The Geant4 Hadronic Verification Suite for the Cascade Energy Range

A Geant4 hadronic process verification suite has been designed to test and optimize Geant4 hadronic models in the cascade energy range. It focuses on quantities relevant to the LHC radiation environment and spallation source targets. The general structure of the suite is presented, including the user interface, stages of verification, management of experimental data, event generation, and comparison of results to data. Verification results for the newly released Binary cascade and Bertini cascade models are presented.Comment: Talk from the 2003 Computing in High Energy and Nuclear Physics (CHEP03), La Jolla, Ca, USA, March 2003, 5 pages, LaTeX, 3 eps figures. PSN MOMT00

Separation of Q from carbon in CR meteorites during stepped combustion

Introduction: The nature of the planetary noble gas carrier (Q) in meteorites remains uncertain. It is known that it is likely to be carbonaceous, but represents only a small fraction of the total macromolecular material. Q is oxidisible with nitric and other oxidizing acids. It seems to be partly destroyed with pyridine and may have an organic structure. Previously, we have shown that during parent body thermal metamorphism Q is less affected than the majority of other carbonaceous materials. If organic matter is graphitized, as has happened in the enstatite chondrite parent bodies, Q remains unaffected. In the present study we have found that Q is also separable from the majority of carbon in type 2 and 3 CR chondrites during stepped combustion. It is possible that this is because Q has become encased within the matrix, in contrast to other carbon phases, during parent body metamorphism

Block height influences the head depth of competitive racing starts

The purpose of this study was to determine whether or not starting block height has an effect on the head depth and head speed of competitive racing starts. Eleven experienced, collegiate swimmers executed competitive racing starts from three different starting heights: 0.21 m (pool deck), 0.46 m (intermediate block), and 0.76 m (standard block). One-way repeated measures ANOVA indicated that starting height had a significant effect on the maximum depth of the center of the head, head speed at maximum head depth, and distance from starting wall at maximum head depth. Racing starts from the standard block and pool deck were significantly deeper, faster, and farther at maximum head depth than starts from the intermediate block. There were no differences between depth, speed, or distance between the standard block and pool deck. We conclude that there is not a positive linear relationship between starting depth and starting height, which means that starts do not necessarily get deeper as the starting height increases

Competitive swimmers modify racing start depth upon request

To expand upon recent findings showing that competitive swimmers complete significantly shallower racing starts in shallower pools, 12 more experienced and 13 less experienced swimmers were filmed underwater during completion of competitive starts. Two starts (1 routine and 1 “requested shallow”) were executed from a 0.76 m block height into water 3.66 m deep. Dependent measures were maximum head depth, head speed at maximum head depth, and distance from the starting wall at maximum head depth. Statistical analyses yielded significant main effects (p < 0.05) for both start type and swimmer experience. Starts executed by the more experienced swimmers were deeper and faster than those executed by the less experienced swimmers. When asked to dive shallowly, maximum head depth decreased (0.19 m) and head speed increased (0.33 ms-1) regardless of experience. The ability of all swimmers to modify start depth implies that spinal cord injuries during competitive swimming starts are not necessarily due to an inherent inability to control the depth of the start

Racing start safety: head depth and head speed during competitive starts into a water depth of 1.22 m

From the perspective of swimmer safety, there have been no quantitative 3-dimensional studies of the underwater phase of racing starts during competition. To do so, 471 starts were filmed during a meet with a starting depth of 1.22 m and block height of 0.76 m. Starts were stratified according to age (8 & U, 9–10, 11–12, 13–14, and 15 & O) and stroke during the first lap (freestyle, breaststroke, and butterfly). Dependent measures were maximum head depth, head speed at maximum head depth, and distance from the wall at maximum head depth. For all three variables, there were significant main effects for age, F(4, 456) = 12.53, p < .001, F(4, 456) = 27.46, p < .001, and F(4, 456) = 54.71, p < .001, respectively, and stroke, F(2, 456) = 16.91, p < .001, F(2, 456) = 8.45, p < .001, and F(2, 456) = 18.15, p < .001, respectively. The older swimmers performed starts that were deeper and faster than the younger swimmers and as a result, the older swimmers may be at a greater risk for injury when performing starts in this pool depth

Start depth modification by adolescent competitive swimmers

To expand upon previous studies showing inexperienced high school swimmers can complete significantly shallower racing starts when asked to start “shallow,” 42 age group swimmers (6-14 years old) were filmed underwater during completion of competitive starts. Two starts (one normal and one “requested shallow”) were executed from a 0.76 m block into 1.83 m of water. Dependent measures were maximum depth of the center of the head, head speed at maximum head depth, and distance from the starting wall at maximum head depth. Statistical analyses yielded significant main effects (p < 0.05) for start type and age. The oldest swimmers’ starts were deeper and faster than the youngest swimmers’ starts. When asked to start shallowly, maximum head depth decreased (0.10 m) and head speed increased (0.32 ms-1) regardless of age group. The ability of all age groups to modify start depth implies that spinal cord injuries during competitive swimming starts are not necessarily due to age-related deficits in basic motor skills