Optimum take-off angle in the standing long jump

The aim of this study was to identify and explain the optimum projection angle that maximises the distance achieved in a standing long jump. Five physically active males performed maximum-effort jumps over a wide range of take-off angles, and the jumps were recorded and analysed using a 2-D video analysis procedure. The total jump distance achieved was considered as the sum of three component distances (take-off, flight, and landing), and the dependence of each component distance on the take-off angle was systematically investigated. The flight distance was strongly affected by a decrease in the jumper’s take-off speed with increasing take-off angle, and the take-off distance and landing distance steadily decreased with increasing take-off angle due to changes in the jumper’s body configuration. The optimum take-off angle for the jumper was the angle at which the three component distances combined to produce the greatest jump distance. Although the calculated optimum take-off angles (19–27º) were lower than the jumpers’ preferred take-off angles (31–39º), the loss in jump distance through using a sub-optimum take-off angle was relatively small

Characterization of the n-TOF EAR-2 neutron beam

The experimental area 2 (EAR-2) at CERNs neutron time-of-flight facility (n-TOF), which is operational since 2014, is designed and built as a short-distance complement to the experimental area 1 (EAR-1). The Parallel Plate Avalanche Counter (PPAC) monitor experiment was performed to characterize the beam prole and the shape of the neutron 'ux at EAR-2. The prompt γ-flash which is used for calibrating the time-of-flight at EAR-1 is not seen by PPAC at EAR-2, shedding light on the physical origin of this γ-flash

Farfield inflight measurement of high-speed turboprop noise

A flight program was carried out to determine the variation of noise level with distance from a model high speed propeller. Noise measurements were obtained at different distances from a SR-3 propeller mounted on a JetStar aircraft, with the test instrumentation mounted on a Lear jet flown in formation. The propeller was operated at 0.8 flight Mach number, 1.12 helical tip Mach number and at 0.7 flight Mach number, 1.0 helical tip Mach number. The instantaneous pressure from individual blades was observed to rise faster at the 0.8 M flight speed, than at the 0.7 M flight speed. The measured levels appeared to decrease in good agreement with a 6 dB/doubling of distance decay, over the measurement range of approximately 16 m to 100 m distance. Further extrapolation, to the distances represented by a community, would suggest that the propagated levels during cruise would not cause a serious community annoyance

Spearfishing-induced behavioral changes of an unharvested species inside and outside a marine protected area.

By prohibiting fishing, marine protected areas (MPAs) provide a refuge for harvested species. Humans are often perceived as predators by prey and therefore respond fearfully to humans. Thus, fish responses to humans inside and outside of an MPA can provide insights into their perception of humans as a predatory threat. Previous studies have found differences in the distance that harvested species of fish initiate flight (flight initiation distance-FID) from humans inside and outside an MPA, but less is known about unharvested species. We focused on whether the lined bristletooth Ctenochaetus striatus, an unharvested surgeonfish, can discriminate between a snorkeler and a snorkeler with a spear gun inside and outside of a no-take MPA in Mo'orea, French Polynesia. Additionally, we incorporated starting distance (the distance between the person and prey at the start of an experimental approach), a variable that has been found to be important in assessing prey escape decisions in terrestrial species, but that has not been extensively studied in aquatic systems. Lined bristletooth FID was significantly greater in the presence of a spear gun and varied depending on if the spear gun encounter was inside or outside of the MPA. These results imply a degree of sophistication of fish antipredator behavior, generate questions as to how a nontargeted species of fish could acquire fear of humans, and demonstrate that behavioral surveys can provide insights about antipredator behavior

Comparison of Reproductive and Flight Capacity of Loxostege sticticalis (Lepidoptera: Pyralidae), Developing From Diapause and Non-Diapause Larvae

The beet webworm, Loxostege sticticalis (L.) (Lepidoptera: Pyralidae), uses both diapause and migration as life history strategies. To determine the role of diapause plays in the population dynamics of L. sticticalis, the reproductive and flight potentials of adults originating from diapause and nondiapause larvae were investigated under controlled laboratory conditions. Preoviposition period, lifetime fecundity, and daily egg production of females originating from diapause larvae were not significantly different from those originating from nondiapause larvae, showing that diapause has no significant effect on reproductive capacity when adults are provided with an adequate carbohydrate source. However, females that developed from diapause larvae lived significantly longer than those from nondiapause larvae. Flight capacity, including flight duration, distance and velocity of 3-d-old adults were all significantly greater in adults originating from diapause larvae than those from nondiapause larvae. L. sticticalisadults developing from diapause larvae tended to have more extreme values of longest flight duration and furthest flight distance than those from nondiapause larvae. Together, these results suggest that long-distance flight potential of L. sticticalis is greater after larval diapause than after direct development to adulthood. However, there were no significant differences between sexes within the two categories of moths in terms of total flight duration, total flight distance, flight velocity, and longest flight duration

Optimum take-off angle in the standing long jump

The aim of this study was to identify and explain the optimum projection angle that maximises the distance achieved in a standing long jump. Five physically active males performed maximum-effort jumps over a wide range of take-off angles, and the jumps were recorded and analysed using a 2-D video analysis procedure. The total jump distance achieved was considered as the sum of three component distances (take-off, flight, and landing), and the dependence of each component distance on the take-off angle was systematically investigated. The flight distance was strongly affected by a decrease in the jumper’s take-off speed with increasing take-off angle, and the take-off distance and landing distance steadily decreased with increasing take-off angle due to changes in the jumper’s body configuration. The optimum take-off angle for the jumper was the angle at which the three component distances combined to produce the greatest jump distance. Although the calculated optimum take-off angles (19–27º) were lower than the jumpers’ preferred take-off angles (31–39º), the loss in jump distance through using a sub-optimum take-off angle was relatively small