Bridged polysilsesquioxanes (BPS) are a family of hybrid organic-inorganic materials prepared by sol-gel polymerization of molecular building blocks that contain a variable organic component and at least two trifunctional silyl groups. The resulting xerogels and aerogels have physical and mechanical properties that are strongly influenced by the organic bridging group. This talk focuses on the synthesis of functional bridged polysilsesquioxanes. Incorporation of functional groups that respond to chemical, photochemical, or thermal stimuli can provide handles for modifying bulk morphology and/or provide function. These materials can find use as ion exchange media, chromatographic stationary phases, photoresists and high capacity selective chemical absorbents.

Calculations of the Hamaker constants representing the van der Waals interactions between conductor, resistor and dielectric materials are performed using Lifshitz theory. The calculation of the parameters for the Ninham-Parsegian relationship for several non-aqueous liquids has been derived based on literature dielectric data. Discussion of the role of van der Waals forces in the dispersion of particles is given for understanding paste formulation. Experimental measurements of viscosity are presented to show the role of dispersant truncation of attractive van der Waals forces.

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Argonne National Laboratory has developed a glass-bonded sodalite waste form to immobilize the salt waste stream from electrometallurgical treatment of spent nuclear fuel. The waste form consists of 75 vol.% crystalline sodalite and 25 vol.% glass. Microindentation fracture toughness measurements were performed on this material and borosilicate glass from the Defense Waste Processing Facility using a Vickers indenter. Palmqvist cracking was confined for the glass-bonded sodalite waste form, while median-radial cracking occurred in the borosilicate glass. The elastic modulus was measured by an acoustic technique. Fracture toughness, microhardness, and elastic modulus values are reported for both waste forms.

The glass production industry is one of the major users of natural gas in the US, and approximately 75% of the energy produced from natural gas is used in the melting process. Industrial scale glass melting furnaces are large devices, typically 5 or more meters wide, and twice as long. To achieve efficient heat transfer to the glass melt below, the natural gas flame must extend over a large portion of the glass melt. Therefore modern high efficiency burners are not used in these furnaces. The natural gas is injected as a jet, and a jet flame forms in the flow of air entering the furnace. In most current glass furnaces the energy required to melt the batch feed stock is about twice the theoretical requirement. An improved understanding of the heat transfer and two phase flow processes in the glass melt and solid batch mix offers a substantial opportunity for energy savings and consequent emission reductions. The batch coverage form and the heat flux distribution have a strong influence on the glass flow pattern. This flow pattern determines to a significant extent the melting rate and the quality of glass.

Testimony issued by the General Accounting Office with an abstract that begins "Pursuant to a congressional request, GAO discussed issues related to H.R. 4181, which would bar delinquent taxpayers from receiving federal contracts and loan assistance."

Doping In{sub 2}O{sub 3} with tin results in an improved transparent conducting oxide (TCO). Although indium tin oxide (ITO) is the most frequently used commercial TCO, its defect structure is still uncertain. Previously, its defect chemistry has been inferred based on the conductivity of the material. To directly study the defect structure of ITO, the authors prepared powders under different processing environments and performed neutron powder diffraction. Structural information was obtained by performing Rietveld analysis. The results include positions of the atoms, their thermal displacements, the fractional occupancy of the defect oxygen site, and the fractional occupancies of Sn on each of the two nonequivalent cation sites, showing a strong preference for the b site. These structural results are correlated with the measured electrical properties of the same samples.

Testimony issued by the General Accounting Office with an abstract that begins "Pursuant to a congressional request, GAO discussed the Department of Defense's (DOD) financial management reform, focusing on the challenges and initiatives that are in place or planned."

A spectral radiation heat transfer model that conserves emitted and absorbed energy has been developed and used to model the combustion space of an industrial glass furnace. This comprehensive radiation heat transfer model coupled with a computational fluid dynamics (CFD) code was used to investigate the effect of spectral dependencies on the computed results. The results of this work clearly indicate the need for a spectral approach as opposed to a gray body approach since the gray body approach (one waveband) severely underestimates the energy emitted via radiation.

EUVL mask blanks consist of a distributed Bragg reflector made of 6.7nm-pitch bi-layers of MO and Si deposited upon a precision Si or glass substrate. The layer deposition process has been optimized for low defects, by application of a vendor-supplied but highly modified ion-beam sputter deposition system. This system is fully automated using SMIF technology to obtain the lowest possible environmental- and handling-added defect levels. Originally designed to coat 150mm substrates, it was upgraded in July, 1999 to 200 mm and has coated runs of over 50 substrates at a time with median added defects >100nm below 0.05/cm{sup 2}. These improvements have resulted from a number of ion-beam sputter deposition system modifications, upgrades, and operational changes, which will be discussed. Success in defect reduction is highly dependent upon defect detection, characterization, and cross-platform positional registration. We have made significant progress in adapting and extending commercial tools to this purpose, and have identified the surface scanner detection limits for different defect classes, and the signatures of false counts and non-printable scattering anomalies on the mask blank. We will present key results and how they have helped reduce added defects. The physics of defect reduction and mitigation is being investigated by a …

A newly designed cryogenically cooled, thin Si crystal monochromator was tested at the European Synchrotrons Radiation Facility (ESRF) beamline BL3. It exhibited less than 1 arcsec of thermal strain up to a maximum incident power of 186 W and average power density of 521 W/mm{sup 2}. Data were collected for the thin (0.7 mm) portion of the crystal and for the thick (>25 mm) part. Rocking curves were measured as a function of incident power. With a low power beam, the Si(333) rocking curve at 30 keV for the thin and thick sections was < 1 arcsec FWHM at room temperature. The rocking curve of the thin section increased to 2.0 arcsec when cooled to 78 K, while the thick part was unaffected by the reduction in temperature. The rocking curve of the this section broadened to 2.5 arcsec FWHM and that of the thick section broadened to 1.7 arcsec at the highest incident power. The proven range of performance for this monochromator has been extended to the power density, but not the absorbed power, expected for the Advanced Photon Source (APS) undulator A in closed-gap operation (first harmonic at 3.27 kev) at a storage-ring current of 300 mA.

A letter report issued by the General Accounting Office with an abstract that begins "Pursuant to a congressional request, GAO reviewed the Department of Defense's (DOD) Joint Strike Fighter (JSF) Program, focusing on: (1) the program's acquisition strategy; and (2) whether the strategy is being implemented in a manner that will ensure that the acquisition strategy objectives will be achieved."

Temperatures inside the flame zone of large regulatory pool fires measured during tests of radioactive materials packages vary widely with both time and position. Measurements made with several Directional Flame Thermometers, in which a thermocouple is attached to a thin metal sheet that quickly approaches flame temperatures, have been used to construct fire temperature distributions and cumulative probability distributions. As an aid to computer simulations of these large fires, these distributions are presented. The distributions are constructed by sorting fire temperature data into bins 10 C wide. A typical fire temperature distribution curve has a gradual increase starting at about 600 C, with the number of observations increasing to a peak near 1000 C, followed by an abrupt decrease in frequency, with no temperatures observed above 1200 C.

Bridged polysilsesquioxanes are a class of hybrid organic-inorganic materials that permit molecular engineering of bulk properties including porosity. Prepared by sol-gel polymerization of monomers with two or more trialkoxysilyl groups, the materials are highly cross-linked amorphous polymers that are readily obtained as gels. The bridging configuration of the hydrocarbon group insures that network polymers are readily formed and that the organic functionality is homogeneously distributed throughout the polymeric scaffolding at the molecular level. This permits the bulk properties, including surface area, pore size, and dielectric constant to be engineered through the selection of the bridging organic group. Numerous bridging groups have been incorporated. This presentation will focus on the effects that the length, flexibility, and substitution geometry of the hydrocarbon bridging groups have on the properties of the resulting bridged polysilsesquioxanes. Details of the preparation, characterization, and some structure property relationships of these bridged polysilsesquioxanes will be given.

The interdiffusion of Ni matrix/Al particle composite coatings and nickel substrates was studied using electron probe microanalysis (EPMA) and a one-dimensional diffusion model. The initial coating microstructure was a two-phase mixture of y(Ni) and y{prime}(Ni{sub 3}Al). The coating/substrate assemblies were aged at 800 to 1,100 C for times up to 2,000 hours. It was found that aluminum losses to the substrate are significant at 1,000 C and above. The experimental results for the diffusion of Al into the substrate were compared to model predictions based on a diffusion equation for a finite layer on an infinite substrate. Using combined experimental and model results, the effects of temperature and coating thickness were determined and a rationale was developed for coating lifetime prediction.

Staged, fluid catalytic cracking (FCC) processes are deemed to have the potential to enhance FCC performance in the areas of product selectivity, operating flexibility, throughput, reliability, operating costs, and emissions. Computational fluid dynamic (CFD) codes are used to analyze various staged FCC concepts to help accelerate their development into commercial products. Three conceptual multi-stage FCC systems were evaluated using a validated CFD code. The results indicated potential increases of gasoline production from these conceptual designs.

A letter report issued by the General Accounting Office with an abstract that begins "Pursuant to a congressional request, GAO provided information on on-line trading, focusing on: (1) the growth in on-line trading; (2) the extent to which on-line broker-dealers had experienced trading system delays and outages, including the causes of these problems and their reported effect on investors; and (3) how on-line broker-dealers address investor protection issues related to margin, privacy of information, risk disclosures, best execution, suitability, and advertising."

A briefing report issued by the General Accounting Office with an abstract that begins "Pursuant to a legislative requirement, GAO reviewed the Overseas Private Investment Corporation's (OPIC) progress in improving the management of its investment funds program, focusing on: (1) how OPIC identifies and approves investment fund concepts and selects fund managers; (2) the funds' performance to date; and (3) the risk levels assigned to the funds."

The authors performed a simple experiment to elucidate phase structure within a pervasively fractured welded tuff. Dyed water was infiltrated from a surface pond over a 36 minute period while a geophysical array monitored the wetted region within vertical planes directly beneath. They then excavated the rock mass to a depth of {approximately}5 m and mapped the fracture network and extent of dye staining in a series of horizontal pavements. Near the pond the network was fully stained. Below, the phase structure immediately expanded and with depth, the structure became fragmented and complicated exhibiting evidence of preferential flow, fingers, irregular wetting patterns, and varied behavior at fracture intersections. Limited transient geophysical data suggested that strong vertical pathways form first followed by increased horizontal expansion and connection within the network. These rapid pathways are also the first to drain. Estimates also suggest that the excavation captured from {approximately}10% to 1% or less of the volume of rock interrogated by the infiltration slug and thus the penetration depth could have been quite large.

Polysilsesquioxanes, [RSiO{sub 1.5}]{sub n} are a class of hybrid organic-inorganic materials in which silicon atoms are linked with up to three siloxane bonds to other monomer units in the polymer and the organic group is a pendent functionality. Polysilsesquioxanes are prepared by the hydrolysis and condensation of organotrialkoxysilanes (Scheme l). Organotrialkoxysilanes RSi(OR{prime}){sub 3}, have been extensively used as coupling agents for composites or surface treatments for materials. Polysilsesquioxanes have become increasingly popular for generating specialty coatings such as low k dielectric materials for microelectronic applications. While there is extensive information on the formation of polysilsesquioxanes, there has not been a survey of the ability of organotrialkoxysilanes to form gels until recently. The formation of polysilsesquioxanes gels has been shown to be very sensitive to the nature of the organic group. Many monomers will only form soluble oligomers or polymers upon hydrolysis and condensation, even when the reaction is conducted solvent-free with neat monomer and aqueous catalyst. Furthermore, there is little information concerning the influence of the organic group, R, on the porosity of the polysilsesquioxanes gels that are formed. In this paper the authors describe the preparation of polysilsesquioxane gels where R = H, methyl, ethyl, cyanoethyl, vinyl, dodecyl, hexadecyl, …

Testimony issued by the General Accounting Office with an abstract that begins "Pursuant to a congressional request, GAO discussed the usage of the social security number (SSN), focusing on: (1) federal laws and regulations directing the number's use; (2) the non-federal purposes for which the number is used; and (3) what businesses and state governments believe the impact would be if federal laws limiting the use of SSNs were passed."

The purpose of Process Validation is to confirm that nominal process operations are consistent with the expected process envelope. The Process Validation activities described in this document are not part of the safety basis, but are expected to demonstrate that the process operates well within the safety basis. Some adjustments to the process may be made as a result of information gathered in Process Validation.

Silsesquioxanes have been the subject of intensive study in the past and are becoming important again as a vehicle for introducing organic functionalities into hybrid organic-inorganic materials through sol-gel processing. Depending on the application, the target hybrid material may be required to be a highly cross-linked, insoluble gel or a soluble polymer that can be cast as a thin film or coating. The former has applications such as catalyst supports and separations media; the latter is an economically important method for surface modification or compatiblization for applying adhesives or introducing fillers. Polysilsesquioxanes are readily prepared through the hydrolysis and condensation of organotrialkoxysilanes, though organotriaminosilane and organotrihalosilane monomers can also be used. This paper explores the kinetics of the preparation route.

Fluctuation microscopy experiments have shown that the as-deposited structure of amorphous silicon thin films is paracrystalline. A paracrystal consists of small (< 3 nm in diameter) topologically crystalline grains separated by a disordered matrix. Here the authors consider the thermodynamics of paracrystalline silicon as a function of the grain size and the temperature. They offer a simple model that qualitatively explains the observed metastability of the ordered structure at low temperature (300 K), the relaxation towards a more disordered structure at intermediate temperatures (600 K), and the recrystallization at high temperatures (1,000 K).