The Evolution of Best Practices with High Performance Steel for Bridges

High Performance Steel, grade 70 (HPS-70W) became available for use in early 1996 for fabrication and testing in bridges. Two (2) states, Nebraska and Tennessee agreed to be the first to implement usage. This paper provides a discussion of 3 Tennessee case histories in which high performance steel has been used to achieve weight and cost economies

The contribution of dance to daily physical activity among adolescent girls

<p>Abstract</p> <p>Background</p> <p>Structured physical activity (PA) programs are well positioned to promote PA among youth, however, little is known about these programs, particularly dance classes. The aims of this study were to: 1) describe PA levels of girls enrolled in dance classes, 2) determine the contribution of dance classes to total moderate-to-vigorous physical activity (MVPA), and 3) compare PA between days with a dance class (program days) and days without a dance class (non-program days).</p> <p>Methods</p> <p>Participants were 149 girls (11-18 years) enrolled in dance classes in 11 dance studios. Overall PA was assessed with accelerometry for 8 consecutive days, and girls reported when they attended dance classes during those days. The percent contribution of dance classes to total MVPA was calculated, and data were reduced to compare PA on program days to non-program days. Data were analyzed using mixed models, adjusting for total monitoring time.</p> <p>Results</p> <p>Girls engaged in 25.0 ± 0.9 minutes/day of MVPA. Dance classes contributed 28.7% (95% CI: 25.9%-31.6%) to girls' total MVPA. Girls accumulated more MVPA on program (28.7 ± 1.4 minutes/day) than non-program days (16.4 ± 1.5 minutes/day) (p < 0.001). Girls had less sedentary behavior on program (554.0 ± 8.1 minutes/day) than non-program days (600.2 ± 8.7 minutes/day) (p < 0.001).</p> <p>Conclusions</p> <p>Dance classes contributed a substantial proportion (29%) to girls' total MVPA, and girls accumulated 70% more MVPA and 8% less sedentary behavior on program days than on non-program days. Dance classes can make an important contribution to girls' total physical activity.</p

Comparisons Between Rail-Trail Users and Nonusers and Men and Women\u27s Patterns of Use in a Suburban Community

Background: Physical activity research on trails is limited. We compared rail-trail users and nonusers on demographics, physical activity, and barriers/concerns about trail use; and described use among men and women. Methods: Four hundred thirteen adults completed a physical activity survey during fall 1998. Chi-square statistics and t-tests were used to compare trail users to nonusers, and men and women on trail use. Results: More trail users (79%) performed recreational physical activity ≥ 3 d/wk, compared to nonusers (47%). Walking was the most common activity for trail users and nonusers. Both groups shared concerns about safe access to the trail and certain trail conditions. A higher percentage of female versus male users traveled to the trail by walking, walked on the trail, used the trail with a friend, and perceived that if the trail were not available their activity would decrease. Conclusions: Trail users perform more recreational physical activity than nonusers. Gender differences in trail use patterns should be considered in the design and promotion of trails

Differential cross section for neutron-proton bremsstrahlung

The neutron-proton bremsstrahlung process $(np \to np\gamma)$ is known to be sensitive to meson exchange currents in the nucleon-nucleon interaction. The triply differential cross section for this reaction has been measured for the first time at the Los Alamos Neutron Science Center, using an intense, pulsed beam of up to 700 MeV neutrons to bombard a liquid hydrogen target. Scattered neutrons were observed at six angles between 12$^\circ$ and 32$^\circ$, and the recoil protons were observed in coincidence at 12$^\circ$, 20$^\circ$, and 28$^\circ$ on the opposite side of the beam. Measurement of the neutron and proton energies at known angles allows full kinematic reconstruction of each event. The data are compared with predictions of two theoretical calculations, based on relativistic soft-photon and non-relativistic potential models.Comment: 5 pages, 3 figure