Physical Sciences and Mathematics Commons^™

Heat Capacities Of Thiane Sulfones And Thiane Sulfoxide: Refining Of Cp Group Values For Organosulfur Compounds And Their Oxides, Marı́A Victoria Roux, Manuel Temprado, Pilar Jiménez, Ramón Guzmán-Mejı́A, Eusebio Juaristi, James S. Chickos

James Chickos

No abstract provided.

Semi-Analytical Stochastic Study Of Radionuclide Transport In The Saturated Zone Below Yucca Mountain, Xiaolong Hu, Craig Shirley, Jichun Wu, Hai Huang

Publications (YM)

The objective of this study is to predict radionuclide solute transport process in the saturated zone below the Yucca Mountain project area. Based on a stochastic perturbation approach, a numerical method of moments has been developed and used to predict the mean, variance and upper bound of the radionuclide mass flux through a control plane 5-km downstream of the footprint of the repository. This study enhances the analysis of the effect of medium’s heterogeneity on solute transport prediction, especially on prediction uncertainty.

The Mass Of Quasar Broad Emission Line Regions, J. A. Baldwin, Gary J. Ferland, K. T. Korista, F. Hamann, M. Dietrich

Physics and Astronomy Faculty Publications

We show that the mass of ionized gas in the broad-line regions (BLRs) of luminous quasars is at least several hundred M_☉, and probably of the order of 10³-10⁴ M_solar. BLR mass estimates in several existing textbooks suggest lower values but pertain to much less luminous Seyfert galaxies or include only a small fraction of the ionized/emitting volume of the BLR. The previous estimates also fail to include the large amounts of BLR gas that emit at low efficiency (in a given line) but that must be present based on reverberation and other …

E/B Decomposition Of Finite Pixelized Cmb Maps, Emory F. Bunn, Matias Zaldarriaga, Max Tegmark, Angelica De Oliveira-Costa

Physics Faculty Publications

Separation of the E and B components of a microwave background polarization map or a weak lensing map is an essential step in extracting science from it, but when the map covers only part of the sky and/or is pixelized, this decomposition cannot be done perfectly. We present a method for decomposing an arbitrary sky map into a sum of three orthogonal components that we term ‘‘pure E,’’ ‘‘pure B,’’ and ‘‘ambiguous.’’ The fluctuations in the pure E and B maps are due only to the E and B power spectra, respectively, whereas the source of those in …

Development Of Microsatellite Markers In Cannabis Sativa For Fingerprinting And Genetic Relatedness Analyses, Hussain J. Al-Ghanim

FIU Electronic Theses and Dissertations

Microsatellite markers were developed for Cannabis sativa L. (marijuana) to estimate the level of polymorphism, usefulness for DNA typing (genotype identification), and to measure the genetic relationships between the different plants. Twelve different oligonucleotide probes were used to screen an enriched microsatellite library of Cannabis sativa in which 49% of the clones contained microsatellite sequences. Characterization of microsatellite loci in Cannabis revealed that GA/CT was the most abundant class of isolated microsatellites representing 50% overall. Eleven polymorphic SSR markers were developed, derived from dinucleotide motifs and eight from trinucleotide motifs. A total of 52 alleles were detected averaging 4.7 alleles/locus. …

Study Of The Azimuthal Asymmetry Of Jets In Neutral Current Deep Inelastic Scattering At Hera, S. Chekanov, D. Krakauer, S. Magill, B. Musgrave, J. Repond, R. Yoshida, Margarita C. K. Mattingly, P. Antonioli, G. Bari, M. Basile, L. Bellagamba, D. Boscherini, A. Bruni, G. Bruni, G. Cara Romeo, L. Cifarelli, F. Cindolo, A. Contin, M. Corradi, S. De Pasquale, P. Giusti, G. Iacobucci, A. Margotti, R. Nania, F. Palmonari, A. Pesci, G. Sartorelli, A. Zichichi, G. Aghuzumtsyan, D. Bartsch, I. Brock

Faculty Publications

The azimuthal distribution of jets produced in the Breit frame in high-Q2 deep inelastic e+p scattering has been studied with the ZEUS detector at HERA using an integrated luminosity of 38.6 pb-1. The measured azimuthal distribution shows a structure that is well described by next-to-leading-order QCD predictions over the Q2 range considered, Q2 > 125 GeV2. © 2002 Elsevier Science B.V. All rights reserved.

Odd Perfect Numbers Have A Prime Factor Exceeding 10^7, Paul M. Jenkins

Faculty Publications

It is proved that every odd perfect number is divisible by a prime greater than 10^7.

Biodiversity And Ecosystem Informatics: Event And Process Tagging For Information Integration For The International Gulf Of Main Watershed, Mary-Kate Beard-Tisdale, Neal Pettigrew, Jeffrey Kahl, Malcolm L. Hunter Jr., Marilyn Lutz

University of Maine Office of Research Administration: Grant Reports

This incubation proposal addresses the issue of integrating large, diverse, and autonomous collections of scientific data within a complex institutional setting. The goal is to convert these autonomous collections into a shareable repository that supports synthesis of data through new metadata structures based on events and processes. The institutional setting is the data and data-gathering activities of over 80 agencies, NGOS, and academic and research institutions operating within the Gulf of Maine watershed. The metadata development will be coordinated by library and spatial information scientists working jointly with domain scientists. An essential task of this incubation effort will be the …

Electrical And Spectroscopic Studies Of The Effects Of Dc Electric Fields On Pre-Mixed Propane-Air Flames, S D. Marcum, G D. Gillen, B N. Ganguly

Physics

The effects of DC electric fields on temperature distributions within pre-mixed propane-air flames have been measured by the technique of thin filament pyrometry (TFP). We have focussed on the dramatic electric-field-induced modifications of the shape and size of the inner cone and the concomitant changes in the temperature profiles of fuel-rich mixtures with equivalence ratios of 1-1.35. Temperature profile measurements show large decreases in the reaction zone volume that is dependent upon the applied voltage polarity, indicating that electron impact excitation is not responsible for the observed effects. Additionally, the observed flame temperature profile modifications are not strongly dependent on …

Nonvolatile Memory Element Based On A Ferroelectric Polymer Langmuir-Blodgett Film, Timothy J. Reece, Stephen Ducharme, A.V. Sorokin, Matt Poulsen

Stephen Ducharme Publications

We report the operation of a potential nonvolatile bistable capacitor memory element consisting of a metal gate, a 170 nm thick ferroelectric Langmuir–Blodgett film of vinylidene fluoride (70%) with trifluoroethylene (30%) copolymer, and a 100 nm thick silicon-oxide insulating layer, all deposited on an n-type silicon semiconductor substrate. The device exhibited clear capacitance hysteresis as the gate voltage was cycled between ±25 V, with a capacitance dynamic range of 8:1 and threshold voltage shift of 2.8 V. The results are in good agreement with the model of Miller and McWhorter [J. Appl. Phys. 72, 5999 (1992)].

3d-Structural Homology Detection Via Unassigned Residual Dipolar Couplings, Christopher James Langmead, Bruce Randall Donald

Computer Science Technical Reports

Recognition of a protein's fold provides valuable information about its function. While many sequence-based homology prediction methods exist, an important challenge remains: two highly dissimilar sequences can have similar folds --- how can we detect this rapidly, in the context of structural genomics? High-throughput NMR experiments, coupled with novel algorithms for data analysis, can address this challenge. We report an automated procedure for detecting 3D-structural homologies from sparse, unassigned protein NMR data. Our method identifies the 3D-structural models in a protein structural database whose geometries best fit the unassigned experimental NMR data. It does not use sequence information and is …

Enthalpies Of Vaporization Of Organic And Organometallic Compounds, 1880-2002, James S. Chickos, William E. Acree

James Chickos

No abstract provided.

Liquid Chromatography–Mass Spectrometry Method For The Analysis Of The Anti-Cancer Agent Capecitabine And Its Nucleoside Metabolites In Human Plasma, Yan Xu, Jean L. Grem

Chemistry Faculty Publications

A reversed-phase high-performance liquid chromatography method with electrospray ionization and mass spectral detection is described for the determination of capecitabine, 5′-deoxy-5-fluorocytidine and 5′-deoxy-5-fluorouridine in human plasma with 5-chloro-2′-deoxyuridine as the internal standard. An on-line sample clean-up procedure allows dilution of the plasma sample with the initial mobile phase. The linear dynamic range is 0.0500–10.0 μg/ml for capecitabine, and 0.0500–25.0 μg/ml for the metabolites, 5′-deoxy-5-fluorocytidine and 5′-deoxy-5-fluorouridine, respectively. This method has been used to analyze plasma samples from patients receiving capecitabine in combination with oxaliplatin.

Two-Point Boundary Value Problems For Higher-Order Linear Differential Equations With Strong Singularities, Ravi P. Agarwal, Ivan T. Kiguradze

Mathematics and System Engineering Faculty Publications

For strongly singular higher-order linear differential equations together with two-point conjugate and right-focal boundary conditions, we provide easily verifiable best possible conditions which guarantee the existence of a unique solution. Copyright © 2006 Hindawi Publishing Corporation. All rights reserved.

Sediment Detachment By Rain Power, Emmanuel Gabet, Thomas Dunne

Faculty Publications

In interrill areas, overland flow is often incapable of detaching soil particles so detachment is primarily by raindrop impact. We derive a mathematical expression, rain power (R, W m−2), relating the energy expenditure of raindrops impacting a soil surface to the rate of detachment of soil particles. Rain power incorporates rainfall, hillslope, and vegetation characteristics and is modulated by flow depths. Rainfall simulation experiments on natural hillslopes were performed to measure detachment rates and across-slope flow depth distributions in surface runoff. Our results indicate that flow depths follow a Poisson distribution, and this observation is used to develop a dimensionless …

Southeastern U.S. Vegetation Response To Enso Events (1989–1999), Albert J. Peters, Lei Ji, Elizabeth A. Walter-Shea

Center for Advanced Land Management Information Technologies: Publications

El Niño/Southern Oscillation (ENSO) is considered one of the most powerful forces driving anomalous global weather patterns. Large-scale seasonal precipitation and temperature changes influenced by ENSO have been examined in many areas of the world. The southeastern United States is one of the regions affected by ENSO events. In this study, remote sensing detection of vegetation response to ENSO phases is demonstrated with one-kilometer biweekly Normalized Difference Vegetation Index (NDVI) data (1989–1999) derived from the Advanced Very High Resolution Radiometer (AVHRR). The impacts of three ENSO phases, cold, warm and neutral, on vegetation were analyzed with a focus on two …

General Guidelines For The Establishment & Evaluation Of Invasive Species Early Detection & Rapid Response Systems

National Invasive Species Council

Preventing the introduction of invasive species is the first line of defense against invasions. However, even the best prevention efforts will not stop all invasive species introductions. Early detection and rapid response (ED&RR) efforts increase the likelihood that invasions will be addressed successfully while populations are still localized and population levels are not beyond that which can be contained and eradicated. Once populations are widely established, all that might be possible is the partial mitigation of negative impacts. In addition, the costs associated with ED&RR efforts are typically far less than those of long-term invasive species management programs.

The charge …

2003 Gloucester Point Station Tide Prediction Calendars, Virginia Institute Of Marine Science, David A. Evans

Miscellaneous

These calendars are produced monthly using David Evans' Tidecal.

The Anorexigenic Fatty Acid Synthase Inhibitor, C75, Is A Nonspecific Neuronal Activator, Kanji A. Takahashi, James L. Smart, Hongyan Liu, Roger D. Cone

Faculty Publications - Department of Biological & Molecular Science

C75, a recently derived compound that potently suppresses feeding and induces weight loss, has been proposed to act mainly by inhibiting fatty acid synthase (FAS) in central neurons that control feeding. For example, normal, fasting- associated, hypothalamic increases in neuropeptide Y (NPY)/Agouti-related protein (AGRP) expression and decreases in proopiomelanocortin (POMC)/cocaine and amphetamine regulated transcript (CART) expression were reported to be blocked by C75. Using loose-patch extracellular recording in acute slices, we tested the effect of C75 on anorexigenic POMC neurons and orexigenic NPY neurons of the hypothalamic arcuate nucleus, which were identified by promoter-driven GFP expression, as well as on …

Virtual Assembly With Biologically Inspired Intelligence, Xiaobu Yuan, Simon X. Yang

Computer Science Publications

This paper investigates the introduction of biologically inspired intelligence into virtual assembly. It develops a approach to assist product engineers making assembly-related manufacturing decisions without actually realizing the physical products. This approach extracts the knowledge of mechanical assembly by allowing human operators to perform assembly operations directly in the virtual environment. The incorporation of a biologically inspired neural network into an interactive assembly planner further leads to the improvement of flexible product manufacturing, i.e., automatically producing alternative assembly sequences with robot-level instructions for evaluation and optimization. Complexity analysis and simulation study demonstrate the effectiveness and efficiency of this approach.

Goal-Converging Behavior Networks And Self-Solving Planning Domains, Bernhard Nebel, Yuliya Lierler

Computer Science Faculty Proceedings & Presentations

Agents operating in the real world have to deal with a constantly changing and only partially predictable environment and are nevertheless expected to choose reasonable actions quickly. One way to address this problem is to use behavior networks as proposed by Maes, which support real-time decision making. Robotic soccer appears to be one domain where behavior networks have been proven to be particularly successful. In this paper, we analyze the reason for the success by identifying conditions that make behavior networks goal converging, i.e., allow them to reach the goals regardless of which particular action selection scheme is used. In …

A Limited-Global Fault Information Model For Fault Tolerant Routing In Dual-Cube, Zhen Jiang, Jie Wu

Computer Science Faculty Publications

No abstract provided.

Low-Mobility Solar Cells: A Device Physics Primer With Application To Amorphous Silicon, Eric A. Schiff

Physics - All Scholarship

The properties of pin solar cells based on photogeneration of charge carriers into lowmobility materials were calculated for two models. Ideal p- and n-type electrode layers were assumed in both cases. The first, elementary case involves only band mobilities and direct electron–hole recombination. An analytical approximation indicates that the power in thick cells rises as the 1 4 power of the lower band mobility, which reflects the buildup of space-charge under illumination. The approximation agrees well with computer simulation. The second model includes exponential bandtail trapping, which is commonly invoked to account for very low hole drift mobilities in amorphous …

Bandtail Limits To Solar Conversion Efficiencies In Amorphous Silicon Solar Cells, Kai Zhu, Weining Wang, Eric A. Schiff, Jianjun Liang, S. Guha

Physics - All Scholarship

We describe a model for a-Si:H based pin solar cells derived primarily from valence bandtail properties. We show how hole drift-mobility measurements and measurements of the temperature-dependence of the open-circuit voltage VOC can be used to estimate the parameters, and we present VOC(T) measurements. We compared the power density under solar illumination calculated with this model with published results for as-deposited a-Si:H solar cells. The agreement is within 4% for a range of thicknesses, suggesting that the power from as-deposited cells is close to the bandtail limit.

Hole Drift-Mobility Measurements In Contemporary Amorphous Silicon, S. Dinca, Eric A. Schiff, V. Vlahos, C. R. Wronski, Q. Yuan

Physics - All Scholarship

We present hole drift-mobility measurements on hydrogenated amorphous silicon from several laboratories. These temperature-dependent measurements show significant variations of the hole mobility for the differing samples. Under standard conditions (displacement/field ratio of 2×10-9 cm2/V), hole mobilities reach values as large as 0.01 cm2/Vs at room-temperature; these values are improved about tenfold over drift-mobilities of materials made a decade or so ago. The improvement is due partly to narrowing of the exponential bandtail of the valence band, but there is presently little other insight into how deposition procedures affect the hole drift-mobility.

Amorphous Silicon Based Solar Cells, Xunming Deng, Eric A. Schiff

Physics - All Scholarship

Crystalline semiconductors are very well known, including silicon (the basis of the integrated circuits used in modern electronics), Ge (the material of the first transistor), GaAs and the other III-V compounds (the basis for many light emitters), and CdS (often used as a light sensor). In crystals, the atoms are arranged in near-perfect, regular arrays or lattices. Of course, the lattice must be consistent with the underlying chemical bonding properties of the atoms. For example, a silicon atom forms four covalent bonds to neighboring atoms arranged symmetrically about it. This “tetrahedral” configuration is perfectly maintained in the “diamond” lattice of …

A Solvent-Free Oxidation Of Alcohols In An Organic Laboratory, John J. Esteb, Michael W. Schelle, Anne N. Wilson

Scholarship and Professional Work - LAS

An oxidation experiment for a first-year organic chemistry class is presented. This oxidation utilizes a solid mixture of CuSO4•5H2O and KMnO4 prepared by mortar and pestle. The oxidations take place under solvent-free conditions and near quantitative yields are obtained for the reactions. Thin-layer chromatography is used to monitor the progress of the reaction. This experiment provides for the simple oxidation of a secondary alcohol to a ketone using a relatively nontoxic oxidizing agent under solvent-free conditions.

Ferroelectric-Field-Induced Tuning Of Magnetism In The Colossal Magnetoresistive Oxide La1Àxsrxmno3, X. Hong, A. Posadas, A. Lin, C. H. Ahn

Xia Hong Publications

A ferroelectric field effect approach is presented for modulating magnetism in the colossal magnetoresistive oxide La_1-xSr_xMnO₃ (LSMO). The ferromagnetic Curie temperature of ultrathin LSMO films was shifted by 35 K reversibly using the polarization field of the ferroelectric oxide Pb(Zr_xTi_1-x)O₃ in a field effect structure. This shift was also observed in magnetoresistance measurements, with the maximum magnetoresistance ratio at 6 T increasing from 64% to 77%. This model system approach does not introduce substitutional disorder or structural distortion, demonstrating that regulating the carrier concentration alone changes the magnetic phase transition …

Selectivities Of Potassium-Calcium And Potassium-Lead Exchange In Two Tropical Soils, Chip Appel, Lena Q. Ma, R. Dean Rhue, William Reve

Earth and Soil Sciences

Measurement of cation selectivity in soils provides important information about the affinity and binding strength of a particular cation on soil surfaces. Gaines-Thomas (K_GT) selectivity coefficients were determined for a variety of K/Ca and K/Pb ratios on an Oxisol and Ultisol soil from Puerto Rico. The calculated K_GT values indicated a preference for K⁺ over Ca²⁺ or Pb²⁺. The selectivity for Pb²⁺ was significantly greater than that for Ca²⁺ due to Pb²⁺'s larger hydrated charge density relative to that of Ca²⁺. The patterns of selectivity were independent …

The Derangement Problem Relative To The Mahonian Process, Jessica Delfert, Hillary Einziger, Don Rawlings

Mathematics

We survey n! plus q-derangement problems. Solutions to four Mahonian statistics arising in connection with cycle placement rules are presented. A few conjectures are also made.