Physical Sciences and Mathematics Commons^™

Heterogeneous Freezing Of Droplets With Immersed Mineral Dust Particles - Measurements And Parameterization, D. Niedermeier, S. Hartmann, R. A. Shaw, D. Covert, T. F. Mentel, J. Schneider, L. Poulain, P. Reitz, C. Spindler, T. Clauss, A. Kiselev, E. Hallbauer, H. Wex, K. Mildenberger, F. Stratmann

Michigan Tech Publications

During the measurement campaign FROST (FReezing Of duST), LACIS (Leipzig Aerosol Cloud Interaction Simulator) was used to investigate the immersion freezing behavior of size selected, coated and uncoated Arizona Test Dust (ATD) particles with a mobility diameter of 300 nm. Particles were coated with succinic acid (C4H6O4), sulfuric acid (H 2SO4) and ammonium sulfate ((NH4)) 2SO4). Ice fractions at mixed-phase cloud temperatures ranging from 233.15K to 239.15K (±0.60 K) were determined for all types of particles. In this temperature range, pure ATD particles and those coated with C4H6O4 or small amounts of H 2SO4 were found to be the most …

Green Chemistry Using Bismuth(Iii) Salts: Synthesis Of Cyclic Acetals And Allylation Of Tetrahydropyranyl Ethers And Aldehydes, Scott W. Krabbe

Honors Projects

Research in our group focuses on environmentally friendly organic synthesis using bismuth compounds. With increasing environmental concerns, the need for environmentally friendly organic synthesis following Green Chemistry principles has assumed increased importance. The Pollution Prevention Act, passed in 1990, was especially important in increasing an interest in Green Chemistry, which is the design and redesign of chemical processes with a view of improving safety. Our group focuses on synthetic methodology i.e. the transformation of one functional group to another. Such transformations are of special relevance in the pharmaceutical industry for manufacture of life saving drugs. Many of the current organic …

Neuronbank: A Tool For Cataloging Neuronal Circuitry, Paul S. Katz, Robert Calin-Jageman, Akshaye Dhawan, Chad Frederick, Shuman Guo, Rasanjalee Dissanayaka, Naveen Hiremath, Wenjun Ma, Xiuyn Shen, Hsui C. Wang, Hong Yang, Sushil Prasad, Rajshekhar Sunderraman, Ying Zhu

Mathematics and Computer Science Faculty Publications

The basic unit of any nervous system is the neuron. Therefore, understanding the operation of nervous systems ultimately requires an inventory of their constituent neurons and synaptic connectivity, which form neural circuits. The presence of uniquely identifiable neurons or classes of neurons in many invertebrates has facilitated the construction of cellular-level connectivity diagrams that can be generalized across individuals within a species. Homologous neurons can also be recognized across species. Here we describe NeuronBank.org, a web-based tool that we are developing for cataloging, searching, and analyzing neuronal circuitry within and across species. Information from a single species is represented in …

Automatic Transition To Peer-To-Peer Download, Roger D. Pack

Theses and Dissertations

For traditional web servers, available bandwidth decreases as the number of clients increases. This can cause servers to serve files slowly or to become completely overwhelmed when load grows too high. BitTorrent is a peer-to-peer solution to this problem, but it requires manual configuration for each file to be delivered this way. We develop a new system that integrates peer-to-peer file delivery with traditional client-server downloads. Clients initially attempt to download a file from a web server; if this is too slow, they transition to peer-to-peer delivery. Experiments with a prototype system show that it serves up to 30x faster …

Zero Divisors Among Digraphs, Heather Christina Smith

Theses and Dissertations

This thesis generalizes to digraphs certain recent results about graphs. There are special digraphs C such that AxC is isomorphic to BxC for some pair of distinct digraphs A and B. Lovasz named these digraphs C zero-divisors and completely characterized their structure. Knowing that all directed cycles are zero-divisors, we focus on the following problem: Given any directed cycle D and any digraph A, enumerate all digraphs B such that AxD is isomorphic to BxD. From our result for cycles, we generalize to an arbitrary zero-divisor C, developing upper and lower bounds for the collection of digraphs B satisfying AxC …

Information Cost Tradeoffs For Augmented Index And Streaming Language Recognition, Amit Chakrabarti, Graham Cormode, Ranganath Kondapally, Andrew Mcgregor

Dartmouth Scholarship

This paper makes three main contributions to the theory of communication complexity and stream computation. First, we present new bounds on the information complexity of AUGMENTED-INDEX. In contrast to analogous results for INDEX by Jain, Radhakrishnan and Sen [J. ACM, 2009], we have to overcome the significant technical challenge that protocols for AUGMENTED-INDEX may violate the “rectangle property” due to the inherent input sharing. Second, we use these bounds to resolve an open problem of Magniez, Mathieu and Nayak [STOC, 2010] that asked about the multi-pass complexity of recognizing Dyck languages. This results in a natural separation between the standard …

Reproducibility Of Soil Moisture Ensembles When Representing Soil Parameter Uncertainty Using A Latin Hypercube–Based Approach With Correlation Control, Alejandro N. Flores, Dara Entekhabi, Rafael L. Bras

Alejandro N. Flores

Representation of model input uncertainty is critical in ensemble-based data assimilation. Monte Carlo sampling of model inputs produces uncertainty in the hydrologic state through the model dynamics. Small Monte Carlo ensemble sizes are desirable because of model complexity and dimensionality but potentially lead to sampling errors and correspondingly poor representation of probabilistic structure of the hydrologic state. We compare two techniques to sample soil hydraulic and thermal properties (SHTPs): (1) Latin Hypercube (LH) based sampling with correlation control and (2) random sampling from SHTP marginal distributions. A hydrology model is used to project SHTP uncertainty onto the soil moisture state …

Rapport: Semantic-Sensitive Namespace Management In Large-Scale File Systems, Yu Hua, Hong Jiang, Yifeng Zhu, Dan Feng

CSE Technical Reports

Explosive growth in volume and complexity of data exacerbates the key challenge to effectively and efficiently manage data in a way that fundamentally improves the ease and efficacy of their use. Existing large-scale file systems rely on hierarchically structured namespace that leads to severe performance bottlenecks and renders it impossible to support real-time queries on multi-dimensional attributes. This paper proposes a novel semantic-sensitive scheme, called Rapport, to provide dynamic and adaptive namespace management and support complex queries. The basic idea is to build files’ namespace by utilizing their semantic correlation and exploiting dynamic evolution of attributes to support namespace management. …

Reproducibility Of Soil Moisture Ensembles When Representing Soil Parameter Uncertainty Using A Latin Hypercube-Based Approach With Correlation Control, Alejandro N. Flores, Dara Entekhabi, Rafael L. Bras

Geosciences Faculty Publications and Presentations

Representation of model input uncertainty is critical in ensemble‐based data assimilation. Monte Carlo sampling of model inputs produces uncertainty in the hydrologic state through the model dynamics. Small Monte Carlo ensemble sizes are desirable because of model complexity and dimensionality but potentially lead to sampling errors and correspondingly poor representation of probabilistic structure of the hydrologic state. We compare two techniques to sample soil hydraulic and thermal properties (SHTPs): (1) Latin Hypercube (LH) based sampling with correlation control and (2) random sampling from SHTP marginal distributions. A hydrology model is used to project SHTP uncertainty onto the soil moisture state …

Least Squares Problems With Inequality Constraints As Quadratic Constraints, Jodi Mead, Rosemary A. Renaut

Jodi Mead

Linear least squares problems with box constraints are commonly solved to find model parameters within bounds based on physical considerations. Common algorithms include Bounded Variable Least Squares (BVLS) and the Matlab function lsqlin. Here, the goal is to find solutions to ill-posed inverse problems that lie within box constraints. To do this, we formulate the box constraints as quadratic constraints, and solve the corresponding unconstrained regularized least squares problem. Using box constraints as quadratic constraints is an efficient approach because the optimization problem has a closed form solution.

The effectiveness of the proposed algorithm is investigated through solving three …

A Newton Root-Finding Algorithm For Estimating The Regularization Parameter For Solving Ill-Conditioned Least Squares Problems, Jodi Mead, Rosemary Renaut

Jodi Mead

We discuss the solution of numerically ill-posed overdetermined systems of equations using Tikhonov a-priori-based regularization. When the noise distribution on the measured data is available to appropriately weight the fidelity term, and the regularization is assumed to be weighted by inverse covariance information on the model parameters, the underlying cost functional becomes a random variable that follows a X2 distribution. The regularization parameter can then be found so that the optimal cost functional has this property. Under this premise a scalar Newton root-finding algorithm for obtaining the regularization parameter is presented. The algorithm, which uses the singular value decomposition of …

A Sequence Stratigraphic And Isotopic Study Of Uppermost Pennsylvanian-Lower Permian Carbonate Strata, Orogrande Basin, New Mexico, Jesse Koch

Department of Earth and Atmospheric Sciences: Dissertations, Theses, and Student Research

Determining how the tropics respond to glaciation is important for improving our global understanding of icehouse worlds. The impetus behind this study is to identify the far-field impacts of Gondwanan glaciation during the Early Permian. Impacts including climate and sea-level change should be evident in sensitive carbonate systems, such as the upper Paleozoic paleotropical strata in the Orogrande Basin. A sequence stratigraphic and stable isotopic approach is used to examine the effects of late Paleozoic climate change in the Orogrande Basin during the acme and subsequent demise of the late Paleozoic ice age.

Sequence stratigraphic analysis suggests the occurrence of …

Memristics: Memristors, Again?, Rudolf Kaehr

Rudolf Kaehr

This collection gives first and short critical reflections on the concepts of memristics, memristors and memristive systems and the history of similar movements with an own focus on a possible interplay between memory and computing functions, at once, at the same place and time, to achieve a new kind of complementarity between computation and memory on a single chip without retarding buffering conditions.

Wright State University Celebration Of Research, Scholarship And Creative Activities 2010 Book Of Abstracts, Wright State University Office Of Undergraduate Research And Stemm Activities

Symposium of Student Research, Scholarship, and Creative Activities Materials

The student abstract booklet is a compilation of abstracts from students' oral and poster presentations at Wright State University's inaugural Celebration of Research, Scholarship and Creative Activities on April 16, 2010.

Trust In Social And Sensor Networks, Pramod Anantharam, Krishnaprasad Thirunarayan, Cory Andrew Henson, Amit P. Sheth

Kno.e.sis Publications

Trust can be defined as the perception of the trustor about the degree to which the trustee would satisfy an expectation about a transaction constituting risk. Trust plays a pivotal role when the risk in believing incorrect information is high. With Web 2.0 where user generated content and real time interactions dominate, the openness of data contribution may hinder the quality of information we can get.

Channel Characterization For Wireless Underground Sensor Networks, Agnelo R. Silva

Department of Computer Science and Engineering: Dissertations, Theses, and Student Research

Wireless Underground Sensor Networks (WUSNs) are natural extensions of the established Wireless Sensor Network (WSN) phenomenon and consist of sensors buried underground which communicate through soil. WUSNs have the potential to impact a wide variety of applications including precision agriculture, environmental monitoring, border patrol, and infrastructure monitoring. The main difference between WUSNs and traditional wireless networks is the communication medium. However, a comprehensive wireless underground channel model for WUSNs has not been developed so far. In this thesis, the Soil Subsurface Wireless Communication (SSWC) channel model is developed based on an extensive empirical study in a large agriculture field. The …

Visual Networking, James Paul

Regis University Student Publications (comprehensive collection)

This research presents a case study of the Regis Academic Research Network (ARNe). It will focus on network bandwidth graphs and the information collected over a six month period of time. The case study will provide comparison of network bandwidth graphs. This case study will be used to theorize what is happening on the ARNE. In addition it will be used for creating hypotheses on what will happen to the network in the future. The research will also include a project. The project is to provide the setup and planning of the installation of open source tool set. This project …

Network-Centric Angle Only Tracking, Randy Paffenroth, Jason Yosinski, Nick Coult

Randy C. Paffenroth

The coordinated use of multiple distributed sensors by network communication has the potential to substantially improve track state estimates even in the presence of enemy countermeasures. In the modern electronic warfare environment, a network-centric tracking system must function in a variety of jamming scenarios. In some scenarios hostile electronic countermeasures (ECM) will endeavor to deny range and range rate information, leaving friendly sensors to depend on passive angle information for tracking. In these cases the detrimental effects of ECM can be at least partially ameliorated through the use of multiple networked sensors, due to the inability of the ECM to …

Ecological Niche Modeling And Local Knowledge Predict New Populations Of Gymnocladus Assamicus A Critically Endangered Tree Species, Shaily Menon, Baharul I. Choudhury, M. Latif Khan, A. Townsend Peterson

Shaily Menon

Gymnocladus assamicus is a critically endangered tree species endemic to northeastern India. Local inhabitants traditionally used this species for a variety of purposes. However, rapid population declines led to the species being considered extinct, until fieldwork in 2004 to 2007 identified 14 discrete populations of 1 to 7 trees each. To overcome constraints on field surveys imposed by the region’s remoteness and rugged terrain, we targeted areas of further field inventories by estimating the potential distribution of the species. Ecological niche modeling enabled us to identify 26 sites which the model predicted to be highly suitable for the species’ occurrence. …

The Impact Of Academic Faculty On Campus Sustainability Initiatives, Aurali Dade

Graduate Research Symposium (2010 - 2017)

The focus of this poster is the role of academic faculty on campus sustainability initiatives at Institutions of Higher Education (IHEs). The 4,000+ IHEs in the United States train future leaders and have a great deal of influence on the environment and attitude of communities in which they reside. Academic faculty has a sizable impact on governance and significant influence on students. They also may have a major role in campus sustainability initiatives, practices, and policies at IHEs. In order to address whether this is the case, a survey of academic faculty at accredited colleges and universities in the United …

Trends In Climate Change Education In Nevada's System Of Higher Education, Amy Northrup

Graduate Research Symposium (2010 - 2017)

This poster presents research into how climate change is taught in Nevada's colleges and universities. A completed inventory of the types of courses in different disciplines and at different institutions that relay information about climate change to students is discussed.

Assessing Invasive Plant Species As Threats In Mojave Desert Parks, Sara L. Mcpherson, Donovan J. Craig, Scott R. Abella

Graduate Research Symposium (2010 - 2017)

The invasion and persistence of exotic plant species threatens the natural features that national parks are designed to protect. For example, park managers have witnessed an increase in the frequency, extent and intensity of fires along with a reduction in native species richness and diversity. Many park managers are familiar with a suite of highly invasive plants, but lack a comprehensive and systematic way of prioritizing invasive plant species based on potential threats to the parks’ resources. We have entered into a collaborative project with the National Park Service’s Inventory and Monitoring program to develop an invasive plant early detection …

29 Years Of Vegetation Community Change Across Environmental Gradients In A Mojave Desert Mountain Range, Christopher L. Roberts, James S. Holland, Scott R. Abella

Graduate Research Symposium (2010 - 2017)

There is a great deal of uncertainty as to how biological communities respond to changes in land use and climate change, a situation particularly relevant in protected areas such as national parks that were designated to conserve specific biological features. Utilizing extant vegetation data sets with repeatable methodology can provide opportunities for insight into previous vegetation change and provide base line data for long-term monitoring projects useful for modeling vegetation community trajectories. We have relocated and resurveyed 106 sites from a vegetation community study initiated in 1979 in the Newberry Mountains, southern Nevada, within Lake Mead National Recreation Area managed …

Optical Distress Beacon For Use In Space Environments, Howard Chen, Andrew Joseph Giles, Nathaniel Pinckney, Sarah Harris, Andrew Danowitz, Samuel Seth Osofsky

Computer Science and Software Engineering

A beacon system includes emitter devices, driver circuitry configured for controlling the emitter devices, and at least one processor programmed to receive and process one or more inputs and control the driver circuitry to actuate the emitter devices. In an example embodiment, the emitter devices include visible light sources that are oriented to provide omnidirectional visibility for the beacon system. In an example embodiment, components of the beacon system including the emitter devices, driver circuitry and at least one processor are configured such that in a space environment heat generated by the beacon system is dissipated sufficiently well to prevent …

Induction Annealing And Subsequent Quenching: Effect On The Thermoelectric Properties Of Boron-Doped Nanographite Ensembles, Ming Xie, Chee Huei Lee, Jiesheng Wang, Yoke Khin Yap, Paola Bruno, Dieter Gruen, Dileep Singh, Jules Routbort

Department of Physics Publications

Boron-doped nanographite ensembles (NGEs) are interesting thermoelectric nanomaterials for high temperature applications. Rapid induction annealing and quenching has been applied to boron-doped NGEs using a relatively low-cost, highly reliable, laboratory built furnace to show that substantial improvements in thermoelectric power factors can be achieved using this methodology. Details of the design and performance of this compact induction furnace as well as results of the thermoelectric measurements will be reported here.

Nanostructured Poly(3,4-Ethylenedioxythiophene)–Metalloporphyrin Films: Improved Catalytic Detection Of Peroxynitrite, Serban Peteu, Pubudu Peiris, Ermias Gebermichael, Mekki Bayachou

Chemistry Faculty Publications

We investigated in this paper the sensing performance of inherently conductive polymer, poly(3,4-ethylenedioxythiophene) (PEDOT), functionalized with hemin (iron protoporphyrin) as an electrocatalytic reporter. The sensing platform is prepared by electrodeposition of a composite film of hemin–PEDOT on a 30-μm diameter carbon fiber electrode (CFE). The polymerized films were characterized by field emission scanning electron microscopy (FESEM), which pointed to nanostructured films with tortuous pores. The electrocatalytic oxidation of peroxynitrite was characterized by cyclic voltammetry as well as other electrochemical methods. The catalytic current is proportional to the analyte's concentration. Optimized hemin–PEDOT modified CFEs were utilized for the first time to …

The Four-Color Theorem And Chromatic Numbers Of Graphs, Sarah E. Cates

Undergraduate Theses and Capstone Projects

We study graph colorings of the form made popular by the four-color theorem. Proved by Appel and Haken in 1976, the Four-Color Theorem states that all planar graphs can be vertex-colored with at most four colors. We consider an alternate way to prove the Four-Color Theorem, introduced by Hadwiger in 1943 and commonly know as Hadwiger’s Conjecture. In addition, we examine the chromatic number of graphs which are not planar. More specifically, we explore adding edges to a planar graph to create a non-planar graph which has the same chromatic number as the planar graph which we started from.

Does Prodan Possess An O-Tict Excited State? Synthesis And Properties Of Two Constrained Derivatives, Christopher J. Abelt

Arts & Sciences Articles

The synthesis and photophysical properties of 7-(dimethylamino)-3,4-dihydrophenanthren-1(2H)-one (7) and 3-(dimethylamino)-8,9,10,11-tetrahydro-7H-cyclohepta[a]naphthalen-7-one (8) are reported. These compounds possess a cycloalkanone substructure that controls the extent of twisting of the carbonyl group. The six-membered ring in 7 forces the carbonyl group to be coplanar with the naphthalene ring, whereas the seven-membered ring in 8 induces a significant twist. Both have the substructure of PRODAN (6-propionyl-2-(dimethylamino)naphthalene, 1). Comparing the photophysical behavior of these compounds with that of PRODAN and 2,2-dimethyl-1-(4-methyl-1,2,3,4-tetrahydrobenzo[f]quinolin-8-yl)propan-1-one (3) indicates that PRODAN likely emits from a PICT excited state rather than from an O-TICT excited state.

On The Catalytic Roles Of His351, Asn510, And His466 In Choline Oxidase And The Kinetic Mechanism Of Pyranose 2-Oxidase, Kunchala Rungsrisuriyachai

Chemistry Dissertations

Choline oxidase (E.C. 1.1.3.17) from Arthrobacter globiformis catalyzes the four-electron oxidation of choline to glycine betaine (N,N,N-trimethylglycine) via two sequential, FAD-dependent reactions in which betaine aldehyde is formed as an enzyme-bound intermediate. In each oxidative half-reaction, molecular oxygen acts as electron acceptor and is converted into hydrogen peroxide. Biochemical, structural, and mechanistic studies on the wild-type and a number of mutant variants of choline oxidase have recently been carried out, allowing for the depiction of the mechanism of alcohol oxidation catalyzed by the enzyme. Catalysis by choline oxidase is initiated by the removal of the hydroxyl proton of alcohol substrate …

Youth Initiative Hector’S Helpers: Quarterly Progress Report, Period Covering February 11, 2010 – April 15, 2011, Hector's Helpers

Anti-littering Programs

The third quarter has progressed with the Hector’s Helpers program. We took action with hands-on classroom activities and lead three clean-up field trips. Students learned how to protect public lands in Southern Nevada through our anti-litter and desert dumping initiative. West Career Technical Academy students completed various GIS projects and finished the Adopt-A-Block Handbook. The Hector’s Helpers staff also submitted a formal proposal to study pre- and post-program surveys of students participating in the Hector's Helpers program.