Microstructurally-induced changes in the local stress state (triaxial constraint) and their effect on fracture-toughness behavior are examined at ambient and cryogenic temperatures in an Al-Li-Cu-Zr alloy, processed in the form of 12.7 mm-thick naturally laminated'' plate containing aligned-weak interfaces and 1.6 mm-thin unlaminated sheet. It is shown that marked improvements in long-transverse (L-T) toughness can be achieved in the plate material at cryogenic temperatures by promoting through-thickness delamination along these interfaces, which relaxes local constraint and promotes a fracture-mode transition from global plane strain to local plane stress. Conversely, in thin sheet material, the absence of such interface delamination leads to a reduction in toughness with decrease in temperature, consistent with the greater degree of crack-tip constraint. 17 refs., 4 figs., 1 tab.

Fatigue-crack propagation behavior in powder-metallurgy (P/M) aluminum-lithium alloys, namely, mechanically-alloyed (MA) Al-4.0Mg-1.5Li-1.1C-0.80{sub 2} (Inco 905-XL) and rapid-solidification-processed (RSP) Al-2.6Li-1.0Cu-0.5Mg-0.5Zr (Allied 644-B) extrusions, has been studied, and results compared with data on an equivalent ingot-metallurgy (I/M) Al-Li alloy, 2090-T81 plate. Fatigue-crack growth resistance of the RSP Al-Li alloy is found to be comparable to the I/M Al-Li alloy; in contrast, crack velocities in MA 905-XL extrusions are nearly three orders of magnitude faster. Growth-rate response in both P/M Al-Li alloys, however, is high anisotropic. Results are interpreted in terms of the microstructural influence of strengthening mechanism, slip mode, grain morphology and texture on the development of crack-tip shielding from crack-path deflection and crack closure. 14 refs., 7 figs., 2 tabs.

Photograph used for a story in the Daily Oklahoman newspaper. Caption: "Jim Davis prepares for the Chickasha Founders' Day festival onion peeling contest."

Photograph used for a story in the Daily Oklahoman newspaper. Caption: "Mary Kay Kennedy, Kimberly Kennedy and Sharon Greene admire a bride doll during Kimberly's wedding shower."

The mission of the Analytical Services Group (ASG) is to provide analytical support for Savannah River Laboratory Research and Development Programs using onsite and offsite analytical labs as resources. A second mission is to provide Savannah River Site (SRS) operations with analytical support for nonroutine material characterization or special chemical analyses. The ASG provides backup support for the SRS process control labs as necessary.

Photograph used for a story in the Daily Oklahoman newspaper.

Photograph used for a story in the Oklahoma Times newspaper. Caption: "Capitol Hill middle school pupils look over test workbooks before getting down to business."

A master plan for the Yakima/Klickitat Production Project (YKPP) was developed by the Northwest Power Planning Council (Council) on October 15, 1987, as a reasonable basis upon which the Bonneville Power Administration (BPA) could proceed to fund predesign work on the project. The Council approved the predesign work on the condition that eight preliminary tasks were completed. These tasks are: Task 1. Agreement on a refined statement of project goals. Task 2. Completion of a technical analysis of water supplies. Task 3. Completion of an experimental design plan. Task 4. Development of a harvest management plan. Task 5. Assessment of potential genetic risks. Task 6. Project coordination with all other affected parties. Task 7. Submission of a preliminary design report to the Council. Task 8. Develop a project management structure. The preliminary design report summarizes the work completed on these tasks. It provides a description of the preliminary design, engineering, and construction phases of project development, and gives an estimate of project costs. Also included is a description of other studies that were conducted to support YKPP planning. The results of studies conducted during the last 30 months indicate that hatchery facilities can be built in the Yakima and Klickitat …

Multilayer structures of W/C, WC/C, and Ru/C, of various periods were prepared and studied by high-resolution transmission electron microscopy. Comparison of the phases in the layered structures is made for as-prepared and annealed samples. Both as-prepared and annealed WC/C multilayers are predominantly amorphous, while the phases in the W/C depend on the periods. The 2 nm period W/C multilayer remains amorphous after annealing, and the longer periods recrystallize to form W{sub 2}C. The layered microstructures of W/C and WC/C are stable on annealing at all periods, while the amorphous Ru-rich layers in the 2 nm period Ru/C multilayer agglomerate upon annealing to form elemental hexagonal Ru crystallites. Larger period Ru/C multilayers show stable layered structures, and indicate hexagonal Ru in the Ru-rich layers. X-ray measurements show that the multilayer periods expand on annealing for all metal-carbon multilayers studied. 15 refs., 5 figs., 1 tab.

Alloys with reduced long-life radioactivity (low activation alloys) are being developed to increase the acceptability of fusion power. The phase stability and swelling resistance of a 12Cr-6.5Mn-1W-0.3V-0.1C martensitic steel were evaluated by transmission electron microscopy following 3.8 MeV Fe{sup ++} ion irradiation with and without He coimplantation. Ion irradiations were performed at 450{degree}C, 550{degree}C, and 650{degree}C to approximately 10, 20, and 40 dpa. At 550{degree}C, approximately 20 appm He/dpa was coimplanted with the 3.8 MeV Fe{sup ++} ions. The specimens were examined at a depth approximately halfway between the surface and the mean ion range in order to minimize the influence of the surface and of injected ions. At all temperatures, M{sub 23}C{sub 6}, also present in the unirradiated structure, was the only precipitate present. A nonuniform distribution of loops also formed at all temperatures. After the 450{degree}C and 650{degree}C irradiations, no voids were present. At 550{degree}C, the helium did not appear to have much effect. Very few faceted voids formed. At 20 and 40 dpa some bubbles were found but their density was very low. At 650{degree}C, a structure similar to a heavily over-tempered steel was produced by the irradiation. At 550{degree}C recovery was seen to a lesser extent. …

Photograph of a historic property located at 500 block N. Queen in Palestine, Texas.

Photograph of a historic property located at 900 block of S. Magnolia in Palestine, Texas.

Photograph of a historic property located at 101 E. Oak in Palestine, Texas.

Photograph of a historic property located at 400 block S. Queen in Palestine, Texas.

Photograph of a historic property located at 100 block S. Michaux in Palestine, Texas.

A 7-Day Full Series Chronic Toxicity test was conducted April 13--20, 1990, for the Savannah River Site to assess the chronic toxicity of Simulated defense waste processing facility (DWPF) effluent to Ceriodaphnia dubia. The simulated effluented consisted of Sodium Nitrate, Sodium Oxalate, Sodium Formate, and Corros. Inib.

The objective of the program was to develop an advanced coal combustion system for firing beneficiated coal fuels (BCFs) capable of being retrofitted to industrial boilers originally designed for firing natural gas. The High Efficiency Advanced Coal Combustor system is capable of firing microfine coal-water fuel (MCWF), MCWF with alkali sorbent (for SO{sub 2} reduction), and dry microfine coal. Design priorities for the system were that it be simple to operate and offer significant reductions in NO{sub x}, SO{sub x}, and particulate emissions as compared with current coal-fired combustor technology. (VC)

One of the early tasks of the Atmospheric Radiation Measurements (ARM) Program is to provide climatic guides for site selection purposes including possible continental, regional, local and on-site locations. The first guide A Preliminary ARM Guide for Climatic Evaluations'' provided some climate data on a continental scale; this one is an attempt to show the variability that exists over a region. Kansas was chosen for this particular guide because it satisfies most of the requirements given in the ARM Program Plan, i.e., climatic significance, potential for synergism with other programs and scientific and logistical viability. Kansas has extreme climatic variations, is centrally located, is compatible with other large scale programs (Fife), has good airfields and accommodations to minimize time and effort in planning and operating an ARM site for continuous use and special campaigns.

Metallic coatings can be fabricated using the intense plasma generated by the metal vapor vacuum arc. We have made and tested an embodiment of vacuum arc plasma source that operates in a pulsed mode, thereby acquiring precise control over the plasma flux and so also over the deposition rate, and that is in the form of a miniature plasma gun, thereby allowing deposition of metallic thin films to be carried out in confined spaces and also allowing a number of such guns to be clustered together. The plasma is created at the cathode spots on the metallic cathode surface, and is highly ionized and of directed energy a few tens of electron volts. Adhesion of the film to the substrate is thus good. Virtually all of the solid metals of the Periodic Table can be used, including highly refractory metals like tantalum and tungsten. Films, including multilayer thin films, can be fabricated of thickness from Angstroms to microns. We have carried out preliminary experiments using several different versions of miniature, pulsed, metal vapor vacuum arc plasma guns to fabricate metallic thin films and multilayers. Here we describe the plasma guns and their operation in this application, and present examples of …

This is the final report of the High Burnup Effects Program (HBEP). It has been prepared to present a summary, with conclusions, of the HBEP. The HBEP was an international, group-sponsored research program managed by Battelle, Pacific Northwest Laboratories (BNW). The principal objective of the HBEP was to obtain well-characterized data related to fission gas release (FGR) for light water reactor (LWR) fuel irradiated to high burnup levels. The HBEP was organized into three tasks as follows: Task 1 -- high burnup effects evaluations; Task 2 -- fission gas sampling; and Task 3 -- parameter effects study. During the course of the HBEP, a program that extended over 10 years, 82 fuel rods from a variety of sources were characterized, irradiated, and then examined in detail after irradiation. The study of fission gas release at high burnup levels was the principal objective of the program and it may be concluded that no significant enhancement of fission gas release at high burnup levels was observed for the examined rods. The rim effect, an as yet unquantified contributor to athermal fission gas release, was concluded to be the one truly high-burnup effect. Though burnup enhancement of fission gas release was observed to …

High speed data transmission using fiber optics in the data acquisition system of the Superconducting Super Collider has been investigated. Emphasis is placed on the high speed data transmission system overview, the local data network and on subassemblies, such as optical transmitters and receivers. Also, the performance of candidate subassemblies having a low power dissipation for the data acquisition system is discussed. 14 refs., 5 figs.

The specific objectives of the bituminous coal program were to explore and evaluate the application of advanced agglomeration technology for: (1)desulphurization of bituminous coals to sulphur content acceptable within the current EPA SO{sub 2} emission guidelines; (2) deashing of bituminous coals to ash content of less than 10 percent; and (3)increasing the calorific value of bituminous coals to above 13,000 Btu/lb. (VC)

In the second year of the current funding period, we continued the study of the following reactions: C({sup 1}D) + H{sub 2} {yields} CH(X{sup 2}{Omicron}) + H, {Delta}H = {minus}6.0 kcal.mol{sup {minus}1}; C({sup 1}D) + HCl {yields} CH(X{sup 2}{Omicron}) + Cl, {Delta}H = 7.0 kcal.mol{sup {minus}1}; and C({sup 1}D) + HCl {yields} CCl(X{sup 2}{Omicron}) + H, {Delta}H = {minus}5.8 kcal.mol{sup {minus}1}. In particular, we concentrated on three issues: the use of two-photon photolysis of C{sub 3}O{sub 2} as a source of C({sup 1}D); the mechanisms of the above reactions and conditions for reliable LIF diagnostics for the CH radical. These studies involved solving several problems both in the generation of C({sup 1}D) and the determination of rotational, spin-orbit and {Lambda}-doublet populations in CH, but they are now nearing completion, and will be written up for publication in the summer. In the third year, we plan to concentrate on three topics: (1) the construction of an efficient laser ablation source for C({sup 3}P); (2) the study of the reaction of C({sup 3}P) with N{sub 2}O and detection of CN and NO products, and (3) a new direction in our lab: enhancement of endoergic reactions of C({sup 3}P) via vibrational excitation of …

The rotary magnetic heat pump has attractive thermodynamic performance but it is strongly influenced by the effectiveness of the regenerator. This study uses local entropy generation analysis to evaluate the regenerator design and to suggest design improvements. The results show that performance of the proposed design is dominated by heat transfer related entropy generation. This suggests that enhancement concepts that improve heat transfer should be considered, even if the enhancement causes a significant increase in viscous losses (pressure drop). One enhancement technique, the use of flow disrupters, was evaluated and the results showed that flow disrupters can significantly reduce thermodynamic losses.