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2003

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Articles 3841 - 3870 of 3876

Full-Text Articles in Physical Sciences and Mathematics

A Solvent-Free Oxidation Of Alcohols In An Organic Laboratory, John Esteb, Michael Schelle, Anne Wilson Dec 2002

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

John Esteb

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.

Note:Link is to the article in a subscription database available to users affiliated with Butler University. Appropriate login information will be required for …


Femtosecond Pulse Shaping Approaches To Multiphoton Imaging., W. Warren, W. Wagner, Peifang Tian, T. Ye Dec 2002

Femtosecond Pulse Shaping Approaches To Multiphoton Imaging., W. Warren, W. Wagner, Peifang Tian, T. Ye

Peifang Tian

No abstract provided.


Transport Coefficients Of Titanium-Doped Sb2te3 Crystals., P. Svanda, P. LošŤÁK, Č. Drašar, Jeffrey Dyck Dec 2002

Transport Coefficients Of Titanium-Doped Sb2te3 Crystals., P. Svanda, P. LošŤÁK, Č. Drašar, Jeffrey Dyck

Jeffrey Dyck

Titanium-doped single crystals (cTi = 0 to 2×1020 atoms cm-3) were prepared from the elements Sb, Ti, and Te of 5N purity by a modified Bridgman method. The obtained crystals were characterized by measurements of the temperature dependence of the electrical resistivity, Hall coefficient, Seebeck coefficient and thermal conductivity in the temperature range of 5-300 K. It was observed that with an increasing Ti content in the samples the electrical resistance, the Hall coefficient and the Seebeck coefficient increase. This means that the incorporation of Ti atoms into the Sb2Te3 crystal structure results in a decrease in the concentration of …


Thermodynamic Model For The Prediction Of Contact Angle Of Oil Droplets On Solid Surfaces In Sds Solutions, Samuel Morton, D. Keffer, R. Counce, D. Depaoli, M. Hu Dec 2002

Thermodynamic Model For The Prediction Of Contact Angle Of Oil Droplets On Solid Surfaces In Sds Solutions, Samuel Morton, D. Keffer, R. Counce, D. Depaoli, M. Hu

Samuel A Morton

No abstract provided.


Length-Preserving Transformations On Polygons, Brad Ballinger Dec 2002

Length-Preserving Transformations On Polygons, Brad Ballinger

Brad Ballinger

Given a polygon in the plane, we may sele t two of its verti es A and B as ut points, thereby splitting the polygon into two hains. We transform one of the hains by (1) re e ting it a ross ! AB or (2) rotating it 180 degrees about the midpoint of AB, and reassemble the two hains into a polygon. If A and B are hosen on a supporting line of the onvex hull of P , we all (1) a ip and (2) a ipturn. If A and B are instead hosen to have a ommon …


Neuroindices Of Cognitive Workload: Neuroimaging, Pupillometric, And Event-Related Potential Studies Of Brain Work, Marcel Adam Just, Patricia A. Carpenter, Akira Miyake Dec 2002

Neuroindices Of Cognitive Workload: Neuroimaging, Pupillometric, And Event-Related Potential Studies Of Brain Work, Marcel Adam Just, Patricia A. Carpenter, Akira Miyake

Marcel Adam Just

No abstract provided.


Scalability And Schedulability In Large, Coordinated, Distributed Robot Systems, John D. Sweeney, Huan Li, Roderic Grupen, Krithi Ramamritham Dec 2002

Scalability And Schedulability In Large, Coordinated, Distributed Robot Systems, John D. Sweeney, Huan Li, Roderic Grupen, Krithi Ramamritham

Roderic Grupen

Multiple, independent robot platforms promise significant advantage with respect to robustness and flexibility. However, coordination between otherwise independent robots requires the exchange of information; either implicitly (as in gestural communication), or explicitly (as in message passing in a communication network.) In either case, control processes resident on all coordinated peers must participate in the collective behavior. This paper evaluates the potential to scale such a coupled control framework to many participating individuals, where scalability is evaluated in terms of the schedulability of coupled distributed control processes. We examine how schedulability affects the scalability of a robot system, and discuss an …


Spectral Distribution Of Hermitian Toeplitz Matrices Formally Generated By Rational Functions, William F. Trench Dec 2002

Spectral Distribution Of Hermitian Toeplitz Matrices Formally Generated By Rational Functions, William F. Trench

William F. Trench

No abstract provided.


Ambiguity In The Brain: What Brain Imaging Reveals About The Processing Of Syntactically Ambiguous Sentences, Robert A. Mason, Marcel Adam Just, Timothy A. Keller, Patricia A. Carpenter Dec 2002

Ambiguity In The Brain: What Brain Imaging Reveals About The Processing Of Syntactically Ambiguous Sentences, Robert A. Mason, Marcel Adam Just, Timothy A. Keller, Patricia A. Carpenter

Marcel Adam Just

No abstract provided.


A Note On Asymptotic Zero Distribution Of Orthogonal Polynomials, William F. Trench Dec 2002

A Note On Asymptotic Zero Distribution Of Orthogonal Polynomials, William F. Trench

William F. Trench

No abstract provided.


A Family Of Isomorphic Fusion Algebras Of Twisted Quantum Doubles Of Finite Groups, Christopher Goff Dec 2002

A Family Of Isomorphic Fusion Algebras Of Twisted Quantum Doubles Of Finite Groups, Christopher Goff

Christopher Goff

Let D<sup>ω</sup>(G) be the twisted quantum double of a finite group, G, where ω∈Z<sup>3</sup>(G,C∗). For each n∈N, there exists an ω such that D(G) and D<sup>ω</sup>(E) have isomorphic fusion algebras, where G is an extraspecial 2-group with 2<sup>2n+1</sup> elements, and E is an elementary abelian group with |E|=|G|.


Server Selection Techniques For Distribution Information Retrieval, Yoshiya Kinuta, Brian Neil Levine, R. Manmatha Dec 2002

Server Selection Techniques For Distribution Information Retrieval, Yoshiya Kinuta, Brian Neil Levine, R. Manmatha

R. Manmatha

Server selection is typically defined as maximizing network performance under the assumption that each server holds an exact replica of all data. We propose and evaluate methods of server selection when servers are not exact replicas such that we maximize both network performance and information retrieval (IR) precision (i.e., the relevance of retrieved data). We show that naive composition of previously proposed techniques from networking and IR perform poorly. We propose improving the performance of current IR selection techniques by using language model/based selection to construct local replicas of databases that network selection predicts are likely to be poor network …


A Statistical Approach To Retrieving Historical Manuscript Images Without Recognition, Toni M. Rath, Victor Lavrenko, R. Manmatha Dec 2002

A Statistical Approach To Retrieving Historical Manuscript Images Without Recognition, Toni M. Rath, Victor Lavrenko, R. Manmatha

R. Manmatha

Handwritten historical document collections in libraries and other areas are often of interest to researchers, students or the general public. Convenient access to such corpora generally requires an index, which allows one to locate individual text units (pages, sentences, lines) that are relevant to a given query (usually provided as ASCII text). Several solutions are possible: manual annotation (very expensive), handwriting recognition (poor results) and word spotting - an image matching approach (computationally expensive).

In this work, we present a novel retrieval approach for historical document collections, which does not require recognition. We assume that word images can be described …


Unsupervised Color Constancy, Kinh Tieu, Erik G. Learned-Miller Dec 2002

Unsupervised Color Constancy, Kinh Tieu, Erik G. Learned-Miller

Erik G Learned-Miller

In [1] we introduced a linear statistical model of joint color changes in images due to variation in lighting and certain non-geometric camera parameters. We did this by measuring the mappings of colors in one image of a scene to colors in another image of the same scene under different lighting conditions. Here we increase the flexibility of this color flow model by allowing flow coefficients to vary according to a low order polynomial over the image. This allows us to better fit smoothly varying lighting conditions as well as curved surfaces without endowing our model with too much capacity. …


Absolute Equal Distribution Of The Spectra Of Hermitian Matrices, William F. Trench Dec 2002

Absolute Equal Distribution Of The Spectra Of Hermitian Matrices, William F. Trench

William F. Trench

No abstract provided.


Retrieving Historical Manuscripts Using Shape, Toni M. Rath, Victor Lavrenko, R. Manmatha Dec 2002

Retrieving Historical Manuscripts Using Shape, Toni M. Rath, Victor Lavrenko, R. Manmatha

R. Manmatha

Convenient access to handwritten historical document collections in libraries generally requires an index, which allows one to locate individual text units (pages, sentences, lines) that are relevant to a given query (usually provided as text). Currently, extensive manual labor is used to annotate and organize such collections, because handwriting recognition approaches provide only poor results on old documents.

In this work, we present a novel retrieval approach for historical document collections, which does not require recognition. We assume that word images can be described using a vocabulary of discretized word features. From a training set of labeled word images, we …


Indexing Of Handwritten Historical Documents - Recent Progress, R. Manmatha, Toni M. Rath Dec 2002

Indexing Of Handwritten Historical Documents - Recent Progress, R. Manmatha, Toni M. Rath

R. Manmatha

Indexing and searching collections of handwritten archival documents and manuscripts has always been a challenge because handwriting recognizers do not perform well on such noisy documents. Given a collection of documents written by a single author (or a few authors), one can apply a technique called word spotting. The approach is to cluster word images based on their visual appearance, after segmenting them from the documents. Annotation can then be performed for clusters rather than documents.

Given segmented pages, matching handwritten word images in historical documents is a great challenge due to the variations in handwriting and the noise in …


Absolute Equal Distribution Of Families Of Finite Sets, William F. Trench Dec 2002

Absolute Equal Distribution Of Families Of Finite Sets, William F. Trench

William F. Trench

No abstract provided.


Pursuing Sustainable Communities: Looking Back, Looking Forward, John C. Dernbach, Scott Bernstein Dec 2002

Pursuing Sustainable Communities: Looking Back, Looking Forward, John C. Dernbach, Scott Bernstein

John C. Dernbach

No abstract provided.


Brain Imaging Of Tongue-Twister Sentence Comprehension: Twisting The Tongue And The Brain, Timothy A. Keller, Patricia A. Carpenter, Marcel Adam Just Dec 2002

Brain Imaging Of Tongue-Twister Sentence Comprehension: Twisting The Tongue And The Brain, Timothy A. Keller, Patricia A. Carpenter, Marcel Adam Just

Marcel Adam Just

No abstract provided.


Novel Examples Of Achiral Bent-Core Azo Compounds Exhibiting B1 And Anticlinic-Antiferroelectric B2 Mesophases, Veena Prasad, Shin-Woong Kang, Satyendra Kumar Dec 2002

Novel Examples Of Achiral Bent-Core Azo Compounds Exhibiting B1 And Anticlinic-Antiferroelectric B2 Mesophases, Veena Prasad, Shin-Woong Kang, Satyendra Kumar

Satyendra Kumar

The first examples of achiral bent-core molecules consisting of an azo linkage and five aromatic rings exhibiting bent-core mesophases are reported. They exhibit B1 and B2 phases as identified by optical microscopy, differential scanning calorimetry, X-ray diffraction, and electro-optical techniques. The B2 phase of these materials is identified to be the anticlinic–antiferroelectric, SmCAPA phase. The mesophases of these compounds have relatively low transition temperatures and wide temperature ranges. The observation of bent-core phases in azo compounds assumes significance from the fact that the introduction of the –NN– linkage adds a new dimension, namely photochromism, to this field.


Bismuth Compounds In Organic Synthesis. Synthesis Of Resorcinarenes Using Bismuth Triflate, Ram S. Mohan, Katherine E. Peterson, Russell C. Smith Dec 2002

Bismuth Compounds In Organic Synthesis. Synthesis Of Resorcinarenes Using Bismuth Triflate, Ram S. Mohan, Katherine E. Peterson, Russell C. Smith

Ram S. Mohan

Bismuth triflate (5 mol%) smoothly catalyzes the condensation of aromatic and aliphatic aldehydes with resorcinol to give tetrameric cyclic products, resorcinarenes. With benzaldehyde, the product is obtained as a mixture of two diastereomers and the ratio of the diastereomers depends on reaction time. On the other hand, a single diastereomer is obtained with aliphatic aldehydes. The low toxicity and ease of handling of bismuth compounds coupled with fast reaction times make this method an attractive alternative to the existing methods for resorcinarene formation


Bismuth Compounds In Organic Synthesis. Deprotection Of Ketoximes Using Bismuth Bromide-Bismuth Triflate, Ram S. Mohan, Joshua N. Arnold, Patrick D. Hayes, Robert L. Kohaus Dec 2002

Bismuth Compounds In Organic Synthesis. Deprotection Of Ketoximes Using Bismuth Bromide-Bismuth Triflate, Ram S. Mohan, Joshua N. Arnold, Patrick D. Hayes, Robert L. Kohaus

Ram S. Mohan

Ketoximes undergo deprotection in CH3CN/acetone/H2O (3:6:1) in the presence of 20–40 mol% BiBr3/5 mol% Bi(OTf)3. Bismuth(III) salts are relatively non-toxic, insensitive to air and inexpensive. These features coupled with the use of a relatively non-toxic solvent system make this method an attractive alternative to existing routes for deprotection of ketoximes.


Open Problems From The Linz2000 Closing Session, Lawrence N. Stout Dec 2002

Open Problems From The Linz2000 Closing Session, Lawrence N. Stout

Lawrence N. Stout

No abstract provided.


Strukturationen Der Interaktivität, Rudolf Kaehr Dec 2002

Strukturationen Der Interaktivität, Rudolf Kaehr

Rudolf Kaehr

No abstract provided.


Long-Run Models Of Oil Stock Prices, Alessandro Lanza, Matteo Manera, Massimo Giovannini, Margherita Grasso Dec 2002

Long-Run Models Of Oil Stock Prices, Alessandro Lanza, Matteo Manera, Massimo Giovannini, Margherita Grasso

Matteo Manera

The identification of the forces that drive oil stock prices is extremely important given the size of the Oil&Gas industry and its links with the energy sector and the environment. In the next decade oil companies will have to deal with international policies to contrast climate change. This issue is likely to affect companies’ shareholder values. In this paper we focus on the long-run financial determinants of the stock prices of six major oil companies (Bp, Chevron-Texaco, Eni, Exxon-Mobil, Royal Dutch Shell, Total-Fina-Elf) using multivariate cointegration techniques and vector error correction models. Weekly oil stock prices are analyzed together with …


Achieving Sustainable Development: The Centrality And Multiple Facets Of Integrated Decisionmaking, John C. Dernbach Dec 2002

Achieving Sustainable Development: The Centrality And Multiple Facets Of Integrated Decisionmaking, John C. Dernbach

John C. Dernbach

No abstract provided.


Connection Between Adam-Gibbs Theory And Spatially Heterogeneous Dynamics, N. Giovambattista, S. V. Buldyrev, Francis W. Starr, H. E. Stanley Dec 2002

Connection Between Adam-Gibbs Theory And Spatially Heterogeneous Dynamics, N. Giovambattista, S. V. Buldyrev, Francis W. Starr, H. E. Stanley

Francis Starr

No abstract provided.


Linear Perturbations Of A Nonoscillatory Second Order Differential Equation Ii, William F. Trench Dec 2002

Linear Perturbations Of A Nonoscillatory Second Order Differential Equation Ii, William F. Trench

William F. Trench

No abstract provided.


Text Alignment With Handwritten Documents, E. Micah Kornfield, R. Manmatha, James Allan Dec 2002

Text Alignment With Handwritten Documents, E. Micah Kornfield, R. Manmatha, James Allan

R. Manmatha

Todays digital libraries increasingly include not only printed text but also scanned handwritten pages and other multimedia material. There are, however, few tools available for manipulating handwritten pages. Here, we propose an algorithm based on dynamic time warping (DTW) for a word by word alignment ofhandwritten documents with their (ASCII) transcripts. We see at least three uses for such alignment al gorithms. First, alignment algorithms allow us to produce displays (for example on the web) which allow a person to easily find their place in the manuscript when reading a transcript. Second, such alignment algorithms will allow us to produce …