Mathematical model for predicting human vertebral fracture

Mathematical model has been constructed to predict dynamic response of tapered, curved beam columns in as much as human spine closely resembles this form. Model takes into consideration effects of impact force, mass distribution, and material properties. Solutions were verified by dynamic tests on curved, tapered, elastic polyethylene beam

The MIDAS experiment: A prototype for the microwave emission of Ultra-High Energy Cosmic Rays

Recent measurements suggest that extensive air showers initiated by ultra-high energy cosmic rays (UHECR) emit signals in the microwave band of the electromagnetic spectrum caused by the collisions of the free-electrons with the atmospheric neutral molecules in the plasma produced by the passage of the shower. Such emission is isotropic and could allow the detection of air showers with 100% duty cycle and a calorimetric-like energy measurement, a significant improvement over current detection techniques. We have built MIDAS (MIcrowave Detection of Air Showers), a prototype of microwave detector, which consists of a 4.5 m diameter antenna with a cluster of 53 feed-horns in the 4 GHz range. The details of the prototype and first results will be presented.Comment: To appear in the proceedings of 12th Topical Seminar on Innovative Particle and Radiation Detectors (IPRD10), Siena, Italy, 7 - 10 June 201

Employment and Income Issues in the Southwest for the 1980\u27s

[Excerpt] As part of the nation\u27s sunbelt, the Southwest has sustained significant growth in its economy, its population and its labor force since the end of World War II. The prospects are that the region can expect more of the same in the foreseeable future. The ascendancy of the Southwest has been paralleled by stagnation and even decline in these same indices in much of the northeastern and north central regions of the nation. The 1981 Report of the President\u27s Commission for an Agenda for the 1980\u27s not only noted these regional trends but it also suggested that the causative factors should not be restrained by federal interventions. Instead, it was suggested by a subcommittee to the Commission that a policy of anticipation, accommodation, and adjustment made more sense

Nature Inspired Prototype Design of Collision Avoidance Aircraft System and Design of a Pair of Wing Flaps in Autodesk Maya Software

AbstractThe paper presents a prototype of collision avoidance aircraft system and to design the horizontal and vertical movements of a pair of such aircraft. The proposed techniques deal with optimization shape, and size of the aircraft and its various parts. The movement of the pair of such aircraft with optimized geometrical shapes has been animated through the application of Autodesk Maya software. The entire aerial behavior commencing from the ground movement of aircraft along the runway, takeoff, and aerial flying, horizontal and vertical movement, turning and landing and safety landing have been animated by using the said optimized structure. An approximation ratio of the aircraft length and its wings dimension (tip to tip), to maintain the safe distance between two aircraft (with respect to horizontal and vertical direction) has been predicted in the present study

Adhesive material transfer in the erosion of an aluminum alloy

In order to study the basic mechanisms of erosion, hardened steel balls were shot into annealed 6061 Al alloy targets at velocity of up to 150 m/sec. The projectiles were collected and examined by a scanning electron microscope combined with energy-dispersive X-ray analyzer and it was found that target material in substantial amounts is adhesively transferred to the projectile. The transferred material forms on the projectile surface a layer the thickness of which increases with increases in impact velocity

Buckling of a beam extruded into highly viscous fluid

Inspired by microscopic paramecies which use trichocyst extrusion to propel themselves away from thermal aggressions, we propose a macroscopic experiment to study the stability of a slender beam extruded in a highly viscous fluid. Piano wires were extruded axially at constant speed in a tank filled with corn syrup. The force necessary to extrude the wire was measured to increase linearly at first until the compressive viscous force causes the wire to buckle. A numerical model, coupling a lengthening elastica formulation with resistive force theory, predicts a similar behaviour. The model is used to study the dynamics at large time when the beam is highly deformed. It is found that at large time, a large deformation regime exists in which the force necessary to extrude the beam at constant speed becomes constant and length-independent. With a proper dimensional analysis, the beam can be shown to buckle at a critical length based on the extrusion speed, the bending rigidity and the dynamic viscosity of the fluid. Hypothesising that the trichocysts of paramercies must be sized to maximise their thrust per unit volume as well as avoid buckling instabilities, we predict that their bending rigidity must be about $3\times 10^{-9}~\mathrm{N\cdot \mu m^2}$. The verification of this prediction is left for future work.Comment: Accepted for publication in PRE on November 18 2014, 7 pages, 6 figure