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1

Microscopic description of nucleon-nucleus total reaction cross sections  

SciTech Connect

Microscopic calculations of the total reaction cross sections for protons on /sup 12/C, /sup 27/Al, /sup 40/Ca, and /sup 208/Pb, and neutrons on /sup 27/Al and /sup 208/Pb have been made, which provide for the first time an excellent description of the data for projectile energies from 15 MeV through 1 GeV. The calculations are based on the experimental nucleon-nucleon total cross sections and explicitly include the effects of the real nuclear potential, the Coulomb potential, Pauli blocking, and Fermi motion.

DiGiacomo, N.J.; DeVries, R.M.; Peng, J.C.

1980-08-18

2

Measurement of correlated b quark cross sections at CDF  

SciTech Connect

Using data collected during the 1992--93 collider run at Fermilab, CDF has made measurements of correlated b quark cross section where one b is detected from a muon from semileptonic decay and the second b is detected with secondary vertex techniques. We report on measurements of the cross section as a function of the momentum of the second b and as a function of the azimuthal separation of the two b quarks, for transverse momentum of the initial b quark greater than 15 GeV. Results are compared to QCD predictions.

Gerdes, D.; CDF Collaboration

1994-09-01

3

b Quark production cross sections and the b {minus} {bar b} correlated production cross section at CDF  

SciTech Connect

Recent results on b quark and B meson production cross sections have been obtained at {radical}s = 1.8 TeV proton-antiproton collisions using the Collider Detector Facility (CDF) at Fermilab, using the exclusive decay modes B{sup {+-}} {yields}J/{Psi} K{sup {+-}} and B{sup 0} {yields} J/{Psi} K*. Another measurement made using data from the 1988--89 run on the correlated b + {bar b} cross section is also presented.

Huffman, B.T. [Pittsburgh Univ., PA (United States); CDF Collaboration

1993-09-01

4

Sequence stratigraphic correlation of well-log cross sections  

SciTech Connect

Correlation of well-log cross sections using the principles of sequence stratigraphy is not as straight forward as it might at first appear. It is a very subjective process, being an interpretation of limited data based on the geologist's knowledge and experience, and consequently, the results can be as varied as the interpreters who do the work. Many decisions are required at each step of the correlation process, and they may be made subjectively (to fit a preconceived understanding of the stratigraphy) or as objectively as possible. Experience has yielded a number of guidelines and [open quotes]rules of thumb[close quotes] that make the process easier and, if not more objective, at least provide a clearer understanding of what assumptions are being made and how they affect the correlation decisions underlying the finished product. This paper provides some of those guidelines. 9 refs., 4 figs.

Mulholland, J.W.

1994-07-01

5

Correlations in the in-medium nucleon-nucleon cross section  

SciTech Connect

The influence of the ground state correlations on the in-medium nucleon-nucleon cross section is investigated in the framework of an extended Brueckner-Hartree-Fock theory of nuclear matter. The effect of the correlations is to overwhelm the suppression of the in-medium {ital NN} cross section already established in previous approximations. Moreover the resulting cross section exceeds largely, particularly for neutron-proton scattering, the free-space values in the low energy range (up to 200{endash}250 MeV) for nuclear medium densities up to two times the saturation density.

Giansiracusa, G.; Lombardo, U.; Sandulescu, N. [Dipartimento di Fisica, Universita di Catania, c.so Italia 57, I-95129 Catania (Italy)]|[Istituto Nazionale di Fisica Nucleare, Sezione di Catania, c.so Italia 57, I-95129 Catania (Italy)]|[Institute of Atomic Physics, P.O. Box MG-6, Bucharest (Romania)

1996-04-01

6

Medical resource use among patients treated for bipolar disorder: A retrospective, cross-sectional, descriptive analysis  

Microsoft Academic Search

Background: Detailed assessments of the direct costs related to bipolar disorder and of the burden it places on the health care system are limited.Objective: In this retrospective, cross-sectional, descriptive analysis, we assessed prescription medication and other medical resource use in bipolar disorder in an insured population in the northeastern United States.Methods: Number and types of prescription drugs, medical encounters, and

Monika Stender; Lynda Bryant-Comstock; Seren Phillips

2002-01-01

7

Semiclassical description of the small angle differential cross section for elastic atom—atom scattering  

NASA Astrophysics Data System (ADS)

The scattering amplitude is investigated for small angles ?* ? 8.5, with ?* = ?/? o a reduced scattering angle. The scaling angle is ? o = (4?/ k2Q3) 1/2, with k the wavenumber and Q3 the total cross section due to the attractive branch of the intermolecular potential. Both pure inverse power potentials and realistic intermolecular potentials are investigated. The method used is a least-square curve fit of the real and imaginary parts of quantum-mechanically calculated scattering amplitudes f(?) with suitable model functions. The shape of these model functions is partially based on the classical and semiclassical results for small angle scattering. For the shape of the attractive contribution to the differential cross section ? 3(?) in the case of an inverse power potential we give a new model function that describe the quantum oscillations (diffraction) modulating the classical result ? e1(?) HE for the differential cross section in the high energy approximation, i.e. the approximation of a straight line trajectory. The first order correction on this straight line approximation is also derived and incorporated in our model function. For s = 6 and 2.5 ? ?* ? 8.5 we find a description of ? 3(?)/? e1(?) HE with a rms deviation of 2.3 × 10 -3. For the shape of the differential cross section at small angles we give a second, new semi-empirical model functions, ? 3(?)/? 3(0) = [1 -1 c1 sin ( c2?* 2) + c3?* 2] -(3 + 1)/3, with s the power of the potential. The asymptotic behaviour of this function for ?* ? 1 and ?* ? is in good agreement with the corresponding semiclassical and classical results. For s = 6 the parameters are c1 = 3.75, c2 = 0.556, and c3 = 2.94, resulting in a description of ? 3(?)/? 3(0) with a rms deviation of 0.9 × 10 -3 for ?* ? 4.0. A simple and accurate model function for the phase angle ? a(?) = arg( f(?)) enables us to include the glory behaviour in the case of a realistic intermolecular potential. For the analysis of the differential cross section of a realistic potential a suitable model function for the glory contribution is added, resulting in a description of ?(?)/?(0) with a rms deviation of 3 × 10 -3 for ?* ? 4.0. A universal set of parameters is presented that can be used for predicting the differential cross section for a realistic intermolecular potential. It is also shown that the velocity dependency of the attractive and the glory contribution to the imaginary part of the scattering amplitude for ?* = 0, i.e. the total cross section, can be effectively used for predicting the small angle behaviour of the differential cross section.

Beijerinck, H. C. W.; van der Kam, P. M. A.; Thijssen, W. J. G.; Verster, N. F.

1980-01-01

8

Microscopic description of measured reaction cross sections at low projectile energies  

SciTech Connect

Systematic and consistent microscopic description of measured reaction cross sections at low projectile energies is presented. Finite-range Glauber model (GM-F) along with the Coulomb modification is used. The required inputs, namely the neutron and proton density distributions of the relevant projectiles and the targets, are calculated in the relativistic mean field framework. The GM-F reproduces the experiment well. At high projectile energies both the GM-F and the zero-range Glauber model in the optical limit (GM-Z) yield almost identical results; however, the GM-F in general is superior at low projectile energies, as expected.

Bhagwat, A. [Department of Physics, I.I.T. Powai, Bombay 400076 (India); KTH, Royal Institute of Technology, Alba Nova University Center, Department of Nuclear Physics, S-106 91 Stockholm (Sweden); Gambhir, Y. K. [Department of Physics, I.I.T. Powai, Bombay 400076 (India)

2006-02-15

9

A cross-sectional descriptive study of pressure ulcer prevalence in a teaching hospital in China.  

PubMed

Surveying pressure ulcer (PU) prevalence is a common practice in some western countries and has served as a tool to improve prevention policies and procedures. Although attention on PU prevention has increased in China, no PU prevalence baseline information is available to help guide care. To obtain this baseline information, a cross-sectional descriptive study was conducted in a 3,000-bed teaching hospital in Wuhan. On the morning of the study, trained clinicians audited the total hospital patient population (61 nursing units, 2,913 inpatients) using the PU survey tool designed by National Database of Nursing Quality Indicators. The majority of the patients (1,648, 56.6) were male, average patient age was 43.91 (+/-21.20) years, range 1 to 94 years. The overall PU prevalence rate was 1.8% (52 patients/79 ulcers). The hospital-acquired prevalence rate was 1.54% (0.82% when Stage I ulcers were excluded). Prevalence rates were highest in the ICU (45.5%) and most ulcers (53.2%) were located in the sacral-coccyx area. The results of this study suggest that overall PU prevalence rates are low compared to data from other countries. Differences in patient acuity, average patient length-of-stay, and prevention practices may explain these observations. The results of this study can guide hospital prevention efforts and serve as a benchmark for PU prevalence studies in China. PMID:20200444

Zhao, Guanghong; Hiltabidel, Elizabeth; Liu, Yilan; Chen, LingLing; Liao, Yongzhen

2010-02-01

10

A Descriptive Analysis of Oral Health Systematic Reviews Published 1991-2012: Cross Sectional Study  

PubMed Central

Objectives To identify all systematic reviews (SRs) published in the domain of oral health research and describe them in terms of their epidemiological and descriptive characteristics. Design Cross sectional, descriptive study. Methods An electronic search of seven databases was performed from inception through May 2012; bibliographies of relevant publications were also reviewed. Studies were considered for inclusion if they were oral health SRs defined as therapeutic or non-therapeutic investigations that studied a topic or an intervention related to dental, oral or craniofacial diseases/disorders. Data were extracted from all the SRs based on a number of epidemiological and descriptive characteristics. Data were analysed descriptively for all the SRs, within each of the nine dental specialities, and for Cochrane and non-Cochrane SRs separately. Results 1,188 oral health (126 Cochrane and 1062 non-Cochrane) SRs published from 1991 through May 2012 were identified, encompassing the nine dental specialties. Over half (n?=?676; 56.9%) of the SRs were published in specialty oral health journals, with almost all (n?=?1,178; 99.2%) of the SRs published in English and almost none of the non-Cochrane SRs (n?=?11; 0.9%) consisting of updates of previously published SRs. 75.3% of the SRs were categorized as therapeutic, with 64.5% examining non-drug interventions, while approximately half (n?=?150/294; 51%) of the non-therapeutic SRs were classified as epidemiological SRs. The SRs included a median of 15 studies, with a meta-analysis conducted in 43.6%, in which a median of 9 studies/1 randomized trial were included in the largest meta-analysis conducted. Funding was received for 25.1% of the SRs, including nearly three-quarters (n?=?96; 76.2%) of the Cochrane SRs. Conclusion Epidemiological and descriptive characteristics of the 1,188 oral health SRs varied across the nine dental specialties and by SR category (Cochrane vs. non-Cochrane). There is a clear need for more updates of SRs in all the dental specialties.

Saltaji, Humam; Cummings, Greta G.; Armijo-Olivo, Susan; Major, Michael P.; Amin, Maryam; Major, Paul W.; Hartling, Lisa; Flores-Mir, Carlos

2013-01-01

11

Fully differential cross sections in single ionization of helium by ion impact: Assessing the role of correlated wave functions  

NASA Astrophysics Data System (ADS)

We study the effect of final state dynamic correlation in single ionization of atoms by ion impact analyzing fully differential cross sections (FDCS). We use a distorted wave model where the final state is represented by a ?2 type correlated function, solution of a non-separable three body continuum Hamiltonian. This final state wave function partially includes the correlation of electron projectile and electron recoil relative motion as coupling terms of the wave equation. A comparison of fully differential results using this model with other theories and experimental data reveals that inclusion of dynamic correlation effects have little influence on FDCS, and do not contribute to a better description of available data in the case of electronic emission out-of scattering plane.

Ciappina, M. F.; Cravero, W. R.

2008-02-01

12

Correlated theoretical uncertainties for the one-jet inclusive cross section  

SciTech Connect

We discuss the correlated systematic theoretical uncertainties that may be ascribed to the next-to-leading order QCD theory used to predict the one-jet inclusive cross section in hadron collisions. We estimate the magnitude of these errors as functions of the jet transverse momentum and rapidity. The total theoretical error is decomposed into a set of functions of transverse momentum and rapidity that give a model for statistically independent contributions to the error. This representation can be used to include the systematic theoretical errors in fits to the experimental data.

Olness, Fredrick I. [Department of Physics, Southern Methodist University, Dallas, Texas 75275-0175 (United States); Soper, Davison E. [Institute of Theoretical Science, University of Oregon, Eugene, Oregon 97403-5203 (United States)

2010-02-01

13

Description of alpha-nucleus interaction cross sections for cosmic ray shielding studies  

NASA Astrophysics Data System (ADS)

Nuclear interactions of high-energy alpha particles with target nuclei important for cosmic ray studies are discussed. Models for elastic, quasi-elastic, and breakup reactions are presented and compared with experimental data. Energy-dependent interaction cross sections and secondary spectra are presented based on theoretical models and the limited experimental data base.

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

1993-04-01

14

Cognitive correlates of cross-sectional differences and longitudinal changes in trail making performance  

PubMed Central

A total of 1,576 adults between 18 and 95 years of age performed a battery of cognitive tests and the Connections version of the trail making test twice, with an average interval between assessments of 2.5 years. Consistent with previous results, speed ability and fluid cognitive ability were strongly correlated with trail making performance. Neither speed nor fluid cognitive ability at the first occasion predicted longitudinal changes in trail making performance, but there were significant correlations between the changes in these abilities and the changes in trail making performance. These results indicate that individual differences in speed and fluid cognitive abilities are associated with individual differences in trail making performance both at a single point in time (cross-sectional differences), and in the changes over time (longitudinal changes).

Salthouse, Timothy A.

2010-01-01

15

A cross-sectional description of social capital in an international sample of persons living with HIV/AIDS (PLWH)  

PubMed Central

Background Social capital refers to the resources linked to having a strong social network. This concept plays into health outcomes among People Living with HIV/AIDS because, globally, this is a highly marginalized population. Case studies show that modifying social capital can lead to improvements in HIV transmission and management; however, there remains a lack of description or definition of social capital in international settings. The purpose of our paper was to describe the degree of social capital in an international sample of adults living with HIV/AIDS. Methods We recruited PLWH at 16 sites from five countries including Canada, China, Namibia, Thailand, and the United States. Participants (n = 1,963) completed a cross-sectional survey and data were collected between August, 2009 and December, 2010. Data analyses included descriptive statistics, factor analysis, and correlational analysis. Results Participant's mean age was 45.2 years, most (69%) identified as male, African American/Black (39.9%), and unemployed (69.5%). Total mean social capital was 2.68 points, a higher than average total social capital score. Moderate correlations were observed between self-reported physical (r = 0.25) and psychological condition (r = 0.36), social support (r = 0.31), and total social capital. No relationships between mental health factors, including substance use, and social capital were detected. Conclusions This is the first report to describe levels of total social capital in an international sample of PLWH and to describe its relationship to self-reported health in this population.

2012-01-01

16

Correlates of Unsupervised Bathing of Infants: A Cross-Sectional Study  

PubMed Central

Drowning represents the third leading cause of fatal unintentional injury in infants (0–1 years). The aim of this study is to investigate correlates of unsupervised bathing. This cross-sectional study included 1,410 parents with an infant. Parents completed a questionnaire regarding supervision during bathing, socio-demographic factors, and Protection Motivation Theory-constructs. To determine correlates of parents who leave their infant unsupervised, logistic regression analyses were performed. Of the parents, 6.2% left their child unsupervised in the bathtub. Parents with older children (OR 1.24; 95%CI 1.00–1.54) were more likely to leave their child unsupervised in the bathtub. First-time parents (OR 0.59; 95%CI 0.36–0.97) and non-Western migrant fathers (OR 0.18; 95%CI 0.05–0.63) were less likely to leave their child unsupervised in the bathtub. Furthermore, parents who perceived higher self-efficacy (OR 0.57; 95%CI 0.47–0.69), higher response efficacy (OR 0.34; 95%CI 0.24–0.48), and higher severity (OR 0.74; 95%CI 0.58–0.93) were less likely to leave their child unsupervised. Since young children are at great risk of drowning if supervision is absent, effective strategies for drowning prevention should be developed and evaluated. In the meantime, health care professionals should inform parents with regard to the importance of supervision during bathing.

van Beelen, Mirjam E. J.; van Beeck, Eduard F.; den Hertog, Paul; Beirens, Tinneke M. J.; Raat, Hein

2013-01-01

17

Measurement of the Total Cross Section and Energy - Correlations for Electron-Positron Annihilation Into Hadrons at 29 GEV.  

NASA Astrophysics Data System (ADS)

This work describes measurements of the total cross section and the energy-energy correlation cross section for hadronic events produced in electron-positron annihilation at a center-of-mass energy of 29 GeV. The performance of the MAC detector at PEP, featuring total absorption calorimetry and charged particle tracking over nearly the full solid angle, is examined and found to meet the original design requirements. The unique and optimal features of MAC are fully exploited to reduce the systematics involved in both measurements, resulting in significant quantitative tests of the theory of quantum chromodynamics. Special attention is focussed on radiative corrections to the total cross section, which constitute a critical component of the acceptance determination, and for the first time the effects of higher order than (alpha)('3) QED processes are included. The total cross section measurement yields R = 3.91 with a total error of (+OR-)2.7%, an accuracy not previously attained by other experiments. For the energy-energy correlation cross section, the consequences of combining pure quantum chromodynamics with contrasting fragmentation models are explored and compared with the data, and result in different values for the strong coupling constant, (alpha)(,s) (TURNEQ) 0.13 (+OR-) 0.02 for incoherent jet formation and 0.24 (+OR-) 0.04 in the string model.

Heltsley, Brian Keith

18

Prevalence and correlates of dieting in college women: a cross sectional study  

PubMed Central

Background Dieting is a common practice among young women, irrespective of age, race, ethnicity, and weight. We aimed to determine the prevalence of dieting and its relationship with eating behavior, body weight, and body mass index (BMI) in college women. Methods This was a cross-sectional survey of female students aged 18–35 years (n = 308). Measures included BMI, restraint, disinhibition, hunger, dieting, weight loss, and perceived weight. Results A high percentage of college females consider themselves overweight or obese, despite having a BMI in the normal range. Dieting was practised by 43%, and 32% were avoiding weight gain, despite 78% having a healthy BMI. Women classified themselves as overweight or obese (27%), while only 11% were actually in these categories. Exercise was a common method of weight loss and positive associations were observed between dieting and BMI. Assessment of eating behavior showed that 27% were classified as high-restraint. Restraint and disinhibition were positively correlated with BMI. Conclusion Despite the widespread availability of nutrition information, there is incongruity in measured and perceived BMI in young educated women. Dieting practices and BMI are associated with restraint and disinhibition. Nutrition professionals should consider educating college women about healthy body weight regardless of their clients’ BMI.

Fayet, Flavia; Petocz, Peter; Samman, Samir

2012-01-01

19

On the SCA-description of the energy- and impact parameter dependence of K-Shell ionization cross sections  

NASA Astrophysics Data System (ADS)

We present the application of the SCA-model to impact-parameter and energy dependent K-shell ionization cross sections for several projectile-target combinations. Then we discuss the successes and failures of the SCA-description and investigate the additional approximations still existing in this approach. It is shown that after the introduction of a fully time-dependent perturbed electronic boundstate wave function many of the former discrepancies between experiment and theory can be resolved and in general very good agreement is obtained.

Trautmann, D.; Kauer, Th.

1989-07-01

20

Correlation of intercondylar notch cross sections to the ACL size: a high resolution MR tomographic in vivo analysis  

Microsoft Academic Search

Introduction  To correlate cross sections of the intercondylar notch to cross sections of the anterior cruciate ligament (ACL) and to analyze\\u000a gender-related differences in notch and ACL morphometry with an attempt to explain the observation that a small intercondylar\\u000a notch and the female gender predispose to a rupture of the ACL.\\u000a \\u000a \\u000a \\u000a Material and methods  High resolution MR imaging was performed on a

Michael Dienst; Guenther Schneider; Katrin Altmeyer; Kristina Voelkering; Thomas Georg; Bernhard Kramann; Dieter Kohn

2007-01-01

21

Measurement of correlated mu-b¯ jet cross sections in pp¯ collisions at s=1.8 TeV  

Microsoft Academic Search

We report on measurements of differential mu-b¯ cross sections, where the muon is from a semileptonic b decay and the b¯ is identified using precision track reconstruction in jets. The semidifferential correlated cross sections dsigma\\/dEb¯T, dsigma\\/dpb¯T, and dsigma\\/ddeltaphi(mu-b¯) for pmuT>~9 GeV\\/c, ||etamu||<0.6,Eb¯T> 10 GeV, ||etab¯||<1.5 are presented and compared to next-to-leading order QCD calculations.

F. Abe; M. G. Albrow; S. R. Amendolia; D. Amidei; J. Antos; C. Anway-Wiese; G. Apollinari; H. Areti; M. Atac; P. Auchincloss; F. Azfar; P. Azzi; N. Bacchetta; W. Badgett; M. W. Bailey; J. Bao; P. de Barbaro; A. Barbaro-Galtieri; V. E. Barnes; B. A. Barnett; P. Bartalini; G. Bauer; T. Baumann; F. Bedeschi; S. Behrends; S. Belforte; G. Bellettini; J. Bellinger; D. Benjamin; J. Benlloch; J. Bensinger; D. Benton; A. Beretvas; J. P. Berge; S. Bertolucci; A. Bhatti; K. Biery; M. Binkley; F. Bird; D. Bisello; R. E. Blair; C. Blocker; A. Bodek; W. Bokhari; V. Bolognesi; D. Bortoletto; C. Boswell; T. Boulos; G. Brandenburg; C. Bromberg; E. Buckley-Geer; H. S. Budd; K. Burkett; G. Busetto; A. Byon-Wagner; K. L. Byrum; J. Cammerata; C. Campagnari; M. Campbell; A. Caner; W. Carithers; D. Carlsmith; A. Castro; Y. Cen; F. Cervelli; H. Y. Chao; J. Chapman; M.-T. Cheng; G. Chiarelli; T. Chikamatsu; C. N. Chiou; L. Christofek; S. Cihangir; A. G. Clark; M. Cobal; M. Contreras; J. Conway; J. Cooper; M. Cordelli; C. Couyoumtzelis; D. Crane; J. D. Cunningham; T. Daniels; F. Dejongh; S. Delchamps; S. dell'agnello; M. dell'orso; L. Demortier; B. Denby; M. Deninno; P. F. Derwent; T. Devlin; M. Dickson; J. R. Dittmann; S. Donati; R. B. Drucker; A. Dunn; K. Einsweiler; J. E. Elias; R. Ely; E. Engels; S. Eno; D. Errede; S. Errede; Q. Fan; B. Farhat; I. Fiori; B. Flaugher; G. W. Foster; M. Franklin; M. Frautschi; J. Freeman; J. Friedman; H. Frisch; A. Fry; T. A. Fuess; Y. Fukui; S. Funaki; G. Gagliardi; S. Galeotti; M. Gallinaro; A. F. Garfinkel; S. Geer; D. W. Gerdes; P. Giannetti; N. Giokaris; P. Giromini; L. Gladney; D. Glenzinski; M. Gold; J. Gonzalez; A. Gordon; A. T. Goshaw; K. Goulianos; H. Grassmann; A. Grewal; L. Groer; C. Grosso-Pilcher; C. Haber; S. R. Hahn; R. Handler; R. M. Hans; K. Hara; B. Harral; R. M. Harris; S. A. Hauger; J. Hauser; C. Hawk; J. Heinrich; D. Cronin-Hennessy; R. Hollebeek; L. Holloway; A. Hölscher; S. Hong; G. Houk; P. Hu; B. T. Huffman; R. Hughes; P. Hurst; J. Huston; J. Huth; J. Hylen; M. Incagli; J. Incandela; H. Iso; H. Jensen; C. P. Jessop; U. Joshi; R. W. Kadel; E. Kajfasz; T. Kamon; T. Kaneko; D. A. Kardelis; H. Kasha; Y. Kato; L. Keeble; R. D. Kennedy; R. Kephart; P. Kesten; D. Kestenbaum; R. M. Keup; H. Keutelian; F. Keyvan; D. H. Kim; H. S. Kim; S. B. Kim; S. H. Kim; Y. K. Kim; L. Kirsch; P. Koehn; K. Kondo; J. Konigsberg; S. Kopp; K. Kordas; W. Koska; E. Kovacs; W. Kowald; M. Krasberg; J. Kroll; M. Kruse; S. E. Kuhlmann; E. Kuns; A. T. Laasanen; N. Labanca; S. Lammel; J. I. Lamoureux; T. Lecompte; S. Leone; J. D. Lewis; P. Limon; M. Lindgren; T. M. Liss; N. Lockyer; C. Loomis; O. Long; M. Loreti; E. H. Low; J. Lu; D. Lucchesi; C. B. Luchini; P. Lukens; J. Lys; P. Maas; K. Maeshima; A. Maghakian; P. Maksimovic; M. Mangano; J. Mansour; M. Mariotti; J. P. Marriner; A. Martin; J. A. Matthews; R. Mattingly; P. McIntyre; P. Melese; A. Menzione; E. Meschi; G. Michail; S. Mikamo; M. Miller; R. Miller; T. Mimashi; S. Miscetti; M. Mishina; H. Mitsushio; S. Miyashita; Y. Morita; S. Moulding; J. Mueller; A. Mukherjee; T. Muller; P. Musgrave; L. F. Nakae; I. Nakano; C. Nelson; D. Neuberger; C. Newman-Holmes; L. Nodulman; S. Ogawa; S. H. Oh; K. E. Ohl; R. Oishi; T. Okusawa; C. Pagliarone; R. Paoletti; V. Papadimitriou; J. Patrick; G. Pauletta; M. Paulini; L. Pescara; M. D. Peters; T. J. Phillips; G. Piacentino; M. Pillai; R. Plunkett; L. Pondrom; N. Produit; J. Proudfoot; F. Ptohos; G. Punzi; K. Ragan; F. Rimondi; L. Ristori; M. Roach-Bellino; W. J. Robertson; T. Rodrigo; J. Romano; L. Rosenson; W. K. Sakumoto; D. Saltzberg; A. Sansoni; V. Scarpine; A. Schindler; P. Schlabach; E. E. Schmidt; M. P. Schmidt; O. Schneider; G. F. Sciacca; A. Scribano; S. Segler; S. Seidel; Y. Seiya; G. Sganos; A. Sgolacchia; M. Shapiro; N. M. Shaw; Q. Shen; P. F. Shepard; M. Shimojima; M. Shochet; J. Siegrist; A. Sill; P. Sinervo; P. Singh; J. Skarha; K. Sliwa; D. A. Smith; F. D. Snider; L. Song; T. Song; J. Spalding; L. Spiegel; P. Sphicas; A. Spies; L. Stanco; J. Steele; A. Stefanini; K. Strahl; J. Strait; D. Stuart; G. Sullivan; K. Sumorok; R. L. Swartz; T. Takahashi; K. Takikawa; F. Tartarelli; W. Taylor; P. K. Teng; Y. Teramoto; S. Tether; D. Theriot; J. Thomas; T. L. Thomas; R. Thun; M. Timko; P. Tipton; A. Titov; S. Tkaczyk; K. Tollefson; A. Tollestrup; J. Tonnison; J. F. de Troconiz; J. Tseng; M. Turcotte; N. Turini; N. Uemura; F. Ukegawa; G. Unal; S. C. van den Brink; S. Vejcik; R. Vidal; M. Vondracek; D. Vucinic; R. G. Wagner; R. L. Wagner; N. Wainer; R. C. Walker; C. Wang; C. H. Wang; G. Wang; J. Wang; M. J. Wang; Q. F. Wang; A. Warburton; G. Watts; T. Watts; R. Webb; C. Wei; C. Wendt; H. Wenzel; W. C. Wester; T. Westhusing; A. B. Wicklund; E. Wicklund; R. Wilkinson; H. H. Williams; P. Wilson; B. L. Winer; J. Wolinski; D. Y. Wu; X. Wu; J. Wyss; A. Yagil; W. Yao; K. Yasuoka; Y. Ye; G. P. Yeh; P. Yeh; M. Yin

1996-01-01

22

b-quark inclusive cross sections and b{bar b} correlations using dimuons from the D0 experiment  

SciTech Connect

Using dimuons collected with the D{null} detector during the 1993- 1995 Tevatron collider run, we have measured the {ital b}-quark cross section and {ital b{anti b}} correlations as given by the difference in azimuthal angle between the two muons. Both measurements agree with the NLO QCD predictions within experimental and theoretical errors.

Vititoe, D.L. [Arizona Univ., Tucson, AZ (United States). Dept. of Physics; D0 Collaboration

1996-11-01

23

Lack of correlation between intracavitary thrombosis detected by cross sectional echocardiography and systemic emboli in patients with dilated cardiomyopathy  

Microsoft Academic Search

The correlation between intracavitary thrombosis detected by cross sectional echocardiography and systemic embolism was studied in 126 consecutive patients with idiopathic dilated cardiomyopathy who were examined from January 1980 to September 1987. A total of 1041 serial echocardiograms were obtained with 3.5 and 5 MHz transducers. The mean follow up period was 41.2 months. The survival rate was 88% at

M Ciaccheri; G Castelli; F Cecchi; M Nannini; G Santoro; V Troiani; A Zuppiroli; A Dolara

1989-01-01

24

Can Physical Activity and Dietary Fat Intake Influence Body Mass Index in a Cross-sectional Correlational Design?  

Microsoft Academic Search

The purpose of this study was to determine the influence of physical activity and dietary fat intake on Body Mass Index (BMI) of lecturers within a higher learning institutionalized setting. The study adopted a Cross-sectional Correlational Design and included 120 lecturers selected proportionately by simple random sampling techniques from a population of 600 lecturers. Data was collected using questionnaires, which

D. O. Omondi; L. O. A. Othuon; G. M. Mbagaya

2010-01-01

25

Correlation Between Absorption Cross Section and Body Surface Area of Human for Far-Field Exposure at GHz Bands  

Microsoft Academic Search

Our previous study revealed that a dominant factor influencing the electromagnetic absorption in a human body for far field exposure at GHz bands is the body surface area. Based on this finding, we discussed the correlation between absorption cross section and body surface area of human for far-field exposure at 2 GHz. We employed an FDTD algorithm for a large-scale

Akimasa Hirata; Yoshio Nagaya; Fujiwara Osamu; A. T. Nagaoka; Soichi Watanabe

2007-01-01

26

Sleep quality and its psychological correlates among university students in Ethiopia: a cross-sectional study  

PubMed Central

Background Sleep is an important physiological process for humans. University students in most resource limited countries often report poor sleep quality due to changing social opportunities and increasing academic demands. However, sleep quality among university students has not been studied in Ethiopia. Thus, this study assessed sleep quality and its demographic and psychological correlates among university students. Methods A cross-sectional survey was conducted in two universities in Ethiopia. Multistage sampling procedures were used to enroll 2,817 students into the study. A self-administered structured questionnaire including the Pittsburgh Sleep Quality Index (PSQI), the Depression Anxiety Stress Scale-21, the Perceived Stress Scale (PSS) and selected modules of the World Health Organization STEPS instrument was used for the study. This research included 2,551 students. Frequency, median, mean with standard deviation and 95% confidence interval were used to characterize sleep quality and other variables. Analysis of variance and binary logistic regression procedures were also used. Result The prevalence of poor sleep quality (total PSQI score?>?5) was 55.8% (1,424). Female students (adjusted odds ratio (AOR) 1.23; 95% CI: 1.00, 1.57), second year (AOR 2.91; 95% CI: 2.1, 4.02) and third year students (AOR 2.25; 95% CI 1.62, 3.12) had statistically significant higher odds of poor sleep quality. Perceived stress level and symptoms of depression and anxiety were strongly associated with sleep quality. Conclusion A substantial proportion of university students are affected by poor sleep quality. If our results are confirmed in prospective studies, health promotion and educational programs for students should emphasize the importance of sleep and mental health.

2012-01-01

27

Correlates of local safety-related concerns in a Swedish Community: a cross-sectional study  

PubMed Central

Background Crime in a neighbourhood has been recognized as a key stressor in the residential environment. Fear of crime is related to risk assessment, which depends on the concentration of objective risk in time and space, and on the presence of subjective perceived early signs of imminent hazard. The aim of the study was to examine environmental, socio-demographic, and personal correlates of safety-related concerns at the local level in urban communities. The specific aim was to investigate such correlates in contiguous neighbourhoods in a Swedish urban municipality. Methods A cross-sectional study design was used to investigate three neighbourhood settings with two pair-wise conterminous but socially contrasting areas within each setting. Crime data were retrieved from police records. Study data were collected through a postal questionnaire distributed to adult residents (n = 2476) (response rate 56%). Composite dimensions of perceived residential safety were derived through a factor analysis. Logistic regression analysis was used to examine associations between high-level scores of the three safety-related dimensions and area-level crime rate, being a victim of crime, area reputation, gender, age, education, country of birth, household civil status and type of housing. Results Three composite dimensions of perceived residential safety were identified: (I) structural indicators of social disorder; (II) contact with disorderly behavior; and (III) existential insecurity. We found that area-level crime rates and individual-level variables were associated with the dimensions structural indicators of social disorder and existential insecurity, but only individual-level variables were associated with the dimension contact with disorderly behavior. Self-assessed less favorable area reputation was found to be strongly associated with all three factors. Being female accorded existential insecurity more than being a victim of crime. Conclusion We have identified environmental, socio-demographic, and personal correlates of safety-related concerns in contiguous neighbourhoods in a Swedish community. The results of this study suggest that residents' self-assessed area reputation is an important underlying mechanism of perceived safety. We also found a difference in crime rates and safety-related concerns between areas with blocks of flats compared with small-scale areas although the neighbourhoods were close geographically.

Kullberg, Agneta; Karlsson, Nadine; Timpka, Toomas; Lindqvist, Kent

2009-01-01

28

Correlates of motivation to prevent weight gain: a cross sectional survey  

Microsoft Academic Search

BACKGROUND: This study is an application of the theory of planned behaviour (TPB) with additional variables to predict the motivations to prevent weight gain. In addition, variations in measures across individuals classified into Precaution Adoption Process stages (PAPM-stages) of behaviour change were investigated. METHODS: A cross-sectional survey among 979 non-obese Dutch adults aged 25–35 years was conducted. Multiple binary logistic

Birgitte Wammes; Stef Kremers; Boudewijn Breedveld; Johannes Brug

2005-01-01

29

Cross-sectional echocardiography in hypoplastic left ventricle: Echocardiographic—angiographic—anatomic correlations  

Microsoft Academic Search

Summary  Although M-mode echocardiography has become a valuable tool in the noninvasive diagnosis of hypoplastic left ventricle (HLV),\\u000a it may not resolve all diagnostic uncertainty. This study compares the findings of M-mode echocardiography, cross-sectional\\u000a echocardiography, and autopsy in a group of 20 infants with HLV. M-mode echocardiograms alone were obtained in eight infants;\\u000a five of these children underwent cardiac catheterization, and

Lothar W. Lange; David J. Sahn; Hugh D. Allen; Theron W. Ovitt; Stanley J. Goldberg

1980-01-01

30

Inclusive D *± meson cross sections and D *± -jet correlations in photoproduction at HERA  

Microsoft Academic Search

Differential photoproduction cross sections are measured for events containing D* mesons. The data were taken with the H1 detector at the ep collider HERA and correspond to an integrated luminosity of 51.1 pb-1. The kinematic region covers small photon virtualities Q2 2 and photon–proton centre-of-mass energies of 171 ??p < 256 GeV. The details of the heavy quark production process are further

A. Aktas; V. Andreev; T. Anthonis; B. Antunovic; S. Aplin; A. Astvatsatourov; A. Baghdasaryan; S. Backovic; P. Baranov; E. Barrelet; W. Bartel; S. Baudrand; S. Baumgartner; M. Beckingham; O. Behnke; O. Behrendt; A. Belousov; N. Berger; J. C. Bizot; M.-O. Boenig; V. Boudry; J. Bracinik; G. Brandt; V. Brisson; D. Bruncko; F. W. Büsser; A. Bunyatyan; G. Buschhorn; L. Bystritskaya; A. J. Campbell; S. Caron; F. Cassol-Brunner; K. Cerny; V. Cerny; V. Chekelian; J. G. Contreras; J. A. Coughlan; B. E. Cox; G. Cozzika; J. Cvach; J. B. Dainton; W. D. Dau; K. Daum; Y. de Boer; B. Delcourt; M. Del Degan; A. De Roeck; E. A. De Wolf; C. Diaconu; V. Dodonov; A. Dubak; G. Eckerlin; V. Efremenko; S. Egli; R. Eichler; F. Eisele; A. Eliseev; E. Elsen; S. Essenov; A. Falkewicz; P. J. W. Faulkner; L. Favart; A. Fedotov; R. Felst; J. Feltesse; J. Ferencei; L. Finke; M. Fleischer; G. Flucke; A. Fomenko; G. Franke; T. Frisson; E. Gabathuler; E. Garutti; J. Gayler; C. Gerlich; S. Ghazaryan; S. Ginzburgskaya; A. Glazov; I. Glushkov; L. Goerlich; M. Goettlich; N. Gogitidze; S. Gorbounov; C. Grab; T. Greenshaw; M. Gregori; B. R. Grell; G. Grindhammer; C. Gwilliam; S. Habib; D. Haidt; M. Hansson; G. Heinzelmann; R. C. W. Henderson; H. Henschel; G. Herrera; M. Hildebrandt; K. H. Hiller; D. Hoffmann; R. Horisberger; A. Hovhannisyan; T. Hreus; S. Hussain; M. Ibbotson; M. Ismail; M. Jacquet; X. Janssen; V. Jemanov; L. Jönsson; D. P. Johnson; A. W. Jung; H. Jung; M. Kapichine; J. Katzy; I. R. Kenyon; C. Kiesling; M. Klein; C. Kleinwort; T. Klimkovich; T. Kluge; G. Knies; A. Knutsson; V. Korbel; P. Kostka; K. Krastev; J. Kretzschmar; A. Kropivnitskaya; K. Krüger; M. P. J. Landon; W. Lange; G. Lastovicka-Medin; P. Laycock; A. Lebedev; G. Leibenguth; V. Lendermann; S. Levonian; L. Lindfeld; K. Lipka; A. Liptaj; B. List; J. List; E. Lobodzinska; N. Loktionova; R. Lopez-Fernandez; V. Lubimov; A.-I. Lucaci-Timoce; H. Lueders; T. Lux; L. Lytkin; A. Makankine; N. Malden; E. Malinovski; P. Marage; R. Marshall; L. Marti; M. Martisikova; H.-U. Martyn; S. J. Maxfield; A. Mehta; K. Meier; A. B. Meyer; H. Meyer; J. Meyer; V. Michels; S. Mikocki; I. Milcewicz-Mika; D. Milstead; D. Mladenov; A. Mohamed; F. Moreau; A. Morozov; J. V. Morris; M. U. Mozer; K. Müller; P. Murín; K. Nankov; B. Naroska; T. Naumann; P. R. Newman; C. Niebuhr; A. Nikiforov; G. Nowak; K. Nowak; M. Nozicka; R. Oganezov; B. Olivier; J. E. Olsson; S. Osman; D. Ozerov; V. Palichik; I. Panagoulias; T. Papadopoulou; C. Pascaud; G. D. Patel; H. Peng; E. Perez; D. Perez-Astudillo; A. Perieanu; A. Petrukhin; D. Pitzl; R. Placakyte; B. Portheault; B. Povh; P. Prideaux; A. J. Rahmat; N. Raicevic; P. Reimer; A. Rimmer; C. Risler; E. Rizvi; P. Robmann; B. Roland; R. Roosen; A. Rostovtsev; Z. Rurikova; S. Rusakov; F. Salvaire; D. P. C. Sankey; M. Sauter; E. Sauvan; S. Schmidt; S. Schmitt; C. Schmitz; L. Schoeffel; A. Schöning; H.-C. Schultz-Coulon; F. Sefkow; R. N. Shaw-West; I. Sheviakov; L. N. Shtarkov; T. Sloan; P. Smirnov; Y. Soloviev; D. South; V. Spaskov; A. Specka; M. Steder; B. Stella; J. Stiewe; A. Stoilov; U. Straumann; D. Sunar; V. Tchoulakov; G. Thompson; P. D. Thompson; T. Toll; F. Tomasz; D. Traynor; T. N. Trinh; P. Truöl; I. Tsakov; G. Tsipolitis; I. Tsurin; J. Turnau; E. Tzamariudaki; K. Urban; M. Urban; A. Usik; D. Utkin; A. Valkárová; C. Vallée; P. Van Mechelen; A. Vargas Trevino; Y. Vazdik; C. Veelken; S. Vinokurova; V. Volchinski; K. Wacker; G. Weber; R. Weber; D. Wegener; C. Werner; M. Wessels; B. Wessling; C. Wissing; R. Wolf; E. Wünsch; S. Xella; W. Yan; V. Yeganov; J. Žá?ek; J. Zálesák; Z. Zhang; A. Zhelezov; A. Zhokin; Y. C. Zhu; J. Zimmermann; T. Zimmermann; H. Zohrabyan; F. Zomer

2007-01-01

31

Descriptive epidemiology of screen and non-screen sedentary time in adolescents: a cross sectional study  

Microsoft Academic Search

BACKGROUND: Much attention has been paid to adolescents' screen time, however very few studies have examined non-screen sedentary time (NSST). This study aimed to (1) describe the magnitude and composition of screen sedentary time (SST) and NSST in Australian adolescents, (2) describe the socio-demographic correlates of SST and NSST, and (3) determine whether screen time is an adequate surrogate for

Tim S Olds; Carol A Maher; Kate Ridley; Daniella M Kittel

2010-01-01

32

Correlation of Intermediate Energy Proton- and Neutron-Induced Fission Cross Sections in the Lead-Bismuth Region  

SciTech Connect

Neutron- and proton-induced fission cross-sections of the lead isotopes 204,206-208Pb and 205Tl in the intermediate energy region have been measured at the Svedberg Laboratory in Uppsala, Sweden. Average fissilities of the composite nuclei and the dependence on the nucleon energy and the parameter Z2/A were determined. On this basis, the correlation between the proton- and neutron-induced fission cross sections has been established in the atomic mass region A {approx} 200 and for nucleon energies above 50 MeV, where shell effects do not play a very significant role. The correlation is discussed in the frame of results from calculations by the code TALYS.

Smirnov, Andrey N.; Eismont, Vilen P.; Filatov, Nikolay P. [V.G. Khlopin Radium Institute, 2oi Murinskiy Prospect 28, Saint-Petersburg 194021 (Russian Federation); Blomgren, Jan; Conde, Henri [Department of Neutron Research, Uppsala University, Box 525, S-751 20 Uppsala (Sweden); Olsson, Nils [Department of Neutron Research, Uppsala University, Box 525, S-751 20 Uppsala (Sweden); Swedish Defence Research Agency (FOI), S-172 90 Stockholm (Sweden); Duijvestijn, Marieke; Koning, Arjan [Nuclear Research and Consultancy Group, Westerduinweg 3, NL - 1755 ZG Petten (Netherlands); Kirillov, Sergey N

2005-05-24

33

Descriptive epidemiology of screen and non-screen sedentary time in adolescents: a cross sectional study  

PubMed Central

Background Much attention has been paid to adolescents' screen time, however very few studies have examined non-screen sedentary time (NSST). This study aimed to (1) describe the magnitude and composition of screen sedentary time (SST) and NSST in Australian adolescents, (2) describe the socio-demographic correlates of SST and NSST, and (3) determine whether screen time is an adequate surrogate for total sedentary behaviour in this population. Methods 2200 9-16 year old Australians provided detailed use of time data for four days. Non-screen sedentary time (NSST) included time spent participating in activities expected to elicit <3 METs whilst seated or lying down (other than sleeping), excluding screen-based activities (television, playing videogames or using computers). Total sedentary time was the sum of screen time and NSST. Results Adolescents spent a mean (SD) of 345 (105) minutes/day in NSST, which constituted 60% of total sedentary time. School activities contributed 42% of NSST, socialising 19%, self-care (mainly eating) 16%, and passive transport 15%. Screen time and NSST showed opposite patterns in relation to key socio-demographic characteristics, including sex, age, weight status, household income, parental education and day type. Because screen time was negatively correlated with NSST (r = -0.58), and exhibited a moderate correlation (r = 0.53) with total sedentary time, screen time was only a moderately effective surrogate for total sedentary time. Conclusions To capture a complete picture of young people's sedentary time, studies should endeavour to measure both screen time and NSST.

2010-01-01

34

D0 results on three-jet production, multijet cross-section ratios, and minimum bias angular correlations  

SciTech Connect

We report the measurement of the cross-section for three-jet production and the ratio of inclusive three-jet to two-jet cross-sections, as well as a study of angular correlations in minimum bias events, based on data taken with the D0 experiment at the Fermilab Tevatron proton-antiproton collider. The differential inclusive three-jet cross section as a function of the invariant three-jetmass (M{sub 3jet}) is measured in p{bar p} collisions at {radical}s = 1.96 TeV using a data set corresponding to an integrated luminosity of 0.7 fb{sup -1}. The measurement is performed in three rapidity regions (|y| < 0.8, |y| < 1.6 and |y| < 2.4) and in three regions of the third (ordered in p{sub T}) jet transverse momenta (p{sub T3} > 40 GeV, p{sub T3} > 70 GeV, p{sub T3} > 100 GeV) for events with leading jet transverse momentum larger than 150 GeV and well separated jets. NLO QCD calculations are found to be in a reasonable agreement with the measured cross sections. Based on the same data set, we present the first measurement of ratios of multi-jet cross sections in p{bar p} collisions at {radical}s = 1.96 TeV at the Fermilab Tevatron Collider. The ratio of inclusive trijet and dijet cross sections, R{sub 3/2}, has been measured as a function of the transverse jet momenta. The data are compared to QCD model predictions in different approximations. Finally, we present a new way to describe minimum bias events based on angular distributions in {approx}5 million minimum bias p{bar p} collisions collected between April 2002 and February 2006 with the D0 detector. We demonstrate that the distribution of {Delta}{phi} in the detector transverse plane between the leading track and all other tracks is a robust observable that can be used for tuning of multiple color interaction models. Pseudorapidity correlations of the {Delta}{phi} distributions are also studied.

Sawyer, Lee; /Louisiana Tech. U.

2010-01-01

35

Auditory Hallucinations in a Cross-Diagnostic Sample of Psychotic Disorder Patients: A Descriptive, Cross-Sectional Study  

PubMed Central

Background Auditory hallucinations (AH) are a cardinal feature of schizophrenia spectrum disorders. They are not disease specific, however, and can occur in other conditions, including affective psychoses. Methods In this descriptive, cross-sectional study, we examined AH in relation to other psychotic symptoms, mood symptoms, illness severity, and functional status in 569 patients with psychosis (n=172 schizophrenia, n=153 schizoaffective disorder, n=244 bipolar disorder with psychotic features). Results 323 (56.7%) patients reported a lifetime history of AH (75.6% of patients with schizophrenia, 71.9% schizoaffective disorder, and 34.0% bipolar disorder). The mean score for the hallucinations item (P3) of the Positive and Negative Syndrome Scale (PANSS) in the AH group was 3.66 ± 1.79, indicating mild to moderate state hallucinations severity. AH were strongly associated with hallucinations in other sensory modalities and with the first-rank symptoms of delusions of control, thought insertion, and thought broadcasting. Multivariate analysis showed that AH were associated with lower education even after controlling for diagnosis, age, and gender. There was no association between AH and functional status as measured by the Multnomah Community Ability Scale (MCAS). Conclusions AH are associated with specific clinical features across the continuum of both schizophrenic and affective psychoses independent of DSM-IV diagnosis.

Shinn, Ann K.; Pfaff, Danielle; Young, Sarah; Lewandowski, Kathryn E.; Cohen, Bruce M.; Ongur, Dost

2011-01-01

36

A Schematic Theory of Nuclear Cross Sections  

Microsoft Academic Search

In this paper a description of the energy dependence of nuclear cross sections, especially for neutrons, is given in terms of simple assumptions on the properties of the nuclei. The results are supposed to represent average values over individual fluctuations and resonances. The total cross section, the reaction cross section, and the transport cross section are calculated as functions of

H. Feshbach; V. F. Weisskope

1949-01-01

37

The recent absolute total np and pp cross section determinations: quality of data description and prediction of experimental observables  

Microsoft Academic Search

The absolute total cross sections for np and pp scattering below 1000 MeV are determined based on partial-wave analyses (PWAs) of nucleon-nucleon scattering data. These cross sections are compared with the most recent ENDF\\/B-VII.0 and JENDL-3.3 data files, and the Nijmegen PWA. Systematic deviations from the ENDF\\/B-VII.0 and JENDL-3.3 evaluations are found to exist in the low-energy region. Comparison of

Alexander B Laptev; Robert C Haight; Richard A Arndt; William J Briscoe; Mark W Paris; Igor I Strakovsky; Ron L Workman

2010-01-01

38

Social correlates of cigarette smoking among Icelandic adolescents: A population-based cross-sectional study  

PubMed Central

Background Previous research has shown that between 80 and 90 percent of adult smokers report having started smoking before 18 years of age. Several studies have revealed that multiple social factors influence the likelihood of smoking during adolescence, the period during which the onset of smoking usually occurs. To better understand the social mechanisms that influence adolescent smoking, we analyzed the relationship and relative importance of a broad spectrum of social variables in adolescent smoking in Iceland, a Nordic country with high per-capita income. Methods We used cross-sectional data from 7,430 14- to 16 year-old students (approximately 81% of all Icelanders in these age cohorts) in the 2006 Youth in Iceland study. The Youth in Iceland studies are designed to investigate the role of several cognitive, behavioral, and social factors in the lives of adolescents, and the data collected are used to inform the design, implementation, and evaluation of substance use prevention programs that are being developed by Icelandic social scientists, policy makers, and practitioners. Results Our analysis revealed that friends' smoking behavior and attitude toward smoking were strongly associated with adolescent smoking and other tobacco use, as well as alcohol consumption during the previous 30 days. Main protective factors were parent's perceived attitude toward smoking, the quantity of time spent with parents, absence of serious verbal conflict between parents and adolescents, and participation in physical activity. Family structure was related to adolescent smoking to a small extent, but other background factors were not. Conclusion We conclude that multiple social factors are related to adolescent smoking. Parents and other primary preventive agents need to be informed about the complicated nature of the adolescent social world in order to maximize their impact.

Kristjansson, Alfgeir L; Sigfusdottir, Inga D; Allegrante, John P; Helgason, Asgeir R

2008-01-01

39

Prevalence and Correlates of Asthma Among Children in Central St. Petersburg, Russia: Cross-sectional Study  

PubMed Central

Aim To estimate the prevalence of asthma among children in central St. Petersburg and to evaluate associations between asthma and socio-demographic, biological, and environmental factors. Methods A cross-sectional study included 1464 children aged 0-18 years from two central districts of St. Petersburg. Parents filled out a questionnaire on children’s respiratory health, characteristics at birth, socio-demographic data, housing situation, and their own history of asthma and allergies. The diagnosis of asthma was based on the results of spirometry in children aged ?5 years and on questionnaire data as reported by parents of younger children. Independent effects of the investigated factors on asthma were assessed by multiple logistic regression analysis. Crude and adjusted odds ratios (OR) with 95% confidence intervals (CI) were calculated. Results The estimated prevalence of asthma was 7.4% (95% CI, 6.2-8.8). A history of allergies (OR, 1.6; 95% CI, 1.0-2.6), bronchitis, bronchiolitis, or pneumonia in infancy (OR, 12.2; 95% CI, 7.3-20.5), and self-reported parental allergies (OR, 3.6; 95% CI, 2.2-5.8 for one parent and OR, 7.1; 95% CI, 3.0-17.0 for both parents) were associated with childhood asthma. Children whose mothers were out of work also had higher prevalence of asthma than the reference group (OR, 3.4; 95% CI, 1.1-10.4). Conclusion The prevalence of asthma is several times higher than what is officially reported for St. Petersburg’s inner city children population. Early life events and socio-demographic and biologic factors were associated with asthma in children.

Glushkova, Anzhela V.; Grjibovski, Andrej M.

2008-01-01

40

Barrier contraception among adolescents and young adults in a tertiary institution in Southwestern Nigeria: a cross-sectional descriptive study.  

PubMed

Nigeria, like most African nations, is basically conservative, but the young people are becoming more sexually liberated, and the incidence of STD/HIV, unwanted pregnancies and abortions among these young people is on the increase. The use of barrier contraception (BC), which is a cost-effective method of preventing STD/HIV, unwanted pregnancies and its attending complications, has therefore become an important issue in reproductive health. This descriptive cross-sectional study was carried out among first year students of Osun State University, Nigeria. Four hundred respondents were studied using pre-tested semi-structured questionnaires. The respondents were selected by balloting. Most respondents (93%) had heard about the male condom as a method of barrier contraception. Most respondents (79.1%) supported the use of barrier contraceptives, but many (62.5%) thought it would promote sexual promiscuity, 33.4% believed that the use of barrier contraception reflected a lack of trust from the partner, and 38.7% felt barrier contraception is not necessary with a stable partner. One hundred and sixty one (40.5%) had used a form of barrier contraception before, but only 130 (32.7%) are currently using BC. The male condom was the most commonly used method (88.2%), followed by female condom and diaphragm (5.6% respectively). The prevention of STI and unwanted pregnancies were the main reasons (59%) given by respondents for using BC, while religion was the main reason given by non-users. The attitudes of these students toward barrier contraception and their practice were poor. The role of sex education at homes and religious gatherings cannot be over-emphasized. PMID:21061934

Olugbenga-Bello, Adenike I; Adekanle, Daniel A; Ojofeitimi, Ebenezer O; Adeomi, Adeleye A

41

Prevalence and correlates of fecal incontinence among nursing home residents: a population-based cross-sectional study  

PubMed Central

Background Fecal incontinence is highly prevalent among nursing home residents. Previous nursing home studies have identified co-morbidity associated with fecal incontinence, but as this population is increasingly old and frail, we wanted to see if the rate of fecal incontinence had increased and to investigate correlates of fecal incontinence further. Methods Cross-sectional study of the entire nursing home population in one Norwegian municipality. Registered nurses filled in a questionnaire for all residents in the municipality (980 residents aged ?65). Statistical methods used are descriptive statistics, binary logistic regression and multivariable logistic regression. Results The response rate of the study was 90.3%. The prevalence of fecal incontinence was 42.3%. In multivariable analysis of FI, residents with diarrhea (OR 7.33, CI 4.39-12.24), urinary incontinence (OR 2.77, CI 1.73-4.42) and dementia (OR 2.17, CI 1.28-3.68) had higher odds of having fecal incontinence compared to those without the condition. Residents residing in a nursing home between 4–5 years had higher odds of having fecal incontinence compared to residents who had stayed under a year (OR 2.65, CI 1.20-5.85). Residents with deficiency in feeding (2.17, CI 1.26-3.71), dressing (OR 4.03, CI 1.39-11.65), toilet use (OR 7.37, CI 2.65-20.44) and mobility (OR 2.54, CI 1.07-6.00) had higher odds of having fecal incontinence compared to residents without deficiencies in activities of daily living (ADL). Needing help for transfer between bed and chair was a protective factor for fecal incontinence compared to residents who transferred independently (OR 0.49, CI 0.26-0.91). Conclusions Fecal incontinence is a prevalent condition in the nursing home population and is associated with ADL decline, frailty, diarrhea and quality of care. This knowledge is important for staff in nursing home in order to provide the best treatment and care for residents with fecal incontinence.

2013-01-01

42

The recent absolute total np and pp cross section determinations: quality of data description and prediction of experimental observables  

SciTech Connect

The absolute total cross sections for np and pp scattering below 1000 MeV are determined based on partial-wave analyses (PWAs) of nucleon-nucleon scattering data. These cross sections are compared with the most recent ENDF/B-VII.0 and JENDL-3.3 data files, and the Nijmegen PWA. Systematic deviations from the ENDF/B-VII.0 and JENDL-3.3 evaluations are found to exist in the low-energy region. Comparison of the np evaluation with the result of most recent np total and differential cross section measurements will be discussed. Results of those measurements were not used in the evaluation database. A comparison was done to check a quality of evaluation and its capabilities to predict experimental observables. Excellent agreement was found between the new experimental data and our PWA predictions.

Laptev, Alexander B [Los Alamos National Laboratory; Haight, Robert C [Los Alamos National Laboratory; Arndt, Richard A [GWU; Briscoe, William J [GWU; Paris, Mark W [GWU; Strakovsky, Igor I [GWU; Workman, Ron L [GWU

2010-01-01

43

Cross-Sectional Investigation of Correlation Between Hepatic Steatosis and IVIM Perfusion on MR Imaging  

PubMed Central

The purpose of this study was to investigate the relationship between liver fat-fraction (FF) and diffusion parameters derived from the intravoxel incoherent motion (IVIM) model. 36 subjects with suspected nonalcoholic fatty liver disease (NAFLD) underwent diffusion weighted (DW) MR imaging with 10 b-values and spoiled gradient recalled echo imaging for fat quantification with six echos. Correlations were measured between FF, R2*, diffusivity (D) and perfusion fraction (f). The primary finding was that no significant correlation was obtained for D vs FF or f vs FF. Significant correlations were obtained for D vs R2* (r = ?0.490, p = 0.002) and f vs D (r = ?0.458, p = 0.005). The conclusion is that hepatic steatosis does not affect measurement of perfusion or diffusion and therefore is unlikely to confound the use of apparent diffusivity to evaluate hepatic fibrosis.

Lee, James T; Liau, Joy; Murphy, Paul; Schroeder, Michael E; Sirlin, Claude B

2011-01-01

44

Correlation of Perforating Vein Incompetence with Extent of Great Saphenous Insufficiency: Cross Sectional Study  

Microsoft Academic Search

To explore the correlation between perforating vein incompetence and the extent of great saphenous vein insufficiency according to Hach. Methods Duplex ultrasound was used to determine the number of incompetent perforators and diameter of per- forating veins, and the level of great saphenous vein reflux and the presence or absence of deep reflux in 118 lower limbs (59 patients). There

Anton Krniæ; Zvonimir Suèiæ

45

The b b production cross section and angular correlations in p p collisions at s = 1.8 TeV  

Microsoft Academic Search

We present measurements of the bb production cross section and angular correlations using the DØ detector at the Fermilab Tevatron pp Collider operating at s = 1.8 TeV. The b quark production cross section for |yb|<1.0 and pTb>6 GeV\\/c is extracted from single muon and dimuon data samples. The results agree in shape with the next-to-leading order QCD calculation of

B Abbott; M Abolins; V Abramov; B. S Acharya; M Adams; V Akimov; G. A Alves; N Amos; E. W Anderson; M. M Baarmand; V. V Babintsev; L Babukhadia; A Baden; B Baldin; S Banerjee; J Bantly; E Barberis; P Baringer; J. F Bartlett; U Bassler; A Bean; A Belyaev; S. B Beri; G Bernardi; I Bertram; V. A Bezzubov; P. C Bhat; V Bhatnagar; M Bhattacharjee; G Blazey; S Blessing; A Boehnlein; N. I Bojko; F Borcherding; A Brandt; R Breedon; G Briskin; R Brock; G Brooijmans; A Bross; D Buchholz; M Buehler; V Buescher; V. S Burtovoi; J. M Butler; F Canelli; W Carvalho; D Casey; Z Casilum; H Castilla-Valdez; D Chakraborty; K. M Chan; S. V Chekulaev; D. K Cho; S Choi; S Chopra; B. C Choudhary; J. H Christenson; M Chung; D Claes; A. R Clark; J Cochran; L Coney; B Connolly; W. E Cooper; D Coppage; D Cullen-Vidal; M. A. C Cummings; D Cutts; O. I Dahl; K Davis; K De; K Del Signore; M Demarteau; D Denisov; S. P Denisov; H. T Diehl; M Diesburg; G Di Loreto; S Doulas; P Draper; Y Ducros; L. V Dudko; S. R Dugad; A Dyshkant; D Edmunds; J Ellison; V. D Elvira; R Engelmann; S Eno; G Eppley; P Ermolov; O. V Eroshin; J Estrada; H Evans; V. N Evdokimov; T Fahland; S Feher; D Fein; T Ferbel; H. E Fisk; Y Fisyak; E Flattum; F Fleuret; M Fortner; K. C Frame; S Fuess; E Gallas; A. N Galyaev; P Gartung; V Gavrilov; R. J Genik II; K Genser; C. E Gerber; Y Gershtein; B Gibbard; R Gilmartin; G Ginther; B Gómez; G Gómez; P. I Goncharov; J. L González Sol??s; H Gordon; L. T Goss; K Gounder; A Goussiou; N Graf; P. D Grannis; J. A Green; H Greenlee; S Grinstein; P Grudberg; S Grünendahl; G Guglielmo; A Gupta; S. N Gurzhiev; G Gutierrez; P Gutierrez; N. J Hadley; H Haggerty; S Hagopian; V Hagopian; K. S Hahn; R. E Hall; P Hanlet; S Hansen; J. M Hauptman; C Hays; C Hebert; D Hedin; A. P Heinson; U Heintz; T Heuring; R Hirosky; J. D Hobbs; B Hoeneisen; J. S Hoftun; A. S Ito; S. A Jerger; R Jesik; T Joffe-Minor; K Johns; M Johnson; A Jonckheere; M Jones; H Jöstlein; A Juste; S Kahn; E Kajfasz; D Karmanov; D Karmgard; R Kehoe; S. K Kim; B Klima; C Klopfenstein; B Knuteson; W Ko; J. M Kohli; A. V Kostritskiy; J Kotcher; A. V Kotwal; A. V Kozelov; E. A Kozlovsky; J Krane; M. R Krishnaswamy; S Krzywdzinski; M Kubantsev; S Kuleshov; Y Kulik; S Kunori; G Landsberg; A Leflat; F Lehner; J Li; Q. Z Li; J. G. R Lima; D Lincoln; S. L Linn; J Linnemann; R Lipton; J. G Lu; A Lucotte; L Lueking; C Lundstedt; A. K. A Maciel; R. J Madaras; V Manankov; S Mani; H. S Mao; T Marshall; M. I Martin; R. D Martin; K. M Mauritz; B May; A. A Mayorov; R McCarthy; J McDonald; T McMahon; H. L Melanson; X. C Meng; M Merkin; K. W Merritt; C Miao; H Miettinen; D Mihalcea; A Mincer; C. S Mishra; N Mokhov; N. K Mondal; H. E Montgomery; M Mostafa; H da Motta; E Nagy; F Nang; M Narain; V. S Narasimham; H. A Neal; J. P Negret; S Negroni; D Norman; L Oesch; V Oguri; B Olivier; N Oshima; P Padley; L. J Pan; A Para; N Parashar; R Partridge; N Parua; M Paterno; A Patwa; B Pawlik; J Perkins; M Peters; R Piegaia; H Piekarz; B. G Pope; E Popkov; H. B Prosper; S Protopopescu; J Qian; P. Z Quintas; R Raja; S Rajagopalan; N. W Reay; S Reucroft; M Rijssenbeek; T Rockwell; M Roco; P Rubinov; R Ruchti; J Rutherfoord; A Santoro; L Sawyer; R. D Schamberger; H Schellman; A Schwartzman; J Sculli; N Sen; E Shabalina; H. C Shankar; R. K Shivpuri; D Shpakov; M Shupe; R. A Sidwell; V Simak; H Singh; J. B Singh; V Sirotenko; P Slattery; E Smith; R. P Smith; R Snihur; G. R Snow; J Snow; S Snyder; J Solomon; X. F Song; V Sor??n; M Sosebee; N Sotnikova; K Soustruznik; M Souza; N. R Stanton; G Steinbrück; R. W Stephens; M. L Stevenson; F Stichelbaut; D Stoker; V Stolin; D. A Stoyanova; M Strauss; K Streets; M Strovink; L Stutte; A Sznajder; W Taylor; S Tentindo-Repond; T. L. T Thomas; J Thompson; D Toback; T. G Trippe; A. S Turcot; P. M Tuts; P van Gemmeren; V Vaniev; R Van Kooten; N Varelas; A. A Volkov; A. P Vorobiev; H. D Wahl; H Wang; J Warchol; G Watts; M Wayne; H Weerts; A White; J. T White; D Whiteson; J. A Wightman; S Willis; S. J Wimpenny; J. V. D Wirjawan; J Womersley; D. R Wood; R Yamada; P Yamin; T Yasuda; K Yip; S Youssef; J Yu; Z Yu; M Zanabria; H Zheng; Z Zhou; Z. H Zhu; M Zielinski; D Zieminska; A Zieminski; V Zutshi; E. G Zverev; A Zylberstejn

2000-01-01

46

The correlates of meeting physical activity recommendations: A population-based cross-sectional study  

Microsoft Academic Search

The aim of this study was to identify correlated factors which explain the recommended level of leisure time physical activity (LTPA) among Portuguese adults. Subjects aged 31–60 years (972 males, 1195 females) were categorized, based on LTPA data obtained using a questionnaire, into two groups according to the PA recommendation for PA:?10 or <10 MET·hr·wk. Chi-square and logistic regression analyses

Adilson Marques; João Martins; José Diniz; Madalena Ramos; Flávia Yazigi; Marcos Onofre; Francisco Carreiro da Costa

2012-01-01

47

Cross-sectional study of correlation between mandibular incisor crowding and third molars in young Brazilians  

PubMed Central

Objectives: The aim of this study was to evaluate transversally the clinical correlation between lower incisor crowding and mandible third molar. Study Design: Three hundred healthy volunteers (134 male and 166 female), aged 20.4 (±2.4) years-old were submitted to a complete clinical examination and filled up a questionnaire about gender, age, total teeth number and presence or absence of superior and inferior third molar. After a recent panoramic radiography were evaluated. The multiple logistic regression showed that none of the studied factors influenced the mandibular incisor crowding. Results: The proportion of both molars present or both absent was higher than the other conditions (Chi-square, p<.0001). The multiple logistic regression showed that any of the studied factors, influenced (p>.05) the mandibular incisor crowding. Despite the statistical significance, wear orthodontics appliances showed a little correlation (odds ratios < 1.0) in the mandibular incisor crowding. Conclusion: Presence of maxillary and/or mandibular third molars has no relation with the lower incisor crowding. Key words:Malocclusion, third molars, lower incisor crowding, mandible.

Karasawa, Lilian H.; Groppo, Francisco C.; Prado, Felippe B.; Caria, Paulo H F.

2013-01-01

48

Correlates of illicit methadone use in New York City: A cross-sectional study  

PubMed Central

Background Despite growing concern about illicit methadone use in the US and other countries, there is little data about the prevalence and correlates of methadone use in large urban areas. We assessed the prevalence and examined correlates of lifetime and recent illicit methadone use in New York City (NYC). Methods 1,415 heroin, crack, and cocaine users aged 15–40 years were recruited in NYC between 2000 and 2004 to complete interviewer-administered questionnaires. Results In multivariable logistic regression, non-injection drug users who used illicit methadone were more likely to be heroin dependent, less than daily methamphetamine users and to have a heroin using sex partner in the last two months. Injection drug users who used illicit methadone were more likely to use heroin daily, share injection paraphernalia and less likely to have been in a detoxification program and to have not used marijuana in the last six months. Conclusion The results overall suggest that illicit (or street) methadone use is likely not a primary drug of choice, but is instead more common in concert with other illicit drug use.

Ompad, Danielle C; Fuller, Crystal M; Chan, Christina A; Frye, Victoria; Vlahov, David; Galea, Sandro

2008-01-01

49

Description of nuclear structure and cross sections for nucleon-nucleus scattering on the basis of effective Skyrme forces  

Microsoft Academic Search

The possibility of constructing such new versions of effective nucleon-nucleon forces that would make it possible to describe\\u000a simultaneously the cross sections for nucleon-nucleus scattering and quantities characterizing nuclear matter and the structure\\u000a of finite even-even nuclei is investigated on the basis of a microscopic nucleon-nucleus optical potential that is calculated\\u000a by using effective Skyrme interaction. A procedure for optimizing

V. I. Kuprikov; V. V. Pilipenko; A. P. Soznik; V. N. Tarasov; N. A. Shlyakhov

2009-01-01

50

Nephropathy in males and females with Fabry disease: cross-sectional description of patients before treatment with enzyme replacement therapy  

Microsoft Academic Search

Background. Fabry disease, an X-linked genetic disorder with deficient ?-galactosidase A activity, is characterized by kidney disease and kidney failure. The spectrum of kidney disease has not been well defined, especially in female patients. Methods. We did a cross-sectional retrospective analysis of natural history of glomerular filtration rate (estimated— eGFR), albuminuria and proteinuria in 1262 adult patients (585 males, 677

Alberto Ortiz; P. Oliveira; S teven Waldek; David G. Warnock; Bruno Cianciaruso; Christoph Wanner

51

Hepatic coagulopathy-intricacies and challenges; a cross-sectional descriptive study of 110 patients from a superspecialty institute in North India with review of literature.  

PubMed

Hemostatic defect in chronic liver disease (CLD) is complex involving opposing factors of primary hemostasis, coagulation, and fibrinolysis. The concept of causal relationship between abnormal tests and clinical bleeding is unclear. This study was undertaken to evaluate and correlate clinical bleeding and the commonly used laboratory tests for hemostasis in CLD patients including the subgroup of acute on chronic liver failure (ACLF) patients and test the reproducibility of international normalized ratio (INR) using different reagents. This was a cross-sectional descriptive study wherein clinical records and laboratory data from 110 patients (95 CLD, 15 ACLF) over a 6-month period were analysed. Variceal bleeding (33.3%) was the commonest followed by mucosal/skin bleeds (5.4%). Thrombocytopenia seen in 70.9% patients was mostly mild (48.2%) to moderate (14.5%). Prothrombin time (PT) prolongation was seen in 81.8% with significant variation in PT/INR using different reagents. Adverse outcome in the form of disseminated intravascular coagulation, septic shock or death was seen in 13.6% patients (eight ACLF and seven CLD). There was no correlation of bleeding with prolonged PT/INR, decreased platelet count and adverse clinical outcome. However, individually, there was significant but weak correlation between variceal bleeding and lower platelet count and superficial bleeding and prolonged PT. Correction of PT/INR post-fresh frozen plasma was significant but platelet count postplatelet concentrate transfusion was not. ACLF patients compared with CLD patients had greater PT prolongation and adverse outcome but no increase in bleeding. Routine tests, although globally deranged inadequately reflect haemostatic imbalance in CLD and poorly predict bleeding risk. PMID:23358200

Kar, Rakhee; Kar, Sitanshu S; Sarin, Shiv K

2013-03-01

52

Methamphetamine use and correlates in two villages of the highland ethnic Karen minority in northern Thailand: a cross sectional study  

PubMed Central

Background The prevalence of methamphetamine use and human immunodeficiency virus (HIV) incidence are high in lowland Thai society. Despite increasing social and cultural mixing among residents of highland and lowland Thai societies, however, little is known about methamphetamine use among ethnic minority villagers in the highlands. Methods A cross-sectional survey examined Karen villagers from a developed and a less-developed village on February 24 and March 26, 2003 to evaluate the prevalence and social correlates of methamphetamine use in northern Thailand. Data were collected in face-to-face interviews using a structured questionnaire. Results The response rate was 79.3% (n = 548). In all, 9.9% (males 17.6%, females 1.7%) of villagers reported methamphetamine use in the previous year. Methamphetamine was used mostly by males and was significantly related to primary or lower education; to ever having worked in town; to having used opium, marijuana, or heroin in the past year; and to ever having been diagnosed with a sexually transmitted infection (STI). Conclusion Since labor migration to towns is increasingly common among ethnic minorities, the prevention of methamphetamine use and of HIV/STI infection among methamphetamine users should be prioritized to prevent HIV in this minority population in Thailand.

2009-01-01

53

Prevalence and correlates of hypertension: a cross-sectional study among rural populations in sub-Saharan Africa.  

PubMed

Substantial evidence suggests an increasing burden of hypertension (HTN) in urban sub-Saharan Africa (SSA). However, data on HTN prevalence in rural SSA are sparse. In a cross-sectional study, we investigated magnitude and correlates of HTN in rural SSA. Study participants (N=1485), 18 years and above, were selected using a stratified random sampling technique from three villages (in Malawi, Rwanda and Tanzania) that participated in the Millennium Villages Project. Information on socio-demographic characteristics, risk factors and blood pressure measures was collected using standardized protocols. Prevalence of HTN and pre-HTN were 22 and 44%, respectively. Older age (P<0.001), higher body mass index (BMI) (P=0.07), television ownership (P=0.01) and less work-related vigorous physical activity (P=0.02) were associated with higher prevalence of HTN and higher blood pressure measures (all P<0.05). Frequent meat and fat intake were associated with higher HTN prevalence (trend P=0.02 and 0.07, respectively). Frequent fruit and vegetable intake was significantly associated with lower blood pressure measures (all P<0.05). HTN and pre-HTN are common in rural SSA. Modifiable risk factors (such as BMI, dietary intake and physical activity) are associated with HTN prevalence in this population, indicating potential opportunities for prevention measures. PMID:20220771

de Ramirez, S Stewart; Enquobahrie, D A; Nyadzi, G; Mjungu, D; Magombo, F; Ramirez, M; Sachs, S Ehrlich; Willett, W

2010-03-11

54

Combined cross sectional scanning tunneling microscopy and high resolution x-ray diffraction study for quantitative structural descriptions of type-II superlattice infrared detectors  

NASA Astrophysics Data System (ADS)

Thorough structural analysis is critical to understanding the effects of device design and modeling on type II superlattice (T2SL) based devices. In this work, structural parameters of T2SL infrared devices were uniquely determined by combining local structural parameters obtained by cross-sectional scanning tunneling microscopy (XSTM) with high resolution x-ray diffraction (HRXRD) spectra. The XSTM results were used to initialize and set tolerances for full dynamical simulation and simultaneous fitting of multiple HRXRD spectra. Using this method, we obtain unique, quantitative description of the superlattice structure, composition, and strain which can be used to evaluate the material effects on device performance.

Yakes, M. K.; Qadri, S. B.; Mahadik, N. A.; Yi, C.; Lubyshev, D.; Fastenau, J. M.; Liu, A. W. K.; Aifer, E. H.

2012-12-01

55

Photoionization of Xe inside C{sub 60}: Atom-fullerene hybridization, giant cross-section enhancement, and correlation confinement resonances  

SciTech Connect

A theoretical study of the subshell photoionization of the Xe atom endohedrally confined in C{sub 60} is presented. Powerful hybridization of the Xe 5s state with the bottom edge of C{sub 60} pi band is found that induces strong structures in the 5s ionization, causing the cross section to differ significantly from earlier results that omit this hybridization. The hybridization also affects the angular distribution asymmetry parameter of Xe 5p ionization near the Cooper minimum. The 5p cross section, on the other hand, is greatly enhanced by borrowing considerable oscillator strength from the C{sub 60} giant plasmon resonance via the atom-fullerene dynamical interchannel coupling. Beyond the C{sub 60} plasmon energy range the atomic subshell cross sections display confinement-induced oscillations in which, over the large 4d shape resonance region, the dominant 4d oscillations induce their 'clones' in all degenerate weaker channels known as correlation confinement resonances.

Madjet, Mohamed E.; Renger, Thomas; Hopper, Dale E.; McCune, Matthew A.; Chakraborty, Himadri S.; Rost, Jan-M.; Manson, Steven T. [Institute of Chemistry and Biochemistry, Free University, Fabeckstrasse 36a, D-14195 Berlin (Germany); Center for Innovation and Entrepreneurship, Department of Chemistry and Physics, Northwest Missouri State University, Maryville, Missouri 64468 (United States); Max-Planck-Institut fuer Physik Komplexer Systeme, Noethnitzer Strasse 38, D-01187 Dresden (Germany); Department Physics and Astronomy, Georgia State University, Atlanta, Georgia 30303 (United States)

2010-01-15

56

The impact of learned resourcefulness on quality of life in type II diabetic patients: a cross-sectional correlational study.  

PubMed

It is well recognized that patients with diabetes encounter a host of daily self-care issues, including controlling blood sugar and preventing and managing complications, which impact significantly upon quality of life. Studies have indicated that learned resourcefulness has a potentially positive effect in dealing with psychosocial and health problems. The purpose of this study was to test the relationship between learned resourcefulness and quality of life in type II diabetic patients. The mediating and moderating effects of learned resourcefulness on the relationship between metabolic control and quality of life of diabetic patients was also examined. This cross-sectional and correlational study included a convenience sample of 131 type II diabetic patients recruited from three hospitals in southern Taiwan. Data were collected through questionnaires, which included the Rosenbaum's Self Control Schedule and World Health Organization's Quality of Life (Short Version). Multiple regression techniques were used to analyze outcome predictors. Study findings include identification of a mediating effect of learned resourcefulness between metabolic control and quality of life. While most DM patients were not satisfied with their health, we found that those with greater learned resourcefulness enjoyed a better quality of life. Learned resourcefulness, gender, and HbA1C explained 35.2% of variance in DM patient quality of life. Male diabetic patients enjoyed a better quality of life than females, even though levels of learned resourcefulness between the two groups were not significantly different. Results indicate that poor metabolic control of diabetic patients has a detrimental effect on quality of life, and when diabetic patients use more self-control skills, they may achieve better quality of life. Results suggest that nurses who use cognitive behavior coping strategies (resourcefulness) may help diabetic patients achieve better metabolic control and promote better quality of life. PMID:19061173

Huang, Chiung-Yu; Perng, Shoa-Jen; Chen, Hisu-Fung; Lai, Chien-Yu

2008-12-01

57

Mental health and behaviour of students of public health and their correlation with social support: a cross-sectional study  

PubMed Central

Background Future public health professionals are especially important among students partly because their credibility in light of their professional messages and activities will be tested daily by their clients; and partly because health professionals' own lifestyle habits influence their attitudes and professional activities. A better understanding of public health students' health and its determinants is necessary for improving counselling services and tailoring them to demand. Our aim was to survey public health students' health status and behaviour with a focus on mental health. Methods A cross-sectional study was carried out among public health students at 1-5-years (N = 194) with a self-administered questionnaire that included standardized items on demographic data, mental wellbeing characterized by sense of coherence (SoC) and psychological morbidity, as well as health behaviour and social support. Correlations between social support and the variables for mental health, health status and health behaviour were characterized by pairwise correlation. Results The response rate was 75% and represented students by study year, sex and age in the Faculty. Nearly half of the students were non-smokers, more than one quarter smoked daily. Almost one-fifth of the students suffered from notable psychological distress. The proportion of these students decreased from year 1 to 5. The mean score for SoC was 60.1 and showed an increasing trend during the academic years. 29% of the students lacked social support from their student peers. Significant positive correlation was revealed between social support and variables for mental health. Psychological distress was greater among female public health students than in the same age female group of the general population; whereas the lack of social support was a more prevalent problem among male students. Conclusions Health status and behaviour of public health students is similar to their non-students peers except for their worse mental health. Future public health professionals should be better prepared for coping with the challenges they face during their studies. Universities must facilitate this process by providing helping services targeted at those with highest risk, and developing training to improve coping skills. Social support is also a potentially amenable determinant of mental health during higher education.

2011-01-01

58

Effects of Instructional Strategies Using Cross Sections on the Recognition of Anatomical Structures in Correlated CT and MR Images  

ERIC Educational Resources Information Center

|This research is an effort to best utilize the interactive anatomical images for instructional purposes based on cognitive load theory. Three studies explored the differential effects of three computer-based instructional strategies that use anatomical cross-sections to enhance the interpretation of radiological images. These strategies include:…

Khalil, Mohammed K.; Paas, Fred; Johnson, Tristan E.; Su, Yung K.; Payer, Andrew F.

2008-01-01

59

Lithium Photoionization Cross-Section and Dynamic Polarizability Using Square Integrable Basis Sets and Correlated Wave Functions.  

National Technical Information Service (NTIS)

The photoionization cross-section and dynamic polarizability for lithium atom are calculated using a discrete basis set to represent both the bound and the continuum-states of the atom, to construct an approximation to the dynamic polarizability. From the...

E. Hollauer M. A. C. Nascimento

1985-01-01

60

Correlation of respiratory symptoms and spirometric lung patterns in a rural community setting, Sindh, Pakistan: a cross sectional survey  

PubMed Central

Background Symptom-based questionnaires can be a cost effective tool enabling identification and diagnosis of patients with respiratory illnesses in resource limited setting. This study aimed to determine the correlation of respiratory symptoms and spirometric lung patterns and validity of ATS respiratory questionnaire in a rural community setting. Methods This cross sectional survey was conducted between January – March 2009 on a sample of 200 adults selected from two villages of district Khairpur, Sindh, Pakistan. A modified version of the American thoracic society division of lung disease questionnaire was used to record the presence of respiratory symptoms. Predicted lung volumes i.e. forced vital capacity (FVC), forced expiratory volume in one second (FEV1) and their ratio (FEV1/FVC) were recorded using portable spirometer. Results In the study sample there were 91 (45.5%) males and 109 (54.5%) females with overall mean age of 34 years (±11.69). Predominant respiratory symptom was phlegm (19%) followed by cough (17.5%), wheeze (14%) and dyspnea (10.5%). Prevalence of physician diagnosed and self-reported asthma was 5.5% and 9.5% respectively. Frequency of obstructive pattern on spirometry was 28.72% and that of restrictive pattern was 19.68%. After adjustment for age, gender, socioeconomic status, spoken dialect, education, smoking status, height, weight and arsenic in drinking water, FVC was significantly reduced for phlegm (OR 3.01; 95% CI: 1.14 – 7.94), wheeze (OR 7.22; 95% CI: 2.52 – 20.67) and shortness of breath (OR 4.91; 95% CI: 1.57 – 15.36); and FEV1 was significantly reduced for cough (OR 2.69; 95% CI: 1.12 – 6.43), phlegm (OR 3.01; 95% CI: 1.26 – 7.16) and wheeze (OR 10.77; 95% CI: 3.45 – 33.6). Presence of respiratory symptoms was significantly associated with restrictive and/or obstructive patterns after controlling for confounders. Similar findings were observed through linear regression where respiratory symptoms were found to be significantly associated with decrements in lung volumes. Specificity and positive predictive values were found to be higher for all the symptoms compared to sensitivity and negative predictive values. Conclusion Symptoms based respiratory questionnaires are a valuable tool for screening of respiratory symptoms in resource poor, rural community setting.

2012-01-01

61

Nuclear cross sections  

Microsoft Academic Search

Nuclear cross sections, sigmaij,i=pi+\\/-, K+, K-, p, p, A; j=p, A have been derived for all energies. A new expression for the average charged particle multiplicity together with new empirical formulas for elastic and inelastic pp cross sections have been derived and used to determine the nuclear cross sections. Extrapolations to high and superhigh energies are given. For instance, at

Arne Liland

1993-01-01

62

Correlation of nasal obstruction with nasal cross-sectional area measured by computed tomography in patients with nasal septal deviation.  

PubMed

Objectives: The objective of the present study was to investigate the relationship between the subjective sensation of nasal obstruction and the corresponding cross-sectional area for nasal airflow in patients with a deviated septum. Methods: Seventy-one patients with a diagnosis of unilateral nasal obstruction due to a deviated nasal septum were evaluated by preoperative computed tomography. Anterior anatomic characteristics (the internal nasal valve angle and the cross-sectional areas at the external nasal valve, the head of the inferior turbinate, and the head of the middle turbinate) and posterior anatomic factors (the cross-sectional areas at the openings of the frontal sinus, maxillary sinus, and end of the nasal septum) were examined. Associations between the computed tomography measurements and the subjective severity of nasal obstruction were analyzed with a visual analog scale (VAS). Results: Anterior and posterior anatomic characteristics were associated with the subjective severity of nasal obstruction. Anterior anatomic factors were related to the VAS scores of patients with anterior septal deviation, and posterior anatomic factors were related to the VAS scores of patients with posterior septal deviation. Conclusions: This study indicated that the anterior and posterior parts of the nasal cavity are both related to nasal obstruction. In some patients, the posterior part of the nasal cavity was more important than other locations in causing nasal obstruction. PMID:22606927

Cho, Gye Song; Kim, Jeoung Hyun; Jang, Yong Ju

2012-04-01

63

The b{bar b} production cross section and correlations in p{bar p} collisions at {radical}s = 1.8 TeV  

SciTech Connect

The authors present measurements of the b{bar b} production cross section and angular correlations between the b and {bar b}-quarks in p{bar p} collisions using the D0 detector at the Fermilab Tevatron operating at {radical}s = 1.8 TeV. The b-quark production cross section for {vert_bar}y{sup b}{vert_bar} < 1.0 and {rho}{sub {tau}}{sup b} > 8 GeV/c is extracted and found to be consistent with next-to-leading order QCD predictions. In addition, the angular correlations between the b and {bar b}-quarks are found to agree in shape with next-to-leading order QCD predictions.

Gomez, B.; Hoeneisen, B.; Negret, J.P. [Universidad de los Andes, Begota (Colombia)] [and others

1996-08-01

64

Prevalence and correlates of tobacco use amongst junior collegiates in twin cities of western Nepal: A cross-sectional, questionnaire-based survey  

Microsoft Academic Search

BACKGROUND: College students are vulnerable to tobacco addiction. Tobacco industries often target college students for marketing. Studies about prevalence of tobacco use and its correlates among college students in Nepal are lacking. METHODS: A cross-sectional survey was carried out in two cities of western Nepal during January-March, 2007. A pre-tested, anonymous, self-administered questionnaire (in Nepali) adapted from Global Youth Tobacco

Chandrashekhar T Sreeramareddy; PV Kishore; Jagadish Paudel; Ritesh G Menezes

2008-01-01

65

Diffraction Effects in Nuclear Cross Sections  

Microsoft Academic Search

Some of the most noticeable resonance structures in the energy dependence of nuclear cross sections and other reaction characteristics, for example, the kinetic energy and angular anisotropy, of fission fragments are correlated for different nuclei irrespective of the parity of their atomic number and mass number. The resonance structures in the neutron cross sections can also correlate with the structure

G. V. Anikin; V. G. Anikin

2003-01-01

66

Solar fusion cross sections  

Microsoft Academic Search

We review and analyze the available information on the nuclear-fusion cross sections that are most important for solar energy generation and solar neutrino production. We provide best values for the low-energy cross-section factors and, wherever possible, estimates of the uncertainties. We also describe the most important experiments and calculations that are required in order to improve our knowledge of solar

Eric G. Adelberger; Sam M. Austin; John N. Bahcall; A. B. Balantekin; Gilles Bogaert; Lowell S. Brown; Lothar Buchmann; F. Edward Cecil; Arthur E. Champagne; Ludwig de Braeckeleer; Charles A. Duba; Steven R. Elliott; Stuart J. Freedman; Moshe Gai; G. Goldring; Christopher R. Gould; Andrei Gruzinov; Wick C. Haxton; Karsten M. Heeger; Ernest Henley; Calvin W. Johnson; Marc Kamionkowski; Ralph W. Kavanagh; Steven E. Koonin; Kuniharu Kubodera; Karlheinz Langanke; Tohru Motobayashi; Vijay Pandharipande; Peter Parker; R. G. Robertson; Claus Rolfs; R. F. Sawyer; N. Shaviv; T. D. Shoppa; K. A. Snover; Erik Swanson; Robert E. Tribble; Sylvaine Turck-Chièze; John F. Wilkerson

1998-01-01

67

On probability distributions of nuclear cross sections  

Microsoft Academic Search

The nuclear cross section probability distributions in heavy nuclei are ; shown to be of simple form and to yield information on the reaction mechanisms ; and the structure of the scattering amplitude. The form of the probability ; distribution obtained provides a consistency check on the results obtained from ; cross section correlation functions. Scattering amplitudes are considered for

Torleif Eric Oskar Ericson

1963-01-01

68

Lifestyle correlates of self-reported sleep duration among Saudi adolescents: a multicentre school-based cross-sectional study.  

PubMed

BACKGROUND: Lifestyle factors are important determinants of adequate sleep among adolescents. However, findings on sleep duration relative to lifestyle factors are conflicting. Therefore, this study examined the association of self-reported sleep duration with physical activity, sedentary behaviours and dietary habits among Saudi adolescents. METHODS: A multicentre school-based cross-sectional study was conducted in three major cities in Saudi Arabia. The sample included 2868 secondary-school students (51.9% girls) aged 15-19 years, randomly selected using a multistage stratified cluster sampling technique. In addition to anthropometric measurements, sleep duration, physical activity, sedentary behaviours and dietary habits were assessed using self-reported questionnaire. RESULTS: Several lifestyle factors were associated with sleep duration in adolescents. While controlling for some potential confounders, the findings showed that high screen time [>5?h/day; adjusted odds ratio (aOR) = 1.505, 95% confidence interval (CI) = 1.180-1.920, P = 0.001] and low (aOR = 1.290, 95% CI = 1.064-1.566, P = 0.010) to medium (aOR = 1.316, 95% CI = 1.075-1.611, P = 0.008) physical activity levels were significantly related to daily sleep of 8?h or longer. Furthermore, having low intake of breakfast (<3 day/week compared with 5 days or more per week) decreased the odd of having adequate sleep duration by a factor of 0.795 (95% CI = 0.667-0.947, P < 0.010). CONCLUSIONS: Short sleep duration (<8?h/day) among Saudi adolescents 15-19 year olds was significantly associated with several lifestyle factors. Intervention programs aiming for improving sleeping habits among adolescents need to consider such potential association of lifestyle variables with sleep duration. PMID:23521148

Al-Hazzaa, H M; Musaiger, A O; Abahussain, N A; Al-Sobayel, H I; Qahwaji, D M

2013-03-22

69

Photodetachment cross section for Ca sup minus  

SciTech Connect

Multiconfiguration Hartree-Fock calculations for photodetachment cross sections in Ca{sup {minus}} are reported, both to the {ital ks} {sup 2}{ital S} and {ital kd} {sup 2}{ital D} final state. Correlation is important to the binding of the 4{ital s}{sup 2}4{ital p} {sup 2}{ital P} state and also to the cross section. In the final state, correlation is particularly important for the {ital kd} partial cross section. The value of the electron affinity in Ca{sup {minus}} is critical to agreement in the length and velocity form of the cross section. Better agreement is obtained when a theoretical value is used. Agreement with an experimental photodetachment cross section is good.

Froese Fischer, C. (Department of Computer Science, Vanderbilt University, Box 6035B, Nashville, TN (USA)); Hansen, J.E. (Zeeman Laboratory, Plantage Muidergracht 4, NL-1018 TV Amsterdam, The Netherlands (NL))

1991-08-01

70

Prevalence of dental caries among a cohort of preschool children living in Gampaha district, Sri Lanka: A descriptive cross sectional study  

PubMed Central

Background Dental caries among young children are a global problem. Scant attention is paid towards primary teeth, leading to high prevalence of dental caries. There are only few studies done in Sri Lanka, addressing oral hygiene among preschool children. Scientific evidence is in need to persuade authorities to establish a programme promoting oral hygiene among preschool children. Methods A descriptive cross sectional study was conducted in Ragama Medical officer of Health area. Consecutive children between 2 – 5?years of age, attending child welfare clinics were recruited for the study. Practices related to dental hygiene and socio-economic characteristics were obtained using an interviewer administered questionnaire. Mouth was examined for evidence of dental caries. Data collection and examination were done by two doctors who were trained for this purpose. The data were analysed using SSPS version 16. Results Total of 410 children were included. None had a routine visits to a dentist. Practices related to tooth brushing were satisfactory. Prevalence of dental caries gradually increased with age to reach 68.8% by 5?years. Mean total decayed-extracted-filled (deft) score for the whole sample was 1.41 and Significant caries index (SIC) was 4.09. Decayed tooth were the main contributor for the deft score and Care index was only 1.55. Girls had a significantly higher prevalence of caries than boys. Conclusions Dental care provided for Sri Lankan preschool children appears to be unsatisfactory as prevalence of dental caries among this cohort of preschool children was very high. There is an urgent need to improve dental care facilities for Sri Lankan preschool children.

2012-01-01

71

Vitamin D status in patients with musculoskeletal pain, fatigue and headache: A cross-sectional descriptive study in a multi-ethnic general practice in Norway  

PubMed Central

Objective To investigate vitamin D levels in patients with non-specific musculoskeletal pain, headache, and fatigue. Design A cross-sectional descriptive study. Setting A health center in Oslo, Norway, with a multi-ethnic population. Subjects A total of 572 patients referred by a general practitioner (GP) for an examination of hypovitaminosis D who reported musculoskeletal pain, headache, or fatigue. The patients' native countries were: Norway (n = 249), Europe, America, and South-East Asia (n = 83), and the Middle East, Africa, and South Asia (n = 240). Both genders and all ages were included. Main outcome measures Vitamin D levels (25-hydroxyvitamin D) in nmol/L. Results Hypovitaminosis D (25-hydroxyvitamin D < 50 nmol/L) was found in 58% of patients. One-third of ethnic Norwegians had hypovitaminosis D, while 83% of patients from the Middle East, Africa, and South Asia had hypovitaminosis D with minimal seasonal variation of levels. One in two women from these countries had a vitamin D level below 25 nmol/L. Mean vitamin D level was lower in patients with headaches compared with patients with other symptoms. Some 15% of patients with low (< 50 nmol/L) vitamin D levels reported headaches, compared with 5% of those with normal vitamin D levels. Conclusion Our study shows a high prevalence of hypovitaminosis D in patients with non-specific musculoskeletal pain, headache, or fatigue for whom the GP had suspected a low vitamin D level. Hypovitaminosis D was not restricted to immigrant patients. These results indicate that GPs should maintain awareness of hypovitaminosis D and refer patients who report headaches, fatigue, and musculoskeletal pain with minimal sun exposure and a low dietary vitamin D intake for assessment.

Knutsen, Kirsten Valebj?rg; Brekke, Mette; Gjelstad, Svein; Lagerl?v, Per

2010-01-01

72

Cross-sectional and longitudinal correlations between disease progression and different health-related quality of life domains in persons with amyotrophic lateral sclerosis.  

PubMed

In ALS it would be expected that quality of life (QoL) would be decreased. However, studies to date show diverging results. Our study focuses on how ALS affects QoL on the different domains of the SF-36 cross-sectionally and during progression. The method used was a prospective cohort study, with assessments at baseline, at six months, and at one year. Patients were included with possible, probable or definite ALS according to the revised El Escorial criteria and were between 30 and 70 years of age. ALS functional rating scale was used to establish disease status, SF-36 as QoL scale. At baseline 73 completed ALSFRS forms were available and 62 completed SF-36 forms. The ALSFRS showed disease progression. SF-36 scores showed lower QoL scores of persons with ALS compared to the general population both in cross-sectional and longitudinal aspects in the domains of Physical Functioning, Role Physical, and Social Functioning, but similar compared with the general population in the Mental Health and Role Emotional domains. This study shows deteriorating physical health but stable mental health, thereby illustrating the diverging correlations between ALS severity and HRQoL. The diverging pattern of physical and mental health suggests a frame-shift in the experience of HRQoL. PMID:18033593

De Groot, Imelda J M; Post, Marcel W M; van Heuveln, Tineke; Van den Berg, Leonard H; Lindeman, Eline

2007-12-01

73

Balanced Cross Sections and Retrodeformation  

NSDL National Science Digital Library

In this exercise, students investigate the use of balanced cross sections and retrodeformation to study faults that do not break the surface and their application to tectonics, folding, and earthquake hazards. Introductory materials explain how to construct geologic cross-sections, the idea of balance in a cross-section, and the concept of retrodeformability, whether or not the structures seen in a cross section can be 'undeformed' into their original positions. Using the Kink Method, students will construct a cross-section and test a balanced cross section to see if it is retrodeformable. Instructions, a blank cross section with data, study questions, and a bibliography are provided.

Pinter, Nicholas

74

Benchmark cross sections for bottom quark production  

SciTech Connect

A summary is presented of theoretical expectations for the total cross sections for bottom quark production, for longitudinal and transverse momentum distributions, and for b, /bar b/ momentum correlations at Fermilab fixed target and collider energies.

Berger, E.L.

1988-01-07

75

Eating disorder pathology among overweight treatment-seeking youth: Clinical correlates and cross-sectional risk modeling  

Microsoft Academic Search

Preliminary research suggests that pediatric overweight is associated with increased eating disorder pathology, however, little is known about which overweight youth are most vulnerable to eating disorder pathology. We therefore investigated 122 overweight treatment-seeking youth to describe eating disorder pathology and mental health correlates, and to identify psychopathological constructs that may place overweight youth at increased risk for eating disorder

Kamryn T. Eddy; Marian Tanofsky-Kraff; Heather Thompson-Brenner; David B. Herzog; Timothy A. Brown; David S. Ludwig

2007-01-01

76

Opportunities for Student Physical Activity in Elementary Schools: A Cross-Sectional Survey of Frequency and Correlates  

Microsoft Academic Search

The objectives of this study were to describe opportunities for student physical activity (PA) in elementary schools and to identify factors in the school environment associated with higher PA opportunity. Self-report questionnaires were completed by school principals and physical education teachers in 277 schools (88% response) in metropolitan Montreal. Correlates of opportunity were identified using ordinal logistic regression. There was

Tracie A. Barnett; Jennifer OLoughlin; Lise Gauvin; Gilles Paradis; Jim Hanley

2006-01-01

77

Correlates of quality of life of pre-obese and obese patients: a pharmacy-based cross-sectional survey  

Microsoft Academic Search

BACKGROUND: The correlates of quality of life (QOL), as measured by the OSQOL questionnaire were investigated in a convenience sample of overweight patients recruited in pharmacies. METHODS: A convenience sample of patients with a Body Mass Index ? 28 kg\\/m2 were recruited in community-based pharmacies. Baseline characteristics and QOL dimensions (1-Physical state, 2-Vitality-desire to do things, 3-Relations with others, 4-Psychological

Laurent Laforest; Eric Van Ganse; Cécile Ritleng; Gaelle Desamericq; Laurent Letrilliart; Alain Moreau; Sarah Rosen; Hubert Mechin; Genevieve Chamba

2009-01-01

78

Personal, Behavioral, and Socio-Environmental Correlates of Physical Activity Among Adolescent Girls: Cross-Sectional and Longitudinal Associations.  

PubMed

BACKGROUND: Physical activity (PA) declines sharply and rapidly during adolescence, especially among girls, posing a risk for inactivity and obesity in adulthood. This study identified personal, behavioral, and socio-environmental correlates of concurrent and 6-month longitudinal PA among adolescent girls. METHODS: Data were gathered from 356 adolescent girls (mean age 15.8 ± 1.2 years; >75% racial/ethnic minorities) in the Minneapolis/St. Paul area in 2007-2009. Linear regression analyses controlling for age, race/ethnicity, and school were conducted predicting baseline and follow-up levels of total PA and moderate-to-vigorous PA (MVPA) assessed via 3-Day Physical Activity Recall. Models were fit for each correlate individually and for all correlates together, mutually adjusted. RESULTS: For concurrent PA, significant positive predictors when adjusting for the influence of all other variables included self-efficacy, support from friends and teachers, and friends' PA. Total screen time and distance from school to PA resources related inversely to concurrent PA. In mutually-adjusted models, 6-month PA was positively related to self-worth, family support, and parent PA and inversely related to total screen time. CONCLUSIONS: PA interventions with adolescent girls might be enhanced by involving adolescents' social networks and also by helping adolescents feel better about their self-worth and athletic abilities. PMID:23250194

Graham, Dan J; Bauer, Katherine W; Friend, Sarah; Barr-Anderson, Daheia J; Nuemark-Sztainer, Dianne

2012-12-17

79

Opportunities for student physical activity in elementary schools: a cross-sectional survey of frequency and correlates.  

PubMed

The objectives of this study were to describe opportunities for student physical activity (PA) in elementary schools and to identify factors in the school environment associated with higher PA opportunity. Self-report questionnaires were completed by school principals and physical education teachers in 277 schools (88% response) in metropolitan Montreal. Correlates of opportunity were identified using ordinal logistic regression. There was substantial variation in PA opportunities between schools. Higher opportunity was associated with role modeling of PA by school principals, their interest in increasing PA through links to the municipality, adequate financial and human resources, access to school sports facilities, adequate space for storing student sports equipment, and suburban location. There is both the need and the potential for intervention to increase PA opportunities in elementary schools. Addressing barriers related to resources and access to sports facilities may help reduce disparities between schools in opportunities for students to engage in PA. PMID:16531514

Barnett, Tracie A; O'Loughlin, Jennifer; Gauvin, Lise; Paradis, Gilles; Hanley, Jim

2006-04-01

80

Exploring correlates of burnout dimensions in a sample of psychiatric rehabilitation practitioners: A cross-sectional study.  

PubMed

Objective: The primary purpose of this article is to investigate demographic and work-related correlates of three burnout dimensions, that is, emotional exhaustion, depersonalization, and diminished personal accomplishment, using a national sample of psychiatric rehabilitation practitioners (PRPs). Method: An online survey was filled out by 1,639 PRPs who provided demographic, work-related, and burnout data. Complete data for hypotheses testing using stepwise regression analyses was available for 813 PRPs. Results: Lower than expected levels of burnout dimensions were found among PRPs. All 3 study hypotheses were at least partially supported. Looking at individual correlates of burnout dimensions, education level was positively related to emotional exhaustion, age was negatively related to depersonalization, and age and length of service were both negatively related to diminished personal accomplishment. Personal involvement was positively related to emotional exhaustion and depersonalization. Regression results were also supportive of the mental health burnout process model, that is, emotional exhaustion explaining depersonalization, which then combined with emotional exhaustion to help further explain diminished personal accomplishment. Conclusions and Implications for Practice: Study limitations are acknowledged. This study updates the results of a prior 1996 PRP survey (Blankertz & Robinson, 1996) using a demographically comparable (i.e., gender, race, education level, primary area of study) sample. Reducing one's personal involvement with clients seems important to reducing PRP emotional exhaustion and depersonalization. Emotional exhaustion is generally acknowledged to be the key component to burnout and reducing it via peer support group sessions is recommended. (PsycINFO Database Record (c) 2013 APA, all rights reserved). PMID:23876178

Blau, Gary; Tatum, Donna S; Ward Goldberg, Casey

2013-07-22

81

Difference between interaction cross sections and reaction cross sections  

Microsoft Academic Search

We study the validity of the substitution of interaction cross sections for total reaction cross sections for a nucleus incident on a target nucleus at relativistic energies. We show that, for incident stable nuclei, the predicted difference between interaction and total reaction cross sections is large enough to probe the nuclear structure, particularly in a mass region of less than

Akihisa Kohama; Kei Iida; Kazuhiro Oyamatsu

2008-01-01

82

Individual, social, environmental, and physical environmental correlates with physical activity among Canadians: a cross-sectional study  

PubMed Central

Background The identification of various individual, social and physical environmental factors affecting physical activity (PA) behavior in Canada can help in the development of more tailored intervention strategies for promoting higher PA levels in Canada. This study examined the influences of various individual, social and physical environmental factors on PA participation by gender, age and socioeconomic status, using data from the 2002 nationwide survey of the Physical Activity Monitor. Methods In 2002, 5,167 Canadians aged 15–79 years, selected by random-digit dialling from household-based telephone exchanges, completed a telephone survey. The short version of the International Physical Activity Questionnaire was used to collect information on total physical activity. The effects of socio-economical status, self-rated health, self-efficacy, intention, perceived barriers to PA, health benefits of PA, social support, and facility availability on PA level were examined by multiple logistic regression analyses. Results Self-efficacy and intention were the strongest correlates and had the greatest effect on PA. Family income, self-rated health and perceived barriers were also consistently associated with PA. The effects of the perceived health benefits, education and family income were more salient to older people, whereas the influence of education was more important to women and the influence of perceived barriers was more salient to women and younger people. Facility availability was more strongly associated with PA among people with a university degree than among people with a lower education level. However, social support was not significantly related to PA in any subgroup. Conclusion This study suggests that PA promotion strategies should be tailored to enhance people's confidence to engage in PA, motivate people to be more active, educate people on PA's health benefits and reduce barriers, as well as target different factors for men and women and for differing socio-economic and demographic groups.

Pan, Sai Yi; Cameron, Christine; DesMeules, Marie; Morrison, Howard; Craig, Cora Lynn; Jiang, XiaoHong

2009-01-01

83

Terahertz radar cross section measurements  

Microsoft Academic Search

We present the result of terahertz radar cross section measurements on various objects including models of aircraft fighters. Application of a time domain system provides both values of radar cross section and ranging information.

Krzysztof Iwaszczuk; Henning Heiselberg; Peter Uhd Jepsen

2010-01-01

84

Photodetachment cross section of Cu⁻  

Microsoft Academic Search

We report the first ab initio calculation of the photodetachment cross section of the bound Cu⁻ ion. The calculated cross section exhibits two shape resonances, the larger of which should be accessible experimentally. The magnitude of the cross section is substantial ((6.8--7.1) x 10⁻¹⁷ cm²) at wavelengths associated with the copper-vapor laser.

K. F. Scheibner; A. U. Hazi

1988-01-01

85

NUCLEAR CROSS SECTION STATUS REPORT  

Microsoft Academic Search

The current status of cross-section knowledge is discussed, and ; experiments and calculations for increasing this knowledge are described. A ; bibliography of available cross-section data is given, and recommendations for a ; program designed to provide more cross-section information are made. (auth)

R. W. Deutsch; N. C. Francis; B. E. Simmons; P. F. Zweifel

1956-01-01

86

International Evaluation of Neutron Cross Section Standards  

SciTech Connect

Neutron cross section standards are the basis for the determination of most neutron cross sections. They are used for both measurements and evaluations of neutron cross sections. Not many cross sections can be obtained absolutely - most cross sections are measured relative to the cross section standards and converted using evaluations of the standards. The previous complete evaluation of the neutron cross section standards was finished in 1987 and disseminated as the NEANDC/INDC and ENDF/B-VI standards. R-matrix model fits for the light elements and non-model least-squares fits for all the cross sections in the evaluation were the basis of the combined fits for all of the data. Some important reactions and constants are not standards, but they assist greatly in the determination of the standard cross sections and reduce their uncertainties - these data were also included in the combined fits. The largest experimental database used in the evaluation was prepared by Poenitz and included about 400 sets of experimental data with covariance matrices of uncertainties that account for all cross-energy, cross-reaction and cross-material correlations. For the evaluation GMA, a least-squares code developed by Poenitz, was used to fit all types of cross sections (absolute and shape), their ratios, spectrum-averaged cross sections and thermal constants in one full analysis. But, the uncertainties derived in this manner, and especially those obtained in the R-matrix model fits, have been judged to be too low and unrealistic. These uncertainties were substantially increased prior to their release in the recommended data files of 1987. Modified percentage uncertainties were reassigned by the United States Cross Section Evaluation Working Group's Standards Subcommittee for a wide range of energies, and no covariance (or correlation) matrices were supplied at that time. The need to re-evaluate the cross section standards is based on the appearance of a significant amount of precise experimental data and improved developments in the methodology of analysis and evaluation. Initial efforts to produce a new evaluation were made by the United States Cross Section Evaluation Working Group which formed a Task Force. It was realized that international cooperation would be needed to produce the evaluation. The Working Party on International Evaluation Cooperation of the Nuclear Energy Agency Nuclear Science Committee formed a Subgroup, and the International Atomic Energy Agency formed a Coordinated Research Project (CRP). These groups worked cooperatively to improve the evaluation process. The major effort in producing the evaluation was through the CRP. The evaluations of the neutron cross section standards were finalized in October 2005. Previous difficulties experienced with a data evaluation problem known as 'Peelle's Pertinent Puzzle' create biases in the fit of correlated data, and they have been addressed to reduce this phenomenon. The new evaluations of the cross section standards also include covariance matrices of the uncertainties that contain fully justifiable values. The product of this international effort has been adopted as the neutron standards for ENDF/B-VII.0.

Carlson, A.D. [National Institute of Standards and Technology, 100 Bureau Drive, Stop 8463, Gaithersburg, MD 20899-8463 (United States)], E-Mail: allan.carlson@nist.gov; Pronyaev, V.G. [Institute of Physics and Power Engineering, Bondarenko Sq. 1, 249 033 Obninsk, Kaluga Region (Russian Federation); Smith, D.L. [Argonne National Laboratory, 1710 Avenida del Mundo 1506, Coronado, CA 92118 (United States); Larson, N.M. [Bldg 5700, Rm 308, MS 6371, Oak Ridge National Laboratory, P.O. Box 2008, Oak Ridge, TN 37831-6371 (United States); Chen, Zhenpeng [Physics Department, Tsinghua University, Beijing 100084 China (China); Hale, G.M. [Los Alamos National Laboratory, Group T-16, MS B-243, Los Alamos NM 87545 (United States); Hambsch, F.-J. [Neutron Physics Unit, EC-JRC-Institute for Reference Materials and Measurements, Retieseweg B-2440 Geel (Belgium); Gai, E.V. [Institute of Physics and Power Engineering, Bondarenko Sq. 1, 249 033 Obninsk, Kaluga Region (Russian Federation); Oh, Soo-Youl [HANARO Center, Korea Atomic Energy Research Institute, P.O. Box 105, Yuseong, Daejeon 305-600 (Korea, Republic of); Badikov, S.A. [Central Research Institute of Management, Economics and Information, Dmitrovskoe sh.2, Moscow 127434 (Russian Federation); Kawano, T. [Los Alamos National Laboratory, Group T-16, MS B-243, Los Alamos NM 87545 (United States); Hofmann, H.M. [Institut fuer Theoretische Physik III, 02.534/B2, Universitaet Erlangen-Nuernberg, Staudtstrasse 7, D-91058 Erlangen (Germany); Vonach, H.; Tagesen, S. [Institut fuer Isotopenforschung und Kernphysik der Universitaet Wien, Waehringerstrasse 17, A-1090 Vienna (Austria)

2009-12-15

87

Correlates of Antioxidant Nutrients and Oxidative DNA Damage Differ by Race in a Cross-Sectional Study of Healthy African American and White Adults  

PubMed Central

Although antioxidant nutrients and oxidative DNA damage have been associated with carcinogenesis, few studies have investigated the factors that influence antioxidant intake and oxidative DNA damage in racially diverse populations. Demographic, behavioral, and diet-related psychosocial correlates of plasma antioxidant (carotenoids, vitamin C, and vitamin E) concentrations and oxidative DNA damage were examined using data from a cross-sectional study of 147 generally healthy, non-smoking African American and White adults in North Carolina, age 20 to 45 years. All participants completed self-administered demographic, diet, and health questionnaires and provided semi-fasting (? 6 hours) blood samples. Multivariate regression analyses were computed separately for each race to determine associations between the potential correlates with plasma antioxidant concentrations and oxidative DNA damage, separately. Our findings suggest appreciable differences by race. Only a few factors (age, supplement use, and several psychosocial factors) were associated with antioxidant concentrations in African Americans, whereas these and additional factors, including physical activity, waist circumference, and passive smoke exposure, were associated with antioxidant concentrations in Whites. For oxidative DNA damage, passive smoke exposure was significantly associated with oxidative DNA damage in African Americans, and age and alcohol were significant in Whites. In addition, the regression models generally explained more of the variance in plasma antioxidant concentrations and oxidative DNA damage in Whites than in African Americans. Considering the salient correlates differed by race, this work has important implications for the design and implementation of future research studies investigating antioxidant nutrients and/or oxidative stress, especially those in racially diverse populations.

Watters, Joanne L.; Satia, Jessie A.; Kupper, Lawrence L.

2008-01-01

88

Hadronic diffractive cross sections and the rise of the total cross section  

Microsoft Academic Search

A model for high-energy hadronic cross sections is proposed. It is based on Regge theory and perturbative QCD, and includes soft and hard mechanisms as well as diffractive processes. The validity range of Regge-pole theory in the description of total, elastic, single-, and double-diffractive cross sections is investigated and inconsistencies found already at CERN LHC and\\/or SSC energies. Examining unitarity

Gerhard A. Schuler; Torbjörn Sjöstrand

1994-01-01

89

The prevalence and correlates of meeting the current physical activity for health guidelines in older people: a cross-sectional study in Brazilian women.  

PubMed

This study aimed to identify the prevalence and correlates of meeting the current physical activity for health (PAfH) guidelines, proposed by the World Health Organization in 2010, in community-dwelling older women from Brazil. A cross-sectional study was performed with 1806 women (aged 60.0-92.7 years) who were randomly selected from eighteen care centers. The short version of the International Physical Activity Questionnaire was used to determine the weekly time spent in physical activities, and this variable was categorized into three categories (0<150min/wk; 1: 150-299.9min/wk; 2: ?300min/wk). Age, race/ethnicity, economic class, education level, occupational and marital status, body mass index and blood pressure status, medical conditions, use of medications, and self-rated health status were the potential correlates. The ordinal logistic regression was used as a measure of association. From the total group of participants, 49.9% followed the current recommendations related to basic health benefits (150-299min/wk), and 35.9% met the guidelines for additional health effects (300 or more min/wk). Women with secondary complete education (OR=1.43, 95% confidence interval [CI]: 1.17-1.74), positive self-rated health (OR=5.25, 95% CI: 2.10-13.09), and high blood pressure (OR=1.33, 95% CI: 1.09-1.62) were more likely to meet the current PAfH guidelines than their peers with primary incomplete education, negative self-rated health, and normal blood pressure. Increasing age was inversely associated with meeting the PAfH guidelines (odds ranging: 0.77-0.48). These results highlighted the elderly population subgroups, in a developing country, that needspecific guidelinesfor inclusion inhealth programs andmotivation toparticipate in physical activities. PMID:23305826

Vagetti, Gislaine Cristina; Barbosa Filho, Valter Cordeiro; Moreira, Natália Boneti; de Oliveira, Valdomiro; Mazzardo, Oldemar; de Campos, Wagner

2013-01-07

90

Hadronic diffractive cross sections and the rise of the total cross section  

NASA Astrophysics Data System (ADS)

A model for high-energy hadronic cross sections is proposed. It is based on Regge theory and perturbative QCD, and includes soft and hard mechanisms as well as diffractive processes. The validity range of Regge-pole theory in the description of total, elastic, single-, and double-diffractive cross sections is investigated and inconsistencies found already at CERN LHC and/or SSC energies. Examining unitarity constraints, modifications of the cross section formulas are proposed which allow a continued use of formulas in the Regge spirit to describe elastic and diffractive events. The nondiffractive cross section is allowed to rise at a rate consistent with unitarization of multiple parton-parton scatterings. However, in our picture, the rise of the total cross section with increasing energy is only partly due to the minijet cross sections; the diffractive topologies rise as well. Fully differential distributions are given and convenient parametrizations derived for the integrated rates of elastic and diffractive events. Predictions for the various partial cross sections at Fermilab Tevatron, LHC, and SSC energies are given and compared to other estimates.

Schuler, Gerhard A.; Sjöstrand, Torbjörn

1994-03-01

91

Systematic study of {sup 8}B breakup cross sections  

SciTech Connect

Breakup cross sections of {sup 8}B are analyzed in a two-body structure model, with an inert {sup 7}Be core and a loosely bound valence proton. The nuclear induced breakup is calculated in an eikonal approximation, and Coulomb dissociation is calculated to first order. There is a strong correlation within this model between the total E1 strength and the one-proton removal cross section {sigma}{sub 1p}. Thus we find that the measured values of {sigma}{sub 1p} for a carbon target are consistent with the E1 strength extracted in recent Coulomb dissociation experiments. The predicted {sigma}{sub 1p} values on high-Z targets are significantly larger than measured. We discuss how this discrepancy can be reduced by improving the description of Coulomb dissociation. (c) 2000 The American Physical Society.

Esbensen, Henning [Physics Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States); Hencken, Kai [Institut fuer Physik, Universitaet Basel, 4056 Basel, (Switzerland)

2000-05-01

92

The total charm cross section  

SciTech Connect

We assess the theoretical uncertainties on the total charm cross section. We discuss the importance of the quark mass, the scale choice and the parton densities on the estimate of the uncertainty. We conclude that the uncertainty on the total charm cross section is difficult to quantify.

Vogt, R

2007-09-14

93

Vocation and avocation: leisure activities correlate with professional engagement, but not burnout, in a cross-sectional survey of UK doctors  

PubMed Central

Background Sir William Osler suggested in 1899 that avocations (leisure activities) in doctors are related to an increased sense of vocation (professional engagement) and a decreased level of burnout. This study evaluated those claims in a large group of doctors practicing in the UK while taking into account a wide range of background variables. Methods A follow-up questionnaire was sent to 4,457 UK-qualified doctors who had been included in four previous studies of medical school selection and training, beginning in 1980, 1985, 1990 and 1989/1991. A total of 2,845 (63.8%) doctors returned the questionnaire. Questions particularly asked about work engagement, satisfaction with medicine as a career, and personal achievement (Vocation/engagement), stress, emotional exhaustion, and depersonalization (BurnedOut), and 29 different leisure activities (Avocation/Leisure), as well as questions on personality, empathy, work experience, and demography. Results Doctors reporting more Avocation/Leisure activities tended to be women, to have older children, to be less surface-rational, more extravert, more open to experience, less agreeable, and to fantasize more. Doctors who were more BurnedOut tended to be men, to be more sleep-deprived, to report a greater workload and less choice and independence in their work, to have higher neuroticism, lower extraversion and lower agreeableness scores, and to have lower self-esteem. In contrast, doctors with a greater sense of Vocation/engagement, tended to see more patients, to have greater choice and independence at work, to have a deep approach to work, to have a more supportive-receptive work environment, to be more extravert and more conscientious, and to report greater self-esteem. Avocation/Leisure activities correlated significantly with Vocation/engagement, even after taking into account 25 background variables describing demography, work, and personality, whereas BurnedOut showed no significant correlation with Avocation/Leisure activities. Popular Culture and High Culture did not differ in their influence on Vocation/engagement, although there was a suggestion that Depersonalization was correlated with more interest in Popular Culture and less interest in High Culture. Conclusion In this cross-sectional study there is evidence, even after taking into account a wide range of individual difference measures, that doctors with greater Avocation/Leisure activities also have a greater sense of Vocation/Engagement. In contrast, being BurnedOut did not relate to Avocation/Leisure activities (but did relate to many other measures). Osler was probably correct in recommending to doctors that, 'While medicine is to be your vocation, or calling, see to it that you also have an avocation'.

2011-01-01

94

International Evaluation of Neutron Cross Section Standards  

Microsoft Academic Search

Neutron cross section standards are the basis for the determination of most neutron cross sections. They are used for both measurements and evaluations of neutron cross sections. Not many cross sections can be obtained absolutely - most cross sections are measured relative to the cross section standards and converted using evaluations of the standards. The previous complete evaluation of the

A. D. Carlson; V. G. Pronyaev; D. L. Smith; N. M. Larson; Zhenpeng Chen; G. M. Hale; F.-J. Hambsch; E. V. Gai; Soo-Youl Oh; S. A. Badikov; T. Kawano; H. M. Hofmann; H. Vonach; S. Tagesen

2009-01-01

95

Cross-sectional assessment of prevalence and correlates of blood-borne and sexually-transmitted infections among Afghan National Army recruits  

PubMed Central

Background Few data are available in Afghanistan to shape national military force health practices, particularly with regard to sexually-transmitted infections (STIs). We measured prevalence and correlates of HIV, syphilis, herpes simplex 2 virus (HSV-2), and hepatitis C virus (HCV) among Afghan National Army (ANA) recruits. Methods A cross-sectional sample of male ANA recruits aged 18–35 years were randomly selected at the Kabul Military Training Center between February 2010 and January 2011. Participants completed an interviewer-administered questionnaire and serum-based rapid testing for syphilis and hepatitis C virus antibody on-site; HIV and HSV-2 screening, and confirmatory testing were performed off-site. Prevalence of each infection was calculated and logistic regression analysis performed to identify correlates. Results Of 5313 recruits approached, 4750 consented to participation. Participants had a mean age of 21.8 years (SD±3.8), 65.5% had lived outside Afghanistan, and 44.3% had no formal education. Few reported prior marijuana (16.3%), alcohol (5.3%), or opiate (3.4%) use. Of sexually active recruits (58.7%, N?=?2786), 21.3% reported paying women for sex and 21.3% reported sex with males. Prevalence of HIV (0.063%, 95% CI: 0.013- 0.19), syphilis (0.65%, 95% CI: 0.44 – 0.93), and HCV (0.82%, 95% CI: 0.58 – 1.12) were quite low. Prevalence of HSV-2 was 3.03% (95% CI: 2.56 - 3.57), which was independently associated with age (Adjusted Odds Ratio (AOR)?=?1.04, 95% CI: 1.00 - 1.09) and having a television (socioeconomic marker) (AOR?=?1.46, 95% CI: 1.03 – 2.05). Conclusion Though prevalence of HIV, HCV, syphilis, and HSV-2 was low, sexual risk behaviors and intoxicant use were present among a substantial minority, indicating need for prevention programming. Formative work is needed to determine a culturally appropriate approach for prevention programming to reduce STI risk among Afghan National Army troops.

2012-01-01

96

Stratigraphic Cross Section of Northeast Texas  

NSDL National Science Digital Library

Cretaceous sedimentary rocks of Northeast Texas provide important clues about paleogeography, paleotectonics, and sea level fluctuation. This website describes several of these rock units and the geologic information they supply. An unpublished report with a thorough discussion, map, cross section, and numerous references is provided. Specific topics include Cretaceous stratigraphy, lithostratigraphic and biostratigraphic correlation, ammonites, Western Interior Seaway, Skull Creek Seaway, paleogeography, and paleotectonics.

Keith, Minor; Cretaceousfossils.com

97

Neutron cross sections: Volume 2, Neutron cross section curves  

Microsoft Academic Search

Data is presented only for total (i.e., integrated) reaction cross sections (and related fission parameters) as a function of incident-neutron energy. The energy range has been limited to 0.01 eV to 200 MeV in order to exclude crystalline and magnetic effects for slow neutrons and relativistic effects for high energy neutrons. Angular distributions and partial reaction cross sections to specific

V. McLane; C. L. Dunford; P. F. Rose

1988-01-01

98

Ocular manifestation of HIV/AIDS and correlation with CD4+ cells count among adult HIV/AIDS patients in Jimma town, Ethiopia: a cross sectional study  

PubMed Central

Background HIV/AIDS is one of twenty first century’s challenges to human being with protean manifestation affecting nearly all organs of our body. It is causing high morbidity and mortality especially in sub-Saharan Africa with numerous ocular complications and blindness. The purpose of this study was to determine the patterns of ocular manifestations of HIV/AIDS and their correlation with CD4+Tcells count. Methods A cross-sectional study was done on 348 HIV-positive patients presented to Anti-Retroviral Therapy clinics. Data were collected using face-to-face interview, clinical examination and laboratory investigation, and analyzed using SPSS version 13 software. Statistical association test was done and p<0.05 was considered significant. Other statistical tests like student t-test and logistic regression were also done. Results Of 348 patients, 175 were on antiretroviral therapy and 173 were not on therapy. The mean duration of therapy was 27?months. The overall prevalence of ocular manifestations was 25.3%. The commonest ocular manifestation was keratoconjunctivitis sicca (11.3%) followed by blepharitis (3.2%), molluscum contagiosum (2.6%), conjunctival squamous cell carcinoma (2.3%), conjunctival microvasculopathy (2.3%), cranial nerve palsies (2%), herpes zoster ophthalmicus (HZO) (1.2%), and HIV retinopathy (0.6%). HIV retinopathy and conjunctival microvasculopathy were common in patient with CD4+ count of <200 cells/?l while HZO and molluscum contagiosum were common in patients with CD4+ count of 200–499 cells/?l. Prevalence of ocular manifestation was higher among patients on HAART (32.6%) than those patients not on HAART (17.9%) (p<0.05). There was statistically significant association between ocular manifestation and sex, CD4+Tcells count, and age (p<0.05). CD4+ count, <200 cells/?l and age >35?years were independent risk factors for ocular manifestations. Conclusion The study showed that the prevalence of ocular manifestation of HIV/AIDS is lower than previous studies and could be due to antiretroviral therapy. Lower CD4 count is a risk as well as predictor for ocular manifestations.

2013-01-01

99

Dietary correlates of an at-risk BMI among Inuit adults in the Canadian high arctic: cross-sectional international polar year Inuit health survey, 2007-2008  

PubMed Central

Background The study’s objective was to investigate the dietary correlates of an at-risk body mass index (BMI) among Inuit adults from thirty-six communities across the Canadian Arctic using data from the cross-sectional International Polar Year Inuit Health Survey, conducted in 2007–2008. Methods The survey included assessments of 24-hr dietary recall, sociodemographics, physical activity, and anthropometry. Dietary characteristics of overweight and obesity were similar and therefore combined into one at- risk BMI category (?25?kg/m2) for analyses. The relationship between an at-risk BMI and energy intake from macronutrients, high sugar drinks, high-fat foods, saturated fatty acids, and traditional foods were examined entering each dietary variable separately into a logistic regression model as an independent variable. Analyses were adjusted for age, sex, region, kcalories, walking, smoking and alcohol consumption. Further multivariable models considered selected dietary variables together in one model. Results An at-risk BMI was present for 64% with a prevalence of overweight and obesity of 28% and 36%, respectively. Consumption of high-sugar drinks (>15.5% E) was significantly related with having an at-risk BMI (OR?=?1.6; 95% CI 1.2; 2.2), whereas the % E from total carbohydrate evaluated as a continuous variable and as quartiles was inversely related to an at-risk BMI (P?-trend

2012-01-01

100

Self-reported sexually transmitted infections and their correlates among men who have sex with men in Norway: an Internet-based cross-sectional survey  

PubMed Central

Background The incidences of reportable sexually transmitted infections (STI) among men who have sex with men (MSM) have increased since the late 1990 s in Norway. The objectives of our study were to assess factors, associated with recent selected STI among MSM, living in Norway in order to guide prevention measures. Methods We conducted a cross-sectional Internet-based survey during 1-19 October 2007 among members of a MSM-oriented Norwegian website using an anonymous questionnaire on demographics, sexual behaviour, drug and alcohol use, and STI. The studied outcomes were gonorrhoea, syphilis, HIV or Chlamydia infection in the previous 12 months. Associations between self-reported selected STI and their correlates were analysed by multivariable Poisson regression. P value for trend (p-trend), adjusted prevalence ratios (PR) with 95% confidence intervals [] were calculated. Results Among 2430 eligible 16-74 years old respondents, 184 (8%) reported having had one of the following: syphilis (n = 17), gonorrhoea (n = 35), HIV (n = 42) or Chlamydia (n = 126) diagnosed in the past 12 months. Reporting Chlamydia was associated with non-western background (PR 2.8 [1.4-5.7]), number of lifetime male partners (p-trend < 0.001), unsafe sex under the influence of alcohol (PR 1.8 [1.1-2.9]) and with younger age (p-trend = 0.002). Reporting gonorrhoea was associated with unrevealed background (PR 5.9 [1.3-26.3]), having more than 50 lifetime male partners (PR 4.5 [1.3-15.6]) and more than 5 partners in the past 6 months (PR 3.1 [1.1-8.8]), while mid-range income was protective (PR 0.1 [0.0-0.6]). Reporting HIV was associated with residing in Oslo or Akershus county (PR 2.3 [1.2-4.6]), non-western background (PR 5.4 [1.9-15.3]), unrevealed income (PR 10.4 [1.5-71.4]), number of lifetime male partners (p-trend < 0.001) and being under the influence of selected drugs during sex in the past 12 months (PR 5.2 [2.7-11.4]). In addition, the frequency of feeling drunk was reversibly associated with HIV. Conclusions Our study demonstrates different associations of demographic and behavioural factors with different STI outcomes in the study population. Number of lifetime male partners was the most important potential predictor for Chlamydia and HIV. The STI prevention efforts among MSM should focus on Oslo and Akershus, promote safe sex practices and tackle sex-related drug and alcohol use.

2010-01-01

101

Charge-state correlated cross sections for the production of low-velocity highly charged Ne ions by heavy-ion bombardment. [1 MeV\\/amu  

Microsoft Academic Search

We report measured cross sections for the collisional production of highly charged low-velocity Ne recoil ions resulting from the bombardment of a thin Ne gas target by highly charged 1-MeV\\/amu C, N, O, and F projectiles. The measurements were made using time-of-flight techniques which allowed the simultaneous identification of the final charge state of both the low-velocity recoil ion and

Tom Gray; C. L. Cocke; E. Justiniano

1980-01-01

102

Charge-state correlated cross sections for the production of low-velocity highly charged Ne ions by heavy-ion bombardment  

Microsoft Academic Search

We report measured cross sections for the collisional production of highly charged low-velocity Ne recoil ions resulting from the bombardment of a thin Ne gas target by highly charged 1-MeV\\/amu C, N, O, and F projectiles. The measurements were made using time-of-flight techniques which allowed the simultaneous identification of the final charge state of both the low-velocity recoil ion and

Tom J. Gray; C. L. Cocke; E. Justiniano

1980-01-01

103

Use of cross section sensitivities in the analysis of fast reactor integral parameters  

Microsoft Academic Search

A cross section adjustment system has been developed at Argonne National Laboratory to study the various discrepancies obtained in the prediction of a range of reactor parameters. Cross section sensitivities are calculated with a generalized perturbation theory code. Discrepancies with experiment are minimized by a least squares adjustment of multigroup cross sections. Correlation data between cross sections and between integral

P. J. Collins; M. J. Lineberry

1978-01-01

104

A cross-sectional study of the individual, social, and built environmental correlates of pedometer-based physical activity among elementary school children  

PubMed Central

Background Children who participate in regular physical activity obtain health benefits. Preliminary pedometer-based cut-points representing sufficient levels of physical activity among youth have been established; however limited evidence regarding correlates of achieving these cut-points exists. The purpose of this study was to identify correlates of pedometer-based cut-points among elementary school-aged children. Method A cross-section of children in grades 5-7 (10-12 years of age) were randomly selected from the most (n = 13) and least (n = 12) 'walkable' public elementary schools (Perth, Western Australia), stratified by socioeconomic status. Children (n = 1480; response rate = 56.6%) and parents (n = 1332; response rate = 88.8%) completed a survey, and steps were collected from children using pedometers. Pedometer data were categorized to reflect the sex-specific pedometer-based cut-points of ?15000 steps/day for boys and ?12000 steps/day for girls. Associations between socio-demographic characteristics, sedentary and active leisure-time behavior, independent mobility, active transportation and built environmental variables - collected from the child and parent surveys - and meeting pedometer-based cut-points were estimated (odds ratios: OR) using generalized estimating equations. Results Overall 927 children participated in all components of the study and provided complete data. On average, children took 11407 ± 3136 steps/day (boys: 12270 ± 3350 vs. girls: 10681 ± 2745 steps/day; p < 0.001) and 25.9% (boys: 19.1 vs. girls: 31.6%; p < 0.001) achieved the pedometer-based cut-points. After adjusting for all other variables and school clustering, meeting the pedometer-based cut-points was negatively associated (p < 0.05) with being male (OR = 0.42), parent self-reported number of different destinations in the neighborhood (OR 0.93), and a friend's (OR 0.62) or relative's (OR 0.44, boys only) house being at least a 10-minute walk from home. Achieving the pedometer-based cut-points was positively associated with participating in screen-time < 2 hours/day (OR 1.88), not being driven to school (OR 1.48), attending a school located in a high SES neighborhood (OR 1.33), the average number of steps among children within the respondent's grade (for each 500 step/day increase: OR 1.29), and living further than a 10-minute walk from a relative's house (OR 1.69, girls only). Conclusions Comprehensive multi-level interventions that reduce screen-time, encourage active travel to/from school and foster a physically active classroom culture might encourage more physical activity among children.

2011-01-01

105

Differential cross sections and angular-correlation parameters for the excitation of hydrogen atoms to {ital n}=3 and {ital n}=2 states by electron impact between 16 and 100 eV  

SciTech Connect

Differential cross sections and angular-correlation parameters relating to elastic scattering and electron-impact excitation of hydrogen atoms to the {ital n}=3 and {ital n}=2 states are presented for energies of 16, 20, 35, 54, and 100 eV. Results are obtained from a close-coupling calculation using a 17-state target basis including seven exact states and ten pseudostates. Comparisons are made with experiment and with other calculations.

Wang, Y.D.; Callaway, J. [Department of Physics and Astronomy, Louisiana State University, Baton Rouge, Louisiana 70803-4001 (United States); Unnikrishnan, K. [Department of Theoretical Physics, Institute of Advanced Studies, Australian National University, Canberra, Australian Capital Territory 0200 (Australia)

1994-03-01

106

Early Mesoderm Development Cross Section  

NSDL National Science Digital Library

In the context of a cross section between the amniotic cavity and yolk sac, this FlashTM animation depicts mesoderm formation and differentiation into somites, dermatomes, myotomes, sclerotomes, notochord and coelom. Simultaneous development of neural tube, gut and vitelline duct is also displayed.

PhD Jack D Thatcher (West Virginia School of Osteopathic Medicine Structural Biology)

2011-07-07

107

Widths of fluctuations in nuclear cross sections  

Microsoft Academic Search

At high energies cross section resonances due to states of compound ; nuclei in nuclear reactions overlap, and the partial reaction cross sections ; fluctuate as a function of energy. Ericson's formuias for the probability ; distribution of a partial cross section sigma are obtained. Additionally, ; relations for the average number of maxima in the cross section per unit

D. M. Brink; R. O. Stephen

1963-01-01

108

Antinucleus-Nucleus Cross Sections Implemented in Geant4  

SciTech Connect

Cross sections of antinucleus ({bar p}, {bar d}, {bar t}, {sup 3}{ovr He}, {sup 4}{ovr He}) interactions with nuclei in the energy range 100 MeV/c to 1000 GeV/c per antinucleon are calculated in the Glauber approximation which provides good description of all known {bar p}Across sections. The results were obtained using a new parameterization of the total and elastic {bar p}p cross sections. Simple parameterizations of the antinucleus-nucleus cross sections are proposed for use in estimating the efficiency of antinucleus detection and tracking in cosmic rays and accelerator experiments. These parameterizations are implemented in the Geant4 toolkit.

Uzhinsky, V.; /CERN /Dubna, JINR; Apostolakis, J.; /CERN; Galoyan, A.; /Dubna, JINR; Folger, G.; /CERN; Grichine, V.M.; /Lebedev Inst.; Ivanchenko, V.N.; /CERN /Lomonosov Moscow State U.; Wright, D.H.; /SLAC

2012-04-26

109

Microscopic cross sections: An utopia?  

NASA Astrophysics Data System (ADS)

The increasing need for cross sections far from the valley of stability poses a challenge for nuclear reaction models. So far, predictions of cross sections have relied on more or less phenomenological approaches, depending on parameters adjusted to available experimental data or deduced from systematical relations. While such predictions are expected to be reliable for nuclei not too far from the experimentally known regions, it is clearly preferable to use more fundamental approaches, based on sound physical bases, when dealing with very exotic nuclei. Thanks to the high computer power available today, all major ingredients required to model a nuclear reaction can now be (and have been) microscopically (or semi-microscopically) determined starting from the information provided by a nucleon-nucleon effective interaction. We have implemented all these microscopic ingredients in the TALYS nuclear reaction code, and we are now almost able to perform fully microscopic cross section calculations. The quality of these ingredients and the impact of using them instead of the usually adopted phenomenological parameters will be discussed.

Hilaire, S.; Koning, A. J.; Goriely, S.

2010-10-01

110

An Investigation into the Total Reaction Cross Section and Production Cross Section of Energetic Particles  

Microsoft Academic Search

New calculations for the total reaction cross sections and production cross sections of the energetic particles are carried out via the nuclear transport theory. The experimental total reaction cross sections can be reproduced. In addition, the effects of some ingredients on the total reaction cross sections can be easily analyzed. It is found that the total reaction cross sections are

Yugang Ma; Wenqing Shen; Jun Feng; Yuqiang Ma

1993-01-01

111

Family and home correlates of children's physical activity in a multi-ethnic population: the cross-sectional child heart and health study in england (CHASE)  

PubMed Central

Background The influence of the family and home environment on childhood physical activity (PA) and whether this differs between ethnic groups remains uncertain. This paper investigates associations between family and home factors and childhood PA in a multi-ethnic population and explores whether associations differ between ethnic groups. Methods Cross-sectional study of 9-10 year-old schoolchildren, in which PA was objectively measured by Actigraph GT1 M accelerometers for ?7 days to estimate average activity counts per minute (CPM). Information on 11 family and home environmental factors were collected from questionnaires. Associations between these factors and CPM were quantified using multi-level linear regression. Interactions with ethnicity were explored using likelihood ratio tests. Results 2071 children (mean ± SD age: 9.95 ± 0.38 years; 47.8% male) participated, including 25% white European, 28% black African-Caribbean, 24% South Asian, and 24% other ethnic origin. Family PA support and having a pet were associated with higher average CPM (adjusted mean difference: 6 (95%CI:1,10) and 13 (95%CI:3,23), respectively) while car ownership and having internet access at home were associated with lower average CPM (adjusted mean difference: -19 (95%CI:-30,-8) and -10 (95%CI:-19,0), respectively). These associations did not differ by ethnicity. Although the number of siblings showed no overall association with PA, there was some evidence of interaction with ethnicity (p for ethnicity interaction = 0.04, 0.05 in a fully-adjusted model); a positive significant association with number of siblings was observed in white Europeans (per sibling CPM difference 10.3 (95% CI 1.7, 18.9)) and a positive non-significant association was observed in black African-Caribbeans (per sibling CPM difference: 3.5 (-4.2, 11.2)) while a negative, non-significant association was observed in South Asians (per sibling CPM difference -6.0 (-15.5, 3.4)). Conclusions Some family and home environmental factors have modest associations with childhood PA and these are mostly similar across different ethnic groups. This suggests that targeting these factors in an intervention to promote PA would be relevant for children in different ethnic groups.

2011-01-01

112

Dietary and other lifestyle correlates of serum folate concentrations in a healthy adult population in Crete, Greece: a cross-sectional study  

PubMed Central

Background Folate has emerged as a key nutrient for optimising health. Impaired folate status has been identified as a risk factor for cardiovascular disease, various types of cancers, and neurocognitive disorders. The study aimed at examining the distribution and determinants of serum folate concentrations in a healthy adult population in Crete, Greece. Methods A cross-sectional sample of 486 healthy adults (250 men, 236 women) aged 39 ± 14 years, personnel of the Medical School and the University Hospital of Crete in Greece, was examined. Serum folate and vitamin B12 concentrations were measured by microbiological assay, and total homocysteine was determined fluorometrically and by high-pressure liquid chromatography. Lifestyle questionnaires were completed, and nutrient intakes and food consumption were assessed by 24-h dietary recalls. Multivariate analyses were performed using SPSS v10.1. Results The geometric mean (95% confidence interval) concentrations of serum folate were 15.6 ?mol/l (14.6–16.8) in men and 19.2 ?mol/l (17.9–20.7) in women (p < 0.001). Inadequate folate levels (?7 nmol/l) were present in 6.8% of men and 2.1% of women (p < 0.001). Approximately 76% of men and 87% of women did not meet the reference dietary intake for folate (400 ?g/day). Serum folate was inversely related to total homocysteine levels (p < 0.001). Increased tobacco and coffee consumption were associated with lower folate concentrations (p < 0.05 for both) but these associations disappeared after controlling for nutrient intakes. In multivariate analysis, intakes of MUFA, fibre, calcium, magnesium, folate, and vitamins A, E, C, B1, and B6 were positively associated with serum folate. Consumption of potatoes, legumes, fruits, and vegetables were favourably related to the serum folate status. Conclusion Serum folate concentrations were associated with various demographic, lifestyle and dietary factors in healthy Cretan adults. Large-scale epidemiological studies should be conducted within the general Greek adult population to assess the prevalence of impaired folate status and further examine associations with dietary patterns and chronic disease risk. Considering the importance of folate in health maintenance, it is important to increase the public's awareness of modifiable lifestyle patterns and diet and tobacco use in particular, which may be associated with improved folate status.

Hatzis, Christos M; Bertsias, George K; Linardakis, Manolis; Scott, John M; Kafatos, Anthony G

2006-01-01

113

Adherence to a Mediterranean diet in Morocco and its correlates: cross-sectional analysis of a sample of the adult Moroccan population  

PubMed Central

Background Dietary habits in Morocco are changing and the causes are not well understood. This study aimed to analyse socio-demographic factors associated with adherence to the Mediterranean diet (MeDi) in a national random sample of the adult Moroccan population. Methods The data collected in this cross-sectional survey included socio-demographic factors and a food frequency questionnaire. MeDi adherence was assessed in 2214 individuals with complete dietary data. MeDi adherence was measured according to a simplified MeDi score based on the weekly frequency of intake of eight food groups (vegetables, legumes, fruits, cereal or potatoes, fish, red meat, dairy products and olive oil) with the use of the sex specific medians of the sample as cut-offs. A value of 0 or 1 was assigned to consumption of each component according to its presumed detrimental or beneficial effect on health. Logistic regression was used to estimate the association between MeDi adherence (low score 1-4 vs. high 5-8) and other factors. Results Mean age of the sample was 41.4 (standard deviation 15.3) years, 45.4% were men and 29.9% had a low MeDi adherence. Married subjects (adjusted odds ratio ORa=0.68, 95% CI 0.55-0.84) were less likely to have a low MeDi adherence compared to single, divorced or widowed persons. Persons from rural areas (ORa=1.46, 95% CI: 1.02-2.08), were more often low MeDi adherents compared to those from urban areas. Obese persons (ORa=1.56, 95% CI: 1.16-2.11) were more prone to low MeDi adherence than normal weight individuals. Conclusion MeDi is far from being a universal pattern in the Moroccan population. Intervention strategies should be implemented in target groups to maintain the traditional MeDi pattern considered as the original diet in Morocco.

2012-01-01

114

Compound-nuclear reaction cross sections from surrogate measurements  

NASA Astrophysics Data System (ADS)

Nuclear reaction cross sections are important for a variety of applications in the areas of astrophysics, nuclear energy, and national security. When these cross sections cannot be measured directly or predicted reliably, it becomes necessary to develop indirect methods for determining the relevant reaction rates. The surrogate nuclear reactions approach is such an indirect method. First used in the 1970s for estimating (n,f) cross sections, the method has recently been recognized as a potentially powerful tool for a wide range of applications that involve compound-nuclear reactions. The method is expected to become an important focus of inverse-kinematics experiments at rare-isotope facilities. The present paper reviews the current status of the surrogate approach. Experimental techniques employed and theoretical descriptions of the reaction mechanisms involved are presented and representative cross section measurements are discussed.

Escher, Jutta E.; Burke, Jason T.; Dietrich, Frank S.; Scielzo, Nicholas D.; Thompson, Ian J.; Younes, Walid

2012-01-01

115

Measurement of Heavy Quark cross-sections at CDF  

SciTech Connect

Abstract: The measurement of heavy quark cross-sections provides important tests of the QCD theory. This paper reviews recent measurements of single b-quark and correlated b-quark cross-sections at CDF. Two new measurements of the single b-quark production at CDF agree with the first result from CDF Run II. This clarifies the experimental situation and confirms the recent agreement of theoretical prediction with data. A new measurement of the correlated b{bar b} cross-section with dimuon events at CDF is presented. It agrees with theory and it does not confirm the anomalously large b{bar b} cross-section seen in Run I by CDF and D0 in dimuon events.

Annovi, Alberto; /Frascati

2007-09-01

116

Neutron Cross Sections of Americium241  

Microsoft Academic Search

Neutron cross sections of Am are evaluated in the energy region of 1 keV–15MeV, by using optical and statistical model calculations. Existing experimental data for this nuclide are very scarce, except for the fission cross section. An empirical formula for the fission cross section is used to reproduce the experimental data. The cross sections on (n, 2n) and (n, 3n)

Sin-iti IGARASI

1977-01-01

117

Terahertz radar cross section measurements.  

PubMed

We perform angle- and frequency-resolved radar cross section (RCS) measurements on objects at terahertz frequencies. Our RCS measurements are performed on a scale model aircraft of size 5-10 cm in polar and azimuthal configurations, and correspond closely to RCS measurements with conventional radar on full-size objects. The measurements are performed in a terahertz time-domain system with freely propagating terahertz pulses generated by tilted pulse front excitation of lithium niobate crystals and measured with sub-picosecond time resolution. The application of a time domain system provides ranging information and also allows for identification of scattering points such as weaponry attached to the aircraft. The shapes of the models and positions of reflecting parts are retrieved by the filtered back projection algorithm. PMID:21164990

Iwaszczuk, Krzysztof; Heiselberg, Henning; Jepsen, Peter Uhd

2010-12-01

118

A new technique for dosimetry reaction cross-section evaluation  

SciTech Connect

Document available in abstract form only, full text of document follows: An objective of this paper is a unification of the procedure for dosimetry reaction cross-section evaluation. A set of requirements for the unified evaluation procedure is presented. A new code (ORTHO) was developed in order to meet these requirements. A statistical model, an algorithm, and the basic formulae employed in the code are described. The code was used for Ti48(n,p) reaction cross-section evaluation. The results of the evaluation are compared to International Reactor Dosimetry File (IRDF)-2002 data. The evaluated cross-sections and their correlations from this work are in good agreement with the IRDF-2002 evaluated data, whereas the uncertainties of the evaluated cross-sections are inconsistent. (authors)

Badikov, S.A. [JSC Energy and Industry Analytica, 127287, Moscow (Russian Federation)

2011-07-01

119

Lead-lag cross-sectional structure and detection of correlated anticorrelated regime shifts: Application to the volatilities of inflation and economic growth rates  

NASA Astrophysics Data System (ADS)

We have recently introduced the “thermal optimal path” (TOP) method to investigate the real-time lead-lag structure between two time series. The TOP method consists in searching for a robust noise-averaged optimal path of the distance matrix along which the two time series have the greatest similarity. Here, we generalize the TOP method by introducing a more general definition of distance which takes into account possible regime shifts between positive and negative correlations. This generalization to track possible changes of correlation signs is able to identify possible transitions from one convention (or consensus) to another. Numerical simulations on synthetic time series verify that the new TOP method performs as expected even in the presence of substantial noise. We then apply it to investigate changes of convention in the dependence structure between the historical volatilities of the USA inflation rate and economic growth rate. Several measures show that the new TOP method significantly outperforms standard cross-correlation methods.

Zhou, Wei-Xing; Sornette, Didier

2007-07-01

120

Recent fission cross section standards measurements  

SciTech Connect

The /sup 235/U(n,f) reaction is the standard by which most neutron induced fission cross sections are determined. Most of these cross sections are derived from relatively easy ratio measurements to /sup 235/U. However, the more difficult /sup 235/U(n,f) cross section measurements require the use of advanced neutron detectors for the determination of the incident neutron fluence. Examples of recent standard cross section measurements are discussed, various neutron detectors are described, and the status of the /sup 235/U(n,f) cross section standard is assessed. 23 refs., 8 figs., 4 tabs.

Wasson, O.A.

1985-01-01

121

Maximum (prior) brain size, not atrophy, correlates with cognition in community-dwelling older people: a cross-sectional neuroimaging study  

Microsoft Academic Search

BACKGROUND: Brain size is associated with cognitive ability in adulthood (correlation ~ .3), but few studies have investigated the relationship in normal ageing, particularly beyond age 75 years. With age both brain size and fluid-type intelligence decline, and regional atrophy is often suggested as causing decline in specific cognitive abilities. However, an association between brain size and intelligence may be

Susan D Shenkin; Carly S Rivers; Ian J Deary; John M Starr; Joanna M Wardlaw

2009-01-01

122

Adherence to physical activity recommendations and the influence of socio-demographic correlates – a population-based cross-sectional study  

Microsoft Academic Search

BACKGROUND: Current physical activity guidelines acknowledge the importance of total health enhancing physical activity (HEPA) compared to leisure time physical activity or exercise alone. Assessing total HEPA may result in different levels of adherence to these as well as the strength and\\/or direction of associations observed between total HEPA and socio-demographic correlates. The aim of this study was to estimate

Patrick Bergman; Andrej M Grjibovski; Maria Hagströmer; Adrian Bauman; Michael Sjöström

2008-01-01

123

Correlates of objectively assessed physical activity and sedentary time in children: a cross-sectional study (The European Youth Heart Study)  

PubMed Central

Background Identifying leisure time activities performed before and after school that influence time in physical activity (PA) and/or time spent sedentary can provide useful information when designing interventions aimed to promote an active lifestyle in young people. The purpose of this study was to examine associations between mode of transportation to school, outdoor play after school, participation in exercise in clubs, and TV viewing with objectively assessed PA and sedentary behaviour in children. Methods A total of 1327 nine- and 15-year-old children from three European countries (Norway, Estonia, Portugal) participated as part of the European Youth Heart Study. PA was measured during two weekdays and two weekend days using the MTI accelerometer, and average percent of time in moderate-to-vigorous PA (MVPA) and time spent sedentary were derived. Potential correlates were assessed by self-report. Independent associations between self-reported correlates with percent time in MVPA and percent time sedentary were analysed by general linear models, adjusted by age, gender, country, measurement period, monitored days and parental socio-economic status. Results In 9-year-olds, playing outdoors after school was associated with higher percent time in MVPA (P < 0.01), while participation in sport clubs was associated with higher percent time in MVPA (P < 0.01) in 15-year-olds. No associations with percent time sedentary were observed in either age group. Conclusion Frequency of outdoor play after school is a significant correlate for daily time in MVPA in 9-year-olds, while this correlate is attenuated in favour of participation in sport and exercise in clubs in 15-year-olds. Targeting walking to school or reduced TV viewing time in order to increase time in daily MVPA in children is unlikely to be sufficient. Correlates related to time spent sedentary need further examination.

Nilsson, Andreas; Bo Andersen, Lars; Ommundsen, Yngvar; Froberg, Karsten; Sardinha, Luis B; Piehl-Aulin, Karin; Ekelund, Ulf

2009-01-01

124

Cross-sectional study on bone density-related sonographic parameters in children with asthma: correlation to therapy with inhaled corticosteroids and disease severity  

Microsoft Academic Search

The aim of this study was to screen asthmatic children for bone density-related sonographic parameters on the calcaneal bone.\\u000a Findings were correlated to therapy with inhaled corticosteroids (ICS) as well as with asthma severity (AS), concomitance\\u000a and severity of atopic dermatitis (AD), and rhinitis (AR). We enrolled 173 children with AS1-3 consecutively; 44% (AS1) had\\u000a not received any ICS medication;

Jochen G. Mainz; Dieter Sauner; Ansgar Malich; Stephanie John; Heike Beyermann; Hans-Joachim Mentzel; Werner A. Kaiser; Felix Zintl

2008-01-01

125

High-Energy Cross Sections. II. Nucleon-Nucleon Cross Section at Cosmic-Ray Energies  

Microsoft Academic Search

Cosmic-ray measurements are capable of yielding reliable results for the cross section of a nucleus for proton or neutron collisions involving a not too small energy transfer. This cross section should therefore be less than, or at most equal to, the true nonelastic cross section (reaction cross section). Results of recent cosmic-ray work are assembled and compared with the reaction

Robert W. Williams

1955-01-01

126

Neutron average cross sections of Np237  

NASA Astrophysics Data System (ADS)

This work reports Np237 neutron resonance parameters obtained from the simultaneous analysis of time-of-flight data measured at the GELINA, ORELA, KURRI, and LANSCE facilities. A statistical analysis of these resonances relying on average R-matrix and optical model calculations was used to establish consistent l-dependent average resonance parameters involved in the description of the unresolved resonance range of the Np237 neutron cross sections. For neutron orbital angular momentum l=0, we obtained an average radiation width =39.3±1.0 meV, a neutron strength function 104S0=1.02±0.14, a mean level spacing D0=0.60±0.03 eV, and a potential scattering length R'=9.8±0.1 fm.

Noguere, G.

2010-04-01

127

A cross-sectional evaluation of correlates of HIV testing practices among men who have sex with men (MSM) in Mongolia.  

PubMed

This study analyzed patterns and associations of HIV testing including sexual practices, HIV related knowledge, and human rights contexts among MSM in Mongolia. 313 participants were accrued using respondent-driven sampling and administered a structured questionnaire. Descriptive statistics are presented with crude and adjusted-point estimates with confidence intervals (95 % CI); and logistic regression models were used to identify factors associated with HIV testing in the last 12 months. RDS-adjustment demonstrated that 48.9 % (95 % CI = 36.7-58.3) of MSM had an HIV test in the past 12 months. Logistic regression revealed that experience of a human rights violation, enacted (OR = 0.50, 95 % CI = 0.26-0.97) or perceived (OR = 0.56, 95 % CI = 0.26-0.97), was inversely associated with a recent HIV test. Higher level of education (OR = 1.84, 95 % CI = 1.14-2.99), knowledge that anal sex is highest risk for HIV infection (OR = 4.54, 95 % CI = 2.41-8.56), and having 5 or more male sexual partners (OR = 1.82, 95 % CI = 1.00-3.30), were positively associated with a recent HIV test. MSM in Mongolia are at high risk for HIV infection and coverage of HIV testing is suboptimal. Understanding the variable sexual risk practices and barriers to HIV testing are vital to designing effective and relevant HIV-status dependent HIV intervention services. PMID:23354852

Yasin, Faiza; Delegchoimbol, Altanchimeg; Jamiyanjamts, Naranchimeg; Sovd, Tugsdelger; Mason, Krystal; Baral, Stefan

2013-05-01

128

Adherence to physical activity recommendations and the influence of socio-demographic correlates - a population-based cross-sectional study  

PubMed Central

Background Current physical activity guidelines acknowledge the importance of total health enhancing physical activity (HEPA) compared to leisure time physical activity or exercise alone. Assessing total HEPA may result in different levels of adherence to these as well as the strength and/or direction of associations observed between total HEPA and socio-demographic correlates. The aim of this study was to estimate the proportion of the population adhering to the recommendation of at least 30 minutes of HEPA on most days, and to examine the influences of socio-demographic correlates on reaching this recommendation. Methods Swedish adults aged 18–74 years (n = 1470) were categorized, based on population data obtained using the IPAQ, into low, moderately and highly physically active categories. Independent associations between the physical activity categories and socio-demographic correlates were studied using a multinomial logistic regression. Results Of the subjects, 63% (95% CI: 60.5–65.4) adhered to the HEPA recommendation. Most likely to reach the highly physical active category were those aged < 35 years (OR = 1.8; 95% CI: 1.1–3.3), living in small towns (OR = 1.8; 95% CI: 1.1–2.7) and villages (OR = 2.4; 95% CI: 1.6–3.7), having a BMI between 25.0–29.9 kg/m2 (OR = 2.7; 95% CI: 1.4–5.3) having a BMI < 25 kg/m2 (OR = 2.5; 95% CI: 1.3–4.9), or having very good (OR = 2.1; 95% CI: 1.3–3.3) or excellent self-perceived health (OR = 4.1; 95% CI: 2.4–6.8). Less likely to reach the high category were women (OR = 0.6; 95% CI: 0.5–0.9) and those with a university degree (OR = 0.5; 95% CI: 0.3–0.9). Similar, but less pronounced associations were observed for the moderate group. Gender-specific patterns were also observed. Conclusion Almost two-thirds of the Swedish adult population adhered to the physical activity recommendation. Due to a large diversity in levels of physical activity among population subgroups, social-ecological approaches to physical activity promotion may be warranted.

Bergman, Patrick; Grjibovski, Andrej M; Hagstromer, Maria; Bauman, Adrian; Sjostrom, Michael

2008-01-01

129

Comparison of intraclass correlation coefficient estimates and standard errors between using cross-sectional and repeated measurement data: the Safety Check cluster randomized trial.  

PubMed

Designing cluster randomized trials in clinical studies often requires accurate estimates of intraclass correlation, which quantifies the strength of correlation between units, such as participants, within a cluster, such as a practice. Published ICC estimates, even when available, often suffer from the problem of wide confidence intervals. Using data from a national, randomized, controlled study concerning violence prevention for children--the Safety Check--we compare the ICC values derived from two approaches only baseline data and using both baseline and follow-up data. Using a variance component decomposition approach, the latter method allows flexibility in handling complex data sets. For example, it allows for shifts in the outcome variable over time and for an unbalanced cluster design. Furthermore, we evaluate the large-sample formula for ICC estimates and standard errors using the bootstrap method. Our findings suggest that ICC estimates range from 0.012 to 0.11 for providers within practice and range from 0.018 to 0.11 for families within provider. The estimates derived from the baseline-only and repeated-measurements approaches agree quite well except in cases in which variation over repeated measurements is large. The reductions in the widths of ICC confidence limits from using repeated measurement over baseline only are, respectively, 62% and 42% at the practice and provider levels. The contribution of this paper therefore includes two elements, which are a methodology for improving the accuracy of ICC, and the reporting of such quantities for pediatric and other researchers who are interested in designing clustered randomized trials similar to the current study. PMID:21070889

Ip, Edward H; Wasserman, Richard; Barkin, Shari

2010-11-08

130

[Fast neutron cross section measurements  

SciTech Connect

From its inception, the Nuclear Data Project at the University of Michigan has concentrated on two major objectives: (1) to carry out carefully controlled nuclear measurements of the highest possible reliability in support of the national nuclear data program, and (2) to provide an educational opportunity for students with interests in experimental nuclear science. The project has undergone a successful transition from a primary dependence on our photoneutron laboratory to one in which our current research is entirely based on a unique pulsed 14 MeV fast neutron facility. The new experimental facility is unique in its ability to provide nanosecond bursts of 14 MeV neutrons under conditions that are clean'' and as scatter-free as possible, and is the only one of its type currently in operation in the United States. It has been designed and put into operation primarily by graduate students, and has met or exceeded all of its important initial performance goals. We have reached the point of its routine operation, and most of the data are now in hand that will serve as the basis for the first two doctoral dissertations to be written by participating graduate students. Our initial results on double differential neutron cross sections will be presented at the May 1993 Fusion Reactor Technology Workshop. We are pleased to report that, after investing several years in equipment assembly and optimization, the project has now entered its data production'' phase.

Knoll, G.F.

1992-10-26

131

HIV-related risk behaviours and the correlates among rickshaw pullers of Kamrangirchar, Dhaka, Bangladesh: a cross-sectional study using probability sampling  

PubMed Central

Background National HIV serological and behavioural surveillance of Bangladesh repeatedly demonstrated a very high proportion of rickshaw pullers in Dhaka city, having sex with female sex workers (FSWs) and using illicit substances. However, no study has been conducted to identify the correlates of having sex with FSWs among this population. This study aimed to describe behavioural profile of rickshaw pullers in Dhaka city using probability samples and to identify the correlates for having sex with FSWs in order to focus HIV prevention intervention. Methods Six hundred rickshaw pullers were randomly selected from rickshaw garages in the Kamrangirchar area, the single largest slum cluster of Dhaka, Bangladesh, during March–April 2008 using the Proportion Probability to Size method. Participants were interviewed, with a response rate of 99.2% (n = 595), using a structured questionnaire and asked about illicit substance use, sexual behaviour and risk perception for HIV and sexually transmitted diseases. Independent predictors of having sex with FSWs were analysed by multivariate analysis. A qualitative study was subsequently conducted with 30 rickshaw pullers to supplement the findings of the initial survey. Results The proportion of survey respondents who had sex with FSWs and those who used illicit substances in the previous 12 months period were 7.9% and 24.9%, respectively, much lower than the results achieved in the 2003–04 behavioural surveillance (72.8% and 89.9%, respectively). Multivariate analysis revealed the characteristics of younger age, being never married, living alone with family remaining in other districts and using illicit substances in the previous 12 months were significantly associated with having sex with FSWs. Conclusion HIV-related risk behaviour of our study population of the rickshaw pullers was lower than what has been suggested by the results of behavioural surveillance. While this discrepancy should be addressed in further studies, our study emphasizes the importance of focused HIV prevention programs for rickshaw pullers as high-risk behaviour is displayed at an unacceptable level and concentrated in identifiable sub-populations.

Hoque, Md Hafiz Ehsanul; Ono-Kihara, Masako; Zamani, Saman; Ravari, Shahrzad Mortazavi; Kihara, Masahiro

2009-01-01

132

Metabolic syndrome is common among middle-to-older aged Mediterranean patients with rheumatoid arthritis and correlates with disease activity: a retrospective, cross-sectional, controlled, study  

PubMed Central

Objectives Patients with rheumatoid arthritis have an increased risk for cardiovascular disease (CVD). The prevalence of metabolic syndrome (MetS)—a major contributor to CVD—in a cohort of patients with rheumatoid arthritis and its relationship with rheumatoid arthritis related factors is investigated here. Methods 200 outpatients with rheumatoid arthritis (147 women and 53 men), with a mean (standard deviation (SD)) age of 63 (11)?years, and 400 age and sex?matched controls were studied. MetS was assessed according to the adult treatment panel III criteria and rheumatoid arthritis disease activity by the disease activity score of 28 joints (DAS28). A standard clinical evaluation was carried out, and a health and lifestyle questionnaire was completed. Results The overall prevalence of MetS was 44% in patients with rheumatoid arthritis and 41% in controls (p?=?0.5). Patients with rheumatoid arthritis were more likely to have low high?density lipoprotein cholesterol compared with controls (p?=?0.02), whereas controls were more likely to have increased waist circumference or raised blood pressure (p?=?0.001 and 0.003, respectively). In multivariate logistic regression analysis adjusting for demographics and rheumatoid arthritis treatment modalities, the risk of having moderate?to?high disease activity (DAS28>3.2) was significantly higher in patients with MetS compared with those with no MetS components (OR 9.24, 95% CI 1.49 to 57.2, p?=?0.016). Conclusion A high, albeit comparable to the control population, prevalence of MetS was found in middle?to?older aged patients with rheumatoid arthritis. The correlation of rheumatoid arthritis disease activity with MetS suggests that the increased prevalence of coronary heart disease in patients with rheumatoid arthritis may, at least in part, be attributed to the inflammatory burden of the disease.

Karvounaris, S A; Sidiropoulos, P I; Papadakis, J A; Spanakis, E K; Bertsias, G K; Kritikos, H D; Ganotakis, E S; Boumpas, D T

2007-01-01

133

Vertically stabilized elongated cross-section tokamak  

DOEpatents

This invention provides a vertically stabilized, non-circular (minor) cross-section, toroidal plasma column characterized by an external separatrix. To this end, a specific poloidal coil means is added outside a toroidal plasma column containing an endless plasma current in a tokamak to produce a rectangular cross-section plasma column along the equilibrium axis of the plasma column. By elongating the spacing between the poloidal coil means the plasma cross-section is vertically elongated, while maintaining vertical stability, efficiently to increase the poloidal flux in linear proportion to the plasma cross-section height to achieve a much greater plasma volume than could be achieved with the heretofore known round cross-section plasma columns. Also, vertical stability is enhanced over an elliptical cross-section plasma column, and poloidal magnetic divertors are achieved.

Sheffield, George V. (Hopewell, NJ)

1977-01-01

134

Perimenopausal contraception in Turkish women: A cross-sectional study  

Microsoft Academic Search

BACKGROUND: Epidemiologic research has shown that perimenopausal contraception is an important medical issue, because women during the perimenopause still need effective contraception. The objective of the study was to assess the contraceptive choices of perimenopausal Turkish women. METHODS: This is a descriptive cross-sectional study that in a non – random fashion recruited 202 perimenopausal and naturally menopausal women who lived

Nevin H ?ahin; Sema B Kharbouch

2007-01-01

135

A theory of fluctuations in nuclear cross sections  

Microsoft Academic Search

A quantitative description of the statistical fluctuations in the region ; of overlapping resonances of nuclear cross sections is given. General nuclear ; reaction theory is used in order to systematically obtain a separation of direct ; interactions and compound nuclear contributions in the region of overlapping ; resonances. (R.E.U.);

Torleif Ericson

1963-01-01

136

Prevalence, correlates and clinical usefulness of antibodies to RNA polymerase III in systemic sclerosis: a cross-sectional analysis of data from an Australian cohort  

PubMed Central

Introduction The prevalence of antibodies to RNA polymerase III (anti-RNAP) differs among systemic sclerosis (SSc) cohorts worldwide. Previously reported associations of anti-RNAP include diffuse cutaneous disease, tendon friction rubs and renal crisis, with recent reports suggesting a close temporal association between malignancy and SSc disease onset among patients with anti-RNAP. Methods Patients with SSc were tested for the presence of anti-RNAP at recruitment into the Australian Scleroderma Cohort Study. We used univariate and multivariable methods to identify and quantify clinical and laboratory correlates of anti-RNAP in SSc. Diagnostic testing procedures were used to determine the usefulness of these antibodies in estimating the likelihood of clinically important outcomes. Results There were 451 patients with mean ± standard deviation age and disease duration at recruitment of 58.1 ± 12.4 and 11.6 ± 10.0 years, respectively; 151 (33.5%) patients were recruited within 5 years of diagnosis of SSc. Overall, 69 (15.3%) patients had anti-RNAP. Univariate associations of anti-RNAP were diffuse disease (75.4% vs. 20.9%, P < 0.0001), joint contractures (73.9% vs. 30.1%, P < 0.0001), greater highest-recorded modified Rodnan skin score (20.6 ± 12.4 vs. 10.1 ± 7.9, P < 0.0001), synovitis (31.9% vs. 19.9%, P = 0.03), myositis (2.9% vs. 0.5%, P = 0.05), systemic hypertension (59.4% vs. 39.7%, P = 0.002), renal crisis (24.6% vs. 1.8%, P < 0.0001) and malignancy diagnosed within 5 years of onset of SSc skin disease (13.3% vs. 3.9%, P = 0.01). In multiple regression analysis, after adjustment for other covariates, anti-RNAP were independently associated with renal crisis (odds ratio (OR) 3.8, 95% confidence interval (CI) 1.2 to 11.5, P = 0.02; positive predictive value (PPV) 24.6%, negative predictive value (NPV) 98.2%), diffuse disease (OR 6.4, 95% CI 2.9 to 13.8, P < 0.0001; PPV 75.4%, NPV 20.9%), joint contractures (OR 2.5, 95% CI 1.2 to 5.3, P = 0.02; PPV 73.9%, NPV 69.9%) and malignancy diagnosed within 5 years of onset of SSc skin disease (OR 4.2, 95% CI 1.3 to 13.4, P = 0.01; PPV 13.3%, NPV 96.1%). Conclusions Anti-RNAP status is a clinically useful prognostic marker in SSc and enables clinicians to identify patients at high risk of developing renal crisis, synovitis, myositis and joint contractures. Patients with anti-RNAP also have an increased risk of malignancy within a 5-year timeframe before or after onset of SSc skin changes.

2011-01-01

137

Rheologic results and their correlation to hemostatic changes in patients with moderate and severe preeclampsia: An observational cross-sectional study.  

PubMed

Previous study have shown an association between failure of physiological hemodilution during 2nd trimester and an increased risk for the development of subsequent pregnancy complications such as early birth, birth of a growth retarded newborn (IUGR), low fetal birth weight and preeclampsia. The latter complication in particular goes along with dramatic changes in the placental perfusion as well as systemic maternal blood flow. Severity of preeclampsia may be preceded by distinct impaired hemodilution and reflected by the results of rheological parameters. A subgroup analysis was performed in a community based retrospective study of 4,985 consecutively recorded singleton pregnant women of whom 423 had preeclampsia. Mean 2nd trimester hemoglobin levels and blood rheological results at the time of delivery were assessed and compared in women with moderate and severe preeclampsia. Mean 2nd trimester hemoglobin levels were calculated from the maternal records. Rheological variables included plasma viscosity (KSPV 1 Fresenius) and Red blood cell aggregation in stasis and under low shear conditions (MA1-Aggregometer; Myrenne). According to the definition of the German Society of Gynecology and Obstetrics (DGGG) 314 women had moderate preeclampsia (74.2%), while 109 had severe preeclampsia due to the presence of a blood pressure >170/110 mmHg (n = 41; 9.7%), and/or IUGR <5th percentile (n = 28; 6.6%), and/or HELLP-Syndrome (n = 10; 2.4%), and/or proteinuria ?5 g/24 h (n = 30; 7.1%). Age, BMI, smoking, and maternal weight were comparable in the groups, while gestational age at delivery as well as fetal outcome parameter were statistically significant unfavourable in patients with severe preeclampsia. Mean 2nd trimester hemoglobin level were statistically significantly higher in women who developed severe vs. moderate preeclampsia (m = 12.75 ± 0.99 g/dL vs. m = 12.50 ± 1.05 g/dL; p = 0.033). However, in the ROC calculations a hemoglobin value of 12.05 g/dL revealed best sensitivity (78%) and specificity (33.8%) in women with subsequent diagnosis of severe preeclampsia, whereas sensitivity was 100% for a value >10.95 g/dL. There were no statistically significant differences for none of the rheological parameters at the time of delivery between groups of patient with moderate v.s severe preeclampsia. Severe preeclampsia and IUGR, however, was associated with statistically significantly higher RBC aggregation as compared to patients with moderate preeclampsia. Plasma viscosity was statistically significantly (p < 0.05) correlated with Fibrinogen values (r = 1.69), leukocyte-(r = 0.11) and platelets-count (r = 0.127), and hemoglobin/hematocrit values in particular (r = 0.23/0.26). Although mean 2nd trimester hemoglobin concentration are higher in patients with subsequent development of severe preeclampsia, due to the low sensitivity and specificity of this parameter clinical use for identifying women at risk is of limited value. On the other hand, a hemoglobin value below 11.0 g/dL excluded the risk for severe preeclampsia to 100%. Blood rheological parameters at the time of delivery in the absence of IUGR are not markedly influenced by severity of preeclampsia. PMID:23089882

Soliman, Amr A; Csorba, Roland; Yilmaz, Asli; von Tempelhoff, Georg-Friedrich

2012-10-22

138

Neutron cross sections: Book of curves  

Microsoft Academic Search

Neuton Cross Sections: Book of Curves represents the fourth edition of what was previously known as BNL-325, Neutron Cross Sections, Volume 2, CURVES. Data is presented only for (i.e., intergrated) reaction cross sections (and related fission parameters) as a function of incident-neutron energy for the energy range 0.01 eV to 200 MeV. For the first time, isometric state production cross

V. McLane; C. L. Dunford; P. F. Rose

1988-01-01

139

A nuclear cross section data handbook  

Microsoft Academic Search

Isotopic information, reaction data, data availability, heating numbers, and evaluation information are given for 129 neutron cross-section evaluations, which are the source of the default cross sections for the Monte Carlo code MCNP. Additionally, pie diagrams for each nuclide displaying the percent contribution of a given reaction to the total cross section are given at 14 MeV, 1 MeV, and

H. O. M

1989-01-01

140

Photoacoustic measurement of absolute overtone cross sections  

NASA Astrophysics Data System (ADS)

Using the photoacoustic effect, integrated absorption cross sections for the 5-0 and 6-0 C?H stretching overtones of ethane and ethylene were calibrated against the well-known cross sections for the 4-0 and 5-0 overtones of HD. The results of this calibration procedure agree well with FT-IR measurements by Quack and co-workers. Thus, these absorption cross sections would serve well as secondary reference standards in overtone measurements.

Gutow, J. H.; Davidsson, J.; Zare, R. N.

1991-10-01

141

The Primitive Streak, Cross Section  

NSDL National Science Digital Library

This FlashTM animation is the third of a seven part series that presents the primitive streak from different angles. This installment displays the cross section, which is conducive to observing invagination. Epiblast cells ingress through the middle of the germ disc, to differentiate into either endoderm or mesenchymal mesoderm. The endoderm proliferates to drive the hypoblast into the extraembryonic endoderm of the yolk sac. The mesenchyme spreads between the epiblast and endoderm. Although not drawn to scale, the progressive thickening from lateral to paraxial mesoderm is depicted. To open the animation using Internet Explorer follow these steps. (1.) Click the link for the animation. (2.) A dialog box may pop up that begins with the statement "Windows cannot open this file:" If this box does not appear proceed to step four. If it does choose "Select the program from a list," then click OK. (3.) Another dialog box will pop up that lists different programs. Make sure "Internet Explorer" is selected, then click OK. (4.) Internet Explorer will pop up. Beneath the toolbars at the top of the window a yellow bar will appear that reads "To help protect your security, Internet Explorer has restricted this webpage from running scripts or Active X controls that could access your computer. Click here for options..." Pass the cursor over this yellow bar and click the right mouse button. (5.) A dialog box will pop up. Left click the option "Allow Blocked Content." (6.) Another dialog box will appear labeled "Security Warning" asking you to confirm that you want to run the content. Click "Yes." (7.) The Flash animation will appear in the Internet Explorer Window. (8.) Instructions for navigating the lesson are provided by the first frame of the animation.

PhD Jack D Thatcher (West Virginia School of Osteopathic Medicine Structural Biology)

2011-06-23

142

PCS a code system for generating production cross section libraries  

SciTech Connect

This document outlines the use of the PCS Code System. It summarizes the execution process for generating FORMAT2000 production cross section files from FORMAT2000 reaction cross section files. It also describes the process of assembling the ASCII versions of the high energy production files made from ENDL and Mark Chadwick`s calculations. Descriptions of the function of each code along with its input and output and use are given. {ital This document is under construction. Please submit entries, suggestions, questions, and corrections to} {bold (ljc@llnl.gov)} 3 tabs.

Cox, L.J.

1997-04-01

143

Computerized cross section balance and restoration  

Microsoft Academic Search

We describe how to make the necessary measurements and manipulations to balance and restore cross sections using the widely available programs Canvas™, Photoshop™, and Excel™. Data or cross sections are input to Canvas from a flatbed scanner or a video camera, or sections are constructed using program drafting tools. Scanned photos and captured video are significantly improved using Photoshop filters.

Jean-Luc Epard

1996-01-01

144

HAUSER5; Nuclear Reaction Cross Sections.  

National Technical Information Service (NTIS)

HAUSER5 calculates angle-integrated and, if desired, angle-differential reaction cross sections which can include capture and fission channels. Cross sections for discrete particle channels can be calculated, as well as the total for each reaction pair. T...

F. M. Mann

1984-01-01

145

Nuclear Cross Sections at Low Energies  

Microsoft Academic Search

The note is concerned with estimates of the accuracy of the one-term formula for the energy dependence of the reaction cross section for charged particles. The second term in an expansion of the cross section in powers of the energy is worked out for a one-body model. Comparison with data of Sawyer and Phillips on the bombardment of Li and

J. L. Johnson; H. M. Jones

1954-01-01

146

Nuclear Cross Sections For Fast Reactors  

Microsoft Academic Search

The 16-group YOM cross section set for fast reactor analysis has been widely used by fast reactor centers during the last three years. Since its publication at the end of 1960, a considerable amount of experimental results as well as some theoretical investigations have become available. Also, various 'users' have kindly sent queries and remarks on the different cross sections

S. Yiftah; M. Sieger

1964-01-01

147

Nuclear Cross Sections for 765 Mev Neutrons  

Microsoft Academic Search

Total cross sections have been measured for the elements H, D, Li, C, O, Al, Cu, Sb and Pb and absorption cross sections for C, Al, Cu and Pb for neutrons of an effective energy of 765 +\\/- 30 Mev. The neutrons were detected by observing the Cerenkov light from charged secondaries produced in a cylinder of Perspex. Large corrections

N. E. Booth; G. W. Hutchinson; B. Ledley

1958-01-01

148

Nuclear Cross Sections for 765 Mev Neutrons  

Microsoft Academic Search

Total cross sections have been measured for the elements H, D, Li, C, O, Al, Cu, Sb and Pb and absorption cross sections for C, Al, Cu and Pb for neutrons of an effective energy of 765 ± 30 Mev. The neutrons were detected by observing the Cerenkov light from charged secondaries produced in a cylinder of Perspex. Large corrections

N. E. Booth; G. W. Hutchinson; B. Ledley

1958-01-01

149

Regional tertiary cross sections: Texas Gulf Coast  

Microsoft Academic Search

Regional studies of the Frio Formation along the Texas Gulf Coast were conducted to evaluate potential geothermal energy from deep, geopressured sandstone reservoirs. Published regional cross sections, unpublished cross sections provided by several major oil companies, and extensive micropaleontological and electrical-log files at the Bureau of Economic Geology served as basic data. These sections are meant to show gross regional

D. G. Debout; P. E. Luttrell; J. H. Seo

1976-01-01

150

Temperature dependence of unshielded cross-sections in multigroup cross-section sets  

Microsoft Academic Search

The self-shielding factor method in the multigroup approach is well known in Reactor Physics. The temperature and background dependent neutron cross-sections are conventionally represented in a problem-independent multigroup cross-section set by specifying for each group and reaction the unshielded cross-section (at 0 K) along with a set of self-shielding factors for various background cross-sections and temperatures. Usually the unshielded group

V. Gopalakrishnan

2000-01-01

151

Core Description, Stratigraphic Correlation, and Mapping: A capstone project for an undergraduate course in Sedimentary Geology  

NSDL National Science Digital Library

This project is intended as a long-term (3 weeks1 month) lab exercise near the end of a combined Stratigraphy/Sedimentology course. The project utilizes real world data provided by CONSOL Energy of Pittsburgh, PA, and the West Virginia Geological and Economic Survey. This project has been assigned once and is being revised. Instructions have been left somewhat vague in an attempt to force students into discovering some of the more mechanical details of this process themselves. By the latter third of the course, students have described sedimentary rocks in detail and have constructed vertical sections of rock at several outcrops around campus. The course is moving from Sedimentology/Petrology into Stratigraphy. This project is designed to illustrate the basic principles of lithostratigraphy, which are covered concurrently in the lecture portion of the class. The project 'unfurls' over several weeks. If students are provided with the entire project at one time they generally get overwhelmed, so the project is presented piecemeal, allowing the students to expand the project as they complete one section. Step 1: Core description 40 feet of core from the Conemaugh Group of southwestern Pennsylvania is made available to the students. They must describe the core, define lithologic units, identify specific sedimentary structures, and construct a stratigraphic column. (Students struggle with detail versus efficiency of completion, given one full lab period (3 hours) and a week to complete the assignment, many students will get lost in the detail) The goal is to build familiarity with the type of data available to geologists as they go about constructing maps for resource estimates. Additionally, the lithologies present in this core will be similar to those described in the geologist and drilling logs necessary to complete the next step. Each step is evaluated independently in this step concern is primarily with identification of basic lithologies (coal, sandstone, shale, limestone). Step 2: construction of strip logs for 25 core holes in northern West Virginia. Students are provided with a location map, logs for 25 holes, and elevation data. They must construct strip logs suitable for correlation, deciding upon scale and detail of presentation. Students are provided with a CD including the location map and a .pdf for each drill record. The logs vary between the simplicity of driller data (60' of "blue" shale) and the detail of geologist descriptions, students must balance the detail and simplicity. Additionally, students were faced with "long" logs (i.e. greater than 500') and "short" logs (i.e. less than 100'). This turned out to be extremely difficult, some students got very lost, producing long detailed logs that left them without much time for the last two steps. Students are again provided with a week to construct the strip logs, including the lab time for the week. Strip logs are evaluated for detail, accuracy, and utility (in many cases too much detail can be as confusing as too little). Step 3: construction of stratigraphic cross sections. The first time this project was assigned, there was little guidance provided to students beyond "choosing logs that covered the largest stratigraphic interval." This exceeded the grasp of most students so additional guidance will be provided in the next iteration of this project. A generalized stratigraphic column illustrating the basic characteristics of the Monongahela and Conemaugh groups will be provided to assist students with recognition of the basic formations. Students will be required to construct a stratigraphic cross section through selected wells on the west side of the project area. This cross section will demonstrate the use of marker beds and the lateral continuity of stratigraphic units. The second cross section will run east-west onto the western flank of the Chestnut Ridge anticline. The datum for this cross section will be surface elevation. This cross section will illustrate the problems of stratigraphic correlation when combined with geological structures. The rock becomes consistently older as one proceeds towards the axis of the anticline. The prominent red beds and the absence of coals, in the eastern portion of the map area indicate the presence of the Chestnut Ridge Anticline. Evaluation of the cross sections will be based upon the accuracy of the correlations. Students are allowed a week to produce cross sections (including lab). The stratigraphic cross section should accurately delineate the Redstone, Pittsburgh, and Sewickley coals. These occur in sequence and are fairly easy to identify. Successful completion of the east-west cross section will require identification of the approximate stratigraphic position of the Monongahela-Conemaugh contact. Step 4: construction of isopach maps. Students are then required to identify specific coal and sandstone units within their cross sections, correlate those across the map region and construct isopach maps of those units. This requires that the students now extend what they have learned from the previous three weeks, extend those correlations to the core holes not included in the basic stratigraphic analysis. The thickness of the coal and sandstone should be identified and isopach maps constructed. The first iteration of this project produced problems similar to those encountered in step 3. Better guidance and evaluation of the cross sections and allowing students less input on the choice of stratigraphic units to isopach should reduce the confusion. Step 5: (optional) Interpretation and report writing : the first iteration of this project was running concurrently with a term paper. Instead of two separate projects, an interpretive report will be required. This is still in the planning stage and has not been assigned to students.

Matchen, David L.

152

Neutron removal cross section as a measure of neutron skin  

SciTech Connect

We study the relation between neutron removal cross section (sigma{sub -N}) and neutron skin thickness for finite neutron-rich nuclei using the statistical abrasion ablation model. Different sizes of neutron skin are obtained by adjusting the diffuseness parameter of neutrons in the Fermi distribution. It is demonstrated that there is a good linear correlation between sigma{sub -N} and the neutron skin thickness for neutron-rich nuclei. Further analysis suggests that the relative increase of neutron removal cross section could be used as a quantitative measure for neutron skin thickness in neutron-rich nuclei.

Fang, D. Q.; Ma, Y. G.; Cai, X. Z.; Tian, W. D.; Wang, H. W. [Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Post Office Box 800-204, Shanghai 201800 (China)

2010-04-15

153

Antiviral Resistance and Correlates of Virologic Failure in the first Cohort of HIV-Infected Children Gaining Access to Structured Antiretroviral Therapy in Lima, Peru: A Cross-Sectional Analysis  

PubMed Central

Background The impact of extended use of ART in developing countries has been enormous. A thorough understanding of all factors contributing to the success of antiretroviral therapy is required. The current study aims to investigate the value of cross-sectional drug resistance monitoring using DNA and RNA oligonucleotide ligation assays (OLA) in treatment cohorts in low-resource settings. The study was conducted in the first cohort of children gaining access to structured ART in Peru. Methods Between 2002–5, 46 eligible children started the standard regimen of AZT, 3TC and NFV Patients had a median age of 5.6 years (range: 0.7-14y), a median viral load of 1.7·105 RNA/ml (range: 2.1·103 – 1.2·106), and a median CD4-count of 232 cells/?L (range: 1–1591). Of these, 20 patients were classified as CDC clinical category C and 31/46 as CDC immune category 3. At the time of cross-sectional analysis in 2005, adherence questionnaires were administered. DNA OLAs and RNA OLAs were performed from frozen PBMC and plasma, RNA genotyping from dried blood spots. Results During the first year of ART, 44% of children experienced virologic failure, with an additional 9% failing by the end of the second year. Virologic failure was significantly associated with the number of resistance mutations detected by DNA-OLA (p < 0.001) during cross-sectional analysis, but also with low immunologic CDC-scores at baseline (p < 0.001). Children who had been exposed to unsupervised short-term antiretrovirals before starting structured ART showed significantly higher numbers of resistance mutations by DNA-OLA (p = 0.01). Detection of M184V (3TC resistance) by RNA-OLA and DNA-OLA demonstrated a sensitivity of 0.93 and 0.86 and specificity of 0.67 and 0.7, respectively, for the identification of virologic failure. The RT mutations N88D and L90M (NFV resistance) detected by DNA-OLA correlated with virologic failure, whereas mutations at RT position 215 (AZT resistance) were not associated with virologic failure. Conclusions Advanced immunosuppression at baseline and previous exposures to unsupervised brief cycles of ART significantly impaired treatment outcomes at a time when structured ART was finally introduced in his cohort. Brief maternal exposures to with AZT +/? NVP for the prevention of mother-to-child transmission did not affect treatment outcomes in this group of children. DNA-OLA from frozen PBMC provided a highly specific tool to detect archived drug resistance. RNA consensus genotyping from dried blood spots and RNA-OLA from plasma consistently detected drug resistance mutations, but merely in association with virologic failure.

2013-01-01

154

Accurate electron inelastic cross sections and stopping powers for liquid water over the 0.1-10 keV range based on an improved dielectric description of the Bethe surface.  

PubMed

Electron inelastic cross sections and stopping powers for liquid water over the 0.1-10 keV range are presented based on a recently developed dielectric response model for liquid water (D. Emfietzoglou, F. Cucinotta and H. Nikjoo, Radiat. Res. 164, 202-211, 2005) that is consistent with the experimental data over the whole energy-momentum plane. Both exchange and second-order Born corrections are included in a material-specific way using the dielectric functions of liquid water. The numerical results are fitted by simple analytic functions to facilitate their further use. Compared to previous studies, differential cross sections are shifted toward smaller energy losses resulting in smaller inelastic and stopping cross sections with differences reaching, on average, the approximately 20% and approximately 50% level, respectively. Contrary to higher energies, it is shown that the dispersion model for the momentum dependence of the dielectric functions (Bethe ridge) is as important as the optical model used. Within the accuracy of the experimental data (a few percent) upon which our dielectric model is based, the calculations are "exact" to first order, while the uncertainty of the results beyond first order is estimated at the 5-10% level. The present work overcomes the limitations of Bethe's theory at low energies by a self-consistent account of inner-shell effects and may serve to extend the ICRU electron stopping power database for liquid water down to 100 eV with a level of uncertainty similar to that for the higher-energy values. PMID:17214512

Emfietzoglou, D; Nikjoo, H

2007-01-01

155

Calculated medium-energy fission cross sections  

SciTech Connect

Calculations were made of neutron-induced fission cross sections on /sup 238/U and /sup 237/Np to compare with new data available up to 100 MeV. This process also produced fission barrier parameters for neptunium and uranium compound systems required for calculation of p + /sup 238/U fission cross sections. To achieve reasonable agreement with higher energy neutron-induced fission data, a phenomenological enhancement to barrier heights based upon the average angular momentum of the compound system was required. These calculational procedures resulted in predictions of /sup 238/U(p,f) cross sections that agree well with available data. 7 refs., 2 figs.

Arthur, E.D.; Young, P.G.

1988-01-01

156

Neutron cross section covariances in the resolved resonance region.  

SciTech Connect

We present a detailed analysis of the impact of resonance parameter uncertainties on covariances for neutron capture and fission cross sections in the resolved resonance region. Our analysis uses the uncertainties available in the recently published Atlas of Neutron Resonances employing the Multi-Level Breit-Wigner formalism. We consider uncertainties on resonance energies along with those on neutron-, radiative-, and fission-widths and examine their impact on cross section uncertainties and correlations. We also study the effect of the resonance parameter correlations deduced from capture and fission kernels and illustrate our approach on several practical examples. We show that uncertainties of neutron-, radiative- and fission-widths are important, while the uncertainties of resonance energies can be effectively neglected. We conclude that the correlations between neutron and radiative (fission) widths should be taken into account. The multi-group cross section uncertainties can be properly generated from both the resonance parameter covariance format MF32 and the cross section covariance format MF33, though the use of MF32 is more straightforward and hence preferable.

Herman,M.; Mughabghab, S.F.; Oblozinsky, P.; Pigni, M.T.; Rochman, D.

2008-04-01

157

Report on 238Pu(n,x) surrogate cross section measurement  

SciTech Connect

The goal of this year's effort is to measure the {sup 238}Pu(n,f) and {sup 238}Pu(n,2n) cross section from 100 keV to 20 MeV. We designed a surrogate experiment that used the reaction {sup 239}Pu(a,a{prime}x) as a surrogate for {sup 238}Pu(n,x). The experiment was conducted using the STARS/LIBERACE experimental facility located at the 88 Inch Cyclotron at Lawrence Berkeley National Laboratory in January 2010. A description of the experiment and status of the data analysis is given. In order to obtain a reliable {sup 238}Pu(n,x) cross section we designed the experiment using the surrogate ratio technique. This technique allows one to measure a desired, unknown, cross section relative to a known cross section. In the present example, the {sup 238}Pu(n,x) cross section of interest is determined relative to the known {sup 235}U(n,x) cross section. To increase confidence in the results, and to reduce overall uncertainties, we are also determining the {sup 238}Pu(n,x) cross section relative to the known {sup 234}U(n,x) cross section. The compound nuclei of interest for this experiment were produced using inelastic alpha scattering. For example, {sup 236}U(a,a{prime}x) served as a surrogate for {sup 235}U(n,x); analogous reactions were considered for the other cross sections. Surrogate experiments determine the probabilities for the decay of the compound nuclei into the various channels of interest (fission, gamma decay) by measuring particle-fission (p-f) or particle?gamma (p?g) reaction spectra. By comparing the decay probabilities associated with the unknown cross section to that of a known cross section it is possible to obtain the ratio of these cross sections and thus determine the unknown, desired cross section.

Burke, J T; Ressler, J J; Henderson, R A; Scielzo, N D; Escher, J E; Thompson, I J; Gostic, J; Bleuel, D; Weideking, M; Bernstein, L A

2010-03-31

158

ConcepTest: Cross Section Explaination  

NSDL National Science Digital Library

During fieldwork in the western U.S., an experienced geologist sketched the cross section below showing three different units of tilted rocks and their relative ages. What could you best infer from this diagram? a. ...

159

Power Corrections in Eikonal Cross Sections.  

National Technical Information Service (NTIS)

We discuss power corrections associated with the behavior of the perturbative running coupling in the eikonal approximation to Drell-Yan and other annihilation cross sections in hadron-hadron scattering. General properties of the eikonal approximation imp...

E. Laenen G. Sterman W. Vogelsang

2000-01-01

160

MODELING AND FISSION CROSS SECTIONS FOR AMERICIUM.  

SciTech Connect

This is the final report of the work performed under the LANL contract on the modeling and fission cross section for americium isotopes (May 2004-June 2005). The purpose of the contract was to provide fission cross sections for americium isotopes with the nuclear reaction model code EMPIRE 2.19. The following work was performed: (1) Fission calculations capability suitable for americium was implemented to the EMPIRE-2.19 code. (2) Calculations of neutron-induced fission cross sections for {sup 239}Am to {sup 244g}Am were performed with EMPIRE-2.19 for energies up to 20 MeV. For the neutron-induced reaction of {sup 240}Am, fission cross sections were predicted and uncertainties were assessed. (3) Set of fission barrier heights for each americium isotopes was chosen so that the new calculations fit the experimental data and follow the systematics found in the literature.

ROCHMAN, D.; HERMAN, M.; OBLOZINSKY, P.

2005-05-01

161

Status of Electron Transport Cross Sections.  

National Technical Information Service (NTIS)

This report describes recent developments and improvements pertaining to cross sections for electron-photon transport calculations. The topics discussed include: (1) electron stopping power (mean excitation energies, density-effect correction); (2) bremss...

S. M. Seltzer M. J. Berger

1982-01-01

162

Nuclear Cross Sections for 95Mev Neutrons  

Microsoft Academic Search

The total cross sections of twelve different elements were measured using the neutron beam from the 184-inch cyclotron operating with deuterons. Bismuth fission ionization chambers were employed as both monitor and detector in conventional \\

James Dejuren; Norman Knable

1950-01-01

163

46 CFR 64.25 - Cross section.  

Code of Federal Regulations, 2011 CFR

...section. 64.25 Section 64.25 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING MARINE PORTABLE TANKS AND CARGO HANDLING SYSTEMS Standards for an MPT § 64.25 Cross section. A tank...

2011-10-01

164

46 CFR 64.25 - Cross section.  

Code of Federal Regulations, 2012 CFR

...section. 64.25 Section 64.25 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING MARINE PORTABLE TANKS AND CARGO HANDLING SYSTEMS Standards for an MPT § 64.25 Cross section. A tank...

2012-10-01

165

Absorption cross section of canonical acoustic holes  

SciTech Connect

We compute numerically the absorption cross section of a canonical acoustic hole for sound waves with arbitrary frequencies. Our outputs are in full agreement with the expected low- and high-frequency limits.

Crispino, Luis C. B.; Oliveira, Ednilton S.; Matsas, George E. A. [Faculdade de Fisica, Universidade Federal do Para, 66075-110, Belem (Brazil); Instituto de Fisica Teorica, Universidade Estadual Paulista, Rua Pamplona 145, 01405-900, Sao Paulo, SP (Brazil)

2007-11-15

166

Charmonium cross-sections and the QGP  

Microsoft Academic Search

In this contribution we summarize experimental information and theoretical results for the dissociation cross-sections of charmonium by light hadrons, which are of great importance for the identification of a quark-gluon plasma (QGP). Recent theoretical predictions for these cross-sections differ by orders of magnitude over the physically relevant energy range. The methods discussed here include a color-dipole model, meson exchange models,

T. Barnes

2003-01-01

167

Calculation of ppgamma cross sections and asymmetries  

Microsoft Academic Search

Proton-proton bremsstrahlung cross sections and asymmetries are calculated in both the Gottschalk and Thorndike geometries. Calculations using model-dependent off-shell terms are compared to calculations where these terms are suppressed. In general, the ppgamma asymmetries are less sensitive to off-shell information than the corresponding ppgamma cross sections. These calculations also indicate that the asymmetry at 204 MeV is smoother than the

J. H. McGuire; W. A. Pearce

1971-01-01

168

Calculation of npgamma cross sections and asymmetries  

Microsoft Academic Search

Neutron-proton bremsstrahlung cross sections and asymmetries are calculated in both the Gottschalk and Thorndike geometries. The influence of off-shell terms is determined by comparing off-shell calculations to calculations using only elastic scattering parameters. The npgamma asymmetry is generally less sensitive to off-shell terms than the corresponding cross section. However, the off-shell influences in the npgamma cases are greater than in

J. H. McGuire; W. A. Pearce

1971-01-01

169

Evaluation methods for neutron cross section standards  

SciTech Connect

Methods used to evaluate the neutron cross section standards are reviewed and their relative merits, assessed. These include phase-shift analysis, R-matrix fit, and a number of other methods by Poenitz, Bhat, Kon'shin and the Bayesian or generalized least-squares procedures. The problems involved in adopting these methods for future cross section standards evaluations are considered, and the prospects for their use, discussed. 115 references, 5 figures, 3 tables.

Bhat, M.R.

1980-01-01

170

Thermal neutron capture cross section in deuterium  

SciTech Connect

The radiative thermal nD capture cross section sigma/sub D/ was measured by the time-of-flight method at the IBR-30 pulsed reactor using Ge(Li) detector, D/sub 2/O water sample and the sigma/sub Cl/ thermal cross section as the standard. The result 487(24) ..mu..b is in favor of the theoretical value found in the frame of the three body problem.

Alfimenkov, V.P.; Borzakov, S.B.; Wierzbicki, J.; Osipenko, B.P.; Pikelner, L.B.; Tishin, V.G.; Sharapov, E.I.

1980-09-01

171

Nonelastic Scattering Cross Sections for Fast Neutrons  

Microsoft Academic Search

Measurements have been made of the nonelastic cross sections of neutrons in Be, C, Al, Ti, Cr, Fe, Ni, Cu, Ag, Sn, Pb, and Bi. These cross sections include all processes except elastic scattering. The experiments have been carried out with monoenergetic neutrons of 3.5, 4.7, 7.1, 12.7, and 14.1 Mev. The neutrons were produced with a Van de Graaff

H. L. Taylor; O. Lönsjö; T. W. Bonner

1955-01-01

172

Thermal Neutron Capture Cross Section in Deuterium  

Microsoft Academic Search

The radiative thermal nD capture cross section sigma\\/sub D\\/ was measured by the time-of-flight method at the IBR-30 pulsed reactor using Ge(Li) detector, DâO water sample and the sigma\\/sub Cl\\/ thermal cross section as the standard. The result 487(24) ..mu..b is in favor of the theoretical value found in the frame of the three body problem.

V. P. Alfimenkov; S. B. Borzakov; J. Wierzbicki; B. P. Osipenko; L. B. Pikelner; V. G. Tishin; E. I. Sharapov

1980-01-01

173

Neutron capture cross section of ²¹Am  

Microsoft Academic Search

The neutron capture cross section of ²¹Am for incident neutrons from 0.02 eV to 320 keV has been measured with the detector for advanced neutron capture experiments (DANCE) at the Los Alamos Neutron Science Center. The thermal neutron capture cross section was determined to be 665{+-}33 b. Our result is in good agreement with other recent measurements. Resonance parameters for

M. Jandel; T. A. Bredeweg; E. M. Bond; M. B. Chadwick; R. R. Clement; A. Couture; J. M. ODonnell; R. C. Haight; T. Kawano; R. Reifarth; R. S. Rundberg; J. L. Ullmann; D. J. Vieira; J. B. Wilhelmy; J. M. Wouters; U. Agvaanluvsan; W. E. Parker; C. Y. Wu; J. A. Becker

2008-01-01

174

Neutron capture cross section of Am241  

Microsoft Academic Search

The neutron capture cross section of Am241 for incident neutrons from 0.02 eV to 320 keV has been measured with the detector for advanced neutron capture experiments (DANCE) at the Los Alamos Neutron Science Center. The thermal neutron capture cross section was determined to be 665±33 b. Our result is in good agreement with other recent measurements. Resonance parameters for

M. Jandel; T. A. Bredeweg; E. M. Bond; M. B. Chadwick; R. R. Clement; A. Couture; J. M. O'Donnell; R. C. Haight; T. Kawano; R. Reifarth; R. S. Rundberg; J. L. Ullmann; D. J. Vieira; J. B. Wilhelmy; J. M. Wouters; U. Agvaanluvsan; W. E. Parker; C. Y. Wu; J. A. Becker

2008-01-01

175

Track structure studies and cross section calculations  

NASA Astrophysics Data System (ADS)

Charged particle Monte Carlo MC track structre simulations are a useful tool for the understanding of early physical and chemical stages of radiation actions on matter They provide detailed information on highly inhomogeneous spatial distributions of energy depositions interaction types and radical species produced This information is used in Radiation Biology to estimate radiation damage to DNA and other cellular structures e g strand break yields and fragment size distributions Monte Carlo track structure simulations follow the primary as well as all secondary particles event-by-event from starting or ejection energies to total stopping They require reliable cross sections for elastic scattering ionization excitation and charge changing events total cross sections as well as energy and angle differential cross sections of the incident charged particles electrons protons alphas light and heavy ions with the atoms and molecules of the material under consideration Cross sections with liquid water are of special interest since liquid water serves as a substitute for soft tissue Ionization and excitation cross sections for charged particles are normally calculated within the framework of the relativistic plane wave first Born approximation PWBA In this theory the double differential cross section differential in energy and momentum transfer can be separated into kinematic factors and the generalized oscillator strength GOS for single atoms in the gas phase or the dielectric response function

Dingfelder, M.

176

Fission cross section measurements at LANSCE  

NASA Astrophysics Data System (ADS)

Neutron induced fission cross sections of actinides are measured at the Los Alamos Neutron Science Center (LANSCE) in support of the Advanced Fuel Cycle Initiative (AFCI) and the National Nuclear Security Administration (NNSA). Nuclear technologies are increasingly dependent on advanced simulations for design and licensing requirements, and nuclear cross section data are important input parameters for the simulation tools. Fast nuclear reactor and stockpile stewardship applications often share nuclear data needs and requirements, and the LANSCE neutron source is ideal for measuring many of these data. The fission cross section measurements are guided by sensitivity studies performed in support of the AFCI program, as well as requests from NNSA. Recent results for the Pu-239 and Pu-241 fission cross sections from 0.01 eV to 200 MeV will be presented, and the discrepancy with current evaluations of the Pu-241 fission cross section discussed. Ongoing activities to extend the fission program will be presented, such as the development of a Time Projection Chamber (TPC) to significantly improve the experimental accuracies in fission cross section measurements.

Tovesson, Fredrik; Hill, Tony

2009-10-01

177

Negative ion detachment cross sections. Interim progress report  

SciTech Connect

The authors have measured absolute cross sections for electron detachment and charge exchange for collision of O and S with atomic hydrogen, have investigated the sputtering and photodesorption of negative ions from gas covered surfaces, and have begun an investigation of photon-induced field emission of electrons from exotic structures. Brief descriptions of these activities as well as future plans for these projects are given below.

Champion, R.L.; Doverspike, L.D.

1992-10-01

178

Absorption cross section at 3.39 ?m of alkanes, aromatics and substituted hydrocarbons  

NASA Astrophysics Data System (ADS)

The present study reports gas phase absorption cross sections at 3.39 ?m of 21 liquid hydrocarbons. Measurements were performed in the temperature range 303-413 K using an infrared He-Ne laser. In addition to n-alkanes, a number of cyclo-alkane, aromatic, and substituted hydrocarbons were investigated. The results demonstrate that (i) the absorption cross sections are temperature independent in the studied range, and that (ii) the aromatic and substituted hydrocarbons exhibit much smaller cross sections than n-alkanes for an identical number of C-H bonds. A tentative empirical correlation has been developed and shown to accurately predicts the cross section.

Mével, R.; Boettcher, P. A.; Shepherd, J. E.

2012-04-01

179

Determining (n,?) cross sections using surrogate reactions  

NASA Astrophysics Data System (ADS)

Direct measurements of neutron-reaction cross sections on unstable nuclei are extremely challenging due to the difficulties associated with radioactive targets and neutron beams. Indirect methods, such as the surrogate reaction method, are currently the only feasible way to determine many of the cross sections for radioactive nuclei that are of interest to nuclear astrophysics, nuclear energy, and other applications. We have used the surrogate reaction method to determine (n,?) cross sections for ^153,155,157Gd nuclei at energies up to 3 MeV through inelastic proton scattering on stable targets. The STARS/LiBerACE silicon and germanium detector arrays were used to detect ? rays in coincidence with the scattered protons to determine ?-ray exit-channel probabilities. Techniques are being explored to extract reliable cross sections at energies for which the Weisskopf-Ewing limit of the Hauser-Feshbach theory is not applicable. This measurement will provide the first determination of the (n,?) cross section for ^153Gd, an s-process branch-point nucleus with a half-life of 240 days. This work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.

Scielzo, Nicholas; Escher, Jutta

2009-10-01

180

Status of the Neutron Cross Section Standards  

NASA Astrophysics Data System (ADS)

An international evaluation of the neutron cross section standards was recently completed. Many of these standards are used directly in neutron dosimetry for fluence determination. Also, almost all measurements of other dosimetry cross sections have been made relative to neutron cross section standards. Evaluations were obtained for the 1H(n,n), 6Li(n,t), 10B(n,?), 10B(n,?1?), Au(n,?), 235U(n,f) and 238U(n,f) standard cross sections. This work also led to evaluations for the 238U(n,?) and 239Pu(n,f) cross sections, which are not standards, but are used for neutron dosimetry. The new evaluations are generally larger than the ENDF/B-VI evaluations by as much as several percent. Also improved thermal constants were obtained that are in good agreement with the ENDF/B-VI values. The data obtained from this evaluation process were used to produce new evaluations for the new ENDF/B-VII library. Recent measurements are reviewed and the effect of the new evaluations on fluence determinations is shown.

Carlson, A. D.

2009-08-01

181

Calculation of np? cross sections and asymmetries  

NASA Astrophysics Data System (ADS)

Neutron-proton bremsstrahlung cross sections and asymmetries are calculated in both the Gottschalk and Thorndike geometries. The influence of off-shell terms is determined by comparing off-shell calculations to calculations using only elastic scattering parameters. The np? asymmetry is generally less sensitive to off-shell terms than the corresponding cross section. However, the off-shell influences in the np? cases are greater than in the corresponding pp? cases. Furthermore, the np? cross sections tend to be large in the same region where the interesting off-shell effects are large. Work supported in part by the Air Force Office of Aerospace Research US Air Force under Grant No. 69-817; and in part by the Research Council.

McGuire, J. H.; Pearce, W. A.

1971-02-01

182

Calculation of pp? cross sections and asymmetries  

NASA Astrophysics Data System (ADS)

Proton-proton bremsstrahlung cross sections and asymmetries are calculated in both the Gottschalk and Thorndike geometries. Calculations using model-dependent off-shell terms are compared to calculations where these terms are suppressed. In general, the pp? asymmetries are less sensitive to off-shell information than the corresponding pp? cross sections. These calculations also indicate that the asymmetry at 204 MeV is smoother than the Rochester experiment suggests. Calculations of the pp? cross section at extreme forward angles in the Gottschalk geometry suggest large model-dependent effects. Work supported in part by the Air Force Office of Aerospace Research US Air Force under Grant No. 69-817; and in part by the Research Council.

McGuire, J. H.; Pearce, W. A.

1971-02-01

183

Top differential cross section measurements (Tevatron)  

SciTech Connect

Differential cross sections in the top quark sector measured at the Fermilab Tevatron collider are presented. CDF used 2.7 fb{sup -1} of data and measured the differential cross section as a function of the invariant mass of the t{bar t} system. The measurement shows good agreement with the standard model and furthermore is used to derive limits on the ratio {kappa}/M{sub Pl} for gravitons which decay to top quarks in the Randall-Sundrum model. D0 used 1.0 fb{sup -1} of data to measure the differential cross section as a function of the transverse momentum of the top-quark. The measurement shows a good agreement to the next-to-leading order perturbative QCD prediction and various other standard model predictions.

Jung, Andreas W.

2012-01-01

184

Photodisintegration Cross Section of {sup 241}Am  

SciTech Connect

The photodisintegration cross section of radioactive {sup 241}Am has been obtained for the first time using monoenergetic {gamma}-ray beams from the HI{gamma}S facility. The induced activity of {sup 240}Am produced via the {sup 241}Am({gamma},n) reaction in the {gamma}-ray energy range from 9.5 to 16 MeV was measured by the activation technique utilizing high resolution HPGe detectors. The {sup 241}Am({gamma},n) cross section was determined both by measuring the absolute {gamma}-ray flux and by comparison to the {sup 197}Au({gamma},n) and {sup 58}Ni({gamma},n) cross section standards. The experimental data for the {sup 241}Am({gamma},n) reaction in the giant dipole resonance energy region is compared with statistical nuclear-model calculations.

Tonchev, A. P.; Howell, C. R.; Hutcheson, A.; Kwan, E.; Rusev, G.; Tornow, W. [Duke University and TUNL, Durham NC 27708 (United States); Hammond, S.; Karwowski, H. J. [University of North Carolina at Chapel Hill and TUNL, Chapel Hill NC 27599 (United States); Huibregtse, C.; Kelley, J. H. [North Carolina State University and TUNL, Raleigh NC 27695 (United States); Vieira, D. J.; Wilhelmy, J. B. [Los Alamos National Laboratory, Los Alamos NM 87545 (United States)

2009-03-10

185

Electron impact double ionization cross-sections of heavy elements  

NASA Astrophysics Data System (ADS)

A user-friendly semi-empirical formula for the description of electron impact double ionization cross-sections of heavy Sc1+, Ti5+, Fe6+, Ni3+, Ga, Kr4+, Rb1+, Mo3+, Ag, Sb1+, In, Xe4+, Cs1+, Ba2+, Pr3+, Sm6+, W6+, Hg, Pb, Bi1+, and U targets for the incident electron energies from threshold to 106 eV is proposed. The formula contains both the direct and indirect components leading to double ionization. The parameters of the model are determined from the best fit to the available experimental cross-sections using a nonlinear least-squares fitting computer program. It was noticed that the formula represents the experimental data for a fairly wide range of atomic heavy species over a wide range of incident energies.

Talukder, M. R.; Shahjahan, M.; Uddin, M. A.

2012-01-01

186

Smooth vasculature reconstruction with circular and elliptic cross sections.  

PubMed

This paper presents a method to segment and reconstruct vascular structure from patient volumetric scan. First, a semi-automatic segmentation phase leads to the vessels centerlines and the estimated circular or elliptic cross section description. Then, the skeleton data are used by the reconstruction phase to generate the three dimensional vascular surface. This structured surface is able to handle interactive visualization, real-time and robust physics-based modeling. The accuracy and consistency of our technique are evaluated on a vascular phantom as well as two clinical data sets. Experiments show that the proposed technique reaches a good balance in terms of mesh smoothness, compactness, and accuracy, where elliptic cross section estimation induces lower error. PMID:16404060

Krissian, Karl; Wu, Xunlei; Luboz, Vincent

2006-01-01

187

Optical Model and Cross Section Uncertainties  

SciTech Connect

Distinct minima and maxima in the neutron total cross section uncertainties were observed in model calculations using spherical optical potential. We found this oscillating structure to be a general feature of quantum mechanical wave scattering. Specifically, we analyzed neutron interaction with 56Fe from 1 keV up to 65 MeV, and investigated physical origin of the minima.We discuss their potential importance for practical applications as well as the implications for the uncertainties in total and absorption cross sections.

Herman,M.W.; Pigni, M.T.; Dietrich, F.S.; Oblozinsky, P.

2009-10-05

188

Cross sections of neutron-induced reactions  

SciTech Connect

We study the properties of the neutron-nucleus total and reaction cross sections for several nuclei. We have applied an analytical model, the nuclear Ramsauer model, justified it from the nuclear reaction theory approach, and extracted the values of 12 parameters used in the model. The given parametrization has an advantage as phenomenological optical model potentials are limited up to 150-200 MeV. The present model provides good estimates of the total cross sections for several nuclei particularly at high energies.

Mukhopadhyay, Tapan; Lahiri, Joydev; Basu, D. N. [Variable Energy Cyclotron Centre, 1/AF Bidhan Nagar, Kolkata 700064 (India)

2010-10-15

189

Neutron Capture Cross Section of ^239Pu  

NASA Astrophysics Data System (ADS)

The ^239Pu(n,?) cross section has been measured at the Los Alamos Neutron Science Center (LANSCE). The Detector for Advanced Neutron Capture Experiments (DANCE) provided a highly segmented 4? measurement of the energy and multiplicity distributions for emitted ?-rays, while a PPAC detected coincidence fission fragments. The simultaneous measurement of (n,?) and (n,f) events resulting from a single sample allowed the (n,?) cross section to be measured as a ratio to fission with reduced systematic uncertainty. Results from the current analysis will be presented.

Mosby, S.; Arnold, C.; Bredeweg, T. A.; Chyzh, A.; Couture, A.; Gostic, J. M.; Henderson, R. A.; Jandel, M.; Kwan, E.; O'Donnell, J. M.; Rusev, G.; Ullmann, J. L.; Wu, C.-Y.

2012-10-01

190

Total cross section in ?? collisions at LEP  

Microsoft Academic Search

The reaction e+e??e+e??????e+e?hadrons for quasi-real photons is studied using data from s=183 GeV up to 202 GeV. Results on the total cross sections ?(e+e??e+e?hadrons) and ?(???hadrons) are given for the two-photon centre-of-mass energies 5 GeV?W???185 GeV. The total cross section of two real photons is described by a Regge parametrisation. We observe a steeper rise with the two-photon centre-of-mass energy as compared to the

M. Acciarri; P. Achard; O. Adriani; M. Aguilar-Benitez; J. Alcaraz; G. Alemanni; J. Allaby; A. Aloisio; M. G. Alviggi; G. Ambrosi; H. Anderhub; V. P. Andreev; T. Angelescu; F. Anselmo; A. Arefiev; T. Azemoon; T. Aziz; P. Bagnaia; A. Bajo; L. Baksay; A. Balandras; S. V. Baldew; S. Banerjee; A. Barczyk; R. Barillère; P. Bartalini; M. Basile; N. Batalova; R. Battiston; A. Bay; F. Becattini; U. Becker; F. Behner; L. Bellucci; R. Berbeco; J. Berdugo; P. Berges; B. Bertucci; B. L. Betev; S. Bhattacharya; M. Biasini; A. Biland; J. J. Blaising; S. C. Blyth; G. J. Bobbink; A. Böhm; L. Boldizsar; B. Borgia; D. Bourilkov; M. Bourquin; S. Braccini; J. G. Branson; F. Brochu; A. Buffini; A. Buijs; J. D. Burger; W. J. Burger; X. D. Cai; M. Capell; G. Carlino; A. M. Cartacci; J. Casaus; G. Castellini; F. Cavallari; N. Cavallo; C. Cecchi; M. Cerrada; F. Cesaroni; M. Chamizo; Y. H. Chang; U. K. Chaturvedi; M. Chemarin; A. Chen; G. Chen; H. F. Chen; H. S. Chen; G. Chiefari; L. Cifarelli; F. Cindolo; C. Civinini; I. Clare; R. Clare; G. Coignet; N. Colino; S. Costantini; F. Cotorobai; A. Csilling; S. Cucciarelli; T. S. Dai; R. D'Alessandro; P. Déglon; A. Degré; K. Deiters; E. Delmeire; P. Denes; F. DeNotaristefani; M. Diemoz; M. Dierckxsens; C. Dionisi; M. Dittmar; A. Dominguez; A. Doria; M. T. Dova; D. Duchesneau; D. Dufournaud; P. Duinker; A. Engler; F. J. Eppling; F. C. Erné; A. Ewers; P. Extermann; M. Fabre; M. A. Falagan; S. Falciano; A. Favara; J. Fay; O. Fedin; M. Felcini; T. Ferguson; H. Fesefeldt; E. Fiandrini; J. H. Field; F. Filthaut; P. H. Fisher; I. Fisk; G. Forconi; K. Freudenreich; C. Furetta; Yu. Galaktionov; S. N. Ganguli; P. Garcia-Abia; M. Gataullin; S. S. Gau; S. Gentile; N. Gheordanescu; S. Giagu; Z. F. Gong; G. Grenier; O. Grimm; M. W. Gruenewald; M. Guida; V. K. Gupta; A. Gurtu; L. J. Gutay; D. Haas; A. Hasan; D. Hatzifotiadou; T. Hebbeker; A. Hervé; P. Hidas; J. Hirschfelder; H. Hofer; G. Holzner; H. Hoorani; S. R. Hou; Y. Hu; I. Iashvili; B. N. Jin; L. W. Jones; I. Josa-Mutuberr??a; R. A. Khan; D. Käfer; M. Kaur; M. N. Kienzle-Focacci; D. Kim; J. K. Kim; J. Kirkby; D. Kiss; W. Kittel; A. Klimentov; A. C. König; M. Kopal; A. Kopp; V. Koutsenko; M. Kräber; R. W. Kraemer; W. Krenz; A. Krüger; A. Kunin; I. Laktineh; G. Landi; M. Lebeau; A. Lebedev; P. Lebrun; P. Lecomte; P. Lecoq; H. J. Lee; R. Leiste; P. Levtchenko; C. Li; S. Likhoded; C. H. Lin; W. T. Lin; F. L. Linde; L. Lista; Z. A. Liu; W. Lohmann; E. Longo; Y. S. Lu; K. Lübelsmeyer; C. Luci; D. Luckey; L. Lugnier; L. Luminari; W. Lustermann; W. G. Ma; M. Maity; L. Malgeri; A. Malinin; C. Maña; D. Mangeol; J. Mans; G. Marian; J. P. Martin; F. Marzano; K. Mazumdar; R. R. McNeil; S. Mele; L. Merola; M. Meschini; W. J. Metzger; A. Mihul; H. Milcent; G. Mirabelli; J. Mnich; G. B. Mohanty; T. Moulik; G. S. Muanza; A. J. M. Muijs; B. Musicar; M. Musy; M. Napolitano; F. Nessi-Tedaldi; H. Newman; T. Niessen; A. Nisati; H. Nowak; R. Ofierzynski; G. Organtini; A. Oulianov; C. Palomares; D. Pandoulas; S. Paoletti; P. Paolucci; R. Paramatti; H. K. Park; I. H. Park; G. Passaleva; S. Patricelli; T. Paul; M. Pauluzzi; C. Paus; F. Pauss; M. Pedace; S. Pensotti; D. Perret-Gallix; B. Petersen; D. Piccolo; F. Pierella; M. Pieri; P. A. Piroué; E. Pistolesi; V. Plyaskin; M. Pohl; V. Pojidaev; H. Postema; J. Pothier; D. O. Prokofiev; J. Quartieri; G. Rahal-Callot; M. A. Rahaman; P. Raics; N. Raja; R. Ramelli; P. G. Rancoita; R. Ranieri; A. Raspereza; G. Raven; P. Razis; D. Ren; M. Rescigno; S. Reucroft; S. Riemann; K. Riles; J. Rodin; B. P. Roe; L. Romero; A. Rosca; S. Rosier-Lees; S. Roth; C. Rosenbleck; B. Roux; J. A. Rubio; G. Ruggiero; H. Rykaczewski; S. Saremi; S. Sarkar; J. Salicio; E. Sanchez; M. P. Sanders; C. Schäfer; V. Schegelsky; S. Schmidt-Kaerst; D. Schmitz; H. Schopper; D. J. Schotanus; G. Schwering; C. Sciacca; A. Seganti; L. Servoli; S. Shevchenko; N. Shivarov; V. Shoutko; E. Shumilov; A. Shvorob; T. Siedenburg; D. Son; B. Smith; P. Spillantini; M. Steuer; D. P. Stickland; A. Stone; B. Stoyanov; A. Straessner; K. Sudhakar; G. Sultanov; L. Z. Sun; S. Sushkov; H. Suter; J. D. Swain; Z. Szillasi; T. Sztaricskai; X. W. Tang; L. Tauscher; L. Taylor; B. Tellili; D. Teyssier; C. Timmermans; Samuel C. C. Ting; S. M. Ting; S. C. Tonwar; J. Tóth; C. Tully; K. L. Tung; Y. Uchida; J. Ulbricht; E. Valente; G. Vesztergombi; I. Vetlitsky; D. Vicinanza; G. Viertel; S. Villa; M. Vivargent; S. Vlachos; I. Vodopianov; H. Vogel; H. Vogt; I. Vorobiev; A. A. Vorobyov; A. Vorvolakos; M. Wadhwa; W. Wallraff; M. Wang; X. L. Wang; Z. M. Wang; A. Weber; M. Weber; P. Wienemann; H. Wilkens; S. X. Wu; S. Wynhoff; L. Xia; Z. Z. Xu; J. Yamamoto; B. Z. Yang; C. G. Yang; H. J. Yang; M. Yang; J. B. Ye; S. C. Yeh; An. Zalite; Yu. Zalite; Z. P. Zhang; G. Y. Zhu; R. Y. Zhu; A. Zichichi; G. Zilizi; B. Zimmermann; M. Zöller

2001-01-01

191

Covariance Evaluation Methodology for Neutron Cross Sections  

SciTech Connect

We present the NNDC-BNL methodology for estimating neutron cross section covariances in thermal, resolved resonance, unresolved resonance and fast neutron regions. The three key elements of the methodology are Atlas of Neutron Resonances, nuclear reaction code EMPIRE, and the Bayesian code implementing Kalman filter concept. The covariance data processing, visualization and distribution capabilities are integral components of the NNDC methodology. We illustrate its application on examples including relatively detailed evaluation of covariances for two individual nuclei and massive production of simple covariance estimates for 307 materials. Certain peculiarities regarding evaluation of covariances for resolved resonances and the consistency between resonance parameter uncertainties and thermal cross section uncertainties are also discussed.

Herman,M.; Arcilla, R.; Mattoon, C.M.; Mughabghab, S.F.; Oblozinsky, P.; Pigni, M.; Pritychenko, b.; Songzoni, A.A.

2008-09-01

192

Simple Calculations of Proton SEU Cross Sections from Heavy Ion Cross Sections  

Microsoft Academic Search

Simple expressions, based on previous analytical and empirical models for the energy deposited by protons through their p+Si interactions, are proposed for calculating proton induced SEU cross sections from heavy ion cross sections in devices with sub-micron sensitive volumes. Calculations for modern devices yield good agreement with the experiments. The implications on calculating SEU rates in space are discussed

J. Barak

2006-01-01

193

Hadron-nucleon total cross section fluctuations from hadron-nucleus total cross sections  

Microsoft Academic Search

The extent to which information about fluctuations in hadron-nucleon total cross sections in the frozen approximation can be extracted from very high energy hadron-nucleus total cross section measurements for a range of heavy nuclei is discussed. The corrections to the predictions of Glauber theory due to these fluctuations are calculated for several models for the distribution functions, and differences of

David R. Harrington

1995-01-01

194

Vibrational cross sections for positron scattering by nitrogen molecules  

SciTech Connect

We present a systematic study of low-energy positron collision with nitrogen molecules. Vibrational elastic and excitation cross sections are calculated using the multichannel version of the continued fractions method in the close-coupling scheme for the positron incident energy up to 20 eV. The interaction potential is treated within the static-correlation-polarization approximation. The comparison of our calculated data with existing theoretical and experimental results is encouraging.

Mazon, K. T.; Tenfen, W.; Michelin, S. E.; Arretche, F.; Lee, M.-T.; Fujimoto, M. M. [Departamento de Fisica, Universidade Federal de Santa Catarina, 88040-900, Florianopolis, Santa Catarina (Brazil); Departamento de Fisica, Universidade do Estado de Santa Catarina, 89223-100, Joinville, Santa Catarina (Brazil); Departamento de Quimica, Universidade Federal de Sao Carlos, 13565-905, Sao Carlos, Sao Paulo (Brazil); Departamento de Fisica, Universidade Federal do Parana, 13565-905, Curitiba, Parana (Brazil)

2010-09-15

195

Inclusive parton cross sections in photoproduction and photon structure  

NASA Astrophysics Data System (ADS)

Photoproduction of 2-jet events is studied with the H1 detector at HERA. Parton cross sections are extracted from the data by an unfolding method using leading order parton-jet correlations of a QCD generator. The gluon distribution in the photon is derived in the fractional momentum range $0.04\\le x_\\gamma \\le 1$ at the average factorization scale $75$ GeV$^2$.

Ahmed, T.; Aid, S.; Andreev, V.; Andrieu, B.; Appuhn, R.-D.; Arpagaus, M.; Babaev, A.; Baehr, J.; Bán, J.; Ban, Y.; Baranov, P.; Barrelet, E.; Bartel, W.; Barth, M.; Bassler, U.; Beck, H. P.; Behrend, H.-J.; Belousov, A.; Berger, Ch.; Bernardi, G.; Bernet, R.; Bertrand-Coremans, G.; Besançon, M.; Beyer, R.; Biddulph, P.; Bispham, P.; Bizot, J. C.; Blobel, V.; Borras, K.; Botterweck, F.; Boudry, V.; Braemer, A.; Brasse, F.; Braunschweig, W.; Brisson, V.; Bruncko, D.; Brune, C.; Buchholz, R.; Büngener, L.; Bürger, J.; Büsser, F. W.; Buniatian, A.; Burke, S.; Burton, M.; Buschhorn, G.; Campbell, A. J.; Carli, T.; Charles, F.; Charlet, M.; Clarke, D.; Clegg, A. B.; Clerbaux, B.; Colombo, M.; Contreras, J. G.; Cormack, C.; Coughlan, J. A.; Courau, A.; Coutures, Ch.; Cozzika, G.; Criegee, L.; Cussans, D. G.; Cvach, J.; Dagoret, S.; Dainton, J. B.; Dau, W. D.; Daum, K.; David, M.; Delcourt, B.; del Buono, L.; de Roeck, A.; de Wolf, E. A.; di Nezza, P.; Dollfus, C.; Dowell, J. D.; Dreis, H. B.; Droutskoi, A.; Duboc, J.; Düllmann, D.; Dünger, O.; Duhm, H.; Ebert, J.; Ebert, T. R.; Eckerlin, G.; Efremenko, V.; Egli, S.; Ehrlichmann, H.; Eichenberger, S.; Eichler, R.; Eisele, F.; Eisenhandler, E.; Ellison, R. J.; Elsen, E.; Erdmann, M.; Erdmann, W.; Evrard, E.; Favart, L.; Fedotov, A.; Feeken, D.; Felst, R.; Feltesse, J.; Ferencei, J.; Ferrarotto, F.; Flamm, K.; Fleischer, M.; Flieser, M.; Flügge, G.; Fomenko, A.; Fominykh, B.; Forbush, M.; Formánek, J.; Foster, J. M.; Franke, G.; Fretwurst, E.; Gabathuler, E.; Gabathuler, K.; Gamerdinger, K.; Garvey, J.; Gayler, J.; Gebauer, M.; Gellrich, A.; Genzel, H.; Gerhards, R.; Goerlach, U.; Goerlich, L.; Gogitidze, N.; Goldberg, M.; Goldner, D.; Gonzalez-Pineiro, B.; Gorelov, I.; Goritchev, P.; Grab, C.; Grässler, H.; Grässler, R.; Greenshaw, T.; Grindhammer, G.; Gruber, A.; Gruber, C.; Haack, J.; Haidt, D.; Hajduk, L.; Hamon, O.; Hampel, M.; Hanlon, E. M.; Hapke, M.; Haynes, W. J.; Heatherington, J.; Heinzelmann, G.; Henderson, R. C. W.; Henschel, H.; Herynek, I.; Hess, M. F.; Hildesheim, W.; Hill, P.; Hiller, K. H.; Hilton, C. D.; Hladký, J.; Hoeger, K. C.; Höppner, M.; Horisberger, R.; Hudgson, V. L.; Huet, Ph.; Hütte, M.; Hufnagel, H.; Ibbotson, M.; Itterbeck, H.; Jabiol, M.-A.; Jacholkowska, A.; Jacobsson, C.; Jaffre, M.; Janoth, J.; Jansen, T.; Jönsson, L.; Johnson, D. P.; Johnson, L.; Jung, H.; Kalmus, P. I. P.; Kant, D.; Kaschowitz, R.; Kasselmann, P.; Kathage, U.; Katzy, J.; Kaufmann, H. H.; Kazarian, S.; Kenyon, I. R.; Kermiche, S.; Keuker, C.; Kiesling, C.; Klein, M.; Kleinwort, C.; Knies, G.; Ko, W.; Köhler, T.; Köhne, J. H.; Kolanoski, H.; Kole, F.; Kolya, S. D.; Korbel, V.; Korn, M.; Kostka, P.; Kotelnikov, S. K.; Krämerkämper, T.; Krasny, M. W.; Krehbiel, H.; Krücker, D.; Krüger, U.; Krüner-Marquis, U.; Kubenka, J. P.; Küster, H.; Kuhlen, M.; Kur?a, T.; Kurzhöfer, J.; Kuznik, B.; Lacour, D.; Lamarche, F.; Lander, R.; Landon, M. P. J.; Lange, W.; Lanius, P.; Laporte, J.-F.; Lebedev, A.; Leverenz, C.; Levonian, S.; Ley, Ch.; Lindner, A.; Lindström, G.; Link, J.; Linsel, F.; Lipinski, J.; List, B.; Lobo, G.; Loch, P.; Lohmander, H.; Lomas, J.; Lopez, G. C.; Lubimov, V.; Lüke, D.; Magnussen, N.; Malinovski, E.; Mani, S.; Mara?ek, R.; Marage, P.; Marks, J.; Marshall, R.; Martens, J.; Martin, R.; Martyn, H.-U.; Martyniak, J.; Masson, S.; Mavroidis, T.; Maxfield, S. J.; McMahon, S. J.; Mehta, A.; Meier, K.; Mercer, D.; Merz, T.; Meyer, C. A.; Meyer, H.; Meyer, J.; Migliori, A.; Mikocki, S.; Milstead, D.; Moreau, F.; Morris, J. V.; Mroczko, E.; Müller, G.; Müller, K.; Murín, P.; Nagovizin, V.; Nahnhauer, R.; Naroska, B.; Naumann, Th.; Newman, P. R.; Newton, D.; Neyret, D.; Nguyen, H. K.; Nicholls, T. C.; Niebergall, F.; Niebuhr, C.; Niedzballa, Ch.; Nisius, R.; Nowak, G.; Noyes, G. W.; Nyberg-Werther, M.; Oakden, M.; Oberlack, H.; Obrock, U.; Olsson, J. E.; Ozerov, D.; Panaro, E.; Panitch, A.; Pascaud, C.; Patel, G. D.; Peppel, E.; Perez, E.; Phillips, J. P.; Pichler, Ch.; Pieuchot, A.; Pitzl, D.; Pope, G.; Prell, S.; Prosi, R.; Rabbertz, K.; Rädel, G.; Raupach, F.; Reimer, P.; Reinshagen, S.; Ribarics, P.; Rick, H.; Riech, V.; Riedlberger, J.; Riess, S.; Rietz, M.; Rizvi, E.; Robertson, S. M.; Robmann, P.; Roloff, H. E.; Roosen, R.; Rosenbauer, K.; Rostovtsev, A.; Rouse, F.; Royon, C.; Rüter, K.; Rusakov, S.; Rybicki, K.; Rylko, R.; Sahlmann, N.; Salesch, S. G.; Sanchez, E.; Sankey, D. P. C.; Schacht, P.; Schiek, S.; Schleper, P.; von Schlippe, W.; Schmidt, C.; Schmidt, D.; Schmidt, G.; Schöning, A.; Schröder, V.; Schuhmann, E.; Schwab, B.; Schwind, A.; Sefkow, F.; Seidel, M.; Sell, R.; Semenov, A.; Shekelyan, V.; Sheviakov, I.; Shooshtari, H.; Shtarkov, L. N.; Siegmon, G.; Siewert, U.; Sirois, Y.; Skillicorn, I. O.; Smirnov, P.

1995-02-01

196

Inclusive parton cross sections in photoproduction and photon structure  

Microsoft Academic Search

Photoproduction of 2-jet events is studied with the H1 detector at HERA. Parton cross sections are extracted from the data by an unfolding method using leading order parton-jet correlations of a QCD generator. The gluon distribution in the photon is derived in the fractional momentum range 0.04 ? x? ? 1 at the average factorization scale 75 GeV2.

T. Ahmed; S. Aid; V. Andreev; B. Andrieu; R.-D. Appuhn; M. Arpagaus; A. Babaev; J. Baehr; Y. Ban; P. Baranov; E. Barrelet; W. Bartel; M. Barth; U. Bassler; H. P. Beck; H.-J. Behrend; A. Belousov; Ch. Berger; G. Bernardi; R. Bernet; G. Bertrand-Coremans; M. Besançon; R. Beyer; P. Biddulph; P. Bispham; J. C. Bizot; V. Blobel; K. Borras; F. Botterweck; V. Boudry; A. Braemer; F. Brasse; W. Braunschweig; V. Brisson; D. Bruncko; C. Brune; R. Buchholz; L. Büngener; J. Bürger; F. W. Büsser; A. Buniatian; S. Burke; M. Burton; G. Buschhorn; A. J. Campbell; T. Carli; F. Charles; M. Charlet; D. Clarke; A. B. Clegg; B. Clerbaux; M. Colombo; J. G. Contreras; C. Cormack; J. A. Coughlan; A. Courau; Ch. Coutures; G. Cozzika; L. Criegee; D. G. Cussans; J. Cvach; S. Dagoret; J. B. Dainton; W. D. Dau; K. Daum; M. David; B. Delcourt; L. Del Buono; A. De Roeck; E. A. De Wolf; P. Di Nezza; C. Dollfus; J. D. Dowell; H. B. Dreis; A. Droutskoi; J. Duboc; D. Düllmann; O. Dünger; H. Duhm; J. Ebert; T. R. Ebert; G. Eckerlin; V. Efremenko; S. Egli; H. Ehrlichmann; S. Eichenberger; R. Eichler; F. Eisele; E. Eisenhandler; R. J. Ellison; E. Elsen; M. Erdmann; W. Erdmann; E. Evrard; L. Favart; A. Fedotov; D. Feeken; R. Felst; J. Feltesse; J. Ferencei; F. Ferrarotto; K. Flamm; M. Fleischer; M. Flieser; G. Flügge; A. Fomenko; B. Fominykh; M. Forbush; J. Formánek; J. M. Foster; G. Franke; E. Fretwurst; E. Gabathuler; K. Gabathuler; K. Gamerdinger; J. Garvey; J. Gayler; M. Gebauer; A. Gellrich; H. Genzel; R. Gerhards; U. Goerlach; L. Goerlich; N. Gogitidze; M. Goldberg; D. Goldner; B. Gonzalez-Pineiro; I. Gorelov; P. Goritchev; C. Grab; H. Grässler; T. Greenshaw; G. Grindhammer; A. Gruber; C. Gruber; J. Haack; D. Haidt; L. Hajduk; O. Hamon; M. Hampel; E. M. Hanlon; M. Hapke; W. J. Haynes; J. Heatherington; G. Heinzelmann; R. C. W. Henderson; H. Henschel; I. Herynek; M. F. Hess; W. Hildesheim; P. Hill; K. H. Hiller; C. D. Hilton; J. Hladký; K. C. Hoeger; M. Höppner; R. Horisberger; V. L. Hudgson; Ph. Huet; M. Hütte; H. Hufnagel; M. Ibbotson; H. Itterbeck; M.-A. Jabiol; A. Jacholkowska; C. Jacobsson; M. Jaffre; J. Janoth; T. Jansen; L. Jönsson; D. P. Johnson; L. Johnson; H. Jung; P. I. P. Kalmus; D. Kant; R. Kaschowitz; P. Kasselmann; U. Kathage; J. Katzy; H. H. Kaufmann; S. Kazarian; I. R. Kenyon; S. Kermiche; C. Keuker; C. Kiesling; M. Klein; C. Kleinwort; G. Knies; W. Ko; T. Köhler; J. H. Köhne; H. Kolanoski; F. Kole; S. D. Kolya; V. Korbel; M. Korn; P. Kostka; S. K. Kotelnikov; T. Krämerkämper; M. W. Krasny; H. Krehbiel; D. Krücker; U. Krüger; U. Krüner-Marquis; J. P. Kubenka; H. Küster; M. Kuhlen; T. Kurca; J. Kurzhöfer; B. Kuznik; D. Lacour; F. Lamarche; R. Lander; M. P. J. Landon; W. Lange; P. Lanius; J.-F. Laporte; A. Lebedev; C. Leverenz; S. Levonian; Ch. Ley; A. Lindner; G. Lindström; J. Link; F. Linsel; J. Lipinski; B. List; G. Lobo; P. Loch; H. Lohmander; J. Lomas; G. C. Lopez; V. Lubimov; D. Lüke; N. Magnussen; E. Malinovski; S. Mani; R. Maracek; P. Marage; J. Marks; R. Marshall; J. Martens; R. Martin; H.-U. Martyn; J. Martyniak; S. Masson; T. Mavroidis; S. J. Maxfield; S. J. McMahon; A. Mehta; K. Meier; D. Mercer; T. Merz; C. A. Meyer; H. Meyer; J. Meyer; A. Migliori; S. Mikocki; D. Milstead; F. Moreau; J. V. Morris; E. Mroczko; G. Müller; K. Müller; P. Murín; V. Nagovizin; R. Nahnhauer; B. Naroska; Th. Naumann; P. R. Newman; D. Newton; D. Neyret; H. K. Nguyen; T. C. Nicholls; F. Niebergall; C. Niebuhr; Ch. Niedzballa; R. Nisius; G. Nowak; G. W. Noyes; M. Nyberg-Werther; M. Oakden; H. Oberlack; U. Obrock; J. E. Olsson; D. Ozerov; E. Panaro; A. Panitch; C. Pascaud; G. D. Patel; E. Peppel; E. Perez; J. P. Phillips; Ch. Pichler; A. Pieuchot; D. Pitzl; G. Pope; S. Prell; R. Prosi; K. Rabbertz; G. Rädel; F. Raupach; P. Reimer; S. Reinshagen; P. Ribarics; H. Rick; V. Riech; J. Riedlberger; S. Riess; M. Rietz; E. Rizvi; S. M. Robertson; P. Robmann; H. E. Roloff; R. Roosen; K. Rosenbauer; A. Rostovtsev; F. Rouse; C. Royon; K. Rüter; S. Rusakov; K. Rybicki; R. Rylko; N. Sahlmann; S. G. Salesch; E. Sanchez; D. P. C. Sankey; P. Schacht; S. Schiek; P. Schleper; W. von Schlippe; C. Schmidt; D. Schmidt; G. Schmidt; A. Schöning; V. Schröder; E. Schuhmann; B. Schwab; A. Schwind; F. Sefkow; M. Seidel; R. Sell; A. Semenov; V. Shekelyan; I. Sheviakov; H. Shooshtari; L. N. Shtarkov; G. Siegmon; U. Siewert; Y. Sirois; I. O. Skillicorn; P. Smirnov; J. R. Smith; V. Solochenko; Y. Soloviev; J. Spiekermann; S. Spielman; H. Spitzer; R. Starosta; M. Steenbock; P. Steffen; R. Steinberg; B. Stella; K. Stephens; J. Stier; J. Stiewe; U. Stösslein; K. Stolze; J. Strachota; U. Straumann; W. Struczinski; J. P. Sutton; S. Tapprogge; V. Tchernyshov; C. Thiebaux; G. Thompson; P. Truöl; J. Turnau; J. Tutas; P. Uelkes; A. Usik; S. Valkár; A. Valkárová; C. Vallée; P. Van Esch; P. Van Mechelen

1995-01-01

197

Correlation of Treatment Time and Ultrafiltration Rate with Serum Albumin and C-Reactive Protein Levels in Patients with End-Stage Kidney Disease Receiving Chronic Maintenance Hemodialysis: A Cross-Sectional Study  

Microsoft Academic Search

Background: The relationship between treatment time, ultrafiltration rate (UFR) and inflammation has received limited exploration so far. Methods: This is a cross-sectional cohort study of 12 hemodialysis clinics. Statistical models explored the association of multiple patient- and dialysis-specific covariates with low albumin (?40 g\\/l) or high C-reactive protein (CRP) (>5 mg\\/dl) and calculated the ORs and 95% CIs. Results: 616

Lajos Zsom; Marianna Zsom; Tibor Fülöp; Catherine Wells; Michael F. Flessner; József Eller; Charlotta Wollheim; Jörgen Hegbrant; Giovanni F. M. Strippoli

2010-01-01

198

Jet Cross Sections in Leptoproduction from QCD.  

National Technical Information Service (NTIS)

We have calculated the longitudinal and other polarization dependent cross sections for jet production in deep inelastic ep, nu p and anti nu p scattering up to order alpha /sub s/ of the quark-gluon coupling constant. Fragmentation of final state partons...

C. Rumpf G. Kramer J. Willrodt

1980-01-01

199

Top production cross section from CDF  

SciTech Connect

Recent top physics results from the CDF at a center-of-mass energy of 1.96 TeV are presented. Measurements of the t{bar t} production cross section in all three decay channels, using a set of complementary experimental methods, are presented as well as results of a search for single top production.

Taffard, Anyes; /Illinois U., Urbana

2004-12-01

200

Thermal Neutron Absorption Cross Section of Deuterium  

Microsoft Academic Search

The absorption cross section of deuterium for 2200-m\\/sec neutrons has been related to that of boron by intercomparison with lithium. A value of 0.57+\\/-0.01 millibarn for deuterium, based on a measured value of 755 barns for boron, has been obtained.

Louis Kaplan; G. R. Ringo; K. E. Wilzbach

1952-01-01

201

Cross-sectional area of the mandible  

Microsoft Academic Search

Purpose: The anatomy of the mandible was examined by measuring the cross-sectional area (CSA) of multiple regions of 10 fully dentulous hemimandibles to provide a better understanding of regional structural differences that may have implications regarding biomechanical strength, surgical reconstruction, and fracture site frequency.Materials and Methods: Fifteen cuts from the condyle to the symphysis were made of each hemimandible (n

Warren Schubert; Brian J Kobienia; Richard A Pollock

1997-01-01

202

SSC 50 mm dipole cross section  

Microsoft Academic Search

In this paper we present the magnetic design of the two dimensional coil and iron cross section, referred to as DSX201\\/W6733, for the 50 mm aperture main ring dipole magnet for the Superconducting Super Collider (SSC). The computed values of the allowed field harmonics as a function of current, the quench performance predictions, the stored energy calculations, the effect of

R. C. Gupta; S. A. Kahn; G. H. Morgan

1991-01-01

203

A Pebble Bed Reactor cross section methodology  

Microsoft Academic Search

A method is presented for the evaluation of microscopic cross sections for the Pebble Bed Reactor (PBR) neutron diffusion computational models during convergence to an equilibrium (asymptotic) fuel cycle. This method considers the isotopics within a core spectral zone and the leakages from such a zone as they arise during reactor operation. The randomness of the spatial distribution of fuel

Nathanael H. Hudson; Abderrafi. M. Ougouag; Farzad Rahnema; Hans Gougar

2009-01-01

204

The Total Neutron Cross Section of Nitrogen  

Microsoft Academic Search

The total cross section of nitrogen has been measured for neutrons in the energy range 200 to 1800 kev, using scatterers of liquid nitrogen and of lithium azide. Eleven resonances were found, corresponding to excited states in the compound nucleus N15, with natural widths of from 3 to 54 kev. Nine of these can be identified with resonances previously known

J. J. Hinchey; P. H. Stelson; W. M. Preston

1952-01-01

205

Nuclear cross sections for nuclear energy  

Microsoft Academic Search

Practical payoffs from utilizing basic research and nuclear cross sections to improve efficiency and safety and cut operating costs in nuclear power plants are reviewed. Improvements in the performance of light water reactors, fast breeders, thermal-neutron breeders, fusion arrangements, handling of fission products, developing safeguards against theft of nuclear materials, and radioactive wastes disposal are discussed. Careful attention to plutonium

J. L. Fowler; William W. Havens

1976-01-01

206

Nuclear Cross Sections for 270Mev Neutrons  

Microsoft Academic Search

The total cross sections of eleven different elements were measured for the neutrons resulting from the bombardment of a 2-in. Be target by the 350-Mev protons of the 184-in. cyclotron. Bismuth fission ionization chambers served as the neutron detectors and had an estimated mean neutron detection energy of 270 Mev for the measurements. The attenuating materials were placed inside the

James Dejuren

1950-01-01

207

Cross sections for positron scattering from ethane  

NASA Astrophysics Data System (ADS)

We report experimental and theoretical cross sections for positron scattering from the fundamental organic-chemistry molecule ethane (C2H6). The experimental total cross sections (TCSs) were obtained using a linear transmission technique, for energies in the range 0.1-70 eV and with an energy resolution of ˜0.25 eV (full width at half maximum). Agreement, over the common energy range, with the earlier TCS measurements of Floeder [J. Phys. BJPAMA40022-370010.1088/0022-3700/18/16/019 18, 3347 (1985)] is excellent, while both the present results and those of Floeder are consistently higher in magnitude than the data of Sueoka and Mori [J. Phys. BJPAMA40022-370010.1088/0022-3700/19/23/021 19, 4035 (1986)]. The present calculations employed the Schwinger multichannel method and were performed in the static plus polarization approximation for energies up to 10 eV. Our calculated elastic integral cross sections (ICSs) indicate a Ramsauer-Townsend minimum at around 1.4 eV in the Ag scattering symmetry, and a virtual state. In addition we calculated from our scattering cross section a scattering length of -13.83a0. Agreement between our measured TCS and calculated elastic ICS is found to be only qualitative, although this is perhaps not so surprising given the TCS below 10 eV in principle includes contributions from rotational, vibrational, and electronic-state excitation and positronium formation whereas the calculation does not.

Chiari, L.; Zecca, A.; Trainotti, E.; Bettega, M. H. F.; Sanchez, S. d'A.; Varella, M. T. do N.; Lima, M. A. P.; Brunger, M. J.

2013-03-01

208

Total dissociation cross section of halo nuclei.  

National Technical Information Service (NTIS)

Calculations of the total dissociation cross section is performed in the impact parameter representation. The case of (sup 11)Be and (sup 11)Li loosing one and two neutron(s), respectively, by collision on a (sup 12)C target, which remains in its ground s...

J. Formanek R. J. Lombard

1996-01-01

209

Neutron capture cross section of Am241  

NASA Astrophysics Data System (ADS)

The neutron capture cross section of Am241 for incident neutrons from 0.02 eV to 320 keV has been measured with the detector for advanced neutron capture experiments (DANCE) at the Los Alamos Neutron Science Center. The thermal neutron capture cross section was determined to be 665±33 b. Our result is in good agreement with other recent measurements. Resonance parameters for En<12 eV were obtained using an R-matrix fit to the measured cross section. The results are compared with values from the ENDF/B-VII.0, Mughabghab, JENDL-3.3, and JEFF-3.1 evaluations. ?n neutron widths for the first three resonances are systematically larger by 5-15% than the ENDF/B-VII.0 values. The resonance integral above 0.5 eV was determined to be 1553±7 b. Cross sections in the resolved and unresolved energy regions above 12 eV were calculated using the Hauser-Feshbach theory incorporating the width-fluctuation correction of Moldauer. The calculated results agree well with the measured data, and the extracted averaged resonance parameters in the unresolved resonance region are consistent with those for the resolved resonances.

Jandel, M.; Bredeweg, T. A.; Bond, E. M.; Chadwick, M. B.; Clement, R. R.; Couture, A.; O'Donnell, J. M.; Haight, R. C.; Kawano, T.; Reifarth, R.; Rundberg, R. S.; Ullmann, J. L.; Vieira, D. J.; Wilhelmy, J. B.; Wouters, J. M.; Agvaanluvsan, U.; Parker, W. E.; Wu, C. Y.; Becker, J. A.

2008-09-01

210

Hydrodynamics of tubes of varying cross section  

Microsoft Academic Search

A method is suggested of reducing the hydrodynamic resistance by replacing circular cylindrical tubes (CT) by socalled asymmetrical wavy tubes of varying cross section with long exist cone and short nozzle portions. Mathematical simulation of laminar motion of an incompressible fluid (the Navier-Stokes equations) has shown that a change in geometric parameters can change the resistance substantially, making it larger

I. L. Povkh; N. V. Finoshin

1992-01-01

211

Log ASCII Standard (LAS) Files for Geophysical (Gamma Ray) Wireline Well Logs and Their Application to Geologic Cross Section C-C' Through the Central Appalachian Basin  

USGS Publications Warehouse

U.S. Geological Survey (USGS) regional geologic cross section C-C' (Ryder and others, 2008) displays key stratigraphic intervals in the central Appalachian basin. For this cross section, strata were correlated by using descriptions of well cuttings and gamma ray well log traces. This report summarizes the procedures used to convert gamma ray curves on paper well logs to the digital Log ASCII (American Standard Code for Information Interchange) Standard (LAS) format using the third-party software application Neuralog. The procedures could be used with other geophysical wireline logs also. The creation of digital LAS files from paper well logs by using Neuralog is very helpful, especially when dealing with older logs with limited or nonexistent digital data. The LAS files from the gamma ray logs of 11 wells used to construct cross section C-C' are included in this report. They may be downloaded from the index page as a single ZIP file.

Trippi, Michael H.; Crangle, Robert D., Jr.

2009-01-01

212

Towards Reliable Cross Sections for National Security Applications  

SciTech Connect

Stockpile stewardship requires the description of weapons performance without resorting to underground nuclear testing. In the earlier tests, selected isotopes were used as detectors, and recovered after irradiation. Aspects of nuclear device performance were inferred by comparing the measured isotopic ratios to those predicted from simulations. The reaction flows that produce the final isotopic distributions proceed through regions of the nuclear chart that include unstable nuclei. Presently, improved nuclear data input is required to reanalyze prior tests and to certify the stockpile's reliability and safety. Many important cross sections are unknown, as is shown in the example of the Yttrium reaction network (Figure 1). The relevant reactions include (n,2n), (n,n'), (n,gamma), (n,p) and other charged-particle emitting reactions. The cross sections have to be calculated or inferred from indirect measurements. In both cases, reliable optical models that are valid a few nucleons away from stability are needed. The UNEDF Nuclear Reaction activities address this need by combining nuclear-structure input from UNEDF structure calculations with modern reaction theory and large-scale computational capabilities to develop microscopic nucleon-nucleus optical potentials that can be extrapolated to unstable nuclei. In addition, the reaction calculation tools and optical models developed in this context are proving valuable for planning and interpreting indirect (surrogate) measurements of the required cross sections.

Escher, J E; Dietrich, F S; Nobre, G A; Thompson, I J

2011-02-24

213

Humeral cross-sectional shape in suspensory primates and sloths.  

PubMed

Studies on the cross-sectional geometry of long bones in African apes have documented that shape ratios derived from second moments of area about principle axes (e.g., Imax /Imin ) are often correlated with habitual locomotor behaviors. For example, humeral cross-sections tend to appear more circular in more arboreal and forelimb suspensory chimpanzees compared with terrestrial quadrupedal gorillas. These data support the hypothesis that cross-sections that are more circular in shape are adapted for multidirectional loading regimes and bending moments encountered when using acrobatic locomotor behaviors. Whether a more circular humerus reflects greater use of forelimb suspension in other primates and nonprimate mammals is unknown. In this study, cross-sections at or near midshaft of the humerus were obtained from anthropoid primates that differ in their use of forelimb suspension, as well as from two genera of suspensory sloths. Imax /Imin ratios were compared within and between groups, and correlations were made with behavioral data. In broad comparisons, observed differences in morphology follow predicted patterns. Humeri of suspensory sloths are circular. Humeri of the more suspensory hominoids tend to be more circular than those of quadrupedal taxa. Humeri of the suspensory atelines are similar to hominoids, while those of Cebus are more like nonsuspensory cercopithecoids. There is, however, considerable overlap between taxa and within finer comparisons variation between species are not in the predicted direction. Thus, although Imax /Imin ratios of the humerus are informative for characterizing generalized locomotor modes (i.e., forelimb suspensory vs. quadrupedal), additional structural information is needed for more fine-grained assessments of locomotion. PMID:23408647

Patel, Biren A; Ruff, Christopher B; Simons, Erin L R; Organ, Jason M

2013-02-13

214

Absolute np and pp Cross Section Determinations Aimed At Improving The Standard For Cross Section Measurements  

NASA Astrophysics Data System (ADS)

Purpose of present research is a keeping improvement of the standard for cross section measurements of neutron-induced reactions. The cross sections for np and pp scattering below 1 GeV are determined based on partial-wave analyses (PWAs) of nucleon-nucleon scattering data. These cross sections are compared with the most recent ENDF/B-VII.0 and JENDL-4.0 data files, and the Nijmegen PWA. Also a comparison of evaluated data with recent experimental data was made to check a quality of evaluation. Excellent agreement was found between the new experimental data and our PWA predictions.

Laptev, A. B.; Haight, R. C.; Tovesson, F.; Arndt, R. A.; Briscoe, W. J.; Paris, M. W.; Strakovsky, I. I.; Workman, R. L.

2011-06-01

215

Tables of nuclear cross sections for galactic cosmic rays: Absorption cross sections  

NASA Astrophysics Data System (ADS)

A simple but comprehensive theory of nuclear reactions is presented. Extensive tables of nucleon, deuteron, and heavy-ion absorption cross sections over a broad range of energies are generated for use in cosmic ray shielding studies. Numerous comparisons of the calculated values with available experimental data show agreement to within 3 percent for energies above 80 MeV/nucleon and within approximately 10 percent for energies as low as 30 MeV/nucleon. These tables represent the culmination of the development of the absorption cross section formalism and supersede the preliminary absorption cross sections published previously in NASA TN D-8107, NASA TP-2138, and NASA TM-84636.

Townsend, L. W.; Wilson, J. W.

1985-05-01

216

Photoionization Cross Section of the Propargyl Radical and Some General Ideas for Estimating Radical Cross Sections  

NASA Astrophysics Data System (ADS)

A combination of velocity map ion imaging, mass spectrometry, and a laser-based vacuum ultraviolet light source was used to perform a new measurement of the absolute photoionization cross section of the propargyl radical. The measurements are in good agreement with the recent determination of Savee et al. [ J. Chem. Phys. 2012, 136, 134307 ], and significantly larger than an earlier determination. The results are discussed and rationalized in terms of some general ideas about absolute photoionization cross sections. The potential utility of these ideas is illustrated by using recent cross section measurements for a number of molecular radicals, including methyl, allyl and 2-propenyl, phenyl, and vinyl.

Xu, Hong; Pratt, S. T.

2013-10-01

217

Neutron cross section standards and flux determinations above thermal energies  

Microsoft Academic Search

The recent worldwide advances in nuclear technology, particularly fast fission and fusion reactors, have revealed the need for accurate neutron reaction cross sections for the design of these systems. The accuracies of these cross sections are generally limited by the standard cross sections relative to which they are measured. With the exception of the hydrogen scattering cross section, there have

1975-01-01

218

Simulation of multistatic and backscattering cross sections for airborne radar  

Microsoft Academic Search

In order to determine susceptibilities of airborne radar to electronic countermeasures and electronic counter-countermeasures simulations of multistatic and backscattering cross sections were developed as digital modules in the form of algorithms. Cross section algorithms are described for prolate (cigar shape) and oblate (disk shape) spheroids. Backscattering cross section algorithms are also described for different categories of terrain. Backscattering cross section

Albert W. Biggs

1986-01-01

219

Systematics of the 14N+159Tb reaction between 6 and 22 MeV/u (II). The cross section balance obtained with the KX-ray method  

NASA Astrophysics Data System (ADS)

The 14N + 159Tb reaction was studied at 5 energies between 8 and 22 MeV/u via the measurement of particle-KX-ray coincidences with the charged particle detector placed near the grazing angle. With this method a very extensive set of partial cross sections d?/d?(PLF, Zres) of projectile-like fragments (PLF's) as a function of the atomic number of the residual nucleus (Zres) was obtained and thus the cross-section balance determined. It is found that the inclusive cross sections can be accounted for to within ~20% by the sum of the (exclusive) partial cross sections with the use of average KX-ray multiplicities. From the partial cross sections it is deduced that a large fraction of the inclusive PLF cross sections originates from ``non-binary'' reaction channels, in which additional charged particles are emitted. The evaporation of light charged particles from the target-like fragment is observed to be only a minor source of these charge non-binary channels. At 115 and 168 MeV probabilities for sequential decay of primary fragments are obtained, which are in good agreement with results from particle-particle correlation measurements. The Qgg dependence does not give a satisfactory description of the cross sections for charge binary channels at the higher energies. The bulk of the reaction channels in which a PLF with Z >= 3 is emitted can be attributed to a quasi-elastic peripheral collision, in which a primary fragment is formed in a particle stable or unstable state. The quasi-elastic character of these channels is underlined by ?-ray multiplicities measured in the same experiments. Present address: Institute for Nuclear Studies, 05-400 Swierk, Poland.

Balster, G. J.; Wilschut, H. W.; Siemssen, R. H.; Crouzen, P. C. N.; Goldhoorn, P. B.; Sujkowski, Z.

1987-06-01

220

A New Method for Estimating Neutron Reaction Cross Sections Based on Wick's Limit  

SciTech Connect

Wick's limit is an inequality that relates the zero-degree differential elastic scattering cross section to the total cross section. The deviation of Wick's limit from an exact equality is small over a wide range of incident energies and target masses. Under these circumstances we show that Wick's limit can be used to correlate the uncertainties in the two terms of the reaction (nonelastic) cross section expressed as the difference between the total and angle-integrated elastic cross sections. When suitable elastic angular distributions are available, we show that the reaction cross section may be obtained with small errors (typically 1.5-3%). Examples are shown for 208Pb, 54-56Fe, 232Th, and 238U.

Dietrich, F.S.; Anderson, J.D.; Bauer, R.W. [Lawrence Livermore National Laboratory, Livermore, CA 94550 (United States); Grimes, S.M. [Ohio University, Athens, OH 45701 (United States)

2005-05-24

221

A New Method for Estimating Neutron Reaction Cross Sections Based on Wick's Limit  

SciTech Connect

Wick's limit is an inequality that relates the zero-degree differential elastic scattering cross section to the total cross section. The deviation of Wick's limit from an exact equality is small over a wide range of incident energies and target masses. Under these circumstances we show that Wick's limit can be used to correlate the uncertainties in the two terms of the reaction (nonelastic) cross section expressed as the difference between the total and angle-integrated elastic cross sections. When suitable elastic angular distributions are available, we show that the reaction cross section may be obtained with small errors (typically 1.5-3%). Examples are shown for {sup 208P}b, {sup 54-56}Fe, {sup 232}Th, and {sup 238}U.

Dietrich, F S; Anderson, J D; Bauer, R W; Grimes, S M

2004-10-13

222

Cross sections and isomeric cross-section ratios in the interactions of fast neutrons with isotopes of mercury  

NASA Astrophysics Data System (ADS)

Excitation functions were measured for the reactions Hg196(n, 2n)Hg195m,g,Hg198(n, 2n)Hg197m,g,Hg204(n, 2n)Hg203,Hg198(n,p)Au198g, and Hg199(n,p)Au199 over the neutron energy range of 7.6 12.5 MeV. Quasimonoenergetic neutrons were produced via the H2(d,n)He3 reaction using a deuterium gas target at the Jülich variable energy compact cyclotron CV 28. Use was made of the activation technique in combination with high-resolution, high-purity Ge detector ?-ray spectroscopy. All the data were measured for the first time over the investigated energy range. The transition from the present low-energy data to the literature data around 14 MeV is generally good. Nuclear model calculations using the codes STAPRE and EMPIRE-2.19, which employ the statistical and precompound model formalisms, were undertaken to describe the formation of both the isomeric and ground states of the products. The total reaction cross section of a particular channel is reproduced fairly well by the model calculations, with STAPRE giving slightly better results. Regarding the isomeric cross sections, the agreement between the experiment and theory is only in approximate terms. A description of the isomeric cross-section ratio by the model was possible only with a very low value of ?, i.e., the ?eff/?rig ratio.

Al-Abyad, M.; Sudár, S.; Comsan, M. N. H.; Qaim, S. M.

2006-06-01

223

Neutron cross section measurements at WNR  

SciTech Connect

The Weapons Neutron Research Facility has been used to obtain moderate-resolution total neutron cross section data for H, C, /sup 208/Pb, /sup 232/Th, /sup 238/U, and /sup 242/Pu over the energy range 5 to 200 MeV. Neutrons were produced by bombarding a 2.5-cm diam by 15-cm long Ta target with an 800 MeV pulsed proton beam from LAMPF. A 10.2-cm diam by 15.2-cm thick NE110 proton recoil detector was used at a flight path of 32 meters, giving a time-of-flight resolution of 60 ps/m. The total cross section results are compared to ENDF/BV evaluations and to previous data where possible.

Lisowski, P.W.; Archampaugh, G.F.; Moore, M.S.; Morgan, G.L.; Shamu, R.E.

1980-01-01

224

Electron-collision cross sections for iodine  

SciTech Connect

We present results from a joint experimental and theoretical study of elastic electron scattering from atomic iodine. The experimental results were obtained by subtracting known cross sections from the measured data obtained with a pyrolyzed mixed beam containing a variety of atomic and molecular species. The calculations were performed using both a fully relativistic Dirac B-spline R-matrix (close-coupling) method and an optical model potential approach. Given the difficulty of the problem, the agreement between the two sets of theoretical predictions and the experimental data for the angle-differential and the angle-integrated elastic cross sections at 40 eV and 50 eV is satisfactory.

Zatsarinny, O.; Bartschat, K. [Department of Physics and Astronomy, Drake University, Des Moines, Iowa 50311 (United States); Garcia, G. [Instituto de Fisica Fundamental, Consejo Superior de Investigaciones Cientificas, Madrid E-28006 (Spain); Blanco, F. [Departamento de Fisica Atomica, Molecular y Nuclear, Universidad Complutense de Madrid, Madrid E-28040 (Spain); Hargreaves, L.R.; Jones, D.B.; Murrie, R.; Brunton, J.R. [ARC Centre for Antimatter-Matter Studies, School of Chemical and Physical Sciences, Flinders University, GPO Box 2100, Adelaide, SA 5001 (Australia); Brunger, M.J. [ARC Centre for Antimatter-Matter Studies, School of Chemical and Physical Sciences, Flinders University, GPO Box 2100, Adelaide, SA 5001 (Australia); Institute of Mathematical Sciences, University of Malaya, 50603, Kuala Lumpur (Malaysia); Hoshino, M. [Department of Materials and Life Sciences, Sophia University, Chiyoda ku, Tokyo 102-8554 (Japan); Buckman, S.J. [ARC Centre for Antimatter-Matter Studies, Research School of Physics and Engineering, Australian National University, Canberra, ACT 0200 (Australia)

2011-04-15

225

Electron ionization cross sections for atomic subshells.  

PubMed

Ionization of atoms is the first step in many analytical procedures. The cross section for ionizing a particular atomic shell is essential for calculating the magnitude of analytical signals. Calculations using atomic wave functions for various shells of all elements relevant for X-ray microanalysis over a range of electron energies up to 400 keV were performed. The calculations for high energies above threshold can be considerably simplified by using the mathematical form of the Bethe ridge that dominates the scattering in this region. Corrections for exchange at low energies above threshold are incorporated in these calculations. A selection of results showing the effects of different approximations on ionization cross sections for K, L, and M shells is presented. PMID:12597786

Rez, Peter

2003-02-01

226

Sketching cross sections with a portable microcomputer  

SciTech Connect

Computer applications have been carried to the field long ago by geophysicists and their dog houses. The advent of inexpensive battery-powered microcomputers promises to allow the field geologist to participate in this application. The field geologist may record data directly onto a computer-readable medium and calculate statistics or plot a cross section. A program for routine plotting of cross sections in the field has been developed and field-tested. The program proved to be useful to 30 computer-illiterate geologists on a 6-week mapping project in New Mexico. The program allows the user to control vertical exaggeration and displays the correct apparent dip along the chosen line of section. Cubic-spline interpolation is used to plot both topography and folded bedding planes. The program executes in Pascal on an Apple IIc in a few seconds.

Kimberley, M.M.

1985-02-01

227

Differential cross sections for positron scattering from alkali atoms  

SciTech Connect

Close-coupling calculations for differential cross sections for elastic and inelastic positron-alkali scattering at incident energies between 1 eV and 100 eV will be presented. Particular emphasis is placed on excitation of the resonant (ns){sup 2}S {yields} (np){sup 2}P{sup o} and the optically forbidden (ns){sup 2}S {yields} (n{prime}d){sup 2}D transitions. The results will be compared with first order DWBA calculations to assess the importance of channel coupling in the theoretical description of these collision processes.

DeVries, K.M.; Bartschat, K.; McEachran, R.P. [and others

1993-05-01

228

Differential cross sections for fragmentation of positronium  

NASA Astrophysics Data System (ADS)

Cross sections differential with respect to energy and angle of ejected positrons and electrons for Ps(1s) fragmentation in collision with He, Ne, Ar, Kr and Xe targets are reported. For Ne, Ar, Kr and Xe, only the case where the target is not excited (target elastic collisions) is considered. For He, fragmentation with target excitation/ionization (target inelastic collisions) is also studied. The impulse approximation has been used for target elastic fragmentation, the first Born approximation for target inelastic processes.

Walters, H. R. J.; Starrett, C.; McAlinden, Mary T.

2006-06-01

229

Inclusive jet cross section measurement at CDF  

SciTech Connect

The CDF Collaboration has measured the inclusive jet cross section using 1992-93 collider data at 1.8 TeV. The CDF measurement is in very good agreement with NLO QCD predictions for transverse energies (E{sub T}) below 200 GeV. However, it is systematically higher than NLO QCD predictions for E{sub T} above 200 GeV.

Pagliarone, C. [Universita di Torino and INFN, Trieste (Italy)

1996-08-01

230

Inclusive jet cross section at D0  

SciTech Connect

Preliminary measurement of the central ({vert_bar}{eta}{vert_bar} {<=} 0.5) inclusive jet cross sections for jet cone sizes of 1.0, 0.7, and 0.5 at D{null} based on the 1992-1993 (13.7 {ital pb}{sup -1}) and 1994-1995 (90 {ital pb}{sup -1}) data samples are presented. Comparisons to Next-to-Leading Order (NLO) Quantum Chromodynamics (QCD) calculations are made.

Bhattacharjee, M. [Delhi Univ. (India). Dept. of Physics and Astrophysics

1996-09-01

231

Neutron cross sections for fusion. [Review  

Microsoft Academic Search

First generation fusion reactors will most likely be based on the ³H(d,n)⁴He reaction, which produces 14-MeV neutrons. In these reactors, both the number of neutrons and the average neutron energy will be significantly higher than for fission reactors of the same power. Accurate neutron cross section data are therefore of great importance. They are needed in present conceptual designs to

Haight

1979-01-01

232

Neutron total cross section for tritium  

Microsoft Academic Search

The neutron total cross sections for hydrogen, deuterium, and tritium have been measured with the neutron-time-of-flight technique. The tritium data span the neutron energy range from 60 keV to 80 MeV, with an overall systematic uncertainty which varies from 0.5% for energies below 17 MeV to 2% at the highest energy measured; the statistical uncertainties exceed these values only below

T. W. Phillips; B. L. Berman; J. D. Seagrave

1980-01-01

233

Experimental test of the bremsstrahlung cross section  

Microsoft Academic Search

The bremsstrahlung cross section has been studied by measuring the activity induced in 63Cu by electrodisintegration and when thin radiators of Cu, Mo, Ta, and Th were placed in the electron beam just ahead of the target. The electron energies were varied from 13.5 to 60 MeV for the electrodisintegration and from 20 to 60 MeV for the radiator-in measurements;

M. N. Martins; E. Hayward; G. Lamaze; X. K. Maruyama; F. J. Schima; E. Wolynec

1984-01-01

234

Capture cross sections for very heavy systems  

Microsoft Academic Search

In intermediate-mass systems, collective excitations of the target and projectile can greatly enhance the subbarrier capture\\u000a cross section ?\\u000a cap by giving rise to a distribution of Coulomb barriers. For such systems, capture essentially leads directly to fusion [formation\\u000a of a compound nucleus (CN)], which then decays through the emission of light particles (neutrons, protons, and alpha particles).\\u000a Thus, the

N. Rowley; N. Grar; S. S. Ntshangase; R. A. Bark; S. V. Förtsch; J. J. Lawrie; E. A. Gueorguieva; S. M. Maliage; L. J. Mudau; S. M. Mullins; O. M. Ndwandwe; R. Neveling; G. Sletten; F. D. Smith; C. Theron

2006-01-01

235

The cross-sectional area of umbilical cord components in normal pregnancy  

Microsoft Academic Search

ObjectiveTo determine the normal cross-sectional areas of the umbilical vein, umbilical artery, and Wharton jelly in healthy pregnancies, and correlate the obtained values with fetal anthropometric parameters.

F. A. Togni; E ARAUJOJUNIOR; F. A. P. Vasques; A. F. Moron; M. R. Torloni; L. M. M. Nardozza

2007-01-01

236

Neutron radiative capture cross sections, total cross sections, and average resonance parameters for the tin isotopes  

Microsoft Academic Search

Cross sections for radiative capture of neutrons in the energy region 20--450 keV and total cross sections from 20 to 1400 keV for the isotopes {sup 112,114--120,122,124}Sn and the natural mixture of tin have been measured by the time-of-flight method in the pulsed electrostatic accelerator EG-1 at our institute. The experimental data were analyzed in the framework of the statistical

V. M. Timokhov; M. V. Bokhovko; A. G. Isakov; L. E. Kazakov; V. N. Kononov; G. N. Manturov; E. D. Poletaev; V. G. Pronyaev

1989-01-01

237

Microscopic optical-model calculations of neutron total cross sections and cross section differences  

Microsoft Academic Search

Using the microscopic optical model of Jeukenne, Lejeune, and Mahaux we have calculated the absolute neutron total cross sections and cross section differences of 140Ce, 139Ce, 141Ce, 142Ce, and 40Ca, 44Ca from 6-60 MeV and have made comparisons with experimental data. Except for 142Ce, reasonable agreement with the mass 140 data was achieved with proton densities rhop of the nuclei

H. S. Camarda; F. S. Dietrich; T. W. Phillips

1989-01-01

238

Quenching of cross sections in nucleon transfer reactions.  

PubMed

Cross sections for proton knockout observed in (e,e'p) reactions are apparently quenched by a factor of ?0.5, an effect attributed to short-range correlations between nucleons. Here we demonstrate that such quenching is not restricted to proton knockout, but a more general phenomenon associated with any nucleon transfer. Measurements of absolute cross sections on a number of targets between 16O and 208Pb were analyzed in a consistent way, with the cross sections reduced to spectroscopic factors through the distorted-wave Born approximation with global optical potentials. Across the 124 cases analyzed here, induced by various proton- and neutron-transfer reactions and with angular momentum transfer ?=0-7, the results are consistent with a quenching factor of 0.55. This is an apparently uniform quenching of single-particle motion in the nuclear medium. The effect is seen not only in (d,p) reactions but also in reactions with A=3 and 4 projectiles, when realistic wave functions are used for the projectiles. PMID:23931360

Kay, B P; Schiffer, J P; Freeman, S J

2013-07-24

239

Cross-section reconstruction during uniaxial loading  

NASA Astrophysics Data System (ADS)

The inelastic response of materials to applied uniaxial loading is typically measured using tensile or compressive specimens of an initially circular cross-section. Under deformation, this cross-section may become elliptical due to anisotropic material behaviour. An optical technique for measuring the elliptical deformation of anisotropic, homogeneous cylindrical specimens undergoing uniaxial deformation is presented. It enables the quantification of anisotropic deformation in situ and provides data for material characterization. Three or more silhouette views of a specimen are obtained using multiple cameras or mirrored views. The positions of the edges are computed using a sub-pixel edge detection method, and 3D tangent rays from the camera through these positions are calculated. These bounding tangents are used as the basis for an elliptical fit by least squares at cross-sections along the length of the specimen. Stochastic error estimates are performed by simulation of the experiment. Error estimates, for the experimental set-up used, are also calculated by reconstructing elliptical prisms of precisely measured dimensions. Example reconstructions from specimens of rolled titanium deformed plastically in tension at quasi-static (7 × 10-4 s-1) and high strain rates (3 × 103 s-1) are presented.

Arthington, M. R.; Siviour, C. R.; Petrinic, N.; Elliott, B. C. F.

2009-07-01

240

Neutron capture cross section of ^243Am  

NASA Astrophysics Data System (ADS)

The Detector for Advanced Neutron Capture Experiments (DANCE) at Los Alamos National Laboratory (LANL) was used for neutron capture cross section measurement on ^243Am. The high granularity of DANCE (160 BaF2 detectors in a 4? geometry) enables the efficient detection of prompt gamma-rays following neutron capture. DANCE is located on the 20.26 m neutron flight path 14 (FP14) at the Manuel Lujan Jr. Neutron Scattering Center at the Los Alamos Neutron Science Center (LANSCE). The methods and techniques established in [1] were used for the determination of the ^243Am neutron capture cross section. The cross sections were obtained in the range of neutron energies from 0.02 eV to 400 keV. The resonance region was analyzed using SAMMY7 and resonance parameters were extracted. The results will be compared to existing evaluations and calculations. Work was performed under the auspices of the U.S. Department of Energy at Los Alamos National Laboratory by the Los Alamos National Security, LLC under Contract No. DE-AC52-06NA25396 and at Lawrence Livermore National Laboratory by the Lawrence Livermore National Security, LLC under Contract No. DE-AC52-07NA27344. [4pt] [1] M. Jandel et al., Phys. Rev. C78, 034609 (2008)

Jandel, M.

2009-10-01

241

(n,?) reactions cross section research at IPPE  

NASA Astrophysics Data System (ADS)

An experimental set-up based on an ionization chamber with a Frisch grid and wave form digitizer was used for (n,?) cross section measurements. Use of digital signal processing allowed us to select a gaseous cell inside the sensitive area of the ionization chamber and determine the target atoms in it with high accuracy. This kind of approach provided us with a powerful method to suppress background arising from the detector structure and parasitic reactions on the working gas components. This method is especially interesting to study neutron reactions with elements for which solid target preparation is difficult (noble gases for example). In the present experiments we used a set of working gases which contained admixtures of nitrogen, oxygen, neon, argon and boron. Fission of 238U was used as neutron flux monitor. The cross section of the (n,?) reaction for 16O, 14N, 20Ne, 36Ar, 40Ar and the yield ratio ?0/?1 of 10B(n,?0) to 10B(n,?1) reactions was measured for neutron energies between 1.5 and 7 MeV. Additionally a measurement of the 50Cr(n,?) cross section using a solid chromium target is also reported.

Khryachkov, V. A.; Bondarenko, I. P.; Kuzminov, B. D.; Semenova, N. N.; Sergachev, A. I.; Ivanova, T. A.; Giorginis, G.

2012-02-01

242

Experimental study on the temperature dependence of ultraviolet absorption cross-sections of sulfur dioxide  

Microsoft Academic Search

The photoabsorption cross-sections of sulfur dioxide were measured in the spectral regions of 200–230 nm and 275–315 nm at\\u000a 298–415 K, using a grating monochromator with a resolution of 0.2 nm. The discrete absorption cross-section is directly correlated\\u000a with the number of quantum excited from the base state. The absorption cross-sections at the peaks of discrete bands decreased\\u000a linearly with

Shiliang Zhang; Jie Zhou; Xiaohu Chen

2008-01-01

243

Neutron activation cross sections on lead isotopes  

NASA Astrophysics Data System (ADS)

The cross sections for the reactions Pb204(n,n'?)Pb204m, Pb204(n,2n)Pb203, Pb204(n,2n)Pb203m1, Pb204(n,3n)Pb202m, Pb206(n,3n)Pb204m, Pb206(n,?)Hg203, and Pb208(n,p)Tl208 were determined at the IRMM van de Graaff laboratory in the neutron energy range from 14 to 21 MeV. Both natural and enriched samples were irradiated with neutrons produced via the H3(d,n)He4 reaction. The induced activities were determined by gamma-ray spectrometry using a HPGe detector in a low-background shield. Neutron fluences were determined with the well-known cross section of the Al27(n,?)Na24 reaction. Enriched samples were essential to determine the cross sections for the reactions with Pb204m and Pb206m isomers in the final state. Accurate results for reactions with Pb204,206 as target nuclei with natural lead samples were enabled through a precise measurement of the isotopic ratios. For a first investigation of the consequences of the present data for nuclear reaction models they were confronted with calculations based on global parameter systematics in a phenomenological and in a microscopic approach and with parameters selected to reproduce the available data. The TALYS code was used for the former two calculations involving parameter systematics while the STAPRE code was used for the latter calculation.

Semkova, V.; Reimer, P.; Altzitzoglou, T.; Plompen, A. J. M.; Quétel, C.; Sudár, S.; Vogl, J.; Koning, A. J.; Qaim, S. M.; Smith, D. L.

2009-08-01

244

Infrared absorption cross sections for trifluoromethane  

NASA Astrophysics Data System (ADS)

High-resolution infrared absorption cross sections for trifluoromethane have been determined over the range 950–1500 cm?1 from spectra recorded using a high-resolution FTIR spectrometer (Bruker IFS 125HR) and a 26-cm-pathlength cell. Spectra of trifluoromethane/dry synthetic air mixtures were recorded at 0.015 cm?1 resolution (calculated as 0.9/MOPD) at a number of temperatures and pressures (23–762 Torr and 188–294 K) appropriate for atmospheric conditions. Intensities were calibrated using composite trifluoromethane spectra taken from the Pacific Northwest National Laboratory (PNNL) IR database.

Harrison, Jeremy J.

2013-11-01

245

Fission Cross Sections of Uranium, Thorium, Bismuth, Lead, and Gold Induced by 58- to 100MeV Alpha Particles  

Microsoft Academic Search

The results presented in this paper have been obtained from experiments using a makrofol (a polycarbonate) detector. After a brief description of the experimental technique, values of measured cross sections are given. These values are discussed in comparison with some known results about spallation reactions, referring to reaction cross sections theoretically calculated from optical models.

J. Ralarosy; M. Debeauvais; G. Remy; J. Tripier; R. Stein; D. Huss

1973-01-01

246

Theoretical and empirical analysis of the average cross-sectional areas of breakup fragments  

NASA Astrophysics Data System (ADS)

This paper compares two different approaches to calculate the average cross-sectional area of breakup fragments. The first one is described in the NASA standard breakup model 1998 revision. This approach visually classifies fragments into several shapes, and then applies formulae developed for each shape to calculate the average cross-sectional area. The second approach was developed jointly by the Kyushu University and the NASA Orbital Debris Program Office. This new approach automatically classifies fragments into plate- or irregular-shapes based on their aspect ratio and thickness, and then applies formulae developed for each shape to calculate the average cross-sectional area. The comparison between the two approaches is demonstrated in the area-to-mass ratio (A/m) distribution of fragments from two microsatellite impact experiments completed in early 2008. A major difference between the two approaches comes from the calculation of the average cross-sectional area of plates. In order to determine which of the two approaches provides a better description of the actual A/m distribution of breakup fragments, a theoretical analysis in the calculation of the average cross-sectional area of an ideal plate is conducted. This paper also investigates the average cross-sectional area of multi-layer insulation fragments. The average cross-sectional area of 214 multi-layer insulation fragments was measured by a planimeter, and then the data were used to benchmark the average cross-sectional areas estimated by the two approaches. The uncertainty in the calculation of the average cross-sectional area with the two approaches is also discussed in terms of size and thickness.

Hanada, T.; Liou, J.-C.

2011-05-01

247

Ab initio method for calculating total cross sections  

NASA Astrophysics Data System (ADS)

A method for calculating total cross sections without formally including nonelastic channels is presented. The idea is to use a one channel T-matrix variational principle with a complex correlation function. The derived T matrix is therefore not unitary. Elastic scattering is calculated from T-parallel-squared, but total scattering is derived from the imaginary part of T using the optical theorem. The method is applied to the spherically symmetric model of electron-hydrogen scattering. No spurious structure arises; results for sigma(el) and sigma(total) are in excellent agreement with calculations of Callaway and Oza (1984). The method has wide potential applicability.

Bhatia, A. K.; Schneider, B. I.; Temkin, A.

1993-03-01

248

Theoretical Fully Differential Cross Sections for Transfer-Excitation Collisions  

NASA Astrophysics Data System (ADS)

Theoretical fully differential cross sections (FDCS) will be compared with experimental results for transfer-excitation occurring in proton-helium collisions. In the experiments, the incident proton captures one electron from a helium atom, and the remaining electron is left an excited bound state of the helium ion. The theoretical approach we use is a full four-body approach, taking each particle and interaction into account. The calculations will address the effects of the projectile-target atom and projectile-residual ion interactions, as well as electron correlation.

Harris, A. L.; Schulz, M.; Peacher, J. L.; Madison, D. H.

2009-05-01

249

Theoretical Fully Differential Cross Sections for Transfer-Ionization Collisions  

NASA Astrophysics Data System (ADS)

Theoretical fully differential cross sections (FDCS) will be compared with experimental results for transfer-ionization occurring in proton-helium collisions. In the experiments, the incident proton captures one electron from a helium atom, and the remaining electron is ionized into the continuum. The theoretical approach we use is a full four-body approach, taking each particle and interaction into account. The calculations will address the effects of the projectile-target atom interaction, projectile-residual ion interaction, electron correlation, and post-collision interaction.

Harris, A. L.; Peacher, J. L.; Madison, D. H.

2009-05-01

250

2. 5 MeV neutron source for fission cross section measurement  

SciTech Connect

A 2.5 MeV neutron source has been established on the beamline of a 100 kV, 0.5 ma ion accelerator. The ion accelerator provides a 100 kV deuteron beam of about 200 ..mu..a into a 3 mm beam spot at the target position. The neutron source is produced by the D(d,n)/sup 3/He reaction with a yield of about 10/sup 7/ n/sec. The time-correlated associated particle method (TCAP) is utilized for the neutron fluence determination and for neutron background elimination. The /sup 3/He associated particles are detected at 90 degrees behind a thin aluminum foil and the corresponding neutrons are emitted at 73.5 degrees with an energy near 2.5 MeV. Also, the protons from the competing D(d,p)T reaction are monitored at 135 degrees for normalization and diagnostic purposes. A fission chamber containing six uranium tetrafluoride deposits has been designed for use in the /sup 235/U(n,f) cross section measurement at 2.5 MeV. The 5 cm diameter deposits range in thickness from 230--300 ..mu..g/cm/sup 2/ and are expected to have good uniformity. A description of the 2.5 MeV neutron source facility is presented along with details of the associated particle detection and neutron beam characteristics. Preparations for the fission cross section measurement are discussed. 6 refs., 4 figs.

Duvall,, K.C.; Wasson, O.A.; Ma, Honchang

1988-01-01

251

Metabolic Syndrome in Alcohol-Dependent Men: A Cross-Sectional Study  

PubMed Central

Background: In the context to mental illness metabolic syndrome (MS) has gained significant attention in the last decade. The present research aimed to study the prevalence of MS and its correlates among the alcohol-dependent men at a deaddiction center in Northern India. Materials and Methods: A cross-sectional analysis was done for consecutive male subjects who met the diagnosis of alcohol-dependence syndrome currently using alcohol according to the International Clinical Diagnostic criteria- tenth revision mental and behavioral disorder- Clinical description and diagnostic guidelines criteria (ICD-10). The subjects were evaluated for alcohol consumption and the components of MS as per the International Diabetic Federation (IDF) and National Cholesterol Education Program Adult Treatment Panel-III (NCEP ATP-III). Results: A total of 200 male subjects were studied: 100 subjects meeting ICD-10 criteria for alcohol dependence currently using alcohol; 50 each of genetically related controls and nongenetically related healthy controls. As per the IDF (with ethnicity specific modifications for waist circumference) and NCEP ATP- III definitions, respectively, MS was found to be less prevalent in alcohol-dependent subjects (27% and 18%) in comparison the healthy controls (30% and 20%). Conclusion: Findings of the study suggest that irrespective of the amount the current alcohol intake is associated with a lower prevalence of MS and a favorable effect on serum high density lipoproteins and waist circumference. However, the cross-sectional nature of our study does not allow any definitive causal inference.

Aneja, Jitender; Basu, Debasish; Mattoo, Surendra Kumar; Kohli, Krishan Kumar

2013-01-01

252

Actinide Targets for Neutron Cross Section Measurements  

SciTech Connect

The Advanced Fuel Cycle Initiative (AFCI) and the Generation IV Reactor Initiative have demonstrated a lack of detailed neutron cross-sections for certain "minor" actinides, those other than the most common (235U, 238U, and 239Pu). For some closed-fuel-cycle reactor designs more than 50% of reactivity will, at some point, be derived from "minor" actinides that currently have poorly known or in some cases not measured (n,?) and (n,f) cross sections. A program of measurements under AFCI has begun to correct this. One of the initial hurdles has been to produce well-characterized, highly isotopically enriched, and chemically pure actinide targets on thin backings. Using a combination of resurrected techniques and new developments, we have made a series of targets including highly enriched 239Pu, 240Pu, and 242Pu. Thus far, we have electrodeposited these actinide targets. In the future, we plan to study reductive distillation to achieve homogeneous, adherent targets on thin metal foils and polymer backings. As we move forward, separated isotopes become scarcer, and safety concerns become greater. The chemical purification and electodeposition techniques will be described.

John D. Baker; Christopher A. McGrath

2006-10-01

253

Measurement of actinide neutron cross sections  

SciTech Connect

The maintenance of strong scientific expertise is criticalto the U.S. nuclear attribution community. It is particularly importantto train students in actinide chemistry and physics. Neutroncross-section data are vital components to strategies for detectingexplosives and fissile materials, and these measurements requireexpertise in chemical separations, actinide target preparation, nuclearspectroscopy, and analytical chemistry. At the University of California,Berkeley and the Lawrence Berkeley National Laboratory we have trainedstudents in actinide chemistry for many years. LBNL is a leader innuclear data and has published the Table of Isotopes for over 60 years.Recently, LBNL led an international collaboration to measure thermalneutron capture radiative cross sections and prepared the EvaluatedGamma-ray Activation File (EGAF) in collaboration with the IAEA. Thisfile of 35,000 prompt and delayed gamma ray cross-sections for allelements from Z=1-92 is essential for the neutron interrogation ofnuclear materials. LBNL has also developed new, high flux neutrongenerators and recently opened a 1010 n/s D+D neutron generatorexperimental facility.

Firestone, Richard B.; Nitsche, Heino; Leung, Ka-Ngo; Perry, DaleL.; English, Gerald

2003-06-15

254

Cross-section measurements for radioactive samples  

SciTech Connect

The measurement of (n,p), (n,..cap alpha..) and (n,..gamma..) cross sections for radioactive nuclei is of interest to both nuclear physics and astrophysics. For example, using these reactions, properties of levels in nuclei at high excitation energies, which are difficult or impossible to study using other reactions, can be investigated. Also, reaction rates for both big-bang and stellar nucleosynthesis can be obtained from these measurements. In the past, the large background associated with the sample activity limited these types of measurements to radioisotopes with very long half-lives. The advent of the low-energy, high-intensity neutron source at the Los Alamos Neutron Scattering CEnter (LANSCE) has greatly increased the number of nuclei which can be studied. Examples of (n,p) measurements on samples with half lives as short as fifty-three days will be given. The nuclear physics and astrophysics to be learned from these data will be discussed. Additional difficulties are encountered when making (n,..gamma..) rather than (n,p) or (n,..cap alpha..) measurements. However, with a properly-designed detector, and the high peak neutron intensities now available, (n,..gamma..) measurements can be made for nuclei with half lives as short as several months. Progress on the Los Alamos (n,..gamma..) cross-section measurement program for radioactive samples will be discussed. 39 refs., 7 figs.

Koehler, P.E.; O'Brien, H.A.

1988-01-01

255

Absorption cross section of absorber cylinders  

NASA Astrophysics Data System (ADS)

The paper covers derivation and calculation of absorption and scattering cross sections of three types of cylinders made out of porous absorber material. These types are, respectively, (a) completely bulk reacting (homogeneous and isotropic), (b) axially locally reacting but bulk reacting about the circumference (rigid partitions inserted normal to the cylinder's axis), and (c) locally reacting in all directions. The sound field may be either plane waves with oblique incidence or diffuse sound fields. The characteristic data used for the absorber materials, propagation constant and wave impedance, are in the form of simple approximations taken from a model theory of fibrous absorbers for low frequencies, with experimental data being used at medium and high frequencies. A formulation of the scattered sound field in series of Bessel function is used. The numerical results show the influence of the frequency, the diameter, the materials' flow resistance and the angle of incidence. Maps are plotted of lines of constant absorption cross-sections for the different types of cylinders and sound fields, revealing the dependence upon these parameters. Acoustical phenomena of the sound absorption by absorber cylinders are discussed, such as resonance scattering, surface waves, frequency ranges with small angular dependence and parameter combinations with only small frequency dependence of the absorption. Such cylinders would be appropriate as calibration objects in round robin tests of sound absorption measurement in reverberant rooms.

Mechel, F. P.

1986-05-01

256

Neutronic Cross Section Calculations on Fluorine Nucleus  

NASA Astrophysics Data System (ADS)

Certain light nuclei such as Lithium (Li), Beryllium (Be), Fluorine (F) (which are known as FL?BE) and its molten salt compounds (LiF, BeF2 and NaF) can serve as a coolant which can be used at high temperatures without reaching a high vapor pressure. These molten salt compounds are also a good neutron moderator. In this study, cross sections of neutron induced reactions have been calculated for fluorine target nucleus. The new calculations on the excitation functions of 19F( n, 2n), 19F( n, p), 19F( n, xn), 19F( n, xp) have been made. In these calculations, the pre-equilibrium and equilibrium effects have been investigated. The pre-equilibrium calculations involve the full exciton model and the cascade exciton model. The equilibrium effects are calculated according to the Weisskopf-Ewing model. Also in the present work, the ( n, 2n) and ( n, p) reaction cross sections have calculated by using evaluated empirical formulas developed by Tel et al. at 14-15 MeV energy. The multiple pre-equilibrium mean free path constant from internal transition have been investigated for 19F nucleus. The obtained results have been discussed and compared with the available experimental data.

Kara, A.; Tel, E.

2013-06-01

257

Photoionization cross sections of Selenium ions (Sterling+, 2011)  

NASA Astrophysics Data System (ADS)

'Direct' and 'Direct and resonant' photoionization cross sections are tabulated for neutral and the first five ions of Se. Note that photoexcitation-autoionization resonances are not included in these data files. Names of the files are given by pxd.dat (px.dat), e.g., se2+pxd.dat (se2+px.dat) for photoionization of Se2+ ions. Comments are indicated by '#' in the first column of a line. The first two lines of a file are header information indicating the number of photon targets (ground state and metastable states in the ground configuration, with 1 the lowest energy) and number of energies. The photoionization cross section of each state is preceded by a comment giving the energy above the ground state (or the total energy, in the case of the ground state), the total energy of the target state, and the energy-order of that state (1 = ground state, 2 = first excited state, etc.). All energies are reported in Rydbergs, and cross sections in megabarns (10-18cm2). Total and partial final state resolved dielectronic recombination rate coefficients are tabulated for the first six ions of Se, in the ADAS adf09 and adf48 formats. Names of the files are given by adf09.dat (adf48), e.g., adf09_se2+.dat (adf48_se2+.dat) gives dielectronic recombination data for Se2+ forming Se+. These files are available in adf subdirectory. The format of these files is complex, and beyond the scope of this README file. The reader is referred to http://amdpp.phys.strath.ac.uk/tamoc/RR/RR_web/appxa-09.pdf for a complete description of the adf09 and adf48 files format. (14 data files).

Sterling, N. C.; Witthoeft, M. C.

2011-02-01

258

EXPLAINING DISCREPANCIES BETWEEN LONGITUDINAL AND CROSS-SECTIONAL MODELS  

EPA Science Inventory

Discrepancies between estimates obtained from longitudinal studies analyzed cross-sectionally and longitudinally pose questions about the validity of cross-sectional estimates of change. n some cases these discrepancies are the result of period effects, cohort effects, or selecti...

259

Total cross sections for electron scattering on chloromethanes: Formulation of the additivity rule  

Microsoft Academic Search

Total cross sections for electron scattering on CH3Cl, CH2Cl2, and CHCl3 have been measured by an absolute method in the (75-4000)-eV energy range. The overall experimental error is below 5%. A formulation of the additivity rule is proposed. The molecular cross sections are approximated by a Born-like two-parameter formula. We show that the low-energy parameter is correlated to the molecular

Grzegorz P. Karwasz; Roberto S. Brusa; Andrea Piazza; Antonio Zecca

1999-01-01

260

Microscopic optical-model calculations of neutron total cross sections and cross section differences  

Microsoft Academic Search

Using the microscopic optical model of Jeukenne, Lejeune, and Mahaux we have calculated the absolute neutron total cross sections and cross section differences of ¹⁴°Ce, ¹³⁹La--¹⁴°Ce, ¹⁴¹Pr--¹⁴°Ce, ¹⁴²Ce--¹⁴°Ce, and ⁴°Ca, ⁴⁴Ca--⁴°Ca from 6--60 MeV and have made comparisons with experimental data. Except for ¹⁴²Ce--¹⁴°Ce, reasonable agreement with the mass 140 data was achieved with proton densities rho\\/sub p\\/ of the

H. S. Camarda; F. S. Dietrich; T. W. Phillips

1989-01-01

261

Electron cross section set for CHF{sub 3}  

SciTech Connect

We describe the development of a consistent set of low-energy electron collision cross sections for trifluoromethane, CHF{sub 3}. First-principles calculations are used to obtain key elastic and inelastic cross sections. These are combined with literature values of the ionization cross section and with vibrational excitation cross sections obtained from the Born approximation to form a preliminary set, which is then adjusted to achieve consistency with measured swarm parameters. {copyright} 2001 American Institute of Physics.

Morgan, W. Lowell; Winstead, Carl; McKoy, Vincent

2001-08-15

262

Photoneutron cross sections of 58Ni and 60Ni  

Microsoft Academic Search

Photoneutron cross sections of 58Ni and 60Ni have been measured, using separated isotopes and nearly monoenergetic photons from in-flight annihilation of positrons. Both (gamma,n) and (gamma,2n) cross sections have been obtained; the (gamma,3n) cross section for both isotopes was found to be essentially negligible up to the highest energy measured, 33.5 MeV. The peak cross section of 27 mb for

S. C. Fultz; R. A. Alvarez; B. L. Berman; P. Meyer

1974-01-01

263

Evaluation of Kerma in Carbon and the Carbon Cross Sections.  

National Technical Information Service (NTIS)

A preliminary simultaneous least squares fit to measurements of kerma in carbon, and carbon cross sections taken from the ENDF/B-V file was carried out. In the calculation the shapes of the total cross section and the various partial cross sections were r...

E. J. Axton

1992-01-01

264

Reanalysis of the e+e-??? reaction cross section  

Microsoft Academic Search

resonance, in order to make a right choice of the minimization solution. In this work the ?'-meson parameters were estimated from the experimental data on the e+e? ? ?? cross section (2, 3). The cross section value in the ?'-resonance maximum obtained from the approximation of the e+e? ? ?? cross section can be translated to the e+e? ? ?'

M. N. Achasov; K. I. Beloborodov; A. V. Berdyugin; A. G. Bogdanchikov; A. D. Bukin; D. A. Bukin; T. V. Dimova; V. P. Druzhinin; V. B. Golubev; A. A. Korol; S. V. Koshuba; E. V. Pakhtusova; S. I. Serednyakov; Z. K. Silagadze; A. V. Vasiljev

2007-01-01

265

EVALUATION OF CROSS SECTIONS FOR Cm242, -243, -244  

Microsoft Academic Search

The work is devoted to the analysis of available experimental and evaluated data on the neutron cross sections for Cm-242, Cm-243, Cm-244. A comparison of experimental data with the results of theoretical calculations and the evaluations of the most important cross sections were performed. As a result the new version of complete files of evaluated neutron cross sections for Cm-242,

A. I. Blokhin; A. S. Badikov; A. V. Ignatyuk; V. P. Lunev; V. N. Manokhin; G. Ya; K. I. Zolotarev

266

Nuclear Cross Sections for 900 MeV Protons  

Microsoft Academic Search

The cross sections of carbon, aluminium, copper, antimony and lead for 900 MeV protons have been measured. Observations were made with a counter telescope in which the final counter subtended a number of different angles at the absorber. Extrapolation of `poor geometry' results gave the inelastic cross sections. Extrapolations for nuclear cross sections, which require `good geometry' measurements, were possible

N. E. Booth; B. Ledley; D. Walker; D. H. White

1957-01-01

267

Why understanding neutrino cross sections is important for astrophysics  

SciTech Connect

Neutrino cross sections are important in many different astrophysical environments. Particularly needed is information about low energy (tens of MeV) cross sections. We review, for a few situations, the importance of neutrino cross sections for supernovae, gamma ray bursts and neutron stars.

McLaughlin, G. C. [Department of Physics North Carolina State University, Raleigh, NC 27695-8202 (United States)

2007-12-21

268

Neutron Fission of 235,237,239U and 241,243Pu: Cross Sections, Integral Cross Sections and Cross Sections on Excited States  

Microsoft Academic Search

In a recent paper submitted to Phys. Rev. C they have presented estimates for (n,f) cross sections on a series of Thorium, Uranium and Plutonium isotopes over the range E{sub n} = 0.1-2.5 MeV. The (n,f) cross sections for many of these isotopes are difficult or impossible to measure in the laboratory. The cross sections were obtained from previous (t,pf)

W Younes; H C Britt

2003-01-01

269

Lunar Radar Cross Section at Low Frequency  

NASA Astrophysics Data System (ADS)

Recent bistatic measurements of the lunar radar cross-section have extended the spectrum to long radio wavelength. We have utilized the HF Active Auroral Research Program (HAARP) radar facility near Gakona, Alaska to transmit high power pulses at 8.075 MHz to the Moon; the echo pulses were received onboard the NASA/WIND spacecraft by the WAVES HF receiver. This lunar radar experiment follows our previous use of earth-based HF radar with satellites to conduct space experiments. The spacecraft was approaching the Moon for a scheduled orbit perturbation when our experiment of 13 September 2001 was conducted. During the two-hour experiment, the radial distance of the satellite from the Moon varied from 28 to 24 Rm, where Rm is in lunar radii.

Rodriguez, P.; Kennedy, E. J.; Kossey, P.; McCarrick, M.; Kaiser, M. L.; Bougeret, J.-L.; Tokarev, Y. V.

2002-01-01

270

Top cross section measurement at CDF  

SciTech Connect

This paper describes the latest measurements of the t{bar t} pair production cross section performed by the CDF Collaboration analyzing p{bar p} collisions at a center-of-mass energy of 1.96 TeV from Fermilab Tevatron, as presented at the XVIII International Workshop on Deep-Inelastic Scattering and Related Subjects. In order to test Standard Model predictions, several analysis methods are explored and all the top decay channels are considered, to better constrain the properties of the top quark and to search for possible sources of new physics affecting the pair production mechanism. Experimental results using an integrated luminosity up to 5.1 fb{sup -1} are presented.

Compostella, Gabriele; /INFN, CNAF /Padua U.

2010-01-01

271

Dielectronic recombination cross sections of neonlike xenon  

SciTech Connect

High-resolution measurements of dielectronic recombination cross sections for neonlike xenon (Xe{sup 44+}) are presented. The experimental method consists of the formation and interaction of ions with electrons in an ion trap followed by an analysis of the extracted ions to determine relative yields. Low beam currents are used to obtain an energy resolution of 16 eV FWHM. Reductions in the number of initial ions of more than 3 orders of magnitude are observed as the strongest resonances are scanned. The relative contributions of the {ital LMM}, {ital LMN}, {ital LMO}, {ital LMP}, and {ital LMQ} groups of resonances are compared to theoretical calculations. The agreement with theory is excellent.

DeWitt, D.R.; Schneider, D.; Chen, M.H.; Clark, M.W.; McDonald, J.W.; Schneider, M.B. (Lawrence Livermore National Laboratory, University of California, Livermore, California 94550 (United States))

1992-03-16

272

Graphs of the cross sections in the Alternate Monte Carlo Cross Section library at the Los Alamos Scientific Laboratory  

SciTech Connect

Graphs of all neutron cross sections and photon production cross sections on the Alternate Monte Carlo Cross Section (AMCCS) library have been plotted along with local neutron heating numbers. The values of ..nu..-bar, the average number of neutrons per fission, are also plotted for appropriate isotopes.

Seamon, R.E.; Soran, P.D.

1980-06-01

273

Theoretical and Empirical Analysis of the Average Cross-sectional Areas of Breakup Fragments  

NASA Astrophysics Data System (ADS)

This paper will compare two different approaches to calculate the average cross-sectional ar-eas of breakup fragments. The first one is described in the NASA standard breakup model 1998 revision. This approach visually classifies fragments into several shapes, and then applies formulae developed for each shape to calculate the average cross-sectional area. The second ap-proach was developed jointly by the Kyushu University and the NASA Orbital Debris Program Office. This new approach automatically classifies fragments into plate-or irregular-shaped objects based on their aspect ratio and thickness, and then applies formulae for each shape to calculate the average cross-sectional area. The comparison between the two approaches will be demonstrated in the area-to-mass ratio (A/m) distribution of fragments from two microsatellite impact tests completed in early 2008. In order to determine which one of the two approaches provides a better description of the actual A/m distribution of breakup fragments, a theoretical analysis of two objects in ideal shape was conducted. The first one is an ideal plate. It is used to investigate the uncertainty of the formula described in the NASA standard breakup model. The second shape is an ideal cylinder. It is used to investigate the uncertainty in the calculation of the average cross-sectional area of needle-like fragments generated from the CFRP layers and side panels of the microsatellite tests. This paper will also investigate the average cross-sectional areas of multi-layer insulation (MLI) fragments. The average cross-sectional areas of 214 MLI fragments were measured by a planime-ter, and then the data were used to benchmark the average cross-sectional areas estimated by the two approaches. The uncertainty in the calculation of the average cross-sectional area with the two approaches will also be discussed in terms of size and thickness.

Hanada, Toshiya; Liou, Jer-Chyi

274

Experiment to measure total cross sections, differential cross sections and polarization effects in pp elastic scattering at RHIC  

SciTech Connect

The author is describing an experiment to study proton-proton (pp) elastic scattering experiment at the Relativistic Heavy Ion Collider (RHIC). Using both polarized and unpolarized beams, the experiment will study pp elastic scattering from {radical}s = 60 GeV to {radical}s = 500 GeV in two kinematical regions .In the Coulomb Nuclear Interference (CNI) region, 0.0005 < {vert_bar}t{vert_bar} < 0.12 (GeV/c){sup 2}, we will measure and study the s dependence of the total and elastic cross sections, {sigma}{sub tot} and {sigma}{sub el}; the ratio of the real to the imaginary part of the forward elastic scattering amplitude, {rho}; and the nuclear slope parameter of the pp elastic scattering, b. In the medium {vert_bar}t{vert_bar}, {vert_bar}t{vert_bar} {le} 1.5 (GeV/c){sup 2}, we plan to study the evolution of the dip structure with s, as observed at ISR in the differential elastic cross section, d{sigma}{sub el}/dt, and the s and {vert_bar}t{vert_bar} dependence of b. With the polarized beams the following can be measured: the difference in the total cross sections as function of initial transverse spin stated {Delta}{sigma}{sub T}, the analyzing power, A{sub N}, and the transverse spin correlation parameter A{sub NN}. The behavior of the analyzing power A{sub N} at RHIC energies in the dip region of d{sigma}{sub el}/dt, where a pronounced structure was found at fixed-target experiments will be studied.

Guryn, W.

1995-12-31

275

Experiment to measure total cross sections, differential cross sections and polarization effects in pp elastic scattering at RHIC  

SciTech Connect

The authors are describing an experiment to study proton-proton (pp) elastic scattering experiment at the Relativistic Heavy Ion Collider (RHIC). Using both polarized and unpolarized beams, the experiment will study pp elastic scattering from {radical}s = 50 GeV to {radical}s = 500 GeV in two kinematical regions. In the Coulomb Nuclear Interference (CNI) region, 0.0005 < {vert_bar}t{vert_bar} < 0.12 (GeV/c){sup 2}, they will measure and study the s dependence of the total and elastic cross sections, {sigma}{sub tot} and {sigma}{sub el}; the ratio of the real to the imaginary part of the forward elastic scattering amplitude, {rho}; and the nuclear slope parameter of the pp elastic scattering, b. In the medium {vert_bar}t{vert_bar}-region, {vert_bar}t{vert_bar} < 1.5 (GeV/c){sup 2}, they plan to study the evolution of the dip structure with s, as observed at ISR in the differential elastic cross section, d{sigma}{sub el}/dt, and the s and {vert_bar}t{vert_bar} dependence of b. With the polarized beams the following can be measured: the difference in the total cross sections as function of initial transverse spin states {Delta}{sigma}{sub T}, the analyzing power, A{sub N}, and the transverse spin correlation parameter A{sub NN}. The behavior of the analyzing power A{sub N} at RHIC energies in the dip region of d{sigma}{sub el}/dt, where a pronounced structure was found at fixed-target experiments will be studied. The relation of pp elastic scattering to the beam polarization measurement at RHIC is also discussed.

Guryn, W.

1998-02-01

276

Proton-Induced Fission Cross Section of 181TA  

NASA Astrophysics Data System (ADS)

We have investigated the total fission cross section of 181Ta+ 1H at 1, 0.8, 0.5 and 0.3 GeV with an specific setup at the FRS (FRagment Separator - GSI). The high-accuracy results obtained in this experiment are compared with calculations performed with an intra-nuclear cascade model (INCL v4.1) coupled to a de-excitation code (ABLAv3p). The calculations reproduce the two different models that describe the fission process at high excitation energies: statistical model of Bohr and Wheeler and the dynamical description of the fission process. Data comparison with previous experiments is also included to point out the existing discrepancies with this new results.

Ayyad, Y.; Benlliure, J.; Casarejos, E.; Álvarez-Pol, H.; Bacquias, A.; Boudard, A.; Enqvist, T.; Föhr, V.; Kelic, A.; Kezzar, K.; Leray, S.; Paradela, C.; Pérez-Loureiro, D.; Pleskac, R.; Tarrío, D.

2011-10-01

277

Neutron average cross sections of {sup 237}Np  

SciTech Connect

This work reports {sup 237}Np neutron resonance parameters obtained from the simultaneous analysis of time-of-flight data measured at the GELINA, ORELA, KURRI, and LANSCE facilities. A statistical analysis of these resonances relying on average R-matrix and optical model calculations was used to establish consistent l-dependent average resonance parameters involved in the description of the unresolved resonance range of the {sup 237}Np neutron cross sections. For neutron orbital angular momentum l=0, we obtained an average radiation width =39.3+-1.0 meV, a neutron strength function 10{sup 4}S{sub 0}=1.02+-0.14, a mean level spacing D{sub 0}=0.60+-0.03 eV, and a potential scattering length R{sup '}=9.8+-0.1 fm.

Noguere, G. [Atomic Energy Commission (CEA), DEN Cadarache, F-13108 Saint Paul Les Durance (France)

2010-04-15

278

FREE ANTINEUTRINO ABSORPTION CROSS SECTION. II. EXPECTED CROSS SECTION FROM MEASUREMENTS OF FISSION FRAGMENT ELECTRON SPECTRUM  

Microsoft Academic Search

A measurement of the electron spectrum from the thermal neutron fission ; of U²³⁵ is described. From this spectrum the antineutrino spectrum is ; calculated, and on the basis of the two-component theory of the antineutrino a ; predicted average cross section for the absorption of antineutrinos by protons is ; (6.1 the J-57 engin 1) x 10⁻⁴³ cm²fission. This

R. E. Carter; F. Reines; J. J. Wagner; M. E. Wyman

1959-01-01

279

Measurements of neutron cross sections and isomeric cross section ratios in Se isotopes  

Microsoft Academic Search

The activation cross sections of 14.7 MeV neutron-induced reactions have been measured in Se isotopes. The experimental results have been compared with the predictions of the statistical theory of the compound nucleus. For some reactions it has been possible to determine the isomeric ratios; these ratios have been analysed using the statistical calculation of Huizenga and Vandenbosch, and estimates have

B. Minetti; A. Pasquarelli

1967-01-01

280

SCWR Once-Through Calculations for Transmutation and Cross Sections  

SciTech Connect

It is the purpose of this report to document the calculation of (1) the isotopic evolution and of (2) the 1-group cross sections as a function of burnup of the reference Super Critical Water Reactor (SCWR), in a format suitable for the Fuel Cycle Option Campaign Transmutation Data Library. The reference SCWR design was chosen to be that described in [McDonald, 2005]. Super Critical Water Reactors (SCWR) are intended to operate with super-critical water (i.e. H2O at a pressure above 22 MPa and a temperature above 373oC) as a cooling – and possibly also moderating – fluid. The main mission of the SCWR is to generate lower cost electricity, as compared to current standard Light Water Reactors (LWR). Because of the high operating pressure and temperature, SCWR feature a substantially higher thermal conversion efficiency than standard LWR – i.e. about 45% versus 33%, mostly due to an increase in the exit water temperature from ~300oC to ~500oC – potentially resulting in a lower cost of generated electricity. The coolant remains single phase throughout the reactor and the energy conversion system, thus eliminating the need for pressurizers, steam generators, steam separators and dryers, further potentially reducing the reactor construction capital cost. The SCWR concept presented here is based on existing LWR technology and on a large number of existing fossil-fired supercritical boilers. However, it was concluded in [McDonald, 2005], that: “Based on the results of this study, it appears that the reference SCWR design is not feasible.” This conclusion appears based on the strong sensitivity of the design to small deviations in nominal conditions leading to small effects having a potentially large impact on the peak cladding temperature of some fuel rods. “This was considered a major feasibility issue for the SCWR” [McDonald, 2005]. After a description of the reference SCWR design, the Keno V 3-D single assembly model used for this analysis, as well as the calculated results, are presented. Additionally, the follwing information, presented in the appendixes, is intended to provide enough guidance that a researcher repeating the same task in the future should be able to obtain a vector of nuclei and cross sections ready for insertion into the transmutation library without any need for further instructions: (1) Complete TRITON/KENO-V input used for the analysis; (2) Inputs and detailed description of the usage of the OPUS utility, used to postproces and to extract the nuclei concentrations for the transmutation library; (3) Inputs and detailed description of the usage of the XSECLIST utility, used to postproces and to extract the 1-group cross sections for the transmutation library; (4) Details of an ad-hoc utility program developed to sort the nuclei and cross sections for the transmutation library.

ganda, francesco (090771)

2012-07-01

281

APPARATUS FOR MEASURING TOTAL NEUTRON CROSS SECTIONS  

DOEpatents

An apparatus is described for measuring high-resolution total neutron cross sections at high counting rate in the range above 50-kev neutron energy. The pulsed-beam time-of-flight technique is used to identify the neutrons of interest which are produced in the target of an electrostatic accelerator. Energy modulation of the accelerator . makes it possible to make observations at 100 energy points simultaneously. 761O An apparatus is described for monitoring the proton resonance of a liquid which is particulariy useful in the continuous purity analysis of heavy water. A hollow shell with parallel sides defines a meander chamber positioned within a uniform magnetic fieid. The liquid passes through an inlet at the outer edge of the chamber and through a spiral channel to the central region of the chamber where an outlet tube extends into the chamber perpendicular to the magnetic field. The radiofrequency energy for the monitor is coupled to a coil positioned coaxially with the outlet tube at its entrance point within the chamber. The improvement lies in the compact mechanical arrangement of the monitor unit whereby the liquid under analysis is subjected to the same magnetic field in the storage and sensing areas, and the entire unit is shielded from external electrostatic influences.

Cranberg, L.

1959-10-13

282

Fragmentation cross sections of protonated water clusters  

NASA Astrophysics Data System (ADS)

We have measured fragmentation cross sections of protonated water cluster cations (H2O)n=30-50H+ by collision with water molecules. The clusters have well-defined sizes and internal energies. The collision energy has been varied from 0.5 to 300 eV. We also performed the same measurements on deuterated water clusters (D2O)n=5-45D+ colliding with deuterated water molecules. The main fragmentation channel is shown to be a sequential thermal evaporation of single molecules following an initial transfer of relative kinetic energy into internal energy of the cluster. Unexpectedly, that initial transfer is very low on average, of the order of 1% of collision energy. We evaluate that for direct collisions (i.e., within the hard sphere radius), the probability for observing no fragmentation at all is more than 35%, independently of cluster size and collision energy, over our range of study. Such an effect is well known at higher energies, where it is attributed to electronic effects, but has been reported only in a theoretical study of the collision of helium atoms with sodium clusters in that energy range, where only vibrational excitation occurs.

Zamith, Sébastien; Labastie, Pierre; L'Hermite, Jean-Marc

2012-06-01

283

Electron scattering from trans 1,3-butadiene molecule: cross-sections, oscillator strength and VUV photoabsorption cross-sections  

NASA Astrophysics Data System (ADS)

Electron energy-loss spectra for the butadiene molecule were measured in the scattering angular range of 2.0° to 8.0°, in an energy-loss range from 2 to 50 eV, using 1000 eV incident electrons. The absolute generalized oscillator strength (GOS) and inelastic cross section have been determined for the {tildeX1}˜X1A g ? 11B u transition. The absolute elastic differential cross section was also determined spanning an angular range from 2.0° to 40.0°. From a small angle electron energy-loss spectrum, the optical oscillator distribution (photoabsorption spectrum) for the butadiene molecule was obtained in the 2 to 100 eV photon energy range. Accurate ab initio calculations have been performed, within the First Born Approximation, for generalized oscillator strength (GOS) and excitation energies for the {tildeX1}˜X1A g ? 11B u and {tildeX1}˜X1A g ? 21A g transitions. Our results emphasize the importance of using highly correlated wavefunctions and accurate methodologies in the calculation of the GOS for electron impact-induced electronic transitions in molecules.

Boechat-Roberty, Heloisa Maria; Uhl, Elmar O.; Rodrigues, Flavio N.; Lopes, Maria Cristina A.; Rocco, Maria Luiza M.; Lucas, Carlos A.; Rocha, Alexandre B.; Bielschowsky, Carlos E.; de Souza, Gerardo Gerson B.

2013-02-01

284

Parabolic versus spherical partial cross sections for photoionization excitation of He near threshold  

SciTech Connect

Spherical and parabolic partial cross sections and asymmetry parameters, defined in the ejected electron frame, are presented for photoionization excitation of the helium atom at 0.1 eV above its double ionization threshold. A quantitative law giving the dominant spherical partial wave l{sub dom} for each excitation level n is obtained. The parabolic partial cross sections are shown to satisfy the same approximate selection rules as the related Rydberg series of doubly excited states (K,T){sub n}{sup A}. The analysis of radial and angular correlations reveals the close relationship between double excitation, ionization excitation, and double ionization. Opposite to a widespread belief, the observed value of the asymmetry parameter is shown to result from the interplay of radial correlations and symmetry constraints, irrespective of angular correlations. Finally, the measurement of parabolic partial cross sections is proposed as a challenge to experimentalists.

Bouri, C.; Selles, P.; Malegat, L.; Kwato Njock, M. G. [LIXAM et Federation LUMAT, CNRS et Universite Paris-Sud 11, 91405 Orsay (France); CEPAMOQ, Faculty of Science, University of Douala, P.O. Box 8580, Douala (Cameroon)

2006-09-15

285

Total and partial photoneutron cross sections for Pb isotopes  

NASA Astrophysics Data System (ADS)

Using quasimonochromatic laser-Compton scattering ? rays, total photoneutron cross sections were measured for 206,207,208Pb near neutron threshold with a high-efficiency 4? neutron detector. Partial E1 and M1 photoneutron cross sections along with total cross sections were determined for 207,208Pb at four energies near threshold by measuring anisotropies in photoneutron emission with linearly polarized ? rays. The E1 strength dominates over the M1 strength in the neutron channel where E1 photoneutron cross sections show extra strength of the pygmy dipole resonance in 207,208Pb near the neutron threshold corresponding to 0.32%-0.42% of the Thomas-Reiche-Kuhn sum rule. Several ?N2 units of B(M1)? strength were observed in 207,208Pb just above neutron threshold, which correspond to an M1 cross section less than 10% of the total photoneutron cross section.

Kondo, T.; Utsunomiya, H.; Goriely, S.; Daoutidis, I.; Iwamoto, C.; Akimune, H.; Okamoto, A.; Yamagata, T.; Kamata, M.; Itoh, O.; Toyokawa, H.; Lui, Y.-W.; Harada, H.; Kitatani, F.; Hilaire, S.; Koning, A. J.

2012-07-01

286

Electron collisions with CO: Elastic and vibrational excitation cross sections  

SciTech Connect

Absolute differential elastic and vibrational excitation cross sections up to v=11 were measured for CO in scattering angle ranges extending to 180 deg. at energies between 0.2 and 5 eV (and an elastic measurement at 10 eV). The lowest angles were 0 deg. for inelastic scattering and between 5 deg. and 20 deg. for elastic scattering, depending on energy. Integral cross sections were derived by integrating under the angular distributions and compared with previous beam and swarm measurements. The sum of the integral cross sections agrees very well with the available transmission measurements of the grand total cross section, thus validating the present measurements. The present elastic differential and integral cross sections are in excellent agreement with the best available measurement [Gibson et al., J. Phys. B 29, 3197 (1996)], but the v=1 inelastic cross section is about 25% higher. This could have consequences for simulations of cometary and planetary atmospheres.

Allan, M. [Department of Chemistry, University of Fribourg, chemin du Musee 9, CH-1700 Fribourg (Switzerland)

2010-04-15

287

Determining the Uncertainty on the Total Heavy Flavor Cross Section  

SciTech Connect

We assess the theoretical uncertainties on the total heavy quark cross section. We discuss the importance of the quark mass, the scale choice, the number of light flavors and the parton densities on the estimate of the uncertainty. At first glance, the uncertainty bands on the total charm cross sections obtained by integrating the FONLL inclusive cross section and by integrating the partonic total cross sections appear to be incompatible. We explain how this apparent difference arises and describe how the two results can be reconciled. The small charm quark mass amplifies the effect of varying the other parameters in the calculation, making the uncertainty on the total charm cross section difficult to quantify. On the other hand, the bottom quark total cross section is under much better theoretical control and differences between the two approaches are small.

Vogt, R

2008-07-22

288

High Intensity Nozzle Beam Source for Use in Molecular Total Cross Section Measurements  

Microsoft Academic Search

A nozzle source which produces beams of neutral molecules, a factor of 102 to 103 more intense than that from effusive sources, is described. Further, the velocity distribution from this source is much narrower than that from effusive sources. The properties of the source and a description of its use in total cross section measurements for the case of a

J. G. Skofronick

1967-01-01

289

Double differential cross sections for ionization of water molecules by ion impact  

NASA Astrophysics Data System (ADS)

Single ionization from water molecules by impact of bare ions is studied. Different approximations are employed, within the post and prior versions of the continuum distorted wave-eikonal initial state model, to calculate double differential cross sections. Post-prior discrepancies are observed between theoretical results. The sensitivity of the calculations to the description of the initial bound orbitals is investigated.

Tachino, C. A.; Monti, J. M.; Fojón, O. A.; Champion, C.; Rivarola, R. D.

2013-09-01

290

Next-to-leading order cross sections for tagged reactions  

NASA Astrophysics Data System (ADS)

We extend the phase space slicing method of Giele, Glover and Kosower for performing next-to-leading order jet cross section calculations in two important ways: we show how to include fragmentation functions and how to include massive particles. These extensions allow the application of this method not just to jet cross sections but also to cross sections in which a particular final state particle, including a D or B meson, is tagged.

Keller, Stéphane; Laenen, Eric

1999-06-01

291

Scaling behavior of radiative recombination cross sections and rate coefficients  

Microsoft Academic Search

Direct radiative recombination (RR) cross sections Ï{sup RR} and rate coefficients α{sup RR} are presented for all ions using the scaling property of the cross section in the parameter η={ital Z}{sub eff}\\/({ital ka}â). The RR cross section is defined simply in terms of two parameters, η and the number of electrons {ital N} in the target ion. The RR rate

Daniel J. McLaughlin; Y. Hahn

1991-01-01

292

High E{sub T} jet cross sections at CDF  

SciTech Connect

The inclusive jet cross section for {ital p}{ital {anti p}} collisions at {radical}s = 1.8 TeV as measured by the CDF collaboration will be presented. Preliminary CDF measurements of the {Sigma} E{sub T} cross section at {radical}s = 1.8 TeV and the central inclusive jet cross section at {radical}s = 0.630 TeV will also be shown.

Flaugher, B.; CDF Collaboration

1996-08-01

293

CROSS SECTION NEAR THE H LYMAN a LINE  

Microsoft Academic Search

Molecular oxygen photoabsorption cross sections have been measured at 0.2-A intervals between 1214.0 and 1218.6 A at temperatures of 294, 195, and 82 K. The measured pressure dependence of the cross sections is in satisfactory agreement with earlier observations, but the room temperature cross sections are found to be significantly different from previously reported high-resolution measurements in the Lyman a

J. H. Carver; H. P. Gies; T. I. Hobbs; B. R. Lewis; D. G. McCoy

1977-01-01

294

Measurements of beauty cross sections at the CMS experiment  

NASA Astrophysics Data System (ADS)

The CMS experiment at the Large Hadron Collider has recorded proton-proton collision data at a center of mass energy of 7 TeV during 2010. Several measurements have been made of production cross sections involving the b quark. The open beauty production cross section is presented as a function of muon transverse momentum and pseudorapidity. The mode B ->?D^0 X is studied. Also presented is a ?b integrated cross section measurement.

Bean, Alice

2011-04-01

295

Thermal Neutron Capture Cross Section of Carbon13  

Microsoft Academic Search

The thermal neutron capture cross section of C13 has been determined from the amount of C14 formed in pile-irradiated samples of graphite, barium carbonate, and carbon dioxide. Because of the impurity reaction, N14(n, p)C14, of comparatively high cross section, the results were consistent only when samples were used which were enriched in C13. The average isotopic cross section determined for

G. R. Hennig

1954-01-01

296

Charge exchange cross sections for the Io plasma torus  

SciTech Connect

An impact parameter method for calculating cross sections as a function of incident ion energy is used in conjunction with an improved exchange energy formulation to update several of the charge exchange cross sections currently used in Io plasma torus modeling. New cross sections for S{sup +} + S{sup 2+} {yields} S{sup 2} + S{sup +} and Na{sup +} on neutral targets, useful in analyzing the fast Na jets observed at Io, are also calculated.

McGrath, M.A.; Johnson, R.E. (Univ. of Virginia, Charlottesville (USA))

1989-03-01

297

Estimate of the cross section for thermal neutrons  

NASA Astrophysics Data System (ADS)

Cross section of the thermal neutrons is considered in the framework of the statistical approach to the complicated nuclei. The probability distribution ?( z = ?/?*) to have given cross section ? (determined by fluctuations of resonance positions and widths), where ?* is the cross section for the model of equidistant resonances with the same width, has been calculated. The last quantity can be represented in terms of the neutron strength function for given nuclei. The probability distribution ?( z) is universal for all nuclei.

Petrov, Yu.; Petrov, V.

2013-08-01

298

Scaling properties of proton-nucleus total reaction cross sections  

NASA Astrophysics Data System (ADS)

We study the scaling properties of proton-nucleus total reaction cross sections for stable nuclei and propose an approximate expression in proportion to Z2/3?pptotal+N2/3?pntotal. Based on this expression, we can derive a relation that enables us to predict a total reaction cross section for any stable nucleus within 10% uncertainty at most, using the empirical value of the total reaction cross section of a given nucleus.

Abu-Ibrahim, Badawy; Kohama, Akihisa

2010-05-01

299

Energy dependence of proton-nucleus reaction cross sections  

NASA Astrophysics Data System (ADS)

Reaction-cross-section data for proton-nucleus scattering up to 1 GeV have been analyzed in a black-disk model. Simple phenomenological relations are derived, which make it possible to predict the energy dependence of proton-nucleus reaction cross sections. The relations require only the total cross sections in nucleon-nucleon scattering and the matter densities of the proton and the target nucleus.

Ingemarsson, A.; Lantz, M.

2005-12-01

300

A method for measuring light ion reaction cross-sections  

Microsoft Academic Search

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

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

2005-01-01

301

A cross-sectional ultrasound imaging for measuring body composition  

Microsoft Academic Search

We have developed a measuring system to visualize a complete cross-sectional image of the human extremity using ultrasonography. This system uses several ultrasound probes, and these probes measure fragmentary graphical images of one cross-sectional plane which are then transformed into a complete cross-sectional image. The developed system is superior to other imaging devices in many respects because it is portable,

Kiyotaka Fukumoto; Masayoshi Tsubai; Satoshi Muraki; Osamu Fukuda; Hironori Sato

2007-01-01

302

Investigation of the barrier discharge structure near the electrode with a cylindrical cross section  

SciTech Connect

The approximate analytical correlations allowing for the investigation of the effect of different geometrical and physical parameters on the barrier discharge evolution near the electrode with a cylindrical cross section are obtained. The found correlations make it possible to estimate the time of the barrier discharge existence. New essential peculiarities of the barrier discharge evolution are revealed and verified.

Andreev, V. V., E-mail: andreev_vsevolod@mail.ru; Vasilyeva, L. A.; Matyunin, A. N.; Pichugin, Yu. P. [Chuvash State University (Russian Federation)

2011-12-15

303

Ab initio method for calculating total cross sections  

SciTech Connect

A method for calculating total cross sections, without formally including non-elastic channels, is presented. The idea is to use a one channel T-matrix variational principle with a complex correlation function. The derived T-matrix is therefore not unitary: elastic scattering is calculated from {vert_bar}T{vert_bar}{sup 2}, but total scattering is derived from the imaginary part of T using the optical theorem. The method is applied to the spherically symmetric model of electron-hydrogen scattering. No spurious structure arises; results for {sigma}{sub el} and {sigma}{sub total} are in excellent agreement with calculations of Callaway and Oza. The method has wide potential applicability.

Bhatia, A.K.; Temkin, A. [NASA/GSFC, Greenbelt, MD (United States); Schneider, B.I. [National Science Foundation, Washington, DC (United States)

1993-05-01

304

[ital Ab] [ital initio] method for calculating total cross sections  

SciTech Connect

A method for calculating total cross sections without formally including nonelastic channels is presented. The idea is to use a one channel [ital T]-matrix variational principle with a complex correlation function. The derived [ital T] matrix is therefore not unitary: Elastic scattering is calculated from [vert bar][ital T][vert bar][sup 2], but total scattering is derived from the imaginary part of [ital T] using the optical theorem. The method is applied to the spherically symmetric model of electron-hydrogen scattering. No spurious structure arises; results for [sigma][sub el] and [sigma][sub total] are in excellent agreement with calculations of Callaway and Oza. The method has wide potential applicability.

Bhatia, A.K.; Schneider, B.I.; Temkin, A. (Goddard Space Flight Center, Code 680, NASA, Greenbelt, Maryland 20771 (United States) Physics Division, National Science Foundation, Washington, D.C. 20550 (United States))

1993-03-29

305

Argon plasma modeling with detailed fine-structure cross sections  

SciTech Connect

Our recently reported fully relativistic distorted-wave electron-impact cross sections from the ground and metastable states of argon to various excited fine-structure levels are incorporated in a collisional-radiative model to obtain the population densities for the 3p{sup 5}4s and 3p{sup 5}4p (1s and 2p) fine-structure manifolds for low temperature argon plasmas. Excitation cross sections from the two 3p{sup 5}4s J = 1 resonance levels, 1s{sub 2} and 1s{sub 4}, to the higher lying 2p fine-structure manifold as well as for transitions among individual levels of the 1s and 2p manifolds are also calculated and included in the present model which were not fully considered in any earlier model. Our results for the population densities of the 1s and 2p levels show good agreement with recent measurements. The variation of population densities of all the 1s and 2p levels with electron temperature and density are presented. We have also calculated and compared the intensities for the 750.38 nm (2p{sub 1}{yields} 1s{sub 2}) and 696.54 nm (2p{sub 2}{yields} 1s{sub 5}) lines with recently reported experimental results. The present work suggests that the inclusion of a complete fine-structure description of the electronic processes occurring in the plasma is important for a collisional radiative model, which includes separate 1s and 2p levels.

Gangwar, R. K.; Sharma, L.; Srivastava, R. [Department of Physics, Indian Institute of Technology, Roorkee 247667 (India); Stauffer, A. D. [Department of Physics and Astronomy, York University, Toronto M3J 1P3 (Canada)

2012-03-01

306

Partial Photoneutron Cross Sections for the Isomeric State Tam180  

NASA Astrophysics Data System (ADS)

Photoneutron cross sections for Ta181(?,n)Tam180 were determined from simultaneous measurements of total cross sections (?tot) and ground-state cross sections (?gs) for Ta180 in photodisintegration of Ta181 with laser Compton-backscattered ? rays. Techniques of direct neutron counting and photoactivation were used for the measurement of ?tot and ?gs, respectively. The partial cross sections for the isomeric state serves as a novel probe of the nuclear level density of Ta180. Implications for the p- and s-process nucleosynthesis of Tam180 are given.

Goko, S.; Utsunomiya, H.; Goriely, S.; Makinaga, A.; Kaihori, T.; Hohara, S.; Akimune, H.; Yamagata, T.; Lui, Y.-W.; Toyokawa, H.; Koning, A. J.; Hilaire, S.

2006-05-01

307

Nucleon-Nucleon Cross Sections in Isospin Asymmetric Nuclear Matter  

NASA Astrophysics Data System (ADS)

The in medium nucleon-nucleon (NN) cross sections in isospin asymmetric nuclear matter at various densities are investigated in the framework of Brueckner-Hartree-Fock theory with the Bonn B two-body nucleon-nucleon interaction supplemented with a new version microscopic three-body force (TBF). The TBF depresses the amplitude of cross sections at high density region. At low densities, the proton-proton and neutron-neutron cross sections decrease while the proton-neutron one increases as the asymmetry increases. But the sensitivity of the NN cross sections to the isospin asymmetry are reduced with the increasing density.

Zhang, Hongfei; Dong, Jianmin; Zuo, Wei; Lombardo, Umberto

308

Positive Scattering Cross Sections using Constrained Least Squares  

SciTech Connect

A method which creates a positive Legendre expansion from truncated Legendre cross section libraries is presented. The cross section moments of order two and greater are modified by a constrained least squares algorithm, subject to the constraints that the zeroth and first moments remain constant, and that the standard discrete ordinate scattering matrix is positive. A method using the maximum entropy representation of the cross section which reduces the error of these modified moments is also presented. These methods are implemented in PARTISN, and numerical results from a transport calculation using highly anisotropic scattering cross sections with the exponential discontinuous spatial scheme is presented.

Dahl, J.A.; Ganapol, B.D.; Morel, J.E.

1999-09-27

309

Derivation of reaction cross sections from experimental elastic backscattering probabilities  

NASA Astrophysics Data System (ADS)

The relationship between the backward elastic scattering probabilities and the reaction cross sections is derived. This is a very simple and useful method to extract reaction cross sections for heavy-ion systems. We compare the results of our method with those that use the traditional full elastic scattering angular distributions for several systems at energies near and above the Coulomb barrier. From the calculated reaction and capture cross sections that use the present method, we derive the cross sections of other mechanisms for weak nearly spherical systems.

Sargsyan, V. V.; Adamian, G. G.; Antonenko, N. V.; Gomes, P. R. S.

2013-10-01

310

Neutron-capture Cross Sections from Indirect Measurements  

SciTech Connect

Cross sections for compound-nuclear reactions play an important role in models of astrophysical environments and simulations of the nuclear fuel cycle. Providing reliable cross section data remains a formidable task, and direct measurements have to be complemented by theoretical predictions and indirect methods. The surrogate nuclear reactions method provides an indirect approach for determining cross sections for reactions on unstable isotopes, which are difficult or impossible to measure otherwise. Current implementations of the method provide useful cross sections for (n,f) reactions, but need to be improved upon for applications to capture reactions.

Escher, J E; Burke, J T; Dietrich, F S; Ressler, J J; Scielzo, N D; Thompson, I J

2011-10-18

311

Neutron-capture cross sections from indirect measurements  

NASA Astrophysics Data System (ADS)

Cross sections for compound-nuclear reactions reactions play an important role in models of astrophysical environments and simulations of the nuclear fuel cycle. Providing reliable cross section data remains a formidable task, and direct measurements have to be complemented by theoretical predictions and indirect methods. The surrogate nuclear reactions method provides an indirect approach for determining cross sections for reactions on unstable isotopes, which are difficult or impossible to measure otherwise. Current implementations of the method provide useful cross sections for (n,f) reactions, but need to be improved upon for applications to capture reactions.

Escher, J. E.; Burke, J. T.; Dietrich, F. S.; Ressler, J. J.; Scielzo, N. D.; Thompson, I. J.

2012-02-01

312

Report on 241,242Am(n,x) surrogate cross section measurement  

SciTech Connect

The main goal of this measurement is to determine the {sup 242}Am(n,f) and {sup 241}Am(n,f) cross sections via the surrogate {sup 243}Am. Gamma-ray data was also collected for the purpose of measuring the (n,2n) cross-sections. The experiment was conducted using the STARS/LIBERACE experimental facility located at the 88 Inch Cyclotron at Lawrence Berkeley National Laboratory the first week of February 2011. A description of the experiment and status of the data analysis follow.

Burke, J T; Ressler, J J; Gostic, J; Henderson, R A; Bernstein, L A; Escher, J E; Bleuel, D; Kritcher, A; Matoon, C; Scielzo, N D; Stoyer, M A

2011-02-16

313

Effect of momentum dependent interactions and nucleonic cross-section on directed flow (v1)  

NASA Astrophysics Data System (ADS)

The descriptive analysis for the effect of momentum dependent interactions and nucleonic cross-section (isospin dependent and isospin-independent) on the neutron-proton directed flow (v1), within the framework of the isospin dependent quantum molecular dynamics model is presented. Our study shows that, the directed flow of both neutrons and protons is affected by the momentum dependence of nuclear equation of state and the isospin dependence of nucleon-nucleon cross-section. A soft momentum dependent (SM) equation of state is found to be more compatible with the experimental data.

Jain, Anupriya; Vinayak, Karan Singh; Kumar, Suneel

2013-07-01

314

Extracting GT matrix elements from (p,n) cross sections  

NASA Astrophysics Data System (ADS)

Nuclear transition matrix elements for the spin-isospin (Gamow-Teller) transition operator have been of considerable interest for several decades as indicators of nuclear structure. Knowledge of these matrix elements is also of vital importance in astrophysical calculations in connection with the general problem of nucleosynthesis, and, more specifically, in connection with the evolution of supernovae. Furthermore, knowledge of these matrix elements is required for the calculation of neutrino absorption cross sections for nuclei used as neutrino detectors. The most precise measures of spin-isospin matrix elements come from beta-decay lifetimes and endpoints with additional information, in some cases of mixed Fermi-GT transitions, from angular correlation measurements. Unfortunately, most transitions of special interest are not energetically accessible to beta decay. It is also well known that the nuclear shell model fails badly for calculating these matrix elements. The best alternative we have is to use the (p,n) reaction which was suggested at least 30 years ago. [1] The (p,n) reaction connects exactly the same nuclear states as beta decay, but to some extent different operators can come into play so that (p,n) cross sections are not exactly proportional to beta decay matrix elements. Considerable experimental effort has now been put into the problem of determining how accurately GT matrix elements can be deduced from (p,n) reaction data which in some cases includes polarization transfer measurements. The body of systematic measurements shows a good correlation between beta decay and (p,n) determinations of matrix elements for transitions between spin-0 and spin-1 states, but problems still exist for odd-A nuclei where the initial and final states necessarily have non-zero spins. Additional measurements are still in progress.

Goodman, Charles D.

1994-09-01

315

Fine structure of high-energy absorption cross sections for black holes  

NASA Astrophysics Data System (ADS)

The high-energy absorption cross section of the Schwarzschild black hole is well approximated, in the eikonal regime, by the sum of two terms: the geometrical cross section of the black hole photon sphere and the contribution of a sinc function involving the geometrical characteristics (orbital period and Lyapunov exponent) of the null unstable geodesics lying on this photon sphere. From a numerical analysis, we show that, beyond the eikonal description, this absorption cross section presents a simple fine structure. We then describe it analytically by using Regge pole techniques and interpret it in geometrical terms. We naturally extend our analysis to arbitrary static spherically symmetric black holes endowed with a photon sphere and we then apply our formalism to Schwarzschild-Tangherlini and Reissner-Nordström black holes. Finally, on the example of the Schwarzschild black hole, we show numerically that a complicated hyperfine structure lying beyond the fine structure can also be observed.

Décanini, Yves; Folacci, Antoine; Raffaelli, Bernard

2011-09-01

316

Isotopic dependence of the cross section for the induced fission of heavy nuclei  

SciTech Connect

The cross sections for the induced fission of {sup 211-223}Ra, {sup 203-211}Rn, and {sup 221-231}Th nuclei undergoing peripheral collisions with {sup 208}Pb nuclei are calculated on the basis of the statistical model. The role of the N = 126 neutron shell is studied. The level density in excited nuclei is determined within the Fermi gas model and a model that takes into account the collective enhancement of the level density. The inclusion of a particle-hole excitation in addition to a collective Coulomb excitation makes it possible to obtain a satisfactory description of experimental cross sections for the fission of radium isotopes. The calculated ratios of the cross sections for the induced fission of {sup 236}U ({sup 237}U) and {sup 238}U ({sup 239}U) nuclei agree with experimental data.

Bolgova, O. N.; Adamian, G. G.; Antonenko, N. V.; Zubov, A. S.; Ivanova, S. P. [Joint Institute for Nuclear Research (Russian Federation); Scheid, W. [Justus-Liebig-Universitaet, Institut fuer Theoretische Physik (Germany)

2009-06-15

317

Towards a prediction of fission cross sections on the basis of microscopic nuclear inputs  

NASA Astrophysics Data System (ADS)

Recently, a sound description of some of the basic nuclear ingredients required in the calculation of fission cross sections has been obtained. These concern in particular fission barriers within the Hartree-Fock-Bogoliubov (HFB) method and nuclear level densities at the fission saddle points within the combinatorial model. Both ingredients are determined coherently, the nuclear level densities being estimated on the basis of the single-particle scheme and pairing strength of the same mean field model that was used to determine the fission saddle points. The aim of the present study is to evaluate the quality of such inputs in the calculation of fission cross sections. Although the barrier height can still not be predicted with an accuracy better than about 700 keV, the use of the full HFB fission path and the corresponding WKB calculation of the probability to penetrate the fission barrier clearly provides a better way to estimate fission cross section in comparison with highly parametrized phenomenological models, when no experimental data is available. It is shown that a satisfactory estimate of the fission cross section for nonenergy applications can be achieved with a global renormalization of the barrier height and the microscopic nuclear level densities at the fission saddle points. Good agreement with experimental data can be obtained if both the fission barrier heights and level densities are independently renormalized. The resulting barrier heights required to reproduce experimental cross sections are found to be smaller by a few hundred keV with respect to previous analyses.

Goriely, S.; Hilaire, S.; Koning, A. J.; Sin, M.; Capote, R.

2009-02-01

318

14 MeV Neutrons SEU Cross Sections in Deep Submicron Devices Calculated Using Heavy Ion SEU Cross Sections  

Microsoft Academic Search

Ananalyticalmodelisdevelopedtocalculateneutron- induced SEU cross section in deep submicron devices from heavy ion SEU cross section. It is based on the energy spectra of the sec- ondaries of nuclear reactions which yields the LET dis- tribution of all secondary ions. The integration of this distribution function with the measured heavy ion cross section vs. LET yields then-SEUcrosssection.Tomakethecalculationsstraightforward, the neutron-induced LET distribution

Avner Haran; Joseph Barak; Leo Weissman; David David; Eitan Keren

2011-01-01

319

In-medium nucleon-nucleon cross section and its effect on total nuclear reaction cross section  

Microsoft Academic Search

A phenomenological formula for in-medium nucleon-nucleon cross section is presented, in which nuclear matter density and incident energy dependencies are included. This formula is used to study total nuclear reaction cross section based on Coulomb-modified Glauber model. The calculated results can reproduce experimental total reaction cross section induced by the stable nuclei and the exotic nuclei over a wide energy

Cai Xiangzhou; Feng Jun; Shen Wenqing; Ma Yugang; Wang Jiansong; Ye Wei

1998-01-01

320

Comparison between the activation cross sections and integrated cross sections for the radiative capture of 14 MeV neutrons  

Microsoft Academic Search

Cross sections obtained by the integration of prompt gamma-ray spectra from the radiative capture of 14 MeV neutrons in a series of elements are presented and compared wilh the activation cross sections reported by different authors. In contrast to the activation cross-section values, which are scattered between 1 mb and 10 mb as a function of mass number, the integrated

F. Cvelbar; A. Hudoklin; M. Potokar

1970-01-01

321

Muscle fibre type distribution, muscle cross-sectional area and maximal voluntary strength in humans.  

PubMed

The relationship between maximum voluntary concentric strength, muscle fibre type distribution and muscle cross-sectional areas were examined in 23 subjects (7 female and 11 male phys. ed. students as well as 5 male bodybuilders). Maximal knee and elbow extension as well as elbow flexion torque at the angular velocities 30, 90 and 180 degrees per second was measured. Muscle biopsies were taken from vastus lateralis and m. triceps brachii. The muscle cross-sectional area of the thigh and upper arm was measured with computed tomography scanning. The maximal torque correlated strongly to the muscle cross-sectional area times an approximative measure on the lever arm (body height). Maximal tension developed per unit of muscle cross-sectional area did not correlate significantly with per cent type I fibre area and did not differ between the female and male students or bodybuilders. Neither did the relative decrease in torque with increasing contraction velocity show any significant relationship to the per cent type I fibre area. The total number of muscle fibres was estimated by dividing the muscle cross-sectional area with the mean fibre area of m. triceps brachii. The number of fibres did not seem to differ between the sexes. PMID:6223509

Schantz, P; Randall-Fox, E; Hutchison, W; Tydén, A; Astrand, P O

1983-02-01

322

Microscopic Calculation of Absolute Values of Two-nucleon Transfer Cross Sections  

SciTech Connect

Arguably, the greatest achievement of many-body physics in the fifties was that of developing the tools for a complete description and a thorough understanding of superconductivity in metals. At the basis of it one finds BCS theory and the Josephson effect. The first recognized the central role played by the appearance of a macroscopic coherent field usually viewed as a condensate of strongly overlapping Cooper pairs, the quasiparticle vacuum. The second made it clear that a true gap is not essential for such a state of matter to exist, but rather a finite expectation value of the pair field. Consequently, the specific probe to study the superconducting state is Cooper pair tunneling. Important progress in the understanding of pairing in atomic nuclei may arise from the systematic study of two-particle transfer reactions. Although this subject of research started about the time of the BCS papers, the quantitative calculation of absolute cross sections taking properly into account the full non-locality of the Cooper pairs (correlation length much larger than nuclear dimensions) is still an open question. In what follows we present results obtained, within a second order DWBA framework, of two-nucleon transfer reactions induced both by heavy and light ions. The calculations were carried out making use of software specifically developed for this purpose. It includes sequential, simultaneous and non-orthogonality contributions to the process. Microscopic form factors are used which take into account the relevant structure aspects of the process, such as the nature of the single-particle wavefunctions, the spectroscopic factors, and the interaction potential responsible for the transfer. Overall agreement with the experimental absolute values of the differential cross section is obtained without any free parameter.

Potel, G. [Dipartimento di Fisica, Universita di Milano, Via Celoria 16, 20133 Milano (Italy); INFN, Sezione di Milano Via Celoria 16, 20133 Milano (Italy); Bayman, B. F. [School of Physics and Astronomy, University of Minnesota, Minneapolis, Minnesota 55455 (United States); Barranco, F. [Departamento de Fisica Aplicada III, Universidad de Sevilla, Escuela Superior de Ingenieros, Sevilla, 41092 Camino de los Descubrimientos s/n (Spain); Vigezzi, E. [INFN, Sezione di Milano Via Celoria 16, 20133 Milano (Italy); Broglia, R. A. [Dipartimento di Fisica, Universita di Milano, Via Celoria 16, 20133 Milano (Italy); Niels Bohr Institute, University of Copenhagen, Blegdamsvej 17, 2100 Copenhagen Oe (Denmark)

2009-08-26

323

Electron and positron atomic elastic scattering cross sections  

NASA Astrophysics Data System (ADS)

A method was developed to calculate the total and differential elastic-scattering cross sections for incident electrons and positrons in the energy range from 0.01eV to 1MeV for atoms of /Z=1-100. For electrons, hydrogen, helium, nitrogen, oxygen, krypton, and xenon, and for positrons, helium, neon, and argon atoms were considered for comparison with experimental data. First, the variationally optimized atomic static potentials were calculated for each atom by solving the Dirac equations for bound electron states. Second, the Dirac equations for a free electron or positron are solved for an atom using the previously calculated static potential accomplished (in the case of electrons) by ``adjusted'' Hara's exchange potential for a free-state particle. Additional to the exchange effects, the charge cloud polarization effects are considered applying the correlation-polarization potential of O'Connell and Lane (with correction of Padial and Norcross) for incident electrons, and of Jain for incident positrons. The total, cutoff and differential elastic-scattering cross sections are calculated for incident electrons and positrons with the help of the relativistic partial wave analysis. The solid state effects for scattering in solids are described by means of a muffin-tin model, i.e. the potentials of neighboring atoms are superpositioned in such a way that the resulting potential and its derivative are zero in the middle distance between the atoms. The potential of isolated atom is calculated up to the radius at which the long-range polarization potential becomes a value of -10-8.

Stepanek, Jiri

2003-02-01

324

The synchrotron and cyclo-synchrotron absorption cross-section  

Microsoft Academic Search

The usefulness of the concept of a cross section for the synchrotron and the cyclosynchrotron absorption process is emphasized. It is shown that the previously known relation between the cross section and the single particle emissivity is most easily derived by applying the Einstein coefficients and their relations to a system with three energy levels. Using this relation and known

Gabriele Ghisellini; Roland Svensson

1991-01-01

325

Incoherent scattering cross sections for some ions of solar abundance  

SciTech Connect

Incoherent scattering cross sections are calculated in a relativistic formalism for a number of ions abundant in the solar atmosphere. It is argued that such cross sections are necessary for properly calculating Compton scattering and radiation transport in this or similar environments.

Kahane, Sylvian [Physics Department, Nuclear Research Center Negev, PO Box 9001, 84190 Beer Sheva (Israel)]. E-mail: skahane@bgu.ac.il

2007-03-15

326

Comparison between EISCAT UHF and VHF backscattering cross section  

Microsoft Academic Search

We present a comparison between the backscattering cross sections at 224 and 933 MHz measured with European Incoherent Scatter (EISCAT) radars during the passage of a discrete arc. It shows a difference of 2 orders of magnitude which cannot simply be explained by normal thermal ionospheric density fluctuations. We claim that the observed difference in the scattering cross sections is

B. Cabrit; H. Opgenoorth; W. Kofman

1996-01-01

327

A New Technique To Investigate Total Reaction Cross Sections  

SciTech Connect

We analyze the total reaction cross sections of several systems, especially weakly bound systems, by the use of a recently developed technique. We show a systematic behavior for the different systems, with larger reaction cross sections for systems with halo nuclei as projectiles.

Shorto, J. M. B.; Gomes, P. R. S.; Lubian, J. [Instituto de Fisica, Universidade Federal Fluminense, Av. Litoranea s/n, Niteroi, 24210-340 (Brazil); Canto, L. F. [Instituto de Fisica, Universidade Federal do Rio de Janeiro, CP 68528, Rio de Janeiro, 21941-972 (Brazil); Chamon, L. C. [Instituto de Fisica, Universidade de Sao Paulo, C.P. 66318, Sao Paulo, 05315-970 (Brazil)

2010-08-04

328

Criteria for the selection of dosimetry cross sections.  

SciTech Connect

This paper defines a process for selecting dosimetry-quality cross sections. The recommended cross-section evaluation depends on screening high-quality evaluations with quantified uncertainties, down-selecting based on comparison to experiments in standard neutron fields, and consistency checking in reference neutron fields. This procedure is illustrated for the {sup 23}Na(n,{gamma}){sup 24}Na reaction.

Griffin, Patrick Joseph

2003-07-01

329

Extraction of Asymptotic Nucleon Cross Sections from Deuterium Data.  

National Technical Information Service (NTIS)

The effect of Fermi motion on the extraction of asymptotic total neutron cross sections from deuterium data is examined in some detail. Particular attention is paid to the threshold condition on the nucleon cross sections. Using realistic hard-core wave f...

W. B. Atwood G. B. West

1972-01-01

330

Optimizing waveguide cross sections with respect to power handling capability  

Microsoft Academic Search

The problem of optimizing power transmission through uniform perfectly conducting waveguides of double symmetric cross section is discussed. Using an efficiency factor specifically created for single-mode propagation in uniform waveguides, the authors previously developed a unique method of geometric parametrization that determines the waveguide cross-sectional size and shape resulting in maximum power transmission between a source and receiver. Here they

Charles S. Kenney; P. L. Overfelt

1992-01-01

331

Total Nuclear Photoabsorption Cross Sections and the Levinger's Factor.  

National Technical Information Service (NTIS)

The Mainz group data on total photoabsorption cross sections of lithium, beryllium, carbon, oxygen, aluminium and calcium, in the energy range 40-150 MeV, are analysed. It is shown that the available cross section data provide physical evidence for an inc...

O. A. P. Tavares J. D. Pinheiro Filho

1979-01-01

332

First measurement of the charged current cross section at HERA  

NASA Astrophysics Data System (ADS)

The cross section of the charged current process e-p --> ve + hadrons is measured at HERA for transverse momenta of the hadron system larger than 25 GeV. The size of the cross section exhibits the W propagator. Supported by the Swiss National Science Foundation.

Ahmed, T.; Andreev, V.; Andrieu, B.; Appuhn, R.-D.; Arpagaus, M.; Babaev, A.; Bán, J.; Baranov, P.; Barrelet, E.; Bartel, W.; Barth, M.; Bassler, U.; Beck, H. P.; Behrend, H.-J.; Belousov, A.; Berger, Ch.; Bergstein, H.; Bernardi, G.; Bernet, R.; Bertrand-Coremans, G.; Besançon, M.; Biddulph, P.; Bizot, J. C.; Blobel, V.; Borras, K.; Boudry, V.; Braemer, A.; Brasse, F.; Braunschweig, W.; Brisson, V.; Bruncko, D.; Brune, C.; Büngener, L.; Bürger, J.; Büsser, F. W.; Buniatian, A.; Burke, S.; Buschhorn, G.; Campbell, A. J.; Carli, T.; Charles, F.; Clarke, D.; Clegg, A. B.; Colombo, M.; Coughlan, J. A.; Courau, A.; Coutures, Ch.; Cozzika, G.; Criegee, L.; Cussans, D. G.; Cvach, J.; Dagoret, S.; Dainton, J. B.; Danilov, M.; Dann, A. W. E.; Dau, W. D.; Daum, K.; David, M.; Deffur, E.; Delcourt, B.; del Buono, L.; de Roeck, A.; de Wolf, E.; Dollfus, C.; Dowell, J. D.; Dreis, H. B.; Duboc, J.; Düllmann, D.; Dünger, O.; Duhm, H.; Ebert, J.; Ebert, T. R.; Eckerlin, G.; Efremenko, V.; Egli, S.; Ehrlichmann, H.; Eichenberger, S.; Eichler, R.; Eisele, F.; Eisenhandler, E.; Ellison, R. J.; Elsen, E.; Erdmann, M.; Evrard, E.; Favart, L.; Fedotov, A.; Feeken, D.; Felst, R.; Feltesse, J.; Ferencei, J.; Ferrarotto, F.; Flamm, K.; Flauger, W.; Fleischer, M.; Flieser, M.; Flügge, G.; Fomenko, A.; Fominykh, B.; Forbush, M.; Formánek, J.; Foster, J. M.; Franke, G.; Fretwurst, E.; Gabathuler, E.; Gamerdinger, K.; Garvey, J.; Gayler, J.; Gebauer, M.; Gellrich, A.; Genzel, H.; Gerhards, R.; Goerlach, U.; Goerlich, L.; Gogitidze, N.; Goldberg, M.; Goldner, D.; Goodall, A. M.; Gorelov, I.; Goritchev, P.; Grab, C.; Grässler, H.; Grässler, R.; Greenshaw, T.; Grindhammer, G.; Gruber, C.; Haack, J.; Haidt, D.; Hajduk, L.; Hamon, O.; Hampel, M.; Hanlon, E. M.; Hapke, M.; Haynes, W. J.; Heatherington, J.; Hedberg, V.; Heinzelmann, G.; Henderson, R. C. W.; Henschel, H.; Herma, R.; Herynek, I.; Hildesheim, W.; Hill, P.; Hilton, C. D.; Hladký, J.; Hoeger, K. C.; Höppner, M.; Huet, Ph.; Hufnagel, H.; Ibbotson, M.; Itterbeck, H.; Jabiol, M.-A.; Jacholkowska, A.; Jacobsson, C.; Jaffre, M.; Janoth, J.; Jansen, T.; Jönsson, L.; Johannsen, K.; Johnson, D. P.; Johnson, L.; Jung, H.; Kalmus, P. I. P.; Kant, D.; Kazarian, S.; Kaschowitz, R.; Kasselmann, P.; Kathage, U.; Kaufmann, H. H.; Kenyon, I. R.; Kermiche, S.; Keuker, C.; Kiesling, C.; Klein, M.; Kleinwort, C.; Knies, G.; Ko, W.; Köhler, T.; Kolanoski, H.; Kole, F.; Kolya, S. D.; Korbel, V.; Korn, M.; Kostka, P.; Kotelnikov, S. K.; Krasny, M. W.; Krehbiel, H.; Krücker, D.; Krüger, U.; Krüner-Marquis, M.; Kubenka, J. P.; Küster, H.; Kuhlen, M.; Kur?a, T.; Kurzhöfer, J.; Kuznik, B.; Lacour, D.; Lamarche, F.; Lander, R.; Landon, M. P. J.; Lange, W.; Lanius, P.; Laporte, J. F.; Lebedev, A.; Leverenz, C.; Levonian, S.; Ley, Ch.; Lindner, A.; Lindström, G.; Linsel, F.; Lipinski, J.; Loch, P.; Lohmander, H.; Lopez, G. C.; Lüers, D.; Lüke, D.; Magnussen, N.; Malinovski, E.; Mani, S.; Marage, P.; Marshall, R.; Martens, J.; Martin, R.; Martyn, H.-U.; Martyniak, J.; Masson, S.; Mavroidis, A.; Maxfield, S. J.; McMahon, S. J.; Mehta, A.; Meier, K.; Mercer, D.; Merz, T.; Meyer, C. A.; Meyer, H.; Meyer, J.; Mikocki, S.; Milone, V.; Milstead, D.; Moreau, F.; Morris, J. V.; Müller, G.; Murín, P.; Nagovizin, V.; Naroska, B.; Naumann, Th.; Nawrath, G.; Newman, P. R.; Newton, D.; Neyret, D.; Nguyen, H. K.; Niebergall, F.; Niebuhr, C.; Nisius, R.; Nowak, G.; Noyes, G. W.; Nyberg-Werther, M.; Oberlack, H.; Obrock, U.; Olsson, J. E.; Panitch, A.; Pascaud, C.; Patel, G. D.; Peppel, E.; Perez, E.; Phillips, J. P.; Pichler, Ch.; Pitzl, D.; Pope, G.; Prell, S.; Prosi, R.; Rädel, G.; Raupach, F.; Reimer, P.; Reinshagen, S.; Ribarics, P.; Riech, V.; Riedlberger, J.; Riess, S.; Rietz, M.; Robertson, S. M.; Robmann, P.; Roosen, R.; Rosenbauer, K.; Rostovtsev, A.; Royon, C.; Rüter, K.; Ruffer, M.; Rusakov, S.; Rybicki, K.; Sahlmann, N.; Sanchez, E.; Sankey, D. P. C.; Savitsky, M.; Schacht, P.; Schleper, P.; von Schlippe, W.; Schmidt, C.; Schmidt, D.; Schöning, A.; Schröder, V.; Schulz, M.; Schwab, B.; Schwind, A.; Seehausen, U.; Sefkow, F.; Sell, R.; Semenov, A.; Shekelyan, V.; Sheviakov, I.; Shooshtari, H.; Shtarkov, L. N.; Siegmon, G.; Siewert, U.; Sirois, Y.; Skillicorn, I. O.; Smirnov, P.; Smith, J. R.; Soloviev, Y.; Spitzer, H.; Staroba, P.; Steenbock, M.; Steffen, P.; Steinberg, R.; Stella, B.; Stephens, K.; Stier, J.; Stiewe, J.; Stösslein, U.; Strachota, J.; Straumann, U.; Struczinski, W.; Sutton, J. P.; Tapprogge, S.; Taylor, R. E.; Tchernyshov, V.; Thiebaux, C.; Thompson, G.; Tichomirov, I.; Truöl, P.; Turnau, J.; Tutas, J.; Usik, A.; Valkar, S.; Valkarova, A.; Vallée, C.; van Esch, P.; van Mechelen, P.; Vartapetian, A.; Vazdik, Y.; Vecko, M.; Verrecchia, P.; Villet, G.; Wacker, K.

1994-03-01

333

Scattering from parallel metallic cylinders with arbitrary cross sections  

Microsoft Academic Search

The integral equations for scattering by a set of parallel metallic cylinders, each cylinder of arbitrary cross section, are solved directly by means of a digital computer program giving the current distribution induced on the scatterer surfaces, the scattering cross section vs azimuthal angle, and the induced field ratio (IFR) for both parallel and perpendicularly polarized incident waves. The present

MOGENS G. ANDREASEN

1964-01-01

334

First measurement of the charged current cross section at HERA  

Microsoft Academic Search

The cross section of the charged current process e-p --> ve + hadrons is measured at HERA for transverse momenta of the hadron system larger than 25 GeV. The size of the cross section exhibits the W propagator. Supported by the Swiss National Science Foundation.

T. Ahmed; V. Andreev; B. Andrieu; R.-D. Appuhn; M. Arpagaus; A. Babaev; J. Bán; P. Baranov; E. Barrelet; W. Bartel; M. Barth; U. Bassler; H. P. Beck; H.-J. Behrend; A. Belousov; Ch. Berger; H. Bergstein; G. Bernardi; R. Bernet; G. Bertrand-Coremans; M. Besançon; P. Biddulph; J. C. Bizot; V. Blobel; K. Borras; V. Boudry; A. Braemer; F. Brasse; W. Braunschweig; V. Brisson; D. Bruncko; C. Brune; L. Büngener; J. Bürger; F. W. Büsser; A. Buniatian; S. Burke; G. Buschhorn; A. J. Campbell; T. Carli; F. Charles; D. Clarke; A. B. Clegg; M. Colombo; J. A. Coughlan; A. Courau; Ch. Coutures; G. Cozzika; L. Criegee; D. G. Cussans; J. Cvach; S. Dagoret; J. B. Dainton; M. Danilov; A. W. E. Dann; W. D. Dau; K. Daum; M. David; E. Deffur; B. Delcourt; L. del Buono; A. de Roeck; E. de Wolf; C. Dollfus; J. D. Dowell; H. B. Dreis; J. Duboc; D. Düllmann; O. Dünger; H. Duhm; J. Ebert; T. R. Ebert; G. Eckerlin; V. Efremenko; S. Egli; H. Ehrlichmann; S. Eichenberger; R. Eichler; F. Eisele; E. Eisenhandler; R. J. Ellison; E. Elsen; M. Erdmann; E. Evrard; L. Favart; A. Fedotov; D. Feeken; R. Felst; J. Feltesse; J. Ferencei; F. Ferrarotto; K. Flamm; W. Flauger; M. Fleischer; M. Flieser; G. Flügge; A. Fomenko; B. Fominykh; M. Forbush; J. Formánek; J. M. Foster; G. Franke; E. Fretwurst; E. Gabathuler; K. Gamerdinger; J. Garvey; J. Gayler; M. Gebauer; A. Gellrich; H. Genzel; R. Gerhards; U. Goerlach; L. Goerlich; N. Gogitidze; M. Goldberg; D. Goldner; A. M. Goodall; I. Gorelov; P. Goritchev; C. Grab; H. Grässler; T. Greenshaw; G. Grindhammer; C. Gruber; J. Haack; D. Haidt; L. Hajduk; O. Hamon; M. Hampel; E. M. Hanlon; M. Hapke; W. J. Haynes; J. Heatherington; V. Hedberg; G. Heinzelmann; R. C. W. Henderson; H. Henschel; R. Herma; I. Herynek; W. Hildesheim; P. Hill; C. D. Hilton; J. Hladký; K. C. Hoeger; M. Höppner; Ph. Huet; H. Hufnagel; M. Ibbotson; H. Itterbeck; M.-A. Jabiol; A. Jacholkowska; C. Jacobsson; M. Jaffre; J. Janoth; T. Jansen; L. Jönsson; K. Johannsen; D. P. Johnson; L. Johnson; H. Jung; P. I. P. Kalmus; D. Kant; S. Kazarian; R. Kaschowitz; P. Kasselmann; U. Kathage; H. H. Kaufmann; I. R. Kenyon; S. Kermiche; C. Keuker; C. Kiesling; M. Klein; C. Kleinwort; G. Knies; W. Ko; T. Köhler; H. Kolanoski; F. Kole; S. D. Kolya; V. Korbel; M. Korn; P. Kostka; S. K. Kotelnikov; M. W. Krasny; H. Krehbiel; D. Krücker; U. Krüger; M. Krüner-Marquis; J. P. Kubenka; H. Küster; M. Kuhlen; T. Kurca; J. Kurzhöfer; B. Kuznik; D. Lacour; F. Lamarche; R. Lander; M. P. J. Landon; W. Lange; P. Lanius; J. F. Laporte; A. Lebedev; C. Leverenz; S. Levonian; Ch. Ley; A. Lindner; G. Lindström; F. Linsel; J. Lipinski; P. Loch; H. Lohmander; G. C. Lopez; D. Lüers; D. Lüke; N. Magnussen; E. Malinovski; S. Mani; P. Marage; R. Marshall; J. Martens; R. Martin; H.-U. Martyn; J. Martyniak; S. Masson; A. Mavroidis; S. J. Maxfield; S. J. McMahon; A. Mehta; K. Meier; D. Mercer; T. Merz; C. A. Meyer; H. Meyer; J. Meyer; S. Mikocki; V. Milone; D. Milstead; F. Moreau; J. V. Morris; G. Müller; P. Murín; V. Nagovizin; B. Naroska; Th. Naumann; G. Nawrath; P. R. Newman; D. Newton; D. Neyret; H. K. Nguyen; F. Niebergall; C. Niebuhr; R. Nisius; G. Nowak; G. W. Noyes; M. Nyberg-Werther; H. Oberlack; U. Obrock; J. E. Olsson; A. Panitch; C. Pascaud; G. D. Patel; E. Peppel; E. Perez; J. P. Phillips; Ch. Pichler; D. Pitzl; G. Pope; S. Prell; R. Prosi; G. Rädel; F. Raupach; P. Reimer; S. Reinshagen; P. Ribarics; V. Riech; J. Riedlberger; S. Riess; M. Rietz; S. M. Robertson; P. Robmann; R. Roosen; K. Rosenbauer; A. Rostovtsev; C. Royon; K. Rüter; M. Ruffer; S. Rusakov; K. Rybicki; N. Sahlmann; E. Sanchez; D. P. C. Sankey; M. Savitsky; P. Schacht; P. Schleper; W. von Schlippe; C. Schmidt; D. Schmidt; A. Schöning; V. Schröder; M. Schulz; B. Schwab; A. Schwind; U. Seehausen; F. Sefkow; R. Sell; A. Semenov; V. Shekelyan; I. Sheviakov; H. Shooshtari; L. N. Shtarkov; G. Siegmon; U. Siewert; Y. Sirois; I. O. Skillicorn; P. Smirnov; J. R. Smith; Y. Soloviev; H. Spitzer; P. Staroba; M. Steenbock; P. Steffen; R. Steinberg; B. Stella; K. Stephens; J. Stier; J. Stiewe; U. Stösslein; J. Strachota; U. Straumann; W. Struczinski; J. P. Sutton; S. Tapprogge; R. E. Taylor; V. Tchernyshov; C. Thiebaux; G. Thompson; I. Tichomirov; P. Truöl; J. Turnau; J. Tutas; A. Usik; S. Valkar; A. Valkarova; C. Vallée; P. van Esch; P. van Mechelen; A. Vartapetian; Y. Vazdik; M. Vecko; P. Verrecchia; G. Villet; K. Wacker; A. Wagener; I. W. Walker; A. Walther; G. Weber; M. Weber; D. Wegener; A. Wegner; H. P. Wellisch; L. R. West; S. Willard; M. Winde; G.-G. Winter; Th. Wolff; A. E. Wright; E. Wünsch; N. Wulff; T. P. Yiou; J. Zácek; Z. Zhang; M. Zimmer; W. Zimmermann; F. Zomer; K. Zuber

1994-01-01

335

Learning of Cross-Sectional Anatomy Using Clay Models  

ERIC Educational Resources Information Center

|We incorporated clay modeling into gross anatomy and neuro-anatomy courses to help students understand cross-sectional anatomy. By making clay models, cutting them and comparing cut surfaces to CT and MR images, students learned how cross-sectional two-dimensional images were created from three-dimensional structure of human organs. Most students…

Oh, Chang-Seok; Kim, Ji-Young; Choe, Yeon Hyeon

2009-01-01

336

Benchmark Calculations of Electron-Impact Differential Cross Sections  

SciTech Connect

The calculation of electron-atom excitation and ionization cross section is considered in both the non-relativistic and relativistic scattering theory. We consider electron collisions with H, He, Cs, and Hg. Differential cross sections for elastic scattering and ionization are presented.

Bray, I.; Bostock, C. J.; Fursa, D. V.; Hines, C. W.; Kadyrov, A. S.; Stelbovics, A. T. [ARC Centre for Antimatter-Matter Studies, Curtin University, GPO Box U1987 Perth, Western Australia 6845 (Australia)

2011-05-11

337

FISSION-NEUTRON CROSS SECTIONS FOR THRESHOLD REACTIONS  

Microsoft Academic Search

Data are presented on fission neutron activation by the (n,p), (n,k ; alpha ), and (n,2n) reacticns. Half lives, cross sections, and gamma-ray ; energies are tabulated for various reactions. Cross sections for these reactions ; are needed for calculating activation levels of reactor coolants and components. ; (J.H.M.);

Rochlin

1959-01-01

338

SOME RECENT RESULTS ON FAST NEUTRON CROSS SECTIONS  

Microsoft Academic Search

A summary of recent neutron cross section work by several groups at Los ; Alamos in the energy range 0.1 to 16 Mev is presented. Calculated aed ; experimental data are presented for the dlfferential elastic scattering cross ; sections of C, Al, Fe, Ca, Sn, Pb, and U for 14.5Mev neutrons. Angular ; distributions of the inelastic neutrons emitted

Coon; J. H. comp

1958-01-01

339

Status of the Neutron Cross-Section Standards Database  

Microsoft Academic Search

A new evaluation of the neutron cross-section standards is now underway. This evaluation has been supported by the Working Party on International Evaluation Cooperation (WPEC), the Cross Section Evaluation Working Group (CSEWG), and an International Atomic Energy Agency Coordinated Research Program (CRP). The CRP has had the dominant role in producing these evaluations. An important goal is to produce the

Franz-Josef Hambsch; Allan D. Carlson; Herbert Vonach

2005-01-01

340

Neutron cross sections and their uncertainties obtained from nuclear systematics  

Microsoft Academic Search

Previously, neutron cross sections in the MeV range for nuclei ranging in Z from 21 through 41 were calculated using a hybrid empirical-statistical model code THRESH. The formalism includes level density, Coulomb barrier, and competing reaction effects and has been useful in the prediction of unmeasured cross sections or normalized to point measurements to generate complete excitation curves. Reaction data

Pearlstein

1975-01-01

341

Isolated photon cross section measurement at D0  

SciTech Connect

We report a new measurement of the isolated photon cross section by the D0 experiment at Fermilab using 326 pb{sup -1} of data from Run II of the Tevatron. The measured cross section agrees with the theoretical predictions within uncertainties.

Kumar, Ashish; /SUNY, Buffalo

2006-05-01

342

Nuclear Cross Sections and the Size of the Nucleus  

Microsoft Academic Search

The recent experiments on the total inelastic cross sections for 190-Mev deuterons on various target nuclei demand a considerably larger nuclear radius than is usually accepted to explain the experimental results. It is shown that this result is not inconsistent with the total nuclear cross sections for 90-Mev neutrons if a nonsquare-well nuclear shape is taken. Taking for numerical simplicity

Warren Heckrotte

1954-01-01

343

Neutron Capture Cross Sections: From Theory to Experiments and Back  

SciTech Connect

The method for an experimental determination of the stellar enhancement factor for the cross section of the 151Sm(n,{gamma}) reaction process is proposed. This study offered the pretext for an excursus on the interconnections between capture and dissociation reactions and the interplay between theory and experiments in the determination of neutron capture cross sections.

Mengoni, A. [CERN, CH-1211 Geneva 23 (Switzerland); ENEA, Via Don Fiammelli, 2 - 40129 Bologna (Italy)

2005-05-24

344

Analysis and Interpretation of Stream Channel Cross-Sectional Data  

Microsoft Academic Search

Stream channel cross-sectional transects can be used to evaluate effects of management on stream channel morphology and therefore on fish habitat quality. We describe four indices that summarize raw data from stream channel cross sections to detect change in channel morphology over time, The net percent change in area under the transect quantifies net degradation or aggradation. The absolute percent

K. M. Olson-Rutz; C. B. Marlow

1992-01-01

345

Cross Section Evaluations for EnDF/B-vii.  

National Technical Information Service (NTIS)

This is the final report of the work performed under the LANL contract on neutron cross section evaluations for ENDF/B-VII (April 2005-May 2006). The purpose of the contract was to ensure seamless integration of the LANL neutron cross section evaluations ...

M. Herman D. Rochman P. Oblozinsky

2006-01-01

346

Single Event Upset cross sections at various data rates  

Microsoft Academic Search

We present data which show that Single Event Upset (SEU) cross section varies linearly with frequency for most devices tested. We show that the SEU cross section can increase dramatically away from a linear relationship when the test setup is not optimized, or when testing near the maximum operating frequency. We also observe non-linear behavior in some complex circuit topologies.

R. A. Reed; M. A. Carts; P. W. Marshall; C. J. Marshall; S. Buchner; M. La Macchia; B. Mathes; D. McMorrow

1996-01-01

347

Fission Cross Section Measurements of Actinides at LANSCE  

SciTech Connect

Fission cross sections of a range of actinides have been measured at the Los Alamos Neutron Science Center (LANSCE) in support of nuclear energy applications. By combining measurement at two LANSCE facilities, Lujan Center and the Weapons Neutron Research center (WNR), differential cross sections can be measured from sub-thermal energies up to 200 MeV. Incident neutron energies are determined using the time-of-flight method, and parallel-plate ionization chambers are used to measure fission cross sections relative to the 235U standard. Recent measurements include the 233, 238U, 239-242Pu, and 243Am neutron-induced fission cross sections. In this paper preliminary results for fission cross sections of 243Am and 233U will be presented.

F. Tovesson; A. B. Laptev; T. S. Hill

2011-08-01

348

Absolute electron scattering cross sections for the CF2 radical.  

PubMed

Using a crossed electron-molecular beam experiment, featuring a skimmed nozzle beam with pyrolytic radical production, absolute elastic cross sections for electron scattering from the CF2 molecule have been measured. A new technique for placing measured cross sections on an absolute scale is used for molecular beams produced as skimmed supersonic jets. Absolute differential cross sections for CF2 are reported for incident electron energies of 30-50 eV and over an angular range of 20-135 deg. Integral cross sections are subsequently derived from those data. The present data are compared to new theoretical predictions for the differential and integral scattering cross sections, as calculated with the Schwinger multichannel variational method using the static-exchange and static-exchange plus polarization approximations. PMID:18352469

Maddern, Todd M; Hargreaves, Leigh R; Francis-Staite, Jessica R; Brunger, Michael J; Buckman, Stephen J; Winstead, Carl; McKoy, Vincent

2008-02-14

349

Theoretical cross sections for keV antiprotons  

NASA Astrophysics Data System (ADS)

Partial and total close-coupled semiclassical (impact parameter) cross sections and total classical Monte-Carlo cross sections for interactions inbar p + Ps andbar p, p+H collisions are computed in the intermediate keV range for antiprotons,bar p, up to 100 keV lab. Total cross sections for antihydrogen,bar H, formation are found to be large, 10-20×10-16 cm2 in a wider energy range than was anticipated earlier, up to some 20 keV lab. New estimates of cross sections for ionisation of atomic hydrogen by antiproton impact are reported for the low-energy range 1 30 keV lab where they are 10-20×10-17 cm2, being much larger than the corresponding cross sections for ionisation of hydrogen by proton impact. Data for excitation of H bybar p impact is also presented.

Ermolaev, A. M.

1989-03-01

350

Fission cross section measurements of actinides at LANSCE  

SciTech Connect

Fission cross sections of a range of actinides have been measured at the Los Alamos Neutron Science Center (LANSCE) in support of nuclear energy applications. By combining measurement at two LANSCE facilities, Lujan Center and the Weapons Neutron Research center (WNR), differential cross sections can be measured from sub-thermal energies up to 200 MeV. Incident neutron energies are determined using the time-of-flight method, and parallel-plate ionization chambers are used to measure fission cross sections relative to the {sup 235}U standard. Recent measurements include the {sup 233,238}U, {sup 239,242}Pu and {sup 243}Am neutron-induced fission cross sections. In this paper preliminary results for cross section data of {sup 243}Am and {sup 233}U will be presented.

Tovesson, Fredrik [Los Alamos National Laboratory; Laptev, Alexander B [Los Alamos National Laboratory; Hill, Tony S [INL

2010-01-01

351

Nuclear cross sections from strong relativity  

Microsoft Academic Search

Some time age, a geometrization of the nuclear field (in particular, inside hadrons) was proposed, which - on the basis of the classical methods of General Relativity - allowed a unified description of gravitational and strong forces. Such as non-phenomenological approach yielded already interesting results in connection, e.g., with the general behavior of hadrons constituents and the spectrum of mesons.

Italiano

1991-01-01

352

Absolute total electron impact ionization cross-sections for many-atom organic and halocarbon species.  

PubMed

The experimental determination of absolute total electron impact ionization cross-sections for polyatomic molecules has traditionally been a difficult task and restricted to a small range of species. This article reviews the performance of three models to estimate the maximum ionization cross-sections of some 65 polyatomic organic and halocarbon species. Cross-sections for all of the species studied have been measured experimentally using the same instrument, providing a complete data set for comparison with the model predictions. The three models studied are the empirical correlation between maximum ionization cross-section and molecular polarizability, the well-known binary encounter Bethe (BEB) model, and the functional group additivity model. The excellent agreement with experiment found for all three models, provided that calculated electronic structure parameters of suitably high quality are used for the first two, allows the prediction of total electron-impact ionization cross-sections to at least 7% precision for similar molecules that have not been experimentally characterized. PMID:22142325

Bull, James N; Harland, Peter W; Vallance, Claire

2011-12-22

353

Study on Effective Average (?, n) Cross Section for Y, Zr, Nb, and Cs and (?, 3n) Cross Section for Tc  

Microsoft Academic Search

A nondestructive detection technique was proposed for the easy assessment of long-lived radionuclides by the use of bremsstrahlung photons. The nuclide of Tc was considered for the assessment over an effective average Tc (?, 3n) Tc cross section. For validating the experimental method on Tc, photonuclear (?, n) cross sections of Y, Zr, Nb, and Cs were measured. Continuous-energy bremsstralung

Kunio KATO; Hidehiko ARIMA; Nobuhiro SHIGYO; Kenji ISHIBASHI; Jun-ichi HORI; Ken NAKAJIMA

2010-01-01

354

Total Cross Sections for Positrons Scattered Elastically from Helium Based on New Measurements of Total Ionization Cross Sections.  

National Technical Information Service (NTIS)

An improved technique is presented for employing the 2.3m spectrometer to measure total ionization cross sections, Q sub ion, for positrons incident on He. The new ionization cross section agree with the values reported earlier. Estimates are also present...

L. M. Diana R. L. Chaplin D. L. Brooks J. T. Adams L. K. Reyna

1990-01-01

355

D0 papers on B-physics submitted to DPF '96: b-quark inclusive cross sections and b anti-b correlations using dimuons from the D0 experiment; Single muon production in the forward region at [radical]s=1. 8 TEV; Rapidity dependence of the inclusive J[psi] production in the forward region [radical]s=1. 8 TEV; A search for b [r arrow] X[mu][sup +][mu][sup [minus  

SciTech Connect

Paper 1: Using dimuons collected with the D0 detector during the 1993--1995 Tevatron collider run, the authors have measured the b-quark cross section and b[anti b] correlations as given by the difference in azimuthal angle between the two muons. Both measurements agree with the NLO QCD predictions within experimental and theoretical errors. (Three other papers are included in this report.)

Vititoe, D.L. (Arizona Univ., Tucson, AZ (United States). Dept. of Physics); Kozelov, Alexander; Jesik, Richard; D0 Collaboration.

1996-11-01

356

Elastic and absorption cross sections for electron-carbon monosulfide collisions  

NASA Astrophysics Data System (ADS)

We report a theoretical study of electron collisions on carbon monosulfide molecules in the low and intermediate energy range. Calculated differential, integral, and momentum-transfer cross sections for elastic e--CS scattering as well as the total absorption cross sections are reported in the 1-500-eV range. A complex optical potential composed by static, exchange, correlation-polarization, plus absorption contributions, derived from a fully molecular wave function, is used to describe the electron-molecule interaction dynamics. The Schwinger variational iterative method combined with the distorted-wave approximation is applied to calculate the scattering amplitudes. Our calculated data are compared with the calculated and experimental results for electron scattering by an isoelectronic molecule N2O. Remarkable similarity in the cross sections is seen for these targets at incident energies of >50 eV.

Sobrinho, A. M. C.; Lee, M.-T.

357

^16O(?,pp) and ^16O(?,pn) Spin Asymmetry and Cross Section Measurements  

NASA Astrophysics Data System (ADS)

Cross sections and asymmetries have been measured for the ^16O(?,pp), and ^16O(?,pn) reactions with polarized photons with energies from 205 to 315 MeV using the LEGS facility at Brookhaven National Laboratory. Protons and neutrons were detected and identified in an ? E-E array of plastic (Bicron 408) and CsI scintillators located 100 cm from a water target covering a broad range of angles above and below the beam line. The pp and pn cross section and asymmetry data are being analyzed in various kinematics including coplanar and symmetric and in quasi-deuteron kinematics (P_miss=0). The cross section and asymmetry data will be compared to recent calculations by the Pavia and Gent Groups, which include the effects of short range correlations, isobar currents, meson-exchange currents, and final state interactions.

Gladyshev, V.; Lindgren, R.; Baghaei, H.; Cichocki, A.; Gresko, T.; Norum, B.; Sealock, R.; Smith, L.; Thornton, S.; Caracappa, A.; Hoblit, S.; Kistner, A.; Miceli, L.; Sandorfi, A.; Thorn, C.; Hicks, K.; Finlay, R.; Rapaport, J.; Lucas, M.; Whisnant, C.; Khandaker, M.

1998-04-01

358

Combined inclusive diffractive cross sections measured with forward proton spectrometers at HERA  

NASA Astrophysics Data System (ADS)

A combination is presented of the inclusive diffractive cross section measurements made by the H1 and ZEUS Collaborations at HERA. The analysis uses samples of diffractive deep inelastic scattering data where leading protons are detected by dedicated spectrometers. Correlations of systematic uncertainties are taken into account by the combination method, resulting in improved precision.

Ruspa, Marta; H1 Collaboration; ZEUS Collaboration

2013-04-01

359

Estimating Mean Fluctuating Cross Section in the Presence of White Gaussian Noise  

Microsoft Academic Search

The mean cross section of a fluctuating radar echo is estimated by the sample mean of a sequence of pulse to pulse echo power measurements. The variance of the sample mean decreases with the number of measurements or observations, but not proportionally because, in general, the measurements are correlated. This phenomenon is well known, but the effect of receiver noise

Harry Urkowitz; Sheldon L. Katz

1992-01-01

360

Development of recognition software of heart to find the standard cross section on echocardiography  

Microsoft Academic Search

We have developed an algorithm to find standard cross sections (the long-axis view and the short-axis view) of the heart from successive echograms. We first divided an echogram into small spatial regions and detected the typical motion of the mitral valve by analyzing the brightness variation and correlation coefficient among the regions. We have obtained 95% accuracy in the position

Kohji Masuda; Hirotaka Matsuura; Takao Imai; Hiroto Inoue

2007-01-01

361

Determinants of maternal and umbilical blood lead levels: a cross-sectional study, Mosul, Iraq  

Microsoft Academic Search

BACKGROUND: The populations who are most sensitive to lead exposure from various sources are pregnant women and their newborns. Aiming to explore the presence of correlation between maternal and cord blood lead levels and to identify potential predictors that may influence both levels, the present study has been conducted. METHODS: A cross-sectional study was conducted covering 350 full terms maternal-newborns

Asma A Al-Jawadi; Zina WA Al-Mola; Raghad A Al-Jomard

2009-01-01

362

Cross Section Adjustment Applied to Estimation of Uncertainty in the Breeding Ratio of an LMFBR.  

National Technical Information Service (NTIS)

Eleven fast-reactor benchmark experiments and two neutron-field benchmark experiments were applied to a least-squares adjustment of a 26-group cross section library based primarily on ENDF/B-IV. The covariance data include correlations between cross secti...

J. H. Marable C. R. Weisbin G. de Saussure

1979-01-01

363

A new descriptive statistic: The parabolic correlation coefficient  

Microsoft Academic Search

This article proposes a new descriptive statistic related to the second order parabola in the same manner in which the familiar correlation coefficient is related to the regression coefficient. The parabolicr describes in standard terms simultaneously the general trend of the regression and the extent and nature of its curvilinearity, and is relatively easy to compute and easy to communicate.

Charles C. Peters

1946-01-01

364

Thermal neutron capture cross sections of the palladium isotopes  

NASA Astrophysics Data System (ADS)

Precise thermal neutron capture ?-ray cross sections ?? were measured for all elements with Z=1-83,90, and 92, except for He and Pm, at the Budapest Reactor. These data were evaluated with additional information from the literature to generate the Evaluated Gamma-ray Activation File (EGAF). Isotopic radiative neutron cross sections can be deduced from the total transition cross section feeding the ground state, ?0=???(GS) if the decay scheme is complete. The EGAF file contains partial ?-ray cross sections for all stable palladium isotopes. None of these decay schemes are complete, although in each case transitions de-exciting low-lying levels are known. We have performed Monte Carlo simulations of the palladium thermal neutron capture decay schemes using the computer code DICEBOX. The simulated populations of low low-lying levels are normalized to the measured ?? values from EGAF and the total radiative neutron cross section ?0 is obtained. The ?0 values derived for the palladium isotopes agree well with previous measurements and were in several cases more precise. Complementary use of ?-ray cross-section data and Monte Carlo calculations has proven effective in determining both the palladium total radiative cross sections and new nuclear structure information.

Krti?ka, M.; Firestone, R. B.; McNabb, D. P.; Sleaford, B.; Agvaanluvsan, U.; Belgya, T.; Revay, Z. S.

2008-05-01

365

Evaluation of kerma in carbon and the carbon cross sections  

SciTech Connect

A preliminary simultaneous least squares fit to measurements of kerma in carbon, and carbon cross sections taken from the ENDF/B-V file was carried out. In the calculation the shapes of the total cross section and the various partial cross sections were rigid but their absolute values were allowed to float in the fit within the constraints of the ENDF/B-V uncertainties. The construction of the ENDF/B-V file imposed improbable shapes, particularly in the case of the (12)C(n,n'3(alpha)) reaction, which were incompatible with direct measurements of kerma and of the reaction cross sections. Consequently a new evaluation of the cross section data became necessary. Since the available time was limited the new evaluation concentrated particularly on those aspects of the ENDF/B-V carbon file which would have most impact on kerma calculations. Following the new evaluation of cross sections new tables of kerma factors were produced. Finally, the simultaneous least squares fit to measurements of kerma and the new cross section file was repeated.

Axton, E.J.

1992-02-01

366

Thermal neutron capture cross sections of the palladium isotopes  

SciTech Connect

Precise thermal neutron capture {gamma}-ray cross sections {sigma}{sub {gamma}} were measured for all elements with Z=1-83,90, and 92, for He and Pm, at the Budapest Reactor. These data were evaluated with additional information from the literature to generate the Evaluated Gamma-ray Activation File (EGAF). Isotopic radiative neutron cross sections can be deduced from the total transition cross section feeding the ground state, {sigma}{sub 0}={sigma}{sigma}{sub {gamma}}(GS) if the decay scheme is complete. The EGAF file contains partial {gamma}-ray cross sections for all stable palladium isotopes. None of these decay schemes are complete, although in each case transitions de-exciting low-lying levels are known. We have performed Monte Carlo simulations of the palladium thermal neutron capture decay schemes using the computer code DICEBOX. The simulated populations of low low-lying levels are normalized to the measured {sigma}{sub {gamma}} values from EGAF and the total radiative neutron cross section {sigma}{sub 0} is obtained. The {sigma}{sub 0} values derived for the palladium isotopes agree well with previous measurements and were in several cases more precise. Complementary use of {gamma}-ray cross-section data and Monte Carlo calculations has proven effective in determining both the palladium total radiative cross sections and new nuclear structure information.

Krticka, M. [Charles University in Prague, Faculty of Mathematics and Physics, V Holesovickach 2, CZ-180 00 Prague 8 (Czech Republic); North Carolina State University, Raleigh, NC 27695 (United States); Firestone, R. B. [Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States); McNabb, D. P.; Sleaford, B.; Agvaanluvsan, U. [Lawrence Livermore National Laboratory, L-414, 7000 East Avenue, Livermore, CA 94551 (United States); Belgya, T.; Revay, Z. S. [Institute of Isotope and Surface Chemistry, H-1525, Budapest (Hungary)

2008-05-15

367

Fission cross sections in the intermediate energy region  

SciTech Connect

Until recently there has been very little cross section data for neutron-induced fission in the intermediate energy region, primarily because no suitable neutron source has existed. At Los Alamos, the WNR target-4 facility provides a high-intensity source of neutrons nearly ideal for fission measurements extending from a fraction of a MeV to several hundred MeV. This paper summarizes the status of fission cross section data in the intermediate energy range (En > 30 MeV) and presents our fission cross section data for {sup 235}U and {sup 238}U compared to intranuclear cascade and statistical model predictions.

Lisowski, P.W.; Gavron, A.; Parker, W.E.; Ullmann, J.L.; Balestrini, S.J. (Los Alamos National Lab., NM (USA)); Carlson, A.D.; Wasson, O.A. (National Inst. of Standards and Technology, Gaithersburg, MD (USA)); Hill, N.W. (Oak Ridge National Lab., TN (USA))

1991-01-01

368

Top quark pair production cross section at Tevatron  

SciTech Connect

An overview of the recent measurements of the top antitop quark pair production cross section in proton antiproton collisions at {radical}s = 1.96 TeV in lepton + jets and dilepton final states is presented. These measurements are based on 1-2.8 fb{sup -1} of data collected with the D0 and CDF experiments at the Fermilab Tevatron collider. The cross section is measured with a precision close to 8 % and found to be compatible with the standard model prediction. Interpretations of the cross-section measurements for charge higgs search and for top quark mass measurement are also discussed.

Shary, V.; /DAPNIA, Saclay

2009-05-01

369

Relative charge transfer cross section from Rb(4d)  

SciTech Connect

Relative charge transfer cross section measurements for the excited state Rb(4d) with 7 keV Na{sup +} is reported. The specific channels reported are Na{sup +}+Rb(4d{sub 5/2}){yields}Na(nl)+Rb{sup +}, where the dominant transfer cross sections channels were nl=3d and 4s. Using a combination of a magneto-optical trap and recoil ion momentum spectroscopy (MOTRIMS methodology), the cross sections were measured relative to the previously studied Na{sup +}+Rb(5s,5p) systems at the same collision energy.

Shah, M.H.; Camp, H.A.; Trachy, M.L.; De Paola, B.D. [J.R. Macdonald Laboratory, Department of Physics, Kansas State University, Manhattan, Kansas 66506-2601 (United States); Flechard, X. [LPC CAEN, Boulevard du Marechal Juin, 14050 CAEN CEDEX (France); Gearba, M.A. [Department of Physics and Astronomy, University of Southern Mississippi, Hattiesburg, Mississippi 39406 (United States); Nguyen, H. [Department of Physics and Astronomy, University of Wisconsin-Stevens Point, Stevens Point, Wisconsin 55481 (United States); Bredy, R. [Laboratoire de Spectrometrie Ionique et Moleculaire, Universite Claude Bernard Lyon1, 69622 Villeurbanne Cedex (France); Lundeen, S.R. [Department of Physics, Colorado State University, Fort Collins, Colorado 80523 (United States)

2005-08-15

370

Actinide Neutron-Induced Fission Cross Section Measurements At LANSCE  

SciTech Connect

Fission cross sections of a range of actinides have been measured at the Los Alamos Neutron Science Center (LANSCE) in support of nuclear energy applications in a wide energy range from sub thermal energies up to 200 MeV. Parallel-plate ionization chambers are used to measure fission cross sections ratios relative to the {sup 235}U standard while incident neutron energies are determined using the time-of-flight method. Recent measurements include the {sup 233,238}U, {sup 239-242}Pu and {sup 243}Am neutron-induced fission cross sections. Obtained data are presented in comparison with existing evaluations and previous data.

Tovesson, F.; Laptev, A. B. [Los Alamos National Laboratory, Los Alamos NM 87545 (United States); Hill, T. S. [Idaho National Laboratory, Idaho Falls ID 83415 (United States)

2011-06-01

371

Elastic and Nonelastic Neutron Cross Sections for Beryllium  

Microsoft Academic Search

A time-of-flight technique has been used to measure angular distributions for the elastic scattering of neutrons from beryllium in the energy range from 2.6 to 6.0 Mev. Total neutron cross sections were also measured and the following nonelastic (total minus elastic) cross sections obtained: 2.60 Mev (0.27+\\/-0.13 barn), 3.50 (0.43+\\/-0.10), 4.10 (0.51+\\/-0.08), 5.00 (0.60+\\/-0.08), and 6.00 (0.73+\\/-0.07). Differential cross sections

J. B. Marion; J. S. Levin; L. Cranberg

1959-01-01

372

Actinide neutron-induced fission cross section measurements at LANSCE  

SciTech Connect

Fission cross sections of a range of actinides have been measured at the Los Alamos Neutron Science Center (LANSCE) in support of nuclear energy applications in a wide energy range from sub-thermal energies up to 200 MeV. A parallel-plate ionization chamber are used to measure fission cross sections ratios relative to the {sup 235}U standard while incident neutron energies are determined using the time-of-flight method. Recent measurements include the {sup 233,238}U, {sup 239-242}Pu and {sup 243}Am neutron-induced fission cross sections. Obtained data are presented in comparison with ex isting evaluations and previous data.

Tovesson, Fredrik K [Los Alamos National Laboratory; Laptev, Alexander B [Los Alamos National Laboratory; Hill, Tony S [INL

2010-01-01

373

Graphical displays of cross sections produced on the computer  

SciTech Connect

Much time is devoted to manually constructing cross sections and interpreting geologic data. Computer-generated displays can save manual effort and provide an interpretive aid for the geologist. This poster session will display computer-generated cross sections containing full curve logs, lithology, oil and gas shows, geologic markers, interpreted dipmeters, and structural relationships. Contouring and the use of color will also be demonstrated as interpretive aids. Two of the methods used in preparing geologic data - the polynominal regression and the Markov process - will also be demonstrated. The poster session summarized the various ways in which the computer may display and aid in the interpretation of cross sections.

Brooks, L.L.

1985-02-01

374

Parameterized total cross sections for pion production in nuclear collisions  

NASA Astrophysics Data System (ADS)

Total inclusive cross sections for neutral and charged pion production in proton nucleus and nucleus nucleus reactions have been calculated and compared to experiment. Nucleon nucleon theoretical cross sections have been scaled up to nuclear collisions using a scaling factor similar to (APAT)2/3, where AP and AT are the nucleon numbers of the projectile and target nuclei. Variations in the power of this scaling factor have been studied and a good fit to experiment is obtained with a small modification of the power. Theoretical cross sections are written in a form that is very suitable for immediate input into transport codes.

Norbury, John W.; Townsend, Lawrence W.

2007-01-01

375

4. DETAIL VIEW OF CROSS SECTION OF STRUCTURE, SHOWING EXTERIOR ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

4. DETAIL VIEW OF CROSS SECTION OF STRUCTURE, SHOWING EXTERIOR FACINGS LINED WITH RUBBLE BACKING AND EARTH INFILL, LOOKING EAST - Rock Wall, North side of Battle Creek Canyon, Shingletown, Shasta County, CA

376

56. CROSS SECTION OF POWERHOUSE, PROJECT 1933, EXHIBIT F, SANTA ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

56. CROSS SECTION OF POWERHOUSE, PROJECT 1933, EXHIBIT F, SANTA ANA POWERHOUSE NO. 1. SCE drawing no. 5206856 (no date; FERC no. 1933-46). - Santa Ana River Hydroelectric System, SAR-1 Powerhouse, Redlands, San Bernardino County, CA

377

Advanced Buckling Analyses of BEAMS with Arbitrary Cross Sections.  

National Technical Information Service (NTIS)

A computer program was developed to study distorsion of the cross section during buckling and the interaction between buckling modes, based on the combination of the spline finite strip method and Koiter's general theory of stability. A theory was develop...

G. M. Vanerp

1989-01-01

378

28. CROSS SECTION OF A RECTANGULAR COKE OVEN SHOWING THE ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

28. CROSS SECTION OF A RECTANGULAR COKE OVEN SHOWING THE INTERNAL STRUCTURE OF THE OVEN. - Tower Hill No. 2 Mine, Approximately 0.47 mile Southwest of intersection of Stone Church Road & Township Route 561, Hibbs, Fayette County, PA

379

New Kr Cross Sections and Astrophysical Constraints on Presolar Grains  

SciTech Connect

A series of neutron-capture cross-section measurements on various krypton isotopes has been performed at the Geel Electron Linear Accelerator (GELINA). The total cross section of 84Kr and the capture cross section of 86Kr and 82Kr have been measured in the energy range from 0 up to 400 keV. Moreover, capture cross-section data for 80Kr and 83Kr have been obtained for a limited energy range, namely from 0 up to 5 keV, from a natural krypton sample. The main goal of the measurement campaign was to provide reliable nuclear data for s-process nucleosynthesis calculation. We performed a series of calculations for stars with mass from M = 1.5M{center_dot} to M = 3M{center_dot} and metallicity from solar down to 1/6 of solar with the aim to reproduce the krypton isotopic ratios found in silicon-carbide grains.

Mutti, P. [Institute Laue-Langevin, B.P.156 - 6 rue Jules Horowitz, 38042 Grenoble Cedex 9 (France); Beer, H. [Forschungszentrum Karlsruhe, Institut fuer Kernphysik, P. O. Box 3640, 76021 Karlsruhe (Germany); Brusegan, A.; Corvi, F. [EC-JRC, Institute for Reference Materials and Measurements, Retieseweg, B-2440 Geel (Belgium); Gallino, R. [Dipartimento di Fisica Generale, Universita di Torino, v. Pietro Giuria 1, 10100 Turin (Italy)

2005-05-24

380

Cross Sections for Producing Some Light-Noble-Gas Nuclides  

NASA Astrophysics Data System (ADS)

Cross sections for making 3He, 20Ne, 21Ne, and 22Ne (including 3H and 22Na decay) from major target elements were compiled and evaluated for proton reactions and, for Ne isotopes from Mg, for neutron reactions.

Reedy, R. C.

2008-03-01

381

XCOM: Photon Cross Sections on a Personal Computer,  

National Technical Information Service (NTIS)

A computer program and data base are presented which can be used to calculate, with a personal computer, photon cross sections for scattering, photoelectric absorption and pair production, as well as total attenuation coefficients, in any element, compoun...

M. J. Berger J. H. Hubbell

1987-01-01

382

36. CROSS SECTIONAL VIEW OF ORIGINAL HORSE MESA DAM POWER ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

36. CROSS SECTIONAL VIEW OF ORIGINAL HORSE MESA DAM POWER PLANT, LOOKING NORTH. ONLY TWO OF THE THREE UNITS ARE VISIBLE - Horse Mesa Dam, Salt River, 65 miles East of Phoenix, Phoenix, Maricopa County, AZ

383

20. CROSS SECTIONAL VIEW OF HORSE MESA, SHOWING RIGHT SPILLWAY ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

20. CROSS SECTIONAL VIEW OF HORSE MESA, SHOWING RIGHT SPILLWAY SUPERSTRUCTURE AND CONCRETE PLACEMENT LINES August 2, 1927 - Horse Mesa Dam, Salt River, 65 miles East of Phoenix, Phoenix, Maricopa County, AZ

384

ConcepTest: Cross-Section of Plate Boundaries  

NSDL National Science Digital Library

The map below shows the plate configurations along the western margin of North America. Which of the four diagrams on the right best represents a cross section through the outer layers of Earth along the line X-Y?

385

ConcepTest: Cross-Sections of Plate Boundaries  

NSDL National Science Digital Library

The map below shows the plate configurations along the western margin of North America. Which of the four diagrams on the right best represents a cross section through the outer layers of Earth along the line X-Y?

386

Calculation of NP Gamma Cross Sections and Asymmetries.  

National Technical Information Service (NTIS)

Neutron-proton bremsstrahlung cross sections and asymmetries are calculated in both the Gottschalk and Thorndike geometries. The influence of off-shell terms is determined by comparing off-shell calculations to calculations using only elastic scattering p...

J. H. McGuire W. A. Pearce

1970-01-01

387

Cross Sections: Frame 140 Looking Aft, Frame 117 Looking Aft, ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

Cross Sections: Frame 140 Looking Aft, Frame 117 Looking Aft, Frame 96 Looking Aft, Frame 78 Looking Aft, Frame 62 Looking Aft, Frame 58 Looking Aft - Wichita, Suisun Bay Reserve Fleet, Benicia, Solano County, CA

388

Factorization of the Drell-Yan cross section  

SciTech Connect

We state the weak and strong factorization theorems for the Drell-Yan cross section and outline the ingredients involved in their proof. We also discuss the physical picture implied by the factorization results and its phenomenological consequences.

Bodwin, G.T.; Brodsky, S.J.; Lepage, G.P.

1985-04-01

389

Cross section for the subthreshold fission of {sup 236}U  

SciTech Connect

The cross section for {sup 236}U fission in the neutron-energy range E{sub n} = 0.001-20 keV was measured by using the INR RAS (Institute of Nuclear Research, Russian Academy of Sciences, Moscow) LSDS-100 neutron spectrometer of the lead slowing-down spectrometer type. The resonance fission areas of the resonances at 5.45 eV and 1.28 keV were found, and the fission widths of these resonances were evaluated. The cross section for the {sup 238}U(n, f) fission process was measured, and the threshold sensitivity of the LSDS-100 to small values of fission cross sections was estimated. The well-known intermediate structure in the cross section for the neutron-induced subbarrier fission of {sup 236}U was confirmed.

Alekseev, A. A.; Bergman, A. A.; Berlev, A. I.; Koptelov, E. A. [Russian Academy of Sciences, Institute for Nuclear Research (Russian Federation); Samylin, B. F.; Trufanov, A. M.; Fursov, B. I.; Shorin, V. S., E-mail: shorin@ippe.r [Institute of Physics and Power Engineering (Russian Federation)

2008-08-15

390

Experimental Determination of Collision Cross Sections for Momentum Transfer.  

National Technical Information Service (NTIS)

Effective collision cross sections for momentum transfer between electrons and neutral particles in argon, nitrogen, oxygen, helium, carbon monoxide and dioxide, nitrogen dioxide, water vapor, and mercury plasmas were measured directly by two independent ...

S. T. Demetriades G. Fonda-Bonardi G. S. Argyropoulos

1969-01-01

391

Precision measurement of the 238Pu(n,?) cross section  

NASA Astrophysics Data System (ADS)

The neutron-capture cross section for 238Pu was measured by using the detector for advanced neutron-capture experiments (DANCE) array, which is a highly segmented and highly efficient 4? ?-ray calorimeter. The neutron-capture events were recognized by the total ?-ray energy deposited in DANCE, which is equal to the reaction Q value plus the incident neutron energy. The absolute neutron-capture cross section was derived as a function of incident neutron energy from thermal to about 30 keV. The measured cross section for incident neutron energy below 18 eV was performed for the first time by using the direct method and does not support the most recently adopted changes in endf/b-vii.1 where the neutron-capture cross section was lowered by as much as a factor of ˜3 in the neighborhood of 0.3 eV from those evaluated in endf/b-vii.0.

Chyzh, A.; Wu, C. Y.; Kwan, E.; Henderson, R. A.; Gostic, J. M.; Bredeweg, T. A.; Couture, A.; Haight, R. C.; Lee, H. Y.; O'Donnell, J. M.; Ullmann, J. L.

2013-10-01

392

Total cross sections for positron and electron scattering from pyrimidine  

NASA Astrophysics Data System (ADS)

In this paper we report original measurements of total cross sections for positron scattering from the important biomolecule pyrimidine. The energy range of these measurements was 0.3-45 eV, while the energy resolution was ~260 meV. In addition, we report theoretical results, calculated within the independent atom-screened additivity rule (IAM-SCAR) formalism, for the corresponding electron impact total cross sections. In that case the energy range is 1-10 000 eV. Total cross sections are very important input data for codes that seek to simulate charged-particle tracks in matter, as they define the mean-free path between collisions. As the present data and computations are to the best of our knowledge the first total cross sections to be reported for either positron or electron scattering from pyrimidine, they fill an important void in our available knowledge in the literature.

Zecca, A.; Chiari, L.; García, G.; Blanco, F.; Trainotti, E.; Brunger, M. J.

2010-11-01

393

Some activation measurements and a comparison with theoretical (n, 2n) cross sections and isomeric cross section ratioss  

Microsoft Academic Search

Cross sections are measured for the reactions Co⁵⁹(n,2n), Zn\\/sup ; 64\\/(n,2n), and Zn⁶⁴(n,p) at 13.5 to 14.8 Mev. At 14.7 plus or minus 0.3 ; Mev, 20 plus or minus 5 mu b is obtained for the S³² (n,t) cross section ; and an upper limit of 0.1 mb for Ca⁴°(a,t). The Co⁵⁸ isomeric cross ; section ratio for the

E. Weigold; R. N. Glover

1962-01-01

394

Theoretical photodetachment cross section for He(4Po)  

Microsoft Academic Search

We report the first calculation of the photodetachment cross section for the metastable, 1s 2s 2p 4Po state of He-. Extensive configuration-interaction wave functions and the Stieltjes-moment-theory technique were used to determine the total cross section from threshold to 3.0 eV. The 1s 2p24Pe state of He- gives rise to a very large (~ 24 × 10-16 cm2) and narrow

A. U. Hazi; K. Reed

1981-01-01

395

Total cross sections for positron and electron scattering from pyrimidine  

Microsoft Academic Search

In this paper we report original measurements of total cross sections for positron scattering from the important biomolecule pyrimidine. The energy range of these measurements was 0.3-45 eV, while the energy resolution was ~260 meV. In addition, we report theoretical results, calculated within the independent atom-screened additivity rule (IAM-SCAR) formalism, for the corresponding electron impact total cross sections. In that

A. Zecca; L. Chiari; G. García; F. Blanco; E. Trainotti; M. J. Brunger

2010-01-01

396

Electron inelastic-scattering cross sections in liquid water  

Microsoft Academic Search

Electron inelastic-scattering cross-section data for use as input in electron track-structure calculations in liquid water are re-examined and improved. The dielectric-response function used in such cross-sections is estimated on the basis of optical data and other experimental and theoretical information. The mean excitation energy for stopping power is obtained to be 81.8 eV, which is close to the recent experimental

Michael Dingfelder; Detlev Hantke; Mitio Inokuti; Herwig G. Paretzke

1999-01-01

397

Photon cross-sections at ECM = 2-TeV  

SciTech Connect

Photon production rates have been studied by the D0 and CDF experiments in Run II of the Fermilab Tevatron Collider. Measurements of the inclusive isolated photon cross section and the di-photon cross section are presented, based on integrated luminosities of 0.3 fb{sup -1} and 0.2 fb{sup -1}, respectively. The results are compared to perturbative QCD calculations in various approximations.

Wobisch, M.; /Fermilab

2006-06-01

398

Double differential cross sections of carbonyl sulfide molecule  

NASA Astrophysics Data System (ADS)

Partial and total double differential cross sections corresponding to various cations produced during the direct and dissociative electron ionization of carbonyl sulfide molecule have been calculated at fixed impinging electron energies 100 and 200eV by using modified Jain-Khare semi empirical approach. The calculation for double differential cross sections is made as a function of energy loss suffered by primary electron and angle of incident. To the best of our knowledge no other data is available for the comparison.

Kumar, Rajeev; Sanju

2013-06-01

399

Intermediate structure studies of 234U cross sections  

Microsoft Academic Search

Neutron induced fission and total cross sections of 234U have been measured over the neutron energy range from a few eV to 8.9 MeV. Neutron and fission widths for 118 cross section resonances below 1500 eV have been determined and give a class I level spacing of 10.6 +\\/- 0.5 eV and an s-wave strength function of (0.86 +\\/- 0.11)

G. D. James; J. W. T. Dabbs; J. A. Harvey; N. W. Hill; R. H. Schindler

1977-01-01

400

International evaluation cooperation Subgroup 7: Multigroup cross section processing  

Microsoft Academic Search

The chairmen of the ENDF\\/B, JEF, EFF, and JENDL evaluated data files adopted a proposal to develop a fine-group processed cross section library based on the VITAMIN'' concept. The authors listed above, with support from others, are participating in this project. The end result will be a pseudo-problem-independent fine-group cross section library generated from the latest evaluated data in ENDF\\/B-VI,

R. W. Roussin; J. E. White; E. Sartori; G. Panini; R. MacFarlane; D. Muir; M. Mattes; I Hasegawa

1991-01-01

401

Neutron Cross Section Evaluations for Actinides at Intermediate Energies  

Microsoft Academic Search

Investigations aimed at the development of neutron cross-section evaluations and creation of the complete nuclear data files for actinides in the range up to 150 MeV are discussed. The coupled-channel optical model has been used to calculate the neutron total, elastic, and reaction cross sections and the elastic scattering angular distributions. The parameters of the optical model have been determined

A. V. IGNATYUK; E. V. GAI; V. P. LUNEV; N. N. TITARENKO; N. SHUBIN; W. Gudowski

402

ELASTIC AND NONELASTIC NEUTRON CROSS SECTIONS FOR BERYLLIUM  

Microsoft Academic Search

A time-of-flight technique was used to measure angunlar distributions ; for the elastic scattering of neutrons from beryllium in the energy range from ; 2.6 to 6.0 Mev. Total neutron cross sections were also measured and the ; following nonelastic (total minus elastic) cross sections obtained: 2.60 Mev ; (0.27 plus or minus 0.13 barn). 3.50 (0.43 plus or minus

J. B. Marion; J. S. Levin; L. Cranberg

1959-01-01

403

Importance of Neutron Cross-Sections for Transmutation  

Microsoft Academic Search

Accurate neutron cross-section data is fundamental to the reliable design of any transmutation device, and, in particular, of an Accelerator-Driven System (ADS). Calculations of the behaviour of the core depend strongly on the cross-section data: parameters such as the multiplication coefficient, power densities or reactivity may vary significantly depending on the nuclear-data (ND) library used. These potential discrepancies justify the

A. HERRERA-MARTÍNEZ; M. DAHLFORS; Y. KADI; G. T. PARKS

404

Calculation of Neutron Cross Sections on Nb for JENDL-4  

Microsoft Academic Search

Nuclear data of Nb in the Japanese Evaluated Nuclear Data Library JENDL-3.3 were reexamined in the incident neutron energy range from 10keV to 20MeV toward JENDL-4. Cross sections, differential and double-differential cross sections were calculated on the basis of nuclear reaction models such as the spherical optical model, the distorted wave Born approximation, the Kalbach preequilibrium model, and the Hauser-Feshbach

Akira ICHIHARA; Satoshi KUNIEDA; Keiichi SHIBATA

2008-01-01

405

Measurement of the cross section for gammagamma-->pp¯  

Microsoft Academic Search

A measurement of the cross section for gammagamma-->pp¯ is performed at two-photon center-of-mass energies between 2.00 and 3.25 GeV. These results are obtained using e+e--->e+e-pp¯ events selected from 1.31 fb-1 of data taken with the CLEO II detector. The measured cross section is in reasonable agreement with previous measurements and is in excellent agreement with recent calculations based on a

M. Artuso; D. He; M. Goldberg; N. Horwitz; R. Kennett; G. C. Moneti; F. Muheim; Y. Mukhin; S. Playfer; Y. Rozen; S. Stone; M. Thulasidas; G. Vasseur; G. Zhu; J. Bartelt; S. E. Csorna; Z. Egyed; V. Jain; P. Sheldon; D. S. Akerib; B. Barish; M. Chadha; S. Chan; D. F. Cowen; G. Eigen; J. S. Miller; C. O'grady; J. Urheim; A. J. Weinstein; D. Acosta; M. Athanas; G. Masek; H. Paar; M. Sivertz; A. Bean; J. Gronberg; R. Kutschke; S. Menary; R. J. Morrison; S. Nakanishi; H. N. Nelson; T. K. Nelson; J. D. Richman; A. Ryd; H. Tajima; D. Schmidt; D. Sperka; M. S. Witherell; M. Procario; S. Yang; R. Balest; K. Cho; M. Daoudi; W. T. Ford; D. R. Johnson; K. Lingel; M. Lohner; P. Rankin; J. G. Smith; J. P. Alexander; C. Bebek; K. Berkelman; D. Besson; T. E. Browder; D. G. Cassel; H. A. Cho; D. M. Coffman; P. S. Drell; R. Ehrlich; R. S. Galik; M. Garcia-Sciveres; B. Geiser; B. Gittelman; S. W. Gray; D. L. Hartill; B. K. Heltsley; C. D. Jones; S. L. Jones; J. Kandaswamy; N. Katayama; P. C. Kim; D. L. Kreinick; G. S. Ludwig; J. Masui; J. Mevissen; N. B. Mistry; C. R. Ng; E. Nordberg; M. Ogg; J. R. Patterson; D. Peterson; D. Riley; S. Salman; M. Sapper; H. Worden; F. Würthwein; P. Avery; A. Freyberger; J. Rodriguez; R. Stephens; J. Yelton; D. Cinabro; S. Henderson; K. Kinoshita; T. Liu; M. Saulnier; F. Shen; R. Wilson; H. Yamamoto; B. Ong; M. Selen; A. J. Sadoff; R. Ammar; S. Ball; P. Baringer; D. Coppage; N. Copty; R. Davis; N. Hancock; M. Kelly; N. Kwak; H. Lam; Y. Kubota; M. Lattery; J. K. Nelson; S. Patton; D. Perticone; R. Poling; V. Savinov; S. Schrenk; R. Wang; M. S. Alam; I. J. Kim; B. Nemati; J. J. O'neill; H. Severini; C. R. Sun; M. M. Zoeller; G. Crawford; C. M. Daubenmier; R. Fulton; D. Fujino; K. K. Gan; K. Honscheid; H. Kagan; R. Kass; J. Lee; R. Malchow; F. Morrow; Y. Skovpen; M. Sung; C. White; J. Whitmore; P. Wilson; F. Butler; X. Fu; G. Kalbfleisch; M. Lambrecht; W. R. Ross; P. Skubic; J. Snow; P. L. Wang; M. Wood; D. Bortoletto; D. N. Brown; J. Fast; R. L. McIlwain; T. Miao; D. H. Miller; M. Modesitt; S. F. Schaffner; E. I. Shibata; I. P. Shipsey; P. N. Wang; M. Battle; J. Ernst; H. Kroha; S. Roberts; K. Sparks; E. H. Thorndike; C. H. Wang; J. Dominick; S. Sanghera; V. Shelkov; T. Skwarnicki; R. Stroynowski; I. Volobouev; P. Zadorozhny

1994-01-01

406

Review of multigroup nuclear cross-section processing  

Microsoft Academic Search

These proceedings consist of 18 papers given at a seminar--workshop on ''Multigroup Nuclear Cross-Section Processing'' held at Oak Ridge, Tennessee, March 14--16, 1978. The papers describe various computer code systems and computing algorithms for producing multigroup neutron and gamma-ray cross sections from evaluated data, and experience with several reference data libraries. Separate abstracts were prepared for 13 of the papers.

D. K. Trubey; H. R. Hendrickson

1978-01-01

407

Total neutron cross sections of molybdenum, cadmium and bismuth  

Microsoft Academic Search

Total cross sections of Mo and Cd were measured by the time-of-flight method in the energy interval from 20 to 1100 keV on the neutron beam from the IBR-30 reactor transmitted through either iron or aluminium filter. The [sgrave]t values were compared with the scattering cross section data. The transmission measurements on bismuth were also made in the interval from

A. B. Popov; G. S. Samosvat

1986-01-01

408

Nucleon-nucleon cross sections in nuclear matter  

SciTech Connect

We provide a microscopic calculation of neutron-proton and neutron-neutron cross sections in symmetric nuclear matter at various densities, using the Brueckner-Hartree-Fock approximation scheme with the Paris potential. We investigate separately the medium effects on the effective mass and on the scattering amplitude. We determine average cross sections suitable for application in the dynamical simulation of heavy ion collisions, including a parametrization of their energy and density dependence. {copyright} {ital 1997} {ital The American Physical Society}

Schulze, H.; Schnell, A.; Roepke, G. [MPG-AG Theoretische Vielteilchenphysik, Universitaet Rostock, D-18051 Rostock (Germany); Lombardo, U. [Dipartimento di Fisica, Universita di Catania, Corso Italia 57, I-95129 Catania (Italy)

1997-06-01

409

Theoretical calculation of dielectronic recombination cross sections for hydrogenlike helium  

SciTech Connect

We have developed a simplified relativistic configuration-interaction method to calculate the dielectronic recombination cross sections and rates. In this method, the infinite resonant doubly excited states can be treated conveniently in the frame of quantum defect theory. As a stringent test, we calculated the dielectronic recombination cross sections for hydrogenlike helium. The results for the {ital KLL} and {ital KLM} resonances are in good agreement with the experimental measurement.

Wang, J.; Qu, Y.; Li, J. [Institute of Physics, P.O. Box 603, Chinese Academy of Sciences, Beijing 100080 (China)

1995-11-01

410

Dielectronic-recombination cross sections of hydrogenlike argon  

SciTech Connect

Relative dielectronic-recombination cross sections for hydrogenlike argon are presented. The contributions of the {ital KLL}, {ital KLM}, {ital KLN}, {ital KLO}, and {ital KLP} groups of resonances are compared to theoretical calculations. The experimental method consists of the formation and interaction of ions with electrons in an ion trap followed by an analysis of the extracted ions to determine relative yields. Comparison with theory shows that the total cross sections agree within {plus minus}6%.

DeWitt, D.R.; Schneider, D.; Clark, M.W.; Chen, M.H. (Lawrence Livermore National Laboratory, University of California, Livermore, California 94550 (United States)); Church, D. (Texas A M University, College Station, Texas 77843 (United States))

1991-12-01

411

K-shell photoionization cross section of Carbon IV  

Microsoft Academic Search

An 11-state R-matrix calculation is performed to obtain cross sections for the photoionization of the 0953-4075\\/30\\/1\\/008\\/img6 ground-state of C IV. For low photon energies, corresponding solely to the 2s photoionization cross section, good agreement is found with previous calculations. For higher photon energies, permitting inner-shell photoionization of the 1s electron, much more resonance structure is found than in previous studies,

C. McGuinness; K. L. Bell; A. Hibbert

1997-01-01

412

Photoionization Cross Section and Resonance Structure of Mn+  

Microsoft Academic Search

A photoionization cross section calculation of Mn+ is performed in the formalism of many-body perturbation theory for photon energies ranging from 48 eV to 56 eV. We consider excitations from the 3p, 3d, and 4s subshells. The effects of the strong 3p?3d and 3p?4s transitions are included as resonant contributions to the total cross sections. Good agreement with experiment is

Lu Peng-Fei; Liu Jin-Chao; Yang Xiang-Dong

2006-01-01

413

Neutron Nonelastic Cross-Section Measurements on Carbon  

Microsoft Academic Search

Neutron nonelastic cross sections for carbon have been measured over the energy range from 5.8 to 12.9 Mev. The main features of the carbon nonelastic cross section as a function of neutron energy are a gradual rise from threshold (4.8 Mev) up to 7 Mev, a steep rise from 7 to 8 Mev, and an approximately constant value from 8

M. H. MacGregor; Rex Booth

1958-01-01

414

Proton-nucleus inelastic cross section at ultra high energy  

NASA Astrophysics Data System (ADS)

Energy dependence of proton-nucleus reaction cross section at very high energy is discussed. It is stressed that depending on the gluon distribution near the nuclear surface, proton-nucleous total cross section increases much more rapidly compared to the usual Glauber independent nucleon estimate. The recent observation of smaller X max than the expected value at UHECR domain can be an indication for such a mechanism.

Kodama, Takeshi; Portugal, Licínio

2011-12-01

415

CROSS SECTION EVALUATIONS FOR ENDF\\/B-VII  

Microsoft Academic Search

This is the final report of the work performed under the LANL contract on neutron cross section evaluations for ENDF\\/B-VII (April 2005-May 2006). The purpose of the contract was to ensure seamless integration of the LANL neutron cross section evaluations in the new ENDF\\/B-VII library. The following work was performed: (1) LANL evaluated data files submitted for inclusion in ENDF\\/B-VII

M. HERMAN; D. ROCHMAN; P. OBLOZINSKY

2006-01-01

416

The evaluation and application of redundant-cross-section covariances  

SciTech Connect

Certain multigroup covariance libraries, notably COVFILS-2, omit all redundant (or summed) reactions on the grounds that the information content of a well-measured total cross section, for example, is implicitly contained in the covariances of the component, or partial, reactions that add up to the total. It is shown that, while redundant reactions can play an important role in cross-section and covariance evaluation, their emission from libraries intended for applications is justifiable. 3 refs.

Muir, D.W.

1986-01-01

417

MR-SDCI study on high-energy electron and X-ray scattering cross-sections of linear molecules  

NASA Astrophysics Data System (ADS)

High-energy electron and X-ray scattering cross-sections of O2, F2, CO and CO2 have been calculated within the framework of the first Born approximation from MR-SDCI wavefunctions recovering up to 92% of the estimated correlation energy. In contrast to the fair agreement found for X-ray scattering cross-sections, comparison with available experimental data shows large deviations in the case of electron scattering. Possible causes for the observed discrepancies are discussed.

Meyer, Hermann

418

Absolute cross sections for electron loss, electron capture, and multiple ionization in collisions of C3+ with noble gases  

Microsoft Academic Search

Absolute charge-state-correlated cross sections for projectile electron loss, electron capture, and target multiple ionization in collisions between C3+ ions and noble gases have been measured for energies between 1.3 and 3.5 MeV. The data have been compared with other similar absolute cross sections existent in the literature for several projectiles. Calculations for the single-loss-multiple-ionization channel have been performed for the

A. C. F. Santos; G. M. Sigaud; W. S. Melo; M. M. Sant'Anna; E. C. Montenegro

2010-01-01

419

Jet-radius dependence of inclusive-jet cross sections in deep inelastic scattering at HERA  

NASA Astrophysics Data System (ADS)

Differential inclusive-jet cross sections have been measured for different jet radii in neutral current deep inelastic ep scattering for boson virtualities Q>125 GeV with the ZEUS detector at HERA using an integrated luminosity of 81.7 pb-1. Jets were identified in the Breit frame using the k cluster algorithm in the longitudinally inclusive mode for different values of the jet radius R. Differential cross sections are presented as functions of Q and the jet transverse energy, ET,Bjet. The dependence on R of the inclusive-jet cross section has been measured for Q>125 and 500 GeV and found to be linear with R in the range studied. Next-to-leading-order QCD calculations give a good description of the measurements for 0.5?R?1. A value of ?(M) has been extracted from the measurements of the inclusive-jet cross section d?/dQ with R=1 for Q>500 GeV: ?(M)=0.1207±0.0014(stat.)-0.0033+0.0035(exp.)-0.0023+0.0022(th.). The variation of ? with ET,Bjet is in a good agreement with the running of ? as predicted by QCD.

Chekanov, S.; ZEUS Collaboration; Derrick, M.; Magill, S.; Miglioranzi, S.; Musgrave, B.; Nicholass, D.; Repond, J.; Yoshida, R.; Mattingly, M. C. K.; Jechow, M.; Pavel, N.; Yagües Molina, A. G.; Antonelli, S.; Antonioli, P.; Bari, G.; Basile, M.; Bellagamba, L.; Bindi, M.; Boscherini, D.; Bruni, A.; Bruni, G.; Cifarelli, L.; Cindolo, F.; Contin, A.; Corradi, M.; de Pasquale, S.; Iacobucci, G.; Margotti, A.; Nania, R.; Polini, A.; Rinaldi, L.; Sartorelli, G.; Zichichi, A.; Bartsch, D.; Brock, I.; Goers, S.; Hartmann, H.; Hilger, E.; Jakob, H.-P.; Jüngst, M.; Kind, O. M.; Paul, E.; Rautenberg, J.; Renner, R.; Samson, U.; Schönberg, V.; Shehzadi, R.; Wang, M.; Wlasenko, M.; Brook, N. H.; Heath, G. P.; Morris, J. D.; Namsoo, T.; Capua, M.; Fazio, S.; Mastroberardino, A.; Schioppa, M.; Susinno, G.; Tassi, E.; Kim, J. Y.; Ma, K. J.; Ibrahim, Z. A.; Kamaluddin, B.; Wan Abdullah, W. A. T.; Ning, Y.; Ren, Z.; Sciulli, F.; Chwastowski, J.; Eskreys, A.; Figiel, J.; Galas, A.; Gil, M.; Olkiewicz, K.; Stopa, P.; Zawiejski, L.; Adamczyk, L.; Bo?d, T.; Grabowska-Bo?d, I.; Kisielewska, D.; ?ukasik, J.; Przybycie?, M.; Suszycki, L.; Kota?ski, A.; S?omi?ski, W.; Adler, V.; Behrens, U.; Bloch, I.; Bonato, A.; Borras, K.; Coppola, N.; Fourletova, J.; Geiser, A.; Gladkov, D.; Göttlicher, P.; Gregor, I.; Haas, T.; Hain, W.; Horn, C.; Kahle, B.; Kötz, U.; Kowalski, H.; Lobodzinska, E.; Löhr, B.; Mankel, R.; Melzer-Pellmann, I.-A.; Montanari, A.; Notz, D.; Nuncio-Quiroz, A. E.; Santamarta, R.; Schneekloth, U.; Spiridonov, A.; Stadie, H.; Stösslein, U.; Szuba, D.; Szuba, J.; Theedt, T.; Wolf, G.; Wrona, K.; Youngman, C.; Zeuner, W.; Lohmann, W.; Schlenstedt, S.; Barbagli, G.; Gallo, E.; Pelfer, P. G.; Bamberger, A.; Dobur, D.; Karstens, F.; Vlasov, N. N.; Bussey, P. J.; Doyle, A. T.; Dunne, W.; Ferrando, J.; Saxon, D. H.; Skillicorn, I. O.; Gialas, I.; Gosau, T.; Holm, U.; Klanner, R.; Lohrmann, E.; Salehi, H.; Schleper, P.; Schörner-Sadenius, T.; Sztuk, J.; Wichmann, K.; Wick, K.; Foudas, C.; Fry, C.; Long, K. R.; Tapper, A. D.; Kataoka, M.; Matsumoto, T.; Nagano, K.; Tokushuku, K.; Yamada, S.; Yamazaki, Y.; Barakbaev, A. N.; Boos, E. G.; Dossanov, A.; Pokrovskiy, N. S.; Zhautykov, B. O.; Son, D.; de Favereau, J.; Piotrzkowski, K.; Barreiro, F.; Glasman, C.; Jimenez, M.; Labarga, L.; Del Peso, J.; Ron, E.; Soares, M.; Terrón, J.; Zambrana, M.; Corriveau, F.; Liu, C.; Walsh, R.; Zhou, C.; Tsurugai, T.; Antonov, A.; Dolgoshein, B. A.; Rubinsky, I.; Sosnovtsev, V.; Stifutkin, A.; Suchkov, S.; Dementiev, R. K.; Ermolov, P. F.; Gladilin, L. K.; Katkov, I. I.; Khein, L. A.; Korzhavina, I. A.; Kuzmin, V. A.; Levchenko, B. B.; Lukina, O. Yu.; Proskuryakov, A. S.; Shcheglova, L. M.; Zotkin, D. S.; Zotkin, S. A.; Abt, I.; Büttner, C.; Caldwell, A.; Kollar, D.; Schmidke, W. B.; Sutiak, J.; Grigorescu, G.; Keramidas, A.; Koffeman, E.; Kooijman, P.; Pellegrino, A.; Tiecke, H.; Vázquez, M.; Wiggers, L.; Brümmer, N.; Bylsma, B.; Durkin, L. S.; Lee, A.; Ling, T. Y.; Allfrey, P. D.; Bell, M. A.; Cooper-Sarkar, A. M.; Cottrell, A.; Devenish, R. C. E.; Foster, B.; Korcsak-Gorzo, K.; Patel, S.; Roberfroid, V.; Robertson, A.; Straub, P. B.; Uribe-Estrada, C.; Walczak, R.; Bellan, P.; Bertolin, A.; Brugnera, R.; Carlin, R.; Ciesielski, R.; Dal Corso, F.; Dusini, S.; Garfagnini, A.; Limentani, S.; Longhin, A.; Stanco, L.; Turcato, M.; Oh, B. Y.; Raval, A.; Ukleja, J.; Whitmore, J. J.; Iga, Y.; D'Agostini, G.; Marini, G.; Nigro, A.; Cole, J. E.; Hart, J. C.; Abramowicz, H.; Gabareen, A.; Ingbir, R.; Kananov, S.; Levy, A.; Kuze, M.; Hori, R.; Kagawa, S.; Okazaki, N.; Shimizu, S.; Tawara, T.; Hamatsu, R.; Kaji, H.; Kitamura, S.; Ota, O.; Ri, Y. D.; Ferrero, M. I.; Monaco, V.; Sacchi, R.; Solano, A.; Arneodo, M.; Ruspa, M.; Fourletov, S.; Martin, J. F.; Boutle, S. K.; Butterworth, J. M.; Gwenlan, C.; Jones, T. W.; Loizides, J. H.; Sutton, M. R.; Targett-Adams, C.; Wing, M.; Brzozowska, B.; Ciborowski, J.; Grzelak, G.; Kulinski, P.; ?u?niak, P.; Malka, J.; Nowak, R. J.; Pawlak, J. M.; Tymieniecka, T.; Ukleja, A.; ?arnecki, A. F.; Adamus, M.; Plucinski, P.; Eisenberg, Y.; Giller, I.; Hochman, D.; Karshon, U.; Rosin, M.; Brownson, E.; Danielson, T.; Everett, A.; Kçira, D.; Reeder, D. D.; Ryan, P.; Savin, A. A.; Smith, W. H.; Wolfe, H.; Bhadra, S.; Catterall, C. D.; Cui, Y.; Hartner, G.; Menary, S.; Noor, U.; Standage, J.; Whyte, J.

2007-05-01

420

Topological Optimization of Beam Cross Section by Employing Extrusion Constraint  

NASA Astrophysics Data System (ADS)

Optimal cross-section design of beams plays a characteristic role which signifies the rigidity of the member in bending, shear and torsion load conditions. Practically modern overhead crane girders, railway bridge girders or rail tracks etc. require constant cross-section along the axial direction. Conventional topological optimization modeling procedures in such cases prove inadequate for the reason that these procedures generate non-uniform topologies along the axis of the bending member. To examine optimal topology of those structural bending members which commonly possess constant cross-section along the axis the topology optimization with extrusion constraint is more appropriate. The extrusion constraint method suggests a fresh approach to investigate optimal topologies of beam cross-section under the influence of realistic loading condition across the section at the beginning of design cycle. Presented study is focused upon the influence of various configuration and location of the load and boundary conditions on the topology of the of the beam cross-section which was not possible prior to the materialization of the extrusion or stamping constraint method. Several realistic loads and boundary conditions have been applied on the 3D beam model and optimal cross-section topologies obtained have uniform compliance history and convergent solutions. The lowest compliance criteria have been suggested to choose topologies as furthers shape and size optimization candidates during beam design process.

Zuberi, Rehan H.

2010-05-01

421

Electron-Impact Excitation Cross Sections for Metal Vapors  

NASA Astrophysics Data System (ADS)

Two simple scaling methods to generate integrated cross sections from plane-wave Born cross sections for dipole-allowed excitations of metal vapors by electron impact(Y.-K. Kim, Phys. Rev. A, 64), in print. are shown to produce cross sections comparable in accuracy to those obtained by more sophisticated collision theories, such as the convergent close-coupling method. The scaled cross sections ?_BE and ?f are: ?_BE=?_PW×[T/(T+B+E)], ?_f=?_PWsc×(f_mc/f_sc), where ?_PW=unscaled plane-wave Born cross section, T=incident electron energy, B=binding energy of the target electron, E=excitation energy, f_mc and f_sc are the dipole f-values calculated from multiconfiguration wave functions and single-configuration wave functions, respectively. The two scalings can be used consecutively. The scaled cross section for the 4s-4p excitation of Cu is in excellent agreement with the experiment by Ismail and Teubner.(M. Ismail and P. J. O. Teubner, J. Phys. B 28) 4149 (1995) Many examples of resonance transitions of atoms, including Ag, Au, and Hg, will be presented.

Kim, Yong-Ki

2001-10-01

422

Mental visualization of objects from cross-sectional images.  

PubMed

We extended the classic anorthoscopic viewing procedure to test a model of visualization of 3D structures from 2D cross-sections. Four experiments were conducted to examine key processes described in the model, localizing cross-sections within a common frame of reference and spatiotemporal integration of cross sections into a hierarchical object representation. Participants used a hand-held device to reveal a hidden object as a sequence of cross-sectional images. The process of localization was manipulated by contrasting two displays, in situ vs. ex situ, which differed in whether cross sections were presented at their source locations or displaced to a remote screen. The process of integration was manipulated by varying the structural complexity of target objects and their components. Experiments 1 and 2 demonstrated visualization of 2D and 3D line-segment objects and verified predictions about display and complexity effects. In Experiments 3 and 4, the visualized forms were familiar letters and numbers. Errors and orientation effects showed that displacing cross-sectional images to a remote display (ex situ viewing) impeded the ability to determine spatial relationships among pattern components, a failure of integration at the object level. PMID:22217386

Wu, Bing; Klatzky, Roberta L; Stetten, George D

2012-01-02

423

Krypton charge exchange cross sections for Hall effect thruster models  

NASA Astrophysics Data System (ADS)

Following discharge from a Hall effect thruster, charge exchange occurs between ions and un-ionized propellant atoms. The low-energy cations produced can disturb operation of onboard instrumentation or the thruster itself. Charge-exchange cross sections for both singly and doubly charged propellant atoms are required to model these interactions. While xenon is the most common propellant currently used in Hall effect thrusters, other propellants are being considered, in particular, krypton. We present here guided-ion beam measurements and comparisons to semiclassical calculations for Kr+ + Kr and Kr2+ + Kr cross sections. The measurements of symmetric Kr+ + Kr charge exchange are in good agreement with both the calculations including spin-orbit effects and previous measurements. For the symmetric Kr2+ + Kr reaction, we present cross section measurements for center-of-mass energies between 1 eV and 300 eV, which spans energies not previously examined experimentally. These cross section measurements compare well with a simple one-electron transfer model. Finally, cross sections for the asymmetric Kr2+ + Kr --> Kr+ + Kr+ reaction show an onset near 12 eV, reaching cross sections near constant value of 1.6 A?2 with an exception near 70-80 eV.

Hause, Michael L.; Prince, Benjamin D.; Bemish, Raymond J.

2013-04-01

424

Cross-sectional area and intensity variations of sausage modes  

NASA Astrophysics Data System (ADS)

Context. The observations obtained using the Rapid Oscillations in the Solar Atmosphere instrument (ROSA) show variations in both cross-sectional area and intensity for magnetic pores in the photosphere. Aims: We study the phase behaviour between cross-sectional area and intensity variations for sausage modes in a photospheric context. We aim to determine the wave mode by looking at the phase difference between the cross-sectional area and intensity variations. Methods: We used a straight cylinder as a model for the flux tube. The plasma is uniform both inside and outside the flux tube with a possible jump in the equilibrium values at the boundary, the magnetic field is directed along the flux tube. We derived analytic expressions for the cross-sectional area variation and the total intensity variation. Using these analytic expressions, we calculated the phase differences between the cross-sectional area and the intensity variations. These phase differences were then used to identify the wave mode. Results: We found that for slow sausage modes the cross-sectional area and intensity variations are always in phase, while for fast sausage modes the variations are in antiphase. Appendix A is available in electronic form at http://www.aanda.org

Moreels, M. G.; Goossens, M.; Van Doorsselaere, T.

2013-07-01

425

Effects of ? centers and symmetry on two-photon absorption cross sections of organic chromophores  

NASA Astrophysics Data System (ADS)

We have theoretically examined a series of organic molecules that exhibit large two-photon absorption cross sections in the visible region and that have been synthesized in different laboratories. One- and two-photon absorption cross sections of the four lowest excited states of each molecule have been calculated at the same theoretical level using ab initio response theory. It is found that the molecular length and the one-photon absorption intensity are quite strongly correlated factors, but that a corresponding correlation for the two-photon absorption is much weaker or is missing. In contrast, a most crucial role for large two-photon absorption is played by the ? center. For molecules with a given ? center a symmetrical structure with strong donor groups can result in a maximum two-photon absorption cross section. Our theoretical findings are consistent with some recent experimental observations. The chromophore based on dithienothiophene as ? center attached with symmetrical N,N-diphenylamine donors is found to have the largest two-photon cross section in the visible region among all known one-dimensional two-photon organic materials that have been reported in the literature.

Wang, Chuan-Kui; Macak, Peter; Luo, Yi; A?Gren, Hans

2001-06-01

426

THE FREE ANTINEUTRINO ABSORPTION CROSS SECTION. PART I. MEASUREMENT OF THE FREE ANTINEUTRINO ABSORPTION CROSS SECTION. PART II. EXPECTED CROSS SECTION FROM MEASUREMENTS OF FISSION FRAGMENT ELECTRON SPECTRUM  

Microsoft Academic Search

Part I. The cross section for the reactioa, vâ+ p yields BETA \\/; sup +\\/ + n, was measured using reactor antineutrinos (vâ). Target protons ; were provided by a 370 gallon liquid scintiliation detector in which the ; scintillator solution (triethylbenzene, terphenyl, and POPOP) was loaded with a ; cadmlum compound (cadmium octoate) to allow the detection of the

F. Reines; C. L. Jr. Cowan; R. E. Carter; J. J. Wagner; M. E. Wyman

1958-01-01

427

Neutron Cross Section Covariances: Recent Workshop and Advanced Reactor Systems  

NASA Astrophysics Data System (ADS)

The recent Workshop on Neutron Cross Section Covariances, organized by BNL and attended by more than 50 scientists, responded to demands of many user groups, including advanced reactor systems, for uncertainty and correlation information. These demands can be explained by considerable progress in advanced neutronics simulation that probe covariances and their impact on design and operational margins of nuclear systems. The Workshop addressed evaluation methodology, recent evaluations as well as user's perspective, marking era of revival of covariance development that started some two years ago. We illustrate urgent demand for covariances in the case of advanced reactor systems, including fast actinide burner under GNEP, new generation of power reactors, Gen-IV, and reactors under AFCI. A common feature of many of these systems is presence of large amount of minor actinides and fission products that require improved nuclear data. Advanced simulation codes rely on quality input, to be obtained by adjusting the data library, such as the new ENDF/B-VII.0, by considering integral experiments as currently pursued by GNEP. To this end the nuclear data community is developing covariances for formidable amount of 112 materials (isotopes).

Oblozinsky, Pavel

2008-10-01

428

Respiratory hazards in hard metal workers: a cross sectional study.  

PubMed Central

A cross sectional study was conducted on 513 employees at three hard metal plants: 425 exposed workers (351 men, 74 women) and 88 controls (69 men, 19 women). Cough and sputum were more frequent in workers engaged in "soft powder" and presintering workshops compared with controls (12.5% and 16.5% v 3.5%). Spirometric abnormalities were more frequent among women in sintering and finishing workshops compared with control women (56.8% v 23.8%) and abnormalities of carbon monoxide test were more frequent in exposed groups than in controls; this difference was more pronounced in women (31.4% v 5.6%) than in men (18.5% v 13%). No significant correlation was observed between duration of exposure and age adjusted lung function tests. Slight abnormalities of chest radiographs (0/1, 1/1 according to ILO classification) were more frequent in exposed men than controls (12.8% v 1.9%) and mostly in soft powder workers. In subjects with abnormal chest radiographs FVC, FEV1 and carbon monoxide indices (fractional uptake of CO or CO transfer index or both) were lower compared with those with normal chest radiographs. Although relatively mild, the clinical, radiological, and functional abnormalities uncovered call for a regular supervision of workers exposed to hard metal dust.

Meyer-Bisch, C; Pham, Q T; Mur, J M; Massin, N; Moulin, J J; Teculescu, D; Carton, B; Pierre, F; Baruthio, F

1989-01-01

429

Inelastic partial cross sections for scattering of HF by neon  

NASA Astrophysics Data System (ADS)

An analytic expression of the potential energy surface (PES) of the ground state of the Ne-HF complex is obtained by utilizing nonlinear least square method to fit the intermolecular interaction energies [Zhang Y. Guizhou Science, 2003, 21(3): 9-13 (in Chinese)], which have been computed using the augmented correlation-consistent polarized quadruple zeta basis set aug-cc-pVQZ at the theoretical level of CCSD (T). On the basis of the PES, the partial cross sections (PCSs) at the incident energies of 60, 75, 100 and 150 meV for collisions between Ne atoms and HF molecules are calculated using the quantum close coupling approach. The effects of the long-range attractive and the short-range anisotropic interactions on the inelastic PCSs are discussed in detail. The results show: (1) The long-range attractive well of the EPS makes the significant contribution to the lower excitation PCSs, especially the tail maximum for j = 0? j' = 1 transitions, whereas no contribution is to the j'?3 inelastic transitions. (2) The short-range (the repulsive and attractive) interaction makes the significant contribution to the lower excitation PCSs, especially the main peak for j = 0? j' = 1, 2. As for the transitions of j'?3, the short-range interaction plays a key role in the inelastic excitation. (3) Although the positions of the maximums and minimums of the inelastic PCSs are different at the collision energies, they correspond to almost the same impact parameter.

Yu, Chunri; Yang, Xiangdong; Cheng, Xinlu

2009-04-01

430

The use of out of hours health services: a cross sectional survey  

Microsoft Academic Search

AbstractObjectives: To determine the use and costs of the principal out of hours health services in Buckinghamshire.Design: Prospective cross sectional survey and cost description of patient contacts with out of hours services.Setting: Buckinghamshire during March and April 1995.Subjects: General practices, accident and emergency departments, ambulance services, and community nursing services.Main outcome measure: Contacts with patients and cost of out of

Catherine Brogan; Diane Pickard; Alastair Gray; Steve Fairman; Alison Hill

1998-01-01

431

Calculation of mean collision cross sections of free radical OH with foreign gases  

Microsoft Academic Search

The mean collision cross sections of OH perturbed by foreign gases have been calculated for microwave and far infrared spectra in the X2Pi electronic ground state. A semi-classical formalism is used, which includes a parabolic description of the trajectory. The interaction potential is described as a sum of electrostatic contributions and both short-range and long-range anisotropic forces by using an

A. Khayar; J. Bonamy

1982-01-01