Marine mammals experience radical seasonal changes in body composition, which would be expected to affect their buoyancy in the water. The aim of this study was to examine the relationship between such changes in buoyancy and diving behavior in northern elephant seals Mirounga angustirostris. This was achieved by modifying the buoyancy of 13 juvenile elephant seals translocated from Año Nuevo S...

We study the Casimir force on a single surface immersed in an inhomoge-neous medium. Specifically we study the vacuum fluctuations of a scalar field with a spatially varying squared mass, m 2 + λ∆(x − a) + V (x), where V is a smooth potential and ∆(x) is a unit-area function sharply peaked around x = 0. ∆(x − a) represents a semi-penetrable thin plate placed at x = a. In the limits {∆(x−a) → δ(...

Control of buoyancy The change in temperature of spermaceti oil necessary to achieve neutral buoyancy The loss of heat from the spermaceti oil necessary to achieve neutral buoyancy The mechanism of losing heat Heat loss via the surface of the head Heat loss via the right naris The time required for heat exchange Heat available for reheating the spermaceti oil Storage of heat Timing of heat loss...

INTRODUCTION Accidental immersion in cold water is an occupational risk. Work suits and life jackets (LJ) should work effectively in combination to keep the airway clear of the water (freeboard) and enable self-righting. We hypothesized that inherent buoyancy, in the suit or LJ, would be beneficial for enabling freeboard, but its distribution may influence LJ self-righting. METHODS Six partic...

Efficient locomotion between prey resources at depth and oxygen at the surface is crucial for breath-hold divers to maximize time spent in the foraging layer, and thereby net energy intake rates. The body density of divers, which changes with body condition, determines the apparent weight (buoyancy) of divers, which may affect round-trip cost-of-transport (COT) between the surface and depth. We...