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1

Neutron quality factor.  

National Technical Information Service (NTIS)

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 modi...

1995-01-01

2

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

PubMed

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. PMID:16381781

Veinot, K G; Hertel, N E

2005-01-01

3

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

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. PMID:22908356

Endo, Akira; Sato, Tatsuhiko

2012-08-19

4

Characterization of the image quality in neutron radioscopy  

NASA Astrophysics Data System (ADS)

Neutron radioscopy, or dynamic neutron radiography, is a non-destructive testing method, which has made big steps in the last years. Depending on the neutron flux, the object and the detector, for single events a time resolution down to a few milliseconds is possible. In the case of repetitive processes the object can be synchronized with the detector and better statistics in the image can be reached by adding radiographies of the same phase with a time resolution down to 100 ?s. By stepwise delaying the trigger signal a radiography movie can be composed. Radiography images of a combustion engine and an injection nozzle were evaluated quantitatively by different methods trying to characterize the image quality of an imaging system. The main factors which influence the image quality are listed and discussed.

Brunner, J.; Engelhardt, M.; Frei, G.; Gildemeister, A.; Lehmann, E.; Hillenbach, A.; Schillinger, B.

2005-04-01

5

Neutron charge radius and the neutron electric form factor  

SciTech Connect

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.

Gentile, T. R. [Stop 8461, National Institute of Standards and Technology, Gaithersburg, Maryland 20899 (United States); Crawford, C. B. [University of Kentucky, Lexington, Kentucky 40506 (United States)

2011-05-15

6

Experienced quality factors: qualitative evaluation approach to audiovisual quality  

Microsoft Academic Search

Subjective evaluation is used to identify impairment factors of multimedia quality. The final quality is often formulated via quantitative experiments, but this approach has its constraints, as subject's quality interpretations, experiences and quality evaluation criteria are disregarded. To identify these quality evaluation factors, this study examined qualitatively the criteria participants used to evaluate audiovisual video quality. A semi-structured interview was

Satu Jumisko-Pyykkö; Jukka Häkkinen; Göte Nyman

2007-01-01

7

The neutron diamagnetic form factor of graphite  

Microsoft Academic Search

The form factor of the diamagnetic moment induced by a field of 4.62 T in a single crystal of graphite has been measured by polarised neutron diffraction. The data are consistent with a pi -electron orbital current having a radius of 1.38(8) AA. A slightly smaller than that of the carbon rings in the planar sheets of the graphite structure

C. Wilkinson; D. A. Keen; P. J. Brown; J. B. Forsyth

1989-01-01

8

Electric Form Factor of the Neutron  

SciTech Connect

Recent polarization-based precision measurements of the nucleons' elastic electric form factors have led to surprising results. The measurement of the ratio of the proton's electromagnetic form factors, $\\mu_p G_E^p/G_M^p$, was found to drop nearly linearly with $Q^2$ out to at least $5 \\mathrm{GeV}^2$, inconsistent with the older Rosenbluth-type experiments. A recent measurement of $G_E^n$, the neutron's electric form-factor saw $G_E^n$ does not fall off as quickly as commonly expected up to $Q^2 \\approx 1.5 \\mathrm{GeV}^2$. Extending this study, a precision measurement of $G_E^n$ up to $Q^2=3.5 \\mathrm{GeV}^2$ was completed in Hall A at Jefferson Lab. The ratio $G_E^n/G_M^n$ was measured through the beam-target asymmetry $A_\\perp$ of electrons quasi-elastically scattered off polarized neutrons in the reaction ${}^{3}\\overrightarrow{He}(\\overrightarrow{e},e' n)$. The experiment took full advantage of the electron beam, recent target developments, as well as two detectors new to Jefferson Lab. The measurement used the accelerator's 100\\% duty-cycle high-polarization (typically 84\\%) electron beam and a new, hybrid optically-pumped polarized ${}^{3}\\overrightarrow{He}$ target which achieved in-beam polarizations in excess of 50\\%. A medium acceptance (80msr) open-geometry magnetic spectrometer (BigBite) detected the scattered electron, while a geometrically matched neutron detector observed the struck neutron. Preliminary results from this measurement will be discussed and compared to modern calculations of $G_E^n$.

Robert Feuerbach

2007-10-13

9

Electric Form Factor of the Neutron  

NASA Astrophysics Data System (ADS)

Recent polarization-based precision measurements of the nucleons' elastic electric form factors have led to surprising results. The measurement of the ratio of the proton's electromagnetic form factors, ?pGE^p/GM^p, was found to drop nearly linearly with Q^2 out to at least 5 GeV^2, inconsistent with the older Rosenbluth-type experiments. A recent measurement of GE^n, the neutron's electric form-factor saw GE^n does not fall off as quickly as commonly expected up to Q^2 1.5 GeV^2. Extending this study, a precision measurement of GE^n up to Q^2=3.5 GeV^2 was completed in Hall A at Jefferson Lab. The ratio GE^n/GM^n was measured through the beam-target asymmetry A of electrons quasi-elastically scattered off polarized neutrons in the reaction ^3He(e,e' n). The experiment took full advantage of the electron beam, recent target developments, as well as two detectors new to Jefferson Lab. The measurement used the accelerator's 100% duty-cycle high-polarization (typically 84%) electron beam and a new, hybrid optically-pumped polarized ^3He target which achieved in-beam polarizations in excess of 50%. A medium acceptance (80msr) open-geometry magnetic spectrometer (BigBite) detected the scattered electron, while a geometrically matched neutron detector observed the struck neutron. Preliminary results from this measurement will be discussed and compared to modern calculations of GE^n.

Feuerbach, Robert

2007-10-01

10

Ranking quality factors for measuring web service quality  

Microsoft Academic Search

In the emerging electronic environment, knowing how to measure Web service quality is of great importance. To attain the desired quality of Website services, it is necessary to produce a framework that enables evaluation of a web service quality. This paper defines and categorizes the quality factors for measuring web service quality. Moreover, the paper includes a framework to establish

Fawaz A. AL Zaghoul; Ayman J. AL Nsour; Osama M. A. Rababah

2010-01-01

11

Factors Affecting the Quality of Health Care.  

National Technical Information Service (NTIS)

Quality assurance is discussed as a health planning objective, and structural and process factors affecting the quality of care are examined. Quality assurance and health planning are explored in relation to the rising cost of health care and the evidence...

A. D. Spiegel B. Backhaut

1977-01-01

12

DIANE stationary neutron radiography system image quality and industrial applications  

NASA Astrophysics Data System (ADS)

The SODERN neutron radiography laboratory has operated since February 1993 using a sealed tube generator (GENIE 46). An experimental programme of characterization (dosimetry, spectroscopy) has confirmed the expected performances concerning: neutron flux intensity, neutron energy range, residual gamma flux. Results are given in a specific report [2]. This paper is devoted to the image performance reporting. ASTM and specific indicators have been used to test the image quality with various converters and films. The corresponding modulation transfer functions are to be determined from image processing. Some industrial applications have demonstrated the capabilities of the system: corrosion detection in aircraft parts, ammunitions filling testing, detection of polymer lacks in sandwich steel sheets, detection of moisture in a probe for geophysics, residual ceramic cores imaging in turbine blades. Various computerized electronic imaging systems will be tested to improve the industrial capabilities.

Cluzeau, S.; Huet, J.; Le Tourneur, P.

1994-05-01

13

Kerma Factors in Interaction of Neutrons with Boron Carbide.  

National Technical Information Service (NTIS)

Heat generation in neutron interactions with boron carbide B/sup 10/; B/sup 11/ and /sup 12/C is calculated. Kerma-factors (kerma-kinetic energy released in materials) were calculated for neutron energies between 10/sup -4/ eV and 15 MeV. No major simplif...

I. M. Bondarenko

1986-01-01

14

Factors affecting leachate quality. Technical note  

SciTech Connect

This technical note describes factors affecting leachate quality for dredged material in confined disposal facilities (CDFs). Factors evaluated include desorption kinetics, sediment concentration, and association of PCBs with soluble and colloidal organic matter.

Brannon, J.M.; Pennington, J.C.; Myers, T.E.; Price, C.B.

1989-12-01

15

Structure factor determination of amorphous materials by neutron diffraction  

NASA Astrophysics Data System (ADS)

An introduction is given to structure factor determination by means of neutron diffraction. The method of isotopic substitution, which allows us to separate the partial correlation functions, is also presented. Suitable instruments, the experimental procedures, and corrections are described. Other less-conventional techniques such as isomorphic substitution and anomalous dispersion are also discussed. Finally, examples of the structure factor determination in chalcogenide, molecular, telluride and phosphate glasses are discussed in order to illustrate the usefulness of the neutron diffraction technique.

Cuello, Gabriel J.

2008-06-01

16

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

PubMed

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 an insight to understanding the response of TEPCs in low-energy neutron fields where the neutrons are moderated using a polyethylene moderator. PMID:21183541

Aslam; Waker, A J

2010-12-23

17

FACTORS CONTRIBUTING TO IMPROVEMENT IN EGG QUALITY  

Microsoft Academic Search

The criteria for assessing external and internal quality of eggs include such diverse and important aspects as safety, nutritional, organoleptic and technological properties of eggs and is influenced by a broad range of factors such as the physiology, genetics, nutrition and management of the hens. Genetics are an efficient tool to improve quality but historically egg productivity was the first

Y. Nys

18

Socioeconomic Factors and Water Quality in California  

Microsoft Academic Search

We investigate the relationships between water quality and socioeconomic factors in California at the county level for the years 1993 to 2006 using 24 water quality indicators coming from seven different types of water bodies. We estimate these relationships using three classes of models: the traditional per capita income-pollution level - Environmental Kuznets Curve (EKC) - specifications, a more inclusive

Y. Hossein Farzin; Kelly A. Grogan

2011-01-01

19

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

National Technical Information Service (NTIS)

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). Li...

G. H. Zeman W. S. Bice

1983-01-01

20

Calculation of neutron fluence-to-dose conversion factors for extremities  

SciTech Connect

The Pacific Northwest Laboratory is developing a standard for the performance testing of personnel extremity dosimeters for the US Department of Energy. Part of this effort requires the calculation of neutron fluence-to-dose conversion factors for finger and wrist extremities. This study focuses on conversion factors for two types of extremity models: namely the polymethyl methacrylate (PMMA) phantom (as specified in the draft standard for performance testing of extremity dosimeters) and more realistic extremity models composed of tissue-and-bone. Calculations for each type of model are based on both bare and D[sub 2]O-moderated [sup 252]Cf sources. The results are then tabulated and compared with whole-body conversion factors. More appropriate energy-averaged quality factors for the extremity models have also been computed from the neutron fluence in 50 equally spaced energy bins with energies from 2.53 [times] 10[sup [minus]8] to 15 MeV. Tabulated results show that conversion factors for both types of extremity phantom are 15 to 30% lower than the corresponcung whole-body phantom conversion factors for [sup 252]Cf neutron sources. This difference in extremity and whole-body conversion factors is attributable to the proportionally smaller amount of back-scattering that occurs in the extremity phantoms compared with whole-body phantoms.

Stewart, R.D.; Harty, R.; McDonald, J.C.; Tanner, J.E.

1993-04-01

21

Factors that Predict Quality Classroom Technology Use  

ERIC Educational Resources Information Center

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.…

Hastings, Tricia A.

2009-01-01

22

Factors that Predict Quality Classroom Technology Use  

ERIC Educational Resources Information Center

|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.…

Hastings, Tricia A.

2009-01-01

23

(Neutron dosimetry)  

Microsoft Academic Search

The traveler attended the Sixth Symposium on Neutron Dosimetry during October 12--14, 1987, at the Gesellschaft fur Strahlen-und Umweltforschung in Neuherberg, Federal Republic of Germany. This conference included a very comprehensive program with technical presentations in all areas of neutron dosimetry including several currently controversial topics such as quality factors, passive personnel dosimeters, bubble detectors, and survey instruments. The conference

Swaja

1987-01-01

24

The Neutron Charge Form Factor at Low Q^2  

NASA Astrophysics Data System (ADS)

At the MIT-Bates Linear Accelerator Center, the neutron charge form factor GE^n has been measured by means of quasielastic scattering of polarized electrons from vector-polarized deuterium ^2H(e,e^'n)p. The experiment used the longitudinally polarized, stored electron beam of the MIT-Bates South Hall Ring along with an isotopically pure, highly polarized internal deuterium target provided by an atomic beam source. The measurements have been carried out with the symmetric Bates Large Acceptance Spectrometer Toroid (BLAST) detector with enhanced neutron detection capability. From the beam-target double polarization asymmetry with the target spin oriented perpendicular to the momentum transfer the form factor GE^n is extracted over a range of four-momentum transfer, Q^2, between 0.1 and 0.55 (GeV/c)^2 with minimized systematic errors.

Geis, Eugene

2007-04-01

25

Digital processing to improve image quality in real-time neutron radiography  

Microsoft Academic Search

Real-time neutron radiography (NTV) has been used for practical applications at the Kyoto University Reactor (KUR). At present, however, the direct image from the TV system is still poor in resolution and low in contrast. In this paper several image improvements are demonstrated, such as a frame summing technique, which are effective in increasing image quality in neutron radiography. Image

Shigenori Fujine; Kenji Yoneda; Keiji Kanda

1985-01-01

26

Measurement of the magnetic form factor of the neutron  

SciTech Connect

The 2H(e,e'n)1H quasielastic cross section was measured at Q2 values of 0.109, 0.176, and 0.255 (GeV/c)2. The neutron detection efficiency was determined by the associated particle technique with the 2H( gamma ,pn) reaction for each of the three neutron kinetic energies. These 2H(e,e'n) measurements of the coincidence cross sections are the first at low Q2. The cross sections are sensitive primarily to the neutron magnetic form factor GnM at these kinematics. The extracted GnM values have smaller uncertainties than previous data and are consistent with the dipole parametrization at the two higher momentum transfers; at the lowest momentum transfer, the value of GnM is ~10% higher than t

Baldwin, Alan; Ni, Benwen; Anderson, Brian; Flanders, Bruce; Chang, C.; Chang, C.C.; Hyde, Charles; Manley, D.; Tieger, Daniel; Barkhuff, David; Keane, Declan; Dodson, George; Arenhovel, Hartmuth; Kelly, James; Mougey, Jean; Cameron, John; Dow, Karen; Beard, Kevin; Weinstein, Lawrence; Farkhondeh, Manouchehr; Spraker, Mark; Finn, Michael; Rutt, Paul; Ulmer, Paul; Markowitz, Pete; Pella, Peter; Whitney, R.; Madey, Richard; Lourie, Robert; Van Verst, Scott; Kowalski, Stanley; Eden, Thomas; Payerle, Thomas; Reichelt, Tilmann; Jiang, W.; Zhang, Wei-Ming; Bertozzi, William; Turchinetz, William; Watson, William; Korsch, Wolfgang

1992-01-01

27

Digital processing to improve image quality in real-time neutron radiography  

NASA Astrophysics Data System (ADS)

Real-time neutron radiography (NTV) has been used for practical applications at the Kyoto University Reactor (KUR). At present, however, the direct image from the TV system is still poor in resolution and low in contrast. In this paper several image improvements are demonstrated, such as a frame summing technique, which are effective in increasing image quality in neutron radiography. Image integration before the A/D converter has a beneficial effect on image quality and the high quality image reveals details invisible in direct images, such as: small holes by a reversed image, defects in a neutron converter screen through a high quality image, a moving object in a contoured image, a slight difference between two low-contrast images by a subtraction technique, and so on. For the real-time application a contouring operation and an averaging approach can also be utilized effectively.

Fujine, Shigenori; Yoneda, Kenji; Kanda, Keiji

1985-01-01

28

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

SciTech Connect

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.

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

1983-12-01

29

Factors affecting the quality of bottled water.  

PubMed

The ever-increasing popularity of bottled water means that it is important to analyze not only its mineral content but also, above all, its content of possible contaminants, especially the organic ones. In this respect, bottled waters are a special case, because apart from organic chemical contaminants derived from the well from which they were acquired, their secondary contamination is always possible, during treatment or storage or transport in unsuitable conditions (sunlight and elevated temperature). This paper describes how various factors, from the area around the well, and the method of drawing and treating water, to the manner in which the finished product is stored and transported may affect the quality of bottled waters. It also summarizes literature information on the levels of organic contaminants in various kinds of bottled water samples. PMID:23093103

Diduch, Malwina; Polkowska, ?aneta; Namie?nik, Jacek

2012-10-24

30

Partial Kerma Factors for Neutron Scattering from ^16O^  

NASA Astrophysics Data System (ADS)

Success for the use of neutron for radiation therapy and other applications in radiological physics depends on the understanding of the interaction of neutron with elements in the tissue. Study of the mechanisms of energy deposition by neutron interaction with matter is very important to improve the understanding of the neutron dosimetry. Cross section data are the basic inputs for many types of calculations in radiation physics. One important quantity in some radiological applications of neutron is the kerma (kinetic energy released in material.) Differential elastic and inelastic neutron scattering from some elements of biological interests are available at energies 18 -- 26 MeV. Optical Model Potentials based on these measured cross sections may be used to calculate various quantities of interest for the neutron dosimetry at higher energies where cross section data may not be available. Kerma values for elastic and inelastic scattering of neutron from ^16O are obtained from differential cross sections.

Islam, Mohammed

2011-10-01

31

Improved models and results for evaluating neutron kerma factors  

SciTech Connect

The problem addressed in this thesis research is the accurate evaluation of neutron fluence-to-kerma (Kinetic Energy Released in Materials) factors from microscopic nuclear data. The algorithms developed for this purpose combine in a consistent manner the two basic methods for computing kerma factors, namely kinematics and direct energy balance. These algorithms are implemented in the code KAOS-V which was used as the main evaluation tool to construct the response function library KAOS/LIB-V. The library contains kerma factors and other nuclear response functions for 43 nonfissionable and 15 fissionable isotopes and elements. The chief source of data is the evaluated nuclear data files ENDF/B-V. Auxiliary nuclear data bases, e.g., the Japanese evaluated nuclear data library JENDL-2 were used as a source of isotopic cross sections when these data are not provided in ENDF/B-V files for a natural element. These are needed mainly to estimate average quantities such as effective Q-values for the natural element. This analysis of local energy disposition was instrumental in detecting and understanding energy-balance deficiencies and other problems in the ENDF/B-V data.

Farawila, Y.M.

1987-01-01

32

Improvements in the Image Quality of Neutron Radiograms of NUR Neutron Radiography Facility by Using Several Exposure Techniques  

SciTech Connect

Since the construction of NUR reactor neutron radiography facility in 1991, only transfer exposure method was used as a non destructive technique. The reason is the excess of gamma rays in the neutron beam. To improve radiation performances of the NR system, a stainless steal hollow conical cylinder is introduced at the bottom of the facility beam port, this filter reduce gamma infiltration through the edges of the NR structure without disturbing neutron beam arriving from the in pool divergent collimator. First results confirm our prediction; a gamma rays diminution and a relatively stable neutron flux at the point object are confirmed, consequently the n/{gamma} ratio reaches a value of 2.104 n/cm{sup 2} mR. Radiograms obtained by using the direct exposure method reveal the feasibility of the technique in the new NR configuration facility, but a weak resolution and contrast of the image is observed. In this paper, we describe a procedure to improve the image quality obtained by direct exposure technique. The process consists of using digitized images obtained by several exposure techniques (NR, gamma radiography or X radiography) for a comparison study and then better image definition can be attained.

Zergoug, T.; Nedjar, A.; Mokeddem, M. Y.; Mammou, L. [Centre de Recherche Nucleaire de Draria, (CRND) BP 43 Draria 16000, Algiers (Algeria)

2008-03-17

33

Extension of carbon kerma factor measurements to 18- and 20-MeV neutron energy  

SciTech Connect

Carbon kerma factor measurements were extended to neutron energies of 18 to 20 MeV. Contributions to the data of low energy interactions are identified and subsequently factored out. 12 refs., 7 figs., 2 tabs.

DeLuca, P.M. Jr.; Barschall, H.H.; Burhoe, M.; Haight, R.C.

1985-01-01

34

Prospects for Using Coherent Elastic Neutrino-Nucleus Scattering to Measure the Nuclear Neutron Form Factor  

NASA Astrophysics Data System (ADS)

We review the prospects of using coherent elastic neutrino-nucleus scattering (CENNS) to measure the nuclear neutron form factor. The merits and limitations of several potential neutrino sources are discussed. The effects of detector shape uncertainty and detector size on a measurement of the neutron RMS radius are also considered. We find that the detector spectral shape uncertainty is the important limiting factor on a measurement of the neutron RMS radius. In order to measure the neutron RMS radius to 5%, the spectral shape uncertainty of the detector needs to be known to 1% or better.

Patton, Kelly M.; McLaughlin, Gail C.; Scholberg, Kate

2013-06-01

35

Independent tuning of frequency and quality factor of microresonators  

NASA Astrophysics Data System (ADS)

This letter reports on a developed approach to control losses in torsional microresonators for applications that require high precision. This methodology is demonstrated through realizing an array of microresonators with independent tuning of both quality factor and resonant frequency. The presented approach enables both boosting and reducing the quality factor of a resonator using proper drive signals to the tuning electrodes. The experimental data demonstrates a tunability of as much as +33% and -37% from the initial quality factor value with negligible frequency change. On the other hand, fine resonant frequency tuning was achieved with a minimal effect on the quality factor.

Rasouli, Mohammad Amin; Bahreyni, Behraad

2011-06-01

36

Nodal weighting factor method for ex-core fast neutron fluence evaluation  

SciTech Connect

The nodal weighting factor method is developed for evaluating ex-core fast neutron flux in a nuclear reactor by utilizing adjoint neutron flux, a fictitious unit detector cross section for neutron energy above 1 or 0.1 MeV, the unit fission source, and relative assembly nodal powers. The method determines each nodal weighting factor for ex-core neutron fast flux evaluation by solving the steady-state adjoint neutron transport equation with a fictitious unit detector cross section for neutron energy above 1 or 0.1 MeV as the adjoint source, by integrating the unit fission source with a typical fission spectrum to the solved adjoint flux over all energies, all angles and given nodal volume, and by dividing it with the sum of all nodal weighting factors, which is a normalization factor. Then, the fast neutron flux can be obtained by summing the various relative nodal powers times the corresponding nodal weighting factors of the adjacent significantly contributed peripheral assembly nodes and times a proper fast neutron attenuation coefficient over an operating period. A generic set of nodal weighting factors can be used to evaluate neutron fluence at the same location for similar core design and fuel cycles, but the set of nodal weighting factors needs to be re-calibrated for a transition-fuel-cycle. This newly developed nodal weighting factor method should be a useful and simplified tool for evaluating fast neutron fluence at selected locations of interest in ex-core components of contemporary nuclear power reactors. (authors)

Chiang, R. T. [AREVA NP Inc., 6399 San Ignacio Ave., San Jose, CA 95119 (United States)

2012-07-01

37

Photon attenuation and neutron moderation correction factors for the inspection of cargo containers with tagged neutrons  

Microsoft Academic Search

The EURopean Illicit TRAfficking Countermeasures Kit (EURITRACK) inspection system uses 14MeV neutrons produced by the D(T,n ?) reaction to detect explosives in cargo containers. Fast-neutron-induced reactions inside the container produce gamma rays, which are detected in coincidence with the associated alpha particle. The definition of the neutron path and the time-of-flight measurement allow positioning the source of the gamma ray

C. Carasco; B. Perot; G. Viesti; V. Valkovic; D. Sudac; S. Bernard; A. Mariani; J.-L. Szabo; G. Sannie; M. Lunardon; C. Bottosso; S. Moretto; S. Pesente; P. Peerani; V. Sequeira; M. Salvato

2007-01-01

38

Application of factor analysis in the assessment of groundwater quality  

NASA Astrophysics Data System (ADS)

Factor analysis is useful for interpreting commonly collected groundwater quality data and relating those data to specific hydrogeologic process. Twenty two groundwater quality samples collected from wells in the second confined layer of Suzhou City were analyzed for major dissolved constituents by factor analysis. Correlations among 11 hydrochemical parameters are statistically examined. Three main factors which explain over 75.01% of the total groundwater quality variation are recognized. Factor 1, composed of concentrations of Ca2+, Mg2+, Cl-, Fe2+, CO2, Mn2+ and pH, represents the influence of water-rock interaction on groundwater quality. Factor 2, composed of concentrations of NH4+ and COD, reflects the impact of reductive organic rich environment on groundwater chemical compositions. Factor 3 including concentration of Na+ shows the effect of cation exchange on groundwater quality.

Zhou, Xiaohai; Ruan, Xiaohong; Pan, Zarong; Zhu, Xiaoming; Sun, Han

2010-11-01

39

Calibration factors for the SNOOPY – NP100 neutron dosimeter  

Microsoft Academic Search

Within CANDU nuclear power facilities, only a small fraction of workers are exposed to neutron radiation. For these individuals, roughly 4.5% of the total radiation equivalent dose is the result of exposure to neutrons. When this figure is considered across all workers receiving external exposure of any kind, only 0.25% of the total radiation equivalent dose is the result of

D. F. Moscu; F. E. McNeill; J. Chase

2007-01-01

40

Understanding the Institutional-Level Factors of Urban School Quality  

ERIC Educational Resources Information Center

|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…

Gottfried, Michael A.

2012-01-01

41

Improved quality factor spiral inductors on GaAs substrates  

Microsoft Academic Search

We present test data for several spiral inductors with improved quality factors fabricated on GaAs substrates. It has been shown experimentally that the quality factor of spiral inductors can be increased by reducing magnetically induced currents and by narrowing the line width of the inner turns similar to the one reported for silicon micromachined inductor. Using this technique, we observed

Inder J. Bahl

1999-01-01

42

Snow shielding factors for cosmogenic nuclide dating inferred from Monte Carlo neutron transport simulations  

NASA Astrophysics Data System (ADS)

Conventional formulations of changes in cosmogenic nuclide production rates with snow cover are based on a mass-shielding approach, which neglects the role of neutron moderation by hydrogen. This approach can produce erroneous correction factors and add to the uncertainty of the calculated cosmogenic exposure ages. We use a Monte Carlo particle transport model to simulate fluxes of secondary cosmic-ray neutrons near the surface of the Earth and vary surface snow depth to show changes in neutron fluxes above rock or soil surface. To correspond with shielding factors for spallation and low-energy neutron capture, neutron fluxes are partitioned into high-energy, epithermal and thermal components. The results suggest that high-energy neutrons are attenuated by snow cover at a significantly higher rate (shorter attenuation length) than indicated by the commonly-used mass-shielding formulation. As thermal and epithermal neutrons derive from the moderation of high-energy neutrons, the presence of a strong moderator such as hydrogen in snow increases the thermal neutron flux both within the snow layer and above it. This means that low-energy production rates are affected by snow cover in a manner inconsistent with the mass-shielding approach and those formulations cannot be used to compute snow correction factors for nuclides produced by thermal neutrons. Additionally, as above-ground low-energy neutron fluxes vary with snow cover as a result of reduced diffusion from the ground, low-energy neutron fluxes are affected by snow even if the snow is at some distance from the site where measurements are made.

Zweck, Christopher; Zreda, Marek; Desilets, Darin

2013-10-01

43

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

SciTech Connect

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.

Bradley Plaster

2004-02-01

44

Factors affecting enhanced video quality preferences.  

PubMed

The development of video quality metrics requires methods for measuring perceived video quality. Most of these 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 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: a) those who preferred enhancement ("Sharp") and b) those who disliked enhancement ("Smooth") and 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

Satgunam, Prem Nandhini; Woods, Russell L; Bronstad, P Matthew; Peli, Eli

2013-12-01

45

Carbon Kerma factor for 18- and 20-MeV neutrons  

SciTech Connect

Earlier measurements of the kerma factor of carbon have been extended to neutron energies of 18 and 20 MeV. The measured values are lower than published values based on estimated microscopic cross sections.

DeLuca, P.M. Jr.; Barschell, H.H.; Burhoe, M.; Haight, R.C.

1986-10-01

46

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

SciTech Connect

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.

Nathan Isgur

1998-12-01

47

Factor Substitution and Unobserved Factor Quality in Nursing Homes  

Microsoft Academic Search

This paper studies factor substitution in one important sector: the nursing home industry. Specifically, we measure the extent to which nursing homes substitute materials for labor when labor becomes relatively more expensive. From a policy perspective, factor substitution in this market is important because materials-intensive methods of care are associated with greater risks of morbidity and mortality among nursing home

John Cawley; David C. Grabowski; Richard A. Hirth

2004-01-01

48

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

SciTech Connect

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.

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

2008-07-01

49

Measuring Banks' Automated Service Quality: A Confirmatory Factor Analysis Approach  

Microsoft Academic Search

Automated service quality has been recognised as the factor which determines the suc cess or failure of electronic commerce. Those models current ly available to measure automated service quality are limited in their focus, encompassing only one electronic channel - the internet - thereby ignoring attributes of the other automated service channels. In relation to the banking sector, research has

Mohammed Al-Hawari; Nicole Hartley; Tony Ward

2005-01-01

50

[Effect of ecological factors on citrus fruit quality].  

PubMed

This paper summarized the research advance on the physiological foundation of citrus fruit's major quality factors such as color formation and organic acid and sugar accumulation, and analyzed the effects of main ecological factors such as temperature, sunshine, water, soil, terrain and landforms on them. The existing problems and the research prospects of citrus ecology were expounded, and a useful proposal on the quality sub-distribution of citrus in China was put forward. PMID:15574012

Bao, Jiangfeng; Xia, Renxue; Peng, Shu'ang

2004-08-01

51

Neutron and photon fluence-to-dose conversion factors for active marrow of the skeleton  

SciTech Connect

Calculation of the absorbed dose to active marrow is a complex problem because charged particle equilibrium may not exist near a soft tissue-bone interface and it is difficult to model the intricate intermixture of soft tissue and bone in the skeleton. This study provides the first definitive calculations for a variety of bones and a wide range of neutron and photon energies. We avoid the assumption of a special geometry by using measured chord-length distributions to represent the microstructure of trabecular bone which contains the active marrow. Results of our calculations for neutrons and photons with energies up to 20 MeV are presented as dose response factors. The response factors can be applied in radiation transport calculations of absorbed dose in active marrow from photons and neutrons externally incident on the body and photons produced by neutrons interactions within the body. 34 references, 6 figures, 2 tables.

Kerr, G.D.; Eckerman, K.F.

1984-01-01

52

Power factor controller-an integrated power quality device  

Microsoft Academic Search

This paper describes a new integrated power quality device-power factor controller (PFC) for power distribution system and industrial power circuit applications. A PFC integrates breaker-switched capacitor banks into a compact design with low cost sensing elements and an intelligent control unit. The device provides more accurate voltage control and power factor correction than traditional shunt capacitor bank installations. The integrated

R. Tinggren; Yi Hu; Le Tang; H. Mathews; R. Tyner

1999-01-01

53

Calculated neutron KERMA factors based on the LLNL ENDL data file. Volume 27  

SciTech Connect

Neutron KERMA factors calculated from the LLNL ENDL data file are tabulated for 15 composite materials and for the isotopes or elements in the ENDL file from Z = 1 to Z = 29. The incident neutron energies range from 1.882 x 10/sup -5/ to 20. MeV for the composite materials and from 1.30 x 10/sup -9/ to 20. MeV for the isotopes and elements.

Howerton, R.J.

1986-01-01

54

Measurement of k 0 Factors in Prompt Gamma-Ray Neutron Activation Analysis  

Microsoft Academic Search

The guided thermal neutron beam at 100 MW Dhruva research reactor facility of Bhabha Atomic Research Centre (BARC) was used to carry out prompt gamma-ray neutron activation analysis (PGNAA). The prompt k\\u000a0-factors have been determined for the isotopes of the elements H, B, K, Co, Cu, Ca, Ti, Cr, Cd, Ba, Hg and Gd with respect to 1951 keV

R. N. Acharya; K. Sudarshan; A. G. C. Nair; Y. M. Scindia; A. Goswami; A. V. R. Reddy; S. B. Manohar

2001-01-01

55

Bulk H analysis using neutrons for routine quality control of cassava and products.  

PubMed

Nuclear and related techniques are useful in addressing the issues of food security and safety facing the world today, via quality control of raw materials and products. In this work, experimental investigations were performed to assess the use of total hydrogen content in cassava and products as a quality control indicator of starch and cyanide contents. The work was carried out using a neutron reflection facility at the Centre for Energy Research and Training, Ahmadu Bello University, Zaria, Nigeria. Cassava samples and products were obtained from retail outlets of Ibadan, Umudike and Zaria, representing three major regions of Nigeria. In general, data obtained indicate a total hydrogen content range of 4.47±0.11-10.71±0.27wt% for the various samples, including raw, dry and processed cassava. Results show that samples having low hydrogen content are generally rich in cyanide compounds and demonstrate an inverse relationship between hydrogen content and cyanide content. The implication of this is that the neutron reflection facility can be used as a quality control setup for routine determination of hydrogen as an indicator of the cyanide content in cassava and products. PMID:21463948

Jonah, S A; Okunade, I O; Abolude, O; Onyike, E; Inuwa, I M

2011-03-23

56

Analysis of quality factors in the sorting problem  

SciTech Connect

The problem of defining an efficient procedure to sort the magnets in a circular accelerator is considered. Using a simplified model of the LHC, we analyze the effects of random errors on the dynamic aperture. Different quality factors are proposed to measure the performances of a given lattice. These quantities are based on the analytical tools of nonlinear maps and normal forms. The correlation between quality factors and dynamic aperture is analyzed and a sorting strategy, based on these indicators of nonlinearity, is proposed. A comparison of the results with a sorting method based on local compensation is given.

Giovannozzi, M. [CERN, PS division Geneva, Chicago 1211 (Switzerland); Grassi, R.; Scandale, W. [CERN, SL Division Geneva, Chicago 1211 (Switzerland); Todesco, E. [INFN, Sezione di Bologna, Via Irnerio 46, Bologna, 40126 (Italy)

1995-09-01

57

Human factors systems approach to healthcare quality and patient safety.  

PubMed

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

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

2013-07-08

58

Factors Affecting Sleep Quality of Patients in Intensive Care Unit  

PubMed Central

Introduction: Sleep disturbance is a frequently overlooked complication of intensive care unit (ICU) stay. Aim: To evaluate sleep quality among patients admitted to ICU and investigate environmental and non-environmental factors that affect sleep quality in ICU. Methods: Over a 22-month period, we consecutively recruited patients who spent ? 2 nights post-endotracheal extubation in ICU and who were orientated to time, place, and person on the day of discharge. Self-reported sleep quality, according to a modified Freedman questionnaire, which provided data on self-reported ICU sleep quality in ICU and environmental factors affecting sleep quality in the ICU, were collected. We also investigated non-environmental factors, such as severity of illness, ICU interventions, and medications that can affect sleep quality. Results: Fifty males and 50 females were recruited with a mean (± SD) age of 65.1 ± 15.2 years. APACHE II score at admission to ICU was 18.1 ± 7.5 with duration of stay 6.7 ± 6.5days. Self-reported sleep quality score at home (1 = worst; 10 = best) was 7.0 ± 2.2; this decreased to 4.0 ± 1.7 during their stay in ICU (p < 0.001). In multivariate analysis with APACHE III as severity of illness (R2 = 0.25), factors [exp(b)(95% CI), p value] which significantly affected sleep in ICU were sex [0.37(0.19-0.72), p < 0.01], age and sex interaction [1.02(1.01-1.03), p < 0.01], bedside phone [0.92(0.87-0.97), p < 0.01], prior quality of sleep at home [1.30(1.05-1.62), p = 0.02], and use of steroids [0.82(0.69-0.98), p = 0.03] during the stay in ICU. Conclusion: Reduced sleep quality is a common problem in ICU with a multifactorial etiology. Citation: Bihari S; McEvoy RD; Kim S; Woodman RJ; Bersten AD. Factors affecting sleep quality of patients in intensive care unit. J Clin Sleep Med 2012;8(3):301-307.

Bihari, Shailesh; Doug McEvoy, R.; Matheson, Elisha; Kim, Susan; Woodman, Richard J.; Bersten, Andrew D.

2012-01-01

59

Model for water factor measurements with fission-neutron logging tools. National Uranium Resource Evaluation  

SciTech Connect

During 1977 and 1978, a Fission Neutron Water Factor Model was designed and constructed by Bendix Field Engineering Corporation (BFEC) for the United States Department of Energy (DOE) at the Grand Junction facility. This model features seven water-filled boreholes with different diameters. All of these boreholes penetrate, in order from the top of the model, a 5-foot-thick (1.52 m), uniform, concrete upper ''barren zone''; a 6-foot-thick (1.83 m), uniform, uranium-enriched, concrete ''ore zone''; and a 4-foot-thick (1.22 m), uniform, concrete lower ''barren zone''. The response of a fission neutron logging tool in a water-filled borehole is affected by variations in the borehole diameter. This diameter-dependent effect can be deduced from logs run in several different boreholes of the Fission Neutron Water Factor Model. This report describes the construction of the Fission Neutron Water Factor Model and also presents values for model parameters which are of interest in fission-neutron logging.

Koizumi, C. J.

1983-05-01

60

Dietary quality, lifestyle factors and healthy ageing in Europe  

Microsoft Academic Search

Keywords:<\\/strong> dietary quality, dietary patterns, lifestyle factors, smoking, physical activity, elderly, mortality, Mediterranean Diet Score, Healthy Diet Indicator, healthy ageing, self-rated health, functional statusThe contribution of diet and lifestyle factors to healthy ageing was investigated in European elderly, born between 1913 and 1918, of the SENECA study. First, the Mediterranean Diet Score (MDS), Healthy Diet Indicator (HDI), and cluster analysis

A. Haveman-Nies

2001-01-01

61

Kerma factor of carbon for 14. 1-MeV neutrons  

SciTech Connect

The paper reports a direct measurement of the kerma factor for carbon for 14-MeV neutrons. The measurements use a small proportional counter with graphite walls. In this counter events caused by neutron and photon interactions can be clearly distinguished, and the gas pressure can be sufficiently low that only a small fraction of the events originate in the gas. Analogous to the ionization chamber kerma factor measurements, the Bragg-Gray relationship is employed to deduce neutron kerma to the wall from energy absorbed in the gas. An internal alpha-particle source is used to calibrate event size in terms of energy. The integral of the event size distribution over energy yields the kerma.

DeLuca, P.M. Jr.; Barschall, H.H.; Haight, R.C.; McDonald, J.C.

1982-01-01

62

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

NASA Astrophysics Data System (ADS)

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).

Popescu, Alina; Risler, Ruedi

2003-07-01

63

Analysis of air quality data using positive matrix factorization  

SciTech Connect

Positive matrix factorization (PMF) was applied to air quality and temperature data collected as part of the Program for Research on Oxidants: Photochemistry, Emissions, and Transport 1997 summer measurement campaign. Unlike more conventional methods of factor analysis such as principal component analysis, PMF produces non-negative factors, aiding factor interpretation, and utilizes error estimates of the data matrix. This work uses PMF as a means of source identification and apportionment, important steps in the development of air pollution control strategies. Measurements of carbon monoxide, particulate matter, peroxyactyl nitrate (PAN), isoprene, temperature, and ozone were taken from a 31 m tower in rural northern Michigan and analyzed in this study. PMF resulted in three physically interpretable factors: an isoprene-dominated factor, a local source factor, and a long-range transport factor. The isoprene-dominated and local source factors exhibited strong and weak diurnal signals, respectively. Factor strengths for the long-range transport factor were relatively high during periods of south and southwesterly flow. The average contribution of the three factors was determined for each pollutant, enabling the modeled matrix to be compared to the data matrix. Good agreement between the fitted and data matrix was achieved for all parameters with the exception of coarse particulate matter. The PMF model explained at least 75% of variation for all species analyzed.

Paterson, K.G.; Sagady, J.L.; Hooper, D.L. [Michigan Technological Univ., Houghton, MI (United States). Dept. of Civil and Environmental Engineering; Bertman, S.B. [Western Michigan Univ., Kalamazoo, MI (United States). Dept. of Chemistry; Carroll, M.A. [Univ. of Michigan, Ann Arbor, MI (United States). Dept. of Atmospheric, Oceanic, and Space Sciences; Shepson, P.B. [Purdue Univ., West Lafayette, IN (United States)

1999-02-15

64

The Exploration of Influencing Factors on Health Care Quality  

Microsoft Academic Search

Since the government brought the National Health Insurance program in practice, the number of health care institutes was increasing as well as the medical treatment and medical expense are also running high on. Meanwhile, in Naderism era, health care institutes not merely care medical effect, but also focus on influcening factors of medical quality for earning customers' loyalty. On the

Wan-I Lee; Bih-Yaw Shih; Chung-Han Wu

65

On the Use of Quality Factor in Seismology (Invited)  

Microsoft Academic Search

Despite its canonical character and widespread use in attenuation studies, suitability of the quality factor Q for describing the Earth still needs to be reviewed. Specifically, we need to consider the following fundamental questions: 1) How close is Q-1 to representing a true medium property? 2) Theoretically, can or should Q-1 be related to complex arguments of the elastic moduli

I. B. Morozov

2009-01-01

66

Designing the quality factor of infiltrated photonic wire slot microcavities.  

PubMed

One-dimensional photonic wire (nanobeam) microcavities are becoming preferred tools for the investigation of enhanced light-matter interaction. Here, the Q-factor of a locally infiltrated slot microcavity in a nanobeam is theoretically investigated. The electric field of the cavity mode is concentrated in the slot region leading to a large overlap with the infiltrated material. Tapering the spacing and diameter of the pores of the adjacent Bragg mirrors a maximum Q-factor of 35,000 is predicted. General design rules for the minimization of scattering losses and the enhancement of quality factors are reviewed and discussed. PMID:21164868

Schriever, Clemens; Bohley, Christian; Schilling, Jörg

2010-11-22

67

On the impact of neutron beam divergence and scattering on the quality of transmission acquired tomographic images  

NASA Astrophysics Data System (ADS)

The impact of the divergence of a thermal neutron beam and the scattered neutrons on the quality of tomographic images acquired by transmission have been evaluated by using a third generation tomographic system incorporating neutron collimators under several different arrangements. The system equipped with a gaseous position sensitive detector has been placed at the main channel outlet of the Argonauta Research Reactor in Instituto de Engenharia Nuclear (CNEN-Brazil) which furnishes a thermal neutron flux of 2.3 × 105 n cm-2 s-1. Experiments have then been conducted using test-objects with well-known inner structure and composition to assess the influence of the collimators arrangement on the quality of the acquired images. Both, beam divergence and scattering expected to spoil the image quality have been reduced by using properly positioned collimators between the neutron source and the object, and in the gap between the object and the detector, respectively. The shadow cast by this last collimator on the projections used to reconstruct the tomographic images has been eliminated by a proper software specifically written for this purpose. Improvement of the tomographic images has been observed, demonstrating the effectiveness of the proposed approach to improve their quality by using properly positioned collimators.

Silvani, Maria Ines; Lopes, Ricardo T.; de Almeida, Gevaldo L.; Gonçalves, Marcelo José; Furieri, Rosanne C. A. A.

2007-10-01

68

Precision measurement of the neutron magnetic form factor from {sup 3}He(e, e')  

SciTech Connect

A precision measurement of the inclusive quasielastic transverse asymmetry A{sub T'} from {sup 3}He(e, e') was completed recently at Hall A at Jefferson Lab (E95-001). The preliminary results on the neutron magnetic form factor at low Q{sup 2} are presented here.

Dipangkar Dutta

2000-12-12

69

g-Factor Measurements Of Isomeric States In Neutron Rich Nuclei  

Microsoft Academic Search

We report on the first application of the TDPAD method to measure the g factor of neutron-rich isomeric states, produced and aligned in a projectile fragmentation reaction. The feasibility of similar measurement opens up a new, unexplored region of the nuclear chart for studies of the magnetic moments of microsecond isomers. Nuclei around 68Ni were produced following the fragmentation of

G. Georgiev; G. Neyens; M. Hass; D. L. Balabanski; C. Bingham; C. Borcea; N. Coulier; R. Coussement; J. M. Daugas; G. de France; F. De Oliveira Santos; M. Gorska; H. Grawe; R. Grzywacz; M. Lewitowicz; H. Mach; I. Matea; R. D. Page; M. Pfützner; Yu. E. Penionzhkevich; Z. Podolyak; P. H. Regan; K. Rykaczewski; M. Sawicka; N. A. Smirnova; Yu. Sobolev; M. Stanoiu; S. Teughels; K. Vyvey

2003-01-01

70

Molecular Targeting of the Epidermal Growth Factor Receptor for Neutron Capture Therapy of Gliomas1  

Microsoft Academic Search

Success of boron neutron capture therapy (BNCT) is dependent on cellular and molecular targeting of sufficient amounts of boron-10 to sustain a lethal 10B (n, ) 7Li capture reaction. The purpose of the present study was to determine the efficacy of boronated epidermal growth factor (EGF) either alone or in combination with boronophe- nylalanine (BPA) as delivery agents for an

F. Barth; Weilian Yang; Dianne M. Adams; Joan H. Rotaru; Supriya Shukla; Masaru Sekido; Werner Tjarks; Robert A. Fenstermaker; Michael Ciesielski; Marta M. Nawrocky; Jeffrey A. Coderre

2002-01-01

71

Comparison of the mean quality factors for astronauts calculated using the Q-functions proposed by ICRP, ICRU, and NASA  

NASA Astrophysics Data System (ADS)

For the estimation of the radiation risk for astronauts, not only the organ absorbed doses but also their mean quality factors must be evaluated. Three functions have been proposed by different organizations for expressing the radiation quality, including the Q(L), Q(y), and QNASA(Z, E) relationships as defined in International Committee of Radiological Protection (ICRP) Publication 60, International Commission on Radiation Units and Measurements (ICRU) Report 40, and National Aeronautics and Space Administration (NASA) TP-2011-216155, respectively. The Q(L) relationship is the most simple and widely used for space dosimetry, but the use of the latter two functions enables consideration of the difference in the track structure of various charged particles during the risk estimation. Therefore, we calculated the mean quality factors in organs and tissues in ICRP/ICRU reference voxel phantoms for the isotropic exposure to various mono-energetic particles using the three Q-functions. The Particle and Heavy Ion Transport code System PHITS was employed to simulate the particle motions inside the phantoms. The effective dose equivalents and the phantom-averaged effective quality factors for the astronauts were then estimated from the calculated mean quality factors multiplied by the fluence-to-dose conversion coefficients and cosmic-ray fluxes inside a spacecraft. It was found from the calculations that QNASA generally gives the largest values for the phantom-averaged effective quality factors among the three Q-functions for neutron, proton, and lighter-ion irradiation, whereas Q(L) provides the largest values for heavier-ion irradiation. Overall, the introduction of QNASA instead of Q(L) or Q(y) in astronaut dosimetry results in the increase the effective dose equivalents because the majority of the doses are composed of the contributions from protons and neutrons, although this tendency may change by the calculation conditions.

Sato, T.; Endo, A.; Niita, K.

2013-07-01

72

Factors affecting quality and safety of fresh-cut produce.  

PubMed

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. PMID:22530712

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

2012-01-01

73

Chaotic microcavity laser with high quality factor and unidirectional output  

NASA Astrophysics Data System (ADS)

We demonstrate a chaotic microcavity laser whose quality is comparable to typical nonchaotic microcavity lasers, yet it has the unique characteristic of unidirectional output. The cavity shape is a disk with the boundary defined by a curve called limaçon of Pascal. For a lasing mode of volume less than 0.2?m3 , the measured quality factor is 23000 . The record-high quality and small modal volume result in extremely low-lasing threshold. The spontaneous emission coupling efficiency is approximately 6% and is the reported value for a chaotic microcavity laser. All the lasing modes have one output beam in the same direction with a divergence angle less than 40° . This universal directionality is determined by the chaotic ray dynamics in the open cavity.

Song, Qinghai; Fang, Wei; Liu, Boyang; Ho, Seng-Tiong; Solomon, Glenn S.; Cao, Hui

2009-10-01

74

Chaotic microcavity laser with high quality factor and unidirectional output  

SciTech Connect

We demonstrate a chaotic microcavity laser whose quality is comparable to typical nonchaotic microcavity lasers, yet it has the unique characteristic of unidirectional output. The cavity shape is a disk with the boundary defined by a curve called limacon of Pascal. For a lasing mode of volume less than 0.2 {mu}m{sup 3}, the measured quality factor is 23 000. The record-high quality and small modal volume result in extremely low-lasing threshold. The spontaneous emission coupling efficiency is approximately 6% and is the reported value for a chaotic microcavity laser. All the lasing modes have one output beam in the same direction with a divergence angle less than 40 deg. This universal directionality is determined by the chaotic ray dynamics in the open cavity.

Song Qinghai; Cao Hui [Department of Applied Physics, Yale University, New Haven, Connecticut 06520-8482 (United States); Fang Wei; Solomon, Glenn S. [Joint Quantum Institute, NIST and University of Maryland, Gaithersburg, Maryland 20899 (United States); Liu Boyang; Ho, S.-T. [Department of Electrical Engineering and Computing Science, Northwestern University, Evanston, Illinois 60208 (United States)

2009-10-15

75

Bound state form factors from knockout in 10Be(d,t) neutron pickup  

NASA Astrophysics Data System (ADS)

Existing 10Be(d,t)9Be neutron pickup data are analyzed using the same bound-state form factors for the <10Be|9Be+n> overlap as in a recent analysis of single-neutron knockout [Grinyer , Phys. Rev. Lett.PRLTAO0031-900710.1103/PhysRevLett.106.162502 106, 162502 (2011)]. While the knockout data were well described by a bound-state form factor calculated using the variational Monte Carlo (VMC) technique, including an appropriate neutron binding potential, the 10Be(d,t)9Be pickup data are significantly overpredicted using this form factor. In addition, the no-core shell model (NCSM) and VMC form factors yield the same calculated pickup cross sections whereas the knockout results using these form factors differed by 20%. We explore possible sources of ambiguity in the pickup calculations that affect our ability to compare the absolute magnitudes in cross sections between these two very different reactions.

Keeley, N.; Kemper, K. W.; Rusek, K.

2012-07-01

76

Trade Show Websites: An Examination of Critical Websites' Quality Factors and Content Items  

Microsoft Academic Search

This study evaluated the quality factors of trade show websites as marketing communication tools. Four factors (system quality, information quality, service quality, and relationship quality) were assessed by measuring their impact on attendees' satisfaction with the trade show website. The relationship between website content items and attendees' satisfaction was also measured. The online survey was distributed to the attendees of

Jumyong Lee; Curtis Love; Taedong Han

2008-01-01

77

Factors affecting the nutritional quality of soya products  

Microsoft Academic Search

The nutritional quality of soya products is determined not only by the quantity and availability of the amino acids which\\u000a make up the protein of such products, but is also markedly affected by the processing conditions which are employed in their\\u000a manufacture. The most important factor in this regard is the application of some form of heat treatment which serves

I. E. Liener; M. Swaminathan; V. Subrahmanyan

1981-01-01

78

Crop management factors influencing yield and quality of crop residues  

Microsoft Academic Search

In the semi-arid tropics, over two-third’s of the world’s people depend on agriculture within which livestock play a major role in building rural livelihoods. Crop residues (fodder\\/stover) are important feed resources for ruminants. This review was undertaken with the objective of improving understanding of the role of various crop management factors in affecting the productivity and quality of crop residues.

B. V. S Reddy; P Sanjana Reddy; F Bidinger; M Blümmel

2003-01-01

79

High-Quality Factor Ni-Zn Ferrite Planar Inductor  

Microsoft Academic Search

Ferrite and air-core planar inductor arrays were fabricated on 4 inch Si wafer to characterize inductor performance. Three micron thick Ni0.5Zn0.5Fe2O4 film was deposited by a low temperature electrophoresis ferrite deposition process. All ferrite inductors in the array showed 35% higher inductance (L) and 130% higher quality factor (Q) than air-core inductor. The maximum Q of ferrite inductor was found

Jae-Jin Lee; Yang-Ki Hong; Seok Bae; Ji-Hoon Park; Jeevan Jalli; Gavin S. Abo; Ryan Syslo; Byoung-Chul Choi; Gregory W. Donohoe

2010-01-01

80

CRITICAL FACTORS OF QUALITY MANAGEMENT USED IN RESEARCH QUESTIONNAIRES: A REVIEW OF LITERATURE  

Microsoft Academic Search

This paper examines the emergence of critical factors of quality management in the development of quality management research questionnaires. A review of literature shows that 27 different critical factors or constructs were developed and used by established researchers in the field. Out of these, 8 most popular critical factors have been identified - top management support, quality information availability, quality

KANAGI KANAPATHY

81

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

PubMed

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. PMID:19518944

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

2009-05-12

82

Factors influencing organizations to improve data quality in their information systems  

Microsoft Academic Search

AbstractAlthough managers consider accurate, timely and relevant information as critical to the quality of their decisions, evidence of large variations in data quality abounds. This research examines factors influencing the level of data quality within a target organization. The results indicate that management's commitment to data quality and the presence of data quality champions strongly influence data quality in the

Sing What Tee; Paul L. Bowen; Peta Doyle; Fiona H. Rohde

2007-01-01

83

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

SciTech Connect

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 GnE. 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 (e, en)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, GnE, 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.

Derek Glazier

2007-09-30

84

(Neutron dosimetry)  

SciTech Connect

The traveler attended the Sixth Symposium on Neutron Dosimetry during October 12--14, 1987, at the Gesellschaft fur Strahlen-und Umweltforschung in Neuherberg, Federal Republic of Germany. This conference included a very comprehensive program with technical presentations in all areas of neutron dosimetry including several currently controversial topics such as quality factors, passive personnel dosimeters, bubble detectors, and survey instruments. The conference was attended by more than 200 people form about 15 countries including many recognized experts in radiation dosimetry, radiobiology, and microdosimetry. The traveler presented a paper containing results of neutron personnel dosimetry research studies conducted since 1974 at the Oak Ridge National Laboratory. During the symposium, the traveler discussed possible future collaborative research efforts with personnel from facilities associated with the Commission of European Communities in areas concerning neutron spectrometry and passive dosimeter testing. These discussions were continued during a visit to the Atomic Energy Authority Laboratories in Harwell, United Kingdom, on October 15, 1987. Through the conference attendance and discussions with dosimetry researchers, the traveler gained information concerning directions and philosophies in neutron dosimetry and made preliminary plans for future cooperative research efforts which will be directly related to DOE programs.

Swaja, R.E.

1987-10-28

85

Kerma factor of carbon for 14.1-MeV neutrons.  

PubMed

Using microdosimetric techniques, a direct measurement was made of the kerma factor of carbon for 14.1-MeV neutrons. Kerma was inferred from charged particle energy depositions measured with a small graphite-walled proportional counter. Measurements with an ionization chamber and a proportional counter, both constructed with A150 plastic walls, as well as induced 24Na activity from the 27Al(n, alpha) reaction, determined the neutron fluence. The resulting carbon kerma factor was 0.178 +/- 0.11 X 10(-8) cGy X cm2 which is lower than published tabulations but in agreement with recent microscopic cross-section measurements. PMID:6494433

DeLuca, P M; Barschall, H H; Haight, R C; McDonald, J C

1984-10-01

86

g -factors of isomeric states in the neutron-rich nuclei  

Microsoft Academic Search

We report the results from the first experiment to measure gyromagnetic factors of µs 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 68 Ni were produced and spin-oriented following the fragmentation of a 76 Ge, 61.4

G. Georgiev; G. Neyens; M. Hass; D. L. Balabanski; C. Bingham; C. Borcea; N. Coulier; R. Coussement; J. M. Daugas; G. de France; M. Górska; H. Grawe; R. Grzywacz; M. Lewitowicz; H. Mach; I. Matea; F. de Oliveira Santos; R. D. Page; M. Pfützner; Yu E. Penionzhkevich; Z. Podolyák; P. H. Regan; K. Rykaczewski; M. Sawicka; N. A. Smirnova; Yu Sobolev; M. Stanoiu; S. Teughels; K. Vyvey

2003-01-01

87

On the quality of quality-factor in gap-closing electrostatic resonators  

NASA Astrophysics Data System (ADS)

We present analytic expressions for three common measures of the dynamic response in gap-closing electrostatic resonators. We show that peak gain, peak sharpness and logarithmic decrement are distinctively different and are not equal to the quality-factor of the unloaded system. We experimentally validate our theoretical predictions by characterizing the dynamic response of test devices. The significance of this work is that it clarifies the correct way in which the performance of MEMS resonators should be reported to avoid ambiguity.

Shmulevich, Shai; Lerman, Michael; Elata, David

2013-11-01

88

Semiconductor nano-gap antennas with high quality factor  

NASA Astrophysics Data System (ADS)

Metallic islands with nano-gap structure are one of the most popular optical antennas [1]. We theoretically propose a new nano-gap antenna utilizing exciton resonance of semiconductor. A light field at the nano-gap (hot spot) formed between two CuCl islands is significantly enhanced by a factor of metallic antennas. However, the hot spot of the semiconducting antenna exhibits much higher quality factor (Q 10^4) at T=40 K than those of metallic antennas which do not exceed Q 100. Our result suggests the semiconducting antenna would function as a new type of photonic cavity. The calculation method is based on a finite element method which can take into account exciton resonance [2]. We also systematically study the geometry dependence of the enhancement factor and Q factor. In contrast to metallic antenna, blunt edges of semiconducting islands at the gap are preferable in order to achieve high enhancement factor. This is because of the fact that exciton wave function extends near the edge for blunt geometry.[4pt] [1] P. M"uhlschlegel et al, Science 308, 5728, 1607-1609 (2005).[0pt] [2] M. Uemoto and H. Ajiki, in preparation.

Uemoto, Mitsuharu; Ajiki, Hiroshi

2013-03-01

89

Carbon nanotubes as ultrahigh quality factor mechanical resonators.  

PubMed

We have observed the transversal vibration mode of suspended carbon nanotubes at millikelvin temperatures by measuring the single-electron tunneling current. The suspended nanotubes are actuated contact-free by the radio frequency electric field of a nearby antenna; the mechanical resonance is detected in the time-averaged current through the nanotube. Sharp, gate-tunable resonances due to the bending mode of the nanotube are observed, combining resonance frequencies of up to nu(0) = 350 MHz with quality factors above Q = 10(5), much higher than previously reported results on suspended carbon nanotube resonators. The measured magnitude and temperature dependence of the Q factor shows a remarkable agreement with the intrinsic damping predicted for a suspended carbon nanotube. By adjusting the radio frequency power on the antenna, we find that the nanotube resonator can easily be driven into the nonlinear regime. PMID:19492820

Hüttel, Andreas K; Steele, Gary A; Witkamp, Benoit; Poot, Menno; Kouwenhoven, Leo P; van der Zant, Herre S J

2009-07-01

90

Variation of groundwater quality in seawater intrusion area using cluster and multivariate factor analysis  

Microsoft Academic Search

Numerous monitoring data and water quality index obtained from 76 regional shallow-layer monitoring wells are simplified and classified by applying the multivariate statistical methods such as factor and cluster analysis to search for the interrelation between the water quality parameters, factors representing the characteristics as well as possible pollution sources of groundwater quality in Pingtung Champaign, Taiwan. Four principal factors

Yi-Chu Huang; Chou-Ping Yang; Yu-Chun Lee; Ping-Kuei Tang; Wen-Ming Hsu; Tien-Nien Wu

2010-01-01

91

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

ERIC Educational Resources Information Center

|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…

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

2010-01-01

92

A polarized target measurement of the electric form factor of the neutron at Jlab  

SciTech Connect

The experiment E93-026 at the Thomas Jefferson National Accelerator Facility (JLab) determined the electric form factor of the neutron G{sub E}{sup n} through quasielastic {rvec d}({rvec e},e'n)p scattering using a longitudinally polarized electron beam and a frozen polarized {sup 15}N D{sub 3} target. The knocked out neutrons were detected in a segmented plastic scintillator detector in coincidence with the scattered electrons. The G{sub E}{sup n} was extracted by comparing the experimental beam-target asymmetry with full theoretical calculations based on different values of G{sub E}{sup n}. Preliminary results of the Fall 2001 run are reported.

N. Savvinov

2004-09-01

93

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

SciTech Connect

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.

Zasneda, Sabriani; Widita, Rena [Department of Physics, Faculty of Mathematics and Natural Sciences, Institut Teknologi Bandung, Jl. Ganesha No. 10 Bandung, 40132 (Indonesia)

2010-06-22

94

The Quality of Factor Solutions in Exploratory Factor Analysis: The Influence of Sample Size, Communality, and Overdetermination  

ERIC Educational Resources Information Center

|The purpose of this study was to investigate the relationship between sample size and the quality of factor solutions obtained from exploratory factor analysis. This research expanded upon the range of conditions previously examined, employing a broad selection of criteria for the evaluation of the quality of sample factor solutions. Results…

Hogarty, Kristine Y.; Hines, Constance V.; Kromrey, Jeffrey D.; Ferron, John M.; Mumford, Karen R.

2005-01-01

95

Measured neutron carbon kerma factors from 14. 1 MeV to 18 MeV  

SciTech Connect

For A-150 tissue-equivalent plastic, the total neutron kerma is dominated by the hydrogen kerma. Tissue kerma is inferred with reasonable accuracy by normalization to the kerma factor ratio between tissue and A-150 plastic. Because of the close match in the hydrogen abundance in these materials, the principal uncertainty is due to the kerma factors of carbon and oxygen. We have measured carbon kerma factor values of 0.183 +- 0.015 10/sup -8/ cGy cm/sup 2/ and 0.210 +- 0.16 10/sup -8/ cGy cm/sup 2/ at 14.1-MeV and 15-MeV neutron energy, respectively. A preliminary value of 0.297 +- 0.03 10/sup -8/ cGy cm/sup 2/ has been determined at 17.9 MeV. A recent microscopic cross section measurement of the (n,n'3..cap alpha..) reaction in carbon at 14.1-MeV energy gives a kerma factor of 0.184 +- 0.019 10/sup 8/ cGy cm/sup 2/ in agreement with the present result. 9 refs., 4 figs., 2 tabs.

Deluca, P.M. Jr.; Barschall, H.H.; Haight, R.C.; McDonald, J.C.

1984-01-01

96

Impact of the neutron detector choice on Bell and Glasstone spatial correction factor for subcriticality measurement  

NASA Astrophysics Data System (ADS)

In subcritical assemblies, the Bell and Glasstone spatial correction factor is used to correct the measured reactivity from different detector positions. In addition to the measuring position, several other parameters affect the correction factor: the detector material, the detector size, and the energy–angle distribution of source neutrons. The effective multiplication factor calculated by computer codes in criticality mode slightly differs from the average value obtained from the measurements in the different experimental channels of the subcritical assembly, which are corrected by the Bell and Glasstone spatial correction factor. Generally, this difference is due to (1) neutron counting errors; (2) geometrical imperfections, which are not simulated in the calculational model, and (3) quantities and distributions of material impurities, which are missing from the material definitions.This work examines these issues and it focuses on the detector choice and the calculation methodologies. The work investigated the YALINA Booster subcritical assembly of Belarus, which has been operated with three different fuel enrichments in the fast zone either: high (90%) and medium (36%), medium (36%), or low (21%) enriched uranium fuel.

Talamo, Alberto; Gohar, Y.; Cao, Y.; Zhong, Z.; Kiyavitskaya, H.; Bournos, V.; Fokov, Y.; Routkovskaya, C.

2012-03-01

97

Factors affecting quality of dried low-rank coals  

SciTech Connect

The chemical and physical properties of coal are strongly affected by the upgrading process employed. For high-moisture coals, upgrading involves thermal dehydration to improve the calorific value of the coal on mass basis. This study evaluates the feasibility of upgrading a low-rank/grade coal using the oven drying method. The objective of this research work is to study the drying characteristics of low-rank coals and to understand the factors affecting the quality of dried low-rank coals. This article describes laboratory experiments conducted on the characterization of the low-rank coals before and after the drying process. The results on drying kinetics, re-absorption of coal samples, and proximate analysis of coal samples before and after drying are discussed. It was found that the upgrading process produced coal with better heating value and combustion characteristics than those of the raw coal samples.

Karthikeyan, M.; Kuma, J.V.M.; Hoe, C.S.; Ngo, D.L.Y. [National University of Singapore, (Singapore)

2007-07-01

98

Multilevel factors affecting quality: examples from the cancer care continuum.  

PubMed

The complex environmental context must be considered as we move forward to improve cancer care and, ultimately, patient and population outcomes. The cancer care continuum represents several care types, each of which includes multiple technical and communication steps and interfaces among patients, providers, and organizations. We use two case scenarios to 1) illustrate the variability, diversity, and interaction of factors from multiple levels that affect care quality and 2) discuss research implications and provide hypothetical examples of multilevel interventions. Each scenario includes a targeted literature review to illustrate contextual influences upon care and sets the stage for theory-informed interventions. The screening case highlights access issues in older women, and the survivorship case illustrates the multiple transition challenges faced by patients, families, and organizations. Example interventions show the potential gains of implementing intervention strategies that work synergistically at multiple levels. While research examining multilevel intervention is a priority, it presents numerous study design, measurement, and analytic challenges. PMID:22623591

Zapka, Jane; Taplin, Stephen H; Ganz, Patricia; Grunfeld, Eva; Sterba, Katherine

2012-05-01

99

High quality factor graphene varactors for wireless sensing applications  

NASA Astrophysics Data System (ADS)

A graphene wireless sensor concept is described. By utilizing thin gate dielectrics, the capacitance in a metal-insulator-graphene structure varies with charge concentration through the quantum capacitance effect. Simulations using realistic structural and transport parameters predict quality factors, Q, >60 at 1 GHz. When placed in series with an ideal inductor, a resonant frequency tuning ratio of 25% (54%) is predicted for sense charge densities ranging from 0.32 to 1.6 ?C/cm2 at an equivalent oxide thickness of 2.0 nm (0.5 nm). The resonant frequency has a temperature sensitivity, df/dT, less than 0.025%/K for sense charge densities >0.32 ?C/cm2.

Koester, Steven J.

2011-10-01

100

Factors impacting quality of experience in stereoscopic images  

NASA Astrophysics Data System (ADS)

The stereoscopic 3D industry has fallen short of achieving acceptable Quality of Experience (QoE) because of various technical limitations, such as excessive disparity, accommodation-convergence mismatch. This study investigates the effect of scene content, camera baseline, screen size and viewing location on stereoscopic QoE in a holistic approach. 240 typical test configurations are taken into account, in which a wide range of disparity constructed from the shooting conditions (scene content, camera baseline, sensor resolution/screen size) was selected from datasets, making the constructed disparities locate in different ranges of maximal disparity supported by viewing environment (viewing location). Second, an extensive subjective test is conducted using a single stimulus methodology, in which 15 samples at each viewing location were obtained. Finally, a statistical analysis is performed and the results reveal that scene content, camera baseline, as well as the interactions between screen size, scene content and camera baseline, have significant impact on QoE in stereoscopic images, while other factors, especially viewing location involved, have almost no significant impact. The generated Mean Opinion Scores (MOS) and the statistical results can be used to design stereoscopic quality metrics and validate their performance.

Xing, Liyuan; You, Junyong; Ebrahimi, Touradj; Perkis, Andrew

2011-02-01

101

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

SciTech Connect

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.

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

1996-07-01

102

Measurement of the Neutron Electric Form Factor GEN at High Q2  

NASA Astrophysics Data System (ADS)

Experiment E02-0131 at Thomas Jefferson National Accelerator Facility (Jefferson Lab) will measure the neutron electric form factor GEn at the high four-momentum transfer values of Q2 ? 1.3, 2.4 and 3.4 (GeV/c)2 via a measurement of the cross section asymmetry AT in the reaction {}3vec He(vec e, e'n)pp . This measurement was approved for 32 days of running by Jefferson Lab PAC 212 in January 2002.

McCormick, Kathy

2003-01-01

103

Bioaccumulation Factor Portions of the Proposed Water Quality Guidance for the Great Lakes System.  

National Technical Information Service (NTIS)

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 pr...

1993-01-01

104

Calculations of anisotropy factors for radionuclide neutron sources due to scattering from source encapsulation and support structures.  

PubMed

A model has been developed for calculating the angular neutron fluence distributions for radionuclide neutron sources that are heavily encapsulated or surrounded by source support structures as a source holder and a source movement system. These structures may cause an anisotropic neutron fluence distribution. This should be taken into account in the neutron-measuring instruments calibration procedure. The calculations were made for two types of widely used neutron sources, (241)Am-Be and (252)Cf, by combining an in-house code simulating the (9)Be(alpha,n) reactions and the Monte Carlo code MCNP-4C. As a result, anisotropy factors in the direction perpendicular to the source capsule axis for bare neutron sources were evaluated to be 1.012, 1.030 and 1.039 for (252)Cf in a standard Amersham X1 capsule, (241)Am-Be in a X3 capsule and (241)Am-Be in a X4 capsule, respectively. These values are in reasonable agreement with the published data. If the support structures are included in the MCNP simulation, the anisotropy factors for these neutron sources increase by approximately 10%. PMID:17575299

Tsujimura, N; Yoshida, T; Momose, T

2007-06-16

105

Simultaneous neutron transmission and diffraction contrast tomography as a non-destructive 3D method for bulk single crystal quality investigations  

NASA Astrophysics Data System (ADS)

Traditional neutron tomography allows to reconstruct the attenuation cross section, a measure for the material distribution, at high spatial resolution and non-destructively. However, it does not state anything about the ordering structure of the atoms inside this material. Extending the setup with a second neutron imaging detector, diffracted neutrons from the ordered crystal lattice could be captured. Emerging iterative reconstruction techniques allow reconstructing the local Bragg reflectivity in the sample, a measure for the spatial distribution in crystal quality (orientation, homogeneity of phases). Simultaneous acquisition ensures optimal use of the neutron flux and a direct comparison of different sample properties.

Peetermans, S.; Lehmann, E. H.

2013-09-01

106

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

Microsoft Academic Search

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 (¹°BPA) and for 2,4-bis (,-dihydroxyethyl)-deutero-porphyrin IX (¹°BOPP).

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

2011-01-01

107

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

ERIC Educational Resources Information Center

|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'…

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

2007-01-01

108

The measurement of sperm motility and factors affecting sperm quality in cultured fish  

Microsoft Academic Search

The fish farming industry has been more focused on the quality of eggs or larvae rather than that of sperm, even though the quality of both gametes may affect fertilisation success and larval survival. In some species, poor sperm quality can be a limiting factor in their culture, however, even when fertilisation success is high, differences in sperm quality between

E Rurangwa; D. E Kime; F Ollevier; J. P Nash

2004-01-01

109

Theoretical Study on New Bias Factor Methods to Effectively Use Critical Experiments for Improvement of Prediction Accuracy of Neutronic Characteristics  

Microsoft Academic Search

Extended bias factor methods are proposed with two new concepts, the LC method and the PE method, in order to effectively use critical experiments and to enhance the applicability of the bias factor method for the improvement of the prediction accuracy of neutronic characteristics of a target core. Both methods utilize a number of critical experimental results and produce a

Teruhiko KUGO; Takamasa MORI; Toshikazu TAKEDA

2007-01-01

110

The Charge Form Factor of the Neutron at Low Q2  

NASA Astrophysics Data System (ADS)

Measurement of the charge form factor of the neutron GEn presents a sensitive test of nucleon models and QCD-inspired theories. In particular, the pion cloud is expected to play a dominant role in the low-momentum transfer region of GEn . At the MIT-Bates Linear Accelerator Center, GEn has been measured by means of quasielastic scattering of polarized electrons from vector-polarized deuterium, 2?c H( {?c e,e'n} ; ). The experiment used the longitudinally polarized stored electron beam of the MIT-Bates South Hall Ring along with an isotopically pure, highly vector-polarized internal atomic deuterium target provided by an atomic beam source. The measurements have been carried out with the symmetric Bates Large Acceptance Spectrometer Toroid (BLAST) with enhanced neutron detection capability. From the beam-target double polarization asymmetry AedV with the target spin oriented perpendicular to the momentum transfer the form factor GEn is extracted over a range of four-momentum transfer Q2 between 0.12 and 0.70 (GeV/c)2 with minimized model dependencies.

Kohl, M.; Milner, R.; Ziskin, V.; Alarcon, R.; Geis, E.

2007-01-01

111

A comparison of quality factors and weighting factors for characterizing astronaut radiation exposures  

NASA Astrophysics Data System (ADS)

Radiation exposures are typically characterized by two quantities. The first is the absorbed dose, or the energy deposited per unit mass for specific types of radiation passing through specified materials. The same amount of energy deposited in material by two different types of radiation, however, can result in two different levels of risk. Because of this, for the purpose of radiation protection operations, absorbed dose is modified by a second factor intended to normalize the risk associated with a given exposure. We present here an inter-comparison of methods for this modification. First is the radiation quality factor (Q), as defined by ICRP publication 60. This quantity is related functionally to the unrestricted linear energy transfer (LET) of a given radiation, and is multiplied by the absorbed dose to derive the dose equivalent (H). The second method for modifying absorbed dose is the radiation weighting factor, also given in ICRP-60, or as modified in NCRP report 115. To implement the weighting factor, the absorbed dose resulting from incidence of a particular radiation is multiplied by a factor assigned to that type of radiation, giving the equivalent dose. We compare calculations done based on identical fields of radiation representative of that encountered by the MIR space station, applying each of these two methods.

Zapp, Neal; Cucinotta, Frank; Atwell, W.

112

Quality of Life Factor as Breast Cancer Risks  

PubMed Central

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.

Gledo, Ibrahim; Pranjic, Nurka; Parsko, Subhija

2012-01-01

113

Survey of ground state neutron spectroscopic factors from Li to Cr isotopes  

NASA Astrophysics Data System (ADS)

The success of the Shell Model has prompted many measurements to extract the spectroscopic factors which describe the configuration of single particle orbitals. We have extracted the ground state to ground state neutron spectroscopic factors for 79 nuclei ranging in Z from 3 to 24 by analyzing the past measurements of the angular distributions of (d,p) and (p,d) reactions in a systematic and consistent manner [1]. For the Ca isotopes from ^40Ca to ^48Ca, the spectroscopic factors follow the predictions of the single particle model predictions as well as predictions from shell model suggesting Ca isotopes have good spherical cores with well defined valence nucleons. For the 59 nuclei where modern shell model calculations [Oxbash] are available, with the exception of the deformed F and Ne isotopes, the experimental spectroscopic factors for most nuclei agree with predictions from modern day shell model to within 20%. This work is supported by the NSF Grant No. NSF-PHY-01-10253 and SURE. Reference: [1] X.D.Liu, M.A.Famiano,W.G.Lynch,M.B.Tsang,and J.A.Tostevin, Phys. Rev. C69 (2004) 1.

Lee, Hui-Ching; Tsang, Betty

2005-04-01

114

Home Video Visual Quality Assessment With Spatiotemporal Factors  

Microsoft Academic Search

Compared with the video programs taken by professionals, home videos are always with low quality content resulted from non-professional capture skills. In this paper, we present a novel spatiotemporal quality assessment scheme in terms of low-level content features for home videos. In contrast to existing frame-level-based quality assessment approaches, a type of temporal segment of video, subshot, is selected as

Tao Mei; Xian-sheng Hua; Cai-zhi Zhu; He-qin Zhou; Shipeng Li

2007-01-01

115

Spallation Neutron Source Availability Top-Down Apportionment Using Characteristic Factors and Expert Opinion  

SciTech Connect

Apportionment is the assignment of top-level requirements to lower tier elements of the overall facility. A method for apportioning overall facility availability requirements among systems and subsystems is presented. Characteristics that influence equipment reliability and maintainability are discussed. Experts, using engineering judgment, scored each characteristic for each system whose availability design goal is to be established. The Analytic Hierarchy Process (AHP) method is used to produce a set of weighted rankings for each characteristic for each alternative system. A mathematical model is derived which incorporates these weighting factors. The method imposes higher availability requirements on those systems in which an incremental increase in availability is easier to achieve, and lower availability requirements where greater availability is more difficult and costly. An example is given of applying this top-down apportionment methodology to the Spallation Neutron Source (SNS) facility.

Haire, M.J.; Schryver, J.C.

1999-10-01

116

Critical Factors Affecting Quality Performance in Construction Projects  

Microsoft Academic Search

The reasons for the underperformance of the quality of Indian construction projects were studied to suggest possible remedial measures. A preliminary survey identified 55 attributes responsible to impact quality performance of the projects. Statistical analysis of questionnaire responses on the attributes resulted into two distinct sets of success and failure attributes. Further analyses of individual sets of success attributes and

K. N. Jha; K. C. Iyer

2006-01-01

117

Inhibiting factors of implementing total quality management on construction sites  

Microsoft Academic Search

Quality systems entail having the organizational structure, responsibilities, procedures, processes and resources for implementing quality management such that there is a guiding framework to ensure that every time a process is performed the same information, method, skills and controls are used and practiced in a consistent manner. With its primary focus being the involvement of everyone, TQM has the potential

Theo C. Haupt; Daniel E. Whiteman

2004-01-01

118

The Impact Factor: Implications of Open Access on Quality  

ERIC Educational Resources Information Center

|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…

Grozanick, Sara E.

2010-01-01

119

Impact Of The Internet On Internal Service Quality Factors: The Travel Industry Case  

Microsoft Academic Search

The growth of multichannel and pure-play companies attests to the changes that technology has brought to business processes. These changes have an effect on the quality of service delivery and customer satisfaction. In this qualitative study, the Service Quality Model was applied to gain insight into the internal service quality factors of two types of travel agencies. In addition, the

Shohreh A. Kaynama

120

Data quality issues for accounting information systems' implementation: Systems, stakeholders, and organizational factors  

Microsoft Academic Search

Quality information is one of the competitive advantages for an organization. In an accounting information system, the quality of the information provided is imperative to the success of the systems. This paper reviews the current literature, and uses a case study to address the important systems, stakeholders, and organizational factors that influence the data quality in accounting information systems' implementation.

Hongjiang Xu

121

On the Use of Quality Factor in Seismology (Invited)  

NASA Astrophysics Data System (ADS)

Despite its canonical character and widespread use in attenuation studies, suitability of the quality factor Q for describing the Earth still needs to be reviewed. Specifically, we need to consider the following fundamental questions: 1) How close is Q-1 to representing a true medium property? 2) Theoretically, can or should Q-1 be related to complex arguments of the elastic moduli of the medium? and 3) What attenuation property is typically measured and transformed into Q? An attempt for answering these questions shows that not Q but the spatial attenuation coefficient, ?, represents a consistent property of energy dissipation by the medium which is also actually measured in most cases. Transformation of ? into the apparent Q = ?f/?V (V is the wave velocity and f - frequency) makes this Q a phenomenological attribute of the wave and also leads to its built-in positive frequency dependence. Such strong positive Q(f) is often reported, particularly for the “scattering Q,” but it may be entirely due to near-constant values of ?. The above transformation is also prone of the well-known uncertainties related to the compensation of geometrical spreading (GS). Q can be adequately used to model wave amplitudes but it includes the effects of the structure (e.g., diving or reflected-wave GS) but becomes ambiguous when applied to describing the in-situ attenuation. By using ?(f) in interpretation, such effects are explicitly measured, and several general observations can be made, such as: 1) ?(f) often shows linear dependencies on f in both real data and modeling, whereas the corresponding Q(f) may be complex; 2) the zero-frequency limit of ?(f)=? can be interpreted as a generalized measure of geometrical spreading, and 3) frequency-dependent in-situ Q is not as widespread as it is commonly thought. Quantity ? is variable and correlates with tectonic age of the lithosphere, whereas the effective frequency-independent Qe is typically significantly higher than the 1-Hz Q0 often found in the Q(f)=Q0f? law with ?>0. Notably, ? appears to be consistently positive for body and surface waves, and negative for normal modes, leading to the apparent absorption band. Turning to the theoretical aspects of Q, energy dissipation is related to multiple external factors such as fracturing, fluid content and saturation, viscosity, porosity, permeability, properties of “dry” friction, and distributions of scatterers. Generally, all of these factors cannot be lumped in an unambiguous Q-1 or relaxation mechanisms included in the in-situ elastic moduli, as it is often assumed in visco-elastic models. Such assumptions may lead to observable discrepancies, such as opposite phases of reflections from attenuation contrasts, compared to the results of direct derivations from wave equations. Thus, the elastic moduli should better be treated as real and "instantaneous," and Lagrangian dissipation functions used to describe the attenuation. Further, and again contrary to what is often assumed, attenuation sensitivity kernels are different from velocity kernels. As illustrated on a 1D Love-wave example, usual assumptions of their equivalence lead to ~20% over-estimated predictions of the observed Love-wave QL-1. Once again, the use of ?(f)) instead of Q rectifies this problem. The above conclusions may have major implications for measuring, modeling, inverting, and interpreting the Earth's attenuation.

Morozov, I. B.

2009-12-01

122

The human factors of quality and QA in R D environments  

SciTech Connect

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.

Hill, S.G.

1990-01-01

123

Assessment of Beijing surface water quality based on principal factor analysis and cluster analysis  

Microsoft Academic Search

According to the field data of surface water quality from Beijing Water Authority, this paper demonstrates a case study on how to utilize principle factor analysis and hierarchical cluster analysis to extract a limited number of principal factors that can best describe the original data and to identify the patterns of surface water quality pollution. 10 auto-monitoring sites dispense in

Chen Gao; Jianzhuo Yan; Suhua Yang; Guohua Tan

2011-01-01

124

Measured Neutron Carbon Kerma Factors from 14.1 MeV to 18 MeV.  

National Technical Information Service (NTIS)

For A-150 tissue-equivalent plastic, the total neutron kerma is dominated by the hydrogen kerma. Tissue kerma is inferred with reasonable accuracy by normalization to the kerma factor ratio between tissue and A-150 plastic. Because of the close match in t...

P. M. Deluca H. H. Barschall R. C. Haight J. C. McDonald

1984-01-01

125

The g-factor of the 12+ isomeric state in 206Pb and the effective orbital g-factor of the neutron  

Microsoft Academic Search

The g-factor of the 12+ two-quasiparticle isomeric state, ¦(vi13\\/2)-2¦ 12+, in 206Pb has been measured by the time-differential perturbed angular correlation method. The result obtained is g(12+, 206Pb) = - 0.155 +\\/- 0.004. Three different methods are applied to deduce the orbital g-factor of the neutron around the 208Pb core, namely (i) the M1 core polarization model, (ii) the configuration

K. Nakai; B. Herskind; J. Blomqvist; A. Filevich; K.-G. Rensfelt; J. Sztarkier; I. Bergström; S. Nagamiya

1972-01-01

126

Precise measurement of the neutron magnetic form factor from quasielastic {sup 3}{rvec H}e({rvec e},e`)  

SciTech Connect

Polarized {sup 3}He targets have proven to be a useful tool for studying the electric and magnetic form factors of the neutron, and the spin structure of the neutron. The neutron magnetic form factor at low Q{sup 2} was determined previously at MIT-Bates from the quasielastic {sup 3}{ital {rvec H}e({rvec e}, e{sup `})} process. New experiment was planned at TJNAF to systematically measure the inclusive {sup 3}He quasielastic transverse asymmetry, A{sub T{sup `}}, at Q{sup 2} = 0.1 - 0.5 (GeV/c){sup 2} with high statistical and systematic accuracy. A 2% statistical uncertainty is aimed at all the pro- posed values of Q{sup 2} , and 3% systematic uncertainty for A{sub T{sup `}} can be achieved for this experiment. The precise data will constrain theoretical calculations of {sup 3}He quasielastic asymmetry. Furthermore, the neutron magnetic form factor at Q{sup 2} = 0.1 - 0.5 (GeV/c){sup 2} will be extracted from the measured asymmetries with an overall uncertainty of 2%. Precise measurements of {ital G{sup n}{sub M}} at low Q{sup 2} will resolve the discrepancy among the existing data in the same Q{sup 2} region.

Gao, H.

1997-02-01

127

Fabrication of high quality factor RF-resonator using embedded inductor and via capacitor  

Microsoft Academic Search

These High quality factor resonators are key components in RF-circuits. Fabrication of on-chip LC tank circuits is costly and suffers from low Q-factor. Design, simulation, and fabrication of a novel off-chip resonator with high quality factor are reported. Minimum feature size of standard PCB fabrication has been used to make imbedded solenoids in Duroid substrate with 2.2 relative permittivity. A

R. Kamali-Sarvestani; John D. Williams

2010-01-01

128

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

SciTech Connect

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 biologic model and could be useful for future experimental studies for the application of BNCT to colon carcinoma.

Dagrosa, Maria Alejandra, E-mail: dagrosa@cnea.gov.a [Department of Radiobiology, National Atomic Energy Commission, Buenos Aires (Argentina); National Research Council (Argentina); Crivello, Martin [Department of Radiobiology, National Atomic Energy Commission, Buenos Aires(Argentina); Perona, Marina [Department of Radiobiology, National Atomic Energy Commission, Buenos Aires (Argentina); National Research Council (Argentina); Thorp, Silvia; Santa Cruz, Gustavo Alberto [Department of Instrumentation and Control, National Atomic Energy Commission, Buenos Aires (Argentina); Pozzi, Emiliano [Argentina Reactor, National Atomic Energy Commission, Buenos Aires (Argentina); Casal, Mariana [Institute of Oncology 'Angel H. Roffo', University of Buenos Aires (Argentina); Thomasz, Lisa; Cabrini, Romulo [Department of Radiobiology, National Atomic Energy Commission, Buenos Aires (Argentina); Kahl, Steven [Department of Pharmaceutical Chemistry, University of California, San Francisco, CA (United States); Juvenal, Guillermo Juan [Department of Radiobiology, National Atomic Energy Commission, Buenos Aires (Argentina); National Research Council (Argentina); Pisarev, Mario Alberto [Department of Radiobiology, National Atomic Energy Commission, Buenos Aires (Argentina); National Research Council (Argentina); Department of Human Biochemistry, School of Medicine, University of Buenos Aires (Argentina)

2011-01-01

129

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

SciTech Connect

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.

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

130

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

NASA Astrophysics Data System (ADS)

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.

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

2009-08-01

131

Perception of rabbit meat quality and major factors influencing the rabbit carcass and meat quality  

Microsoft Academic Search

The meat quality concept is continuously changing and, nowadays, the consumer is very interested in the healthiness of meat, hedonistic quality, sensory properties, cooking easiness and swiftness, and price. During the last two decades, rabbit meat researchers have focused their interests on how to increase live performance and carcass yield. Considerable human resources have been expended to widely study the

A Dalle Zotte

2002-01-01

132

[Correlations between wild Polygonatum odoratum quality and main ecological factors].  

PubMed

By the methods of stepwise regression, principal component analysis, and grey relational grade analysis, this paper studied the correlations between the effective components (polysaccharides and water- and alcohol-soluble substances) contents and antioxidant activity of wild Polygonatum odoratum in different places and the ecological factors. Among the test ecological factors, the mean air temperature in January and in July, mean annual precipitation, frost-free period, and soil pH and total potassium were the main factors affecting the effective component contents of P. odoratum, with a contribution rate of 99.0%. As compared with soil factors, climatic factors made more contribution to the effective component contents. Soil total potassium was the key factor controlling the effective component contents, mean annual precipitation was the main decision factor, and mean air temperature in January was the main limiting factor. The plant polysaccharides and water-soluble substance contents were the key factors affecting the antioxidant activity of P. odoratum, and the capability of P. odoratum in excavating DPPH free radical increased with increasing contents of polysaccharides and water-soluble substances. PMID:22937629

Bu, Jing; Li, Deng-Wu; Wang, Dong-Mei

2012-06-01

133

KAOS-V code: An evaluation tool for neutron kerma factors and other nuclear responses  

SciTech Connect

The accurate evaluation of neutron fluence-to-kerma factors from microscopic nuclear data is the subject of this report. The algorithms developed for this purpose combine in a consistent manner the two basic methods for computing kerma factors, namely kinematics and direct energy balance. These algorithms are implemented in the code KAOS-V which was used as the main evaluation tool to construct the response function library KAOS/LIB-V. KAOS-V uses data from the evaluated nuclear data files ENDF/B/V. Auxiliary nuclear data bases, e.g., the Japanese evaluated nuclear data library JENDL-2 can be used as a source of isotopic cross sections when these data are not provided in ENDF/B-V files for a natural element. These are needed mainly to estimate average quantities such as effective Q-values for the natural element. The code has the ability to compare the different results which aids in the choice of a consistent set of algorithms to evaluate kerma factors. Data in ENDF/B-IV and ENDF/B-V format can be processed. For resonance treatment, the code has the ability to access NJOY and NPTXS interface files in formatted or binary forms. No input instructions are necessary to run the code interactively. The user can simply respond to the interactive messages sent by the code if an INPUT file is absent. An INPUT file is automatically generated following an interactive run, and can be edited and used to rerun or produce different results. Grouped and point output data can be produced along with graphic representation. These features are instrumental in detecting and understanding energy balance deficiencies and other problems in the nuclear data files. 60 refs., 4 figs.

Farawila, Y.; Gohar, Y.; Maynard, C. (Georgia Inst. of Tech., Atlanta, GA (USA); Argonne National Lab., IL (USA); Wisconsin Univ., Madison, WI (USA). Dept. of Nuclear Engineering and Engineering Physics)

1989-09-01

134

Factors Affecting Quality Enhancement Procedures for E-Learning Courses  

ERIC Educational Resources Information Center

|Purpose: This paper reports on an empirical study exploring the way in which campus-based higher education institutions (HEIs) in the UK apply their internal quality assurance and enhancement (QA/QE) procedures to their e-learning courses. The purpose of this paper is to identify those characteristics of e-learning courses which affected the…

Jara, Magdalena; Mellar, Harvey

2009-01-01

135

Factors influencing quality of life in patients with active tuberculosis  

Microsoft Academic Search

BACKGROUND: With effective treatment strategies, the focus of tuberculosis (TB) management has shifted from the prevention of mortality to the avoidance of morbidity. As such, there should be an increased focus on quality of life (QoL) experienced by individuals being treated for TB. The objective of our study was to identify areas of QoL that are affected by active TB

Carlo A Marra; Fawziah Marra; Victoria C Cox; Anita Palepu; J Mark Fitzgerald

2004-01-01

136

Do Non-Economic Quality of Life Factors Drive Immigration?  

ERIC Educational Resources Information Center

|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…

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

2013-01-01

137

Investigation of factors affecting the quality of americium electroplating.  

PubMed

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. PMID:22424746

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

2012-03-04

138

Factors Affecting the Quality of Freeze-Dried Green Beans.  

National Technical Information Service (NTIS)

The effect of extended blanching, sulfiting and packaging on the quality of freeze-dried green beans prepared from commercially frozen products and stored for six months at 100F were investigated. Results indicated that acceptable freeze-dried green beans...

A. R. Rahman G. R. Taylor K. Miller K. R. Johnson

1969-01-01

139

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...

140

Integrating Human Factors Models into Statistical Quality Control  

Microsoft Academic Search

Recent progress in the statistical quality control field has led to the design of sampling plans which do not assume perfect inspection. Simple methods now exist for analyzing the effect of inspector error on the operating characteristic (OC) curve of a plan and further for redesigning the plan so that a predetermined OC curve is obtained. However, the usual assumption

Colin G. Drury

1978-01-01

141

Factors influencing bank financing quality of SMEs in clusters  

Microsoft Academic Search

This paper proposes a Box-Cox transformation on linear function based on foreign research and makes an empirical study on relationship between SMEspsila bank financing quality and SMEspsila vertical relation with bank as well as their inter-firm relationship in clusters, and in order to explore the results deeply, we hold focus discussion with sample companies. The empirical study indicates that hard

Song Hua; Yu Kang-kang

2008-01-01

142

Factors Affecting Quality and Safety of Fresh-Cut Produce  

Microsoft Academic Search

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,

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

2012-01-01

143

Factors Affecting Quality Enhancement Procedures for E-Learning Courses  

ERIC Educational Resources Information Center

Purpose: This paper reports on an empirical study exploring the way in which campus-based higher education institutions (HEIs) in the UK apply their internal quality assurance and enhancement (QA/QE) procedures to their e-learning courses. The purpose of this paper is to identify those characteristics of e-learning courses which affected the…

Jara, Magdalena; Mellar, Harvey

2009-01-01

144

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

SciTech Connect

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.

Lachniet, J. [Carnegie Mellon University, Pittsburgh, Pennsylvania 15213 (United States); Old Dominion University, Norfolk, Virginia 23529 (United States); Afanasev, A. [Hampton University, Hampton, Virginia 23668 (United States); Arenhoevel, H. [Institut fuer Kernphysik, Johannes Gutenberg-Universitat, 55099 Mainz (Germany); Brooks, W. K. [Universidad Tecnica Federico Santa Maria, Casilla 110-V Valparaiso (Chile); Gilfoyle, G. P. [University of Richmond, Richmond, Virginia 23173 (United States); 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. [Thomas Jefferson National Accelerator Facility, Newport News, Virginia 23606 (United States)] (and others)

2009-05-15

145

Examination and comparison of the critical factors of total quality management (TQM) across countries  

Microsoft Academic Search

Various empirical studies have been published about the critical success factors of TQM extracted using a survey approach in a particular country or region. Several studies compared critical TQM factors across different countries, but overall there has been little attempt in the literature to analyse the TQM factors within the context of a contingency approach. Quality gurus such as Deming

Ismail Sila; M. Ebrahimpour

2003-01-01

146

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

ERIC Educational Resources Information Center

|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…

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

2006-01-01

147

Factors affecting quality and safety of fresh-cut produce  

Microsoft Academic Search

Quality of fresh-cut fruit and vegetable products includes a combination of attributes, such as appearance, texture and flavour, 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 fibre, and fresh-cut produce satisfy consumer demand for freshly prepared, convenient, healthy food. However, fresh-cut

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

2011-01-01

148

Style and quality in research supervision: the supervisor dependency factor  

Microsoft Academic Search

Research degree supervision is a bi-lateral process, a complexinteraction between the supervisor and the student. This interaction plays asignificant role in affecting the quality of the supervisory process. Using250 responses to a mail-out questionnaire sent to 932 post-graduate researchstudents, this study examines the extent to which students of disparatecharacteristics are dependent on their supervisors in a range ofresearch-related tasks, and

Booi Hon Kam

1997-01-01

149

Limits of metastability in amorphous ices: the neutron scattering Debye-Waller factor.  

PubMed

Recently, it became clear that relaxation effects in amorphous ices play a very important role that has previously been overlooked. The thermodynamic history of amorphous samples strongly affects their transition behavior. In particular, well-relaxed samples show higher thermal stability, thereby providing a larger window to investigate their glass transitions. We here present neutron scattering experiments using fixed elastic window scans on relaxed forms of amorphous ice, namely expanded high density amorphous ice (eHDA), a variant of low density amorphous ice (LDA-II) and hyperquenched glassy water (HGW). These amorphous ices are expected to be true glassy counterparts of deeply supercooled liquid water, therefore fast precursor dynamics of structural relaxation are expected to appear below the calorimetric glass transition temperature. The Debye-Waller factor shows a very weak sub-T(g) anomaly in some of the samples, which might be the signature of such fast precursor dynamics. However, we cannot find this behavior consistently in all samples at all reciprocal length scales of momentum transfer. PMID:23132426

Amann-Winkel, Katrin; Löw, Florian; Handle, Philip H; Knoll, Wiebke; Peters, Judith; Geil, Burkhard; Fujara, Franz; Loerting, Thomas

2012-11-06

150

Neutron dosimetry with the ORNL badge  

SciTech Connect

The ORNL red-dot badge was designed to provide radiation dose estimation for personnel working in neutron, gamma, and mixed-field environments. The primary quantitative radiation-sensing components in the red-dot badge are TLDs, used to measure direct neutron, gamma, and albedo neutron response. The TLDs were calibrated with radium gammas and HPRR-generated neutrons. In this study, the badge is used as a crude spectrometer as well as a dosimeter. Intercomparison results from the Tenth PDIS are favorable, as would be expected since the exposures in the intercomparison were from the same source as the original calibrations. Other neutron- and gamma-emitting sources are being sought in order to confirm the sensitivity of the red-dot badge in a wide range of radiation environments. Whenever possible, dosimeter calibration factors should be determined from independent measurements of neutron spectral quality.

Berger, C.D.; Lane, B.H.

1985-08-01

151

Quality factor of circular laser diode beam tailored by optical interference  

NASA Astrophysics Data System (ADS)

The quality factor of a laser diode beam tailored by Lloyd's mirror interference was investigated numerically and experimentally. The far and near-field patterns were analyzed by numerical calculations based on Huygens' integral. An almost circular tailored beam was calculated to have a quality factor as low as 1.08. This beam-shaping technique was experimentally demonstrated using a commercial 640 nm laser diode and a mirror-polished GaAs substrate. The optical beam tailored by Lloyd's mirror interference was nearly circular and its beam quality factor was measured to be 1.24. Although this measured beam quality factor is slightly higher than the numerically calculated one, it is acceptably low.

Fukushima, Takehiro; Sakaguchi, Koichiro; Tokuda, Yasunori

2012-09-01

152

Quality-Related Pay Adjustment Factors for Pavements. NCHRP Research Results Digest 371.  

National Technical Information Service (NTIS)

This digest summarizes the findings of the research conducted under NCHRP Project 10-79 to develop guidance pertaining to the quality-related pay adjustment factors used for flexible and rigid pavement construction. Highway agencies generally specify cert...

2013-01-01

153

Determination of the kerma factors for 14-MeV neutrons in TEP, C, Mg, and Fe  

SciTech Connect

Kerma factors, defined as kerma per unit neutron fluence, for 14 MeV D-T neutrons in tissue equivalent plastic, C, Mg and Fe were determined in this work. Rossi-type TEP, C, Mg and Fe walled proportional counters filled with propane-based tissue-equivalent gas and Ar gas at low pressure were employed to measure the energy deposition in the counters. Based upon the concept of Crossers, Insiders, Starters and Stoppers (CISS) developed by Caswell, a theoretical model was used for the analysis of energy deposition in spherical detectors. Because of the detailed analyses the uncertainties in the kerma factors as obtained in this work are evaluated to be between 8 to 11% which are significantly lower than those reported previously for experimental measurements.

Not Available

1985-01-01

154

Measurement of the neutron magnetic form factor at high Q-2 using the ratio method on deuterium  

SciTech Connect

The 12-GeV Upgrade at Jefferson Lab will create an opportunity to dramatically extend our knowledge of the magnetic form factor of the neutron G^n_M and the other elastic, electromagnetic form factors. We describe here an approved experiment that will cover a Q2 range (3.5 – 14 GeV2) with significant discovery potential. Different theoretical approaches (generalized parton distributions, Dyson-Schwinger equations, etc) diverge is this region and existing data cannot distinguish among them. The proposed measurement will be performed in Hall B with the CLAS12 detector and will have statistical and systematic uncertainties below 3%. It is based on the ratio of electron-neutron to electron-proton scattering that was successfully applied in the CLAS detector at Jefferson Lab.

G.P. Gilfoyle, W.K. Brooks, K. Hafidi

2011-05-01

155

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

ERIC Educational Resources Information Center

|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…

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

2012-01-01

156

Factors influencing quality of life in patients with active tuberculosis in Pakistan  

Microsoft Academic Search

Evidently Tuberculosis remains a major threat to public health globally. Latterly academia with exertion dedication has tried to extract the health related quality of life of the people with active tuberculosis. Meager studies in Pakistan have tried to explore the factors that influences patient’s health related quality of life besides the disease. The intentions of this study were to scrutinize

Sarwar Awan Masood; Waqas Muhammad; Amir Aslam Muhammad

2012-01-01

157

Frontline employees' views on organizational factors that affect the delivery of service quality in call centers  

Microsoft Academic Search

Purpose – This paper aims to report on a study that investigated employees' views on the organizational factors that affect their ability to deliver service quality to customers. The study is important because call centers represent unique work environments and they have not been used in the development of service quality theory. Design\\/methodology\\/approach – Ten focus groups of frontline employees

Alison M. Dean; Al Rainnie

2009-01-01

158

Factors Influencing the Reporting of Adverse Perioperative Outcomes to a Quality Management Program  

Microsoft Academic Search

Quality management programs have used several data reporting sources to identify adverse perioperative out- comes. We compared reporting sources and identified factors that might improve data capture. Adverse periop- erative outcomes between January 1, 1992, and December 31, 1994, were reported to the Department of Anesthesiol- ogy Quality Management program by anesthesiologists, hospital chart reviewers, and other hospital personnel us-

Robert I. Katz; Robert S. Lagasse

2000-01-01

159

Critical Factors Affecting Quality of Life of Adult Patients With Anorectal Malformations or Hirschsprung's Disease  

Microsoft Academic Search

OBJECTIVE:The first objective was to compare the quality of life of adult patients with anorectal malformations (ARM) or Hirschsprung's disease (HD) and to compare both groups with healthy people. And the second objective was to examine the factors that affect the quality of life of patients with ARM or HD, using a theoretical model in which patients' background characteristics explain

Esther E. Hartman; Frans J. Oort; Daniel C. Aronson; Marianne J. G. Hanneman; David C. van der Zee; Paul N. M. A. Rieu; Gerard C. Madern; Zacharias J. De Langen; L. W. Ernest van Heurn; M. van Silfhout-Bezemer; N. Looyaard; Mirjam A. G. Sprangers

2004-01-01

160

Numerical approach to laser beam propagation through turbulent atmosphere and evaluation of beam quality factor  

Microsoft Academic Search

In this paper, propagation of a Gaussian laser beam through turbulent atmosphere is evaluated numerically. The beam quality factor for the propagated beam has been estimated for different turbulent conditions that are characterized by parameter Cn. The calculations show that the beam quality can be affected dramatically by atmospheric turbulence and the laser beam size and wavelength have major role

M. H. Mahdieh

2008-01-01

161

M2 quality factor as a key to mastering laser beam propagation  

Microsoft Academic Search

One of the most important properties of a laser resonator is the highly collimated or spatially coherent nature of the laser output beam. The spatial beam quality of the output beam, namely beam diameter and propagation factor M2 are critical parameters in a wide range of practical laser applications. This is because the spatial beam quality determines how tightly the

Mohamed Bouafia; Halim Bencheikh; Larbi Bouamama; Horst Weber

2004-01-01

162

The influence of attitude and psychogenic factors on the quality of semen collected by masturbation  

Microsoft Academic Search

The primary investigation of male infertility usually depends on semen samples collected by masturbation, yet very little is known about possible psychological influences on their quality. An exploratory assessment of 89 men's attitudes to semen analysis and the influence of psychogenic factors (mood, anxiety and sexual excitement) on the quality of the ejaculate has been performed. Specifically the hypothesis has

M. Dziegielewski; J. P. P. Tyler

1989-01-01

163

The relationship between risk factors for falling and the quality of life in older adults  

Microsoft Academic Search

BACKGROUND: Falls are one of the major health problems that effect the quality of life among older adults. The aim of this study was to explore the relationship between quality of life (Short Form-12) and the risk factors of falls (balance, functional mobility, proprioception, muscle strength, flexibility and fear of falling) in older adults. METHODS: One hundred sixteen people aged

Ayse Ozcan; Hulya Donat; Nihal Gelecek; Mehtap Ozdirenc; Didem Karadibak

2005-01-01

164

Risk factors associated with selected indicators of milk quality in semiarid northeastern Brazil  

Microsoft Academic Search

The aim of this study was to gain information on quality traits, mainly bacterial and somatic cell counts of bulk milk, produced by small- and medium-scale producers in a semiarid northeastern region of Brazil and to identify and characterize possible risk factors associated with those quality traits. A cross-sectional study was performed on 50 farms. Bulk milk samples were collected

C. J. B. Oliveira; W. D. Lopes Júnior; R. C. R. E. Queiroga; P. E. N. Givisiez; P. S. Azevedo; W. E. Pereira; W. A. Gebreyes

2011-01-01

165

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

ERIC Educational Resources Information Center

|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…

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

166

Factors affecting the quality of diabetes care in primary health care centres in Tunis  

Microsoft Academic Search

We have conducted a retrospective medical record review of a random sample of 580 patients with diabetes from 12 primary health care centres (PHCCs) in Greater Tunis. The aim was to assess the quality of diabetes care in PHCCs and to explore factors associated with quality of care. Data were collected concerning patient characteristics, health centre characteristics and process of

Hugh Alberti; Nessiba Boudriga; Mounira Nabli

2005-01-01

167

Integration of Multiple Readouts into the Z' Factor for Assay Quality Assessment  

Microsoft Academic Search

Methods that monitor the quality of a biological assay (i.e., its ability to discriminate between positive and negative controls) are essential for the development of robust assays. In screening, the most commonly used parameter for monitoring assay quality is the Z' factor, which is based on 1 selected readout. However, biological assays are able to monitor multiple readouts. For example,

Anne Kümmel; Hanspeter Gubler; Patricia Gehin; Martin Beibel; Daniela Gabriel; Christian N. Parker

2010-01-01

168

Dynamic variations of water quality in Taihu Lake and multivariate analysis of its influential factors  

Microsoft Academic Search

Dynamic variation of water quality in Meiliang Bay and part of western Taihu Lake has been analysed based on the data from\\u000a 1991 to 1992. Principal component analysis is used to reveal the mutual relationships of various factors. It is shown that\\u000a there exists an obvious spatial and temporal variation in the main factors of water quality. Annual values of

Qiming Cai; Xiyun Gao; Yuwei Chen; Shengwei Ma; Dokulil Martin

1996-01-01

169

Influence of Surgery-related Factors on Quality of Life after Esophageal or Cardia Cancer Resection  

Microsoft Academic Search

Knowledge of how factors related to esophageal cancer resection affect long-term quality of life after surgery is scarce,\\u000a and no population-based studies are available. Therefore, we conducted a Swedish nationwide, prospective, population-based\\u000a study of how esophageal surgery–related factors influence quality of life 6 months postoperatively. The Swedish Esophageal\\u000a and Cardia Cancer register (SECC-register) encompasses 174 hospital departments (97%). Microscopically radically

Pernilla Viklund; Mats Lindblad; Jesper Lagergren

2005-01-01

170

Measurement of the magnetic form factor of the neutron with quasielastic electron scattering from vector-polarized deuterium with BLAST  

NASA Astrophysics Data System (ADS)

With the BLAST experiment at MIT-Bates, precision measurements of single and double polarization observables were carried out by scattering longitudinally polarized electrons from internal, isotopically pure and highly polarized hydrogen and deuterium targets in elastic and quasi-elastic kinematics. Analysis of inclusive scattering data acquired with vector-polarized deuterium has provided new results at low momentum transfer for the neutron magnetic form factor GM^n which will be presented. )

Alarcon, Ricardo

2010-02-01

171

Skeletal muscle fibres as factors for pork quality  

Microsoft Academic Search

Interaction between muscle fibres, perimortem energy metabolism and different environmental factors determine postmortem transformation from muscle to meat. Muscle fibres are not static structures, but easily adapt to altered functional demands, hormonal signals, and changes in neural input. Their dynamic nature makes it difficult to categorise them into distinct units. It must be realised that some properties may change without

Anders H. Karlsson; Ronald E. Klont; Xavier Fernandez; J. Boyazoglu; P. Rafai; C. Thomas; M. Zjalic

1999-01-01

172

Maximization of the quality factor of an optical resonator  

Microsoft Academic Search

We consider resonance phenomena for the scalar wave equation in an inhomogeneous medium. Resonance is a solution to the wave equation which is spatially localized while its time dependence is harmonic except for decay due to radiation. The decay rate, which is inversely proportional to the qualify factor, depends on the material properties of the medium. In this work, the

Chiu-Yen Kao; Fadil Santosa

2008-01-01

173

Studies on the Factors of Interaction Quality in Public Service Quality Management  

Microsoft Academic Search

The public service satisfaction is becoming the key point in government management. Since service is a process, people's perception to the public service does not only depend on the service result, but also on the interaction process. However, at present, the dimension of interaction quality still deserves in-depth study in this academic field. Thus, the paper firstly reviews some correlative

Yang Kun; Hu Jing; Wang Bingjie

2010-01-01

174

Specific mixing energy: A key factor for cement slurry quality  

SciTech Connect

In this paper, the relationships between cement mixing and cement slurry quality are investigated. Laboratory mixing conditions, using a high shear mixer, are compared to field mixing conditions, including conventional jet mixer, recirculating type mixer and batch mixer. All the mixing conditions can be reduced according to a single parameter, the specific mixing energy, that allows the comparison of laboratory and field mixing with confidence. Typical cement slurry properties, like rheology, free water, fluid loss, thickening time and compressive strength, are measured as a function of the specific mixing energy. All these properties improve when the specific mixing energy increases. The efficiency of cement additives, like dispersants and fluid-loss agents, is also found to vary significantly with the energy. A tentative explanation is proposed through a mechanism of particle deflocculation and dissolution, leading to an increase in the available specific surface area.

Orban, J.A.; Parcevaux, P.A.; Guillot, D.J.

1986-01-01

175

Determination of Canine Dose Conversion Factors in Mixed Neutron and Gamma Radiation Fields.  

National Technical Information Service (NTIS)

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...

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

1996-01-01

176

Quality determinants and hospital satisfaction. Perceptions of the facility and staff might be key influencing factors.  

PubMed

Perceptions of service quality ultimately affect consumer satisfaction, but objective measures of quality can be hard to come by when evaluating the quality of clinical care in a hospital. To determine if dimensions other than those found in models such as SERVQUAL were at play, the authors undertook a survey of 472 consumers, who were divided into two groups: those who had been hospital patients within the last three years (users) and those who were visitors (observers). The results suggest that facilities-related and human-factor related considerations helped shape the quality assessments of both groups, with observers generally giving higher marks to the hospitals with which they were familiar on the dimension of facilities-related quality and users expressing a less critical view of the human-factor dimension. PMID:10179390

Oswald, S L; Turner, D E; Snipes, R L; Butler, D

1998-01-01

177

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

SciTech Connect

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.

Volz, Heather M. [Los Alamos National Laboratory; Rennie, John A. [Los Alamos National Laboratory; Lovejoy, Christopher M. [Los Alamos National Laboratory; Martinez, Diana E. R [Los Alamos National Laboratory; Dempsey, Michael A. [Los Alamos National Laboratory; Livesay, Jake [ORNL; Lousteau, Angela [ORNL

2012-07-12

178

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

ERIC Educational Resources Information Center

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…

Neff, Bryan D.; Olden, Julian D.

2010-01-01

179

On the mechanical quality factors of cryogenic test masses from fused silica and crystalline quartz  

Microsoft Academic Search

Current interferometric gravitational wave detectors (IGWDs) are operated at room temperature with test masses made from fused silica. Fused silica shows very low absorption at the laser wavelength of 1064 nm. It is also well suited to realize low thermal noise floors in the detector signal band since it offers low mechanical loss, i. e. high quality factors (Q factors)

Anja Schroeter; Ronny Nawrodt; Roman Schnabel; Stuart Reid; Iain Martin; Sheila Rowan; Christian Schwarz; Torsten Koettig; Ralf Neubert; Matthias Thürk; Wolfgang Vodel; Andreas Tünnermann; Karsten Danzmann; Paul Seidel

2007-01-01

180

Epilepsy: comprehensive care, quality of life, and factors preventing people with epilepsy from being employed  

Microsoft Academic Search

This article reviews several studies of patients with intractable epilepsy carried out at the National Epilepsy Center, Shizuoka, Japan. These studies have evaluated the factors that affect the employment status of people with epilepsy and the effect of resective surgery for epilepsy on quality of life. It has been shown that although seizure status is a major factor in determining

Kazuichi Yagi

1998-01-01

181

Charge Form Factor of the Neutron at Low Momentum Transfer from the H?2(e?,e'n)H1 Reaction  

NASA Astrophysics Data System (ADS)

We report new measurements of the neutron charge form factor at low momentum transfer using quasielastic electrodisintegration of the deuteron. Longitudinally polarized electrons at an energy of 850 MeV were scattered from an isotopically pure, highly polarized deuterium gas target. The scattered electrons and coincident neutrons were measured by the Bates Large Acceptance Spectrometer Toroid (BLAST) detector. The neutron form factor ratio GEn/GMn was extracted from the beam-target vector asymmetry AedV at four-momentum transfers Q2=0.14, 0.20, 0.29, and 0.42(GeV/c)2.

Geis, E.; Kohl, M.; Ziskin, V.; Akdogan, T.; Arenhövel, H.; Alarcon, R.; Bertozzi, W.; Booth, E.; Botto, T.; Calarco, J.; Clasie, B.; Crawford, C. B.; Degrush, A.; Donnelly, T. W.; Dow, K.; Farkhondeh, M.; Fatemi, R.; Filoti, O.; Franklin, W.; Gao, H.; Gilad, S.; Hasell, D.; Karpius, P.; Kolster, H.; Lee, T.; Maschinot, A.; Matthews, J.; McIlhany, K.; Meitanis, N.; Milner, R. G.; Rapaport, J.; Redwine, R. P.; Seely, J.; Shinozaki, A.; Širca, S.; Sindile, A.; Six, E.; Smith, T.; Steadman, M.; Tonguc, B.; Tschalaer, C.; Tsentalovich, E.; Turchinetz, W.; Xiao, Y.; Xu, W.; Zhang, C.; Zhou, Z.; Zwart, T.

2008-07-01

182

Objective picture quality scale for video images (PQSvideo): definition of distortion factors  

NASA Astrophysics Data System (ADS)

We propose a PQSvideo (Picture Quality Scale for moving image), a method of objective quality assessment for coded moving images. We expect that the proposed PQSvideo approximates subjective assessment well. In PQSvideo, we define essential distortion factors considering not only global distortions (such as random noise) but also distortions on local features. Then, we describe each distortion metrically considering human visual perception. The PQSvideo is given by a linear combination of define each essential distortion factor, utilizing the principal component analysis method and the multiple regression analysis method between quantity of each essential distortion factor and MOS (Mean Opinion Score) obtained by assessment test. We have confirmed that the PQSvideo approximates MOS successfully.

Tetsuji, Yamashita; Kameda, Masashi; Miyahara, Makoto M.

2000-05-01

183

New Vistas of the Structure of Neutron-Rich Nuclei - Single Particle States and g-FACTORS  

NASA Astrophysics Data System (ADS)

Prompt ?-?-? coincidence studies of neutron-rich nuclei populated in the spontaneous fission of 252Cf led to the discoveries of many important processes like neutron-less binary and ternary fragmentation in spontaneous fission, binary and ternary hot fission modes, hyper-deformation, cluster radioactivity and quasi-molecular states in ternary fission. The high statistics data, 5.7 × 1011 triples and higher folds, opened up discoveries of new band structures and significant extensions of previously known bands. These data were used to measure the angular correlations of cascades of ?-rays from the excited states of neutron-rich fission fragments stopped in an unmagnetized iron foil. By using this ?-? angular correlation technique, the single particle configurations of the known rotational bands were assigned and confirmed in the present work. In other words, the multipole mixing ratios of ?I=1 transitions in the rotational bands were measured. These experimental mixing ratios are compred with the theoretical ones of particle and axial-rotor model. The configuration of the ground states in 109,111Ru were, for the first time, assigned. And magnetic g-factors of excited states in even-even neutron-rich nuclei were meaured, too. Two sets of ?I=1 alternating parity doublets with opposite parities were observed in Ba and Ce isotopes. The B(E1)/B(E2) branching ratios and D0 values may indicate that the octupole correlations are strong in Ba and Ce isotopes because of the Z=56 and N=88 octupole shell gaps. High-spin, even-parity bands in neutron-rich 108,110,112Ru nuclei indicate two-phonon quasi-gamma bands in 110,112Ru.

Ramayya, A. V.; Hamilton, J. H.; Luo, Y. X.; Zhu, S. J.; Hwang, J. K.; Rasmussen, J. O.; Ter-Akopian, G. M.; Daniel, A. V.; Brewer, N.; Oganessian, Y.

2012-01-01

184

The electric form factor of the neutron at low momentum transfers as measured at Bates Large Acceptance Spectrometer Toroid  

NASA Astrophysics Data System (ADS)

Elastic form factors are characteristic signatures of the electromagnetic properties of hadronic matter. The more precisely we can measure these values, the more powerful becomes the predictability of our theory. The proton's form factors ( GpE,GpM ) have been measured remarkably well compared to the neutron. While the Magnetic form factor of the neutron is reasonably well known, the Electric Form Factor still retains difficulties due to its small magnitude and the relative inefficiency of detecting neutral particles. The lack of a pure neutron source is another obstacle. Although we are in pursuit of the elastic form factors, the two-nucleon system of deuterium has been shown to be a worthy target for extracting data on the structure of nucleons as well as properties of few-body hadronic systems. Data from unpolarized cross section measurements have proven insufficient for extracting GnE , but polarized scattering from a polarized Deuterium target has been shown to be well suited for determination of GnE . The double polarization observables of a vector polarized Deuterium target and polarized electron beam is proportional to the product of the electric and magnetic form factors of the neutron. The Bates Large Acceptance Spectrometer Toroid (BLAST) has been developed specifically to measure the scattering of a polarized electron beam off a vector and tensor polarized deuterium target and thus fulfills our needs for extracting GnE . The Bates accelerator provides a high-duty polarized electron beam stored in the South Hall Ring (SHR) that is passing through an internal target of both vector and tensor polarized monatomic deuterium as well as polarized monatomic hydrogen provided by an Atomic Beam Source (ABS). A large acceptance detector, BLAST, has been installed to measure several scattering reactions including the directly applicable H2? e?,e'n p reaction. This work summarizes the experimental investigations of the extraction of GnE from the BLAST data. Points were extracted at four values of four-momentum transfers (Q2 = 0.14, 0.20, 0.29, 0.41 GeV 2). The world's data and the new BLAST data were fit to determine GnE to +/-5.8% from 0 < Q2 < 1.8 GeV2. The best fit includes model dependent contributions from a low Q2 bump and a smooth dipole term. A second fit is shown using a model independent sum of gaussians in order to provide a more reliable determination of the uncertainty of the world's measurement of GnE from double polarized scattering.

Geis, Eugene J.

185

A set of invariant quality factors measuring the deviation from the Kerr metric  

NASA Astrophysics Data System (ADS)

A number of scalar invariant characterizations of the Kerr solution are presented. These characterizations come in the form of quality factors defined in stationary space-times. A quality factor is a scalar quantity varying in the interval [0,1] with the value 1 being attained if and only if the space-time is locally isometric to the Kerr solution. No knowledge of the Kerr solution is required to compute these quality factors. A number of different possibilities arise depending on whether the space-time is Ricci-flat and asymptotically flat, just Ricci-flat, or Ricci non-flat. In each situation a number of quality factors are constructed and analysed. The relevance of these quality factors is clear in any situation where one seeks a rigorous formulation of the statement that a space-time is "close" to the Kerr solution, such as: its non-linear stability problem, the asymptotic settlement of a radiating isolated system undergoing gravitational collapse, or in the formulation of some uniqueness results.

Gómez-Lobo, Alfonso García-Parrado; Senovilla, José M. M.

2013-06-01

186

Psychosocial factors associated with diet quality in a working adult population.  

PubMed

The associations between specific intra- and inter-personal psychosocial factors and dietary patterns were explored in a healthy, working adult sample of university and health center employees (N = 640) who were enrolled in a prospective predictive health study. Participants had a mean age of 48 (SD = 11) years and were 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

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

2013-02-13

187

The quality of different types of child care at 10 and 18 months: a comparison between types and factors related to quality  

Microsoft Academic Search

The quality of care offered in four different types of non?parental child care to 307 infants at 10 months old and 331 infants at 18 months old was compared and factors associated with higher quality were identified. Observed quality was lowest in nurseries at each age point, except that at 18 months they offered more learning activities. There were few

Penelope Leach; Jacqueline Barnes; Kathy Sylva; Alan Stein

2008-01-01

188

The Quality of Different Types of Child Care at 10 and 18 Months: A Comparison between Types and Factors Related to Quality  

ERIC Educational Resources Information Center

The quality of care offered in four different types of non-parental child care to 307 infants at 10 months old and 331 infants at 18 months old was compared and factors associated with higher quality were identified. Observed quality was lowest in nurseries at each age point, except that at 18 months they offered more learning activities. There…

Leach, Penelope; Barnes, Jacqueline; Malmberg, Lars-Erik; Sylva, Kathy; Stein, Alan

2008-01-01

189

[The impact of risk factors of non-communicable chronic diseases on quality of life].  

PubMed

Quality of life has become an important yardstick of the impact on health. Its evaluation related to diseases and associated risk factors has increased in the population in general. This article seeks to assess the quality of life and the presence of the association with risk factors for non-communicable chronic diseases in the urban population of the city of Montes Claros in the State of Minas Gerais. It is a population-based cross-sectional study. The sample was calculated considering the prevalence of risk factors of overweight of 30% and corrected for a variation of 30%. Cluster sampling was conducted on urban census sectors. Seventeen census sectors were selected and 648 residents aged e" 18 years were interviewed. The risk factors for non-communicable chronic diseases as well as the quality of life were verified using the SF-36 questionnaire. Some risk factors were associated with the lowest scores on the SF-36 questionnaire. The presence of some risk factors for chronic diseases has an impact on quality of life. PMID:23546214

Oliveira-Campos, Maryane; Rodrigues-Neto, João Felício; Silveira, Marise Fagundes; Neves, Daniele Malard Rocha; Vilhena, Janine Moraes; Oliveira, Juliana Fonseca; Magalhães, Júlio César; Drumond, Daniel

2013-03-01

190

Factors associated with the utilization and quality of prenatal care in western rural regions of China  

Microsoft Academic Search

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 questionnaire, designed in Chinese, composed of two segments: general information on

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

2012-01-01

191

Psychosocial Factors and Health-Related Quality of Life in Hemodialysis Patients  

Microsoft Academic Search

Several sociodemographic and clinical variables are known to influence the health-related quality of life (HRQOL) of patients with kidney disease, yet the relationship between psychological factors and the HRQOL measured by the Kidney Disease Quality of Life Short-Form (KDQOL-SF) is incompletely understood. The objective of this study was to examine the relationship between psychosocial status (depressive symptoms, trait anxiety, and

Isabel Vázquez; Fernando Valderrábano; Joan Fort; Rosa Jofré; Juan Manuel López-Gómez; Fuensanta Moreno; Dámaso Sanz-Guajardo

2005-01-01

192

An examination of factors affecting Chinese financial analysts’ information comprehension, analyzing ability, and job quality  

Microsoft Academic Search

This paper examines various factors affecting Chinese financial analysts’ information comprehension, analyzing ability and\\u000a job quality. We hypothesized that financial analysts with better educational background, more experience, superior resources\\u000a provided by large brokerage firms and more information sources have better information comprehension, stronger analyzing ability,\\u000a and higher job quality. Using a survey method to collect data, we found that information

Yiming Hu; Thomas W. Lin; Siqi Li

2008-01-01

193

Dietary Quality Is Associated with Diabetes and Cardio-Metabolic Risk Factors  

Microsoft Academic Search

In this study, our aim was to investigate the associations between diet quality and newly diagnosed diabetes, prediabetes, and cardio-metabolic risk factors. The analysis was based on 7441 participants of the Australian Diabetes, Obesity and Lifestyle study, a cross-sectional study of adults aged $25 y involving a 75-g oral glucose tolerance test. Diet quality was assessed via a dietary guideline

Sarah A. McNaughton; D avid W. Dunstan; Kylie Ball; Jonathan Shaw; David Crawford

2009-01-01

194

Effect of a quality improvement intervention in the control of cardiovascular risk factors in hypertensive patients  

Microsoft Academic Search

The purpose of this study was to measure the effect of a quality improvement intervention in the control of cardiovascular risk factors of hypertensive patients.METHODS: This controlled study included 2 Primary Care Centers in Salamanca, Spain. One center was assigned to receive a quality improvement intervention (n = 482 hypertensive patients, 64% females, mean age 61.4 years (SD 6.8)), while

Pedro Luis Sanchez; Luis Garcia; Ignacio Santos; Manuel Ventura Muñoz; Angel Maderuleo; Jose Arganda; Ma Camino Mora; Teresa Rodriguez

2001-01-01

195

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

PubMed

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. PMID:23617768

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

2013-05-01

196

Determination of 232Th by neutron activation analysis using isotope-related ki factors.  

PubMed

Neutron activation analysis was applied to determine the 232Th activity in different matrices. Since in nature thorium consists of almost 100% of the long-lived 232Th, the instrumental trace element analysis method of neutron activation analysis can be applied to determine the thorium content in a sample. which can then be converted into the corresponding specitic activity. For the analysis about 100 mg of the sample was irradiated at a thermal neutron flux of phi(th) = 8 x 10(13) n.cm(-2) x s(-1). After irradiation the activity of the indicator nuclid 232Pa--produced by the (n,gamma) reaction--was measured by gamma spectrometry. The content of thorium was calculated using the activation equation and the isotope-related ki constant. Finally, the concentration of thorium in the sample was converted into the specific activity. The activities of 232Th measured by applying neutron activation analysis in different samples were compared with the results found by a spectrometry and gamma spectrometry for the daughter nuclides 228Ac and 224Ra. PMID:11843352

Küppers, G

2001-01-01

197

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

SciTech Connect

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.

Huang, Zhenyu [University of Tennessee, Knoxville (UTK); Alonzo, Jose [Clemson University; Liu, Ming [ORNL; Ji, Haining [ORNL; Yin, Fang [University of Utah; Smith, Grant [ORNL; Mays, Jimmy [ORNL; Kilbey, II, S Michael [ORNL; Dadmun, Mark D [ORNL

2008-01-01

198

Dislocation density-dependent quality factors in InGaN quantum dot containing microdisks  

NASA Astrophysics Data System (ADS)

Microdisks incorporating InGaN quantum dots were fabricated using SiO2 microspheres as a hard mask in conjunction with a photoelectrochemical etch step from a structure containing a sacrificial InGaN/InGaN superlattice. Formation of microdisks from two near-identical structures with differing dislocation densities was carried out and investigated using microphotoluminescence. This confirmed the existence of quantum dots through the presence of resolution limited spectral lines and showed a clear correlation between the resulting modes quality factors and the dislocation densities within the disks. The disks with higher dislocation densities showed up to 80% lower quality factors than the low dislocation density disks.

El-Ella, H. A. R.; Rol, F.; Kappers, M. J.; Russell, K. J.; Hu, E. L.; Oliver, R. A.

2011-03-01

199

Quality of life and temperament factors in schizophrenia: comparative study of patients, their siblings and controls.  

PubMed

This study aimed to determine which temperament factors are associated with quality of life (QOL) in schizophrenia based on a triplet design comparing patients with their non-affected siblings and healthy control subjects. Forty-seven DSM-IV clinically stable schizophrenia outpatients, 47 non-affected siblings, and 56 non-patients matched for gender and age were evaluated using the Tridimensional Personality Questionnaire and the Quality of Life Enjoyment and Life Satisfaction Questionaire. As expected, schizophrenia patients reported significantly poorer QOL in most specific domains and in general. They also revealed significantly higher scores on harm avoidance and scored lower on reward dependence, than both their siblings and controls. Tridimensional Personality Questionnaire temperament factors revealed no differences between the controls and the siblings. When differences between patients, their siblings and controls were adjusted for gender, age at examination, and education, ANOVA demonstrated that temperament factors contributed to poor satisfaction with physical health, social relationships and subjective feelings in schizophrenia patients. Harm avoidance was associated with general QOL independent of severity of psychopathology. Thus, this study suggests that temperament factors that are not necessarily part of the deterioration process of the illness are associated with the quality of life of schizophrenia patients. These and other non-illness related factors should be considered when evaluating quality of life outcomes in intervention studies. PMID:15892432

Kurs, Rena; Farkas, Herman; Ritsner, Michael

2005-03-01

200

Quality of carrots as affected by pre- and postharvest factors and processing.  

PubMed

The aim of this review is to provide an update on factors contributing to quality of carrots, with special focus on the role of pre- and postharvest factors and processing. The genetic factor shows the highest impact on quality variables in carrots, causing a 7-11-fold difference between varieties in content of terpenes, ?-carotene, magnesium, iron and phenolics as well as a 1-4-fold difference in falcarindiol, bitter taste and sweet taste. Climate-related factors may cause a difference of up to 20-fold for terpenes, 82% for total sugars and 30-40% for ?-carotene, sweet taste and bitter taste. Organic farming in comparison with conventional farming has shown 70% higher levels for magnesium and 10% for iron. Low nitrogen fertilisation level may cause up to 100% increase in terpene content, minor increase in dry matter (+4 to +6%) and magnesium (+8%) and reduction in ?-carotene content (-8 to -11%). Retail storage at room temperature causes the highest reduction in ?-carotene (-70%) and ascorbic acid (-70%). Heat processing by boiling reduces shear force (-300 to -1000%) and crispiness (-67%) as well as content of phenolics (-150%), terpenes (-85%) and total carotenes (-20%) and increases the risk of furan accumulation. Sensory and chemical quality parameters of carrots are determined mainly by genetic and climate-related factors and to a minor extent by cultivation method. Retail temperature and storage atmosphere as well as heating procedure in processing have the highest impact in quality reduction. © 2013 Society of Chemical Industry. PMID:23744724

Seljåsen, Randi; Kristensen, Hanne L; Lauridsen, Charlotte; Wyss, Gabriela S; Kretzschmar, Ursula; Birlouez-Aragone, Inès; Kahl, Johannes

2013-04-23

201

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

SciTech Connect

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.

Not Available

1993-08-01

202

Insufficient quality of sputum submitted for tuberculosis diagnosis and associated factors, in Klaten district, Indonesia  

PubMed Central

Background Sputum smear microscopy is the standard diagnostic method for detection of smear positive pulmonary tuberculosis (TB). Insufficient quality of sputum might result in missing cases. In this study we aimed at assessing the quality of sputum in a district in Central Java and determining patient and health worker factors associated with submission of three good quality sputum samples. Methods In 16 health centers information was collected on the quality of sputum submitted by TB suspects, i.e. volume, color, and viscosity. TB suspects were interviewed to assess their knowledge of TB, motivation to provide sputum and whether they were informed why and how to produce a sputum sample. Health workers were interviewed to assess what information they provided to TB suspects about the reason for sputum examination, methods to produce sputum and characteristics of a good quality sputum sample. All health worker and patient factors were evaluated for association with sputum quality. Results Of 387 TB suspects, 294 (76.0%) could be traced and interviewed, and of 272 (70.3%) information about sputum quality was available. Of those 203 (74.6%) submitted three samples, 90 (33.1%) provided at least one good sample, and 37 (13.6%) provided three good quality sputum samples. Of the 272 TB suspects, 168 (61.8%) mentioned that information on the reason for sputum examination was provided, 66 (24.3%) remembered that they were informed about how to produce sputum and 40 (14.7%) recalled being informed about the characteristics of good quality sputum. Paramedics reported to provide often/always information on the importance of sputum examination, and when to produce sputum. Information on how to produce sputum and characteristics of a good sputum sample was less often provided. None of the studied patient characteristics or health worker factors was associated with providing good quality sputum. Conclusion A considerable number of TB suspects did not provide three sputum samples and a large number of sputum samples were of insufficient quality. Training of health workers in providing health education to the TB suspect about the reason for sputum examination and how to produce a good quality sputum sample should be a priority of the TB program.

Sakundarno, Mateus; Nurjazuli, Nurjazuli; Jati, Sutopo Patria; Sariningdyah, Retna; Purwadi, Sumarsono; Alisjahbana, Bachti; van der Werf, Marieke J

2009-01-01

203

Factors Predicting Dynamic Balance and Quality of Life in Home-Dwelling Elderly Women  

Microsoft Academic Search

Background: Proper balance seems to be a critical factor in terms of fall prevention among the elderly. Objective: The purpose of this cross-sectional study was to examine factors that are associated with dynamic balance and health-related quality of life in home-dwelling elderly women. Methods: One hundred and fifty-three healthy postmenopausal women (mean age: 72 years, height: 159 cm, weight: 72

S. Karinkanta; A. Heinonen; H. Sievänen; K. Uusi-Rasi; P. Kannus

2005-01-01

204

Neutron effects in humans: protection considerations  

SciTech Connect

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.

Fry, R.J.M.

1985-01-01

205

Projected Shell Model Description of e2 Transition Probabilities and g-FACTORS of Even-Even Neutron-Rich Nuclei from Xe to Nd  

NASA Astrophysics Data System (ADS)

The systematics of E2 transition probabilities and g-factors of even-even N ? 86 Xe, Ba, Ce and Nd have been studied by using the projected shell model approach. The E2 transition probabilities and g-factors have been calculated by using the many-body wave functions that reproduce the low-lying ground state energy levels. The calculated B(E2) values show an increasing trend with spin and neutron number. The calculated g-factors reproduce the observed decreasing trend of g(21+) with neutron number except Nd nuclei.

Krishan, Gopal; Devi, Rani; Khosa, S. K.

2012-11-01

206

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

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.

J.M. Finn

2004-11-01

207

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

PubMed

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. PMID:22104504

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

2011-11-21

208

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

SciTech Connect

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.

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

1981-01-01

209

Quality of Life and the Associated Psychological Factors in Caregivers of Children with PKU  

PubMed Central

Objectives The main objective of this study was to investigate the association of psychological factors and life stressors with quality of life in caregivers of children with PKU. Methods Participants were caregivers of children with PKU who were referred to a child and adolescent consultation-liaison psychiatry clinic for a clinical follow up. Their demographic characteristics were recorded at first. WHOQOL-BREF and Depression-Anxiety-Stress Scale (DASS) were used to assess quality of life, depression, anxiety and stress in participants. Data analysis was performed using SPSS-11.5 statistical software. Results A total number of 49 caregivers were enrolled for the study. The mean age of participants and their children were 35.63±8.82, and 9.84±6.62 respectively. Of the participants, 59.2% were mothers and 40.8% were fathers. Of the children, 51% were girls and 49% were boys. According to the results, 57.1, 50.1 and 57.1 percent of the participants had mild to severe levels of depression, anxiety and stress scores respectively. The most associated factors with quality of life were as follows: caregivers’ occupation; anxiety; and depression mean scores. Conclusion Results of the current study showed that caregivers of children with PKU have lower levels of quality of life in comparison with the general population; and the most correlated factors with quality of life were the caregivers’ occupation (especially unemployment), and high levels of depression and anxiety.

Mahmoudi-Gharaei, Javad; Mostafavi, Saeedeh

2011-01-01

210

A Kramers-Kronig-based quality factor for shear wave propagation in soft tissue.  

PubMed

Shear wave propagation techniques have been introduced for measuring the viscoelastic material properties of tissue, but assessing the accuracy of these measurements is difficult for in vivo measurements in tissue. We propose using the Kramers-Kronig relationships to assess the consistency and quality of the measurements of shear wave attenuation and phase velocity. In ex vivo skeletal muscle we measured the wave attenuation at different frequencies, and then applied finite bandwidth Kramers-Kronig equations to predict the phase velocities. We compared these predictions with the measured phase velocities and assessed the mean square error (MSE) as a quality factor. An algorithm was derived for computing a quality factor using the Kramers-Kronig relationships. PMID:19759409

Urban, M W; Greenleaf, J F

2009-09-17

211

Factors Affecting Quality of English Language Teaching and Learning in Secondary Schools in Nigeria  

ERIC Educational Resources Information Center

|This study examined the factors responsible for the poor quality of the teaching of English as a second language in public secondary schools in Nigeria. To guide the study three research questions were posed. The questions examined the following three variables: (1) Frequency of the use of instructional media; (2) Frequency of the use of…

Aduwa-Ogiegbaen, S. E.; Iyamu, E. O. S.

2006-01-01

212

Improvement of the quality factor of RF integrated inductors by layout optimization  

Microsoft Academic Search

A systematic method to improve the quality (Q) factor of RF integrated inductors is presented in this paper. The proposed method is based on the layout optimization to minimize the series resistance of the inductor coil, taking into account both ohmic losses, due to conduction currents, and magnetically induced losses, due to eddy currents. The technique is particularly useful when

José M. López-Villegas; Josep Samitier; Charles Cané; Pere Losantos; Joan Bausells

2000-01-01

213

Measurement Model Quality, Sample Size, and Solution Propriety in Confirmatory Factor Models  

ERIC Educational Resources Information Center

Sample size recommendations in confirmatory factor analysis (CFA) have recently shifted away from observations per variable or per parameter toward consideration of model quality. Extending research by Marsh, Hau, Balla, and Grayson (1998), simulations were conducted to determine the extent to which CFA model convergence and parameter estimation…

Gagne, Phill; Hancock, Gregory R.

2006-01-01

214

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

ERIC Educational Resources Information Center

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…

Maroti-Nagy, Agnes; Paulik, Edit

2011-01-01

215

Quality factor and finesse optimization in buried InGaAsP/InP ring resonators  

NASA Astrophysics Data System (ADS)

Quality factor and finesse of buried In1 xGaxAsyP1 y / InP ring resonators have been optimized in this paper by a very general modelling technique. Limiting effect of propagation loss within the ring has been investigated using a three-dimensional (3D) highly accurate complex mode solver based on mode matching method to analyze bending loss dependence on ring radius and wavelength. Coupling between straight input/output (I/O) bus waveguides and ring resonator has been studied by 3D Beam Propagation Method (BPM), deriving coupling loss and coupling coefficient for a large range of ring radius and bus waveguides-ring distance values (for both polarizations). Ring resonator has been modelled by the transfer-matrix approach, while finesse and quality factor dependence on radius has been estimated for two resonator architectures (including one or two I/O bus waveguides) and for quasi-TE and quasi-TM modes. Guiding structure has been optimized to enhance resonator performance. The modelling approach has been validated by comparing results obtained by our algorithm with experimental data reported in literature. Influence of rejection (at resonance wavelength) at through port on quality factor and finesse has been widely discussed. A quality factor larger than 8105 has been predicted for the ring resonator employing only one I/O bus waveguide and having a radius of 400 mm. This resonator exhibits a rejection of -8 dB at through port.

Ciminelli, C.; Passaro, V. M. N.; Dell'Olio, F.; Armenise, M. N.

2009-06-01

216

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

ERIC Educational Resources Information Center

|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…

Spokus, Diane

2008-01-01

217

Health-related quality of life and associated psychosocial factors in irritable bowel syndrome: A review  

Microsoft Academic Search

Irritable Bowel Syndrome (IBS) is a chronic recurring disorder with variable illness episodes that may continue for many years. Diagnosis is based on symptoms such as abdominal pain and irregular bowel habits. These symptoms, plus the influence of psychological factors and extraintestinal symptoms, adversely affect the health-related quality of life (HRQoL) of individuals with IBS. This paper summarizes publications relating

Faye A. Luscombe

2000-01-01

218

Measurement Model Quality, Sample Size, and Solution Propriety in Confirmatory Factor Models  

ERIC Educational Resources Information Center

|Sample size recommendations in confirmatory factor analysis (CFA) have recently shifted away from observations per variable or per parameter toward consideration of model quality. Extending research by Marsh, Hau, Balla, and Grayson (1998), simulations were conducted to determine the extent to which CFA model convergence and parameter estimation…

Gagne, Phill; Hancock, Gregory R.

2006-01-01

219

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

ERIC Educational Resources Information Center

|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…

Richmond, Lori M.

2011-01-01

220

Quality factor of an electrically small antenna radiating close to a conducting plane  

Microsoft Academic Search

Expressions are derived for the smallest achievable radiation quality factor (Q) of an electrically small antenna in front of a conducting plane. Applying the low-frequency approximation to the source region involving an electric or a magnetic point dipole plus their images behind the plane, an expression is formed for the field in the radiation zone. The contribution of non-propagating energy

J. C.-E. Sten; A. Hujanen; P. K. Koivisto

2001-01-01

221

The Effect of Certain Factors upon the Keeping Quality of Butter  

Microsoft Academic Search

The factors which have been considered in a study of the causes for the spoilage of butter held at temperatures which might permit the growth of microorganisms were: the presence of the natural enzymes of milk; the increase in numbers of certain types of bacteria; the ripening of the cream ; and the addition of salt. Quality was determined by

E. S. Guthrie; B. J. Scheib; C. N. Stark

1936-01-01

222

Key factors in the successful application of quality function deployment (QFD)  

Microsoft Academic Search

In the product design and development process, quality function deployment (QFD) provides a comprehensive, systematic approach to ensure that new products meet or exceed customer expectations. This paper reports on the results of a survey of more than 400 companies in the United States and Japan using QFD. The objective of the study was to understand the key factors that

John J. Cristiano; Jeffrey K. Liker; Chelsea C. White

2001-01-01

223

Power Stored and Quality Factors in Frequency Selective Surfaces at THz Frequencies  

Microsoft Academic Search

A study of the external, loaded and unloaded quality factors for frequency selective surfaces (FSSs) is presented. The study is focused on THz frequencies between 5 and 30 THz, where ohmic losses arising from the conductors become important. The influence of material properties, such as metal thickness, conduc- tivity dispersion and surface roughness, is investigated. An equiv- alent circuit that

Juan José Sanz-Fernandez; Rebecca Cheung; George Goussetis; Carolina Mateo-Segura

2011-01-01

224

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

ERIC Educational Resources Information Center

|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…

Maroti-Nagy, Agnes; Paulik, Edit

2011-01-01

225

Factor Analysis of Quality of Life for Individuals with Severe Disabilities in Transition.  

ERIC Educational Resources Information Center

A study of 398 young adults (ages 21-26) with severe disabilities who had been out of school for 1.75 to 5 years was conducted to validate a four-factor model of quality of life for youth with severe disabilities in transition from school to community and from youth to adulthood. Information was gathered on life satisfaction, employment-economic…

Lin, Hung-Chih

226

Nature versus nurture: an examination of factors that contribute to IT service quality  

Microsoft Academic Search

As the IT unit increases its strategic alignment with the organization, technical people of all levels are required to become more customer-focused. It has been suggested that a service orientation on the part of IT personnel can be a contributing factor to the IT unit's service quality. However, IT workers do not exist in a vacuum, but must work within

Janette Moody

2009-01-01

227

Measuring the quality factor of a microwave cavity using superconducting qubit devices  

Microsoft Academic Search

We propose a method to create superpositions of two macroscopic quantum states of a single-mode microwave cavity field interacting with a superconducting charge qubit. The decoherence of such superpositions can be determined by measuring either the Wigner function of the cavity field or the charge qubit states. Then the quality factor Q of the cavity can be inferred from the

Yu-Xi Liu; L. F. Wei; Franco Nori

2005-01-01

228

Free NH 3 quantum rotations in Hofmann clathrates: structure factors and line widths studied by inelastic neutron scattering  

NASA Astrophysics Data System (ADS)

Quantum rotations of NH 3 groups in Hofmann clathrates Ni-Ni-C 6H 6 and Ni-Ni-C 12H 10 have been studied using inelastic neutron scattering. Calculations of the dynamical structure factor for a free uniaxial quantum rotor reproduce the neutron scattering data with respect to their Q- and T-dependence as well as the relative intensities for the 0 ? 1, 0 ? 2 and 1 ? 2 transitions. Though the effective NH 3 rotation constant is different from the gas phase value, the effective radius of rotation (i.e., the average distance of protons from the rotation axis) is equal or very close to the geometrical value r = 0.94 Å for a NH 3 group. Comparing the experimental data with the calculated dynamical structure factor for the 0 ? 3 transition it could be shown, that the corresponding transition line, in contrast to transitions between j = 0,1,2 levels measured so far, has a finite width at T = 0 K.

Sobolev, O.; Vorderwisch, P.; Desmedt, A.

2005-01-01

229

Calculation and evaluation of cross sections and kerma factors for neutrons up to 100 MeV on carbon  

SciTech Connect

The authors present an evaluation of the interaction of neutrons with energies between 20 and 100 MeV with carbon nuclei. The aim is to accurately represent integrated cross sections, inclusive emission spectra, and kerma factors, in a data library for use in radiation transport simulations of fast neutron radiotherapy. They apply the Feshbach-Kerman-Koonin-GNASH nuclear model code, which includes Hauser-Feshbach, pre-equilibrium, and direct reaction mechanisms, and use experimental measurements to optimize the calculations. They determine total, elastic, and nonelastic cross sections; angle-energy-correlated emission spectra for light ejectiles with A {le} 4 and gamma rays; and average energy depositions. Coupled-channel optical model calculations describe the total, elastic, and nonelastic cross sections well. The results for charged-particle emission spectra agree fairly well with University of California-Davis as well as new Los Alamos National Laboratory and Louvain-la-Neuve measurements. They compare the results with the recent ENDF/B-VI evaluation and argue that some of the exclusive channels between 20 and 32 MeV should be modified. They also compare kerma factors derived from the evaluated cross sections with the measurements, providing an integral benchmark for the work. The evaluated data libraries are available as electronic files.

Chadwick, M.B.; Cox, L.J. [Lawrence Livermore National Lab., CA (United States); Young, P.G. [Los Alamos National Lab., NM (United States); Meigooni, A.S. [Univ. of Kentucky, Lexington, KY (United States). Dept. of Radiation Medicine

1996-05-01

230

Design and Measurement of a Digital Phase Locked BWO for Accurately Extracting the Quality Factors in a Biconcave Resonator System  

NASA Astrophysics Data System (ADS)

A long loop phase locked backward-wave oscillator (BWO) for a high quality factor resonator system operating at D-band frequencies (130-170GHz) was described, the phase noise of the phased locked BWO was analyzed and measured at typical frequencies. When it used with a high quality factor open resonator for measuring the quality factor of simple harmonic resonators based on the magnitude transfer characteristic, this system has proven to be capable of accurate measuring the quality factor as high as 0.8 million with an uncertainty of less than 1.3% (Lorentzian fitting) at typical frequencies in the range of 130GHz-170GHz.

Gao, Yuanci; Charles, Jones R.; Yu, Guofen; Jyotsna, Dutta M.

2012-03-01

231

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

PubMed Central

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 technical expertise with the data.

Davies, E; Cleary, P

2005-01-01

232

Envionmental Setting and the Effects of Natural and Human-Related Factors on Water Quality and Aquatic Biota, Oahu, Hawaii.  

National Technical Information Service (NTIS)

The purpose of this report is to describe the natural and human factors that affect water quality in the Oahu Study Unit. This report describes the natural factors, including the physiography, climate, geology, soils, and hydrology that determine the natu...

D. S. Oki A.M. Brasher

2003-01-01

233

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

SciTech Connect

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.

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

1994-12-31

234

Cross-Sectional Versus Sequential Quality Indicators of Risk Factor Management in Patients with Type 2 Diabetes  

Microsoft Academic Search

Background: The fairness of quality assessment methods is under debate. Quality indicators incorporating the longitudinal nature of care have been advocated but their usefulness in comparison to more commonly used cross-sectional measures is not clear. Aims: To compare cross-sectional and sequential quality indicators for risk factor management in patients with type 2 diabetes. Methods: The study population consisted of 1912

Jaco Voorham; Petra Denig; Bruce H. R. Wolffenbuttel; Flora M. Haaijer-Ruskamp

2008-01-01

235

Numerical analysis of beam quality factor ? on coherent combination of multiple laser beams  

NASA Astrophysics Data System (ADS)

numerical simulation model for coherent combination of multiple rectangular beams, square beams and circular beams has been developed. The beam quality factor ? of wavelet and its combination was obtained by numerical calculation through fast Fourier transform (FFT) when each wavelet has Zernike aberrations with twenty-one polynomials. The influence of piston on coherent beam combination was analyzed too. It's demonstrated that the influence of piston on CBC(coherent beam combination) was small if each wavelet has many other higher order aberrations. The relationship between the averaged beam quality factor ? of all wavelets and beam quality factor ? of CBC based on these wavelets was also obtained by numerical calculation. A fitting formula was used to fit the discrete data. By this way, an expression of the relationship was acquired. Fitting coefficients between numerical calculation and theoretical result were compared and the affecting factor of the difference was analyzed. We concluded that fitting coefficients of numerical calculation result was smaller than theoretical result because of wavelet arrangement and filling ratio.

Tan, Yi; Li, Xinyang

2012-11-01

236

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

SciTech Connect

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.

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

237

Using optical anisotropy as a quality factor to rapidly characterize structural qualities of large-area graphene films.  

PubMed

In this study, we find that the optical anisotropy of graphene films could be used as an alternative quality factor for the rapid characterization of large-area graphene films prepared through chemical vapor deposition. We develop an angle-variable spectroscopic method to rapidly determine the optical anisotropy of graphene films. Unlike approaches using Raman scattering spectroscopy, this optical anisotropy method allows ready characterization of the structural quality of large-area graphene samples without the application of high-intensity laser irradiation or complicated optical setups. Measurements of optical anisotropy also allow us to distinguish graphene samples with different extents of structural imperfections; the results are consistent with those obtained from using Raman scattering spectroscopy. In addition, we also study the properties of graphene-based transparent conductive films at wide incident angles because of the advantage of the optical anisotropic properties of graphene. The transmittance of graphene is much higher than that of indium tin oxide films, especially at large incident angles. PMID:23323974

Liu, Yu-Lun; Yu, Chen-Chieh; Fang, Cheng-Yi; Chen, Hsuen-Li; Chen, Chun-Wei; Kuo, Chun-Chiang; Chang, Cheng-Kai; Chen, Li-Chyong; Chen, Kuei-Hsien

2013-01-16

238

Neutron Scattering Facility for the Measurement of Light Quenching Factors of Dark Matter Detectors at Low Temperatures  

NASA Astrophysics Data System (ADS)

The light yield of scintillating crystals which is quantified by light Quenching Factors (QFs) strongly depends on the kind of interaction in the crystal. For Dark Matter experiments like CRESST the precise knowledge of QFs is crucial for the discrimination of background events from possible WIMP signals. At the tandem accelerator of the Maier-Leibnitz-Laboratorium (MLL) in Garching a low-temperature scattering facility was set up, which in its current phase aims at the determination of the QFs of O, Ca, and W in CaWO4 crystals as used in the CRESST experiment. A CRESST detector module consists of a 300 g CaWO4 target crystal operated as a phonon detector and a separate silicon-on-sapphire (SOS) light detector to detect the corresponding scintillation light simultaneously. In order to disentangle the light yield corresponding to O, Ca and W recoils, monoenergetic neutrons (11 MeV) produced by the accelerator are scattered off an especially developed CRESST-like detector module, which is operated at mK temperatures in a dilution refrigerator. Arrays of liquid-scintillator detectors placed at fixed scattering angles allow one to identify the recoiling nuclei by a neutron time-of-flight measurement. The unique facility is suited for the characterization of different detector materials and will be a powerful tool also for the future multi-material experiment EURECA. We report on the experimental approach, the low-temperature setup and present first results.

Strauss, R.; Ciemniak, C.; Deuter, G.; von Feilitzsch, F.; Gütlein, A.; Hagn, H.; Jochum, J.; Lanfranchi, J.-C.; Lepelmeier, J.; Pfister, S.; Potzel, W.; Roth, S.; Rottler, K.; Sailer, C.; Scholl, S.; von Sivers, M.; Thalhammer, U.; Wawoczny, S.; Willers, M.; Usherov, I.

2012-06-01

239

Impact of probe configuration and calibration techniques on quality factor determination of on-wafer inductors for GHz applications  

Microsoft Academic Search

We demonstrate that the quality factors measured on on-wafer (spiral) inductor test-structures are largely influenced by the choice between ground-signal and ground-signal-ground probe configuration. In particular when the SOLT network analyzer calibration technique is used in combination with ground-signal probing, the quality factor value can be overestimated significantly.

R. J. Havens; L. F. Tiemeijer; L. Garnbus

2002-01-01

240

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

NSDL National Science Digital Library

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 to cite more papers than those published a decade ago. We analyzed citation data from 75,312 papers from 70 ecological journals published during 1998âÂÂ2007. We found that papers published in 2007 cited an average of seven more papers than those published a decade earlier. This increase accounts for about 80% of the observed impact factor inflation rate of 0.23. In examining the 70 journals we found that nearly 50% showed increases in their impact factors, but at rates lower than the background inflation rate. Therefore, although those journals appear to be increasing in quality as measured by the impact factor, they are actually failing to keep pace with inflation.

Bryan Neff (University of Western Ontario;Department of Biology); Julian Olden (University of Washington;School of Aquatic and Fishery Science)

2010-06-01

241

Chemical sensors and biosensors in liquid environment based on microcantilevers with amplified quality factor  

Microsoft Academic Search

A new technique is presented for bio\\/chemical sensors, based on microcantilevers, for detection in liquid environment. The low quality factor of the cantilever in liquid is increased up to three orders of magnitude by using Q-control. This enables AC detection that is immune to the long-term drift of the DC cantilever response in liquids, and to temperature variations. This technique

J Tamayo; A. D. L Humphris; A. M Malloy; M. J Miles

2001-01-01

242

Primary Factors Affecting Water Quality and Quantity in Four Watersheds in Eastern Puerto Rico  

Microsoft Academic Search

As part of the U.S. Geological Survey (USGS) Water, Energy, and Biogeochemical Budgets (WEBB) program, four small watersheds in eastern Puerto Rico were monitored to identify and evaluate the effects of geology, landcover, atmospheric deposition, and other factors on stream water quality and quantity. Two catchments are located on coarse-grained granitic plutonic rocks, which weather to quartz- and clay-rich, sandy

Sheila F. Murphy; Robert F. Stallard

2008-01-01

243

Seismic quality factor observations for gas-hydrate-bearing sediments on the western margin of India  

Microsoft Academic Search

Any propagating wave undergoes attenuation, which is primarily governed by the physical properties of the medium, determined\\u000a in terms of quality factor (Q). Research into the characteristics of both P- and S-wave Q with reference to gas-hydrates exploration remains in its infancy. Presence of gas-hydrates increases the Q, and this again depends on the nature of distribution and amount of

Kalachand Sain; A. K. Singh; N. K. Thakur; Ramesh Khanna

2009-01-01

244

Study on estimate method of wave velocity and quality factor to fault seals  

Microsoft Academic Search

Based on ultrasonic test of fault rocks, the responses for wave velocity and quality factor (Q value) to lithology, porosity and permeability of fault rocks and mechanical property of faults are studied. In this paper,\\u000a a new quantitative estimate method of fault seals is originally offered. The conclusions are as follows: (1) Wave velocity\\u000a andQ value increase and porosity decreases

Zhensheng Li; Deliang Liu; Bo Liu; Qiang Yang; Jingming Li

2005-01-01

245

Longitudinal health-related quality of life outcomes and related factors after pediatric SCT  

Microsoft Academic Search

Our purpose was to investigate longitudinally health-related quality of life (HRQOL) outcomes and related factors up to 2 years post-pediatric SCT. A total of 99 mothers of patients, aged 1.5–17 years, completed two standardized HRQOL questionnaires, generic and disease specific (DS), about the child, and reported on their own symptoms of depression and family function pre-SCT, 12 and 24 months

M Barrera; E Atenafu; K Hancock

2009-01-01

246

The quality of medical care, behavioral risk factors, and longevity growth  

Microsoft Academic Search

The rate of increase of longevity has varied considerably across U.S. states since 1991. This paper examines the effect of\\u000a the quality of medical care, behavioral risk factors (obesity, smoking, and AIDS incidence), and other variables (education,\\u000a income, and health insurance coverage) on life expectancy and medical expenditure using longitudinal state-level data. We\\u000a examine the effects of three different measures

Frank R. Lichtenberg

2011-01-01

247

Factors Associated with Quality of Life Among Rural Women with HIV Disease  

Microsoft Academic Search

This cross-sectional study examined physical, psychological, and social factors associated with quality of life (QOL) among\\u000a a sample of 399 rural women with HIV disease living in the Southeastern United States. Of the socio-demographic variables,\\u000a age (p = .003), race (p p = .03) were significantly associated with QOL. In bi-variate analysis, HIV symptoms (frequency and extent symptoms were bothersome),\\u000a perceived stigma, internalized stigma, and

Medha Vyavaharkar; Linda Moneyham; Carolyn Murdaugh; Abbas Tavakoli

248

Teleseismic localization of velocity and quality factor: Application to Patagonia, Antarctica, D", and the whole mantle  

NASA Astrophysics Data System (ADS)

This thesis discusses a variety of teleseismic localization techniques with application to various regions within the Earth. Two common threads continue through this thesis: (1) Differential waveform analyses produce more accurate measurements of localized anomalies than do individual waveform analyses. (2) Combining multiple data types and techniques in order to constrain the same problem yields more unique interpretations of Earth's structure, composition and dynamics. This thesis is divided into two different aspects of teleseismic studies: (1) Joint receiver function and interstation phase velocity inversions with niching genetic algorithms provide accurate crustal and upper mantle seismic models for Patagonia and Antarctica. (2) Differential attenuation and travel-time measurements better constrain velocity and quality factor in the whole mantle than do direct attenuation and travel-time measurements. In the scope of this thesis I develop seismic models that demonstrate variation in crustal thickness for Patagonia and Antarctica and relate the results to tectonic models. The Patagonia crustal thickness is 30 +/- 3 km having a pattern consistent with isostatic compensation. In Antarctica, the crustal thickness varies from 20--40 km under the Transantarctic Mountains (TAMs), which are a ˜4500 km long ˜4 km high mountain range that divides East and West Antarctica. Seismic velocity increases by ˜2--5% under the TAMS. The free-air gravity and bedrock topography of the Transantarctic Mountains are consistent with an elastic flexural model for mountain uplift. This thesis also develops seismic models of quality factor and velocity, which indicate a dynamic set of processes occurring within the lowermost mantle and mantle at large. The different sensitivities of velocity and quality factor to temperature, grain size, stress, and chemical composition may be used to infer the cause for seismically imaged anomalies. The overarching pattern of high quality factor and velocity under subduction zones and large, low quality factor and low velocity zones beneath the Pacific and Africa indicate that temperature is the dominant controlling factor. However, water content in the upper mantle, stress, and grain size cannot be discounted. The pattern is consistent with cold downwelling slabs sinking into the lower mantle and warm buoyant material rising from the core-mantle boundary.

Lawrence, Jesse Fisher

249

Investigating factors associated with quality of life of vitiligo patients in Singapore.  

PubMed

Skin disease is often visible to others. People who have dermatological condition may also suffer from its psychological consequences. The purpose of this study is to explore the quality of life of patients with vitiligo and to identify factors associated with their quality of life. A descriptive correlational study was conducted with 222 patients with vitiligo recruited from two skin centres in Singapore from 2009 to 2011. Data were collected by a structured questionnaire. Three outcome variables were measured in the study: predisposal, clinical and psychological outcomes. Results showed that almost two-thirds of the participants reported vitiligo had moderate to extreme impact on their quality of life. Multiple regression analyses showed that patients who were depressed, had thyroid disease and had not used multiclear treatment were more likely to report poor quality of life. It is recommended that providing health care consultation for patients with vitiligo may help reduce depressive symptoms and maintain their psychological health, thus enhance their quality of life. PMID:24090292

Chan, Moon Fai; Thng, Tien Guan Steven; Aw, Chen Wee Derrick; Goh, Boon Kee; Lee, Sze Min; Chua, Tse Lert

2013-09-01

250

The quality of medical care, behavioral risk factors, and longevity growth.  

PubMed

The rate of increase of longevity has varied considerably across U.S. states since 1991. This paper examines the effect of the quality of medical care, behavioral risk factors (obesity, smoking, and AIDS incidence), and other variables (education, income, and health insurance coverage) on life expectancy and medical expenditure using longitudinal state-level data. We examine the effects of three different measures of the quality of medical care. The first is the average quality of diagnostic imaging procedures, defined as the fraction of procedures that are advanced procedures. The second is the average quality of practicing physicians, defined as the fraction of physicians that were trained at top-ranked medical schools. The third is the mean vintage (FDA approval year) of outpatient and inpatient prescription drugs. Life expectancy increased more rapidly in states where (1) the fraction of Medicare diagnostic imaging procedures that were advanced procedures increased more rapidly; (2) the vintage of self- and provider-administered drugs increased more rapidly; and (3) the quality of medical schools previously attended by physicians increased more rapidly. States with larger increases in the quality of diagnostic procedures, drugs, and physicians did not have larger increases in per capita medical expenditure. We perform several tests of the robustness of the life expectancy model. Controlling for per capita health expenditure (the "quantity" of healthcare), and eliminating the influence of infant mortality, has virtually no effect on the healthcare quality coefficients. Controlling for the adoption of an important nonmedical innovation also has little influence on the estimated effects of medical innovation adoption on life expectancy. PMID:21188512

Lichtenberg, Frank R

2010-12-25

251

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

PubMed

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 be used to correct the dose equivalent at the patient surface. PMID:19472632

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

2009-04-01

252

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

PubMed Central

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 be used to correct the dose equivalent at the patient surface.

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

2009-01-01

253

Characterization of Network Vibrational Modes by Means of Dynamic Structure Factors from Neutron Scattering.  

National Technical Information Service (NTIS)

Vibrational modes observed in the density of states of glasses may be characterized by consideration of the dynamic structure factor S(Q,E). The Q dependence of this function depends on the character of the modes with energy E through the phase factor and...

D. L. Price S. Susman K. J. Volin R. J. Dejus

1988-01-01

254

Z' factor including siRNA design quality parameter in RNAi screening experiments.  

PubMed

RNA interference (RNAi) high-content screening (HCS) enables massive parallel gene silencing and is increasingly being used to reveal novel connections between genes and disease-relevant phenotypes. The application of genome-scale RNAi relies on the development of high quality HCS assays. The Z' factor statistic provides a way to evaluate whether or not screening run conditions (reagents, protocols, instrumentation, kinetics, and other conditions not directly related to the test compounds) are optimized. Z' factor, introduced by Zhang et al., ( 1) is a dimensionless value that represents both the variability and the dynamic range between two sets of sample control data. This paper describe a new extension of the Z' factor, which integrates bioinformatics RNAi non-target compounds for screening quality assessment. Currently presented Z' factor is based on positive and negative control, which may not be sufficient for RNAi experiments including oligonucleotides (oligo) with lack of knock-down. This paper proposes an algorithm which extends existing algorithm by using additional controls generetaed from on-target analysis. PMID:22614837

Mazur, S?awomir; Kozak, Karol

2012-05-01

255

g factors of first 2+ states of neutron-rich Xe, Ba, and Ce isotopes  

NASA Astrophysics Data System (ADS)

Using new techniques developed for measuring angular correlations with large detector arrays, the g factors of 2+ states in Xe140,142 are measured for the first time by the method of correlation attenuation in randomly oriented magnetic fields. g factors in Ba146 and Ce146,148 are measured to establish the method by comparison with previous values. The results are discussed in terms of IBM-2 and rotation-vibration models.

Goodin, C.; Stone, J. R.; Stone, N. J.; Ramayya, A. V.; Daniel, A. V.; Hamilton, J. H.; Li, K.; Hwang, J. K.; Ter-Akopian, G. M.; Rasmussen, J. O.

2009-03-01

256

The endocrine interface of environmental and egg factors affecting chick quality.  

PubMed

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 eggs set for incubation, storage duration, and age of breeders, there will be a period between hatch and first feeding of variable length. This may have repercussions on overall growth and many related physiological processes such as yolk uptake, metabolic level, and gastrointestinal development. In its turn, time of first feeding is related to some crucial hormone levels and enzyme activities for growth that are strongly influenced by posthatch food intake such as insulin and p70S6 kinase activity, a key enzyme in the control of protein synthesis. The magnitude of the effect of delayed feeding is dependent on the spread of hatching as well as on the hatching period within the hatching window. This may be related to the different intrinsic quality or characteristics of chicks, e.g., early vs. late hatchers, as is shown by their respective hormonal levels. The latter may be a causal factor for the actual hatching time within the hatching window as well as for the later intrinsic quality of the hatched chick, which is not reflected in any of the actual scoring systems for chick quality. This is largely ignored in previous studies and in hatchery practice so far. PMID:17435044

Decuypere, E; Bruggeman, V

2007-05-01

257

A Technical Assessment of Current Water Quality Conditions and Factors Affecting Water Quality in the Upper Potomac Estuary.  

National Technical Information Service (NTIS)

Water quality problems in the Potomac River Basin, their sources and corrective actions required, are the subject of continuing investigations by the Chesapeake Technical Support Laboratory. The water quality conditions in the Potomac Estuary are monitore...

N. A. Jaworski D. W. Lear J. A. Aalto

1969-01-01

258

Elastic electron-deuteron scattering and the electric neutron form factor at four-momentum transfers 5 fm-2 < q2 < 14 fm-2  

Microsoft Academic Search

The cross section for elastic electron-deuteron scattering was measured for ten four-momentum transfers squared in the range 5fm-2factors was determined. The experimental values are compared with theoretical predictions including relativistic corrections. Different deuteron wave functions and different parametrizations for the electric neutron form factor GEN were

S. Galster; H. Klein; J. Moritz; K. H. Schmidt; D. Wegener; J. Bleckwenn

1971-01-01

259

Interaction between bacterial outer membrane proteins and periplasmic quality control factors: a kinetic partitioning mechanism.  

PubMed

The OMPs (outer membrane proteins) of Gram-negative bacteria have to be translocated through the periplasmic space before reaching their final destination. The aqueous environment of the periplasmic space and high permeability of the outer membrane engender such a translocation process inevitably challenging. In Escherichia coli, although SurA, Skp and DegP have been identified to function in translocating OMPs across the periplasm, their precise roles and their relationship remain to be elucidated. In the present paper, by using fluorescence resonance energy transfer and single-molecule detection, we have studied the interaction between the OMP OmpC and these periplasmic quality control factors. The results of the present study reveal that the binding rate of OmpC to SurA or Skp is much faster than that to DegP, which may lead to sequential interaction between OMPs and different quality control factors. Such a kinetic partitioning mechanism for the chaperone-substrate interaction may be essential for the quality control of the biogenesis of OMPs. PMID:21671888

Wu, Si; Ge, Xi; Lv, Zhixin; Zhi, Zeyong; Chang, Zengyi; Zhao, Xin Sheng

2011-09-15

260

Sleep quality and associated factors in ankylosing spondylitis: relationship with disease parameters, psychological status and quality of life.  

PubMed

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. PMID:22940709

Batmaz, ?brahim; Sar?y?ld?z, Mustafa Akif; Dilek, Banu; Bez, Yasin; Karakoç, Mehmet; Çevik, Remzi

2012-09-02

261

Modeling study on the factors affecting regional air quality during the Beijing 2008 Olympic Games  

NASA Astrophysics Data System (ADS)

Chinese government took measures to control emissions of pollutants before and during the Beijing 2008 Olympic Games in order to get better air quality for the event. A 3-dimensional regional chemical transport model, the University of Iowa’s Sulfur Transport and dEposition Model (STEM), is used to evaluate the effects of emission reductions on regional air quality by this event. The emission inventories with and without the consideration of emission reductions are used in case studies. Impacts of the emissions from different regions and sectors on Beijing and regional air quality are discussed in this study. Meteorological factor on the improvement of air quality during this event is also assessed by using the meteorological conditions from different years to drive the model. Model performance is evaluated by comparing the modeled trace gases and aerosols with the surface measurements from Beijing, the field observations from the Cheju ABC Plume-Asian Monsoon Experiment (CAPMEX) during this summer, and satellite data from NASA.

Wei, C.; Carmichael, G. R.; Adhikary, B.; D'Allura, A.; Cheng, Y.; Tang, Y.; Zhang, Q.; Streets, D. G.; Pierce, R.; Al-Saadi, J. A.; Flowers, B. A.; Dubey, M. K.; Krotkov, N. A.; Pickering, K. E.; Ramanathan, V.

2009-12-01

262

Factors dominating stratification cycle and seasonal water quality variation in a Korean estuarine reservoir.  

PubMed

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. PMID:21491676

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

263

Ambient air quality trends and driving factor analysis in Beijing, 1983-2007.  

PubMed

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. PMID:22432333

Zhang, Ju; Ouyang, Zhiyun; Miao, Hong; Wang, Xiaoke

2011-01-01

264

Technique for Measuring Angular Correlations and g-FACTORS of Excited States with Large Multi-Detector Arrays:. AN Application to Neutron Rich Nuclei Produced in Spontaneous Fission  

NASA Astrophysics Data System (ADS)

Triple coincidences between prompt ?-rays emitted in the spontaneous fission of 252Cf were measured with Gammasphere. These data are used to measure the angular correlation of cascades of ?-rays from excited states of neutron rich fission fragments stopped in an unmagnetized iron foil. The hyperfine fields in the iron lattice cause attenuations of the angular correlations between ? rays emitted from the excited states which have sufficiently long lifetimes. This attenuation is measured and used to calculate the g-factors of excited states in many neutron rich nuclei.

Ramayya, A. V.; Goodin, C.; Li, K.; Hwang, J. K.; Hamilton, J. H.; Luo, Y. X.; Daniel, A. V.; Ter-Akopian, G. M.; Stone, N. J.; Stone, J. R.; Rasmussen, J. O.; Lee, I. Y.; Zhu, S. J.; Stoyer, M.

2008-04-01

265

Measurement of the neutron's electric form factor G(E)(n) via doubly polarized, quasi-elastic scattering at Jefferson Lab  

SciTech Connect

We determined the electric form factor of the neutron GEn via the reaction d(e,e?n)p using a longitudinally polarized electron beam and a frozen, polarized 15ND3 target at Jefferson Lab. The knocked out neutrons were detected in a segmented plastic scintillator in coincidence with the quasi-elastically scattered electrons which were tracked in Hall C's High Momentum Spectrometer. To extract GEn, we compared the experimental beam-target asymmetry with theoretical calculations based on different GEn models. We report the results of the fall 2001 run at Q2=0.5 and 1.0 (GeV/c)2.

Frank Wesselmann

2004-11-01

266

Evaluated cross-section libraries and kerma factors for neutrons up to 100 MeV on {sup 12}C  

SciTech Connect

A program is being carried out at Lawrence Livermore National Laboratory to develop high-energy evaluated nuclear data libraries for use in Monte Carlo simulations of cancer radiation therapy. In this report we describe evaluated cross sections and kerma factors for neutrons with incident energies up to 100 MeV on {sup 12}C. The aim of this effort is to incorporate advanced nuclear physics modeling methods, with new experimental measurements, to generate cross section libraries needed for an accurate simulation of dose deposition in fast neutron therapy. The evaluated libraries are based mainly on nuclear model calculations, benchmarked to experimental measurements where they exist. We use the GNASH code system, which includes Hauser-Feshbach, preequilibrium, and direct reaction mechanisms. The libraries tabulate elastic and nonelastic cross sections, angle-energy correlated production spectra for light ejectiles with A{le}and kinetic energies given to light ejectiles and heavy recoil fragments. The major steps involved in this effort are: (1) development and validation of nuclear models for incident energies up to 100 MeV; (2) collation of experimental measurements, including new results from Louvain-la-Nueve and Los Alamos; (3) extension of the Livermore ENDL formats for representing high-energy data; (4) calculation and evaluation of nuclear data; and (5) validation of the libraries. We describe the evaluations in detail, with particular emphasis on our new high-energy modeling developments. Our evaluations agree well with experimental measurements of integrated and differential cross sections. We compare our results with the recent ENDF/B-VI evaluation which extends up to 32 MeV.

Chadwick, M.B.; Blann, M.; Cox, L. [Lawrence Livermore National Lab., CA (United States); Young, P.G. [Los Alamos National Lab., NM (United States); Meigooni, A. [Kentucky Univ., Lexington, KY (United States). Dept. of Radiation Medicine

1995-04-11

267

High quality factor 1-D Er³?-activated dielectric microcavity fabricated by RF-sputtering.  

PubMed

Rare earth-activated 1-D photonic crystals were fabricated by RF-sputtering technique. The cavity is constituted by an Er3+-doped SiO2 active layer inserted between two Bragg reflectors consisting of ten pairs of SiO2/TiO2 layers. Scanning electron microscopy is employed to put in evidence the quality of the sample, the homogeneities of the layers thickness and the good adhesion among them. Near infrared transmittance and variable angle reflectance spectra confirm the presence of a stop band from 1500 nm to 2000 nm with a cavity resonance centered at 1749 nm at 0° and a quality factor of 890. The influence of the cavity on the ?I??/? -->?I??/? emission band of Er3+ ion is also demonstrated. PMID:23037245

Valligatla, Sreeramulu; Chiasera, Alessandro; Varas, Stefano; Bazzanella, Nicola; Rao, D Narayana; Righini, Giancarlo C; Ferrari, Maurizio

2012-09-10

268

[Output factor calculations for intensity modulation radiation therapy as dosimetry quality assurance].  

PubMed

Because intensity-modulated radiation therapy (IMRT) is complicated by many small, irregular, and off-center fields, dosimetry quality assurance (QA) is extremely important. QA is performed with verifications of both dose distributions and some arbitrary point doses. In most institutes, verifications are carried out in comparison with dose values generated from radiation treatment planning systems (RTPs) and actually measured doses. However, the estimation of arbitrary point doses without RTPs should be feasible in order to perform IMRT delivery more safely and accurately in terms of the clinical aspect. In this paper, we propose a new algorithm for calculating output factors at the center point of the collimations in an IMRT field with step and shoot delivery machines in which the lower jaws were replaced with multileaf collimators (MLC). We assumed that output is independently affected by collimator scatter and total scatter according to the position of the upper jaws and each of the MLC leaves (lower jaws). Then, the two scatter factors are accurately measured when changing their position. Thus, the output factor for an irregular field could be calculated with the new algorithm. We adopted this technique for some irregular fields and actual IMRT fields for head-and-neck cancer and found that the differences between calculated and measured output values were both small and acceptable. This study suggests that our methods and this algorithm are useful for dosimetry quality assurance. PMID:12518100

Tateoka, Kunihiko; Oouchi, Atushi; Nagase, Daiki; Waka, Masaaki; Saikawa, Tsunehiko; Shimizume, Kazunari; Sugimoto, Harumi; Hareyama, Masato

2002-06-01

269

The Ephithermal Neutron Multiplicity Counter Design and Performance Manual: More Rapid Plutonium and Uranium Inventory Verifications by Factors of 5-20  

SciTech Connect

Thermal neutron multiplicity counters (TNMCs) assay {sup 240}Pu-effective mass, isolating spontaneous-fission (SF), induced-fission, and ({alpha},n) neutrons emitted from plutonium metal, oxide, scrap, and residue items. Three independent parameters are measured: single, double, and triple neutron-pulse-coincidence count rates. TNMC assays can become precision limited by high ({alpha},n) neutron rates arising from low-Z impurities and {sup 241}Am. TNMCs capture thermal neutrons in 4-atm {sup 3}He tubes after fast-source-neutron moderation by polyethylene. TNMCs are {approximately}50% efficient with {approximately}-{micro}s die-away times. Simultaneously increasing efficiency and reducing die-away time dramatically improve assay precision. Using 10-atm {sup 3}He tubes, they've developed and performance-tested the first of a new generation of neutron assay counters for a wide range of plutonium items. The Epithermal Neutron Multiplicity Counter (ENMC) has an efficiency of 65% and a 22-{micro}s die-away time. The ENMC detects neutrons before thermalization using higher {sup 3}He pressure counters and less moderator than TNMCs. A special insert raises efficiency to 80% for small samples. For five bulk samples containing 50 to 875 g of {sup 240}Pu-effective, ENMC assay times are reduced by factors of 5 to 21, compared with prior state-of-the-art TNMCs. The largest relative gains are for the most impure items, where gains are needed most. In active mode, the ENMC assay times are reduced by factors of 5 to 11, compared with the Active Well Coincidence Counter (AWCC). The ENMC, with high precision and low multiplicity dead time (37 ns), can be used in standards verification mode to precisely and accurately characterize plutonium standards and isotopic sources. The ENMC's performance is very competitive with calorimetry. This report describes the ENMC; presents results of characterization, calibration, and verification measurements; and shows the clear performance and economic advantages of implementing the ENMC for nuclear materials control and accountability.

J. E. Stewart; H. O. Menlove; D. R. Mayo; W. H. Geist; L. A. Carrillo; G. D. Herrera

2000-08-01

270

Measurement of the neutron electric form factor G[sub E][sup n] in D-vector(e-vector,e[sup [prime  

SciTech Connect

We have determined the electric form factor of the neutron G{sup n}/{sub E} from the reaction D(e, e'n)p using a longitudinally polarized electron beam and a polarized deuterium target at Jefferson Lab's Hall C. The knocked out neutron was detected in coincidence with the electron in a shielded neutron detector. The beam-target asymmetry of quasi-elastically scattered electrons was measured for opposite orientations of the beam helicity which allowed the extraction of G{sup n}/{sub E}. This method is insensitive to the deuteron structure and avoids longitudinal/transverse Rosenbluth separation, both potential sources of large systematic errors. We present the results of a preliminary analysis for G{sup n}/{sub E} at Q{sup 2} = 0.5(GeV/c){sup 2}.

Marko Zeier

2000-12-12

271

Factors associated with the impact of quality improvement collaboratives in mental healthcare: An exploratory study  

PubMed Central

Background Quality improvement collaboratives (QICs) bring together groups of healthcare professionals to work in a structured manner to improve the quality of healthcare delivery within particular domains. We explored which characteristics of the composition, participation, functioning, and organization of these collaboratives related to changes in the healthcare for patients with anxiety disorders, dual diagnosis, or schizophrenia. Methods We studied three QICs involving 29 quality improvement (QI) teams representing a number of mental healthcare organizations in the Netherlands. The aims of the three QICs were the implementation of multidisciplinary practice guidelines in the domains of anxiety disorders, dual diagnosis, and schizophrenia, respectively. We used eight performance indicators to assess the impact of the QI teams on self-reported patient outcomes and process of care outcomes for 1,346 patients. The QI team members completed a questionnaire on the characteristics of the composition, participation in a national program, functioning, and organizational context for their teams. It was expected that an association would be found between these team characteristics and the quality of care for patients with anxiety disorders, dual diagnosis, and schizophrenia. Results No consistent patterns of association emerged. Theory-based factors did not perform better than practice-based factors. However, QI teams that received support from their management and both active and inspirational team leadership showed better results. Rather surprisingly, a lower average level of education among the team members was associated with better results, although less consistently than the management and leadership characteristics. Team views with regard to the QI goals of the team and attitudes towards multidisciplinary practice guidelines did not correlate with team success. Conclusions No general conclusions about the impact of the characteristics of QI teams on the quality of healthcare can be drawn, but support of the management and active, inspirational team leadership appear to be important. Not only patient outcomes but also the performance indicators of monitoring and screening/assessment showed improvement in many but not all of the QI teams with such characteristics. More studies are needed to identify factors associated with the impact of multidisciplinary practice guidelines in mental healthcare.

2012-01-01

272

Quality factors for the nano-mechanical tubes with thermoelastic damping and initial stress  

NASA Astrophysics Data System (ADS)

The Quality factors (Q-factor) are defined as the ratio of the kinetic and potential energy to dissipation for various damping mechanisms of structures. Therefore, improvement in the Q-factors is an important issue in micro- and nano-resonator applications for the high performance. Also, it is well known that the thermoelastic damping is more crucial than the other damping factors in a device. Thus, the vibration of nano-mechanical circular tube is investigated with thermoelastic damping and initial stress effects in this work. To simplify the shell equations for the transverse displacement-dominated problems, the Donnell-Mushtari-Vlasov (DMV) approach is adopted. Applying the stress function, the equations of motion for deflection, compatibility equation and heat conduction equation are derived. Using an iterative scheme, the natural frequencies and the Q-factors under the initial stress are obtained, and the influences of the dimensions of the shell, the mode numbers and initial stress are discussed in detail.

Kim, Sun-Bae; Kim, Ji-Hwan

2011-03-01

273

Factors associated with health-related quality of life among Belgrade University students  

Microsoft Academic Search

Purpose  The aims of the study were to evaluate health-related quality of life (HRQoL) among students of University of Belgrade (Serbia)\\u000a and to identify factors that might have associated with their HRQoL including relationship with depression.\\u000a \\u000a \\u000a \\u000a \\u000a Methods  Between April and June, 2009, 1624 students were enrolled in the cross-sectional study. HRQoL was assessed by using SF-36\\u000a questionnaire and general depressive status by

Aleksandra Popovic; Darija Kisic Tepavcevic; Tatjana Gazibara; Mila Paunic

2011-01-01

274

Chip scale mechanical spectrum analyzers based on high quality factor overmoded bulk acouslic wave resonators  

SciTech Connect

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.

Olsson, R. H., III

2012-03-01

275

Factors affecting perceived quality of life of older persons with self-reported visual disability  

Microsoft Academic Search

Purpose  The purpose of this paper was to determine the extent to which factors thought to be related to quality of life (QoL) among\\u000a older persons with a visual disability impact on their perceived QoL (PQol).\\u000a \\u000a \\u000a \\u000a \\u000a Method  Analysis was conducted on responses from the second wave of a large population-based longitudinal study of those aged 57–72 years\\u000a (i.e., HWR Study). The sample was

Steven La Grow; Fiona Alpass; Christine Stephens; Andrew Towers

2011-01-01

276

Measurements of the Electric Form Factor of the Neutron at Q^2=0.45 and 1.13 (GeV/c)^2  

SciTech Connect

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({approx}e, e0{approx}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 measurements of Gn E at the two higher Q2 values of 1.13 and 1.45 (GeV/c)2 are more precise than prior measurements at lower Q2. In this dissertation, the data analyses and our results for g and Gn E at Q2=0.45 (GeV/c)2 and Q2=1.13 (GeV/c)2 are given. Our high-accuracy data are included with the ?world? data for Gn E to form an improved data set that was fit with an empirical function to give a simple parameterization of Gn E as a function of Q2. In addition, the data for the ratio Gn E/Gn M are compared to theoretical models of the nucleon. We found that no theoretical model predicts both proton and neutron form factor data.

Shigeyuki Tajima

2003-12-31

277

Consistent partial structure factors for amorphous Ni0.33(ZryHf1-y)0.67 using x-ray and neutron diffraction  

NASA Astrophysics Data System (ADS)

We have determined all three partial radial distribution functions for amorphous Ni0.33Zr0.67. Two independent sets of (Faber-Ziman) partial structure factors were obtained, one from x-ray diffraction on seven alloys with Hf isomorphously substituted for Zr and the other from combined x-ray and neutron diffraction on Ni0.33Zr0.67 and Ni0.33Hf0.67. The results are in agreement to better than 4%. Our study confirmed the reliability of the isomorphous substitution method in evaluating the partial structure factors of amorphous Ni-Zr(Hf) alloys providing that the size difference between Hf and Zr is taken into account. As a result, we have derived the Ni-Ni correlations for this composition. The sensitivity of the neutron structure factor to the light Ni atoms has revealed evidence for a Ni-Zr-Ni correlation beyond the first-neighbor shell.

Xu, Yan; Muir, W. B.; Altounian, Z.; Buyers, W. J. L.; Donaberger, R. L.

1996-04-01

278

Neutron interactions with biological tissue. Final report  

SciTech Connect

This program was aimed at creating a quantitative physical description, at the micrometer and nanometer levels, of the physical interactions of neutrons with tissue through the ejected secondary charged particles. The authors used theoretical calculations whose input includes neutron cross section data; range, stopping power, ion yield, and straggling information; and geometrical properties. Outputs are initial and slowing-down spectra of charged particles, kerma factors, average values of quality factors, microdosimetric spectra, and integral microdosimetric parameters such as {bar y}{sub F}, {bar y}{sub D}, y{sup *}. Since it has become apparent that nanometer site sizes are also relevant to radiobiological effects, the calculations of event size spectra and their parameters were extended to these smaller diameters. This information is basic to radiological physics, radiation biology, radiation protection of workers, and standards for neutron dose measurement.

NONE

1998-02-17

279

Spin Assignments, Mixing Ratios, and g-FACTORS in Neutron Rich 252Cf Fission Products  

NASA Astrophysics Data System (ADS)

We present a new technique for measuring angular correlations between ?-rays emitted by the fragments from the spontaneous fission of 252Cf and measured with Gammasphere. For states with short lifetimes (?10ps), these correlations can be used to determine the spin and parity of unknown levels. For states with long lifetimes, the technique can be used to determine the g-factor of the level in question by measuring the attenuation of the correlation caused by rotation of the nucleus about the randomly oriented domains in an un-magnetized iron foil. Applying our new method to our set of triple coincidence data, we have been able to assign spins to new levels in 108,110,112Ru. Mixing ratio and g-factor measurements are also discussed.

Goodin, C.; Daniel, A. V.; Li, K.; Ramayya, A. V.; Hwang, J. K.; Hamilton, J. H.; Stone, N. J.; Stone, J. R.; Rasmussen, J. O.

2008-08-01

280

Measuring research quality using the journal impact factor, citations and ‘Ranked Journals’: blunt instruments or inspired metrics?  

Microsoft Academic Search

This paper examines whether three bibliometric indicators—the journal impact factor, citations per paper and the Excellence in Research for Australia (ERA) initiative's list of ‘ranked journals’—can predict the quality of individual research articles as assessed by international experts, both overall and within broad disciplinary groupings. The analysis is based on data obtained from a Mock Research Quality Framework (RQF) exercise

Som D. Jarwal; Andrew M. Brion; Maxwell L. King

2009-01-01

281

A Friend in NeedThe Role of Friendship Quality as a Protective Factor in Peer Victimization and Bullying  

Microsoft Academic Search

This study examined friendship quality as a possible moderator of risk factors in predicting peer victimization and bullying. Children (50 boys and 49 girls, ages 10 to 13 years) reported on the quality of their best friendship, as well as their bullying and victimization tendencies. Parents reported on their child’s internalizing and externalizing behaviors, in addition to bullying and victimization

Julie M. Bollmer; Richard Milich; Monica J. Harris; Melissa A. Maras

2005-01-01

282

A Friend in Need: The Role of Friendship Quality as a Protective Factor in Peer Victimization and Bullying  

Microsoft Academic Search

This study examined friendship quality as a possible moderator of risk factors in predicting peer victimization and bullying. Children (50 boys and 49 girls, ages 10 to 13 years) reported on the quality of their best friendship, as well as their bullying and victimization tendencies. Parents reported on their child’s internalizing and externalizing behaviors, in addition to bullying and victimization

Julie M. Bollmer; Richard Milich; Monica J. Harris; Melissa A. Maras

2005-01-01

283

Examining the Relationship between Global and Domain Measures of Quality of Life by Three Factor Structure Models  

ERIC Educational Resources Information Center

|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…

Wu, Chia-Huei; Yao, Grace

2007-01-01

284

Factors contributing to the implicit dynamic quality of static abstract designs.  

PubMed

Participants rated the dynamic quality of a set of twelve-element nonrepresentational or abstract visual designs each composed of one of four types of triangles or four types of quadrilaterals. We investigated the contribution to the perceived or implicit dynamics of the design of the four factors edge alignment of compositional elements, physical weight distribution about the horizontal axis, activity directions within the designs, and type of compositional element. It was found that edge alignment of elements was the most influential factor contributing to the dynamics both of triangle and of quadrilateral designs. In addition, dynamics was found to be positively correlated with the number of perceived activity directions within both types of stimuli. Triangle designs, but not quadrilateral ones, with greater structural weight above the horizontal axis were rated as more dynamic. Results suggest that implicit dynamics of nonrepresentational designs arises from a percept based on a global spatial analysis of the stimulus characteristics studied. PMID:12375874

Locher, Paul J; Stappers, Pieter Jan

2002-01-01

285

An optical nanocavity incorporating a fluorescent organic dye having a high quality factor.  

PubMed

We have fabricated an L3 optical nanocavity operating at visible wavelengths that is coated with a thin-film of a fluorescent molecular-dye. The cavity was directly fabricated into a pre-etched, free-standing silicon-nitride (SiN) membrane and had a quality factor of Q = 2650. This relatively high Q-factor approaches the theoretical limit that can be expected from an L3 nanocavity using silicon nitride as a dielectric material and is achieved as a result of the solvent-free cavity-fabrication protocol that we have developed. We show that the fluorescence from a red-emitting fluorescent dye coated onto the cavity surface undergoes strong emission intensity enhancement at a series of discrete wavelengths corresponding to the cavity modes. Three dimensional finite difference time domain (FDTD) calculations are used to predict the mode structure of the cavities with excellent agreement demonstrated between theory and experiment. PMID:20499907

Adawi, Ali M; Murshidy, Mohamed M; Fry, Paul W; Lidzey, David G

2010-06-22

286

Mediators of Maternal Depression and Family Structure on Child BMI: Parenting Quality and Risk Factors for Child Overweight  

Microsoft Academic Search

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

Regina L. McConley; Sylvie Mrug; M. Janice Gilliland; Richard Lowry; Marc N. Elliott; Mark A. Schuster; Laura M. Bogart; Luisa Franzini; Soledad L. Escobar-Chaves; Frank A. Franklin

2011-01-01

287

Factors Relating to Quality of Life After Esophagectomy for Cancer Patients in Taiwan.  

PubMed

BACKGROUND:: Little is known regarding the short-term quality of life (QoL) and predictive factors for QoL after esophagectomy for cancer in Eastern countries. OBJECTIVE:: The aims of this study were to assess QoL and symptoms within 1 and 6 months after surgery for esophageal cancer (EC) and to identify factors predictive of QoL within 6 months after esophagectomy in Taiwan. METHODS:: A longitudinal, prospective design was used, where convenience samples of 99 patients who had undergone esophagectomy for cancer were recruited from 2 medical centers in northern Taiwan. All participants responded to a questionnaire with a QLQ-C30 (Quality of Life Questionnaire-Cancer) core and a QLQ-OES18 (esophageal module of the European Organization for Research and Treatment [EORTC] QLQ-C30) module in structured interviews at baseline and 1 and 6 months after surgery. RESULTS:: The results showed significant decline in social function and global QoL; fatigue, insomnia, eating problems, reflux, and dry mouth were major problems within 6 months. Body mass index, body weight loss before surgery, activity performance status, and anastomosis site showed no significant association with the function and symptom aspect of QoL. Surgical complications, advanced cancer, neoadjuvant therapy before surgery, and tumor location other than at the EC junction had significant deleterious effects on several aspects of QoL. CONCLUSIONS:: This study describes the demographics of EC and short-term changes in QoL and also the predictive impact factor for QoL after surgery for EC. IMPLICATIONS FOR PRACTICE:: Knowledge of risk factors for poor postoperative QoL would be useful for health providers in detecting and prioritizing problems and treatment options in a busy clinical site. PMID:23357884

Chang, Yu-Ling; Tsai, Yun-Fang; Wu, Yi-Cheng; Hsieh, Ming-Ju

2013-01-25

288

Theoretical and empirical quality assessment of transcription factor-binding motifs  

PubMed Central

Position-specific scoring matrices (PSSMs) are routinely used to predict transcription factor (TF)-binding sites in genome sequences. However, their reliability to predict novel binding sites can be far from optimum, due to the use of a small number of training sites or the inappropriate choice of parameters when building the matrix or when scanning sequences with it. Measures of matrix quality such as E-value and information content rely on theoretical models, and may fail in the context of full genome sequences. We propose a method, implemented in the program ‘matrix-quality’, that combines theoretical and empirical score distributions to assess reliability of PSSMs for predicting TF-binding sites. We applied ‘matrix-quality’ to estimate the predictive capacity of matrices for bacterial, yeast and mouse TFs. The evaluation of matrices from RegulonDB revealed some poorly predictive motifs, and allowed us to quantify the improvements obtained by applying multi-genome motif discovery. Interestingly, the method reveals differences between global and specific regulators. It also highlights the enrichment of binding sites in sequence sets obtained from high-throughput ChIP-chip (bacterial and yeast TFs), and ChIP–seq and experiments (mouse TFs). The method presented here has many applications, including: selecting reliable motifs before scanning sequences; improving motif collections in TFs databases; evaluating motifs discovered using high-throughput data sets.

Medina-Rivera, Alejandra; Abreu-Goodger, Cei; Thomas-Chollier, Morgane; Salgado, Heladia; Collado-Vides, Julio; van Helden, Jacques

2011-01-01

289

High quality factor mg-scale silicon mechanical resonators for 3-mode optoacoustic parametric amplifiers  

NASA Astrophysics Data System (ADS)

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.

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

290

Using condition factor and blood variable biomarkers in fish to assess water quality.  

PubMed

The condition factor and blood variables, including erythrocyte lipid peroxidation (LPO) and the activity of antioxidant enzymes such as superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx), in two ecologically distinct fish species (Astyanax fasciatus and Pimelodus maculatus) were evaluated at five sites in the Furnas Hydroelectric Power Station reservoir (Brazil) to assess water quality. Aldrin/dieldrin, endosulfan, heptachlor epoxide, and metolachlor were detected at different concentrations in four of the sites. Condition factor was not directly affected by such contaminants. A negative correlation between hematocrit and heptachlor was detected in P. maculatus. Positive correlations between red blood cells and heptachlor as well as an interactive effect of metolachlor and aldrin/dieldrin were detected in A. fasciatus. The erythrocytes of both species collected from the contaminated sites showed high levels of LPO, an increase in SOD and GPx activities and a decrease in CAT activity. Although the leukocyte number and the differential percentage of leukocytes varied among the sites, the hematological variables, the LPO levels, and the antioxidant enzyme activities could be used to assess water quality, regardless of the differences in the responses of the fish species. PMID:21152972

Sadauskas-Henrique, Helen; Sakuragui, Marise M; Paulino, Marcelo G; Fernandes, Marisa N

2010-12-09

291

Quality-Shaping Factors and Endodontic Treatment amongst General Dental Practitioners with a Focus on Denmark.  

PubMed

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

Demant, Sune; Markvart, Merete; Bjørndal, Lars

2012-03-26

292

The influence of different technique factors on image quality of chest radiographs as evaluated by modified CEC image quality criteria  

Microsoft Academic Search

The Commission of the European Communities (CEC) research project ''Predictivity and optimisation in medical radiation protection'' addressed fundamental operational limitations in existing radiation protection mechanisms. The first part of the project aimed at investigating (1) whether the CEC image quality criteria could be used for optimization of a radiographic process and (2) whether significant differences in image quality based on

B LANHEDE; MB ATH; S KHEDDACHE; P SUND; L BJORNELD; M WIDELL; A ALMEN; J BESJAKOV; S MATTSSON; A TINGBERG; W PANZER; M ZANKL

293

Dissection of genetic and environmental factors involved in tomato organoleptic quality  

PubMed Central

Background One of the main tomato breeding objectives is to improve fruit organoleptic quality. However, this task is made somewhat challenging by the complex nature of sensory traits and the lack of efficient selection criteria. Sensory quality depends on numerous factors, including fruit colour, texture, aroma, and composition in primary and secondary metabolites. It is also influenced by genotypic differences, the nutritional regime of plants, stage of ripening at harvest and environmental conditions. In this study, agronomic, biochemical and sensory characterization was performed on six Italian heirlooms grown in different environmental conditions. Result We identified a number of links among traits contributing to fruit organoleptic quality and to the perception of sensory attributes. PCA analysis was used to highlight some biochemical, sensory and agronomic discriminating traits: this statistical test allowed us to identify which sensory attributes are more closely linked to environmental conditions and those, instead, linked to the genetic constitution of tomato. Sweetness, sourness, saltiness and tomato flavour are not only grouped in the same PCA factor, but also result in a clear discrimination of tomato ecotypes in the three different fields. The three different traditional varieties cluster on the basis of attributes like juiciness, granulosity, hardness and equatorial diameter, and are therefore more closely related to the genetic background of the cultivar. Conclusion This finding suggests that a different method should be undertaken to improve sensory traits related to taste perception and texture. Our results might be used to ascertain in what direction to steer breeding in order to improve the flavour characteristics of tomato ecotypes.

2011-01-01

294

Factors affecting the incidence of first-quality wheels of Trentingrana cheese.  

PubMed

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 smaller associated farms, and showed lower variation across years and seasons of production. Results support the relevance of routinely assessing and monitoring the quality of Trentingrana cheese. PMID:21700060

Bittante, G; Cecchinato, A; Cologna, N; Penasa, M; Tiezzi, F; De Marchi, M

2011-07-01

295

Determination of the neutron electric form factor G{sub En} in double polarized electron scattering from {sup 3}H  

SciTech Connect

The neutron electric form factor G{sub En} has been measured at the cw electron accelerator MAMI in the double polarized exclusive reactions {sup 3}H-vectore(e-vector,e{sup '}n) and D(e-vector,e{sup '}n-vector) in quasi elastic kinematics with one common detector system. Experimental set-up and analysis of a {sup 3}H-vectore(e-vector,e{sup '}n)-measurement in the range of momentum transfer Q{sup 2}=0.27-0.5 (GeV/c){sup 2} are discussed in this article. For events with low missing momentum (|P-vector{sub m}|{<=}100 MeV/c) the PWIA analysis yields G{sub En}=0.0352{+-}0.0033{+-}0.0024 with statistical and systematical error, corresponding to a quadratically added total error of 11.6% relativ. This result will be compared with preliminary results obtained from the D(e-vector,e{sup '}n-vector)-reaction and with data from elastic D(e,e{sup '}) scattering.

Andresen, H. G.; Blume-Werry, J.; Dombo, Th.; Eyl, D.; Frey, A.; Hartmann, P.; Herberg, C.; Moeller, H.; Ostrick, M.; Schmieden, H.; Sprengard, R.; Steffens, K.-H.; Walcher, Th. [Institut fuer Kernphysik, Universitaaet Mainz (Germany); Annand, J.; Hall, S.; Ireland, D.; Kellie, J.; Miller, G.; Owens, R. O.; Watson, R. [Department of Physics and Astronomy, University of Glasgow, Scotland (United Kingdom)] (and others)

1998-01-20

296

Biological effectiveness of neutron irradiation on animals and man  

SciTech Connect

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.

Straume, T.

1982-11-01

297

Three factors that influence the overall quality of the stereoscopic 3D content: image quality, comfort, and realism  

NASA Astrophysics Data System (ADS)

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.

Vlad, Raluca; Ladret, Patricia; Guérin, Anne

2013-01-01

298

Beyond air quality--factors that affect prevalence estimates of sick building syndrome.  

PubMed

If the prevalence of sick building syndrome (SBS) is estimated before intervention begins, then a reduction in the estimate may later be used to measure success of the intervention, and in particular, those efforts toward improving air quality. However, the measure of success will be distorted if factors other than air quality affect the SBS prevalence estimate. In this study the background prevalence of SBS was estimated and study factors identified that alone affected the estimate. Two symptom questionnaires were randomly administered to workers from 39 offices before routine physical examinations; one questionnaire described the SBS study, the other did not. SBS was defined as a symptom in the prior 24-hour or 7-day recall period that was more severe at work and not related to suspected confounders--allergy, cold, flu. Prevalence and prevalence ratios were estimated along with 95% confidence intervals (CI). Symptoms were reported by 45% of 1088 workers surveyed, but most reported them as more severe outside work or related them to confounders. SBS prevalence was 5%. It was 3.2 times higher (95% CI: 1.8, 5.7) among workers cognizant of the study relative to those blinded, 2.2 times higher (95% CI: 1.2, 4.1) for the 7-day relative to the 24-hour recall period, and 2.5 times higher (95% CI: 1.4, 5.0) for females. SBS prevalence did not differ by workday or age. Since study factors alone affected prevalence estimates, a standardized assessment method seems necessary for SBS. PMID:7502997

Mikatavage, M A; Rose, V E; Funkhouser, E; Oestenstad, R K; Dillon, K; Reynolds, K D

1995-11-01

299

"Out of Sight, Out of Mind": Housestaff Perceptions of Quality-Limiting Factors in Discharge Care at Teaching Hospitals  

PubMed Central

BACKGROUND Improving hospital discharge has become a national priority for teaching hospitals, yet little is known about physician perspectives on factors limiting the quality of discharge care. OBJECTIVES To describe the discharge process from the perspective of housestaff physicians, and to generate hypotheses about quality-limiting factors and key strategies for improvement. METHODS Qualitative study with in-depth, in-person interviews with a diverse sample of 29 internal medicine housestaff, in 2010–2011, at 2 separate internal medicine training programs, including 7 different hospitals. We used the constant comparative method of qualitative analysis to explore the experiences and perceptions of factors affecting the quality of discharge care. RESULTS We identified 5 unifying themes describing factors perceived to limit the quality of discharge care: (1) competing priorities in the discharge process; (2) inadequate coordination within multidisciplinary discharge teams; (3) lack of standardization in discharge procedures; (4) poor patient and family communication; and (5) lack of postdischarge feedback and clinical responsibility. CONCLUSIONS Quality-limiting factors described by housestaff identified key processes for intervention. Establishment of clear standards for discharge procedures, including interdisciplinary teamwork, patient communication, and postdischarge continuity of care, may improve the quality of discharge care by housestaff at teaching hospitals.

Greysen, S. Ryan; Schiliro, Danise; Horwitz, Leora I.; Curry, Leslie; Bradley, Elizabeth H.

2012-01-01

300

Multivariate statistical analysis to identify the major factors governing groundwater quality in the coastal area of Kimje, South Korea  

Microsoft Academic Search

The main purpose of this study is to identify the major factors affecting groundwater quality by means of multivariate statistical analysis of the physico-chemical compositions. Cluster analysis results show that the groundwater in the study area is classified into four groups (A, B, C and D), and factor analysis indicates that groundwater composition, 81.9% of the total variance of 17

Ji-Hoon Kim; Rak-Hyeon Kim; Jeongho Lee; Tae-Jin Cheong; Byoung-Woo Yum; Ho-Wan Chang

2005-01-01

301

Perforated diode neutron sensors  

NASA Astrophysics Data System (ADS)

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.

McNeil, Walter J.

302

g factor measurements of mus isomeric states in neutron-rich nuclei around 68Ni produced in projectile-fragmentation reactions  

Microsoft Academic Search

We report the first g factor measurement on microsecond isomers of neutron-rich nuclei produced in projectile-fragmentation reactions at intermediate energies. The nuclides in the vicinity of 68Ni were produced and spin oriented following the fragmentation of a 76Ge, 61.4 MeV u-1 beam at GANIL. The LISE spectrometer was used to select the nuclei of interest. The time-dependent perturbed angular distribution

G. Georgiev; G. Neyens; M. Hass; D. L. Balabanski; C. Bingham; C. Borcea; N. Coulier; R. Coussement; J. M. Daugas; G. DeFrance; F. de Oliveira Santos; M. Górska; H. Grawe; R. Grzywacz; M. Lewitowicz; H. Mach; I. Matea; R. D. Page; M. Pfützner; Yu E. Penionzhkevich; Z. Podolyák; P. H. Regan; K. Rykaczewski; M. Sawicka; N. A. Smirnova; Yu G. Sobolev; M. Stanoiu; S. Teughels; K. Vyvey

2002-01-01

303

Neutron multiplication factor and calculational bias from ²⁵²Cf source-driven frequency analysis measurements with subcritical arrays of PWR fuel pins  

Microsoft Academic Search

The ability of the ²⁵²Cf-source-driven noise analysis method to measure the subcritical neutron multiplication factor has been demonstrated for a variety of experimental configurations of fissile materials. In 1983 a measurement was performed at the critical experiments facility of the Babcox and Wilcox Company, Lynchburg, Virginia, with an array of 2.46 wt% ²³⁵U enriched pressurized water reactor (PWR) fuel pins

T. E. Valentine; J. T. Mihalczo; W. T. King; E. D. Blakeman

1996-01-01

304

[Analysis on the key water quality factors to phytoplankton community in Wujingang Region of Taihu Lake].  

PubMed

Field investigations on the phytoplankton community were carried out in July 2009 and January 2010 in Wujingang Region of Taihu Lake (WRTL). Results show that there are 46 genus, 24 families and 6 phylum phytoplankton were identified in wet season, which is mainly composed of the Chlorophyta and Cyanophyta, the average phytoplankton abundance of this season is 14. 8 x 10(6) cell/L. There are 29 genus, 18 families and 5 phylum phytoplankton were found in level season, and Diatoms were the dominant category, the average phytoplankton abundance of the season is 3 113 cell/L. It shows that a remarkable discrepancy in community and density between the two seasons. The principal component analysis (PCA) and canonical correspondence analysis (CCA) were used to assess the phytoplankton community structure with regard to 8 aquatic environmental factors and their spatial distribution, which result on the key aquatic environmental quality factors show that NH4(+) -N and TN were the most extraordinary pollution factors which affect the phytoplankton community and WRTL was in extrophication level. PMID:21922813

Su, Yu; Wen, Hang; Wang, Dong-Wei; Sun, Jin-Hua; Huang, Yi

2011-07-01

305

Morning-evening type and burnout level as factors influencing sleep quality of shift nurses: a questionnaire study  

PubMed Central

Aim To assess the relationship between sleep quality and demographic variables, morning-evening type, and burnout in nurses who work shifts. Methods We carried out a cross-sectional self-administered study with forced choice and open-ended structured questionnaires – Pittsburg Sleep Quality Index, Morningness-eveningness Questionnaire, and Maslach Burnout Inventory. The study was carried out at Gazi University Medicine Faculty Hospital of Ankara on 524 invited nurses from July to September 2008, with a response rate of 89.94% (n?=?483). Descriptive and inferential statistics were applied to determine the risk factors of poor sleep quality. Results Most socio-demographic variables did not affect sleep quality. Participants with poor sleep quality had quite high burnout levels. Most nurses who belonged to a type that is neither morning nor evening had poor sleep quality. Nurses who experienced an incident worsening their sleep patterns (P?quality. The subjective sleep quality and sleep latency points of evening types within created models for the effect of burnout dimensions were high. Conclusions Nurses working consistently either in the morning or at night had better sleep quality than those working rotating shifts. Further studies are still needed to develop interventions that improve sleep quality and decrease burnout in nurses working shifts.

Demir Zencirci, Ayten; Arslan, Sumeyye

2011-01-01

306

Microstructured semiconductor neutron detectors  

NASA Astrophysics Data System (ADS)

Perforated semiconductor neutron detectors are compact diode detectors that operate at low power and can be fashioned to have high thermal neutron detection efficiency. Fabricated from high-purity Si wafers, the perforations are etched into the diode surface with ICP-RIE and backfilled with 6LiF neutron reactive material. The intrinsic thermal neutron detection efficiency depends upon many factors, including the perforation geometry, size, and depth. Devices were fabricated from high resistivity 10k? cm n-type Si with conformal p-type shallow junction diffusions into the perforations, which demonstrate improved neutron detection performance over previous selectively diffused designs. A comparison was made to previous selectively diffused designs, and pulse height spectra show improved signal-to-noise ratio, higher neutron counting efficiency, and excellent gamma-ray discrimination. Devices with 20(average)?m wide 100?m deep sinusoidal trenches yielded intrinsic thermal neutron detection efficiencies of 11.94±0.078%.

McGregor, D. S.; McNeil, W. J.; Bellinger, S. L.; Unruh, T. C.; Shultis, J. K.

2009-09-01

307

Varying Cavity Quality Factor in situ for a Transmon in Circuit QED  

NASA Astrophysics Data System (ADS)

Superconducting transmon qubits have recently been studied within 3D cavities. In addition to increasing the coherence times of the qubits this has enabled a simple scheme for varying the quality factor Q (or decay rate ?) of a cavity in situ. This decay rate plays an important role in our understanding of a number of effects in circuit quantum electrodynamics, many of which have direct bearing on qubit decoherence processes. Here we study how adjusting the cavity Q affects the coherence times of a single qubit within the 3D architecture. We demonstrate that varying the coupling enables us to not only examine the limitations of qubit T1 due to the Purcell Effect, but also probe new decoherence mechanisms such as the dephasing due to photon shot noise. By understanding and minimizing these effects, we obtain record coherences times T2 and T2^Echo of ˜27 ?s and ˜47 ?s respectively.

Petrenko, Andrei; Sears, Adam; Kirchmair, Gerhard; Paik, Hanhee; Sun, Luyan; Catelani, Gianluigi; Glazman, Leonid; Schoelkopf, Robert

2012-02-01

308

High quality factor two dimensional GaN photonic crystal cavity membranes grown on silicon substrate  

NASA Astrophysics Data System (ADS)

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.

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

309

High quality factor AlN nanocavities embedded in a photonic crystal waveguide  

NASA Astrophysics Data System (ADS)

We present a spectroscopic study of nanocavities obtained by small modifications of a W1 waveguide in an AlN photonic crystal membrane. The AlN film containing GaN quantum dots is grown on silicon. The photonic crystal structure is defined by e-beam lithography and etched by inductively coupled plasma reactive ion etching, while the membrane is released by selective etching of the silicon substrate. The room temperature photoluminescence of the embedded quantum dots reveals the existence of even-symmetry and odd-symmetry confined cavity modes and guided modes. Cavity mode quality factors up to 4400 at 395 nm and 2300 at 358 nm are obtained.

Sam-Giao, D.; Néel, D.; Sergent, S.; Gayral, B.; Rashid, M. J.; Semond, F.; Duboz, J. Y.; Mexis, M.; Guillet, T.; Brimont, C.; David, S.; Checoury, X.; Boucaud, P.

2012-05-01

310

Ultra-high quality factor planar Si3N4 ring resonators on Si substrates.  

PubMed

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. PMID:21747510

Tien, Ming-Chun; Bauters, Jared F; Heck, Martijn J R; Spencer, Daryl T; Blumenthal, Daniel J; Bowers, John E

2011-07-01

311

Beam Formation and Characterization for Neutron Radiography  

Microsoft Academic Search

Neutron flux and geometrical parameters (L\\/D and D) have been used as principal parameters to characterize a neutron beam. The parameters are also important from the standpoint of obtaining a neutron beam which provides a high quality image. Aneffective energy of the neutron beam, which is easily modulated by insertion of filters, is also important, and the quantification of these

H. Kobayashi; R. H. Plaut

2001-01-01

312

Factors affecting quality of life in epilepsy in a multi-ethnic urban population.  

PubMed

We examined factors associated with quality of life (QOL) among predominantly ethnic minority, low-income patients with epilepsy (PWE). Ninety-four PWE ?14years old completed standardized questionnaires, including the QOLIE-31. The patients were born in 17 countries, and most of them identified culturally with the United States (44%), the Caribbean (35%), or Latin America (9%). Fifty-three percent of patients received no income other than public assistance. The mean QOLIE-31 score for all subjects was 57.6 (SD: 15.1). A step-wise regression analysis revealed that of 11 possible predictor variables, only perceived epilepsy stigma, seizure frequency, and gender were significantly associated with the QOLIE-31 score and respectively accounted for 16%, 9%, and 5% of its variance. These results suggest that perceived epilepsy stigma is at least as important as seizure freedom in determining quality of life, at least in some populations of PWE. Epilepsy health care providers should take every opportunity to help patients overcome and reduce perceived stigma. PMID:23507303

Grant, Arthur C; Prus, Nehama; Nakhutina, Luba

2013-03-17

313

Factors determining milk quality and implications for production structure under somatic cell count standard modification.  

PubMed

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. PMID:22981577

Dong, F; Hennessy, D A; Jensen, H H

2012-09-12

314

Neutronic design of a fission converter-based epithermal neutron beam for neutron capture therapy  

Microsoft Academic Search

To meet the needs for neutron capture theory (NCT) irradiations, a high-intensity, high-quality fusion converter-based epithermal neutron beam has been designed for the MITR-II research reactor. This epithermal neutron beam, capable of delivering treatments in a few minutes with negligible background contamination from fast neutrons and photons, will be installed in the present thermal column and hohlraum of the 5-MW

W. S. Kiger; S. Sakamoto; O. K. Harling

1999-01-01

315

Rootstock as a fruit quality factor in citrus and deciduous tree crops  

Microsoft Academic Search

This mini?review provides a definition of fruit quality, a comparison of rootstock effects and importance in deciduous and citrus crops, and a detailed examination of fruit quality in relation to citrus rootstocks. Fruit quality is defined in simple, complex, and specific terms recognising that it is eventually a matter of consumer preference. When fruit quality is measured as physical traits

William S. Castle

1995-01-01

316

Health-related quality of life and its associated factors in Chinese myocardial infarction patients.  

PubMed

Background: Healthcare providers are called on to assess and improve the health-related quality of life (HRQL) of patients with myocardial infarction (MI). However, there is lack of empirical data on HRQL of such individuals in mainland China. The purpose of this study is to assess HRQL and identify associated factors in hospitalized Chinese MI patients.Methods: A single group, cross-sectional design was adopted with a sample of 192 hospitalized MI patients at two teaching hospitals in Xi'an, People's Republic of China. HRQL was assessed using the Chinese Mandarin versions of the Short Form 36 health survey (SF-36), the Myocardial Infarction Dimensional Assessment Scale (MIDAS), and the Hospital Anxiety and Depression Scale (HADS).Results: Chinese MI patients reported poor HRQL as measured by both the generic (SF-36) and disease-specific (MIDAS) instruments. Advancing age and the presence of heart failure, anxiety, and depression were significant predictors of overall HRQL. Smoking and hypertension were significant predictors of the physical aspects of HRQL.Conclusions: Assessing HRQL of hospitalized Chinese MI patients and identifying associated factors may help health professionals in the design and delivery of appropriately tailored and culturally relevant interventions to this group of patients. PMID:22767965

Wang, Wenru; Thompson, David R; Ski, Chantal F; Liu, Meili

2012-07-01

317

Identifying key factors in homeowner's adoption of water quality best management practices.  

PubMed

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. PMID:23609309

Brehm, Joan M; Pasko, Danielle K; Eisenhauer, Brian W

2013-04-23

318

Quality of life and factors related to perceived satisfaction with quality of life after allogeneic bone marrow transplantation  

Microsoft Academic Search

The quality of life after bone marrow transplantation (BMT) was studied in 109 adult allogeneic BMT recipients transplanted on at the Helsinki University Central hospital for a haematological malignancy. Physical, functional, emotional and social well-being was measured on the Functional Assessment of Cancer Therapy Scale (FACT-BMT) and a shortened version of the Profile of Mood States Scale (POMS) and by

Heikki Heinonen; Liisa Volin; Antti Uutela; Michael Zevon; Chris Barrick; Tapani Ruutu

2001-01-01

319

A directional dose equivalent monitor for neutrons.  

PubMed

A directional dose equivalent monitor is introduced which consists of a 30 cm diameter spherical phantom hosting a superheated drop detector embedded at a depth of 10 mm. The device relies on the similarity between the fluence response of neutron superheated drop detectors based on halocarbon-12 and the quality-factor-weighted kerma factor. This implies that these detectors can be used for in-phantom dosimetry and provide a direct reading of dose equivalent at depth. The directional dose equivalent monitor was characterised experimentally with fast neutron calibrations and numerically with Monte Carlo simulations. The fluence response was determined at angles of 0, 45, 90, 135 and 180 degrees for thermal to 20 MeV neutrons. The response of the device is closely proportional to the fluence-to-directional dose equivalent conversion coefficient, h'phi (10; alpha, E). Therefore, our monitor is suitable for a direct measurement of neutron directional dose equivalent, H'(10), regardless of angle and energy distribution of the neutron fluence. PMID:11548358

d'Errico, F; Alberts, W G; Curzio, G; Matzke, M; Nath, R; Siebert, B R

2001-01-01

320

Factors Associated With Nursing Assistant Quality-of-Life Ratings for Residents With Dementia in Long-Term Care Facilities  

Microsoft Academic Search

Purpose: We identify resident, nursing assistant, and facility factors associated with nursing assistant quality-of-life ratings for residents with dementia in long-term care. Design and Methods: We used a cross-sectional survey of 143 nursing assistants providing care to 335 residents in 38 residential care\\/assisted living (RC\\/AL) facilities and nursing homes in four states. We assessed resident quality of life by using

Gary S. Winzelberg; Christianna S. Williams; John S. Preisser; Sheryl Zimmerman; Philip D. Sloane

2005-01-01

321

Factors that impact health-related quality of life in adults with celiac disease: A multicenter study  

Microsoft Academic Search

AIM: To evaluate the factors involved in the impairment of health-related quality of life (HRQOL) in patients with celiac disease. METHODS: A multicenter, cross-sectional prospective study was performed in patients with celiac disease who completed two HRQOL questionnaires: the gastrointestinal quality of life index (GIQLI) and the EuroQol-5D (EQ). RESULTS: Three hundred and forty patients (163 controlled with a gluten-free

F Casellas; L Rodrigo; J López Vivancos; S Riestra; C Pantiga; JS Baudet; F Junquera; V Puig Diví; C Abadia; M Papo; J Gelabert; Vivancos JL; Baudet JS

2008-01-01

322

Overcoming Si3N4 film stress limitations for high quality factor ring resonators.  

PubMed

Silicon nitride (Si3N4) ring resonators are critical for a variety of photonic devices. However the intrinsically high film stress of silicon nitride has limited both the optical confinement and quality factor (Q) of ring resonators. We show that stress in Si3N4 films can be overcome by introducing mechanical trenches for isolating photonic devices from propagating cracks. We demonstrate a Si3N4 ring resonator with an intrinsic quality factor of 7 million, corresponding to a propagation loss of 4.2 dB/m. This is the highest quality factor reported to date for high confinement Si3N4 ring resonators in the 1550 nm wavelength range. PMID:24104169

Luke, Kevin; Dutt, Avik; Poitras, Carl B; Lipson, Michal

2013-09-23

323

Stage number and refractive index dependence of the quality factor of the localized electromagnetic eigenmodes in the Menger sponge fractal.  

PubMed

The eigenfrequency and quality factor of the localized electromagnetic modes of the dielectric Menger sponge fractal were investigated theoretically for stage number 1 to 4 with a dielectric constant of 2.8 to 12.0 in the normalized frequency range of omegaa/2 pic = 0.4 to 1.6, where a is the size of the Menger sponge and c is the light speed in free space. It was found that the quality factor of the eigenmode is larger on average when the spatially averaged dielectric constant of the fractal structure is larger, which is consistent with the mechanism of the usual refractive index confinement. Particularly the largest quality factor of 1720 was found for stage 1. These features imply that the fractal nature is irrelevant to the localization in this frequency range. The theoretical results are compared with previous experimental observation and the reason for their discrepancy is discussed. PMID:19532416

Sakoda, Kazuaki

2007-02-19

324

Pre-adoptive Factors Predicting Lesbian, Gay, and Heterosexual Couples' Relationship Quality Across the Transition to Adoptive Parenthood  

PubMed Central

The current study examined pre-adoptive factors as predictors of relationship quality (love, ambivalence, and conflict) among 125 couples (44 lesbian couples, 30 gay couples, and 51 heterosexual couples) across the first year of adoptive parenthood. On average, all new parents experienced declines in their relationship quality across the first year of parenthood, regardless of sexual orientation, with women experiencing steeper declines in love. Parents who, pre-adoption, reported higher levels of depression, greater use of avoidant coping, lower levels of relationship maintenance behaviors, and less satisfaction with their adoption agencies reported lower relationship quality at the time of the adoption. The effect of avoidant coping on relationship quality varied by gender. Parents who, pre-adoption, reported higher levels of depression, greater use of confrontative coping, and higher levels of relationship maintenance behaviors reported greater declines in relationship quality. These findings have implications for professionals who work with adoptive parents both pre- and post-adoption.

Goldberg, Abbie E.; Smith, JuliAnna Z.; Kashy, Deborah A.

2010-01-01

325

Producing persistent, high-current, high-duty-factor H{sup -} beams for routine 1 MW operation of Spallation Neutron Source (invited)  

SciTech Connect

Since 2009, the Spallation Neutron Source (SNS) has been producing neutrons with ion beam powers near 1 MW, which requires the extraction of {approx}50 mA H{sup -} ions from the ion source with a {approx}5% duty factor. The 50 mA are achieved after an initial dose of {approx}3 mg of Cs and heating the Cs collar to {approx}170 deg. C. The 50 mA normally persist for the entire 4-week source service cycles. Fundamental processes are reviewed to elucidate the persistence of the SNS H{sup -} beams without a steady feed of Cs and why the Cs collar temperature may have to be kept near 170 deg. C.

Stockli, Martin P.; Han, B. X.; Hardek, T. W.; Kang, Y. W.; Murray, S. N.; Pennisi, T. R.; Piller, C.; Santana, M.; Welton, R. [Spallation Neutron Source, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States)

2012-02-15

326

Reference dosimetry condition and beam quality correction factor for CyberKnife beam  

SciTech Connect

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.

Kawachi, Toru; Saitoh, Hidetoshi; Inoue, Mitsuhiro; Katayose, Tetsurou; Myojoyama, Atsushi; Hatano, Kazuo [Tokyo Metropolitan University Graduate School of Human Health Sciences, Tokyo, Japan and Chiba Cancer Center, Chiba (Japan); Tokyo Metropolitan University Graduate School of Human Health Sciences, Tokyo (Japan); Yokahama CyberKnife Center, Yokohama (Japan); Tokyo Metropolitan University Graduate School of Human Health Sciences, Tokyo (Japan); Chiba Cancer Center, Chiba (Japan)

2008-10-15

327

Dynamic factor analysis of groundwater quality trends in an agricultural area adjacent to Everglades National Park.  

PubMed

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-NO3-, N-NH4+, P-PO4(3-), 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-NO3-, P-PO4(3-)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-NH4+, 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 land use patterns in the watershed. The results indicate that peak concentrations of agrochemicals in groundwater could be reduced by improving fertilization practices (by splitting and modifying timing of applications) and by operating the regional canal system to maintain the water table low, especially during the rainy periods. PMID:16102872

Muñoz-Carpena, R; Ritter, A; Li, Y C

2005-08-15

328

Impact of medical and demographic factors on long-term quality of life and body image of breast cancer patients  

Microsoft Academic Search

Background: The impact of various medical and demographic factors on the quality of life (QoL) of breast cancer patients has been discussed controversially. We investigated the influence of six different factors on long-term QoL and body image of women with primary breast cancer. Patients and methods: Two-hundred and seventy-four breast cancer patients were administered the QoL questionnaire following a mean

K. Härtl; W. Janni; R. Kästner; H. Sommer; B. Strobl; B. Rack; M. Stauber

329

Associations between psychological factors and quality of life ratings in persons with spinal cord injury: a systematic review  

Microsoft Academic Search

Study design:Systematic review.Objectives:To review the literature on relationships between psychological factors and quality of life (QOL) of persons with spinal cord injury (SCI).Setting:NA.Methods:A systematic literature search was conducted in several online databases (PubMed, Embase and PsychInfo). Articles were included if they provided quantitative information on associations between QOL-related dependent variables and psychological factors as independent variables in an SCI population.

C M C van Leeuwen; S Kraaijeveld; E Lindeman; M W M Post; MWM Post

2012-01-01

330

Monte-Carlo-based perturbation and beam quality correction factors for thimble ionization chambers in high-energy photon beams  

Microsoft Academic Search

This paper presents a detailed investigation into the calculation of perturbation and beam quality correction factors for ionization chambers in high-energy photon beams with the use of Monte Carlo simulations. For a model of the NE2571 Farmer-type chamber, all separate perturbation factors as found in the current dosimetry protocols were calculated in a fixed order and compared to the currently

J. Wulff; J. T. Heverhagen; K. Zink

2008-01-01

331

Investigation of systematic uncertainties in Monte Carlo-calculated beam quality correction factors.  

PubMed

Modern Monte Carlo codes allow for the calculation of ion chamber specific beam quality correction factors k(Q), which are needed for dosimetry in radiotherapy. While statistical (type A) uncertainties of the calculated data can be minimized sufficiently, the influence of systematic (type B) uncertainties is mostly unknown. This study presents an investigation of systematic uncertainties of Monte Carlo-based k(Q) values for a NE2571 thimble ion chamber, calculated with the EGSnrc system. Starting with some general investigation on transport parameter settings, the influence of geometry and source variations is studied. Furthermore, a systematic examination of uncertainties due to cross section is introduced by determining the sensitivity of k(Q) results to changes in cross section data. For this purpose, single components of the photon cross sections and the mean excitation energy I in the electron stopping powers are varied. The corresponding sensitivities are subsequently applied with information of standard uncertainties for the cross section data found in the literature. It turns out that the calculation of k(Q) factors with EGSnrc is mostly insensitive to transport settings within the statistical uncertainties of approximately 0.1%. Severe changes in the dimensions of the chamber lead to comparatively small, insignificant changes. Further, the inclusion of realistic beam models, delivering a complete phase space instead of simple photon spectra, does not significantly influence the result. However, the uncertainties in electron cross sections have an impact on the final uncertainty of k(Q) to a comparatively large degree. For the NE2571 chamber investigated in this work, this uncertainty amounts to 0.4% at 24 MV, decreasing to 0.2% at 6 MV. PMID:20668340

Wulff, J; Heverhagen, J T; Zink, K; Kawrakow, I

2010-07-29

332

Research on the Influencing Factors of Information System Outsourcing Success: A Relationship Quality Perspective  

Microsoft Academic Search

This study first constructs a mechanism model for relationship quality's effect on the success of information system(IS) outsourcing; empirically studies the principle of influence of relationship quality toward IS outsourcing success by carrying out a questionnaire survey on enterprises having outsourcing businesses. Through data analysis, the paper then discovers that relationship quality has obvious influence on IS outsourcing success: Trust

Dayong Wang

2011-01-01

333

Predictive factors of subjective sleep quality and insomnia complaint in patients with stroke: implications for clinical practice.  

PubMed

The complaints regarding sleep problems have not been well identified after a stroke. The aim of this study was to investigate the predictive factors of sleep quality and insomnia complaints in patients with stroke. A total of 70 subjects, 40 patients (57 ± 7 years) and 30 healthy controls (52 ± 6 years) assessed by the Pittsburgh Sleep Quality Index (PSQI) and the Sleep Habits Questionnaire took part in the study. The data were analyzed using the chi-square test, the Student's t-test and logistic regression analysis. On average, the patients showed poor sleep quality (patients: 6.3 ± 3.5; controls: 3.9 ± 2.2; p= 0.002) and insomnia complaint was the most prevalent (patients: 37.5%; controls: 6.7%; p= 0.007). The absence of insomnia complaint (OR= 0.120; 95%CI= 0.017-0.873; p= 0.036) and the decreased latency of sleep (OR= 0.120; 95%CI= 0.017-0.873; p= 0.036) were the protective factors of sleep quality. Female sex (OR= 11.098; 95%CI= 1.167-105.559; p= 0.036) and fragmented sleep (OR= 32.040; 95%CI= 3.236-317.261; p= 0.003) were the risk factors for insomnia complaint. We suggest that complaints of poor sleep quality and insomnia should be given priority assessment during clinical diagnosis of sleep disorders in stroke. PMID:24068099

Da Rocha, Patrícia C; Barroso, Marina T M; Dantas, Ana Amália T S G; Melo, Luciana P; Campos, Tania F

2013-08-28

334

A basic fibroblast growth factor improved the quality of skin grafting in burn patients.  

PubMed

To avoid hypertrophic scars in burn wounds, the simultaneous application of basic fibroblast growth factor (bFGF) with regular surgical debridement and skin grafting was investigated for skin hardness by clinical examination and instrumental measurement. As little is known about the role of bFGF in wounds, burn wound scars were tested for hardness. Burn scars in various anatomical locations at least 1 year after final wound healing clinically demonstrated a significantly lower hard score in bFGF-treated wounds than in non-bFGF wounds (0.95+/-0.51 versus 2.3+/-0.66, respectively, p<0.01). In addition, a durometer, which is widely used in industry to measure materials similar to skin, such as rubber and thread-balls, demonstrated a significantly lower reading in bFGF-treated wounds than in non-bFGF wounds (7.9+/-3.64 versus 15.5+/-4.39, bFGF versus non-bFGF, respectively, p<0.01). The results demonstrated that burn wounds treated with clinically approved bFGF might contribute to a better cutaneous wound quality, at least in terms of hardness. PMID:16199295

Akita, Sadanori; Akino, Kozo; Imaizumi, Toshifumi; Hirano, Akiyoshi

2005-11-01

335

Factors affecting the relationship between psychological status and quality of life in COPD patients  

PubMed Central

Background This study aims to (i) evaluate the association between anxiety and depressive symptoms and health-related quality of life (HRQoL); and (ii) identify the effect modifiers of this relationship in patients with chronic obstructive pulmonary disease (COPD). Methods A total of 337 clinically stable COPD patients answered the St. George's Respiratory Questionnaire (SGRQ) (assessing HRQoL) and the Hospital Anxiety and Depression Scale (HADS). Socio-demographic information, lung function, and other clinical data were collected. Results Most patients (93%) were male; they had a mean (SD) age of 68 (9) years and mild to very severe COPD (post-bronchodilator FEV1 52 (16)% predicted). Multivariate analyses showed that anxiety, depression, or both conditions were associated with poor HRQoL (for all SGRQ domains). The association between anxiety and total HRQoL score was 6.7 points higher (indicating a worse HRQoL) in current workers than in retired individuals. Estimates for patients with "both anxiety and depression" were 5.8 points lower in stage I-II than in stage III-IV COPD, and 10.2 points higher in patients with other comorbidities than in those with only COPD. Conclusions This study shows a significant association between anxiety, depression, or both conditions and impaired HRQoL. Clinically relevant factors affecting the magnitude of this association include work status, COPD severity, and the presence of comorbidities.

2010-01-01

336

Quality of Life and its Related Factors Among Iranian Cervical Cancer Survivors  

PubMed Central

Background Cervical cancer is the main cause of malignancy-related death among women living in developing countries Objective The aim of this study is to evaluate the quality of life (QOL) among Iranian cervical cancer survivors and its relationships with demographic and disease related factors. Patients and Methods A descriptive correlational study was carried out on 65 consecutive cervical cancer survivors in three different oncology centers related to Shahid Beheshti University of Medical Sciences, Tehran. The QOL was evaluated using three different standard questionnaires: 1) EORTC QLQ-C30 for patients with malignant tumors; 2) EORTC QLQ-CX24 for cervical cancer patients; and 3) SSQ for assessing the social support. The data was obtained by telephone interviews. The test-retest reliability and internal consistency of the scales were examined. Cronbach's alpha was calculated to assess internal consistency among items. Content validity was assessed to review the scales. Results Cervical cancer survivors stated a good QOL. However, its score was negatively associated with symptoms including short breathing, lack of appetite, nausea and vomiting, sleep disorders, peripheral neuropathy, and menopausal symptoms. Also, there was a positive association between QOL and economic conditions as well as QOL and social functioning. Conclusions Although, the QOL in cervical cancer survivors was good, treatment of related symptoms can influence the QOL and improve the care of these patients.

Torkzahrani, Shahnaz; Rastegari, Leila; Khodakarami, Nahid; Akbarzadeh-Baghian, Alireza; Alizadeh, Kamyab

2013-01-01

337

Identifying and ranking critical success factors for implementation of total quality management in the Indian manufacturing industry using TOPSIS  

Microsoft Academic Search

Purpose – The purpose of this paper is to review critical success factors (CSFs) of total quality management (TQM), and to rank these in the Indian manufacturing industry. Design\\/methodology\\/approach – To rank the CSFs, Technique for Order Preference by Similarity to Ideal Solution (TOPSIS) was used. The data were collected using questionnaires as the research instrument. Findings – Process management,

Harjeev K. Khanna; D. D. Sharma; S. C. Laroiya

2011-01-01

338

Liquid damping isolation on quartz crystal microbalance for effective preservation of high quality factor and sensitivity in liquid  

Microsoft Academic Search

This paper reports a novel design of a quartz crystal microbalance (QCM) for effective preservation of high quality factor and sensitivity in liquid. Many previous attempts have not achieved effective solutions to improve the QCM's performance in liquid. It is challenging to create a device without serious liquid damping effect. Our new design removes this dependence through an acoustic loss

Christopher R. Kirkendall; Jae W. Kwon

2009-01-01

339

The effect of online service quality factors on internet usage : The web delivery system of the taxation department  

Microsoft Academic Search

Purpose – This study aims to examine online service quality factors as main driving forces in the degree of intention of using the Taxation Department web site expressed by certified accountants. Design\\/methodology\\/approach – Drawing on a quantitative methodological approach, a survey was undertaken among a sample of 351 certified accountants to empirically test the proposed model. The paper used an

José Carlos Pinho; Maria de Lurdes Martins; Isabel Macedo

2011-01-01

340

Evaluating the air quality impacts of the 2008 Beijing Olympic Games: On-road emission factors and black carbon profiles  

Microsoft Academic Search

The aggressive traffic interventions and emission control measures implemented to improve air quality during the 2008 Beijing Olympic Games created a valuable case study to evaluate the effectiveness of these measures on mitigating air pollution and protecting public health. In this paper, we report the results from our field campaign in summer 2008 on the on-road emission factors of carbon

Xing Wang; Dane Westerdahl; Lung Chi Chen; Ye Wu; Jiming Hao; Xiaochuan Pan; Xinbiao Guo; K. Max Zhang

2009-01-01

341

Effect of Intense Lifestyle Modification and Cardiac Rehabilitation on Psychosocial Cardiovascular Disease Risk Factors and Quality of Life  

ERIC Educational Resources Information Center

|This study examined the effect of the Ornish Program for Reversing Heart Disease and cardiac rehabilitation(CR) on psychosocial risk factors and quality of life in patients with confirmed coronary artery disease. Participants had previously undergone a revascularization procedure. The 84 patients self-selected to participate in the Ornish Program…

Aldana, Steven G.; Whitmer, William R.; Greenlaw, Roger; Avins, Andrew L.; Thomas, Dean; Salberg, Audrey; Greenwell, Andrea; Lipsenthal, Lee; Fellingham, Gill W.

2006-01-01

342

The Influence of Supports Strategies, Environmental Factors, and Client Characteristics on Quality of Life-Related Personal Outcomes  

ERIC Educational Resources Information Center

|The concept of quality of life (QOL) is increasingly being used as a support provision and outcomes evaluation framework in the field of intellectual disability (ID). The present study used a hierarchical multiple regression research design to determine the role that available supports strategies, environmental factors, and client characteristics…

Claes, Claudia; Van Hove, Geert; Vandevelde, Stijn; van Loon, Jos; Schalock, Robert

2012-01-01

343

Factors influencing quality of life in Moroccan postmenopausal women with osteoporotic vertebral fracture assessed by ECOS 16 questionnaire  

Microsoft Academic Search

OBJECTIVE: The aim of the study was to evaluate factors influencing quality of life (QOL) in Moroccan postmenopausal women with osteoporotic vertebral fracture assessed by the Arabic version of ECOS 16 questionnaire. METHODS: 357 postmenopausal women were included in this study. The participants underwent bone mineral density (BMD) measurements by DXA of the lumbar spine and the total hip as

Fatima E Abourazzak; Fadoua Allali; Samira Rostom; Ihsane Hmamouchi; Linda Ichchou; Laila El Mansouri; Loubna Bennani; Hamza Khazzani; Redouane Abouqal; Najia Hajjaj-Hassouni

2009-01-01

344

Geologically and well-log constrained quality factor (Q) analysis for seismic reservoir characterization  

NASA Astrophysics Data System (ADS)

The principal objective of this work is to answer the problems following questions: (1) Can one extract Q directly from 2D reflection seismic in a way? (2) Can the attenuation of a plane wave propagating through a medium be accurately quantified? (3) What are the factors that complicate the measurement of attenuation from a propagating plane seismic wave? (4) How does quality factor (Q) affect the near and far offset trace attenuation? (5) Can one design a forward model that can effectively resolve effects of the complicating factors? (6)What is the significance of measuring attenuation due to anelastic rock properties? A forward model using 2D reflection seismic is used to observe effects of different values of Q and of offset on the seismic wavelet, both in the time domain and frequency domain. The result indicates Q inversely affects amplitude decay (i.e. the higher value of Q, the smaller the amplitude decay), while offset directly affects amplitude decay. In addition, preferential attenuation of the higher frequency content is prevalent, but phase distortion is not observed. Measurements of P- and S-wave velocities are conducted on alternating layers of acrylic and aluminum. In this experiment, both thickness of the layers, and frequency of the propagating wave are varied. Based on these observations, for wavelength/thickness (lambda/d) >> 1, the medium behaves as a transversely isotropic medium, and for (lambda/d) << 1 the medium; is represented by individual homogeneous pieces. Velocity dispersion is minimal in both cases. However, when (lambda/d) is between the two extreme cases there is a significant velocity dispersion due to interbed multiple scattering. P- and S-wave velocities, Qp and Qs were measured on 46 core samples collected from Well C-276, La Concepcion Field, Lake Maracaibo Venezuela. Measured Vp/Vs and Qp/Qs are correlated with petrophysical properties such as porosity and permeability of the core samples. QpQs has shown a very good relationship with porosity and permeability. Finally, Q is estimated from a CMP-gather extracted 3D survey from La Concepcion Field, Venezuela. The computed Q values are correlated with Q values from the well, and there is a very good relationship between the two. Furthermore, all Q measurements show correlation with the porous and permeable layers. Therefore, properly measured Q can be used together with other geophysical methods in reservoir characterization.

Gebretsadik, Eshetu

345

Neutron Radiography.  

National Technical Information Service (NTIS)

Thermal neutron output from a moderated 14 Mev D-T reaction is discussed as applicable to neutron radiography. Detectors for radiography are evaluated and the results using the thermal beam of the Naval Ordnance Laboratory's Neutron Diffraction Facility a...

P. W. Hesse

1970-01-01

346

DS02 fluence spectra for neutrons and gamma rays at Hiroshima and Nagasaki with fluence-to-kerma coefficients and transmission factors for sample measurements  

Microsoft Academic Search

Fluence spectra at several ground distances in Hiroshima and Nagasaki are provided along with associated fluence-to-kerma\\u000a coefficients from the Dosimetry System 2002 (DS02). Also included are transmission factors for calculating expected responses\\u000a of in situ sample measurements of neutron activation products such as 32P,36Cl,39Ar,41Ca, 60Co,63Ni,152Eu,  and 154Eu. The free-in-air (FIA) fluences calculated in 2002 are available for 240 angles, 69 energy

Stephen D. Egbert; George D. Kerr; Harry M. Cullings

2007-01-01

347

Magnetization screening from gluonic currents and scaling-law violation in the ratio of magnetic form factors for neutron and proton  

NASA Astrophysics Data System (ADS)

Gluon exchange currents can explain the decrease of the ratio ?p GpE / GpM for four-momentum transfer beyond Q2 ˜1 GeV2 . The SU(6) breaking induced by gluonic currents predicts furthermore that the ratio of neutron to proton magnetic form factors ?p GnM / ?n GpM falls with increasing Q2 . We find that the experimental data are consistent with our expectations of an almost linear decrease of the ratio ?p GnM / ?n GpM with increasing Q2 .

Kaskulov, Murat M.; Grabmayr, Peter

2004-02-01

348

Measuring Quality Factors From Multicomponent Reflection Seismic Data and its Significance for Lithology and Fluid Type Prediction  

NASA Astrophysics Data System (ADS)

Relationships among shear and compressional wave velocities (VP and VS) and quality factors (QP and QS) for predicting lithology and fluid content, have been previously studied and proposed by some researchers. Thus, for example, VP/VS has been used as a lithology indicator for sandstone, shale and limestone. Likewise, QP/QS has been related to fluid content, mainly to discriminate oil, brine, and gas saturation. The velocities and quality factors for both P and S waves can be obtained from multicomponent reflection seismic data. Multicomponent data are most commonly recorded from compressional sources in the oil industry. Converted P to S waves or PS waves are generally measured in the radial component. In cases where there are heterogeneity and/or azimuthal anisotropy, the transverse component is also considered. Processing of the converted wave results in a PS image and an interpreted converted-wave velocity field (VPS). Likewise, it is possible to estimate a converted-wave quality factor (QPS) field. The converted-wave quality factor can also be used as a lithology and fluid content indicator since this parameter depends on VP/VS and QP/QS ratios. Crossplots involving QPS obtained from previously published laboratory measurements of P- and S-wave velocities and quality factors, reveal the significance of estimating QPS from multicomponent seismic data. An important advantage of using QPS as a lithology indicator is that it can be mapped directly from multicomponent surface seismic data. In this work we present a new methodology to obtain QPS. In the pure mode case, approaches for estimating Q are well known. However for converted-waves, some simplifying assumptions need to be made due to the propagation characteristics of the converted P- to S-wavepath.

Ortiz-Osornio, M.; Calder¢n-Macias, C.; Ramos-Matinez, J.

2003-12-01

349

Factors influencing subjective quality of life in patients with schizophrenia and other mental disorders: a pooled analysis.  

PubMed

Subjective quality of life (SQOL) is an important outcome in the treatment of patients with schizophrenia. However, there is only limited evidence on factors influencing SQOL, and little is known about whether the same factors influence SQOL in patients with schizophrenia and other mental disorders. This study aimed to identify the factors associated with SQOL and test whether these factors are equally important in schizophrenia and other disorders. For this we used a pooled data set obtained from 16 studies that had used either the Lancashire Quality of Life Profile or the Manchester Short Assessment of Quality of Life for assessing SQOL. The sample comprised 3936 patients with schizophrenia, mood disorders, and neurotic disorders. After controlling for confounding factors, within-subject clustering, and heterogeneity of findings across studies in linear mixed models, patients with schizophrenia had more favourable SQOL scores than those with mood and neurotic disorders. In all diagnostic groups, older patients, those in employment, and those with lower symptom scores had higher SQOL scores. Whilst the strength of the association between age and SQOL did not differ across diagnostic groups, symptom levels were more strongly associated with SQOL in neurotic than in mood disorders and schizophrenia. The association of employment and SQOL was stronger in mood and neurotic disorders than in schizophrenia. The findings may inform the use and interpretation of SQOL data for patients with schizophrenia. PMID:20483566

Priebe, Stefan; Reininghaus, Ulrich; McCabe, Rosemarie; Burns, Tom; Eklund, Mona; Hansson, Lars; Junghan, Ulrich; Kallert, Thomas; van Nieuwenhuizen, Chijs; Ruggeri, Mirella; Slade, Mike; Wang, Duolao

2010-05-18

350

From Social Structural Factors to Perceptions of Relationship Quality and Loneliness: The Chicago Health, Aging, and Social Relations Study  

PubMed Central

Objectives The objective of this study was to test a conceptual model of loneliness in which social structural factors are posited to operate through proximal factors to influence perceptions of relationship quality and loneliness. Methods We used a population-based sample of 225 White, Black, and Hispanic men and women aged 50 through 68 from the Chicago Health, Aging, and Social Relations Study to examine the extent to which associations between sociodemographic factors and loneliness were explained by socioeconomic status, physical health, social roles, stress exposure, and, ultimately, by network size and subjective relationship quality. Results Education and income were negatively associated with loneliness and explained racial/ethnic differences in loneliness. Being married largely explained the association between income and loneliness, with positive marital relationships offering the greatest degree of protection against loneliness. Independent risk factors for loneliness included male gender, physical health symptoms, chronic work and/or social stress, small social network, lack of a spousal confidant, and poor-quality social relationships. Discussion Longitudinal research is needed to evaluate the causal role of social structural and proximal factors in explaining changes in loneliness.

Hawkley, Louise C.; Hughes, Mary Elizabeth; Waite, Linda J.; Masi, Christopher M.; Thisted, Ronald A.; Cacioppo, John T.

2009-01-01

351

Clr4/Suv39 and RNA quality control factors cooperate to trigger RNAi and suppress antisense RNA.  

PubMed

Pervasive transcription of eukaryotic genomes generates a plethora of noncoding RNAs. In fission yeast, the heterochromatin factor Clr4/Suv39 methyltransferase facilitates RNA interference (RNAi)-mediated processing of centromeric transcripts into small interfering RNAs (siRNAs). Clr4 also mediates degradation of antisense RNAs at euchromatic loci, but the underlying mechanism has remained elusive. We show that Clr4 and the RNAi effector RITS (RNA-induced transcriptional silencing) interact with Mlo3, a protein related to mRNA quality control and export factors. Loss of Clr4 impairs RITS interaction with Mlo3, which is required for centromeric siRNA production and antisense suppression. Mlo3 also interacts with the RNA surveillance factor TRAMP, which suppresses antisense RNAs targeted by Clr4 and RNAi. These findings link Clr4 to RNA quality control machinery and suggest a pathway for processing potentially deleterious RNAs through the coordinated actions of RNAi and other RNA processing activities. PMID:21436456

Zhang, Ke; Fischer, Tamas; Porter, Rebecca L; Dhakshnamoorthy, Jothy; Zofall, Martin; Zhou, Ming; Veenstra, Timothy; Grewal, Shiv I S

2011-03-25

352

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)

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.

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

1997-02-01

353

Quality of Life and Psychosocial Factors in African Americans with Hypertensive Chronic Kidney Disease  

PubMed Central

Health-related quality of life (HRQOL) is poorly understood in patients with chronic kidney disease (CKD) prior to end-stage renal disease. The association between psychosocial measures and HRQOL has not been fully explored in CKD, especially in African Americans. We performed a cross-sectional analysis of HRQOL and its association with sociodemographic and psychosocial factors in African Americans with hypertensive CKD. There were 639 participants in the African American Study of Kidney Disease and Hypertension Cohort Study. The Short Form-36 was used to measure HRQOL. The Diener Satisfaction with Life Scale measured life satisfaction, the Beck Depression Inventory-II assessed depression, the Coping Skills Inventory-Short Form measured coping, and the Interpersonal Support Evaluation List-16 was used to measure social support. Mean participant age was 60 years at enrollment, and 61% were male. Forty-two percent reported a household income below $15,000/year. Higher levels of social support, coping skills, and life satisfaction were associated with higher HRQOL, while unemployment and depression were associated with lower HRQOL (p<0.05). There was a significant positive association between higher estimated glomerular filtration rate (eGFR) with the Physical Health Composite (PHC) score (p=0.004) but not the Mental Health Composite (MHC) score (p=0.24). Unemployment was associated with lower HRQOL, and lower eGFR was associated with lower PHC. African Americans with hypertensive CKD with better social support and coping skills had higher HRQOL. This study demonstrates an association between CKD and low HRQOL and highlights the need for longitudinal studies to further examine this association.

Porter, Anna; Fischer, Michael J.; Brooks, Deborah; Bruce, Marino; Charleston, Jeanne; Cleveland, William H.; Dowie, Donna; Faulkner, Marquetta; Gassman, Jennifer; Greene, Tom; Hiremath, Leena; Kendrick, Cindy; Kusek, John W.; Thornley-Brown, Denyse; Wang, Xuelei; Norris, Keith; Unruh, Mark; Lash, James

2011-01-01

354

Quality of life and psychosocial factors in African Americans with hypertensive chronic kidney disease.  

PubMed

Health-related quality of life (HRQOL) is poorly understood in patients with chronic kidney disease (CKD) prior to end-stage renal disease. The association between psychosocial measures and HRQOL has not been fully explored in CKD, especially in African Americans. We performed a cross-sectional analysis of HRQOL and its association with sociodemographic and psychosocial factors in African Americans with hypertensive CKD. There were 639 participants in the African American Study of Kidney Disease and Hypertension Cohort Study. The Short Form-36 was used to measure HRQOL. The Diener Satisfaction with Life Scale measured life satisfaction, the Beck Depression Inventory-II assessed depression, the Coping Skills Inventory-Short Form measured coping, and the Interpersonal Support Evaluation List-16 was used to measure social support. The mean participant age was 60 years at enrollment, and men comprised 61% of participants. Forty-two percent reported a household income less than $15,000/year. Higher levels of social support, coping skills, and life satisfaction were associated with higher HRQOL, whereas unemployment and depression were associated with lower HRQOL (P < 0.05). A significant positive association between higher estimated glomerular filtration rate (eGFR) was observed with the Physical Health Composite (PHC) score (P = 0.004) but not in the Mental Health Composite (MHC) score (P = 0.24). Unemployment was associated with lower HRQOL, and lower eGFR was associated with lower PHC. African Americans with hypertensive CKD with better social support and coping skills had higher HRQOL. This study demonstrates an association between CKD and low HRQOL, and it highlights the need for longitudinal studies to examine this association in the future. PMID:22153804

Porter, Anna; Fischer, Michael J; Brooks, Deborah; Bruce, Marino; Charleston, Jeanne; Cleveland, William H; Dowie, Donna; Faulkner, Marquetta; Gassman, Jennifer; Greene, Tom; Hiremath, Leena; Kendrick, Cindy; Kusek, John W; Thornley-Brown, Denyse; Wang, Xuelei; Norris, Keith; Unruh, Mark; Lash, James

2011-10-12

355

Factors influencing the quality of food extracts for in vitro and in vivo diagnosis.  

PubMed

Food extracts for diagnostic purposes often lack sufficient activity and consistency. Biologically standardized food extracts are not available on the market. Using extracts from plant-derived foods as examples, we investigated factors which may be important for the quality of such extracts. Divergent allergenic activities were found between strains of apples, but not within varieties of celery tuber (celeriac), hazelnut, and peanut, respectively. Heating of the food remarkably reduced the activity of apple, hazelnut, and celeriac, but had little effect on peanut. By contrast, heating of semipurified protein extracts from celery tuber and apple for 30 min at 100 degrees C did not deplete the immunoreactivity of the major allergens, indicating that this is an inappropriate test for identifying labile food allergens. Due to their high endogenous enzyme activities, apples and other fruits require special extraction procedures applying either low temperature or enzyme inhibitors. Variation of extraction conditions had little effect on the composition and activity of extracts from hazelnut. The storage stability of skin test solutions from plant foods can be improved by avoiding phenol as an additive and by including 50% of glycerol. For model studies considering neoallergens, IgE was raised in mice against native and heated celery tuber, respectively. When extracts from nonthermally and thermally processed celeriac were subjected to an RBL-cell mediator release assay with these sera, an inverse ranking was obtained with anti-heated celeriac IgE and anti-native celeriac IgE, respectively. These data indicated that new epitopes had been formed by the heating process. Since all parameters were tested in model experiments with either human or murine IgE, their relevance has to be proven in further clinical investigations. PMID:9826003

Vieths, S; Hoffmann, A; Holzhauser, T; Müller, U; Reindl, J; Haustein, D

1998-01-01

356

Neutron capture therapies  

SciTech Connect

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.

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

1999-11-02

357

Use of Ecological Momentary Assessment to Determine Which Structural Factors Impact Perceived Teaching Quality of Attending Rounds  

PubMed Central

Introduction Providing high-quality teaching to residents during attending rounds is challenging. Reasons include structural factors that affect rounds, which are beyond the attending's teaching style and control. Objective To develop a new evaluation tool to identify the structural components of ward rounds that most affect teaching quality in an internal medicine (IM) residency program. Methods The authors developed a 10-item Ecological Momentary Assessment (EMA) tool and collected daily evaluations for 18 months from IM residents rotating on inpatient services. Residents ranked the quality of teaching on rounds that day, and questions related to their service (general medicine, medical intensive care unit, and subspecialty services), patient census, absenteeism of team members, call status, and number of teaching methods used by the attending. Results Residents completed 488 evaluation cards over 18 months. This found no association between perceived teaching quality and training level, team absenteeism, and call status. We observed differences by service (P?quality, regardless of service or census (P for trend?quality, but the results were also influenced by the type of teaching service. We found that, regardless of census or teaching service, attendings can improve their teaching by diversifying the number of methods used in daily rounds.

Willett, Lisa; Houston, Thomas K.; Heudebert, Gustavo R.; Estrada, Carlos

2012-01-01

358

Impact of Environmental Factors on Product Quality of Greenhouse Vegetables for Fresh Consumption  

Microsoft Academic Search

Consumer interest worldwide in the quality of vegetable products has increased in recent years. Product quality is a complex issue. As well as visual characteristics, properties such as texture, the content of minerals and vitamins, flavor and other organoleptic characteristics must be considered. In addition, new knowledge shows that vegetables are appreciated for their beneficial health effects in humans and

N. Gruda

2005-01-01

359

Modeling study on the factors affecting regional air quality during the Beijing 2008 Olympic Games  

Microsoft Academic Search

Chinese government took measures to control emissions of pollutants before and during the Beijing 2008 Olympic Games in order to get better air quality for the event. A 3-dimensional regional chemical transport model, the University of Iowa's Sulfur Transport and dEposition Model (STEM), is used to evaluate the effects of emission reductions on regional air quality by this event. The

C. Wei; G. R. Carmichael; B. Adhikary; A. D'Allura; Y. Cheng; Y. Tang; Q. Zhang; D. G. Streets; R. Pierce; J. A. Al-Saadi; B. A. Flowers; M. K. Dubey; N. A. Krotkov; K. E. Pickering; V. Ramanathan

2009-01-01

360

Factors Affecting University Music Students' Perceptions of Lesson Quality and Teacher Effectiveness.  

ERIC Educational Resources Information Center

|Examines the effects of music teacher delivery skills, lesson content, and student academic standing on 511 university music students' perceptions of lesson quality or teacher appeal. Indicates that student interest and preference varied by academic standing, teacher delivery, and lesson quality. Includes references. (CMK)|

Hamann, Donald L.; Baker, Dawn S.; McAllister, Peter A.; Bauer, William I.

2000-01-01

361

Determination of the kerma factors in tissue-equivalent plastic, C, Mg, and Fe for 14. 7-MeV neutrons  

SciTech Connect

Microdosimetric measurements were made with tissue-equivalent plastic, (TEP), C-, Mg-, and Fe-, walled proportional counters filled with propane-based TE gas and Ar gas and irradiated with 14.7-MeV neutrons. A theoretical model was used for the analysis of energy deposition in spherical detectors. An effective average mass stopping-power ratio and a W correction were calculated to convert the gas ionization to the kerma in the wall material. The neutron fluence at the position of microdosimetric measurements was determined with an associated particle chamber mounted with surface barrier detectors. The experimental measurements along with the calculated correction factors yielded kerma factors of 0.660 x 10/sup -8/ cGy cm/sup 2/ for TEP, 0.219 x 10/sup -8/ cGy cm/sup 2/ for C, 0.122 x 10/sup -8/ cGy cm/sup 2/ for Mg, and 0.479 x 10/sup -9/ cGy cm/sup 2/ for Fe. The estimated uncertainties are 8.0% for TEP, 10.5% for C, and 9.3% for Mg and Fe.

Wuu, C.S.; Milavickas, L.R.

1987-11-01

362

Neutron multiplication factor and calculational bias from {sup 252}Cf source-driven frequency analysis measurements with subcritical arrays of PWR fuel pins  

SciTech Connect

The ability of the {sup 252}Cf-source-driven noise analysis method to measure the subcritical neutron multiplication factor has been demonstrated for a variety of experimental configurations of fissile materials. In 1983 a measurement was performed at the critical experiments facility of the Babcox and Wilcox Company, Lynchburg, Virginia, with an array of 2.46 wt% {sup 235}U enriched pressurized water reactor (PWR) fuel pins as a first step in a demonstration that this method could measure the subcriticality of PWR spent-fuel arrays. This measurement contained the equivalent of 18 PWR fuel elements (17 x 17 fuel pins each). With the ability to measure the subcriticality of spent fuel, burnup credit could be taken for storage, shipping, and other applications with spent fuel. Analysis of previous measured data has been limited by interpretations dependent on the validity of point kinetics. The development of the Monte Carlo code MCNP-DSP has allowed the use of a very general Monte Carlo model for the interpretation of the measured data to obtain the subcritical neutron multiplication factor and the bias in calculational methods. This paper presents an analysis for a small portion of these measurements, i.e., the 4961-fuel-pin configuration with boron concentrations of 2300 and 4303 ppm and a 17 x 17 fuel pin array simulating a single PWR fuel element with 15010 ppm boron in the water.

Valentine, T.E.; Mihalczo, J.T.; King, W.T.; Blakeman, E.D. [Oak Ridge National Laboratory, TN (United States)

1996-12-31

363

Pre-existing disease: the most important factor for health related quality of life long-term after critical illness: a prospective, longitudinal, multicentre trial  

Microsoft Academic Search

INTRODUCTION: The aim of the present multicenter study was to assess long term (36 months) health related quality of life in patients after critical illness, compare ICU survivors health related quality of life to that of the general population and examine the impact of pre-existing disease and factors related to ICU care on health related quality of life. METHODS: Prospective,

Lotti Orwelius; Anders Nordlund; Peter Nordlund; Eva Simonsson; Carl Bäckman; Anders Samuelsson; Folke Sjöberg

2010-01-01

364

Study of Factors Affecting the Surface Quality in Ultra-Precision Diamond Turning  

Microsoft Academic Search

This paper deals with an investigation of the process factors and the material factors affecting the surface roughness in ultra-precision diamond turning. The process factors involve cutting conditions, tool geometry, and relative tool-work vibration which are related to the cutting geometry and the dynamic characteristics of the cutting process. The material factors considered are material anisotropy, swelling, and crystallographic orientation

C. F. Cheung; W. B. Lee

2000-01-01

365

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

SciTech Connect

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.

Verbeke, Jerome M. [University of California, Berkeley (United States); Chen, Allen S. [University of California, Berkeley (United States); Vujic, Jasmina L. [University of California, Berkeley (United States); Leung, Ka-Ngo [Lawrence Berkeley National Laboratory (United States)

2000-08-15

366

Evaluated cross section libraries and kerma factors for neutrons up to 100 MeV on {sup 16}O and {sup 14}N  

SciTech Connect

We present evaluations of the interaction of 20 to 100 MeV neutrons with oxygen and nitrogen nuclei, which follows on from our previous work on carbon. Our aim is to accurately represent integrated cross sections, inclusive emission spectra, and kerma factors, in a data library which can be used in radiation transport calculations. We apply the FKK-GNASH nuclear model code, which includes Hauser-Feshbach, preequilibrium, and direct reaction mechanisms, and use experimental measurements to optimize the calculations. We determine total, elastic, and nonelastic cross sections, angle-energy correlated emission spectra, for light ejectiles with A{<=}4 and gamma-rays, and average energy depositions. Our results for charged-particle emission spectra agree well with the measurements of Subramanian et al.. We compare kerma factors derived from our evaluated cross sections with experimental data, providing an integral benchmarking of our work. The evaluated data libraries are available as electronic files.

Chadwick, M.B.; Young, P.G.

1995-07-01

367

Calculation and evaluation of cross sections and kerma factors for neutrons up to 100 MeV on {sup 16}O and {sup 14}N  

SciTech Connect

The authors present evaluations of the interaction of neutrons with energies between 20 and 100 MeV with oxygen and nitrogen nuclei, which follows from their previous work on carbon. Their aim is to accurately represent integrated cross sections, inclusive emission spectra, and kerma factors, in a data library that can be used in radiation transport calculations. They apply the Feshbach-Kerman-Koonin-GNASH nuclear model code, which includes Hauser-Feshbach, pre-equilibrium, and direct reaction mechanisms, and use experimental measurements to optimize the calculations. They determine total, elastic, and nonelastic cross sections; angle-energy-correlated emission spectra for light ejectiles with A {le} 4 and gamma rays; and average energy depositions. The results for charged-particle emission spectra agree well with measurements of Subramanian et al. They compare kerma factors derived from their evaluated cross sections with experimental data, providing an integral benchmarking of their work.

Chadwick, M.B. [Lawrence Livermore National Lab., CA (United States); Young, P.G. [Los Alamos National Lab., NM (United States)

1996-05-01

368

Evaluated cross section libraries and kerma factors for neutrons up to 100 MeV on {sup 40}Ca and {sup 31}P  

SciTech Connect

The authors present evaluations of the interaction of 20 to 100 MeV neutrons with calcium and phosphorus, which follows on from the previous work on carbon, nitrogen, and oxygen. The aim is to accurately represent integrated cross sections, inclusive emission spectra, and kerma factors, in a data library which can be used in radiation transport calculations. They apply the GNASH nuclear model code, which includes Hauser-Feshbach, preequilibrium, and direct reaction mechanisms, and use experimental measurements to optimize the calculations. Total, elastic, and nonelastic cross sections, angle-energy correlated emission spectra for light ejectiles with A {le} 4 and gamma-rays, and average energy depositions, are determined. The expected accuracy of the calculated cross sections and kerma factors is discussed.

Chadwick, M.B. [Lawrence Livermore National Lab., CA (United States). Nuclear Data Group

1995-11-01

369

Neutron radiography using neutron imaging plate.  

PubMed

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. PMID:19828321

Chankow, Nares; Punnachaiya, Suvit; Wonglee, Sarinrat

2009-09-16

370

Estimating quality factor from surface seismic data: A comparison of current approaches  

NASA Astrophysics Data System (ADS)

The performances of the spectral ratio (SR), frequency centroid shift (FCS), and frequency peak shift (FPS) methods to estimate the effective quality factor Q are compared. These methods do not demand true amplitude data and their implementations were done following an "as simple as possible" approach to highlight their intrinsic potentials and limitations. We use synthetic zero-offset seismic data generated with a simple layer-cake isotropic model. The methods can be ranked from simple to complex in terms of automation as: FPS, FCS and SR. This is a consequence of: (i) peak identification consists basically of a sorting procedure, (ii) centroid estimation involves basically the evaluation of two well-behaved integrals, and (iii) implementation of the SR method involves at least choosing a usable frequency bandwidth and fitting a gradient. The methods can be ranked from robust to sensitive in the presence of noise content in the sequence SR, FCS, and FPS. This is consequence of: (i) the gradient estimate associated to the SR method averages out the noise content in the entire usable frequency bandwidth, (ii) in the presence of moderate-to-high noise level, the centroid estimation is biassed towards overestimating Q due to noise contribution in the tail of the amplitude spectrum, and (iii) peak identification is unstable due to local noise fluctuation in the amplitude spectrum around the peak frequency. Regarding the stability of the estimates relative to the attenuation amount, SR and FCS methods show similar behaviours, whereas FPS method presents an inferior performance. This fact is an indirect consequence of the sensitivity of FPS method to the noise content because the higher is the attenuation the lower is the signal-to-noise ratio. Finally, regarding the robustness of the methods to the presence of dipping layers, only SR and FCS methods provide good estimates, at least to typical dips in non-faulted sedimentary layers, with the estimates obtained with SR method being more accurate that those obtained with FCS method. Except in relation to the automation complexity, which is less important than the performances of the methods, SR method was superior or showed similar performance to FCS method in all scenarios we tried.

de Castro Nunes, Bonnie Ives; Eugênio de Medeiros, Walter; Farias Do Nascimento, Aderson; de Morais Moreira, José Antonio

2011-10-01

371

Comparison of Diode Quality Plus Other Factors in Polycrystalline Cells and Modules from Outdoor and Indoor Measurements  

SciTech Connect

The Outdoor Test Facility (OTF) at NREL is equipped with data acquisition systems that monitor the performance of modules deployed outdoors in real time, including the measurement of current-voltage traces every 15 minutes during all daylight hours. This affords us the ability to analyze performance across many levels of illumination which allows the determination of factors that affect module performance and that serve as indicators of module quality, including average diode quality factors, series resistances values, and reverse-saturation currents of the cells. This study focuses on several polycrystalline thin-film modules, including cadmium telluride. CIS, and polycrystalline silicon. We present these parameters, acquired from outdoor measurements, and compare the results with measurements obtained from more canonical methods.

del Cueto, J. A.; Rummel, S. R.

2005-02-01

372

The age of entry into high-quality preschool, child and family factors, and developmental outcomes in early childhood  

Microsoft Academic Search

Three blocks of factors were considered as predictors of four year old children's (N = 286) personality, non-verbal intelligence and social behaviour in preschool: (a) personality characteristics at time 1 (T1) when the participants were three years old; (b) parental education and parenting practices measured at T1; and (c) age of child's entry to high-quality preschool. Child personality was rated

Maja Zupancic; Tina Kavcic

2006-01-01

373

Experimental factors affecting the quality and reproducibility of MALDI TOF mass spectra obtained from whole bacteria cells  

Microsoft Academic Search

Numerous experimental factors are shown to significantly influence the spectra obtained when bacteria are analyzed by MALDI\\u000a TOF\\/MS. Detailed investigation of the instrument parameters and sample preparation are all shown to influence the spectra.\\u000a Of these, the preanalysis sample preparation steps incorporate the most important elements influencing the quality and reproducibility\\u000a of the spectra. Some of the most important sample

Tracie L. Williams; Denis Andrzejewski; Jackson O. Lay; Steven M. Musser

2003-01-01

374

Quality of life in inflammatory bowel disease in remission: the impact of IBS-like symptoms and associated psychological factors  

Microsoft Academic Search

OBJECTIVES:Quality of life is reduced in inflammatory bowel disease (IBD). Whether or not this is true in IBD patients in long-standing remission is unclear. Symptoms compatible with irritable bowel syndrome (IBS) are common in IBD patients in remission. The importance of psychological factors in this process is a matter of controversy.METHODS:Forty-three patients with ulcerative colitis (UC) and 40 with Crohn's

Magnus Simrén; Jenny Axelsson; Rolf Gillberg; Hasse Abrahamsson; Jan Svedlund; Einar S. Bjornsson

2002-01-01

375

Effects of design factors on store image and expectation of merchandise quality in web-based stores  

Microsoft Academic Search

This study investigates two design factors of store atmosphere in relation to store image and consumers' expectations of merchandise quality for web-based stores. We address this purpose through the use of the Stimulus-Organism-Response (S-O-R) model on which five hypotheses were drawn based on research conducted with brick-and-mortar and web-based stores. In order to test the hypotheses, four treatment combination stimuli

Jungmi Oh; Susan S. Fiorito; Hira Choc; Charles F. Hofacker

376

Stability and quality factor of a one-dimensional subwavelength cavity resonator containing a left-handed material  

Microsoft Academic Search

The characteristics of a one-dimensional subwavelength cavity resonator (SWCR) formed by a left-handed material layer and a right-handed material layer are studied. Some previously published conclusions for some fundamental issues are discussed and rectified. Our analysis for the stability and the quality factor of the SWCR shows that the two materials should be mismatched in the impedance in order to

Linfang Shen; Sailing He; Sanshui Xiao

2004-01-01

377

The Effect of Socioeconomic Factors on Quality of Life After Treatment in Patients With Head and Neck Cancer  

Microsoft Academic Search

Purpose: To determine the effect of socioeconomic factors on quality of life (QoL) after treatment in patients with head and neck carcinoma (HNC). Patients and Methods: The study population included 50 HNC patients seen in their control examinations after radiotherapy during a 2-month interval and who were willing to complete the Short-Form 36 QoL questionnaire. Socioeconomic, demographic, and tumor- and

Ayse Nur Demiral; Mehmet Sen; Yuecel Demiral; Muenir Kinay

2008-01-01

378

Sleep quality and acute pain severity among young adults with and without chronic pain: the role of biobehavioral factors  

Microsoft Academic Search

Adequate sleep is essential for health across the lifespan and is likely to be influenced by different factors among those\\u000a with chronic pain than among others. Questionnaires were administered to 362 college students, some of whom reported chronic\\u000a pain from varied sources. Among chronic pain sufferers (n = 108), pain severity was uniquely associated with sleep quality after controlling for gender, BMI,

Jennifer E. GrahamKatherine; Katherine L. Streitel

2010-01-01

379

Evaluation of the factors that determine quality in higher education: an empirical study  

Microsoft Academic Search

Purpose – The aim of this paper is to identify the quality determinants for education services provided by higher education institutions (HEIs) in Greece and to measure their relative importance from the students' points of view. Design\\/mthodology\\/approach – A multi-criteria decision-making methodology was used for assessing the relative importance of quality determinants that affect student satisfaction. More specifically, the analytical

Maria Tsinidou; Vassilis Gerogiannis; Panos Fitsilis

2010-01-01

380

Fast neutrons from annihilation  

NASA Astrophysics Data System (ADS)

We analyzed experimental data on fast neutron production in ¯p+64Cu and ¯p+238U annihilation and the ratio of231Th/231Ac isotopes from ¯p+232Th annihilation at rest. The contributions from standard reaction channels are calculated by cascade model. The annihilation pion rescattering and absorption in nuclear medium as well as the preequilibrium nucleon emission were analyzed. The calculation based on the assumption that neutron density distribution ?uals the proton one multiplied by factor N/Z does not reproduce the experimental data. We discussed the influence of the neutron density distribution on fast neutron and isotope production. It was found that the hypothesis of the neutron halo allows one to get a reasonable description of the experimental data.

Sibirtsev, A.

1994-09-01

381

Factor Structure of the World Health Organization's Quality of Life Questionnaire-BREF in Patients with Coronary Artery Disease  

PubMed Central

Background: The World Health Organization Quality of Life Questionnaire (WHOQOL)-BREF is one of the most known general questionnaires for assessment of quality of life (QOL) in both healthy populations and in various diseases subgroups. The aim of the present study was to examine the construct validity of this questionnaire in patients with coronary artery disease (CAD) using factor analysis. Methods: Two hundred and seventy-five patients aged 35-80 years old with the diagnosis of CAD admitted to the Tehran Heart Center operating room for coronary artery bypass were consecutively entered into the study. QOL was assessed using the WHOQOL-BREF. To estimate the reliability of the QOL questionnaire, Cronbach's a coefficient was measured. To assess the structure of the questionnaire, we firstly performed confirmatory factor analysis to test the hypothesized factor models. Exploratory factor analysis was then performed using the principal component method with varimax rotation. Results: Reliability of the questionnaire was low (Cronbach's a for different domains ranged from 0.24 to 0.74). In confirmatory factor analysis, only the 1-factor model indicated a good fit to the data. The exploratory factor analysis indicated a five-factor solution that jointly accounted for 55.7% of the variance observed. Also, the pattern of item loading was very different from the original structure of the questionnaire. Conclusions: The findings suggest that the WHOQOL-BREF might only be a measure of the overall QOL in patients with CAD, and is not a suitable instrument for measuring the different QOL dimensions as expected in this population.

Najafi, Mahdi; Sheikhvatan, Mehrdad; Montazeri, Ali; Sheikhfatollahi, Mahmood

2013-01-01

382

The impact of heavy metals from environmental tobacco smoke on indoor air quality as determined by Compton suppression neutron activation analysis  

Microsoft Academic Search

The method of instrumental neutron activation analysis (NAA) has been improved for air filter samples in the determination of low level heavy metals in indoor air. By using the techniques of epithermal neutron irradiation in conjunction with Compton suppression, the detection limits of cadmium, arsenic and antimony measurements have been dramatically reduced to 2 ng for Cd, 0.2 ng for

S. landsberger; D. Wu

1995-01-01

383

Towards more accurate microcavity sensors: maximum likelihood estimation applied to a combination of quality factor and wavelength shifts.  

PubMed

Optical microcavities are widely used for biological and chemical sensing applications. In these devices, a sensing event is estimated by measuring the shift in the resonant wavelength, or in the quality factor of the microcavity. However, all published works to date only use one of these measures to estimate the sensing event. Here, we show that the estimation accuracy of a sensing event can be improved by employing a combination of both the quality factor and the resonant wavelength measurements in a microcavity sensor. We further demonstrate an experimental application of this model by introducing a refractive index change for a microtoroidal cavity sensor immersed in a liquid. By further using the finite element method simulations in conjunction with the estimator model, we show the existence of three distinct measurement regimes as a function of the quality factor of the microcavity. Finally, the estimator model is extended to develop a sensing metric to compare performance of optical or non-optical sensors. PMID:24104168

Cheema, M Imran; Khan, Usman A; Armani, Andrea M; Kirk, Andrew G

2013-09-23

384

Soliton compression to few-cycle pulses with a high quality factor by engineering cascaded quadratic nonlinearities.  

PubMed

We propose an efficient approach to improve few-cycle soliton compression with cascaded quadratic nonlinearities by using an engineered multi-section structure of the nonlinear crystal. By exploiting engineering of the cascaded quadratic nonlinearities, in each section soliton compression with a low effective order is realized, and high-quality few-cycle pulses with large compression factors are feasible. Each subsequent section is designed so that the compressed pulse exiting the previous section experiences an overall effective self-defocusing cubic nonlinearity corresponding to a modest soliton order, which is kept larger than unity to ensure further compression. This is done by increasing the cascaded quadratic nonlinearity in the new section with an engineered reduced residual phase mismatch. The low soliton orders in each section ensure excellent pulse quality and high efficiency. Numerical results show that compressed pulses with less than three-cycle duration can be achieved even when the compression factor is very large, and in contrast to standard soliton compression, these compressed pulses have minimal pedestal and high quality factor. PMID:23187563

Zeng, Xianglong; Guo, Hairun; Zhou, Binbin; Bache, Morten

2012-11-19

385

Modelling factors in primary care quality improvement: a cross-sectional study of premature CHD mortality  

PubMed Central

Objectives To identify features of primary care quality improvement associated with improved health outcomes using premature coronary heart disease (CHD) mortality as an example, and to determine impacts of different modelling approaches. Design Cross-sectional study of mortality rates in 229 general practices. Setting General practices from three East Midlands primary care trusts. Participants Patients registered to the practices above between April 2006 and March 2009. Main outcome measures Numbers of CHD deaths in those aged under 75 (premature mortality) and at all ages in each practice. Results Population characteristics and markers of quality of primary care were associated with variations in premature CHD mortality. Increasing levels of deprivation, percentages of practice populations on practice diabetes registers, white, over 65 and male were all associated with increasing levels of premature CHD mortality. Control of serum cholesterol levels in those with CHD and the percentage of patients recalling access to their preferred general practitioner were both associated with decreased levels of premature CHD mortality. Similar results were found for all-age mortality. A combined measure of quality of primary care for CHD comprising 12 quality outcomes framework indicators was associated with decreases in both all-age and premature CHD mortality. The selected models suggest that practices in less deprived areas may have up to 20% lower premature CHD mortality than those with median deprivation and that improvement in the CHD care quality from 83% (lower quartile) to 86% (median) could reduce premature CHD mortality by 3.6%. Different modelling approaches yielded qualitatively similar results. Conclusions High-quality primary care, including aspects of access to and continuity of care, detection and management, appears to be associated with reducing CHD mortality. The impact on premature CHD mortality is greater than on all-age CHD mortality. Determining the most useful measures of quality of primary care needs further consideration.

Honeyford, Kate; Baker, Richard; Bankart, M John G; Jones, David

2013-01-01

386

The optimum Ga-67-citrate gamma camera imaging quality factors as first calculated and shown by the Taguchi's analysis.  

PubMed

In this work gallium-67 ((67)Ga) gamma camera imaging quality was optimized using the Taguchi's analysis and a planar phantom. The acrylic planar phantom was LASER-cut to form groups of slits 1mm wide and 5mm deep, to determine the spatial resolution and contrast ratio that could be achieved in a (67)Ga citrate nuclear medicine examination. The (67)Ga-citrate solution was injected into the slits to form an active radioactive line source which was placed between regular acrylic plates for optimization. Then, nine combinations of four operating factors: L9 (3((4)), of the gamma camera imaging system were used and followed the Taguchi's analysis. The four operating factors were: a) the type of collimator in front of the NaI(Tl) detector, b) the region of interest of (67)Ga gamma rays spectrum, c) the scanning speed of NaI(Tl) detector head and d) the activity of (67)Ga. The original judged grade of the planar phantom image quality was increased 36% and factors a) and b) were confirmed to dominate. The cross interaction among factors was also discussed. Our results showed that the optimal factor settings of the gamma camera imaging system were verified by performing a routine nuclear medicine examination in ten cases. Nine cases showed the same optimal settings as estimated by three highly trained radio-diagnostic physicians. Additionally, the optimal setting yielded clearer images with greater contrast than did the conventional settings. In conclusion, this work suggests for practical use an optimized process for determining both the spatial resolution and the contrast ratio of a gamma camera imaging system using Taguchi's optimal analysis and a planar phantom. The Taguchi's method is most effective in targeting a single quality characteristic but can also be extended to satisfy multiple requirements under specific conditions by revising the definition of signal to noise ratio. PMID:23529390

Yeh, Da Ming; Chang, Pai Jung; Pan, Lung Kwang

2013-03-26

387

Quality of life and related factors for people living with HIV/AIDS in Northern Taiwan.  

PubMed

The purpose of this study was to identify the variables related to quality of life in the population of individuals living with HIV/AIDS (PLWHA) in Taiwan. Purposive sampling was used to identify subjects from the outpatient departments (OPD) of three teaching hospitals and one sexually transmitted disease (STD) clinic in the Taipei area. For this study, the questionnaire included a demographic data sheet, physical-symptom distress and mood-disturbance scales, a personal-resource questionnaire (PRQ85-II) and a quality-of-life index (QLI). A total of 114 subjects completed the questionnaire. The results revealed that higher quality of life was associated with less mood disturbance (r = -.72; p <.001), reduced physical-symptom distress (r = -.47; r <.001), and higher levels of social support (r =.57; p <.001). PLWHA life quality was reflected accurately by mood disturbance, social support, physical-symptom distress, self-perceived mode of HIV transmission, and major source of financial support. These variables accounted for 60.9 % of QOL variance. As mood disturbance was the strongest predictor of quality of life, psychosocial intervention for mood disturbance should be emphasized and developed in future studies. PMID:14579199

Yang, Meei-Horng; Chen, Yi-Ming; Kuo, Benjamin In-Tian; Wang, Kwua-Yun

2003-09-01

388

Dehydration process of fish analyzed by neutron beam imaging  

NASA Astrophysics Data System (ADS)

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.

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

2009-06-01

389

Effective neutron targets  

SciTech Connect

Because of the lack of a free neutron target, deuterium targets have been used extensively in studying the neutron structure. The unique spin structure of the {sup 3}He ground state wave function and the recent developments in laser technologies made polarized {sup 3}He targets widely used in many experiments from neutron electromagnetic form factor studies to nucleon spin structure function measurements at all major electron accelerator facilities. In this talk, the current status of the polarized {sup 3}He targets will be reviewed. The author will focus on neutron electromagnetic form factor studies using polarized {sup 3}He targets. The polarized nucleon spin structure function measurements using polarized {sup 3}He targets will also be discussed.

Gao, H.

1997-07-01

390

Psychosocial factors and health as determinants of quality of life in community-dwelling older adults  

Microsoft Academic Search

Purpose  It is important to understand the determinants of differences in quality of life in old age and to include a wide range of\\u000a possible predictors. The present study investigated the determinants of quality of life in two groups of older adults for\\u000a whom there was an unusually informative set of possible predictor variables.\\u000a \\u000a \\u000a \\u000a \\u000a Method  Participants were members of the Lothian Birth

Caroline E. Brett; Alan J. Gow; Janie Corley; Alison Pattie; John M. Starr; Ian J. Deary

391

Influence of natural factors on the quality of midwestern streams and rivers  

USGS Publications Warehouse

Streams flowing through cropland in the Midwestern Corn Belt differ considerably in their chemical and ecological characteristics, even though agricultural land use is highly intensive throughout the entire region. These differences likely are attributable to differences in riparian vegetation, soil properties, and hydrology. This conclusion is based on results from a study of the upper Midwest region conducted during seasonally low-flow conditions in August 1997 by the U.S. Geological Survey (USGS) National Water Quality Assessment (NAWQA) Program. This report summarizes significant results from the study and presents some implications for the design and interpretation of water-quality monitoring and assessment studies based on these results.

Porter, Stephen D.; Harris, Mitchell A.; Kalkhoff, Stephen J.

2001-01-01

392

[Contribution to the study of some factors affecting semolina quality (author's transl)].  

PubMed

In order to identify certain chemical characteristics of semolina that might provide "a priori" information about its pasta making quality, their relationship to pasta cooking chatacteristics were analyzed. The correlation analysis gave significant values for the relationship between semolina reactive SH content and pasta resistance to disintegration and between urea dispersible protein protein content of semolina and pasta volume increase on cooking. The results obtained suggest that possibility of considering separately the results of the various pasta cooking tests in order to express a conclusive quality evaluation. PMID:989936

Scarascia Venezian, M E; Lombardi, M

393

Factors affecting surface quality in diamond turning of oxygen-free high-conductance copper.  

PubMed

In identical cutting conditions, it has been shown that the surface quality of ultraprecisely machined oxygen-free high-conductance copper samples, for which a single-point diamond tool is used, depends on the microstructure and properties of the materials, as well as the processing sequence. It has been found that samples subjected to colddeformation-recrystallization annealing have the best surface quality after being diamond turned. In addition, crystal uniformity and the processing sequence affect the roughness and residual stress of the finished surface. PMID:20885541

Zhang, H; Zhang, X

1994-04-01

394

Cylindrical detector and preamplifier design for detecting neutrons  

NASA Astrophysics Data System (ADS)

Tissue equivalent proportional counters are frequently used to measure dose and dose equivalent in mixed radiation fields that include neutrons; however, detectors simulating sites 1mum in diameter underestimate the quality factor, Q, for low energy neutrons because the recoil protons do not cross the detectors. Proportional counters simulating different site-sizes can be used to get a better neutron dose equivalent measurement since the range and stopping power of protons generated by neutrons in the tissue-equivalent walls depend on the energy of the primary neutrons. The differences in the spectra measured by different size detectors will provide additional information on the incident neutron energy. Monte Carlo N-particle extended (MCNPX) code was used to simulate neutron transportation in proportional counters of different simulated tissue diameter. These Monte Carlo results were tested using two solid walled tissue equivalent proportional counters, 2mm and 10mm in diameter, simulating tissue volumes 0.1mum and 0.5mum in diameter, housed in a single vacuum chamber. Both detectors are built with 3mm thick tissue equivalent plastic (A-150) walls and propane gas inside for dose measurement. Using these two detectors, the spectra were compared to determine the underestimation of y for large detector, and thereby obtain more information of the incident neutron particles. Based on the MCNPX simulation and experimental results, we can see that the smaller detector produces a larger average lineal energy than the larger detector, which means the larger detector (0.5mum diameter tissue equivalent size) underestimates the Q value for the low energy neutron, therefore underestimates the effective dose. These results confirm the results of the typical analysis of lineal energy as a function of site size.

Xia, Zhenghua

395

A study of neutron room scattering at RPCF  

SciTech Connect

High energy physics facilities must monitor the radiation doses received by their personnel. This monitoring can only be effective if the radiation detection devices can be calibrated with a good degree of accuracy. Radiation fields are usually composed of several types of radiation, including gamma rays, beta radiation, neutrons, etc. The neutron detection instruments respond not only to the neutrons coming directly from the source but also those scattered from the floor, walls, and ceiling. The amount of neutron scattering varies from site to site depending on the construction materials and layout of the building. The purpose of this study was to determine the scattered neutron fraction in the central volume of the calibration mezzanine of the Radiation Physics Calibration Facility (RPCF) at the Fermi National Accelerator Laboratory (Fermilab). At Fermilab, radiation workers dosimeters use CR39 for neutron detection, which are sent to an outside vendor for reading. As part of the quality assurance program, Fermilab routinely sends the vendor ``spiked`` badges, i.e. badges exposed to a known amount of neutron dosage at RPCF. This study determines a correction factor due to scattered neutron to the spiked badges. The study was conducted in a room with floor dimensions of 12 m by 9.5 m. The walls and ceiling are thin steel and insulation supported by steel 1-beams. We determined the total amount of radiation at three heights above the floor, and at three distances from an AmBe neutron source at each height in the RPCF using the Bonner Sphere technique.

Kemp, A.; Boehnlein, D.; Elwyn, A.; Vaziri, K.

1996-09-01

396

The Effect of Landuse and Other External Factors on Water Quality Within two Creeks in Northern Kentucky  

NASA Astrophysics Data System (ADS)

The purpose of this study was to monitor the water quality in two creeks in Northern Kentucky. These are the Banklick Creek in Kenton County and the Woolper Creek in Boone County, Kentucky. The objective was to evaluate the effect of landuse and other external factors on surface water quality. Landuse within the Banklick watershed is industrial, forest and residential (urban) whereas that of Woolper Creek is agricultural and residential (rural). Two testing sites were selected along the Banklick Creek; one site was upstream the confluence with an overflow stream from an adjacent lake; the second site was downstream the confluence. Most of the drainage into the lake is over a near-by industrial park and the urban residential areas of the cities of Elsmere and Erlanger, Kentucky. Four sampling locations were selected within the Woolper Creek watershed to evaluate the effect of channelization and subsequent sedimentation on the health of the creek. Water quality parameters tested for include dissolved oxygen, phosphates, chlorophyll, total suspended sediments (TSS), pH, oxidation reduction potential (ORP), nitrates, and electrical conductivity. Sampling and testing were conducted weekly and also immediately after storm events that occurred before the regular sampling dates. Sampling and testing proceeded over a period of 29 weeks. Biological impact was determined, only in Woolper Creek watershed, by sampling benthic macroinvertebrates once every four weeks. The results showed significant differences in the water quality between the two sites within the Banklick Creek. The water quality may be affected by the stream overflow from the dammed lake. Also, channelization in the Woolper Creek seemed to have adverse effects on the water quality. A retention pond, constructed to prevent sediments from flowing into the Woolper Creek, did not seem to be effective. This is because the water quality downstream of the retention pond was significantly worse than that of the upstream site. The benthic macroinvertebrates sampled indicate worse water quality downstream of the sediment retention pond. Overall, landuse and the channelization have some effect on the water quality in the two creeks.

Boateng, S.

2006-05-01

397

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

PubMed

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 optimized. PMID:10435523

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

1999-07-01

398

Quality of life in relation to social and disease factors in patients with type 2 diabetes in Lithuania  

PubMed Central

Background Diabetic patients are more than twice as costly to manage as non-diabetic patients, due mainly to the high costs associated with management of diabetic complications. As in most nations of the world, the number of patients with DM is increasing every year in Lithuania. The aim of this study was to determine relation between quality of the life and disease and social factors of patients with type 2 diabetes in Lithuania. Material/Methods Independently prepared questions about the subjects of the survey were: gender; age; weight; education; social and marital status; duration of the disease (in years); treatment method; complications; morbidity with arterial hypertension; change in dietary habits after diagnosis of diabetes (started to eat accordingly to recommendations of the therapist); how often nourishment is taken accordingly to recommendations of the therapist; if beginning to exercise after diagnosis of the diabetes; and if exercising, exercises at least 2–3 times per week. Body mass index was calculated as the relation between body mass in kg and height m square (BMI=kg/m2). The hospital anxiety and depression (HAD) scale was used for the evaluation of depression and anxiety. Quality of life of patients was evaluated with the SF-36 questionnaire. We surveyed 1022 patients with type 2 diabetes (372 men and 650 women). Association between quality of the life and explanatory parameters (disease and social factors) were analyzed using the logistic regression analysis model. Results We found that women had lower scores than men in all fields of quality of life (p<0.001). Peroral treatment had a positive impact on the quality of life (QL) fields of the role limitations due to emotional problems (ORa 0.16. 95% CI 0.07–0.34; p<0.001). Treatment with insulin had a positive effect on restriction of activity because of emotional problems (ORa ? 0.23. 95% CI 0.11–0.49; p<0.001) and mental health (ORa ? 0.38. 95% CI 0.19–0.78; p=0.008), but had a negative impact on bodily pain (ORa ? 3.95. 95% CI 1.41–11.09; p=0.009) and physical health (ORa ? 4.14. 95% CI 2.03–8.47; p<0.001). Conclusions Age and BMI are less important factors that can influence quality of life. Peroral treatment positively acted on the role limitations due to emotional problems, bodily pain, and mental health, but had a strong negative effect on emotional state.

Mikailiukstiene, Aldona; Juozulynas, Algirdas; Narkauskaite, Laura; Zagminas, Kestutis; Salyga, Jonas; Stukas, Rimantas

2013-01-01

399

The Postgraduate Hospital Educational Environment Measure (PHEEM) Questionnaire Identifies Quality of Instruction as a Key Factor Predicting Academic Achievement  

PubMed Central

OBJECTIVE This study analyzes the reliability of the PHEEM questionnaire translated into Portuguese. We present the results of PHEEM following distribution to doctors in three different medical residency programs at a university hospital in Brazil. INTRODUCTION Efforts to understand environmental factors that foster effective learning resulted in the development of a questionnaire to measure medical residents’ perceptions of the level of autonomy, teaching quality and social support in their programs. METHODS The questionnaire was translated using the modified Brislin back-translation technique. Cronbach’s alpha test was used to ensure good reliability and ANOVA was used to compare PHEEM results among residents from the Surgery, Anesthesiology and Internal Medicine departments. The Kappa coefficient was used as a measure of agreement, and factor analysis was employed to evaluate the construct strength of the three domains suggested by the original PHEEM questionnaire. RESULTS The PHEEM survey was completed by 306 medical residents and the resulting Cronbach’s alpha was 0.899. The weighted Kappa was showed excellent reliability. Autonomy was rated most highly by Internal Medicine residents (63.7% ± 13.6%). Teaching was rated highest in Anesthesiology (66.7% ± 15.4%). Residents across the three areas had similar perceptions of social support (59.0% ± 13.3% for Surgery; 60.5% ± 13.6% for Internal Medicine; 61.4% ± 14.4% for Anesthesiology). Factor analysis suggested that nine factors explained 58.9% of the variance. CONCLUSIONS This study indicates that PHEEM is a reliable instrument for measuring the quality of medical residency programs at a Brazilian teaching hospital. The results suggest that quality of teaching was the best indicator of overall response to the questionnaire.

Vieira, Joaquim Edson

2008-01-01

400

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

SciTech Connect

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 {times} 10{sup 8} n/cm{sup 2} {center_dot} s. The fast neutron and gamma radiation KERMA factors are 10 {times} 10{sup {minus}11}cGy{center_dot}cm{sup 2}/n{sub epi} and 20 {times} 10{sup {minus}11} cGy{center_dot}cm{sup 2}/n{sub epi}, 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.

Burns, T.D. Jr.

1995-05-01

401

A New Concept of the Power Quality Temperature Factor and Its Experimental Verification  

Microsoft Academic Search

One of the features of ship power systems is the presence of different power quality disturbances, such as frequency and voltage root-mean-square (rms) value deviations, unbalance, and voltage waveform distortions. The disturbances (including their synergy) cause an increase in the windings temperature of marine induction machines that are exposed to overheating, even if the voltage parameters fulfill the requirements of

Piotr Gnacinski; Janusz Mindykowski; Tomasz Tarasiuk

2008-01-01

402

Compassion Fatigue, Compassion Satisfaction, and Burnout: Factors Impacting a Professional's Quality of Life  

Microsoft Academic Search

This study examined the relationship between three variables, compassion fatigue (CF), compassion satisfaction (CS), and burnout, and provider and setting characteristics in a sample of 1,121 mental health providers in a rural southern state. Respondents completed the Professional Quality of Life Scale as part of a larger survey of provider practice patterns. Female gender was associated with higher levels of

Ginny Sprang; James J. Clark; Adrienne Whitt-Woosley

2007-01-01

403

On the quality of construction engineering design projects : criteria and impacting factors  

Microsoft Academic Search

Utilizes approaches from systems analysis, quality management and previous empirical results to formulate the framework for the study. Took selected engineering consulting firms in Taiwan as research subjects for the empirical portion of the studies. The scope is restricted to the design phase of the construction project. Synthesizes an AHP architecture from the system concept and total management philosophy and

Raykun R. Tan; Yaw-Guang Lu

1995-01-01

404

Compassion Fatigue, Compassion Satisfaction, and Burnout: Factors Impacting a Professional's Quality of Life  

ERIC Educational Resources Information Center

|This study examined the relationship between three variables, compassion fatigue (CF), compassion satisfaction (CS), and burnout, and provider and setting characteristics in a sample of 1,121 mental health providers in a rural southern state. Respondents completed the Professional Quality of Life Scale as part of a larger survey of provider…

Sprang, Ginny; Whitt-Woosley, Adrienne; Clark, James J.

2007-01-01

405

Economic Factors and Relationship Quality among Young Couples: Comparing Cohabitation and Marriage  

ERIC Educational Resources Information Center

|Are economic resources related to relationship quality among young couples, and to what extent does this vary by relationship type? To answer these questions, we estimated regression models predicting respondent reports of conflict and affection in cohabiting and married partner relationships using the National Longitudinal Study of Youth, 1997…

Hardie, Jessica Halliday; Lucas, Amy

2010-01-01

406

QUALITY OF SLEEP AND PSYCHOSOCIAL FACTORS FOR PATIENTS UNDERGOING PERITONEAL DIALYSIS  

Microsoft Academic Search

? ? ? ? ? Objectives: Sleep disorders are common in end-stage renal disease patients. This study examined the relation- ship between self-reported quality of sleep (QoS) and cer- tain psychosocial domains for patients on peritoneal dialysis (PD). ? ? ? ? ? Methods: The study subjects included 190 PD patients from 7 urban dialysis clinics in Northern Taiwan, from

Ju-Yeh Yang; Jenq-Wen Huang; Yu-Sen Peng; Shou-Shang Chiang; Chwei-Shiun Yang; Chin-Ching Yang; Huey-Wen Chen; Ming-Shiou Wu; Kwan-Dun Wu; Tun-Jun Tsai; Wan-Yu Chen

407

Children of Incarcerated Mothers and Their Caregivers: Factors Affecting the Quality of Their Relationship  

Microsoft Academic Search

We examined the quality of the relationship between children of incarcerated mothers and their kinship caregivers, to investigate whether perceived levels of warmth and acceptance were related to assessments of the children's behaviors. The sample consisted of 69 children (6 to 12 years) with currently incarcerated mothers who attended a recreational summer camp, and 25 of their caregivers. Children who

Virginia H. Mackintosh; Barbara J. Myers; Suzanne S. Kennon

2006-01-01

408

Mineral Mixture Composition - a Factor in Chick Bioassays of the Protein Quality of Fish Meals.  

National Technical Information Service (NTIS)

The evaluation of the quality of the protein in fish meals fed to chicks as a sole source protein is influenced by the composition of the mineral mixture included in the test diet. Antiacids were found to be beneficial supplements for some fish meals. The...

D. Miller

1970-01-01

409

Characterization and Factors Associated with Sleep Quality in Adolescents with Bipolar I Disorder  

ERIC Educational Resources Information Center

|Sleep disturbance is an early marker for bipolar disorder (BD) onset in youth. We characterized sleep quality in adolescents experiencing mania within the last 6-12 months. We examined the association between mood and sleep in 27 adolescents with BD and 24 matched healthy controls (HC). Subjects were assessed by parent and teen report of sleep, a…

Roybal, Donna J.; Chang, Kiki D.; Chen, Michael C.; Howe, Meghan E.; Gotlib, Ian H.; Singh, Manpreet K.

2011-01-01

410

The Quality of Reflection in Student Journals: A Review of Limiting and Enabling Factors  

ERIC Educational Resources Information Center

Although reflective journals are widely used across many disciplines in higher education, the research that examines their use presents an unclear picture of the quality of reflection found in them. Some research reveals that student journals contain primarily deeply reflective entries. Yet other research presents a less optimistic perspective,…

Dyment, Janet E.; O'Connell, Timothy S.

2010-01-01

411

Validity of the Quality of School Life Scale: A Primary and Second-Order Factor Analysis  

Microsoft Academic Search

A primary and second-order principal components analysis was performed on the Quality of School Life Scale (QSL), a popular measure of elementary school climate. The scale was administered to 141 fourth-, fifth-, and sixth-grade students in an elementary school in the Southwestern United States. The findings of this study, like the information reported in the Administration and Technical Manual for

William L. Johnson; Annabel M. Johnson

1993-01-01

412

Examining the Impact of Environmental Factors on Quality of Life across Massachusetts  

Microsoft Academic Search

Several studies indicate that there are significant relationships among quality of life, green vegetation, and socioeconomic conditions, particularly in urban environments. The purpose of this research is twofold: (1) to compare two weighting and aggregation techniques, data envelopment analysis (DEA) and principal components analysis (PCA), in the development of a socioeconomic index; and (2) to test for and explore spatial

Yelena Ogneva-Himmelberger; Rahul Rakshit; Hamil Pearsall

2012-01-01

413

A Taxonomy of Factors to Promote Quality Web-Supported Learning  

ERIC Educational Resources Information Center

|This article reports on a case study of the e-learning production unit at the University of Pretoria, South Africa. Phase 1 of the study, completed in 2003, was the design and development of a process-based quality management system for web-supported learning (WSL) using a basic ISO 9000 approach (University of Pretoria, 2003). The second phase,…

Fresen, Jill

2007-01-01

414

Linking Public Attitudes with Perceptions of Factors Impacting Water Quality and Attending Learning Activities  

ERIC Educational Resources Information Center

|Increasingly, people are being asked to make decisions about water use in the semi-arid regions of the United States. "Good decisions" depend on an understanding of the linkages between sustainability of the resource, management, and economic development. This article reports on findings from a water quality survey conducted in Colorado, Montana,…

Clay, D. E.; Ren, C.; Reese, C.; Waskom, R.; Bauder, J.; Mesner, N.; Paige, G.; Reddy, K.; Neibauer, M.; Mahler, R.

2007-01-01

415

A Comparison of Factors that Influence the Quality of PEPs in Title I Schools  

ERIC Educational Resources Information Center

The purpose of this study was to investigate the relationship between school-based organizational structures that support teachers' development of Personalized Education Plans (PEPs) and their quality as written for third through fifth grade students in each of two Title I schools. A causal comparative design was implemented. Teachers' responses…

Williams, Connie Jean

2009-01-01

416

Factors affecting quality of life after minimally invasive Heller myotomy for achalasia.  

PubMed

The effect of prior nonoperative treatment, type of fundoplication, and surgical approach on quality of life after minimally invasive Heller myotomy (MIHM) for achalasia in not known. MIHM for achalasia was performed in 105 patients (primary 102; redo 3). Sixty-five patients had prior nonoperative treatment (dilations in 41; botulinum toxin injections in 13; dilations and botulinum toxin injections in 11). Primary laparoscopic MIHM with fundoplication (Dor in 32; Toupet in 56) was performed in 88 patients and thoracoscopic MIHM without fundoplication in 14. Achalasia and quality-of-life-related symptoms were evaluated prospectively with a visual analogue scoring scale. Median follow-up was 25 months. There was a trend toward a higher incidence of intraoperative esophageal perforation and recurrent dysphagia in patients with prior nonoperative treatment. Patients with prior nonoperative treatment had significant improvement in achalasia-related symptoms postoperatively. Patients with prior botulinum toxin injections with or without dilations had no improvement in quality of life after MIHM. The operative success of MIHM may be compromised if prior nonoperative treatment is used. Botulinum toxin injections may blunt the beneficial effect of MIHM on quality of life. The outcome of MIHM is good regardless of the type of fundoplication or surgical approach. PMID:15019914

Raftopoulos, Yannis; Landreneau, Rodney J; Hayetian, Fernando; Papasavas, Pavlos; Naunheim, Keith S; Hazelrigg, Steven R; Santos, Ricardo; Gagné, Daniel; Caushaj, Philip; Keenan, Robert J

417

Paternal Relationship Quality as a Protective Factor: Preventing Alcohol Use among African American Adolescents  

ERIC Educational Resources Information Center

|This study examines the effects of father involvement on alcohol consumption in African American adolescents. A representative sample of 1,027 students was selected from a national longitudinal study of adolescents in grades 7 through 12. Family structure and relationship quality were examined for three groups of fathers: nonresidential fathers,…

Jordan, Lisa C.; Lewis, Melissa L.

2005-01-01

418

Factors Influencing the Success and Failure of Two Quality Circle Programs  

Microsoft Academic Search

Quality circle (QC) programs instituted in two Department of Defense (DOD) organizations were evaluated within the framework of a nonequivalent control group design. Two waves of survey data were collected from 107 members of a military maintenance organization and 165 employees of a medical facility located on the same DOD installation. Analysis of covariance procedures on data from the maintenance

Robert P. Steel; Anthony J. Mento; Benjamin L. Dilla; Nestor K. Ovalle; Russell F. Lloyd

1985-01-01

419

Genetic and management factors affecting beef quality in grazing Hereford steers.  

PubMed

Attributes contributing to differences in beef quality of 206 Hereford steers finished on pasture were assessed. Beef quality traits evaluated were: Warner-Bratzler meat tenderness and muscle and fat color at one and seven days after slaughter and trained sensory panel traits (tenderness, juiciness, flavor, and marbling) at seven days. Molecular markers were CAPN1 316 and an SNP in exon 2 on the leptin gene (E2FB). Average daily live weight gain, ultrasound monthly backfat thickness gain and rib-eye area gain were estimated. Molecular markers effects on meat quality traits were analyzed by mixed models. Association of meat quality with post weaning growth traits was analyzed by canonical correlations. Muscle color and marbling were affected by CAPN1 316 and E2FB and Warner-Bratzler meat tenderness by the former. The results confirm that marker assisted selection for tenderness is advisable only when beef aging is a common practice. The most important sources of variation in tenderness and color of meat remained unaccounted for. PMID:22818350

Melucci, L M; Panarace, M; Feula, P; Villarreal, E L; Grigioni, G; Carduza, F; Soria, L A; Mezzadra, C A; Arceo, M E; Papaleo Mazzucco, J; Corva, P M; Irurueta, M; Rogberg-Muñoz, A; Miquel, M C

2012-06-29

420

Quality of offspring? Sociocultural factors, pre-natal testing and reproductive decision-making in Japan  

Microsoft Academic Search

Japan is one of the few countries to have enacted legislation on eugenics. Consequently, there has been active public debate about the practice of selective abortion for over 35 years. Furthermore, discrimination against disabilities is deep-rooted in Japanese society and the quality of offspring is a common concern. Given this background, the obvious conclusion might be that couples in Japan

Masae Kato

2010-01-01

421

Management Tools and Organization as Key Factors Towards Quality Care: Reflections from Experience  

Microsoft Academic Search

Health care organization in French hospitals has become an increasingly important issue, as efforts to ensure better cost control have Increased financial constraints, as patients hare demanded ever better results and quality, and as nurses' expectations for better working conditions have grown. Organiz- ing a health care unit requires an articulation between individual efforts — necessary both for gathering accurate

DOMINIQUE TONNEAU

1997-01-01

422

Study on the various factors affecting the quality of precipitated non-metallurgical alumina trihydrate particles  

Microsoft Academic Search

Processes for production of superfine white alumina trihydroxide (ATH) powders from actual plant Bayer liquor have been developed for use in non-metallurgical applications. The specialty grade hydroxides suitable for non-metallurgical application should conform to certain qualities such as fineness, purity, brightness, etc. The effect of a number of parameters such as precipitation temperature, amount of seed, seed surface area, precipitation

J. K. Pradhan; P. K. Gochhayat; I. N. Bhattacharya; S. C. Das

2001-01-01

423

Pollutant fate and spatio-temporal variability in the choptank river estuary: factors influencing water quality  

Technology Transfer Automated Retrieval System (TEKTRAN)

Restoration of the Chesapeake Bay, a national treasure and the largest estuary in the United States, is a national priority, and documentation of progress of this restoration effort is needed. A study was conducted to examine water quality conditions in a tributary of the Chesapeake, the Choptank R...

424

Small scale biomass heating systems: Standards, quality labelling and market driving factors – An EU outlook  

Microsoft Academic Search

In the present study a comparative evaluation of several existing quality labels and standards for small scale biomass heating systems (BHS) and the biomass fuels they use was performed. With the introduction of pellet fuels, biomass heating technology achieved enough maturity to successfully compete with oil\\/gas heating devices in terms of ease of use, utilization of energy and pollutant emissions.From

V. K. Verma; S. Bram; J. De Ruyck

2009-01-01

425

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

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.

Thomas, J.T.

1984-10-01

426

Effects of bioprocessed antinutritional factors on bean protein quality, with special emphasis on Phaseolus vulgaris L  

Microsoft Academic Search

Legumes, e.g. beans and peas, can contain antinutritional factors. Some varieties of faba beans (Vicia faba), soya beans (Glycine max ) and white kidney beans (Phaseolus vulgaris) can contain in their raw state antinutritional factors such as tannins, trypsin inhibitors and lectins respectively which negatively effect the protein digestibility by nonruminants e.g. pigs. Also the storage protein is not easily

F. H. M. G. Savelkoul

1994-01-01

427

Capacitive power factor and power quality correction of a light rail transportation system  

Microsoft Academic Search

This paper discusses an application of a method for dynamic power factor correction and voltage regulation in light rail transportation systems. The MV underground power cables installed for the distribution of 34.5 kV power substations cause a very poor capacitive reactive power factor. The technical specification of the customer was based on the dynamic compensation of the consumed electrical energy

U. Celtekligil

2008-01-01

428

Improving the Quality and Scientific Understanding of Trophic Magnification Factors (TMFs)  

EPA Science Inventory

This short 1000 word report presents a series of research needs for improving the measurement and understanding of trophic magnification factors (TMFs). TMFs are useful measures of trophic magnification and represent the diet-weighted average biomagnification factor (BMF) of che...

429

Pollutant fate and spatio-temporal variability in the choptank river estuary: factors influencing water quality.  

PubMed

Restoration of the Chesapeake Bay, the largest estuary in the United States, is a national priority. Documentation of progress of this restoration effort is needed. A study was conducted to examine water quality in the Choptank River estuary, a tributary of the Chesapeake Bay that since 1998 has been classified as impaired waters under the Federal Clean Water Act. Multiple water quality parameters (salinity, temperature, dissolved oxygen, chlorophyll a) and analyte concentrations (nutrients, herbicide and herbicide degradation products, arsenic, and copper) were measured at seven sampling stations in the Choptank River estuary. Samples were collected under base flow conditions in the basin on thirteen dates between March 2005 and April 2008. As commonly observed, results indicate that agriculture is a primary source of nitrate in the estuary and that both agriculture and wastewater treatment plants are important sources of phosphorus. Concentrations of copper in the lower estuary consistently exceeded both chronic and acute water quality criteria, possibly due to use of copper in antifouling boat paint. Concentrations of copper in the upstream watersheds were low, indicating that agriculture is not a significant source of copper loading to the estuary. Concentrations of herbicides (atrazine, simazine, and metolachlor) peaked during early-summer, indicating a rapid surface-transport delivery pathway from agricultural areas, while their degradation products (CIAT, CEAT, MESA, and MOA) appeared to be delivered via groundwater transport. Some in-river processing of CEAT occurred, whereas MESA was conservative. Observed concentrations of herbicide residues did not approach established levels of concern for aquatic organisms. Results of this study highlight the importance of continued implementation of best management practices to improve water quality in the estuary. This work provides a baseline against which to compare future changes in water quality and may be used to design future monitoring programs needed to assess restoration strategy efficacy. PMID:20171715

Whitall, David; Hively, W Dean; Leight, Andrew K; Hapeman, Cathleen J; McConnell, Laura L; Fisher, Thomas; Rice, Clifford P; Codling, Eton; McCarty, Gregory W; Sadeghi, Ali M; Gustafson, Anne; Bialek, Krystyna

2010-02-20

430

Visual factors and image analysis in the encoding of high-quality still images  

NASA Astrophysics Data System (ADS)

In the encoding of high quality images beyond current standards, a reexamination of issues in the representation, processing and encoding problems is needed. The fundamental reason for that change of emphasis is that the image representation, sampling density, color and motion parameters are no longer given by accepted practices or standards and, thus, require study. Some basic issues that should be reconsidered are as follows: (1) The theoretical or limiting information content of images viewed at a fixed viewing distance, as the scanning grid becomes denser and denser. This limit is determined fundamentally by the properties of the human visual system. In particular, attention must be given to the representation of very high quality color images, an issue that is currently poorly handled in television engineering practice. (2) The display or output in print or on other media of high quality color images. Since the possibility now exists of using an output device which has a resolution substantially higher than the representation or scanning grid, the interpolation of images to take advantage of this higher output grid becomes an important issue. Common approaches to interpolation are not suited to maintain high image quality. (3) With increasing resolution, the critical image information to the perception of high quality occurs, in general, in a few portions of the image, and is associated to definite image structures, such as edges, streaks, corners, and texture. It may therefore be important, for both encoding and interpolation purposes, to perform some image analysis that will detect the presence of a structure of interest, and determine accordingly the most effective encoding or processing strategy. In this paper, we examine briefly each of these issues, establish some preliminary results, and illustrate some of the issues and approaches to these problems. The purpose of this paper is to cast the problem formulations in broad terms and then follow with a few specific results and a discussion.

Algazi, V. Ralph; Reed, Todd R.; Ford, Gary E.; Estes, Robert R.

1991-11-01

431

Traditional and emerging forms of dental practice. Cost, accessibility, and quality factors.  

PubMed Central

The traditional and predominant manner of delivering dental care is through a fee-for-service, private practice system. A number of alternative dental care delivery systems have emerged and are being tested, and others are just emerging. These systems include department store practices, hospital dental services, health maintenance organizations, the independent practice of dental hygiene, and denturism. Although it is too soon to draw final conclusions about the efficacy and effectiveness of these systems, we examine them for their potential to compete with and change the way dental care is currently delivered. Using the parameters of cost, accessibility, and quality, we compare these systems to traditional dental practice. Some of these emerging forms clearly have the potential to complete favorably with traditional practice. Other seem less likely to alter the existing system substantially. The system which can best control costs, increase accessibility, and enhance quality will gain the competitive edge.

Rovin, S; Nash, J

1982-01-01

432

Dietary Quality and Lifestyle Factors in Relation to 10Year Mortality in Older Europeans  

Microsoft Academic Search

The single and combined effects of three healthy lifestyle behaviors—nonsmoking, being physically active, and having a high-quality diet—on survival were investigated among older people in the SENECA Study. This European longitudinal study started with baseline measurements in 1988-1989 and lasted until April 30, 1999. The study population consisted of 631 men and 650 women aged 70-75 years from Belgium, Denmark,

Annemien Haveman-Nies; P. G. M. de Groot; Jan Burema; José A. Amorim Cruz; Merete Osler; Wija A. van Staveren

2002-01-01

433

Potential factors affecting semen quality in the Asian elephant (Elephas maximus)  

Microsoft Academic Search

BACKGROUND: One of the major obstacles in using artificial insemination to manage genetics of elephant population in captivity is the large variations in semen quality among ejaculates within the same and among individuals. The objectives of this study were to determine the influences of (1) age (2) seasonality (3) and circulating testosterone (SrTest), triiodothyronine (SrT3) and tetraiodothyronine (SrT4), as well

Nikorn Thongtip; Jumnian Saikhun; Sittidet Mahasawangkul; Kornchai Kornkaewrat; Pornsawan Pongsopavijitr; Nucharin Songsasen; Anuchai Pinyopummin

2008-01-01

434

Characterization and Factors Associated with Sleep Quality in Adolescents with Bipolar I Disorder  

Microsoft Academic Search

Sleep disturbance is an early marker for bipolar disorder (BD) onset in youth. We characterized sleep quality in adolescents\\u000a experiencing mania within the last 6-12 months. We examined the association between mood and sleep in 27 adolescents with\\u000a BD and 24 matched healthy controls (HC). Subjects were assessed by parent and teen report of sleep, a semi-structured clinical\\u000a interview, the Young

Donna J. Roybal; Kiki D. Chang; Michael C. Chen; Meghan E. Howe; Ian H. Gotlib; Manpreet K. Singh

435

Factors Affecting Groundwater Quality in the Valley and Ridge Aquifers, Eastern United States, 1993-2002.  

National Technical Information Service (NTIS)

Chemical and microbiological analyses of water from 230 wells and 35 springs in the Valley and Ridge Physiographic Province, sampled between 1993 and 2002, indicated that bedrock type (carbonate or siliciclastic rock) and land use were dominant factors in...

B. D. Lindsey E. L. Gross G. C. Johnson T. M. Zimmerman

2011-01-01

436

Review of factors influencing underground construction quality and the performance of engineered features.  

National Technical Information Service (NTIS)

This report describes research to identify and rank the factors that should be considered for an assessment of the radioactive containment capability of repository engineered features. Containment is to be achieved through the use of multiple barriers to ...

R. Talbot D. Moy C. D. Breeds C. M. Kostelec S. J. Emsley

1992-01-01

437

Risk Factors for Superficial vs Deep/Organ-Space Surgical Site Infections: Implications for Quality Improvement Initiatives.  

PubMed

IMPORTANCE Surgical site infections (SSIs) are the focus of numerous quality improvement initiatives because they are a common and costly cause of potentially preventable patient morbidity. Superficial and deep/organ-space SSIs differ in terms of anatomical location and clinical severity. OBJECTIVE To identify risk factors that are uniquely predictive of superficial vs deep/organ-space SSIs occurring after colectomy procedures. DESIGN Retrospective cohort study. SETTING American College of Surgeons National Surgical Quality Improvement Program. PARTICIPANTS Patients undergoing colectomy procedures in 2011 were identified by Current Procedural Terminology codes. INTERVENTION Colectomy procedures. MAIN OUTCOMES AND MEASURES We compared rates of superficial SSI and deep/organ-space SSI associated with perioperative variables of interest: demographics; preoperative clinical severity, risk factors, and comorbidities and variables related to the hospitalization or procedure. Hierarchical multivariable logistic regression models were developed to identify risk-adjusted predictors of each SSI type. RESULTS Among 27?011 patients identified from 305 hospitals, 6.2% developed a superficial SSI and 4.7% developed a deep/organ-space SSI. Risk factors common to the occurrence of both SSI types were identified: open surgery (vs laparoscopic) and current smoker. Risk factors with differential effects on each SSI type included specific postoperative diagnoses, disseminated cancer, and irradiation therapy, which were all associated with increased odds of deep/organ-space SSI only. The graded relationship between increasing body mass index and SSI occurrence appeared to be stronger for superficial SSI. CONCLUSIONS AND RELEVANCE Risk factors for superficial SSI and deep/organ-space SSI vary in terms of magnitude and significance, suggesting that these SSI types are somewhat different disease processes. Groups interested in preventing SSIs might improve success by considering these SSI types independently for root-cause analyses and development of best practices and interventions. PMID:23864108

Lawson, Elise H; Hall, Bruce Lee; Ko, Clifford Y

2013-09-01

438

Factors Affecting Sperm Quality Before and After Mating of Calopterygid Damselflies  

PubMed Central

Damselflies (Odonata: Zygoptera) have a more complex sperm transfer system than other internally ejaculating insects. Males translocate sperm from the internal reproductive organs to the specific sperm vesicles, a small cavity on the body surface, and then transfer them into the female. To examine how the additional steps of sperm transfer contribute to decreases in sperm quality, we assessed sperm viability (the proportion of live sperm) at each stage of mating and after different storage times in male and female reproductive organs in two damselfly species, Mnais pruinosa and Calopteryx cornelia. Viability of stored sperm in females was lower than that of male stores even just after copulation. Male sperm vesicles were not equipped to maintain sperm quality for longer periods than the internal reproductive organs. However, the sperm vesicles were only used for short-term storage; therefore, this process appeared unlikely to reduce sperm viability when transferred to the female. Males remove rival sperm prior to transfer of their own ejaculate using a peculiar-shaped aedeagus, but sperm removal by males is not always complete. Thus, dilution occurs between newly received sperm and aged sperm already stored in the female, causing lower viability of sperm inside the female than that of sperm transferred by males. If females do not remate, sperm viability gradually decreases with the duration of storage. Frequent mating of females may therefore contribute to the maintenance of high sperm quality.

Tsuchiya, Kaori; Hayashi, Fumio

2010-01-01

439

Aitchbone hanging and ageing period are additive factors influencing pork eating quality.  

PubMed

The effects of abattoir, carcase weight (60 or 80kg HCW), hanging method (Achilles or aitchbone) and ageing period (2 or 7day post-slaughter) on eating quality attributes of pork were investigated in this 3×2×2×2 factorial study. A total of 144 Large White×Landrace female pigs were slaughtered at one of three abattoirs and sides hung from either the Achilles tendon or the aitchbone. After 24h chilling, loin (M. longissimus thoracis et lumborum) and topside (M. semimembranosus) muscles were individually vacuum packaged and aged for 2 or 7days post-slaughter. Consumers (n=852) evaluated eating quality. Neither abattoir nor carcase weight influenced tenderness, flavour or overall liking of pork. Improvements in tenderness, flavour and overall liking were found due to aitchbone hanging (P<0.001) and ageing (P<0.001) for 7days compared with Achilles-hung carcases and pork aged for 2days, respectively. This study demonstrated that aitchbone hanging and 7day ageing can improve eating quality, but these effects were additive as the interaction term was not significant. PMID:24013699

Channon, H A; Taverner, M R; D'Souza, D N; Warner, R D

2013-08-14

440

Factors influencing quality of life in Moroccan postmenopausal women with osteoporotic vertebral fracture assessed by ECOS 16 questionnaire  

PubMed Central

Objective The aim of the study was to evaluate factors influencing quality of life (QOL) in Moroccan postmenopausal women with osteoporotic vertebral fracture assessed by the Arabic version of ECOS 16 questionnaire. Methods 357 postmenopausal women were included in this study. The participants underwent bone mineral density (BMD) measurements by DXA of the lumbar spine and the total hip as well as X-ray examination of the thoraco-lumbar spine to identify subclinical vertebral fractures. Patients were asked to complete a questionnaire on clinical and sociodemographic parameters, and osteoporosis risk factors. The Arabic version of the ECOS16 (Assessment of health related quality of life in osteoporosis questionnaire) was used to assess quality of life. Results The mean age was