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open access

An Analytic Tool to Investigate the Effect of Binder on the Sensitivity of HMX-Based Plastic Bonded Explosives in the Skid Test

Description: This project will develop an analytical tool to calculate performance of HMX based PBXs in the skid test. The skid-test is used as a means to measure sensitivity for large charges in handling situations. Each series of skid tests requires dozens of drops of large billets. It is proposed that the reaction (or lack of one) of PBXs in the skid test is governed by the mechanical properties of the binder. If true, one might be able to develop an analytical tool to estimate skid test behavior for new… more
Date: February 1, 2005
Creator: Hayden, D. W.
open access

Angular correlations in beauty production at the Tevatron at sqrt(s) = 1.96 TeV

Description: Measurements of the b quark production cross section at the Tevatron and at Hera in the final decades of the 20th century have consistently yielded higher values than predicted by Next-to-Leading Order (NLO) QCD. This discrepancy has led to a large efforts by theorists to improve theoretical calculations of the cross sections and simulations of b quark production. As a result, the difference between theory and experiment has been much reduced. New measurements are needed to test the development… more
Date: June 1, 2005
Creator: Wijngaarden, Daniel A. & Nijmegen, /Radboud U.
open access

Angular-momentum-dominated electron beams and flat-beam generation

Description: In the absence of external forces, if the dynamics within an electron beam is dominated by its angular momentum rather than other effects such as random thermal motion or self Coulomb-repulsive force (i.e., space-charge force), the beam is said to be angular-momentum-dominated. Such a beam can be directly applied to the field of electron-cooling of heavy ions; or it can be manipulated into an electron beam with large transverse emittance ratio, i.e., a flat beam. A flat beam is of interest for … more
Date: June 1, 2005
Creator: Sun, Yin-e
open access

ATCOM: Automatically Tuned Collective Communication System for SMP Clusters

Description: 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-i… more
Date: December 17, 2005
Creator: Wu, Meng-Shiou
open access

B Flavor Tagging Calibration and Search for B(s) Oscillations in Semileptonic Decays with the CDF Detector at Fermilab

Description: In this thesis we present a search for oscillations of B{sub s}{sup 0} mesons using semileptonic B{sub s}{sup 0} {yields} D{sub s}{sup -}{ell}{sup +}{nu} decays. Data were collected with the upgraded Collider Detector at Fermilab (CDFII) from events produced in collisions of 980 GeV protons and antiprotons accelerated in the Tevatron ring. The total proton-antiproton center-of-mass energy is 1.96 TeV. The Tevatron is the unique source in the world for B{sub s}{sup 0} mesons, to be joined by the… more
Date: September 1, 2005
Creator: Giurgiu, Gavril A.
open access

Balancing a U-Shaped Assembly Line by Applying Nested Partitions Method

Description: 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… more
Date: December 17, 2005
Creator: Bhagwat, Nikhil V.
open access

Beam Diagnosis and Lattice Modeling of the Fermilab Booster

Description: A realistic lattice model is a fundamental basis for the operation of a synchrotron. In this study various beam-based measurements, including orbit response matrix (ORM) and BPM turn-by-turn data are used to verify and calibrate the lattice model of the Fermilab Booster. In the ORM study, despite the strong correlation between the gradient parameters of adjacent magnets which prevents a full determination of the model parameters, an equivalent lattice model is obtained by imposing appropriate c… more
Date: September 1, 2005
Creator: Huang, Xiaobiao
open access

Biomolecular Assembly of Gold Nanocrystals

Description: Over the past ten years, methods have been developed to construct discrete nanostructures using nanocrystals and biomolecules. While these frequently consist of gold nanocrystals and DNA, semiconductor nanocrystals as well as antibodies and enzymes have also been used. One example of discrete nanostructures is dimers of gold nanocrystals linked together with complementary DNA. This type of nanostructure is also known as a nanocrystal molecule. Discrete nanostructures of this kind have a number … more
Date: May 20, 2005
Creator: Micheel, Christine Marya
open access

The breakdown of de Gennes Scaling in TbxEr1-xNi2B2C and its mean field theory explanation

Description: The Neel temperatures, T{sub N}, of Tb{sub x}Er{sub 1-x}Ni{sub 2}B{sub 2}C samples have been determined from the temperature dependence of magnetization measurements. A breakdown of the de Gennes scaling of T{sub N} with a clear turning point around x = 0.45 has been observed. The T{sub N} values of Tb{sub x}Er{sub 1-x}Ni{sub 2}B{sub 2}C do not change much within the range of O < x < 0.45 and then, for larger x they increase almost linearly with concentration until T{sub N} = 14.9K is rea… more
Date: May 1, 2005
Creator: Gao, Chunwang
open access

CDF Grid computing and the decay X(3872) ---> J/psi pi+ pi- with J/psi ---> e+ e-

Description: The main aim of physics research is to obtain a consistent description of nature leading to a detailed understanding of the phenomena observed in experiments. The field of particle physics focuses on the discovery and understanding of the fundamental particles and the forces by which they interact with each other. Using methods from group theory, the present knowledge can be mathematically described by the so-called ''Standard Model'', which interprets the fundamental particles (quarks and lept… more
Date: November 1, 2005
Creator: Kerzel, Ulrich
open access

Character and Effective Leadership of the Knowledge Worker

Description: Ulrich in the forward to the Zenger and Folkman (2002) book, ''The Extraordinary Leader'', wrote about the importance of character in leadership stating, ''Everything about great leaders radiates from character. Character improves the probability of exhibiting strong interpersonal skill. Some of this perceived character is innate . . . but more is driven by the leader's self-awareness and interactions with others'' (p. ix). The purpose of this study was to explore the relationship between leade… more
Date: April 20, 2005
Creator: Khoury, A E
open access

Characterization of piesoelectric ZnO thin films and the fabrication of piezoelectric micro-cantilevers

Description: In Atomic Force Microscopy (AFM), a microcantilever is raster scanned across the surface of a sample in order to obtain a topographical image of the sample's surface. In a traditional, optical AFM, the sample rests on a bulk piezoelectric tube and a control loop is used to control the tip-sample separation by actuating the piezo-tube. This method has several disadvantages--the most noticeable one being that response time of the piezo-tube is rather long which leads to slow imaging speeds. One p… more
Date: August 1, 2005
Creator: Johnson, Raegan Lynn
open access

The Charge asymmetry in W bosons produced in p anti-p collisions at center of mass energy - 1.96 TeV

Description: The primary mode of production of W{sup +} bosons in a p{bar p} collider is u + {bar d} {yields} W{sup +}. The u quark generally carries more momentum than the {bar d} and the resultant W{sup +} tends to be boosted in the proton direction. Similarly, W bosons are boosted in the anti-proton direction. This is observed as an asymmetry in the rapidity distributions of positive and negative W bosons. Measurement of this asymmetry serves as a probe of the momentum distribution of partons within the … more
Date: July 1, 2005
Creator: Torborg, Julie M. & U., /Notre Dame
open access

Chip-Scale Bioassays Based on Surface-Enhanced Raman Scattering: Fundamentals and Applications

Description: This work explores the development and application of chip-scale bioassays based on surface-enhanced Raman scattering (SERS) for high throughput and high sensitivity analysis of biomolecules. The size effect of gold nanoparticles on the intensity of SERS is first presented. A sandwich immunoassay was performed using Raman-labeled immunogold nanoparticles with various sizes. The SERS responses were correlated to particle densities, which were obtained by atomic force microscopy (AFM). The respon… more
Date: December 17, 2005
Creator: Park, Hye-Young
open access

Cobalt Nanocrystals as Starting Materials for Shape Modificationand Assembly Formation

Description: 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 ori… more
Date: December 20, 2005
Creator: Erdonmez, Can Kerem
open access

Computational Study and Analysis of Structural Imperfections in 1D and 2D Photonic Crystals

Description: Dielectric reflectors that are periodic in one or two dimensions, also known as 1D and 2D photonic crystals, have been widely studied for many potential applications due to the presence of wavelength-tunable photonic bandgaps. However, the unique optical behavior of photonic crystals is based on theoretical models of perfect analogues. Little is known about the practical effects of dielectric imperfections on their technologically useful optical properties. In order to address this issue, a fin… more
Date: June 1, 2005
Creator: Maskaly, Karlene Rosera
open access

Controlled Electron Injection into Plasma Accelerators and SpaceCharge Estimates

Description: Plasma based accelerators are capable of producing electron sources which are ultra-compact (a few microns) and high energies (up to hundreds of MeVs) in much shorter distances than conventional accelerators. This is due to the large longitudinal electric field that can be excited without the limitation of breakdown as in RF structures.The characteristic scale length of the accelerating field is the plasma wavelength and for typical densities ranging from 1018 - 1019 cm-3, the accelerating fiel… more
Date: September 1, 2005
Creator: Fubiani, Gwenael J.
open access

Cool Cluster Correctly Correlated

Description: 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… more
Date: December 17, 2005
Creator: Varganov, Sergey Aleksandrovich
open access

Coordination of dibensothiophenes and corannulenes to organometallic ruthenium (II) fragments

Description: This dissertation contains five papers in the format required for journal publication which describe (in part) my research accomplishments as a graduate student at Iowa State University. This work can be broadly categorized as the binding of weakly-coordinating ligands to cationic organometallic ruthenium fragments, and consists of two main areas of study. Chapters 2-4 are investigations into factors that influence the binding of dibenzothiophenes to {l_brace}Cp'Ru(CO){sub 2}{r_brace}{sup +} fr… more
Date: May 1, 2005
Creator: Vecchi, Paul Anthony
open access

Cosmic ray muon charge ratio in the MINOS far detector

Description: 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 muon… more
Date: December 1, 2005
Creator: Beall, Erik B
open access

The Cryogenic Dark Matter Search and Background Rejection with Event Position Information

Description: Evidence from observational cosmology and astrophysics indicates that about one third of the universe is matter, but that the known baryonic matter only contributes to the universe at 4%. A large fraction of the universe is cold and non-baryonic matter, which has important role in the universe structure formation and its evolution. The leading candidate for the non-baryonic dark matter is Weakly Interacting Massive Particles (WIMPs), which naturally occurs in the supersymmetry theory in particl… more
Date: January 1, 2005
Creator: Wang, Gen-sheng & U., /Case Western Reserve
open access

Cubic Spline Collocation Method for the Simulation of Turbulent Thermal Convection in Compressible Fluids

Description: A collocation method using cubic splines is developed and applied to simulate steady and time-dependent, including turbulent, thermally convecting flows for two-dimensional compressible fluids. The state variables and the fluxes of the conserved quantities are approximated by cubic splines in both space direction. This method is shown to be numerically conservative and to have a local truncation error proportional to the fourth power of the grid spacing. A ''dual-staggered'' Cartesian grid, whe… more
Date: January 12, 2005
Creator: Castillo, V M
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