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2006

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Articles 4621 - 4650 of 4906

Full-Text Articles in Physical Sciences and Mathematics

Zero Effluent Stretch Target (Zest), Orla O'Connor Jan 2006

Zero Effluent Stretch Target (Zest), Orla O'Connor

Theses

The goals of this project were to assess the viability of avoiding water use and of “cascading” water uses, i.e. using outlet water from one process in another activity, possibly with some purification, including the upgrading of the final effluent stream for internal reuse. Water use has been inventoried at FMC Biopolymer, Cork. Avoidance and reduction measures were identified that could reduce water consumption from 49m /hr to 19 m /hr (a reduction in excess of 60%), with an annual saving in excess of €350,000. These projects were assessed for feasibility and implementation. Potential streams that could be subject to …

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An Euler-Type Formula For Ζ(2k +1), Tian-Xiao He, Michael Dancs Jan 2006

An Euler-Type Formula For Ζ(2k +1), Tian-Xiao He, Michael Dancs

Scholarship

In this short paper, we give several new formulas for ζ(n) when n is an odd positive integer. The method is based on a recent proof, due to H. Tsumura, of Euler’s classical result for even n. Our results illuminate the similarities between the even and odd cases, and may give some insight into why the odd case is much more difficult.

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Numerical Approximation To Ζ(2n+1), Tian-Xiao He, Michael Dancs Jan 2006

Numerical Approximation To Ζ(2n+1), Tian-Xiao He, Michael Dancs

Scholarship

In this short paper, we establish a family of rapidly converging series expansions ζ(2n +1) by discretizing an integral representation given by Cvijovic and Klinowski [3] in Integral representations of the Riemann zeta function for odd-integer arguments, J. Comput. Appl. Math. 142 (2002) 435–439. The proofs are elementary, using basic properties of the Bernoulli polynomials.

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Multivariate Expansion Associated With Sheffer-Type Polynomials And Operators, Tian-Xiao He, Leetsch Hsu, Peter Shiue Jan 2006

Multivariate Expansion Associated With Sheffer-Type Polynomials And Operators, Tian-Xiao He, Leetsch Hsu, Peter Shiue

Scholarship

With the aid of multivariate Sheffer-type polynomials and differential operators, this paper provides two kinds of general expansion formulas, called respectively the first expansion formula and the second expansion formula, that yield a constructive solution to the problem of the expansion of A(ˆt)f([g(t)) (a composition of any given formal power series) and the expansion of the multivariate entire functions in terms of multivariate Sheffer-type polynomials, which may be considered an application of the first expansion formula and the Sheffer-type operators. The results are applicable to combinatorics and special function theory.

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On The Convergence Of The Summation Formulas Constructed By Using A Symbolic Operator Approach, Tian-Xiao He, Leetsch Hsu, Peter Shiue Jan 2006

On The Convergence Of The Summation Formulas Constructed By Using A Symbolic Operator Approach, Tian-Xiao He, Leetsch Hsu, Peter Shiue

Scholarship

This paper deals with the convergence of the summation of power series of the form Σa ≤ k ≤ bf(k)xk, where 0 ≤ a ≤ b < ∞, and {f(k)} is a given sequence of numbers with k ∈ [a, b) or f(t) a differentiable function defined on [a, b). Here, the summation is found by using the symbolic operator approach shown in [1]. We will give a different type of the remainder of the summation formulas. The convergence of the corresponding power series will be determined consequently. Several examples such as the generalized Euler's transformation series will also be given. In addition, we will compare the convergence of the given series transforms.

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Construction Of Rational Points On Elliptic Curves Over Finite Fields, Andrew Shallue, Christiaan Van De Woestijne Jan 2006

Construction Of Rational Points On Elliptic Curves Over Finite Fields, Andrew Shallue, Christiaan Van De Woestijne

Scholarship

We give a deterministic polynomial-time algorithm that computes a nontrivial rational point on an elliptic curve over a finite field, given a Weierstrass equation for the curve. For this, we reduce the problem to the task of finding a rational point on a curve of genus zero.

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Characterization Of An Acrylaminde Based Photopolymer For Fabrication Of Liquid Crystal Devices, Pavani Kotakonda Jan 2006

Characterization Of An Acrylaminde Based Photopolymer For Fabrication Of Liquid Crystal Devices, Pavani Kotakonda

Conference Papers

Photopolymers are increasingly interesting as new materials for the fabrication of electro optical liquid crystal devices. Photoinduced surface relief gratings in dry, self developing acrylamide based photopolymers can be used to align liquid crystals (LCs) as an alternative to the rubbing technique. These optically recorded surface relief patterns can be used to fabricate electro-optical switchable LC Bragg gratings. An investigation of the dependence of photoinduced surface relief gratings on recording intensity and thickness of the photopolymer layer is reported. The surface relief gratings were filled with E7 LCs and a switchable LC diffraction grating was fabricated.

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Holographic Recording In Nanoparticle-Doped Photopolymer, Izabela Naydenova, Hosam Sherif, Svetlana Mintova, Suzanne Martin, Vincent Toal Jan 2006

Holographic Recording In Nanoparticle-Doped Photopolymer, Izabela Naydenova, Hosam Sherif, Svetlana Mintova, Suzanne Martin, Vincent Toal

Conference Papers

A nanoparticle-doped acrylic photopolymer is characterised as a material for holographic recording. The influence of nanoparticles on the photopolymer dynamic range, dynamics of recording, temporal stability and mechanical stability in terms of shrinkage has been studied. The dynamics of recording and the temporal stability are investigated by real time monitoring of the build up of diffraction gratings of spatial frequencies of 200 to 2000 l/mm. The shrinkage has been characterised by recording slanted transmission gratings and observation of the change in the Bragg angle.

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Two Way Diffusion Model For The Recording Mechanism In A Self-Developing Dry Acrylamide Photopolymer, Suzanne Martin, Izabela Naydenova, Raghavendra Jallapuram, Robert Howard, Vincent Toal Jan 2006

Two Way Diffusion Model For The Recording Mechanism In A Self-Developing Dry Acrylamide Photopolymer, Suzanne Martin, Izabela Naydenova, Raghavendra Jallapuram, Robert Howard, Vincent Toal

Conference Papers

In our most recent study [1] diffusion constants were measured in the simplified monoacrylamide version of a dry acrylamide based photopolymer holographic recording material developed in the Centre for Industrial and Engineering Optics. In this paper we report diffusion constants for the commonly used photopolymer formulation, which also contains the crosslinker bisacrylamide. A physical model for the recording mechanism is proposed which explains the two way diffusion observed in both systems, and is in agreement with much of the previously observed behaviour of the material, particularly in regard to dependence of diffraction efficiency growth on spatial frequency and persistence of …

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In-Use Emission Measurements Of Snowmobiles And Snowcoaches In Yellowstone National Park, Gary A. Bishop, Daniel A. Burgard, Thomas R. Dalton, Donald H. Stedman Jan 2006

In-Use Emission Measurements Of Snowmobiles And Snowcoaches In Yellowstone National Park, Gary A. Bishop, Daniel A. Burgard, Thomas R. Dalton, Donald H. Stedman

Fuel Efficiency Automobile Test Publications

No abstract provided.

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Using Sketches And Knowledge Bases For Geo-Spatial Image Retrieval, Michela Bertolotto, James Carswell, E Mcloughlin, D O'Sullivan, C Wilson Jan 2006

Using Sketches And Knowledge Bases For Geo-Spatial Image Retrieval, Michela Bertolotto, James Carswell, E Mcloughlin, D O'Sullivan, C Wilson

Articles

This paper presents research in the field of knowledge management for geo-spatial imagery including scanned aerial photos and satellite images. We have developed a web-based system that allows users to query a database of images not only using metadata, but also drawing sketches of configurations of objects they are interested in as well as inputting textual descriptions of their intended task. Our system integrates case-based reasoning techniques to form a knowledge base from previously issued queries that can be exploited to improve future query processing and to build organizational memory through experience capture. The effective design and implementation of a …

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Energy And Communication Efficient Group Key Management Protocol For Hierarchical Sensor Networks, Biswajit Panja, Sanjay Kumar Madria, Bharat Bhargava Jan 2006

Energy And Communication Efficient Group Key Management Protocol For Hierarchical Sensor Networks, Biswajit Panja, Sanjay Kumar Madria, Bharat Bhargava

Computer Science Faculty Research & Creative Works

In this paper, we describe group key management protocosl for hierarchical sensor networks where instead of using pre-deployed keys, each sensor node generates a partial key dynamically using a function. The function takes partial keys of its children as input. The design of the protocol is motivated by the fact that traditional cryptographic techniques are impractical in sensor networks because of high energy and computational overheads. The group key management protocol supports the establishment of two types of group keys; one for the sensor nodes within a group, and the other in a group of cluster heads. The protocol handles …

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Some General Notions Of Stochastic Orderings For Weighted Reliability And Uncertainty Measures With Applications, Broderick O. Oluyede Jan 2006

Some General Notions Of Stochastic Orderings For Weighted Reliability And Uncertainty Measures With Applications, Broderick O. Oluyede

Mathematical Sciences: Faculty Publications

In this note, stochastic comparisons of reliability measures and related functions are presented. Inequalities for uncertainty of a residual life distribution and certain modified cross-entropy or discrimination information measures under weighted models are established. Comparisons of the expected uncertainty about the remaining lifetime of a component for weighted conditional distributions and unweighted conditional distributions are presented.

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Crystal Growth And The Search For Highly Correlated Ternary Intermetallic Antimonides And Stannides, Evan Lyle Thomas Jan 2006

Crystal Growth And The Search For Highly Correlated Ternary Intermetallic Antimonides And Stannides, Evan Lyle Thomas

LSU Doctoral Dissertations

This dissertation describes the crystal growth, chemical structures, and efforts made towards the understanding of the physical properties of novel ternary rare-earth intermetallics, which may display signature behavior such as superconductivity, heavy fermion behavior, intermediate valence, and/or large magnetoresistance. To address the problem of correlating these characteristics with structural features, several ternary antimony- and tin-containing phases, Ln-T-X (Ln = lanthanide; T = Co, Ni, Pd; X = Sn, Sb), have been synthesized in single crystalline form by metallic flux-growth methods and characterized by X-ray diffraction. The antimonide compounds LnNi1-xSb2 (Ln = Y, Gd-Tb, Er, Yb), alpha, beta-LnNiSb3 (Ln = La, …

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Circuits And Structure In Matroids And Graphs, Brian Daniel Beavers Jan 2006

Circuits And Structure In Matroids And Graphs, Brian Daniel Beavers

LSU Doctoral Dissertations

This dissertation consists of several results on matroid and graph structure and is organized into three main parts. The main goal of the first part, Chapters 1-3, is to produce a unique decomposition of 3-connected matroids into more highly connected pieces. In Chapter 1, we review the definitions and main results from the previous work of Hall, Oxley, Semple, and Whittle. In Chapter 2, we introduce operations that allow us to decompose a 3-connected matroid M into a pair of 3-connected pieces by breaking the matroid apart at a 3-separation. We also generalize a result of Akkari and Oxley. In …

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Numerical Techniques For Fresnel Diffraction In Computational Holography, Richard Patrick Muffoletto Jan 2006

Numerical Techniques For Fresnel Diffraction In Computational Holography, Richard Patrick Muffoletto

LSU Doctoral Dissertations

Optical holography can produce very realistic virtual images due to its capability to properly convey the depth cues that we use to interpret three-dimensional objects. Computational holography is the use of digital representations plus computational methods to carry out the holographic operations of construction and reconstruction. The large computational requirements of holographic simulations prohibit present-day existence of real-time holographic displays comparable in size to traditional two-dimensional displays. Fourier-based approaches to calculate the Fresnel diffraction of light provide one of the most efficient algorithms for holographic computations because this permits the use of the fast Fourier transform (FFT). The limitations on …

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Ecology Of Lesser Scaup Amphipods In The Upper-Midwest: Scope And Mechanisms Of The Spring Condition Hypothesis And Implications For Migration Habitat Conservation, Michael Jason Anteau Jan 2006

Ecology Of Lesser Scaup Amphipods In The Upper-Midwest: Scope And Mechanisms Of The Spring Condition Hypothesis And Implications For Migration Habitat Conservation, Michael Jason Anteau

LSU Doctoral Dissertations

I tested the scope of the Spring Condition Hypothesis in explaining the continental population decline of lesser scaup (Aythya affinis; hereafter scaup) and explored potential mechanisms affecting female body condition to assist conservation efforts for population recovery. Lipid reserves of females currently are lower than historical values during spring migration throughout Iowa, Minnesota, and North Dakota; females catabolized lipids throughout this area (indexed by concentrations of plasma-lipid metabolites, which accounted for 75% of the variation in mass change). My results indicate that a large segment of the continental scaup population likely is affected by decreased lipid reserves, which could cause …

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High Harmonic Generation By Short Laser Pulses: Time-Frequency Behavior And Applications To Attophysics, Mitsuko Murakami Jan 2006

High Harmonic Generation By Short Laser Pulses: Time-Frequency Behavior And Applications To Attophysics, Mitsuko Murakami

LSU Doctoral Dissertations

High harmonic generation (HHG) is a process in which noble gas atoms excited by an intense laser field at frequency ω1 emit radiation of higher frequencies that are odd integer multiples of ω1. Driven by an infrared laser, high harmonic radiation can span from the optical into the extreme ultraviolet (XUV) frequency range. In this thesis, I study HHG using short laser pulses by solving the time-dependent Schrödinger equation (TDSE). In particular, I will focus on calculating and controlling the time-dependent instantaneous frequency (chirp) of high harmonics. The harmonic chirp is a direct consequence of the atom-field …

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Integrating Micro-Scale Separations To Matrix Assisted Laser Desorption And Ioniation Time Of Flight Mass Spectrometry (Maldi-Tof-Ms) For Protein Analysis, Harrison K. Musyimi Jan 2006

Integrating Micro-Scale Separations To Matrix Assisted Laser Desorption And Ioniation Time Of Flight Mass Spectrometry (Maldi-Tof-Ms) For Protein Analysis, Harrison K. Musyimi

LSU Doctoral Dissertations

This dissertation describes the integration of micro-scale separations to matrix assisted laser desorption and ionization time-of-flight mass spectrometry (MALDI TOF MS) for protein analysis. MALDI MS provides unsurpassed accurate mass measurements of intact bio-molecules, for example peptides and proteins, which in turn generate high molecular specificity enabling the identity, function and structure of these molecules to be characterized. However, in order to realize the full potential of MS in proteomic studies, integrated sample processing on automated and high throughput platforms is required to address the complexity, diversity and the dynamic range of proteomic analysis. The work described here contributes towards …

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Direct Detection Of Homocysteine And Syntheses Of Lanthanide Complexes As Biosensors, Weihua Wang Jan 2006

Direct Detection Of Homocysteine And Syntheses Of Lanthanide Complexes As Biosensors, Weihua Wang

LSU Doctoral Dissertations

At elevated levels, homocysteine (Hcy) is a risk factor for cardiovascular diseases and Alzheimer’s disease. It’s also implicated in a number of other diseases such as neural tube defects, pregnancy complications, and renal failures. The monitoring of Hcy levels in plasma is of current concern. To date, the biochemical mechanism by which Hcy is involved in disease states is unclear. Herein, we describe highly selective colorimetric methods for the direct determination of Hcy. Inexpensive, commercially available materials are reported. The results show potential application for the detection of Hcy in human blood plasma. Additionally, new HPLC postcolumn detection methods for …

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Modeling The Effects Of Endocrine Disrupting Chemicals On Atlantic Croaker: Understanding Biomarkers And Predicting Population Responses, Cheryl Anne Murphy Jan 2006

Modeling The Effects Of Endocrine Disrupting Chemicals On Atlantic Croaker: Understanding Biomarkers And Predicting Population Responses, Cheryl Anne Murphy

LSU Doctoral Dissertations

A number of environmental stressors have been shown to interfere with reproductive and behavioral processes of fish by interfering with endocrine function. Most biomarkers of endocrine disturbance tend to be static measurements from dynamic systems making them difficult to evaluate within the context of an individual, or subtle effects that do not relate well to endpoints of ecological significance. I present an approach that uses a series of models, based on Atlantic croaker, to extrapolate laboratory results to indicators of individual and population health. First, I created a physiologically based model that simulates vitellogenesis in a female fish. The model …

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Effects Of An External Field And Dissipation On Decoherence, Jian Zuo Jan 2006

Effects Of An External Field And Dissipation On Decoherence, Jian Zuo

LSU Doctoral Dissertations

Decoherence is the suppression of the interference of quantum states. It plays important roles in the study of the quantum-classical transition. It is also the major obstacle in the implementation of various schemes of quantum computers. Decoherence can be affected by many factors. The interactions between quantum systems of interest and dissipative environments cause the extensively studied environment-induced-decoherence. Decoherence can also occur as the result of a temperature effect. A recent experiment investigated the engineering of decoherence, which involves applying an external field to the quantum system. In this thesis, we study the effect of an external field on decoherence …

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Incremental Generation Of Spatial Referring Expressions In Situated Dialogue, John D. Kelleher, Geert-Jan Kruijff Jan 2006

Incremental Generation Of Spatial Referring Expressions In Situated Dialogue, John D. Kelleher, Geert-Jan Kruijff

Conference papers

This paper presents an approach to incrementally generating locative expressions. It addresses the issue of combinatorial explosion inherent in the construction of relational context models by: (a) contextually defining the set of objects in the context that may function as a landmark, and (b) sequencing the order in which spatial relations are considered using a cognitively motivated hierarchy of relations, and visual and discourse salience.

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Extension Of Shor's Period-Finding Algorithm To Infinite Dimensional Hilbert Spaces, Jeremy James Becnel Jan 2006

Extension Of Shor's Period-Finding Algorithm To Infinite Dimensional Hilbert Spaces, Jeremy James Becnel

LSU Doctoral Dissertations

Over the last decade quantum computing has become a very popular field in various disciplines, such as physics, engineering, and mathematics. Most of the attraction stemmed from the famous Shor period--finding algorithm, which leads to an efficient algorithm for factoring positive integers. Many adaptations and generalizations of this algorithm have been developed through the years, some of which have not been ripened with full mathematical rigor. In this dissertation we use concepts from white noise analysis to rigorously develop a Shor algorithm adapted to find a hidden subspace of a function with domain a real Hilbert space. After reviewing the …

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Bluetooth Assassin: A Location-Based Game For Mobile Devices, Miao Wang, Brian Mac Namee Jan 2006

Bluetooth Assassin: A Location-Based Game For Mobile Devices, Miao Wang, Brian Mac Namee

Conference papers

This short paper will describe Bluetooth Assassin, a location-based game developed for mobile devices.

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Photoionization Broadening Of The 1s-2s Transition In A Beam Of Atomic Hydrogen, Nikolai N. Kolachevsky, Martin K. Haas, Ulrich D. Jentschura, Maximilian Herrmann, Peter Fendel, Marc P. Fischer, Ronald Holzwarth, Th H. Udem, Christoph H. Keitel, Theodor Wolfgang Hansch Jan 2006

Photoionization Broadening Of The 1s-2s Transition In A Beam Of Atomic Hydrogen, Nikolai N. Kolachevsky, Martin K. Haas, Ulrich D. Jentschura, Maximilian Herrmann, Peter Fendel, Marc P. Fischer, Ronald Holzwarth, Th H. Udem, Christoph H. Keitel, Theodor Wolfgang Hansch

Physics Faculty Research & Creative Works

We consider the excitation dynamics of the two-photon 1S - 2S transition in a beam of atomic hydrogen by 243 nm laser radiation. Specifically, we study the impact of ionization damping on the transition line shape, caused by the possibility of ionization of the 2S level by the same laser field. Using a Monte Carlo simulation, we calculate the line shape of the 1S - 2S transition for the experimental geometry used in the two latest absolute frequency measurements [M. Niering, Phys. Rev. Lett. 84, 5496 (2000) and M. Fischer, Phys. Rev. Lett. 92, 230802 (2004)]. The calculated line shift …

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Comparison Of Classical And Second Quantized Description Of The Dynamic Stark Shift, Martin K. Haas, Ulrich D. Jentschura, Christoph H. Keitel Jan 2006

Comparison Of Classical And Second Quantized Description Of The Dynamic Stark Shift, Martin K. Haas, Ulrich D. Jentschura, Christoph H. Keitel

Physics Faculty Research & Creative Works

We compare the derivation of the dynamic Stark shift of hydrogenic energy levels in a classical framework with an adiabatically damped laser-atom interaction, which is equivalent to the Gell-Mann-Low-Sucher formula, and a treatment based on time-independent perturbation theory, with a second-quantized laser-atom dipole interaction Hamiltonian. Our analysis applies to a laser that excites a two-photon transition in atomic hydrogen or in a hydrogenlike ion with low nuclear charge number. Our comparisons serve to demonstrate why the dynamic Stark shift may be interpreted as a stimulated radiative correction and illustrates connections between the two derivations. The simplest of the derivations is …

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Crystal And Electronic Structures Of Linh₂, Jinbo Yang, X.-D. Zhou, Qingsheng Cai, William Joseph James, William B. Yelon Jan 2006

Crystal And Electronic Structures Of Linh₂, Jinbo Yang, X.-D. Zhou, Qingsheng Cai, William Joseph James, William B. Yelon

Materials Science and Engineering Faculty Research & Creative Works

The crystal structure of LiNH2 was reinvestigated using powder neutron diffraction with high sensitivity. The compound crystallizes in the tetragonal space group I4 with lattice parameters α = b= 5.034 42 (24) Å, c = 10.255 58 (52) Å. It is found that H atoms occupy 8g1(0.2429, 0.1285, 0.1910) and 8g2 (0.3840, 0.3512, 0.1278) sites. The bond lengths between the nearest nitrogen and hydrogen atoms are 0.986 and 0.942 Å, respectively. The bond angle between H-N-H is about 99.97°. These results are significantly different from those of previous experiments. The electronic structure was calculated according to the revised structural …

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Effect Of Amplification On Conductance Distribution Of A Disordered Waveguide, Alexey Yamilov, Hui Cao Jan 2006

Effect Of Amplification On Conductance Distribution Of A Disordered Waveguide, Alexey Yamilov, Hui Cao

Physics Faculty Research & Creative Works

Introduction of optical gain in a disordered system results in enhanced fluctuations [F(2)=var(g-tilde)/2] of the dimensionless conductance g-tilde, similar to the effect of Anderson localization in a passive medium. Using numerical simulations we demonstrate that, despite such qualitative similarity, the whole distribution of the conductance of amplifying random media is drastically different from that of a passive system with the same value of F(2).

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Initial-State Correlation Effects In Low-Energy Proton Impact Ionization, M. Foster, Jerry Peacher, Ahmad Hasan, Michael Schulz, Don H. Madison Jan 2006

Initial-State Correlation Effects In Low-Energy Proton Impact Ionization, M. Foster, Jerry Peacher, Ahmad Hasan, Michael Schulz, Don H. Madison

Physics Faculty Research & Creative Works

In this paper, we will report on fully differential cross sections (FDCS) for single ionization of helium by 75 keV proton impact for fixed ejected electron energies and different momentum transfers. These measurements show major discrepancies in the absolute magnitude between experiment and the theoretical, 3DW (three-distorted-wave) model. The 3DW model treats the collision as a three-body process (projectile, ion, ejected electron), and for the scattering plane it has accurately predicted the FDCS for higher energy C6+ impact ionization of helium. The lack of agreement between the 3DW model and experiment for low energy collisions suggests that a three-body …

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