A growth algorithm has been developed to build coral shapes out of a tree of spheres. A volume density defined by the spheres is contoured to give a soft object.'' The resulting contour surfaces are rendered by ray tracing, using a generalized volume texture to produce shading and bump mapped'' normal perturbations. 16 refs., 8 figs.

For the next generation of fusion lasers reflecting mirrors with laser damage thresholds of at least 40 J/cm{sup 2} for 10 ns laser pulses at 1.064 {mu}m are needed. Up to now, no deposition technique has been developed to produce such mirrors. Best R D-values realized today are around 30 J/cm{sup 2} for e-beam evaporated mirrors. R D on conventional e-beam coating processes over the last 10 years has come up with marginal improvements in laser damage thresholds only. However, new technologies, like PICVD developed for the fabrication of ultra-low loss fiber preforms, seem to offer the potential to solve this problem. It is well known that fused silica produced by CVD processes can have laser damage thresholds as high as 80 J/cm{sup 2}. However, the thickness of a single deposited film is in the {mu}m-range for most of the CVD processes used for preform manufacturing; since interference optics need films in the{lambda}/4n range the use of preform-fabrication processes for the purpose of interference mirror fabrication is limited to a few plasma based CVD technologies, namely PCVD. Especially PICVD is a very powerful technology to fabricate thin film multilayers for interference mirrors, because this technique is able to produce films …

The assessed phase diagram of Fe-V exhibits a continuous high temperature bcc solid solution intersected at lower temperatures by a complex sigma phase centered around equiatomic composition. Slow kinetics of the bcc to sigma transformation make it possible to retain the bcc solid solution at low temperature. It has been observed that this metastable solid solution has a tendency to order with a CsCl type structure (B2) below 970 K. As a first attempt to describe this behavior from an electronic structure approach, this paper will study the phase stability on the bcc lattice using a realistic tight-binding Hamiltonian. Main features are as follows: Element and structure specific Slater-Koster parameters are used and lattice parameter effects are incorporated through scaling. Charge transfer is set to zero by rigidly shifting the onsite energies of one constituent. The Coherent Potential Approximation (CPA) is invoked with four levels corresponding to states with s, p, t{sub 2g} and e{sub g} like symmetry. Effects of off-diagonal disorder (ODD) have not been included, instead, an average alloy Hamiltonian was defined using the Slater-Koster parameters of the components weighted by concentration. At equiatomic composition the effect of this approximation has been evaluated by repeating the electronic structure …

Tags and seals have long been recognized as important tools in arms control. The trend in control of armaments is to limit militarily significant equipment that is capable of being verified through direct and cooperative means, chiefly on-site inspection or monitoring. Although this paper will focus on the CFE treaty, the role of tags and seals for other treaties will also be addressed. Published technology and concepts will be reviewed, based on open sources. Arms control verification tags are defined as unique identifiers designed to be tamper-revealing; in that respect, seals are similar, being used as indicators of unauthorized access. Tamper-revealing tags might be considered as single-point markers, seals as two-point couplings, and nets as volume containment. The functions of an arms control tag can be considered to be two-fold: to provide field verification of the identity of a treaty-limited item (TLI), and to have a means of authentication of the tag and its tamper-revealing features. Authentication could take place in the field or be completed elsewhere. For CFE, the goal of tags and seals can be to reduce the overall cost of the entire verification system.

To demonstrate the accounting framework and give some practical meaning to the concept of external costs of various stages of the fuel cycle, we will apply the approach to a limited number of case studies. These case studies will emphasize two of the major sectors for which energy sources are needed: electricity production and transportation. Because the intent here is to illustrate the approach and not to derive sweeping generalizations or comparisons, criteria and proposed selections for the two sectors were not constrained to be identical. However, applications to either sector require the resolution of a number of general issues. 1 fig.