Aerodynamic characteristics of a hypersonic parachute

Newtonian theory, both in the form of the Modified-Newtonian and the Newton- Busemann pressure laws, is used to find the shape, cloth area and drag of the axisymmetric canopy of a hypersonic parachute, whose only load-carrying fibres are longitudinal ones. As an example, an estimate is made of the size of canopy needed to give a drag of 20,000 lb. in flight at a Mach number of 10 at 100,000 feet altitude

Effect of jumping style on the performance of large and medium elite agility dogs

Dog agility is a rapidly progressing sport worldwide. Consequentially, research and methods to improve technique and performance are becoming highly sought after. Video data were collected of elite agility dogs during a training session, with downstream analysis examining differences in apparent topline angle and jumping speed of large and medium dogs as well as collie breeds and non-collie breeds. The study further examined any correlations between topline angle and jumping speed. Findings suggest that there is a difference between the jump kinematics of large and medium dogs (P=0.001) and between collie breeds and non-collie breeds (P<0.001) with collie breeds jumping faster than non-collie breeds (P=0.013). This information could be used to inform future training regimes and competitive strategies in a breed and size specific way, with the aim to improve long-term health and welfare of canine participants, whilst also ensuring that training and competitive expectations are within biological capabilities

CAN THE UNITED STATES COMPETE WITH DAIRY EXPORTING NATIONS?

International Relations/Trade,

LANDSAT Range Resource Information System

A series of test products were developed from LANDSAT data sets for North Central Texas that paralleled the needs of ranchers, technical personnel, and the media. The products and evaluation questionnaires were mailed to approximately 150 ranchers who had reported an interest in evaluating the information systems. In addition to the rancher group, fourteen media people and a thirty-three member group in the agri business/technical community was also chosen to receive test products. The group responses are analyzed. Examples of the test products and associated questionnaires are included

Small and medium agility dogs alter their kinematics when the distance between hurdles differs

There is currently a lack of research examining the health and welfare implications for competitive agility dogs. The aim of this study was to examine if jump kinematics and apparent joint angles in medium (351 mm - 430 mm to the withers) and small (< 350 mm to the withers) agility dogs altered when distances between consecutive upright hurdles differ. Dogs ran a course of nine hurdles; three set at 3.6 m apart; three at 4 m apart and three at 5 m apart. Both medium (P=0.044) and small (P=0.006) dogs landed closer to the hurdle when consecutive hurdles were set at 3.6 m apart, with small dogs jumping slower at this distance (P=0.006). Results indicate that jump kinematics, but not apparent joint angles, alter when the spacing between hurdles differs. These findings may have implications for the health and welfare of agility dogs and should be used to inform future changes to rules and regulations

Variational analysis of self-focusing of intense ultrashort pulses in gases

By using perturbation theory we derive an expression for the electrical field of a Gaussian laser pulse propagating in a gas medium. This expression is used as a trial solution in a variational method to get quasianalytical solutions for the width, intensity and self-focusing distance of ultrashort pulse. The approximation gives an improved agreement with results of numerical simulations for a broad range of values of the input power of the pulse than previous analytical results available in the literature.Comment: 19 pages, 8 figure