GSFC Ada programming guidelines

A significant Ada effort has been under way at Goddard for the last two years. To ease the center's transition toward Ada (notably for future space station projects), a cooperative effort of half a dozen companies and NASA personnel was started in 1985 to produce programming standards and guidelines for the Ada language. The great richness of the Ada language and the need of programmers for good style examples makes Ada programming guidelines an important tool to smooth the Ada transition. Because of the natural divergence of technical opinions, the great diversity of our government and private organizations and the novelty of the Ada technology, the creation of an Ada programming guidelines document is a difficult and time consuming task. It is also a vital one. Steps must now be taken to ensure that the guide is refined in an organized but timely manner to reflect the growing level of expertise of the Ada community

Spontaneous Expulsion of Giant Lipid Vesicles Induced by Laser Tweezers

Irradiation of a giant unilamellar lipid bilayer vesicle with a focused laser spot leads to a tense pressurized state which persists indefinitely after laser shutoff. If the vesicle contains another object it can then be gently and continuously expelled from the tense outer vesicle. Remarkably, the inner object can be almost as large as the parent vesicle; its volume is replaced during the exit process. We offer a qualitative theoretical model to explain these and related phenomena. The main hypothesis is that the laser trap pulls in lipid and ejects it in the form of submicron objects, whose osmotic activity then drives the expulsion.Comment: Plain TeX file; uses harvmac and epsf; .ps available at http://dept.physics.upenn.edu/~nelson/expulsion.p

An Analysis of Pricing Strategy and Price Dispersion on the Internet

Using prices obtained from shopbots, we test several hypotheses regarding the economics of information and optimal search. We find that price dispersion is positively (negatively) related to product price and the number of sellers in cross-sectional (time series) analysis. Price dispersion increases over time when the sample includes new entrants, but decreases in the absence of entry. Controlling for shipping charges and seller heterogeneity reduces, but does not eliminate, price dispersion. Finally, prices appear to be correlated across products and over time – low price sellers for one product (time period) generally charge low prices for all items (time periods).

And Now to Define the Terms...

The quality of any debate depends to a large extent on a concise, accurate, and honest appraisal of the main terms in a resolution. Al though almost all textbooks on argumentation carry chapters on definitions of terms and principles to be followed, yet many high school and college debaters arc perfunctory in analyzing the questions they debate. In listening to hundreds of debates over a period of years, I have observed many recurring deficiencies in the interpretation of the resolution. Among the most common faults have been: 1. Strained and limited definitions for purpose of strategy. 2. Quibbling over terms when no issue is at stake. 3. Failure to contend definitions when they are issues. 4. Failure of affirmative plan to correspond to the terms as defined. 5. Reliance on dictionary definitions. 6. Inefficiency in the use of language. 7. Confusion over the meaning of the word should

Lantana camara L.

https://thekeep.eiu.edu/herbarium_specimens_byname/18898/thumbnail.jp

Cooling by Evaporization in Moving Air

There is present no satisfactory theory for the wet and dry bulb hygrometer in moving air and these experiments were started with idea of getting more information about the effect of the rate of evaporation and the shape of the covered bulb on the lowering of temperature. So far in this investigation only the cylindrical shape has been used. Only a section of the cylinder is covered with moistened muslin and with constant air velocity and humidity, the rates of cooling are compared when the covered section makes different angles with the air stream

Science in a Changing World - Paper Presented at the Fifty-Sixth Annual Meeting

This year Iowa Wesleyan College celebrates the Centennial Anniversary of its founding and the Iowa Academy of Science pays tribute to that institution by holding its Fifty-sixth Annual meeting here in Mount Pleasant. Scarcely a decade after the first permanent settlers had taken up their abode in what later became the state of Iowa, this institution had its beginnings. It ranks among the oldest institutions of higher learning west of the Mississippi River

Wind Noise: Its Effect on Human Audition

An examination was made of the acoustic characteristics of wind turbulence generated noise in a car traveling at 70 mph over smoothly paved highway with the driver\u27s window down. The overall noise level was found to be at 112 dB SPL with the predominance of energy in the low frequencies. The study was concerned with the effects of such noise on human audition in terms of temporary threshold shift. Twenty normal hearing young adults were exposed to a tape recording of wind noise for 15 minutes. Post-exposure auditory thresholds at seven discreet frequencies were compared to pre-exposure auditory thresholds at the same seven frequencies. Threshold shift was taken as the difference between pre-exposure and post-exposure thresholds. Post-exposure thresholds were obtained immediately after exposure and at five, ten and fifteen minutes after exposure. The results of the study indicate to significant difference in the amount of threshold shift or the rate of recover based on sex. A significant difference was observed int he amount of threshold shift at different test frequencies. The rate of recovery at different test frequencies was also significantly different. Decisions of significance were made at the .01 level of confidence. The statistical tool utilized was analysis of variance