Table and charts of equilibrium normal-shock properties for hydrogen-helium mixtures with velocities to 70 km/sec. Volume 3: 0.85 H2-0.15 He (by volume)

For abstract, see N77-18234

Table charts of equilibrium normal-shock properties for hydrogen-helium mixtures with velocities to 70 km/sec. Volume 2: 0.90 H2-0.10 He (by volume)

For abstract, see N77-18234

Table and charts of equilibrium normal-shock properties for hydrogen-helium mixtures with velocities to 70 km/sec. Volume 1: 0.95 H2-0.05 He (by volume)

Equilibrium thermodynamic and flow properties are presented in tabulated and graphical form for moving, standing, and reflected normal shock waves into hydrogen-helium mixtures representative of postulated outer planet atmospheres. These results are presented in four volumes and the volmetric compositions of the mixtures are 0.95H2-0.05He in Volume 1, 0.90H2-0.10He in Volume 2, 0.85H2-0.15He in Volume 3, and 0.75H2-0.25He in Volume 4. Properties include pressure, temperature, density, enthalpy, speed of sound, entropy, molecular-weight ratio, isentropic exponent, velocity, and species mole fractions. Incident (moving) shock velocities are varied from 4 to 70 km/sec for a range of initial pressure of 5 N/sq m to 100 kN/sq m. Results are applicable to shock-tube flows and for determining flow conditions behind the normal portion of the bow shock about a blunt body at high velocities in postulated outer planet atmospheres. The document is a revised version of the original edition of NASA SP-3085 published in 1974

Tables and charts of equilibrium normal shock and shock tube solutions for pure CO2 with velocities to 16 km/second

Equilibrium thermodynamic and flow properties are presented in tabulated and graphical form for moving, standing, and reflected normal shock waves in pure CO2, representative of Mars and Venus atmospheres. Properties include pressure, temperature, density, enthalpy, speed of sound, entropy, molecular weight ratio, isentropic exponent, velocity and species mole fractions. Incident (moving) shock velocities are varied from 1 to 16 km/sec for a range of initial pressure of 5 Newtons per square meter to 500 kilo Newtons per square meter. The present results are applicable to shock tube flows, and to free-flight conditions for a blunt body at high velocities. Working charts illustrating idealized shock-tube performance with CO2 test gas and heated helium and hydrogen driver gases are also presented

Costs and Returns Analysis for South Carolina Shrimp Trawlers

This document provides an explanation on how shrimp trawler owners/operators can analyze the effects of changing costs and ex-vessel prices on the profitability of operating a shrimp trawler. An Excel spreadsheet is provided with sample boat costs and revenues. The spreadsheet allows the trawler owner/operator to enter costs and revenues data for their own vessel. This can be used to estimate average costs of landing a pound of shrimp by the vessel owner/operator and the profit (loss) per pound of landed shrimp. As input costs vary for key items like fuel, ice, BRDS, etc, the trawler owner can estimate the impact of these input costs on the total average cost of landing a pound of shrimp. Similarly, as the ex-vessel (landed) price for a pound of shrimp changes, the vessel owner/operator can estimate the impact of these price changes on the profitability of operating the trawler.Resource /Energy Economics and Policy,

Time lost from work among the currently employed population, United States--1968

[by Charles S. Wilder]Includes bibliographical references

Uses and Potentials of Wikis in the Classroom

As Prensky (2001) observes, "Our students have changed radically. Today's students are no longer the people our educational system was designed to teach " (1). Prensky sees today's students as digital natives while most of today's teachers remain digital immigrants. In particular, today's educators are acculturated to a print paradigm while students are increasingly products of a digitally-based secondary-oral paradigm. Happily for educators, electronic and cyber technologies can potentially combine the best aspects of both print and secondary-oral paradigms, allowing educators to move freely across the print-oral continuum. One cyber technology enabling this movement is the wiki, a unique interface where information is not fixed (as in a print model) but fluid and flexible to meet the needs of the community (as in the pre-literate age). In this article we describe how teaching and learning have changed across oral, print, and secondary-oral paradigms; in turn, after addressing some controversies over the use of wikis as scholarly and educational resources, we advocate the use of wikis as a teaching and learning tool. Technology and Learning Paradigms As technologies have changed through the millennia, so have teaching methods. From the one-to-one oral teaching style of the early agrarian age (pre-writing and pre-printing cultures) to the apprenticeship system and one-to-many lectures of the pre-industrial ages (writing and print cultures), teaching was predominantl