21,447 research outputs found
The Insects. Peter Farb and the editors of Life. New York: Time Inc., 1962. 192 pp. $4.00.
Excerpt: It is a pleasant surprise to find a book that can effectively communicate much information about insects to the lay public, amateur entomologist, and professional entomologist alike. In straight-forward language the author gives genuine insight into the morphology, physiology, behavior, evolution, and adaptation of insects. These areas are not treated as unrelated topics but are skillfully blended into a meaningful whole. The text is supported liberally with pertinent facts, clear drawings, and many photographs of remarkable quality. The lack of obvious mistakes indicates that editing has been carried out carefully
Food Plants of Some Adult Sphinx Moths (Lepidoptera: Sphingidae)
Excerpt: While food plants of many species of sphinx moth larvae are well known, food plants of the adults are not. Many observations of the feeding habits of adult sphinx moths undoubtedly have been made, but much of the information is probably resting in the field notebooks and memories of the observers.
To my knowledge no summary of known feeding information has been presented previously for American Sphingidae. A rather thorough list of food plants for adult European sphinx moths has been published by Wahlgren (1941). This list also includes other moth families as well and it can be a useful reference for many workers
Salt intake and regulation in two passerine nectar drinkers: white-bellied sunbirds and New Holland honeyeaters
Avian nectarivores face the dilemma of having to conserve salts while consuming large volumes of a dilute, electrolyte-deficient diet. This study evaluates the responses to salt solutions and the regulation of salt intake in white-bellied sunbirds (Cinnyris talatala) and New Holland honeyeaters (Phylidonyris novaehollandiae). Birds were first offered a choice of four sucrose diets, containing no salt or 25, 50 or 75 mM NaCl. The experiment was repeated using five sucrose concentrations (0.075-0.63 M) as the base solution. Both species ingested similar amounts of all diets when fed the concentrated base solutions. However, when birds had to increase their intake to obtain enough energy on the dilute sucrose diets, there was a general avoidance of the higher salt concentrations. Through this diet switching, birds maintained constant intakes of both sucrose and sodium; the latter may contribute to absorption of their sugar diets. A second, no-choice experiment was designed to elucidate the renal concentrating abilities of these two nectarivores, by feeding them 0.63 M sucrose containing 5-200 mM NaCl over a 4-h trial. In both species, cloacal fluid osmolalities increased with diet NaCl concentration, but honeyeaters tended to retain ingested Na+, while sunbirds excreted it. Comparison of Na+ and K+ concentrations in ureteral urine and cloacal fluid showed that K+, but not Na+, was reabsorbed in the lower intestine of both species. The kidneys of sunbirds and honeyeaters, like those of hummingbirds, are well suited to diluting urine; however, they also appear to concentrate urine efficiently when necessary
Slicing of silicon into sheet material. Silicon sheet growth development for the large area silicon sheet task of the low cost silicon solar array project
Fabrication of a prototype large capacity multiple blade slurry saw is considered. Design of the bladehead which will tension up to 1000 blades, and cut a 45 cm long silicon ingot as large as 12 cm in diameter is given. The large blade tensioning force of 270,000 kg is applied through two bolts acting on a pair of scissor toggles, significantly reducing operator set-up time. Tests with an upside-down cutting technique resulted in 100% wafering yields and the highest wafer accuracy yet experienced with MS slicing. Variations in oil and abrasives resulted only in degraded slicing results. A technique of continuous abrasive slurry separation to remove silicon debris is described
Angular Momentum on the Lattice: The Case of Non-Zero Linear Momentum
The irreducible representations (IRs) of the double cover of the Euclidean
group with parity in three dimensions are subduced to the corresponding cubic
space group. The reduction of these representations gives the mapping of
continuum angular momentum states to the lattice in the case of non-zero linear
momentum. The continuous states correspond to lattice states with the same
momentum and continuum rotational quantum numbers decompose into those of the
IRs of the little group of the momentum vector on the lattice. The inverse
mapping indicates degeneracies that will appear between levels of different
lattice IRs in the continuum limit, recovering the continuum angular momentum
multiplets. An example of this inverse mapping is given for the case of the
``moving'' isotropic harmonic oscillator.Comment: v3) Little groups for lattice momenta corrected. Includes corrections
from erratum submitted to Phys. Rev. D and a more consistent labeling scheme.
v2) Minor changes to little groups. (9 pages
- …