Physical Sciences and Mathematics Commons^™

Behavior Of Copper Electrodeposition In Copper Electroplating Solution With Different Peg Molecular Weight, Lie Yin, Zeng-Lin Wang

Journal of Electrochemistry

The effect of the polyethylene glycol(PEG) molecular weight(MW) upon via-hole filling with diameter of 50 μm and aspect ratio of 1 in the acid copper plating solution was studied.The cathodic polarization in copper electroplating bath with PEG of different molecule weights was investigated by linear sweep voltammetry.The surface roughness,crystallography,and the resistivity of copper films were characterized by X-ray diffraction(XRD),atomic force microscopy(AFM) and the four-point probe measurements.The results showed that the polarization on the cathode and the hole-filling capability of electroplating copper bath were increased evidently with an increase of PEG molecular weight from 600 to 8000.When the PEG MW was …

Dynamics Of Quasiconformal Fields, Tadeusz Iwaniec, Leonid V. Kovalev, Jani Onninen

Mathematics - All Scholarship

A uniqueness theorem is established for autonomous systems of ODEs, x= f(x), where f is a Sobolev vector field with additional geometric structure, such as delta-monoticity or reduced quasiconformality. Specifically, through every non-critical point of f there passes a unique integral curve.

Comparison Of Three Models For Predicting Gross Primary Production Across And Within Forested Ecoregions In The Contiguous United States, Nicholas C. Coops, Colin J. Ferster, Richard H. Waring, Joanne Nightingale

United States National Aeronautics and Space Administration: Publications

Gross primary production (GPP), the photosynthetic uptake of carbon, is an important variable in the global carbon cycle. Although continuous measurements of GPP are being collected from a network of micrometeorological towers, each site represents a small area with records available for only a limited period. As a result, GPP is commonly modeled over forested landscapes as a function of climatic and soil variables, often supplemented with satellite-derived estimates of the vegetation's light-absorbing properties. Since the late 1990s, a number of models have been developed to provide seasonal and annual estimates of GPP across much of the Earth. Each model, …

Graphical User Interfaces As Updatable Views, James Felger Terwilliger

Dissertations and Theses

In contrast to a traditional setting where users express queries against the database schema, we assert that the semantics of data can often be understood by viewing the data in the context of the user interface (UI) of the software tool used to enter the data. That is, we believe that users will understand the data in a database by seeing the labels, dropdown menus, tool tips, help text, control contents, and juxtaposition or arrangement of controls that are built in to the user interface. Our goal is to allow domain experts with little technical skill to understand and query …

Cycles In Metabolic Networks, Tim Nunamaker

Computer Science Honors Theses

Modeling sophisticated biological systems in a way that makes them more apprehensible, without losing comprehension or robustness, is challenging task. The flux balance analysis FBA) model describes metabolic networks of single-celled organisms with the goal of simulating their steady-state behavior. FBA simulations yield reliable and biologically relevant growth rate values, but do not simulate intra-cellular behavior well.

Solutions to the FBA model are often degenerate and non-unique. Ideally, the model should simulate metabolic activity in exactly one way under any given circumstances--the way the real organism's metabolism behaves. The ultimate goal of this project is to better understand the FBA …

An Analysis Of Document Retrieval And Clustering Using An Effective Semantic Distance Measure, Nathan Scott Davis

Theses and Dissertations

As large amounts of digital information become more and more accessible, the ability to effectively find relevant information is increasingly important. Search engines have historically performed well at finding relevant information by relying primarily on lexical and word based measures. Similarly, standard approaches to organizing and categorizing large amounts of textual information have previously relied on lexical and word based measures to perform grouping or classification tasks. Quite often, however, these processes take place without respect to semantics, or word meanings. This is perhaps due to the fact that the idea of meaningful similarity is naturally qualitative, and thus difficult …

Parameters Of Pseudorandom Quantum Circuits, Yaakov S. Weinstein, Winton G. Brown, Lorenza Viola

Dartmouth Scholarship

Pseudorandom circuits generate quantum states and unitary operators which are approximately distributed according to the unitarily invariant Haar measure. We explore how several design parameters affect the efficiency of pseudorandom circuits, with the goal of identifying relevant tradeoffs and optimizing convergence. The parameters we explore include the choice of single- and two-qubit gates, the topology of the underlying physical qubit architecture, the probabilistic application of two-qubit gates, as well as circuit size, initialization, and the effect of control constraints. Building on the equivalence between pseudorandom circuits and approximate t-designs, a Markov matrix approach is employed to analyze asymptotic convergence properties …

Measurement Of The Electron Charge Asymmetry In Pp → W + X → Eν + X Events At √S = 1.96 Tev, V. M. Abazov, Kenneth A. Bloom, Gregory Snow, D0 Collaboration

Kenneth Bloom Publications

We present a measurement of the electron charge asymmetry in pp → W + X → eν + X events at a center of mass energy of 1.96 TeV using 0.75 fb^-1 of data collected with the D0 detector at the Fermilab Tevatron Collider. The asymmetry is measured as a function of the electron transverse momentum and pseudorapidity in the interval (-3.2, 3.2) and is compared with expectations from next-to-leading order calculations in perturbative quantum chromodynamics. These measurements will allow more accurate determinations of the proton parton distribution functions.

Molecular Hydrogen Formation On Low Temperature Surfaces In Temperature Programmed Desorption Experiments, Gianfranco Vidali, Ling Li, J. Roser, E. Congiu

Physics - All Scholarship

The study of the formation of molecular hydrogen on low temperature surfaces is of interest both because it allows to explore elementary steps in the heterogeneous catalysis of a simple molecule and because of the applications in astrochemistry. Here we report results of experiments of molecular hydrogen formation on amorphous silicate surfaces using temperature-programmed desorption (TPD). In these experiments beams of H and D atoms are irradiated on the surface of an amorphous silicate sample. The desorption rate of HD molecules is monitored using a mass spectrometer during a subsequent TPD run. The results are analyzed using rate equations and …

Search For Gravitational-Wave Bursts From Soft Gamma Repeaters, B. Abbott, R. Abbott, R. Adhikari, P. Ajith, B. Allen, G. Allen, R. S. Amin, S. B. Anderson, W. G. Anderson, M. A. Arain, M. Araya, H. Armandula, P. Armor, Y. Aso, S. Aston, P. Aufmuth, C. Aulbert, S. Babak, S. Ballmer, H. Bantilan, B. C. Barish, C. Barker, D. Barker, B. Barr, P. Barriga, M. A. Barton, I. Bartos, M. Bastarrika, K. Bayer, J. Betzwieser, P. T. Beyersdorf, Tiffany Z. Summerscales

Faculty Publications

We present a LIGO search for short-duration gravitational waves (GWs) associated with soft gamma ray repeater (SGR) bursts. This is the first search sensitive to neutron star f modes, usually considered the most efficient GW emitting modes. We find no evidence of GWs associated with any SGR burst in a sample consisting of the 27 Dec. 2004 giant flare from SGR 1806-20 and 190 lesser events from SGR 1806-20 and SGR 1900+14. The unprecedented sensitivity of the detectors allows us to set the most stringent limits on transient GW amplitudes published to date. We find upper limit estimates on the …

Predicting Intra-Urban Variation In Air Pollution Concentrations With Complex Spatio-Temporal Interactions, Adam A. Szpiro, Paul D. Sampson, Lianne Sheppard, Thomas Lumley, Sara D. Adar, Joel Kaufman

UW Biostatistics Working Paper Series

We describe a methodology for assigning individual estimates of long-term average air pollution concentrations that accounts for a complex spatio-temporal correlation structure and can accommodate unbalanced observations. This methodology has been developed as part of the Multi-Ethnic Study of Atherosclerosis and Air Pollution (MESA Air), a prospective cohort study funded by the U.S. EPA to investigate the relationship between chronic exposure to air pollution and cardiovascular disease. Our hierarchical model decomposes the space-time field into a “mean” that includes dependence on covariates and spatially varying seasonal and long-term trends and a “residual” that accounts for spatially correlated deviations from the …

Nutrient Loading And Eutrophication In The Great Salt Lake, Wayne A. Wurtsbaugh

Watershed Sciences Faculty Publications

No abstract provided.

Parameter Estimation For The Beta Distribution, Claire Elayne Bangerter Owen

Theses and Dissertations

The beta distribution is useful in modeling continuous random variables that lie between 0 and 1, such as proportions and percentages. The beta distribution takes on many different shapes and may be described by two shape parameters, alpha and beta, that can be difficult to estimate. Maximum likelihood and method of moments estimation are possible, though method of moments is much more straightforward. We examine both of these methods here, and compare them to three more proposed methods of parameter estimation: 1) a method used in the Program Evaluation and Review Technique (PERT), 2) a modification of the two-sided power …

A See-Ability Metric To Improve Mini Unmanned Aerial Vehicle Operator Awareness Using Video Georegistered To Terrain Models, Cameron Howard Engh

Theses and Dissertations

Search and rescue operations conducted in wilderness environments can be greatly aided by the use of video filmed from mini-UAVs. While lightweight, inexpensive and easily transportable, these small aircraft suffer from wind buffeting and may produce video that is difficult to search. To aid in the video search process, we have created a system to project video frames into a 3D representation of the search region. This projection allows us to tie each frame of video to a real-world location, enabling a myriad of novel views, mosaics and metrics that can be used to guide the search including a new …

Temperature Dependence Of The Training Effect In Exchange Coupled Ferromagnetic Bilayers, Christian Binek, Srinivas Polisetty, Sarbeswar Sahoo

Christian Binek Publications

The temperature dependence of the training effect is studied in an exchange coupled thin-film bilayer composed of a hard ferromagnetic pinning (CoPtCrB) layer in proximity of a soft ferromagnetic pinned (CoCr) layer. Interlayer exchange shifts the hysteresis loops of the soft layer along the magnetic-field axis. This shift is quantified by the bias field in far reaching analogy to the exchange bias field of conventional antiferromagnetic/ferromagnetic heterostructures. A ferromagnetic domain state induced in the hard layer experiences aging very similar to the training behavior of the antiferromagnetic domain state in conventional exchange bias systems. Training originates from changes in the …

Benchmarking Corn Water Productivity In Nebraska Irrigated Cropping Systems, Kenneth Cassman

Nebraska Center for Energy Sciences Research: White Papers and Presentations

Improving corn water productivity is the key to meet the challenge of ever tightening water resources for irrigation and greater demands for food, feed and fuel. Corn grain yield per unit of water supply must therefore be increased dramatically in Nebraska and globally. In Nebraska, ≈80% of the irrigated land is for corn production. At present, there is a substantial exploitable gap between actual farm yields and attainable yields. This reflects, in part, inefficient use of water supply, and/or other non‐water related yield constraints. Boundary functions define the relationship of yield with water supply and are used to benchmark crop …

Improving The Efficiency Of Water And Energy Use In Nebraska’S Irrigation Soybean Production Systems, James Specht

Nebraska Center for Energy Sciences Research: White Papers and Presentations

The use of irrigation in Nebraska’s soybean production systems has steadily increased to the extent that irrigated soybean acreage in recent years has accounts for about 45% of State total soybean acreage. Technological advances in irrigation equipment can greatly improve on‐farm water application efficiencies (with respect to both energy and water). However, producer adoption of these advances is very slow because of the capital expenditures required for irrigation system upgrades. An alternative approach is greater producer adoption and use of irrigation water management strategies that ensure that water is scheduled and applied in a just‐in‐time fashion, which also optimizes water …

Energy Conservation Through Improved Irrigation Pumping Plant Performance, William Kranz

Nebraska Center for Energy Sciences Research: White Papers and Presentations

Nebraska has approximately 90,000 active irrigation wells that are powered by electric motors or gasoline, natural gas, propane or diesel fueled engines. Pumping plant performance data collected prior to 1990 indicated an average performance rating of 77 percent of the Nebraska Pumping Plant Performance Criteria (NPPPC). More recent tests confirm that pumping plant performance remains well below the Nebraska Criteria. Though significant improvement has been made in the brake horsepower output per unit of fuel for internal combustion engines, recent increases in fuel costs have more than doubled pumping costs during the past 3 years. Efficient irrigation pumping plants could …

Reversal In Declining Trend Of Adult Mortality In Many States Of India, 1970-2001: Is It Due To Aids?, Abhaya Indrayan, Ajay Kumar Bansal

COBRA Preprint Series

Objectives: To investigate the reversal in adult mortality trend from declining to rising in some segments of population in India, and to use an indirect demographic method to examine if this increase could be due to AIDS mortality. Also, to estimate the total excess deaths.

Design: Cross-sectional data on age-specific death rate in 5-year age-intervals from 25 to 44 years for the years 1970 to 1998 for rural/urban and male/female segments for each of 16 major states of India obtained from the government reports, and their projections till the year 2001.

Methods: In view of reversal of trend in some …

Quantum Nondemolition Measurement Of Discrete Fock States Of A Nanomechanical Resonator, E. Buks, E. Segev, S. Zaitsev, B. Abdo, M. P. Blencowe

Dartmouth Scholarship

We study theoretically a radio frequency superconducting interference device integrated with a nanomechanical resonator and an LC resonator. By applying adiabatic and rotating-wave approximations, we obtain an effective Hamiltonian that governs the dynamics of the mechanical and LC resonators. Nonlinear terms in this Hamiltonian can be exploited for performing a quantum nondemolition measurement of Fock states of the nanomechanical resonator. We address the feasibility of experimental implementation and show that the nonlinear coupling can be made sufficiently strong to allow the detection of discrete mechanical Fock states.

Computer-Aided Trauma Decision Making Using Machine Learning And Signal Processing, Soo-Yeon Ji

Theses and Dissertations

Over the last 20 years, much work has focused on computer-aided clinical decision support systems due to a rapid increase in the need for management and processing of medical knowledge. Among all fields of medicine, trauma care has the highest need for proper information management due to the high prevalence of complex, life-threatening injuries. In particular, hemorrhage, which is encountered in most traumatic injuries, is a dominant factor in determining survival in both civilian and military settings. This complication can be better managed using a more in-depth analysis of patient information. Trauma physicians must make precise and rapid decisions, while …

Pfisr Nightside Observations Of Naturally Enhanced Ion Acoustic Lines, And Their Relation To Boundary Auroral Features, R. G. Michell, K. A. Lynch, C. J. Heinselman, H. C. Stenbaek-Nielsen

Dartmouth Scholarship

We present results from a coordinated camera and radar study of the auroral ionosphere conducted during March of 2006 from Poker Flat, Alaska. The campaign was conducted to coincide with engineering tests of the first quarter installation of the Poker Flat Incoherent Scatter Radar (PFISR). On 31 March 2006, a moderately intense auroral arc, (~10 kR at 557.7 nm), was located in the local magnetic zenith at Poker Flat. During this event the radar observed 7 distinct periods of abnormally large backscattered power from the F-region. These were only observed in the field-aligned radar beam, and radar spectra from these …

Practical Strengthening Of Preconditions, Ashish Kundu, Patrick Eugster

Department of Computer Science Technical Reports

No abstract provided.

Global Existence Of Some Infinite Energy Solutions For A Perfect Incompressible Fluid, Ralph A. Saxton, Feride Tiğlay

Mathematics Faculty Publications

This paper provides results on local and global existence for a class of solutions to the Euler equations for an incompressible, inviscid fluid. By considering a class of solutions which exhibits a characteristic growth at infinity we obtain an initial value problem for a nonlocal equation. We establish local well-posedness in all dimensions and persistence in time of these solutions for three and higher dimensions. We also examine a weaker class of global solutions.

Phase Separation Induced Polar Electrooptical Effect In A Doped Nematic Liquid Crystal Cell, Ji-Hoon Lee, Daeseung Kang, Rolfe G. Petschek, Charles Rosenblatt

Faculty Scholarship

A cell prepared for vertical alignment was filled with a mixture of the liquid crystal octylcyano biphenyl, doped with a three-legged molecule, in the isotropic phase in the presence of an imposed temperature gradient perpendicular to the substrates. After cooling the cell through the nematic phase and restoring the temperature uniformity, an electrooptic response was observed on applying an electric field across the cell in one direction but not in the other. This unipolar effect was absent for cells prepared in the absence of a temperature gradient. The results are discussed in terms of phase separation and preferential adsorption of …

Alkoxyamine Polymers: Versatile Materials For Surface Ligation Applications, Lindsey Hines, Jessica Moore, David Dahl, Belinda Lady, Johnathan Brantley, Hasan Palandoken

Chemistry and Biochemistry

Immobilization of biomolecules (i.e., proteins, carbohydrates), on polymeric surfaces has been an area of intense research. The resultant bioconjugates often display increased stability, bioavailability and activity. Our research program seeks to explore the utility of the alkoxyamine (RONH2) functional group in new materials as versatile ligating sites for the immobilization of various compounds.

The ease with which alkoxyamines (RONH2) condense with aldehydes or ketones has prompted their widespread use in labelling liposome, bacterial and mammalian cell surfaces as well as chemoselectively ligating small molecule ‘recognition elements' onto polyfunctional substrates. These condensation reactions proceed in aqueous media to afford the robust …

Cariporide Prodrugs: Targeting Brain Cancer Cells Through Sodium-Proton Exchange Inhibition, Jacob Vervynckt, Johnathan Brantley, Jessica Moore, Mark Graves Ii, William Harley, Fredric A. Gorin, Hasan Palandoken

Chemistry and Biochemistry

More than 200,000 people in the United States are diagnosed with a primary or metastatic brain tumor annually. The life expectancy for these individuals is approximately 9-12 months from the time of diagnosis. This poor prognosis is due to the ineffectiveness of existing therapies (i.e., chemotherapy and radiotherapy) against brain cancer, where the primary problem is the inability to differentiate cancer cells from healthy brain cells.

Relative to healthy brain tissue, the heightened metabolism of cancer cells increases their reliance on the ion transport proteins NHE (sodium-proton exchanger) and NCX (sodium-calcium exchanger). Inhibition of these proteins disrupts the intricate pH …

Synthesis And First X-Ray Structures Of Cobalt(Ii) And Cobalt(Iii) Complexes Bearing 2,4-Dioxo-Alkanoic Acid Dialkylamide Ligands, Brian Pagenkopf, Jian Wang, Nicholas A. Morra, Hongda Zhao, Vincent Lynch, Robert Mcdonald, John F. Reichwein

Chemistry Publications

The aerobic oxidation of 5-hydroxy pentenes to trans-tetrahydrofurans (THFs), the Mukaiyama oxidation, has in recent years emerged as a powerful tool in synthetic chemistry. In this report we describe the first crystal structures of 2,4-dioxo-alkanoic acid dialkylamide complexes for both Co(II) and Co(III) salts. The Co(II) structures show an unprecedented arrangement of atoms, with a central Co(II)(H₂O)₆ flanked by two Co(II) atoms each coordinated with three anionic chelating ligands. The dimeric Co(III) structures show two anionic chelating ligands and bridging hydroxyl groups.

Relaxations In Ba2bisbo6 Double Complex Perovskite Ceramics, Manoel Carvalho Castro Jr., Carlos William De Araujo Paschoal, Frank C. Snyder, Michael W. Lufaso

Chemistry Faculty Research and Scholarship

The electric properties of the complex double perovskite Ba2BiSbO6 have been investigated using impedance spectroscopy in the frequency range from 1 Hz up to 1 MHz and in the temperature range from room temperature up to 560 K. There are two contributions to the electrical properties due to the grain and grain boundary. The oxygen vacancies play an important role in the conductivity and strongly increase the dielectric constant at high temperatures. The analysis of the frequency dependence of the conductivity clearly shows the structural phase transition of this compound near 515 K.

The Hybrid Game Architecture: Distributing Bandwidth For Mmogs While Maintaining Central Control, Jared L. Jardine

Theses and Dissertations

Current Massively Multi-player Online Games (MMOGs) have enormous server-side bandwidth requirements. The costs of providing this bandwidth is in turn passed on to the consumer in the form of high monthly subscription fees. Prior work has primarily focused on distributing this bandwidth using peer-to-peer architectures, but these architectures have difficulty preventing cheating, overwhelming low resource peers, and maintaining consistent game state. We have developed a hybrid game architecture that combines client-server and peer-to-peer technologies to prevent cheating, maintain centralized and consistent game state, significantly reduce central server bandwidth, and prevent lower capacity players from being overwhelmed. By dramatically reducing the …