This dissertation describes two different projects from two different experiments. We have performed a search for CPT violation in neutral charm meson oscillations using data from the FOCUS Experiment. While flavor mixing in the charm sector is predicted to be small in the Standard Model, it is still possible to investigate CPT violation through a study of the proper time dependence of a CPT asymmetry in right-sign decay rates for D{sup 0} {yields} K{sup -} {pi}{sup +} and {bar D}{sup 0} {yields} K{sup +}{pi}{sup -}. This asymmetry is related to the CPT violating complex parameter {xi} and the mixing parameters x and y: A{sub CPT} {infinity} Re{xi}y - Im{xi}x. We determine a 95% confidence level limit of -0.0068 < Re{xi}y - Im{xi}x < 0.0234. Within the framework of the Standard Model Extension incorporating general CPT violation, we also find 95% confidence level limits for the expressions involving coefficients of Lorentz violation of (-2.8 < N(x,y,{delta}))({Delta}a{sub 0} + 0.6 {Delta}a{sub Z} < 4.8) x 10{sup -16} GeV, (-7.0 < N(x,y,{delta}){Delta}a{sub x} < 3.8) x 10{sup -16} GeV, and (-7.0 < N(x,y,{delta}){Delta}a{sub y} < 3.8) x 10{sup -16} GeV, where N(x,y,{delta}) is a normalization factor that incorporates mixing parameters x, y and …

A review of spectroscopic imaging issues, applications, and technology is presented. Compton cameras based on solid state semiconductor detectors stands out as the best system for the nondestructive assay of special nuclear materials. A camera for this application has been designed based on an efficient specific purpose Monte Carlo code developed for this project. Preliminary experiments have been performed which demonstrate the validity of the Compton camera concept and the accuracy of the code. Based on these results, a portable prototype system is in development. Proposed future work is addressed.

The objective of this study was to evaluate the effectiveness of two unsaturated flow models in arid regions. The area selected for the study was the Area 5 Radioactive Waste Management Site (RWMS) at the Nevada Test Site in Nye County, Nevada. The two models selected for this evaluation were HYDRUS-1D [Simunek et al., 1998] and the SHAW model [Flerchinger and Saxton, 1989]. Approximately 5 years of soil-water and atmospheric data collected from an instrumented weighing lysimeter site near the RWMS were used for building the models with actual initial and boundary conditions representative of the site. Physical processes affecting the site and model performance were explored. Model performance was based on a detailed sensitivity analysis and ultimately on storage comparisons. During the process of developing descriptive model input, procedures for converting hydraulic parameters for each model were explored. In addition, the compilation of atmospheric data collected at the site became a useful tool for developing predictive functions for future studies. The final model results were used to evaluate the capacities of the HYDRUS and SHAW models for predicting soil-moisture movement and variable surface phenomena for bare soil conditions in the arid vadose zone. The development of calibrated models along …

A prototype Compton scatter camera for imaging gamma rays has been built and tested. This camera addresses unique aspects of gamma-ray imaging at nuclear industrial sites, including gamma-ray energies in the 0.5 to 3.0 MeV range and polychromatic fields. Analytic models of camera efficiency, resolution and contaminating events are developed. The response of the camera bears strong similarity to emission computed tomography devices used in nuclear medicine. A direct Fourier based algorithm is developed to reconstruct two-dimensional images of measured gamma-ray fields. Iterative ART and MLE algorithms are also investigated. The point response of the camera to gamma rays of energies from 0.5 to 2.8 MeV is measured and compared to the analytic models. The direct reconstruction algorithm is at least ten times more efficient than the iterative algorithms are also investigated. The point response of the camera to gamma rays energies from 0.5 to 2.8 MeV is measured and compared to the analytic models. The direct reconstruction algorithm is at least ten times more efficient than the iterative algorithms and produces images that are, in general, of the same quality. Measured images of several phantoms are shown. Important results include angular resolutions as low as 4.4{degrees}, reproduction of phantom …

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The literature does not clearly describe the potential moral and ethical conflicts that can exist between technology sponsors and the technical communicators whose job it is to present potentially risky technology to the non-technical people most likely to be imperiled by such risk. Equally important, the literature does not address the issue of uncertainty -- not the uncertainty likely to be experienced by the community at risk, but the unreliable processes and methodologies used by technology sponsors to define, quantify, and develop strategies to mitigate technological risks. In this paper, the author goes beyond a description of risk communication, the nature of the generally predictable interaction between technology advocates and non-technically trained individuals, and current trends in the field. Although that kind of information is critical to the success of any risk communication activity, and he has included it when necessary to provide background and perspective, without knowing how and why risk assessment is done, it has limited practical applicability outside the sterile, value-free vacuum in which it is usually framed. Technical communicators, particularly those responsible for communicating potential technological risk, must also understand the social, political, economic, statistical, and ethical issues they will invariably encounter.

This research addresses the application of a large eddy simulation (LES) to Arbitrary Lagrangian Eulerian (ALE) simulations of Rayleigh-Taylor instability. First, ALE simulations of simplified Rayleigh-Taylor instability are studied. The advantages of ALE over Eulerian simulations are shown. Next, the behavior of the LES is examined in a more complicated ALE simulation of Rayleigh-Taylor instability. The effects of eddy viscosity and stochastic backscatter are examined. The LES is also coupled with ALE to increase grid resolution in areas where it is needed. Finally, the methods studied above are applied to two sets of experimental simulations. In these simulations, ALE allows the mesh to follow expanding experimental targets, while LES can be used to mimic the effect of unresolved instability modes.

Although having recently been extremely successful gathering data on the surface of Mars, robotic missions are not an effective substitute for the insight and knowledge about our solar system that can be gained though first-hand exploration. Earlier this year, President Bush presented a ''new course'' for the U.S. space program that shifts NASA's focus to the development of new manned space vehicles to the return of humans to the moon. Re-establishing the human presence on the moon will eventually lead to humans permanently living and working in space and also serve as a possible launch point for missions into deeper space. There are several obstacles to the realization of these goals, most notably the lack of life support and environmental regeneration and monitoring hardware capable of functioning on long duration spaceflight. In the case of the latter, past experience on the International Space Station (ISS), Mir, and the Space Shuttle has strongly underscored the need to develop broad spectrum in-flight chemical sensors that: (1) meet current environmental monitoring requirements on ISS as well as projected requirements for future missions, and (2) enable the in-situ acquisition and analysis of analytical data in order to further define on-orbit monitoring requirements. Additionally, systems …

During slow encounters between projectile and target atoms, the electronic atomic wave functions of the two collision partners distort and form molecular orbitals (MOs). K vacancy formation in slow heavy-ion collisions, which occur when electrons are excited out of the 2psigma and 1ssigma MOs, is considered. Experimental work using 200 MeV Kr ions is described. The main interest is the excitation of electrons from the 1ssigma MO. The 1ssigma vacancy production is only observed in very asymmetric collisions: as Kr K x rays in encounters with target atoms between H and Ar, and as target K x rays in encounters with atoms between Ce and U. Theoretical approximate calculations of 1ssigma ionization cross sections are described. (JFP)

Many of the current methods for pathogenic bacterial detection require long sample-preparation and analysis time, as well as complex instrumentation. This dissertation explores simple analytical approaches (e.g., flow cytometry and diffuse reflectance spectroscopy) that may be applied towards ideal requirements of a microbial detection system, through method and instrumentation development, and by the creation and characterization of immunosensing platforms. This dissertation is organized into six sections. In the general Introduction section a literature review on several of the key aspects of this work is presented. First, different approaches for detection of pathogenic bacteria will be reviewed, with a comparison of the relative strengths and weaknesses of each approach, A general overview regarding diffuse reflectance spectroscopy is then presented. Next, the structure and function of self-assembled monolayers (SAMs) formed from organosulfur molecules at gold and micrometer and sub-micrometer patterning of biomolecules using SAMs will be discussed. This section is followed by four research chapters, presented as separate manuscripts. Chapter 1 describes the efforts and challenges towards the creation of imunosensing platforms that exploit the flexibility and structural stability of SAMs of thiols at gold. 1H, 1H, 2H, 2H-perfluorodecyl-1-thiol SAM (PFDT) and dithio-bis(succinimidyl propionate)-(DSP)-derived SAMs were used to construct the platform. Chapter …

A unique phonon progression in the phosphorescence spectrum of pyrene-PMDA (Py-PMDA) in naphthalene-PMDA (N-PMDA) is reported. Calculations of the electron-phonon coupling strength parameter for the ground and excited states indicate strong coupling for the fractional CT contribution of Py-PMDA to the observed phosphorescent state. Model calculations indicate that the observed low frequency phonon mode corresponds to a low energy rotation of the rigid guest complex and not a symmetric donor-acceptor stretch. The unusual reduction of the phonon mode frequency in the excited ground state is explained in terms of a contracted complex that can more easily rotate in a larger cavity. A brief phonon progression is also observed for the mixed crystal A-PMDA in N-PMDA. For both mixed crystals, Py-PMDA in N-PMDA and A-PMDA in N-PMDA, the energy spacing between the zero-phonon vibrational bands in the mixed CT crystal phosphorescence spectrum are very similar to those obtained from the phosphorescence spectrum of the pure donor in a rigid matrix. There is a large blue shift between the origin band of the mixed CT crystal phosphorescence spectrum and the origin band of the pure donor phosphorescence spectrum for the A-PMDA mixed crystal, but not for the Py-PMDA mixed crystal. The structureless …

The main focus of this dissertation is the design, development, and ground and microgravity validation of methods for monitoring drinking water quality on-board NASA spacecraft using clorimetric-solid phase extraction (C-SPE). The Introduction will overview the need for in-flight water quality analysis and will detail some of the challenges associated with operations in the absence of gravity. The ability of C-SPE methods to meet these challenges will then be discussed, followed by a literature review on existing applications of C-SPE and similar techniques. Finally, a brief discussion of diffuse reflectance spectroscopy theory, which provides a means for analyte identification and quantification in C-SPE analyses, is presented. Following the Introduction, four research chapters are presented as separate manuscripts. Chapter 1 reports the results from microgravity testing of existing C-SPE methods and procedures aboard NASA's C-9 microgravity simulator. Chapter 2 discusses the development of a C-SPE method for determining the total concentration of biocidal silver (i.e., in both dissolved and colloidal forms) in water samples. Chapter 3 presents the first application of the C-SPE technique to the determination of an organic analyte (i.e., formaldehyde). Chapter 4, which is a departure from the main focus of the thesis, details the results of an investigation …

Samples from three time-series sediment traps deployed in the Santa Monica Basin off the California coast were analyzed to study the flux and scavenging of uranium and thorium series isotopes. Variations of uranium and thorium series isotopes fluxes in the water column were obtained by integrating these time-series deployment results. Mass and radionuclide fluxes measured from bottom sediment traps compare favorably with fluxed determined from sediment core data. This agreement suggests that the near-bottom sediment traps are capable of collecting settling particles representative of the surface sediment. The phase distributions of {sup 234}Th in the water column were calculated by an inverse method using sediment trap data, which help to study the variations of {sup 234}Th scavenging in the water column. Scavenging and radioactive decay of {sup 234}Th are the two principal processes for balancing {sup 234}Th budget in the water column. The residence times of dissolved and particulate {sup 234}Th were determined by a {sup 234}Th scavenging model.

Catalytic reactions of cyclohexene, benzene, n-hexane, 2-methylpentane, 3-methylpentane, and 1-hexene on platinum catalysts were monitored in situ via sum frequency generation (SFG) vibrational spectroscopy and gas chromatography (GC). SFG is a surface specific vibrational spectroscopic tool capable of monitoring submonolayer coverages under reaction conditions without gas-phase interference. SFG was used to identify the surface intermediates present during catalytic processes on Pt(111) and Pt(100) single-crystals and on cubic and cuboctahedra Pt nanoparticles in the Torr pressure regime and at high temperatures (300K-450K). At low pressures (<10{sup -6} Torr), cyclohexene hydrogenated and dehydrogenates to form cyclohexyl (C{sub 6}H{sub 11}) and {pi}-allyl C{sub 6}H{sub 9}, respectively, on Pt(100). Increasing pressures to 1.5 Torr form cyclohexyl, {pi}-allyl C{sub 6}H{sub 9}, and 1,4-cyclohexadiene, illustrating the necessity to investigate catalytic reactions at high-pressures. Simultaneously, GC was used to acquire turnover rates that were correlated to reactive intermediates observed spectroscopically. Benzene hydrogenation on Pt(111) and Pt(100) illustrated structure sensitivity via both vibrational spectroscopy and kinetics. Both cyclohexane and cyclohexene were produced on Pt(111), while only cyclohexane was formed on Pt(100). Additionally, {pi}-allyl c-C{sub 6}H{sub 9} was found only on Pt(100), indicating that cyclohexene rapidly dehydrogenates on the (100) surface. The structure insensitive production of cyclohexane was found …

This dissertation describes a measurement of the neutrino oscillation parameters #1;{Delta}m{sup 2}{sub 21}, θ{sub 12} and constraints on θ{sub 13} based on a study of reactor antineutrinos at a baseline of ∼ 180 km with the KamLAND detector. The data presented here was collected between April 2002 and November 2009, and amounts to a total exposure of 2.64 � 0.07 � 10{sup 32} proton-years. For this exposure we expect 2140 � 74(syst) antineutrino candidates from reactors, assuming standard model neutrino behavior, and 350�88(syst) candidates from background. The number observed is 1614. The ratio of background-subtracted candidates observed to expected is (N{sub Obs} − N{sub Bkg})/N{sub Exp} = 0.59 � 0.02(stat) � 0.045(syst) which confirms reactor neutrino disappearance at greater than 5σ significance. Interpreting this deficit as being due to neutrino oscillation, the best-fit oscillation parameters from a three-flavor analysis are #1;{Delta}m{sup 2}{sub 21} = 7.60{sup +0.20}{sub −0.19}�10{sup −5}eV{sup 2}, θ{sub 12} = 32.5 � 2.9 degrees and sin{sup 2} θ{sub 13} = 0.025{sup +0.035}{sub −0.035}, the 95% confidence-level upper limit on sin{sup 2} θ{sub 13} is sin{sup 2} θ{sub 13} < 0.083. Assuming CPT invariance, a combined analysis of KamLAND and solar neutrino data yields best-fit values: #1;{Delta}m{sup 2}{sub 21} …

This dissertation presents the development of the novel mechanical testing technique of in situ nanoindentation in a transmission electron microscope (TEM). This technique makes it possible to simultaneously observe and quantify the mechanical behavior of nano-scale volumes of solids.

The reliability of microelectronic systems is often limited by electromigration failure in Al-based thin-film conducting lines which interconnect devices to form an integrated circuit. Under an applied electric field Al atoms migrate with the electron flow, causing a counterflow of vacancies that accumulate into voids, eventually leading to an open circuit failure. The work reported here is concerned with clarifying the microstructural mechanism of electromigration failure, and with developing a metallurgical method to improve the electromigration resistance of Al-based interconnects. Pure Al, Al-2Cu, and Al-2Cu-1Si lines with quasi-bamboo microstructures are explored as a function of heat treatment conditions and current density. The {open_quotes}weakest{close_quotes} microstructural unit that causes failure is identified by electron microscopy; with rare exceptions, failure occurs at the upstream end of the longest polygranular segment in a given line. This microstructural characteristic of electromigration failure is even observed in lines whose maximum segment lengths are less than a few microns. The time to failure appears to increase exponentially with decreasing longest polygranular segment length. A simple constitutive equation is reported to describe the failure kinetics as a function of the polygranular segment length that leads to failure. Given correct values of the kinetic constants included in the equation, …

Monitored data play a very important part in the implementation and evaluation of energy conservation technologies and programs. However, these data can be expensive to collect, so there is a need for lower-cost alternatives. In many situations, using the computerized Energy Management and Control Systems (EMCSs)--already installed in many buildings--to collect these commercial building performance data has advantages over more conventional methods. This method provides data without installing incremental hardware, and the large amounts of available operational data can be a very rich resource for understanding building performance. This dissertation addresses several of these issues. One specific objective is to describe a monitoring-project planning process that includes definition of objectives, constraints, resources and approaches for the monitoring. The choice of tools is an important part of this process. The dissertation goes on to demonstrate, through eight case studies, that EMCS monitoring is possible, and to identify and categorize the problems and issues that can be encountered. These issues lead to the creation, use, and testing of a set of methods for evaluation of EMCS monitoring, in the form of guidelines. Finally, EMCS monitoring is demonstrated and compared with conventional monitoring more methodically in a detailed case study.

The search for the fundamental constituents of matter has been pursued and studied since the dawn of civilization. As early as the fourth century BCE, Democritus, expanding the teachings of Leucippus, proposed small, indivisible entities called atoms, interacting with each other to form the Universe. Democritus was convinced of this by observing the environment around him. He observed, for example, how a collection of tiny grains of sand can make out smooth beaches. Today, following the lead set by Democritus more than 2500 years ago, at the heart of particle physics is the hypothesis that everything we can observe in the Universe is made of a small number of fundamental particles interacting with each other. In contrast to Democritus, for the last hundred years we have been able to perform experiments that probe deeper and deeper into matter in the search for the fundamental particles of nature. Today's knowledge is encapsulated in the Standard Model of particle physics, a model describing the fundamental particles and their interactions. It is within this model that the work in this thesis is presented. This work attempts to add to the understanding of the Standard Model by measuring the relative branching fraction of the …

In this work, the author applied a systematic calibration, validation and application procedure based on the methodology of mathematical modeling to international thermonuclear experimental reactor (ITER) ignition studies. The multi-mode plasma transport model used here includes a linear combination of drift wave branch and ballooning branch instabilities with two a priori uncertain constants to account for anomalous plasma transport in tokamaks. A Bayesian parameter estimation method is used including experimental calibration error/model offsets and error bar rescaling factors to determine the two uncertain constants in the transport model with quantitative confidence level estimates for the calibrated parameters, which gives two saturation levels of instabilities. This method is first tested using a gyroBohm multi-mode transport model with a pair of DIII-D discharge experimental data, and then applied to calibrating a nominal multi-mode transport model against a broad database using twelve discharges from seven different tokamaks. The calibrated transport model is then validated on five discharges from JT-60 with no adjustable constants. The results are in a good agreement with experimental data. Finally, the resulting class of multi-mode tokamak plasma transport models is applied to the transport analysis of the ignition probability in a next generation machine, ITER. A reference simulation of …

The author presents and analyzes three approaches to calculating explicit two-dimensional (2D) depth-extrapolation filters for all propagation modes (P, SV, and SH) in transversely isotropic media with vertical and tilted axis of symmetry. These extrapolation filters are used to do 2D poststack depth migration, and also, just as for isotropic media, these 2D filters are used in the McClellan transformation to do poststack 3D depth migration. Furthermore, the same explicit filters can also be used to do depth-extrapolation of prestack data. The explicit filters are derived by generalizations of three different approaches: the modified Taylor series, least-squares, and minimax methods initially developed for isotropic media. The examples here show that the least-squares and minimax methods produce filters with accurate extrapolation (measured in the ability to position steep reflectors) for a wider range of propagation angles than that obtained using the modified Taylor series method. However, for low propagation angles, the modified Taylor series method has smaller amplitude and phase errors than those produced by the least-squares and minimax methods. These results suggest that to get accurate amplitude estimation, modified Taylor series filters would be somewhat preferred in areas with low dips. In areas with larger dips, the least-squares and minimax …

The computing infrastructures of the modern high energy physics experiments need to address an unprecedented set of requirements. The collaborations consist of hundreds of members from dozens of institutions around the world and the computing power necessary to analyze the data produced surpasses already the capabilities of any single computing center. A software infrastructure capable of seamlessly integrating dozens of computing centers around the world, enabling computing for a large and dynamical group of users, is of fundamental importance for the production of scientific results. Such a computing infrastructure is called a computational grid. The SAM-Grid offers a solution to these problems for CDF and DZero, two of the largest high energy physics experiments in the world, running at Fermilab. The SAM-Grid integrates standard grid middleware, such as Condor-G and the Globus Toolkit, with software developed at Fermilab, organizing the system in three major components: data handling, job handling, and information management. This dissertation presents the challenges and the solutions provided in such a computing infrastructure.

Negative ion photoelectron spectroscopy has been used to study two types of transient neutral species: bound free radicals (NO{sub 2} and NO{sub 3}) and unstable neutral species ([IHI] and [FH{sub 2}]). The negative ion time-of-flight photoelectron spectrometer used for these experiments is described in detail.

Gas atomization reaction synthesis (GARS) was employed as a simplified method for producing precursor powders for oxide dispersion strengthened (ODS) ferritic stainless steels (e.g., Fe-Cr-Y-(Ti,Hf)-O), departing from the conventional mechanical alloying (MA) process. During GARS processing a reactive atomization gas (i.e., Ar-O{sub 2}) was used to oxidize the powder surfaces during primary break-up and rapid solidification of the molten alloy. This resulted in envelopment of the powders by an ultra-thin (t < 150 nm) metastable Cr-enriched oxide layer that was used as a vehicle for solid-state transport of O into the consolidated microstructure. In an attempt to better understand the kinetics of this GARS reaction, theoretical cooling curves for the atomized droplets were calculated and used to establish an oxidation model for this process. Subsequent elevated temperature heat treatments, which were derived from Rhines pack measurements using an internal oxidation model, were used to promote thermodynamically driven O exchange reactions between trapped films of the initial Cr-enriched surface oxide and internal Y-enriched intermetallic precipitates. This novel microstructural evolution process resulted in the successful formation of nano-metric Y-enriched dispersoids, as confirmed using high energy X-ray diffraction and transmission electron microscopy (TEM), equivalent to conventional ODS alloys from MA powders. The thermal …