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2010

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Articles 5431 - 5460 of 8625

Full-Text Articles in Physical Sciences and Mathematics

I-Kinetic And Mechanistic Investigations Of Amino Acid Substrates Reactivities With Ferryl Species, Ahmed Ibrahim Youssef Abouelatta Jan 2010

I-Kinetic And Mechanistic Investigations Of Amino Acid Substrates Reactivities With Ferryl Species, Ahmed Ibrahim Youssef Abouelatta

Wayne State University Dissertations

ABSTRACT

I-KINETIC AND MECHANISTIC INVESTIGATIONS OF AMINO ACID SUBSTRATES REACTIVITIES WITH FERRYL SPECIES

II-SYNTHESIS AND CHARACTERIZATION OF DERIVATIVES OF THE BN-TPEN LIGAND AND THEIR METAL COMPLEXES

by

AHMED IBRAHIM YOUSSEF ABOUELATTA

MAY 2011

Advisor: Dr. Jeremy Jacob Kodanko

Major: Chemistry (Organic)

Degree: Doctor of philosophy

The reactivity of tryptophan, methionine, aspartic acid, glutamic acid, histidine and hydrochloride salt of lysine amino acid substrates with the N4Py ferryl species was studied by UV-vis spectroscopy and product characterization. Based on kinetic isotope effect studies and product analysis, an ET-PT mechanism was proposed for the reaction of tryptophan substrate with N4Py ferryl and …


Measuring The Nanomechanics Of Nanoconfined Water Layers, Shah Haidar Khan Jan 2010

Measuring The Nanomechanics Of Nanoconfined Water Layers, Shah Haidar Khan

Wayne State University Dissertations

Nanoconfined water has been the subject of special interest due to its applications in various fields such as biology, geology, medicine, and engineering tribology. While there is a general agreement on the layering of water molecules along atomically smooth surfaces, the behavior and properties of nanoconfined water is still poorly understood. A significant controversy exists whether there is a phase transformation imposed by confinement. We have measured the stiffness and damping coefficient of nanoconfined water using a small amplitude (0.5-1 Å) atomic force microscope. The results were analyzed with the help of two viscoelastic models, the Kelvin model and the …


Electro-Optic And Magneto-Dielectric Properties Of Multifunctional Nitride And Oxide Materials, Ambesh Dixit Jan 2010

Electro-Optic And Magneto-Dielectric Properties Of Multifunctional Nitride And Oxide Materials, Ambesh Dixit

Wayne State University Dissertations

ABSTRACT

Materials that simultaneously exhibit different physical properties provide a rich area of research leading to the development of new devices. For example, materials having a strong coupling between charge and spin degrees of freedom are essential to realizing a new class of devices referred to generally as spintronics. However, these multifunctional systems pose new scientific challenges in understanding the origin and mechanisms for cross-control of different functionalities. The core of this Ph.D. dissertation deals with multifunctional nitride and oxide compound semiconductors as well as multiferroic magnetic oxide systems by investigating structural, optical, electrical, magnetic, magnetodielectric and magnetoelectric properties.

Thin …


The Synthesis, Structure, And Properties Of Group 2 Poly(Pyrazolyl)Borates And Their Use For The Atomic Layer Deposition Of Group 2 Borates, Mark J. Saly Jan 2010

The Synthesis, Structure, And Properties Of Group 2 Poly(Pyrazolyl)Borates And Their Use For The Atomic Layer Deposition Of Group 2 Borates, Mark J. Saly

Wayne State University Dissertations

A series of heavy alkaline earth complexes containing TpR2-based ligands has been synthesized, structurally characterized, and their properties were investigated. Salt metathesis routes involving MI2 (M = Ca, Sr, Ba) with either KTpEt2 or KTpnPr2 afforded MTpEt22 or MTpnPr22 in good to moderate yields. All of these complexes are volatile and exceptionally thermally stable, and have acceptable properties for use as group 2 atomic layer deposition (ALD) precursors. In addition, a series of group 2 complexes containing BpR2-based ligand systems were synthesized. Treatment of MI2 (M = Ca, Sr, Ba) with two equivalents of TlBptBu2, KBp, and KBpiPr2 in tetrahydrofuran …


Clustering-Based Pre-Processing Approaches To Improve Similarity Join Techniques, Yufen Tan Jan 2010

Clustering-Based Pre-Processing Approaches To Improve Similarity Join Techniques, Yufen Tan

Wayne State University Dissertations

Research on similarity join techniques is becoming one of the growing practical areas for study, especially with the increasing E-availability of vast amounts of digital data from more and more source systems. This research is focused on pre-processing clustering-based techniques to improve existing similarity join approaches.

Identifying and extracting the same real-world entities from different data sources is still a big challenge and a significant task in the digital information era. Dissimilar extracts may indeed represent the same real-world entity because of inconsistent values and naming conventions, incorrect or missing data values, or incomplete information. Therefore discovering efficient and accurate …


Optimal Control And Feedback Design Of State-Constrained Parabolic Systems In Uncertainty Conditions, Boris S. Mordukhovich Jan 2010

Optimal Control And Feedback Design Of State-Constrained Parabolic Systems In Uncertainty Conditions, Boris S. Mordukhovich

Mathematics Research Reports

The paper concerns minimax control problems for linear multidimensional parabolic systems with distributed uncertain perturbations and control functions acting in the Dirichlet boundary conditions. The underlying parabolic control system is functioning under hard/pointwise constraints on control and state variables. The main goal is to design a feedback control regulator that ensures the required state performance and robust stability under any feasible perturbations and minimize an energy-type functional under the worst perturbations from the given area. We develop a constructive approach to the minimax control design of constrained parabolic systems that is based on certain characteristic features of the parabolic dynamics …


The Analysis Of Cyanide And Its Breakdown Products In Biological Samples, Brian A. Logue, Diane M. Hinkens, Steven I. Baskin, Gary A. Rockwood Jan 2010

The Analysis Of Cyanide And Its Breakdown Products In Biological Samples, Brian A. Logue, Diane M. Hinkens, Steven I. Baskin, Gary A. Rockwood

Chemistry and Biochemistry Faculty Publications

Cyanide is a toxic chemical that may be introduced into living organisms as a result of natural processes and/or anthropogenic uses (legal or illicit). Exposure to cyanide can be verified by analysis of cyanide or one of its breakdown products from biological samples. This verification may be important for medical, law-enforcement, military, forensic, research, or veterinary purposes. This review will discuss current bioanalytical techniques used for the verification of cyanide exposure, identify common problems associated with the analysis of cyanide and its biological breakdown products, and briefly address the metabolism and toxicokinetics of cyanide and its breakdown products in biological …


Rayleigh Wave Dispersion Curve Inversion: Occam Versus The L1-Norm, Matthew M. Haney, Leming Qu Jan 2010

Rayleigh Wave Dispersion Curve Inversion: Occam Versus The L1-Norm, Matthew M. Haney, Leming Qu

Mathematics Faculty Publications and Presentations

We compare inversions of Rayleigh wave dispersion curves for shear wave velocity depth profiles based on the L2-norm (Occam's Inversion) and L1-norm (TV Regularization). We forward model Rayleigh waves using a finite-element method instead of the conventional technique based on a recursion formula and root-finding. The forward modeling naturally leads to an inverse problem that is overparameterized in depth. Solving the inverse problem with Occam's Inversion gives the smoothest subsurface model that satisfies the data. However, the subsurface need not be smooth and we therefore also solve the inverse problem with TV Regularization, a procedure that does not penalize discontinuities. …


Science-Technology Division News From The Chair-Elect, Joseph Kraus Jan 2010

Science-Technology Division News From The Chair-Elect, Joseph Kraus

Sci-Tech News

No abstract provided.


Sci-Tech Candidates For Chair-Elect And Treasurer, Christine Whitaker Jan 2010

Sci-Tech Candidates For Chair-Elect And Treasurer, Christine Whitaker

Sci-Tech News

No abstract provided.


The Sla 2010 Annual Conference: A Newbie's Account, Molly Tebo Jan 2010

The Sla 2010 Annual Conference: A Newbie's Account, Molly Tebo

Sci-Tech News

No abstract provided.


Engineering Division, Laurie Allen Jan 2010

Engineering Division, Laurie Allen

Sci-Tech News

No abstract provided.


Call For Articles Jan 2010

Call For Articles

Sci-Tech News

No abstract provided.


The World's Thinnest Capacitor, Brian Skinner, M S. Loth, B I. Shklovskii Jan 2010

The World's Thinnest Capacitor, Brian Skinner, M S. Loth, B I. Shklovskii

Brian Skinner

A short poster providing a conceptual explanation of the mechanism of very large capacitance in ion-conducting devices.


Fddb: A Benchmark For Face Detection In Unconstrained Settings, Vidit Jain, Erik Learned-Miller Jan 2010

Fddb: A Benchmark For Face Detection In Unconstrained Settings, Vidit Jain, Erik Learned-Miller

Erik G Learned-Miller

Despite the maturity of face detection research, it re- mains difficult to compare different algorithms for face de- tection. This is partly due to the lack of common evaluation schemes. Also, existing data sets for evaluating face detec- tion algorithms do not capture some aspects of face appear- ances that are manifested in real-world scenarios. In this work, we address both of these issues. We present a new data set of face images with more faces and more accurate annotations for face regions than in previous data sets. We also propose two rigorous and precise methods for evaluat- ing the …


Adapting Blstm Neural Network Based Keyword Spotting Trained On Modern Data To Historical Documents, Volkmar Frinken, Andreas Fischer, Horst Bunke, R. Manmatha Jan 2010

Adapting Blstm Neural Network Based Keyword Spotting Trained On Modern Data To Historical Documents, Volkmar Frinken, Andreas Fischer, Horst Bunke, R. Manmatha

R. Manmatha

Being able to search for words or phrases in historic handwritten documents is of paramount importance when preserving cultural heritage. Storing scanned pages of written text can save the information from degradation, but it does not make the textual information readily available. Automatic keyword spotting systems for handwritten historic documents can fill this gap. However, most such systems have trouble with the great variety of writing styles. It is not uncommon for handwriting processing systems to be built for just a single book. In this paper we show that neural network based keyword spotting systems are flexible enough to be …


Image Retrieval Using Markov Random Fields And Global Image Features, Ainhoa Llorente, R. Manmatha, Stefan Rüger Jan 2010

Image Retrieval Using Markov Random Fields And Global Image Features, Ainhoa Llorente, R. Manmatha, Stefan Rüger

R. Manmatha

In this paper, we propose a direct image retrieval framework based on Markov Random Fields (MRFs) that exploits the semantic context dependencies of the image. The novelty of our approach lies in the use of different kernels in our non-parametric density estimation together with the utilization of configurations that explore semantic relationships among concepts at the same time as low-level features, instead of just focusing on correlation between image features like in previous formulations. Hence, we introduce several configurations and study which one achieve the best performance. Results are presented for two datasets, the usual benchmark Corel 5k and the …


Optimizing Semantic Coherence In Topic Models, D. Mimno, Hanna Wallach, E. Talley, M. Leenders, A. Mccallum Jan 2010

Optimizing Semantic Coherence In Topic Models, D. Mimno, Hanna Wallach, E. Talley, M. Leenders, A. Mccallum

Hanna M. Wallach

Large organizations often face the critical challenge of sharing information and maintaining connections between disparate subunits. Tools for automated analysis of document collections, such as topic models, can provide an important means for communication. The value of topic modeling is in its ability to discover interpretable, coherent themes from unstructured document sets, yet it is not unusual to find semantic mismatches that substantially reduce user confidence. In this paper, we first present an expert-driven topic annotation study, undertaken in order to obtain an annotated set of baseline topics and their distinguishing characteristics. We then present a metric for detecting poor-quality …


Learning The Structure Of Deep Sparse Graphical Models, Ryan Adams, Hanna Wallach, Zoubin Ghahramani Jan 2010

Learning The Structure Of Deep Sparse Graphical Models, Ryan Adams, Hanna Wallach, Zoubin Ghahramani

Hanna M. Wallach

Deep belief networks are a powerful way to model complex probability distributions. However, it is difficult to learn the structure of a belief network, particularly one with hidden units. The Indian buffet process has been used as a nonparametric Bayesian prior on the structure of a directed belief network with a single infinitely wide hidden layer. Here, we introduce the cascading Indian buffet process (CIBP), which provides a prior on the structure of a layered, directed belief network that is unbounded in both depth and width, yet allows tractable inference. We use the CIBP prior with the nonlinear Gaussian belief …


An Alternative Prior Process For Nonparametric Bayesian Clustering, Hanna Wallach, Shane Jensen, Lee Dicker, Katherine Heller Jan 2010

An Alternative Prior Process For Nonparametric Bayesian Clustering, Hanna Wallach, Shane Jensen, Lee Dicker, Katherine Heller

Hanna M. Wallach

Prior distributions play a crucial role in Bayesian approaches to clustering. Two commonly-used prior distributions are the Dirichlet and Pitman-Yor processes. In this paper, we investigate the predictive probabilities that underlie these processes, and the implicit "rich-get-richer" characteristic of the resulting partitions. We explore an alternative prior for nonparametric Bayesian clustering---the uniform process---for applications where the "rich-get-richer" property is undesirable. We also explore the cost of this process: partitions are no longer exchangeable with respect to the ordering of variables. We present new asymptotic and simulation-based results for the clustering characteristics of the uniform process and compare these with known …


Anytime Planning For Decentralized Pomdps Using Expectation Maximization, Akshat Kumar, Shlomo Zilberstein Jan 2010

Anytime Planning For Decentralized Pomdps Using Expectation Maximization, Akshat Kumar, Shlomo Zilberstein

Shlomo Zilberstein

Decentralized POMDPs provide an expressive framework for multi-agent sequential decision making. While finite-horizon DEC-POMDPs have enjoyed significant success, progress remains slow for the infinite-horizon case mainly due to the inherent complexity of optimizing stochastic controllers representing agent policies. We present a promising new class of algorithms for the infinite-horizon case, which recasts the optimization problem as inference in a mixture of DBNs. An attractive feature of this approach is the straightforward adoption of existing inference techniques in DBNs for solving DEC-POMDPs and supporting richer representations such as factored or continuous states and actions. We also derive the Expectation Maximization (EM) …


A Bland–Altman Comparison Of The Lead Care® System And Inductively Coupled Plasma Mass Spectrometry For Detecting Low-Level Lead In Child Whole Blood Samples, Christina Sobin, Tanner Schaub, Natali Parisi, Eva De La Riva Jan 2010

A Bland–Altman Comparison Of The Lead Care® System And Inductively Coupled Plasma Mass Spectrometry For Detecting Low-Level Lead In Child Whole Blood Samples, Christina Sobin, Tanner Schaub, Natali Parisi, Eva De La Riva

Christina Sobin, Ph.D.

Chronic childhood lead exposure, yielding blood lead levels consistently below 10 μg/dL, remains a major public health concern. Low neurotoxic effect thresholds have not yet been established. Progress requires accurate, efficient, and cost-effective methods for testing large numbers of children. The LeadCare® System (LCS) may provide one ready option. The comparability of this system to the “gold standard” method of inductively coupled plasma mass spectrometry (ICP-MS) for the purpose of detecting blood lead levels below 10 μg/dL has not yet been examined. Paired blood samples from 177 children ages 5.2–12.8 years were tested with LCS and ICP-MS. Triplicate repeat tests …


Theoretical Description Of A Dna-Linked Nanoparticle Self-Assembly, Chia Wei Hsu, Francesco Sciortino, Francis Starr Jan 2010

Theoretical Description Of A Dna-Linked Nanoparticle Self-Assembly, Chia Wei Hsu, Francesco Sciortino, Francis Starr

Francis Starr

No abstract provided.


Rapid Transport Of Water Via A Carbon Nanotube Syringe, Jose Rivera, Francis Starr Jan 2010

Rapid Transport Of Water Via A Carbon Nanotube Syringe, Jose Rivera, Francis Starr

Francis Starr

No abstract provided.


Morphology And Transport Properties Of Two-Dimensional Sheet Polymers, Scott Knauert, Jack Douglas, Francis Starr Jan 2010

Morphology And Transport Properties Of Two-Dimensional Sheet Polymers, Scott Knauert, Jack Douglas, Francis Starr

Francis Starr

Whereas there has been extensive theoretical and experimental investigation of the properties of linear polymer chains in solution, there has been far less work on sheet-like polymers having 2D connectivity and 3D crumpled or collapsed shapes caused by thermal fluctuations, attractive self-interactions, or both. Sheet-like polymers arise in a variety of contexts ranging from self-assembled biological membranes (e.g., the spectrin network of red blood cells, microtubules, etc.) to nanocomposite additives to polymers (carbon nanotubes, graphene, and clay sheets) and polymerized monolayers. We investigate the equilibrium properties of this broad class of polymers using a simple model of a sheet polymer …


Current Issues In Research On Structure-Property Relationships In Polymer Nanocomposites, J. Jancar, J. Douglas, Francis Starr, S. Kumar, P. Cassagnau, A. Lesser, S. Sternstein, M. Buehler Jan 2010

Current Issues In Research On Structure-Property Relationships In Polymer Nanocomposites, J. Jancar, J. Douglas, Francis Starr, S. Kumar, P. Cassagnau, A. Lesser, S. Sternstein, M. Buehler

Francis Starr

No abstract provided.


Deformation And Alteration Associated With Oceanic And Continental Detachment Fault Systems: Are They Similar?, Barbara John, Michael Cheadle Jan 2010

Deformation And Alteration Associated With Oceanic And Continental Detachment Fault Systems: Are They Similar?, Barbara John, Michael Cheadle

Barbara John

No abstract provided.


Detecting Wikipedia Vandalism Via Spatio-Temporal Analysis Of Revision Metadata, Andrew G. West, Sampath Kannan, Insup Lee Jan 2010

Detecting Wikipedia Vandalism Via Spatio-Temporal Analysis Of Revision Metadata, Andrew G. West, Sampath Kannan, Insup Lee

Andrew G. West

Blatantly unproductive edits undermine the quality of the collaboratively-edited encyclopedia, Wikipedia. They not only disseminate dishonest and offensive content, but force editors to waste time undoing such acts of vandalism. Language- processing has been applied to combat these malicious edits, but as with email spam, these filters are evadable and computationally complex. Meanwhile, recent research has shown spatial and temporal features effective in mitigating email spam, while being lightweight and robust.

In this paper, we leverage the spatio-temporal properties of revision metadata to detect vandalism on Wikipedia. An administrative form of reversion called rollback enables the tagging of malicious edits, …


Assessment Of The Impact Of Using Alternative Fuels In A Cement Kiln On The Emissions Of Selected Substances Into The Air, Robert Oleniacz Jan 2010

Assessment Of The Impact Of Using Alternative Fuels In A Cement Kiln On The Emissions Of Selected Substances Into The Air, Robert Oleniacz

Robert Oleniacz

The chapter presents the results of analyses concerning the impact of using alternative fuels in one of the Polish cement plants on the volume of continuously measured emissions into the air for the following substances: carbon dioxide (CO2), carbon monoxide (CO), nitric oxides (NOx), sulphur dioxide (SO2), hydrogen chloride (HCl), gaseous and volatile organic compounds expressed as total organic carbon (TOC), and total dust. The analyses covered a 15-month period of the operation of a dry cement kiln, approximately 100m-long, equipped with four-stage cyclone exchangers and a calciner, constituting an additional chamber for waste co-combustion. The results obtained confirmed the …


Emisja Zanieczyszczeń Pyłowo-Gazowych Z Procesu Wypalania Półproduktów Grafitowych W Piecu Tunelowym, Marek Bogacki, Robert Oleniacz, Marian Mazur, Przemysław Szczygłowski Jan 2010

Emisja Zanieczyszczeń Pyłowo-Gazowych Z Procesu Wypalania Półproduktów Grafitowych W Piecu Tunelowym, Marek Bogacki, Robert Oleniacz, Marian Mazur, Przemysław Szczygłowski

Robert Oleniacz

The baking of semi-finished graphite products in a tunnel furnace is the source of many air pollutants present in both the gaseous and solid phases. The goal of this study was to assess emission rates into the air of the substances such as: CO, NOx, SO2, H2S, CH4, aliphatic hydrocarbons up to C6, benzene and its homologues (BTEX), total dust and tar substances, and polycyclic aromatic hydrocarbons (PAHs) contained in the dust. The research showed a small time-dependence of the emission rates for the majority of the substances analysed, which is, to a large extent, a result of the long …