Physical Sciences and Mathematics Commons^™

On Stochastic Comparisons Of Energy Functions With Applications, Broderick O. Oluyede

Mathematical Sciences: Faculty Publications

We develop simple methods for the stochastic comparisons of informational energy functions. We introduce modified informational energy functions and uncertainty of parameter functions are introduced for models with realistic parameter spaces. We present inequalities, comparisons, and applications including test procedures for testing the equality of informational energy functions. Some illustrative examples are also presented.

Electric Field Controlled, Pulsed Autoionization In Two Electron Wave Packets, J. Greg Story, Heider N. Ereifej

Physics Faculty Research & Creative Works

In this paper, control of the evolution of a two electron wave packet through the application of a static electric field is demonstrated. Specifically, application of a small electric field is used to produce pulsed autoionization events, the timing of which can be controlled on a picosecond time scale. The technique is demonstrated by exciting calcium atoms using a short-pulsed laser to the 4p_3/219d doubly excited state, which is energy degenerate with the 4p_1/2nk stark states. Evolution of the resultant wave packet is monitored through the application of a second short laser pulse, which stimulates the …

Structural, Electronic, And Magnetic Properties Of Lani₅₋ₓtₓ (T = Fe, Mn) Compounds, Jinbo Yang, Chiu-Ying Tai, G. K. Marasinghe, George Daniel Waddill, Oran Allan Pringle, William Joseph James, Y. Kong

Physics Faculty Research & Creative Works

Structures and magnetic properties of the LaNi_5-xFe_x and LaNi_5-xMn_x compounds have been investigated using neutron diffraction and first-principles tight-binding-linear-muffin-tin-orbital methods. Both neutron diffraction refinement data and total energy calculations show that the Fe and Mn atoms preferentially occupy the 3g sites in the hexagonal CaCu₅-type structure. The calculated magnetic moments of Fe and Ni atoms are of 2.4-2.5μ_B and 0.2-0.5μ_B in LaNi_5-xFe_x, respectively. The magnetic structure exhibits more localized moments at Fe atoms in LaNi_5-xFe_x when x ≤ 1.0. Electronic structure calculations indicate …

Electronic Structures And Magnetism Of Lani₅₋ₓfeₓ Compounds, Jinbo Yang, Chiu-Ying Tai, G. K. Marasinghe, George Daniel Waddill, Oran Allan Pringle, William Joseph James

Physics Faculty Research & Creative Works

A systematic study of the magnetic moments and hyperfine interactions of the LaNi_5-xFe_x compounds was performed using the spin-polarized tight-binding-linear-muffin-tin-orbital methods (TBLMTO). The calculated results were compared with neutron diffraction and Mössbauer experimental data and found to be in good agreement. Fe atoms exhibit more localized magnetic moments in LaNi_5-xFe_x when the Fe content x is lower than 1.0. The calculated magnetic moments of the Fe atoms approach values as large as 2.5μ_B due to the dilution effect. The strong s-d hybridization between the Ni and La atoms and the neighboring Fe in …

Dynamics Of The Fragmentation Of D2 By Fast Protons And Slow Highly Charged Xe26+, I. Ali, Robert D. Dubois, C. L. Cocke, S. Hagmann, C. R. Feeler, Ronald E. Olson

Physics Faculty Research & Creative Works

Using recoil-ion momentum spectroscopy, combined with a multihit detector system, the full momentum vectors of both fragment ions produced by fragmentation of D₂ by fast 50-kV protons and slow (9.56–0.191 keV/u) keV/u! Xe²⁶⁺ ions have been measured. The data are kinematically complete and make it possible to separate the laboratory momentum of the center of mass of the molecule from the momentum of each fragment in the center-of-mass system of the molecule. Using this separation, we find that, for higher collision velocities, the overall reaction can be described as double-electron capture, followed in a second and separate step …

Magnetization And Heat Capacity Of R1/3sr2/3feo3-Δ (R = La And Pr), V. P.S. Awana, M. Karppinen, H. Yamauchi, S. K. Malik, William B. Yelon, Apurva Mehta, A. V. Narlikar

Physics Faculty Research & Creative Works

Results of magnetization and heat capacity (CP) measurements are presented for R₁/₃Sr₂/₃FeO_3-δ compounds with R = La and Pr. The change in entropy (ΔS) near the magnetic transition amounts to only 15% of the theoretically expected value for the Fe³⁺ or Fe⁵⁺ spins magnetic ordering. The lower value of ΔS is explained on the basis of reported Mössbauer studies, which revealed a substantial amount of nonmagnetic Fe⁴⁺ in the compound across the magnetic transition. The C_P peak height across the magnetic transition increases substantially after annealing the …

Crystal And Magnetic Structure Of Pr0.7sr0.3-Xmno3 (0 ≤ X ≤ 0.2) Compounds, Q. Cai, William B. Yelon, M. Ellouze, W. Boujelben, A. Cheikh-Rouhou

Physics Faculty Research & Creative Works

The electronic and magnetic properties of the ABO3 type manganite's (A = rare earth, B = Mn) depend sensitively on the ratio of divalent and trivalent atoms on the A sublattice. The substitution of rare-earth by Ca or Sr not only affects the total valence, but also the lattice spacing, which, in turn may affect the structure and magnetic ordering temperature. If these compounds are synthesized with less than stoichiometric amounts of the A site constituents, (relative to the Mn content), three possible outcomes may be considered: a) single phase materials with vacancies on the A sublattice may be formed, …

A Neutron Diffraction Study Of The Deuterium Site Occupancy In Nd5fe17d15.5, Z. Chu, William B. Yelon, R. K. Murakami, P. S.M. Da Silva, V. Villas-Boas, F. P. Missell

Physics Faculty Research & Creative Works

The intermetallic compound Nd₅Fe₁₇ has potentially important magnetic properties and is being investigated as a possible permanent magnetic material. As with many other rare-earth transition metal compounds, this phase can absorb significant quantities of H(D) and lesser amounts of N. Gravimetric measurement indicate that ∼14-16H(D) atoms can be absorbed per formula unit leading to roughly a 20% increase in saturation magnetization and Curie temperature. We have carried out powder neutron diffraction studies to determine the location of D atoms in a sample of Nd₅Fe₁₇ containing approximately 15.5D/f.u. The large, complex unit cell of Nd …

Storage Free Terrain Simulation, Warren Creemers

Theses : Honours

Landscape visualisation is the process of recreating a natural environment and displaying it in an interactive graphical simulation. To do this a terrain is displayed together with accompanying plant life and other objects. Present landscape visualisation software is capable in theory of displaying very detailed and large landscapes. The software is also in theory capable of simulating environments with thousands if not millions of individually structured plants. In practice though, the simulation of such landscapes requires such a large amount of storage space that it is not achievable on personal computers. Even storing small landscapes with a moderate amount plant …

Mine Dewatering In Arid, Saline Environments In Western Australia: The Response Of Biota Emerging From Rehydrated Sediments, Charelle Harkins

Theses : Honours

Mine dewatering is a critical part of the mining process to prevent flooding of underground or open pits, to allow for the excavation of the available resources. Groundwater is abstracted from underground pits to the surface through extraction bores. The issue of where to discharge the excess water is a major concern. The use of natural wetlands is one option for mine water discharge. Saline lakes in arid areas are ideal receiving environments for discharge options, acting as evaporation facilities for the storage and disposal of excess mine water. Mine water discharge into ephemeral lake systems modifies the volume of …

Adequacy Of Terrestrial Fauna Surveys For The Preparation Of Environmental Impact Assessments In The Mining Industry Of Western Australia [Thesis], Jason L. Fraser

Theses : Honours

The Environmental protection Authority has indicated that terrestrial fauna surveys as undertaken for the purpose of preparing Environmental Impact Assessment (EIA) are not providing adequate information to enable decision-makers to assess development impacts on biodiversity and ecosystems. In the absence of a protocol to assess current standards of terrestrial fauna surveys, 'best practice' was defined through discussions held with an 'expert panel', and quantified through a questionnaire. This study examined current standards of terrestrial vertebrate fauna surveys, prepared for the purpose of EIA, with 'best practice' as defined by relevant expert opinion. Strengths and weaknesses of terrestrial fauna surveys were …

Efficient Algorithms For Graphs With Few P-4’S, Luitpold Babel, Ton Kloks, Jan Kratochvíl, Dieter Kratsch, Kaiko Müller, Stephan Olariu

Computer Science Faculty Publications

We show that a large variety of NP-complete problems can be solved efficiently for graphs with 'few' P₄'s. We consider domination problems (domination, total domination, independent domination. connected domination and dominating clique), the Steiner tree problem, the vertex ranking problem, the pathwidth problem, the path cover number problem, the hamiltonian circuit problem, the list coloring problem and the precoloring extension problem. We show that all these problems can be solved in linear time for the class of (q,q - 4)-graphs, for every fixed q. These are graphs for which no set of at most q. vertices induces more …

Annual Meeting Of The Iowa Academy Of Science

Journal of the Iowa Academy of Science: JIAS

No abstract provided.

Lessons From An Inventory Of The Ames, Iowa, Flora (1859-2000), William R. Norris, Deborah Q. Lewis, Mark P. Widrlechner, Jimmie D. Thompson, Richard O. Pope

Journal of the Iowa Academy of Science: JIAS

A botanical survey of the vascular flora of the "planning and zoning jurisdiction" of the city of Ames, Iowa (i.e., the area within a boundary 3.2 km beyond the current city limits) was compiled from 1990 to 2000. During this survey, 916 taxa (71 % native) were encountered within chis boundary. Literature reviews and a survey of Iowa State University's Ada Hayden Herbarium for specimens that had been collected in Ames since 1859 add 204 taxa to the flora. This total of 1,120 taxa exceeds the number of taxa known from any comparable area (including counties) in Iowa. We produced …

Back Cover

Journal of the Iowa Academy of Science: JIAS

No abstract provided.

Duane Isely (1918-2000): A Tribute, Stanley L. Welsh, Deborah Q. Lewis

Journal of the Iowa Academy of Science: JIAS

Duane Isely, Distinguished Professor Emeritus, Department of Botany, Iowa State University, Ames, Iowa, died on 6 December 2000. Dr. Isely was an outstanding plant taxonomist with expertise in other fields as well, especially in seed technology and weed identification and control. He was born in Bentonville, Arkansas, on 24 October 1918 into a family of academicians. His father, Dwight Isely, was professor and later Dean of Agriculture at the University of Arkansas, and his mother, Blessie Elise Dort Isely, also taught at the University of Arkansas and eventually received her Ph.D.

External Memory Algorithms For Factoring Sparse Matrices, Florin Dobrian

Computer Science Theses & Dissertations

We consider the factorization of sparse symmetric matrices in the context of a two-layer storage system: disk/core. When the core is sufficiently large the factorization can be performed in-core. In this case we must read the input, compute, and write the output, in this sequence. On the other hand, when the core is not large enough, the factorization becomes out-of-core, which means that data movement and computation must be interleaved.

We identify two major out-of-core factorization scenarios: read-once/write-once (R1/W1) and read-many/write-many (RM/WM). The former requires minimum traffic, exactly as much as the in-core factorization: reading the input and writing the …

Arc - An Oai Service Provider For Digital Library Federation, Xiaoming Liu, Kurt Maly, Mohammad Zubair, Michael L. Nelson

Computer Science Faculty Publications

The usefulness of the many on-line journals and scientific digital libraries that exist today is limited by the inability to federate these resources through a unified interface. The Open Archive Initiative (OAI) is one major effort to address technical interoperability among distributed archives. The objective of OAI is to develop a framework to facilitate the discovery of content in distributed archives. In this paper, we describe our experience and lessons learned in building Arc, the first federated searching service based on the OAI protocol. Arc harvests metadata from several OAI compliant archives, normalizes them, and stores them in a search …

Smart Objects And Open Archives, Michael L. Nelson, Kurt Maly

Computer Science Faculty Publications

Within the context of digital libraries (DLs), we are making information objects "first-class citizens". We decouple information objects from the systems used for their storage and retrieval, allowing the technology for both DLs and information content to progress independently. We believe dismantling the stovepipe of "DL-archive-content" is the first step in building richer DL experiences for users and insuring the long-term survivability of digital information. To demonstrate this partitioning between DLs, archives and information content, we introduce "buckets": aggregative, intelligent, object-oriented constructs for publishing in digital libraries. Buckets exist within the "Smart Object, Dumb Archive" (SODA) DL model, which promotes …

An Evaluation Of Environmental Disclosures Produced In Australian Local Government Annual Reports, Royston J. Tan

Theses : Honours

This thesis is an evaluation of the environmental disclosures published in Australian local governments' annual reports. The study is aimed in identifying disclosures of environmental information by Australian local governments and providing explanations for the variations in the quantity and quality of information disclosed. Various social responsibility theories were used in this study. The theories employed in this study were institutional factors, stakeholder theory, social and political theories. Institutional factors included issues such as local government characteristics and pressures exerted from various government and non·government organizations to implement and disclose environmental measures. A content analysis methodology was used in this …

Video Compression Using Wavelets And Hierarchical Motion Estimation, Andrew Peter Byrne

Theses : Honours

This thesis investigates the benefits and the significant compression that can be obtained from data that has been decomposed using a wavelet transform. A video compression algorithm was developed that employs the wavelet transform and a hierarchical motion estimation algorithm which itself utilises benefits of the wavelet transform. Using MATLAB, a popular software tool for matrix based computation and analysis, several functions were developed which together formed the video compression algorithm. A variety of tests were conducted on a sample video sequence to ascertain the strengths and weaknesses of the techniques employed. The results, although not the same as the …

Bluetooth Software On Linux, Wireless Hand-Held Devices, Teck Khoon Low

Theses : Honours

In order to enable existing computers (non-Bluetooth ready) to connect to a Bluetooth piconet, a Bluetooth hardware device comprising of the Radio antenna, the baseband and control circuit is used. The digital portion of this device is also known as a Host Controller, HC. In the traditional communication lingo, the Bluetooth Hardware functions, as the Data Communication Equipment (DCE) while the Host is the Data terminal Equipment (DTE). This report discusses the theory and implementation of the communication protocol between the Host and the Host Controller, enabling communication between the computer and the Bluetooth hardware

The Design Of 3d Cyberspace As User Interface: Advantages And Limitations, Maria Borisovna Quick

Theses : Honours

Virtual reality propagandists, technologists and the Internet community have long debated the issue of the usability of online three-dimensional (3D) environments. A lot of work was published about the benefits of 3D spaces for human-computer interaction and information visualisation due to their realism (Anders, Kalawsky, Crossley, Davies, McGrath, Rejman-Greene, 1998, Hamit, 1993, Heim, 1992, Aukstakalnis, Blatner, Roth, 1992). This topic also receives continuous industry support including standardisation of Virtual Reality Modeling Language ( VRML, VRML Consortium, 1997) and the more recent Macromedia & Intel alliance "to bring web 3D to the mainstream" (200 1, Intel Corporation). The actual implementation …

Meeting The Challenge Of Dynamic User Requirements Using Data-Driven Techniques On A 4gl-Database Environment, Christopher Bolan

Theses : Honours

Accompanying the ever-growing reliance on computers within contemporary organisations, the task of software maintenance is, increasingly, becoming a resource burden. The author has identified that there is a need for proven techniques to allow the modelling of flexible/changing user requirement, to enable systems to cope with requirements creep without suffering major code change and associated down-time from rebuilds of the database. This study ascertains the applicability of extension to current data modelling techniques that allows innate flexibility within the data model. The extension of the data model is analysed for potential benefits in the provision of such a dynamic/flexible base …

The Long-Period Orbit Of The Dwarf Nova V630 Cassiopeiae, J. A. Orosz, J. R. Thorstensen, R. K. Honeycutt

Dartmouth Scholarship

We present extensive spectroscopy and photometry of the dwarf nova V630 Cassiopeiae. A late-type (K4-5) absorption spectrum is easily detectable, from which we derive the orbital parameters. We find a spectroscopic period of P=2.56387 +/- (4 times 10^{-5}) days and a semiamplitude of K_2=132.9 +/- 4.0 km/s. The resulting mass function, which is a firm lower limit on the mass of the white dwarf, is then f(M)=0.624 +/- 0.056 solar masses. The secondary star is a ``stripped giant'', and using relations between the core mass and the luminosity and the core mass and the radius we derive a lower limit …

The Annual Meeting Of The Iowa Academy Of Science April 20-21, 2001 [Program, 113th Meeting], Iowa Academy Of Science

Iowa Academy of Science Documents

Contents:

Program Summary --- 1
General Session Speakers --- 4
Awards --- 7
Symposia Programs --- 8
Special Events --- 8
Poster Sessions --- 9
Section Programs/Special Sessions --- 9
Agricultural Sciences --- 9
Anthropology --- 10
Botany --- 11
Cellular, Molecular & Microbiology --- 15
Chemical Education --- 13
Chemistry: Inorganic, Analytical & Physical --- 16
Chemistry: Organic & Biological --- 16
Conservation --- 17, 24
Earth Science Teaching --- 13
Elementary Science Teaching --- 13
Engineering --- 12
Geology --- 17, 19
Physics --- 20
Physiology --- 20
Psychology & Linguistics --- 10
Science Teaching --- 13, 22, …

Iowa Academy Of Science 113th Annual Meeting [2001]: Advance Program, Iowa Academy Of Science

Iowa Academy of Science Documents

No abstract provided.

Ichnology Of Holocene Carbonate Eolianites Of The Bahamas, H. Allen Curran, Brian White

Geosciences: Faculty Publications

No abstract provided.

Behavioral Plasticity Of Modern And Cenozoic Burrowing Thalassinidean Shrimp, M. F. Miller, H. Allen Curran

Geosciences: Faculty Publications

No abstract provided.

Resilience And Recovery Of Coral Reefs From Large-Scale Disturbances: Contrasting Patterns For San Salvador Island, Bahamas, And Belize, Paulette M. Peckol, H. Allen Curran, Martha Robbart, Benjamin J. Greenstein

Geosciences: Faculty Publications

Benjamin J. Greenstein and Cindy K. Carney (eds)

San Salvador, Gerace Research Center