In this study, a genetics-based method is used to truncate acetyl-coenzyme A synthase from Clostridium thermoaceticum (ACS), an alpha2beta2 tetrameric 310 kda bifunctional enzyme. ACS catalyzes the reversible reduction of CO2 to CO and the synthesis of acetyl-CoA from CO (or CO2 in the presence of low-potential reductants), CoA, and a methyl group bound to a corrinoid-iron sulfur protein (CoFeSP). ACS contains 7 metal-sulfur clusters of 4 different types called A, B, C, and D. The B, C, and D clusters are located in the 72 kda beta subunit while the A-cluster, a Ni-X-Fe4S4 cluster that serves as the active site for acetyl-CoA synthase activity, is located in the 82 kda alpha subunit. The extent to which the essential properties of the cluster, including catalytic, redox, spectroscopic, and substrate-binding properties, were retained as ACS was progressively truncated was determined. Acetyl-CoA synthase catalytic activity remained when the entire alpha subunit was removed, as long as CO, rather than CO2 and a low-potential reductant, was used as a substrate. Truncating an {approx} 30 kda region from the N-terminus of the alpha subunit yielded a 49 kda protein that lacked catalytic activity but exhibited A-cluster-like spectroscopic, redox, and CO binding properties. Further truncation …

Testing was performed to define technical issues that may impact long-term viability of the segregation strategy for processing and storing evaporator concentrates. The primary concern is increased potential for nuclear criticality from uranium accumulation. This statistically designed testing examines the fate of uranium when Al and Si rich concentrates are either purposefully or inadvertently combined.

The Gordon Research Conference (GRC) on Chemical Physics Summer School was held at Roger Williams University, Bristol, RI. Emphasis was placed on current unpublished research and discussion of the future target areas in this field.

Three short Nb{sub 3}Sn dipole models based on a single-bore cos-theta coil and a cold iron yoke have been fabricated and tested at Fermilab. This paper summarizes the results of magnetic measurements in those models. The geometrical harmonics, coil magnetization effects, cable eddy currents with and without a stainless steel core, and the ''snap-back'' effect at injection are presented.

A high beam power in the proposed Fermilab Proton Drivers--1.2 MW in 16-GeV PD-I and 0.48 MW in 8-GeV PD-II--implies serious constraints on beam losses in these machines. Only with a very efficient beam collimation system can one reduce uncontrolled beam losses in the machine to an allowable level. The entire complex must be well shielded to allow acceptable hands-on maintenance conditions in the tunnel and a non-controlled access to the outside shielding at normal operation and accidental beam loss. Collimation and shielding performances are calculated and compared for both Proton Drivers.

The overall goal of the proposed research is to provide an improved understanding and predictive capability of the mechanisms that allow metal-reducing bacteria to be effective in the bioremediation of redox sensitive toxic metals and radionuclides. The study is motivated by the likelihood that subsurface metal-reducing bacteria can be stimulated to effectively alter the redox state of contaminants so that they are immobilized in situ for long time periods. The work described in this proposal will advance the technological and scientific needs associated with the long-term management of the enormous inground inventories of Cr, U, Tc, and Co present at numerous DOE installations throughout the country. The objectives of our project are to (1) develop an improved understanding and predictive capability of the rates and mechanisms controlling microbially mediated reduction of toxic metals and radionuclides in heterogeneous field settings, (2) quantify the impacts of hydrological and geochemical processes on the effectiveness of indigenous microorganisms to transform and immobilize radionuclides and metals in situ, (3) provide an improved understanding of the importance of microbial consortia interactions in the bacterial immobilization of radionuclides and toxic metals, and (4) determine intrinsic bioreduction rate parameters to improve our generic predictive capability of in situ …

Final report describing laboratory, pilot scale and production scale evaluation of advanced oxidation systems for emissions and cost reduction in metal casting green sand systems.

The issue of magnetic orientation transitions in thin films combines interesting physics and importance for applications. We study the magnetic transition and phase diagram of a 0.1{micro}m thick (YLaGd){sub 3}(FeGa){sub 5}O{sub 12} films grown on GGG substrate by liquid phase epitaxy. Observed transitions are compared with those in BiGa:TmIG thin films, studied in previous work by one of the authors. A general picture of orientation transitions in thin films of substituted YIG is discussed.

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A five-year, large- and small-scale, static and dynamic experimental research program, in which more than 700 tests were conducted, has demonstrated that unreinforced masonry infills are more ductile and resist lateral loads more effectively than anticipated by conventional code procedures. The tests were conducted both in the laboratory and on existing structures at the Department of Energy's Y-12 National Security Complex. The experimental data indicate that the combination of a steel frame and infill material efficiently resists lateral loads--the infilling provides significant lateral stiffness while the surrounding frame adds ductility and confinement to the overall system. The results from approximately 25 moderate- and full-scale tests on infills showed that with simulated seismic loads, the frames confined the masonry, and the load-carrying capacity of the infill was considerably above the load that caused initial cracking. This finding was a significant departure from classical code approaches that assumed first cracking to be failure of an unreinforced masonry wall. The experimental program, performed for the US Department of Energy, consisted of the following large-scale tests on infills: in situ airbag pressure testing, shake-table tests, and the application of quasi-static in-plane and out-of-plane drift loads. This paper provides a summary of the overall experimental …

The Center for Public Environmental Oversight (CPEO) convened a roundtable in Washington, DC on June 28, 2002 to discuss innovative approaches to long-term management in the cleanup of contaminated property. Twenty participants attended the meeting, including representatives of federal agencies, local government, state regulatory agencies, environmental organizations, and thinking tanks, as well as private consultants with experience in site remediation and redevelopment.

Two MiniPlug calorimeters, designed to measure the energy and lateral position of particles in the (forward) pseudorapidity region of 3.6 < |{nu}| < 5.2 of the CDF detector, have been recently installed as part of the Run II CDF upgrade at the Tevatron {bar p}p collider. They consist of lead/liquid scintillator read out by wavelength shifting fibers arranged in a pixel-type towerless geometry suitable for ''calorimetric tracking''. The design concept, the prototype performance and the final design of the MiniPlugs are here described. A recent cosmic ray test resulted in a light yield of approximately 100 pe/MIP, which exceeds our design requirements.

This report summarize our research accomplishments using funding by DOE grant (DE-FG03-99ER14948) for the period of January 15,1999 C 1/14, 2002. In the last three years, we have published 16 papers. My Postdoctoral Research Associates, my students and myself have presented our results at many conferences.

The Steven test and associated modeling has greatly increased the fundamental knowledge of practical predictions of impact safety hazards for confined and unconfined explosive charges. Building on a database of initial work, experimental and modeling studies of crush, puncture, and perforation scenarios were investigated using the Steven impact test. The descriptions of crush, puncture, and perforation arose from safety scenarios represented by projectile designs that ''crush'' the energetic material or either ''puncture'' with a pinpoint nose or ''perforate'' the front cover with a transportation hook. As desired, these scenarios offer different aspects of the known mechanisms that control ignition: friction, shear and strain. Studies of aged and previously damaged HMX-based high explosives included the use of embedded carbon foil and carbon resistor gauges, high-speed cameras, and blast wave gauges to determine the pressure histories, time required for an explosive reaction, and the relative violence of those reactions, respectively. Various ignition processes were modeled as the initial reaction rate expression in the Ignition and Growth reaction rate equations. Good agreement with measured threshold velocities, pressure histories, and times to reaction was calculated for LX-04 impacted by several projectile geometries using a compression dependent ignition term and an elastic-plastic model with a …

On May 10 and 11, 2002, a workshop entitled ''Theory and Modeling in Nanoscience'' was held in San Francisco, California, sponsored by the offices of Basic Energy Science and Advanced Scientific Computing Research of the Department of Energy. The Basic Energy Sciences Advisory Committee and the Advanced Scientific Computing Advisory Committee convened the workshop to identify challenges and opportunities for theory, modeling, and simulation in nanoscience and nanotechnology, and additionally to investigate the growing and promising role of applied mathematics and computer science in meeting those challenges. This report is the result of those contributions and the discussions at the workshop.

Breweries in the United States spend annually over $200 Million on energy. Energy consumption is equal to 3-8% of the production costs of beer, making energy efficiency improvement an important way to reduce costs, especially in times of high energy price volatility. After a summary of the beer making process and energy use, we examine energy efficiency opportunities available for breweries. We provide specific primary energy savings for each energy efficiency measure based on case studies that have implemented the measures, as well as references to technical literature. If available, we have also listed typical payback periods. Our findings suggest that there may still be opportunities to reduce energy consumption cost-effectively for breweries. Major brewing companies have and will continue to spend capital on cost effective measures that do not impact the quality of the beer. Further research on the economics of the measures, as well as their applicability to different brewing practices, is needed to assess implementation of selected technologies at individual breweries.

The default running mode of the storage ring at the Advanced Photon Source is top-up injection with a horizontal emittance of 3.0 nm-rad and a coupling of 2.0%. For a stored current of 100 mA in 23 bunches the lifetime is 7 h. The ability to run in low beam-lifetime conditions gives us the opportunity to make upgrades that would otherwise be futile. Some of the possible upgrade paths are presented here, such as lower emittance and higher-current operation.

The APS linac modulators provide DC pulses to Thales 35/45-MW klystrons. The modulators are pulse forming network (PFN)-type pulsers with EMI 40-kV switch-mode charging supplies. The PFN consists of two 8-cell lines connected in parallel. EEV CX1836A thyratrons are used as discharge switches. The PSpice simulation of the modulators using OrCAD release 9.1 made it possible to find appropriate parameters of RC circuits that reduce high-frequency ringing of the pulse transformer primary voltage. In order to improve pulse top flatness (originally {+-}3%), new coils were built and installed. The coils allow discrete tuning of pulse waveforms by changing the amount of used turns. The advantage of two parallel-line PFN configurations was also used. An equivalent method using a low-voltage generator was used for PFN fine tuning.

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The Gordon Research Conference (GRC) on CATALYSIS was held at Colby-Sawyer College from 6/23/02 thru 6/28/02. The Conference was well-attended with 118 participants. The attendees represented the spectrum of endeavor in this field coming from academia, industry, and government laboratories, both U.S. and foreign scientists, senior researchers, young investigators, and students.

We present the design, performance, and recent upgrade of a high-resolution, high-charge-sensitivity imaging camera and beam position monitor (BPM) system for the APS linac beam profile measurement. Visible light is generated from the incoming electron beam using standard YAG or optical transition radiation (OTR) converter screens. Two CCD cameras share the light through a beam splitter, each with its own imaging optics. Normally, one camera is configured with high magnification and the other with large field of view. In a different lens configuration, one of the cameras focuses at the far field, allowing the measurement of beam divergence using an OTR screen, while the other camera simultaneous measures the beam size. A four-position actuator was installed recently to provide the option of two screens, a wakefield shield, and an in situ calibration target. A compact S-band beam position monitor electrode was designed to mount directly on the flag. The BPM rf circuit was fabricated from a machinable ceramic (MACOR) cylinder substrate, and the copper electrodes were deposited on the substrate. The new design and precision fabrication process make it viable to explore more complex microstrip components printed on the substrate and higher frequency applications. The proximity of the BPM and …

The Savannah River Technology Center (SRTC) is investigating the viability of vitrification treatment of Argentine ion exchange material as part of a Department of Energy (DOE) - Office of Science and Technology Development Task Plan. Bench-scale studies were performed by the SRTC to define the necessary vitrification process for this material. However, the process had to be demonstrated in a melter system before vitrification could be considered a viable treatment option.