Physical Sciences and Mathematics Commons^™

Gamma-Ray Spectroscopy: Meteorite Samples And The Search For 98tc, Kristopher L. Merolla

Physics

The focus of this project is low-count-level gamma-ray spectroscopy on meteorite samples in search of a particular isotope of Technetium (98Tc), which according to stellar theory, should be present in the universe. The spectral lines for 99Tc have, however, been observed in S-, M-, and N- type stars, which makes finding 98Tc created naturally a possibility, and thus a search can be justified.

Culturally-Adapted And Audio-Technology Assisted Hiv/Aids Awareness And Education Program In Rural Nigeria: A Cohort Study, Ighovwerha Ofotokun, Jose Nilo G. Binongo, Eli S. Rosenberg, Michael Kane, Rick Ifland, Jeffrey L. Lennox, Kirk A. Easley

Faculty Articles

Background: HIV-awareness programs tailored toward the needs of rural communities are needed. We sought to quantify change in HIV knowledge in three rural Nigerian villages following an integrated culturally adapted and technology assisted educational intervention.

Methods: A prospective 14-week cohort study was designed to compare short-term changes in HIV knowledge between seminar-based education program and a novel program, which capitalized on the rural culture of small-group oral learning and was delivered by portable digital-audio technology.

Results: Participants were mostly Moslem (99%), male (53.5%), with no formal education (55%). Baseline HIV knowledge was low (< 80% correct answers for 9 of the 10 questions). Knowledge gain was higher (p < 0.0001 for 8 of 10 questions) in the integrated culturally adapted and technology-facilitated (n = 511) compared with the seminar-based (n = 474) program.

Conclusions: Baseline HIV-awareness was low. Culturally …

A Lanthanide-Based Chemosensor For Bioavailable Fe3+ Using A Fluorescent Siderophore: An Assay Displacement Approach, Karen M. Orcutt, William Scott Jones, Andrea Mcdonald, David Schrock, Karl J. Wallace

Faculty Publications

The measurement of trace analytes in aqueous systems has become increasingly important for understanding ocean primary productivity. In oceanography, iron (Fe) is a key element in regulating ocean productivity, microplankton assemblages and has been identified as a causative element in the development of some harmful algal blooms. The chemosenor developed in this study is based on an indicator displacement approach that utilizes time-resolved fluorescence and fluorescence resonance energy transfer as the sensing mechanism to achieve detection of Fe3+ ions as low as 5 nM. This novel approach holds promise for the development of photoactive chemosensors for ocean deployment.

Flexible Object Manipulation, Matthew P. Bell

Dartmouth College Ph.D Dissertations

Flexible objects are a challenge to manipulate. Their motions are hard to predict, and the high number of degrees of freedom makes sensing, control, and planning difficult. Additionally, they have more complex friction and contact issues than rigid bodies, and they may stretch and compress. In this thesis, I explore two major types of flexible materials: cloth and string. For rigid bodies, one of the most basic problems in manipulation is the development of immobilizing grasps. The same problem exists for flexible objects. I have shown that a simple polygonal piece of cloth can be fully immobilized by grasping all …

Two-Dimensional Descent Through A Compressible Atmosphere: Sequential Deceleration Of An Unpowered Load, Mark P. Silverman

Faculty Scholarship

Equations, based on Rayleigh's drag law valid for high Reynolds number, are derived for two-dimensional motion through a compressible atmosphere in isentropic equilibrium, such as characterizes the Earth's troposphere. Solutions yield horizontal and vertical displacement, velocity, and acceleration as a function of altitude and ground-level temperature. An exact analytical solution to the equations linearized in the aero-thermodynamic parameter is given; in general the equations must be solved numerically. The theory, applied to the unpowered fall of a large aircraft stabilized to flat descent by symmetrical, sequential deployment of horizontal and vertical decelerators, shows that such an aircraft can be brought …

Modelling The Impacts Of A Mixed Forestry Plantation On Groundwater Resources In The Beaufort River Area, Western Australia, Paul Raper, Richard J. George Dr

Resource management technical reports

No abstract provided.

Water Management Plan For The Town Of Pingelly, Mark Pridham

Resource management technical reports

No abstract provided.

An In Vitro Spectroscopic Analysis To Determine Whether Para-Chloroaniline Is Produced From Mixing Sodium Hypochlorite And Chlorhexidine, John Thomas, Daniel S. Sem

Chemistry Faculty Research and Publications

Introduction: The purpose of this in vitro study was to determine whether para-chloroaniline (PCA) is formed through the reaction of mixing sodium hypochlorite (NaOCl) and chlorhexidine (CHX).

Methods: Initially, commercially available samples of chlorhexidine acetate (CHXa) and PCA were analyzed with ¹H nuclear magnetic resonance (NMR) spectroscopy. Two solutions, NaOCl and CHXa, were warmed to 37ºC, and when mixed they produced a brown precipitate. This precipitate was separated in half, and pure PCA was added to 1 of the samples for comparison before they were each analyzed with ¹H NMR spectroscopy.

Results: The peaks in …

Highway Hull Revisited, Greg Aloupis, Jean Cardinal, Sébastien Collette, Ferran Hurtado, Stefan Langerman, Joseph O'Rourke, Belén Palop

Computer Science: Faculty Publications

A highway H is a line in the plane on which one can travel at a greater speed than in the remaining plane. One can choose to enter and exit H at any point. The highway time distance between a pair of points is the minimum time required to move from one point to the other, with optional use of H. The highway hull H(S,H) of a point set S is the minimal set containing S as well as the shortest paths between all pairs of points in H(S,H), using the highway time distance. We provide a Θ(nlogn) worst-case …

Combined Single-Molecule Photon-Stamping Spectroscopy And Femtosecond Transient Absorption Spectroscopy Studies Of Interfacial Electron Transfer Dynamics, Lijun Guo, Yuanmin Wang, H. Peter Lu

Chemistry Faculty Publications

The inhomogeneous interfacial electron transfer (IET) dynamics of 9-phenyl-2,3,7-trihydroxy-6-fluorone (PF)-sensitized TiO2 nanoparticles (NPs) has been probed by a single-molecule photon-stamping technique as well as ensemble-averaged femtosecond transient absorption spectroscopy. The forward electron transfer (FET) time shows a broad distribution at the single-molecule level, indicating the inhomogeneous interactions and ET reactivity of the PF/TiO2 NP system. The broad distribution of the FET time is measured to be 0.4 ± 0.1 ps in the transient absorption and picoseconds to nanoseconds in the photon-stamping measurements. The charge recombination time, having a broad distribution at the single-molecule level, clearly shows a biexponential dynamic behavior …

Improved Automated Monitoring And New Analysis Algorithm For Circadean Phototaxis Rhythms In Chlamydomonas, Christa Gaskill, Jennifer Forbes-Stovall, Bruce Kessler, Mike Young, Claire A. Rinehart, Sigrid Jacobshagen

Mathematics Faculty Publications

Automated monitoring of circadian rhythms is an efficient way of gaining insight into oscillation parameters like period and phase for the underlying pacemaker of the circadian clock. Measurement of the circadian rhythm of phototaxis (swimming towards light) exhibited by the green alga Chlamydomonas reinhardtii has been automated by directing a narrow and dim light beam through a culture at regular intervals and determining the decrease in light transmittance due to the accumulation of cells in the beam. In this study, the monitoring process was optimized by constructing a new computercontrolled measuring machine that limits the test beam to wavelengths reported …

Higher Homotopy Operations And Cohomology, David Blanc, Mark W. Johnson, James M. Turner

University Faculty Publications and Creative Works

We explain how higher homotopy operations, defined topologically, may be identified under mild assumptions with (the last of) the Dwyer-Kan-Smith cohomological obstructions to rectifying homotopy-commutative diagrams. © 2010 ISOPP.

Ua35/1 Doers & Deeds Vol. 7, No. 14, Wku Provost

WKU Administration Documents

Newsletter created by the WKU Provost & Vice President of Academic Affairs to highlight the activities of faculty, staff and alumni.

Design, Construction And Load Testing Of The Bridge On Arnault Branch, Washington County, Missouri Using Innovative Technologies, Dongming Yan, Genda Chen, Nestore Galati, Sahra Sedigh

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

The superstructure and instrumentation designs of a three-span bridge are presented in this report. The three spans include a precast box-girder bridge, a precast deck on steel girder and a precast deck on concrete girder. They were designed to compare the performance of various bridge decks reinforced with fiber reinforced polymers (FRP) through field instrumentations. A wireless monitoring system was designed to facilitate the collection of field data after the completion of bridge construction. The collected data will allow the study of FRP bars and stay-in-place FRP grid systems.

Player Performance Prediction In Massively Multiplayer Online Role-Playing Games (Mmorpgs), Kyong Jin Shim, Richa Sharan, Jaideep Srivastava

Research Collection School Of Computing and Information Systems

Recent years have seen an ever increasing number of people interacting in the online space. Massively multiplayer online role-playing games (MMORPGs) are personal computer or console-based digital games where thousands of players can simultaneously sign on to the same online, persistent virtual world to interact and collaborate with each other through their in-game characters. In recent years, researchers have found virtual environments to be a sound venue for studying learning, collaboration, social participation, literacy in online space, and learning trajectory at the individual level as well as at the group level. While many games today provide web and GUI-based reports …

Estimating The Quality Of Postings In The Real-Time Web, Hady W. Lauw, Alexandros Ntoulas, Krishnaram Kenthapadi

Research Collection School Of Computing and Information Systems

Millions of users are posting their status updates, interesting findings, news, ideas and observations in real-time on microblogging services such as Twitter, Jaiku and Plurk. This real-time Web can be a great resource of valuable timely information. Since the real-time Web is completely open and decentralized and anyone may post information at whim, distinguishing interesting and popular postings from the mundane ones is a challenging task. In this paper we study the problem of estimating the quality (or “interestingness”) of postings in the real-time Web. We identify several important factors that are indicative of the quality of postings, and present …

Making Our Communities Greener: A Case Study Of Promoting Biogas Energy By Tongwei Evergreen Libraries In China, Wenjie Zhou, Tim J. Zou, Elaine X. Dong

University Libraries Faculty Publications and Presentations

Promoting the consumption of new energies, particularly of biogas, in rural areas is a strategic initiative of the Chinese government. The government has incorporated this initiative into many of its rural development plans. Likewise, Tongwei Evergreen Libraries (TEL, 通渭青树图书馆) has also integrated ideas of the initiative into its library services. This paper describes the Biogas Promotion Program (BPP) that TEL implemented, discusses the BPP model and roles of TEL in the program, and analyzes the initial results of the program through surveying local farmers. A survey was developed for this assessment study. The survey results show that the government biogas …

2010 Spring Engr333 Project Assignment, Matthew K. Heun

ENGR 333

The Spring 2010 ENGR333 project assessed options for the design of a redundant data center for the Calvin campus.

I asked the students “What would it take to build a redundant data center at Calvin that is 30% more energy efficient than the existing data center?”

Note: Because I was on sabbatical in Fall 2009, ENGR333 was moved to Spring 2010.

Customer

The customer for this project was Calvin’s VP for finance Henry DeVries.

[Diphenyldi(Pyrazol-1-Yl)Methane]Dinitratocobalt(Ii), Janet L. Shaw, Bruce C. Noll

Faculty Articles

In the title compound, [Co(NO₃)₂(C₁₉H₁₆N₄)], the diphenyldipyrazolylmethane ligand coordinates to Co^II in a bidentate fashion forming a six-membered ring with an approximate boat configuration. The mean planes of the two pyrazolyl rings are separated by an angle of 39.6 (2)°. The coordination at the Co^II center is best described as distorted octahedral with two NO₃^- anions serving as bidentate ligands for charge balance. The dihedral angle between the mean planes of the two nitrate rings is 85.0 (1)° and that between the mean planes of the …

Computing Highly Accurate Or Exact P-Values Using Importance Sampling (Revised), Chris Lloyd

Chris J. Lloyd

Especially for discrete data, standard first order P-values can suffer from poor accuracy, even for quite large sample sizes. Moreover, different test statistics can give practically different results. There are several approaches to computing P-values which do not suffer these defects, such as parametric bootstrap P-values or the partially maximised P-values of Berger & Boos (1994).

Both these methods require computing the exact tail probability of the approximate P-value as a function of the nuisance parameter/s, known as the significance profile. For most practical problems this is not computationally feasible. I develop an importance sampling approach to this problem. A …

Alteration Of Groundwater And Sediment Geochemistry In A Sulfidic Backswamp Due To Melaleuca Quinquenervia Encroachment, Scott G. Johnston, Peter G. Slavich, Phillip Hirst

Professor Scott G Johnston

Extensive encroachment of the native tree species Melaleuca quinquenervia (Cav.) Blake has occurred on a coastal floodplain sulfidic backswamp in eastern Australia. Almost 50% of the open swamp area c. 1870 is now monospecific M. quinquenervia forest. Encroachment has been associated with shortened hydroperiods and land management changes following drainage for agriculture. Large differences to shallow groundwater and sediment geochemistry were observed beneath both individual M. quinquenervia trees and encroaching forests compared to open swamp. Groundwater beneath M. quinquenervia had enhanced titratable acidity and acidic metal cations, increased concentrations of other ionic species (Cl–, SO42–), altered ionic ratios, and increased …

Perturbed Spherical Objects In Acoustic And Fluid Flow Fields, Manmeet Kaur

Dissertations

In this study, the time averaged acoustic radiation force and drag on a small, nearly spherical object suspended freely in a stationary sound wave field in a compressible, low viscosity fluid is to be calculated. This problem has been solved for a spherical object, and it has many important engineering applications related to segregation and separation processes for particles in fluids such as water. Small but significant errors have occurred in the predicted behavior of the particles using the existing approximate solutions based on perfect spheres. The classical approach has been extended in this research to objects that deviate slightly …

Algorithms In Comparative Genomics, Satish Chikkagoudar

Dissertations

The field of comparative genomics is abundant with problems of interest to computer scientists. In this thesis, the author presents solutions to three contemporary problems: obtaining better alignments for phylogeny reconstruction, identifying related RNA sequences in genomes, and ranking Single Nucleotide Polymorphisms (SNPs) in genome-wide association studies (GWAS).

Sequence alignment is a basic and widely used task in bioinformatics. Its applications include identifying protein structure, RNAs and transcription factor binding sites in genomes, and phylogeny reconstruction. Phylogenetic descriptions depend not only on the employed reconstruction technique, but also on the underlying sequence alignment. The author has studied and established a …

Understanding Cognitive Differences In Processing Competing Visualizations Of Complex Systems, Madhavi Mukul Chakrabarty

Dissertations

Node-link diagrams are used represent systems having different elements and relationships among the elements. Representing the systems using visualizations like node-link diagrams provides cognitive aid to individuals in understanding the system and effectively managing these systems. Using appropriate visual tools aids in task completion by reducing the cognitive load of individuals in understanding the problems and solving them. However, the visualizations that are currently developed lack any cognitive processing based evaluation. Most of the evaluations (if any) are based on the result of tasks performed using these visualizations. Therefore, the evaluations do not provide any perspective from the point of …

Integration Of Electronic And Optical Techniques In The Design And Fabrication Of Pressure Sensors, Ivan Padron

Dissertations

Since the introduction of micro-electro-mechanical systems fabrication methods, piezoresistive pressure sensors have become the more popular pressure transducers. They dominate pressure sensor commercialization due to their high performance, stability and repeatability. However, increasing demand for harsh environment sensing devices has made sensors based on Fabry-Perot interferometry the more promising optical pressure sensors due to their high degree of sensitivity, small size, high temperature performance, versatility, and improved immunity to environmental noise and interference. The work presented in this dissertation comprises the design, fabrication, and testing of sensors that fuse these two pressure sensing technologies into one integrated unit. A key …

Nonlinear Evolution Of Annular Layers And Liquid Threads In Electric Fields, Qiming Wang

Dissertations

The nonlinear dynamics of viscous perfectly conducting liquid jets or threads under the action of a radial electric field are studied theoretically and numerically here. The field is generated by a potential difference between the jet surface and a concentrically placed electrode of given radius. A long-wave nonlinear model that is used to predict the dynamics of the system and in particular to address the effect of the radial electric field on jet breakup is developed, Two canonical regimes are identified that depend on the size of the gap between the outer electrode and the unperturbed jet surface. For relatively …

Relationship Between Photospheric Magnetic Fields And Coronal Activities, Changyi Tan

Dissertations

Coronal emission comes in two forms, a steady component where the corona is heated to million degrees and a much hotter transient component of solar flares. Both components are known to be related to the evolution of surface magnetic fields. This dissertation studies the evolution of photospheric magnetic fields and flow fields and their relation to the properties of these two coronal emission components.

The key issue in the study of the steady coronal emission is the coronal heating problem: how the corona is heated to millions of degrees while the underlying solar photosphere is only a few thousand degrees. …

Job Seeking And Job Application In Social Networking Sites : Predicting Job Seekers' Behavioral Intentions, Maria Marcella Plummer

Dissertations

Social networking sites (SNSs) are revolutionizing the way in which employers and job seekers connect and interact with each other. Despite the reported benefits of SNSs with respect to finding a job, there are issues such as privacy concerns that might be deterring job seekers from using these sites in their attempts to secure a job. It is therefore important to understand the factors that are salient in predicting job seekers' use of SNSs in applying for jobs.

In this research, a theoretical model was developed to explicate job seekers' intentions to use SNSs to apply for jobs. Two aspects …

Semantics And Efficient Evaluation Of Partial Tree-Pattern Queries On Xml, Xiaoying Wu

Dissertations

Current applications export and exchange XML data on the web. Usually, XML data are queried using keyword queries or using the standard structured query language XQuery the core of which consists of the navigational query language XPath. In this context, one major challenge is the querying of the data when the structure of the data sources is complex or not fully known to the user. Another challenge is the integration of multiple data sources that export data with structural differences and irregularities. In this dissertation, a query language for XML called Partial Tree-Pattern Query (PTPQ) language is considered. PTPQs generalize …

Institutional Controls And Brownfield Redevelopment, Ronnachai Tiyarattanachai

Dissertations

Institutional controls (ICs) are used to reduce risks to human health and environment from exposure to contaminants at Brownfield sites. Regulators approve use of ICs in Brownfield redevelopment with the expectation that ICs will remain effective over the long-term under proper oversight mechanisms. However, a recent review of compliance statuses of Brownfield sites with ICs implemented in Massachusetts and New Jersey indicated a significant percentage of the sites are out of compliance status.

Implementation of ICs depends on compliance efforts by humans. Thus, consistency of implementation over the long-term is questionable because there are several potential problems due to human …