Physical Sciences and Mathematics Commons^™

Forest Invasives In Iowa: Current Problems And Future Issues, John Walkowiak, John Haanstad

Journal of the Iowa Academy of Science: JIAS

Iowa's forest resources of primarily deciduous trees covers over 0.8 million hectares (2 million acres) of upland and floodplain sites too steep or too wet for traditional row crop agriculture. These limited natural forests along with urban trees and shelterbelts plantings of trees are critical for environmental and economic enhancement in the state. Although not yet established in the state, exotic insects, such as gypsy moth, Asian longhorned beetle, and pine shoot beetle, threaten native tree vitality. Established exotic diseases such as oak wilt and Dutch elm disease continue to plague the survival of Iowa's oak and elm resources, respectively. …

Non-Native Amphibians And Reptiles In Iowa, James L. Christiansen

Journal of the Iowa Academy of Science: JIAS

Only a few species appear as introductions into Iowa in the last 30 years. The bullfrog, Rana catesbeiana, was systematically introduced along with fish stocked from hatcheries in the 1930s and this species continues to spread in northern Iowa where it poses a hazard to smaller frogs. Turtles sold as pets, primarily map turtles (Graptemys pseudogeographica and G. geographica) and red-eared turtles (Trachemys scripta) continue to be found in scattered ponds, usually rural, throughout the state. The eastern box turtle (Terrapene carolma) has been reported in or on the edge of most major Iowa cities even though no breeding population …

Invasive Birds In Iowa: Status, Problems, And Threats, James J. Dinsmore

Journal of the Iowa Academy of Science: JIAS

A total of 18 invasive bird species has been introduced into or have expanded their range to include Iowa. These include ten non-North American species, one North American species that has been displaced and now is established in Iowa, and seven native species that have been released to reestablish Iowa populations. Twelve of those are regularly occurring species in Iowa, and they comprise 3.0% (12 of 404) of the species known from Iowa and 5% (10 of 199) of Iowa's nesting avifauna. These percentages are similar to those found in neighboring states. Several more species are likely to become established …

Index For The Journal Of The Iowa Academy Of Science Volume 108 And Erratum

Journal of the Iowa Academy of Science: JIAS

No abstract provided.

Back Cover

Journal of the Iowa Academy of Science: JIAS

No abstract provided.

Techniques For The Regeneration Of Wideband Speech From Narrowband Speech, Jason A. Fuemmeler, Russell C. Hardie, William R. Gardner

Electrical and Computer Engineering Faculty Publications

This paper addresses the problem of reconstructing wideband speech signals from observed narrowband speech signals. The goal of this work is to improve the perceived quality of speech signals which have been transmitted through narrowband channels or degraded during acquisition. We describe a system, based on linear predictive coding, for estimating wideband speech from narrowband. This system employs both previously identified and novel techniques. Experimental results are provided in order to illustrate the system’s ability to improve speech quality. Both objective and subjective criteria are used to evaluate the quality of the processed speech signals.

Solid Waste Management In Oil And Gas Pipelines Application To Asab Field, Abdulqader M Alkamali

Theses

Managing solid waste, and any other wastes in general, is an environmental need, an economical choice and a legal requirement. Preserving the environment while lowering the cost becomes a necessity when liabilities are of concern.

Solid wastes generated from oil and gas industrial activities are very diverse in their characteristics, large in their amounts and many of which are hazardous in nature. Thus, the need to manage these wastes is an obvious mandate. Oil and gas industrial activities include exploration, drilling, production, processing, refining, manufacturing and exporting. Associated with these activities, other supporting services; such as, maintenance, civil, transportation, storage, …

Petrological And Geochemical Analyses And Economic Potential Of Some Milestones And Siliceous Rocks In Northern United Arab Emirates., Mohammed Ahmed A. Ibrahim

Theses

Combined microscopic, heavy mineral, X-ray diffraction and chemical analyses have been carried out on the Jurassic limestone, the upper cretaceous Hawasina cherts and the coastal and inland sand dunes in several localities in the Ras Al Khaimah Emirate. The obtained results revealed that a number of represents cherts subfacies; namely: ferruginous radiolarian ribbon chert, carbonaceous radiolarian ribbon chert, colloform ribbon chert, calcareous chert and siliceous mud stone. These rocks consist of (in order of decreasing abundance): quartz, calcite, dolomite and hematite. The carbonate rocks are made up of lime mudstone, wackestone; pack stone and, rarely, crystalline limestone. Various types of …

Pan, Ppn And Mpan Measurements And The Quantitative Relationship Of Pan And Mpan In Biogenic Hydrocarbon Conditions, Chen Wangchun

Masters Theses

Simultaneous measurements of PAN, PPN and MPAN were made during the SOS 1999 Nashville campaign at Dickson site. The PANs data at this site were rich and complex. PAN and MP AN showed obvious diurnal change but PPN did not during this period. PAN and ozone have a clear positive relationship. Due to the special location of the site, winds from different directions bring anthropogenic hydrocarbons (AHCs) or biogenic hydrocarbons (BHCs) to the site. The data showed that the influence of AHCs and BHCs on PANs compounds varied on different days. Average values of PAN/PPN and PAN/MPAN from MLR may …

Discrete Maximum Principle For Nonsmooth Optimal Control Problems With Delays, Boris S. Mordukhovich, Ilya Shvartsman

Mathematics Research Reports

We consider optimal control problems for discrete-time systems with delays. The main goal is to derive necessary optimality conditions of the discrete maximum principle type in the case of nonsmooth minimizing functions. We obtain two independent forms of the discrete maximum principle with transversality conditions described in terms of subdifferentials and superdifferentials, respectively. The superdifferential form is new even for non-delayed systems and may be essentially stronger than a more conventional subdifferential form in some situations.

Computer Sound Card Assisted Measurements Of The Acoustic Doppler Effect For Accelerated And Unaccelerated Sound Sources, Thomas J. Bensky, S. E. Frey

Physics

An approach to experimentally measuring the speed of a moving object by direct application of the Doppler effect for sound is discussed. The method presented here uses a Windows computer and sound card to record Doppler shifted sound from a moving source. This sound card approach allows for direct acquisition of Doppler shifted sound intensity as a function of time, affording much analytical and pedagogical freedom in undergraduate lab instruction. In addition, the acquisition of such data allows for the experimental study of not only constant velocity sound sources, but of accelerated sound sources as well.

Deploying Integrated Web-Based Spatial Applications Within An Oracle Database Environment, James Carswell

Conference papers

In this paper, we describe the architectural and functional characteristics of e-Spatial™ technology, comprising an innovative software package that represents a timely alternative to traditional and complex proprietary GIS application packages. The two main components of the package, developed by e- Spatial Solutions, are the iSMART™ database development technology and the i-Spatial™ Information Server (iSIS), both implemented within an Oracle 9i Spatial database environment. This technology allows users to build and deploy spatially enabled or standard Internet applications without requiring any application-specific source code. It can be deployed on any Oracle supported hardware platform and on any device that supports …

Effect Of Rare Locally Ordered Regions On A Disordered Itinerant Quantum Antiferromagnet With Cubic Anisotropy, Rajesh S. Narayanan, Thomas Vojta

Physics Faculty Research & Creative Works

We study the quantum phase transition of an itinerant antiferromagnet with cubic anisotropy in the presence of quenched disorder, paying particular attention to the locally ordered spatial regions that form in the Griffiths region. We derive an effective action where these rare regions are described in terms of static annealed disorder. A one-loop renormalization-group analysis of the effective action shows that for order-parameter dimensions p<4, the rare regions destroy the conventional critical behavior, and the renormalized disorder flows to infinity. For order-parameter dimensions p>4, the critical behavior is not influenced by the rare regions; it is described by the conventional dirty cubic fixed point. We also discuss the influence of the rare regions on the fluctuation-driven first-order transition …

Mobile-Agent Versus Client/Server Performance: Scalability In An Information-Retrieval Task, Robert S. Gray, David Kotz, Ronald A. Peterson, Joyce Barton, Daria Chacon, Peter Gerken, Martin Hofmann, Jeffrey Bradshaw, Maggie Breedy, Renia Jeffers, Niranjan Suri

Dartmouth Scholarship

Building applications with mobile agents often reduces the bandwidth required for the application, and improves performance. The cost is increased server workload. There are, however, few studies of the scalability of mobile-agent systems. We present scalability experiments that compare four mobile-agent platforms with a traditional client/server approach. The four mobile-agent platforms have similar behavior, but their absolute performance varies with underlying implementation choices. Our experiments demonstrate the complex interaction between environmental, application, and system parameters.

Electronic-Structure Modifications Induced By Surface Segregation In La0.65Pb0.35Mno3 Thin Films, C.N. Borca, B. Xu, T. Komesu, H.-K. Jeong, M.T. Liu, Sy_Hwang Liou, Shane Stadler, Y. Idzerda, Peter A. Dowben

Sy-Hwang Liou Publications

Using spin-polarized inverse photoemission and X-ray absorption spectroscopy techniques, we show that the electronic structure of La_0.65Pb_0.35MnO₃ thin films depends on the composition at the surface. With a gentle annealing procedure, the surface provides a maximum of 80% spin asymmetry at 0.5 eV above the Fermi level in spite of extensive Pb segregation. A heavily annealed (restructured) surface exhibits a reduced surface "ordering" temperature of 240 K (compared to the approximately 335 K bulk value) as well as a reduced spin asymmetry value of 40% at 0.5 eV above Fermi energy.

A Case Study Of The 8 March 1999 Freezing Rain Event For North Platte, Nebraska, Shari Mutchler

United States Department of Commerce: Staff Publications

During the morning hours of 8 March 1999, freezing precipitation fell over portions of western Nebraska, including the communities of McCook, North Platte and Valentine between midnight and 10:00 A.M. CST. The freezing precipitation resulted in dangerous travel conditions, causing several automobile accidents, along with the delay and temporary closing of area public schools 8 March 1999. The freezing rain changed over to snow later the same morning.
A forecast for snow, rather than freezing precipitation, was issued by the local forecast office. The forecast issued was based predominately on numerical weather prediction guidance, and the observed temperature profile of …

Comparison Of Instream Methods For Measuring Hydraulic Conductivity In Sandy Streambeds, Matthew K. Landon, David L. Rus, F. Edwin Harvey

School of Natural Resources: Faculty Publications

Streambed hydraulic conductivity (K) values were determined at seven stream transects in the Platte River Basin in Nebraska using different instream measurement techniques. Values were compared to determine the most appropriate technique(s) for use in sandy streambeds. Values of K determined from field falling- and constant-head permeameter tests analyzed using the Darcy equation decreased as permeameter diameter increased. Seepage meters coupled with hydraulic gradient measurements failed to yield K values in 40% of the trials. Consequently, Darcy permeameter and seepage meter tests were not preferred approaches. In the upper 0.25 m of the streambed, field falling- and constant-head permeameter tests …

Dual Heuristic Programming For Fuzzy Control, George G. Lendaris, Thaddeus T. Shannon, Larry J. Schultz, Steven Hutsell, Alec Rogers

Complex Systems Faculty Publications and Presentations

Overview material for the Special Session (Tuning Fuzzy Controllers Using Adaptive Critic Based Approximate Dynamic Programming) is provided. The Dual Heuristic Programming (DHP) method of Approximate Dynamic Programming is described and used to the design a fuzzy control system. DHP and related techniques have been developed in the neurocontrol context but can be equally productive when used with fuzzy controllers or neuro-fuzzy hybrids. This technique is demonstrated by designing a temperature controller for a simple water bath system. In this example, we take advantage of the TSK model framework to initialize the tunable parameters of our plant model with reasonable …

Fluorescence And Light Scattering Studies Of Aromatic Polymers Near The Critical Concentration C*, M.Sean Healy

Seton Hall University Dissertations and Theses (ETDs)

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The Cataclysmic Variable Cw 1045+525: A Secondary-Dominated Dwarf Nova?, C. Tappert, J. R. Thorstensen, W. H. Fenton, N. Bennert, L. Schmidtobreick, A. Bianchini

Physics

We present spectroscopic and photometric observations of the cataclysmic variable CW 1045+525. Both the optical spectrum and the photometric lightcurve show a strong contribution of a K5V-M0V secondary. We derive an orbital period d by measuring the radial velocities of the absorption lines of the secondary. The period and spectral type of the secondary suggest a distance of 350-700 pc. There is evidence for additional sources of line- and continuum emission, but no direct evidence of an accretion disc. We discuss several scenarios for the nature of CW 1045+525 on the basis of our results, finding a dwarf nova classification …

The Suitability Of Reclaimed Agricultural Lands Along The Lower Colorado River For Native Riparian Habitat Restoration, Patti Aaron

UNLV Theses, Dissertations, Professional Papers, and Capstones

The purpose of this paper is to determine the suitability of agricultural lands for use in native riparian restoration efforts under development for the Lower Colorado River Multi-Species Conservation Program. Assuming these fields are productive for crops, would they be productive for cottonwood-willow restoration? There are two aspects to consider: (1) the edaphic conditions required for three major LCR agricultural crops; alfalfa, cotton, and wheat, and (2) whether those conditions are consistent with the conditions required for the restoration of native LCR riparian habitat, primarily Fremont cottonwood (Populus fremontii) and Goodding willow (Salix gooddingii). Using the case study research approach …

Characterization Of Organo-Tin And Organo-Mercury Compounds With Electrospray Mass Spectrometry, Kan Zhu

Masters Theses

Metal-containing compounds are often found as pollutants in the environment. Obtaining speciation information about these compounds is important to understanding toxieity and bioaccumulation. Electrospray Mass Spectrometry (ESMS) is a technique that has the potential to provide rapid and direct speciation information of solution phase metal compounds. The ionization behavior of chemical species is related to their electron affinities. The higher the electron affinity, the easier it will be reduced during the ionization process. Additionally, solvent with different polarity and surface tension will also affect the ionization and reduction products. Organo-tin compounds with more alkyl groups will be ionized more efficiently, …

One-Gas Models With Height-Dependent Mean Molecular Weight: Effects On Gravity Wave Propagation, R. L. Walterscheid, Michael P. Hickey Ph.D.

Publications

Many models of the thermosphere employ the one-gas approximation where the governing equations apply only to the total gas and the physical properties of the gas that depend on composition (mean molecular weight and specific heats) are height-dependent. It is further assumed that the physical properties of the gas are locally constant; thus motion-induced perturbations are nil. However, motion in a diffusively separated atmosphere perturbs local values of mean molecular weight and specific heats. These motion-induced changes are opposed by mutual diffusion of the constituent gases, which attempts to restore diffusive equilibrium. Assuming that composition is locally constant is equivalent …

Discrete Singular Convolution For The Prediction Of High Frequency Vibration Of Plates, Yibao Zhao, G. W. Wei, Y. Xiang

Research Collection Lee Kong Chian School Of Business

Theoretical analysis of high frequency vibrations is indispensable in a variety of engineering designs. Much effort has been made on this subject in the past few decades. However, there is no single technique which can be applied with confidence to various engineering structures for high frequency predictions at present. This paper introduces a novel computational approach, the discrete singular convolution (DSC) algorithm, for high frequency vibration analysis of plate structures. Square plates with six distinct boundary conditions are considered. To validate the proposed method, a completely independent approach, the Levy method, is employed to provide exact solutions for a comparison. …

A Confidence Measure For Boundary Detection And Object Selection, William A. Barrett, Eric N. Mortensen

Faculty Publications

We introduce a confidence measure that estimates the assurance that a graph arc (or edge) corresponds to an object boundary in an image. A weighted, planar graph is imposed onto the watershed lines of a gradient magnitude image and the confidence measure is a function of the cost of fixed-length paths emanating from and extending to each end of a graph arc. The confidence measure is applied to automate the detection of object boundaries and thereby reduces (often greatly) the time and effort required for object boundary definition within a user-guided image segmentation environment.

Fast Focal Length Solution In Partial Panoramic Image Stitching, William A. Barrett, Kirk L. Duffin

Faculty Publications

Accurate estimation of effective camera focal length is crucial to the success of panoramic image stitching. Fast techniques for estimating the focal length exist, but are dependent upon a close initial approximation or the existence of a full circle panoramic image sequence. Numerical solutions of the focal length demonstrate strong coupling between the focal length and the angles used to position each component image about the common spherical center. This paper demonstrates that parameterizing panoramic image positions using spherical arc length instead of angles effectively decouples the focal length Ji.om the image position. This new parameterization does not require an …

Houghing The Hough: Peak Collection For Detection Of Corners, Junctions And Line Intersections, William A. Barrett, Kevin D. Petersen

Faculty Publications

We exploit the Accumulator Array of the Hough Transform by finding collections of (2 or more) peaks through which a given sinusoid will pass. Such sinusoids identify points in the original image where lines intersect. Peak collection (or line aggregation) is performed by making a second pass through the edge map, but instead of laying points down in the accumulator array (as with the original Hough Transform), we compute the line integral over each sinusoid that corresponds to the current edge point. If a sinusoid passes through greater than or equal to 2 peaks, we deposit that sum/integral into a …

Space-Group Revision For 4-Formylphenylboronic Acid, Frank R. Fronczek, Nadia N. St Luce, Robert M. Strongin

Chemistry Faculty Publications and Presentations

The space group of the title compound, C₇H₇BO₃, previously reported to be P, is properly Cc. There is no disorder of the formyl group or in the H atoms of the B(OH)₂ group. Molecules lie on approximate twofold axes and are related by approximate centers, which relate all but the formyl O atom and boronic acid H atoms. The B-O distances are 1.363 (2) and 1.370 (2) Å.

Image Compression By Wavelet Transform., Panrong Xiao

Electronic Theses and Dissertations

Digital images are widely used in computer applications. Uncompressed digital images require considerable storage capacity and transmission bandwidth. Efficient image compression solutions are becoming more critical with the recent growth of data intensive, multimedia-based web applications.

This thesis studies image compression with wavelet transforms. As a necessary background, the basic concepts of graphical image storage and currently used compression algorithms are discussed. The mathematical properties of several types of wavelets, including Haar, Daubechies, and biorthogonal spline wavelets are covered and the Enbedded Zerotree Wavelet (EZW) coding algorithm is introduced. The last part of the thesis analyzes the compression results to …

Hazardous Materials Transportation Flow Survey: An Evaluation Of Hazardous Materials Transported In Washington County., Daniel John O'Brien

Electronic Theses and Dissertations

This study examines the transportation of hazardous materials through Washington County, Tennessee. This study incorporates federal, state, and local data in assessing current transportation trends. Data gathering activities included local chemical inventories, hazardous materials transportation flow surveys, hazardous materials rail transportation trends, and hazardous materials incident data.

All data were compiled and then analyzed to identify hazardous materials transportation trends in Washington County, Tennessee. This information is pertinent to emergency planners for the preparation of hazardous materials transportation incidents. The data gathered further revealed the need for this type of study to identify changing trends in the transportation of hazardous …