Biology of the Genus \u3ci\u3eHemileuca\u3c/i\u3e (Lepidoptera: Saturniidae) in Michigan

The habitats and host plants of buckmoths (Hemileuca: Saturniidae: Hernileucinae) in Michigan are described and compared to those of the three species known from eastern North America, H. maia, H. nevadensls, and H. lucina. Michigan populations show variation in host plant and habitat use spanning the entire range of all three species. The presence of transitional phenotypes and the host plant and habitat data suggest that Michigan populations are a single, variable species. These things combined with the intermediate geographical location of Michigan\u27s populations call into question the taxonomic distinctness of the three eastern buckmoth species

Dew Chemistry

From July, 1989 to July 1990 a total of 98 dews and 9 frosts were collected at the University of Arkansas Agricultural Experiment Station, Fayetteville. The total water flux from dews and frosts per year is less than 2% of that from rains. Acid and nutrient fluxes are also much lower in dew. In the following series of ions the number in parenthesis gives the % of the yearly flux of the ion in dew compared to rain for an average year: H+ (0.08), Ca2+ (23), Mg2+(9), K+(20), Na+(5), NH+(12), Cl-(7), S02/4-(5) and N0-/3 (6). A typical dew has a pH of 6.25 compared to 4.9 for the average rain, and is thus much less acidic. Acetate and formate ions in the April-June period were, in equivalents, higher in dew than in the rain and equal to about one half of the nitrate-sulfate total. The steps governing dew composition are indicated to be (1) nucleation on dry-deposition solids identified as illite, kaolinite, quartz, feldspar, calcite, and dolomite (2) dissolving the soluble portion of the dry deposition by dew water and (3) dissolving of gaseous NH3, acetic, and formic acids into the dew solution

Acoustic characteristics of externally blown flap systems with mixer nozzles

Noise tests were conducted on a large scale, cold flow model of an engine-under-the-wing externally blown flap lift augmentation system employing a mixer nozzle. The mixer nozzle was used to reduce the flap impingement velocity and, consequently, try to attenuate the additional noise caused by the interaction between the jet exhaust and the wing flap. Results from the mixer nozzle tests are summarized and compared with the results for a conical nozzle. The comparison showed that with the mixer nozzle, less noise was generated when the trailing flap was in a typical landing setting (e.g., 60 deg). However, for a takeoff flap setting (20 deg), there was little or no difference in the acoustic characteristics when either the mixer or conical nozzle was used

Shift of the surface-barrier part of the irreversibility line due to columnar defects in Bi_2Sr_2CaCu_2O_8 thin films

We report the results of studying the influence of the uranium-ion irradiation of the Bi_2Sr_2CaCu_2O_8 thin films on the high-temperature part (close to critical temperature) of their irreversibility line. We studied irreversible properties of the films by measuring the hysteresis of nonresonant microwave absorption. The results have revealed the shift of irreversibility line towards low temperatures and magnetic fields. The effect is most significant for the films irradiated with large doses, more than 1T. This fact is in good agreement with the theoretical prediction by Koshelev and Vinokur of suppression of surface barrier by columnar defects.Comment: LaTeX2e, 9 pages with 3 figures, to be published in Physica

Simple Max-Min Ant Systems and the Optimization of Linear Pseudo-Boolean Functions

With this paper, we contribute to the understanding of ant colony optimization (ACO) algorithms by formally analyzing their runtime behavior. We study simple MAX-MIN ant systems on the class of linear pseudo-Boolean functions defined on binary strings of length 'n'. Our investigations point out how the progress according to function values is stored in pheromone. We provide a general upper bound of O((n^3 \log n)/ \rho) for two ACO variants on all linear functions, where (\rho) determines the pheromone update strength. Furthermore, we show improved bounds for two well-known linear pseudo-Boolean functions called OneMax and BinVal and give additional insights using an experimental study.Comment: 19 pages, 2 figure

Vapor-Pressure Lowering of Sulfur Dioxide Solutions of Potassium Thiocyanate from 15 to 25 C. (Abstract)

The vapor-pressure lowering of sulfur dioxide by potassium thiocyanate at 15°, 20° and 25° C. was measured by means of a differential mercury manometer connected to an all glass apparatus which employed no stopcocks. Readings were made to 0.001 cm. with a cathetometer. All concentrations were corrected for the amount of sulfur dioxide in the vapor phase. The molal lowering was approximately one-half the theoretical value at 0.005 molal and decreased with increasing concentration up to 1 molal, the highest concentration studied

Vapor Density, Liquid Density and Surface Tension of Solutions of Potassium Thiocyanate in Liquid Sulfur Dioxide for 10° to 25° C

The vapor density, liquid density and differential capillary rise of pure liquid sulfur dioxide, and sulfur dioxide solutions of potassium thiocyanate were measured at 10, 15, 20, and 25°C in a sealed apparatus which allowed the measurement of all these quantities on the same solution. The apparatus consisted of two Pyrex capillaries sealed on to a Pyrex tube of 16.3 mm diameter in which a quartz bob was suspended from a calibrated quartz spring. By weighing the bob in the vapor, inverting, and weighing in the liquid, the densities could be determined to ± 0.02 mg/ml. All distances including the capillary heights were measured by a special microscope which could be read to ±0.00006 cm. Differential capillary rises could be duplicated to better than ± 0.0002 cm. From the surface tension and its rate of change with temperature the Fötvös constant, critical temperature, total surface energy and Paracor for sulfur dioxide were calculated. For the concentrations of potassium thiocyanate studied, a rise in the surface tension and liquid density was found at each temperature

The Formation of Gas Bubbles in Liquids

Gas bubbles which were formed by passing nitrogen through a glass capillary into liquids were studied by means of stroboscopic frequency measurements, rate of gas flow, and instantaneous ( approx. 10-5 sec. exposure) photographs. The size of the bubbles was determined both from the frequency and rate of gas flow and from measurements of the photographic images of the bubbles. The following pure liquids and solutions were used at room temperature: ethyl alcohol, n-propyl alcohol, aniline, acetone, benzene, chloroform, carbon tetrachloride, methyl alcohol, n-butyl alcohol, ether, and three aqueous solutions of ethyl alcohol. The pressures used were varied from the lowest pressure which would give a steady stream of bubbles (approx. 0.6 cm. of Hg) up to about 2.3 cm. of Hg. Capillary diameters were from 0.0137 to 0.0341 cm. The bubble frequency was practically constant (45-50 bubbles/sec.) for the pure liquids studied at all pressures and capillary diameters used. It follows therefore that the size of each bubble (cm3) is directly proportional to the rate of gas flow (cm3/sec.) and is independent of the properties of the liquid and the capillary diameter in the range of experimental conditions used. Higher pressures, larger capillary diameters, and lower surface tension give larger bubbles as a result of the increased rate of flow. In the case of 20.2, 70.0, and 40.7 per cent aqueous solutions of ethyl alcohol the bubble frequency was greater than with pure liquids and showed a much greater variation with pressure