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1

Topics for a statistical description of radar cross section  

Microsoft Academic Search

A comprehensive guide to the statistical description of radar cross section (RCS) is presented. The topics discussed include: definition of field quantities and Maxwell's equations, constitutive relations, boundary conditions and surface currents, Green's functions, diffraction of a plane wave by a perfectly absorbing half-plane, asymptotic approximation methods, and diffraction approximation methods. Also considered are: numerical approximations and numerical methods, RCS

Andrew Lewis Maffett

1989-01-01

2

Complex Correlation Calculation of e-H Total Cross Sections  

NASA Technical Reports Server (NTRS)

Calculation of e - H total and elastic partial wave cross sections is being carried out using the complex correlation variational T-matrix method. In this preliminary study, elastic partial wave phase shifts are calculated with the correlation functions which are confined to be real. In that case the method reduces to the conventional optical potential approach with projection operators.

Bhatia, A. K.; Temkin, Aaron; Fisher, Richard R. (Technical Monitor)

2001-01-01

3

Topics for a statistical description of radar cross section  

NASA Astrophysics Data System (ADS)

A comprehensive guide to the statistical description of radar cross section (RCS) is presented. The topics discussed include: definition of field quantities and Maxwell's equations, constitutive relations, boundary conditions and surface currents, Green's functions, diffraction of a plane wave by a perfectly absorbing half-plane, asymptotic approximation methods, and diffraction approximation methods. Also considered are: numerical approximations and numerical methods, RCS measurements, RCS of simple and complex shapes, new method for comparing experimental and theoretical data, elements of detection theory, impedance boundary condition, reflection and transmission, stratified media, gyroelectromagnetic layers, and the inverse problem for biaxial materials. As examples, the 727 at 0.94 GHz and the Firebee at 9.0 GHz are examined.

Maffett, Andrew Lewis

4

Complex Correlation Calculation of e-H Total Cross Sections  

NASA Technical Reports Server (NTRS)

Calculation of e-H total and elastic partial wave cross sections is being carried out using the complex correlation variational T-matrix method. In this preliminary study, elastic partial wave phase shifts are calculated with the correlation functions which are confined to be real. In that case the method reduces to the conventional optical potential approach with projection operators. The number of terms in the Hylleraas-type wave function for the S phase shifts is 95 while for the S it is 56, except for k=0.8 where it is 84. Our results, which are rigorous lower bounds, are given. They are seen to be in general agreement with those of Schwartz, but they are of 0 greater accuracy and outside of his error limits for k=0.3 and 0.4 for S. The main aim of this approach' is the application to higher energy scattering. By virtue of the complex correlation functions, the T matrix is not unitary so that elastic and total scattering cross sections are independent of each other. Our results will be compared specifically with those of Bray and Stelbovics.

Bhatia, A. K.; Temkin, A.; Fisher, Richard R. (Technical Monitor)

2001-01-01

5

Complex Correlation Calculation of e(-) - H Total Cross Sections  

NASA Technical Reports Server (NTRS)

Calculation of e(-) - H total and elastic partial wave cross sections is being carried out using the complex correlation variational T-matrix method. In this preliminary study, elastic partial wave phase shifts are calculated with the correlation functions which are confined to be real. In that case the method reduces to the conventional optical potential approach with 2 projection operators. The number of terms in the Hylleraas-type wave function for the S-1 phase shifts is 95 while for the S-3 it is 56, except for k = 0.8 where it is 84. Our results, which are rigorous lower bounds, are seen to be in general agreement with those of Schwartz, but they are of greater accuracy and outside of his error limits for k = 0.3 and 0.4 for S-1. The main aim of this approach is the application to higher energy scattering. By virtue of the complex correlation functions, the T-matrix is not unitary so that elastic and total scattering cross sections are independent of each other. Our results will be compared specifically with those of Bray and Stelbovics.

Bhatia, A. K.; Temkin, A.; Fisher, Richard R. (Technical Monitor)

2001-01-01

6

Correlation analysis of optical absorption cross section and rate coefficient measurements in reacting systems  

SciTech Connect

A technique was developed for determining relative importance and correlation between reactions making up a complex kinetic system. This technique was used to investigate measurements of optical absorption cross sections and the correlation between cross sections and measured rate coefficients. It is concluded that (1) species, initial conditions, and temporal regions may be identified where cross sections may be measured without interference from the kinetic behavior of the observed species and (2) experiments designed to measure rate coefficients will always be correlated with the absorption cross section of the observed species. This correlation may reduce the accuracy of rate coefficient measurements.

Hessler, J.P. [Argonne National Lab., IL (United States); Ogren, P.J. [Earlham College, Richmond, IN (United States). Dept. of Chemistry

1992-08-31

7

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)] [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

8

Correlation between radar cross section and ballistic coefficient for orbiting objects  

NASA Astrophysics Data System (ADS)

The correlation between radar cross sections and ballistic coefficients for orbiting objects is studied using orbital element data from NORAD and radar cross section data from the radar systems at Eglin Air Force Base. The time variation of the orbital elements is used to calculate an accurate effective ballistic coefficient for representative orbiting objects of various sizes. These are compared with radar cross sections from several observations of the same object. The results of the study tend to support Kessler's conjecture that the correlation between radar cross section and effective area is poor in the absence of detailed information about the target and that the correlation is worse for the smallest detectable objects than for larger objects.

Culp, Robert D.; Dickey, Michael R.

9

Description of sub-barrier fusion cross sections by the proximity potential  

Microsoft Academic Search

In search of a global and intrinsically consistent description of the sub-barrier fusion cross sections, an optical-model calculation for systems with colliding nuclei in the 9 <= A <= 20 mass region is presented here, with the proximity potential as real part and an energy-independent Woods-Saxon form as imaginary part. The parameters of the model are carefully determined by fitting

Q. Haider; B. Ujec

1984-01-01

10

Endoanal MRI of the anal sphincter complex: correlation with cross-sectional anatomy and histology.  

PubMed Central

The purpose of this study was to correlate the in vivo endoanal MRI findings of the anal sphincter with the cross-sectional anatomy and histology. Fourteen patients with rectal tumours were examined with a rigid endoanal MR coil before undergoing abdominoperineal resection. In addition, 12 cadavers were used to obtain cross-sectional anatomical sections. The images were correlated with the histology and anatomy of the resected rectal specimens as well as with the cross-sectional anatomical sections of the 12 cadavers. The findings in 8 patients, 11 rectal preparations, and 10 cadavers, could be compared. In these cases, there was an excellent correlation between endoanal MRI and the cross-sectional cadaver anatomy and histology. With endoanal MRI, all muscle layers of the anal canal wall, comprising the internal anal sphincter, longitudinal muscle, the external anal sphincter and the puborectalis muscle were clearly visible. The levator ani muscle and ligamentous attachments were also well demonstrated. The perianal anatomical spaces, containing multiple septae, were clearly visible. In conclusion, endoanal MRI is excellent for visualising the anal sphincter complex and the findings show a good correlation with the cross-sectional anatomy and histology. Images Fig. 1 Fig. 2

Hussain, S M; Stoker, J; Zwamborn, A W; Den Hollander, J C; Kuiper, J W; Entius, C A; Lameris, J S

1996-01-01

11

Correlated reduction in micropipe cross sections in SiC growth  

NASA Astrophysics Data System (ADS)

We reveal a correlated reduction in the cross sections of two neighboring micropipes (MPs) in the crystal growth of silicon carbide using computer simulation of phase contrast images. The correlated reduction is explained by the exchange of full-core dislocations in a contact-free reaction between two parallel MPs. We develop a theoretical model that describes the energetics of this process.

Gutkin, M. Yu.; Sheinerman, A. G.; Smirnov, M. A.; Kohn, V. G.; Argunova, T. S.; Je, J. H.; Jung, J. W.

2008-10-01

12

Correlated reduction in micropipe cross sections in SiC growth  

Microsoft Academic Search

We reveal a correlated reduction in the cross sections of two neighboring micropipes (MPs) in the crystal growth of silicon carbide using computer simulation of phase contrast images. The correlated reduction is explained by the exchange of full-core dislocations in a contact-free reaction between two parallel MPs. We develop a theoretical model that describes the energetics of this process.

M. Yu. Gutkin; A. G. Sheinerman; M. A. Smirnov; V. G. Kohn; T. S. Argunova; J. H. Je; J. W. Jung

2008-01-01

13

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

NASA Technical Reports Server (NTRS)

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.

1993-01-01

14

Screening premorbid metabolic syndrome in community pharmacies: a cross-sectional descriptive study  

PubMed Central

Background Premorbid metabolic syndrome (pre-MetS) is a cluster of cardiometabolic risk factors characterised by central obesity, elevated fasting glucose, atherogenic dyslipidaemia and hypertension without established cardiovascular disease or diabetes. Community pharmacies are in an excellent position to develop screening programmes because of their direct contact with the population. The main aim of the study was to determine the prevalence of pre-MetS in people who visited community pharmacies for measurement of any of its five risk factors to detect the presence of other risk factors. The secondary aims were to study the presence of other cardiovascular risk factors and determine patients’ cardiovascular risk. Methods Cross-sectional, descriptive, multicentre study. Patients meeting selection criteria aged between 18 and 65 years who visited participating community pharmacies to check any of five pre-MetS diagnostic factors were included.The study involved 23 community pharmacies in Catalonia (Spain). Detection criteria for pre-MetS were based on the WHO proposal following IDF and AHA/NHBI consensus. Cardiovascular risk (CVR) was calculated by Regicor and Score methods. Other variables studied were smoking habit, physical activity, body mass index (BMI), and pharmacological treatment of dyslipidemia and hypertension. The data were collected and analysed with the SPSS programme. Comparisons of variables were carried out using the Student’s T-test, Chi-Squared test or ANOVA test. Level of significance was 5% (0.05). Results The overall prevalence of pre-MetS was 21.9% [95% CI 18.7-25.2]. It was more prevalent in men, 25.5% [95% CI 22.1-28.9], than in women, 18.6% [95% CI 15.5-21.7], and distribution increased with age. The most common risk factors were high blood pressure and abdominal obesity. About 70% of people with pre-MetS were sedentary and over 85% had a BMI ?25 Kg/m2. Some 22.4% had two metabolic criteria and 27.2% of patients with pre-MetS had no previous diagnosis. Conclusions The prevalence of pre-MetS in our study (21.9%) was similar to that found in other studies carried out in Primary Care in Spain. The results of this study confirm emergent cardiometabolic risk factors such as hypertension, obesity and physical inactivity. Our study highlights the strategic role of the community pharmacy in the detection of pre-MetS in the apparently healthy population.

2014-01-01

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

Target correlation effects on neutron-nucleus total, absorption, and abrasion cross sections  

NASA Technical Reports Server (NTRS)

Second order optical model solutions to the elastic scattering amplitude were used to evaluate total, absorption, and abrasion cross sections for neutron nucleus scattering. Improved agreement with experimental data for total and absorption cross sections is found when compared with first order (coherent approximation) solutions, especially below several hundred MeV. At higher energies, the first and second order solutions are similar. There are also large differences in abrasion cross section calculations; these differences indicate a crucial role for cluster knockout in the abrasion step.

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

1991-01-01

17

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

18

Social, cultural and economical determinants of diabetes mellitus in Kalutara district, Sri Lanka: a cross sectional descriptive study  

PubMed Central

Introduction Sri Lanka is a country that is expected to face a high burden of diabetes mellitus (DM). There is a paucity of data on social and demographic determinants of DM, especially in the plantation sector. Aims To describe social and economic correlates and inequalities of DM in Kalutara District. Methods A cross sectional descriptive study was carried out among adults over the age of 35 years. A sample of 1300 individuals was selected using stratified random cluster sampling method from 65 Grama Niladari Divisions (GND), which were representative of urban, rural and plantation sectors. Twenty households were randomly selected from each division and one adult was randomly selected from each household. Data were collected using a pre-tested questionnaire. Fasting plasma blood sugar of ?126mg/dl was used to define DM. Significance of prevalence of diseases and risk factors across different socio-economic strata were determined by chi square test for trend. Results Of 1234 adults who were screened (628 males), 202 (14.7%) had DM. Higher DM proportions (16.1%) were seen in the highest income quintile and in those educated up to Advanced Levels (AL) and above (17.3%). Prevalence in the urban, rural and plantation sectors were 23.6%, 15.5% and 8.5% respectively. Prevalence among Sinhalese, Tamils and Muslims were 14.4%, 29.0% and 20.0% respectively. There was a gradient in prevalence according to the unsatisfactory basic needs index of the GND with the highest proportion (20.7%) observed in the richest GND. The highest social status quintile demonstrated the highest proportion (17.4%) with diabetes mellitus. Conclusion There is a higher prevalence of diabetes mellitus in the more affluent and educated segments of society. There is also a higher prevalence among urban compared to rural and estates. Sri Lanka is in an early stage of the epidemic where the wealthy people are at a higher risk of DM.

2012-01-01

19

Correlates of COPD and chronic bronchitis in nonsmokers: data from a cross-sectional study  

PubMed Central

Purpose Our objective was to assess the prevalence of chronic bronchitis and chronic obstructive pulmonary disease (COPD) and their correlates among a Lebanese nonsmoker group. Material and methods A cross-sectional study was conducted between October 2009 and September 2010, using a multistage cluster sample throughout Lebanon including Lebanese residents aged 40 years and above with no exclusion criteria. Pre- and postbronchodilator spirometry measurements were performed and carbon monoxide level was measured in exhaled air. COPD was defined and classified according to the Global Initiative for Chronic Obstructive Lung Disease guidelines or according to the lower limit of normal (forced expiratory volume in 1 second/forced vital capacity postbronchodilator < 5th percentile of the healthy population having the same age and sex). Chronic bronchitis was defined by the declaration of morning cough and expectorations for more than 3 months a year over more than 2 years in individuals with normal spirometry. Results Out of 2201 individuals, 732 were never-smokers: 25 (3.4%) of them had COPD, and 86 (11.75%) fulfilled the definition of chronic bronchitis. Correlates of COPD included a childhood respiratory disease, house heated by diesel, and older age. On the other hand, correlates of chronic bronchitis included childhood respiratory diseases, living in southern Lebanon versus other regions, heating home by gas, older age, number of smokers at work, and lower height. Conclusion A substantial percentage of the nonsmoking population may exhibit chronic bronchitis or COPD. The significant correlates mentioned above should be taken into consideration in order to reduce the risk of developing such chronic and debilitating respiratory diseases.

Waked, Mirna; Salame, Joseph; Khayat, Georges; Salameh, Pascale

2012-01-01

20

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

21

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

22

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

23

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

24

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

PubMed

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 regression analysis was conducted to assess the associations of Body Mass Index (BMI), demographic factors and psychosocial variables from the TPB with the intention to prevent weight gain. Differences in BMI, demographic and psychosocial factors between PAPM-stages were explored using one-way analysis of variance and chi-square tests. RESULTS: Eighty-five percent of respondents intended to prevent weight gain. Age, attitudes and risk perceptions related to weight gain were the strongest correlates of intention (age: OR = 1.12, 95%CI: 1.04-1.20; attitude OR = 7.91, 95%CI: 5.33-11.74; risk perception OR = 1.24, 95%CI: 1.11-1.38). Significant differences were detected between the PAPM-stages in almost all variables. Notably, perceived behavioural control was lowest among people who had decided to prevent weight gain. CONCLUSION: Messages to influence attitudes towards the prevention of weight gain and risk perception may affect people who are not yet motivated to prevent weight gain. Interventions increasing people's perceived behavioural control in overcoming barriers to prevent weight gain may help people to act on their intentions. PMID:15771774

Wammes, Birgitte; Kremers, Stef; Breedveld, Boudewijn; Brug, Johannes

2005-03-16

25

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

26

Correlates of tobacco cessation counseling among Hispanic physicians in the US: A cross-sectional survey study  

PubMed Central

Background Physician advice is an important motivator for attempting to stop smoking. However, physicians' lack of intervention with smokers has only modestly improved in the last decade. Although the literature includes extensive research in the area of the smoking intervention practices of clinicians, few studies have focused on Hispanic physicians. The purpose of this study was to explore the correlates of tobacco cessation counseling practices among Hispanic physicians in the US. Methods Data were collected through a validated survey instrument among a cross-sectional sample of self-reported Hispanic physicians practicing in New Mexico, and who were members of the New Mexico Hispanic Medical Society in the year 2001. Domains of interest included counseling practices, self-efficacy, attitudes/responsibility, and knowledge/skills. Returned surveys were analyzed to obtain frequencies and descriptive statistics for each survey item. Other analyses included: bivariate Pearson's correlation, factorial ANOVAs, and multiple linear regressions. Results Respondents (n = 45) reported a low level of compliance with tobacco control guidelines and recommendations. Results indicate that physicians' familiarity with standard cessation protocols has a significant effect on their tobacco-related practices (r = .35, variance shared = 12%). Self-efficacy and gender were both significantly correlated to tobacco related practices (r = .42, variance shared = 17%). A significant correlation was also found between self-efficacy and knowledge/skills (r = .60, variance shared = 36%). Attitudes/responsibility was not significantly correlated with any of the other measures. Conclusion More resources should be dedicated to training Hispanic physicians in tobacco intervention. Training may facilitate practice by increasing knowledge, developing skills and, ultimately, enhancing feelings of self-efficacy.

Mas, Francisco G Soto; Balcazar, Hector G; Alberola, Julia Valderrama; Ed Hsu, Chiehwen

2008-01-01

27

Correlation of discrete Minnelusa porosity intervals and identification of common reservoirs aided by computer-drawn geologic cross sections, Powder River basin, northeast Wyoming  

SciTech Connect

The upper Minnelusa Formation in the northeastern Wyoming portion of the Powder River basin continues to challenge geologists. Oil exploration and development success depends heavily on correct correlation of discrete porosity intervals within the sand-dolomite series of the upper Minnelusa oil-bearing interval. Drill cores generally are not available. Correlation work must be performed on the basis of electric logs, drill cutting descriptions, and the expertise provided by the experienced geologist. Correlation of discrete porosity units and reservoir delineation can be improved by greater uses of the resistivity log, which is generally available in conjunction with the sonic porosity log. The salinity of the water (R/sub W/) commonly shows variance within the upper Minnelusa section, and thus suggests separate confined reservoirs. Software has been developed for Apple's Macintosh computer that allows a screen display of digitized electric-log data and calculated results. Geologic markers can be picked by user interaction with the screen display. Geologic cross sections can then be printed quickly on the dot matrix printer and no costly plotter bed is required. The cross sections can be presented on either a subsea datum or a user-defined geologic marker. Detailed foot-by-foot water saturation calculations are performed on the digitized data, and plotted on the log cross sections. By means of known or what-if water resistivity inputs, identification of separately confined reservoirs is possible. Computer generated cross sections showing examples of how correlation work can be aided by detailed calculations from digitized well log data will be presented for poster display. The hardware, consisting of Apple's Macintosh computer, Image Writer printer, and device for digitizing well logs will be displayed and demonstrated for interested viewers.

Borgerding, J.H.

1987-08-01

28

Correlations among measures of quality in HIV care in the United States: cross sectional study  

Microsoft Academic Search

Objective To determine whether a selected set of indicators can represent a single overall quality construct.Design Cross sectional study of data abstracted during an evaluation of an initiative to improve quality of care for people with HIV.Setting 69 sites in 30 states.Data sources Medical records of 9020 patients.Main outcome measures Adjusted performance rates at site level for eight measures of

Ira B Wilson; Bruce E Landon; Peter V Marsden; Lisa R Hirschhorn; Keith McInnes; Lin Ding; Paul D Cleary

2007-01-01

29

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

30

Diffusion in a tube of varying cross section: Numerical study of reduction to effective one-dimensional description  

NASA Astrophysics Data System (ADS)

Brownian dynamics simulations of the particle diffusing in a long conical tube (the length of the tube is much greater than its smallest radius) are used to study reduction of the three-dimensional diffusion in tubes of varying cross section to an effective one-dimensional description. The authors find that the one-dimensional description in the form of the Fick-Jacobs equation with a position-dependent diffusion coefficient, D(x), suggested by Zwanzig [J. Phys. Chem. 96, 3926 (1992)], with D(x) given by the Reguera-Rubí formula [Phys. Rev. E 64, 061106 (2001)], D(x)=D/1+R'(x)2, where D is the particle diffusion coefficient in the absence of constraints, and R(x) is the tube radius at x, is valid when |R'(x)|<=1. When |R'(x)|>1, higher spatial derivatives of the one-dimensional concentration in the effective diffusion equation cannot be neglected anymore as was indicated by Kalinay and Percus [J. Chem. Phys. 122, 204701 (2005)]. Thus the reduction to the effective one-dimensional description is a useful tool only when |R'(x)|<=1 since in this case one can apply the powerful standard methods to analyze the resulting diffusion equation.

Berezhkovskii, A. M.; Pustovoit, M. A.; Bezrukov, S. M.

2007-04-01

31

Inclusive jet cross sections and dijet correlations in D ? ± photoproduction at HERA  

Microsoft Academic Search

Inclusive jet cross sections in photoproduction for events containing a D? meson have been measured with the ZEUS detector at HERA using an integrated luminosity of 78.6 pb?1. The events were required to have a virtuality of the incoming photon, Q2, of less than 1 GeV2, and a photon–proton centre-of-mass energy in the range 130W?p280 GeV. The measurements are compared with next-to-leading-order

S. Bhadra; C. D. Catterall; Y. Cui; G. Hartner; S. Miglioranzi; U. Noor; M. Soares; J. Standage; J. Whyte; N. Pavel; A. G. Yagües Molina; P. Antonioli; G. Bari; M. Basile; L. Bellagamba; D. Boscherini; A. Bruni; G. Bruni; G. Cara Romeo; L. Cifarelli; F. Cindolo; A. Contin; M. Corradi; S. de Pasquale; P. Giusti; G. Iacobucci; A. Margotti; A. Montanari; R. Nania; F. Palmonari; A. Pesci; A. Polini; L. Rinaldi; G. Sartorelli; A. Zichichi; G. Aghuzumtsyan; D. Bartsch; I. Brock; S. Goers; H. Hartmann; E. Hilger; P. Irrgang; H.-P. Jakob; O. M. Kind; U. Meyer; E. Paul; J. Rautenberg; R. Renner; M. Wang; M. Wlasenko; D. S. Bailey; N. H. Brook; J. E. Cole; G. P. Heath; T. Namsoo; S. Robins; M. Capua; S. Fazio; A. Mastroberardino; M. Schioppa; G. Susinno; E. Tassi; J. Y. Kim; K. J. Ma; M. Helbich; Y. Ning; Z. Ren; W. B. Schmidke; F. Sciulli; J. Chwastowski; A. Eskreys; J. Figiel; A. Galas; M. Gil; K. Olkiewicz; P. Stopa; D. Szuba; L. Zawiejski; L. Adamczyk; T. Bold; I. Grabowska-Bold; D. Kisielewska; J. Lukasik; M. Przybycien; L. Suszycki; J. Szuba; A. Kotanski; W. Slominski; V. Adler; U. Behrens; I. Bloch; K. Borras; G. Drews; J. Fourletova; A. Geiser; D. Gladkov; P. Göttlicher; O. Gutsche; T. Haas; W. Hain; C. Horn; B. Kahle; U. Kötz; H. Kowalski; G. Kramberger; H. Lim; B. Löhr; R. Mankel; I.-A. Melzer-Pellmann; C. N. Nguyen; D. Notz; A. E. Nuncio-Quiroz; A. Raval; R. Santamarta; U. Schneekloth; H. Stadie; U. Stösslein; G. Wolf; C. Youngman; W. Zeuner; S. Schlenstedt; G. Barbagli; E. Gallo; C. Genta; P. G. Pelfer; A. Bamberger; A. Benen; F. Karstens; D. Dobur; N. N. Vlasov; P. J. Bussey; A. T. Doyle; W. Dunne; J. Ferrando; J. H. McKenzie; D. H. Saxon; I. O. Skillicorn; I. Gialas; T. Carli; T. Gosau; U. Holm; N. Krumnack; E. Lohrmann; M. Milite; H. Salehi; P. Schleper; T. Schörner-Sadenius; S. Stonjek; K. Wichmann; K. Wick; A. Ziegler; C. Collins-Tooth; C. Foudas; C. Fry; R. Gonçalo; K. R. Long; A. D. Tapper; M. Kataoka; K. Nagano; K. Tokushuku; S. Yamada; Y. Yamazaki; A. N. Barakbaev; E. G. Boos; N. S. Pokrovskiy; B. O. Zhautykov; D. Son; J. de Favereau; K. Piotrzkowski; F. Barreiro; C. Glasman; M. Jimenez; L. Labarga; J. Del Peso; J. Terrón; M. Zambrana; F. Corriveau; C. Liu; M. Plamondon; A. Robichaud-Veronneau; R. Walsh; C. Zhou; T. Tsurugai; A. Antonov; B. A. Dolgoshein; I. Rubinsky; V. Sosnovtsev; A. Stifutkin; S. Suchkov; R. K. Dementiev; P. F. Ermolov; L. K. Gladilin; I. I. Katkov; L. A. Khein; I. A. Korzhavina; V. A. Kuzmin; B. B. Levchenko; O. Yu. Lukina; A. S. Proskuryakov; L. M. Shcheglova; D. S. Zotkin; S. A. Zotkin; I. Abt; C. Büttner; A. Caldwell; X. Liu; J. Sutiak; N. Coppola; G. Grigorescu; A. Keramidas; E. Koffeman; P. Kooijman; E. Maddox; H. Tiecke; M. Vázquez; L. Wiggers; N. Brümmer; B. Bylsma; L. S. Durkin; A. Lee; T. Y. Ling; P. D. Allfrey; M. A. Bell; A. M. Cooper-Sarkar; A. Cottrell; R. C. E. Devenish; B. Foster; C. Gwenlan; T. Kohno; K. Korcsak-Gorzo; S. Patel; V. Roberfroid; P. B. Straub; R. Walczak; P. Bellan; A. Bertolin; R. Brugnera; R. Carlin; R. Ciesielski; F. Dal Corso; S. Dusini; A. Garfagnini; S. Limentani; A. Longhin; L. Stanco; M. Turcato; E. A. Heaphy; F. Metlica; B. Y. Oh; J. J. Whitmore; Y. Iga; G. D'Agostini; G. Marini; A. Nigro; J. C. Hart; H. Abramowicz; A. Gabareen; S. Kananov; A. Kreisel; A. Levy; M. Kuze; S. Kagawa; T. Tawara; R. Hamatsu; H. Kaji; S. Kitamura; K. Matsuzawa; O. Ota; Y. D. Ri; M. Costa; M. I. Ferrero; V. Monaco; R. Sacchi; A. Solano; M. Arneodo; M. Ruspa; S. Fourletov; J. F. Martin; J. M. Butterworth; R. Hall-Wilton; T. W. Jones; J. H. Loizides; M. R. Sutton; C. Targett-Adams; M. Wing; J. Ciborowski; G. Grzelak; P. Kulinski; P. Luzniak; J. Malka; R. J. Nowak; J. M. Pawlak; J. Sztuk; T. Tymieniecka; A. Ukleja; J. Ukleja; A. F. Zarnecki; M. Adamus; P. Plucinski; Y. Eisenberg; D. Hochman; U. Karshon; M. S. Lightwood; E. Brownson; T. Danielson; A. Everett; D. Kçira; S. Lammers; L. Li; D. D. Reeder; M. Rosin; P. Ryan; A. A. Savin; W. H. Smith; S. Dhawan; S. Menary

2005-01-01

32

Attitudes of students and teachers on cheating behaviors: descriptive cross-sectional study at six dental colleges in India.  

PubMed

Cheating behavior has been a serious problem in dental institutions across the globe. Attitudes of dental students have an impact on the quality of health care provided to their patients. This descriptive cross-sectional study had the following objectives: to assess and compare the attitudes of dental students and teachers about cheating behaviors, to assess students' opinions of various justifications for their cheating, and to assess teachers' attitudes towards various punishment options for cheating behaviors. The study sample consisted of 1,261 undergraduate students and 131 teachers from six randomly chosen dental colleges in Tamil Nadu State, India. A closed-ended questionnaire was used for respondents to rate the seriousness of cheating behaviors. The students were asked to justify their cheating behavior, and the teachers were asked to assign punishments for the cheating behaviors. The attitudes of students and teachers on the cheating behaviors were analyzed and compared using a Pearson chisquare test, with a confidence interval of 95 percent and significance level of p?0.05. The attitudes of the teachers and students were statistically different in two cheating behaviors: copying during exams and helping other students copy in exams. The two main justifying reasons students gave for cheating behavior were to pass the exam (59.3 percent) and to obtain a better grade (31.3 percent). Warning and counseling to help the students reassess their moral values were preferred to penalizing punishments by the teachers. PMID:24098043

Asokan, Sharath; John, J Baby; Janani, D; Jessy, P; Kavya, S; Sharma, Khushbu

2013-10-01

33

A rare presentation of lymphoma of the cervix with cross-sectional imaging correlation.  

PubMed

Non-Hodgkin's lymphoma of the cervix is an extremely uncommon entity, with no standard established treatment protocol. A 43-year-old asymptomatic female with a history of dual hit blastic B-cell lymphoma/leukemia in complete remission presented with an incidental cervical mass, which was initially felt to represent a cervical fibroid on computed tomography (CT). It was further evaluated with ultrasound, biopsy, and positron emission tomography-computed tomography (PET-CT), which demonstrated a growing biopsy-proven lymphomatous mass and new humeral head lesion. The patient was started on chemotherapy to control the newly diagnosed humeral head lesion, which then regressed. She then underwent radiation to the cervix with significant improvement in the cervical lymphoma. A review of cross-sectional imaging findings of lymphoma of the cervix is provided, including how to differentiate it from other more common diseases of the cervix. Clinical awareness of rare cervical masses such as lymphoma is very important in order to achieve timely diagnosis and appropriate treatment. PMID:24864220

Korivi, Brinda Rao; Jensen, Corey T; Patnana, Madhavi; Patel, Keyur P; Bathala, Tharakeswara K

2014-01-01

34

A Rare Presentation of Lymphoma of the Cervix with Cross-Sectional Imaging Correlation  

PubMed Central

Non-Hodgkin's lymphoma of the cervix is an extremely uncommon entity, with no standard established treatment protocol. A 43-year-old asymptomatic female with a history of dual hit blastic B-cell lymphoma/leukemia in complete remission presented with an incidental cervical mass, which was initially felt to represent a cervical fibroid on computed tomography (CT). It was further evaluated with ultrasound, biopsy, and positron emission tomography-computed tomography (PET-CT), which demonstrated a growing biopsy-proven lymphomatous mass and new humeral head lesion. The patient was started on chemotherapy to control the newly diagnosed humeral head lesion, which then regressed. She then underwent radiation to the cervix with significant improvement in the cervical lymphoma. A review of cross-sectional imaging findings of lymphoma of the cervix is provided, including how to differentiate it from other more common diseases of the cervix. Clinical awareness of rare cervical masses such as lymphoma is very important in order to achieve timely diagnosis and appropriate treatment.

Korivi, Brinda Rao; Jensen, Corey T.; Patnana, Madhavi; Patel, Keyur P.; Bathala, Tharakeswara K.

2014-01-01

35

Adult criminal involvement: A cross-sectional inquiry into correlates and mechanisms over the life course  

PubMed Central

In this paper, we examine the relative contribution of four domains of predictors that have been linked to adult criminal involvement: (1) socio-demographic characteristics, (2) family-of-origin factors, (3) proximal processes developed during adolescence, and (4) current lifestyle and situational factors. Cross-sectional data were collected through face-to-face interviews with 242 community-recruited adults. Data analysis involved negative binomial regression. Being male, family size, juvenile delinquency, aggression, living with someone involved in illegal activity and recent violent victimization were independently associated with non-violent criminal involvement. Aggression, association with deviant peers, and recent violent victimization were independently associated with violent criminal involvement. Juvenile delinquency and aggression mediated the affect of multiple family-of-origin characteristics on non-violent criminal involvement and aggression mediated the effect of childhood physical abuse on violent criminal involvement. The results emphasize the importance of investigating both antecedents and proximal risk factors predictive of different types of criminal involvement, which, in turn, will assist in developing risk-focused prevention and intervention programs.

DePadilla, Lara; Perkins, Molly M.; Elifson, Kirk W.; Sterk, Claire E.

2013-01-01

36

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

2010-01-01

37

Prevalence and correlates of complementary and alternative medicine use among diabetic patients in Beirut, Lebanon: a cross-sectional study  

PubMed Central

Background Patients with Type 2 Diabetes Mellitus (T2DM) are increasingly using complementary and alternative medicine (CAM) therapies due to difficulty in adhering to the therapeutic regimens and lifestyle changes necessary for disease management. Little is known about the prevalence and mode of CAM use among patients with T2DM in Lebanon. Objective To assess the prevalence and modes of CAM use among patients with T2DM residing in Beirut, Lebanon. Methods A cross-sectional survey of T2DM patients was conducted on patients recruited from two major referral centers in Beirut- a public hospital and a private academic medical center. In a face-to-face interview, participants completed a questionnaire comprised of three sections: socio-demographic, diabetes characteristics and types and modes of CAM use. Descriptive statistics, univariate and multivariate logistic regression analyses were utilized to assess the prevalence and correlates of CAM use, as well as whether the use was complementary or alternative to mainstream medicine. The main outcome in this study, CAM use, was defined as using CAM at least once since diagnosis with T2DM. Results A total of 333 T2DM patients completed the survey (response rate: 94.6%). Prevalence of CAM use since diagnosis with the disease was 38%. After adjustment, CAM use was significantly associated with a “married” status, a longer duration of T2DM, the presence of disease complications, and a positive family history of the disease. Folk foods and herbs were the most commonly used CAM followed by natural health products. One in five patients used CAM as alternative to conventional treatment. Only 7% of CAM users disclosed the CAM use to their treating physician. Health care practitioners were the least cited (7%) as influencing the choice of CAM among users. Conclusion The use of CAM therapies among T2DM patients in Lebanon is prevalent. Decision makers and care providers must fully understand the potential risks and benefits of CAM therapies to appropriately advise their patients. Attention must be dedicated to educating T2DM patients on the importance of disclosing CAM use to their physicians especially patients with a family history of diabetes, and those who have had the disease for a long time.

2014-01-01

38

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

39

Cross Section Flyer  

NSDL National Science Digital Library

In this activity, students use slider bars to move a cross section of a cone, cylinder, prism, or pyramid. This activity allows students to explore conic sections and the 3-dimensional shapes from which they are derived. This activity includes supplemental materials, including background information about the topics covered, a description of how to use the application, and exploration questions for use with the java applet.

2010-01-01

40

Cross-sectional investigation of correlation between hepatic steatosis and IVIM perfusion on MR imaging.  

PubMed

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. Thirty-six subjects with suspected nonalcoholic fatty liver disease underwent diffusion-weighted magnetic resonance imaging with 10 b-values and spoiled gradient recalled echo imaging with six echoes for fat quantification. Correlations were measured between FF, transverse relaxivity (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=.002) and f vs. D (r=-0.458, P=.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. PMID:22285877

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

2012-05-01

41

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; D. L Adams; 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

42

Patterns and correlates of physical activity: a cross-sectional study in urban Chinese women  

PubMed Central

Background Inactivity is a modifiable risk factor for many diseases. Rapid economic development in China has been associated with changes in lifestyle, including physical activity. The purpose of this study was to investigate the patterns and correlates of physical activity in middle-aged and elderly women from urban Shanghai. Methods Study population consisted of 74,942 Chinese women, 40–70 years of age, participating in the baseline survey of the Shanghai Women's Health Study (1997–2000), an ongoing population-based cohort study. A validated, interviewer-administered physical activity questionnaire was used to collect information about several physical activity domains (exercise/sports, walking and cycling for transportation, housework). Correlations between physical activity domains were evaluated by Spearman rank-correlation coefficients. Associations between physical activity and socio-demographic and lifestyle factors were evaluated by odds ratios derived from logistic regression. Results While more than a third of study participants engaged in regular exercise, this form of activity contributed only about 10% to daily non-occupational energy expenditure. About two-thirds of women met current recommendations for lifestyle activity. Age was positively associated with participation in exercise/sports and housework. Dietary energy intake was positively associated with all physical activity domains. High socioeconomic status, unemployment (including retirement), history of chronic disease, small household, non-smoking status, alcohol and tea consumption, and ginseng intake were all positively associated with exercise participation. High socioeconomic status and small household were inversely associated with non-exercise activities. Conclusion This study demonstrates that physical activity domains other than sports and exercise are important contributors to total energy expenditure in women. Correlates of physical activity are domain-specific. These findings provide important information for research on the health benefits of physical activity and have public health implications for designing interventions to promote participation in physical activity.

Jurj, Adriana L; Wen, Wanqing; Gao, Yu-Tang; Matthews, Charles E; Yang, Gong; Li, Hong-Lan; Zheng, Wei; Shu, Xiao-Ou

2007-01-01

43

Correlation Between Haemoglobin Level and Electrocardiographic (ECG) Findings in Anaemia: A Cross-Sectional Study  

PubMed Central

Background: Anaemia affects the body by decreased oxygen (O2) carrying capacity of the blood. There is growing evidence that anaemia contributes to cardiac disease and death. It causes O2 supply – demand myocardial mismatch causing myocardial ischemia. There is diversity of opinion available in literature on reports of electrocardiographic (ECG) changes in anaemia. Aim: To study the ECG changes in anemic population and to correlate ECG changes seen with increasing severity of anaemia. Materials and Methods: In hundred anemic adults, haemoglobin level and resting ECG were recorded. They were grouped according to haemoglobin level. ECG findings and varying severity of haemoglobin (Hb) level of each group were correlated using Pearson ’s co-relation co-efficient and association was calculated using Chi-square test. Results: ECG changes in patients with Hb level of 0-5gm% showed ST segment depression in 50-75%, T wave changes in 29-50% and Left Ventricular Hypertrophy (LVH) in 25-30% of patients. Less percentage of patients with 5-7gm% Hb showed such changes, and patients with 7-8gm% Hb, showed no changes. As the Hb level decreased there was more percentage of patients having tachycardia and ECG changes. There was a strong negative correlation between Hb level and tachycardia and ECG changes. Conclusion: Diagnosing anaemia in critical care can be supported by ECG changes like ST depression, T wave changes, with/without associated QRS abnormalities to avoid misdiagnosis and also as dramatic clinical and ECG recovery can be achieved with anaemia correction.

PK, Shashidhar; Herur, Anita; Chinagudi, Surekharani; Patil, Shailaja S; Ankad, Roopa B; Badami, Sukanya V

2014-01-01

44

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

45

Correlates of foot pain severity in adults with hallux valgus: a cross-sectional study  

PubMed Central

Background Hallux valgus (HV) is highly prevalent and associated with progressive first metatarsophalangeal joint subluxation and osteoarthritis. The link between structural HV deformity and foot pain is unclear. This study investigated possible explanatory factors surrounding foot pain in HV, including radiographic HV angle and signs of joint degeneration. Methods Participants were 60 adults (53 female) with HV aged 20 to 75 years. Participant demographics and a range of radiographic, clinical and functional measures were considered potential correlates of foot pain. Self-reported foot pain (visual analogue scales and a dichotomous definition) was considered the dependent variable. Multivariate modelling was used to determine which characteristics and measures explained pain, with univariate analyses first used to screen potential variables. Results Approximately 20 to 30% of the variance in foot pain associated with HV could be explained by patient characteristics such as poorer general health status, lower educational attainment and increased occupational physical activity levels, in combination with some dynamic physical characteristics such as hallux plantarflexion weakness and reduced force-time integral under the second metatarsal during gait. Neither increasing lateral deviation of the hallux (HV angle) nor presence of first metatarsophalangeal joint osteoarthritis was associated with foot pain. Conclusions This study shows that passive structural factors, including HV angle, do not appear to be significant correlates of foot pain intensity in HV. Our data demonstrate the importance of considering patient characteristics such as general health and physical activity levels when assessing foot pain associated with HV.

2014-01-01

46

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

47

Factors associated with anxiety and depression among type 2 diabetes outpatients in Malaysia: a descriptive cross-sectional single-centre study  

PubMed Central

Objective To determine the prevalence and factors associated with anxiety and depression among type 2 diabetes outpatients in Malaysia. Design Descriptive, cross-sectional single-centre study with universal sampling of all patients with type 2 diabetes. Setting Endocrinology clinic of medical outpatient department in a Malaysian public hospital. Participants All 169 patients with type 2 diabetes (men, n=99; women, n=70) aged between 18 and 90?years who acquired follow-up treatment from the endocrinology clinic in the month of September 2013. Main outcome measures The validated Hospital Anxiety and Depression Scale (HADS), sociodemographic characteristics and clinical health information from patient records. Results Of the total 169 patients surveyed, anxiety and depression were found in 53 (31.4%) and 68 (40.3%), respectively. In multivariate analysis, age, ethnicity and ischaemic heart disease were significantly associated with anxiety, while age, ethnicity and monthly household income were significantly associated with depression. Conclusions Sociodemographics and clinical health factors were important correlates of anxiety and depression among patients with diabetes. Integrated psychological and medical care to boost self-determination and confidence in the management of diabetes would catalyse optimal health outcomes among patients with diabetes.

Ganasegeran, Kurubaran; Renganathan, Pukunan; Manaf, Rizal Abdul; Al-Dubai, Sami Abdo Radman

2014-01-01

48

Complex Correlation Kohn-T Method of Calculating Total and Elastic Cross Sections. Part 1; Electron-Hydrogen Elastic Scattering  

NASA Technical Reports Server (NTRS)

We report on the first part of a study of electron-hydrogen scattering, using a method which allows for the ab initio calculation of total and elastic cross sections at higher energies. In its general form the method uses complex 'radial' correlation functions, in a (Kohn) T-matrix formalism. The titled method, abbreviated Complex Correlation Kohn T (CCKT) method, is reviewed, in the context of electron-hydrogen scattering, including the derivation of the equation for the (complex) scattering function, and the extraction of the scattering information from the latter. The calculation reported here is restricted to S-waves in the elastic region, where the correlation functions can be taken, without loss of generality, to be real. Phase shifts are calculated using Hylleraas-type correlation functions with up to 95 terms. Results are rigorous lower bounds; they are in general agreement with those of Schwartz, but they are more accurate and outside his error bounds at a couple of energies,

Bhatia, A. K.; Temkin, A.; Fisher, Richard R. (Technical Monitor)

2001-01-01

49

Socio-demographic, medical and social-cognitive correlates of physical activity behavior among older adults (45-70 years): a cross-sectional study  

PubMed Central

Background Present study aimed to identify socio-demographic, medical and social-cognitive correlates of physical activity among Dutch older individuals. Methods A systematic random sample of 2,568 Dutch participants aged 45–70 years filled out the validated modified Community Healthy Activities Model Program for Seniors (CHAMPS) questionnaire on physical activity. Socio-demographic and social-cognitive correlates were measured with validated instruments; medical correlates were checked by a general practitioner. The study had a cross-sectional design and the data collection ran from March 2005 until August 2006. Linear regression analyses were conducted to identify correlates of PA. We separated the findings for men from those for women to explore potential gender-specific associations. Results Being female, living in North Limburg or North-Brabant, having a higher educational level, a higher perceived behavioral control, more knowledge about PA advantages, a stronger habitual PA behavior, having more action plans and a stronger intention to engage in PA were significantly associated with higher PA levels. Being older, being a smoker, having a higher body mass index (BMI), having a paid job, observing others being physically active and overestimating one's PA level were associated with being less physically active. Socio-demographic and medical correlates significantly explained 20% of the variance of PA behavior while social-cognitive correlates as attitude explained an additional 4% and intention together with actual control explained another 1% of the variance of PA behavior. Conclusion There may be stable individual differences that influence PA in view of the fact that several socio-demographic and medical factors were not completely mediated by the socio-cognitive factors. The current study may help to focus PA interventions for individuals aged 45–70 years on influential socio-demographic, medical and social-cognitive correlates. Physical activity was significantly associated with age, gender, education, BMI, work situation, region of residence, smoking, awareness, advantages, descriptive norm, perceived behavioral control, habit, action plans and intention.

2014-01-01

50

Description of Elastic Scattering, Fusion and Total Reaction Cross Sections in the 6He+209Bi System, using the Direct Reaction Technique.  

NASA Astrophysics Data System (ADS)

In a recent work, an exceptionally strong 4He group was discovered in the interaction of the exotic "Borromean" nucleus 6He with a 209Bi target at sub-Coulomb barrier energies (E.F. Aguilera et al., Phys. Rev. Lett. 84, 5058, 2000; Phys. Rev. C 2001, submitted), which has been ascribed to the presence of transfer and/or breakup modes. The elastic and fusion (J.J. Kolata et al., Phys. Rev. Lett. 81, 4580, 1998) channels have been also measured for this system and the total reaction cross sections were calculated as the sum of the fusion plus "breakup/transfer" yields. Two different optical model descriptions using energy-dependent absorptive potentials have been given which match the elastic and total reaction data equivalently well. In one of them the Woods-Saxon imaginary potential well becomes more diffuse at lower energies, while the other approach uses a folding model and involves an increasing radius for the imaginary well at lower energies. No description is given of the fusion data alone. In this work, the possibility of including in addition a description of the fusion excitation function is investigated through the use of the direct reaction approach, in which the imaginary well is separated into two parts, one of them describing the fusion part of the total reaction cross section and the other one accounting for the remaining direct reactions.

Aguilera, Eli F.; Gomez-Camacho, Arturo

2001-10-01

51

Description of Light Ion Production Cross Sections and Fluxes on the Mars Surface using the QMSFRG Model  

NASA Technical Reports Server (NTRS)

The atmosphere of Mars significantly attenuates the heavy ion component of the primary galactic cosmic rays (GCR), however increases the fluence of secondary light ions (neutrons, and hydrogen and helium isotopes) because of particle production processes. We describe results of the quantum multiple scattering fragmentation (QMSFRG) model for the production of light nuclei through the distinct mechanisms of nuclear abrasion and ablation, coalescence, and cluster knockout. The QMSFRG model is shown to be in excellent agreement with available experimental data for nuclear fragmentation cross sections. We use the QMSFRG model and the space radiation transport code, HZETRN to make predictions of the light particle environment on the Martian surface at solar minimum and maximum. The radiation assessment detector (RAD) experiment will be launched in 2009 as part of the Mars Science Laboratory (MSL). We make predictions of the expected results for time dependent count-rates to be observed by RAD experiment. Finally, we consider sensitivity assessments of the impact of the Martian atmospheric composition on particle fluxes at the surface.

Cucinotta, Francis A.; Kim, Myung-Hee; Schneider, Irene; Hassler, Donald M.

2006-01-01

52

Descriptions and Interpretations of the ACCORD-Lipid Trial in the News and Biomedical Literature: A Cross-Sectional Analysis.  

PubMed

The lipid component of the Action to Control Cardiovascular Risk in Diabetes (ACCORD-Lipid) trial was a landmark, publicly funded study demonstrating that fenofibrate, when added to statin therapy, was not associated with improved cardiovascular outcomes among patients with diabetes mellitus. We performed a cross-sectional study of all articles describing the results of ACCORD-Lipid in the news and biomedical literature in the 15 months following its publication. For articles published in biomedical journals, we determined whether there was an association between authors' conflicts of interest and trial interpretation. We identified 67 news articles and 141 biomedical journal articles discussing ACCORD-Lipid. Approximately 30% of news and biomedical journal articles described fenofibrate as ineffective, whereas nearly 20% concluded it was effective. Among articles making a recommendation, approximately 50% of news and 67% of biomedical journal articles supported continued fibrate use. Authors with conflicts of interest were more likely to describe fenofibrate as effective (27.1% vs 8.9%; relative risk, 3.03; 95% CI, 1.22-7.50; P?=?.008) and support continued fibrate use (77.4% vs 45.8%; 1.69; 1.07-2.67; P?=?.006). The ACCORD-Lipid trial was described inconsistently in news and biomedical journal articles, possibly creating uncertainty among patients and physicians. In addition, conflicts of interest were associated with more favorable trial interpretation. PMID:24796406

Downing, Nicholas S; Cheng, Theresa; Krumholz, Harlan M; Shah, Nilay D; Ross, Joseph S

2014-07-01

53

Clinical and cognitive correlates of employment among patients with schizophrenia: a cross-sectional study in Malaysia  

PubMed Central

Background Gainful employment is one major area of functioning which is becoming an important goal in psychiatric rehabilitation of patients with schizophrenia. Studies in western countries are pointing to evidence that certain sociodemographic and clinical factors may contribute to employment outcomes in this group of people. However, the area is still largely unexplored in Malaysia. The aim of this study was to examine the sociodemographic, clinical and cognitive correlates of employment status among patients with Schizophrenia. Methods This was a cross-sectional study. All participants who fulfilled the requirements of the study according to the inclusion and exclusion criteria were enrolled. Study instruments included a demographic data questionnaire, Positive and Negative Symptom Scale (PANSS), Trail Making Tests, Rey's Auditory Verbal Learning Test (RAVLT) and Digit Span. Bivariate analyses were done using chi-square for categorical data and t-test for continuous data and multiple logistic regression analysis was done to identify predictors of employment status. Results A total of 95 participants who fulfilled the inclusion criteria were enrolled into the study. Among the sociodemographic, clinical and cognitive variables studied marital status, educational level, mean scores of negative symptoms, Digit Span and RAVLT and Trail Making Tests were found to show significant association with employment status on bivariate analyses. However, when entered into a logistic regression model, only cognitive variables ie. Trail A and B, Digit Span and RAVLT were significant predictors of employment status. Conclusions The results from this study support the role of cognitive function, particularly, attention, working memory and executive functioning on attaining and maintaining employment in persons with schizophrenia as measured by the RAVLT, Digit Span and Trail Making Tests. These findings may act as preliminary evidence suggesting the importance of integrating cognitive rehabilitation in the psychosocial rehabilitation program for patients with schizophrenia in Malaysia.

2011-01-01

54

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

55

Serological cross-sectional studies on salmonella incidence in eight European countries: no correlation with incidence of reported cases  

PubMed Central

Background Published incidence rates of human salmonella infections are mostly based on numbers of stool culture-confirmed cases reported to public health surveillance. These cases constitute only a small fraction of all cases occurring in the community. The extent of underascertainment is influenced by health care seeking behaviour and sensitivity of surveillance systems, so that reported incidence rates from different countries are not comparable. We performed serological cross-sectional studies to compare infection risks in eight European countries independent of underascertainment. Methods A total of 6,393 sera from adults in Denmark, Finland, France, Italy, Poland, Romania, Sweden, and The Netherlands were analysed, mostly from existing serum banks collected in the years 2003 to 2008. Immunoglobulin A (IgA), IgM, and IgG against salmonella lipopolysaccharides were measured by in-house mixed ELISA. We converted antibody concentrations to estimates of infection incidence (‘sero-incidence’) using a Bayesian backcalculation model, based on previously studied antibody decay profiles in persons with culture-confirmed salmonella infections. We compared sero-incidence with incidence of cases reported through routine public health surveillance and with published incidence estimates derived from infection risks in Swedish travellers to those countries. Results Sero-incidence of salmonella infections ranged from 56 (95% credible interval 8–151) infections per 1,000 person-years in Finland to 547 (343–813) in Poland. Depending on country, sero-incidence was approximately 100 to 2,000 times higher than incidence of culture-confirmed cases reported through routine surveillance, with a trend for an inverse correlation. Sero-incidence was significantly correlated with incidence estimated from infection risks in Swedish travellers. Conclusions Sero-incidence estimation is a new method to estimate and compare the incidence of salmonella infections in human populations independent of surveillance artefacts. Our results confirm that comparison of reported incidence between countries can be grossly misleading, even within the European Union. Because sero-incidence includes asymptomatic infections, it is not a direct measure of burden of illness. But, pending further validation of this novel method, it may be a promising and cost-effective way to assess infection risks and to evaluate the effectiveness of salmonella control programmes across countries or over time.

2012-01-01

56

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

57

Depressive symptoms and alcohol correlates among Brazilians aged 14 years and older: a cross-sectional study  

PubMed Central

Background The associations between depressive symptoms and alcohol-related disorders, drinking patterns and other characteristics of alcohol use are important public health issues worldwide. This study aims to study these associations in an upper middle-income country, Brazil, and search for related socio-demographic correlations in men and women. Methods A cross-sectional study was conducted between November 2005 and April 2006. The sample of 3,007 participants, selected using a multistage probabilistic sampling method, represents the Brazilian population aged 14 and older. Depressive symptoms were assessed using the Center for Epidemiologic Studies Depression Scale and alcohol dependence was assessed using the Composite International Diagnostic Interview. Associations assessed using bi-variate analysis were tested using Rao-Scott measures. Gender specific multinomial logistic regression models were developed. Results Among the participants with alcohol dependence, 46% had depressive symptoms (17.2% mild/moderate and 28.8% major/severe; p?

2014-01-01

58

Negative ion detachment cross sections  

SciTech Connect

During past year, we have measured cross sections for associative and collisional detachment for several negative ions in collisions with atomic hydrogen. Additional experiments have been performed in which the formation of secondary negative ions and electrons by means of low energy ion impact on surfaces has been studied. Brief descriptions of these activities along with future plans for the project follow.

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

1991-12-01

59

Radar cross section  

Microsoft Academic Search

The technological evolution in signal processing that has been made in last decades led to improvements in radar performances. Increasing the radar range by improving its sensitivity has been made by the designers of aircraft and other military systems to try to decrease the radar cross section of these types of equipment. The radar cross section is a matter of

L. Nicolaescu; Teofil Oroian

2001-01-01

60

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

Microsoft Academic Search

Background  Children who participate in regular physical activity obtain health benefits. Preliminary pedometer-based cut-points representing\\u000a sufficient levels of physical activity among youth have been established; however limited evidence regarding correlates of\\u000a achieving these cut-points exists. The purpose of this study was to identify correlates of pedometer-based cut-points among\\u000a elementary school-aged children.\\u000a \\u000a \\u000a \\u000a \\u000a Method  A cross-section of children in grades 5-7 (10-12 years of

Gavin R McCormack; Billie Giles-Corti; Anna Timperio; Georgina Wood; Karen Villanueva

2011-01-01

61

Correlates of susceptibility to smoking among Mexican origin youth residing in Houston, Texas: A cross-sectional analysis  

PubMed Central

Background Survey data suggest that in Texas Latino youth exhibit higher rates of susceptibility to smoking than youth from other ethnic groups. In this analysis we examined the relationship between susceptibility to smoking and well-known risk factors associated with smoking initiation among a cohort of 11 to 13 year old Mexican origin youth residing in Houston, Texas. Methods We analyzed cross-sectional survey data from 1,187 participants who reported they had never smoked, even a puff of a cigarette. The survey assessed peer and family social influence, school and neighborhood characteristics, level of family acculturation and socioeconomic status, and attitudes toward smoking. Bivariate associations, Student's t-tests, and logistic regression analysis were used to examine predictors of susceptibility. Results Overall, 22.1% of the never-smokers were susceptible to smoking. Boys were more likely to be susceptible than girls (25.6% vs. 18.9%), and susceptible children were slightly older than non-susceptible children (12.1 vs. 11.8 years). In addition, multivariate analyses revealed that positive expectations about smoking exerted the strongest influence on susceptibility status (odds ratio = 4.85). Multivariate analyses further revealed that compared to non-susceptible participants, susceptibles were more likely to report peer influences supportive of smoking, lower subjective social status and more detentions at school, more temptations to try smoking and to have a mother and a brother who smokes. Conclusion Our findings suggest that interventions that target positive expectations about smoking may be useful in this population. Furthermore, because youth encounter smoking-initiation risk factors in different social environments, our results underscore the continued need for both family- and school-based primary prevention programs to adequately combat their influence. The results also can be used to inform the development of culturally sensitive programs for Mexican origin youth.

Wilkinson, Anna V; Waters, Andrew J; Vasudevan, Vandita; Bondy, Melissa L; Prokhorov, Alexander V; Spitz, Margaret R

2008-01-01

62

Born Wave Calculation of Atom-Atom Inelastic Cross Sections: Description of Target Atoms by Elastic and Inelastic X-Ray Form Factors  

Microsoft Academic Search

Total electron-loss cross sections for H atoms in collision with He, Ne, Ar, Kr, C, N, and O over the range of incident energy 1 keV-100 MeV and total (1s-2l) excitation cross sections for H atoms in collision with He, Ne, Ar, and Kr over the range of incident energy 0.1 keV-10 MeV are calculated by using the first Born

H. Levy

1969-01-01

63

Prevalence and correlates of dizziness in community-dwelling older people: a cross sectional population based study  

PubMed Central

Background Dizziness is a common complaint among older adults and has been linked to a wide range of health conditions, psychological and social characteristics in this population. However a profile of dizziness is still uncertain which hampers clinical decision-making. We therefore sought to explore the relationship between dizziness and a comprehensive range of demographic data, diseases, health and geriatric conditions, and geriatric syndromes in a representative sample of community-dwelling older people. Methods This is a cross-sectional, population-based study derived from FIBRA (Network for the Study of Frailty in Brazilian Elderly Adults), with 391 elderly adults, both men and women, aged 65 years and older. Elderly participants living at home in an urban area were enrolled through a process of random cluster sampling of census regions. The outcome variable was the self-report of dizziness in the last year. Several feelings of dizziness were investigated including vertigo, spinning, light or heavy headedness, floating, fuzziness, giddiness and instability. A multivariate logistic regression analysis was conducted to estimate the adjusted odds ratios and build the probability model for dizziness. Results The complaint of dizziness was reported by 45% of elderly adults, from which 71.6% were women (p=0.004). The multivariate regression analysis revealed that dizziness is associated with depressive symptoms (OR = 2.08; 95% CI 1.29–3.35), perceived fatigue (OR = 1.93; 95% CI 1.21-3.10), recurring falls (OR = 2.01; 95% CI 1.11-3.62) and excessive drowsiness (OR = 1.91; 95% CI 1.11–3.29). The discrimination of the final model was AUC = 0.673 (95% CI 0.619-0.727) (p< 0.001). Conclusions The prevalence of dizziness in community-dwelling elderly adults is substantial. It is associated with other common geriatric conditions usually neglected in elderly adults, such as fatigue and drowsiness, supporting its possible multifactorial manifestation. Our findings demonstrate the need to expand the design in future studies, aiming to estimate risk and identify possible causal relations.

2013-01-01

64

Radar cross section measurements  

Microsoft Academic Search

The present status of radar cross section (RCS) measurements is addressed. The fundamental considerations and definitions associated with RCS measurements are reviewed, including radar waveform, polarization requirements, far-field requirements, and target dimensional scaling. Different types of measurement facilities are examined, including their range geometries, target support systems, calibration standards, and facility evaluation. Instrumentation radar requirements and designs are reviewed, and

Robert B. Dybdal

1987-01-01

65

Group Cross Sections Calculations.  

National Technical Information Service (NTIS)

Just a few methods have been developped to compute multigroup cross-sections from ENDF data. We have developped an original method in order to get accuracy and to reduce the number of discretization points in the same time; this is why we have tried to us...

D. Verwaerde

1985-01-01

66

What is killing? People's knowledge about coronary heart disease, attitude towards prevention and main risk reduction barriers in Ismailia, Egypt (Descriptive cross-sectional study)  

PubMed Central

Introduction Cardiovascular diseases are a public health concern everywhere, especially ischemic or coronary heart diseases (CHD) which are on top of causes list of mortality and morbidity in both genders globally. From which nearly 80% can be because of modifiable risks. In Egypt, there is a lack of studies on the knowledge of people about coronary heart diseases and its modifiable risks. So, this research reported here we designed to measure the dimensions of peoples knowledge about CHD and their attitude towards prevention, and to identify the main risk reduction barriers. Methods By using comprehensive cross-sectional, descriptive research design, all adult individuals attending the family health clinic at Suez Canal University Hospital were eligible for inclusion with total number 125 participants. An interview questionnaire designed and used to collect data. Results The study revealed that (10.4%) of participants had a history of CHD, and (7.2%) had a family history of CHD. 79.2% Had a satisfactory total knowledge about CHD, and (94.4%) had a positive total attitude towards prevention. Risk reduction barriers as a medical setting barriers were (24%), patient related barriers were (22.4%). Community-societal barriers were almost the same as knowledge barriers which were around (16%). At last the systemic-organizational barriers were (9.6%). Conclusion The findings settled that, total knowledge about CHD was satisfactory but lower than the level total of attitude. More effort the health system needs to improve the settings and engage patients in their plans and breaking related barriers, with development of health education programs based on needs assessment. Further studies we recommend to explore the reasons and follow up the changes.

Seef, Sameh; Jeppsson, Anders; Stafstrom, Martin

2013-01-01

67

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

68

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

69

Comparative description of the cross sections for excitation of the levels 2\\/sup +\\/(4. 43 MeV) and 3⁻(9. 64 MeV) in ¹²C by 1GeV protons and by electrons  

Microsoft Academic Search

A comparative description of the cross sections for excitation of the levels 2\\/sup +\\/(4.43 MeV) and 3⁻(9.64 MeV) in ¹²C by 1-GeV protons and by electrons is presented within the framework of the single inelastic collision approximation in the Glauber theory. It is shown that a good description of the proton data calls for a careful fitting of the form

L. A. Kondratyuk; R. M. Lombard; I. Ahmad

1978-01-01

70

On your bike! a cross-sectional study of the individual, social and environmental correlates of cycling to school  

Microsoft Academic Search

Background: Active school transport (AST) has declined rapidly in recent decades. While many studies have examined walking, cycling to school has received very little attention. Correlates of cycling are likely to differ to those from walking and cycling enables AST from further distances. This study examined individual, social and environmental factors associated with cycling to school among elementary school-aged children,

Georgina S A Trapp; Billie Giles-Corti; Hayley E Christian; Max Bulsara; Anna F Timperio; Gavin R McCormack; Karen P Villaneuva

2011-01-01

71

Investigating the Correlates and Predictors of Affective and Continuance Organizational Commitment: A Cross sectional Survey of Malaysian Academic Librarians  

Microsoft Academic Search

This study attempts to identify the correlates and predictors of affective and continuance organizational commitment. Meyer & Allen's (1997) conceptualization and operationalization of organizational commitment has been adopted for this study. This study was carried out to determine whether work related variables such as job satisfaction, job involvement, job autonomy, job performance feedback, role conflict and role clarity would have

Noor Hasrul; Nizan Mohammd Noor

72

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

73

Comparison of approximate and exact description of isoviscous flow velocity profile formed in rectangular cross-section channel for field-flow fractionation  

Microsoft Academic Search

The shape of the velocity profile established in a carrier liquid flowing in a duct of rectangular cross-section under conditions of isoviscous flow is well known and can be calculated by using an approximate or the exact solution of Navier-Stokes equation. The series evaluated when applying the exact solution were found to converge very rapidly. Consequently, computing can be substantially

J. Jan?a; M. Hoyos; M. Martin

1992-01-01

74

Fatty acid composition of the follicular fluid of normal weight, overweight and obese women undergoing assisted reproductive treatment: a descriptive cross-sectional study  

PubMed Central

Background It has been well documented that the maturing oocyte is very vulnerable to changes in its micro-environment, the follicular fluid (FF). Recent research has focused on different components within this FF, like hormones, growth factors and metabolites, and how their concentrations are altered by diet and the metabolic health of the mother. It has been proposed that fatty acids (FAs) are potential factors that influence oocyte maturation and subsequent embryo development. However, a thorough study of the specific FF FA composition per lipid fraction and how this may be affected by BMI is currently lacking. Therefore, we investigated the BMI-related concentration of FAs in the phospholipid (PL), cholesteryl-ester (CHE), triglyceride (TG) and non-esterified (NE) lipid fraction in the FF of women undergoing assisted reproductive treatment (ART). Methods In this descriptive cross-sectional study, the FF of normal weight (18.5???BMI?

2014-01-01

75

Prevalence of acanthosis nigricans and its correlates in a cross-section of Nigerians with type 2 diabetes mellitus.  

PubMed

Acanthosis nigricans (AN) is a dermatological condition that is often associated with obesity and may be a physical marker of insulin resistance. Studies have documented a high prevalence rate of AN in people with diabetes mellitus (DM). However, there have been no Nigerian reports on AN and DM. This report bridges the information gap and documents the prevalence of AN in Nigerians with type 2 DM as well as its clinical correlates. Three hundred and forty consecutive subjects with type 2 DM were examined for the presence of AN and its associated clinical features. The prevalence of AN in type 2 DM in this report is 17%. Factors associated with AN include obesity, a family history of DM, female gender, the presence of hypertension and poor glycaemic control. PMID:19762579

Ogbera, A O; Akinlade, A; Ajose, O; Awobusuyi, J

2009-10-01

76

A novel approach to elemental analysis by Laser Induced Breakdown Spectroscopy based on direct correlation between the electron impact excitation cross section and the optical emission intensity  

Microsoft Academic Search

In Laser Induced Plasma Spectroscopy (LIPS) or Laser Induced Breakdown Spectroscopy (LIBS) the relation between recombining electrons and optical emission intensity has been studied in hydrogen and different metals targets. The role played by the electron impact excitation cross section on the temporal trend of emission lines has addressed and a methodology for the evaluation of the excitation cross sections

Alessandro De Giacomo

77

Inverse correlation between serum interleukin-6 and iron levels among Japanese adults: a cross-sectional study  

PubMed Central

Background Interleukin-6 (IL-6) is a multifunctional cytokine that is produced by many different cell types, and plays an important role in the regulation of inflammation, immune responses, the acute-phase response, and hematopoiesis. Previous laboratory and clinical studies have shown that IL-6 causes a significant decrease in serum iron levels. Therefore, we conducted an epidemiological study to examine the association between serum IL-6 and iron levels. Methods In total, 280 Japanese individuals aged 20–78 years were enrolled when they visited a clinic located in an urban area for Helicobacter pylori (H. pylori) infection tests and subsequent eradication; 65.3% were infected with H. pylori. Subjects with gastric cancer, idiopathic thrombocytopenia, or IL-6?>?10 pg/mL were excluded from the study. Serum iron and IL-6 levels were measured using the 2-nitroso-5-(N-propyl-3-sulfopropylamino) phenol method and chemiluminescence enzyme immunoassay, respectively. Results Geometric mean iron and IL-6 levels were 111.5 ?g/dL and 1.77 pg/mL, respectively, for men, and 89.4 ?g/dL and 1.55 pg/mL, respectively, for women. The logarithm of serum iron levels was negatively correlated with the logarithm of IL-6 levels in men (r?=??0.19, p?=?0.047), but not in women (r?=??0.035, p?=?0.65). Regression analysis, adjusted for sex, age, and H. pylori infection status, showed that the logarithm of serum iron levels was significantly associated with a decreased logarithm of IL-6 levels (??=??0.053, p?=?0.041). The odds ratio for low serum iron levels adjusted for sex, age, and H. pylori infection status was 7.88 (95% CI 1.29–48.06) in those with an IL-6 level?>?4 pg/mL. Conclusion Lower serum iron levels are significantly associated with higher serum IL-6 levels among Japanese adults.

2014-01-01

78

On your bike! a cross-sectional study of the individual, social and environmental correlates of cycling to school  

PubMed Central

Background Active school transport (AST) has declined rapidly in recent decades. While many studies have examined walking, cycling to school has received very little attention. Correlates of cycling are likely to differ to those from walking and cycling enables AST from further distances. This study examined individual, social and environmental factors associated with cycling to school among elementary school-aged children, stratified by gender. Methods Children (n = 1197) attending 25 Australian primary schools located in high or low walkable neighborhoods, completed a one-week travel diary and a parent/child questionnaire on travel habits and attitudes. Results Overall, 31.2% of boys and 14.6% of girls cycled ? 1 trip/week, however 59.4% of boys and 36.7% of girls reported cycling as their preferred school transport mode. In boys (but not girls), school neighborhood design was significantly associated with cycling: i.e., boys attending schools in neighborhoods with high connectivity and low traffic were 5.58 times more likely to cycle (95% CI 1.11-27.96) and for each kilometer boys lived from school the odds of cycling reduced by 0.70 (95% CI 0.63-0.99). Irrespective of gender, cycling to school was associated with parental confidence in their child's cycling ability (boys: OR 10.39; 95% CI 3.79-28.48; girls: OR 4.03; 95% CI 2.02-8.05), parental perceived convenience of driving (boys: OR 0.42; 95% CI 0.23-0.74; girls: OR 0.40; 95% CI 0.20-0.82); and child's preference to cycle (boys: OR 5.68; 95% CI 3.23-9.98; girls: OR 3.73; 95% CI 2.26-6.17). Conclusion School proximity, street network connectivity and traffic exposure in school neighborhoods was associated with boys (but not girls) cycling to school. Irrespective of gender, parents need to be confident in their child's cycling ability and must prioritize cycling over driving.

2011-01-01

79

A cross-sectional survey of prevalence and correlates of suicidal ideation and suicide attempts among prisoners in New South Wales, Australia  

PubMed Central

Background We aimed to estimate the prevalence of suicidal ideation and suicide attempt among prisoners in New South Wales, Australia; and, among prisoners reporting suicidal ideation, to identify factors associated with suicide attempt. Methods A cross-sectional design was used. Participants were a random, stratified sample of 996 inmates who completed a telephone survey. The estimated population prevalence of suicidal ideation and suicide attempt were calculated and differences by sex and Aboriginality were tested using ?2 tests. Correlates of suicidal ideation and suicide attempt were tested using logistic regression. Results One-third of inmates reported lifetime suicidal ideation and one-fifth had attempted suicide. Women and Aboriginal participants were significantly more likely than men and non-Aboriginal participants, respectively, to report attempting suicide. Correlates of suicidal ideation included violent offending, traumatic brain injury, depression, self-harm, and psychiatric hospitalisation. Univariate correlates of suicide attempt among ideators were childhood out-of-home care, parental incarceration and psychiatric hospitalization; however, none of these remained significant in a multivariate model. Conclusions Suicidal ideation and attempts are highly prevalent among prisoners compared to the general community. Assessment of suicide risk is a critical task for mental health clinicians in prisons. Attention should be given to ensuring assessments are gender- and culturally sensitive. Indicators of mental illness may not be accurate predictors of suicide attempt. Indicators of childhood trauma appear to be particularly relevant to risk of suicide attempt among prisoners and should be given attention as part of risk assessments.

2012-01-01

80

Difference between interaction cross sections and reaction cross sections  

SciTech Connect

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 around 40. For analyses of the difference, we construct ''pseudo data'' for the reaction cross sections because empirical data are very limited at high energies. The construction of the pseudo data is based on our assumption that empirically unknown total reaction cross sections are precisely predicted by the phenomenological black-sphere model of nuclei that we developed recently. The comparison with the empirical interaction cross sections suggests a significant difference between the reaction and interaction cross sections for stable projectiles on a carbon target, which is of the order of 0-100 mb.

Kohama, Akihisa [RIKEN Nishina Center, RIKEN, 2-1 Hirosawa, Wako-shi, Saitama 351-0198 (Japan); Iida, Kei [RIKEN Nishina Center, RIKEN, 2-1 Hirosawa, Wako-shi, Saitama 351-0198 (Japan); Department of Natural Science, Kochi University, Kochi 780-8520 (Japan); Oyamatsu, Kazuhiro [RIKEN Nishina Center, RIKEN, 2-1 Hirosawa, Wako-shi, Saitama 351-0198 (Japan); Department of Media Theories and Production, Aichi Shukutoku University, Nagakute, Nagakute-cho, Aichi-gun, Aichi 480-1197 (Japan)

2008-12-15

81

International Evaluation of Neutron Cross Section Standards  

NASA Astrophysics Data System (ADS)

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

2009-12-01

82

Theory and computation of electron correlation in the continuous spectrum:Double photoionization cross section of H- and He near and far from threshold  

NASA Astrophysics Data System (ADS)

We present a theoretical approach to the ab initio calculation of single or multiphoton double electron ionization cross sections, ?++(E), of polyelectronic atoms, near (Wannier region) and far from threshold. The overall computational method is variational, uses functions of real as well as of complex coordinates, and follows the many-electron, many-photon theory proposed by Mercouris and Nicolaides [J. Phys. B 21, L285 (1988); 23, 2037 (1990)]. It incorporates the electronic structure and the pair correlations in the continuum via configuration-interaction techniques. ?++(E) is obtained as the imaginary part of a complex eigenvalue that is computed by diagonalizing a state-specific non-Hermitian matrix constructed from separately optimized function spaces Q and P representing the field-induced resonance state. Q contains correlated wave functions of bound or quasibound states expanded over numerical and analytic orbitals of real coordinates. P is composed, in principle, of subspaces P1 and P2, representing the one- and the two-electron channels, respectively, which are optimized separately and then are allowed to mix via the construction of the total non-Hermitian matrix. Both are spanned by basis sets of real coordinates for the ionized core and of complex coordinates for the outgoing part of the one- and the two-electron resonance state. The two-electron square integrable 'continuum' function space is made orthogonal to the available single electron channels in order for ?++(E) not to include portions of the single electron ionization cross section ?+(E). Application is made to the single photon ?++(E) of the prototypical systems H- and He, but without the mixing of P2 and P1, due to numerical instabilities. The two-electron ionization channels were composed of Slater-type orbitals, symmetry-coupled according to (sp), (pd), and (df ). Higher symmetries would also be needed at higher energies, with corresponding increase of angular correlation terms in the initial-state wave function. The continuous energy ranged from E=0 to E=250 eV. In the threshold region E=0-2 eV, the length and velocity results are in good agreement with experiment for H- and in reasonable agreement with experiment for He. Far from threshold, there is discrepancy between length and velocity forms in this as well as in previous works by other methods. Apart from whatever inadequacies of the basis functions, this is possibly due to the exclusion of mixing of the single electron open channels into the correlated wave function of the two free electrons. By comparing the results from the use of correlated wave functions with those obtained when the calculation of the transition matrix element is done with wave functions of real coordinates, where the initial state is correlated but the final one is only a product of Coulomb wave functions, the effect of correlation of the two free electrons is deduced for the case of He, without considering the mixing of one- and two-electron channels. Finally, a by-product of the present development was the calculation of the He ?+(E) to the n=1 single ionization threshold. Comparison with previous accurate experimental results reveals very good agreement.

Nicolaides, Cleanthes A.; Haritos, Costas; Mercouris, Theodoros

1997-04-01

83

Prevalence and correlates of erectile dysfunction in type 2 diabetes mellitus: a cross-sectional single-center study among Turkish patients.  

PubMed

Abstract Objective: The aim of this study was to evaluate prevalence of erectile dysfunction (ED) in patients with type 2 diabetes mellitus (T2DM) in relation to vascular and neurogenic correlates. Methods: A total of 116 males including T2DM patients [n=68; mean age, 56.7 (5.8) years] and age-matched healthy controls [n=48; mean age, 57.0 (6.6) years] were included in this cross-sectional single-center study. Data on anthropometrics, blood biochemistry, concomitant hypertension, hyperlipidemia, and coronary artery disease (CAD) were recorded in each subject along with measurement of carotid artery intima media thickness (CIMT) and evaluation of erectile dysfunction (ED) via International Index of Erectile Function (IIEF-5) Questionnaire. A univariate analysis was performed to determine the relationship of cardiovascular risk factors and diabetes-related complications to ED. Results: Patient and control groups were similar in terms of percentage patients with hyperlipidemia (51.5% and 39.6%, respectively) and CAD (33.8% and 22.9%, respectively), whereas concomitant hypertension was more common (P=0.05) and CIMT values were significantly higher (P=0.020) in patients with T2DM compared with controls. Polyneuropathy was noted in 46.2% of patients, nephropathy in 30.8%, and retinopathy in 33.8%. ED scores were significantly lower in patients than controls [14.3 (7.3) vs. 18.2 (6.3), P=0.004] with a significantly higher percentage of patients than controls in the category of severe dysfunction (29.4 vs. 10.4%, P=0.014). Univariate analysis revealed that diabetic polyneuropathy was the only factor to be associated with higher likelihood (93.3% in the presence and 60.0% in the absence of neuropathy) and severity (43.3% in the presence and 14.3% in the absence of neuropathy) of ED (P=0.004). Conclusion: Findings from the present cross-sectional single-center study revealed the prevalence of ED to be considerably higher in patients with T2DM than age-matched healthy controls, with identification of diabetic polyneuropathy as the only risk factor associated with higher likelihood and more severe forms of ED. PMID:24666397

Cander, Soner; Coban, Soner; Altuner, Sakir; Oz Gul, Ozen; Yetgin, Zeynel Abidin; Akkurt, Aysen; Ucar, Hakan; Tuncel, Ercan

2014-08-01

84

A social ecological approach to understanding correlates of lifetime sexual assault among sexual minority women in Toronto, Canada: results from a cross-sectional internet-based survey.  

PubMed

Stigma, discrimination and violence contribute to health disparities among sexual minorities. Lesbian, bisexual and queer (LBQ) women experience sexual violence at similar or higher rates than heterosexual women. Most research with LBQ women, however, has focused on measuring prevalence of sexual violence rather than its association with health outcomes, individual, social and structural factors. We conducted a cross-sectional online survey with LBQ women in Toronto, Canada. Multivariate logistic regression analyses were conducted to assess correlates of lifetime sexual assault (LSA). Almost half (42%) of participants (n = 415) reported experiences of LSA. Participants identifying as queer were more likely to have experienced LSA than those identifying as lesbian. When controlling for socio-demographic characteristics, experiencing LSA was associated with higher rates of depression, sexually transmitted infections (STIs), receiving an STI test, belief that healthcare providers were not comfortable with their LBQ sexual orientation, and sexual stigma (overall, perceived and enacted). A history of sexual violence was associated with lower: self-rated health, overall social support, family social support and self-esteem. This research highlights the salience of a social ecological framework to inform interventions for health promotion among LBQ women and to challenge sexual stigma and sexual violence. PMID:24412812

Logie, C H; Alaggia, R; Rwigema, M J

2014-08-01

85

Low-energy cross-section calculations of single molecules by electron impact: a classical Monte Carlo transport approach with quantum mechanical description  

NASA Astrophysics Data System (ADS)

The present state of modeling radio-induced effects at the cellular level does not account for the microscopic inhomogeneity of the nucleus from the non-aqueous contents (i.e. proteins, DNA) by approximating the entire cellular nucleus as a homogenous medium of water. Charged particle track-structure calculations utilizing this approximation are therefore neglecting to account for approximately 30% of the molecular variation within the nucleus. To truly understand what happens when biological matter is irradiated, charged particle track-structure calculations need detailed knowledge of the secondary electron cascade, resulting from interactions with not only the primary biological component—water-–but also the non-aqueous contents, down to very low energies. This paper presents our work on a generic approach for calculating low-energy interaction cross-sections between incident charged particles and individual molecules. The purpose of our work is to develop a self-consistent computational method for predicting molecule-specific interaction cross-sections, such as the component molecules of DNA and proteins (i.e. nucleotides and amino acids), in the very low-energy regime. These results would then be applied in a track-structure code and thereby reduce the homogenous water approximation. The present methodology—inspired by seeking a combination of the accuracy of quantum mechanics and the scalability, robustness, and flexibility of Monte Carlo methods—begins with the calculation of a solution to the many-body Schrödinger equation and proceeds to use Monte Carlo methods to calculate the perturbations in the internal electron field to determine the interaction processes, such as ionization and excitation. As a test of our model, the approach is applied to a water molecule in the same method as it would be applied to a nucleotide or amino acid and compared with the low-energy cross-sections from the GEANT4-DNA physics package of the Geant4 simulation toolkit for the energy ranges of 7 eV to 1 keV.

Madsen, J. R.; Akabani, G.

2014-05-01

86

Prevalence, patterns and correlates of alcohol consumption and its' association with tobacco smoking among Sri Lankan adults: a cross-sectional study  

PubMed Central

Background Most studies on alcohol consumption carried out in Sri Lanka are limited to single/few provinces in the island. The objective of this study was to determine the prevalence, patterns and correlates of alcohol consumption among a larger sample of adults in Sri Lanka. Methods This cross-sectional study was conducted in seven of all nine provinces in Sri Lanka, between 2005 and 2006. A nationally representative sample of 5000 adults aged ?18 years was selected using multi-stage random cluster sampling. Data of 4532 participants were collected using an interviewer administered questionnaire. Data analysis included chi-squared test, multiple logistic regression analysis and Spearman correlation using Stata/SE 10.0 (StataCorp LP., Texas, USA) software package. Results Males were 40%; mean age was 46.1 years (±15.1). The overall, urban and rural prevalence (95% CI) of current drinking was 23.7% (21.7 – 25.7), 29.5% (25.7 – 33.3) and 22.2% (19.8 – 24.7) respectively (p?=?0.001). Current (M: 48.1%, F: 1.2%, p?70 years age-group. Hazardous drinking was seen in 5.2% of men and 0.02% of women. Male sex, urban living and current smoking correlated with both current and hazardous drinking. Lower level of education, and age >70 years positively correlated with hazardous drinking. Conclusions Alcohol is predominantly a problem in Sri Lankan males. In males, both current and hazardous drinking positively correlated with urban living, white collar occupation, Burgher ethnicity and current smoking. Hazardous drinking positively correlated with lower level of education and older age. The data shown here are useful in planning interventions simultaneously targeting alcohol and tobacco.

2014-01-01

87

Correlation of Aggregatibacter actinomycetemcomitans Detection with Clinical/Immunoinflammatory Profile of Localized Aggressive Periodontitis Using a 16S rRNA Microarray Method: A Cross-Sectional Study  

PubMed Central

Objective The objective of this study was to determine whether the detection of Aggregatibacter actinomycetemcomitans (Aa) correlates with the clinical and immunoinflammatory profile of Localized Aggressive Periodontitis (LAP), as determined by by 16S rRNA gene-based microarray. Subjects and Methods Subgingival plaque samples from the deepest diseased site of 30 LAP patients [PD ? 5 mm, BoP and bone loss] were analyzed by 16S rRNA gene-based microarrays. Gingival crevicular fluid (GCF) samples were analyzed for 14 cyto/chemokines. Peripheral blood was obtained and stimulated in vitro with P.gingivalis and E.coli to evaluate inflammatory response profiles. Plasma lipopolysaccharide (LPS) levels were also measured. Results Aa was detected in 56% of LAP patients and was shown to be an indicator for different bacterial community structures (p<0.01). Elevated levels of pro-inflammatory cyto/chemokines were detected in LPS-stimulated blood samples in both Aa-detected and Aa-non-detected groups (p>0.05). Clinical parameters and serum LPS levels were similar between groups. However, Aa-non-detected GCF contained higher concentration of IL-8 than Aa-detected sites (p<0.05). TNF? and IL1? were elevated upon E.coli LPS stimulation of peripheral blood cells derived from patients with Aa-detected sites. Conclusions Our findings demonstrate that the detection of Aa in LAP affected sites, did not correlate with clinical severity of the disease at the time of sampling in this cross-sectional study, although it did associate with lower local levels of IL-8, a different subgingival bacterial profile and elevated LPS-induced levels of TNF? and IL1?.

Goncalves, Patricia F.; Klepac-Ceraj, Vanja; Huang, Hong; Paster, Bruce J.; Aukhil, Ikramuddin; Wallet, Shannon M.; Shaddox, Luciana M.

2013-01-01

88

Radar cross section of insects  

NASA Astrophysics Data System (ADS)

X-band measurements of radar cross section as a function of the angle between insect body axis and the plane of polarization are presented. A finding of particular interest is that in larger insects, maximum cross section occurs when the E-vector is perpendicular to the body axis. A new range of measurements on small insects (aphids, and planthoppers) is also described, and a comprehensive summary of insect cross-section data at X-band is given.

Riley, J. R.

1985-02-01

89

Generalized x-ray scattering cross section from nonequilibrium plasmas  

SciTech Connect

We propose a modified x-ray form factor that describes the scattering cross section in warm dense matter valid for both the plasma and the solid (crystalline) state. Our model accounts for the effect of lattice correlations on the electron-electron dynamic structure, as well as provides a smooth transition between the solid and the plasma scattering cross sections. In addition, we generalize the expression of the dynamic structure in the case of a two-temperature system (with different electron and ion temperatures). This work provides a unified description of the x-ray scattering processes in warm and dense matter, as the one encountered in inertial confinement fusion, laboratory astrophysics, material science, and high-energy density physics and it can be used to verify temperature relaxation mechanisms in such environments.

Gregori, G.; Glenzer, S. H.; Landen, O. L. [CCLRC, Rutherford Appleton Laboratory, Chilton, Didcot OX11 0QX, Great Britain and Clarendon Laboratory, University of Oxford, Parks Road, Oxford, OX1 3PU, Great Britain (United Kingdom); Lawrence Livermore National Laboratory, University of California, P.O. Box 808, California 94551 (United States)

2006-08-15

90

A Cross-sectional Descriptive Study was to Estimate the Prevalence of the Early Initiation of and Exclusive Breast Feeding in the Rural Health Training Centre of a Medical College in Tamilnadu, South India  

PubMed Central

Introduction The World Health Organization and the National guidelines on infant and young child feeding recommend the practice of exclusive breastfeeding of infants for the first 6 months after their birth. The objective of this study was to estimate the prevalence of the early initiation of and exclusive breast feeding. Method A cross sectional, descriptive study was done. 79 infants and children who attended the under five clinic in the Rural Health Training Centre (RHTC), Pulipakkam Village, were chosen for the study by convenient sampling. This study was conducted by interviewing 79 mothers of the children in the ages of 0–24 months, who attended the under five clinic of RHTC, Pulipakkam. The data was collected by using a pre tested, structured questionnaire to obtain the information on the breast feeding and the hygienic feeding practices among mothers. The statistical analysis was done by the authors by using the SPSS, version 16. The significance in the differences were evaluated by using the Chi square test and the relationship between the variables were evaluated by using Kendall’s tau correlation. A p value of <0.05 was considered as statistically significant. Results The prevalence of the early Initiation of breast feeding was 97.5% and the prevalence of exclusive breast feeding in the study population was 68%. Inadequate exclusive breast feeding and the lack of hygienic feeding practices among the mothers were significantly associated with an increased incidence of upper and lower respiratory tract infections and gastro intestinal infections in the infants and the children. Conclusion The education of the antenatal mothers on the benefits of breast feeding and hygienic feeding practices and making all hospitals baby friendly have to be focused on, in order to achieve 80% exclusive breast feeding as per the national guidelines on infant and young child feeding. We need to strengthen the MCH services in the study area in order to achieve 100% immunization.

Jennifer, H. Gladius; Muthukumar, K.

2012-01-01

91

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

92

XCOM: Photon Cross Sections Database  

National Institute of Standards and Technology Data Gateway

SRD 8 XCOM: Photon Cross Sections Database (Web, free access)   A web database is provided which can be used to calculate photon cross sections for scattering, photoelectric absorption and pair production, as well as total attenuation coefficients, for any element, compound or mixture (Z <= 100) at energies from 1 keV to 100 GeV.

93

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

94

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

95

Correlation of magnesium intake with metabolic parameters, depression and physical activity in elderly type 2 diabetes patients: a cross-sectional study  

PubMed Central

Background Type 2 diabetes mellitus is a major global public health problem in the worldwide and is increasing in aging populations. Magnesium intake may be one of the most important factors for diabetes prevention and management. Low magnesium intake may exacerbate metabolic abnormalities. In this study, the relationships of magnesium intake with metabolic parameters, depression and physical activity in elderly patients with type 2 diabetes were investigated. Methods This cross-sectional study involved 210 type 2 diabetes patients aged 65?years and above. Participants were interviewed to obtain information on lifestyle and 24-hour dietary recall. Assessment of depression was based on DSM-IV criteria. Clinical variables measured included anthropometric measurements, blood pressure, and biochemical determinations of blood and urine samples. Linear regression was applied to determine the relationships of magnesium intake with nutritional variables and metabolic parameters. Results Among all patients, 88.6% had magnesium intake which was less than the dietary reference intake, and 37.1% had hypomagnesaemia. Metabolic syndromes and depression were associated with lower magnesium intake (p?correlated with triglyceride, waist circumference, body fat percent and body mass index (p?

2012-01-01

96

Awareness and correlates of the role of physical activity in breast cancer prevention among Japanese women: results from an internet-based cross-sectional survey  

PubMed Central

Background Although considerable evidence has demonstrated that physical activity is associated with breast cancer prevention, few studies have assessed the level of awareness of this association. Awareness is a key first step to successful of behavior change. Increasing awareness may contribute to promote physical activity and prevent breast cancer at the population level. The present study examined the prevalence and correlates of awareness about the role of physical activity in breast cancer prevention among Japanese women. Methods 1,000 Japanese women aged 20–69 years (mean age: 44.3?±?13.4 years) who responded to an internet-based cross-sectional survey. Awareness of the role of physical activity in breast cancer prevention, knowledge of breast cancer (symptom, risk factor, screening), exposure to information about physical activity and cancer, a self-reported physical activity, and sociodemographic variables (age, marital status, having a child, education level, employment status, and household income) were obtained. Force-entry logistic regression analysis was used. Results The prevalence of awareness was 31.5% (95%?CI: 28.6-34.4). Factors significantly associated with awareness included sociodemographic variables, exposure to information, and knowledge of breast cancer. Being married (AOR, 95% CI: 1.75, 1.05–2.92) was positively related to awareness, while having children (0.65, 0.36–0.86) was negatively related. College graduates or those with higher levels of education (1.50, 1.01–2.22) were significantly more likely to be aware than those who had not graduated high school. Moreover, exposure to information (2.11, 1.51–2.95), and high knowledge of symptoms (2.43, 1.75–3.36) were positively associated with awareness. Finally, low knowledge of risk factors (0.30, 0.22–0.40) was negatively associated with awareness. Conclusions Japanese women through internet-based study were poorly aware of the role of physical activity in breast cancer prevention. Awareness was especially low among individuals with children and higher knowledge of risk factors whereas high in married women, those with higher educational level, exposure to information, and greater knowledge of symptoms. The findings suggest that strategies to increase the awareness about the preventive role of physical activity are needed for breast cancer prevention in consideration of subgroups with low awareness.

2014-01-01

97

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

98

Measurement of cross sections at low p-pbar momenta  

SciTech Connect

In a recent experiment at the Low Energy Anti-Proton Ring (LEAR) at CERN, the p-pbar differential elastic and charge exchange (CEX) cross sections as well as the annihilation to charged and neutral pions cross section have been measured. A description of the experiment and some preliminary results are presented.

Brueckner, W.; Doebbeling, H.; von Harrach, D.; Kneis, H.; Majewski, S.; Nomachi, M.; Paul, S.; Povh, B.; Ransome, R.; Shibata, T.

1984-11-15

99

The bboverline production cross section and angular correlations in ppoverline collisions at /sqrt(s)=1.8 TeV  

NASA Astrophysics Data System (ADS)

We present measurements of the bboverline production cross section and angular correlations using the DØ detector at the Fermilab Tevatron ppoverline Collider operating at /sqrt(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 heavy flavor production but are greater than the central values of these predictions. The angular correlations between /b and boverline quarks, measured from the azimuthal opening angle between their decay muons, also agree in shape with the next-to-leading order QCD prediction.

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

2000-08-01

100

Low Energy Neutrino Cross Sections  

NASA Astrophysics Data System (ADS)

Present atmospheric and accelerator based neutrino oscillation experiments operate at low neutrino energies (Ev ~ 1 GeV) to access the relevant regions of oscillation parameter space. As such, they require precise knowledge of the cross sections for neutrino-nucleon interactions in the sub-to-few GeV range. At these energies, neutrinos predominantly interact via quasi-elastic (QE) or single pion production processes, which historically have not been as well studied as the deep inelastic scattering reactions that dominate at higher energies. Data on low energy neutrino cross sections come mainly from bubble chamber, spark chamber, and emulsion experiments that collected their data decades ago. Despite relatively poor statistics and large neutrino flux uncertainties, these measurements provide an important and necessary constraint on Monte Carlo models in present use. The following sections discuss the current status of QE, resonant single pion, coherent pion, and single kaon production cross section measurements at low energy.

Zeller, G. P.

2004-10-01

101

Absolute photoionization cross sections of atomic oxygen  

NASA Technical Reports Server (NTRS)

The absolute values of photoionization cross sections of atomic oxygen were measured from the ionization threshold to 120 A. An auto-ionizing resonance belonging to the 2S2P4(4P)3P(3Do, 3So) transition was observed at 479.43 A and another line at 389.97 A. The experimental data is in excellent agreement with rigorous close-coupling calculations that include electron correlations in both the initial and final states.

Samson, J. A. R.; Pareek, P. N.

1985-01-01

102

Absolute photoionization cross sections of atomic oxygen  

NASA Technical Reports Server (NTRS)

The absolute values of photoionization cross sections of atomic oxygen were measured from the ionization threshold to 120 A. An auto-ionizing resonance belonging to the 2S2P4(4P)3P(3Do, 3So) transition was observed at 479.43 A and another line at 389.97 A. The experimental data is in excellent agreement with rigorous close-coupling calculations that include electron correlations in both the initial and final states.

Samson, J. A. R.; Pareek, P. N.

1982-01-01

103

Measurement of the cross section and angular correlations for associated production of a Z boson with b hadrons in pp collisions at = 7 TeV  

NASA Astrophysics Data System (ADS)

A study of proton-proton collisions in which two b hadrons are produced in association with a Z boson is reported. The collisions were recorded at a centre-of-mass energy of 7 TeVwith the CMS detector at the LHC, for an integrated luminosity of 5.2 fb-1. The b hadrons are identified by means of displaced secondary vertices, without the use of reconstructed jets, permitting the study of b-hadron pair production at small angular separation. Differential cross sections are presented as a function of the angular separation of the b hadrons and the Z boson. In addition, inclusive measurements are presented. For both the inclusive and differential studies, different ranges of Z boson momentum are considered, and each measurement is compared to the predictions from different event generators at leading-order and next-to-leading-order accuracy. [Figure not available: see fulltext.

Chatrchyan, S.; Khachatryan, V.; Sirunyan, A. M.; Tumasyan, A.; Adam, W.; Bergauer, T.; Dragicevic, M.; Erö, J.; Fabjan, C.; Friedl, M.; Frühwirth, R.; Ghete, V. M.; Hörmann, N.; Hrubec, J.; Jeitler, M.; Kiesenhofer, W.; Knünz, V.; Krammer, M.; Krätschmer, I.; Liko, D.; Mikulec, I.; Rabady, D.; Rahbaran, B.; Rohringer, C.; Rohringer, H.; Schöfbeck, R.; Strauss, J.; Taurok, A.; Treberer-Treberspurg, W.; Waltenberger, W.; Wulz, C.-E.; Mossolov, V.; Shumeiko, N.; Gonzalez, J. Suarez; Alderweireldt, S.; Bansal, M.; Bansal, S.; Cornelis, T.; De Wolf, E. A.; Janssen, X.; Knutsson, A.; Luyckx, S.; Mucibello, L.; Ochesanu, S.; Roland, B.; Rougny, R.; Staykova, Z.; Van Haevermaet, H.; Van Mechelen, P.; Van Remortel, N.; Van Spilbeeck, A.; Blekman, F.; Blyweert, S.; D'Hondt, J.; Kalogeropoulos, A.; Keaveney, J.; Maes, M.; Olbrechts, A.; Tavernier, S.; Van Doninck, W.; Van Mulders, P.; Van Onsem, G. P.; Villella, I.; Clerbaux, B.; De Lentdecker, G.; Favart, L.; Gay, A. P. R.; Hreus, T.; Léonard, A.; Marage, P. E.; Mohammadi, A.; Perniè, L.; Reis, T.; Seva, T.; Thomas, L.; Velde, C. Vander; Vanlaer, P.; Wang, J.; Adler, V.; Beernaert, K.; Benucci, L.; Cimmino, A.; Costantini, S.; Dildick, S.; Garcia, G.; Klein, B.; Lellouch, J.; Marinov, A.; Mccartin, J.; Rios, A. A. Ocampo; Ryckbosch, D.; Sigamani, M.; Strobbe, N.; Thyssen, F.; Tytgat, M.; Walsh, S.; Yazgan, E.; Zaganidis, N.; Basegmez, S.; Beluffi, C.; Bruno, G.; Castello, R.; Caudron, A.; Ceard, L.; Delaere, C.; du Pree, T.; Favart, D.; Forthomme, L.; Giammanco, A.; Hollar, J.; Jez, P.; Lemaitre, V.; Liao, J.; Militaru, O.; Nuttens, C.; Pagano, D.; Pin, A.; Piotrzkowski, K.; Popov, A.; Selvaggi, M.; Garcia, J. M. Vizan; Beliy, N.; Caebergs, T.; Daubie, E.; Hammad, G. H.; Alves, G. A.; Martins, M. Correa; Martins, T.; Pol, M. E.; Souza, M. H. G.; Aldá, W. L.; Carvalho, W.; Chinellato, J.; Custódio, A.; Da Costa, E. M.; De Jesus Damiao, D.; De Oliveira Martins, C.; De Souza, S. Fonseca; Malbouisson, H.; Malek, M.; Figueiredo, D. Matos; Mundim, L.; Nogima, H.; Da Silva, W. L. Prado; Santoro, A.; Sznajder, A.; Manganote, E. J. Tonelli; Pereira, A. Vilela; Bernardes, C. A.; Dias, F. A.; Tomei, T. R. Fernandez Perez; Gregores, E. M.; Lagana, C.; Mercadante, P. G.; Novaes, S. F.; Padula, Sandra S.; Genchev, V.; Iaydjiev, P.; Piperov, S.; Rodozov, M.; Sultanov, G.; Vutova, M.; Dimitrov, A.; Hadjiiska, R.; Kozhuharov, V.; Litov, L.; Pavlov, B.; Petkov, P.; Bian, J. G.; Chen, G. M.; Chen, H. S.; Jiang, C. H.; Liang, D.; Liang, S.; Meng, X.; Tao, J.; Wang, J.; Wang, X.; Wang, Z.; Xiao, H.; Xu, M.; Asawatangtrakuldee, C.; Ban, Y.; Guo, Y.; Li, Q.; Li, W.; Liu, S.; Mao, Y.; Qian, S. J.; Wang, D.; Zhang, L.; Zou, W.; Avila, C.; Montoya, C. A. Carrillo; Sierra, L. F. Chaparro; Gomez, J. P.; Moreno, B. Gomez; Sanabria, J. C.; Godinovic, N.; Lelas, D.; Plestina, R.; Polic, D.; Puljak, I.; Antunovic, Z.; Kovac, M.; Brigljevic, V.; Duric, S.; Kadija, K.; Luetic, J.; Mekterovic, D.; Morovic, S.; Tikvica, L.; Attikis, A.; Mavromanolakis, G.; Mousa, J.; Nicolaou, C.; Ptochos, F.; Razis, P. A.; Finger, M.; Finger, M.; Abdelalim, A. A.; Assran, Y.; Elgammal, S.; Kamel, A. Ellithi; Mahmoud, M. A.; Radi, A.; Kadastik, M.; Müntel, M.; Murumaa, M.; Raidal, M.; Rebane, L.; Tiko, A.; Eerola, P.; Fedi, G.; Voutilainen, M.; Härkönen, J.; Karimäki, V.; Kinnunen, R.; Kortelainen, M. J.; Lampén, T.; Lassila-Perini, K.; Lehti, S.; Lindén, T.; Luukka, P.; Mäenpää, T.; Peltola, T.; Tuominen, E.; Tuominiemi, J.; Tuovinen, E.; Wendland, L.; Korpela, A.; Tuuva, T.; Besancon, M.; Choudhury, S.; Couderc, F.; Dejardin, M.; Denegri, D.; Fabbro, B.; Faure, J. L.; Ferri, F.; Ganjour, S.; Givernaud, A.; Gras, P.; de Monchenault, G. Hamel; Jarry, P.; Locci, E.; Malcles, J.; Millischer, L.; Nayak, A.; Rander, J.; Rosowsky, A.; Titov, M.; Baffioni, S.; Beaudette, F.; Benhabib, L.; Bianchini, L.; Bluj, M.; Busson, P.; Charlot, C.; Daci, N.; Dahms, T.; Dalchenko, M.; Dobrzynski, L.; Florent, A.; de Cassagnac, R. Granier; Haguenauer, M.; Miné, P.; Mironov, C.; Naranjo, I. N.; Nguyen, M.; Ochando, C.; Paganini, P.; Sabes, D.; Salerno, R.; Sirois, Y.; Veelken, C.; Zabi, A.; Agram, J.-L.; Andrea, J.; Bloch, D.; Bodin, D.; Brom, J.-M.; Chabert, E. C.; Collard, C.; Conte, E.; Drouhin, F.; Fontaine, J.-C.; Gelé, D.; Goerlach, U.; Goetzmann, C.; Juillot, P.; Le Bihan, A.-C.; Van Hove, P.; Gadrat, S.; Beauceron, S.; Beaupere, N.; Boudoul, G.; Brochet, S.; Chasserat, J.; Chierici, R.; Contardo, D.; Depasse, P.; El Mamouni, H.; Fay, J.; Gascon, S.; Gouzevitch, M.; Ille, B.; Kurca, T.; Lethuillier, M.; Mirabito, L.; Perries, S.; Sgandurra, L.; Sordini, V.; Tschudi, Y.; Donckt, M. Vander; Verdier, P.; Viret, S.; Tsamalaidze, Z.; Autermann, C.; Beranek, S.; Calpas, B.; Edelhoff, M.; Feld, L.

2013-12-01

104

Photoneutron cross sections for Au  

SciTech Connect

Photoneutron cross sections were measured for Au in the entire energy range of the ({gamma},n) channel based on a direct neutron-counting technique with quasimonochromatic {gamma} rays produced in inverse Compton-scattering of laser photons with relativistic electrons. We present results of the measurement in comparison with the past data.

Itoh, O.; Utsunomiya, H.; Akimune, H.; Yamagata, T.; Kondo, T.; Kamata, M. [Department of Physics, Konan University, Okamoto 8-9-1, Higashinada, Kobe 658-8501 (Japan); Toyokawa, H. [National Institute of Advanced Industrial Science and Technology, Tsukuba 305-8568 (Japan); Harada, H.; Kitatani, F. [Japan Atomic Energy Agency, Tokai-mura, Naka, Ibaraki 319-1195 (Japan); Goko, S. [Japan Atomic Energy Agency, Tokai-mura, Naka, Ibaraki 319-1195 (Japan); Faculty of Engineering, Hokkaido University, Sapporo 060-8628 (Japan); Nair, C. [Institut fuer Strahlenphysik, Forschungszentrum Dresden-Rossendorf, D-01314 Dresden (Germany); Nuclear Engineering Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States); Lui, Y.-W. [Cyclotron Institute, Texas A and M University, College Station, Texas 77843 (United States)

2011-10-28

105

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

106

Radar Cross Section of Ships  

Microsoft Academic Search

A laboratory method to determine the magnitude and position of radar reflection sources on complex targets is described. In addition the method provides a way to measure the modification of the radar cross section (RCS) due to multipath. The method has application in modeling RCS for radar and electronic countermeasure (ECM) system performance analysis and in the study of the

F. C. Paddison; C. A. Shipley; A. L. Maffett; M. H. Dawson

1978-01-01

107

Cavity Radar Cross Section Prediction  

Microsoft Academic Search

Alternative models are discussed for the determination of the interior irradiation contribution to the radar cross section (RCS) of open-ended cavities. Typical applications of practical interest include radiation field prediction of open-ended waveguides and signature prediction of jet engine air intakes and exhaust outlets. It is shown and explained why the classic perfectly conducting (PEC) ground plane (GP) model sometimes

Adam Zdunek; Waldemar Rachowicz

2008-01-01

108

Low energy e-Ar momentum transfer cross-section  

SciTech Connect

Recent work has shown that solutions of the Boltzmann equation which use the so called {open_quotes}two-term{close_quotes} approximation provide an inadequate description of the transverse diffusion of electrons in argon gas at low values of E/N, contrary to earlier evidence. Previous determinations of the momentum transfer cross section for argon from the analysis of transport data have used two-term codes in good faith. Progress towards the determination of a new cross section in the energy range O - 4 eV, including an analysis of the energy dependence of the uncertainty in the derived cross section is reported.

Brennan, M.J.

1992-12-01

109

LUMEN Cross-Section Tutorial  

NSDL National Science Digital Library

The Loyola University Medical Education Network (LUMEN) presents this anatomy tutorial. The site is divided up into categories of cross-sectional images of the human body: Head and Neck, Upper Limb, male and female Thorax, Abdomen, male and female Pelvis, and Lower Limb. By clicking on each section, users select a cross-section of that part of the anatomy, and by clicking on each number, can find out the specific name of that area. Users can also choose to see an illustration of the area (by choosing âÂÂImageâÂÂ), or an image from a CAT scan (by choosing âÂÂCTâÂÂ). This is an excellent resource for students in any health care or allied medical field, including nursing or nursesâ aides, patient care assistants, and diagnostic imaging technicians.

Mcnulty, John A.

2010-07-20

110

Gait speed correlates in a multiracial population of community-dwelling older adults living in Brazil: a cross-sectional population-based study  

PubMed Central

Background Gait speed is a strong predictor of a wide range of adverse health outcomes in older adults. Mean values for gait speed in community-dwelling older adults vary substantially depending on population characteristics, suggesting that social, biological, or health factors might explain why certain groups tend to self-select their gait speed in different patterns. The vast majority of studies reported in the literature present data from North American and European populations. There are few population-based studies from other regions with a different ethnicity and/or social and health conditions. To address this, the present study identified the mean usual and fast gait speeds in a representative multiracial population of community-dwelling older adults living in a developing country, and explored their association with sociodemographic, mental and physical health characteristics. Methods This was a cross-sectional population-based study of a sample of 137 men and 248 women, aged 65 years and over. Usual gait speed and fast gait speed were measured on a 4.6 m path. Participants were classified into slow, intermediate, and faster groups by cluster analysis. Logistic regression analysis was used to estimate the independent effect of each factor on the odds of presenting with a slower usual and slower fast gait speeds. Results Participants had a mean (SD) usual gait speed of 1.11 (0.27) m/s and a mean fast gait speed of 1.39 (0.34) m/s. We did not observe an independent association between gait speed and race/ethnicity, educational level, or income. The main contributors to present a slower usual gait speed were low physical activity level, stroke, diabetes, urinary incontinence, high concern about falling, and old age. A slower fast gait speed was associated with old age, low physical activity, urinary incontinence and high concern about falling. Conclusion A multiracial population of older adults living in a developing country showed a similar mean gait speed to that observed in previously studied populations. The results suggest that low physical activity, urinary incontinence and high concern about falling should not be neglected and may help identify those who might benefit from early intervention.

2013-01-01

111

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

112

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

113

The impact of the 2011 Great East Japan Earthquake on hospitalisation for respiratory disease in a rapidly aging society: a retrospective descriptive and cross-sectional study at the disaster base hospital in Ishinomaki  

PubMed Central

Objective To investigate the impact in an aging society of the 2011 Great East Japan earthquake on hospitalisation for respiratory disease at the disaster base hospital. Design Descriptive and cross-sectional study. Setting Emergency care in Japanese Red Cross Ishinomaki Hospital, a regional disaster base hospital in Miyagi, Japan. Participants 322 emergency patients who were hospitalised for respiratory disease from 11 March to 9 May 2011, and 99 and 105 emergency patients who were hospitalised in the corresponding periods in 2009 and 2010, respectively. Main outcome measures Description and comparison of patient characteristics and disease distribution in terms of age, time after the disaster and activities of daily living (ADL). Results 1769 patients were admitted to our hospital during the study period (compared to 850 in 2009 and 1030 in 2010), among whom 322 were hospitalised for respiratory disease (compared to 99 in 2009 and 105 in 2010). Pneumonia (n=190, 59.0%) was the most frequent cause of admission for pulmonary disease, followed by acute exacerbation of chronic obstructive pulmonary disease (AE-COPD) (n=53, 16.5%), asthma attacks (n=27, 8.4%) and progression of lung cancer (n=22, 6.8%). Compared with the corresponding periods in 2009 and 2010, the increase in the absolute numbers of admissions was highest for pneumonia, followed by AE-COPD and asthma attacks. At hospitalisation, 195 patients were ‘dependent’ and 54 patients were ‘partially dependent’. Respiratory admissions accompanied by deterioration of ADL after the disaster were more frequent in elderly and female patients. Conclusions After the Great East Japan Earthquake, admissions for pneumonia and exacerbation of chronic respiratory disease in the elderly increased at the disaster base hospital.

Yamanda, Shinsuke; Hanagama, Masakazu; Kobayashi, Seiichi; Satou, Hikari; Tokuda, Shinsaku; Niu, Kaijun; Yanai, Masaru

2013-01-01

114

Photoionization cross section of Fe7+ ion  

NASA Astrophysics Data System (ADS)

The fully relativistic R-matrix calculation is performed for the photoionization cross section of Fe7+. The results are compared with available experimental spectrum and previous calculations of the cross section.

Gao, L. C.; Xie, L. Y.; Zhang, D. H.; Wang, J. G.; Shi, Y. L.; Dong, C. Z.

2014-04-01

115

Correlation of discrete Minnelusa porosity intervals and identification of common reservoirs aided by computer-drawn geologic cross sections, Powder River basin, northeast Wyoming  

Microsoft Academic Search

The upper Minnelusa Formation in the northeastern Wyoming portion of the Powder River basin continues to challenge geologists. Oil exploration and development success depends heavily on correct correlation of discrete porosity intervals within the sand-dolomite series of the upper Minnelusa oil-bearing interval. Drill cores generally are not available. Correlation work must be performed on the basis of electric logs, drill

James H. Borgerding

1987-01-01

116

Molecular dynamical and structural studies for the bakelite by neutron cross section measurements  

Microsoft Academic Search

Neutron reaction cross sections were determined by transmission and scattering measurements, to study the dynamics and molecular structure of calcined bakelites. Total cross sections were determined, with a deviation smaller than 5%, from the literature values, by neutron transmission method and a specially devised approximation. These cross sections were then correlated with data obtained with infrared spectroscopy, elemental analysis, and

D. L. Voi

1992-01-01

117

Dynamic panel estimation and homogeneity testing under cross section dependence &ast  

Microsoft Academic Search

Summary. This paper deals with cross section dependence, homogeneity restrictions and small sample bias issues in dynamic panel regressions. To address the bias problem we develop a panel approach to median unbiased estimation that takes account of cross section dependence. The estimators given here considerably reduce the effects of bias and gain precision from estimating cross section error correlation. This

Peter C. B. Phillips; Donggyu Sul

2003-01-01

118

Neutron cross sections: Book of curves  

SciTech Connect

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 sections have been included. 11 refs., 4 figs.

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

1988-01-01

119

Hadronic absorption cross sections of B c  

Microsoft Academic Search

The absorption cross sections Bc meson by hadronic commoving systems (nucleons) are investigated using a gauged SU5 hadronic Lagrangian in mesonic exchange model. The energy dependence of dissociation cross sections are calculated from the threshold to higher energies with monopole form factor. Depending on values of the monopole form factor cut off parameter used, the peak cross sections are found

M. A. K. Lodhi; Rain Marshall

2007-01-01

120

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

121

Intrapersonal and Social Environment Correlates of Leisure-Time Physical Activity for Cancer Prevention: A Cross-Sectional Study Among Canadian Adults.  

PubMed

BACKGROUND: Little is known about the intrapersonal and social factors associated with sufficient physical activity (PA) for cancer prevention, which is greater than for cardiovascular health. METHODS: 1,087 and 1,684 randomly selected men and women, age 35 to 64, completed self-administered questionnaires on PA behaviour and psycho-social characteristics. Using gender-stratified logistic regression, we investigated correlates of compliance with Public Health Agency of Canada PA guidelines for general health (150 minutes//week), and the American Cancer Society (ACS) (225 minutes/week) and World Cancer Research Fund/American Institute for Cancer Research (WCRF/AIRC) (420 minutes/week) guidelines for cancer prevention. RESULTS: Only 39% and 19% of men and women met ACS and WCRF/AICR guidelines, respectively. Self-efficacy, scheduling PA and friend social support were positively correlated with recommended PA for cancer prevention. In men, poor self-rated health and perceived negative outcomes were negatively correlated and hypertension was positively correlated with meeting cancer prevention guidelines. For women, not being married and having a companion for PA were positively correlated with meeting cancer prevention guidelines. CONCLUSIONS: Few adults participate in sufficient PA for cancer risk reduction. Multidimensional public health strategies that incorporate intrapersonal and social factors and are tailored for each gender are needed to promote PA for cancer prevention. PMID:23574766

Aparicio-Ting, Fabiola E; Friedenreich, Christine M; Plotnikoff, Ronald C; Bryant, Heather E

2013-04-01

122

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

123

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

124

SNL RML recommended dosimetry cross section compendium  

SciTech Connect

A compendium of dosimetry cross sections is presented for use in the characterization of fission reactor spectrum and fluence. The contents of this cross section library are based upon the ENDF/B-VI and IRDF-90 cross section libraries and are recommended as a replacement for the DOSCROS84 multigroup library that is widely used by the dosimetry community. Documentation is provided on the rationale for the choice of the cross sections selected for inclusion in this library and on the uncertainty and variation in cross sections presented by state-of-the-art evaluations.

Griffin, P.J.; Kelly, J.G.; Luera, T.F. [Sandia National Labs., Albuquerque, NM (United States)] [Sandia National Labs., Albuquerque, NM (United States); VanDenburg, J. [Science and Engineering Associates, Inc., Albuquerque, NM (United States)] [Science and Engineering Associates, Inc., Albuquerque, NM (United States)

1993-11-01

125

Prevalence and Clinical Correlates of Coronary Artery Disease among New Dialysis Patients in the United States: A Cross-Sectional Study  

Microsoft Academic Search

Despite the high prevalence of coronary artery dis- ease (CAD) among patients with end-stage renal disease (ESRD), few studies have identified clinical correlates using national data. The purpose of this study was to determine the prevalence and clinical associations of CAD in a national random sample of new ESRD in the United States in 1996\\/ 1997 (n 5 4025). Data

AUSTIN G. STACK; WENDY E. BLOEMBERGEN

126

Clinical correlation of magnetic resonance imaging with symptom complex in prolapsed intervertebral disc disease: A cross-sectional double blind analysis  

PubMed Central

Introduction: Low backache (LBA) is one of the most common problems and herniated lumbar disc is one of the most commonly diagnosed abnormalities associated with LBA. Disc herniation of the same size may be asymptomatic in one patient and can lead to severe nerve root compromise in another patient. Objective: To evaluate correlation between the clinical features of disc collapse and magnetic resonance imaging (MRI) finding to determine the clinical importance of anatomical abnormalities identified by MRI technique. Summary: From January 2010 to January 2012, 75 otherwise healthy patients (43 males 32 females) between the age of 19 and 55 years (average age was 44.5 years) with low back pain and predominant complaint of root pain who presented to our clinic were included in the study. Materials and Methods: Proper screening was done to rule out previous spine affection and subjected to MRI. Results: The results were analyzed under four headings viz. disc herniation, disc degeneration, thecal sac deformation and neural foramen effacement. All patients had a visual analog score (VAS) score more than 6. The interrater correlation coefficient kappa was calculated to be k=0.51. There were total 44 patients with herniation, 25 patients had mild, one patient had moderate degree of thecal sac deformation, 21 patients had one or more levels of foraminal effacement by the herniated tissue, 100% of the patients had disc degeneration ranging from grade 1 to 3 at different levels; and 48 patients (64%) had radiculopathy, six (8%) patients had bilateral and others had ipsilateral affection. Conclusion: In our study, the correlation was made between clinical findings and MRI findings. It can safely be concluded that treating physician should put more emphasis on history, clinical examination, and make the inference by these and then should correlate the clinical findings with that of MRI to reach a final diagnosis.

Bajpai, Jeetendra; Saini, Sumit; Singh, Rakhi

2013-01-01

127

Estimation and correlation of salivary thiocyanate levels in healthy and different forms of tobacco users having chronic periodontitis: A cross-sectional biochemical study  

PubMed Central

Background: Periodontitis is a common inflammatory disease with complex and multi-factorial origin. Tobacco usage has shown its adverse effect on periodontal health. Various components within saliva not only protect the integrity of oral tissues, but also provide clues to local and systemic diseases and conditions. Salivary thiocyanate (SCN) has been shown to be a chemical indicator in smokers and smokeless tobacco users. Noninvasive nature of salivary testing has made it an attractive and effective alternative to blood and urine testing. Limited studies are there comparing and correlating the salivary SCN levels in smokers with chronic periodontitis (CP). However, no studies show correlation of salivary SCN among gutka chewers with CP. Aims and Objectives: The objective of the following study is to estimate, compare, and correlate the SCN levels in periodontally healthy, CP, smokers with CP and gutka chewers with CP subjects. Materials and Methods: Study includes 120 subjects with age 18-55 years, categorized as periodonally healthy (n = 30), CP (n = 30), smokers (n = 30), and gutka chewers (n = 30) with CP. Required clinical parameters such as gingival index, probing depth and clinical attachment loss were recorded and salivary SCN levels were estimated through ultraviolet-spectrophotometer. Results: Mean salivary SCN level were shown to be higher among smokers and gutka chewers with CP as compared to healthy and CP alone. Conclusion: The present study exhibited the significant increase in salivary SCN levels among smokers and gutka chewers when compared to others, concluding that the analysis of salivary SCN levels could be used as an adjunctive means of diagnosis.

Kalburgi, C. Veena; Naik, K. Lavanya; Kokatnur, M. Vijayalaxmi; Warad, Shivaraj

2014-01-01

128

Correlation of cone beam computed tomography (CBCT) findings in the maxillary sinus with dental diagnoses: a retrospective cross-sectional study.  

PubMed

This study was conducted to assess the coincidence of mucosal hyperplasia in the maxillary sinus and related clinical diagnoses of posterior maxillary teeth found in cone beam computed tomography (CBCT) scans. A total of 204 patients who underwent CBCT examinations between 2006 and 2008 were evaluated retrospectively. Clinical and CBCT findings were correlated using patient records. Absolute frequencies, odds ratios (OR), and 95% confidence intervals (95% CI) were calculated for statistical evaluations. There was a pronounced association between periodontitis and radiological signs of sinusitis. Basal mucosal wall thickening was more likely in patients with decayed and non-vital teeth compared to patients with sound teeth (OR = 5.2; 95% CI = 1.2-23.1). Basal mucosal wall thickening was also more likely than total mucosal thickening (OR = 10.4; 95% CI = 2.6-42.2). Patients with decayed and endodontically treated teeth were more likely to exhibit involvement of the basal wall (OR = 9.2; 95% CI = 3.3-25.2) than were patients with healthy teeth. CBCT examinations revealed a correlation between basal mucosal thickening in the maxillary sinus and decayed posterior maxillary teeth or periodontitis. Chronic symptoms involving the sinuses are one of the most common reasons for patients to consult physicians. One reason for chronic orofacial pain is the prevalence of undiagnosed sinus conditions. PMID:21968552

Brüllmann, Dan Dominik; Schmidtmann, Irene; Hornstein, Silke; Schulze, Ralf K

2012-08-01

129

A cross-sectional examination of socio-demographic and school-level correlates of children's school travel mode in Ottawa, Canada  

PubMed Central

Background Active school transport (AST) is an important source of children’s daily physical activity (PA). However, decreasing rates of AST have been reported in multiple countries during the last decades. The purpose of the present study was to examine the socio-demographic and school-level correlates of AST. Methods A stratified sample of children (N?=?567, mean age?=?10.0 years; 57.8% female) was recruited in the Ottawa area. Four sources of data were used for analyses: 1) child questionnaire including questions on school travel mode and time; 2) parent questionnaire providing information on household socio-demographic characteristics; 3) school administrator survey assessing school policies and practices pertaining to PA; and 4) school site audit performed by the study team. Generalized linear mixed models were used to identify socio-demographic and school-level correlates of AST while controlling for school clustering. Results Individual factors associated with higher odds of AST were male gender (OR?=?1.99; 95% CI?=?1.30-3.03), journey time <5 minutes vs. >15 minutes (OR?=?2.26; 95% CI?=?1.17-4.37), and 5–15 minutes vs. >15 minutes (OR?=?2.27; 95% CI?=?1.27-4.03). Children were more likely to engage in AST if school administrators reported that crossing guards were employed (OR?=?2.29; 95% CI?=?1.22-4.30), or if they expressed major or moderate concerns about crime in the school neighbourhood (OR?=?3.34; 95% CI?=?1.34-8.32). In schools that identified safe routes to school and where traffic calming measures were observed, children were much more likely to engage in AST compared to schools without these features (OR?=?7.87; 95% CI?=?2.85-21.76). Moreover, if only one of these features was present, this was not associated with an increased likelihood of AST. Conclusion These findings suggest that providing crossing guards may facilitate AST. Additionally, there was a synergy between the identification of safe routes to school and the presence of traffic calming measures, suggesting that these strategies should be used in combination.

2014-01-01

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

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

132

Negative ion detachment cross sections. Interim progress report  

SciTech Connect

During past year, we have measured cross sections for associative and collisional detachment for several negative ions in collisions with atomic hydrogen. Additional experiments have been performed in which the formation of secondary negative ions and electrons by means of low energy ion impact on surfaces has been studied. Brief descriptions of these activities along with future plans for the project follow.

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

1991-12-01

133

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

134

Annular-Cross-Section CFE Chamber  

NASA Technical Reports Server (NTRS)

Proposed continuous-flow-electrophoresis (CFE) chamber of annular cross section offers advantages over conventional CFE chamber, and wedge-cross-section chamber described in "Increasing Sensitivity in Continuous-Flow Electrophoresis" (MFS-26176). In comparison with wedge-shaped chamber, chamber of annular cross section virtually eliminates such wall effects as electro-osmosis and transverse gradients of velocity. Sensitivity enhanced by incorporating gradient maker and radial (collateral) flow.

Sharnez, Rizwan; Sammons, David W.

1994-01-01

135

Theoretical antideuteron-nucleus absorptive cross sections  

NASA Technical Reports Server (NTRS)

Antideuteron-nucleus absorptive cross sections for intermediate to high energies are calculated using an ion-ion optical model. Good agreement with experiment (within 15 percent) is obtained in this same model for (bar p)-nucleus cross sections at laboratory energies up to 15 GeV. We describe a technique for estimating antinucleus-nucleus cross sections from NN data and suggest that further cosmic ray studies to search for antideuterons and other antinuclei be undertaken.

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

1993-01-01

136

Cross-section Regression with Common Shocks  

Microsoft Academic Search

This paper considers regression models for cross-section data that exhibit cross-section dependence due to common shocks, such as macroeconomic shocks. The paper analyzes the properties of least squares (LS) and instrumental variables (IV) estimators in this context. The results of the paper allow for any form of cross-section dependence and heterogeneity across population units. The probability limits of the LS

Donald W. K. Andrews

2004-01-01

137

Cross-section Regression with Common Shocks  

Microsoft Academic Search

This paper considers regression models for cross-section data that exhibit cross-section dependence due to common shocks, such as macroeconomic shocks. The paper analyzes the properties of least squares (LS) and instrumental variables (IV) estimators in this context. The results of the paper allow for any form of cross-section dependence and heterogeneity across population units. The probability limits of the LS

Donald W. K. Andrews

2003-01-01

138

{sup 16}O neutron cross section evaluation  

SciTech Connect

This work has resulted from a need to compute more accurately the neutron scattering cross sections and angular distributions for {sup 16}O. Several oxygen evaluations have been performed in the past with R-Matrix theory, including ENDF/B-V and ENDF/B-VI. ENDF/B-VI is an improvement over ENDF/B-V, but still underpredicts in general the forward scattering of neutrons below 2.5 MeV. R-Matrix theory is used in describing cross sections at and near the resonance energies; but may not always be adequate in describing cross sections between resonances, especially when they are widely spaced. The optical (potential well) model of the nucleus is very good in representing cross sections that vary smoothly with energy, but not at describing all of the detailed resonance cross sections. A combination of the potential well model and R-Matrix theory was used for this work to represent cross sections with isolated resonances with large spacings between them. The total neutron cross section of oxygen-16 below 3.0 MeV has widely separated resonances and a dip in the cross section at 2.35 MeV. In the vicinity of resonances, where cross sections vary rapidly with energy, R-Matrix theory has been successful in fitting experimental data. In the region between resonances, an analytical procedure with physical basis is needed that agrees with data over a wide range of energies bracketing regions where experimental measurements are lacking.

Caro, E. [Lockheed Martin Corp., Schenectady, NY (United States)

1998-06-01

139

Production cross section of rotating string  

Microsoft Academic Search

We calculate production cross sections of a single rotating string from a collision of two light states in bosonic string theory. We find that the cross sections are written in terms of the modified Bessel function of the first kind with the degree given by the angular momentum in the high energy regime. We also obtain a similar formula from

Tsunehide Kuroki; Toshihiro Matsuo

2008-01-01

140

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

141

Quality at general practice consultations: cross sectional survey  

Microsoft Academic Search

Objectives To measure quality of care at general practice consultations in diverse geographical areas, and to determine the principal correlates associated with enablement as an outcome measure. Design Cross sectional multipractice questionnaire based study. Setting Random sample of practices in four participating regions: Lothian, Coventry, Oxfordshire,

John G R Howie; David J Heaney; Margaret Maxwell; Jeremy J Walker; George K Freeman; Harbinder Rai

1999-01-01

142

Inclined Bodies of Various Cross Sections at Supersonic Speeds  

NASA Technical Reports Server (NTRS)

To aid in assessing effects of cross-sectional shape on body aerodynamics, the forces and moments have been measured for bodies with circular, elliptic, square, and triangular cross sections at Mach numbers 1.98 and 3.88. Results for bodies with noncircular cross sections have been compared with results for bodies of revolution having the same axial distribution of cross-sectional area (and, thus, the same equivalent fineness ratio). Comparisons have been made for bodies of fineness ratios 6 and 10 at angles of attack from 0 deg to about 20 deg and for Reynolds numbers, based on body length, of 4.0 x 10(exp 6) and 6.7 x 10(exp 6). The results of this investigation show that distinct aerodynamic advantages can be obtained by using bodies with noncircular cross sections. At certain angles of bank, bodies with elliptic, square, and triangular cross sections develop considerably greater lift and lift-drag ratios than equivalent bodies of revolution. For bodies with elliptic cross sections, lift and pitching-moment coefficients can be correlated with corresponding coefficients for equivalent circular bodies. It has been found that the ratios of lift and pitching-moment coefficients for an elliptic body to those for an equivalent circular body are practically constant with change in both angle of attack and Mach number. These lift and moment ratios are given very accurately by slender-body theory. As a result of this agreement, the method of NACA Rep. 1048 for computing forces and moments for bodies of revolution has been simply extended to bodies with elliptic cross sections. For the cases considered (elliptic bodies of fineness ratios 6 and 10 having cross-sectional axis ratios of 1.5 and 2), agreement of theory with experiment is very good. As a supplement to the force and moment results, visual studies of the flow over bodies have been made by use of the vapor-screen, sublimation, and white-lead techniques. Photographs from these studies are included in the report.

Jorgensen, Leland H.

1958-01-01

143

Silicon Detector System for Cross Section Measurements  

NASA Technical Reports Server (NTRS)

In order to estimate the radiation shielding effectiveness of materials it is necessary to know cosmic ray particles are broken up as they pass though these materials. The breakup of cosmic ray particles is characterized by the nuclear fragmentation cross sections, i.e. an effective geometrical cross section assigned to each target nucleus that represents its apparent size for fragmenting the incident particle. The values of these cross sections depend on the details of nuclear physics and cannot be calculated from first principles owing to the many-body nature of the interactions. The only way to determine them is to measure them. Once a sufficient number of cross sections have been measured, the systematic nature of the interactions allows other cross-sections to be estimated. The number of cross sections that contribute to the estimation of shielding effectiveness is very large 10,000. Fortunately most make minor contributions. These can be estimated from nuclear systematics. Only those who's uncertainties make significant contributions to the error in the shielding effectiveness estimations need to be measured. In the past it has proven difficult to measure light fragment production cross sections from the interactions of heavy cosmic rays owing to the size of the detectors used. We have developed a highly pixilated silicon (Si) detector system that can individually identify these light fragments while making efficient use of costly accelerator time. This system is an outgrowth of detector technology developed under a CDDF and a Code S sponsored cosmic ray experiment.

2003-01-01

144

Cross Section Evaluations for Arsenic Isotopes  

SciTech Connect

The authors present an evaluation of cross sections describing reactions with neutrons incident on the arsenic isotopes with mass numbers 75 and 74. Particular attention is paid to (n,2n) reactions. The evaluation for {sup 75}As, the only stable As isotope, is guided largely by experimental data. Evaluation for {sup 74}As is made through calculations with the EMPIRE statistical-model reaction code. Cross sections describing the production and destruction of the 26.8 ns isomer in {sup 74}As are explicitly considered. Uncertainties and covariances in some evaluated cross sections are also estimated.

Pruet, J; McNabb, D P; Ormand, W E

2005-03-10

145

Nucleon-Nucleon Total Cross Section  

NASA Technical Reports Server (NTRS)

The total proton-proton and neutron-proton cross sections currently used in the transport code HZETRN show significant disagreement with experiment in the GeV and EeV energy ranges. The GeV range is near the region of maximum cosmic ray intensity. It is therefore important to correct these cross sections, so that predictions of space radiation environments will be accurate. Parameterizations of nucleon-nucleon total cross sections are developed which are accurate over the entire energy range of the cosmic ray spectrum.

Norbury, John W.

2008-01-01

146

Relative cross section and depolarization of NOCl  

NASA Technical Reports Server (NTRS)

A standard photon counting technique and an argon-ion laser with 4545, 4579, 4727, 4765, 4880, 4965, 5017 and 5145-A lasing lines, providing a measurable Raman spectrum from NOCl, were used in the measurement of the Raman scattering cross section of NOCl at a Raman shift of 334.4 plus or minus 1.6/cm in relation to the N2 Raman cross section. A polarization analyzer and a quartz wedge were placed in front of the entrance slit of the double monochromator for depolarization measurements. Diagrams are plotted to show the scattering cross section and depolarization measurement results.

Hoell, J. M.; Wade, W. R.

1974-01-01

147

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

148

Measurement of electron-impact excitation cross section of the germanium atom  

Microsoft Academic Search

The description of an experimental arrangement and method is given for measurement of the electron-impact excitation cross section of atomic germanium. The 1900--6000-A spectral range was investigated, in which 45 spectral lines of germanium were observed. The results of measurements for the excitation cross sections of the atomic germanium lines as well as typical excitation functions are shown.

P. A. Kolosov; Yu. M. Smirnov

1982-01-01

149

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

150

Genital herpes evaluation by quantitative TaqMan PCR: correlating single detection and quantity of HSV-2 DNA in cervicovaginal lavage fluids with cross-sectional and longitudinal clinical data  

PubMed Central

Objective To evaluate the utility of a single quantitative PCR (qPCR) measurement of HSV (HSV-1&2) DNA in cervicovaginal lavage (CVL) specimens collected from women with predominantly chronic HSV-2 infection in assessing genital HSV shedding and the clinical course of genital herpes (GH) within a cohort with semiannual schedule of follow up and collection of specimens. Methods Two previously described methods used for detection of HSV DNA in mucocutaneous swab samples were adapted for quantification of HSV DNA in CVLs. Single CVL specimens from 509 women were tested. Presence and quantity of CVL HSV DNA were explored in relation to observed cross-sectional and longitudinal clinical data. Results The PCR assay was sensitive and reproducible with a limit of quantification of ~50 copies per milliliter of CVL. Overall, 7% of the samples were positive for HSV-2 DNA with median log10 HSV-2 DNA copy number of 3.9 (IQR: 2.6-5.7). No HSV-1 was detected. Presence and quantity of HSV-2 DNA in CVL directly correlated with the clinical signs and symptoms of presence of active symptomatic disease with frequent recurrences. Conclusion Single qPCR measurement of HSV DNA in CVL fluids of women with chronic HSV-2 infection provided useful information for assessing GH in the setting of infrequent sampling of specimens. Observed positive correlation of the presence and quantity of HSV-2 DNA with the presence of active and more severe course of HSV-2 infection may have clinical significance in the evaluation and management of HSV-2 infected patients.

2010-01-01

151

Weak and strong cross-section dependence and estimation of large panels  

Microsoft Academic Search

Summary This paper introduces the concepts of time-specific weak and strong cross-section dependence, and investigates how these notions are related to the concepts of weak, strong and semi-strong common factors, frequently used for modelling residual cross-section correlations in panel data models. It then focuses on the problems of estimating slope coefficients in large panels, where cross-section units are subject to

Alexander Chudiky; M. Hashem Pesaran; Elisa Tosetti

2011-01-01

152

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

153

Bibliography of photoabsorption cross-section data  

NASA Technical Reports Server (NTRS)

This bibliography contains only references which report a measured or calculated photoabsorption cross section (relative or normalized) in regions of continuous absorption. The bibliography is current as of January 1, 1970.

Hudson, R. D.; Kieffer, L. J.

1970-01-01

154

Radar Cross Section Target Supports, Plastic Materials.  

National Technical Information Service (NTIS)

The results of studies into the scattering properties of cellular plastic materials are presented. A mathematical model for scattering from cellular plastics, developed to provide a method of determining the optimum low cross section target support for a ...

C. H. Smith C. C. Freeny E. F. Knott T. B. A. Senior

1964-01-01

155

The radar cross section of dielectric disks  

NASA Technical Reports Server (NTRS)

A solution is presented for the backscatter (nonstatic) radar cross section of dielectric disks of arbitrary shape, thickness and dielectric constant. The result is obtained by employing a Kirchhoff type approximation to obtain the fields inside the disk. The internal fields induce polarization and conduction currents from which the scattered fields and the radar cross section can be computed. The solution for the radar cross section obtained in this manner is shown to agree with known results in the special cases of normal incidence, thin disks and perfect conductivity. The solution can also be written as a product of the reflection coefficient of an identically oriented slab times the physical optics solution for the backscatter cross section of a perfectly conducting disk of the same shape. This result follows directly from the Kirchhoff type approximation without additional assumptions.

Levine, D. M.

1982-01-01

156

Total cross section for top quark production.  

National Technical Information Service (NTIS)

We summarize our calculation of the total cross section for top quark production at hadron colliders within the context of perturbative quantum chromodynamics, including resummation of the effects of initial-state soft gluon radiation to all orders in the...

E. L. Berger H. Contopanagos

1996-01-01

157

Status of neutron dosimetry cross sections  

SciTech Connect

Several new cross section libraries, such as ENDF/B-VI(release 2), IRDF-90,JEF-2.2, and JENDL-3 Dosimetry, have recently been made available to the dosimetry community. the Sandia National Laboratories (SNL) Radiation Metrology Laboratory (RML) has worked with these libraries since pre-release versions were available. this paper summarizes the results of the intercomparison and testing of dosimetry cross sections. As a result of this analysis, a compendium of the best dosimetry cross sections was assembled from the available libraries for use within the SNL RML. this library, referred to as the SNLRML Library, contains 66 general dosimetry sensors and 3 special dosimeters unique to the RML sensor inventory. The SNLRML cross sections have been put into a format compatible with commonly used spectrum determination codes.

Griffin, P.J.; Kelly, J.G.

1992-12-31

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

Low energy antiproton nuclear absorption cross sections  

SciTech Connect

We have studied the absorption cross section of antiprotons on Al, Cu, and Pb for T = 131.6 and 193.6 MeV. These results are compared with predictions of an optical model fitted to antiproton elastic scattering data on these nuclei and are in agreement with these predictions. The cross sections have an exponential dependence on the mass number A with an exponent of approximately 0.61.

Ashford, V.; Sainio, M.E.; Sakitt, M.; Skelly, J.; Debbe, R.; Fickinger, W.; Marino, R.; Robinson, D.K.

1985-02-01

160

Electron impact cross sections for molecular lasers  

NASA Astrophysics Data System (ADS)

This project deals with electron impact experiments on atoms and molecules relevant to the development of the N2-CO2 and rare-gas halide lasers. Cross sections for state-of-state transitions in a variety of collisional processes (rotational, vibrational, and electronic excitation; dissociative attachment) have been determined in the first 4 eV of threshold and are generally found to exhibit great enhancement attributable to resonances. Highlights of the methods of cross-section measurement are also presented.

Wong, S. F.

1984-04-01

161

Path forward for dosimetry cross sections  

SciTech Connect

In the 1980's the dosimetry community embraced the need for a high fidelity quantification of uncertainty in nuclear data used for dosimetry applications. This led to the adoption of energy-dependent covariance matrices as the accepted manner of quantifying the uncertainty data. The trend for the dosimetry community to require high fidelity treatment of uncertainty estimates has continued to the current time where requirements on nuclear data are codified in standards such as ASTM E 1018. This paper surveys the current state of the dosimetry cross sections and investigates the quality of the current dosimetry cross section evaluations by examining calculated-to-experimental ratios in neutron benchmark fields. In recent years more nuclear-related technical areas are placing an emphasis on uncertainty quantification. With the availability of model-based cross sections and covariance matrices produced by nuclear data codes, some nuclear-related communities are considering the role these covariance matrices should play. While funding within the dosimetry community for cross section evaluations has been very meager, other areas, such as the solar-related astrophysics community and the US Nuclear Criticality Safety Program, have been supporting research in the area of neutron cross sections. The Cross Section Evaluation Working Group (CSEWG) is responsible for the creation and maintenance of the ENDF/B library which has been the mainstay for the reactor dosimetry community. Given the new trends in cross section evaluations, this paper explores the path forward for the US nuclear reactor dosimetry community and its use of the ENDF/B cross-sections. The major concern is maintenance of the sufficiency and accuracy of the uncertainty estimate when used for dosimetry applications. The two major areas of deficiency in the proposed ENDF/B approach are: 1) the use of unrelated covariance matrices in ENDF/B evaluations and 2) the lack of 'due consideration' of experimental data in the evaluation. (authors)

Griffin, P.J. [Sandia National Laboratories, Albuquerque, NM 87185-1146 (United States); Peters, C.D. [Sandia Staffing Alliance, Albuquerque, NM 87110 (United States)

2011-07-01

162

Upper bound on neutrino cross sections  

NASA Technical Reports Server (NTRS)

Asymptotic bounds on the total cross sections of neutrino (weak) scattering processes are obtained. It is shown that the elastic neutrino-neutrino cross section obeys the following bound in the high energy region: sigma sub T (S) equals ImF(S,0)/S is less than or equal to const. (LogS) squared. Assumptions of analyticity, crossing, unitarity, polynomial boundaries, and a zero-condition on the absorptive part of the scattering amplitude, are used to obtain this bound.

Mickens, R. E.

1975-01-01

163

Propagation of sound waves in tubes of noncircular cross section  

NASA Technical Reports Server (NTRS)

Plane-acoustic-wave propagation in small tubes with a cross section in the shape of a flattened oval is described. Theoretical descriptions of a plane wave propagating in a tube with circular cross section and between a pair of infinite parallel plates, including viscous and thermal damping, are expressed in similar form. For a wide range of useful duct sizes, the propagation constant (whose real and imaginary parts are the amplitude attenuation rate and the wave number, respectively) is very nearly the same function of frequency for both cases if the radius of the circular tube is the same as the distance between the parallel plates. This suggests that either a circular-cross-section model or a flat-plate model can be used to calculate wave propagation in flat-oval tubing, or any other shape tubing, if its size is expressed in terms of an equivalent radius, given by g = 2 x (cross-sectional area)/(length of perimeter). Measurements of the frequency response of two sections of flat-oval tubing agree with calculations based on this idea. Flat-plate formulas are derived, the use of transmission-line matrices for calculations of plane waves in compound systems of ducts is described, and examples of computer programs written to carry out the calculations are shown.

Richards, W. B.

1986-01-01

164

Photon scattering cross sections of H2 and He measured with synchrotron radiation  

NASA Technical Reports Server (NTRS)

Total (elastic + inelastic) differential photon scattering cross sections have been measured for H2 gas and He, using an X-ray beam. Absolute measured cross sections agree with theory within the probable errors. Relative cross sections (normalized to theory at large S) agree to better than one percent with theoretical values calculated from wave functions that include the effect of electron-electron Coulomb correlation, but the data deviate significantly from theoretical independent-particle (e.g., Hartree-Fock) results. The ratios of measured absolute He cross sections to those of H2, at any given S, also agree to better than one percent with theoretical He-to-H2 cross-section ratios computed from correlated wave functions. It appears that photon scattering constitutes a very promising tool for probing electron correlation in light atoms and molecules.

Ice, G. E.

1977-01-01

165

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

166

SSC 50 mm dipole cross section  

SciTech Connect

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 random errors on the coil placement and the Lorentz forces on the coil will be presented. The yoke has been optimized to reduce iron saturation effects on the field harmonics. We shall present the summary of this design which will include the expected overall performance of this cross section. Prototypes of these dipoles are being built at the Brookhaven National Laboratory (BNL) and at the Fermi National Accelerator Laboratory (FNAL). There are slight differences between the cross sections at the two laboratories. 7 refs., 6 figs., 11 tabs.

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

1991-01-01

167

Photoneutron Cross Sections of Astrophysical Significance  

NASA Astrophysics Data System (ADS)

Presented in this paper are some of the latest measurements of photoneutron cross sections of direct relevance to the p-process nucleosynthesis in the context of the statistical model of compound nuclear reactions. We discuss the p-process origin of the rarest nuclide and the only naturally occurring isomer 180Tam, a serious underproduction problem of 138La, and the nuclear level density of 180Ta determined from the partial photoneutron cross section for 180Tam. As the laser-Compton scattering ? ray at AIST has enabled one to directly determine (?,n) cross sections, the blackbody synchrotron radiation to be produced by a ten-Tesla superconducting wiggler at SPring-8 is expected to be a promising tool for exploring (?,?) and (?,p) reactions in the future.

Utsunomiya, H.

2007-02-01

168

Very high energy proton-proton cross section  

SciTech Connect

The recent Pierre Auger Observatory result suggesting a coincidence of extensive air showers arrival directions with 'nearby' active galactic nuclei and HiRes discovery of the Greisen-Zatsepin-Kuzmin cutoff indicates protons to be only or at least the strongly dominant component of primary extra galactic cosmic ray flux. However, showers initiated by these ultrahigh energy particles developed faster than predicted by the simulation calculations with conventional interaction models. This could be evidence of the substantial increase of the p-air cross section. The progress in understanding the proton-proton cross section description allows us to examine this possibility, and eventually reject it as an explanation of the ultrahigh energy cosmic ray 'pure proton' controversy.

Wibig, Tadeusz [University of Lodz, Department of Physics (Poland)and Andrzej Soltan Institute for Nuclear Studies, Uniwersytecka 5, 90-950 Lodz (Poland)

2009-05-01

169

Universal Parameterization of Absorption Cross Sections  

NASA Technical Reports Server (NTRS)

Our prior nuclear absorption cross sections model is extended for light systems (A less than or equal to 4) where either both projectile and target are light particles or one is a light particle and the other is a medium or heavy nucleus. The agreement with experiment is excellent for these cases as well. Present work in combination with our original model provides a comprehensive picture of absorption cross sections for light, medium, and heavy systems, a very valuable input for radiation protection studies.

Tripathi, R. K.; Cucinotta, Francis A.; Wilson, John W.

1999-01-01

170

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

171

Cross section for 246Cm subbarrier fission  

NASA Astrophysics Data System (ADS)

The cross section for 246Cm fission induced by neutrons of energy in the range 0.1 eV-20 keV was measured by the neutron lead slowing-down spectrometer (LSDS-100) of the Institute for Nuclear Research (INR, Russian Academy of Sciences, Moscow). The parameters of the resonance area and of the fission width were evaluated for several low-lying s-wave neutron resonances. The parameters of the intermediate structure in the cross section for the subbarrier fusion of 246Cm nuclei were found. The results obtained in this way were compared with available experimental data and with recommended evaluated data.

Alekseev, A. A.; Bergman, A. A.; Berlev, A. I.; Koptelov, E. A.; Samylin, B. F.; Trufanov, A. M.; Fursov, B. I.; Shorin, V. S.

2010-10-01

172

Infrared absorption cross sections of alternative CFCs  

NASA Technical Reports Server (NTRS)

Absorption cross sections have obtained in the infrared atmospheric window, between 600 and 1500 cm(exp -1), for 10 alternative hydrohalocarbons: HCFC-22, HCFC-123, HCFC-124, HCFC-141b, HCFC-142b, HCFC-225ca, HCFC-225cb, HFC-125, HFC-134a, and HFC-152a. The measurements were made at three temperatures (287K, 270K and 253K) with a Fourier transform spectrometer operating at 0.03 cm(exp -1) apodized resolution. Integrated cross sections are also derived for use in radiative models to calculate the global warming potentials.

Clerbaux, Cathy; Colin, Reginald; Simon, Paul C.

1994-01-01

173

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

174

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

175

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

176

Muscle cross-section measurement by magnetic resonance imaging  

Microsoft Academic Search

Summary  Muscle cross-section areas were measured by magnetic resonance imaging (MRI) in the thigh of a human cadaver,. the results being compared with those obtained by photography of corresponding anatomic macroslices. A close correlation was found between MRI and photographic evaluation, differences between the methods ranging from nil to 9.5%, depending on the scan position and the muscle groups. In vivo

Ralph Beneke; JiJrg Neuerburg; Klaus Bohndorf

1991-01-01

177

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

178

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

179

Photoelectric absorption cross sections with variable abundances  

NASA Technical Reports Server (NTRS)

Polynomial fit coefficients have been obtained for the energy dependences of the photoelectric absorption cross sections of 17 astrophysically important elements. These results allow the calculation of X-ray absorption in the energy range 0.03-10 keV in material with noncosmic abundances.

Balucinska-Church, Monika; Mccammon, Dan

1992-01-01

180

Cross Sections From Scalar Field Theory  

NASA Technical Reports Server (NTRS)

A one pion exchange scalar model is used to calculate differential and total cross sections for pion production through nucleon- nucleon collisions. The collisions involve intermediate delta particle production and decay to nucleons and a pion. The model provides the basic theoretical framework for scalar field theory and can be applied to particle production processes where the effects of spin can be neglected.

Norbury, John W.; Dick, Frank; Norman, Ryan B.; Nasto, Rachel

2008-01-01

181

NIST XCOM: Photon Cross Sections Database  

NSDL National Science Digital Library

This web program is used to calculate photon cross sections for scattering, photoelectric absorption and pair production, as well as total attenuation coefficients, in any element, compound or mixture, at energies from 1 keV to 100 GeV

2003-11-10

182

Testing (Validating?) Cross Sections with ICSBEP Benchmarks  

SciTech Connect

We discuss how to use critical benchmarks from the International Handbook of Evaluated Criticality Safety Benchmark Experiments to determine the applicability of specific cross sections to the end-user's problem of interest. Particular attention is paid to making sure the selected suite of benchmarks includes the user's range of applicability (ROA).

Kahler, Albert C. III [Los Alamos National Laboratory

2012-06-28

183

Small Boat HF Radar Cross Sections.  

National Technical Information Service (NTIS)

The HF radar cross section of three small ocean-going craft were measured in full scale with the SEA ECHO radar. The measurements were made over a wide band of frequencies. Care was taken in the calibration of the system to insure accurate absolute values...

R. W. Bogle D. B. Trizna

1976-01-01

184

Total cross section for top quark production  

SciTech Connect

We summarize our calculation of the total cross section for top quark production at hadron colliders within the context of perturbative quantum chromodynamics, including resummation of the effects of initial-state soft gluon radiation to all orders in the strong coupling strength.

Berger, E.L.; Contopanagos, H.

1996-08-30

185

Total cross section for top quark production  

Microsoft Academic Search

We summarize our calculation of the total cross section for top quark production at hadron colliders within the context of perturbative quantum chromodynamics, including resummation of the effects of initial-state soft gluon radiation to all orders in the strong coupling strength.

E. L. Berger; H F Contopanagos

1996-01-01

186

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

187

Cross-sectional structural parameters from densitometry  

NASA Technical Reports Server (NTRS)

Bone densitometry has previously been used to obtain cross-sectional properties of bone from a single X-ray projection across the bone width. Using three unique projections, we have extended the method to obtain the principal area moments of inertia and orientations of the principal axes at each scan cross-section along the length of the scan. Various aluminum phantoms were used to examine scanner characteristics to develop the highest accuracy possible for in vitro non-invasive analysis of cross-sectional properties. Factors considered included X-ray photon energy, initial scan orientation, the angle spanned by the three scans (included angle), and I(min)/I(max) ratios. Principal moments of inertia were accurate to within +/-3.1% and principal angles were within +/-1 degrees of the expected value for phantoms scanned with included angles of 60 degrees and 90 degrees at the higher X-ray photon energy (140 kVp). Low standard deviations in the error (0.68-1.84%) also indicate high precision of calculated measurements with these included angles. Accuracy and precision decreased slightly when the included angle was reduced to 30 degrees. The method was then successfully applied to a pair of excised cadaveric tibiae. The accuracy and insensitivity of the algorithms to cross-sectional shape and changing isotropy (I(min)/I(max)) values when various included angles are used make this technique viable for future in vivo studies.

Cleek, Tammy M.; Whalen, Robert T.

2002-01-01

188

Dijet cross sections in photoproduction at HERA  

Microsoft Academic Search

Dijet production by almost real photons has been studied at HERA with the ZEUS detector. Jets have been identified using the cone algorithm. A cut on x?OBS, the fraction of the photon energy participating in the production of the two jets of highest transverse energy, is used to define cross sections sensitive to the parton distributions in the proton and

S. Bhadra; M. L. Cardy; C.-P. Fagerstroem; W. R. Frisken; K. M. Furutani; M. Khakzad; W. B. Schmidke; R. L. Talaga; H. Zhang; R. Ayad; G. Bari; M. Basile; L. Bellagamba; D. Boscherini; A. Bruni; G. Bruni; P. Bruni; G. Cara Romeo; G. Castellini; M. Chiarini; L. Cifarelli; F. Cindolo; A. Contin; M. Corradi; I. Gialas; P. Giusti; G. Iacobucci; G. Laurenti; G. Levi; A. Margotti; T. Massam; R. Nania; C. Nemoz; F. Palmonari; A. Polini; G. Sartorelli; R. Timellini; Y. Zamora Garcia; A. Zichichi; A. Bargende; J. Crittenden; K. Desch; B. Diekmann; T. Doeker; M. Eckert; L. Feld; A. Frey; M. Geerts; G. Geitz; M. Grothe; T. Haas; H. Hartmann; D. Haun; K. Heinloth; E. Hilger; H.-P. Jakob; U. F. Katz; S. M. Mari; A. Mass; S. Mengel; J. Mollen; E. Paul; Ch. Rembser; R. Schattevoy; D. Schramm; J. Stamm; R. Wedemeyer; S. Campbell-Robson; A. Cassidy; N. Dyce; B. Foster; S. George; R. Gilmore; G. P. Heath; H. F. Heath; T. J. Llewellyn; C. J. S. Morgado; D. J. P. Norman; J. A. O'Mara; R. J. Tapper; S. S. Wilson; R. Yoshida; R. R. Rau; M. Arneodo; L. Iannotti; M. Schioppa; G. Susinno; A. Bernstein; A. Caldwell; N. Cartiglia; J. A. Parsons; S. Ritz; F. Sciulli; P. B. Straub; L. Wai; S. Yang; Q. Zhu; P. Borzemski; J. Chwastowski; A. Eskreys; K. Piotrzkowski; M. Zachara; L. Zawiejski; L. Adamczyk; B. Bednarek; K. Jelen; D. Kisielewska; T. Kowalski; E. Rulikowska-Zarebska; L. Suszycki; J. Zajac; A. Kotanski; M. Przybycien; L. A. T. Bauerdick; U. Behrens; H. Beier; J. K. Bienlein; C. Coldewey; O. Deppe; K. Desler; G. Drews; M. Flasinski; D. J. Gilkinson; C. Glasman; P. Göttlicher; J. Große-Knetter; B. Gutjahr; W. Hain; D. Hasell; H. Heßling; H. Hultschig; Y. Iga; P. Joos; M. Kasemann; R. Klanner; W. Koch; L. Köpke; U. Kötz; H. Kowalski; J. Labs; A. Ladage; B. Löhr; M. Löwe; D. Lüke; O. Manczak; J. S. T. Ng; S. Nickel; D. Notz; K. Ohrenberg; M. Roco; M. Rohde; J. Roldán; U. Schneekloth; W. Schulz; F. Selonke; E. Stiliaris; B. Surrow; T. Voß; D. Westphal; G. Wolf; C. Youngman; J. F. Zhou; H. J. Grabosch; A. Kharchilava; A. Leich; M. Mattingly; A. Meyer; S. Schlenstedt; N. Wulff; G. Barbagli; P. Pelfer; G. Anzivino; G. Maccarrone; S. de Pasquale; L. Votano; A. Bamberger; S. Eisenhardt; A. Freidhof; S. Söldner-Rembold; J. Schroeder; T. Trefzger; N. H. Brook; P. J. Bussey; A. T. Doyle; J. I. Fleck; D. H. Saxon; M. L. Utley; A. S. Wilson; A. Dannemann; U. Holm; D. Horstmann; T. Neumann; R. Sinkus; K. Wick; E. Badura; B. D. Burow; L. Hagge; E. Lohrmann; J. Mainusch; J. Milewski; M. Nakahata; N. Pavel; G. Poelz; W. Schott; F. Zetsche; T. C. Bacon; I. Butterworth; E. Gallo; V. L. Harris; B. Y. H. Hung; K. R. Long; D. B. Miller; P. P. O. Morawitz; A. Prinias; J. K. Sedgbeer; A. F. Whitfield; U. Mallik; E. McCliment; M. Z. Wang; S. M. Wang; J. T. Wu; Y. Zhang; P. Cloth; D. Filges; S. H. An; S. M. Hong; S. W. Nam; S. K. Park; M. H. Suh; S. H. Yon; R. Imlay; S. Kartik; H.-J. Kim; R. R. McNeil; W. Metcalf; V. K. Nadendla; F. Barreiro; G. Cases; R. Graciani; J. M. Hernández; L. Hervás; L. Labarga; J. del Peso; J. Puga; J. Terron; J. F. de Trocóniz; G. R. Smith; F. Corriveau; D. S. Hanna; J. Hartmann; L. W. Hung; J. N. Lim; C. G. Matthews; P. M. Patel; L. E. Sinclair; D. G. Stairs; M. St. Laurent; R. Ullmann; G. Zacek; V. Bashkirov; B. A. Dolgoshein; A. Stifutkin; G. L. Bashindzhagyan; P. F. Ermolov; L. K. Gladilin; Y. A. Golubkov; V. D. Kobrin; V. A. Kuzmin; A. S. Proskuryakov; A. A. Savin; L. M. Shcheglova; A. N. Solomin; N. P. Zotov; M. Botje; F. Chlebana; A. Dake; J. Engelen; M. de Kamps; P. Kooijman; A. Kruse; H. Tiecke; W. Verkerke; M. Vreeswijk; L. Wiggers; E. de Wolf; R. van Woudenberg; D. Acosta; B. Bylsma; L. S. Durkin; K. Honscheid; C. Li; T. Y. Ling; K. W. McLean; W. N. Murray; I. H. Park; T. A. Romanowski; R. Seidlein; D. S. Bailey; G. A. Blair; A. Byrne; R. J. Cashmore; A. M. Cooper-Sarkar; D. Daniels; R. C. E. Devenish; N. Harnew; M. Lancaster; P. E. Luffman; L. Lindemann; J. D. McFall; C. Nath; V. A. Noyes; A. Quadt; H. Uijterwaal; R. Walczak; F. F. Wilson; T. Yip; G. Abbiendi; A. Bertolin; R. Brugnera; R. Carlin; F. Dal Corso; M. de Giorgi; U. Dosselli; S. Limentani; M. Morandin; M. Posocco; L. Stanco; R. Stroili; C. Voci; J. Bulmahn; J. M. Butterworth; R. G. Feild; B. Y. Oh; J. J. Whitmore; G. D'Agostini; G. Marini; A. Nigro; E. Tassi; J. C. Hart; N. A. McCubbin; K. Prytz; T. P. Shah; T. L. Short; E. Barberis; T. Dubbs; C. Heusch; M. van Hook; B. Hubbard; W. Lockman; J. T. Rahn; H. F.-W. Sadrozinski; A. Seiden; J. Biltzinger; R. J. Seifert; A. H. Walenta; G. Zech; H. Abramowicz; G. Briskin; S. Dagan; A. Levy; T. Hasegawa; M. Hazumi; T. Ishii; M. Kuze; S. Mine; Y. Nagasawa; M. Nakao; I. Suzuki; K. Tokushuku; S. Yamada; Y. Yamazaki; M. Chiba; R. Hamatsu; T. Hirose; K. Homma; S. Kitamura; Y. Nakamitsu; K. Yamauchi; R. Cirio; M. Costa; M. I. Ferrero; L. Lamberti; S. Maselli; C. Peroni

1995-01-01

189

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

190

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

2013-04-01

191

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

192

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

NASA Technical Reports Server (NTRS)

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.

1985-01-01

193

Absolute np and pp cross section determinations aimed at improving the standard for cross section measurements  

SciTech Connect

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 1000 MeV are determined based on partial-wave analyses (PW As) of nucleon-nucleon scattering data. These cross sections are compared with the most recent ENDF/B-V11.0 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, Alexander B [Los Alamos National Laboratory; Haight, Robert C [Los Alamos National Laboratory; Tovesson, Fredrik [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

194

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

195

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

196

New cross sections for H on H2 collisional transitions  

NASA Astrophysics Data System (ADS)

The cross section for H on H2 collisions is important for astrophysics as well as our understanding of the simple chemical systems. This is the simplest atom-molecule cross section. With a new H3 potential surface by Mielke et al., we have modified the ABC code by Skouteris, Castillo and Manolopoulos to calculate new cross sections. These cross sections are compared to previous cross section calculations.

Zou, Qianxia

197

Electron-collision cross sections for iodine  

NASA Astrophysics Data System (ADS)

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.; Garcia, G.; Blanco, F.; Hargreaves, L. R.; Jones, D. B.; Murrie, R.; Brunton, J. R.; Brunger, M. J.; Hoshino, M.; Buckman, S. J.

2011-04-01

198

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

199

Measurement of Neutrino-Nucleus Cross Sections  

NASA Astrophysics Data System (ADS)

For more than 50 years, neutrinos have surprised us: not only by their mere presence, but by the recent revelation that these ghostlike particles can oscillate from one type to another. This stunning discovery has opened up a host of new questions about neutrinos and their properties; questions which we are currently in a global race to answer. The results inherently hinge upon knowledge of neutrino interaction cross sections. Such cross sections are generally poorly known and have not been updated for decades. With the advent of intense man-made neutrino beams, this situation is quickly changing. Detailed studies of low energy neutrino-nucleus interactions are now being made and revealing surprises of their own. Recent neutrino scattering measurements from a variety of experiments will be presented along with a projection for what the future holds.

Zeller, Geralyn

2011-04-01

200

Accurate universal parameterization of absorption cross sections  

NASA Technical Reports Server (NTRS)

We present a simple universal parameterization of total reaction cross sections for any system of colliding nuclei valid for the entire energy range from a few A MeV to a few A GeV. The universal picture presented here treats the proton-nucleus collision as a special case of the nucleus-nucleus collision, where the projectile has charge and mass number one. The parameters are associated with the physics of the collision system. In general terms Coulomb interaction modifies cross sections at lower energies and the effects of Pauli blocking are important at higher energies. The agreement between the calculated and experimental data is better than all earlier published results.

Tripathi, R. K.; Cucinotta, F. A.; Wilson, J. W.

1996-01-01

201

Practical restoration of extension cross sections  

SciTech Connect

Cross section restoration must be based on assumptions valid for the type of terrane considered. Restore' was designed specifically for extensional terranes, representing an easy and efficient tool to routinely restore cross sections on a Macintosh personal computer. Accurate reconstructions are produced without undue complexity or the necessity for computer expertise. Success of restorations is judged by compatibility between fault blocks and reasonableness of the restored structures. Incompatibilities may indicate revisions of the original interpretation or adjustment of restoration parameters such as shear and rotation angles. The sequential reconstruction of a section's evolution is an invaluable aid to inferring the creations, migration, and trapping of hydrocarbons, or to understanding the structural and tectonic processes involved.

Schultz-Ela, D.D. (Univ. of Texas, Austin (United States))

1991-12-01

202

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

2013-07-26

203

Time-Series-Cross-Section Methods  

Microsoft Academic Search

Time-series-cross-section (TSCS) data consist of comparable time series data observed on a variety of units. The paradigmatic applications are to the study of comparative politi-cal economy, where the units are countries (often the advanced industrial democracies) and where for each country we observe annual data on a variety of political and economic vari-ables. A standard question for such studies relates

Nathaniel Beck

204

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

205

Electron impact excitation cross sections for CO  

Microsoft Academic Search

The R-matrix method has been used to calculate electron impact excitation cross sections for the lowest seven electronically excited states of CO in the energy range 6-18 eV. These states are represented using configuration interaction (CI) expansions and an algorithm for treating long CI expansions in scattering calculations is presented. The calculations are carried out for a range of internuclear

L. A. Morgan; J. Tennyson

1993-01-01

206

Electron impact excitation cross sections for phosphorus  

Microsoft Academic Search

:   An analytic atomic independent-particle-model is used to generate wave functions for the valence and excited states of the\\u000a neutral phosphorus atom. These wave functions are used to calculate generalized oscillator strengths, and from these quantities\\u000a the cross sections are obtained in Born approximation. Various excitations from the ground state are considered, and results are presented for electron impact energies

P. S. Ganas

1998-01-01

207

How to Calculate Colourful Cross Sections Efficiently  

SciTech Connect

Different methods for the calculation of cross sections with many QCD particles are compared. To this end, CSW vertex rules, Berends-Giele recursion and Feynman-diagram based techniques are implemented as well as various methods for the treatment of colours and phase space integration. We find that typically there is only a small window of jet multiplicities, where the CSW technique has efficiencies comparable or better than both of the other two methods.

Gleisberg, Tanju; Hoeche, Stefan; Krauss, Frank

2008-09-03

208

Neutron-Proton Capture Cross Section  

Microsoft Academic Search

The mean lifetime of thermal neutrons in water is measured with a large moderator (radius ~7 diffusion lengths), for which the correction for escape is only about 5%. The geometry is such that the perturbing effect of the immersed BF3 neutron detector can be almost rigorously calculated. The value obtained is tau=206.3+\\/-5.0 musec, giving the neutron-proton capture cross section as

Robert W. Stooksberry; Marshall F. Crouch

1959-01-01

209

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

210

Radar Cross Section Reduction by Absorber Covering  

Microsoft Academic Search

Radar cross section (RCS) reduction by absorber covering is experimentally studied by employing microwave diversity imaging. Experimental results show that broadband absorber covering is not effective at reducing the co-polarized (the transmitting andreceiving antennas have opposite sense of circular polarization) RCS of a plate when the incident wave approximates the edge-on direction but is effective at reducing the cross-polarized (both

H. J. Li; N. H. Farhat; Y. Shen

1989-01-01

211

Backscattering Cross Section of Ultrawideband Antennas  

Microsoft Academic Search

Backscattering of ultrawideband (UWB) antennas is theoretically and experimentally studied in this letter. The finite-difference time-domain (FDTD) method using Berenger's perfectly matched layer absorbing boundary condition (PML-ABC) is employed for simulation and the measurement is carried out in indoor environment. Monostatic radar cross section (RCS) of square-slot antenna and printed circular-disc monopole antenna (PCDMA) terminated with three different kinds of

Sanming Hu; Honghui Chen; C. K. Law; Z. Shen; L. Zhu; W. Zhang; W. Dou

2007-01-01

212

First measurement of the Rayleigh cross section  

Microsoft Academic Search

Summary form only given. A century ago Lord Rayleigh formulated a theory of light scattering by ideal gases that not only explained the molecular origin of atmospheric scattering and the blue colour of the sky but also provided a quantitative expression for the amount of light scattered. The cross section (in cm2) is given by the well known equation: ?(?)=(24?3?4(n2-1)2

H. Naus; W. Ubachs

2000-01-01

213

Radar cross section reduction by absorber covering  

Microsoft Academic Search

Radar cross section (RCS) reduction by absorber covering is experimentally studied by employing microwave diversity imaging. Experimental results show that broadband absorber covering is not effective at reducing the co-polarized (the transmitting and receiving antennas have opposite sense of circular polarization) RCS of a plate when the incident wave approximates the edge-on direction but is effective at reducing the cross-polarized

H. J. Li; N. H. Farhat; Y. Shen

1989-01-01

214

WW cross sections and | Vcs| measurement  

NASA Astrophysics Data System (ADS)

Data collected by the four LEP experiments at collision energies up to 209 GeV have been analysed to extract the W pair production cross section. Combining all LEP2 centre-of-mass energies has allowed the determination of the W decay branching ratios into leptons and hadrons and to derive the value of the CKM matrix element | Vcs|. A review of existing direct and indirect | Vcs| measurements is also presented.

Ealet, A.

2003-02-01

215

MXS cross-section preprocessor user's manual  

SciTech Connect

The MXS preprocessor has been designed to reduce the execution time of programs using isotopic cross-section data and to both reduce the execution time and improve the accuracy of shielding-factor interpolation in the SIMMER-II accident analysis program. MXS is a dual-purpose preprocessing code to: (1) mix isotopes into materials and (2) fit analytic functions to the shelf-shielding data. The program uses the isotope microscopic neutron cross-section data from the CCCC standard interface file ISOTXS and the isotope Bondarenko self-shielding data from the CCCC standard interface file BRKOXS to generate cross-section and self-shielding data for materials. The materials may be a mixture of several isotopes. The self-shielding data for the materials may be the actual shielding factors or a set of coefficients for functions representing the background dependence of the shielding factors. A set of additional data is given to describe the functions necessary to interpolate the shielding factors over temperature.

Parker, F.; Ishikawa, M.; Luck, L.

1987-03-01

216

(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

217

A global analysis of inclusive diffractive cross sections at HERA  

NASA Astrophysics Data System (ADS)

We describe the most recent data on the diffractive structure functions from the H1 and ZEUS Collaborations at HERA using four models. First, a Pomeron Structure Function (PSF) model, in which the pomeron is considered as an object with parton distribution functions. Then, the Bartels-Ellis-Kowalski-Wüsthoff (BEKW) approach is discussed, assuming the simplest perturbative description of the pomeron using a two-gluon ladder. A third approach, the Bialas-Peschanski (BP) model, based on the dipole formalism is then described. Finally, we discuss the Golec-Biernat-Wüsthoff (GBW) saturation model which takes into account saturation effects. The best description of all available measurements can be achieved with either the PSF based model or the BEKW approach. In particular, the BEKW prediction allows to include the highest ? measurements, which are dominated by higher twists effects and provide an efficient and compact parametrisation of the diffractive cross section. The two other models also give a good description of cross section measurements at small x with a small number of parameters. The comparison of all predictions allows us to identify interesting differences in the behavior of the effective pomeron intercept and in the shape of the longitudinal component of the diffractive structure functions. In this last part, we present some features that can be discriminated by new experimental measurements, completing the HERA program.

Royon, C.; Schoeffel, L.; Sapeta, S.; Peschanski, R.; Sauvan, E.

2007-10-01

218

Cross-section evaluation utilizing integral reaction-rate measurements in fast neutron fields  

SciTech Connect

The role of integral reaction-rate data for cross-section evaluation is reviewed. The subset of integral data considered comprises integral reaction rates measured for dosimeter, fission-product, and actinide-type materials irradiated in reactor dosimetry fast neutron benchmark fields and in the EBR-II. Utilization of these integral data for integral testing, multigroup cross-section adjustment and pointwise cross section adjustment is treated in some detail. Examples are given that illustrate the importance of considering a priori uncertainty and correlation information for these analyses. 3 figures, 3 tables.

Anderl, R.A.

1980-01-01

219

Neutron activation cross sections on lead isotopes  

SciTech Connect

The cross sections for the reactions {sup 204}Pb(n,n{sup '}{gamma}){sup 204}Pb{sup m}, {sup 204}Pb(n,2n){sup 203}Pb, {sup 204}Pb(n,2n){sup 203}Pb{sup m1}, {sup 204}Pb(n,3n){sup 202}Pb{sup m}, {sup 206}Pb(n,3n){sup 204}Pb{sup m}, {sup 206}Pb(n,{alpha}){sup 203}Hg, and {sup 208}Pb(n,p){sup 208}Tl 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 {sup 3}H(d,n){sup 4}He 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 {sup 27}Al(n,{alpha}){sup 24}Na reaction. Enriched samples were essential to determine the cross sections for the reactions with {sup 204}Pb{sup m} and {sup 206}Pb{sup m} isomers in the final state. Accurate results for reactions with {sup 204,206}Pb 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.; Quetel, C.; Sudar, S.; Vogl, J.; Koning, A. J.; Qaim, S. M.; Smith, D. L. [European Commission, Joint Research Centre, Institute for Reference Materials and Measurements, B-2440 Geel (Belgium); Nuclear Research and Consultancy Group NRG, P. O. Box 25, 1755 ZG Petten (Netherlands); Institut fuer Nuklearchemie, Forschungszentrum Juelich GmbH, D-52425 Juelich (Germany); Nuclear Engineering Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States)

2009-08-15

220

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

221

NIST XCOM: Photon Cross Sections Database  

NSDL National Science Digital Library

This web program, funded in part by the National Institute of Standards and Technology (U.S.) is used to calculate photon cross sections for scattering, photoelectric absorption and pair production, as well as total attenuation coefficients, in any element, compound or mixture, at energies from 1 keV to 100 GeV. The contents section of the site contains an introduction, database for elements, interpolation and combination, instructions on how to run the XCOM program, and references. The site allows you to download a copy of XCOM (v. 3.1) for personal use.

2009-04-02

222

Top Production Cross Sections at D0  

SciTech Connect

We report on measurements of the ttbar production cross section at a center-of-mass energy of 1.96 TeV at the D0 experiment during Run II of the Fermilab Tevatron collider. We use candidate events in lepton+jets and dilepton final states. In the most sensitive channel (lepton+jets channel), a neural network algorithm that uses lifetime information to identify b-quark jets is used to distinguish signal from background processes. We also present measurements of single top quark production at D0 using several multivariate techniques to separate signal from background.

Kvita, Jiri

2009-07-01

223

Cross section measurements with monoenergetic muon neutrinos  

NASA Astrophysics Data System (ADS)

The monoenergetic 236 MeV muon neutrino from charged kaon decay at rest (K+??+??) can be used to produce a novel set of cross section measurements. Applicable for short- and long-baseline accelerator-based neutrino oscillation experiments, among others, such measurements would provide a "standard candle" for the energy reconstruction and interaction kinematics relevant for charged current neutrino events near this energy. This neutrino can also be exercised as a unique known-energy, purely weak interacting probe of the nucleus. A number of experiments are set to come online in the next few years that will be able to collect and characterize thousands of these events.

Spitz, J.

2014-04-01

224

Radar cross section reduction by absorber covering  

NASA Technical Reports Server (NTRS)

Radar cross section (RCS) reduction by absorber covering is experimentally studied by employing microwave diversity imaging. Experimental results show that broadband absorber covering is not effective at reducing the co-polarized (the transmitting and receiving antennas have opposite sense of circular polarization) RCS of a plate when the incident wave approximates the edge-on direction but is effective at reducing the cross-polarized (both the transmitting and receiving antennas have the same sense of circular polarization) RCS for all incident directions. The surface current absorber covering is effective at reducing the nonspecular energy and multiple bounces regardless of the polarization status of the measurement.

Li, H. J.; Farhat, N. H.; Shen, Y.

1989-01-01

225

NASA-Lewis experiences with multigroup cross sections and shielding calculations.  

NASA Technical Reports Server (NTRS)

Description of the nuclear reactor shield analysis procedures employed at NASA-Lewis Research Center. Emphasis is placed on the generation, use, and testing of multigroup cross-section data. Although coupled neutron and gamma ray cross-section sets are useful in two-dimensional Sn transport calculations, much insight has been gained from examination of uncoupled calculations. These have led to experimental and analytic studies of areas deemed to be of first-order importance to reactor shield calculations. A discussion is given of problems encountered in using multigroup cross sections in the resolved resonance energy range. The addition to ENDF files of calculated and/or measured neutron-energy-dependent capture gamma ray spectra for shielding calculations is questioned for the resonance region. Anomalies inherent in two-dimensional Sn transport calculations which may overwhelm any cross-section discrepancies are illustrated.

Lahti, G. P.

1972-01-01

226

Testing hypotheses about direction of causation using cross-sectional family data  

Microsoft Academic Search

We review the conditions under which cross-sectional family data (e.g., data on twin pairs or adoptees and their adoptive and biological relatives) are informative about direction of causation. When two correlated traits have rather different modes of inheritance (e.g., family resemblance is determined largely by family background for one trait and by genetic factors for the other trait), cross-sectional family

A. C. Heath; R. C. Kessler; M. C. Neale; J. K. Hewitt; L. J. Eaves; K. S. Kendler

1993-01-01

227

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

228

Electron Collision Cross Sections for Iodine  

NASA Astrophysics Data System (ADS)

We performed a joint experimental and theoretical study of elastic electron scattering from atomic and molecular iodine. The experimental results for atomic iodine 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 [1] and an optical model potential approach [2]. 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 very encouraging. It suggests that the present results are suitable for use in modeling plasma kinetic behavior when iodine is an important constituent.[4pt] [1] O. Zatsarinny and K. Bartschat, Phys. Rev. A 77 (2008) 062701.[0pt] [2] F. Blanco and G. Garcia, Phys. Lett. A 317 (2003) 458 (2003).

Bartschat, K.; Zatsarinny, O.; Garcia, G.; Blanco, F.; Hargreaves, L. R.; Jones, D. B.; Murrie, R.; Brunton, J. R.; Brunger, M. J.; Hoshino, M.; Buckman, S. J.

2011-06-01

229

Pion production cross sections and associated parameters  

SciTech Connect

Negative pions have been used for radiotherapy at the meson factories LAMPF (USA), SIN (Switzerland), and TRIUMF (Canada) and have been planned for use at new meson facilities under construction (USSR) and at proposed dedicated medical facilities. Providing therapeutically useful dose rates of pions requires a knowledge of the pion production cross sections as a function of primary proton energy (500 to 1000 MeV), pion energy (less than or equal to100 MeV), production angle, and target material. The current status of the data base in this area is presented including theoretical guidelines for extrapolation purposes. The target material and geometry, as well as the proton and pion beam parameters, will affect the electron (and muon) contamination in the beam which may have an important effect on both the LET characteristics of the dose and the dose distribution. In addition to cross-section data, channel characteristics such as length of pion trajectory, solid-angle acceptance, and momentum analysis will affect dose rate, distribution, and quality. Such considerations are briefly addressed in terms of existing facilities and proposed systems. 16 refs., 6 figs.

Bradbury, J.N.

1985-01-01

230

Single-level resonance parameters fit nuclear cross-sections  

NASA Technical Reports Server (NTRS)

Least squares analyses of experimental differential cross-section data for the U-235 nucleus have yielded single level Breit-Wigner resonance parameters that fit, simultaneously, three nuclear cross sections of capture, fission, and total.

Drawbaugh, D. W.; Gibson, G.; Miller, M.; Page, S. L.

1970-01-01

231

FT-IR Measurements of Cold Cross Sections of Hydrocarbons  

NASA Astrophysics Data System (ADS)

We discuss temperature dependent cross sections of hydrocarbons by analyzing laboratory spectra in two approaches; 1) direct measurements of the cold cross sections, 2) derivation of pseudolines by fitting the laboratory spectra simultaneously.

Sung, K.; Toon, G. C.; Brown, L. R.

2014-02-01

232

Electron-Impact Excitation Cross Sections for Metal Vapors  

Microsoft Academic Search

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 sigma_BE and sigmaf

Yong-Ki Kim

2001-01-01

233

Mental Visualization of Objects from Cross-Sectional Images  

ERIC Educational Resources Information Center

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…

Wu, Bing; Klatzky, Roberta L.; Stetten, George D.

2012-01-01

234

Peculiar radar cross section properties of metamaterials with negative permittivity  

Microsoft Academic Search

In this paper, we discuss the peculiar radar cross section properties of metamaterials with negative permittivity, and the connections between the radar cross section, the polarizability and the permittivity of metamaterials are investigated, respectively. These results have shown that the polarizability and radar cross section of the spherical object made of metamaterials whose permittivity is less than - 2 are

Wanzhao Cui; Jia Chen; Enrang Zheng

2008-01-01

235

Cross-Sectional and Longitudinal Surveys of Dental Student Values: Limitations of Cross-Sectional Design.  

ERIC Educational Resources Information Center

Surveys of dental student values are described that were designed to assess value ratings by four dental classes in 1976, annual value ratings of a freshman class as they progressed through their four year program, and the usefulness of the cross-sectional design versus the longitudinal design. Each of the two surveys, which were conducted by the…

Sakumura, Joseph S.

236

Status of high energy neutron cross sections  

SciTech Connect

Review is presented of the current status of neutron-induced reactions of interest to the fusion community in the 10- to 50-MeV neutron energy range. Although there has been significant activity in this area since the 1977 BNL Symposium on Neutron Cross Sections from 10 to 40 MeV, this review concludes that there are many areas which require more experimentation to obtain the requested accuracy. Examples of various neutron data obtained since 1977 are presented and compared to determine the extent of agreement. An attempt is made to determine what the prospects are for satisfying the fusion data needs defined by the US DOE based upon progress to date.

Browne, J.C.; Lisowski, P.W.

1980-01-01

237

Lunar Radar Cross Section at Low Frequency  

NASA Technical Reports Server (NTRS)

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

238

Geophysical Fluid Flow Cell (GFFC) Cross Section  

NASA Technical Reports Server (NTRS)

This drawing shows a cross-section view of the test cell at the heart of the Geophysical Fluid Flow Cell (GFFC) that flew on two Spacelab missions. The middle and lower drawings depict the volume of the silicone oil layer that served as the atmosphere as the steel ball rotated and an electrostatic field pulled the oil inward to mimic gravity's effects during the experiments. The GFFC thus produced flow patterns that simulated conditions inside the atmospheres of Jupiter and the Sun and other stars. The principal investigator was John Hart of the University of Colorado at Boulder. It was managed by NASA's Marshall Space Flight Center (MSFC). An Acrobat PDF copy of this drawing is available at http://microgravity.nasa.gov/gallery. (Credit: NASA/Marshall Space Flight Center)

1995-01-01

239

Flow duct with cross-sectional step  

US Patent & Trademark Office Database

In heat generators and burners, it is frequently necessary to realize discontinuous cross-sectional expansions of a flow duct. When the flow (U) passes over the step (10) formed in the wall (8) of the flow duct, coherent lateral separation vortices form which are propagated almost undamped downstream of the step and frequently represent the cause of thermo-acoustic vibrations of high amplitude. In accordance with the invention, vortex-generating elements (20) with a lateral pitch dimension (t) are arranged on a line transverse to the main flow (U) a distance (s) upstream of the step (10). Given an expedient selection of the pitch dimension (t), the lateral coherence of the separation vortex is enduringly destroyed.

2001-04-17

240

Determination of tire cross-sectional geometric characteristics from a digitally scanned image  

NASA Technical Reports Server (NTRS)

A semi-automated procedure is described for the accurate determination of geometrical characteristics using a scanned image of the tire cross-section. The procedure can be useful for cases when CAD drawings are not available or when a description of the actual cured tire is desired. Curves representing the perimeter of the tire cross-section are determined by an edge tracing scheme, and the plyline and cord-end positions are determined by locations of color intensities. The procedure provides an accurate description of the perimeter of the tire cross-section and the locations of plylines and cord-ends. The position, normals, and curvatures of the cross-sectional surface are included in this description. The locations of the plylines provide the necessary information for determining the ply thicknesses and relative position to a reference surface. Finally, the locations of the cord-ends provide a means to calculate the cord-ends per inch (epi). Menu driven software has been developed to facilitate the procedure using the commercial code, PV-Wave by Visual Numerics, Inc., to display the images. From a single user interface, separate modules are executed for image enhancement, curve fitting the edge trace of the cross-sectional perimeter, and determining the plyline and cord-end locations. The code can run on SUN or SGI workstations and requires the use of a mouse to specify options or identify items on the scanned image.

Danielson, Kent T.

1995-01-01

241

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

242

CFRMF spectrum update and application to dosimeter cross-section data testing  

SciTech Connect

The Coupled Fast Reactivity Measurements Facility (CFRMF) at the Idaho National Engineering Laboratory (INEL) is a Cross Section Evaluation Working Group (CSEWG) benchmark for data testing of dosimetry, fission-product and actinide cross sections important to fast-reactor technology. In this paper we present the results of our work in updating the CFRMF spectrum characterization and in applying CFRMF integral data to testing ENDF/B-V dosimeter cross sections. Updated characterization of the central neutron spectrum includes the results of neutronics calculations with ENDF/B-V nuclear data, the generation of a fine-group spectrum representation for integral data-testing applications, and a sensitivity and uncertainty analysis which provides a flux-spectrum covariance matrix related to uncertainties and correlations in the nuclear data used in a neutronics calculation. Our application of CFRMF integral data to cross section testing has included both conventional integral testing analyses and least-squares-adjustment analyses with the FERRET code. The conventional integral data-testing analysis, based on C/E ratios, indicates discrepancies outside the estimated integral test uncertainty for the /sup 6/Li(n,He), /sup 10/B(n,He), /sup 47/Ti(n,p), /sup 58/Fe(n,..gamma..), /sup 197/Au(n,..gamma..) and /sup 232/Th(n,..gamma..) cross sections. The integral test uncertainty included contributions from the measured integral data and from the spectrum and cross sections used to obtain the calculated integral data. Within the uncertainty and correlation specifications for the input spectrum and dosimeter cross sections, the least-squares-adjustment analysis indicated a high degree of consistency between the measured integral data and the ENDF/B-V dosimeter cross sections for all reactions except /sup 10/B(n,He).

Anderl, R.A.; Harker, Y.D.; Millsap, D.A.; Rogers, J.W.; Ryskamp, J.M.

1982-01-01

243

Differential cross sections for collisional excitation of the potassium 4 2P states by noble-gas atoms  

Microsoft Academic Search

Relative differential cross sections are presented for the collisional excitation of K(4 2P) by He, Ne, Ar, Kr and Xe. The inelastic process is identified by measuring the time correlation between the scattered alkali atom and the emitted photon in a particle-photon coincidence experiment. The measured cross sections are used to identify the curve crossings responsible for the excitation process

L. Zehnle; E. Clemens; P. J. Martin; W. Schauble; V. Kempter

1978-01-01

244

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

245

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

246

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

247

Cross-sectional study of health effects of cryolite production.  

PubMed

A cross-sectional health study of 101 cryolite workers was performed, using spirometry and a questionnaire. Multiple regression analysis revealed a significant correlation between the index of smoking and a decrease in FEV1 (per cent). There was no significant correlation between work-related exposure and lung function. Many cryolite workers described a group of symptoms appearing after 15 to 30 min of heavy dust exposure: nausea, followed by epigastric pain with relief after spontaneous or provoked vomiting. Thirty-four (33.6 per cent) workers complained of nausea, vomiting or diarrhoea in relation to work, compared to 3.8 per cent of 1752 men participating in the Copenhagen Male Study. PMID:2622142

Friis, H; Clausen, J; Gyntelberg, F

1989-01-01

248

Correlates of smoking susceptibility among adolescents in a peri-urban area of Nepal: a population-based cross-sectional study in the Jhaukhel-Duwakot Health Demographic Surveillance Site  

PubMed Central

Background Susceptibility to smoking is defined as an absence of firm commitment not to smoke in the future or when offered a cigarette by best friends. Susceptibility begins in adolescence and is the first step in the transition to becoming an established smoker. Many scholars have hypothesized and studied whether psychosocial risk factors play a crucial role in preventing adolescent susceptibility to smoking or discourage susceptible adolescents from becoming established smokers. Our study examined sociodemographic and family and childhood environmental factors associated with smoking susceptibility among adolescents in a peri-urban area of Nepal. Design We conducted a population-based cross-sectional study during October–November 2011 in the Jhaukhel-Duwakot Health Demographic Surveillance Site (JD-HDSS) located in a peri-urban area near Kathmandu, the capital city of Nepal, where tobacco products are easily available. Trained local enumerators conducted face-to-face interviews with 352 respondents aged 14–16. We used stepwise logistic regression to assess sociodemographic and family and childhood environmental factors associated with smoking susceptibility. Results The percentage of smoking susceptibility among respondents was 49.70% (95% CI: 44.49; 54.93). Multivariable analysis demonstrated that smoking susceptibility was associated with smoking by exposure of adolescents to pro-tobacco advertisements (AOR [adjusted odds ratio] =2.49; 95% CI: 1.46–4.24), the teacher (2.45; 1.28–4.68), adolescents attending concerts/picnics (2.14; 1.13–4.04), and smoking by other family members/relatives (1.76; 1.05–2.95). Conclusions Smoking susceptible adolescents are prevalent in the JD-HDSS, a peri-urban community of Nepal. Several family and childhood environmental factors increased susceptibility to smoking among Nepalese non-smoking adolescents. Therefore, intervention efforts need to be focused on family and childhood environmental factors with emphasis on impact of role models smoking, refusal skills in social gatherings, and discussing harmful effects of smoking with family members and during gatherings with friends.

Aryal, Umesh R.; Petzold, Max; Bondjers, Goran; Krettek, Alexandra

2014-01-01

249

Spectroscopy and photoabsorption cross sections of FNO  

SciTech Connect

The spectroscopy and photoabsorption cross sections of nitrosyl fluoride are investigated in the spectral region 350-180 nm. Results for 350-250 nm are in good agreement with the initial measurements of Johnston and Bertin and later measurements from Solgadi and Flament and Huber et al. The spectrum is assigned to a series of vibrational progressions which arise from (0, 0, 0)[double prime] and involve excitation of the [nu][sub 1][prime] mode. Excitations to (n, 0, 0)[prime] and (n, 0, 1)[prime] make up the bulk of the spectrum, with promotions to (n, 1, 0)[prime], (n, 0, 2)[prime], and (n, 1, 2)[prime] becoming dominant at higher energies. Analysis of the spectrum results in values of [nu][sub 1][prime] = 1,096 cm[sup [minus]1], [nu][sub 2][prime] = 480 cm[sup [minus]1] and [nu][sub 3][prime] and [nu][sub 3][prime] is distinctly stronger than that for [nu][sub 2][prime]. Below 250 nm, a broad, featureless continuum absorption is observed, which rises in intensity from [sigma] = 1.77 [times] 10[sup [minus]20] cm[sub 2] at 245 nm to 5.24 [times] 10[sup [minus]19] cm[sub 2] at 180 nm.

Burley, J.D.; Miller, C.E.; Johnston, H.S. (Lawrence Berkeley Lab., CA (United States))

1993-04-01

250

[Fast neutron cross section measurements]. Progress report  

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

251

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

252

Electron collisions with CO: Elastic and vibrational excitation cross sections  

NASA Astrophysics Data System (ADS)

Absolute differential elastic and vibrational excitation cross sections up to v=11 were measured for CO in scattering angle ranges extending to 180° at energies between 0.2 and 5 eV (and an elastic measurement at 10 eV). The lowest angles were 0° for inelastic scattering and between 5° and 20° 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 , 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.

2010-04-01

253

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

254

Experimental verification of theoretical cross sections for FIB PIXE  

NASA Astrophysics Data System (ADS)

X-ray production cross sections were found for films of Cr, Cu, Ge, Ag, W and Au, using incident H + and Be + ions at energies from 300 keV to 3.5 MeV. These experimental cross section results were compared with the cross section results obtained using software which calculates inner shell ionization and X-ray production cross sections. The software uses the ECPSSR-UA approach to finding X-ray production cross sections. This program was found to be useful for predicting cross sections for H + and Be + ions at the energies in this study. The software was then used to predict results for Li +, Be + and B + ions at 280 keV, energies available in the Arizona State University focused ion beam laboratory.

Streib, Kenneth L.; Alford, Terry L.; Mayer, James W.

2006-08-01

255

Criticality benchmark comparisons leading to cross-section upgrades  

SciTech Connect

For several years criticality benchmark calculations with COG. COG is a point-wise Monte Carlo code developed at Lawrence Livermore National Laboratory (LLNL). It solves the Boltzmann equation for the transport of neutrons and photons. The principle consideration in developing COG was that the resulting calculation would be as accurate as the point-wise cross-sectional data, since no physics computational approximations were used. The objective of this paper is to report on COG results for criticality benchmark experiments in concert with MCNP comparisons which are resulting in corrections an upgrades to the point-wise ENDL cross-section data libraries. Benchmarking discrepancies reported here indicated difficulties in the Evaluated Nuclear Data Livermore (ENDL) cross-sections for U-238 at thermal neutron energy levels. This led to a re-evaluation and selection of the appropriate cross-section values from several cross-section sets available (ENDL, ENDF/B-V). Further cross-section upgrades anticipated.

Alesso, H.P.; Annese, C.E.; Heinrichs, D.P.; Lloyd, W.R.; Lent, E.M.

1993-03-01

256

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

257

Knowledge and Practice Related to Trachoma Among Children in Vietnam: A Cross-Sectional Study  

Microsoft Academic Search

A cross-sectional descriptive survey to determine the magnitude and determinants of knowledge and practice in relation to trachoma among children in Vietnam is presented. Interviews were conducted with 358 children ages 6 to 15 years in three districts of Northern Vietnam using a closed-ended questionnaire. Responses related to causes, prevention methods, consequences, and observed preventive practices were standardized. The knowledge

RAJIV KHANDEKAR; MARTIN BULLARD; TON THI KIM THANH; TRAN QUOC BINH

2004-01-01

258

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

259

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

260

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

261

Inelastic Electron-Deuteron Scattering Cross Sections at High Energies  

Microsoft Academic Search

The effects on the cross sections for the inelastic electron-deuteron scattering process e+d-->e+n+p of interactions between the outgoing nucleons are examined in detail. The cross sections are calculated in the first Born approximation with respect to the electromagnetic interaction using nucleon wave functions modified by the final state interactions. Crude estimates indicate that the peak value of the cross section

Loyal Durand

1959-01-01

262

Nonlinear acoustic waves in channels with variable cross sections  

NASA Astrophysics Data System (ADS)

The point symmetry group is studied for the generalized Webster-type equation describing nonlinear acoustic waves in lossy channels with variable cross sections. It is shown that, for certain types of cross section profiles, the allowed symmetry group is extended and the invariant solutions corresponding to these profiles are obtained. Approximate analytic solutions to the generalized Webster equation are derived for channels with smoothly varying cross sections and arbitrary initial conditions.

Kovalev, V. F.; Rudenko, O. V.

2012-05-01

263

Radiation shape factors for channels with varying cross sections  

NASA Astrophysics Data System (ADS)

Robin's (1961) method of blocking by an intermediate segment is extended to include blocking by the horizon and by the orientation of the area radiated to, with application to radiative heat transfer in underground coal gasification. Good approximations are obtained for converting irregular cross sections to effective circular cross sections. Techniques for using these view factors to model radiation within irregularly shaped enclosures with nonisothermal cross sections are presented.

Eddy, T. L.; Nielsson, G. E.

1988-02-01

264

Total ionization cross-sections for fluoro acetylene molecule  

NASA Astrophysics Data System (ADS)

Total ionization cross-sections for Fluoro acetylene molecule is calculated by applying Binary Encounter Bethe (BEB) model by electron impact. The cross-sections are calculated in the energy range from ionization threshold to 2 keV. No experimental or theoretical work is reported in the literature to the best of my knowledge for comparison. Present work is a maiden attempt to find electron impact ionization cross section.

Pandya, C. V.

2014-04-01

265

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

266

Projectile and Lab Frame Differential Cross Sections for Electromagnetic Dissociation  

NASA Technical Reports Server (NTRS)

Differential cross sections for electromagnetic dissociation in nuclear collisions are calculated for the first time. In order to be useful for three - dimensional transport codes, these cross sections have been calculated in both the projectile and lab frames. The formulas for these cross sections are such that they can be immediately used in space radiation transport codes. Only a limited amount of data exists, but the comparison between theory and experiment is good.

Norbury, John W.; Adamczyk, Anne; Dick, Frank

2008-01-01

267

Neutron Cross Section Uncertainties in the Thermal and Resonance Regions  

SciTech Connect

In the 'Atlas of Neutron Resonances', special care was expended to ensure that the resonance parameter information reproduces the various measured thermal cross sections, as well as the infinite dilute resonance integrals for Z = 1-100. In contrast, the uncertainties of the recommended quantities do not match those generated from the uncertainties of the resonance parameters. To address this problem, the present study was initiated to achieve consistency for 15 actinides and 21 structural and coolant moderator materials. This is realized by assigning uncertainties to the parameters of the negative-energy resonances and changing, if necessary, significantly the uncertainties of the low-lying positive-energy resonances. The influence of correlations between parameters on the derived uncertainties is examined and discussed.

Mughabghab,S.F.; Oblozinsky, P.

2008-06-24

268

Neutron Cross Section Uncertainties in the Thermal and Resonance Regions  

SciTech Connect

In the Atlas of Neutron Resonances, special care was expended to ensure that the resonance parameter information reproduces the various measured thermal cross sections, as well as the infinite dilute resonance integrals for Z = 1-100. In contrast, the uncertainties of the recommended quantities do not match those generated from the uncertainties of the resonance parameters. To address this problem, the present study was initiated to achieve consistency for 15 actinides and 21 structural and coolant moderator materials. This is realized by assigning uncertainties to the parameters of the negative-energy resonances and changing, if necessary, significantly the uncertainties of the low-lying positive-energy resonances. The influence of correlations between parameters on the derived uncertainties is examined and discussed.

Mughabghab, S.F. [National Nuclear Data Center, Brookhaven National Laboratory, Upton, NY 11973-5000 (United States)], E-mail: mugabgab@bnl.gov; Oblozinsky, P. [National Nuclear Data Center, Brookhaven National Laboratory, Upton, NY 11973-5000 (United States)

2008-12-15

269

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

270

Exploring the anomaly in the interaction cross section and matter radius of (23)O  

SciTech Connect

New measurements of the interaction cross sections of {sup 22,23}O at 900A MeV performed at the GSI, Darmstadt are reported that address the unsolved puzzle of the large cross section previously observed for {sup 23}O. The matter radii for these oxygen isotopes extracted through a Glauber model analysis are in good agreement with the new predictions of the ab initio coupled-cluster theory reported here. They are consistent with a {sup 22}O + neutron description of {sup 23}O as well.

Kanungo, R. [St. Marys University, Canada; Uchida, M. [St. Marys University, Canada; Perro, C. [St. Marys University, Canada; Prochazka (et al.), A. [GSI-Hemholtzzentrum fur Schwerionenforschung, Darmstadt, Germany; Lenske, H. [University Giessen, Germany; Boutin, D. [University Giessen, Germany; Farinon, F. [University Giessen, Germany; Knoebel, R. [University Giessen, Germany; Horiuchi, W. [RIKEN, Nishina Ctr Accelerator Based Sci, Wako, Saitama, Japan; Suzuki, Y. [RIKEN, Nishina Ctr Accelerator Based Sci, Wako, Saitama, Japan; Hagen, Gaute [ORNL; Papenbrock, T. [University of Tennessee, Knoxville (UTK) & Oak Ridge National Laboratory (ORNL); Aumann, T. [Technische Universitat Darmstadt, Germany; Cortina-Gil, D. [University of Santiago de Compostela, Spain; Davids, B. [TRIUMF, Canada; Diakaki, M. [National Technical University of Athens, Athens, Greece; Gernhaeuser, R. [Technical University, Munich, Germany; Kruecken, R. [Technical University, Munich, Germany; Maierbeck, P. [Technical University, Munich, Germany; Janik, R. [Comenius University, Slovakia; Sitar, B. [Comenius University, Slovakia; Strmen, P. [Comenius University, Slovakia; Szarka, I. [Comenius University, Slovakia; Jensen, O. [University of Oslo, Norway; Jonson, B. [Chalmers, S-41296, Gothenburg, Sweden; Lantz, M. [Chalmers, S-41296, Gothenburg, Sweden; Nilsson, T. [Chalmers University of Technology, Sweden; Litvinov, Y. [Max-Planck Institut fur Kernphysik, Heidelberg, Germany; Musumarra, A. [University of Catania, Italy; Sun, B. [Beihang University, Beijing, China; Tanihata, I. [Osaka University

2011-01-01

271

Hafnium neutron cross sections and resonance analysis  

NASA Astrophysics Data System (ADS)

The focus of this thesis is to determine resonance parameters for the stable hafnium isotopes in the 0.005--200 eV region, with emphasis on the overlapping 176Hf and 178Hf resonances near 8 eV. The large neutron cross section of hafnium, combined with its corrosion resistance and excellent mechanical properties, make it an ideal material for controlling nuclear reactions. Experiments measuring neutron capture and transmission were performed at the Rensselaer Polytechnic Institute (RPI) LINAC using the time of flight method. Transmission experiments utilized 6Li glass scintillation detectors at flight path lengths of 15 and 25 m. Capture experiments were done using a sixteen section NaI(Tl) multiplicity type detector at a flight path length of 25 m. These experiments utilized various thicknesses of metallic and isotope-enriched liquid samples. The liquid samples were designed to provide information on the 176Hf and 178Hf contributions to the 8 eV doublet without saturation. Data analysis was done using the R-matrix Bayesian fitting code SAMMY version M6 beta. SAMMY is able to account for experimental resolution effects for each of the experimental setups at the RPI LINAC, and also can correct for some of the multiple scattering effects in yield data. The resolution function for specific experimental setups was determined. A method was developed for estimating errors on the fitted resonance parameters due to uncertainties in the resolution function parameters. The combined capture and transmission data analysis yielded resonance parameters for all stable hafnium isotopes from 0.005--200 eV. Resonance integrals were calculated along with errors for each of the hafnium isotopes using the NJOY and INTER codes. The isotopic resonance integrals calculated were significantly different than some of the previous values; however the calculated elemental hafnium resonance integral changed very little.

Trbovich, Michael J.

272

Thermal Neutron Capture Cross Section of 22Ne  

NASA Astrophysics Data System (ADS)

The radiative thermal neutron capture cross section of the astrophysically important 22Ne nucleus has been measured at the guided cold neutron beam of the Budapest Research Reactor. High-pressure gas-bottles filled with mixtures of enriched 22Ne and CH4 were used. The cross section was determined by means of the comparator method, and an improved decay-scheme obtained in this work. The new value for the thermal neutron cross section is 52.7+/-0.7 mb, 18% larger than the accepted value. The influence of the new cross section on the astrophysical reaction rate is under investigation.

Belgya, T.; Uberseder, E.; Petrich, D.; Käppeler, F.

2009-01-01

273

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

274

Common Carotid Intima Media Thickness and Ankle-Brachial Pressure Index Correlate with Local but Not Global Atheroma Burden: A Cross Sectional Study Using Whole Body Magnetic Resonance Angiography  

PubMed Central

Background Common carotid intima media thickness (CIMT) and ankle brachial pressure index (ABPI) are used as surrogate marker of atherosclerosis, and have been shown to correlate with arterial stiffness, however their correlation with global atherosclerotic burden has not been previously assessed. We compare CIMT and ABPI with atheroma burden as measured by whole body magnetic resonance angiography (WB-MRA). Methods 50 patients with symptomatic peripheral arterial disease were recruited. CIMT was measured using ultrasound while rest and exercise ABPI were performed. WB-MRA was performed in a 1.5T MRI scanner using 4 volume acquisitions with a divided dose of intravenous gadolinium gadoterate meglumine (Dotarem, Guerbet, FR). The WB-MRA data was divided into 31 anatomical arterial segments with each scored according to degree of luminal narrowing: 0?=?normal, 1?=?<50%, 2?=?50–70%, 3?=?70–99%, 4?=?vessel occlusion. The segment scores were summed and from this a standardized atheroma score was calculated. Results The atherosclerotic burden was high with a standardised atheroma score of 39.5±11. Common CIMT showed a positive correlation with the whole body atheroma score (? 0.32, p?=?0.045), however this was due to its strong correlation with the neck and thoracic segments (? 0.42 p?=?0.01) with no correlation with the rest of the body. ABPI correlated with the whole body atheroma score (? ?0.39, p?=?0.012), which was due to a strong correlation with the ilio-femoral vessels with no correlation with the thoracic or neck vessels. On multiple linear regression, no correlation between CIMT and global atheroma burden was present (? 0.13 p?=?0.45), while the correlation between ABPI and atheroma burden persisted (? ?0.45 p?=?0.005). Conclusion ABPI but not CIMT correlates with global atheroma burden as measured by whole body contrast enhanced magnetic resonance angiography in a population with symptomatic peripheral arterial disease. However this is primarily due to a strong correlation with ilio-femoral atheroma burden.

Weir-McCall, Jonathan R.; Khan, Faisel; Lambert, Matthew A.; Adamson, Carly L.; Gardner, Michael; Gandy, Stephen J.; Ramkumar, Prasad Guntur; Belch, Jill J. F.; Struthers, Allan D.; Rauchhaus, Petra; Morris, Andrew D.; Houston, J. Graeme

2014-01-01

275

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

276

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

NASA Astrophysics Data System (ADS)

The cross sections for the induced fission of 211-223Ra, 203-211Rn, and 221-231Th nuclei undergoing peripheral collisions with 208Pb 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 236U (237U) and 238U (239U) nuclei agree with experimental data.

Bolgova, O. N.; Adamian, G. G.; Antonenko, N. V.; Zubov, A. S.; Ivanova, S. P.; Scheid, W.

2009-06-01

277

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

278

Determination of the Ce142(?,n) cross section using quasi-monoenergetic Compton backscattered ? rays  

NASA Astrophysics Data System (ADS)

Background: Knowing the energy dependence of the (?,n) cross section is mandatory to predict the abundances of heavy elements using astrophysical models. The data can be applied directly or used to constrain the cross section of the inverse (n,?) reaction. Purpose: The measurement of the reaction Ce142(?,n)141Ce just above the reaction threshold amends the existing experimental database in that mass region for p-process nucleosynthesis and helps to understand the s-process branching at the isotope Ce141. Method: The quasi-monoenergetic photon beam of the High Intensity ?-ray Source (HI?S), TUNL, USA, is used to irradiate naturally composed Ce targets. The reaction yield is determined afterwards with high-resolution ?-ray spectroscopy. Results: The experimental data are in agreement with previous measurements at higher energies. Since the cross-section prediction of the Ce142(?,n) reaction is exclusively sensitive to the ?-ray strength function, the resulting cross-section values were compared to Hauser-Feshbach calculations using different ?-ray strength functions. A microscopic description within the framework of the Hartree-Fock-BCS model describes the experimental values well within the measured energy range. Conclusions: The measured data show that the predicted (?,n) reaction rate is correct within a factor of 2 even though the closed neutron shell N =82 is approached. This agreement allows us to constrain the (n,?) cross section and to improve the understanding of the s-process branching at Ce141.

Sauerwein, A.; Sonnabend, K.; Fritzsche, M.; Glorius, J.; Kwan, E.; Pietralla, N.; Romig, C.; Rusev, G.; Savran, D.; Schnorrenberger, L.; Tonchev, A. P.; Tornow, W.; Weller, H. R.

2014-03-01

279

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

280

A database of 660 peptide ion cross sections: Use of intrinsic size parameters for bona fide predictions of cross sections  

Microsoft Academic Search

An ion trap\\/ion mobility\\/time-of-flight mass spectrometry technique has been used to measure collision cross sections for\\u000a 660 peptide ions generated by tryptic digestion of 34 common proteins. Measured cross sections have been compiled into a database\\u000a that contains peptide molecular weight and sequence information. The database is used to generate average intrinsic contributions\\u000a to cross section (size parameters) for different

Stephen J. Valentine; Anne E. Counterman; David E. Clemmer

1999-01-01

281

Total cross sections for positrons scattered elastically from helium based on new measurements of total ionization cross sections  

NASA Technical Reports Server (NTRS)

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 presented of total elastic scattering cross section, Q sub el, obtained by subtracting from total scattering cross sections, Q sub tot, reported in the literature, the Q sub ion and Q sub Ps (total positronium formation cross sections) and total excitation cross sections, Q sub ex, published by another researcher. The Q sub ion and Q sub el measured with the 3m high resolution time-of-flight spectrometer for 54.9eV positrons are in accord with the results from the 2.3m spectrometer. The ionization cross sections are in fair agreement with theory tending for the most part to be higher, especially at 76.3 and 88.5eV. The elastic cross section agree quite well with theory to the vicinity of 50eV, but at 60eV and above the experimental elastic cross sections climb to and remain at about 0.30 pi a sub o sq while the theoretical values steadily decrease.

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

1990-01-01

282

Broadband ultrasound attenuation (BUA) of the heel bone and its correlates in men and women in the EPIC-Norfolk cohort: a cross-sectional population-based study  

Microsoft Academic Search

Osteoporotic fractures have substantial clinical and public health impact. Bone quality is an important determinant of fracture risk. Quantitative ultrasound (QUS) of bone measured as broadband ultrasound attenuation (BUA) has been shown to predict fracture risk. However, there have been very few large population studies, particularly in men. We investigated the correlates of calcaneal BUA using a CUBA clinical machine

Ailsa Welch; Joanna Camus; Nichola Dalzell; Suzy Oakes; Jonathan Reeve; K. T. Khaw

2004-01-01

283

TOTAL CROSS SECTIONS FOR NEUTRON ENERGIES NEAR 14 Mev  

Microsoft Academic Search

The total cross section of C, Mg, Sd, Fe, Cu, Pb, and U has been ; measured for neutron energies near 14 Mev by transmission experiments with good ; geometry. The agreement with previous measurements is satisfactory; the general ; form of total cross section curves is the same for elements with neighboring A-; values; giant resonances have been found

J. F. Vervier; A. Martegani

1958-01-01

284

Temperature dependence of the HNO3 UV absorption cross sections  

NASA Technical Reports Server (NTRS)

The temperature dependence of the HNO3 absorption cross sections between 240 and 360 K over the wavelength range 195 to 350 nm has been measured using a diode array spectrometer. Absorption cross sections were determined using both (1) absolute pressure measurements at 298 K and (2) a dual absorption cell arrangement in which the absorption spectrum at various temperatures is measured relative to the room temperature absorption spectrum. The HNO3 absorption spectrum showed a temperature dependence which is weak at short wavelengths but stronger at longer wavelengths which are important for photolysis in the lower stratosphere. The 298 K absorption cross sections were found to be larger than the values currently recommended for atmospheric modeling (DeMore et al., 1992). Our absorption cross section data are critically compared with the previous measurements of both room temperature and temperature-dependent absorption cross sections. Temperature-dependent absorption cross sections of HNO3 are recommended for use in atmospheric modeling. These temperature dependent HNO3 absorption cross sections were used in a two-dimensional dynamical-photochemical model to demonstrate the effects of the revised absorption cross sections on loss rate of HNO3 and the abundance of NO2 in the stratosphere.

Burkholder, James B.; Talukdar, Ranajit K.; Ravishankara, A. R.; Solomon, Susan

1993-01-01

285

Differential cross sections for muonic hydrogen scattering on hydrogen molecules  

Microsoft Academic Search

The results of first calculations of the differential cross sections for muonic hydrogen scattering on hydrogen molecules are presented. They are functions of the initial and final kinetic energy of the system and the scattering angle. These calculations are based on the respective set of cross sections for muonic hydrogen scattering on hydrogen nuclei, obtained within the framework of the

Andrzej Adamczak

1993-01-01

286

Total electron impact excitation cross sections of Ar and Kr  

Microsoft Academic Search

A simple accurate method for normalizing the absolute magnitude of measured relative rare-gas excitation cross-section data to published measurements of the first Townsend coefficient is presented. Using a code which solved the Boltzmann equation we have determined that the predicted first Townsend coefficient is a very sensitive function of the electron impact excitation cross section. In Ar and Kr we

J. H. Jacob; J. A. Mangano

1976-01-01

287

Review of electron impact excitation cross sections for copper atom  

Microsoft Academic Search

Excitation of atomic copper by electron impact plays an important role in the copper vapor laser and accurate cross sections are needed for understanding and modeling laser performance. During the past seven years, there have been several attempts to normalize the relative elastic and inelastic cross sections measured by Trajmar and coworkers. However, each of these efforts have yielded different

N. W. Winter; A. U. Hazi

1982-01-01

288

Measurement of electron impact excitation cross sections for heliumlike titanium  

Microsoft Academic Search

The first measurement of electron impact excitation cross sections as a function of energy has been obtained for a highly charged ion. Collisional excitation cross sections to four n = 2 levels of He-like titanium were measured from threshold to 1.7 times threshold. The data conform well to established theory, especially for direct excitation; however, significant differences are found with

S. Chantrenne; P. Beiersdorfer; R. Cauble; M. B. Schneider

1992-01-01

289

ORELA Measurements to Meet Fusion Energy Neutron Cross Section Needs.  

National Technical Information Service (NTIS)

Major neutron cross section measurements made at the Oak Ridge Electron Linear Accelerator (ORELA) that are useful to the fusion energy program are reviewed. Cross sections for production of gamma rays with energies 0.3 < E/sub gamma / < 10.5 MeV were mea...

D. C. Larson

1980-01-01

290

Photoabsorption cross sections of methane from 1400 to 1850 A  

NASA Technical Reports Server (NTRS)

Photoabsorption cross sections of methane in the 1400-1850-A spectral region have been measured. Cross sections at wavelengths greater than 1475 A are approximately 200 times smaller than those currently accepted. This has a significant effect on the interpretation of spectral measurements of the Jovian planets in this wavelength region.

Mount, G. H.; Warden, E. S.; Moos, H. W.

1977-01-01

291

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

292

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

293

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

294

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

295

MEASUREMENTS OF RADIATIVE CAPTURE CROSS SECTIONS FOR FAST NEUTRONS  

Microsoft Academic Search

Cross-section measurements of radiative capture were made both for ; monoenergetic fast neutrons and for a wide spectra of fast neutrons by means of ; an activation method, as well as by neutron halance in the spherical geometry of ; the experiment, by capture gamma rays, and by reactivity measurements. ; Measurements of capture cross sections for a number of

A. I. Leipunskii; O. D. Kazachkovskii; G. Y. Artyukov

1959-01-01

296

Collision cross sections of gas phase DNA ions  

Microsoft Academic Search

Collision cross sections of negative ions of a 28-, 40- and 55-mer of single stranded DNA have been measured by an energy loss method, and compared to collision cross sections of proteins of nearly the same molecular weight—ubiquitin, cytochrome c and apomyoglobin, respectively. The oligonucleotides produce negative charge states in electrospray ionization (ESI) similar to the positive charge states produced

Annie Moradian; Mark Scalf; Michael S. Westphall; Lloyd M. Smith; D. J. Douglas

2002-01-01

297

Analysis of cross sections using various nuclear potential  

NASA Astrophysics Data System (ADS)

The relevant astrophysical reaction rates which are derived from the reaction cross sections are necessary input to the reaction network. In this work, we analyse several theoretical models of the nuclear potential which give better prediction of the cross sections for some selected reactions.

Aziz, Azni Abdul; Kassim, Hasan Abu; Yusof, Norhasliza; Muhammad Zamrun, F.

2014-05-01

298

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

299

Radar cross section analysis of various objects and RCS optimisation  

Microsoft Academic Search

This work is based on the analysis and optimization of the radar cross section that is indispensable for today's defense industry. In this study, radar cross section analysis of many objects from simple geometric structures to military vehicles are made. Nowadays, when the electronic war technology is growing rapidly in, the stealth technology in radar systems became one of the

Ozan Yurduseven; Okan Yurduseven; Ahmet Serdar Turk

2010-01-01

300

Radar cross section: Its prediction measurement and reduction  

Microsoft Academic Search

An introduction to the echo characteristics of radar targets is presented. An overview is first given of radar fundamentals and electromagnetic scattering. Exact prediction techniques, including those pertaining to high-frequency radar cross section (RCS), are addressed. Examples of RCS behavior for simple and complex bodies are shown and discussed. Radar cross section reduction methods and techniques for measuring absorber properties

E. F. Knott; J. F. Shaeffer; M. T. Tuley

1985-01-01

301

Born cross sections for ion-atom collisions  

Microsoft Academic Search

Selected total cross sections are calculated in the closure-Born approximation for the ions Li+, Cs+, and Au+ incident on several gas constituents. Targets included are H, H2, He, C, N, and O. Four general types of cross sections are considered depending on whether the incident ion or target atom is scattered elastically or inelastically. Expressions are given for the Born

George H. Gillespie; Yong-Ki Kim; Kwok-Tsang Cheng

1978-01-01

302

Difiractive and Total pp Cross Sections at LHC  

Microsoft Academic Search

The single-difiractive and total pp cross sections at the LHC are predicted in a phenomeno- logical approach that obeys all unitarity constraints. The approach is based on the renor- malization model of difiraction and a saturated Froissart bound for the total cross section yielding æt = (…=so) ¢ ln2(s=sF ) for s > sF , where the parameters so and

Konstantin Goulianos

303

Flow in Tubes of Non-Circular Cross-Sections  

Microsoft Academic Search

In this thesis steady, laminar, viscous, incompressible flow in tubes of non-circular cross sections is investigated. The specific aims of the investigation are (a) to look at the problems of both developing flow and fully developed flow, (b) to consider non-circular cross sections in a more systematic manner than has been done in the past, and (c) to develop a

Raushan Ara Quadir

1993-01-01

304

Neutron Induced Cross Sections for Radiochemistry for Isotopes of Arsenic  

SciTech Connect

We have developed a set of modeled nuclear reaction cross sections for use in radiochemical diagnostics. Local systematics for the input parameters required by the Hauser-Feshbach statistical model were developed and used to calculate neutron induced nuclear reaction cross sections for isotopes of Arsenic (Z = 33) in the mass range 71 {le} A {le} 77.

Kelley, K; Hoffman, R D; Dietrich, F S; Mustafa, M

2006-01-10

305

Temperature-dependent absorption cross sections for hydrogen peroxide vapor  

NASA Technical Reports Server (NTRS)

Relative absorption cross sections for hydrogen peroxide vapor were measured over the temperature ranges 285-381 K for lambda = 230 nm-295 nm and 300-381 K for lambda = 193 nm-350 nm. The well established 298 K cross sections at 202.6 and 228.8 nm were used as an absolute calibration. A significant temperature dependence was observed at the important tropospheric photolysis wavelengths lambda over 300 nm. Measured cross sections were extrapolated to lower temperatures, using a simple model which attributes the observed temperature dependence to enhanced absorption by molecules possessing one quantum of O-O stretch vibrational excitation. Upper tropospheric photodissociation rates calculated using the extrapolated cross sections are about 25 percent lower than those calculated using currently recommended 298 K cross sections.

Nicovich, J. M.; Wine, P. H.

1988-01-01

306

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

307

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

308

Estudo da estrutura e da dinamica moleculares da baquelite atraves de medidas de secoes de choque para neutrons. (Study of the molecular structure and dynamics of bakelite with neutron cross section measurements).  

National Technical Information Service (NTIS)

The molecular structure and dynamics of calcined bakelite were studied with neutron transmission and scattering cross section measurements. The total cross sections determined were correlated with data obtained with infra-red spectroscopy, elemental analy...

D. L. Voi

1990-01-01

309

The Scattering Cross Section for a Target Irradiated by Time-varying Electromagnetic Waves  

Microsoft Academic Search

Based on the analysis of the target cross section, the cross section expression for a target irradiated by the time-varying electromagnetic waves is presented utilizing its cross section in frequency domain. Result shows that the cross section of a target is easy obtained in time domain if only its cross section in frequency domain is known. This cross section is

Y.-L. Li; J.-Y. Huang; M.-J. Wang; S.-H. Gong

2007-01-01

310

AFCI-2.0 Neutron Cross Section Covariance Library  

SciTech Connect

The cross section covariance library has been under development by BNL-LANL collaborative effort over the last three years. The project builds on two covariance libraries developed earlier, with considerable input from BNL and LANL. In 2006, international effort under WPEC Subgroup 26 produced BOLNA covariance library by putting together data, often preliminary, from various sources for most important materials for nuclear reactor technology. This was followed in 2007 by collaborative effort of four US national laboratories to produce covariances, often of modest quality - hence the name low-fidelity, for virtually complete set of materials included in ENDF/B-VII.0. The present project is focusing on covariances of 4-5 major reaction channels for 110 materials of importance for power reactors. The work started under Global Nuclear Energy Partnership (GNEP) in 2008, which changed to Advanced Fuel Cycle Initiative (AFCI) in 2009. With the 2011 release the name has changed to the Covariance Multigroup Matrix for Advanced Reactor Applications (COMMARA) version 2.0. The primary purpose of the library is to provide covariances for AFCI data adjustment project, which is focusing on the needs of fast advanced burner reactors. Responsibility of BNL was defined as developing covariances for structural materials and fission products, management of the library and coordination of the work; LANL responsibility was defined as covariances for light nuclei and actinides. The COMMARA-2.0 covariance library has been developed by BNL-LANL collaboration for Advanced Fuel Cycle Initiative applications over the period of three years, 2008-2010. It contains covariances for 110 materials relevant to fast reactor R&D. The library is to be used together with the ENDF/B-VII.0 central values of the latest official release of US files of evaluated neutron cross sections. COMMARA-2.0 library contains neutron cross section covariances for 12 light nuclei (coolants and moderators), 78 structural materials and fission products, and 20 actinides. Covariances are given in 33-energy groups, from 10?5 eV to 19.6 MeV, obtained by processing with LANL processing code NJOY using 1/E flux. In addition to these 110 files, the library contains 20 files with nu-bar covariances, 3 files with covariances of prompt fission neutron spectra (238,239,240-Pu), and 2 files with mu-bar covariances (23-Na, 56-Fe). Over the period of three years several working versions of the library have been released and tested by ANL and INL reactor analysts. Useful feedback has been collected allowing gradual improvements of the library. In addition, QA system was developed to check basic properties and features of the whole library, allowing visual inspection of uncertainty and correlations plots, inspection of uncertainties of integral quantities with independent databases, and dispersion of cross sections between major evaluated libraries. The COMMARA-2.0 beta version of the library was released to ANL and INL reactor analysts in October 2010. The final version, described in the present report, was released in March 2011.

Herman, M.; Herman, M; Oblozinsky, P.; Mattoon, C.M.; Pigni, M.; Hoblit, S.; Mughabghab, S.F.; Sonzogni, A.; Talou, P.; Chadwick, M.B.; Hale, G.M.; Kahler, A.C.; Kawano, T.; Little, R.C.; Yount, P.G.

2011-03-01

311

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

312

A New Scaling Law of Resonance in Total Scattering Cross Section in Gases  

NASA Astrophysics Data System (ADS)

Electrical discharges in gases continue to be an active area of research because of industrial applications such as power systems, environmental clean up, laser technology, semiconductor fabrication etc. A fundamental knowledge of electron-gas neutral interaction is indispensable and, the total scattering cross section is one of the quantities that have been measured extensively. The energy dependence of the total cross sections shows peaks or resonance processes that are operative in the collision process. These peaks and the energies at which they occur are shown to satisfy a broad relationship involving the polarizability and the dipole moment of the target particle. Data on 62 target particles belonging to the following species are analyzed. (Eq 1) Rare gas atoms (Eq 2) Di-atomic molecules with combinations of polar, non-polar, attaching, and non-attaching properties Poly-atomic molecules with combinations of polar, non-polar, attaching, and non-attaching properties. Methods of improving the newly identified scaling law and possible application have been identified. 1 INTRODUCTION: Data on electron-neutral interactions are one of the most fundamental in the study of gaseous electronics and an immense literature, both experimental and theoretical, has become available since about the year 1920. [1-5]. In view of the central role which these data play in all facets of gas discharges and plasma science, it is felt that a critical review of available data is timely, mainly for the community of high voltage engineers and industries connected with plasma science in general. The electron-neutral interaction, often referred to as scattering in the scientific literature, is quantified by using the quantity called the total scattering cross section (QT, m^2). In the literature on cross section, total cross section and total scattering cross section are terms used synonymously and we follow the same practice. A definition may be found in reference [1]. This paper concerns scaling of total cross section of gases at resonance energy and the electron energy at which resonance occurs. The meaning of resonance is briefly explained in the following section. Here, we use the term scaling to relate the two quantities mentioned, namely, the resonance energy and the total cross section at that energy. Consistent with the definition of scaling, if the law proposed holds, one of the two quantities mentioned above may be calculated if the other is known. Such a method is very useful in gas discharge modeling and calculation of breakdown voltages, as more fully explained in the later section of the paper. 2 DESCRIPTION OF RESONANCE: A brief description of resonance phenomena in several types of target particles, viz., atomic, poly atomic, polar, non-polar phenomena are presented. 3 PREVIOUS SCALING LAWS: A common representation of a given characteristic with as few adjustable parameters as possible is generally known as the scaling law. The Paschen curve for breakdown voltage is such a familiar scaling law. With reference to cross sections several attempts have been made to obtain a scaling law, with varying degree of success. If the cross section-energy curve is qualitatively similar without having sharp peaks and oscillations, moderately successful scaling laws may be devised. For example, the ionization cross section- energy curves for most gases follow a general pattern. Several published scaling laws are discussed. 4 A NEW SCALING LAW AND DISCUSSION: In this work the author has compiled the resonance details for more than 60 gasest hat include the range from simple atoms to complex molecules that are polyatomic, dipolar, electron-attaching and isomers. The target particles exhibit a number of distinct features, as far as their total cross section variation with electron energy is concerned as already explained.

Raju, Gorur Govinda

2009-10-01

313

Radar cross section measurement by subscale models  

Microsoft Academic Search

The paper focuses on the methodology of the RCS measurement by using radar object subscale model and on the description of the measurement facilities. The first phase of the RCS measurement by applying comparison method is the reference object (shape) design. There are some necessary conditions of the RCS calculation according to comparison method and subscale modeling. Experimental results, obtained

Jan Ochodnicky; Zdenek Matousek; Mikulas Sostronek; Arnost Hykel

2008-01-01

314

Cross-section adjustment techniques for BWR adaptive simulation  

NASA Astrophysics Data System (ADS)

Computational capability has been developed to adjust multi-group neutron cross-sections to improve the fidelity of boiling water reactor (BWR) modeling and simulation. The method involves propagating multi-group neutron cross-section uncertainties through BWR computational models to evaluate uncertainties in key core attributes such as core k-effective, nodal power distributions, thermal margins, and in-core detector readings. Uncertainty-based inverse theory methods are then employed to adjust multi-group cross-sections to minimize the disagreement between BWR modeling predictions and measured plant data. For this work, measured plant data were virtually simulated in the form of perturbed 3-D nodal power distributions with discrepancies with predictions of the same order of magnitude as expected from plant data. Using the simulated plant data, multi-group cross-section adjustment reduces the error in core k-effective to less than 0.2% and the RMS error in nodal power to 4% (i.e. the noise level of the in-core instrumentation). To ensure that the adapted BWR model predictions are robust, Tikhonov regularization is utilized to control the magnitude of the cross-section adjustment. In contrast to few-group cross-section adjustment, which was the focus of previous research on BWR adaptive simulation, multigroup cross-section adjustment allows for future fuel cycle design optimization to include the determination of optimal fresh fuel assembly designs using the adjusted multi-group cross-sections. The major focus of this work is to efficiently propagate multi-group neutron cross-section uncertainty through BWR lattice physics calculations. Basic neutron cross-section uncertainties are provided in the form of multi-group cross-section covariance matrices. For energy groups in the resolved resonance energy range, the cross-section uncertainties are computed using an infinitely-dilute approximation of the neutron flux. In order to accurately account for spatial and energy resonance self-shielding effects, the multi-group cross-section covariance matrix has been reformulated to include the uncertainty in resonance correction factors, or self-shielding factors, which are used to calculate the self-shielded multi-group cross-sections used in the lattice physics neutron transport model. This is shown to change the U-238 capture cross-section uncertainty contribution to Beginning-of-Life (BOL) lattice k-infinity by 14% (i.e. 0.291% relative standard deviation in k-infinity (self-shielded) compared to 0.255% (infinitely-dilute)). Using the reformulated multi-group cross-section covariance matrix, Efficient Subspace Methods (ESM) are used to propagate multi-group cross-section uncertainty through the lattice physics calculation. ESM algorithms have been developed by H. S. Abdel-Khalik and P. J. Turinsky to calculate low-rank approximations to large, dense sensitivity and covariance matrices used in data adjustment and uncertainty propagation applications. Using ESM, the singular value spectrum of the multi-group cross-section covariance matrix reveals an effective rank of the order of 103. Using this singular value decomposition of the multigroup cross-section covariance matrix reduces the number of lattice physics calculations per lattice from ˜107 to ˜10 3. In addition, a BOL sensitivity analysis using generalized perturbation theory at the lattice physics level is shown to further reduce the rank by a factor of 5.

Jessee, Matthew Anderson

315

Effects of resonant and continuum states on the neutrino-nucleus cross section  

SciTech Connect

Estimates of the neutrino-nucleus cross section, for the charged-current process {nu}+{sup 208}Pb {yields}e{sup -}+{sup 208}Bi*, are presented. The nuclear structure calculations were performed by considering bound, resonant, and continuum states in the single-particle basis used to construct correlated proton-particle neutron-hole configurations. The observed features of the spectrum of {sup 208}Bi were reproduced, as accurately as possible, by diagonalizing a phenomenological multipole-multipole interaction. Calculations of the cross section, for values of q{<=}200 MeV, were performed, and the dependence of the results on the choice of the residual proton-neutron interaction was investigated. It is found that the inclusion of resonant states in the calculation of the nuclear wave functions increases the neutrino-nucleus cross section and that the contribution of the continuum is negligible.

Civitarese, O. [Department of Physics, University of La Plata c.c. 67 1900, La Plata (Argentina); Liotta, R. J. [KTH, Albanova University Center, SE-10691 Stockholm (Sweden); Mosquera, M. E. [Faculty of Astronomy and Geophysics, University of La Plata, La Plata (Argentina)

2008-12-15

316

^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

317

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.

318

Line shape cross sections of HD immersed in He and H2 gas. I - Pressure broadening cross sections  

Microsoft Academic Search

The results of two tests of the electronic potential energy surface of hydrogenlike systems are reported here, including the second virial coefficient of para hydrogen at low temperatures and HD-D2 elastic and inelastic differential scattering cross sections. Formulas are given for Dicke narrowing as well as for the line broadening and calculated shift cross sections. Close coupling calculations are performed

Joachim Schaefer; Louis Monchick

1987-01-01

319

PANEL UNIT ROOT TESTS WITH CROSS-SECTION DEPENDENCE: A FURTHER INVESTIGATION  

Microsoft Academic Search

An effective way to control for cross-section correlation when conducting a panel unit root test is to remove the common factors from the data. However, there remain many ways to use the defactored residuals to construct a test. In this paper, we use the panel analysis of nonstationarity in idiosyncratic and common components (PANIC) residuals to form two new tests.

Jushan Bai; Serena Ng

2010-01-01

320

Electron-impact ionization cross sections of atmospheric molecules  

SciTech Connect

A theoretical model for electron-impact total ionization cross sections, which has been found to be reliable for a wide range of molecules, is applied to molecules of interest to atmospheric science. The new theory, the binary-encounter-Bethe (BEB) model, combines the binary-encounter theory and the Bethe theory for electron-impact ionization, and uses simple theoretical data for the ground state of the target molecule, which are readily available from molecular structure codes. Total ionization cross sections of 11 molecules, CS, CS{sub 2}, COS, CH{sub 4}, H{sub 2}S, NH{sub 3}, NO{sub 2}, N{sub 2}O, O{sub 3}, S{sub 2}, and SO{sub 2}, are presented for incident electron energies from threshold to 1 keV with an average accuracy of 15{percent} or better at the cross section peak. We also found that the use of vertical ionization potentials (IPs) rather than adiabatic IPs for the lowest IPs significantly improves BEB cross sections between the threshold and cross section peak for molecules whose adiabatic and vertical IPs are different by {approximately}1 eV or more (CH{sub 4} and NH{sub 3}). The BEB cross sections are presented in a compact analytic form with a small number of constants, making the cross sections suitable for modeling applications. {copyright} {ital 1997 American Institute of Physics.}

Kim, Y.; Hwang, W.; Weinberger, N.M. [National Institute of Standards and Technology, Gaithersburg, Maryland 20899 (United States)] [National Institute of Standards and Technology, Gaithersburg, Maryland 20899 (United States); Ali, M.A. [Department of Chemistry, Howard University, Washington, D.C. 20059 (United States)] [Department of Chemistry, Howard University, Washington, D.C. 20059 (United States); Rudd, M.E. [Department of Physics and Astronomy, University of Nebraska-Lincoln, Lincoln, Nebraska 68588-0111 (United States)] [Department of Physics and Astronomy, University of Nebraska-Lincoln, Lincoln, Nebraska 68588-0111 (United States)

1997-01-01

321

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

322

Potential biases in the classification, analysis and interpretations in cross-sectional study: commentaries - surrounding the article "resting heart rate: its correlations and potential for screening metabolic dysfunctions in adolescents"  

PubMed Central

Background Resting heart rate reflects sympathetic nerve activity. A significant association between resting heart rate (HR) and all causes of cardiovascular mortality has been reported by some epidemiologic studies. Despite suggestive evidence, resting heart rate (RHR) has not been formally explored as a prognostic factor and potential therapeutic outcome and, therefore, is not generally accepted in adolescents. Discussion The core of the debate is the methodological aspects used in "Resting heart rate: its correlations and potential for screening metabolic dysfunctions in adolescents"; the points are: cutoff used for cluster RHR, two different statistical models used to analyze the same set of variables, one for continuous data, and another for categorical data; interpretation of p-value

2014-01-01

323

Hypertension prevalence, awareness, treatment and control in national surveys from England, the USA and Canada, and correlation with stroke and ischaemic heart disease mortality: a cross-sectional study  

PubMed Central

Objective Comparison of recent national survey data on prevalence, awareness, treatment and control of hypertension in England, the USA and Canada, and correlation of these parameters with each country stroke and ischaemic heart disease (IHD) mortality. Design Non-institutionalised population surveys. Setting and participants England (2006 n=6873), the USA (2007–2010 n=10?003) and Canada (2007–2009 n=3485) aged 20–79?years. Outcomes Stroke and IHD mortality rates were plotted against countries’ specific prevalence data. Results Mean systolic blood pressure (SBP) was higher in England than in the USA and Canada in all age–gender groups. Mean diastolic blood pressure (DBP) was similar in the three countries before age 50 and then fell more rapidly in the USA, being the lowest in the USA. Only 34% had a BP under 140/90?mm?Hg in England, compared with 50% in the USA and 66% in Canada. Prehypertension and stages 1 and 2 hypertension prevalence figures were the highest in England. Hypertension prevalence (?140?mm?Hg SBP and/or ?90?mm?Hg DBP) was lower in Canada (19·5%) than in the USA (29%) and England (30%). Hypertension awareness was higher in the USA (81%) and Canada (83%) than in England (65%). England also had lower levels of hypertension treatment (51%; USA 74%; Canada 80%) and control (<140/90?mm?Hg; 27%; the USA 53%; Canada 66%). Canada had the lowest stroke and IHD mortality rates, England the highest and the rates were inversely related to the mean SBP in each country and strongly related to the blood pressure indicators, the strongest relationship being between low hypertension awareness and stroke mortality. Conclusions While the current prevention efforts in England should result in future-improved figures, especially at younger ages, these data still show important gaps in the management of hypertension in these countries, with consequences on stroke and IHD mortality.

Joffres, Michel; Falaschetti, Emanuela; Gillespie, Cathleen; Robitaille, Cynthia; Loustalot, Fleetwood; Poulter, Neil; McAlister, Finlay A; Johansen, Helen; Baclic, Oliver; Campbell, Norm

2013-01-01

324

Momentum transfer cross sections for the heavy noble gases  

NASA Astrophysics Data System (ADS)

We present momentum transfer cross sections for elastic electron scattering from argon, krypton and xenon atoms over the energy range from zero to 1 keV. These have been calculated using the Dirac equations with a relativistic complex optical potential which includes polarization of the target atom by the incident electron and allows for the absorption of some of the incident electron flux into channels representing excitation and ionization of the atom. In order to aid in plasma modelling calculations, we provide simple analytic fits to these cross sections as well as to the elastic scattering cross sections. Comparisons are made with previous experimental and theoretical results.

McEachran, R. P.; Stauffer, A. D.

2014-06-01

325

Aerodynamic Research on Fuselages with Rectangular Cross Section  

NASA Technical Reports Server (NTRS)

The influence of the deflected flow caused by the fuselage (especially by unsymmetrical attitudes) on the lift and the rolling moment due to sideslip has been discussed for infinitely long fuselages with circular and elliptical cross section. The aim of this work is to add rectangular cross sections and, primarily, to give a principle by which one can get practically usable contours through simple conformal mapping. In a few examples, the velocity field in the wing region and the induced flow produced are calculated and are compared with corresponding results from elliptical and strictly rectangular cross sections.

Maruhn, K.

1958-01-01

326

Modifying excitation transfer cross sections with an ac Stark effect.  

PubMed

We show that it is possible to manipulate electronic energy transfer collision cross sections between different atomic species by using a strong electromagnetic field close to resonance with a transition between two excited states to modify the energy levels (i.e., to create dressed states), which may be placed in or out of resonance with populated states (forming a population reservoir) in one of the species. We outline an estimate for a transfer cross section for a demonstration scheme and show that cross-section enhancements up to the order of 10(3) are possible. PMID:19745896

Coutts, J; Cooper, J; Burnett, K

1988-05-01

327

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

328

Absolute OH absorption cross sections (for lidar measurements)  

NASA Technical Reports Server (NTRS)

Experimental data are employed to calculate absorption cross sections for several rotational lines in the OH A-X system. The cross sections are computed as functions of the spectral and line widths and temperature of a laser beam, and account for lifetimes and branching ratios. Detection limits for the P1(2) transition of the (1,0) band were examined. The oscillator strengths and cross-sections obtained are important for quantifying OH concentrations in the stratosphere from lidar return signals.

Mcgee, T. J.; Mcilrath, T. J.

1984-01-01

329

CROSS SECTION MEASUREMENTS FOR CHARM PRODUCTION BY MUONS AND PHOTONS  

SciTech Connect

Interactions of 209-GeV muons in the Multimuon Spectrometer at Fermilab have yielded 20072 dimuon final states, with (81±10)% attributed to production of charmed states decaying to muons. The cross section for diffractive charm muoproduction is 6.9{sub -1.4}{sup +1.9} nb. Extrapolated to Q{sup 2} =0, the effective cross section for 178(100)-GeV photons is 750{sup +180}{sub -130} (560{sup +200}{sub -130}) nb, too small to explain the high-energy rise in the photon-nucleon total cross section.

Clark, A.R.; Johnson, K.J.; Kerth, L.T.; Loken, S.C.; Markiewicz, T.W.; Meyers, P.D.; Smith, W.H.; Strovink, M.; Wenzel, W.A.; Johnson, R.P.; Moore, C.; Mugge, M.; Shafer, R.E.; Gollin, G.D.; Shoemaker, F.C.; Surko, P.

1980-04-01

330

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

331

Benchmark result on the ^4He photoabsorbtion cross section  

NASA Astrophysics Data System (ADS)

We present the results of a benchmark calculation of the ^4He photoabsorbtion cross section via the Lorentz integral transform approach, using both the no-core shell model (NCSM) and the effective interaction hyperspherical harmonic (EIHH) expansion methods. The present study, which is fully microscopic in the treatment of the dynamics in both the initial and final states, uses a semirealistic nucleon-nucleon potential, with the goal to test the reliability of the NCSM for the description of such processes. We find that the results of both EIHH and NCSM agree, which opens the the way for the use of two- and three-body forces obtained from EFT, and for applications to heavier nuclei by means of the NCSM. S.Q., I.S., and B.R.B acknowledge partial support by NFS grants PHY0070858 and PHY0244389. The work was performed in part under the auspices of the U. S. Department of Energy by the University of California, Lawrence Livermore National Laboratory under contract No. W-7405-Eng-48. P.N. received support from LDRD contract 04-ERD-058. W.L. and G.O. acknowledge support by the grant COFIN03 of the Italian Ministry of University and Research. N.B. acknowledges support by the Israel Science Foundation (Grant No. 202/02). C.W.J. acknowledges USDOE grant No.DE-FG02-03ER41272.

Quaglioni, Sofia; Stetcu, Ionel; Barrett, Bruce R.; Bacca, Sonia; Navrátil, Petr; Leidemann, Winfried; Orlandini, Giuseppina; Barnea, Nir; Johnson, Calvin W.

2006-04-01

332

Transport cross sections and collision integrals for N(4S0)-O(+)(4S0) and N(+)(3P)-O(3P) interactions  

NASA Technical Reports Server (NTRS)

The transport cross sections and collision integrals are reported for the N(+)-O and N-O(+) interactions. The cross sections are determined using accurate potential energy curves and a semiclassical description of the scattering. The computed collision integrals differ substantially from the estimated values currently recommended for flow-field studies.

Partridge, Harry; Stallcop, James R.; Levin, E.

1991-01-01

333

Prevalence and correlates of HIV, syphilis, and hepatitis B and C infection and harm reduction program use among male injecting drug users in Kabul, Afghanistan: A cross-sectional assessment  

PubMed Central

Background A nascent HIV epidemic and high prevalence of risky drug practices were detected among injecting drug users (IDUs) in Kabul, Afghanistan from 2005-2006. We assessed prevalence of HIV, hepatitis C virus (HCV), hepatitis B surface antigen (HBsAg), syphilis, and needle and syringe program (NSP) use among this population. Methods IDUs were recruited between June, 2007 and March, 2009 and completed questionnaires and rapid testing for HIV, HCV, HBsAg, and syphilis; positive samples received confirmatory testing. Logistic regression was used to identify correlates of HIV, HCV, and current NSP use. Results Of 483 participants, all were male and median age, age at first injection, and duration of injection were 28, 24, and 2.0 years, respectively. One-fifth (23.0%) had initiated injecting within the last year. Reported risky injecting practices included ever sharing needles/syringes (16.9%) or other injecting equipment (38.4%). Prevalence of HIV, HCV Ab, HBSAg, and syphilis was 2.1% (95% CI: 1.0-3.8), 36.1% (95% CI: 31.8-40.4), 4.6% (95% CI: 2.9-6.9), and 1.2% (95% CI: 0.5-2.7), respectively. HIV and HCV infection were both independently associated with sharing needles/syringes (AOR = 5.96, 95% CI: 1.58 - 22.38 and AOR = 2.33, 95% CI: 1.38 - 3.95, respectively). Approximately half (53.8%) of the participants were using NSP services at time of enrollment and 51.3% reported receiving syringes from NSPs in the last three months. Current NSP use was associated with initiating drug use with injecting (AOR = 2.58, 95% CI: 1.22 - 5.44), sharing injecting equipment in the last three months (AOR = 1.79, 95% CI: 1.16 - 2.77), prior incarceration (AOR = 1.57, 95% CI: 1.06 - 2.32), and greater daily frequency of injecting (AOR = 1.40 injections daily, 95% CI: 1.08 - 1.82). Conclusions HIV and HCV prevalence appear stable among Kabul IDUs, though the substantial number having recently initiated injecting raises concern that transmission risk may increase over time. Harm reduction programming appears to be reaching high-risk drug user populations; however, monitoring is warranted to determine efficacy of prevention programming in this dynamic environment.

2011-01-01

334

Cross-section and analyzing power measurements for neutron scattering from [sup 27]Al and [sup 59]Co and spin-spin cross section calculations  

SciTech Connect

Differential cross sections and analyzing power data have been measured for [sup 27]Al and [sup 59]Co at 15.5 MeV. Cross section data was also measured for [sup 59]Co at 10,12,14,17, and 19 MeV using standard time-of-flight techniques at the Triangle Universities Nuclear Laboratory (TUNL). Absolute normalization of the [sigma]([theta]) data was performed using n-p scattering measurements. Both [sigma]([theta]) and A[sub y]([theta]) were corrected for finite geometry, attenuation, relative efficiency, and multiple scattering effects using Monte Carlo techniques. A large data base was formed from our data and the existing data on [sup 27]Al and [sup 59]Co. This data base was used to develop a Dispersive Optical Model (DOM) and a Coupled Channels Model (CCM). The DOM model describes the data quite well above 8 MeV for [sup 27]Al and [sup 59]Co. However, for data below 8 MeV the model is not as satisfactory, perhaps because of angular momentum l-dependencies in the absorptive potential. The CCM improved the description of the data over the DOM, but still does not describe the data well at low energies. The DOM and CCM for [sup 27]Al and [sup 59]Co were used to describe the spin-spin cross section data for [sup 27]Al and [sup 59]Co. The author obtained a good fit for the spin-spin cross section with both the DOM and CCM with the spin-spin real surface parameters of V[sub ss] = 0.80 MeV, r[sub ss] = 1.00 fm and a[sub ss] = 0.654 for both [sup 27]Al and [sup 59]Co. A surprising relation between the spin-spin cross section and the derivative of the total cross section with respect to energy, was discovered: [sigma][sub ss] = c(d[sigma][sub T]/dE) where c is a constant related to the slope of the real central potential and spin-spin potential strength. This observation is not yet understood.

Nagadi, M.M.

1992-01-01

335

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

336

Cross section for the subthreshold fission of 236U  

NASA Astrophysics Data System (ADS)

The cross section for 236U fission in the neutron-energy range E 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 238U( 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 236U was confirmed.

Alekseev, A. A.; Bergman, A. A.; Berlev, A. I.; Koptelov, E. A.; Samylin, B. F.; Trufanov, A. M.; Fursov, B. I.; Shorin, V. S.

2008-08-01

337

Measurement of the Z??? cross section with the ATLAS detector  

NASA Astrophysics Data System (ADS)

The Z??? cross section is measured with the ATLAS experiment at the LHC in four different final states determined by the decay modes of the ? leptons: muon-hadron, electron-hadron, electron-muon, and muon-muon. The analysis is based on a data sample corresponding to an integrated luminosity of 36pb-1, at a proton-proton center-of-mass energy of s=7TeV. Cross sections are measured separately for each final state in fiducial regions of high detector acceptance, as well as in the full phase space, over the mass region 66-116 GeV. The individual cross sections are combined and the product of the total Z production cross section and Z??? branching fraction is measured to be 0.97±0.07(stat)±0.06(syst)±0.03(lumi)nb, in agreement with next-to-next-to-leading order calculations.

Aad, G.; Abbott, B.; Abdallah, J.; Abdelalim, A. A.; Abdesselam, A.; Abdinov, O.; Abi, B.; Abolins, M.; Abramowicz, H.; Abreu, H.; Acerbi, E.; Acharya, B. S.; Adams, D. L.; Addy, T. N.; Adelman, J.; Aderholz, M.; Adomeit, S.; Adragna, P.; Adye, T.; Aefsky, S.; Aguilar-Saavedra, J. A.; Aharrouche, M.; Ahlen, S. P.; Ahles, F.; Ahmad, A.; Ahsan, M.; Aielli, G.; Akdogan, T.; Åkesson, T. P. A.; Akimoto, G.; Akimov, A. V.; Akiyama, A.; Alam, M. S.; Alam, M. A.; Albert, J.; Albrand, S.; Aleksa, M.; Aleksandrov, I. N.; Alessandria, F.; Alexa, C.; Alexander, G.; Alexandre, G.; Alexopoulos, T.; Alhroob, M.; Aliev, M.; Alimonti, G.; Alison, J.; Aliyev, M.; Allport, P. P.; Allwood-Spiers, S. E.; Almond, J.; Aloisio, A.; Alon, R.; Alonso, A.; Alviggi, M. G.; Amako, K.; Amaral, P.; Amelung, C.; Ammosov, V. V.; Amorim, A.; Amorós, G.; Amram, N.; Anastopoulos, C.; Andari, N.; Andeen, T.; Anders, C. F.; Anderson, K. J.; Andreazza, A.; Andrei, V.; Andrieux, M.-L.; Anduaga, X. S.; Angerami, A.; Anghinolfi, F.; Anjos, N.; Annovi, A.; Antonaki, A.; Antonelli, M.; Antonov, A.; Antos, J.; Anulli, F.; Aoun, S.; Aperio Bella, L.; Apolle, R.; Arabidze, G.; Aracena, I.; Arai, Y.; Arce, A. T. H.; Archambault, J. P.; Arfaoui, S.; Arguin, J.-F.; Arik, E.; Arik, M.; Armbruster, A. J.; Arnaez, O.; Arnault, C.; Artamonov, A.; Artoni, G.; Arutinov, D.; Asai, S.; Asfandiyarov, R.; Ask, S.; Åsman, B.; Asquith, L.; Assamagan, K.; Astbury, A.; Astvatsatourov, A.; Atoian, G.; Aubert, B.; Auerbach, B.; Auge, E.; Augsten, K.; Aurousseau, M.; Austin, N.; Avolio, G.; Avramidou, R.; Axen, D.; Ay, C.; Azuelos, G.; Azuma, Y.; Baak, M. A.; Baccaglioni, G.; Bacci, C.; Bach, A. M.; Bachacou, H.; Bachas, K.; Bachy, G.; Backes, M.; Backhaus, M.; Badescu, E.; Bagnaia, P.; Bahinipati, S.; Bai, Y.; Bailey, D. C.; Bain, T.; Baines, J. T.; Baker, O. K.; Baker, M. D.; Baker, S.; Baltasar Dos Santos Pedrosa, F.; Banas, E.; Banerjee, P.; Banerjee, Sw.; Banfi, D.; Bangert, A.; Bansal, V.; Bansil, H. S.; Barak, L.; Baranov, S. P.; Barashkou, A.; Barbaro Galtieri, A.; Barber, T.; Barberio, E. L.; Barberis, D.; Barbero, M.; Bardin, D. Y.; Barillari, T.; Barisonzi, M.; Barklow, T.; Barlow, N.; Barnett, B. M.; Barnett, R. M.; Baroncelli, A.; Barone, G.; Barr, A. J.; Barreiro, F.; Barreiro Guimarães da Costa, J.; Barrillon, P.; Bartoldus, R.; Barton, A. E.; Bartsch, D.; Bartsch, V.; Bates, R. L.; Batkova, L.; Batley, J. R.; Battaglia, A.; Battistin, M.; Battistoni, G.; Bauer, F.; Bawa, H. S.; Beare, B.; Beau, T.; Beauchemin, P. H.; Beccherle, R.; Bechtle, P.; Beck, H. P.; Beckingham, M.; Becks, K. H.; Beddall, A. J.; Beddall, A.; Bedikian, S.; Bednyakov, V. A.; Bee, C. P.; Begel, M.; Behar Harpaz, S.; Behera, P. K.; Beimforde, M.; Belanger-Champagne, C.; Bell, P. J.; Bell, W. H.; Bella, G.; Bellagamba, L.; Bellina, F.; Bellomo, M.; Belloni, A.; Beloborodova, O.; Belotskiy, K.; Beltramello, O.; Ben Ami, S.; Benary, O.; Benchekroun, D.; Benchouk, C.; Bendel, M.; Benedict, B. H.; Benekos, N.; Benhammou, Y.; Benjamin, D. P.; Benoit, M.; Bensinger, J. R.; Benslama, K.; Bentvelsen, S.; Berge, D.; Bergeaas Kuutmann, E.; Berger, N.; Berghaus, F.; Berglund, E.; Beringer, J.; Bernardet, K.; Bernat, P.; Bernhard, R.; Bernius, C.; Berry, T.; Bertin, A.; Bertinelli, F.; Bertolucci, F.; Besana, M. I.; Besson, N.; Bethke, S.; Bhimji, W.; Bianchi, R. M.; Bianco, M.; Biebel, O.; Bieniek, S. P.; Biesiada, J.; Biglietti, M.; Bilokon, H.; Bindi, M.; Binet, S.; Bingul, A.; Bini, C.; Biscarat, C.; Bitenc, U.; Black, K. M.; Blair, R. E.; Blanchard, J.-B.; Blanchot, G.; Blazek, T.; Blocker, C.; Blocki, J.; Blondel, A.; Blum, W.; Blumenschein, U.; Bobbink, G. J.; Bobrovnikov, V. B.; Bocchetta, S. S.; Bocci, A.; Boddy, C. R.; Boehler, M.; Boek, J.; Boelaert, N.; Böser, S.; Bogaerts, J. A.; Bogdanchikov, A.; Bogouch, A.; Bohm, C.; Boisvert, V.; Bold, T.; Boldea, V.; Bolnet, N. M.; Bona, M.; Bondarenko, V. G.; Boonekamp, M.; Boorman, G.; Booth, C. N.; Bordoni, S.; Borer, C.; Borisov, A.; Borissov, G.; Borjanovic, I.; Borroni, S.; Bos, K.; Boscherini, D.; Bosman, M.; Boterenbrood, H.; Botterill, D.; Bouchami, J.; Boudreau, J.; Bouhova-Thacker, E. V.; Boulahouache, C.; Bourdarios, C.; Bousson, N.; Boveia, A.; Boyd, J.; Boyko, I. R.; Bozhko, N. I.; Bozovic-Jelisavcic, I.; Bracinik, J.; Braem, A.; Branchini, P.; Brandenburg, G. W.; Brandt, A.; Brandt, G.; Brandt, O.; Bratzler, U.; Brau, B.; Brau, J. E.; Braun, H. M.; Brelier, B.; Bremer, J.; Brenner, R.; Bressler, S.; Breton, D.; Britton, D.; Brochu, F. M.; Brock, I.; Brock, R.; Brodbeck, T. J.; Brodet, E.; Broggi, F.; Bromberg, C.; Brooijmans, G.; Brooks, W. K.; Brown, G.; Brown, H.; Bruckman de Renstrom, P. A.; Bruncko, D.; Bruneliere, R.; Brunet, S.; Bruni, A.; Bruni, G.; Bruschi, M.; Buanes, T.; Bucci, F.; Buchanan, J.

2011-12-01

338

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

339

56. CROSS SECTIONS OF CANAL AND TUNNELS. POWER CANAL, SALT ...  

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

56. CROSS SECTIONS OF CANAL AND TUNNELS. POWER CANAL, SALT RIVER RESERVOIR Courtesy of U.S.G.S., Reclamation Service - Roosevelt Power Canal & Diversion Dam, Parallels Salt River, Roosevelt, Gila County, AZ

340

Calculation of the cross section for top quark production.  

National Technical Information Service (NTIS)

The authors summarize calculations of the cross section for top quark production at hadron colliders within the context of perturbative quantum chromodynamics, including resummation of the effects of initial-state soft gluon radiation to all orders in the...

E. L. Berger H. Contopanagos

1996-01-01

341

Scaling Cross Sections for Ion-atom Impact Ionization  

SciTech Connect

The values of ion-atom ionization cross sections are frequently needed for many applications that utilize the propagation of fast ions through matter. When experimental data and theoretical calculations are not available, approximate formulas are frequently used. This paper briefly summarizes the most important theoretical results and approaches to cross section calculations in order to place the discussion in historical perspective and offer a concise introduction to the topic. Based on experimental data and theoretical predictions, a new fit for ionization cross sections is proposed. The range of validity and accuracy of several frequently used approximations (classical trajectory, the Born approximation, and so forth) are discussed using, as examples, the ionization cross sections of hydrogen and helium atoms by various fully stripped ions.

Igor D. Kaganovich; Edward Startsev; Ronald C. Davidson

2003-06-06

342

8. VIEW OF CROSS SECTION OF THE EASTERNMOST WALL SEGMENT ...  

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

8. VIEW OF CROSS SECTION OF THE EASTERNMOST WALL SEGMENT THAT SHOWS THE TRENCHING AND 1960 PIPELINE CORRIDOR BETWEEN THE WALL SEGMENTS, LOOKING WEST-NORTHWEST - Rock Wall, North side of Battle Creek Canyon, Shingletown, Shasta County, CA

343

On the cyclo-synchrotron cross-section  

NASA Astrophysics Data System (ADS)

The study of the synchrotron and cyclotron absorption processes and their relative cross-sections, recently analysed by Ghisellini & Svensson, is extended to the case of photons propagating along the direction of the magnetic field. In the relativistic regime we follow a quantum approach, which requires first the derivation of the particle emissivity for the assumed configuration. The expression for the cross-section coincides with that obtained through a classical treatment of the problem in the non-relativistic regime. In the frequency range where absorption is important, the cross-section is larger than the Thomson cross-section by several orders of magnitude, implying a strong coupling between radiation and magnetized plasma. The possible atrophysical implications of this process are briefly discussed; in particular, in a magnetized plasma the Eddington luminosity for synchrotron interaction can be much lower than the standard value.

Gliozzi, M.; Bodo, G.; Ghisellini, G.; Trussoni, E.

1996-06-01

344

Uncertainty Analysis for NRaD Radar Cross Section Measurements.  

National Technical Information Service (NTIS)

The Naval Command, Control and Ocean Surveillance Center RDT&E Division (NRaD) conducts Radar Cross Section (RCS) measurements on US naval ships and other targets. This document discusses the assessment of measurement uncertainty and follows general guide...

M. J. Prickett R. A. Bloomfield G. A. Kinzel R. C. Wittmann L. A. Muth

1997-01-01

345

Hadronic cross sections, elastic slope and physical bounds  

SciTech Connect

An almost model-independent parametrization for the ratio of the total hadronic cross section to elastic slope is discussed. Its applicability in studies of asymptotia and analyses of extensive air shower in cosmic-ray physics is also outlined.

Fagundes, D. A.; Menon, M. J. [Instituto de Fisica Gleb Wataghin, Universidade Estadual de Campinas, UNICAMP, 13083-859 Campinas SP (Brazil)

2013-03-25

346

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

347

Absolute two-photon excitation cross-sections in NO  

NASA Technical Reports Server (NTRS)

A technique has been developed which allows the determination of a two-photon absorption cross-section to be made relative to the Raman scattering cross-section in nitrogen. Spatial and temporal effects associated with the lasers are ratioed out to give a result independent of laser parameters. The necessary theory to extract a cross-section from the measured ratio of a Coherent Anti-Stokes Raman Scattering (CARS) signal in N2 to a four-wave mixing signal in NO has been developed. The technique has been demonstrated on the R(22) + S(12) (J-double-prime = 9 1/2) line in NO and a cross-section of (2.9 + or - 1.8) x 10 to the -49th (cm to the 4th power)-s was determined. This technique appears to be applicable to a number of other diatomic molecules.

Burris, J.; Mcgee, T.; Mcilrath, T.

1984-01-01

348

Evaluation of Electron Ionization Cross Sections for Carbon Fullerenes  

NASA Astrophysics Data System (ADS)

Recently, we have introduced a semi empirical formulation for the calculation of partial and total integral ionization cross sections for C60 and C70 in the energy range from ionization threshold to 1000 eV which yielded results which were in satisfactory agreement with available experimental and theoretical data. Subsequently, we extended and generalized the same revisited JK semi empirical formulation for the evaluation of partial integral ionization cross sections for C2 dimmer and C3 trimmer. The major input data required in the formulation is the oscillator strength which is taken from the statistical sum of individual carbon atoms. The results are found in satisfactory agreement with the only theoretical calculation based on the modified additive rule (MAR). In addition to the partial integral ionization cross sections, we have also evaluated the ionization rate coefficients using the calculated ionization cross sections and Maxwell-Boltzmann distribution for the electrons as a function of energy.

Pal, Satyendra; Kumar, Neeraj

2011-11-01

349

Radar Cross Sections of Standard and Complex Shape Targets.  

National Technical Information Service (NTIS)

The theoretical, analytical, and experimental results are described for radar cross sections (RCS) of different-shaped targets. Various techniques for predicting RCS are given, and RCS of finite standard targets are presented. Techniques used to predict t...

M. S. Sohel

1974-01-01

350

Giant dipole resonance parameters with uncertainties from photonuclear cross sections  

SciTech Connect

Updated values and corresponding uncertainties of isovector giant dipole resonance (IVGDR or GDR) model parameters are presented that are obtained by the least-squares fitting of theoretical photoabsorption cross sections to experimental data. The theoretical photoabsorption cross section is taken as a sum of the components corresponding to excitation of the GDR and quasideuteron contribution to the experimental photoabsorption cross section. The present compilation covers experimental data as of January 2010. - Highlights: {yields} Experimental {sigma} ({gamma}, abs) or a sum of partial cross sections are taken as input to the fitting. {yields} Data include contributions from photoproton reactions. {yields} Standard (SLO) or modified (SMLO) Lorentzian approaches are used for formulating GDR models. {yields} Spherical or axially deformed nuclear shapes are used in GDR least-squares fit. {yields} Values and uncertainties of the SLO and SMLO GDR model parameters are tabulated.

Plujko, V.A. [Taras Shevchenko National University, Kyiv (Ukraine); Institute for Nuclear Research, Kyiv (Ukraine); Capote, R., E-mail: R.CapoteNoy@iaea.org [NAPC-Nuclear Data Section, International Atomic Energy Agency, P.O. Box 100, A-1400,Vienna (Austria); Gorbachenko, O.M. [Taras Shevchenko National University, Kyiv (Ukraine)

2011-09-15

351

Line shape cross sections of HD immersed in He and H2 gas. I - Pressure broadening cross sections  

NASA Astrophysics Data System (ADS)

The results of two tests of the electronic potential energy surface of hydrogenlike systems are reported here, including the second virial coefficient of para hydrogen at low temperatures and HD-D2 elastic and inelastic differential scattering cross sections. Formulas are given for Dicke narrowing as well as for the line broadening and calculated shift cross sections. Close coupling calculations are performed for the R(0) and R(1) transitions of HD immersed in He and for the R(0) transition of HD immersed in H2. These cross sections are anticipated to be reliable at temperatures above 50 K.

Schaefer, Joachim; Monchick, Louis

1987-07-01

352

Relativistic Distorted-Wave Calculations of Electron Impact Excitation Cross Sections of BeLike C2+ Ions  

Microsoft Academic Search

A fully relativistic distorted-wave program is developed based on the Grasp92 and Ratip packages to calculate electron impact excitation (EIE) cross sections. As a first application of the program, the EIE cross sections of Be-like C2+ ions from the metastable 1s22s2p 3P to 1s22p2 3P excitation and the inner-shell excitations are calculated systematically. Meanwhile, the correlation effects of target states

Jun Jiang; Chen-Zhong Dong; Lu-You Xie; Jian-Guo Wang; Jun Yan; Fritzsche Stephan

2007-01-01

353

Electron-impact-excitation cross sections of hydrogenlike ions  

Microsoft Academic Search

Convergent close-coupling (CCC) and Coulomb-Born with exchange and normalization (CBE) methods are used to study electron-impact excitation of hydrogenlike ions. The nl-->n|IHl|IH cross sections demonstrate (i) good agreement between the CCC and CBE results, (ii) a scaling over ion nuclear charge z, (iii) a domination of the dipole (l|IH=l+\\/-1) contributions in total n-->n|IH cross sections, and (iv) significant effect of

Vladimir I. Fisher; Yuri V. Ralchenko; Vladimir A. Bernshtam; Alexander Goldgirsh; Yitzhak Maron; Leonid A. Vainshtein; Igor Bray; Helen Golten

1997-01-01

354

Electron-impact excitation cross sections of atomic silver  

Microsoft Academic Search

The method of extended crossed beams is used to measure excitation cross sections of atomic silver. The results, together\\u000a with theoretical data on the transition probabilities of AgI, are used to calculate the excitation cross sections of the energy\\u000a levels of the silver atom and the contribution of cascade population of states. It is found that the dependence of the

Yu. M. Smirnov

1999-01-01

355

Electron-impact-excitation cross sections of lithiumlike ions  

Microsoft Academic Search

We present an easy to use expression for cross sections of electron-impact-induced 1s2nl-->1s2n'l' excitation transitions with 2<=n<=n'<=4 in multiply charged ions of lithium isoelectronic sequence. This expression is based on our computations by convergent close-coupling (CCC) and Coulomb-Born with exchange and normalization (CBE) methods. We show scaling of the CCC and CBE cross sections with atomic number Z and use

V. I. Fisher; Yu. V. Ralchenko; V. A. Bernshtam; A. Goldgirsh; Y. Maron; L. A. Vainshtein; Igor Bray

1997-01-01

356

Asymptotic neutrino-nucleon cross section and saturation effects  

SciTech Connect

In this paper we present a simple analytic expression for the (spin-averaged) neutrino-nucleon cross section for ultrahigh energies at twist-2, obtained as the asymptotic limit of our previous findings. This expression gives values for the cross section in remarkable numerical agreement with the previous numerical evaluation in the energy region relevant for forthcoming neutrino experiments. Moreover, we discuss the role and the relevance of saturation and recombination effects in our approach, in comparison with other recent suggestions.

Fiore, R.; Papa, A. [Dipartimento di Fisica, Universita della Calabria, Istituto Nazionale di Fisica Nucleare, Gruppo collegato di Cosenza, I-87036 Arcavacata di Rende, Cosenza (Italy); Jenkovszky, L.L. [Bogolyubov Institute for Theoretical Physics, Academy of Sciences of Ukraine, UA-03143 Kiev (Ukraine); Kotikov, A.V. [Bogolyubov Laboratory of Theoretical Physics, Joint Institute for Nuclear Research, RU-141980 Dubna (Russian Federation); Paccanoni, F. [Dipartimento di Fisica, Universita di Padova, Istituto Nazionale di Fisica Nucleare, Sezione di Padova, via F. Marzolo 8, I-35131 Padova (Italy)

2006-03-01

357

Total photoproduction cross section measurement at HERA energies  

Microsoft Academic Search

We present first results on the total photoproduction cross section measurement with the H1 detector at HERA. The data were extracted from low Q2 collisions of 26.7 GeV electrons with 820 GeV protons. The gammap total cross section has been measured by two independent methods in the gammap center of mass energy range from 90 to 290 GeV. For an

T. Ahmed; V. Andreev; B. Andrieu; M. Arpagaus; A. Babaev; H. Bärwolff; J. Bán; P. Baranov; E. Barrelet; W. Bartel; U. Bassler; G. A. Beck; H. P. Beck; H.-J. Behrend; A. Belousov; Ch. Berger; H. Bergstein; G. Bernardi; R. Bernet; U. Berthon; G. Bertrand-Coremans; M. Besançon; P. Biddulph; E. Binder; J. C. Bizot; V. Blobel; K. Borras; P. C. Bosetti; V. Boudry; C. Bourdarios; F. Brasse; U. Braun; W. Braunschweig; V. Brisson; D. Bruncko; 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; J. Cvach; J. B. Dainton; M. Danilov; A. W. E. Dann; W. D. Dau; M. David; E. Deffur; B. Delcourt; L. del Buono; M. Devel; A. de Roeck; P. Dingus; C. Dollfus; J. D. Dowell; H. B. Dreis; A. Drescher; J. Duboc; D. Düllmann; O. Dünger; H. Duhm; M. Eberle; J. Ebert; T. R. Ebert; G. Eckerlin; V. Efremenko; S. Egli; S. Eichenberger; R. Eichler; F. Eisele; E. Eisenhandler; N. N. Ellis; R. J. Ellison; E. Elsen; M. Erdmann; E. Evrard; L. Favart; A. Fedotov; D. Feeken; R. Felst; J. Feltesse; Y. Feng; I. F. Fensome; J. Ferencei; F. Ferrarotto; W. Flauger; M. Fleischer; P. S. Flower; G. Flügge; A. Fomenko; B. Fominykh; M. Forbush; J. Formánek; J. M. Foster; G. Franke; E. Fretwurst; P. Fuhrmann; E. Gabathuler; K. Gamerdinger; J. Garvey; J. Gayler; A. Gellrich; M. Gennis; U. Gensch; H. Genzel; R. Gerhards; D. Gillespie; L. Godfrey; U. Goerlach; L. Goerlich; M. Goldberg; A. M. Goodall; I. Gorelov; P. Goritchev; C. Grab; H. Grässler; T. Greenshaw; H. Greif; G. Grindhammer; C. Gruber; J. Haack; D. Haidt; L. Hajduk; O. Hamon; D. Handschuh; E. M. Hanlon; M. Hapke; J. Harjes; P. Hartz; R. Haydar; W. J. Haynes; J. Heatherington; V. Hedberg; R. Hedgecock; G. Heinzelmann; R. C. W. Henderson; H. Henschel; R. Herma; I. Herynek; W. Hildesheim; P. Hill; C. D. Hilton; J. Hladký; K. C. Hoeger; Ph. Huet; H. Hufnagel; N. Huot; M. Ibbotson; M. A. Jabiol; A. Jacholkowska; C. Jacobsson; M. Jaffre; L. Jönsson; K. Johannsen; D. P. Johnson; L. Johnson; H. Jung; P. I. P. Kalmus; S. Kasarian; R. Kaschowitz; P. Kasselmann; U. Kathage; H. H. Kaufmann; I. R. Kenyon; S. Kermiche; C. Kiesling; M. Klein; C. Kleinwort; G. Knies; 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; J. P. Kubenka; H. Küster; M. Kuhlen; T. Kurça; J. Kurzhöfer; B. Kuznik; R. Lander; M. P. J. Landon; R. Langkau; P. Lanius; J. F. Laporte; A. Lebedev; A. Leuschner; C. Leverenz; D. Levin; S. Levonian; Ch. Ley; A. Lindner; G. Lindström; P. Loch; H. Lohmander; G. C. Lopez; D. Lüers; N. Magnussen; E. Malinovski; S. Mani; P. Marage; J. Marks; 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; T. Merz; C. A. Meyer; H. Meyer; J. Meyer; S. Mikocki; V. Milone; E. Monnier; F. Moreau; J. Moreels; J. V. Morris; J. M. Morton; K. Müller; P. Murín; S. A. Murray; V. Nagovizin; B. Naroska; Th. Naumann; D. Newton; H. K. Nguyen; F. Niebergall; R. Nisius; G. Nowak; G. W. Noyes; M. Nyberg; H. Oberlack; H. Obrock; J. E. Olsson; S. Orenstein; F. Ould-Saada; C. Pascaud; G. D. Patel; E. Peppel; S. Peters; H. T. Phillips; J. P. Phillips; Ch. Pichler; W. Pilgram; D. Pitzl; R. Prosi; F. Raupach; K. Rauschnabel; P. Reimer; P. Ribarics; V. Riech; J. Riedlberger; M. Rietz; S. M. Robertson; P. Robmann; R. Roosen; A. Rostovtsev; C. Royon; M. Rudowicz; M. Ruffer; S. Rusakov; K. Rybicki; E. Ryseck; J. Sacton; N. Sahlmann; E. Sanchez; D. P. C. Sankey; M. Savitsky; P. Schacht; P. Schleper; W. von Schlippe; C. Schmidt; D. Schmidt; W. Schmitz; V. Schröder; M. Schulz; A. Schwind; W. Scobel; U. Seehausen; R. Sell; M. Seman; A. Semenov; V. Shekelyan; I. Sheviakov; H. Shooshtari; G. Siegmon; U. Siewert; Y. Sirois; I. O. Skillicorn; P. Smirnov; J. R. Smith; L. Smolik; Y. Soloviev; H. Spitzer; P. Staroba; M. Steenbock; P. Steffen; R. Steinberg; H. Steiner; B. Stella; K. Stephens; J. Stier; J. Strachota; U. Straumann; W. Struczinski; J. P. Sutton; R. E. Taylor; G. Thompson; R. J. Thompson; I. Tichomirov; C. Trenkel; P. Truöl; V. Tchernyshov; J. Turnau; J. Tutas; L. Urban; A. Usik; S. Valkar; A. Valkarova; C. Vallee; P. van Esch; A. Vartapetian; Y. Vazdik; M. Vecko; P. Verrecchia; R. Vick; G. Villet; E. Vogel; K. Wacker; I. W. Walker; A. Walther; G. Weber; D. Wegener; A. Wegner; H. P. Wellisch; S. Willard; M. Winde; G.-G. Winter; Th. Wolff; L. A. Womersley; A. E. Wright; N. Wulff; T. P. Yiou; J. Áçek; P. Závada; C. Zeitnitz; H. Ziaeepour; M. Zimmer; W. Zimmermann; F. Zomer

1993-01-01

358

The nucleon-nucleon collision profile and cross section fluctuations  

NASA Astrophysics Data System (ADS)

The nucleon-nucleon collision profile, being the basic entity of the wounded nucleon model, is usually adopted in the form of a hard sphere or Gaussian shape. We suggest that the cross section fluctuations given by the gamma distribution leads to the profile function which smoothly ranges between both limiting forms. Examples demonstrating the sensitivity of the profile function on cross section fluctuations are discussed.

Rybczy?ski, Maciej; W?odarczyk, Zbigniew

2014-01-01

359

Electron differential cross section for H--He stripping collisions  

NASA Astrophysics Data System (ADS)

The Born approximation and a closure technique are employed to obtain the single and double differential cross sections for the ejected electron produced by electron detachment of H- ions in collisions with He. Comparison is made to the recent measurements of Menendez and Duncan at 0.5 MeV. The theoretical results show that the experimentally observed structure in the double differential cross sections in the forward direction can be explained in terms of single-electron-loss processes alone.

Franz, M. R.; Wright, L. A.; Genoni, T. C.

1981-08-01

360

Absorption cross sections of the ClO dimer  

NASA Technical Reports Server (NTRS)

The absorption cross sections of the ClO dimer, ClOOCl, are important to the photochemistry of ozone depletion in the Antarctic. In this work, new measurements were made of the dimer cross sections at 195 K. the results yield somewhat lower values in the long wavelength region, compared to those currently recommended in the NASA data evaluation (JPL 94-26). The corresponding solar photodissociation rates in the Antarctic are reduced by about 40%.

Huder, K. J.; DeMore, W. B.

1995-01-01

361

Nuclear deformation and sub-barrier fusion cross sections  

Microsoft Academic Search

We present calculations of sub-barrier fusion cross sections for spherical projectiles and deformed targets. For a given spherical-projectile and deformed-target combination we calculate exactly the sum of the Coulomb and nuclear potentials. There are no free parameters in the calculations, except for a simple energy shift of the calculated cross sections. The shapes of the target nuclei are taken from

Akira Iwamoto; Peter Möller

1996-01-01

362

Absolute measurement of neutron cross sections. Progress report  

SciTech Connect

The procedures and status of the absolute measurement of the neutron capture cross sections for /sup 115/In and /sup 232/Th are described. Work on the /sup 239/Pu fission fragment anisotropy and absolute measurement of the fast neutron fission cross section for /sup 233/U are briefly described. Progress in establishing the 14 MeV neutron measurements at the facility are discussed. (WHK)

Knoll, G.F.

1981-02-19

363

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)] [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)] [Dipartimento di Fisica, Universita di Catania, Corso Italia 57, I-95129 Catania (Italy)

1997-06-01

364

Inclusive jet differential cross sections in photoproduction at HERA  

Microsoft Academic Search

Inclusive jet differential cross sections for the reaction ep ? jet + X at Q2 below 4 GeV2 have been measured with the ZEUS detector at HERA using an integrated luminosity of 0.55 pb?1. These cross sections are given in the kinematic region 0.2 < y < 0.85, for jet pseudorapidities in the ep-laboratory range ?1 < ?jet < 2

S. Bhadra; W. R. Frisken; K. M. Furutani; B. Musgrave; J. Repond; J. Schlereth; R. Stanek; R. L. Talaga; J. Thron; F. Arzarello; R. Ayad; G. Bari; M. Basile; L. Bellagamba; D. Boscherini; A. Bruni; G. Bruni; P. Bruni; G. Cara Romeo; G. Castellini; M. Chiarini; L. Cifarelli; F. Cindolo; F. Ciralli; A. Contin; S. D'Auria; F. Frasconi; I. Gialas; P. Giusti; G. Iacobucci; G. Laurenti; G. Levi; A. Margotti; T. Massam; R. Nania; C. Nemoz; F. Palmonari; A. Polini; G. Sartorelli; R. Timellini; Y. Zamora Garcia; A. Zichichi; A. Bargende; J. Crittenden; K. Desch; B. Diekmann; T. Doeker; M. Eckart; L. Feld; A. Frey; M. Geerts; G. Geitz; M. Grothe; H. Hartmann; D. Haun; K. Heinloth; E. Hilger; H.-P. Jakob; U. F. Katz; S. M. Mari; A. Mass; S. Mengel; J. Mollen; E. Paul; Ch. Rembser; R. Schattevoy; J.-L. Schneider; D. Schramm; J. Stamm; R. Wedemeyer; S. Campbell-Robson; A. Cassidy; N. Dyce; B. Foster; S. George; R. Gilmore; G. P. Heath; H. F. Heath; T. J. Llewellyn; C. J. S. Morgado; D. J. P. Norman; J. A. O'Mara; R. J. Tapper; S. S. Wilson; R. Yoshida; R. R. Rau; M. Arneodo; L. Iannotti; M. Schioppa; G. Susinno; A. Bernstein; A. Caldwell; J. A. Parsons; S. Ritz; F. Sciulli; P. B. Straub; L. Wai; S. Yang; P. Borzemski; J. Chwastowski; A. Eskreys; K. Piotrzkowski; M. Zachara; L. Zawiejski; L. Adamczyk; B. Bednarek; K. Eskreys; K. Jelen; D. Kisielewska; T. Kowalski; E. Rulikowska-Zarebska; L. Suszycki; J. Zajac; T. Kedzierski; A. Kotanski; M. Przybycien; L. A. T. Bauerdick; U. Behrens; J. K. Bienlein; S. Böttcher; C. Coldewey; G. Drews; M. Flasinski; D. J. Gilkinson; P. Göttlicher; B. Gutjahr; T. Haas; W. Hain; D. Hasell; H. Heßling; H. Hultschig; Y. Iga; P. Joos; M. Kasemann; R. Klanner; W. Koch; L. Köpke; U. Kötz; H. Kowalski; W. Kröger; J. Krüger; J. Labs; A. Ladage; B. Löhr; M. Löwe; D. Lüke; O. Manczak; J. S. T. Ng; S. Nickel; D. Notz; K. Ohrenberg; M. Roco; M. Rohde; J. Roldán; U. Schneekloth; W. Schulz; F. Selonke; E. Stiliaris; T. Voß; D. Westphal; G. Wolf; C. Youngman; H. J. Grabosch; A. Leich; A. Meyer; C. Rethfeldt; S. Schlenstedt; G. Barbagli; P. Pelfer; G. Anzivino; G. Maccarrone; S. de Pasquale; S. Qian; L. Votano; A. Bamberger; A. Freidhof; T. Poser; S. Söldner-Rembold; J. Schroeder; G. Theisen; T. Trefzger; N. H. Brook; P. J. Bussey; A. T. Doyle; I. Fleck; V. A. Jamieson; D. H. Saxon; M. L. Utley; A. S. Wilson; A. Dannemann; U. Holm; D. Horstmann; H. Kammerlocher; B. Krebs; T. Neumann; R. Sinkus; K. Wick; E. Badura; B. D. Burow; A. Fürtjes; L. Hagge; E. Lohrmann; J. Mainusch; J. Milewski; M. Nakahata; N. Pavel; G. Poelz; W. Schott; J. Terron; F. Zetsche; T. C. Bacon; R. Beuselinck; I. Butterworth; E. Gallo; V. L. Harris; B. H. Hung; K. R. Long; D. B. Miller; P. P. O. Morawitz; A. Prinias; J. K. Sedgbeer; A. F. Whitfield; U. Mallik; E. McCliment; M. Z. Wang; S. M. Wang; J. T. Wu; Y. Zhang; P. Cloth; D. Filges; S. H. An; S. M. Hong; S. W. Nam; S. K. Park; M. H. Suh; S. H. Yon; R. Imlay; S. Kartik; H.-J. Kim; R. R. McNeil; W. Metcalf; V. K. Nadendla; F. Barreiro; G. Cases; R. Graciani; J. M. Hernández; L. Hervás; L. Labarga; J. del Peso; J. Puga; J. F. de Trocóniz; F. Ikraiam; J. K. Mayer; G. R. Smith; F. Corriveau; D. S. Hanna; J. Hartmann; L. W. Hung; J. N. Lim; C. G. Matthews; P. M. Patel; L. E. Sinclair; D. G. Stairs; M. St. Laurent; R. Ullmann; G. Zacek; V. Bashkirov; B. A. Dolgoshein; A. Stifutkin; G. L. Bashindzhagyan; P. F. Ermolov; L. K. Gladilin; Y. A. Golubkov; V. D. Kobrin; V. A. Kuzmin; A. S. Proskuryakov; A. A. Savin; L. M. Shcheglova; A. N. Solomin; N. P. Zotov; S. Bentvelsen; M. Botje; F. Chlebana; A. Dake; J. Engelen; P. de Jong; M. de Kamps; P. Kooijman; A. Kruse; V. O'dell; A. Tenner; H. Tiecke; W. Verkerke; M. Vreeswijk; L. Wiggers; E. de Wolf; R. van Woudenberg; D. Acosta; B. Bylsma; L. S. Durkin; K. Honscheid; C. Li; T. Y. Ling; K. W. McLean; W. N. Murray; I. H. Park; T. A. Romanowski; R. Seidlein; D. S. Bailey; G. A. Blair; A. Byrne; R. J. Cashmore; A. M. Cooper-Sarkar; D. Daniels; R. C. E. Devenish; N. Harnew; M. Lancaster; P. E. Luffman; L. Lindemann; J. McFall; C. Nath; A. Quadt; H. Uijterwaal; R. Walczak; F. F. Wilson; T. Yip; G. Abbiendi; A. Bertolin; R. Brugnera; R. Carlin; F. dal Corso; M. de Giorgi; U. Dosselli; S. Limentani; M. Morandin; M. Posocco; L. Stanco; R. Stroili; C. Voci; J. Bulmahn; J. M. Butterworth; R. G. Feild; B. Y. Oh; J. J. Whitmore; G. D'Agostini; M. Iori; G. Marini; M. Mattioli; A. Nigro; E. Tassi; J. C. Hart; N. A. McCubbin; K. Prytz; T. P. Shah; T. L. Short; E. Barberis; N. Cartiglia; T. Dubbs; C. Heusch; M. van Hook; B. Hubbard; W. Lockman; J. T. Rahn; H. F.-W. Sadrozinski; A. Seiden; J. Biltzinger; R. J. Seifert; A. H. Walenta; G. Zech; H. Abramowicz; G. Briskin; S. Dagan; A. Levy; T. Hasegawa; M. Hazumi; T. Ishii; M. Kuze; S. Mine; Y. Nagasawa; T. Nagira; M. Nakao; I. Suzuki; K. Tokushuku; S. Yamada

1995-01-01

365

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

366

A shelf in the ''subthreshold'' photofission cross section  

Microsoft Academic Search

The influence of a double-humped fission barrier on the photofission ; cross section far below the top of the barrier is considered. In the region ; about 2 MeV below the top of the outer barrier and at a cross section in the ; region of 10⁻⁹⁻⁻¹°sup -6$ b the photofission is expected to become almost ; entirely isomeric or

Charles Bowman

1975-01-01

367

Thermal Neutron Capture Cross Sections Of The Palladium Isotopes  

Microsoft Academic Search

We have measured precise thermal neutron capture gamma-ray cross sections cry for all stable Palladium isotopes with the guided thermal neutron beam from the Budapest Reactor. The data were compared with other data from the literature and have been evaluated into the Evaluated Gamma-ray Activation File (EGAF). Total radiative neutron capture cross-sections sigmagamma can be deduced from the sum of

R. B. Firestone; M. Krtiáka; D. P. McNabb; B. Sleaford; U. Agvaanluvsan; T. Belgya; Zs. Révay

2006-01-01

368

Thermal Neutron Capture Cross Sections of The Palladium Isotopes  

Microsoft Academic Search

We have measured precise thermal neutron capture γ-ray cross sections Ï{sub γ} for all stable Palladium isotopes with the guided thermal neutron beam from the Budapest Reactor. The data were compared with other data from the literature and have been evaluated into the Evaluated Gamma-ray Activation File (EGAF)[1]. Total radiative neutron capture cross-sections Ïâ can be deduced from the sum

R B Firestone; M Krticka; D P McNabb; B Sleaford; U Agvaanluvsan; T Belgya; Z Revay

2005-01-01

369

Cross section of hadron production in gammagamma collisions at LEP  

Microsoft Academic Search

The reaction e+e- -> e+e-gamma*gamma* -> e+e-hadrons is analysed using data collected by the L3 detector during the LEP runs at &surd;s= 130-140 GeV and &surd;s= 161 GeV. The cross sections sigma(e+e- -> e+e-hadrons) and sigma(gammagamma -> hadrons) are measured in the interval 5 <= Wgammagamma hadrons) cross section is consistent with the universal Regge behaviour of total hadronic cross

M. Acciarri; O. Adriani; M. Aguilar-Benitez; S. Ahlen; J. Alcaraz; G. Alemanni; J. Allaby; A. Aloisio; G. Alverson; M. G. Alviggi; G. Ambrosi; H. Anderhub; V. P. Andreev; T. Angelescu; F. Anselmo; A. Arefiev; T. Azemoon; T. Aziz; P. Bagnaia; L. Baksay; S. Banerjee; K. Banicz; A. Barczyk; R. Barillère; L. Barone; P. Bartalini; A. Baschirotto; M. Basile; R. Battiston; A. Bay; F. Becattini; U. Becker; F. Behner; J. Berdugo; P. Berges; B. Bertucci; B. L. Betev; S. Bhattacharya; M. Biasini; A. Biland; G. M. Bilei; J. J. Blaising; S. C. Blyth; G. J. Bobbink; R. Bock; A. Böhm; L. Boldizsar; B. Borgia; D. Bourilkov; M. Bourquin; S. Braccini; J. G. Branson; V. Brigljevic; I. C. Brock; A. Buffini; A. Buijs; J. D. Burger; W. J. Burger; J. Busenitz; A. Button; X. D. Cai; M. Campanelli; M. Capell; G. Cara Romeo; 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; S. V. Chekanov; M. Chemarin; A. Chen; G. Chen; H. F. Chen; H. S. Chen; X. Chereau; G. Chiefari; C. Y. Chien; L. Cifarelli; F. Cindolo; C. Civinini; I. Clare; R. Clare; H. O. Cohn; G. Coignet; A. P. Colijn; N. Colino; V. Commichau; S. Costantini; F. Cotorobai; B. de La Cruz; A. Csilling; T. S. Dai; R. D'Alessandro; R. de Asmundis; A. Degré; K. Deiters; D. della Volpe; P. Denes; F. Denotaristefani; D. Dibitonto; M. Diemoz; D. van Dierendonck; F. di Lodovico; C. Dionisi; M. Dittmar; A. Dominguez; A. Doria; M. T. Dova; D. Duchesneau; P. Duinker; I. Duran; S. Dutta; S. Easo; Yu. Efremenko; H. El Mamouni; A. Engler; F. J. Eppling; F. C. Erné; J. P. Ernenwein; P. Extermann; M. Fabre; R. Faccini; S. Falciano; A. Favara; J. Fay; O. Fedin; M. Felcini; B. Fenyi; T. Ferguson; F. Ferroni; H. Fesefeldt; E. Fiandrini; J. H. Field; F. Filthaut; P. H. Fisher; I. Fisk; G. Forconi; L. Fredj; K. Freudenreich; C. Furetta; Yu. Galaktionov; S. N. Ganguli; P. Garcia-Abia; S. S. Gau; S. Gentile; N. Gheordanescu; S. Giagu; S. Goldfarb; J. Goldstein; Z. F. Gong; A. Gougas; G. Gratta; M. W. Gruenewald; V. K. Gupta; A. Gurtu; L. J. Gutay; B. Hartmann; A. Hasan; D. Hatzifotiadou; T. Hebbeker; A. Hervé; W. C. van Hoek; H. Hofer; S. J. Hong; H. Hoorani; S. R. Hou; G. Hu; V. Innocente; K. Jenkes; B. N. Jin; L. W. Jones; P. de Jong; I. Josa-Mutuberria; A. Kasser; R. A. Khan; D. Kamrad; Yu. Kamyshkov; J. S. Kapustinsky; Y. Karyotakis; M. Kaur; M. N. Kienzle-Focacci; D. Kim; J. K. Kim; S. C. Kim; Y. G. Kim; W. W. Kinnison; A. Kirkby; D. Kirkby; J. Kirkby; D. Kiss; W. Kittel; A. Klimentov; A. C. König; A. Kopp; I. Korolko; V. Koutsenko; R. W. Kraemer; W. Krenz; A. Kunin; P. Ladron de Guevara; I. Laktineh; G. Landi; C. Lapoint; K. Lassila-Perini; P. Laurikainen; M. Lebeau; A. Lebedev; P. Lebrun; P. Lecomte; P. Lecoq; P. Le Coultre; J. M. Le Goff; R. Leiste; E. Leonardi; P. Levtchenko; C. Li; C. H. Lin; W. T. Lin; F. L. Linde; L. Lista; Z. A. Liu; W. Lohmann; E. Longo; W. Lu; Y. S. Lu; K. Lübelsmeyer; C. Luci; D. Luckey; L. Luminari; W. Lustermann; W. G. Ma; M. Maity; G. Majumder; L. Malgeri; A. Malinin; C. Maña; D. Mangeol; S. Mangla; P. Marchesini; A. Marin; J. P. Martin; F. Marzano; G. G. G. Massaro; D. McNally; R. R. McNeil; S. Mele; L. Merola; M. Meschini; W. J. Metzger; M. von der Mey; Y. Mi; A. Mihul; A. J. W. van Mil; G. Mirabelli; J. Mnich; P. Molnar; B. Monteleoni; R. Moore; S. Morganti; T. Moulik; R. Mount; S. Müller; F. Muheim; A. J. M. Muijs; S. Nahn; M. Napolitano; F. Nessi-Tedaldi; H. Newman; T. Niessen; A. Nippe; A. Nisati; H. Nowak; Y. D. Oh; H. Opitz; G. Organtini; R. Ostonen; C. Palomares; D. Pandoulas; S. Paoletti; P. Paolucci; H. K. Park; I. H. Park; G. Pascale; G. Passaleva; S. Patricelli; T. Paul; M. Pauluzzi; C. Paus; F. Pauss; D. Peach; Y. J. Pei; S. Pensotti; D. Perret-Gallix; B. Petersen; S. Petrak; A. Pevsner; D. Piccolo; M. Pieri; J. C. Pinto; P. A. Piroué; E. Pistolesi; V. Plyaskin; M. Pohl; V. Pojidaev; H. Postema; N. Produit; D. Prokofiev; G. Rahal-Callot; N. Raja; P. G. Rancoita; M. Rattaggi; G. Raven; P. Razis; K. Read; D. Ren; M. Rescigno; S. Reucroft; T. van Rhee; S. Riemann; K. Riles; A. Robohm; J. Rodin; B. P. Roe; L. Romero; S. Rosier-Lees; Ph. Rosselet; W. van Rossum; S. Roth; J. A. Rubio; D. Ruschmeier; H. Rykaczewski; J. Salicio; E. Sanchez; M. P. Sanders; M. E. Sarakinos; S. Sarkar; M. Sassowsky; C. Schäfer; V. Schegelsky; S. Schmidt-Kaerst; D. Schmitz; P. Schmitz; N. Scholz; H. Schopper; D. J. Schotanus; J. Schwenke; G. Schwering; C. Sciacca; D. Sciarrino; L. Servoli; S. Shevchenko; N. Shivarov; V. Shoutko; J. Shukla; E. Shumilov; A. Shvorob; T. Siedenburg; D. Son; A. Sopczak; B. Smith; P. Spillantini; M. Steuer; D. P. Stickland; A. Stone; H. Stone; B. Stoyanov; A. Straessner; K. Strauch; K. Sudhakar; G. Sultanov; L. Z. Sun; G. F. Susinno; H. Suter; J. D. Swain; X. W. Tang; L. Tauscher; L. Taylor

1997-01-01

370

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

371

Covariances for neutron cross sections calculated using a regional model based on local-model fits to experimental data  

SciTech Connect

We suggest a procedure for estimating uncertainties in neutron cross sections calculated with a nuclear model descriptive of a specific mass region. It applies standard error propagation techniques, using a model-parameter covariance matrix. Generally, available codes do not generate covariance information in conjunction with their fitting algorithms. Therefore, we resort to estimating a relative covariance matrix a posteriori from a statistical examination of the scatter of elemental parameter values about the regional representation. We numerically demonstrate our method by considering an optical-statistical model analysis of a body of total and elastic scattering data for the light fission-fragment mass region. In this example, strong uncertainty correlations emerge and they conspire to reduce estimated errors to some 50% of those obtained from a naive uncorrelated summation in quadrature. 37 references.

Smith, D.L.; Guenther, P.T.

1983-11-01

372

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

2012-04-01

373

Asymptotic behaviour of pion-pion total cross-sections  

NASA Astrophysics Data System (ADS)

We derive a sum rule which shows that the Froissart-Martin bound for the asymptotic behaviour of the ?? total cross sections at high energies, if modulated by the Lukaszuk-Martin coefficient of the leading log2 s behaviour, cannot be an optimal bound in QCD. We next compute the total cross sections for ? + ? -, ? ± ? 0 and ? 0 ? 0 scattering within the framework of the constituent chiral quark model (C ?QM) in the limit of a large number of colours N c and discuss their asymptotic behaviours. The same ?? cross sections are also discussed within the general framework of Large- N c QCD and we show that it is possible to make an Ansatz for the isospin I = 1 and I = 0 spectrum which satisfy the Froissart-Martin bound with coefficients which, contrary to the Lukaszuk-Martin coefficient, are not singular in the chiral limit and have the correct Large- N c counting. We finally propose a simple phenomenological model which matches the low energy behaviours of the cross section predicted by the C ?QM with the high energy behaviour predicted by the Large- N c Ansatz. The magnitude of these cross sections at very high energies is of the order of those observed for the pp and scattering total cross sections.

Greynat, David; de Rafael, Eduardo; Vulvert, Grégory

2014-03-01

374

Mental visualization of objects from cross-sectional images  

PubMed Central

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.

Wu, Bing; Klatzky, Roberta L.; Stetten, George D.

2011-01-01

375

Minimizing the statistical error in capture cross-section measurements  

NASA Astrophysics Data System (ADS)

Measurements of the neutron capture cross-section are performed by measurement of the capture rate of a sample placed in a neutron beam. The capture rate is measured by surrounding the sample with gamma-ray detectors. The capture rate is corrected for background and divided by the rate of neutrons incident on the sample in order to obtain the capture yield. The neutron capture cross-section can be obtained from the capture yield if additional information such as the total or scattering cross-section is known. An error analysis was performed on the measured capture cross-section. The error was minimized with respect to the experimental time split of the capture, background and incident neutron rates and also with respect to the sample thickness. These calculations are useful for the planning of an efficient capture cross-section experiment. The derived equations are compared to experimental data and show excellent agreement. This type of error analysis and minimization is also valid for other types of partial cross-section measurements such as fission and scattering which have similar expressions for the measured yield.

Danon, Yaron; Block, Robert C.

2005-06-01

376

Determining neutron capture cross sections via the surrogate reaction technique  

SciTech Connect

Indirect methods play an important role in the determination of nuclear reaction cross sections that are hard to measure directly. In this paper we investigate the feasibility of using the so-called surrogate method to extract neutron capture cross sections for low-energy compound-nuclear reactions in spherical and near-spherical nuclei. We present the surrogate method and develop a statistical nuclear reaction simulation to explore different approaches to utilizing surrogate reaction data. We assess the success of each approach by comparing the extracted cross sections with a predetermined benchmark. In particular, we employ regional systematics of nuclear properties in the 34{<=}Z{<=}46 region to calculate (n,{gamma}) cross sections for a series of Zr isotopes and to simulate a surrogate experiment and the extraction of the desired cross section. We identify one particular approach that may provide very useful estimates of the cross section, and we discuss some of the limitations of the method. General recommendations for future (surrogate) experiments are also given.

Forssen, C. [Fundamental Physics, Chalmers University of Technology, SE-41296 Goeteborg (Sweden); Lawrence Livermore National Laboratory, P.O. Box 808, L-414, Livermore, California 94551 (United States); Dietrich, F. S.; Escher, J.; Hoffman, R. D.; Kelley, K. [Lawrence Livermore National Laboratory, P.O. Box 808, L-414, Livermore, California 94551 (United States)

2007-05-15

377

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

378

A genetic algorithm to reduce stream channel cross section data  

USGS Publications Warehouse

A genetic algorithm (GA) was used to reduce cross section data for a hypothetical example consisting of 41 data points and for 10 cross sections on the Kootenai River. The number of data points for the Kootenai River cross sections ranged from about 500 to more than 2,500. The GA was applied to reduce the number of data points to a manageable dataset because most models and other software require fewer than 100 data points for management, manipulation, and analysis. Results indicated that the program successfully reduced the data. Fitness values from the genetic algorithm were lower (better) than those in a previous study that used standard procedures of reducing the cross section data. On average, fitnesses were 29 percent lower, and several were about 50 percent lower. Results also showed that cross sections produced by the genetic algorithm were representative of the original section and that near-optimal results could be obtained in a single run, even for large problems. Other data also can be reduced in a method similar to that for cross section data.

Berenbrock, C.

2006-01-01

379

Prevalence of child sexual abuse among adolescents in Geneva: results of a cross sectional survey  

Microsoft Academic Search

AbstractObjective: To measure the cumulative prevalence of child sexual abuse in a representative sample of the adolescent population of Geneva.Design: Cross sectional survey with an anonymous self administered questionnaire centred on a factual description of sexual activities.Setting: 68 classes (17 schools) randomly selected from the 201 ninth grade classes of the public school system in Geneva.Subjects: 1193 adolescents aged 13-17

Daniel S. Halperin; Paul Bouvier; Philip D Jaffe; Roger-luc. Mounoud; Claus H. Pawlak; Jerome. Laederack; Helene Rey Wicky; Florence Astie

1996-01-01

380

Preliminary geostatistical modeling of thermal conductivity for a cross section of Yucca Mountain, Nevada  

Microsoft Academic Search

Two-dimensional, heterogeneous, spatially correlated models of thermal conductivity and bulk density have been created for a representative, east-west cross section of Yucca Mountain, Nevada, using geostatistical simulation. The thermal conductivity models are derived from spatially correlated, surrogate material-property models of porosity, through a multiple linear-regression equation, which expresses thermal conductivity as a function of porosity and initial temperature and saturation.

Rautman

1995-01-01

381

Sensitivity of the Reaction Cross Section Calculation in the Glauber Theory Framework to the Parameters of Random Number Generation  

NASA Astrophysics Data System (ADS)

To extract the nuclear size information, the experimentally measured interaction cross-section is compared to cross-sections calculated in the framework of Glauber theory or in its various approximations. These calculations are usually performed using a Monte Carlo technique. In the presented paper, we discuss the sensitivity of the reaction and interaction cross sections' calculation to the parameters of the Metropolis-Hasting algorithm which is used to produce nucleon coordinates distributed according to the chosen nuclear density distribution. We evaluate generated sequence of the random nucleon coordinates using lag-1 autocorrelation, correlation of multiple data sets, and running first and second moments. We show that an non-optimal Metropolis-Hasting proposal distribution increases uncertainty of the cross section calculation. The obtained dependence of the accuracy of the determined nuclear density parameters on the various statistical diagnostics of the Metropolis-Hasting for the various types of nuclear density distributions is also discussed.

Wilson, John

2011-10-01

382

Activation energy and capture cross section of majority carrier traps in Zn doped InP  

NASA Technical Reports Server (NTRS)

Schottky barrier diodes were fabricated on Zn doped InP Wafers. The diodes were radiation damaged with 2 MeV protons to a dose of 2 x 10(exp 12)cm(sup -2). The damage was analyzed by DLTS (deep level transient spectroscopy) using the double correlation technique. Capture cross sections were measured directly. Two major defects were observed in the DLTS spectra. The first defect, was H4 at Ev + 0.29 eV, with capture cross section 1.1 x 10(exp -17)cm(sup 2). The second defect, was H5 at Ev + 0.53 eV. Its capture cross section varied with temperature as described by the relationship sigma = sigma(sub 0) exp(delta(E)/kT) where sigma(sub 0) = 1.3 x 10(exp -19)cm(sup 2) and delta(E) = .08 eV. This relationship yields a sigma of 5.9 x 10(exp -21)cm(sup 2) at room temperature. The surprisingly small capture cross section of H5 and its temperature dependence are discussed in terms of the multiphonon emission process for carrier capture at the defect. The advantages of the improved experimental techniques used are also discussed.

Rybicki, George; Williams, Wendell

1993-01-01

383

243Am neutron-induced fission cross section in the fast neutron energy range  

NASA Astrophysics Data System (ADS)

The existing evaluations of the 243Am neutron-induced fission cross section have been questioned by recent measurements performed at the GNEISS facility. In the neutron energy range from 1 to 6 MeV, the GNEISS data present deviations of more than 15% with respect to the evaluations. In order to solve this problem, we have measured this cross section in reference to three different standard cross sections. The first standard reaction used corresponds to the neutron on proton elastic scattering cross section, which is known with a precision better than 0.5% over a wide neutron-energy range of 1 meV to 20 MeV. The other two experiments were conducted in reference to the 235U(n, f) and 238U(n, f) reactions. The comparison between these three standard reactions ensures that systematic parameters have been correctly evaluated. Moreover, a sensitivity analysis of parameters and correlations of parameters is described and a complete variance-covariance matrix of the measurements is presented and discussed.

Kessedjian, G.; Barreau, G.; Aïche, M.; Jurado, B.; Bidaud, A.; Czajkowski, S.; Dassié, D.; Haas, B.; Mathieu, L.; Tassan-Got, L.; Wilson, J. N.; Hambsch, F.-J.; Oberstedt, S.; AlMahamid, I.; Floyd, J.; Lukens, W.; Shuh, D.

2012-04-01

384

Measurements of pion single charge exchange cross sections in deuterium  

SciTech Connect

Cross sections for the d({pi}{sup {minus}},{pi}{sup 0})nn reaction at incident pion energies of 164, 263, and 371 MeV have been measured. One crate of the LAMPF Neutral Meson Spectrometer, composed of 60 CsI crystals, was used to detect both photons from the {pi}{sup 0} decay. The acceptance of the detector was obtained by comparing measured p({pi}{sup {minus}}, {pi}{sup 0})n yields to the known cross sections. No previous measurement of single charge exchange cross sections for deuterim exists between 164 MeV and 500 MeV. An impulse approximation calcuation including a realistic nucleon momentum distribution describes the energy spectra in the doubly differential cross section well. The low energy tail deviating from the calculation can be attributed to multiple-scattering effects. A Faddeev calculation at 164 MeV incorporating Pauli-blocking and multiple-scattering agrees well with the measured angular distribution. At the two higher energies the d({pi}{sup {minus}},{pi}{sup 0})nn differential cross section is essentially identical to that for p({pi}{sup {minus}},{pi}{sup 0})n, except at forward angles where the former is suppressed by the Pauli principle.

Matthews, J.L.; Park, H.T.; Pate, S.F. [and others

1995-04-01

385

Electromagnetic Dissociation Cross Sections using Weisskopf-Ewing Theory  

NASA Technical Reports Server (NTRS)

It is important that accurate estimates of crew exposure to radiation are obtained for future long-term space missions. Presently, several space radiation transport codes exist to predict the radiation environment, all of which take as input particle interaction cross sections that describe the nuclear interactions between the particles and the shielding material. The space radiation transport code HZETRN uses the nuclear fragmentation model NUCFRG2 to calculate Electromagnetic Dissociation (EMD) cross sections. Currently, NUCFRG2 employs energy independent branching ratios to calculate these cross sections. Using Weisskopf-Ewing (WE) theory to calculate branching ratios, however, is more advantageous than the method currently employed in NUCFRG2. The WE theory can calculate not only neutron and proton emission, as in the energy independent branching ratio formalism used in NUCFRG2, but also deuteron, triton, helion, and alpha particle emission. These particles can contribute significantly to total exposure estimates. In this work, photonuclear cross sections are calculated using WE theory and the energy independent branching ratios used in NUCFRG2 and then compared to experimental data. It is found that the WE theory gives comparable, but mainly better agreement with data than the energy independent branching ratio. Furthermore, EMD cross sections for single neutron, proton, and alpha particle removal are calculated using WE theory and an energy independent branching ratio used in NUCFRG2 and compared to experimental data.

Adamczyk, Anne M.; Norbury, John W.

2011-01-01

386

Low Frequency Impedance of Tapered Transitions with Arbitrary Cross Sections  

SciTech Connect

We study the impedance of a tapered transition at small frequencies for an arbitrary shape of the transition cross section. Our approach does not require a symmetry axis in the system (unlike round geometry). We show that the calculation of the impedance reduces to finding a few auxiliary potential functions that satisfy two-dimensional Poisson equations with Dirichlet boundary conditions. In simple cases such solutions can be obtained analytically; for more complicated geometries they can easily be found numerically. We apply our method to axisymmetric geometry and reproduce results known from the literature. We then calculate the impedance of a taper with rectangular cross section in which the vertical dimension of the cross section is a slowly changing function of the longitudinal coordinate. Finally, we find a transverse kick experienced by a beam passing near a conducting wall with a variable distance from the beam to the wall.

Stupakov, G.; /SLAC

2007-07-23

387

Measurement of the W + jet cross section at CDF  

SciTech Connect

A measurement of W {yields} ev + n-jet cross sections in p{bar p} collisions at {radical}s = 1.96 TeV using the Collider Detector at Fermilab in Run II is presented. The measurement is based on an integrated luminosity of 320 pb{sup -1}, and includes events with jet multiplicity from {ge} 1 to {ge} 4. In each jet multiplicity sample the differential and cumulative cross sections with respect to the transverse energy of the n{sup th}-leading jet are measured. For W + {ge} 2 jets the differential cross section with respect to the 2-leading jets invariant mass m{sub j{sub 1}j{sub 2}} and angular separation {Delta}R{sub j{sub 1}j{sub 2}} is also reported. The data are compared to predictions from Monte Carlo simulations.

Messina, Andrea; /Michigan State U.

2006-10-01

388

Measurement of Neutron Capture Cross Sections of Selenium Isotopes  

NASA Astrophysics Data System (ADS)

There have been numerous measurements of the neutron capture cross sections of the stable Se isotopes, most dating from at least 40 years ago. The various results for individual isotopes are often in poor agreement with one another, but as yet there has been no attempt at a systematic measurement of the capture cross sections leading to all seven radioisotopes formed from capture by natural Se, which range in halflife from 17 s to 120 d. Using cadmium-shielded and unshielded irradiations of natural Se in various irradiation sites in OSU's TRIGA reactor, we have determined the thermal cross sections and resonance integrals for captures leading to ^75,77m,79m,81g,81m,83g,83mSe.

Dearmon, Howard D.; Krane, Kenneth S.

2011-10-01

389

Cross-Sectional HIV Incidence Estimation in HIV Prevention Research  

PubMed Central

Accurate methods for estimating HIV incidence from cross-sectional samples would have great utility in prevention research. This report describes recent improvements in cross-sectional methods that significantly improve their accuracy. These improvements are based on the use of multiple biomarkers to identify recent HIV infections. These multi-assay algorithms (MAAs) use assays in a hierarchical approach for testing that minimizes the effort and cost of incidence estimation. These MAAs do not require mathematical adjustments for accurate estimation of the incidence rates in study populations in the year prior to sample collection. MAAs provide a practical, accurate, and cost-effective approach for cross-sectional HIV incidence estimation that can be used for HIV prevention research and global epidemic monitoring.

Brookmeyer, Ron; Laeyendecker, Oliver; Donnell, Deborah; Eshleman, Susan H.

2013-01-01

390

A new method for the calculation of photodissociation cross sections  

NASA Technical Reports Server (NTRS)

A time-independent quantum mechanical approach to the calculation of photodissociation cross sections is developed. The method is based on the use of a discrete variable representation and the application of absorbing boundary conditions. Both total photodissociation cross sections and partial cross sections (hence product state distributions) are obtained using the same basic technique, but the calculation is particularly efficient when only the former quantity is required. The method is applied to the photodissociation of HCl(+) for which accurate potential energy curves and dipole moment functions are available, to the photodissociation of ClCN which is a direct process, involving a single excited electrosonic state, and to the photodissociation of ICN, which involves several strongly coupled excited electronic states.

Seideman, Tamar

1993-01-01

391

Lactiferous vessel detection from microscopic cross-sectional images  

NASA Astrophysics Data System (ADS)

This paper presents the methods to detect and segment lactiferous vessels or rubber latex vessels from gray scale microscopic cross-sectional images using polynomial curve-fitting with maximum and minimum stationary points. Polynomial curve-fitting is used to detect the location of lactiferous vessels from an image of a non-dyed cross-sectional slice which was taken by a digital camera through microscope lens. The lactiferous vessels are then segmented from an image using maximum and minimum stationary points with morphological closing operation. Two species of rubber trees of age between one to two years old are sampled namely, RRIM600 and RRIT251. Two data sets contain 30 microscopic cross-sectional images of one-year old rubber tree's stems from each species are used in the experiments and the results reveal that most of the lactiferous vessel areas can be segmented correctly.

Jariyawatthananon, Jirapath; Cooharojananone, Nagul; Lipikorn, Rajalida

2014-04-01

392

Neutrino Cross Section Measurements @ SciBooNE  

SciTech Connect

We report measurements of cross sections of neutrinos of 0.7 GeV average energy scattering off a carbon target cross sections with by the SciBooNE experiment at Fermilab. These measurements are important inputs for current and future accelerator-based neutrino oscillation experiments in the interpretation of neutrino oscillation signals. The measurement of neutrino mixing angle {theta}{sub 13} is one of the most important goals in current neutrino experiments. For the current and next generation of long baseline neutrino oscillation experiments, T2K, NOvA and LBNE, the precise measurement of neutrino-nucleus cross sections in the few GeV energy range is an essential ingredient in the interpretation of neutrino oscillation signals.

Mariani, C.; /Columbia U.

2011-10-01

393

Testing wave packet dynamics in computing radiative association cross sections  

NASA Astrophysics Data System (ADS)

A time-dependent wave packet method is used to compute cross sections for radiative recombination reactions using the Li(2S)+H+-->LiH+(X 2?+)+? as a test case. Cross sections are calculated through standard time-to-energy mapping of the time-dependent transition moment and a useful method is introduced to deal with the low collision energy regime. Results are in quantitative agreement over the whole energy range 10-4-5 eV with previous time-independent results for the same system [I. Baccarelli, L. Andric, T. Grozdanov, and R. McCarroll, J. Chem. Phys. 117, 3013 (2002)], thereby suggesting that the method can be of help in computing radiative association cross sections for more complicated systems.

Martinazzo, Rocco; Tantardini, Gian Franco

2005-03-01

394

Nucleon-nucleon cross sections in dense nuclear matter  

SciTech Connect

We present microscopic calculations of cross sections for scattering of identical and nonidentical nucleons in symmetric nuclear matter at various densities, using the Brueckner-Hartree-Fock approximation scheme with the Argonne v{sub 14} potential including the contribution of microscopic three-body forces. We investigate separately the effects of three-body forces on the effective mass and on the scattering amplitude. In the present calculation, the rearrangement contribution of the three-body force is considered, which reduces the neutron and proton effective mass and suppresses the magnitude of the cross section. The presence of 'Z diagrams' in the three-body force enables us to make a comparison with the medium effects on the nucleon-nucleon cross sections obtained with the Dirac-Brueckner-Hartree-Fock approximation.

Zhang, H. F. [School of Nuclear Science and Technology, Lanzhou University, Lanzhou 730000 (China); Li, Z. H. [INFN-LNS, Via S. Sofia 64, I-95123 Catania (Italy); Lombardo, U. [INFN-LNS, Via S. Sofia 64, I-95123 Catania (Italy); Dipartimento di Fisica e Astronomia, Via A. Doria 6, I-95123 Catania (Italy); Luo, P. Y.; Zuo, W. [Institute of Modern Physics, Chinese Academy of Science, Lanzhou 730000 (China); Sammarruca, F. [Physics Department, University of Idaho, Moscow, Idaho 83844-0903 (United States)

2007-11-15

395

Inversion of rotationally inelastic differential cross sections under sudden conditions  

SciTech Connect

An inversion method for rotationally inelastic atom--diatom differential cross sections based on the infinite-order-sudden (IOS) approximation is presented. It consists of two separate steps: (1) The scattering phase shift, which is a function of the partial wave parameter l and the orientation angle ..gamma.., is determined by least-squares fitting of the reference cross sections. (2) For fixed orientation ..gamma.. the R dependence of the interaction potential in obtained from the l dependence of the phase shift using the Firsov technique. This method is applicable in the so-called strong coupling case when rotational rainbow features are dominant and yields information about the anisotropy of the potential surface in the repulsive region. Because of the centrifugal sudden condition, scattering systems with deep potential wells cannot be treated by the present method. Test calculations are performed using theoretical IOS cross sections obtained from a realistic He--Na/sub 2/ surface as reference data.

Schinke, R.

1980-12-15

396

Theoretical cross sections for inner-shell vacancy production by high-energy electrons  

NASA Astrophysics Data System (ADS)

The creation of inner shell vacancies can play an important role in the transport of and energy deposition by fast incident particles. Most high energy electron transport models include this phenomenology. A large body of cross section data is available for this purpose, but many gaps remain to be filled by interpolation or extrapolation methods. The use of relativistic Bethe-Born theory for inelastic electron scattering to augment the existing data for inner shell vacancy production is described. The data required to implement this technique were calculated with both a Hartree-Fock and a relativistic Hartree-Fock description used to define the target structure. The resulting cross sections are available for most elements and for most of their orbitals if the valence electrons are excluded. Comparisons of these data with existing experimental and theoretical inner shell ionization information are summarized.

Peek, J. M.

397

Reduced backscattering cross section (Sigma degree) data from the Skylab S-193 radar altimeter  

NASA Technical Reports Server (NTRS)

Backscattering cross section per unit scattering area data, reduced from measurements made by the Skylab S-193 radar altimeter over the ocean surface are presented. Descriptions of the altimeter are given where applicable to the measurement process. Analytical solutions are obtained for the flat surface impulse response for the case of a nonsymmetrical antenna pattern. Formulations are developed for converting altimeter AGC outputs into values for the backscattering cross section. Reduced data are presented for Missions SL-2, 3 and 4 for all modes of the altimeter where sufficient calibration existed. The problem of interpreting land scatter data is also discussed. Finally, a comprehensive error analysis of the measurement is presented and worst case random and bias errors are estimated.

Brown, G. S.

1975-01-01

398

The data base of the standards and related cross sections after ENDF/B-VI  

SciTech Connect

A brief description is given of the procedure used in the global evaluation of the standards and other important cross sections for ENDF/B-VI. The standards involved were {sup 6}Li(n,t), {sup 10}B(n,{alpha}{sub 1}), {sup 197}Au(n,{gamma}), and {sup 235}U(n,f). Other standards evaluated independently were H(n,p), {sup 3}He(n,p), C(n,f). The other cross sections involved were {sup 238}U(n,{gamma}), {sup 238}U(n,f), and {sup 239}Pu(n,f). The results of the evaluation are compared with new or revised experimental data which have become available after the completion of ENDF/B-VI. Overall good agreement is found, but a few problems are indicated by the new data.

Poenitz, W.P. [Argonne National Lab. - West, Idaho Falls, ID (United States); Carlson, A.D. [National Institute of Standards and Technology, Washington, DC (United States)

1992-12-31

399

Electron impact ionization cross-sections of SF3 and SF5  

NASA Astrophysics Data System (ADS)

We report experimental and theoretical studies of the total electron impact ionization cross-sections for the radicals SF3 and SF5. It is shown that for radicals with strongly polar fluoride bonds, the shielding of the attractive dipole interaction potential in the bonding region is important in a proper description of the collision process. The siBED model, which has incorporated the shielding factor, was found to provide cross-sections in agreement with recently re-analyzed experimental data for the species CFx and NFx (x=1-3), whereas the DM model and the BEB model, on the other hand, showed large discrepancies with experiment. These findings also hold for the two free radicals SF3 and SF5 studied here, providing further evidence on the importance of a proper shielding of the dipole potential.

Huo, W. M.; Tarnovsky, V.; Becker, K.

2004-04-01

400

Collision cross sections for few electron systems. Final report, August 1, 2992--July 31, 1995  

SciTech Connect

The purpose of this project was to produce accurate cross sections for collisionally induced reactions from the ground stated and excited states of species of ions and at present in a hot fusion plasma. The collisional constituents may be divided into two categories for the purpose of calculations: Those in which a bare projectile excites a one electron or two electron ion or atom from its ground state, or excited states to higher excited states or ionized states. Those in which the projectile has one or more electrons attached to it and excites a one electron or two electron ion or atom from its ground state, or excited states to higher excited states or ionized states. During the collision the projectile itself may change its state being simultaneously excited or ionized. Cross sections are needed typically over the whole energy range from low velocities where molecular, orbitals begin to form to high velocities where first Born or more sophisticated asymptotic theories can be used. These high energy cross sections are very useful for experimentalists to check the absolute normalization of their cross sections. The theoretical tools used were therefore both analytical and numerical in character. Numerical calculations were restricted to expansions of the wavefunctions in a set of finite hilbert basis states (FHBS). The many body aspects of the problem, i.e. the important presence of the interelectron force, or correlation mandate a careful systematic approach. But this section was tempered in our strategy by the fact that many of the cross sections needed, especially from excited states, have never been calculated or measured at all. Thus any information we can provide is useful even if later work may modify our results.

Reading, J.F.; Ford, A.L.

1995-12-31

401

Reexamination of the neutron skin thickness using neutron removal cross sections  

SciTech Connect

The neutron removal cross section [{sigma}{sub -N}(Z)] is defined for the projectile-like fragment isotopes and extended to the lower Z isotopes in the projectile fragmentation reaction. The cross sections of fragments in 1 A GeV even {sup 42-52}Ca+{sup 12}C projectile fragmentation reactions are calculated using the statistical abrasion-ablation model. The correlations between {sigma}{sub -N}(Z) of different fragment isotopes and neutron skin thickness (S{sub n}) for finite neutron-rich nuclei are revisited. Good linear {sigma}{sub -N}(Z)-S{sub n} correlations are observed in fragment isotopes, and it is suggested that {sigma}{sub -N}(Z) be used as an observable to determine S{sub n} of neutron-rich nucleus in addition to {sigma}{sub -N} for isotopes of the projectile nucleus.

Ma Chunwang; Wei Huiling; Yu Mian [Department of Physics, Henan Normal University, Xinxiang 453007 (China); Department of Life Sciences and Technology, Xinxiang Medical University, Xinxiang 453003 (China)

2010-11-15

402

Total cross sections for photoabsorption on light nuclei in the energy range 600-1500 MeV  

NASA Astrophysics Data System (ADS)

Experimental data of the GRAAL Collaboration on the total cross sections for photoabsorption on deuterium and carbon targets at gamma-ray energies in the range between 600 and 1500 MeV are presented. The experiment was performed in a beam of photons obtained by the method of the Compton backscattering of laser photons at the electron storage ring of the European Synchrotron Radiation Facility (ESRF, Grenoble, France) by using a wide-aperture detector covering a solid angle close to 4 ?. The total photoabsorption cross sections were determined by two independent methods: by subtracting the emptytarget background and by summing partial cross sections for meson photoproduction. The total cross sections for photoabsorption on quasifree protons and neutrons are shown to agree both in magnitude and in shape within a 5% precision of the measurements. In contrast to data previously available in the literature, both cross sections show distinctly the F 15(1680) resonance at a photon energy of about 1 GeV. Data obtained in the present experiment for the cross sections for photoabsorption on a free and a bound nucleon are compared. This comparison reveals a substantial role of two-nucleon correlations in estimating the nuclear-medium effect on meson photoproduction.

Rudnev, N. V.; Ignatov, A. S.; Lapik, A. M.; Mushkarenkov, A. N.; Nedorezov, V. G.; Turinge, A. A.

2010-08-01

403

Muscle strength and cross-sectional area in man: a comparison of strength-trained and untrained subjects.  

PubMed Central

This study has examined muscle strength and cross-sectional area in a group of 35 healthy untrained male subjects and 8 subjects who had been engaged in a strenuous weight-training programme. The maximum voluntary knee extension force which could be produced by the untrained subjects was 742 +/- 100 N (mean +/- SD). The trained subjects could produce a significantly (p less than 0.001) greater force (992 +/- 162 N). Cross-sectional area of the knee-extensor muscle group was 81.6 +/- 11.8 cm2 in the untrained subjects and 104.1 +/- 12.3 cm2 in the trained subjects (p less than 0.001). In the untrained subjects, a significant correlation existed between strength and muscle cross-sectional area (r = 0.56, p less than 0.001). In the same group of subjects, there was a significant inverse relationship between muscle cross-sectional area and the ratio of strength to cross-sectional area (r = 0.55, p less than 0.001). The mean ratio of strength to cross-sectional area was 9.20 +/- 1.29 for the untrained group whereas for the trained group this ratio was 9.53 +/- 1.01. It is suggested that the inverse relationship between strength per unit cross-sectional area and cross-sectional area results in part from an increased angle of pennation in the larger muscles. Images p149-a p149-b p149-c

Maughan, R. J.; Watson, J. S.; Weir, J.

1984-01-01