This report summarizes the work done during the fourth quarter of the project. Effort was directed in two areas, namely, continued further development of the model on the role of connectivity on ionic conductivity of porous bodies, including the role of grain boundaries and space charge, and its relationship to cathode polarization; and fabrication of samaria-doped ceria porous (SDC). The work on the model development involves calculation of the effect of space charge on transport through porous bodies. Three specific cases have been examined: (1) Space charge resistivity greater than the grain resistivity, (2) Space charge resistivity equal to the grain resistivity, and (3) Space charge resistivity lower than the grain resistivity. The model accounts for transport through three regions: the bulk of the grain, the space charge region, and the structural part of the grain boundary. The effect of neck size has been explicitly incorporated. In future work, the effective resistivity will be incorporated into the effective cathode polarization resistance. The results will then be compared with experiments.

A letter report issued by the General Accounting Office with an abstract that begins "Approximately 6,600 miles of Alaska's coastline and many of the low-lying areas along the state's rivers are subject to severe flooding and erosion. Most of Alaska's Native villages are located on the coast or on riverbanks. In addition to the many federal and Alaska state agencies that respond to flooding and erosion, Congress established the Denali Commission in 1998 to, among other things, provide economic development services and to meet infrastructure needs in rural Alaska communities. Congress directed GAO to study Alaska Native villages affected by flooding and erosion and to 1) determine the extent to which these villages are affected, 2) identify federal and state flooding and erosion programs, 3) determine the current status of efforts to respond to flooding and erosion in nine villages, and 4) identify alternatives that Congress may wish to consider when providing assistance for flooding and erosion."

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The response of high permeability ({mu}{sub r} {ge} 50) conductive spheroids of moderate aspect ratios (0.25 to 4) to excitation by uniform magnetic fields in the axial or transverse directions is approximated by the response of spheres of appropriate diameters, of the same conductivity and permeability, with magnitude rescaled based on the differing volumes, D.C. magnetizations, and high frequency limit responses of the spheres and modeled spheroids.

The research discussed within involves the development of novel applications of real-time imaging of adenosine 5'-triphosphate (ATP). ATP was detected via bioluminescence and the firefly luciferase-catalyzed reaction of ATP and luciferin. The use of a microscope and an imaging detector allowed for spatially resolved quantitation of ATP release. Employing this method, applications in both biological and chemical systems were developed. First, the mechanism by which the compound 48/80 induces release of ATP from human umbilical vein endothelial cells (HUVECs) was investigated. Numerous enzyme activators and inhibitors were utilized to probe the second messenger systems involved in release. Compound 48/80 activated a G{sub q}-type protein to initiate ATP release from HUVECs. Ca{sup 2+} imaging along with ATP imaging revealed that activation of phospholipase C and induction of intracellular Ca{sup 2+} signaling were necessary for release of ATP. Furthermore, activation of protein kinase C inhibited the activity of phospholipase C and thus decreased the magnitude of ATP release. This novel release mechanism was compared to the existing theories of extracellular release of ATP. Bioluminescence imaging was also employed to examine the role of ATP in the field of neuroscience. The central nervous system (CNS) was dissected from the freshwater snail Lymnaea stagnalis. …

In this dissertation, they have undertaken the challenge to understand the unusual propagation properties of the photonic crystal (PC). The photonic crystal is a medium where the dielectric function is periodically modulated. These types of structures are characterized by bands and gaps. In other words, they are characterized by frequency regions where propagation is prohibited (gaps) and regions where propagation is allowed (bands). In this study they focus on two-dimensional photonic crystals, i.e., structures with periodic dielectric patterns on a plane and translational symmetry in the perpendicular direction. They start by studying a two-dimensional photonic crystal system for frequencies inside the band gap. The inclusion of a line defect introduces allowed states in the otherwise prohibited frequency spectrum. The dependence of the defect resonance state on different parameters such as size of the structure, profile of incoming source, etc., is investigated in detail. For this study, they used two popular computational methods in photonic crystal research, the Finite Difference Time Domain method (FDTD) and the Transfer Matrix Method (TMM). The results for the one-dimensional defect system are analyzed, and the two methods, FDTD and TMM, are compared. Then, they shift their attention only to periodic two-dimensional crystals, concentrate on their …

This report provides a description of the main accomplishments of the EMSP funded research, including products such as conference presentations and publications (including those still in preparation). The purpose of this study was to better understand the chemical interactions between dissolved aqueous contaminants and carbonate minerals occurring as coatings on mineral grains in the vadose zone beneath the Hanford reserve. This information is important for construction of improved reactive transport models intended to predict the subsurface migration of contaminants. We made improvements to the hydrothermal atomic force microscope (HAFM) design to be used in this project. The original HAFM was built with funding from the U.S. DOE, Office of Basic Energy Sciences. Improvements include operating limits of 70 bars and 170 C, from an original limit of 12 bars and 150 C. This product is patented. We completed a series of studies of magnesite, MgCO3, because this mineral is structurally equivalent to calcite but reacts much more slowly, allowing us to study carbonate reactivity under pH conditions (i.e., low pH) that are much more problematic for studies of calcite but which are nevertheless relevant to in-situ conditions. We found that dissolving magnesite exhibits a dramatic change in step orientation, and …

Land management and land-use change can either release carbon (as CO{sub 2}) to the atmosphere, for example when forests are converted to agricultural lands, or withdraw carbon from the atmosphere as forests grow on cleared lands or as management practices sequester carbon in soil. The purpose of this work was to calculate the annual sources and sinks of carbon from changes in land use and management, globally and for nine world regions, over the period 1850 to 2000. The approach had three components. First, rates of land-use change were reconstructed from historical information on the areas of croplands, pastures, forests, and other lands and from data on wood harvests. In most regions, land-use change included the conversion of natural ecosystems to cultivated lands and pastures, including shifting cultivation, harvest of wood (for timber and fuel), and the establishment of tree plantations. In the U.S., woody encroachment and woodland thickening as a result of fire suppression were also included. Second, the amount of carbon per hectare in vegetation and soils and changes in that carbon as a result of land-use change were determined from data obtained in the ecological and forestry literature. These data on land-use change and carbon stocks were …

This report describes the remittance market place, and then using selected Latin American and Caribbean countries as examples shows how competition and government regulation affect the price of remittances.

Cleanup at the Savannah River Site brings with it the need to clean out and close down the radioactive waste tanks constructed in support of the fuel rod dissolution process. An innovative technique for assaying waste tanks has been developed at the Savannah River Site. The technique uses a gamma detector in the annular space between the inner and outer walls of double walled tanks. Unique shielding, counting electronics, and deployment techniques were developed to facilitate mapping interstitial liquid levels, sludge layers and other structures in the waste tank located near the tank walls. The techniques used, results, and lessons learned will be discussed.

Precipitation and characterization of nickel hydroxide powders were investigated. A comprehensive precipitation model incorporating the metal ion hydrolysis, complexation and precipitation reactions was developed for the production of the powders with urea precipitation method. Model predictions on Ni{sup 2+} precipitation rate were confirmed with precipitation experiments carried out at 90 C. Experimental data and model predictions were in remarkable agreement. Uncertainty in the solubility product data of nickel hydroxides was found to be the large contributor to the error. There were demonstrable compositional variations across the particle cross-sections and the growth mechanism was determined to be the aggregation of primary crystallites. This implied that there is a change in the intercalate chemistry of the primary crystallites with digestion time. Predicted changes in the concentrations of simple and complex ions in the solution support the proposed mechanism. The comprehensive set of hydrolysis reactions used in the model described above allows the investigation of other systems provided that accurate reaction constants are available. the fact that transition metal ions like Ni{sup 2+} form strong complexes with ammonia presents a challenge in the full recovery of the Ni{sup 2+}. On the other hand, presence of Al{sup 3+} facilitates the complete precipitation of Ni{sup …

We show that long scale-length ablator roughness sets a limit to the enhanced IR layering power possible in a NIF ignition hohlraum. This limit can be more restrictive than the limit set by thermal conduction. High IR power absorption, characteristic of the ablator material, combined with ablator roughness can produce ice thickness variations which exceed the NIF ice layer roughness specification. For example, if the capsule IR absorption coefficient is greater than 13 cm{sup -1}, the max IR power is less than the 4 Q{sub DT} limit set by thermal conduction.

Qualification of storage canisters due to the expansion behavior of plutonium metal during phase transitions requires a combined experimental and analytical modeling effort. Tests were conducted at Los Alamos National Laboratory to define the expansion behavior of plutonium metal during the alpha-beta-gamma phase transitions. Test results showed that the expansion is anisotropic due to the container wall constraint. The plutonium expansion parameters were calculated from test data, and combined with a finite element analysis to determine the stress state of the storage canisters. Strain values were computed and compared with the ASME Code secondary and peak stress limits. Since the applied expansion strain exceeds the strain of 10 cycles in the ASME Code design fatigue curve, the ASME Code design fatigue curve was extended to values below 10 cycles.

The objective of this work was to develop predictive models to assess offgas flammability for a low activity radioactive waste melter. The models had to be comprehensive enough to explicitly describe the effects of key melter operating variables such as total organic carbon in the feed, melter air purge and vapor space temperature. Once validated against pilot melter data, these models were used to simulate a series of safety scenarios involving over-batching of sugar, used as a reducing agent, and off-gas surges. The overall scope of the work was broken down into two parts, each focusing on a physically distinct region in the melter.

A letter report issued by the General Accounting Office with an abstract that begins "The Army continues to transform units, known as Stryker brigades, into lighter, rapidly deployable, and more capable forces. Because Stryker brigades are an entirely new design, the fiscal year 2002 National Defense Authorization Act required the Army to conduct an evaluation of the design, to include deployment of the brigade and execution of combat missions across the full spectrum of potential threats. The act also required the Secretary of Defense to certify that the evaluation results indicate the design is both operationally effective and suitable. As one in a series of reviews of Army transformation, GAO monitored the evaluation to assess (1) whether the Army and the Secretary of Defense met legislative requirements, (2) how the Army evaluated both the operational effectiveness and suitability of the brigade's design, (3) what the brigade's performance was during the evaluation, and (4) how the Army plans to mitigate issues identified during the evaluation."

Organic electronic materials are a new class of emerging materials. Organic light emitting devices (OLEDs) are the most promising candidates for future flat panel display technologies. The photophysical characterization is the basic research step one must follow to understand this new class of materials and devices. The light emission properties are closely related to the transport properties of these materials. The objective of this dissertation is to probe the relation between transport and photophysical properties of organic semiconductors. The transport characteristics were evaluated by using thermally stimulated current and thermally stimulated luminescence techniques. The photoluminescence detected magnetic resonance and photoluminescence quantum yield studies provide valuable photophysical information on this class of materials. OLEDs are already in the market. However, detailed studies on the degradation mechanisms are still lacking. Since both optically detected magnetic resonance and thermal activation spectroscopy probe long-lived defect-related states in organic semiconductors, the combined study generates new insight on the OLED operation and degradation mechanisms.

Organic Light-Emitting Devices (OLEDs), both small molecular and polymeric have been studied extensively since the first efficient small molecule OLED was reported by Tang and VanSlyke in 1987. Burroughes' report on conjugated polymer-based OLEDs led to another track in OLED development. These developments have resulted in full color, highly efficient (up to {approx} 20% external efficiency 60 lm/W power efficiency for green emitters), and highly bright (> 140,000 Cd/m{sup 2} DC, {approx}2,000,000 Cd/m{sup 2} AC), stable (>40,000 hr at 5 mA/cm{sup 2}) devices. OLEDs are Lambertian emitters, which intrinsically eliminates the view angle problem of liquid crystal displays (LCDs). Thus OLEDs are beginning to compete with the current dominant LCDs in information display. Numerous companies are now active in this field, including large companies such as Pioneer, Toyota, Estman Kodak, Philipps, DuPont, Samsung, Sony, Toshiba, and Osram, and small companies like Cambridge Display Technology (CDT), Universal Display Corporation (UDC), and eMagin. The first small molecular display for vehicular stereos was introduced in 1998, and polymer OLED displays have begun to appear in commercial products. Although displays are the major application for OLEDs at present, they are also candidates for nest generation solid-state lighting. In this case the light source needs …

This dissertation comprises two main research projects. The first project, presented in Chapter 1, involves the synthesis and thermochemistry of germacyclobutanes (germetanes). Four new germetanes (spirodigermetane, diallylgermetane, dichlorogermetane, and germacyclobutane) have been synthesized using a modified di-Grignard synthesis. Diallylgermetane is shown to be a useful starting material for obtaining other germetanes, particularly the parent germetane, germacyclobutane. The gas-phase thermochemistries of spirodigermetane, diallylgermetane and germacyclobutane have been explored via pulsed stirred-flow reactor (SFR) studies, showing remarkable differences in decomposition, depending on the substitution at the germanium atom. The second project investigates the thermochemical, photochemical, and catalytic additions of several digermanes to acetylenes. The first examples of thermo- and photochemical additions of Ge-Ge bonds to C{triple_bond}C are demonstrated. Mechanistic investigations are described and comparisons are made to analogous disilane addition reactions, previously studied in their group.

Correspondence issued by the General Accounting Office with an abstract that begins "This letter responds to a Congressional request that we provide answers to questions relating to our September 9, 2003, testimony on transportation security."

SRTC investigated several options to remediate the contents of Tank 48H. Three options were examined: the Fenton reaction, Hydrolysis and Catalysis. Each option was investigated using a series of six reactions. These reactions were exploratory in nature; optimization is planned for a later date. Each experiment was conducted over a two-week period. The results of the experiments indicate that each process is a viable in-tank option, but there are limitations (discussed below) that must be addressed. For all three options, tetraphenylborate destruction (i.e., conversion of TPB into any other species) efficiencies proved higher at pH 7-8 than 11. However, parallel studies show that the corrosion rate for any in-tank option increases as pH decreases. TBP destruction efficiency (i.e., percent conversion of TPB into other species) at pH 11 for the Fenton reactions ranged between 22 per cent (600 mg/L TAML, 45 degrees C, 30 mL H2O2) to 68 per cent (100 mg/L TAML, 45 degrees C, 264 mL H 2O2). TBP destruction efficiency at pH 11, 45 degrees C for the hydrolysis reaction measured 84 per cent. TBP destruction efficiency at pH 11, 45 degrees C for the 1000 ppm Pd-catalysis reaction equaled 56 per cent. The TPB destruction efficiency …

In this work, they try to understand the protein folding problem using pair-wise hydrophobic interaction as the dominant interaction for the protein folding process. They found a strong correlation between amino acid sequences and the corresponding native structure of the protein. Some applications of this correlation were discussed in this dissertation include the domain partition and a new structural threading method as well as the performance of this method in the CASP5 competition. In the first part, they give a brief introduction to the protein folding problem. Some essential knowledge and progress from other research groups was discussed. This part includes discussions of interactions among amino acids residues, lattice HP model, and the design ability principle. In the second part, they try to establish the correlation between amino acid sequence and the corresponding native structure of the protein. This correlation was observed in the eigenvector study of protein contact matrix. They believe the correlation is universal, thus it can be used in automatic partition of protein structures into folding domains. In the third part, they discuss a threading method based on the correlation between amino acid sequences and ominant eigenvector of the structure contact-matrix. A mathematically straightforward iteration scheme provides …

The implementation of x-ray computerized tomography (CT) on agricultural soils has been used in this research to quantify soil physical properties to be compared with standard laboratory (STD) methods. The overall research objective was to more accurately quantify soil physical properties for long-term management systems. Two field studies were conducted at Iowa State University's Northeast Research and Demonstration Farm near Nashua, IA using two different soil management strategies. The first field study was conducted in 1999 using continuous corn crop rotation for soil under chisel plow with no-till treatments. The second study was conducted in 2001 and on soybean crop rotation for the same soil but under chisel plow and no-till practices with wheel track and no-wheel track compaction treatments induced by a tractor-manure wagon. In addition, saturated hydraulic (K{sub s}) conductivity and the convection-dispersion (CDE) model were also applied using long-term soil management systems only during 2001. The results obtained for the 1999 field study revealed no significant differences between treatments and laboratory methods, but significant differences were found at deeper depths of the soil column for tillage treatments. The results for standard laboratory procedure versus CT method showed significant differences at deeper depths for the chisel plow treatment …

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