Measurements of the production cross section of W{sup +}W{sup -} pairs in p{bar p} collisions at 1.96 TeV and limits on trilinear gauge boson coupling (TGC) parameters are presented. The data were recorded with the CDF experiment at Tevatron during the 2001 and 2002 data taking periods in which a total integrated luminosity of 184 pb{sup -1} was collected. The data sample was filtered for events with two leptonic w boson decays where the charged leptons can be either electrons or muons. 17 events are observed against an expected background of 5.0{sub -0.8}{sup +2.2} events. The resulting cross-section is found to be {sigma}(p{bar p} {yields} W{sup +}W{sup -}) = 14.5{sub -5.1}{sup +5.8}(stat){sub -3.0}{sup +1.8}(syst) {+-} 0.9(lum) pb and agrees well with the Standard Model expectation. Limits on the TGC parameters {Delta}{kappa} and {lambda} are set under both the equal coupling scheme, that assumes the W boson couples identically to the Z and {gamma}, and the HISZ coupling scheme, that requires the couplings to respect SU(2){sub L} x &(1){sub Y} gauge symmetry. In both cases this is achieved by using a likelihood fit to the lepton-P{sub T} distribution of the 17 candidate events. The resulting limits are found to be: -0.4 …

CDF (Collider Detector at Fermilab) is a particle detector located at Fermi National Laboratories, near Chicago. it allows to study decay products of p{bar p} collisions at center-of-mass energy of 1.96 TeV. During its first period of data taking (RunI), CDF observed for the first time the top quark (1995). The current period of data taking (RunII) is devoted to precise measurements of top properties and to search for new physics. This thesis work is about the top decay channel named {tau} + jets. A t{bar t} pair decays in two W bosons and two b quarks. In a {tau} + jets event, one out of the two W decays into two jets of hadrons, while the other produces a {tau} lepton and a neutrino; the {tau} decays semileptonically in one or more charged and neutral pions while b quarks hadronize producing two jets of particles. Thus the final state of a {tau} + jets event has this specific signature: five jets, one {tau}-like, i.e. narrow and with low track multiplicity, two from b quarks, two from a W boson and a large amount of missing energy from two {tau} neutrinos. They search for this signal in 311 pb{sup -1} …

Medication adherence is a formidable challenge for the elderly who may have several prescribed medications while dealing with limited incomes and declining health. The primary purpose of this study was to evaluate the Liberty 6000, an automated capsule and tablet dispenser that provides proper medication dosages and is intended to encourage and track medication adherence. Seven focus groups were assembled; these comprised 49 men and women ages 65 to 98 years of Black, Anglo, and Hispanic descent who met the following criteria: living independently or semi-independently, had suffered one or more impairments, and were taking at least three prescription medications. Each focus group session lasted 90 minutes and was tape-recorded and transcribed verbatim, resulting in about 2,600 lines of text. Each question was designed to be open-ended to avoid introducing any bias that might influence the response. The Health Belief Model conceptually guided the study that addressed perceptions of illness susceptibility and severity, barriers, benefits, and cues to action associated with medication adherence. Main benefits of taking medications included avoiding inherited illnesses (or tendencies for illnesses), and reducing illness symptoms. Barriers to taking medications included forgetting, dexterity problems, and high cost. Benefits of the proposed intervention included reminding, caregiver notification, …

Concerto for Solo Percussion and Concert Band was commissioned by Staff Sergeant Rone Sparrow, a percussionist with the West Point Military Academy Band. Funding for the project was provided by the Barlow Foundation. The piece was premiered April 13, 2005 in the Eisenhower Hall Theater at West Point, New York. Rone Sparrow performed with the USMA band, and Colonel Thomas Rotondi Jr., Commander/Conductor, conducted the piece. The concerto consists of three movements, and each movement features a different instrument: the first features marimba, the second, vibraphone, and the third movement features the drum kit together with a rhythm section (piano, bass, and drums). In addition to the piece, the dissertation paper discusses important technical detail related to the piece, including: harmony, form, rhythm, programmatic ideas as they relate to motivic strands, and the process of generating and discarding material. The paper also focuses on a number of factors that were influential to the piece, such as postmodern philosophy.

Generalized Parton Distributions (GPDs), introduced in the late 90s, provide a universal description of hadrons in terms of the underlying degrees of freedom of Quantum Chromodynamics: quarks and gluons. GPDs appear in a wide variety of hard exclusive reactions and the advent of high luminosity accelerator facilities has made the study of GPDs accessible to experiment. Deeply Virtual Compton Scattering (DVCS) is the golden process involving GPDs. The first dedicated DVCS experiment ran in the Hall A of Jefferson Lab in Fall 2004. An electromagnetic calorimeter and a plastic scintillator detector were constructed for this experiment, together with specific electronics and acquisition system. The experiment preparation, data taking and analysis are described in this document. Results on the absolute cross section difference for opposite beam helicities provide the first measurement of a linear combination of GPDs as a function of the momentum transfer to the nucleon.

Guest-host interaction has long been a subject of interest in many disciplines. Emphasis is often on how a small amount of guest substance could significantly affect the properties of a host material. This thesis describe our work in studying a guest-host effect where dye-doping of liquid crystalline materials greatly enhances the optical Kerr nonlinearity of the material. The dye molecules, upon excitation and via intermolecular interaction, provides an extra torque to reorient the host molecules, leading to the enhanced optical Kerr nonlinearity. We carried out a comprehensive study on the dynamics of the photoexcited dye-doped liquid crystalline medium. Using various experimental techniques, we separately characterized the dynamical responses of the relevant molecular species present in the medium following photo-excitation, and thus were able to follow the transient process in which photo-excitation of the dye molecules exert through guest-host interaction a net torque on the host LC material, leading to the observed enhanced molecular reorientation. We also observed for the first time the enhanced reorientation in a pure liquid crystal system, where the guest population is created through photoexcitation of the host molecules themselves. Experimental results agree quantitatively with the time-dependent theory based on a mean-field model of the guest-host interaction.

Surfactant-coated cobalt nanocrystals can be prepared with areasonable degree of control over particle size and shape using athermolytic route. The small crystallite size, enhanced reactivity andtunable interparticle interactions enable use of this material asstarting material for demonstration of achievement of novel structuresusing extremely simple solution-based approaches. In particular,formation of hollow cobalt sulfide nanocrystals upon chemicalmodification and emergence of long-range orientational order upondrying-mediated assembly of cobalt nanocrystals is reportedhere.Colloidal preparation of Co nanocrystals has been well-studied.Here, we emphasize general principles and crystallographic/morphologicalcharacterization of disk-shaped hcp-Co nanocrystals. Use of surfactantmolecules enables achievement of multiple morphologies in one syntheticsystem.Formation of hollow structures upon in-solution sulfidation of Conanocrystals is presented and discussed. A Kirkendall-type effect,involving dominant outward mass transport during formation of the ionicshell material explains the results naturally. It is expected that thisphenomenon will generalize extensively to formation of hollow structuresof an enormous variety of compositions. Detailed study of particlemorphology as a function of reaction conditions suggest phenomena likelyto be generally relevant to use of this approach. A short report ofcrystallographic co-alignment into vortex-like structures is alsoprovided. Our current best picture of this process involves an interplayof packing and magnetic interactions between facetedparticles.

The MINOS Far Detector is a 5.4 kiloton (5.2 kt steel plus 0.2 kt scintillator plus aluminum skin) magnetized tracking calorimeter located 710 meters underground in the Soudan mine in Northern Minnesota. MINOS is the first large, deep underground detector with a magnetic field and thus capable of making measurements of the momentum and charge of cosmic ray muons. Despite encountering unexpected anomalies in distributions of the charge ratio (N{sub {mu}{sup +}}/N{sub {mu}{sup -}}) of cosmic muons, a method of canceling systematic errors is proposed and demonstrated. The result is R{sub eff} = 1.346 {+-} 0.002 (stat) {+-} 0.016 (syst) for the averaged charge ratio, and a result for a rising fit to slant depth of R(X) = 1.300 {+-} 0.008 (stat) {+-} 0.016 (syst) + (1.8 {+-} 0.3) x 10{sup -5} x X, valid over the range of slant depths from 2000 < X < 6000 MWE. This slant depth range corresponds to minimum surface muon energies between 750 GeV and 5 TeV.

Left unprotected, both transmissive and reflective final optics in a laser-driven inertial fusion power plant would quickly fail from melting, pulsed thermal stress, or degradation of optical properties as a result of ion implantation. One potential option for mitigating this threat is to magnetically deflect the ions such that they are directed to a robust energy dump. In this paper we detail integrated studies that have been carried out to assess the viability of this approach for protecting final optics.

A distributed system is a collection of computers that are connected via a communication network. Distributed systems have become commonplace due to the wide availability of low-cost, high performance computers and network devices. However, the management infrastructure often does not scale well when distributed systems get very large. Some of the considerations in building a distributed system are the choice of the network topology and the method used to construct the distributed system so as to optimize the scalability and reliability of the system, lower the cost of linking nodes together and minimize the message delay in transmission, and simplify system resource management. We have developed a new distributed management system that is able to handle the dynamic increase of system size, detect and recover the unexpected failure of system services, and manage system resources. The topologies used in the system are the tree-structured network and the ring-structured network. This thesis presents the research background, system components, design, implementation, experiment results and the conclusions of our work. The thesis is organized as follows: the research background is presented in chapter 1. Chapter 2 describes the system components, including the different node types and different connection types used in the system. …

Conventional implementations of collective communications are based on point-to-point communications, and their optimizations have been focused on efficiency of those communication algorithms. However, point-to-point communications are not the optimal choice for modern computing clusters of SMPs due to their two-level communication structure. In recent years, a few research efforts have investigated efficient collective communications for SMP clusters. This dissertation is focused on platform-independent algorithms and implementations in this area. There are two main approaches to implementing efficient collective communications for clusters of SMPs: using shared memory operations for intra-node communications, and overlapping inter-node/intra-node communications. The former fully utilizes the hardware based shared memory of an SMP, and the latter takes advantage of the inherent hierarchy of the communications within a cluster of SMPs. Previous studies focused on clusters of SMP from certain vendors. However, the previously proposed methods are not portable to other systems. Because the performance optimization issue is very complicated and the developing process is very time consuming, it is highly desired to have self-tuning, platform-independent implementations. As proven in this dissertation, such an implementation can significantly out-perform the other point-to-point based portable implementations and some platform-specific implementations. The dissertation describes in detail the architecture of the platform-independent …

The combination of giant magnetoresistive sensors, magnetic labeling strategies, and biomolecule detection is just beginning to be explored. New readout methods and assay formats are necessary for biomolecules detection to flourish. The work presented in this dissertation describes steps toward the creation of a novel detection method for bioassays utilizing giant magnetoresistive sensors as the readout method. The introduction section contains a brief review of some of the current methods of bioassay readout. The theoretical underpinnings of the giant magnetoresistive effect are also discussed. Finally, the more prominent types of giant magnetoresistive sensors are described, as well as their complicated fabrication. Four data chapters follow the introduction; each chapter is presented as a separate manuscript, either already published or soon to be submitted. Chapter 1 presents research efforts toward the production of a bioassay on the surface of a gold-modified GMR sensor. The testing of this methodology involved the capture of goat a-mouse-coated magnetic nanoparticles on the mouse IgG-modified gold surface. The second, third and fourth chapters describe the utilization of a self-referenced sample stick for scanning across the GMR sensor. The sample stick consisted of alternating magnetic reference and bioactive gold addresses. Chapter 2 is concerned with the characterization …

In this study, we applied the Nested Partitions method to a U-line balancing problem and conducted experiments to evaluate the application. From the results, it is quite evident that the Nested Partitions method provided near optimal solutions (optimal in some cases). Besides, the execution time is quite short as compared to the Branch and Bound algorithm. However, for larger data sets, the algorithm took significantly longer times for execution. One of the reasons could be the way in which the random samples are generated. In the present study, a random sample is a solution in itself which requires assignment of tasks to various stations. The time taken to assign tasks to stations is directly proportional to the number of tasks. Thus, if the number of tasks increases, the time taken to generate random samples for the different regions also increases. The performance index for the Nested Partitions method in the present study was the number of stations in the random solutions (samples) generated. The total idle time for the samples can be used as another performance index. ULINO method is known to have used a combination of bounds to come up with good solutions. This approach of combining different performance …

The purposes of our research were: (1) To characterize subunits of highly fluorescent protein R-Phycoerythrin (R-PE) and check their suitability for single-molecule detection (SMD) and cell imaging, (2) To extend the use of R-PE subunits through design of similar proteins that will be used as probes for microscopy and spectral imaging in a single cell, and (3) To demonstrate a high-throughput spectral imaging method that will rival spectral flow cytometry in the analysis of individual cells. We first demonstrated that R-PE subunits have spectroscopic and structural characteristics that make them suitable for SMD. Subunits were isolated from R-PE by high-performance liquid chromatography (HPLC) and detected as single molecules by total internal reflection fluorescence microscopy (TIRFM). In addition, R-PE subunits and their enzymatic digests were characterized by several separation and detection methods including HPLC, capillary electrophoresis, sodium dodecyl sulfate-polyacrilamide gel electrophoresis (SDS-PAGE) and HPLC-electrospray ionization mass spectrometry (ESI-MS). Favorable absorption and fluorescence of the R-PE subunits and digest peptides originate from phycoerythrobilin (PEB) and phycourobilin (PUB) chromophores that are covalently attached to cysteine residues. High absorption coefficients and strong fluorescence (even under denaturing conditions), broad excitation and emission fluorescence spectra in the visible region of electromagnetic spectrum, and relatively low molecular …

This work is presented in the following order: A review of the relevant physics and discussion of theoretical predictions for a two gap superconducting compound is given in chapter 2. Chapter 3 provides a review of the basic properties of MgB{sub 2}. Details of sample synthesis and characterization are given in chapter 4. Chapter 5 presents normal state and superconducting properties of Mg(B{sub 1-x}C{sub x}){sub 2} wires. Attempts to increase critical current densities in filaments via titanium additions are discussed in chapter 6. In chapters 7 and 8 alternative methods for synthesizing doped MgB{sub 2} powders are explored. In chapter 7 we synthesize Mg(B{sub 1-x}C{sub x}){sub 2} up to x=0.069 using a mixture of Mg, B, and the binary compound B{sub 4}C. Chapter 8 explores an alternative method, plasma spray synthesis, to produce nanometer sized doped boron powders for powder-in-tube applications. The effects of neutron irradiation on pure MgB{sub 2} wires is discussed in chapter 9. This is followed by a study of the effects of neutron irradiation on Mg(B{sub .962}C{sub .038}){sub 2} wires, presented in chapter 10. I will summarize the results of all of these studies in chapter 11 and discuss future directions for research in understanding the …

Quantification in liquid chromatography (LC) is becoming very important as more researchers are using LC, not as an analytical tool itself, but as a sample introduction system for other analytical instruments. The ability of LC instrumentation to quickly separate a wide variety of compounds makes it ideal for analysis of complex mixtures. For elemental speciation, LC is joined with inductively coupled plasma mass spectrometry (ICP-MS) to separate and detect metal-containing, organic compounds in complex mixtures, such as biological samples. Often, the solvent gradients required to perform complex separations will cause matrix effects within the plasma. This limits the sensitivity of the ICP-MS and the quantification methods available for use in such analyses. Traditionally, isotope dilution has been the method of choice for LC-ICP-MS quantification. The use of naturally abundant isotopes of a single element in quantification corrects for most of the effects that LC solvent gradients produce within the plasma. However, not all elements of interest in speciation studies have multiple naturally occurring isotopes; and polyatomic interferences for a given isotope can develop within the plasma, depending on the solvent matrix. This is the case for reverse phase LC separations, where increasing amounts of organic solvent are required. For such …

Atomic clusters are unique objects, which occupy an intermediate position between atoms and condensed matter systems. For a long time it was thought that physical and chemical properties of atomic dusters monotonically change with increasing size of the cluster from a single atom to a condensed matter system. However, recently it has become clear that many properties of atomic clusters can change drastically with the size of the clusters. Because physical and chemical properties of clusters can be adjusted simply by changing the cluster's size, different applications of atomic clusters were proposed. One example is the catalytic activity of clusters of specific sizes in different chemical reactions. Another example is a potential application of atomic clusters in microelectronics, where their band gaps can be adjusted by simply changing cluster sizes. In recent years significant advances in experimental techniques allow one to synthesize and study atomic clusters of specified sizes. However, the interpretation of the results is often difficult. The theoretical methods are frequently used to help in interpretation of complex experimental data. Most of the theoretical approaches have been based on empirical or semiempirical methods. These methods allow one to study large and small dusters using the same approximations. However, …

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 …

Metal on semiconductor surfaces has been the topic of intense studies due to its technological applications. As nano-devices shrink in size, the conventional understanding of electronic devices are no longer applicable as quantum effects start to play an important role in the behavior of the devices. At the same time, when structures are approaching atomic scale, the precise fabrication by lithographic techniques, for example, are not even applicable. Very often, the fabrication of regular structures rely on self-assembly which is susceptible to fluctuations. Therefore, a deeper understanding to exploit the quantum behavior of nano-devices and precise control of building nano-structures are highly desired. Si(100) and Si(111) surfaces are the most studied system because they are the Si surfaces with the lowest surface energy. Pb on Si(100) and Si(111) is often chosen as the prototype system for the study of metal/semiconductor interfaces because Pb is not reactive with Si thus forming a clean well-defined hetero-interface. A prominent problem for studying the physics of metal/semiconductor interfaces is that the interface structures are usually not known. While various experimental techniques can be employed to provide clues to the atomic geometries, definite conclusions usually cannot be drawn due to the intrinsic limitations of the …

This research project concerns changes in hydrology resulting from urbanization of the upper sub-basin of the White Rock Creek Watershed in Collin and Dallas Counties, Texas. The objectives of this study are: to calculate the percent watershed urbanized for the period of 1961 through 1968 and the period of 2000 through 2005; to derive a 1960s average unit hydrograph and a 2000s average unit hydrograph; and, to use the two averaged hydrographs to develop a range of hypothetical storm scenarios to evaluate how the storm response of the watershed has changed between these two periods. Results of this study show that stormflow occurs under lower intensity precipitation in the post-urbanized period and that stormflow peaks and volumes are substantially larger compared to the pre-urbanized period. It is concluded that changes in watershed surface conditions resulting from urbanization have lowered the precipitation-intensity threshold that must be surpassed before storm run-off is generated.

The purpose of this study was to examine three components of Donaldson and Graham's (1999) model of college outcomes for adults: (a) Prior Experience & Personal Biographies, (b) the Connecting Classroom, and (c) Life-World Environment, and to assess their application to traditional and nontraditional students in community colleges in both technical and nontechnical courses. The study sample was comprised of 311 community college students enrolled in technical and nontechnical courses during fall 2005. A survey instrument was developed based on the three model components through a review of the literature. Demographic data collected were utilized to classify students into a technical or nontechnical grouping as well as four classifications of traditionalism: (a) traditional, (b) minimally nontraditional, (c) moderately nontraditional, and (d) highly traditional. This study found that nontraditional students vary from traditional students in regards to the three model constructs. A post hoc descriptive discriminate analysis determined that the Life-World Environment component contributed the most to group differences with the minimally nontraditional group scoring the highest on this construct.

The authors study the yields of charged kaons, charged pions, and protons produced in association with B mesons produced in proton-antiproton collisions at center of mass energy 1960 GeV using 355 pb{sup -1} of data collected with the CDF detector at the Fermilab Tevatron. This is the first reported measurements of these yields at a hadron collider. The B mesons are reconstructed using their semileptonic decays: B{sup 0} {yields} {ell}{sup +}D{sup -}X, D{sup -} {yields} K{sup +}{pi}{sup -}{pi}{sup -}; B{sup 0} {yields} {ell}{sup +}D*{sup -}X, D*{sup -} {yields} {pi}{sup -}{bar D}{sup 0},{bar D}{sup 0} {yields} K{sup +}{pi}{sup -}; B{sup +} {yields} {ell}{sup +}{bar D}{sup 0}X, {bar D}{sup 0} {yields} K{sup +}{pi}{sup -}; B{sub s}{yields}{ell}{sup +}D{sub s}{sup -}X, D{sub s}{sup -} {yields} {pi}{sup -}{phi},{phi} {yields} K{sup +}K{sup -}. The K, {pi}, and p are identified using the Time of Flight detector (TOF), the CDF spectrometer, and the specific ionization (dE/dx) measured in the central drift chamber (COT). The fraction of charged kaons produced in association with {bar B}{sub s}{sup 0} mesons is found to be larger than the fraction produced in association with the {bar B}{sup 0} and B{sup -} mesons, as expected from naive models of heavy quark hadronization to …

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This thesis concerns the development and characterization of a prototype Silicon micro-strip detector that can be used in the forward (high rapidity) region of a hadron collider. These detectors must operate in a high radiation environment without any important degradation of their performance. The innovative feature of these detectors is the readout electronics, which, being completely data-driven, allows for the direct use of the detector information at the lowest level of the trigger. All the particle hits on the detector can be readout in real-time without any external trigger and any particular limitation due to dead-time. In this way, all the detector information is available to elaborate a very selective trigger decision based on a fast reconstruction of tracks and vertex topology. These detectors, together with the new approach to the trigger, have been developed in the context of the BTeV R&D program; our aim was to define the features and the design parameters of an optimal experiment for heavy flavour physics at hadron colliders. Application of these detectors goes well beyond the BTeV project and, in particular, involves the future upgrades of experiments at hadron colliders, such as Atlas, CMS and LHCb. These experiments, indeed, are already considering for …