Building on recent work by N. Arkani-Hamed and the present authors, we construct realistic models that break supersymmetry dynamically and give rise to composite quarks and leptons, all in a single strongly-coupled sector. The most important improvement compared to earlier models is that the second-generation composite states correspond to dimension-2 ''meson'' operators in the ultraviolet. This leads to a higher scale for flavor physics, and gives a completely natural suppression of flavor-changing neutral currents. We also construct models in which the hierarchy of Yukawa couplings is explained by the dimensionality of composite states. These models provide an interesting and viable alternative to gravity- and gauge-mediated models. The generic signatures are unification of scalar masses with different quantum numbers at the compositeness scale, and lighter gaugino, Higgsino, and third-generation squark and slepton masses. We also analyze large classes of models that give rise to both compositeness and supersymmetry breaking, based on gauge theories with confining, fixed-point, or free-magnetic dynamics.

Using defect thermodynamics, we discuss physical factors that affect doping limits in semiconductors. The dependencies of the defect formation enthalpy on the atomic chemical potentials and on the electron Fermi energy are demonstrated. These dependencies, in particular on the Fermi energy, lead to spontaneous formation of charge-compensating defects that can limit doping. Experimental data compiled for III-V, II-VI, and I-III-VI2 compounds support this view and further provide insight into the connections among different host materials. We argue that what matters is not the magnitude of the band gap that determines the dopability of a material, but rather, the relative position of the conduction-band minimum (in the case of n-doping) and the valence-band maximum (in the case of p-doping) with respect to vacuum.

We have studied the restoration of chiral symmetry in lattice QCD at the finite temperature transition from hadronic matter to a quark-gluon plasma. By measuring the screening masses of flavour singlet and non-singlet meson excitations, we have seen evidence that, although flavour chiral symmetry is restored at this transition, flavour singlet (U(1)) axial symmetry is not. We conclude that this indicates that instantons continue to play an important role in the quark-gluon plasma phase.

The results of studies of energy consumption and emission inventories in Asia are discussed. These data primarily reflect emissions from fuel combustion (both biofuels and fossil fuels) and were collected to determine emissions of acid-deposition precursors (SO{sub 2} and NO{sub x}) and greenhouse gases (CO{sub 2} CO, CH{sub 4}, and NMHC) appropriate to RAINS-Asia regions. Current work is focusing on black carbon (soot), volatile organic compounds, and ammonia.

The role of extended and point defects, and key impurities such as C, O and H, on the electrical and optical properties of GaN is reviewed. Recent progress in the development of high reliability contacts, thermal processing, dry and wet etching techniques, implantation doping and isolation and gate insulator technology is detailed. Finally, the performance of GaN-based electronic and photonic devices such as field effect transistors, UV detectors, laser diodes and light-emitting diodes is covered, along with the influence of process-induced or grown-in defects and impurities on the device physics.

A toroid cavity nuclear magnetic resonance (NMR) detector capable of recording radial concentration profiles, diffusion constants, and displacements of charge carriers was employed to investigate the lithium ion distribution in an electrochemical cell containing a carbonaceous material synthesized from pyrene and pillared clays as inorganic templates. A carbon rod was used in a control experiment to assign the Li{sup +} spectrum and to calibrate the one dimensional radial images.

We describe the application of Dyson-Schwinger equations to the calculation of hadron observable. The studies at zero temperature (T) and quark chemical potential ({mu}) provide a springboard for the extension to finite-(T, {mu}). Our exemplars highlight that much of hadronic physics can be understood as simply a manifestation of the nonperturbative, momentum-dependent dressing of the elementary Schwinger functions in QCD.

The need to establish benchmarks for available power-generating cycles having reduced atmospheric emissions of CO{sub 2} served as the basis for this study. Innovative process technologies need this benchmark so they can be appreciated in their proper perspective. An oxygen-blown KRW coal-gasification plant producing hydrogen, electricity, and supercritical-CO{sub 2}, was studied in a full-energy cycle analysis extending from the coal mine to the final destination of the gaseous product streams. A location in the mid-western US 100 mi from Old Ben No.26 mine was chosen. Three parallel gasifier trains, each capable of providing 42% of the plant's 413.5 MW nominal capacity use 3,845 tons/day of Illinois No.6 coal from this mine. The plant produces a net 52 MW of power and 131 MMscf/day of 99.999% purity hydrogen which is sent 62 mi by pipeline at 34 bars. The plant also produces 112 MMscf/day of supercritical-CO{sub 2} at 143 bars, which is sequestered in enhanced oil recovery operations 310 mi away.

The authors report zero-field inelastic neutron scattering experiments on a 14-gram deuterated sample of Mn{sub 12}-Acetate consisting of a large number of identical spin-10 magnetic clusters. Their resolution enables them to see a series of peaks corresponding to transitions between the anisotropy levels within the spin-10 manifold. A fit to the spin Hamiltonian H = {minus}DS{sub z}{sup 2} + {mu}{sub B}B{center_dot}g{center_dot}S-BS{sub z}{sup 4} + C(S{sub +}{sup 4} + S{sub {minus}}{sup 4}) yields an anisotropy constant D = (0.54 {+-} 0.02) K and a fourth-order diagonal anisotropy coefficient B = (1.2 {+-} 0.1) x 10{sup {minus}3}K. Unlike EPR measurements, their experiments do not require a magnetic field and yield parameters that do not require knowledge of the g-value.

Targets for Inertial Confinement Fusion (ICF) typically consist of a hollow, spherical capsule filled with a mixture of hydrogen isotopes. Typically, these capsules are irradiated by short, intense pulses of either laser light (``direct drive``) or laser-generated. x-rays (``indirect drive``), causing them to implode This compresses and heats the fuel, leading to thermonuclear fusion. This process is highly sensitive to hydrodynamic (e.g., Rayleigh-Taylor) instabilities, which can be initiated by imperfections in the target. Thus, target capsules must be spherical and smooth One of the lead capsule designs for the National Ignition Facility, a 1.8 MJ laser being built at Livermore, calls for a 2-mm- diam capsule with a 150-{micro}m-thick copper-doped beryllium wall. These capsules can be fabricated by sputter depositing the metal onto a spherical plastic mandrel. This results in surfaces with measured Rq`s of 50 to 150 nm, as measured with an atomic force microscope For optimal performance the roughness should be below 10 nm rms We have begun studying the use of ion cluster beam polishing as a means of improving the surface finish of as-deposited capsules In this approach, a batch of capsules would be agitated in a bounce pan inside a vacuum chamber during exposure to …

We have developed a semi-automated method for determining the series resistance profiles of dot capacitors and for obtaining corrected oxide fields at breakdown. This method is based upon a least-squares-fit of IV data obtained from a voltage-ramp test to the Fowler-Nordheim leakage model. The profiles provide insight into the general characteristics of series resistance. Certain features of the profiles can be associated with charge trapping and the onset of oxide breakdown.

We have studied numerically the evolution and decay of axion strings. These global defects decay mainly by axion emission and thus contribute to the cosmological axion energy density. The relative importance of this source relative to misalignment production of axions depends on the spectrum. Radiation spectra for various string loop configurations are presented. They support the contention that the string decay contribution is of the same order of magnitude as the contribution from misalignment.

Enhanced transmission of a low intensity laser beam is observed when crossed with an identical-frequency beam in a plasma with a flow velocity near the ion sound speed. The time history of the enhancement and the dependence on the flow velocity strongly suggest that this is due to energy transfer between the beams via a resonant ion wave with zero frequency in the laboratory frame. The maximum energy transfer has been observed when the beams cross in a region with Mach 1 flow. The addition of frequency modulation on the crossing beams is seen to reduce the energy transfer by a factor of two. Implications for indirect-drive fusion schemes are discussed.

In 1989, the Agency for Toxic Substances and Disease Registry evaluated the entire 35,000-acre U. S: Department of Energy (DOE) Oak Ridge Reservation (ORR, located in Oak Ridge, TN) and placed it on the National Priorities List (NPL), making the ORR subject to Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) regulations. Although much of the ORR has not been impacted by previous federal activities, without investigation it is difficult to discern which parcels of land are free of surface contamination. In 1996, the DOE Oak Ridge Environmental Management Program (EM) funded the Footprint Reduction Project to: 1) develop a process to study the large areas of the ORR that are believed to be free of surface contamination and 2) initiate the delisting of the "clean" areas from the NPL. Although this project's goals do not include the transfer of federal property to non-federal entities, the process development team aimed to provide a final product with multiple uses. Therefore, the process was developed to meet the requirements of NPL delisting and the transfer of non- contaminated federal lands to future land users. Section 120 (h) of the CERCLA law identifies the requirements for the transfer of federal property that is …

The Savannah River Site is in the process of removing waste (sludge and salt cake) from million gallon waste tanks. The authors are conducted a test program to determine mixer requirements for suspending sludge heels using shrouded axial impeller mixers. The authors will present and discuss the data generated during the tests.

A sonoluminescing bubble has been modeled as a thermally conducting, partially ionized, two-component radiating plasma. The recent measurements of {approximately} 100ps pulse widths by Gompf et al. are useful for constructing a consistent plasma thermal conduction model that refines our previous model. Normal thermal conduction in the gas and liquid, vapor pressure, and temperature-dependent surface tension are also included in our nonlinear hydrodynamic simulations of the growth and collapse of a gas bubble and the liquid that surrounds it. We validate the model by comparing our simulations with the experimental data of Gaitan and Holt [R{sub 0}, R{sub max}, and intensity, for different driving pressures]. We also calculate the 2D collapse of a sonoluminescing bubble in a uniform magnetic field. The numerical results show that the magnetic field induces an aspherical collapse that reduces the peak temperature in the gas and quenches SBSL. The calculated quenching is consistent with experimental data.

To probe directly the analyte/film interactions that characterize molecular recognition in gas sensors, we recorded changes to the in-situ surface vibrational spectra of specifically fictionalized surface acoustic wave (SAW) devices concurrently with analyte exposure and SAW measurement of the extent of sorption. Fourier-lmnsform infrared external- reflectance spectra (FTIR-ERS) were collected from operating 97-MH2 SAW delay lines during exposure to a range of analytes as they interacted with thin-film coatings previously shown to be selective: cyclodextrins for chiral recognition, Ni-camphorates for Lewis bases such as pyridine and organophosphonates, and phthalocyanines for aromatic compounds. In most cases where specific chemical interactions-metal coordination, "cage" compound inclusion, or z stacking-were expected, analyte dosing caused distinctive changes in the IR spectr~ together with anomalously large SAW sensor responses. In contrast, control experiments involving the physisorption of the same analytes by conventional organic polymers did not cause similar changes in the IR spectra, and the SAW responses were smaller. For a given conventional polymer, the partition coefficients (or SAW sensor signals) roughly followed the analyte fraction of saturation vapor pressure. These SAW/FTIR results support earlier conclusions derived from thickness-shear mode resonator data.

The Agile Manufacturing Prototyping System (AMPS) is being integrated at Sandia National Laboratories. AMPS consists of state of the industry flexible manufacturing hardware and software enhanced with Sandia advancements in sensor and model based control; automated programming, assembly and task planning; flexible fixturing; and automated reconfiguration technology. AMPS is focused on the agile production of complex electromechanical parts. It currently includes 7 robots (4 Adept One, 2 Adept 505, 1 Staubli RX90), conveyance equipment, and a collection of process equipment to form a flexible production line capable of assembling a wide range of electromechanical products. This system became operational in September 1995. Additional smart manufacturing processes will be integrated in the future. An automated spray cleaning workcell capable of handling alcohol and similar solvents was added in 1996 as well as parts cleaning and encapsulation equipment, automated deburring, and automated vision inspection stations. Plans for 1997 and out years include adding manufacturing processes for the rapid prototyping of electronic components such as soldering, paste dispensing and pick-and-place hardware.

The Biofilm mode of growth provides such significant advantages to the members of the consortium that most organisms in important habitats are found in biofilms. The study of factors that allow manipulation of biofilm microbes in the biofilm growth state requires that reproducible biofilms by generated. The most effective monitoring of biofilm formation, succession and desquamation is with on-line monitoring of microbial biofilms with flowcell for direct observation. The biofilm growth state incorporates a second important factor, the heterogeneity in the distribution in time and space of the component members of the biofilm consortium. This heterogeneity is reflected not only in the cellular distribution but in the metabolic activity within a population of cells. Activity and cellular distribution can be mapped in four dimensions with confocal microscopy, and function can be ascertained by genetically manipulated reporter functions for specific genes or by vital stains. The methodology for understanding the microbial ecology of biofilms is now much more readily available and the capacity to manipulate biofilms is becoming an important feature of biotechnology.

In the US, impure Pu-containing materials such as residues and scrapes are in storage, in known quantities, and in materials of various compositions with known Pu contents. However, in Russia, there are no substantial quantities of accumulated impure Pu-containing materials awaiting processing either for disposition or for transuranic (TRU) geologic disposal as there are in the Us. during the Cold War, the Russian approach to Pu processing for weapons production was different from that of the US. All impure Pu- containing materials were routinely reprocessed, and the residual Pu was recovered and purified for reuse until residual Pu levels of less than 200 mg/kg (less than 200 ppm) in any discharged solid process waste streams were reached. Wastes containing less than 200 ppm Pu were routinely discharged for burial in cement waste forms. Russia is studying changing from this practice of recovery of impure Pu for reuse to immobilizing future impure Pu-containing materials into solids at higher concentrations of Pu than 200 ppm for eventual geologic disposal.

The direct connection of information, captured in forms such as CAD databases, to the factory floor is enabling a revolution in manufacturing. Rapid response to very dynamic market conditions is becoming the norm rather than the exception. In order to provide economical rapid fabrication of small numbers of variable products, one must design with manufacturing constraints in mind. In addition, flexible manufacturing systems must be programmed automatically to reduce the time for product change over in the factory and eliminate human errors. Sensor based machine control is needed to adapt idealized, model based machine programs to uncontrolled variables such as the condition of raw materials and fabrication tolerances.

The authors examined the ability of a halophilic bacterium (WIPP 1A) isolated from the Waste Isolation Pilot Plant (WIPP) site to accumulate uranium in order to determine the potential for biocolloid facilitated actinide transport. The bacterial cell surface functional groups involved in the complexation of the actinide were determined by titration. Uranium, added as uranyl nitrate, was removed from solution at pH 5 by cells but at pH 7 and 9 very little uranium was removed due to its limited solubility. Although present as soluble species, uranyl citrate at pH 5, 7, and 9, and uranyl carbonate at pH 9 were not removed by the bacterium because they were not bioavailable due to their neutral or negative charge. Addition of uranyl EDTA to brine at pH 5, 7, and 9 resulted in the immediate precipitation of U. Transmission electron microscopy (TEM) and energy dispersive X-ray spectroscopy (EDS) analysis revealed that uranium was not only associated with the cell surface but also accumulated intracellularly as uranium-enriched granules. Extended X-ray absorption fine structure (EXAFS) analysis of the bacterial cells indicated the bulk sample contained more than one uranium phase. Nevertheless these results show the potential for the formation of actinide bearing bacterial …

A review is made of the infrastructure, technology and capabilities of Sandia National Laboratories for the development of micromechanical systems that have potential space applications. By incorporating advanced fabrication processes, such as chemical mechanical polishing, and several mechanical polysilicon levels, the range' of rrticromechanical systems that can be fabricated in these technologies is virtually limitless. Representative applications include a micro- engine driven mirror, and a micromachined lock. Using a novel integrated MEM!YCMOS technology, a six degree-of-freedom accelerometer/gyroscope system has been designed by researchers at U.C. Berkeley and fabricated on the same silicon chip as the CMOS control circuits to produce an integrated micro-navigational unit.

DISTRIBUTED SENSING AND COOPERATING CONTROL FOR SWARMS OF ROBOTIC VEHICLES Key words: Distributed Sensing, Cooperative Control. ABSTRACT We discuss an approach to effectively control a large swarm of autonomous, robotic vehicles, as they per- form a search and tag operation. In particular, the robotic agents are to find the source of a chemical plume. The robotic agents work together through dis- tributed sensing and cooperative control. Distributed sensing is achieved through each agent sampling and sharing his information with others. Cooperative con- trol h accomplished by each agent u-sing its neighbors information to determine an update strategy. INTRODUCTION There is currently considerable interest in expanding the role of robotic vehicles in surveillance and inspec- tion; searching, following and t aggir-g and locating and identifying targets. In particular, researchers are beginning to focus on using small autonomous robotic vehicles for these tasks. This focus has been brought about largely because of the many recent advances in microelectronics and sensors, which include small, low power, CCD cameras; small microprocessors with ex- panded capabilities; autonomous navigation systems using GPS; and severrd types of small sensors. It seems likely that these technological advances will lead to in- expensive, easy to fabricate, autonomous vehicles out- …