonant metallic antennas. We experimentally demonstrate a dispersion-engineered metamaterial based on a meta-atom made from alumina, and we show that its resonance has a much larger quality factor than metal-based meta-atoms. Finally, we show that our dielectric meta-atom can be used to create sheet metamaterials with negative permittivity or permeability.

  2. Silicon nitride membrane resonators at millikelvin temperatures with quality factors exceeding 108

    NASA Astrophysics Data System (ADS)

    Yuan, Mingyun; Cohen, Martijn A.; Steele, Gary A.

    2015-12-01

    We study the mechanical dissipation of the fundamental mode of millimeter-sized, high quality-factor (Q) metalized silicon nitride membranes at temperatures down to 14 mK using a three-dimensional optomechanical cavity. Below 200 mK, high-Q modes of the membranes show a diverging increase of Q with decreasing temperature, reaching Q =1.27 ×108 at 14 mK, an order of magnitude higher than that reported before. The ultra-low dissipation makes the membranes highly attractive for the study of optomechanics in the quantum regime, as well as for other applications of optomechanics such as microwave to optical photon conversion.

  3. Genetically designed L3 photonic crystal nanocavities with measured quality factor exceeding one million

    SciTech Connect

    Lai, Y.; Badolato, A.; Pirotta, S.; Urbinati, G.; Gerace, D.; Galli, M.; Minkov, M.; Savona, V.

    2014-06-16

    We report on the experimental realization of ultra-high quality factor (Q) designs of the L3-type photonic crystal nanocavity. Based on genetic optimization of the positions of few nearby holes, our design drastically improves the performance of the conventional L3 as experimentally confirmed by direct measurement of Q ≃ 2 × 10{sup 6} in a silicon-based photonic crystal membrane. Our devices rank among the highest Q/V ratios ever reported in photonic crystal cavities, holding great promise for the realization of integrated photonic platforms based on ultra-high-Q resonators.

  4. Chip scale mechanical spectrum analyzers based on high quality factor overmoded bulk acouslic wave resonators

    SciTech Connect

    Olsson, R. H., III

    2012-03-01

    The goal of this project was to develop high frequency quality factor (fQ) product acoustic resonators matched to a standard RF impedance of 50 {Omega} using overmoded bulk acoustic wave (BAW) resonators. These resonators are intended to serve as filters in a chip scale mechanical RF spectrum analyzer. Under this program different BAW resonator designs and materials were studied theoretically and experimentally. The effort resulted in a 3 GHz, 50 {Omega}, sapphire overmoded BAW with a fQ product of 8 x 10{sup 13}, among the highest values ever reported for an acoustic resonator.

  5. Quality of Life and its Association with Cardiovascular Risk Factors in a Community Health Care Program Population

    PubMed Central

    Martinelli, Luiz Mário Baptista; Mizutani, Bruno Moreira; Mutti, Anibal; Dèlia, Maria Paula Barbieri; Coltro, Rodrigo Soler; Matsubara, Beatriz Bojikian

    2008-01-01

    OBJECTIVE To evaluate quality of life in a population that attended a specific community event on health care education, and to investigate the association of their quality of life with the presence of cardiovascular risk factors INTRODUCTION Interest in health-related quality of life is growing worldwide as a consequence of increasing rates of chronic disease. However, little is known about the association between quality of life and cardiovascular risk factors. METHODS This study included 332 individuals. Demographics, blood pressure, body mass index, and casual glycemia were evaluated. The brief version of the World Health Organization Quality of Life questionnaire on quality of life was given to them. The medians of the scores obtained for the physical, psychological, emotional, and environmental domains were used as cutoffs to define “higher” and “lower” scores. A multinomial logistic regression model was used to define the parameters associated with lower scores. RESULTS Diabetes mellitus, dyslipidemia, and obesity were associated with lower scores in the physical domain. Dyslipidemia was also associeted with lower scores in the psychological domain. Male gender and regular physical activity had protective effects on quality of life. Aging was inversely associated with decreased quality of life in the environmental domain. CONCLUSION The presence of cardiovascular risk factors is related to a decreased quality of life. Conversely, male gender and regular physical activity had protective effects on quality of life. These findings suggest that exercising should be further promoted by health-related public programs, with a special focus on women. PMID:19061001

  6. Laser-vibrometric ultrasonic characterization of resonant modes and quality factors of Ge membranes

    PubMed Central

    Trushkevych, Oksana; A Shah, Vishal; Myronov, Maksym; E Halpin, John; D Rhead, Stephen; J Prest, Martin; R Leadley, David; S Edwards, Rachel

    2014-01-01

    The vibrations of a single-crystal germanium (Ge) membrane are studied in air and vacuum using laser vibrometry, in order to determine mechanical properties such as Q-factors, tensile stress, anisotropy, and robustness to shock. Resonance modes up to 3:2 are identified, giving a residual stress measurement of 0.22 GPa, consistent with the value obtained from x-ray relaxation studies. The membrane is found to be isotropic, with Q-factors ranging from around 40 at atmospheric pressure to over 3200 at mbar, significantly lower than those found in polycrystalline Ge micromechanical devices. The robustness to shock is explained through the high resonance mode frequencies and the dissipation mechanism into the substrate, which is a direct consequence of having a high quality film with low residual tensile stress, giving the potential for such films to be used in optoelectronic devices. PMID:27877665

  7. A primary role for release factor 3 in quality control during translation elongation in Escherichia coli.

    PubMed

    Zaher, Hani S; Green, Rachel

    2011-10-14

    Release factor 3 (RF3) is a GTPase found in a broad range of bacteria where it is thought to play a critical "recycling" role in translation by facilitating the removal of class 1 release factors (RF1 and RF2) from the ribosome following peptide release. More recently, RF3 was shown in vitro to stimulate a retrospective editing reaction on the bacterial ribosome wherein peptides carrying mistakes are prematurely terminated during protein synthesis. Here, we examine the role of RF3 in the bacterial cell and show that the deletion of this gene sensitizes cells to other perturbations that reduce the overall fidelity of protein synthesis. We further document substantial effects on mRNA stability and protein expression using reporter systems, native mRNAs and proteins. We conclude that RF3 plays a primary role in vivo in specifying the fidelity of protein synthesis thus impacting overall protein quantity and quality.

  8. Barium fluoride whispering-gallery-mode disk-resonator with one billion quality-factor.

    PubMed

    Lin, Guoping; Diallo, Souleymane; Henriet, Rémi; Jacquot, Maxime; Chembo, Yanne K

    2014-10-15

    We demonstrate a monolithic optical whispering-gallery-mode resonator fabricated with barium fluoride (BaF₂) with an ultra-high quality (Q) factor above 10⁹ at 1550 nm, and measured with both the linewidth and cavity-ring-down methods. Vertical scanning optical profilometry shows that the root mean square surface roughness of 2 nm is achieved for our mm-size disk. To the best of our knowledge, we show for the first time that one billion Q-factor is achievable by precision polishing in relatively soft crystals with mohs hardness of 3. We show that complex thermo-optical dynamics can take place in these resonators. Beside usual applications in nonlinear optics and microwave photonics, high-energy particle scintillation detection utilizing monolithic BaF₂ resonators potentially becomes feasible.

  9. A high-quality factor hybrid plasmonic nanocavity based on distributed Bragg reflectors

    NASA Astrophysics Data System (ADS)

    Tu, Linlin; Zhang, Chi; Huang, Zhong; Yau, Jason; Zhan, Peng; Wang, Zhenlin

    2016-09-01

    Herein, we propose a high-quality (Q) factor hybrid plasmonic nanocavity based on distributed Bragg reflectors (DBRs) with low propagation loss and extremely strong mode confinement. This hybrid plasmonic nanocavity is composed of a high-index cylindrical nanowire separated from a metal surface possessing shallow DBRs gratings by a sufficiently thin low-index dielectric layer. The hybrid plasmonic nanocavity possesses advantages such as a high Purcell factor (Fp) of up to nearly 20000 and a gain threshold approaching 266 cm-1 at 1550 nm, promising a greater potential in deep sub-wavelength lasing applications. Project supported by the National Key Basic Research Special Foundation of China (Grant Nos. 2012CB921501 and 2013CB632703) and the National Natural Science Foundation of China (Grant Nos. 11274160, 91221206, and 51271092).

  10. Facility for fast neutron irradiation tests of electronics at the ISIS spallation neutron source

    SciTech Connect

    Andreani, C.; Pietropaolo, A.; Salsano, A.; Gorini, G.; Tardocchi, M.; Paccagnella, A.; Gerardin, S.; Frost, C. D.; Ansell, S.; Platt, S. P.

    2008-03-17

    The VESUVIO beam line at the ISIS spallation neutron source was set up for neutron irradiation tests in the neutron energy range above 10 MeV. The neutron flux and energy spectrum were shown, in benchmark activation measurements, to provide a neutron spectrum similar to the ambient one at sea level, but with an enhancement in intensity of a factor of 10{sup 7}. Such conditions are suitable for accelerated testing of electronic components, as was demonstrated here by measurements of soft error rates in recent technology field programable gate arrays.

  11. Measurement of lineal-energy distributions for neutrons of 8 keV to 65 MeV by using a tissue-equivalent proportional counter.

    PubMed

    Nunomiya, T; Kim, E; Kurosaw, T; Taniguchi, S; Nakamura, T; Nakane, Y; Sakamoto, Y; Tanaka, S

    2002-01-01

    The lineal-energy spectra for monoenergetic and quasi-monoenergetic neutrons of 8 keV to 65 MeV were obtained using a tissue-equivalent proportional counter (TEPC). The frequency-mean lineal energy, the dose-average lineal energy and mean quality factor were estimated from the measured data. The neutron absorbed doses obtained with this TEPC were compared with the kerma coefticient for A-150 plastic defined by ICRP 26 and the mean quality factors were compared with the data of ICRP 74. respectively. These comparisons indicated good agreement between them.

  12. Adsorbate migration effects on continuous and discontinuous temperature-dependent transitions in the quality factors of graphene nanoresonators.

    PubMed

    Jiang, Jin-Wu; Wang, Bing-Shen; Park, Harold S; Rabczuk, Timon

    2014-01-17

    We perform classical molecular dynamics simulation to investigate the mechanisms underpinning the unresolved, experimentally observed temperature-dependent scaling transition in the quality factors of graphene nanomechanical resonators (GNMRs). Our simulations reveal that the mechanism underlying this temperature scaling phenomenon is the out-of-plane migration of adsorbates on GNMRs. Specifically, the migrating adsorbate undergoes frequent collisions with the GNMR, which strongly influences the resulting mechanical oscillation, and thus the quality factors. We also predict a discontinuous transition in the quality factor at a lower critical temperature, which results from the in-plane migration of the adsorbate. Overall, our work clearly demonstrates the strong effect of adsorbate migration on the quality factors of GNMRs.

  13. Factors influencing quality of life (QOL) for Korean patients with rheumatoid arthritis (RA).

    PubMed

    Cho, Soo-Kyung; Kim, Dam; Jun, Jae-Bum; Bae, Sang-Cheol; Sung, Yoon-Kyoung

    2013-01-01

    The aim of the study was to identify factors influencing the health-related quality of life (HR-QOL) for Korean RA patients and factors associated with each dimension of the EQ-5D. Two hundred and twenty-five RA patients were recruited from one University Hospital in Seoul, South Korea. Their clinical and socio-demographic data were widely collected by means of interviews, self-administered questionnaires, and clinical examinations. Multiple logistic regression analyses were performed to determine the factors influencing QOL and factors associated with each dimension of the EQ-5D. The mean EQ-5D utility observed for Korean RA patients was 0.60 (-0.29 to 1.0). Functional disability measured with Health Assessment Questionnaire (OR = 10.0, CI 2.8-34.5), disease activity score (DAS) 28 (OR = 2.6, CI 1.4-4.9), and pain VAS (OR = 2.2, CI 1.2-4.1) was three main factors influencing on QOL of RA patients. Although the functional disability consistently showed significant associations with all dimensions, various factors were associated with the each five specific dimension of EQ-5D. Pain (OR = 2.5, CI 1.4-4.6), history of hospitalization (OR = 2.1, CI 1.0-4.3), and men (OR = 2.6, CI 1.0-6.8) were associated with lower QOL in mobility. Use of alternative medicine (OR = 2.0, CI 1.1-3.7) and disease activity (OR = 3.1, CI 1.7-5.7) were associated with lower self-care QOL. For the patients with discomfort in usual activity, pain (OR = 4.7, CI 2.4-9.2) and the presence of anemia (OR = 2.3, CI 1.2-4.5) were major influencing factors. Higher disease activity (OR = 4.5, CI 1.0-21.2) and pain (OR = 3.3, CI 1.9-5.8) were associated with the pain/discomfort dimension of EQ-5D, and the pain (OR = 3.3, CI 1.9-5.8) was an independent associating factor of anxiety/depression. The strongest determinants of lower QOL in Korean RA patients were functional disability, higher disease activity, and subjective pain. However, various factors are influencing on the QOL for RA patients according

  14. An Accelerator Neutron Source for BNCT

    SciTech Connect

    Blue, Thomas, E

    2006-03-14

    The overall goal of this project was to develop an accelerator-based neutron source (ABNS) for Boron Neutron Capture Therapy (BNCT). Specifically, our goals were to design, and confirm by measurement, a target assembly and a moderator assembly that would fulfill the design requirements of the ABNS. These design requirements were 1) that the neutron field quality be as good as the neutron field quality for the reactor-based neutron sources for BNCT, 2) that the patient treatment time be reasonable, 3) that the proton current required to treat patients in reasonable times be technologially achievable at reasonable cost with good reliability, and accelerator space requirements which can be met in a hospital, and finally 4) that the treatment be safe for the patients.

  15. NEUTRONIC REACTORS

    DOEpatents

    Vernon, H.C.

    1959-01-13

    A neutronic reactor of the heterogeneous, fluid cooled tvpe is described. The reactor is comprised of a pressure vessel containing the moderator and a plurality of vertically disposed channels extending in spaced relationship through the moderator. Fissionable fuel material is placed within the channels in spaced relationship thereto to permit circulation of the coolant fluid. Separate means are provided for cooling the moderator and for circulating a fluid coolant thru the channel elements to cool the fuel material.

  16. High quality factor polymeric Fabry-Perot resonators utilizing a polymer waveguide.

    PubMed

    Tadayon, Mohammad Amin; Baylor, Martha-Elizabeth; Ashkenazi, Shai

    2014-03-10

    Optical resonators are used in a variety of applications ranging from sensors to lasers and signal routing in high volume communication networks. Achieving a high quality (Q) factor is necessary for higher sensitivity in sensing applications and for narrow linewidth light emission in most lasing applications. In this work, we propose a new approach to achieve a very high Q-factor in polymeric Fabry-Perot resonators by conquering light diffraction inside the optical cavity. This can be achieved by inducing a refractive index feature inside the optical cavity that simply creates a waveguide between the two mirrors. This approach eliminates diffraction loss from the cavity and therefore the Q-factor is only limited by mirror loss and absorption. To demonstrate this claim, a device has been fabricated consisting of two dielectric Bragg reflectors with a 100 μm layer of photosensitive polymer between them. The refractive index of this polymer can be modified utilizing standard photo-lithography processes. The measured finesse of the fabricated device was 692 and the Q-factor was 55000.

  17. Monte Carlo calculations of electron beam quality conversion factors for several ion chamber types

    SciTech Connect

    Muir, B. R.; Rogers, D. W. O.

    2014-11-01

    Purpose: To provide a comprehensive investigation of electron beam reference dosimetry using Monte Carlo simulations of the response of 10 plane-parallel and 18 cylindrical ion chamber types. Specific emphasis is placed on the determination of the optimal shift of the chambers’ effective point of measurement (EPOM) and beam quality conversion factors. Methods: The EGSnrc system is used for calculations of the absorbed dose to gas in ion chamber models and the absorbed dose to water as a function of depth in a water phantom on which cobalt-60 and several electron beam source models are incident. The optimal EPOM shifts of the ion chambers are determined by comparing calculations of R{sub 50} converted from I{sub 50} (calculated using ion chamber simulations in phantom) to R{sub 50} calculated using simulations of the absorbed dose to water vs depth in water. Beam quality conversion factors are determined as the calculated ratio of the absorbed dose to water to the absorbed dose to air in the ion chamber at the reference depth in a cobalt-60 beam to that in electron beams. Results: For most plane-parallel chambers, the optimal EPOM shift is inside of the active cavity but different from the shift determined with water-equivalent scaling of the front window of the chamber. These optimal shifts for plane-parallel chambers also reduce the scatter of beam quality conversion factors, k{sub Q}, as a function of R{sub 50}. The optimal shift of cylindrical chambers is found to be less than the 0.5 r{sub cav} recommended by current dosimetry protocols. In most cases, the values of the optimal shift are close to 0.3 r{sub cav}. Values of k{sub ecal} are calculated and compared to those from the TG-51 protocol and differences are explained using accurate individual correction factors for a subset of ion chambers investigated. High-precision fits to beam quality conversion factors normalized to unity in a beam with R{sub 50} = 7.5 cm (k{sub Q}{sup ′}) are provided. These

  18. Confirmatory factor analysis for indicators of perceived environmental quality of the stadium (IPEQS).

    PubMed

    Manca, Sara; Fornara, Ferdinando

    2015-09-01

    Studies conducted in the 1980s (see Canter et al. in Football in its place. An environmental psychology of football grounds. Routledge, London, 1989) highlighted the prominent role of the spatial-physical features of football grounds in influencing users' perception of safety, comfort, and general satisfaction towards the stadium experience. In particular, the importance of fulfilling the spectators' needs of personal space (e.g. presence of an open view, proper distance between the seats) and movement opportunity was analysed. The aim of this study is to confirm the factorial structure of a set of indicators--the IPEQS--concerning the perceived quality of an array of aspects (i.e. architectural, social, functional, and safety issues) related to the stadium design. Participants (N = 255), who were selected on the basis of their stadium experience, filled in a self-report questionnaire measuring a set of indicators developed on the basis of both validated tools [i.e. the perceived residential environment quality indicators (PREQIs): Bonaiuto et al. in J Environ Psychol 19:331-352, 1999] and outcomes of semi-structured interviews. Confirmatory factor analyses (CFA) were performed for each scale, and reliability assessments were then carried out for each indicator. IPEQS' factorial structures found through the CFA procedure substantially confirm the results of exploratory factor analyses run with previous data. Outcomes of this study should provide a useful tool for managers and designers of football grounds, in order to improve the overall experience of the spectators.

  19. Visual Steering and Verification of Mass Spectrometry Data Factorization in Air Quality Research.

    PubMed

    Engel, D; Greff, K; Garth, C; Bein, K; Wexler, A; Hamann, B; Hagen, H

    2012-12-01

    The study of aerosol composition for air quality research involves the analysis of high-dimensional single particle mass spectrometry data. We describe, apply, and evaluate a novel interactive visual framework for dimensionality reduction of such data. Our framework is based on non-negative matrix factorization with specifically defined regularization terms that aid in resolving mass spectrum ambiguity. Thereby, visualization assumes a key role in providing insight into and allowing to actively control a heretofore elusive data processing step, and thus enabling rapid analysis meaningful to domain scientists. In extending existing black box schemes, we explore design choices for visualizing, interacting with, and steering the factorization process to produce physically meaningful results. A domain-expert evaluation of our system performed by the air quality research experts involved in this effort has shown that our method and prototype admits the finding of unambiguous and physically correct lower-dimensional basis transformations of mass spectrometry data at significantly increased speed and a higher degree of ease.

  20. Planning to improve the mechanical quality factor in the transducer impedance matchers for Mario Schenberg detector

    NASA Astrophysics Data System (ADS)

    Frajuca, Carlos; da Silva Bortoli, Fabio

    2006-03-01

    "Mario Schenberg" is a spherical resonant-mass gravitational wave (GW) detector that will be part of a GW detection array of two detectors. Another one is been built in The Netherlands. Their resonant frequencies will be around 3.2 kHz with a bandwidth of about 200 Hz. This range of frequencies is new in a field where the typical frequencies lay below 1 kHz, making the transducer development much more complex. Some studies indicated that using low mass mechanical resonators (used for impedance matching to the parametric transducer, in a cold damping regime) allow the detector to reach the standard quantum limit. In this work we describe the procedures that are being developed to quickly test the mechanical quality factor of a very small resonator in the quest to find the best machining method and thermal annealing for the impedance matching resonator, one key part that makes a good coupling between the sphere and the transducer. The main goal is to optimize the mechanical quality factor in a reasonable time.

  1. Quality-Shaping Factors and Endodontic Treatment amongst General Dental Practitioners with a Focus on Denmark

    PubMed Central

    Demant, Sune; Markvart, Merete; Bjørndal, Lars

    2012-01-01

    There is a gap between the endodontic outcome that can be achieved and the outcome observed on the basis of worldwide general dental practitioner data. The quality of root canal treatment (RCT) is shaped by the dentist's knowledge, attitude, and skills, but it may also be influenced by the patient's demands and degree of satisfaction. The topic has only been sparsely investigated. Although dental health has increased over the years in Denmark, the number of performed root fillings has also increased, probably because the number of tooth extractions have declined and more molar teeth have been treated. Caries appears to be the main cause for performing RCT and a preventive approach by employing stepwise excavation may reduce RCT, but this strategy does not remove the gap. Factors influencing RCT quality could be the status on adoption of nickel-titanium rotary technology, more focus on infection control (rubber dam use, knowledge of factors important for prognosis), as dentists often think that they are good at doing RCT, but often perform inadequately, an alteration of clinician's awareness of their performance in the context of dental practices, seems warranted. Finally, the development of new preventive modalities for pulp and apical inflammation are crucial. PMID:22536241

  2. High quality factor mg-scale silicon mechanical resonators for 3-mode optoacoustic parametric amplifiers

    NASA Astrophysics Data System (ADS)

    Torres, F. A.; Meng, P.; Ju, L.; Zhao, C.; Blair, D. G.; Liu, K.-Y.; Chao, S.; Martyniuk, M.; Roch-Jeune, I.; Flaminio, R.; Michel, C.

    2013-07-01

    Milligram-scale resonators have been shown to be suitable for the creation of 3-mode optoacoustic parametric amplifiers, based on a phenomena first predicted for advanced gravitational-wave detectors. To achieve practical optoacoustic parametric devices, high quality factor resonators are required. We present millimetre-scale silicon resonators designed to exhibit a torsional vibration mode with a frequency in the 105-106 Hz range, for observation of 3-mode optoacoustic interactions in a compact table-top system. Our design incorporates an isolation stage and minimizes the acoustic loss from optical coating. We observe a quality factor of 7.5 × 105 for a mode frequency of 401.5 kHz, at room temperature and pressure of 10-3 Pa. We confirmed the mode shape by mapping the amplitude response across the resonator and comparing to finite element modelling. This study contributes to the development of 3-mode optoacoustic parametric amplifiers for use in novel high-sensitivity signal transducers and quantum measurement experiments.

  3. High-Quality-Factor Mid-Infrared Toroidal Excitation in Folded 3D Metamaterials.

    PubMed

    Liu, Zhe; Du, Shuo; Cui, Ajuan; Li, Zhancheng; Fan, Yuancheng; Chen, Shuqi; Li, Wuxia; Li, Junjie; Gu, Changzhi

    2017-02-22

    With unusual electromagnetic radiation properties and great application potentials, optical toroidal moments have received increasing interest in recent years. 3D metamaterials composed of split ring resonators with specific orientations in micro-/nanoscale are a perfect choice for toroidal moment realization in optical frequency considering the excellent magnetic confinement and quality factor, which, unfortunately, are currently beyond the reach of existing micro-/nanofabrication techniques. Here, a 3D toroidal metamaterial operating in mid-infrared region constructed by metal patterns and dielectric frameworks is designed, by which high-quality-factor toroidal resonance is observed experimentally. The toroidal dipole excitation is confirmed numerically and further demonstrated by phase analysis. Furthermore, the far-field radiation intensity of the excited toroidal dipoles can be adjusted to be predominant among other multipoles by just tuning the incident angle. The related processing method expands the capability of focused ion beam folding technologies greatly, especially in 3D metamaterial fabrication, showing great flexibility and nanoscale controllability on structure size, position, and orientation.

  4. Student Motivation and the "Feel Good" Factor: An Empirical Examination of Motivational Predictors of University Service Quality Evaluation

    ERIC Educational Resources Information Center

    Chong, Yit Sean; Ahmed, Pervaiz K.

    2015-01-01

    With the globalisation of the higher education industry, service quality in the higher education services is seen as a vital factor in determining a university's competitive advantage. The purpose of this study is to extend current conceptualisation of quality research in higher education by investigating the influence of self-determination and…

  5. Examining the Relationship between Global and Domain Measures of Quality of Life by Three Factor Structure Models

    ERIC Educational Resources Information Center

    Wu, Chia-Huei; Yao, Grace

    2007-01-01

    This study examined the relationship between global and domain measures of quality of life from a psychometric perspective by three different factor structure models. Three hundred and four students at National Taiwan University participated in this study. They completed the Satisfaction with Life Scale (SWLS, a global measurement for quality of…

  6. Factors Associated with Subjective Quality of Life of Adults with Autism Spectrum Disorder: Self-Report versus Maternal Reports

    ERIC Educational Resources Information Center

    Hong, Jinkuk; Bishop-Fitzpatrick, Lauren; Smith, Leann E.; Greenberg, Jan S.; Mailick, Marsha R.

    2016-01-01

    We examined factors related to subjective quality of life (QoL) of adults with autism spectrum disorder (ASD) aged 25-55 (n = 60), using the World Health Organization Quality of Life measure (WHOQOL-BREF). We used three different assessment methods: adult self-report, maternal proxy-report, and maternal report. Reliability analysis showed that…

  7. Factors Affecting Water Quality in Selected Carbonate Aquifers in the United States,1993-2005

    USGS Publications Warehouse

    Lindsey, Bruce D.; Berndt, Marian P.; Katz, Brian G.; Ardis, Ann F.; Skach, Kenneth A.

    2009-01-01

    Carbonate aquifers are an important source of water in the United States; however, these aquifers can be particularly susceptible to contamination from the land surface. The U.S. Geological Survey National Water-Quality Assessment (NAWQA) Program collected samples from wells and springs in 12 carbonate aquifers across the country during 1993-2005; water-quality results for 1,042 samples were available to assess the factors affecting ground-water quality. These aquifers represent a wide range of climate, land-use types, degrees of confinement, and other characteristics that were compared and evaluated to assess the effect of those factors on water quality. Differences and similarities among the aquifers were also identified. Samples were analyzed for major ions, radon, nutrients, 47 pesticides, and 54 volatile organic compounds (VOCs). Geochemical analysis helped to identify dominant processes that may contribute to the differences in aquifer susceptibility to anthropogenic contamination. Differences in concentrations of dissolved oxygen and dissolved organic carbon and in ground-water age were directly related to the occurrence of anthropogenic contaminants. Other geochemical indicators, such as mineral saturation indexes and calcium-magnesium molar ratio, were used to infer residence time, an indirect indicator of potential for anthropogenic contamination. Radon exceeded the U.S. Environmental Protection Agency proposed Maximum Contaminant Level (MCL) of 300 picocuries per liter in 423 of 735 wells sampled, of which 309 were drinking-water wells. In general, land use, oxidation-reduction (redox) status, and degree of aquifer confinement were the most important factors affecting the occurrence of anthropogenic contaminants. Although none of these factors individually accounts for all the variation in water quality among the aquifers, a combination of these characteristics accounts for the majority of the variation. Unconfined carbonate aquifers that had high

  8. Factors Determining Quality of Care in Family Planning Services in Africa: A Systematic Review of Mixed Evidence

    PubMed Central

    Tessema, Gizachew Assefa; Streak Gomersall, Judith; Mahmood, Mohammad Afzal; Laurence, Caroline O.

    2016-01-01

    Background Improving use of family planning services is key to improving maternal health in Africa, and provision of quality of care in family planning services is critical to support higher levels of contraceptive uptake. The objective of this systematic review was to synthesize the available evidence on factors determining the quality of care in family planning services in Africa. Methods Quantitative and qualitative studies undertaken in Africa, published in English, in grey and commercial literature, between 1990 and 2015 were considered. Methodological quality of included studies was assessed using standardized tools. Findings from the quantitative studies were summarized using narrative and tables. Client satisfaction was used to assess the quality of care in family planning services in the quantitative component of the review. Meta-aggregation was used to synthesize the qualitative study findings. Results From 4334 records, 11 studies (eight quantitative, three qualitative) met the review eligibility criteria. The review found that quality of care was influenced by client, provider and facility factors, and structural and process aspects of the facilities. Client’s waiting time, provider competency, provision/prescription of injectable methods, maintaining privacy and confidentiality were the most commonly identified process factors. The quality of stock inventory was the most commonly identified structural factor. The quality of care was also positively associated with privately-owned facilities. The qualitative synthesis revealed additional factors including access related factors such as ‘pre-requisites to be fulfilled by the clients and cost of services, provider workload, and providers’ behaviour. Conclusion There is limited evidence on factors determining quality of care in family planning services in Africa that shows quality of care is influenced by multiple factors. The evidence suggests that lowering access barriers and avoiding unnecessary

  9. Neutron relative biological effectiveness in Hiroshima and Nagasaki atomic bomb survivors: a critical review.

    PubMed

    Sasaki, Masao S; Endo, Satoru; Hoshi, Masaharu; Nomura, Taisei

    2016-11-01

    The calculated risk of cancer in humans due to radiation exposure is based primarily on long-term follow-up studies, e.g. the life-span study (LSS) on atomic bomb (A-bomb) survivors in Hiroshima and Nagasaki. Since A-bomb radiation consists of a mixture of γ-rays and neutrons, it is essential that the relative biological effectiveness (RBE) of neutrons is adequately evaluated if a study is to serve as a reference for cancer risk. However, the relatively small neutron component hampered the direct estimation of RBE in LSS data. To circumvent this problem, several strategies have been attempted, including dose-independent constant RBE, dose-dependent variable RBE, and dependence on the degrees of dominance of intermingled γ-rays. By surveying the available literature, we tested the chromosomal RBE of neutrons as the biological endpoint for its equivalence to the microdosimetric quantities obtained using a tissue-equivalent proportional counter (TEPC) in various neutron fields. The radiation weighting factor, or quality factor, Qn, of neutrons as expressed in terms of the energy dependence of the maximum RBE, RBEm, was consistent with that predicted by the TEPC data, indicating that the chromosomally measured RBE was independent of the magnitude of coexisting γ-rays. The obtained neutron RBE, which varied with neutron dose, was confirmed to be the most adequate RBE system in terms of agreement with the cancer incidence in A-bomb survivors, using chromosome aberrations as surrogate markers. With this RBE system, the cancer risk in A-bomb survivors as expressed in unit dose of reference radiation is equally compatible with Hiroshima and Nagasaki cities, and may be potentially applicable in other cases of human radiation exposure.

  10. Neutron relative biological effectiveness in Hiroshima and Nagasaki atomic bomb survivors: a critical review

    PubMed Central

    Sasaki, Masao S.; Endo, Satoru; Hoshi, Masaharu; Nomura, Taisei

    2016-01-01

    The calculated risk of cancer in humans due to radiation exposure is based primarily on long-term follow-up studies, e.g. the life-span study (LSS) on atomic bomb (A-bomb) survivors in Hiroshima and Nagasaki. Since A-bomb radiation consists of a mixture of γ-rays and neutrons, it is essential that the relative biological effectiveness (RBE) of neutrons is adequately evaluated if a study is to serve as a reference for cancer risk. However, the relatively small neutron component hampered the direct estimation of RBE in LSS data. To circumvent this problem, several strategies have been attempted, including dose-independent constant RBE, dose-dependent variable RBE, and dependence on the degrees of dominance of intermingled γ-rays. By surveying the available literature, we tested the chromosomal RBE of neutrons as the biological endpoint for its equivalence to the microdosimetric quantities obtained using a tissue-equivalent proportional counter (TEPC) in various neutron fields. The radiation weighting factor, or quality factor, Qn, of neutrons as expressed in terms of the energy dependence of the maximum RBE, RBEm, was consistent with that predicted by the TEPC data, indicating that the chromosomally measured RBE was independent of the magnitude of coexisting γ-rays. The obtained neutron RBE, which varied with neutron dose, was confirmed to be the most adequate RBE system in terms of agreement with the cancer incidence in A-bomb survivors, using chromosome aberrations as surrogate markers. With this RBE system, the cancer risk in A-bomb survivors as expressed in unit dose of reference radiation is equally compatible with Hiroshima and Nagasaki cities, and may be potentially applicable in other cases of human radiation exposure. PMID:27614201

  11. Influence of sociodemographic factors on quality of life in women living in Lublin Province in Poland

    PubMed Central

    Kulik, Teresa B.; Janiszewska, Mariola; Stefanowicz, Agata

    2014-01-01

    The aim of the study The aim of the study is to evaluate the impact of sociodemographic factors on the quality of life (QOL) in 45-65-year-old women. Material and methods The research by means of a survey method, postal questionnaire technique, comprised 2143 women – a representative sample of the female population living in Lublin Province. Three standardized questionnaires – WHOQOL-BREF, Women's Health Questionnaire and SF-36 – as well as an original questionnaire were used as research tools. In statistical analysis Student's t-test for two groups, an analysis of variance, Dunnett's T3 test for multiple comparisons, a one-way analysis of variance (one-way ANOVA) and a stepwise logistic regression analysis were used. Results In the population of peri- and postmenopausal women a significantly better quality of life in comparison with the rest of the studied women was established in women aged 45-49 years, respondents living permanently in urban areas as well as better educated women, those with full-time employment, especially those doing intellectual work, women remaining in a long-lasting relationship, and women assessing their financial situation and living conditions as well. Logistic regression analysis showed that the strong predictors of poor quality of life were as follows: self-assessment of living conditions as poor, self-assessment of financial situation as poor, permanent place of residence in the country, lower education level (incomplete primary education, primary education). Conclusions The group of women with worse quality of life should become the main addressee of preventive programmes and health policy programmes designed for peri- and postmenopausal women. PMID:26327822

  12. Factors contributing to quality of life in COPD patients in South Korea

    PubMed Central

    Kwon, Hye-Young; Kim, Eugene

    2016-01-01

    Objectives Chronic obstructive pulmonary disease (COPD) is a chronic lung disease, and the burden of COPD is expected to increase in the rapidly aging nation of South Korea. This study aims to examine the factors contributing to health-related quality of life (HRQOL) in COPD patients. Patients and methods This study was based on 6-year-data obtained from the Korean National Health and Nutrition Examination Survey 2007–2012. COPD was diagnosed in 2,734 survey participants and the severity was graded according to the criteria set by the Global Initiative for Chronic Obstructive Lung Disease. The EuroQol-5D (EQ-5D) index was used to assess the quality of life. Results The EQ-5D index scores for COPD patients and the general population were 0.915±0.003 and 0.943±0.001, respectively. Males, younger people, and patients with higher education attainment and income levels had a higher utility score. In addition, the adjusted EQ-5D index scores for severity level IV significantly decreased by 0.100 (P=0.041), compared to the severity group I scores. No significant differences were found in stage II and III patients. Comorbidities (excluding cancer and hypertension) appeared to negatively influence HRQOL among COPD patients. In particular, depression (EQ-5D index score =−0.089, P=0.0003) and osteoporosis (EQ-5D index score=−0.062, P=0.0039) had a significant influence, while smoking status did not appear to influence patient HRQOL. Conclusion In this study, we found that the higher the severity of COPD, the lower the quality of life. In particular, patients with depression and osteoporosis had a relatively low utility score. Therefore, these comorbidities should be carefully monitored in order to improve quality of life. PMID:26834467

  13. Perceived quality of life in obsessive-compulsive disorder: related factors

    PubMed Central

    Rodriguez-Salgado, Beatriz; Dolengevich-Segal, Helen; Arrojo-Romero, Manuel; Castelli-Candia, Paola; Navio-Acosta, Mercedes; Perez-Rodriguez, Maria M; Saiz-Ruiz, Jeronimo; Baca-Garcia, Enrique

    2006-01-01

    Background Obsessive-compulsive disorder (OCD) affects young adults and has great impact on the social, emotional and work spheres. Methods We measured perceived quality of life (QOL) in OCD patients, in order to analyse socio-demographic and clinical factors that may be associated with QOL perception. 64 OCD outpatients were assessed with the Mini International Neuropsychiatric Interview for DSM-IV, the Yale-Brown Obsessions and Compulsions scale (Y-BOCS), Hamilton's depression scale and the SF-36 self-administered global QOL perception scale. Results We found a correlation among Hamilton's scale scores and all SF-36 subscales. The severity of the obsessive-compulsive disorder was correlated with all SF-36 subscales and with the highest scores in Hamilton's scale. The obsessions subscale was correlated to all SF-36 subscales, while the compulsions subscale was correlated only to social functioning, emotional role, mental health and vitality. Compulsions were not related to general health perception. There were significant differences between OCD patients and the Spanish general population in all SF-36 subscales except those related to physical health and pain. Gender, age, age of onset of the disorder, years of evolution and marital status of the patients did not significantly affect quality of life perception. Being employed was related to better scores in the subscale of physical role. Patients with medical comorbidity scored lower in the subscales of general health, social functioning and mental health. Patients with comorbid psychiatric disorders had worse scores in the subscales of pain, general health, social functioning and mental health. Conclusion Quality of life perception was different in OCD patients and the general population. Quality of life perception was related to severity of the disorder, physical and psychiatric comorbidity and employment status. PMID:16684346

  14. Factors affecting the incidence of first-quality wheels of Trentingrana cheese.

    PubMed

    Bittante, G; Cecchinato, A; Cologna, N; Penasa, M; Tiezzi, F; De Marchi, M

    2011-07-01

    Trentingrana (or Grana Trentino) is a Protected Designation of Origin hard cheese produced in the eastern Italian Alps by small cooperative dairy factories. To obtain the certification of quality, wheels are evaluated at 9±1 mo of ripening and those classified as first quality are revaluated at 18±1 mo. Traditionally, the assessment is based on 2 sensory features: namely, the external aspect of the wheel and the internal texture; the latter is evaluated through the sound produced by beating the wheel with a special hammer. Traits considered in the study were the percentage of first-quality wheels of total wheels examined at 9±1 (QW(9 mo)) and 18±1 (QW(18 mo)) mo of ripening, and their combination [i.e., the percentage of first-quality wheels at 18±1 mo of ripening of the number of wheels evaluated at 9±1 mo (QW(tot))]. The experimental unit was the batch of 2 mo of production of each of 10 cooperative dairy factories from 2002 to 2008. Data were analyzed with a model that included fixed effects of dairy factory, year and season of production, and interactions between dairy factory and year, and dairy factory and season. The coefficients of determination of the models were 0.57, 0.68, and 0.67 for QW(9mo), QW(18 mo), and QW(tot), respectively. All factors significantly influenced the traits, with dairy factory being the most important source of variation, followed by season and year of production. Remarkable differences were found between the best and the worst dairy factory for QW(9 mo) (11.5%), QW(18 mo) (21.1%), and QW(tot) (25.6%). The first 4 yr of production had a negative effect on the percentage of wheels labeled as first quality and QW(tot) decreased from 74 to 64%; nevertheless, a complete recovery was detected in the following years. The season of production strongly influenced the studied traits with the best results in spring and summer, and the worst in autumn and winter. Compared with average, the 3 best dairy factories were smaller, with

  15. Predicting the Displacement Gain from the Mechanical Quality Factor in Ultrasonic Transducers

    NASA Astrophysics Data System (ADS)

    DeAngelis, Dominick A.

    The displacement gain is the most important performance parameter for power ultrasonic transducers typically used for welding or cutting: it controls the proportional relationship between the displacement of the tool and the voltage or current input to the transducer, a key process parameter. However, due to the aging effects of the PZT piezoceramics typically used in these transducers, and other variables such as gradual preload loss or tool clamp wear, this displacement gain can drift over time causing a shift in process, and loss of machine-to-machine portability in mass production environments. The "re-calibration" of the displacement gain usually involves a time consuming procedure of standardized controlled tests, and/or measurements using an expensive device such as a laser vibrometer. However, elementary engineering vibrations theory asserts that the displacement gain should be proportional to the static displacement (i.e., 0 Hz or DC) and the mechanical quality factor Qm at resonance, derived from a simple Bode plot, which is already familiar to most transducer designers. This research investigates the methods for obtaining the mechanical quality factor from Bode plots (e.g., constant current or constant voltage sweeps), and ring-down techniques using logarithmic decrement, based on their predictability for determining the displacement gain via the static displacement. The investigation focuses solely on welding transducers for semiconductor wire bonding which employ common hard PZT4 or PZT8 piezoelectric materials. Several other metrics are investigated such as impedance, capacitance and electro-mechanical coupling factor. The experimental and theoretical research methods include Bode plots, equivalent circuits, mechanical analogies and scanning laser vibrometry.

  16. Neutron storage time measurement for the neutron EDM experiment

    NASA Astrophysics Data System (ADS)

    Griffith, W. Clark; Ito, Takeyasu; Ramsey, John; Makela, Mark; Clayton, Steven; Hennings-Yeomans, Raul; Saidur Rahaman, M.; Currie, Scott; Womack, Todd; Sondheim, Walter; Cooper, Martin

    2010-11-01

    A new experiment to search for the neutron electric dipole moment (nEDM) is under development for installation at the Spallation Neutron Source (SNS) at Oakridge National Laboratory. The experiment will use ultra-cold neutrons (UCN) stored in superfluid helium, along with ^3He atoms acting as a neutron spin analyzer and comagnetometer. One crucial factor affecting the ultimate sensitivity of the experiment is the neutron storage time that can be obtained in the acrylic measurement cell. The acrylic cell walls will be coated with deuterated polystyrene (dPS), which is expected to give a wall loss factor of ˜< 10-5 per bounce when cooled below the point where upscattering by hydrogen impurities contribute to UCN losses. We are currently preparing a measurement at Los Alamos to verify that a 10-5 wall loss factor can be achieved in a dPS coated acrylic test cell. The planned measurement will investigate the temperature dependence of the UCN storage time in the dPS coated test cell between room temperature and below 20 K.

  17. Three factors that influence the overall quality of the stereoscopic 3D content: image quality, comfort, and realism

    NASA Astrophysics Data System (ADS)

    Vlad, Raluca; Ladret, Patricia; Guérin, Anne

    2013-01-01

    In today's context, where 3D content is more abundant than ever and its acceptance by the public is probably de_nitive, there are many discussions on controlling and improving the 3D quality. But what does this notion represent precisely? How can it be formalized and standardized? How can it be correctly evaluated? A great number of studies have investigated these matters and many interesting approaches have been proposed. Despite this, no universal 3D quality model has been accepted so far that would allow a uniform across studies assessment of the overall quality of 3D content, as it is perceived by the human observers. In this paper, we are making a step forward in the development of a 3D quality model, by presenting the results of an exploratory study in which we started from the premise that the overall 3D perceived quality is a multidimensional concept that can be explained by the physical characteristics of the 3D content. We investigated the spontaneous impressions of the participants while watching varied 3D content, we analyzed the key notions that appeared in their discourse and identi_ed correlations between their judgments and the characteristics of our database. The test proved to be rich in results. Among its conclusions, we consider of highest importance the fact that we could thus determine three di_erent perceptual attributes ( image quality, comfort and realism ( that could constitute a _rst simplistic model for assessing the perceived 3D quality.

  18. Factors Associated With Quality Of Life In Women Undergoing Surgery For Stress Urinary Incontinence

    PubMed Central

    Sirls, Larry T.; Tennstedt, Sharon; Albo, Mike; Chai, Toby; Kenton, Kim; Huang, Liyuan; Stoddard, Anne M; Arisco, Amy; Gormley, E. Ann

    2014-01-01

    Purpose To determine the association of clinicodemographic factors with urinary incontinence (UI) related quality of life (QoL) in women having surgery for stress urinary incontinence (SUI) and to compare the incontinence-specific IIQ (Incontinence Impact Questionnaire) and the ICIQ (International Consultation on Incontinence Questionnaire). Secondary objectives evaluated the contributions of incontinence severity and sexual function to QoL. Materials and Methods Baseline data from 597 women in the Trial of Mid Urethral Slings (TOMUS). Correlates of QoL tested included health status and history, type, severity and bother of UI, and sexual function. Results Lower QoL by both the IIQ and ICIQ included younger age, higher BMI, more SUI symptoms, and more severe and bothersome UI symptoms. Each measure identified factors associated with lower QoL not identified by the other (IIQ; Hispanic ethnicity, poor health status and more urge UI symptoms, and ICIQ; prior UI treatment and more UI episodes per day). Sexually active women had similar QoL but also increased incontinence episodes (IIQ and ICIQ) and more sexual dysfunction (IIQ only). Conclusion In women planning SUI surgery, QoL is associated with non-UI factors as well as with the type, severity and degree of bother from UI symptoms. Many factors are associated with QoL as measured by both IIQ and ICIQ. However more non-UI factors were associated with QoL when measured by the IIQ than by the ICIQ. More than one scale may be needed to evaluate QoL after SUI treatment. PMID:20952014

  19. High energy neutron radiography

    SciTech Connect

    Gavron, A.; Morley, K.; Morris, C.; Seestrom, S.; Ullmann, J.; Yates, G.; Zumbro, J.

    1996-06-01

    High-energy spallation neutron sources are now being considered in the US and elsewhere as a replacement for neutron beams produced by reactors. High-energy and high intensity neutron beams, produced by unmoderated spallation sources, open potential new vistas of neutron radiography. The authors discuss the basic advantages and disadvantages of high-energy neutron radiography, and consider some experimental results obtained at the Weapons Neutron Research (WNR) facility at Los Alamos.

  20. Psychological factors mediating health-related quality of life in COPD.

    PubMed

    Popa-Velea, O; Purcarea, V L

    2014-03-15

    COPD is a chronic disease that has not only a high prevalence and social costs, but is tightly connected to a significant decrease of health-related quality of life (HRQoL). The aim of this study was to evaluate the comparative impact on HRQoL of two psychological factors (self-efficacy, optimism) vs. classical medical determinants (forced expiratory volume in 1 second (FEV1), peak expiratory flow (PEF), functional impairment). 26 women and 28 men, aged 45-64 years old (mean = 58.1; standard deviation = 9.7), diagnosed with COPD and with self-reported dyspnea requiring medication were administered COPD Self-Efficacy Scale, LOT-R (Life Orientation Test - Revised) to evaluate optimism, Quality of Well-Being (QWB) Scale, as an accepted measure of HRQoL and Functional Impairment Scale (FIS), used to assess the deterioration of functionality in respiratory diseases. Their respiratory parameters (FEV1, PEF) were also measured, via spirometry. Results showed that self-efficacy and optimism were positively correlated to HRQoL (r = .34 (p < .05) and r = .29 (p < .05), respectively). A reduced model that eliminated the direct influence of respiratory parameters on HRQoL proved to be equally satisfactory in terms of predictor value, compared to the full model (that contained all studied variables) (χ² = 0.067, ns). The functional impairment (FI) scores were inversely correlated with HRQoL (r = -.46, p < .01). These results have implications in considering self-efficacy and optimism as important factors when aiming HRQoL improvement in COPD, and for the inclusion of psychological interventions in the treatment plan of COPD patients. Abbreviations COPD = chronic obstructive pulmonary disease; WHO = World Health Organization; HRQoL = health-related quality of life; PEF = peak expiratory flow; FEV1 = forced expiratory flow in one second; LOT-R = Life Orientation Test - Revised; QWB = Quality of Well-Being; FI = functional impairment; SE = self-efficacy; Opt. = optimism.

  1. Dose measurements around spallation neutron sources.

    PubMed

    Fragopoulou, M; Stoulos, S; Manolopoulou, M; Krivopustov, M; Zamani, M

    2008-01-01

    Neutron dose measurements and calculations around spallation sources appear to be of great importance in shielding research. Two spallation sources were irradiated by high-energy proton beams delivered by the Nuclotron accelerator (JINR), Dubna. Neutrons produced by the spallation sources were measured by using solid-state nuclear track detectors. In addition, neutron dose was calculated after polyethylene and concrete, using a phenomenological model based on empirical relations applied in high-energy physics. The study provides an analytical and experimental neutron benchmark analysis using the transmission factor and a comparison between the experimental results and calculations.

  2. Fast neutron dosemeter using pixelated detector Timepix.

    PubMed

    Bulanek, Boris; Ekendahl, Daniela; Prouza, Zdenek

    2014-10-01

    A Timepix detector covered with polyethylene convertors of different thicknesses is presented as a fast neutron real-time dosemeter. The application of different weighting factors in connection with the position of a signal in a Timepix detector enables one to obtain an energy-dependent signal equal to neutron dose equivalents. A simulation of a Timepix detector covered with polyethylene convertors using monoenergetic neutrons is presented. The experimental set-up of a dosemeter was also produced. The first results of detector response using different fast neutron sources are presented.

  3. Spectrum tailoring of the neutron energy spectrum in the context of delayed neutron detection

    SciTech Connect

    Koehler, William E; Tobin, Steve J; Sandoval, Nathan P; Fensin, Mike L

    2010-01-01

    For the purpose of measuring plutonium mass in spent fuel, a delayed neutron instrument is of particular interest since, if properly designed, the delayed neutron signal from {sup 235}U is significantly stronger than the signature from {sup 239}Pu or {sup 241}Pu. A key factor in properly designing a delayed neutron instrument is to minimize the fission of {sup 238}U. This minimization is achieved by keeping the interrogating neutron spectrum below {approx} 1 MeV. In the context of spent fuel measurements it is desirable to use a 14 MeV (deuterium and tritium) neutron generator for economic reasons. Spectrum tailoring is the term used to describe the inclusion of material between the 14 MeV neutrons and the interrogated object that lower the neutron energy through nuclear reactions and moderation. This report quantifies the utility of different material combination for spectrum tailoring.

  4. The Distribution of Neutron Absorbing Time in the Neutron Detector of the GAMMA-400 Space Observatory

    NASA Astrophysics Data System (ADS)

    Gnezdilov, I. I.; Mukhin, V. I.; Demichev, M. A.

    The neutron detectors (ND) have been designed for the future GAMMA-400 space observatory with 3He-counters and 6LiF/ZnS(Ag) scintillation screens. The ND contribution in the rejection factor for protons in the GAMMA-400 is considered with significantly different number of neutrons generated in the electromagnetic and hadronic cascades. The ND is predominantly made from polyethylene, it has sizes of 100×100×10 cm3. GEANT4 simulation was obtained by the differential distribution of neutron absorbing time as the function of the registration time for different 3He, 6Li concentration. Nomograms were constructed for determining neutrons miscount depending on the number of neutrons crossing the ND and time resolution of the ND. The simulation results showed that the ND with 33 3He-counters detected the neutron fluence 0.23 n/cm2 without neutrons miscount.

  5. Protein crystallography with spallation neutrons

    SciTech Connect

    Langan, P.; Schoenborn, Benno P.

    2003-01-01

    proteins and oriented molecular complexes. With spallation neutrons and their time dependent wavelength structure, one can select data with an optimal wavelength bandwidth and cover the whole Laue spectrum as time (wavelength) resolved diffraction data. This optimizes data quality with best peak to background ratios and provides spatial and energy resolution to eliminate peak overlaps. Such a Protein Crystallography Station (PCS) has been built and tested at Los Alamos Neutron Science Center. A partially coupled moderator is used to increase flux and data are collected by a Cylindrical He3 detector covering 120' with 200mm height. The PCS is described along with examples of data collected from a number of proteins.

  6. NEUTRON COUNTER

    DOEpatents

    Curtis, C.D.; Carlson, R.L.; Tubinis, M.P.

    1958-07-29

    An ionization chamber instrument is described for cylindrical electrodes with an ionizing gag filling the channber. The inner electrode is held in place by a hermetic insulating seal at one end of the outer electrode, the other end of the outer electrode being closed by a gas filling tube. The outer surface of the inner electrode is coated with an active material which is responsive to neutron bombardment, such as uranium235 or boron-10, to produce ionizing radiations in the gas. The transverse cross sectional area of the inner electrode is small in relation to that of the channber whereby substantially all of the radiations are directed toward the outer electrode.

  7. NEUTRON SOURCE

    DOEpatents

    Reardon, W.A.; Lennox, D.H.; Nobles, R.G.

    1959-01-13

    A neutron source of the antimony--beryllium type is presented. The source is comprised of a solid mass of beryllium having a cylindrical recess extending therein and a cylinder containing antimony-124 slidably disposed within the cylindrical recess. The antimony cylinder is encased in aluminum. A berylliunn plug is removably inserted in the open end of the cylindrical recess to completely enclose the antimony cylinder in bsryllium. The plug and antimony cylinder are each provided with a stud on their upper ends to facilitate handling remotely.

  8. Neutron albedo imager for land mine detection

    NASA Astrophysics Data System (ADS)

    McFee, John E.; Andrews, H. Robert; Ing, Harry; Cousins, Thomas; Faust, Anthony A.; Haslip, Dean S.

    2002-08-01

    Neutron albedo land mine detection involves irradiating the ground with fast neutrons and subsequently detecting the thermalized neutrons which return. This technique has been studied since the 1950's, but only using non-imaging detectors. Without imaging, natural variations in hydrogen content in the soil, chiefly due to moisture, and surface irregularities, produce enough false alarms to render the method impractical in all but the driest conditions. This paper describes research to design and build a prototype landmine detector based on neutron albedo imaging. Realistic Monte Carlo simulations were performed to assess the signal-to-noise ratio for various soil types and moisture contents, assuming a perfect two dimensional neutron imaging system. The study showed that a neutron albedo imager was feasible for mine detection and that image quality could be good enough to significantly improve detector performance and reduce false alarm rates compared to non-imaging albedo detection, particularly in moist soils and where surface irregularities exist. After reviewing various neutron detector technologies, a design concept was developed. It consisted of a novel thermal neutron imaging system, a unique neutron source to uniformly irradiate the underlying ground and hardware and software for image generation and enhancement. Performance capability, including spatial resolution and detection times, were estimated by modeling. A proof-of-principle imager is now being constructed with an expected completion date of Spring 2002. The detector design is described and preliminary results are discussed.

  9. [Patient satisfaction-subjective quality assessment by patients and success factor for clinics].

    PubMed

    Olandt, H; Krentz, H

    1998-12-01

    In the field of measuring patient satisfaction (in other words, the quality perceived subjectively by hospital patients) there is still a great need for more knowledge. Therefore, the Institute of Medical Computer Science and Biometry of the University of Rostock carried out a questioning of 497 patients at the Hospital for Internal Medicine of the University Rostock to measure the patient satisfaction with the hospital. In addition, an employee questioning was performed in order to gain further information. In addition to univariate and bivariate analyses a special focus was set on the analysis of the hospitals' competitive situation, to take into account the importance of patient satisfaction as strategic success factor within the competitive situation. A competition analysis and a Key-Issue Analysis were performed. Finally, focus is on the problems of external hospital comparison and a comparison of trends of patient satisfaction at hospitals in Hamburg and Rostock was made.

  10. Ultra-high quality factor planar Si3N4 ring resonators on Si substrates.

    PubMed

    Tien, Ming-Chun; Bauters, Jared F; Heck, Martijn J R; Spencer, Daryl T; Blumenthal, Daniel J; Bowers, John E

    2011-07-04

    We demonstrate planar Si3N4 ring resonators with ultra-high quality factors (Q) of 19 million, 28 million, and 7 million at 1060 nm, 1310 nm, and 1550 nm, respectively. By integrating the ultra-low-loss Si3N4 ring resonators with laterally offset planar waveguide directional couplers, optical add-drop and notch filters are demonstrated to have ultra-narrow bandwidths of 16 MHz, 38 MHz, and 300 MHz at 1060 nm, 1310 nm, and 1550 nm, respectively. These are the highest Qs reported for ring resonators with planar directional couplers, and ultra-narrowband microwave photonic filters can be realized based on these high-Q ring resonators.

  11. Quality Factor Effect on the Wireless Range of Microstrip Patch Antenna Strain Sensors

    PubMed Central

    Daliri, Ali; Galehdar, Amir; Rowe, Wayne S. T.; John, Sabu; Wang, Chun H.; Ghorbani, Kamran

    2014-01-01

    Recently introduced passive wireless strain sensors based on microstrip patch antennas have shown great potential for reliable health and usage monitoring in aerospace and civil industries. However, the wireless interrogation range of these sensors is limited to few centimeters, which restricts their practical application. This paper presents an investigation on the effect of circular microstrip patch antenna (CMPA) design on the quality factor and the maximum practical wireless reading range of the sensor. The results reveal that by using appropriate substrate materials the interrogation distance of the CMPA sensor can be increased four-fold, from the previously reported 5 to 20 cm, thus improving considerably the viability of this type of wireless sensors for strain measurement and damage detection. PMID:24451457

  12. High quality factor two dimensional GaN photonic crystal cavity membranes grown on silicon substrate

    NASA Astrophysics Data System (ADS)

    Vico Triviño, N.; Rossbach, G.; Dharanipathy, U.; Levrat, J.; Castiglia, A.; Carlin, J.-F.; Atlasov, K. A.; Butté, R.; Houdré, R.; Grandjean, N.

    2012-02-01

    We report on the achievement of freestanding GaN photonic crystal L7 nanocavities with embedded InGaN/GaN quantum wells grown by metal organic vapor phase epitaxy on Si (111). GaN was patterned by e-beam lithography, using a SiO2 layer as a hard mask, and usual dry etching techniques. The membrane was released by underetching the Si (111) substrate. Micro-photoluminescence measurements performed at low temperature exhibit a quality factor as high as 5200 at ˜420 nm, a value suitable to expand cavity quantum electrodynamics to the near UV and the visible range and to develop nanophotonic platforms for biofluorescence spectroscopy.

  13. Note: Calibration of atomic force microscope cantilevers using only their resonant frequency and quality factor

    SciTech Connect

    Sader, John E.; Friend, James R.

    2014-11-15

    A simplified method for calibrating atomic force microscope cantilevers was recently proposed by Sader et al. [Rev. Sci. Instrum. 83, 103705 (2012); Sec. III D] that relies solely on the resonant frequency and quality factor of the cantilever in fluid (typically air). This method eliminates the need to measure the hydrodynamic function of the cantilever, which can be time consuming given the wide range of cantilevers now available. Using laser Doppler vibrometry, we rigorously assess the accuracy of this method for a series of commercially available cantilevers and explore its performance under non-ideal conditions. This shows that the simplified method is highly accurate and can be easily implemented to perform fast, robust, and non-invasive spring constant calibration.

  14. Quality factor effect on the wireless range of microstrip patch antenna strain sensors.

    PubMed

    Daliri, Ali; Galehdar, Amir; Rowe, Wayne S T; John, Sabu; Wang, Chun H; Ghorbani, Kamran

    2014-01-02

    Recently introduced passive wireless strain sensors based on microstrip patch antennas have shown great potential for reliable health and usage monitoring in aerospace and civil industries. However, the wireless interrogation range of these sensors is limited to few centimeters, which restricts their practical application. This paper presents an investigation on the effect of circular microstrip patch antenna (CMPA) design on the quality factor and the maximum practical wireless reading range of the sensor. The results reveal that by using appropriate substrate materials the interrogation distance of the CMPA sensor can be increased four-fold, from the previously reported 5 to 20 cm, thus improving considerably the viability of this type of wireless sensors for strain measurement and damage detection.

  15. SWET for secure water suppression on probes with high quality factor.

    PubMed

    Wu, Peter S C; Otting, Gottfried

    2005-07-01

    Water suppression by selective preirradiation is increasingly difficult to achieve on probeheads with high quality factor because of the opposing forces of radiation damping. Here we show that a simple modification to the WET scheme provides reliable water suppression in aqueous solutions of proteins and peptides with minimal saturation of the H(alpha) protons. The scheme is shown to work also with dilute peptide solutions. It is recommended to maintain the water suppression during the evolution time of COSY experiments by weak selective irradiation that causes only minimal Bloch-Siegert shifts. The new water-suppression scheme suppresses the water magnetization by spatial scrambling. Traditional water suppression by preirradiation is similarly based more on water scrambling due to the radiofrequency inhomogeneity than on relaxation effects.

  16. High Quality Factor MBE-grown Aluminum on Silicon Planar Resonators

    NASA Astrophysics Data System (ADS)

    Megrant, Anthony; Chen, Z.; Chiaro, B.; Dunsworth, A.; Quintana, C.; Campbell, B.; Barends, R.; Chen, Y.; Fowler, A.; Hoi, I.-C.; Jeffrey, E.; Kelly, J.; Mutus, J.; Neill, C.; O'Malley, P. J. J.; Roushan, P.; Sank, D.; Vainsencher, A.; Wenner, J.; White, T.; Palmstrom, C.; Martinis, J. M.; Cleland, A. N.

    2015-03-01

    Linear arrays of planer Xmon qubit circuits fabricated using thin aluminum films on sapphire substrates have resulted in long coherence times and high fidelity gates. Scaling up to larger circuits, including two-dimensional qubit arrays, may however benefit from building circuits on silicon instead of sapphire substrates. I will present recent tests in this direction, reporting on measurements of superconducting coplanar waveguide resonators fabricated using aluminum films deposited on silicon in a molecular beam epitaxy (MBE) system. These resonators exhibit exceptional performance, with quality factors at low temperatures and single photon excitation energies exceeding 5x106. This research was funded by the Office of the Director of National Intelligence (ODNI), Intelligence Advanced Research Projects Activity (IARPA), through the Army Research Office Grant W911NF-09-1-0375.

  17. Macroscopic tuning of nanomechanics: substrate bending for reversible control of frequency and quality factor of nanostring resonators.

    PubMed

    Verbridge, Scott S; Shapiro, Daniel Finkelstein; Craighead, Harold G; Parpia, Jeevak M

    2007-06-01

    We have employed a chip-bending method to exert continuous and reversible control over the tensile stress in doubly clamped nanomechanical beam resonators. Tensile stress is shown to increase the quality factor of both silicon nitride and single-crystal silicon resonators, implying that added tension can be used as a general, material-independent route to increased quality factor. With this direct stretching technique, we demonstrate beam resonators with unprecedented tunability of both frequency and quality factor. Devices can be tuned back and forth between a high and low stress state, with frequency tunability as large as several hundred percent demonstrated. Over this wide range of frequency, quality factor is also tuned by as much as several hundred percent, providing insights into the loss mechanisms in these materials and this class of nanoresonator. Devices with frequencies in the 1-100 MHz range are studied, with quality factor as high as 390,000 achieved at room temperature, for a silicon nitride device with cross-sectional dimensions below 1 microm, operating in a high stress state. This direct stretching technique may prove useful for the identification of loss mechanisms that contribute to the energy balance in nanomechanical resonators, allowing for the development of new designs that would display higher quality factors. Such devices would have the ability to resolve smaller addendum masses and thus allow more sensitive detection and offer the potential for providing access to previously inaccessible dissipation regimes at low temperatures. This technique provides the ability to dramatically tune both frequency and quality factor, enabling future mechanical resonators to be used as variable frequency references as well as variable band-pass filters in signal-processing applications.

  18. Factors Influencing Quality of Life of Obese Students in Hangzhou, China

    PubMed Central

    Chen, Ying-Ping; Wang, Hong-Mei; Edwards, Todd C.; Wang, Ting; Jiang, Xiao-Ying; Lv, Yi-Ran; Patrick, Donald L.

    2015-01-01

    Objective To evaluate the quality of life (QOL) of overweight and obese middle or high school students and identify relevant factors influencing their QOL scores. Methods 716 students were recruited from 6 middle or high schools in Hangzhou, China. The Chinese version of the Youth Quality of Life Instrument–Weight Module (YQOL-W) was self administered. The YQOL-W scores were compared among different BMI groups, gender, educational status, annual household income, parental education and recruitment community using t test or one-way analysis of variance. The independent association of these variables with QOL among overweight and obese students was examined using multivariable linear regression modeling. Results Overweight and obese students reported lower total scores, self, social and environment scores than their normal weight peers (all P<0.001). The QOL of overweight and obese middle and high school students was associated with BMI value, gender, educational status, parental education, and recruitment community. Girls had lower total scores, self, social and environment domain scores than boys (all P<0.001); high school students had lower total and three domain scores than middle school students (all P<0.05). Students whose fathers had higher education reported higher total scores, self and social scores than students with less educated fathers (all P<0.05). Students whose mothers had higher education reported higher environment scores than students with less educated mothers (P = 0.01). Students from migrant communities reported significantly lower total scores, self and social scores than those from rural communities (all P<0.05), but comparable scores with those from urban communities (P>0.05). Students from migrant communities reported comparable environment scores with those from rural and urban communities (P>0.05). Conclusions Overweight and obesity have negative effects on students’ quality of life. Therefore weight specific QOL could be included in

  19. A Measurement of the Neutron Electric Form Factor in Dvec ($\\vec{e}$,e'n)p Quasielastic Scattering at Q2=0.5(GeV/c)2

    SciTech Connect

    Zhu, Hongguo

    2000-08-01

    The form factors of the neutron give information on fundamental properties of the nucleons and provide a critical testing ground for models based on QCD. In late 1998, Jefferson Lab (JLAB) experiment E93-026 measured the spin-dependent part of the exclusive (e, e'n) scattering cross section from a polarized deuterated ammonia (15ND3) target at a four momentum transfer squared of Q2 = 0.5 (GeV/c)2. A longitudinally polarized electron beam was scattered from the polarized target and the quasi-elastically scattered electron was detected in coincidence with the knocked-out neutron. The data have been analyzed in terms of the spin-correlation parameter, or the electron-deuteron vector asymmetry (A$V\\atop{ed}$), of (e, e'n) to determine the neutron electric form factor G$n\\atop{E}$. The result is consistent with data from existing experiments and shows a good agreement with the Galster parameterization of G$n\\atop{E}$ within experimental uncertainty.

  20. Symptomatic pelvic organ prolapse at midlife, quality of life, and risk factors

    PubMed Central

    Fritel, Xavier; Varnoux, Noëlle; Zins, Marie; Breart, Gérard; Ringa, Virginie

    2009-01-01

    Objective To estimate quality of life (QoL), prevalence, and risk factors associated with symptomatic pelvic organ prolapse (POP) among middle-aged women. Methods A questionnaire was mailed to 3114 women aged 50–61 years in the GAZEL cohort; 2640 (85%) returned it. Symptomatic POP was defined by feeling a bulge from the vagina (sometimes, often, or all the time versus never or rarely). QoL was determined with the Nottingham Health Profile (NHP) questionnaire. Multiple linear regression was used to examine the association between frequency of POP symptoms and the QoL score. Logistic regression was used to estimate the impact of risk factors on past or present symptomatic POP (current symptoms or previous surgery for POP). Results The prevalence of symptomatic POP was 3.6% (96) and that of surgery for POP, 2.7% (70). POP symptoms were associated with difficulty defecating, lower abdominal pain, and difficulty voiding. The frequency of POP symptoms was associated with a poorer QoL score in each NHP domain (physical mobility, pain, emotional reaction, social isolation, energy and sleep). Even when we took general characteristics, medical history, and lifestyle associated with QoL into account, the global NHP score was significantly impaired by POP symptoms. Factors significantly associated with past or present symptomatic POP were high body mass index and the number of vaginal deliveries. Conclusion In our population of women in their 50s, POP symptoms are associated with impaired QoL, and the number of vaginal deliveries is a risk factor for past or present symptomatic POP. PMID:19300324

  1. Neutron multiplication error in TRU waste measurements

    SciTech Connect

    Veilleux, John; Stanfield, Sean B; Wachter, Joe; Ceo, Bob

    2009-01-01

    Total Measurement Uncertainty (TMU) in neutron assays of transuranic waste (TRU) are comprised of several components including counting statistics, matrix and source distribution, calibration inaccuracy, background effects, and neutron multiplication error. While a minor component for low plutonium masses, neutron multiplication error is often the major contributor to the TMU for items containing more than 140 g of weapons grade plutonium. Neutron multiplication arises when neutrons from spontaneous fission and other nuclear events induce fissions in other fissile isotopes in the waste, thereby multiplying the overall coincidence neutron response in passive neutron measurements. Since passive neutron counters cannot differentiate between spontaneous and induced fission neutrons, multiplication can lead to positive bias in the measurements. Although neutron multiplication can only result in a positive bias, it has, for the purpose of mathematical simplicity, generally been treated as an error that can lead to either a positive or negative result in the TMU. While the factors that contribute to neutron multiplication include the total mass of fissile nuclides, the presence of moderating material in the matrix, the concentration and geometry of the fissile sources, and other factors; measurement uncertainty is generally determined as a function of the fissile mass in most TMU software calculations because this is the only quantity determined by the passive neutron measurement. Neutron multiplication error has a particularly pernicious consequence for TRU waste analysis because the measured Fissile Gram Equivalent (FGE) plus twice the TMU error must be less than 200 for TRU waste packaged in 55-gal drums and less than 325 for boxed waste. For this reason, large errors due to neutron multiplication can lead to increased rejections of TRU waste containers. This report will attempt to better define the error term due to neutron multiplication and arrive at values that are

  2. Environmental and genetic factors affecting milk yield and quality in three Italian sheep breeds.

    PubMed

    Selvaggi, Maria; D'Alessandro, Angela Gabriella; Dario, Cataldo

    2017-02-01

    The aims of the study described in the Research Communication were to determine the level of influence of some environmental factors on milk yield and quality traits, including lactose, and lactation length in ewes belonging to three different Italian breeds and to estimate the heritability for the same traits. A total of 2138 lactation records obtained from 535 ewes belonging to three different Italian breeds (Comisana, Leccese, and Sarda) were used. Breed significantly affected all of the considered traits. Moreover, year of lambing affected milk yield and lactation length without influence on milk quality traits. Parity affected significantly only the milk yield, whereas type of birth showed its effect on milk yield, fat, protein, and lactose yield. On the whole, the presently reported heritability estimates are within the range of those already obtained in other dairy breeds by other authors, with values for lactation length being very low in all the investigated populations. Considering the heritability estimates for lactose content and yield, to the best of our knowledge, there is a lack of information on these parameters in ovine species and this is the first report on heritability of lactose content and yield in dairy sheep breeds. Our results suggest that genetic variability for milk traits other than lactation length is adequate for selection indicating a good response to selection in these breeds.

  3. Factors determining milk quality and implications for production structure under somatic cell count standard modification.

    PubMed

    Dong, F; Hennessy, D A; Jensen, H H

    2012-11-01

    Consumer and processor demand for high-quality milk has placed increasing pressure on US milk producers to achieve higher product standards. International standards for somatic cell count (SCC) are becoming more stringent, but in May 2011, the United States National Conference on Interstate Milk Shipments chose to retain the 750,000 cells/mL standard. Using ordinary least squares and quantile regressions on US Department of Agriculture Agricultural Resource Management Survey Dairy Costs and Returns Report data for 2005, we model producer and farm-level characteristics associated with SCC. Quantile regression analysis allows for a more parsed inquiry into statistical associations. Dairy Costs and Returns Report data provide cross-sectional information on the physical structure, input expenses, demographics, and outputs for farms in selected states. Location outside the Southeast, lower herd age, full-time farming status, use of biosecurity guidelines, good milking facilities and operations management, and application of related quality tests are all associated with lower SCC levels. Size of operation had little effect on SCC levels after controlling for other factors. Many of the operations that did not attain a more demanding SCC standard of 400,000 cells/mL had older operators, operators who expressed intention to exit within 10 yr, smaller size, and location in the Southeast when compared with those meeting the tighter standard. The results suggest that the stricter scheme favors larger farms that are more committed to production and are less likely to be sole or family proprietorships.

  4. Dental caries and social factors: impact on quality of life in Brazilian children.

    PubMed

    Martins, Milene Torres; Sardenberg, Fernanda; Vale, Míriam Pimenta; Paiva, Saul Martins; Pordeus, Isabela Almeida

    2015-01-01

    The objective of this study was to evaluate the impact of dental caries and social determinants in the Oral Health Related Quality of Life (OHRQoL) of children in Belo Horizonte, Brazil. This is a population-based cross-sectional study with a representative sample of 1,204 children aged 8 to 10 years randomly selected from 19 public and private schools. The children were clinically examined at school by two trained and calibrated examiners (Kappa = 0.78 - 1.00). The Decayed, Missing and Filled Teeth Index (DMF-T and dmf-t) was used for the diagnosis of dental caries. The social factors were determined by parents'/caregivers' schooling, household income, number of people in the household, type of school, and by the Social Vulnerability Index. The Brazilian version of the Child Perceptions Questionnaire for ages 8 to 10 years was used to assess the impact on quality of life. A total of 278 (23.1%) out of 1,204 children had at least one cavitated carious lesion and 47.0% presented a negative impact on OHRQoL. In the final multivariate Poisson's regression model, household income and presence of untreated dental caries were statistically associated with a negative impact on OHRQoL (p < 0.001).Children with dental caries and from low-income families had a higher negative impact on OHRQoL.

  5. Pressure dependence of the quality factor of a micromachined cantilever in rarefied gases

    NASA Astrophysics Data System (ADS)

    Stifter, Michael; Sachse, Matthias; Sauter, Thilo; Hortschitz, Wilfried; Keplinger, Franz

    2012-05-01

    We present a study of the damping behavior of monocrystalline silicon cantilevers in different rarefied gas regimes. Mechanical quality factors Q were analyzed at controlled ambient pressures in the range of 0.01 Pa to 100 Pa. Emphasis was laid on the investigation of the fundamental vibration mode. Hence, the test structures were harmonically excited by the Lorentz force acting on the current carrying lead attached to the top surface of the cantilever. The micromachined clamped-free cantilevers featuring a length of 2 mm, a width of 1.5 mm and a thickness of 20 μm, were manufactured in SOI technology. The experimental results were compared with existing theories revealing an underestimate of the damping parameter for the Knudsen range Kn = 0.1 to 10. So far, squeeze-film damping by free molecular flow and kinetic damping were taken into account in damping models for the quasi-molecular regime. However, our measurements indicate that also the ongoing molecular flow around the test structures has to be considered. Hence the damping coefficient has to be calculated with methods of the free molecular aerodynamics. Thus, we used an algorithm based on the random walk model that allows the usage of already available knowledge in the field of Direct Simulation Monte Carlo. With this approach the quality factor of a squeezed-film damped cantilever in the quasi-molecular regime was derived. The results were compared with the most recent stochastic model, where the theoretical predictions and the experimental investigations indicate significant squeezing up to a Knudsen number of 10. In a superposition of both damping mechanisms, kinetic and squeeze-film damping, a satisfactory characterization of the damping behavior of an oscillating cantilever in the quasi-molecular regime with Knudsen numbers in the range of 10 down to 0.02 was achieved.

  6. Oral health-related quality of life and associated factors in Norwegian adults.

    PubMed

    Dahl, Kari Elisabeth; Wang, Nina J; Skau, Irene; Ohrn, Kerstin

    2011-07-01

    OBJECTIVE. To investigate associations between oral health-related quality of life assessed with the Oral Health Impact Profile (OHIP)-14 and demographic factors, number of teeth present, dental visits, dental health behaviour and self-rated oral health in a representative sample of 20-80-year-old Norwegians. MATERIAL AND METHODS. The study was conducted in a stratified random sample of 3538 individuals. Questionnaires including questions on demographic factors, number of remaining teeth, dental visits, dental health behaviour, self-rated oral health and OHIP-14 were mailed to the sample. Bivariate and multivariate analyses were performed. RESULTS. The response rate was 69%. The mean OHIP-14 score was 4.1 (standard deviation = 6.2). No problem was reported by 35% of the respondents. The most frequently reported problems were: physical pain (56%), psychological discomfort (39%) and psychological disability (30%). When the effect of all independent variables was analysed in multivariate analysis, self-rated oral health, frequency of dental visits, number of teeth, age and sex were significantly (P < 0.05) associated with the prevalence of having problems and frequent problems. Self-rated oral health had the strongest association with having problems [odds ratio (OR) 4.5; 95% confidence interval (CI) 3.4-6.0] and with having frequent problems (OR 4.0; 95% CI 2.7-5.8). Dental health behaviour, use of floss and toothpicks and oral rinsing were not associated with having problems related to oral quality of life in multivariate analyses. CONCLUSION. In this Norwegian adult sample, self-rated oral health, frequency of dental visits, number of teeth, age and sex were associated with having problems as estimated using the OHIP-14.

  7. Factors associated with quality of life in patients with severe asthma: the impact of pharmacotherapy

    PubMed Central

    Souza, Daiane Silva; Noblat, Lúcia de Araújo Costa Beisl; Santos, Pablo de Moura

    2015-01-01

    ABSTRACT OBJECTIVE: To identify, characterize, and quantify associations of various factors with quality of life (QoL) in patients with asthma, according to the pharmacotherapy employed. METHODS: This was a cross-sectional study involving 49 patients (≥ 18 years of age) with severe uncontrolled or refractory asthma treated at a specialized outpatient clinic of the Brazilian Unified Health Care System, regularly using high doses of inhaled corticosteroids (ICs) or other medications, and presenting comorbidities. At a single time point, QoL was assessed with the Asthma Quality of Life Questionnaire (AQLQ). The overall AQLQ score and those of its domains were correlated with demographic variables (gender and age); Asthma Control Questionnaire score; pharmacotherapy (initial IC dose, inhaler devices, and polytherapy); and comorbidities. RESULTS: Better AQLQ scores were associated with asthma control-overall (OR = 0.38; 95% CI: 0.004-0.341; p < 0.001), "symptoms" domain (OR = 0.086; 95% CI: 0.016-0.476; p = 0.001), and "emotional function" domain (OR = 0.086; 95% CI: 0.016-0.476; p = 0.001)-and with IC dose ≤ 800 µg-"activity limitation" domain (OR = 0.249; 95% CI: 0.070-0.885; p = 0.029). Worse AQLQ scores were associated with polytherapy-"activity limitation" domain (OR = 3.651; 95% CI: 1.061-12.561; p = 0.036)-and number of comorbidities ≤ 5-"environmental stimuli" domain (OR = 5.042; 95% CI: 1.316-19.317; p = 0.015). CONCLUSIONS: Our results, the importance of this issue, and the lack of studies taking pharmacotherapy into consideration warrant longitudinal studies to establish a causal relationship between the identified factors and QoL in asthma patients. PMID:26785957

  8. Neutron transport simulation (selected topics)

    NASA Astrophysics Data System (ADS)

    Vaz, P.

    2009-10-01

    Neutron transport simulation is usually performed for criticality, power distribution, activation, scattering, dosimetry and shielding problems, among others. During the last fifteen years, innovative technological applications have been proposed (Accelerator Driven Systems, Energy Amplifiers, Spallation Neutron Sources, etc.), involving the utilization of intermediate energies (hundreds of MeV) and high-intensity (tens of mA) proton accelerators impinging in targets of high Z elements. Additionally, the use of protons, neutrons and light ions for medical applications (hadrontherapy) impose requirements on neutron dosimetry-related quantities (such as kerma factors) for biologically relevant materials, in the energy range starting at several tens of MeV. Shielding and activation related problems associated to the operation of high-energy proton accelerators, emerging space-related applications and aircrew dosimetry-related topics are also fields of intense activity requiring as accurate as possible medium- and high-energy neutron (and other hadrons) transport simulation. These applications impose specific requirements on cross-section data for structural materials, targets, actinides and biologically relevant materials. Emerging nuclear energy systems and next generation nuclear reactors also impose requirements on accurate neutron transport calculations and on cross-section data needs for structural materials, coolants and nuclear fuel materials, aiming at improved safety and detailed thermal-hydraulics and radiation damage studies. In this review paper, the state-of-the-art in the computational tools and methodologies available to perform neutron transport simulation is presented. Proton- and neutron-induced cross-section data needs and requirements are discussed. Hot topics are pinpointed, prospective views are provided and future trends identified.

  9. Small angle neutron scattering

    NASA Astrophysics Data System (ADS)

    Cousin, Fabrice

    2015-10-01

    Small Angle Neutron Scattering (SANS) is a technique that enables to probe the 3-D structure of materials on a typical size range lying from ˜ 1 nm up to ˜ a few 100 nm, the obtained information being statistically averaged on a sample whose volume is ˜ 1 cm3. This very rich technique enables to make a full structural characterization of a given object of nanometric dimensions (radius of gyration, shape, volume or mass, fractal dimension, specific area…) through the determination of the form factor as well as the determination of the way objects are organized within in a continuous media, and therefore to describe interactions between them, through the determination of the structure factor. The specific properties of neutrons (possibility of tuning the scattering intensity by using the isotopic substitution, sensitivity to magnetism, negligible absorption, low energy of the incident neutrons) make it particularly interesting in the fields of soft matter, biophysics, magnetic materials and metallurgy. In particular, the contrast variation methods allow to extract some informations that cannot be obtained by any other experimental techniques. This course is divided in two parts. The first one is devoted to the description of the principle of SANS: basics (formalism, coherent scattering/incoherent scattering, notion of elementary scatterer), form factor analysis (I(q→0), Guinier regime, intermediate regime, Porod regime, polydisperse system), structure factor analysis (2nd Virial coefficient, integral equations, characterization of aggregates), and contrast variation methods (how to create contrast in an homogeneous system, matching in ternary systems, extrapolation to zero concentration, Zero Averaged Contrast). It is illustrated by some representative examples. The second one describes the experimental aspects of SANS to guide user in its future experiments: description of SANS spectrometer, resolution of the spectrometer, optimization of spectrometer

  10. Measurements of the Electric Form Factor of the Neutron up to Q2 = 3.4 GeV2 using the Reaction He-3(e,e'n)pp

    SciTech Connect

    Riordan, Seamus; Craver, Brandon; Kelleher, Aidan; Kolarkar, Ameya; Miller, Jonathan; Cates, Gordon; Liyanage, Nilanga; Wojtsekhowski, Bogdan; Quimper, Armando Acha; Allada, Kalyan; Anderson, Byron; Aniol, Konrad; Annand, John; Arrington, John; Averett, Todd; Beck, Arie; Bellis, Matthew; Boeglin, Werner; Breuer, Herbert; Calarco, John; Chen, Jian-Ping; Chudakov, Eugene; Coman, Luminita; Crowe, Benjamin; Cusanno, Francesco; Day, Donal; Degtiarenko, Pavel; Dolph, P.A.M.; Dutta, Chiranjib; Ferdi, Catherine; Fernandez-Ramirez, Cezar; Feuerbach, Robert; Fraile Prieto, Luis; Franklin, Gregg; Frullani, Salvatore; Fuchs, Sabine; Garibaldi, Franco; Gevorgyan, Nerses; Gilman, Ronald; Glazmazdin, Oleksandr; Gomez, Javier; Grimm, Klaus; Hansen, Jens-Ole; Herraiz, Joaquin Lopez; Higinbotham, Douglas; Holmes, Richard; Holmstrom, Timothy; Howell, David; De Jager, Cornelis; Jiang, Xiaodong; Jones, Mark; Katich, Joseph; Kaufman, Lisa; Khandaker, Mahbubul; Kelly, James; Kiselev, Daniela; Korsch, Wolfgang; LeRose, John; Markowitz, Pete; Margaziotis, Demetrius; May-Tal Beck, Sharon; Mayilyan, Samvel; McCormick, Kathy; Meziani, Zein-Eddine; Michaels, Robert; Moffit, Bryan; Nanda, Sirish; Nelyubin, Vladimir; Ngo, Tim; Nikolenko, Dmitri; Norum, Blaine; Pentchev, Lubomir; Perdrisat, Charles; Piasetzky, Eliazer; Pomatsalyuk, Roman; Protopoescu, Dan; Puckett, Andrew; Punjabi, Vina; Qian, XIn; Qiang, Yi; Quinn, Brian; Rachek, Igor; Ransome, Ronald; Reimer, Paul; Reitz, Bodo; Roche, Julie; Ron, Guy; Rondon-Aramayo, Oscar; Rosner, Guenther; Saha, Arunava; Sargsian, Misak; Sawatzky, Bradley; Segal, John; Shabestari, Mitra Hashemi; Shahinyan, Albert; Singh, Jaideep; Sirca, Simon; Souder, Paul; Stepanyan, Samuel; Stibunov, Victor; Sulkosky, Vince; Sulkosky, Vincent; Tajima, Shigeyuki; Tobias, William; Moinelo, Jose Udias; Urciuoli, Guido; Vlahovic, Branislav; Voskanyan, Hakob; Wang, Kebin; Wesselmann, Frank; Vignote, Javier Rodriguez; Wood, Stephen; Wright, Justin; Yao, Huan; Zhu, Zianfang

    2010-12-01

    The electric form factor of the neutron was determined from studies of the reaction \\rea{} in quasi-elastic kinematics in Hall A at Jefferson Lab. Longitudinally polarized electrons were scattered off a polarized target in which the nuclear polarization was oriented perpendicular to the momentum transfer. The scattered electrons were detected in a magnetic spectrometer in coincidence with neutrons that were registered in a large-solid-angle detector. More than doubling the $Q^2$-range over which it is known, we find \\GEn{}$ = 0.0225 \\pm 0.0017 (stat) \\pm 0.0024 (syst)$, $0.0200 \\pm 0.0023 \\pm 0.0018$, and $0.0142 \\pm 0.0019 \\pm 0.0013$ for $Q^2$ = 1.72, 2.48, and 3.41~\\gevsq, respectively.

  11. Neutron Stars

    NASA Astrophysics Data System (ADS)

    van den Heuvel, Ed

    Radio pulsars are unique laboratories for a wide range of physics and astrophysics. Understanding how they are created, how they evolve and where we find them in the Galaxy, with or without binary companions, is highly constraining of theories of stellar and binary evolution. Pulsars' relationship with a recently discovered variety of apparently different classes of neutron stars is an interesting modern astrophysical puzzle which we consider in Part I of this review. Radio pulsars are also famous for allowing us to probe the laws of nature at a fundamental level. They act as precise cosmic clocks and, when in a binary system with a companion star, provide indispensable venues for precision tests of gravity. The different applications of radio pulsars for fundamental physics will be discussed in Part II. We finish by making mention of the newly discovered class of astrophysical objects, the Fast Radio Bursts, which may or may not be related to radio pulsars or neutron stars, but which were discovered in observations of the latter.

  12. Intense neutron source

    SciTech Connect

    Walko, R.J.; Bacon, F.M.; Brainard, J.P.; O'Hagan, J.B.; Riedel, A.A.

    1983-04-01

    A ScD/sub 2/ target film 5x10/sup -5/ m thick, tested in a UHV compatible 200 keV deuterium accelerator baked to 470/sup 0/C, maintained a D-D neutron output rate of 1.0-1.2x10/sup 11//s for 80 out of 140 hours of operation. This result demonstrates that a D-T neutron generator capable of a neutron output rate of 1x10/sup 13//s and having a target lifetime suitable for cancer therapy is possible. Contrary to sputter rate data, ErD/sub 2/ target films appear to erode about twice as fast as ScD/sub 2/ films, making ErD/sub 2/ unsuitable as a target material. A low pressure ion source has been developed to replace the high pressure duopigatron. Experiments have verified that the single ring magnetic cusp ion source can deliver 200 mA of deuterium ions (approx. =60% D/sup +/) at 10-15 A of arc current with a background deuterium pressure of 0.27-0.40 Pa. This source will improve the safety of a D-T machine by reducing the tritium inventory by a factor of 6, and by utilizing the Zr-Al getter as the gas reservoir.

  13. Intense neutron source

    SciTech Connect

    Walko, R.J.; Brainard, J.P.; Riedel, A.A.; O'Hagan, J.B.; Bacon, F.M.

    1982-01-01

    A ScD/sub 2/ target film 5 x 10/sup -5/ m thick, tested in a UHV compatible 200 keV deuterium accelerator baked to 470/sup 0/C, maintained a D-D neutron output rate of 1.0-1.2x10'' /s for 80 out of 140 hours of operation. This result demonstrates that a D-T neutron generator capable of a neutron output rate of 1 x 10/sup 13//s and having a target lifetime suitable for cancer therapy is possible. Contrary to sputter rate data, ErD/sub 2/ target films appear to erode about twice as fast as ScD/sub 2/ films, making ErD/sub 2/ unsuitable as a target material. A low pressure ion source has been developed to replace the more complicated duopigatron. Experiments have verified that the single ring magnetic cusp ion source can deliver 200 mA of deuterium ions (approx. = 60% D/sup +/) at 10-15 A of arc current with a background deuterium pressure of 0.27-0.40 Pa. This source will improve the safety of a D-T machine by reducing the tritium inventory by a factor of 6, and by utilizing the Zr-Al getter as the gas reservoir.

  14. Neutron Thermal Cross Sections, Westcott Factors, Resonance Integrals, Maxwellian Averaged Cross Sections and Astrophysical Reaction Rates Calculated from the ENDF/B-VII.1, JEFF-3.1.2, JENDL-4.0, ROSFOND-2010, CENDL-3.1 and EAF-2010 Evaluated Data Libraries

    NASA Astrophysics Data System (ADS)

    Pritychenko, B.; Mughabghab, S. F.

    2012-12-01

    We present calculations of neutron thermal cross sections, Westcott factors, resonance integrals, Maxwellian-averaged cross sections and astrophysical reaction rates for 843 ENDF materials using data from the major evaluated nuclear libraries and European activation file. Extensive analysis of newly-evaluated neutron reaction cross sections, neutron covariances, and improvements in data processing techniques motivated us to calculate nuclear industry and neutron physics quantities, produce s-process Maxwellian-averaged cross sections and astrophysical reaction rates, systematically calculate uncertainties, and provide additional insights on currently available neutron-induced reaction data. Nuclear reaction calculations are discussed and new results are presented. Due to space limitations, the present paper contains only calculated Maxwellian-averaged cross sections and their uncertainties. The complete data sets for all results are published in the Brookhaven National Laboratory report.

  15. Neutron Thermal Cross Sections, Westcott Factors, Resonance Integrals, Maxwellian Averaged Cross Sections and Astrophysical Reaction Rates Calculated from the ENDF/B-VII.1, JEFF-3.1.2, JENDL-4.0, ROSFOND-2010, CENDL-3.1 and EAF-2010 Evaluated Data Libraries

    SciTech Connect

    Pritychenko, B.; Mughabghab, S.F.

    2012-12-15

    We present calculations of neutron thermal cross sections, Westcott factors, resonance integrals, Maxwellian-averaged cross sections and astrophysical reaction rates for 843 ENDF materials using data from the major evaluated nuclear libraries and European activation file. Extensive analysis of newly-evaluated neutron reaction cross sections, neutron covariances, and improvements in data processing techniques motivated us to calculate nuclear industry and neutron physics quantities, produce s-process Maxwellian-averaged cross sections and astrophysical reaction rates, systematically calculate uncertainties, and provide additional insights on currently available neutron-induced reaction data. Nuclear reaction calculations are discussed and new results are presented. Due to space limitations, the present paper contains only calculated Maxwellian-averaged cross sections and their uncertainties. The complete data sets for all results are published in the Brookhaven National Laboratory report.

  16. New determination of period and quality factor of Chandler wobble, considering geophysical excitations

    NASA Astrophysics Data System (ADS)

    Vondrák, J.; Ron, C.; Chapanov, Ya.

    2017-03-01

    Polar motion consists of both free (Chandler wobble, with approximately 14-month period) and forced components. The latter are caused by different excitations of geophysical origin. Very long-periodic (or secular) part is most probably due to post-glacial rebound, shorter periodic part (with dominant annual period) are caused mainly by motions of the atmosphere and oceans. Recently it was also proposed that impulse-like excitations due to geomagnetic jerks might be responsible for rapid changes of the amplitude and phase of Chandler wobble. In order to precisely determine the parameters of the free part, it is necessary to consider all these influences. We use the IERS combined solution C04 together with ERA atmospheric/oceanic excitations in the interval 1974.0-2014.0, and also additional excitations due to nine geomagnetic jerks, registered during this interval, to determine the period and quality factor of Chandler wobble, free from these geophysical effects. We obtained solutions for three different time intervals: 1974.0-1994.0, 1994.0-2014.0, and 1974.0-2014.0. The estimated values of Q-factor are much smaller if GMJ excitations are used in addition to atmospheric and oceanic ones, and they are determined with higher accuracy. Our preferred values, valid for the whole interval 1974.0-2014.0, are P = 432.86 ± 0.04 days and Q = 35.0 ± 0.3 .

  17. Tools for developing a quality management program: human factors and systems engineering tools.

    PubMed

    Caldwell, Barrett S

    2008-01-01

    During the past 10 years, there has been growing acceptance and encouragement of partnerships between medical teams and engineers. Using human factors and systems engineering descriptions of process flows and operational sequences, the author's research laboratory has helped highlight opportunities for reducing adverse events and improving performance in health care and other high-consequence environments. This research emphasized studying human behavior that enhances system performance and a range of factors affecting adverse events, rather than a sole emphasis on human error causation. Developing a balanced evaluation requires novel approaches to causal analyses of adverse events and, more importantly, methods of recovery from adverse conditions. Recent work by the author's laboratory in collaboration with the Regenstrief Center for Healthcare Engineering has started to address possible improvements in taxonomies describing health care tasks. One major finding includes enhanced understanding of events and how event dynamics influence provider tasks and constraints. Another element of this research examines team coordination tasks that strongly affect patient care and quality management, but may be undervalued as "indirect patient care" activities.

  18. Tools for Developing a Quality Management Program: Human Factors and Systems Engineering Tools

    SciTech Connect

    Caldwell, Barrett S.

    2008-05-01

    During the past 10 years, there has been growing acceptance and encouragement of partnerships between medical teams and engineers. Using human factors and systems engineering descriptions of process flows and operational sequences, the author's research laboratory has helped highlight opportunities for reducing adverse events and improving performance in health care and other high-consequence environments. This research emphasized studying human behavior that enhances system performance and a range of factors affecting adverse events, rather than a sole emphasis on human error causation. Developing a balanced evaluation requires novel approaches to causal analyses of adverse events and, more importantly, methods of recovery from adverse conditions. Recent work by the author's laboratory in collaboration with the Regenstrief Center for Healthcare Engineering has started to address possible improvements in taxonomies describing health care tasks. One major finding includes enhanced understanding of events and how event dynamics influence provider tasks and constraints. Another element of this research examines team coordination tasks that strongly affect patient care and quality management, but may be undervalued as 'indirect patient care' activities.

  19. Identifying key factors in homeowner's adoption of water quality best management practices.

    PubMed

    Brehm, Joan M; Pasko, Danielle K; Eisenhauer, Brian W

    2013-07-01

    The recognition of the significance of the residential environment in contributing to non-point source (NPS) pollution and the inherently dispersed nature of NPS pollution itself that presents significant challenges to effective regulation has led to the creation and dissemination of best management practices (BMPs) that can reduce the impacts of NPS pollution (Environmental Protection Agency US, Protecting water quality from urban runoff, http://www.epa.gov/npdes/pubs/nps_urban-facts_final.pdf , 2003). However, very few studies have examined the factors that influence the adoption of BMPs by residential homeowners, despite the fact that residential environments have been identified as one of the most significant contributors to NPS pollution. Given this need, the purpose of this project was to explore how demographic and knowledge-based factors predict adoption of residential BMPs in an urbanizing watershed in Northern Illinois using statistical analyses of survey data collected as part of a watershed planning process. The findings indicate that broad knowledge of BMPs is the strongest predictor of use for a specific BMP. Knowledge of BMPs is strongly correlated with their use, which reinforces the need for educational programs, even among those assumed to be knowledgeable about BMPs.

  20. Identifying Factors Influencing Pancreatic Cancer Management to Inform Quality Improvement Efforts and Future Research: A Scoping Systematic Review.

    PubMed

    Gagliardi, Anna R; Soong, Daniel; Gallinger, Steven

    2016-02-01

    Pancreatic cancer (PC) patients appear to receive suboptimal care. We conducted a systematic review to identify factors that influence PC management which are amenable to quality improvement. MEDLINE, EMBASE, and the references of eligible studies were searched from 1996 to July 2014. Two authors independently selected and reviewed eligible studies. Identified factors were mapped onto a framework of determinants of care delivery and outcomes. Methodological quality of studies was assessed using Downs and Black criteria. Most of the 33 eligible studies were population-based observational studies conducted in the United States. Patient (age, socioeconomic status, race) and institutional (case volume, academic status) factors influence care delivery and outcomes (complications, mortality, readmission, survival). Two studies implemented interventions to improve quality of care (centralization to high-volume hospitals, multidisciplinary care). One study examined system determinants (referral wait times). No studies examined the influence of guideline or provider characteristics. The overall lack of health services research in PC is striking. Factors and interventions identified here can be used to plan PC quality improvement programs. Further research is needed to explore the influence of guideline and provider factors on PC management and evaluate the impact of quality improvement interventions.

  1. Individual, Organizational, and Job Factors Affecting the Quality of Work Life Among Navy Nurse Corps Officers

    DTIC Science & Technology

    1987-03-01

    predicted performance, job satisfaction, turnover, and perceived quality of nursing care in the Navy. The majority of nurses were dissatisfied or ambivalent...with the quality of nursing care delivered in the Navy, and they were dissatisfied or ambivalent with the quality of their work lives. Keywords: Job satisfaction, Job performance, Quality of nursing care .

  2. Status and outlook of the neutron time-of-flight facility n_TOF at CERN

    NASA Astrophysics Data System (ADS)

    Gunsing, F.; Abbondanno, U.; Aerts, G.; Álvarez, H.; Álvarez-Velarde, F.; Andriamonje, S.; Andrzejewski, J.; Assimakopoulos, P.; Audouin, L.; Badurek, G.; Baumann, P.; Bečvář, F.; Berthoumieux, E.; Calviño, F.; Cano-Ott, D.; Capote, R.; de Albornoz, A. Carrillo; Cennini, P.; Chepel, V.; Chiaveri, E.; Colonna, N.; Cortes, G.; Couture, A.; Cox, J.; Dahlfors, M.; David, S.; Dillman, I.; Dolfini, R.; Domingo-Pardo, C.; Dridi, W.; Duran, I.; Eleftheriadis, C.; Ferrant, L.; Ferrari, A.; Ferreira-Marques, R.; Frais-Koelbl, H.; Fujii, K.; Furman, W.; Goncalves, I.; González-Romero, E.; Goverdovski, A.; Gramegna, F.; Griesmayer, E.; Guerrero, C.; Haas, B.; Haight, R.; Heil, M.; Herrera-Martinez, A.; Igashira, M.; Isaev, S.; Jericha, E.; Käppeler, F.; Kadi, Y.; Karadimos, D.; Karamanis, D.; Kerveno, M.; Ketlerov, V.; Koehler, P.; Konovalov, V.; Kossionides, E.; Krtička, M.; Lampoudis, C.; Leeb, H.; Lindote, A.; Lopes, I.; Lozano, M.; Lukic, S.; Marganiec, J.; Marques, L.; Marrone, S.; Martínez, T.; Massimi, C.; Mastinu, P.; Mengoni, A.; Milazzo, P. M.; Moreau, C.; Mosconi, M.; Neves, F.; Oberhummer, H.; O'Brien, S.; Oshima, M.; Pancin, J.; Papachristodoulou, C.; Papadopoulos, C.; Paradela, C.; Patronis, N.; Pavlik, A.; Pavlopoulos, P.; Perrot, L.; Pigni, M. T.; Plag, R.; Plompen, A.; Plukis, A.; Poch, A.; Pretel, C.; Quesada, J.; Rauscher, T.; Reifarth, R.; Rosetti, M.; Rubbia, C.; Rudolf, G.; Rullhusen, P.; Salgado, J.; Sarchiapone, L.; Savvidis, I.; Stephan, C.; Tagliente, G.; Tain, J. L.; Tassan-Got, L.; Tavora, L.; Terlizzi, R.; Vannini, G.; Vaz, P.; Ventura, A.; Villamarin, D.; Vincente, M. C.; Vlachoudis, V.; Vlastou, R.; Voss, F.; Walter, S.; Wendler, H.; Wiescher, M.; Wisshak, K.; n TOF Collaboration

    2007-08-01

    The neutron time-of-flight facility n_TOF at CERN, fully operational since 2002, combines a high instantaneous neutron flux with high energy resolution. The wide energy range and the high neutron flux per time-of-flight burst result in a much enhanced signal to background ratio for neutron capture of radioactive isotopes and makes this facility well suited for the measurement of high quality neutron-induced reaction cross-sections. Neutrons are created by spallation reactions induced by a pulsed 20 GeV/c proton beam impinging on a lead target. A 5 cm water slab surrounding the lead target serves as a coolant and at the same time as a moderator of the spallation neutron spectrum, providing a wide energy spectrum from 0.1 eV to about 250 MeV. By the end of 2005, a first phase of data taking has been successfully terminated. Fission and capture experiments have been performed on a variety of isotopes of interest for nuclear astrophysics, advanced nuclear technologies and for basic nuclear physics. The instrumentation developed for this facility consists of parallel plate avalanche counter and fission ionization chamber detectors for the fission experiments and of low mass C6D6 detectors and a 4 pi BaF2 total absorption calorimeter for capture experiments. A new data acquisition system, based on sampling of the detector signals, has been developed to cope with the high count rates and to minimize the effective dead time to only a few tens of nanosecond. A second phase of data taking is planned to start in 2007, after an upgrade of the spallation target. On the longer term, the construction of a flight path at 20 m resulting in an increased neutron flux of about a factor of 100 opens new possibilities.

  3. Neutron matter, symmetry energy and neutron stars

    NASA Astrophysics Data System (ADS)

    Gandolfi, S.; Steiner, A. W.

    2016-01-01

    Recent progress in quantum Monte Carlo with modern nucleon-nucleon interactions have enabled the successful description of properties of light nuclei and neutron- rich matter. Of particular interest is the nuclear symmetry energy, the energy cost of creating an isospin asymmetry, and its connection to the structure of neutron stars. Combining these advances with recent observations of neutron star masses and radii gives insight into the equation of state of neutron-rich matter near and above the saturation density. In particular, neutron star radius measurements constrain the derivative of the symmetry energy.

  4. Neutron matter, symmetry energy and neutron stars

    SciTech Connect

    Stefano, Gandolfi; Steiner, Andrew W

    2016-01-01

    Recent progress in quantum Monte Carlo with modern nucleon-nucleon interactions have enabled the successful description of properties of light nuclei and neutron-rich matter. Of particular interest is the nuclear symmetry energy, the energy cost of creating an isospin asymmetry, and its connection to the structure of neutron stars. Combining these advances with recent observations of neutron star masses and radii gives insight into the equation of state of neutron-rich matter near and above the saturation density. In particular, neutron star radius measurements constrain the derivative of the symmetry energy.

  5. Borner Ball Neutron Detector

    NASA Technical Reports Server (NTRS)

    2002-01-01

    The Bonner Ball Neutron Detector measures neutron radiation. Neutrons are uncharged atomic particles that have the ability to penetrate living tissues, harming human beings in space. The Bonner Ball Neutron Detector is one of three radiation experiments during Expedition Two. The others are the Phantom Torso and Dosimetric Mapping.

  6. Mediators of maternal depression and family structure on child BMI: parenting quality and risk factors for child overweight.

    PubMed

    McConley, Regina L; Mrug, Sylvie; Gilliland, M Janice; Lowry, Richard; Elliott, Marc N; Schuster, Mark A; Bogart, Laura M; Franzini, Luisa; Escobar-Chaves, Soledad L; Franklin, Frank A

    2011-02-01

    Risk factors for child obesity may be influenced by family environment, including maternal depression, family structure, and parenting quality. We tested a path model in which maternal depression and single parent status are associated with parenting quality, which relates to three risk factors for child obesity: diet, leisure, and sedentary behavior. Participants included 4,601 5th-grade children and their primary caregivers who participated in the Healthy Passages study. Results showed that associations of maternal depression and single parenthood with child BMI are mediated by parenting quality and its relation to children's leisure activity and sedentary behavior. Interventions for child obesity may be more successful if they target family environment, particularly parenting quality and its impact on children's active and sedentary behaviors.

  7. A pilot's assessment of helicopter handling-quality factors common to both agility and instrument flying tasks

    NASA Technical Reports Server (NTRS)

    Gerdes, R. M.

    1980-01-01

    A series of simulation and flight investigations were undertaken to evaluate helicopter flying qualities and the effects of control system augmentation for nap-of-the-Earth (NOE) agility and instrument flying tasks. Handling quality factors common to both tasks were identified. Precise attitude control was determined to be a key requirement for successful accomplishment of both tasks. Factors that degraded attitude controllability were improper levels of control sensitivity and damping, and rotor system cross coupling due to helicopter angular rate and collective pitch input. Application of rate command, attitude command, and control input decouple augmentation schemes enhanced attitude control and significantly improved handling qualities for both tasks. The NOE agility and instrument flying handling quality considerations, pilot rating philosophy, and supplemental flight evaluations are also discussed.

  8. Processing of Neutron Diffraction Data for Strain Measurement in Geological Materials

    SciTech Connect

    Polsky, Yarom; An, Ke; Anovitz, Lawrence {Larry} M; Bingham, Philip R; Carmichael, Justin R; Dessieux Jr, Luc Lucius

    2014-01-01

    : Conventional rock mechanics testing techniques typically involve the loading of samples and measurement of displacements or strains on the outer boundary of the specimen surface. Neutron diffraction based strain measurement techniques represent a unique and powerful tool for measuring the strain within geological materials under load. The structural variability and non-uniform crystallinity of geological materials, however, create many complexities in the intensity patterns that must be analyzed to quantify strains within the material. The attenuating and scattering properties of the pressure cell housing the sample further add difficulties to the data analysis. This paper describes the methods and processes used to process neutron scattering data for strain measurement in geological materials. It is intended to provide a primer for those in the rock mechanics community that are interested in utilizing this technique along with additional discussion of neutron diffraction experimental factors that may affect data quality.

  9. Shielding experiment of heavy-ion produced neutrons using a tissue-equivalent proportional counter.

    PubMed

    Nunomiya, T; Yonai, S; Takada, M; Fukumura, A; Nakamura, T

    2003-01-01

    A shielding experiment was performed at the HIMAC (Heavy Ion Medical Accelerator in Chiba), of National Institute of Radiological Sciences (NIRS), to measure neutron dose using a spherical TEPC (tissue-equivalent proportional counter) of 12.55 cm inner diameter. Neutrons are produced from a 5 cm thick stopping length Cu target bombarded by 400 MeV/nucleon C6+ ions and penetrate concrete or iron shields of various thicknesses at 0 degree to the beam direction. From this shielding experiment. y-distribution, mean lineal energy, absorbed dose, dose equivalent and mean-quality factor were obtained behind the shield as a function of shield thickness. The neutron dose attenuation lengths were also obtained as 126 g cm(-2) for concrete and 211 g cm(-2) for iron. The measured results were compared with the calculated results using the MARS Monte Carlo code.

  10. Neutron reflecting supermirror structure

    DOEpatents

    Wood, James L.

    1992-01-01

    An improved neutron reflecting supermirror structure comprising a plurality of stacked sets of bilayers of neutron reflecting materials. The improved neutron reflecting supermirror structure is adapted to provide extremely good performance at high incidence angles, i.e. up to four time the critical angle of standard neutron mirror structures. The reflection of neutrons striking the supermirror structure at a high critical angle provides enhanced neutron throughput, and hence more efficient and economical use of neutron sources. One layer of each set of bilayers consist of titanium, and the second layer of each set of bilayers consist of an alloy of nickel with carbon interstitially present in the nickel alloy.

  11. Ultra-high quality factors in superconducting niobium cavities in ambient magnetic fields up to 190 mG

    SciTech Connect

    Romanenko, A. Grassellino, A.; Crawford, A. C.; Sergatskov, D. A.; Melnychuk, O.

    2014-12-08

    Ambient magnetic field, if trapped in the penetration depth, leads to the residual resistance and therefore sets the limit for the achievable quality factors in superconducting niobium resonators for particle accelerators. Here, we show that a complete expulsion of the magnetic flux can be performed and leads to: (1) record quality factors Q > 2 × 10{sup 11} up to accelerating gradient of 22 MV/m; (2) Q ∼ 3 × 10{sup 10} at 2 K and 16 MV/m in up to 190 mG magnetic fields. This is achieved by large thermal gradients at the normal/superconducting phase front during the cooldown. Our findings open up a way to ultra-high quality factors at low temperatures and show an alternative to the sophisticated magnetic shielding implemented in modern superconducting accelerators.

  12. Effect of Threading Dislocations on the Quality Factor of InGaN/GaN Microdisk Cavities

    PubMed Central

    2014-01-01

    In spite of the theoretical advantages associated with nitride microcavities, the quality factors of devices with embedded indium gallium nitride (InGaN) or gallium nitride (GaN) optical emitters still remain low. In this work we identify threading dislocations (TDs) as a major limitation to the fabrication of high quality factor devices in the nitrides. We report on the use of cathodoluminescence (CL) to identify individual TD positions within microdisk lasers containing either InGaN quantum wells or quantum dots. Using CL to accurately count the number, and map the position, of dislocations within several individual cavities, we have found a clear correlation between the density of defects in the high-field region of a microdisk and its corresponding quality factor (Q). We discuss possible mechanisms associated with defects, photon scattering, and absorption, which could be responsible for degraded device performance. PMID:25839048

  13. Gallium nitride L3 photonic crystal cavities with an average quality factor of 16 900 in the near infrared

    SciTech Connect

    Vico Triviño, Noelia; Carlin, Jean-François; Butté, Raphaël; Grandjean, Nicolas; Minkov, Momchil Savona, Vincenzo; Urbinati, Giulia; Galli, Matteo

    2014-12-08

    Photonic crystal point-defect cavities were fabricated in a GaN free-standing photonic crystal slab. The cavities are based on the popular L3 design, which was optimized using an automated process based on a genetic algorithm, in order to maximize the quality factor. Optical characterization of several individual cavity replicas resulted in an average unloaded quality factor Q = 16 900 at the resonant wavelength λ∼1.3 μm, with a maximal measured Q value of 22 500. The statistics of both the quality factor and the resonant wavelength are well explained by first-principles simulations including fabrication disorder and background optical absorption.

  14. Plutonium Detection with Straw Neutron Detectors

    SciTech Connect

    Mukhopadhyay, Sanjoy; Maurer, Richard; Guss, Paul

    2014-03-27

    A kilogram of weapons grade plutonium gives off about 56,000 neutrons per second of which 55,000 neutrons come from spontaneous fission of 240Pu (~6% by weight of the total plutonium). Actually, all even numbered isotopes (238Pu, 240Pu, and 242Pu) produce copious spontaneous fission neutrons. These neutrons induce fission in the surrounding fissile 239Pu with an approximate multiplication of a factor of ~1.9. This multiplication depends on the shape of the fissile materials and the surrounding material. These neutrons (typically of energy 2 MeV and air scattering mean free path >100 meters) can be detected 100 meters away from the source by vehicle-portable neutron detectors. [1] In our current studies on neutron detection techniques, without using 3He gas proportional counters, we designed and developed a portable high-efficiency neutron multiplicity counter using 10B-coated thin tubes called straws. The detector was designed to perform like commercially available fission meters (manufactured by Ortec Corp.) except instead of using 3He gas as a neutron conversion material, we used a thin coating of 10B.

  15. Two neutron correlations in photo-fission

    NASA Astrophysics Data System (ADS)

    Dale, D. S.; Kosinov, O.; Forest, T.; Burggraf, J.; Stave, S.; Warren, G.; Starovoitova, V.

    2016-09-01

    A large body of experimental work has established the strong kinematical correlation between fission fragments and fission neutrons. Here, we report on the progress of investigations of the potential for strong two neutron correlations arising from the nearly back-to-back nature of the two fission fragments that emit these neutrons in the photo-fission process. In initial measurements, a pulsed electron linear accelerator was used to generate bremsstrahlung photons that impinged upon an actinide target, and the energy and opening angle distributions of coincident neutrons were measured using a large acceptance neutron detector array. A planned comprehensive set of measurements of two neutron correlations in the photo-fission of actinides is expected to shed light on several fundamental aspects of the fission process including the multiplicity distributions associated with the light and heavy fission fragments, the nuclear temperatures of the fission fragments, and the mass distribution of the fission fragments as a function of energy released. In addition to these measurements providing important nuclear data, the unique kinematics of fission and the resulting two neutron correlations have the potential to be the basis for a new tool to detect fissionable materials. A key technical challenge of this program arises from the need to perform coincidence measurements with a low duty factor, pulsed electron accelerator. This has motivated the construction of a large acceptance neutron detector array, and the development of data analysis techniques to directly measure uncorrelated two neutron backgrounds.

  16. Two neutron correlations in photo-fission

    SciTech Connect

    Dale, D. S.; Kosinov, O.; Forest, T.; Burggraf, J.; Stave, S.; Warren, G.; Starovoitova, V.

    2016-01-01

    A large body of experimental work has established the strong kinematical correlation between fission fragments and fission neutrons. Here, we report on the progress of investigations of the potential for strong two neutron correlations arising from the nearly back-to-back nature of the two fission fragments that emit these neutrons in the photo-fission process. In initial measurements, a pulsed electron linear accelerator was used to generate bremsstrahlung photons that impinged upon an actinide target, and the energy and opening angle distributions of coincident neutrons were measured using a large acceptance neutron detector array. A planned comprehensive set of measurements of two neutron correlations in the photo-fission of actinides is expected to shed light on several fundamental aspects of the fission process including the multiplicity distributions associated with the light and heavy fission fragments, the nuclear temperatures of the fission fragments, and the mass distribution of the fission fragments as a function of energy released. In addition to these measurements providing important nuclear data, the unique kinematics of fission and the resulting two neutron correlations have the potential to be the basis for a new tool to detect fissionable materials. A key technical challenge of this program arises from the need to perform coincidence measurements with a low duty factor, pulsed electron accelerator. This has motivated the construction of a large acceptance neutron detector array, and the development of data analysis techniques to directly measure uncorrelated two neutron backgrounds.

  17. NEUTRONIC REACTORS

    DOEpatents

    Wigner, E.P.; Young, G.J.

    1958-10-14

    A method is presented for loading and unloading rod type fuel elements of a neutronic reactor of the heterogeneous, solld moderator, liquid cooled type. In the embodiment illustrated, the fuel rods are disposed in vertical coolant channels in the reactor core. The fuel rods are loaded and unloaded through the upper openings of the channels which are immersed in the coolant liquid, such as water. Unloading is accomplished by means of a coffer dam assembly having an outer sleeve which is placed in sealing relation around the upper opening. A radiation shield sleeve is disposed in and reciprocable through the coffer dam sleeve. A fuel rod engaging member operates through the axial bore in the radiation shield sleeve to withdraw the fuel rod from its position in the reactor coolant channel into the shield, the shield snd rod then being removed. Loading is accomplished in the reverse procedure.

  18. NEUTRONIC REACTOR

    DOEpatents

    Stewart, H.B.

    1958-12-23

    A nuclear reactor of the type speclfically designed for the irradiation of materials is discussed. In this design a central cyllndrical core of moderating material ls surrounded by an active portlon comprlsed of an annular tank contalning fissionable material immersed ln a liquid moderator. The active portion ls ln turn surrounded by a reflector, and a well ls provided in the center of the core to accommodate the materlals to be irradiated. The over-all dimensions of the core ln at least one plane are equal to or greater than twice the effective slowing down length and equal to or less than twlce the effective diffuslon length for neutrons in the core materials.

  19. Effects of environmental factors on edible oil quality of organically grown Camelina sativa.

    PubMed

    Kirkhus, Bente; Lundon, Aina R; Haugen, John-Erik; Vogt, Gjermund; Borge, Grethe Iren A; Henriksen, Britt I F

    2013-04-03

    The aim of the present study was to evaluate the potential for the production of edible oil from organically grown camelina ( Camelina sativa L. Crantz), focusing on the influence of environmental factors on nutritional quality parameters. Field experiments with precrop barley were conducted in Norway in the growing seasons 2007, 2008, and 2009. Trials were fully randomized with two levels of nitrogen (N) fertilization, 0 and 120 kg total N ha(-1), and two levels of sulfur (S) fertilization, 0 and 20 kg total S ha(-1). Weather conditions, that is, temperature and precipitation, were recorded. Additional experiments were performed in the years 2008 and 2009 to evaluate the effects of replacing precrop barley with precrop pea. Seed oil content was measured by near-infrared transmittance, and crude oil compositions of fatty acids, phytosterols, tocopherols, and phospholipids were analyzed by chromatography and mass spectrometry. Results showed significant seasonal variations in seed oil content and oil composition of fatty acids, tocopherols, phytosterols, and phospholipids that to a great extent could be explained by the variations in weather conditions. Furthermore, significant effects of N fertilization were observed. Seed oil content decreased at the highest level of N fertilization, whereas the oil concentrations of α-linolenic acid (18:3n-3), erucic acid (22:1n-9), tocopherols, and campesterol increased. Pea compared to barley as precrop also increased the 18:3n-3 content of oil. S fertilization had little impact on oil composition, but an increase in tocopherols and a decrease in brassicasterol were observed. In conclusion, organically grown camelina seems to be well suited for the production of edible oil. Variations in nutritional quality parameters were generally small, but significantly influenced by season and fertilization.

  20. Neutronic effects on tungsten-186 double neutron capture

    NASA Astrophysics Data System (ADS)

    Garland, Marc Alan

    Rhenium-188, a daughter product of tungsten-188, is an isotope of great interest in therapeutic nuclear medicine, being used in dozens of laboratory and clinical investigations worldwide. Applications include various cancer therapy strategies, treatment of rheumatoid arthritis, prevention of restenosis following coronary artery angioplasty, and palliation of bone pain associated with cancer metastases. With its half-life of 17 hours, 2.12 MeV (maximum) beta-particle emission, chemical similarity to technetium-99m (the most widely used diagnostic radioisotope), and its availability in a convenient tungsten-188/rhenium-188 generator system, rhenium-188 is a superb candidate for a broad range of applications. Production of 188W is typically via double neutron capture by 186W in a high flux nuclear reactor, predominantly the High Flux Isotope Reactor at the Oak Ridge National Laboratory in Tennessee. Experience at HFIR has shown that production yields (measured in Ci of 188W produced per g of 186W target) decrease considerably as target size increases. While the phenomenon of neutron resonance self-shielding would be expected to produce such an effect, temperature effects on neutron flux distribution and neutron capture rates may also be involved. Experimental investigations of these phenomena have not been previously performed. The work presented in this thesis evaluates the factors that contribute to the decrease in 188W yield from both theoretical and experimental standpoints. Neutron self-shielding and temperature effects were characterized to develop a strategy for target design that would optimize production yield, an important factor in minimizing health care costs. It was determined that decrease in yield due to neutron self-shielding can be attributed to depletion of epithermal neutrons at resonant energies, most significantly within the initial 0.4 mm depth of the target. The results from these studies further show that 188W yield in the interior of the

  1. Preliminary On-Orbit Neutron Dose Equivalent and Energy Spectrum Results from the ISS-RAD Fast Neutron Detector (FND)

    NASA Technical Reports Server (NTRS)

    Semones, Edward; Leitgab, Martin

    2016-01-01

    The ISS-RAD instrument was activated on ISS on February 1st, 2016. Integrated in ISS-RAD, the Fast Neutron Detector (FND) performs, for the first time on ISS, routine and precise direct neutron measurements between 0.5 and 8 MeV. Preliminary results for neutron dose equivalent and neutron flux energy distributions from online/on-board algorithms and offline ground analyses will be shown, along with comparisons to simulated data and previously measured neutron spectral data. On-orbit data quality and pre-launch analysis validation results will be discussed as well.

  2. Evaluation of image quality and factor for international telepathology through the Internet

    NASA Astrophysics Data System (ADS)

    Yagi, Yukako; Azumi, Norio; Elsayed, Alaa M.; Mun, Seong K.

    1997-05-01

    In the telepathology, rendering devices significantly influence the perceived image quality. If the resolution and color depth are reduced beyond a certain point, however, it is not possible to obtain images which can be used in telepathology even in an ideal situation. With this in mind, we evaluated image quality, compression, size and rates of data exchange with several histological cases on several kinds of systems for our International Consortium for Internet Telepathology (ICIT) project. The ICIT network uses widely available nonpropriety hardware and software with the Internet as a means of communication.In this study, we discuss the effective image acquisition methods for telepathology. To evaluate microscopic images, various resolution size were used. The images were also evaluated at different JPEG compression ratio, including zero compression, and different format. To evaluate an entire glass slide image, a scanner in transparency mode and an NTSC camera were used. Every case showed similar results. For he microscopic image, although the high resolution images, such as 2k X 1.5k or higher, contain more diagnostic information than lower resolution images; sufficient data was retained in the latter that it does not appear to negatively effect diagnosis. The circumstance and condition for image acquisition, such as specimen thickness or dast of glass slide, are most influenced on the highest image resolution. Usually, we use 5-10 images/case for a telepathology conference. To see all images of a case at a glance before detailed observation, or to switch to the other images immediately, a lower resolution,such as 1k X 0.7k is useful. For the entire glass slide, the reviewer could select the desired area by scanner; however, selecting it by the NTSC camera, was not easy to do. On the monitor, the scanned image has almost the same information as the microscopic image captured by the NTSC camera with 2x objective lens. To ge ta high enough quality image, the

  3. Quality assurance and risk management: Perspectives on Human Factors Certification of Advanced Aviation Systems

    NASA Technical Reports Server (NTRS)

    Taylor, Robert M.; Macleod, Iain S.

    1994-01-01

    This paper is based on the experience of engineering psychologists advising the U.K. Ministry of Defense (MoD) on the procurement of advanced aviation systems that conform to good human engineering (HE) practice. Traditional approaches to HE in systems procurement focus on the physical nature of the human-machine interface. Advanced aviation systems present increasingly complex design requirements for human functional integration, information processing, and cognitive task performance effectiveness. These developing requirements present new challenges for HE quality assurance (QA) and risk management, requiring focus on design processes as well as on design content or product. A new approach to the application of HE, recently adopted by NATO, provides more systematic ordering and control of HE processes and activities to meet the challenges of advanced aircrew systems design. This systematic approach to HE has been applied by MoD to the procurement of mission systems for the Royal Navy Merlin helicopter. In MoD procurement, certification is a judicial function, essentially independent of the service customer and industry contractor. Certification decisions are based on advice from MoD's appointed Acceptance Agency. Test and evaluation (T&E) conducted by the contractor and by the Acceptance Agency provide evidence for certification. Certification identifies limitations of systems upon release to the service. Evidence of compliance with HE standards traditionally forms the main basis of HE certification and significant non-compliance could restrict release. The systems HE approach shows concern for the quality of processes as well as for the content of the product. Human factors certification should be concerned with the quality of HE processes as well as products. Certification should require proof of process as well as proof of content and performance. QA criteria such as completeness, consistency, timeliness, and compatibility provide generic guidelines for

  4. Dynamic factor analysis of groundwater quality trends in an agricultural area adjacent to Everglades National Park

    NASA Astrophysics Data System (ADS)

    Muñoz-Carpena, R.; Ritter, A.; Li, Y. C.

    2005-11-01

    The extensive eastern boundary of Everglades National Park (ENP) in south Florida (USA) is subject to one of the most expensive and ambitious environmental restoration projects in history. Understanding and predicting the water quality interactions between the shallow aquifer and surface water is a key component in meeting current environmental regulations and fine-tuning ENP wetland restoration while still maintaining flood protection for the adjacent developed areas. Dynamic factor analysis (DFA), a recent technique for the study of multivariate non-stationary time-series, was applied to study fluctuations in groundwater quality in the area. More than two years of hydrological and water quality time series (rainfall; water table depth; and soil, ground and surface water concentrations of N-NO 3-, N-NH 4+, P-PO 43-, Total P, F -and Cl -) from a small agricultural watershed adjacent to the ENP were selected for the study. The unexplained variability required for determining the concentration of each chemical in the 16 wells was greatly reduced by including in the analysis some of the observed time series as explanatory variables (rainfall, water table depth, and soil and canal water chemical concentration). DFA results showed that groundwater concentration of three of the agrochemical species studied (N-NO 3-, P-PO 43-and Total P) were affected by the same explanatory variables (water table depth, enriched topsoil, and occurrence of a leaching rainfall event, in order of decreasing relative importance). This indicates that leaching by rainfall is the main mechanism explaining concentration peaks in groundwater. In the case of N-NH 4+, in addition to leaching, groundwater concentration is governed by lateral exchange with canals. F -and Cl - are mainly affected by periods of dilution by rainfall recharge, and by exchange with the canals. The unstructured nature of the common trends found suggests that these are related to the complex spatially and temporally varying

  5. Reference dosimetry condition and beam quality correction factor for CyberKnife beam

    SciTech Connect

    Kawachi, Toru; Saitoh, Hidetoshi; Inoue, Mitsuhiro; Katayose, Tetsurou; Myojoyama, Atsushi; Hatano, Kazuo

    2008-10-15

    This article is intended to improve the certainty of the absorbed dose determination for reference dosimetry in CyberKnife beams. The CyberKnife beams do not satisfy some conditions of the standard reference dosimetry protocols because of its unique treatment head structure and beam collimating system. Under the present state of affairs, the reference dosimetry has not been performed under uniform conditions and the beam quality correction factor k{sub Q} for an ordinary 6 MV linear accelerator has been temporally substituted for the k{sub Q} of the CyberKnife in many sites. Therefore, the reference conditions and k{sub Q} as a function of the beam quality index in a new way are required. The dose flatness and the error of dosimeter reading caused by radiation fields and detector size were analyzed to determine the reference conditions. Owing to the absence of beam flattening filter, the dose flatness of the CyberKnife beam was inferior to that of an ordinary 6 MV linear accelerator. And if the absorbed dose is measured with an ionization chamber which has cavity length of 2.4, 1.0 and 0.7 cm in reference dosimetry, the dose at the beam axis for a field of 6.0 cm collimator was underestimated 1.5%, 0.4%, and 0.2% on a calculation. Therefore, the maximum field shaped with a 6.0 cm collimator and ionization chamber which has a cavity length of 1.0 cm or shorter were recommended as the conditions of reference dosimetry. Furthermore, to determine the k{sub Q} for the CyberKnife, the realistic energy spectrum of photons and electrons in water was simulated with the BEAMnrc. The absence of beam flattening filter also caused softer photon energy spectrum than that of an ordinary 6 MV linear accelerator. Consequently, the k{sub Q} for ionization chambers of a suitable size were determined and tabulated as a function of measurable beam quality indexes in the CyberKnife beam.

  6. Neutron Transversity at Jefferson Lab

    SciTech Connect

    Jian-Ping Chen; Xiaodong Jiang; Jen-chieh Peng; Lingyan Zhu

    2005-09-07

    Nucleon transversity and single transverse spin asymmetries have been the recent focus of large efforts by both theorists and experimentalists. On-going and planned experiments from HERMES, COMPASS and RHIC are mostly on the proton or the deuteron. Presented here is a planned measurement of the neutron transversity and single target spin asymmetries at Jefferson Lab in Hall A using a transversely polarized {sup 3}He target. Also presented are the results and plans of other neutron transverse spin experiments at Jefferson Lab. Finally, the factorization for semi-inclusive DIS studies at Jefferson Lab is discussed.

  7. Method and apparatus for detecting neutrons

    DOEpatents

    Perkins, Richard W.; Reeder, Paul L.; Wogman, Ned A.; Warner, Ray A.; Brite, Daniel W.; Richey, Wayne C.; Goldman, Don S.

    1997-01-01

    The instant invention is a method for making and using an apparatus for detecting neutrons. Scintillating optical fibers are fabricated by melting SiO.sub.2 with a thermal neutron capturing substance and a scintillating material in a reducing atmosphere. The melt is then drawn into fibers in an anoxic atmosphere. The fibers may then be coated and used directly in a neutron detection apparatus, or assembled into a geometrical array in a second, hydrogen-rich, scintillating material such as a polymer. Photons generated by interaction with thermal neutrons are trapped within the coated fibers and are directed to photoelectric converters. A measurable electronic signal is generated for each thermal neutron interaction within the fiber. These electronic signals are then manipulated, stored, and interpreted by normal methods to infer the quality and quantity of incident radiation. When the fibers are arranged in an array within a second scintillating material, photons generated by kinetic neutrons interacting with the second scintillating material and photons generated by thermal neutron capture within the fiber can both be directed to photoelectric converters. These electronic signals are then manipulated, stored, and interpreted by normal methods to infer the quality and quantity of incident radiation.

  8. Method and apparatus for detecting neutrons

    DOEpatents

    Perkins, R.W.; Reeder, P.L.; Wogman, N.A.; Warner, R.A.; Brite, D.W.; Richey, W.C.; Goldman, D.S.

    1997-10-21

    The instant invention is a method for making and using an apparatus for detecting neutrons. Scintillating optical fibers are fabricated by melting SiO{sub 2} with a thermal neutron capturing substance and a scintillating material in a reducing atmosphere. The melt is then drawn into fibers in an anoxic atmosphere. The fibers may then be coated and used directly in a neutron detection apparatus, or assembled into a geometrical array in a second, hydrogen-rich, scintillating material such as a polymer. Photons generated by interaction with thermal neutrons are trapped within the coated fibers and are directed to photoelectric converters. A measurable electronic signal is generated for each thermal neutron interaction within the fiber. These electronic signals are then manipulated, stored, and interpreted by normal methods to infer the quality and quantity of incident radiation. When the fibers are arranged in an array within a second scintillating material, photons generated by kinetic neutrons interacting with the second scintillating material and photons generated by thermal neutron capture within the fiber can both be directed to photoelectric converters. These electronic signals are then manipulated, stored, and interpreted by normal methods to infer the quality and quantity of incident radiation. 5 figs.

  9. Deepening our Understanding of Quality in Australia (DUQuA): a study protocol for a nationwide, multilevel analysis of relationships between hospital quality management systems and patient factors

    PubMed Central

    Taylor, Natalie; Clay-Williams, Robyn; Hogden, Emily; Pye, Victoria; Li, Zhicheng; Groene, Oliver; Suñol, Rosa; Braithwaite, Jeffrey

    2015-01-01

    Introduction Despite the growing body of research on quality and safety in healthcare, there is little evidence of the association between the way hospitals are organised for quality and patient factors, limiting our understanding of how to effect large-scale change. The ‘Deepening our Understanding of Quality in Australia’ (DUQuA) study aims to measure and examine relationships between (1) organisation and department-level quality management systems (QMS), clinician leadership and culture, and (2) clinical treatment processes, clinical outcomes and patient-reported perceptions of care within Australian hospitals. Methods and analysis The DUQuA project is a national, multilevel, cross-sectional study with data collection at organisation (hospital), department, professional and patient levels. Sample size calculations indicate a minimum of 43 hospitals are required to adequately power the study. To allow for rejection and attrition, 70 hospitals across all Australian jurisdictions that meet the inclusion criteria will be invited to participate. Participants will consist of hospital quality management professionals; clinicians; and patients with stroke, acute myocardial infarction and hip fracture. Organisation and department-level QMS, clinician leadership and culture, patient perceptions of safety, clinical treatment processes, and patient outcomes will be assessed using validated, evidence-based or consensus-based measurement tools. Data analysis will consist of simple correlations, linear and logistic regression and multilevel modelling. Multilevel modelling methods will enable identification of the amount of variation in outcomes attributed to the hospital and department levels, and the factors contributing to this variation. Ethics and dissemination Ethical approval has been obtained. Results will be disseminated to individual hospitals in de-identified national and international benchmarking reports with data-driven recommendations. This ground

  10. Validity, reliability and factor analysis of Persian version of schizophrenia quality of life scale

    PubMed Central

    Masaeli, Nasrin; Omranifard, Victoria; Maracy, Mohammad Reza; Kheirabadi, Gholam Reza; Khedri, Anahita

    2016-01-01

    Context: Exact measurement of quality of life (QOL) in schizophrenia patients for evaluation of the patient's deterioration and also to assess the efficacy of therapeutic Interventions has become a daily task, which requires accurate assessment tools. Aims: This study was aimed to assess the psychometric properties of a Persian version of schizophrenia QOL scale (SQLS) as a common transcultural instrument. Settings and Design: One hundred and fifty schizophrenia patients who referred to Psychiatric Clinic in Noor Hospital (Isfahan, Iran) have been selected using simple sampling method. Subjects and Methods: Aside with SQLS, short form-36 general health (SF-36) and World Health Organization QOL-brief-26 (WHOQOL-BREF-26). Questionnaires were completed by the cases for determination of correlation coefficients. Statistical Analysis Used: The data were analyzed using descriptive statistics, factor analysis, Cronbach's coefficient alpha, Pearson correlation coefficient by Statistical Package for Social Sciences software, version 18 (SPSS-18). Results: Total reliability of the questionnaire was reported by using Cronbach's coefficient alpha 0.84, reliability of individual relationships subscales was 0.91, signs 0/87, symptoms 0/72 and motivation/energy 0/61. Correlation coefficients of SF-36 with a total scale of SQLS and correlation coefficient of WHOQOL-BREF-26 with a total scale of SQLS were acceptable. Exploratory factor analysis using varimax rotation identified four principle components (interpersonal relationship, symptoms, signs, motivation, and energy), which will determine QOL at 52.7% variance. Conclusions: Persian version of the SQLS can be used as a simple, reliable and valid tool in Iranian population. PMID:27512702

  11. Rotating night shift work, sleep quality, selected lifestyle factors and prolactin concentration in nurses and midwives.

    PubMed

    Bukowska, Agnieszka; Sobala, Wojciech; Peplonska, Beata

    2015-04-01

    The pattern of secretion of many hormones, including prolactin, is dependent on the circadian rhythm. Night shift work involves exposure to artificial light at night and sleep deficiency, which in turn can affect prolactin synthesis. The aim of this study was to evaluate a possible association between night shift work characteristics, sleep quality, lifestyle factors and prolactin concentration, using data from a cross-sectional study of nurses and midwives. A cross-sectional study was conducted among 327 nurses and midwives currently working on rotating night shifts, and 330 nurses and midwives working during the day (aged 40-60 years) (388 premenopausal and 269 postmenopausal). Information about night shift work characteristics, lifestyle, reproductive factors, sleep pattern and other covariates was collected through a face-to-face interview, and from a one-week work and sleep diary completed by the subjects. Weight and height were measured. Prolactin concentration was measured in the morning blood sample using the electrochemiluminesence immunoassay method. Associations were analyzed using linear regression models adjusted for important confounders. Analyses were carried out separately in pre- and postmenopausal women. None of the night shift work or sleep characteristics was significantly associated with prolactin concentration. Prolactin concentration was significantly (p < 0.05) inversely associated with smoking and time of blood sample collection. These results were consistent among both pre- and postmenopausal women. Nulliparity was significantly positively associated with prolactin among premenopausal women, but inversely among postmenopausal. Age was related to prolactin among postmenopausal women only. Our study indicates that rotating night shift work is not associated with prolactin concentration. Smoking, parity, time of blood collection and age among postmenopausal women were significant determinants of prolactin.

  12. Measurements and Characterization of Neutron and Gamma Dose Quantities in the Vicinity of an Independent Spent Fuel Storage Installation

    SciTech Connect

    Darois, E.L.; Keefer, D.G.; Plazeski, P.E.; Connell, J.

    2006-07-01

    As part of the decommissioning of the Maine Yankee Atomic Power Company (MYAPCo) nuclear power plant, the spent nuclear fuel is being temporarily stored in a dry cask storage facility on a portion of the original licensed property. Each of the spent nuclear fuel (SNF) storage casks hold approximately 25 spent fuel assemblies. Additional storage casks for the greater-than-Class C waste (GTCC) are also used. This waste is contained in 64 casks (60 SNF, 4 GTCC), each of which contain a substantial amount of concrete for shielding and structural purposes. The vertical concrete casks (VCCs) are typically separated by a distance of 4 and 6 feet. The storage casks are effective personnel radiation shields for most of the gamma and neutron radiation emitted from the fuel. However measurable gamma and neutron radiation levels are present in the vicinity of the casks. In order to establish a controlled area boundary around the facility such that a member of the public annual dose level of 0.25-mSv could be demonstrated, measurements of gamma and neutron dose equivalents were conducted. External gamma exposure rates were measured with a Pressurized Ion Chamber (PIC). Neutron absorbed dose and dose equivalent rates were measured with a Rossi-type tissue equivalent proportional counter (TEPC). Both gamma and neutron measurements were made at increasing distances from the facility as well as at a background location. The results of the measurements show that the distance to the 0.25-mSv per year boundary for 100% occupancy conditions varies from 321 feet to 441 feet from the geometric center of the storage pads, depending on the direction from the pad. For the TEPC neutron measurements, the average quality factor from the facilities was approximately 7.4. This quality factor compares well with the average quality factor of 7.6 that was measured during a calibration performed with a bare Cf-252 source. (authors)

  13. Medication-related factors associated with health-related quality of life in patients older than 65 years with polypharmacy

    PubMed Central

    2017-01-01

    In the current public health framework, the importance of medication as a determinant of citizens’ health has emerged as a factor warranting special attention. Most studies investigating the relationship between medication and quality of life do so from the perspective of adherence. However, other medication-related factors identified at home visits may be associated with health-related quality of life. Methods and design Objective: To describe the relationship between medication-related factors and the health-related quality of life in patients older than 65 years who use multiple medications (polypharmacy). Design: Cross-sectional descriptive study. Setting: Primary care. Participants: Patients older than 65 years who use multiple medications (n = 375). Measurements: The main outcome measure was health-related quality of life according to the EuroQol-5D instrument. Sociodemographic, clinical and medication-related variables were recorded during home interviews. Results Mean age was 74.72 ± 5.59 years, and 65.5% of our participants were women. The global level of health-related quality of life according to the EQ-5D visual analog scale was 59.25 ± 20.92. Of the five EuroQol dimensions, anxiety/depression and pain were the most frequently reported, while mobility and self-care were the dimensions with the greatest impact on self-reported quality of life. Multivariate analysis indicated that functional independence was the factor most strongly associated (β = 14.27 p < 0.001) with better health-related quality of life, while illiteracy (β = −13.58 p < 0.001), depression (β = −10.13 p < 0.001), social risk (β = −7.23 p = 0.004) and using more than 10 medicines (β = −4.85 p = 0.009) were strongly associated with a poorer health-related quality of life. Conclusions Factors inherent within the patient such as functional incapacity, cognitive impairment and social and emotional problems were the main constraints to quality of life in our study population

  14. Neutron field for boron neutron capture therapy

    SciTech Connect

    Kanda, K.; Kobayashi, T.

    1986-01-01

    Recently, the development of an epithermal neutron source has been required by medical doctors for deeper neutron penetrations, which is to be used for deep tumor treatment and diagnosis of metastasis. Several attempts have already been made to realize an epithermal neutron field, such as the undermoderated neutron beam, the filtered neutron beam, and the use of a fission plate. At present, these facilities can not be used for actual therapy. For the treatment of deep tumor, another method has been also proposed in normal water in the body is replaced by heavy water to attain a deeper neutron penetration. At Kyoto University's Research Reactor Institute, almost all physics problems have been settled relative to thermal neutron capture therapy that has been used for treating brain tumors and for biological experiments on malignant melanoma. Very recently feasibility studies to use heavy water have been started both theoretically and experimentally. The calculation shows the deeper penetration of neutrons as expected. Two kinds of experiments were done by using the KUR guide tube: 1. Thermal neutron penetration measurement. 2. Heavy water uptake in vitro sample. In addition to the above experiment using heavy water, the development of a new epithermal neutron source using a large fission plate is in progress, which is part of a mockup experiment of an atomic bomb field newly estimated.

  15. Role of Socio-Psychological Factors in Perceived Quality of Care Rendered by Traditional Medical Practitioners in Ibadan, Nigeria

    PubMed Central

    Adejumo, Adebayo; Faluyi, Moyolebi; Adejuwon, Adebukola

    2013-01-01

    Background: It was the aim of the current research to investigate perceived service quality rendered by traditional medical practitioners and the role of socio-psychological factors in the perception. Methods: The first part, a quantitative cross-sectional survey utilized a 93-item questionnaire to examine the influence of quality of life, general health perception, socio-economic status and personality factors on perceived service quality. The second part, a qualitative study utilized 5 FGDs and 2 KIIs to explore consumers’ evaluation of perceived service quality. Five research questions were raised. The 336 purposively-selected participants were attendees of traditional-health clinics/centers in Ibadan with a mean age of X̄=30.60±9.97. Findings: The FGD respondents opined that the scope of orthodox-medicine does not cover certain illnesses. 77.8% of the participants attested to the affordability and promptness of services in traditional hospitals; acknowledging that its perceived efficacy (i.e. 56.8%) motivate patronage of traditional-health service. The 2x2x3 ANOVA revealed significant main effect of quality of life (F[1,270]=41.05, p<.001) and socio-economic status (F[2,270]=36.34; p<.001); as well as interaction effect of quality of life, general health and socio-economic status (F[1,270]=9.624, p<.002); while the regression analysis showed independent influence of extraversion (β=0.31; p<.001), agreeableness (β=0.303; p<.001) and openness to experience (β=0.166; p<.01). Conclusion: This sample acknowledged that traditional health care met quality standards. The role of socio-psychological factors in the quality appraisal was established. The need for better regulation and validation of traditional health care in assuring evidence based care was suggested. PMID:24171887

  16. Is the Best Evidence Good Enough: Quality Assessment and Factor Analysis of Meta-Analyses on Depression

    PubMed Central

    Wang, Meijuan; Mei, Xinchun; Hou, Jiaojiao; Shi, Zhongyong; Shuai, Yu; Shen, Yuan

    2016-01-01

    Background The quality of meta-analyses (MAs) on depression remains uninvestigated. Objective To assess the overall reporting and methodological qualities of MAs on depression and to explore potential factors influencing both qualities. Methods MAs investigating epidemiology and interventions for depression published in the most recent year (2014–2015) were selected from PubMed, EMBASE, PsycINFO and Cochrane Library. The characteristics of the included studies were collected and the total and per-item quality scores of the included studies were calculated based on the two checklists. Univariate and multivariate linear regression analyses were used to explore the potential factors influencing the quality of the articles. Results A total of 217 MAs from 74 peer-reviewed journals were included. The mean score of Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) was 23.0 of 27 and mean score of Assessment of Multiple Systematic Reviews (AMSTAR) was 8.3 of 11. Items assessing registration and protocol (14.2%, 37/217) in PRISMA and item requiring a full list of included and excluded studies (16.1%, 40/217) in AMSTAR had poorer adherences than other items. The MAs that included only RCTs, pre-registered, had five more authors or authors from Cochrane groups and the MAs found negative results had better reporting and methodological qualities. Conclusions The reporting and methodological qualities of MAs on depression remained to be improved. Design of included studies, characteristics of authors and pre-registration in PROSPERO database are important factors influencing quality of MAs in the field of depression. PMID:27336624

  17. Response of six neutron survey meters in mixed fields of fast and thermal neutrons.

    PubMed

    Kim, S I; Kim, B H; Chang, I; Lee, J I; Kim, J L; Pradhan, A S

    2013-10-01

    Calibration neutron fields have been developed at KAERI (Korea Atomic Energy Research Institute) to study the responses of commonly used neutron survey meters in the presence of fast neutrons of energy around 10 MeV. The neutron fields were produced by using neutrons from the (241)Am-Be sources held in a graphite pile and a DT neutron generator. The spectral details and the ambient dose equivalent rates of the calibration fields were established, and the responses of six neutron survey meters were evaluated. Four single-moderator-based survey meters exhibited an under-responses ranging from ∼9 to 55 %. DINEUTRUN, commonly used in fields around nuclear reactors, exhibited an over-response by a factor of three in the thermal neutron field and an under-response of ∼85 % in the mixed fields. REM-500 (tissue-equivalent proportional counter) exhibited a response close to 1.0 in the fast neutron fields and an under-response of ∼50 % in the thermal neutron field.

  18. Effective Use of Discovery Learning to Improve Understanding of Factors That Affect Quality

    ERIC Educational Resources Information Center

    Mukherjee, Arup

    2015-01-01

    Undergraduate business majors are required to take a course in operations management. In this course, a great deal of emphasis is put on developing a good understanding of quality because this is likely to be the only required course that covers this important topic. Quality of output exhibits a great deal of variation. To produce high quality on…

  19. Advanced Neutron Source (ANS) Project progress report

    SciTech Connect

    McBee, M.R.; Chance, C.M. ); Selby, D.L.; Harrington, R.M.; Peretz, F.J. )

    1990-04-01

    This report discusses the following topics on the advanced neutron source: quality assurance (QA) program; reactor core development; fuel element specification; corrosion loop tests and analyses; thermal-hydraulic loop tests; reactor control concepts; critical and subcritical experiments; material data, structural tests, and analysis; cold source development; beam tube, guide, and instrument development; hot source development; neutron transport and shielding; I C research and development; facility concepts; design; and safety.

  20. Childhood bruxism: Related factors and impact on oral health-related quality of life.

    PubMed

    Antunes, Lívia Azeredo Alves; Castilho, Thuanny; Marinho, Marcello; Fraga, Renato Silva; Antunes, Leonardo Santos

    2016-01-01

    This study aimed to assess childhood bruxism relating associated factors and the bruxism's impact on oral health-related quality of life (OHRQoL). A case-control study was performed with 3- to 6-year-old children obtained from public preschools in Brazil. The case and control groups had 21 and 40 children, respectively. Associations between bruxism and respiratory problems (p = 0.04, OR: 0.33, CI: 0.09 to 1.14), dental wear (p < 0.01, OR: 0.01, CI: 0.00 to 0.05), malocclusion (p < 0.01, OR: 0.06, CI: 0.01 to 0.35), and dental caries (p = 0.02, OR: 0.22, CI: 0.04 to 1.04) were observed. The OHRQoL overall mean score and subscales were relatively low independent of the evaluated group (p > 0.05). The association between presence and absence of impact with bruxism or other variables showed no statistical relationship (p > 0.05). It could be concluded that childhood bruxism is related to respiratory problems, dental wear, dental caries, and malocclusion. Despite being a topic that demands special care in dentistry, bruxism does not significantly affect the OHRQoL.