Results 1 - 10 of 1860
Results 1 - 10 of 1860. Search took: 0.027 seconds
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[en] The size of sports fields considerably varies from a few meters for table tennis to hundreds of meters for golf. We first show that this size is mainly fixed by the range of the projectile, that is, by the aerodynamic properties of the ball (mass, surface, drag coefficient) and its maximal velocity in the game. This allows us to propose general classifications for sports played with a ball. (paper)
[en] A method of analyzing the missile-target interaction problem is presented. The method is capable of accounting for the loss of energy of missile penetration when computing the rebounding velocity of the missile. It was shown that accounting for the loss of energy due to missile penetration can affect the computed rebounding velocity of the missile. The method can account for different properties of the missile-target system in a simple way. (orig.)
[en] In view of the failure situation of the vibration sensor carried by the projectile without anti-overload treatment, two failure cases of the vibration sensor on the projectile are analyzed, and the internal structure of the vibration sensor on the projectile is simplified as the mechanical model of the fixed beam. The results show that the interior structure of the projectile-borne vibration sensor has a direct impact on its impact resistance, and the impact resistance of the projectile-borne vibration sensor placed parallel to the direction of acceleration propagation is higher than that of the projectile-borne vibration sensor perpendicular to the direction of acceleration propagation. The results can provide reference for selection and placement of vibration sensors. (paper)
[en] We consider the orbit of projectiles launched with arbitrary speeds from the Earth's surface. This is a generalization of Newton's discussion about the transition from parabolic to circular orbits, when the launch speed approaches the value ν=√(g RE). We find the range for arbitrary launch speeds and angles, and calculate the eccentricity of the elliptical orbits.
[en] A maximum of the S(E) factor is evidence for an onset of sub-barrier fusion hindrance and it can be well described by a radius-of-curvature expression near the maximum. The systematics of this radius of curvature has been studied over a wide range of projectile-target combinations. It follows a tentative general trend as a function of the parameter ζ=Z1Z2√(μ), and is strongly affected by effects associated with the nuclear structure of the nuclei in the entrance channel. It also explains the reason why the S factor maximum is not easily recognized visually for lighter, astrophysically interesting fusion systems
[en] The data of J/ψ suppression at large xF in pA collisions are used to infer the existence of gluon depletion as the projectile proton traverses the nucleus. The modification of the gluon distribution is studied by use of a convolution equation whose nonperturbative splitting function is determined phenomenologically. The depletion factor at x1=0.8 is found to be about 25% at A=100
[en] The 22+ state in 132Te is identified as the one-phonon mixed-symmetry state in a projectile Coulomb excitation experiment presenting a firm example of a mixed-symmetry state in unstable, neutron-rich nuclei. The results of shell-model calculations based on the low-momentum interaction Vlow-k are in good agreement with experiment demonstrating the ability of the effective shell-model interaction to produce states of mixed-symmetry character.
[en] This study investigates the dynamic response characteristics of the structure impacted by the high speed projectile. Projectile of 300 kg is example to impact the water storage tank and it is simulated by general purpose computer codes Annoys and L S-Dyna. Several methods to simulate impact are tried and their results are compared to propose an alternative method of impact analysis which is equivalent to the explicit dynamic analysis. Also the effect of fluid on the responses of the tank is addressed
[en] The expansion of ballistic gun range facilities at LLL has introduced state-of-the-art diagnostic techniques to glovebox-enclosed ballistic guns systems. These enclosed ballistic ranges are designed for the study of one-dimensional shock phenomena in extremely toxic material such as plutonium. The extension of state-of-the-art phtographic and interferometric diagnostic systems to glovebox-enclosed gun systems introduces new design boundaries and performance criteria on optical and mechanical components. A technique for experimentally evaluating design proposals is illustrated, and several specific examples (such as, target alignment, collateral shrapnel damage, and soft recovery) are discussed