Physical Sciences and Mathematics Commons^™

An Investigation Of The Ends Of Finitely Generated Groups, Daniel T. Murphree

All Graduate Plan B and other Reports, Spring 1920 to Spring 2023

Geometric group theory is a relatively new branch of mathematics, studied as a distinct area since the 1990's. It explores invariant properties of groups based on group actions defined on topological or geometrical spaces. One of the pioneering works in geometric group theory is the article "Topological Methods in Group Theory" by Peter Scott and Terry Wall, written in 1977. This article was an overview of revised notes from an advanced course give in Liverpool in the same year. This report is an attempt to make these notes more accessible to lower level graduate students in the fields of topology …

Generalized Q-Functions And Dirichlet-To-Neumann Maps For Elliptic Differential Operators, Daniel Alpay, Jussi Behrndt

Mathematics, Physics, and Computer Science Faculty Articles and Research

The classical concept of Q-functions associated to symmetric and selfadjoint operators due to M.G. Krein and H. Langer is extended in such a way that the Dirichlet-to-Neumann map in the theory of elliptic differential equations can be interpreted as a generalized Q-function. For couplings of uniformly elliptic second order differential expression on bounded and unbounded domains explicit Krein type formulas for the difference of the resolvents and trace formulas in an H2-framework are obtained.

Arkosic Rocks From The San Andreas Fault Observatory At Depth (Safod)Borehole, Central California, S. D. Springer, J. P. Evans, J. I. Garver, D. Kirschner, Susanne U. Janecke

Susanne U. Janecke

http://lithosphere.geoscienceworld.org/content/1/4/206 The San Andreas Fault Observatory at Depth (SAFOD) drill hole encountered indurated, high-seismic-velocity arkosic sedimentary rocks west of the active trace of the San Andreas fault in central California. The arkosic rocks are juxtaposed against granitic rocks of the Salinian block to the southwest and against fine-grained Great Valley Group and Jurassic Franciscan rocks to the northeast. We identify three distinct lithologic units using cuttings, core petrography, electrical resistivity image logs, zircon fission-track analyses, and borehole-based geophysical logs. The upper arkose occurs from 1920 to 2530 m measured depth (mmd) in the borehole and is composed of five structural …

Using A Mathematical Model Of Cadherin-Based Adhesion To Understand The Function Of The Actin Cytoskeleton, J. C. Dallon, Elijah Newren, Marc Hansen

Faculty Publications

The actin cytoskeleton plays a role in cell-cell adhesion but its specific function is not clear. Actin might anchor cadherins or drive membrane protrusions in order to facilitate cell-cell adhesion. Using a mathematical model of the forces involved in cadherin-based adhesion we investigate its possible functions. The immersed boundary method is used to model the cell membrane and cortex with cadherin binding forces added as linear springs. The simulations indicate that cells in suspension can develop normal cell-cell contacts without actin-based cadherin anchoring or membrane protrusions. The cadherins can be fixed in the membrane or free to move and the …

Time Reversal Of Continuous-Wave, Steady-State Signals In Elastic Media, Brian E. Anderson, Robert A. Guyer, Paul A. Johnson, Timothy J. Ulrich

Faculty Publications

Experimental observations of spatial focusing of continuous-wave, steady-state elastic waves in a reverberant elastic cavity using time reversal are reported here. Spatially localized focusing is achieved when multiple channels are employed, while a single channel does not yield such focusing. The amplitude of the energy at the focal location increases as the square of the number of channels used, while the amplitude elsewhere in the medium increases proportionally with the number of channels used. The observation is important in the context of imaging in solid laboratory samples as well as problems involving continuous-wave signals in Earth.

Author Entropy Vs. File Size In The Gnome Suite Of Applications, Jason R. Casebolt, Daniel P. Delorey, Charles D. Knutson, Jonathan Krein, Alexander C. Maclean

Faculty Publications

We present the results of a study in which author entropy was used to characterize author contributions per file. Our analysis reveals three patterns: banding in the data, uneven distribution of data across bands, and file size dependent distributions within bands. Our re- sults suggest that when two authors contribute to a file, large files are more likely to have a dominant author than smaller files.

Psoda: Open Source Phylogenetic Search And Dna Analysis, Mark J. Clement, Quinn O. Snell, Kenneth Sundberg

Faculty Publications

PSODA is an open source (GPL v2) sequence analysis package that implements sequence alignment using biochemical properties, phylogeny search with parsimony or maximum likelihood criteria and selection detection using biochemical properties (TreeSAAP ). PSODA is compatible with PAUP and the search algorithms are competitive with those in PAUP. PSODA also adds a basic scripting language to the PAUP block, making it possible to easily create advanced meta-searches. Because PSODA is open-source, we have also been able to easily add in advanced search techniques and characterize the benefits of various optimizations. PSODA is available for Macintosh OS X, Windows, and Linux.

Hardware Accelerated Sequence Alignment With Traceback, Scott Lloyd, Quinn O. Snell

Faculty Publications

Biological sequence alignment is an essential tool used in molecular biology and biomedical applications. The growing volume of genetic data and the complexity of sequence alignment present a challenge in obtaining alignment results in a timely manner. Known methods to accelerate alignment on reconfigurable hardware only address sequence comparison, limit the sequence length, or exhibit memory and I/O bottlenecks. A space-efficient, global sequence alignment algorithm and architecture is presented that accelerates the forward scan and traceback in hardware without memory and I/O limitations. With 256 processing elements in FPGA technology, a performance gain over 300 times that of a desktop …

Synthesizing Correlated Rss News Articles Based On A Fuzzy Equivalence Relation, Yiu-Kai D. Ng, Maria Soledad Pera

Faculty Publications

Tens of thousands of news articles are posted on-line each day, covering topics from politics to science to current events. To better cope with this overwhelming volume of information, RSS (news) feeds are used to categorize newly posted articles. Nonetheless, most RSS users must filter through many articles within the same or different RSS feeds to locate articles pertaining to their particular interests. Due to the large number of news articles in individual RSS feeds, there is a need for further organizing articles to aid users in locating non-redundant, informative, and related articles of interest quickly. In this paper, we …

Effective Medium Theory, Rough Surfaces, And Moth’S Eyes, David D. Allred, Zephne Larsen, Joseph Muhlestein, R. Steven Turley, Anthony Willey

Faculty Publications

Optics in the extreme ultraviolet (XUV) have important applications in microelectronics, microscopy, space physics, and in imaging plasmas. Because of the short wavelengths involved in these applications, it is critical to account for interfacial roughness to accurately predict the reflection and absorption of XUV optics. This paper examines two possible effects of roughness on optical absorption, non-specular reflection and enhanced transmission and compares these to measured experimental data on a rough Y2O3 thin film.

Comment On "Generation Of Cold Low Divergent Atomic Beam Of Indium By Laser Ablation", A. Denning, A. Booth, S. Lee, M. Amonson, Scott D. Bergeson

Faculty Publications

We present measurements of the velocity distribution of calcium atoms in an atomic beam generated using a dual-stage laser back-ablation apparatus. Distributions are measured using a velocity selective Doppler time-of-flight technique. They are Boltzmann-like with rms velocities corresponding to temperatures above the melting point for calcium. Contrary to a recent report in the literature, this method does not generate a subthermal atomic beam.

Overviewand Summary Of The Spread F Experiment (Spreadfex), D. C. Fritts, M. A. Abdu, B. R. Batista, I. S. Batista, P. P. Batista, R. Buritii, B. R. Clemesha, J. Comberiate, T. Dautermann, E. De Paula, B. J. Fechine, Bela G. Fejer, D. Gobbi, J. Haase, F. Kalamabadi, B. Laughman, P. P. Lima, H. L. Liu, A. Medeiros, D. Pautet, F. Sao Sabbas, J. H.A. Sobral, P. Stamus, H. Takahashi, M. J. Taylor, S. L. Vadas, C. Wrasse

Bela G. Fejer

We provide here an overview of, and a summary of results arising from, an extensive experimental campaign (the Spread F Experiment, or SpreadFEx) performed from September to November 2005, with primary measurements in Brazil. The motivation was to define the potential role of neutral atmosphere dynamics, specifically gravity wave motions propagating upward from the lower atmosphere, in seeding Rayleigh-Taylor instability (RTI) and plasma bubbles extending to higher altitudes. Campaign measurements focused on the Brazilian sector and included ground-based optical, radar, digisonde, and GPS measurements at a number of fixed and temporary sites. Related data on convection and plasma bubble structures …

Climatology Of Early Night Equatorial Spread F Over Jicamarca, N. P. Chapagain, Bela G. Fejer

Bela G. Fejer

[1] We use radar observations from 1996 to 2006 to study the climatology of postsunset equatorial 3-m spread F irregularities over Jicamarca during all seasons. We show that the spread F onset times do not change with solar flux and that their onset heights, which occur near the altitude of the evening F region velocity vortex, increase linearly from about 260 to 400 km from solar minimum to solar maximum. Higher onset heights generally lead to stronger radar echoes. During the equinox, spread F onset occurs near vertical drift evening reversal times, while during the December solstice, they occur near …

What Makes A “Good” Statistics Student And A “Good” Statistics Teacher In Service Courses?, Sue Gordon, Peter Petocz, Anna Reid

The Mathematics Enthusiast

Statistics is taught within a diverse array of disciplines and degree programs at university. In recent research we investigated international educators’ ideas about teaching and learning ‘service’ statistics. This paper investigates what these educators think are important attributes, knowledge and skills for learners and teachers of statistics. Results show that educators are in agreement about qualities of ‘good’ statistics students, such as curiosity and critical thinking. An emerging issue was the role mathematics plays in learning statistics as a service subject with some academics postulating mathematics as the basis of statistical learning, others proposing it has limited or little importance …

Undergraduate Student Difficulties With Independent And Mutually Exclusive Events Concepts, Adriana D'Amelio

The Mathematics Enthusiast

The concepts of disjunctive events and independent events are didactical ideas that are used widely in the classroom. Previous observations of attitudes in assessments given to students at university level who attended the introductory Statistics course helped to detect the confusion between disjunctive and independent events, and indicate the spontaneous ideas that students tend to elaborate about both concepts in different situations in which these appear. However the didactical relation between these ideas and their formal definitions is not known in detail. In this work, we analyze students’ misconceptions, their persistence, and the process by which the student confronts his …

Fostering Connections Between The Verbal, Algebraic, And Geometric Representations Of Basic Planar Curves For Student’S Success In The Study Of Mathematics, Margo F. Kondratieva, Oana G. Radu

The Mathematics Enthusiast

We discuss the significance of making connections between the verbal, algebraic, and geometric representations of basic mathematical objects for students’ understanding of mathematical instructions. Our survey of 499 students enrolled in a precalculus university course reveals that such connections are not always present, even if the objects themselves are familiar to the students. We stress that the ability of making these connections needs to be specifically addressed in teaching mathematics at various levels. A proper attention to the matter contributes to the formation of students’ mathematical background, which makes a difference for their success in study of calculus, in particular.

Art, Water, And Circles: In What Ways Do Study Circles Empower Artists To Become Community Leaders Around Water Issues, Jill Beth Jacoby

Antioch University Dissertations & Theses

This research explored the use of study circles as a means of engaging artists in dialogue with their peers about water related concerns. The question driving this research was, “In what ways do study circles empower artists to become community leaders around water issues?” Secondary questions focused on emerging environmental, water, and social justice themes as well as examples of increased water awareness and behavior change occurring as a result of individual participation in the study circles. Artists have a unique way of commanding attention and communicating about environmental concerns while functioning as catalysts for activism on a variety of …

Silicone Rubber Passive Samplers For Water Quality Monitoring Of Persistent Organic Pollutants In The Marine Environment, Susan O'Hara

Masters

Polychlorinated Biphenyls (PCBs) and Polyaromatic Hydrocarbons (PAHs) are internationally considered as persistent organic pollutants (POPs) which can be mutagenic, carcinogenic and may accumulate in aquatic organisms and potentially in the human chain. PCBs and PAHs are thus listed as priority pollutants in the Water Framework Directive (WFD) and under the Convention for the protection of the Marine Environment of the North-East Atlantic (Oslo Paris Convention: OSPAR). Currently most marine monitoring programmes involving such compounds rely on the collection and analysis of discrete water/sediment grab samples or on the analysis of filter feeding indicator organisms e.g. mussels. Such measurements can provide …

Holographic Liquid Crystal Devices, Kotakonda Pavani

Doctoral

Liquid crystals have become natural candidates for use in electro-optic devices for their ability to change the orientation of the director with the application of an electric field, and exhibiting large range of refractive index. The aim of the work presented in this thesis is to fabricate liquid crystal optoelectronic devices such as electrically switchable liquid crystal diffraction gratings and polarization rotators by exploiting the holographic surface relief effect in photopolymer and by developing novel polymer dispersed liquid crystals (PDLCs). Alignment of liquid crystals is commercially achieved by creating grooves on a conducting layer such as polyimide or indium tin …

Calculating Dependent Probabilities, Mike Fletcher

The Mathematics Enthusiast

In the 2004 European soccer competition France were one of the favourites to win the World Cup and Thierry Henry, their star forward, was one of the favourites to be top goal scorer. Bookkeepers were offering odds of 4 :1 on France winning the competition and odds of 8: 1 on Thierry Henry being the top scorer. A large number of punters went into betting shops in the United Kingdom and made a single bet that France would win the competition and that Thierry Henry would be top scorer. The counter clerks in the betting shops accepted the bets and …

For The Rest Of Your Life, Mike Fletcher

The Mathematics Enthusiast

‘For the Rest of Your Life’ is a new TV game show. Contestants play to win money every month. This can be for as little as one month or, if every one of their guesses is correct, for the rest of their lives.

Comparision Of High Achievers With Low Achievers: Discussion Of Juter’S (2007) Article, T. P. Hutchinson

The Mathematics Enthusiast

The use of questionnaires and interviews to compare the responses to a mathematical task of high achievers with low achievers has limitations. The partial information that they have provides a way of comparing high and low achievers. Some references are given here to relevant task formats and theories. An example is given of how examinees’ performance with unusual task formats (specifically, answer-until-correct) may be analysed to throw light on the mathematical description of partial information.

Development And Characterization Of Sulfur Dioxide Gas Analyzer, Samira Mohamed Saeed Mohamed Baomran

Theses

Sulfur dioxide (SO₂) is considered one of the main contaminants in air because of its major contribution to acid rain and due to the major health concerns associated with exposure to high concentrations of SO₂. Hence, there has been a great interest in the determination of SO₂ because of continuous monitoring its impacts on the environment and public health. However, limited reports targeted SO₂ in gas streams.

Therefore, the primary objective of the present work was to develop affordable gas analyzer for continuous monitoring of SO₂ in gas streams. The principle of operation …

Influence Of Iron And Iron-Bearing Minerals On Soil Magnetic Properties, Suzan Marwan Ramadan Shahin

Theses

In this study, soil magnetic properties (magnetic susceptibility/ permeability) due to iron and iron bearing minerals have been evaluated by using MS2B on different percentage levels from pure iron, hematite and magnetite content at different conditions. The study shows that soil magnetic behavior has a strong dependency on grain size, temperature, water content, pH and compositional content.

Also, soil electrical behaviors have been studied due to iron and iron bearing minerals by using Impedance/ gain-phase Analyzer on different soil magnetic inclusion at different percentages. The study has established the strong effect of the magnetic inclusion on the measurements of relative …

Development Of A Gis Database For Water Resources Management In Ajman Emirate, Uae., Mohammad Rehan Yusuf

Theses

The lack of freshwater resources represents a major constraint against the sustainable development in arid and semi-arid regions. Because of the scarcity and randomness nature of rainfall in arid regions, surface water resources are almost absent. Groundwater resources are always under stress and in many cases do not suffice the water demands for different sectors. Desalination plants are widely constructed to substitute for the water shortage. The UAE, including Ajman emirate, is witnessing a rapid development in the industrial, commercial, construction and agricultural fields which has led to a tremendous increase in water demands.

Proper management of the limited water …

Aspects Of The Microbiological Quality And Safety Of Ready-To-Eat Foods In Sharjah Supermarket Stores, Najla Ali Al-Mualla

Theses

Ready to eat foods covers a wide range of pre-processed food products that are readily eaten by consumers without further processing. Recently, there has been considerable increase in the demand of processed and convenience foods that are mildly pre-cooked, rapidly chilled, portioned and distributed for refrigeration prior to reheating and consumption by consumers. However, some of these foods such as, luncheon meals, ready to eat vegetables, fruit salad, spinach salad, and other deli-style meat and poultry products can be a harbor for pathogenic bacteria that are harmful to health when consumed by people especially with weak immune system.

Unfortunately, these …

Germination Ecology Of Two Indigenous Range Grasses Lasiurus Scindicus And Panicum Turgidum, Naeema Sultan Abdullah Al-Shamisi

Theses

The utilization of indigenous forage species to replace the exotic ones could help in saving large amounts of water. The indigenous forage grasses Lasiurus scindicus and Panicum turgidum have been ranked among the plants that could tolerate drought during vegetative and reproductive stages and are currently being successfully used as fodders under experimental conditions in the UAE and in some parts of the world. However, there are no enough information about their dormancy and the environmental factors affecting their seed germination. In this study, the innate dormancy, light and temperature requirements, drought and salinity tolerances and the impact of dormancy …

Water Demand Forecasting In Umm Al Quwain Using The Iwr-Main, Aysha Abdulla Al Mualla

Theses

Water demand forecasting has become an essential component in effective water resources planning and management. It provides valuable trigger in determining the time and the capacity for new water resources development. In the United Arab Emirates, the need for an accurate water demand forecasting becomes particularly important. The reasons for this include, and are not limited to, high temperature throughout the year, high population growth rates, and high development growth.

The main objective of this study is to forecast the water demand in UAQ for the next 25 years using the IWR-MAIN software. Two methods; namely the Constant Use Rate …

Investigation On The Minimization Of Sulfur Dioxide Emissions At Abu Dhabi Gas Liquefaction Company Limited (Adgas) And Its Impact On Ambient Air Quality, Haitham Salmeen Abdulla Babahar

Theses

The processing of sour gases within Abu Dhabi Gas Liquefaction Company (ADGAS) LNG Trains located in Das Island involves sulfur dioxide (SO₂) emissions that mainly result from fuel gas usage to produce steam and electricity, and incomplete recovery of sulfur from acid gases. ADGAS SO₂ emissions affect the ambient air quality in Das Island, and this has the potential to affect the health of the residents of the island. The aim of this work is to explore the feasible technologies to minimize SO₂ emissions from ADGAS, and study the impact of such on the ambient air …

Quantitative Analyses Of Dispersion, Doping And Electronic Separation Of Single Wall Hipco Carbon Nanotubes, Priya Baskar Rao

Doctoral

As prepared SWNTs are obtained in bundles with a mixture of both metallic and semi conducting tubes. For many specific applications, electronically separated single individual tubes are required and in order to reach these application criteria, the tubes should be processed. This thesis reports on a systematic exploration of methods to routinely process, electronically separate and characterise commercially available single walled carbon nanotubes (SWNTs). Commercially available HiPco SWNTs were dispersed in water with the assistance of 1 % by weight sodium dodecyl benzene sulphate (SDBS). The tubes were dispersed in the water surfactant system through the aid of sonication and …