Open Access. Powered by Scholars. Published by Universities.®

Physical Sciences and Mathematics Commons™

Open Access. Powered by Scholars. Published by Universities.®

2010

Discipline
Institution
Keyword
Publication
Publication Type
File Type

Articles 2491 - 2520 of 8620

Full-Text Articles in Physical Sciences and Mathematics

Unh Eelgrass (Zostera Marina) Monitoring Program For 2010-2014: Quality Assurance Project Plan, Frederick T. Short, Phil Trowbridge Jul 2010

Unh Eelgrass (Zostera Marina) Monitoring Program For 2010-2014: Quality Assurance Project Plan, Frederick T. Short, Phil Trowbridge

PREP Reports & Publications

Eelgrass (Zostera marina) is essential to estuarine ecology because it filters nutrients and suspended particles from water, stabilizes sediments, provides food for wintering waterfowl, and provides habitat for juvenile fish and shellfish, as well as being the basis of an important estuarine food web. Healthy eelgrass both depends on and contributes to good water quality. The UNH Seagrass Ecology Lab, has mapped the distribution of eelgrass every year from 1986 through 2009 in the Great Bay. The entire Great Bay Estuary (Great Bay, Little Bay, tidal tributaries, Piscataqua River, Little Harbor, and Portsmouth Harbor) was mapped by these researchers in …

Go to article

A Toolkit For The Construction And Understanding Of 3-Manifolds, Lee R. Lambert Jul 2010

A Toolkit For The Construction And Understanding Of 3-Manifolds, Lee R. Lambert

Theses and Dissertations

Since our world is experienced locally in three-dimensional space, students of mathematics struggle to visualize and understand objects which do not fit into three-dimensional space. 3-manifolds are locally three-dimensional, but do not fit into 3-dimensional space and can be very complicated. Twist and bitwist are simple constructions that provide an easy path to both creating and understanding closed, orientable 3-manifolds. By starting with simple face pairings on a 3-ball, a myriad of 3-manifolds can be easily constructed. In fact, all closed, connected, orientable 3-manifolds can be developed in this manner. We call this work a tool kit to emphasize the …

Go to article

Prediction And Study Of Binary Alloys Using First-Principles Methods, Richard Hansen Taylor Ii Jul 2010

Prediction And Study Of Binary Alloys Using First-Principles Methods, Richard Hansen Taylor Ii

Theses and Dissertations

The utility of first-principles methods in the study and prediction of binary alloys is showcased by three detailed studies. In particular, the T = 0K cluster expansion methodology in conjunction with finite temperature statistical modeling by a Monte Carlo method is used to study two systems of practical interest, Mg-Li (magnesium-lithium) and Rh-W (rhodium-tungsten). Also, an empirically-informed, high-throughput approach to crystal structure prediction is shown by a study of the Pt$_8$Ti (the Pietrokowsky phase) phase and a broad and detailed analysis of binary Mg-X phases in 39 systems (X=Ag, Al, Au, Ca, Cd, Cu, Fe, Ga, Ge, Hf, Hg, In, …

Go to article

Do Scientists Agree About Climate Change? Public Perceptions From A New Hampshire Survey, Lawrence C. Hamilton Jul 2010

Do Scientists Agree About Climate Change? Public Perceptions From A New Hampshire Survey, Lawrence C. Hamilton

Carsey School of Public Policy

This report, a collaboration of the Carsey Institute, the UNH Survey Center, and the UNH Office of Sustainability, is the first of a new initiative that will track public perceptions about climate change as they change over time. Questions related to climate change were asked as part of New Hampshire's Granite State Poll, which surveyed 512 New Hampshire residents in April 2010.

Go to article

Finding Similarity Relations In Presence Of Taxonomic Relations In Ontology Learning Systems, A. R. Vazifedoost, Farhad Oroumchian, M. Rahgozar Jul 2010

Finding Similarity Relations In Presence Of Taxonomic Relations In Ontology Learning Systems, A. R. Vazifedoost, Farhad Oroumchian, M. Rahgozar

Farhad Oroumchian

Ontology learning tries to find ontological relations, by an automatic process. Similarity relationships are one of non-taxonomic relations which may be included in ontology. Our idea is that in presence of taxonomic relations we are able to extract more useful non-taxonomic similarity relations. In this paper we investigate the specifications of an implemented system for extracting these relations by means of new context extraction method which uses taxonomic relations.

Go to article

Persian Email Classification Based On Rocchio And K-Nearest Neighbor Approach, H. Bashiri, Farhad Oroumchian, A. Moeini Jul 2010

Persian Email Classification Based On Rocchio And K-Nearest Neighbor Approach, H. Bashiri, Farhad Oroumchian, A. Moeini

Farhad Oroumchian

These days, electronic mail (email) has become an essential form of communication in all aspects of ever day life. The main reason for this popularity among other things like the speed of delivery and the low cost is the convenience of managing and handling emails. However this convenience is diminishing by the growth and availability of the emails. Managing emails is becoming more difficult every day. Not only SPAM (unsolicited emails) is flooding our mailboxes but locating important and vital information among the huge number of emails that are finding their ways into our mailboxes has turned into a laborious …

Go to article

Talif Investigation And Modelling Of The Absolute N(4s) Density In A N2-Ch4 Late Afterglow, C.D. Pintassilgo, Et. Es-Sebbar, Y. Benilan, M-C. Gazeau, A. Jolly Jul 2010

Talif Investigation And Modelling Of The Absolute N(4s) Density In A N2-Ch4 Late Afterglow, C.D. Pintassilgo, Et. Es-Sebbar, Y. Benilan, M-C. Gazeau, A. Jolly

Dr. Et-touhami Es-sebbar

The purpose of the present work is the experimental and numerical study of the absolute ground-state nitrogen atoms density N(4S) in the late afterglow of a pure N2 flowing microwave discharge in which different amounts of CH4 have been injected at 25 cm downstream from the nitrogen discharge. The absolute N(4S) concentrations have been measured using Two-photon Absorption Laser-Induced Fluorescence (TALIF), while a detailed kinetic model has been developed to simulate both the discharge and the post-discharge regions. Theoretical predictions are then compared to experimental measurements.

Go to article

Investigating Impact Of Quorum Construction On Data Processing In Mobile Ad Hoc Networks, Takahiro Hara, Sanjay K. Madria, Shojiro Nishio Jul 2010

Investigating Impact Of Quorum Construction On Data Processing In Mobile Ad Hoc Networks, Takahiro Hara, Sanjay K. Madria, Shojiro Nishio

Computer Science Faculty Research & Creative Works

In a mobile ad hoc network (MANET), since mobility of mobile hosts causes frequent network partitioning, consistency management of data operations on replicas becomes a crucial issue. in our previous work, we have defined several consistency levels for MANET applications and designed protocols to achieve these consistency levels. These protocols are mainly based on a dynamic quorum system to cope with network partitioning and node and network failures. in this paper, we further investigate the impact of quorum construction on the system performance through simulation studies. Specifically, we change the number of mobile hosts that replicate data items, and which …

Go to article

Core-Shell Nanoparticles: Synthesis, Design, And Characterization, Kyler Carroll Jul 2010

Core-Shell Nanoparticles: Synthesis, Design, And Characterization, Kyler Carroll

Theses and Dissertations

The design of core/shell nanoparticles is of great interest for a wide range of applications. The primary focus of this dissertation is on the design and optimization of two synthetic routes. The first one is an aqueous reduction method using sodium borohydride and sodium citrate. This method was extended to design two types of core/shell nanoparticles, both of which have many applications in bio-sensing, magnetic resonance imaging, and magnetically guided SERS for the identification of environmental threats. The first, Fe/Ag core/shell nanoparticles were designed using a novel one-pot method by varying the AgNO3 addition time in the system. For …

Go to article

The Nature Of The O-2/O-5 Cooperative Effect And Its Role In Chemical Glycosylation, Laurel Kathryn Mydock Jul 2010

The Nature Of The O-2/O-5 Cooperative Effect And Its Role In Chemical Glycosylation, Laurel Kathryn Mydock

Dissertations

Since carbohydrates were first discovered, understanding the structure, reactivity, and function of these bioorganic compounds has remained of great priority. However, as the appreciation for the biological roles of carbohydrates intensifies, a growing demand for efficient and scalable methods towards the synthesis of these challenging molecules has become even more imperative. While modern synthetic techniques have allowed us to readily achieve most glycosidic linkages, it is the inability to effectively predict and control the stereoselectivity of the glycosylation reaction that has remained the synthetic hurdle. Herein, much effort has been placed in the investigation of “mixed-patterned” glycosyl donors as they …

Go to article

Deep-Sea Fishes Of The Mid-Atlantic Ridge: Results Of The 2009 Henry Bigelow Expedition, Tracey Sutton, April B. Cook, John K. Galbraith, M. Vecchione Jul 2010

Deep-Sea Fishes Of The Mid-Atlantic Ridge: Results Of The 2009 Henry Bigelow Expedition, Tracey Sutton, April B. Cook, John K. Galbraith, M. Vecchione

Marine & Environmental Sciences Faculty Proceedings, Presentations, Speeches, Lectures

As part of an ongoing study of the northern Mid-Atlantic Ridge biodiversity and ecology (CoML field project MAR-ECO), a detailed survey of the pelagic and demersal fishes in the region of the Charlie-Gibbs Fracture Zone (~ 600 n.m. south of Greenland) was conducted. A total of 17181 pelagic fishes (92 spp., 35 families) were sampled from 0-3000+ m, with the Myctophidae the most species-rich. The bristlemouth Cyclothone microdon was by far the dominant species in numbers (82% of total), while the sawtooth eel Serrivomer beani dominated biomass (27%). A total of 441 deep-demersal fishes (28 spp., 13 families) were sampled …

Go to article

A Mass-Loss Rate Determination For Zeta Puppis From The Quantitative Analysis Of X-Ray Emission-Line Profiles, David H. Cohen, M. A. Leutenegger, Emma Edwina Wollman , '09, J. Zsargó, D. J. Hillier, R. H.D. Townsend, S. P. Owocki Jul 2010

A Mass-Loss Rate Determination For Zeta Puppis From The Quantitative Analysis Of X-Ray Emission-Line Profiles, David H. Cohen, M. A. Leutenegger, Emma Edwina Wollman , '09, J. Zsargó, D. J. Hillier, R. H.D. Townsend, S. P. Owocki

Physics & Astronomy Faculty Works

We fit every emission line in the high-resolution Chandra grating spectrum of. Pup with an empirical line profile model that accounts for the effects of Doppler broadening and attenuation by the bulk wind. For each of 16 lines or line complexes that can be reliably measured, we determine a best-fitting fiducial optical depth, tau(*) equivalent to kappa(M) over dot/4 pi R(*)upsilon(infinity), and place confidence limits on this parameter. These 16 lines include seven that have not previously been reported on in the literature. The extended wavelength range of these lines allows us to infer, for the first time, a clear …

Go to article

Stable Isotope Analysis Of The Sandbar Shark, Carcharinus Plumbeus: A Minimally Invasive Method For Comparison Of Diet And Trophic Relationships Between Genders, Locations, And Age Classes, David Shiffman, Gorka Sancho, Bryan Frazier, John Kucklick, Dan Abel, Tracey Sutton, Kristene T. Parsons Jul 2010

Stable Isotope Analysis Of The Sandbar Shark, Carcharinus Plumbeus: A Minimally Invasive Method For Comparison Of Diet And Trophic Relationships Between Genders, Locations, And Age Classes, David Shiffman, Gorka Sancho, Bryan Frazier, John Kucklick, Dan Abel, Tracey Sutton, Kristene T. Parsons

Marine & Environmental Sciences Faculty Proceedings, Presentations, Speeches, Lectures

The 2006 National Marine Fisheries Service SEDAR for large coastal sharks recommended the gathering of additional diet and trophic relationship data for the sandbar shark, Carcharinus plumbeus. No diet studies of any kind have been performed on South Carolina subpopulations of C. plumbeus, and stable isotope analysis has never been performed on this species. Muscle samples were taken from C. plumbeus caught by the South Carolina Department of Natural Resources and the Virginia Institute of Marine Science shark surveys. The analysis of δ13C and δ 15N from this muscle tissue is ongoing and will be compared with prey …

Go to article

Distribution And Trophic Ecology Of Bathylagus Euryops (Teleostei: Microstomatidae) Along The Northern Mid-Atlantic Ridge, Christopher J. Sweetman, Tracey Sutton Jul 2010

Distribution And Trophic Ecology Of Bathylagus Euryops (Teleostei: Microstomatidae) Along The Northern Mid-Atlantic Ridge, Christopher J. Sweetman, Tracey Sutton

Marine & Environmental Sciences Faculty Proceedings, Presentations, Speeches, Lectures

The assemblage structure and ecology of meso- and bathypelagic fishes are poorly known in general, particularly over mid-ocean ridges. In June 2004, the month-long MAR-ECO (Census of Marine Life) research expedition aboard the R/V G.O. Sars sampled the deep-pelagic fauna over the northern Mid-Atlantic Ridge with the objective of quantitatively assessing the nekton associated with the ridge from Iceland to the Azores. A total of 115 discrete-depth trawl samples were taken from the surface to depths of 3000+ meters using two different double-warp midwater trawls, one of commercial fishing size (a large ‘Akra' trawl) and one of oceanographic research size …

Go to article

Quiescent Superhumps Detected In The Dwarf Nova V344 Lyrae By Kepler, Martin D. Still, Steve B. Howell, Matt A. Wood, John K. Cannizzo, Alan P. Smale Jul 2010

Quiescent Superhumps Detected In The Dwarf Nova V344 Lyrae By Kepler, Martin D. Still, Steve B. Howell, Matt A. Wood, John K. Cannizzo, Alan P. Smale

Aerospace, Physics, and Space Science Faculty Publications

The timing capabilities and sensitivity of Kepler, NASA's observatory to find Earth-sized planets within the habitable zone of stars, are well matched to the timescales and amplitudes of accretion disk variability in cataclysmic variables. This instrumental combination provides an unprecedented opportunity to test and refine stellar accretion paradigms with high-precision, uniform data, and containing none of the diurnal or season gaps that limit ground-based observations. We present a 3 month, 1 minute cadence Kepler light curve of V344 Lyr, a faint, little-studied dwarf nova within the Kepler field. The light curve samples V344 Lyr during five full normal outbursts and …

Go to article

Vanishing Of Ext And Tor Over Complete Intersections, Olgur Celikbas Jul 2010

Vanishing Of Ext And Tor Over Complete Intersections, Olgur Celikbas

Department of Mathematics: Dissertations, Theses, and Student Research

Let (R,m) be a local complete intersection, that is, a local ring whose m-adic completion is the quotient of a complete regular local ring by a regular sequence. Let M and N be finitely generated R-modules. This dissertation concerns the vanishing of Tor(M, N) and Ext(M, N). In this context, M satisfies Serre's condition (S_{n}) if and only if M is an nth syzygy. The complexity of M is the least nonnegative integer r such that the nth Betti number of M is bounded by a polynomial of degree r-1 for all sufficiently large n. We use this notion of …

Go to article

Shark Assemblage Structure In The Chesapeake Bight, Kristene T. Parsons, Tracey Sutton, John A. Musick Jul 2010

Shark Assemblage Structure In The Chesapeake Bight, Kristene T. Parsons, Tracey Sutton, John A. Musick

Marine & Environmental Sciences Faculty Proceedings, Presentations, Speeches, Lectures

The role and importance of the Chesapeake Bight region as essential fish habitat for several species of sharks is well represented in primary literature and US fisheries management plans. Diverse assemblages of shark taxa utilize the Chesapeake Bay and adjacent coasts at various stages throughout their lives. As top predators in most of the environments where they occur, sharks are key to maintaining healthy, diverse ecosystems. The estuarine waters of the Chesapeake Bay are exposed to extreme ranges in temperature and salinity, and consequently the environmental suitability of the Bay is spatially and temporally restricted to select taxa. By identifying …

Go to article

Heart And Skeletal Muscle Inflammation Of Farmed Salmon Is Associated With Infection With A Novel Reovirus, Torstein Tengs Jul 2010

Heart And Skeletal Muscle Inflammation Of Farmed Salmon Is Associated With Infection With A Novel Reovirus, Torstein Tengs

Dr. Torstein Tengs

Atlantic salmon (Salmo salar L.) mariculture has been associated with epidemics of infectious diseases that threaten not only local production, but also wild fish coming into close proximity to marine pens and fish escaping from them. Heart and skeletal muscle inflammation (HSMI) is a frequently fatal disease of farmed Atlantic salmon. First recognized in one farm in Norway in 1999, HSMI was subsequently implicated in outbreaks in other farms in Norway and the United Kingdom. Although pathology and disease transmission studies indicated an infectious basis, efforts to identify an agent were unsuccessful. Here we provide evidence that HSMI is associated …

Go to article

The Role Of Rater Motivation In Personnel Selection Validation Studies, Dan Ispas Jul 2010

The Role Of Rater Motivation In Personnel Selection Validation Studies, Dan Ispas

USF Tampa Graduate Theses and Dissertations

Personnel selection validation studies are routinely conducted in contemporary organizations for selecting and placing employees. Although numerous studies have been conducted with the goal of identifying new predictors, less research was focused on the criterion side. In the current paper, across three studies and five samples, I examined the role played by rater motivation in validation studies. I proposed that rater motivation would impact criterion-related validity of various predictors, the reliability, and the variance of performance ratings. In Study 1, these hypotheses were tested in two samples with varied operationalizations of predictors and of rater motivation. In Study 2, I …

Go to article

Synthesis Of Glycolipids And Evaluation Of Their Nkt Cell Stimulatory Properties, Yang Liu Jul 2010

Synthesis Of Glycolipids And Evaluation Of Their Nkt Cell Stimulatory Properties, Yang Liu

Theses and Dissertations

Natural killer T (NKT) cells are a subset of T cells that modify a variety of immune responses. NKT cells recognize glycolipid antigen presented by a molecule called CD1d, a nonclassical antigen-presenting molecule. The best known subset of CD1d-dependent NKT cells expresses an invariant T cell receptor Vα (TCR-α) chain. These are referred to as type I or invariant NKT (iNKT) cells. When stimulated by a glycolipid, NKT cells rapidly release large amounts of cytokines. Cytokines released by NKT cells can induce either Th1 or Th2 responses. Th1 cytokines are effective in regulating bacterial, parasitic, and viral infections. But Th1 …

Go to article

Real-Space Approach To Time Dependent Current Density Functional Theory, Daniel S. Jensen Jul 2010

Real-Space Approach To Time Dependent Current Density Functional Theory, Daniel S. Jensen

Theses and Dissertations

A real-space time-domain calculation of the frequency-dependent dielectric constant of nonmetallic crystals is outlined and the integrals required for this calculation are computed. The outline is based on time dependent current density functional theory and is partially implemented in the ab initio density functional theory FIREBALL program. The addition of a vector potential to the Hamiltonian of the system is discussed as well as the need to include the current density in addition to the particle density. The derivation of gradient integrals within a localized atomic-like orbital basis is presented for use in constructing the current density. Due to the …

Go to article

A Hybrid Radial Basis Function-Pseudospectral Method For Thermal Convection In A 3-D Spherical Shell, Grady Wright, Natasha Flyer, David A. Yuen Jul 2010

A Hybrid Radial Basis Function-Pseudospectral Method For Thermal Convection In A 3-D Spherical Shell, Grady Wright, Natasha Flyer, David A. Yuen

Mathematics Faculty Publications and Presentations

A novel hybrid spectral method that combines radial basis function (RBF) and Chebyshev pseudospectral methods in a “2 + 1” approach is presented for numerically simulating thermal convection in a 3‐D spherical shell. This is the first study to apply RBFs to a full 3‐D physical model in spherical geometry. In addition to being spectrally accurate, RBFs are not defined in terms of any surface‐based coordinate system such as spherical coordinates. As a result, when used in the lateral directions, as in this study, they completely circumvent the pole issue with the further advantage that nodes can be “scattered” over …

Go to article

Physical And Chemical Properties Of Ice In A Main Valley Glacier And A Tributary Glacier, Gornergletscher, Canton Valais, Switzerland, Annika M. Quick Jul 2010

Physical And Chemical Properties Of Ice In A Main Valley Glacier And A Tributary Glacier, Gornergletscher, Canton Valais, Switzerland, Annika M. Quick

Theses and Dissertations

Glacier models often fail to incorporate the geometry and/or physical properties of tributaries included in complex glaciers. Tributary glaciers have different source areas and flow conditions than the adjacent main valley glacier. Ice cores (~3m depth) and surface samples (<0.5m depth) were collected from Grenzgletscher (main valley glacier) and Zwillingsgletscher (tributary glacier) in the Gornergletscher system of the Swiss Alps. Stable water isotopes indicate seasonal variation, showing 1-2 annual layers. The mean d18O for Grenzgletscher is ~4.8‰ lower than for Zwillingsgletscher. This difference may be accounted for in part by elevation differences between the accumulation areas (~1.1‰ δ18O), increased avalanching in Grenzgletscher (~1.8 ‰ δ18O), and by varying climatic conditions at the time of precipitation (~0.9-1.4‰ variation in δ18O). Using a kinematic ice flow model, core ages were estimated using effective annual layer thickness (based on seasonal variations), annual accumulation rate and ice thickness. The Grenzgletscher core is ~4 years older than the Zwillingsgletscher core. Based on ages and flow distances, the tributary has a lower flow velocity (63-87 m/yr) compared to Grenzgletscher (61-134 m/yr). To understand thermal properties of the tributary, a 775 m GPR survey (200 MHz) was conducted along a flow line of Zwillingsgletscher. Topographic waves (ogives) observed on the surface are mimicked by the onset of reflectivity 10-20 m below the surface. Reflective regions are interpreted as warmer ice at the pressure melting point, overlain by colder ice. This thermal structure is likely related to acceleration through an ice fall. Since most tributary glaciers include ice falls, thermal properties of tributary glaciers may be different from those of the main valley glacier. The properties and geometry of tributary glaciers are significantly different from main valley glaciers and should therefore be incorporated into glacier models in the future.

Go to article

A Location-Aware Framework For Intelligent Real-Time Mobile Applications, Sean J. Barbeau, Rafael A. Perez, Miguel A. Labrador, Alfredo J. Perez, Nevine Labib Georggi, Philip L. Winters Jul 2010

A Location-Aware Framework For Intelligent Real-Time Mobile Applications, Sean J. Barbeau, Rafael A. Perez, Miguel A. Labrador, Alfredo J. Perez, Nevine Labib Georggi, Philip L. Winters

Computer Science Faculty Publications

The Location-Aware Information Systems Client (LAISYC) supports intelligent, real-time, mobile applications for GPS-enabled mobile phones by dynamically adjusting platform parameters for application performance while conserving device resources such as battery life.

Go to article

A Probabilistic Morphological Analyzer For Syriac, Peter J. Mcclanahan Jul 2010

A Probabilistic Morphological Analyzer For Syriac, Peter J. Mcclanahan

Theses and Dissertations

We show that a carefully crafted probabilistic morphological analyzer significantly outperforms a reasonable, naive baseline for Syriac. Syriac is an under-resourced Semitic language for which there are no available language tools such as morphological analyzers. Such tools are widely used to contribute to the process of annotating morphologically complex languages. We introduce and connect novel data-driven models for segmentation, dictionary linkage, and morphological tagging in a joint pipeline to create a probabilistic morphological analyzer requiring only labeled data. We explore the performance of this model with varying amounts of training data and find that with about 34,500 tokens, it can …

Go to article

Conformational Dynamics Associated With Calcium Binding To Calcium Transducers, Gangadhar Dhulipala Jul 2010

Conformational Dynamics Associated With Calcium Binding To Calcium Transducers, Gangadhar Dhulipala

FIU Electronic Theses and Dissertations

The Ca2+ association to calcium binding proteins (CaBPs) represents an essential step in Ca2+ signal transduction. This study presents a characterization of Ca interactions with two CaBPs, calmodulin and DREAM, using time-resolved photothermal and fluorescence techniques. Calcium binding to the calmodulin C-terminal domain is associated with a volume change of 40 mL mol-1and an enthalpy change of 35 ± 16 kcal mol-1. These parameters are consistent with the Ca2+ triggered exposure of hydrophobic patches on the calmodulin surface. Also, the rate limiting step for Ca2+ binding to calmodulin is the closed-to-open transition …

Go to article

Improving Thermoelectric Properties Of Chemically Synthesized Bi2te3-Based Nanocrystals By Annealing, Yixin Zhao, Jeffrey Dyck, Brett Hernandez, Clemens Burda Jul 2010

Improving Thermoelectric Properties Of Chemically Synthesized Bi2te3-Based Nanocrystals By Annealing, Yixin Zhao, Jeffrey Dyck, Brett Hernandez, Clemens Burda

Jeffrey Dyck

The power factors of chemically synthesized Bi2Te3 and Bi0.5Sb1.5Te3 nanocrystals (NCs) were improved up to 2.4 and 7.8 μW cm−1 K−2, respectively, which are significantly higher than previously reported values for chemically synthesized Bi2Te3 NCs and even comparable to the recently reported highest power factor of 5 μW cm−1 K−2 for Bi2Te3 NCs consolidated by spark plasma sintering. This improvement was achieved by annealing the NCs under argon protection, and the crystal structures and morphologies of these annealed NCs were characterized via XRD, SEM, and TEM measurements. The temperature-dependent thermoelectric properties of these modified NCs were explored on cold-pressed pellets …

Go to article

Palladium(Ii)-Catalyzed Dicarboxymethylation Of Chiral Allylic Alcohols: Chirality Transfer Affording Optically Active Diesters Containing Three Contiguous Chiral Centers, Othman Hamed, Patrick M. Henry, Daniel P. Becker Jul 2010

Palladium(Ii)-Catalyzed Dicarboxymethylation Of Chiral Allylic Alcohols: Chirality Transfer Affording Optically Active Diesters Containing Three Contiguous Chiral Centers, Othman Hamed, Patrick M. Henry, Daniel P. Becker

Chemistry: Faculty Publications and Other Works

This manuscript describes the extension of Stille’s palladium-catalyzed olefin dicarbonylation reaction to chiral allylic alcohols with chirality transfer to afford the corresponding chiral alcohol functionalized with bis-carbomethoxy esters, containing three contiguous chiral centers, in good to excellent diastereoselectivities (78–98%).

Go to article

Combined Experimental And Theoretical Studies On Methane Photolysis At 121.6 Nm And 248 Nm- Implications On A Program Of Laboratory Simulations Of Titan’S Atmosphere, C. Romanzin, E. Arzoumanian, Et. Es-Sebbar, A. Jolly, S. Perrier, M.-C. Gazeau, Y. Bénilan Jul 2010

Combined Experimental And Theoretical Studies On Methane Photolysis At 121.6 Nm And 248 Nm- Implications On A Program Of Laboratory Simulations Of Titan’S Atmosphere, C. Romanzin, E. Arzoumanian, Et. Es-Sebbar, A. Jolly, S. Perrier, M.-C. Gazeau, Y. Bénilan

Dr. Et-touhami Es-sebbar

Methane is, together with N2, the main precursor of Titan’s atmospheric chemistry. In our laboratory, we are currently developing a program of laboratory simulations of Titan’s atmosphere, where methane is intended to be dissociated by multiphotonic photolysis at 248 nm. A preliminary study has shown that multiphotonic absorption of methane at 248 nm is efficient and leads to the production of hydrocarbons such as C2H2 (Romanzin et al., 2008). Yet, at this wavelength, little is known about the branching ratios of the hydrocarbon radicals (CH3, CH2 and CH) and their following photochemistry. This paper thus aims at investigating methane photochemistry …

Go to article

Comprehensive Peroxidase-Based Hematologic Profiling For The Prediction Of 1-Year Myocardial Infarction And Death, Marie Luise Brennan, Anupama Reddy, W.H. Wilson Tang, Yuping Wu, Danielle M. Brennan, Amy Hsu, Shirley A. Mann, Peter L. Hammer, Stanley L. Hazen Jul 2010

Comprehensive Peroxidase-Based Hematologic Profiling For The Prediction Of 1-Year Myocardial Infarction And Death, Marie Luise Brennan, Anupama Reddy, W.H. Wilson Tang, Yuping Wu, Danielle M. Brennan, Amy Hsu, Shirley A. Mann, Peter L. Hammer, Stanley L. Hazen

Mathematics and Statistics Faculty Publications

Background— Recognition of biological patterns holds promise for improved identification of patients at risk for myocardial infarction (MI) and death. We hypothesized that identifying high- and low-risk patterns from a broad spectrum of hematologic phenotypic data related to leukocyte peroxidase-, erythrocyte- and platelet-related parameters may better predict future cardiovascular risk in stable cardiac patients than traditional risk factors alone. Methods and Results— Stable patients (n=7369) undergoing elective cardiac evaluation at a tertiary care center were enrolled. A model (PEROX) that predicts incident 1-year death and MI was derived from standard clinical data combined with information captured by a high-throughput peroxidase-based …

Go to article

First Prev Next Last