Search

Your search keyword '"Lang, John M."' showing total 19 results
Start Over Author "Lang, John M."
19 results on '"Lang, John M."'

4. Shockwave compression and dissociation of ammonia gas.

Author

Dattelbaum, Dana M., Lang, John M., Goodwin, Peter M., Gibson, Lloyd L., Gammel, William P., Coe, Joshua D., Ticknor, Christopher, and Leiding, Jeffery A.

Subjects
*AMMONIA gas, *SHOCK waves, *DISSOCIATION (Chemistry), *VELOCIMETRY, *PYROMETRY
Abstract

We performed a series of plate impact experiments on NH3 gas initially at room temperature and at a pressure of ∼100 psi. Shocked states were determined by optical velocimetry and the temperatures by optical pyrometry, yielding compression ratios of ∼5–10 and second shock temperatures in excess of 7500 K. A first-principles statistical mechanical (thermochemical) approach that included chemical dissociation yielded reasonable agreement with experimental results on the principal Hugoniot, even with interparticle interactions neglected. Theoretical analysis of reshocked states, which predicts a significant degree of chemical dissociation, showed reasonable agreement with experimental data for higher temperature shots; however, reshock calculations required the use of interaction potentials. We rationalize the very different shock temperatures obtained, relative to previous results for argon, in terms of atomic versus molecular heat capacities. [ABSTRACT FROM AUTHOR]

Published
2019
Full Text
View/download PDF

10. Shockwave compression of Ar gas at several initial densities

Author

Dattelbaum, Dana M., primary, Goodwin, Peter M., additional, Garcia, Daniel B., additional, Gustavsen, Richard L., additional, Lang, John M., additional, Aslam, Tariq D., additional, Sheffield, Stephen A., additional, Gibson, Lloyd L., additional, and Morris, John S., additional

Published
2017
Full Text
View/download PDF

12. Fiber-Interferometric Detection of Gun-Launched Projectiles.

Author

Goodwin, Peter M., Marshall, Bruce R., Gustavsen, Richard L., Lang, John M., Pacheco, Adam H., Loomis, Eric N., and Dattelbaum, Dana M.

Subjects
PROJECTILES, BALLISTICS, OPTICAL fibers, INTERFEROMETERS, PLASMA diagnostics
Abstract

We are developing a new diagnostic useful for the non-invasive detection of projectile passage in the launch tube of a gas gun. The sensing element consists of one or more turns of single-mode optical fiber that is epoxy-bonded around the external circumference of the launch tube. The hoop strain induced in the launch tube by the passage of the projectile causes a momentary expansion of the fiber loop. This transient change in path length is detected with high sensitivity using a fiber optic-based interferometer developed by the NSTec Special Technologies Laboratory. We have fielded this new diagnostic, along with fiber optic Bragg grating (FBG) strain gauges we previously used for this purpose, on a variety of gas guns used for shock compression studies at Los Alamos and Sandia National Laboratories.We anticipate that, when coupled with a broad-range analog demodulator circuit, the fiber optic interferometer will have improved dynamic range over that of the FBG strain gauge approach. Moreover, in contrast to the FBG strain gauge which is somewhat temperature sensitive, the interferometric approach requires no alignment immediately prior to the experiment and is therefore easier to implement. Both approaches provide early, pre-event signals useful for triggering high-latency diagnostics. [ABSTRACT FROM AUTHOR]

Published
2017
Full Text
View/download PDF

15. MARKET FORCES.

Author

Lang, John M.

Subjects
RESTAURANTS, MENUS, FARMERS' markets, BUTCHERS, TRAINING of restaurant personnel, BUSINESS expansion
Abstract

The article discusses a range of services offered by restaurants in the U.S. including evening farmers market, cooking demonstration and live music. It notes the menu trend that has created opportunities for chefs to add retail like butcher shops which double as production facilities for the restaurant. It offers tips on expansion opportunities and rules of retail which include integrating retail production in the dining room to stabilize costs and training of all staff to build add-on sales.

Published
2014

Catalog

Books, media, physical & digital resources
See catalog results