Algorithms to solve the Sutherland model

We give a self-contained presentation and comparison of two different algorithms to explicitly solve quantum many body models of indistinguishable particles moving on a circle and interacting with two-body potentials of $1/\sin^2$-type. The first algorithm is due to Sutherland and well-known; the second one is a limiting case of a novel algorithm to solve the elliptic generalization of the Sutherland model. These two algorithms are different in several details. We show that they are equivalent, i.e., they yield the same solution and are equally simple.Comment: 15 pages, LaTe

Remote sensing applied to the evaluation of crop freeze protection devices

Thermal images from an aircraft-mounted scanner are used to evaluate the effectiveness of crop freeze protection devices. Fuel oil heaters, wind machines and irrigation systems are evaluated from flights at an altitude of 450 m over an experimental citrus grove of 1.5 hectares

FOOD SAFETY ISSUES IN CANADA

Food Consumption/Nutrition/Food Safety,

Towton, 1461: An integrated approach to battlefield archaeology

Ye

Comparative jet wake structure and swimming performance of salps

Salps are barrel-shaped marine invertebrates that swim by jet propulsion. Morphological variations among species and life-cycle stages are accompanied by differences in swimming mode. The goal of this investigation was to compare propulsive jet wakes and swimming performance variables among morphologically distinct salp species (Pegea confoederata, Weelia (Salpa) cylindrica, Cyclosalpa sp.) and relate swimming patterns to ecological function. Using a combination of in situ dye visualization and particle image velocimetry (PIV) measurements, we describe properties of the jet wake and swimming performance variables including thrust, drag and propulsive efficiency. Locomotion by all species investigated was achieved via vortex ring propulsion. The slow-swimming P. confoederata produced the highest weight-specific thrust (T =53 N kg^(–1)) and swam with the highest wholecycle propulsive efficiency (η_wc= 55%). The fast-swimming W. cylindrica had the most streamlined body shape but produced an intermediate weight-specific thrust (T=30 N kg^(–1)) and swam with an intermediate whole-cycle propulsive efficiency (η_wc =52%). Weak swimming performance variables in the slow-swimming C. affinis, including the lowest weight-specific thrust (T=25 N kg^(–1)) and lowest whole-cycle propulsive efficiency (η_wc=47%), may be compensated by low energetic requirements. Swimming performance variables are considered in the context of ecological roles and evolutionary relationships