Edge Of Bed Research Articles

MODELING OF THE FLUID FLOW AND HEAT TRANSFER AT THE EDGE OF A FIXED BED

As a preliminary study of the nature of heat transfer between a packed bed and a bounding wall, a first-order model is considered where the bed is taken to be a row of rectangular compacts. Results are obtained numerically for the fluid flow and heat transfer in the voids between compacts and to the wall. Different gap sizes and compact-plane separations, with Prandtl numbers of 0.72 and 7 and Reynolds numbers ranging from 0 to 100, are considered. As the compact separation and the Reynolds number increase, the heat transfer from the void increases and the maximum temperature decreases. Increasing the Prandtl number improves the heat transfer from the void, and when the compact-bounding plane separation increases, the fluid flow and heat transfer settle down to essentially a stationary value, independent of the Reynolds number.

The role of behavioral responses to predators in modifying urchins' (Strongylocentrotus droebachiensis) destructive grazing and seasonal foraging patterns

We documented spatial and temporal patterns of urchins (Strongylocentrotus droebachiensis) and periwinkles (Littorina littorea) in three habitats: a persistent Laminaria longicruris and L. digitata bed; an urchin dominated barrens, and the edge of the kelp bed that formed a boundary between the two. Urchins were rare in the kelp and, when present, always large and well hidden, a pattern we interpret as a response to crab and lobster predation. Urchins were abundant in the barrens, and, in the summer when predaceous fish were active during the day, foraged only at nigh. We observed the formation of a dense urchin feeding front along the kelp bed edge, and these urchins remained exposed and feeding even during the summer. Laboratory experiments demonstrated that aggregations are an effective defense against some predators, and that the presence of crabs increases the tendency of large urchins to aggregate. We hypothesize that healthy Laminaria spp. beds persist because kelp bed associated predators keep urchins at low densities and in hiding. A reduction in predation pressure permits urchin densities to increase to the point where they form aggregations, which provide better defense than hiding. These aggregations then graze destructively on Laminaria spp., forming barrens. These barrens seem to be a new, stable configuration of the system.

Unusual application of obstetrical forceps.

To the Editor:— This reports a proctologic procedure wherein a petroleum jelly jar was delivered from the rectum with the assistance of obstetrical forceps. Report of a Case:— At 9 AM, a 67-year-old man of average intelligence was massaging his rear end with a jar of petroleum jelly to relieve a bothersome itch. He coughed and sneezed at the same time, which caused the rectum to relax and allowed the jar to slip in as he sat down at the edge of the bed. After this Rube Goldberg-chain reaction-rectal jar syndrome, the patient encountered difficulty in passing the newly adopted contents. After drinking copious amounts of sauerkraut juice, all that was accomplished was the discharge of watery movements, plus pain. After four hours of labor (breech presentations can cause problems), the patient notified me by phone that he had had a rectal accident and needed urgent care. Digital rectal examination