We have developed an addition to the Steinberg–Guinan high strain-rate constitutive model that extends its validity to strain rates as low as 10−4 s−1. With this new model, we have successfully reproduced a number of rate-dependent, shock-induced phenomena in tantalum, such as precursor on reshock, precursor decay, and shock smearing. We have also successfully calculated a plate-impact experiment at a loading stress of 230 GPa as well as extensive data for yield strength versus strain rate at room temperature and yield strength versus temperature at a strain rate of 10−4 s−1.

Supply chains can improve their performance by developing competitive priorities in a specified sequence: quality, reliability, flexibility, agility, and finally, cost efficiency. This paper extends Ferdows and De Meyer's (1990) sand cone model and Vokurka and Fliedner's (1998) sand cone model extension incorporating agility to supply chain management priorities. This work provides a framework for a cumulative and sustainable improvement process by which supply chains can build a strategic competitive advantage.

R6sume' -Nous avons de'veloppe's une a m e ' l i o r a t i o n au modble c o n s t i t u t i f de S t e i n b e r g e t Guinan p o u r l ' a n a l y s e des mate'riaux k t a u x de de'formation u n i t a i r e e'leve'. Nous avons e'tendus l a v a l i d i t e ' de ce mod'ele aux re'gimes o' J l e s t a u x de d 6 f o r m a t i o n a p p r o c h e n t 1 0 -~s -l e t , en exposant du t a n t a l u m au choc, nous avons r e ' u s s i s ' a r e p r o d u i r e un nombre de ph6nom'enes dgpendant au t a u x de d e ' f o r m a t i o n , comme l e p r e ' c u r s e u r de rechoc, l e d 6 c l i n du p r e c u r s e u r , e t l e re'pansion d u choc. Nous avons a u s s i c o n d u i t s une s i m u l a t i o n 2 plaque-choc ob une f o r c e de c h a r g e de 230 GPa f u t applique'e e t nous avons (l'~ork performed under the auspices of the U . S . Department of Energy by the Lawrence ~iverrnore ~a t i o n a l under Contract W-7405-Eng-48

An inexpensive and easy experiment to measure the electrical resistance of high-T c superconductors as a function of temperature Am.

Two-dimensional radiation magnetohydrodynamic simulations are presented that demonstrate the effects of magnetically driven Rayleigh-Taylor instabilities on the soft x-ray output from Z pinches. Instability models, which reproduce the current drive wave form and match visible framing camera data for instability wavelength and amplitude for implosions on capacitively driven inductive store systems, are used to study the structure of the x-ray output and the spectrum of radiation emitted from the pinch. The results indicate that standard magnetohydrodynamics is capable of reproducing much of the observed data when two-dimensional effects associated with Rayleigh-Taylor instabilities are included.

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