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

Physical Sciences and Mathematics Commons™

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

2014

Discipline
Institution
Keyword
Publication
Publication Type
File Type

Articles 11491 - 11520 of 12299

Full-Text Articles in Physical Sciences and Mathematics

Qsar Study Of Chalcone Derivatives As Anti-Leishmania Agents, Maryam Iman, Asghar Davood, Nasim Banarouei Jan 2014

Qsar Study Of Chalcone Derivatives As Anti-Leishmania Agents, Maryam Iman, Asghar Davood, Nasim Banarouei

Turkish Journal of Chemistry

Quantitative structure activity relationship analyses were used to identify the ideal physicochemical characteristics of potential chalcone derivatives as anti-Leishmania agents. The HyperChem program was used to build chalcone structures and to perform conformational analyses through the semiempirical method followed by the PM3 force field. Dragon calculated a large number of molecular descriptors. Multilinear regression was used for quantitative structure activity relationship modeling. Based on our computational studies, 4 descriptors, SEigv, RDF125v, RDF055u, and O-058, can affect the activity of chalcone derivatives.

Go to article

Performance Degradation Of Li_Xfepo_4 (X = 0, 1) Induced By Postannealing, Xiaofei Sun, Youlong Xu, Xiaoyu Zheng, Xiangfei Meng, Rui Zhang Jan 2014

Performance Degradation Of Li_Xfepo_4 (X = 0, 1) Induced By Postannealing, Xiaofei Sun, Youlong Xu, Xiaoyu Zheng, Xiangfei Meng, Rui Zhang

Turkish Journal of Chemistry

Olivine LiFePO_4 has been studied for more than a decade as a promising cathode material for rechargeable lithium batteries. However, the low electric conductivity and tap density still hinder its large-scale commercialization. Micro-sized LiFePO_4 is prepared by an optimized hydrothermal method in this paper. The influence of postannealing on the physicochemical properties of LiFePO_4 and FePO_4 is investigated to understand the plausible mechanism for performance degradation. It is found that postannealing even chemical delithiation greatly affects the particle size, morphology, pore distribution, surface area, and probably the lattice strain of Li_xFePO_4 (x = 0, 1). Consequently, the electrochemical performances of …

Go to article

Novel Metal-Free And Metallophthalocyanines Containing Four 21-Membered Pentathiadiaza Macrocycles: Synthesis, Characterization, And Study Of Aggregation Properties, Hali̇l Zeki̇ Gök, Berna Farsak, Hülya Keleş, Mustafa Keleş Jan 2014

Novel Metal-Free And Metallophthalocyanines Containing Four 21-Membered Pentathiadiaza Macrocycles: Synthesis, Characterization, And Study Of Aggregation Properties, Hali̇l Zeki̇ Gök, Berna Farsak, Hülya Keleş, Mustafa Keleş

Turkish Journal of Chemistry

Metal-free phthalocyanine 3 and its metallophthalocyanine derivatives 4, 5, and 6 (M = Zn, Co, and Ni) substituted with four 21-membered pentathiadiaza macrocycles were synthesized and their structures identified by elemental analysis, IR, ^1H NMR, mass, and UV-Vis spectroscopy techniques. The aggregation properties of phthalocyanines 4, 5, and 6 were investigated in different solvents and at different concentrations of dimethylformamide.

Go to article

Synthesis And Characterization Of Novel 2-{[2-(Dimethylamino)Ethyl](Methyl)Amino} Ethoxy-Substituted Metallophthalocyanines, Hi̇lal Zengi̇n, Hacer Yasemi̇n Yeni̇lmez, Ayfer Kalkan Burat, Zehra Altuntaş Bayir Jan 2014

Synthesis And Characterization Of Novel 2-{[2-(Dimethylamino)Ethyl](Methyl)Amino} Ethoxy-Substituted Metallophthalocyanines, Hi̇lal Zengi̇n, Hacer Yasemi̇n Yeni̇lmez, Ayfer Kalkan Burat, Zehra Altuntaş Bayir

Turkish Journal of Chemistry

The synthesis of novel, symmetrical, tetrasubstituted metallophthalocyanines (cobalt, zinc, and copper) bearing four 2-{[2-(dimethylamino)ethyl](methyl)amino} ethoxy units was reported. The dinitrile derivative was converted into the water-soluble quaternized product by its reaction with methyl iodide. The quaternized zinc phthalocyanine was obtained from the reaction of the water-soluble dinitrile derivative with zinc acetate. The structures of the newly synthesized molecules were proposed according to elemental analysis, ^1H NMR, FT-IR, and UV-Vis spectral data.

Go to article

Synthesis And Spectral And Thermal Characterization Of New Metal-Free And Metallophthalocyanines: Investigation Of Their Photophysical, Photochemical, And Thin Film Properties, Eli̇f Çelenk Kaya, Mahmut Durmuş, Ekrem Yanmaz, Hali̇t Kanteki̇n Jan 2014

Synthesis And Spectral And Thermal Characterization Of New Metal-Free And Metallophthalocyanines: Investigation Of Their Photophysical, Photochemical, And Thin Film Properties, Eli̇f Çelenk Kaya, Mahmut Durmuş, Ekrem Yanmaz, Hali̇t Kanteki̇n

Turkish Journal of Chemistry

Novel tetrasubstituted metal-free (2), zinc (II) (3), cobalt (II) (4), and copper (II) (5) phthalocyanines bearing 2-phenylethanolate groups on the peripheral positions were synthesized by the cyclotetramerization reaction of the phthalonitrile derivative 1. The new compounds were characterized by a combination of IR, ^1H NMR, ^{13}C NMR, UV-Vis, elemental analysis, and MS spectra data. The thermal stabilities of the phthalocyanine compounds were determined by thermogravimetric analysis. For metal-free (2) and zinc (3) phthalocyanines, photochemical (photodegradation and singlet oxygen quantum yields) and photophysical (fluorescence quantum yields and fluorescence lifetimes) properties were analyzed in dimethylsulfoxide (DMSO). The cobalt (4) and copper (5) …

Go to article

Species Composition And Spatial Ecology Of Amazonian Understory Mixed-Species Flocks In A Fragmented Landscape, Karl Mokross Jan 2014

Species Composition And Spatial Ecology Of Amazonian Understory Mixed-Species Flocks In A Fragmented Landscape, Karl Mokross

LSU Doctoral Dissertations

With the ongoing advance of the agricultural frontier in the Amazon basin, it is inevitable that heterogeneous landscapes will play a key role in conservation. These landscapes are mostly composed of patchworks of small forest fragments, secondary forests and roads. Conservation, however must take species interactions into consideration as they play a pivotal part the maintenance of several biological processes in the tropics. One of the most conspicuous interspecific interactions are seen in mixed-species flocks of birds, which in the Amazon, represent one of the best organized systems of bird aggregations. In this research, I assess how flock spatial behavior …

Go to article

An Efficient Storage And Retrieval Mechanism For Large Unstructured Grids, Oyindamola Akande Jan 2014

An Efficient Storage And Retrieval Mechanism For Large Unstructured Grids, Oyindamola Akande

Electronic Theses and Dissertations

The size of spatial scientific datasets is steadily increasing due to improvements in instruments and availability of computational resources. Scientific datasets today are often far too large to fit into a single machine's memory or even a single disk. However, much of the research on efficient storage and access to spatial datasets has focused on large multidimensional arrays. In contrast, unstructured grids consisting of collections of implices (e.g. triangles or tetrahedra) present special challenges that have received less attention. Data values found at the vertices of the simplices may be dispersed throughout a datafile, producing especially poor disk locality. Partitioning …

Go to article

Emplacement Of Pleistocene Basalt Flows Near Mccoy, Colorado, Andrea Bowen Jan 2014

Emplacement Of Pleistocene Basalt Flows Near Mccoy, Colorado, Andrea Bowen

Electronic Theses and Dissertations

No abstract provided.

Go to article

Conical Representations For Direct Limits Of Riemannian Symmetric Spaces., Matthew Glenn Dawson Jan 2014

Conical Representations For Direct Limits Of Riemannian Symmetric Spaces., Matthew Glenn Dawson

LSU Doctoral Dissertations

We extend the definition of conical representations for Riemannian symmetric space to a certain class of infinite-dimensional Riemannian symmetric spaces. Using an infinite-dimensional version of Weyl's Unitary Trick, there is a correspondence between smooth representations of infinite-dimensional noncompact-type Riemannian symmetric spaces and smooth representations of infinite-dimensional compact-type symmetric spaces. We classify all smooth conical representations which are unitary on the compact-type side. Finally, a new class of non-smooth unitary conical representations appears on the compact-type side which has no analogue in the finite-dimensional case. We classify these representations and show how to decompose them into direct integrals of irreducible conical …

Go to article

Space-Efficient Data Structures For String Searching And Retrieval, Sharma Valliyil Thankachan Jan 2014

Space-Efficient Data Structures For String Searching And Retrieval, Sharma Valliyil Thankachan

LSU Doctoral Dissertations

Let D = {d_1, d_2, ...} be a collection of string documents of n characters in total, which are drawn from an alphabet set Sigma =[sigma] ={1,2,3,...sigma}. The top-k document retrieval problem is to maintain D as a data structure, such that when ever a query Q=(P, k) comes, we can report (the identifiers of) those k documents that are most relevant to the pattern P (of p characters). The relevance of a document d_r with respect to a pattern P is captured by score(P, d_r), which can be any function of the set of locations where P occurs in …

Go to article

Observations Of Terrestrial Gamma Flashes With Tetra And Lago, Rebecca Ringuette Jan 2014

Observations Of Terrestrial Gamma Flashes With Tetra And Lago, Rebecca Ringuette

LSU Doctoral Dissertations

Terrestrial Gamma ray Flashes (TGFs) -- very short, intense bursts of electrons, positrons, and energetic photons originating from terrestrial thunderstorms -- have been detected with satellite instruments. The TGF and Energetic Thunderstorm Rooftop Array (TETRA), an array of NaI(Tl) scintillators at Louisiana State University, has now been used to detect similar bursts of 50 keV to over 2 MeV gamma rays at ground level. After 3.3 years of observation, twenty-eight events with durations 0.02 - 4.2 msec have been detected associated with nearby lightning, three of them coincident events observed by detectors separated by ~1000 m. Nine of the events …

Go to article

Exponentially Convergent Generalized Finite Element Method For Multi-Scale Problems, Xu Huang Jan 2014

Exponentially Convergent Generalized Finite Element Method For Multi-Scale Problems, Xu Huang

LSU Doctoral Dissertations

The overall approach I take in the thesis falls into the category of multiscale finite element methods(MsFEM). I work to identify a new class of local approximation spaces with good approximation properties. This is carried out for the equilibrium problem of linear elasticity. The choice of local approximation spaces is motivated by the kolmogorov n-width. Part of my thesis work develops an estimate to show that it is possible to achieve a local approximation error of ô with respect to the energy norm using at most lnd+1 &frac1ô local basis functions. The global approximation error ôis controlled by the …

Go to article

Research Needs In The Colorado River Basin: A Summary Of Policy-Related Topics To Explore Further In Support Of Solution-Oriented Decision-Making, Colorado River Governance Initiative, University Of Colorado Boulder. Getches-Wilkinson Center For Natural Resources, Energy, And The Environment Western Water Policy Program Jan 2014

Research Needs In The Colorado River Basin: A Summary Of Policy-Related Topics To Explore Further In Support Of Solution-Oriented Decision-Making, Colorado River Governance Initiative, University Of Colorado Boulder. Getches-Wilkinson Center For Natural Resources, Energy, And The Environment Western Water Policy Program

Books, Reports, and Studies

14 p. ; 28 cm

Go to article

Substitution And Disorder Effects In Ternary Intermetallics, Larico Juan Treadwell Jan 2014

Substitution And Disorder Effects In Ternary Intermetallics, Larico Juan Treadwell

LSU Doctoral Dissertations

The focal point of this dissertation is the investigation of substitution and disorder effects in ternary intermetallics. The crystal growth, crystal structure, and physical properties are reported on single crystals of Ln6W4-xAl43-yTx+y (Ln = Gd, Yb; T= Mn, Fe), LnCr2FexAl20-x (Ln = Yb, Gd), Sm1.33Pd3Ga8, and CeCo2-xMxAl8 (M = Mn, Fe, Ni; 0 ≤ x < 1). The reported compounds were grown via the flux growth method with the strategic synthetic parameters described. Correlations between the structural and physical properties in relation to substitution and disorder of Ln6W4-xAl43-yTx+y (Ln = Gd, Yb; T= Mn, Fe), LnCr2FexAl20-x (Ln = Yb, Gd), Sm1.33Pd3Ga8, and CeCo2-xMxAl8 (M = Mn, Fe, Ni; 0 ≤ x < 1) are discussed. The synthesis and characterization of Mn- and Fe- substituted Ln6W4Al43 (Ln = Gd, Yb) are reported. The compounds adopt the Ho6Mo4Al43 structure type with lattice parameters of a ~ 11 Å and c ~ 17.8 Å with structural site preferences for Mn and Fe. The magnetization of Yb6W4Al43 is sensitive to Mn and Fe doping, which is evident by an increase in the field dependent magnetization. Gd6W4Al43, Gd6W4Al42.31(11)Mn0.69(11), and Gd6W4Al41.69(12)Fe1.30(12) order antiferromagnetically in the ab- and c-direction at 15, 14, and 13 K, respectively, with positive Weiss constants, suggesting the presence of ferromagnetic exchange interactions. Anisotropic magnetization data of Gd6W4Al43-yTy (T= Mn, Fe) analogs are discussed. Crystal growth, structure determination, and magnetic properties of LnCr2Al20-xFex (Ln = La, Gd, Yb) adopting the CeCr2Al20 structure type with space group Fd3¯ m, a ~ 14.5 Å, type are reported. Single crystal X-ray diffraction and Mössbauer spectroscopy are employed to fully characterize the crystal structure of LnCr2Al20-xFex (Ln = La, Gd, Yb). LnCr2Al20-xFex (Ln = La, Gd, Yb) are the first pseudo-ternaries adopting the CeCr2Al20 structure type with a transition metal occupying the main group site. The Yb analogues are Pauli paramagnets with the Yb ion adopting an electronic configuration close to Yb2+, while the Gd analogues show paramagnetic behavior with no magnetic order down to 3 K. The synthesis and characterization of Sm1.33Pd3Ga8 is reported. Sm1.33Pd3Ga8 adopts a disordered variant of the Er4Pt9Al24-structure type with lattice parameters of a = 4.353(5) and c = 38.98(4) Å and V = 639.70(12) Å3. The structure of Sm1.33Pd3Ga8 is composed of three distinct building blocks: Pd2Ga4, PdGa2, and Sm0.67Ga. The Sm0.67Ga slab does not magnetically order, which directly affect the structure. Sm1.33Pd3Ga8 is a temperature independent paramagnet. Field dependent magnetization of Sm1.33Pd3Ga8 displays anisotropic behavior. Single crystals of CeCo2-xMxAl8 (M = Mn, Fe, Ni; 0 ≤ x < 1) were grown and crystallize in the CaCo2Al8 structure type with space group Pbam. Single crystal X-ray diffraction data suggest that the Ce 4f-state is valence fluctuating as Fe concentration increases, whereas the Ni-doped analogues do not exhibit valence fluctuating. The results suggest that hole doping leads to an admixture of Ce3+/Ce4+.

Go to article

Design, Synthesis, And Exploration Of A Chimeric Antioxidant And New Crosslinkers For Molecular Imprinting, Danielle Songe Meador Jan 2014

Design, Synthesis, And Exploration Of A Chimeric Antioxidant And New Crosslinkers For Molecular Imprinting, Danielle Songe Meador

LSU Doctoral Dissertations

The improvement and utility of crosslinkers are important topics of molecular imprinting. Crosslinker significance is evident when molecularly imprinted polymer (MIP) composition related to performance as separation media is examined. Crosslinkers account for the bulk of MIP formulations made through traditional imprinting (80-90%) and is even greater when the One Monomer Molecularly Imprinted Polymer (OMNiMIP) approach is utilized (100%.) It is not surprising that alteration of the bulk component will result in different separation performances. Crosslinkers studied in this work were designed, synthesized, and evaluated toward improvement in OMNiMIP selectivity. In particular, functionality and number of polymerizable groups, addition of …

Go to article

Problem Solving Strategies And Metacognitive Skills For Gifted Students In Middle School, Lorena Aguelo Java Jan 2014

Problem Solving Strategies And Metacognitive Skills For Gifted Students In Middle School, Lorena Aguelo Java

LSU Master's Theses

This study is conducted to investigate if the designed four-step method strategy (GEAR strategy adapted from Polya, 1973) in solving math problems has improved students’ performance scores and enhanced the metacognitive skills of gifted students. The respondents of this study include middle school gifted students who took math eight course in the school year 2013-2014 at Westdale Middle School in East Baton Rouge Parish School System. There are four classes of math eight gifted students who participated in the study. The classes were chosen randomly for experimental and controlled group and were equalized on the basis of the pre-test results …

Go to article

Polymer Micro- And Nanofluidic Systems For In Vitro Diagnostics: Analyzing Single Cells And Molecules, Swathi Reddy Pullagurla Jan 2014

Polymer Micro- And Nanofluidic Systems For In Vitro Diagnostics: Analyzing Single Cells And Molecules, Swathi Reddy Pullagurla

LSU Doctoral Dissertations

Polymer micro- and nanofluidic systems, with their critical dimensions, offer a potential to outperform conventional analysis techniques and diagnostic methods by enhancing speed, accuracy, sensitivity and specificity. In this work, applications of microfluidics have been demonstrated to address the existing challenges in stroke diagnosis, by mRNA expression profiling from whole blood within <20 min. A brief overview of various biomarkers for stroke diagnosis is given in chapter 1 followed by design and testing of individual microfluidic modules (chapter 2 and 3) required for the development of POC diagnostic strategy for stroke. We have designed and evaluated the performance of polymer microfluidic devices for the isolation of leukocyte subsets, known for their differential gene expression in the event of stroke. Target cells (T-cells and neutrophils) were selected from with greater purities, from 50 µl whole human blood by using affinity based capture in COC devices within a 6.6 min processing time. In addition, we have also demonstrated the ability to isolate and purify total RNA by using UV activated polycarbonate solid phase extraction platform. Polymer-based nanofluidic devices were used to study the effects of surface charge on the electrodynamic transport dynamics of target molecules. In this work, we report the fabrication of mixed-scale micro- and nanofluidic networks in poly(methylmethacrylate), PMMA, using thermal nanoimprint lithography using a resin stamp and surface modification of polymer nanoslits and nanochannels for the assessment of the associated electrokinetic parameters – surface charge density, zeta potential and electroosmotic flow. This study provided information on possible routes that can be adopted to engineer proper wall chemistry of polymer nanochannels for the enhancement or reduction of solute/wall interactions in a variety of relevant single-molecule studies.

Go to article

Fabrication Of Yttrium Ferrite Nanoparticles By Solution Combustion Synthesis, A. A. Saukhimov, Mkhitar A. Hobosyan, Gamage C. Dannangoda, N. N. Zhumabekova, S. E. Kumekov Jan 2014

Fabrication Of Yttrium Ferrite Nanoparticles By Solution Combustion Synthesis, A. A. Saukhimov, Mkhitar A. Hobosyan, Gamage C. Dannangoda, N. N. Zhumabekova, S. E. Kumekov

Physics and Astronomy Faculty Publications and Presentations

The ternary oxide system Y-Fe-O presents fascinating magnetic properties that are sensitive to the crystalline size of particles. There is a major challenge to fabricate these materials in nano-crystalline forms due to particle conglomeration during nucleation and synthesis. In this paper we report the fabrication of nano sized crystalline yttrium ferrite by solution combustion synthesis (SCS) where yttrium and iron nitrates were used as metal precursors with glycine as a fuel. The magnetic properties of the product can be selectively controlled by adjusting the ratio of glycine to metal nitrates. Yttrium ferrite nano-powder was obtained by using three concentration of …

Go to article

Performance Improvement Of Distributed Computing Framework And Scientific Big Data Analysis, Praveenkumar Kondikoppa Jan 2014

Performance Improvement Of Distributed Computing Framework And Scientific Big Data Analysis, Praveenkumar Kondikoppa

LSU Doctoral Dissertations

Analysis of Big data to gain better insights has been the focus of researchers in the recent past. Traditional desktop computers or database management systems may not be suitable for efficient and timely analysis, due to the requirement of massive parallel processing. Distributed computing frameworks are being explored as a viable solution. For example, Google proposed MapReduce, which is becoming a de facto computing architecture for Big data solutions. However, scheduling in MapReduce is coarse grained and remains as a challenge for improvement. Related with MapReduce scheduler when configured over distributed clusters, we identify two issues: data locality disruption and …

Go to article

Search-Based Model-Driven Loop Optimizations For Tensor Contractions, Ajay Panyala Jan 2014

Search-Based Model-Driven Loop Optimizations For Tensor Contractions, Ajay Panyala

LSU Doctoral Dissertations

Complex tensor contraction expressions arise in accurate electronic structure models in quantum chemistry, such as the coupled cluster method. The Tensor Contraction Engine (TCE) is a high-level program synthesis system that facilitates the generation of high-performance parallel programs from tensor contraction equations. We are developing a new software infrastructure for the TCE that is designed to allow experimentation with optimization algorithms for modern computing platforms, including for heterogeneous architectures employing general-purpose graphics processing units (GPGPUs). In this dissertation, we present improvements and extensions to the loop fusion optimization algorithm, which can be used with cost models, e.g., for minimizing memory …

Go to article

Gumbos- And Ionic Liquid-Coated Quartz Crystal Microbalance Sensors For Detection And Molecular Weight Determination Of Organic Vapors, Bishnu Prasad Regmi Jan 2014

Gumbos- And Ionic Liquid-Coated Quartz Crystal Microbalance Sensors For Detection And Molecular Weight Determination Of Organic Vapors, Bishnu Prasad Regmi

LSU Doctoral Dissertations

There has been an ever-increasing demand for the development of high-performance sensing devices for detection and discrimination of volatile organic compounds (VOCs) present in different environments. Among a number of sensing devices currently available, sorption-based sensors are particularly attractive because they are simple and inexpensive, require low power, and are appropriate for fabrication of multisensor arrays. A sorption-based sensor is comprised of a chemically active coating immobilized on the surface of a physical transducer. The chemically active film interacts with analytes, and the transducer converts the binding event into an electrical signal. This dissertation is focused on a sorption-based sensor …

Go to article

The Synthesis Of A Bisbenzothiophene (Bbt) Based Organic Semiconductor With Increased Function And Increased Solubility, Mary England Jan 2014

The Synthesis Of A Bisbenzothiophene (Bbt) Based Organic Semiconductor With Increased Function And Increased Solubility, Mary England

Senior Honors Theses

Organic semiconductors are growing in applications for use in modern technology.1 The main interest in these molecules can be attributed to their low cost (compared to silicon) and their ability to be used on flexible substrates. There are four features that make a good organic semiconductor. First, the molecule should be conjugated, having alternating single and double bonds (lone electron pairs act similarly to double bonds). Secondly, the molecule should be planar, or flat, in shape. Thirdly, the molecule should have a narrow band gap to increase the overall conductivity. Lastly, the molecule should be soluble to ease application. …

Go to article

The 6th Mode Of Transportation, Robert O. Walton Jan 2014

The 6th Mode Of Transportation, Robert O. Walton

Publications

The five modes of freight transportation are normally characterized as motor carriers, railroads, airlines, water carriers, and pipelines. This paper will attempt to position the Internet as the sixth mode of transportation. This paper compares the strengths and weaknesses of the traditional five modes of transportation against the proposed 6th mode of the Internet. Without including the Internet as a mode of transportation, and tracking the economic value that it adds to the economy, the economic impact of the Internet as a mode is not considered. The recommendation of this study is that the Internet should be added to the …

Go to article

Educating The Next Generation Of Cyberforensic Professionals, Mark Pollitt, Philip Craiger Jan 2014

Educating The Next Generation Of Cyberforensic Professionals, Mark Pollitt, Philip Craiger

Publications

This paper provides a historical overview of the development of cyberforensics as a scientific discipline, along with a description of the current state of training, educational programs, certification and accreditation. The paper traces the origins of cyberforensics, the acceptance of cyberforensics as a forensic science and its recognition as a component of information security. It also discusses the development of professional certification and standardized bodies of knowledge that have had a substantial impact on the discipline. Finally, it discusses the accreditation of cyberforensic educational programs, its linkage with the bodies of knowledge and its effect on cyberforensic educational programs.

Go to article

Book Review: Robotic Exploration Of The Solar System: Pt. 4: The Modern Era, 2004-2013, T. D. Oswalt Jan 2014

Book Review: Robotic Exploration Of The Solar System: Pt. 4: The Modern Era, 2004-2013, T. D. Oswalt

Publications

This document is Dr. Oswalt’s review of Robotic Exploration of the Solar System : Pt. 4: the Modern Era, 2004-2013 by Paolo Ulivi with David Harland Springer, 2014 567p bibl index afp, 9781461448112 $44.99, 9781461448129 $29.99

Go to article

Book Review: The Observer's Guide To Planetary Motion: Explaining The Cycles Of The Night Sky, T. D. Oswalt Jan 2014

Book Review: The Observer's Guide To Planetary Motion: Explaining The Cycles Of The Night Sky, T. D. Oswalt

Publications

This document is Dr. Oswalt’s review of The Observer's Guide to Planetary Motion : Explaining the Cycles of the Night Sky by Dominic Ford. Springer, 2014 240p index afp, 9781493906284 $34.99.

Go to article

Standoff Methods For The Detection Of Threat Agents: A Review Of Several Promising Laser-Based Techniques, J. Bruce Johnson, Susan D. Allen, Jonathan Merten, Lewis Johnson, Daniel Pinkham, Scott W. Reeve Jan 2014

Standoff Methods For The Detection Of Threat Agents: A Review Of Several Promising Laser-Based Techniques, J. Bruce Johnson, Susan D. Allen, Jonathan Merten, Lewis Johnson, Daniel Pinkham, Scott W. Reeve

Publications

Detection of explosives, explosive precursors, or other threat agents presents a number of technological challenges for optical sensing methods. Certainly detecting trace levels of threat agents against a complex background is chief among these challenges; however, the related issues of multiple target distances (from standoff to proximity) and sampling time scales (from passive mines to rapid rate of march convoy protection) for different applications make it unlikely that a single technique will be ideal for all sensing situations. A number of methods for spanning the range of optical sensor technologies exist which, when integrated, could produce a fused sensor system …

Go to article

Differential Spectral Imaging Of The Cn Violet Band In Laser-Induced Plasmas On Tnt Simulant Molecules, J. Merten, M. Jones, S. Hoke, S. Allen Jan 2014

Differential Spectral Imaging Of The Cn Violet Band In Laser-Induced Plasmas On Tnt Simulant Molecules, J. Merten, M. Jones, S. Hoke, S. Allen

Publications

Dual channel emission imaging of m-nitrobenzoic acid and benzoic acid was performed in order to visualize the morphology of the CN violet band emission of a TNT analogue. The CN channel was corrected for continuum emission using a simultaneously imaged background channel. Simultaneous dual channel imaging alleviated problems with shot to shot variation in the plasma morphology due to the friable substrates and showed differences between plasmas formed on the two targets.

Go to article

Dispersive And Dissipative Errors In The Dpg Method With Scaled Norms For Helmholtz Equation, Jay Gopalakrishnan, Ignacio Muga, Nicole Olivares Jan 2014

Dispersive And Dissipative Errors In The Dpg Method With Scaled Norms For Helmholtz Equation, Jay Gopalakrishnan, Ignacio Muga, Nicole Olivares

Mathematics and Statistics Faculty Publications and Presentations

This paper studies the discontinuous Petrov--Galerkin (DPG) method, where the test space is normed by a modified graph norm. The modification scales one of the terms in the graph norm by an arbitrary positive scaling parameter. The main finding is that as the parameter approaches zero, better results are obtained, under some circumstances, when the method is applied to the Helmholtz equation. The main tool used is a dispersion analysis on the multiple interacting stencils that form the DPG method. The analysis shows that the discrete wavenumbers of the method are complex, explaining the numerically observed artificial dissipation in the …

Go to article

A Posteriori Estimates Using Auxiliary Subspace Techniques, Harri Hakula, Michael Neilan, Jeffrey S. Ovall Jan 2014

A Posteriori Estimates Using Auxiliary Subspace Techniques, Harri Hakula, Michael Neilan, Jeffrey S. Ovall

Mathematics and Statistics Faculty Publications and Presentations

A posteriori error estimators based on auxiliary subspace techniques for second order elliptic problems in Rd (d ≥ 2) are considered. In this approach, the solution of a global problem is utilized as the error estimator. As the continuity and coercivity of the problem trivially leads to an efficiency bound, the main focus of this paper is to derive an analogous effectivity bound and to determine the computational complexity of the auxiliary approximation problem. With a carefully chosen auxiliary subspace, we prove that the error is bounded above by the error estimate up to oscillation terms. In addition, we show …

Go to article

First Prev Next Last