Physical Sciences and Mathematics Commons^™

Continuities Of Metric Projection And Geometric Consequences, Robert Huotari, Wu Li

Mathematics & Statistics Faculty Publications

We discuss the geometric characterization of a subset K of a normed linear space via continuity conditions on the metricprojection onto K. The geometric properties considered includeconvexity, tubularity, and polyhedral structure. The continuityconditions utilized include semicontinuity, generalized stronguniqueness and the non-triviality of the derived mapping. Infinite-dimensional space with the uniform norm we show thatconvexity is equivalent to rotation-invariant almost convexityand we characterize those sets every rotation of which has continuousmetric projection. We show that polyhedral structure underliesgeneralized strong uniqueness of the metric projection.

The Effect Of Three-Dimensional Freestream Disturbances On The Supersonic Flow Past A Wedge, Peter W. Duck, D. Glenn Lasseigne, M. Y. Hussaini

Mathematics & Statistics Faculty Publications

The interaction between a shock wave (attached to a wedge) and small amplitude, three-dimensional disturbances of a uniform, supersonic, freestream flow are investigated. The paper extends the two-dimensional study of Duck et al. [P W. Duck, D. G. Lasseigne, and M. Y. Hussaini, ''On the interaction between the shock wave attached to a wedge and freestream disturbances,'' Theor. Comput. Fluid Dyn. 7, 119 (1995) (also ICASE Report No. 93-61)] through the use of vector potentials, which render the problem tractable by the same techniques as in the two-dimensional case, in particular by expansion of the solution by means of …

Superconvergence Of The Iterated Collocation Methods For Hammerstein Equations, Hideaki Kaneko, Richard D. Noren, Peter A. Padilla

Mathematics & Statistics Faculty Publications

In this paper, we analyse the iterated collocation method for Hammerstein equations with smooth and weakly singular kernels. The paper expands the study which began in [16] concerning the superconvergence of the iterated Galerkin method for Hammerstein equations. We obtain in this paper a similar superconvergence result for the iterated collocation method for Hammerstein equations. We also discuss the discrete collocation method for weakly singular Hammerstein equations. Some discrete collocation methods for Hammerstein equations with smooth kernels were given previously in [3, 18].

Scattering From Stellar Acoustic-Gravity Potentials: Ii. Phase Shifts Via The First Born Approximation, J. A. Adam, I. Mckaig

Mathematics & Statistics Faculty Publications

Using the first Born approximation, properties of the scattering phase shift are investigated for waves that are scattered by a schematic representation of a large-scale “stellar potential,” i.e., one for which the star itself is viewed as the potential inducing a phase shift in an incoming wave. In particular, the phase shift properties are examined as functions of the relative wavenumber (α) and the azimuthal wavenumber (l), high l-values being of interest in helioseismology.

Determination Of Asphaltenes In Petroleum Crude Oils By Fourier Transform Infrared Spectroscopy, Brian K. Wilt

Theses, Dissertations and Capstones

An analytical method was developed to quantitatively determine the asphaltene content in petroleum crude oils by Fourier transform infrared spectroscopy (FT-IR). Asphaltenes are a solubility class of compounds found in crude oils. They are black to dark brown solids defined by their insolubility in n-alkane solvents. The structure of asphaltene molecules is polynuclear aromatic rings with alkyl side chains and heteroatoms, such as nitrogen, oxygen, and sulfur attached. Asphaltenes are known to cause oil well plugging and irreversible catalyst deactivation in refineries. The asphaltene content of 50 crude oils from a wide array of geochemical conditions was determined by the …

Three-Body Models Of Electron-Hydrogen Ionization, Stephenie J. Jones, Don H. Madison, Dmitry A. Konovalov

Physics Faculty Research & Creative Works

In this paper, we report calculations of electron-hydrogen ionization whereby the final-state wave Function is approximated by recently reported analytical three-body wave functions. In a first model we use the wave function of Alt and Mukhamedzhanov [Phys. Rev. A 47, 2004 (1993)], and in a second model we use the wave function of Berakdar [Phys. Rev. A 53, 2314 (1996)].

Observation Of Upper Tropospheric Sulfur Dioxide- And Acetone-Pollution: Potential Implications For Hydroxyl Radical And Aerosol Formation, F. Arnold, J. Schneider, K. Gollinger, H. Schlager, P. Schulte, Donald E. Hagen, Philip D. Whitefield, Peter F. J. Van Velthoven

Physics Faculty Research & Creative Works

Aircraft-based measurements of sulfur dioxide, acetone, carbon dioxide, and condensation nuclei (CN) were made over the north-eastern Atlantic at upper tropospheric altitudes, around 9000 m. On October 14, 1993, strong SO ₂- and acetone-pollution (both up to 3 ppbv) were observed, which were accompanied by a CO ₂-enhancement of up to 6 ppmv, and large CN-concentrations of up to about 1500 cm ^-3 (for radii ≥ 6 nm). CN, excess CO ₂, and to a lesser degree also acetone, were positively correlated with SO ₂. Air mass trajectory analyses indicate, that most of the air masses …

Ionization Of Helium In The Attosecond Equivalent Light Pulse Of 1 Gev/Nucleon U⁹²⁺ Projectiles, R. Moshammer, W. Schmitt, J. Ullrich, H. Kollmus, A. Cassimi, R. Dörner, O. Jagutzki, R. Mann, Ronald E. Olson, H. T. Prinz, H. Schmidt-Böcking, L. Spielberger

Physics Faculty Research & Creative Works

Single and double ionization of helium by 1 GeV/nucleon U92+ impact was explored in a kinematically complete experiment. The relativistic ion generates a subattosecond (10−18s) superintense (I > 1019W/cm2) electromagnetic pulse, which is interpreted as a field of equivalent photons (Weizsäcker-Williams method). Cross sections, the emission characteristics of ions and electrons as well as momentum balances, are quantitatively discussed in terms of photoionization of the atom in this broadband, ultrashort virtual photon field. © 1997 The American Physical Society.

Complete Momentum Balance For Single Ionization Of Helium By Fast Ion Impact: Experiment, R. Moshammer, J. Ullrich, H. Kollmus, W. Schmitt, M. Unverzagt, H. Schmidt-Böcking, C. J. Wood, Ronald E. Olson

Physics Faculty Research & Creative Works

The collision dynamics of He single ionization by [Formula Presented] impact was explored using the reaction microscope of the Gesellschaft für Schwerionenforschung, a high-resolution integrated multielectron recoil-ion momentum spectrometer. The complete three-particle final-state momentum distribution (nine Cartesian components [Formula Presented]) was imaged with a resolution of [Formula Presented] by measuring the three momentum components of the emitted electron and the recoiling target ion in coincidence. The projectile energy loss has been determined on a level of [Formula Presented] and projectile scattering angles as small as [Formula Presented] became accessible. The experimental data which are compared with results of classical trajectory …

Projectile Charge-State Dependence On Final-State Momentum Distributions For Single Ionization Of Helium, C. J. Wood, C. R. Feeler, Ronald E. Olson

Physics Faculty Research & Creative Works

Single-ionization cross sections and final-state momentum distributions have been calculated for the single-ionization collision reactions H[Formula Presented], [Formula Presented], He[Formula Presented], C[Formula Presented], and C[Formula Presented] + He at 100 keV/u. The classical trajectory Monte Carlo method has been used with a Wigner distribution to improve both the He electron classical radial and momentum distributions. Final-state ionized electron momenta are projected into a collision plane defined by the initial projectile momentum and the final transverse component of the He[Formula Presented] recoil momentum, with the results displayed differentially in various components of electron and recoil momenta. Positively charged projectile impact shows …

The Interaction Of Fast Alpha Particles With Pellet Ablation Clouds, J. M. Mcchesney, P. B. Parks, R. K. Fisher, Ronald E. Olson

Physics Faculty Research & Creative Works

The energy spectra of energetic confined alpha particles are being measured using the pellet charge exchange method [R. K. Fisher, J. S. Leffler, A. M. Howald, and P. B. Parks, Fusion Technol. 13, 536 (1988)]. The technique uses the dense ablation cloud surrounding an injected impurity pellet to neutralize a fraction of the incident alpha particles, allowing them to escape from the plasma where their energy spectrum can be measured using a neutral particle analyzer. The signal calculations given in the above-mentioned reference disregarded the effects of the alpha particles' helical Larmor orbits, which causes the alphas to make multiple …

Walking Thoughts, Hunter R. Rawlings Iii

Journal of the Iowa Academy of Science: JIAS

I've borrowed my title from a poem by Marvin Bell, a member of our Writers' Workshop, because I cannot think of state parks without thinking of my love for their hiking trails and the expansion of spirit they have brought me. State parks are more than nature preserves, more than recreational areas, though these functions are very important. They are also cultural and even spiritual resources, centers of emotional and psychic renewal.

Editorial Board & Iowa Academy Of Science Officers And Directors

Journal of the Iowa Academy of Science: JIAS

No abstract provided.

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Journal of the Iowa Academy of Science: JIAS

No abstract provided.

Back Cover

Journal of the Iowa Academy of Science: JIAS

No abstract provided.

Editorial Board & Iowa Academy Of Science Officers And Directors

Journal of the Iowa Academy of Science: JIAS

No abstract provided.

Time-Optimal Tree Computations On Sparse Meshes, D. Bhagavathi, V. Bokka, H. Gurla, S. Olariu, J. L. Schwing

Computer Science Faculty Publications

The main goal of this work is to fathom the suitability of the mesh with multiple broadcasting architecture (MMB) for some tree-related computations. We view our contribution at two levels: on the one hand, we exhibit time lower bounds for a number of tree-related problems on the MMB. On the other hand, we show that these lower bounds are tight by exhibiting time-optimal tree algorithms on the MMB. Specifically, we show that the task of encoding and/or decoding n-node binary and ordered trees cannot be solved faster than Ω(log n) time even if the MMB has an infinite …

Webassess, Justin Anthony Brown

Theses : Honours

This project and research has resulted in the development of a World Wide Web (WWW) based testing system. WEBassess can be accessed and used from any point in the world that has a connection to the WWW. The WEBassess system allows for the creation and completion of tests through the WWW interface. Scoring and feedback of submitted tests is completely automated, allowing students to see their test result immediately, including visual indicators for correct and incorrect answers. These test results may then be viewed by academic staff, showing complete test details, such as unit code, test title, score, percentage, date …

An Evaluation Of The Productivity Of Two Oil Mallee Species In A Revegetation Trial In The Central Wheatbelt Of Western Australia, Beatrice Lucie Hedwig Franke

Theses : Honours

Two of Western Australia's most pressing land degradation problems are waterlogging and increasing soil salinity. Extensive clearing of the native. deep-rooted vegetation and its replacement with shallow-rooted crop and pasture plants has resulted in increased recharge of groundwater tables. causing them to rise. Salts stored in the soil are being brought to the soil surface with the rising watertables. Revegetation with deep-rooted native plants has been identified as the most likely strategy to achieve increased groundwater usage and a lowering of watertables. One area seriously affected by waterlogging and increasing salinity is the Western Australian central wheatbelt region. The Department …

Coastal Zone Monitoring And Evaluation : A Descriptive Analysis Of Western Australian Practices, Michael F. Williams

Theses : Honours

Currently there is no information available which documents the monitoring and evaluation practices undertaken in the coastal zone of Western Aust1alia by coastal zone managers. A review of current Australian-wide management practices in coastal management reveals that monitoring and evaluation are limited in their application. The adequacy of the links between coastal monitoring and evaluation, on which our understanding of the state of the coastal zone environment is based, is one of two central themes throughout this research. The other theme is that without an accurate, reliable and effectively managed monitoring and research information base, coastal management will be haphazard …

Does Good Project Management Ensure Successful Software Development?, Julie Lisa Eldridge

Theses : Honours

For many years the development of computer software has been plagued by poor customer satisfaction caused by missed schedules, underestimated budgets and the development of products which do not meet requirements. The ever increasing reliance on computers, as reported by Sommerville ''the result of the proliferation of computer systems into all aspects of life and business is that personal, corporate, national and international economies are [becoming] increasingly dependant on computers and software systems" ( 1992, p.2), calls for more stable software which can be developed within time and budget constraints. To achieve this, software development activities must be analysed and …

Scope Of Justice, Delegitimisation, Sentience And Ecosystemic Integrity As Predictors Of Protection, Rob Gulley

Theses : Honours

It is argued that the continuing environmental destruction results from an instrumental valuation of the non-human world. Fox's (1995) alternative intrinsic value approach to environmental protection is introduced. Two aspects of Fox's descriptive model may represent fundamental motives, or ethical bases, for behaviour. They are sentience -the quality of being capable of experiencing pain, and ecosystemic-integrity -the quality of contributing to the self-regenerating capacity of an ecosystem. The inconsistency between the presumed ethical bases for behaviour, and actual behaviour is noted. It is suggested that delegitimisation- the discounting of some desirable quality in a competitor during conflict, and the scope …

Electromagnetic Reaction Cross Sections In Relativistic Heavy Ion Collisions, Jack Dostal

Presidential Scholars Theses (1990 – 2006)

The goal of this project was to produce a computer program to predict the cross section of relativistic heavy ion collisions between given projectile and target nuclei. An explanation of the usefulness of relativistic heavy ion collision analysis is presented. The use of the Weiszacker-Williams method of virtual quanta for enhancing reaction cross sections of this type is discussed. Quantum-mechanical corrections to the semiclassical Weiszacker-Williams method are introduced. C++ computer code has been developed to calculate both semiclassical (as a check) and quantum-mechanical cross sections for these types of reactions. Preliminary results are given for the heavy ion reaction ( …

Les Deux Faces De La Pensée De E. A. Martel, Jacques Choppy

International Journal of Speleology

Réunion de textes de Martel: 1 - Extraits du Nouveau Traité des Eaux Souterraines (1921), donnant l’essentiel de la pensée de l’auteur sur l’hydraulique et la morphologie du karst. 2 - En opposition à cette vision, rappelée de nombreuses fois par l’auteur, extraits de diverses publications (de 1894 à 1930), admettant qu’un fonctionnement en régime noyé était possible: Martel est donc l’un des tout premiers ayant observé des formes de creusement en régime noyé, et les ayant interprétées comme telles.

Glycals : An Extended Study Of The Ferrier-Dimerization, Andreas H. Franz

University of the Pacific Theses and Dissertations

C-linked disaccharides were synthesized from 3,4,6-tri-O-acetyl-D-glucal 1 (1,5- anhydro-3,4,6-tri-O-acetyl-1,2-dideoxy-D-arabino-hex-I-enopyranose), 3,4,6-tri-O- acetyl-D-galactal 2 (1,5-anhydro-3,4,6-tri-O-acetyl-1,2-dideoxy-D-lyxo-hex-1- enopyranose) and 3,4-di-O-acetyl-L-fucal 3 (1,5-anhydro-3,4-di-O-acetyl-1,2,6-tri-deoxy- L-lyxo-hex-1-enopyranose) under Lewis acid catalysis (Scheme 1) and compound 4 was further derivatized at the double bond. Dihydroxylation of the glucose dimer 4 gave high allo-diastereoselectivity. The reactions used in the derivatization of 1 were subsequently applied to 2 and 3. The overall yield of 3 was improved to 70 %. All three glycals (10% solution in toluene) reacted quickly with boron trifluoride to give dimerization products in 40-60% yield. Futile attempts at de-O-acetylation of the 2',3'-unsaturated dimer revealed the necessity of …

Lyceum: A Multi-Protocol Digital Library Gateway, Ming-Hokng Maa, Michael L. Nelson, Sandra L. Esler

Computer Science Faculty Publications

Lyceum is a prototype scalable query gateway that provides a logically central interface to multi-protocol and physically distributed, digital libraries of scientific and technical information. Lyceum processes queries to multiple syntactically distinct search engines used by various distributed information servers from a single logically central interface without modification of the remote search engines. A working prototype (http://www.larc.nasa.gov/lyceum/) demonstrates the capabilities, potentials, and advantages of this type of meta-search engine by providing access to over 50 servers covering over 20 disciplines.

The Hawaiian Cave Planthoppers (Homoptera: Fulgoroidea: Cixiidae) - A Model For Rapid Subterranean Speciation?, Hannelore Hoch

International Journal of Speleology

After the successful colonization of a single ancestral species in the Hawaiian Islands, planthoppers of the cixiid genus Oliarus underwent intensive adaptive radiation resulting in 80 described endemic species. Oliarus habitats range from montaneous rain forests to dry coastal biotopes and subterranean environments. At least 7 independant evolutionary lines represented by different species have adapted to lava tubes on Molokai (1), Maui (3), and Hawaii Island (3). Behavioral and morphological studies on one of these evolutionary lines on Hawaii Island, the blind, flight- and pigmentless Oliarus polyphentus have provided evidence for reproductive isolation between allopatric populations which may in fact …

Genetic Divergence And Evolutionary Times: Calibrating A Protein Clock For South-European Stenasellus Species (Crustacea Isopoda), Valerio Ketmaier, Roberto Argano, Marina Cobolli, Elvira De Matthaeis

International Journal of Speleology

We studied genetic divergence in a group of exclusively stygobiont isopods of the family Stenasellidae. In particular, we assessed evolutionary relationships among several populations of Stenasellus racovitzai and Stenasellus virei. To place this study in a phylogenetic context. we used another species of Stenasellus, S. assorgiai, as an outgroup. S. racovitzai occurs in Corsica, Sardinia and in the fossil islands of the Tuscan Archipelago, while S. virei is a polytypic species widely distributed in the central France and Pyrenean area. This vicariant distribution is believed to be the result of the disjunction of the Sardinia-Corsica microplate from …

Evaluation Of Groundwater Quality In Shallow Aquifers Under Cultivated Lands At Al Oha Area, United Arab Emirates, Waleed Nasser Ahmed Bin Braik

Theses

To assess the impact of application of chemical fertilizers in agriculture on the Quaternary aquifer at AI Oha area, United Arab Emirates, 76 groundwater samples were collected during February 1995 - March 1996. Samples were analyzed for major, minor and trace chemical constituents in the Food Control Laboratory, Abu Dhabi.

The Total Dissolved Solids (TDS) of collected samples varied between 500 milligrams per liter (mg/l) in the east and 3,500 mg/l in the west. Except for bicarbonate ion (HC03-), concentration of major cations (Ca²⁺, Mg²⁺, Na⁺ and K⁺) and anions (CO₃^{2- …}

Fernandez Bay, San Salvador, Bahamas: A Natural Laboratory For Assessment Of The Preservation Of Coral Reef Community Structure, Benjamin J. Greenstein, Lora A. Harris, H. Allen Curran

Geosciences: Faculty Publications

Reprinted from: James L. Carew (ed.), Proceedings of the 8th Symposium on the Geology of the Bahamas: San Salvador, Bahamian Field Station