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Articles 2221 - 2250 of 2496

Full-Text Articles in Physical Sciences and Mathematics

On The Behavior Of The 5f Electrons, Pratik Pankajkumar Dholabhai Aug 2005

On The Behavior Of The 5f Electrons, Pratik Pankajkumar Dholabhai

Physics Theses

Considerable theoretical efforts have been devoted in recent years to studying the electronic and geometric structures and related properties of surfaces to high accuracy. One of the many motivations for this burgeoning effort has been a desire to understand the detailed mechanisms that lead to surface corrosion in the presence of environmental gases; a problem that is not only scientifically and technologically challenging but also environmentally important. Such efforts are particularly important for systems like the actinides for which experimental work is relatively difficult to perform due to material problems and toxicity. As is known, the actinides are characterized by …

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Utility Based Resource Aware Framework For Information Caching And Sharing In Mobile And Distributed Systems, Huaping Shen Aug 2005

Utility Based Resource Aware Framework For Information Caching And Sharing In Mobile And Distributed Systems, Huaping Shen

Computer Science and Engineering Dissertations

Along with the technology advancements in mobile and wireless networks, ubiquitous information service is becoming a reality in which users can access the information anytime anywhere. However, the user mobility, network heterogeneity and resource constraints impose significant challenges to provide ubiquitous information services. In this dissertation, a utility based resource aware framework is proposed to enhance ubiquitous information availability to mobile users through data caching and peer-to-peer sharing. The framework considers the constrained resources of mobile and distributed environments and provides flexible, efficient and scalable data access services to the mobile users. The major contributions of this framework are as …

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On The Image Of The Totalling Functor, Kristen Ann Beck Aug 2005

On The Image Of The Totalling Functor, Kristen Ann Beck

Mathematics Theses

Let A denote a DG algebra and k a field. The totalling functor, from the category of chain complexes over the graded A-modules to the catagory of DG modules over A, can be extended to one between their derived categories. If this extension were onto, the derived category of the category of DG modules would be superfluous. This paper investigates the image of the extension of Tot in the fundamental case when A is the polynomial ring in d variables over k. When d is at least 2, there are semifree DG modules of rank n, where n is at …

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On A Class Of Abcs, Sridevi Lalgudi Ganapathy Aug 2005

On A Class Of Abcs, Sridevi Lalgudi Ganapathy

Physics Theses

The local density approximation to density functional theory (LDA-DFT) has been used to study the different possible relaxations and reconstructions of In-rich InSb (100) surface. Various electronic and geometric structure properties such as, bond lengths, cohesive energies, band gaps and density of states of the ideal (1x1) surface and the (2x1), (4x2) and c(8x2) reconstructed InSb surfaces are reported. Adsorptions of lithium atom as well as other halogen atoms such as chlorine, bromine and iodine on the (1x1), (2x1), (4x2) and c (8x2) InSb surfaces in the different symmetric sites, such as, top, bridge, hollow, cave, trough and also interstitial …

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First Observation Of Dijet Events With An Antiproton Tag At [Square Root]S = 1.96 Tev Using The Dø Forward Proton Detector, Michael Strang Aug 2005

First Observation Of Dijet Events With An Antiproton Tag At [Square Root]S = 1.96 Tev Using The Dø Forward Proton Detector, Michael Strang

Physics Dissertations

The Forward Proton Detector (FPD) is a new sub-system of the DØ detector, a 5000 ton particle physics detector located at the Fermilab Tevatron proton-antiproton collider. The FPD was implemented for the Tevatron Run II and gives access to a wide range of diffractive scattering processes, where one or both of the beam particles remain intact. The analysis described in this thesis makes use of the dipole spectrometer of the FPD to tag outgoing antiprotons in events that have a dijet signature in the central D0 calorimeter. Properties of jets with a diffractive tag signature are compared to jets without …

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Efficient And Adaptive Schemes For Consistent Information Sharing In Wireless Mobile And Peer-To-Peer Networks, Zhijun Wang Aug 2005

Efficient And Adaptive Schemes For Consistent Information Sharing In Wireless Mobile And Peer-To-Peer Networks, Zhijun Wang

Computer Science and Engineering Dissertations

With the tremendous growth of applications in wireless mobile and Peer-to-Peer (P2P) networks, significant research efforts have been made to improve the quality of sevice. Caching and replicating frequently used data objects or files in user's local buffers are popular mechanisms to effectively reduce the communication bandwidth requirement and thus improve the overall system performance. However, the frequent disconnections of users make data consistency a difficult task in wireless mobile and P2P networks. In this dissertation, we design and analyze a Scalable Asynchronous Cache Consistency Scheme (SACCS) for single cell wireless cellular networks. SACCS is a highly scalable, efficient, and …

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Finding Blood In Capsule Endoscopy Video, Jay Frederick Cox Aug 2005

Finding Blood In Capsule Endoscopy Video, Jay Frederick Cox

Computer Science and Engineering Theses

Capsule Endoscopy (CE) is a new procedure where endoscopists can visualize and discriminate anomalies of the human gastrointestinal track by allowing the patient to swallow a camera pill. The digital video obtained from the pill is used to safely pinpoint the location of these abnormalities in areas previously unavailable for view. One of the main functions of CE is determining the location of bleeding. Given Imaging, currently the only maker of a FDA approved CE device, has a proprietary and unspecified blood test, called Suspected Blood Index, which can be used to automatically detect where blood occurs in the video. …

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An Emperical Evaluation Of Adequacy Criteria For Testing Concurrent Programs, Gaurav Saini Aug 2005

An Emperical Evaluation Of Adequacy Criteria For Testing Concurrent Programs, Gaurav Saini

Computer Science and Engineering Theses

A concurrent program contains two or more threads that execute concurrently and work together to perform some task. Concurrency increases the efficiency of a program. Testing of concurrent programs has been a challenging task because of the inherent non-determinism. Most approaches proposed for concurrent program testing employ, explicitly or implicitly, a coverage criterion to measure test adequacy. In order to apply those approaches, we must first choose a criterion that suits best for our programs. There is a need for quantitative results of evaluation regarding the effectiveness of the various coverage criteria used for the testing of concurrent programs. Such …

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Comparison Of Search-Based And Kernel-Based Methods For Graph-Based Relational Learning, Chris Manuel Gonsalves Aug 2005

Comparison Of Search-Based And Kernel-Based Methods For Graph-Based Relational Learning, Chris Manuel Gonsalves

Computer Science and Engineering Theses

Graph-based relational learning has been the focus of relational learning for quite some time. As most of the real-world data is structured, and hence cannot be represented in a single table, various logic-based and graph-based techniques have been proposed for dealing with structured data. Our goal is to perform an in-depth analysis of two such graph-based learning systems. We have selected Subdue to represent the search-based approach and support vector machine (SVM) with graph kernels to represent the kernel-based approach. We perform a comparison between search-based and kernel-based approaches and evaluate their performance in various domains. A search-based approach to …

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A Framework For A Dynamic Invocation Interface And High-Level Interoperability For Mobile Agent Platforms, Vamsi K. Putrevu Aug 2005

A Framework For A Dynamic Invocation Interface And High-Level Interoperability For Mobile Agent Platforms, Vamsi K. Putrevu

Computer Science and Engineering Theses

The mobile agent paradigm for distributed systems is inherently suitable for many applications ranging from network management to e-commerce. One inherent problem to its wide spread use is communication between disparate agent platforms and reducing overheads while doing the same. Not all platforms for mobile agents are the same. The Mobile Agent Facility (MAF) proposal is an attempt to standardize this execution environment, this thesis proposes a framework extending the current MAF specification, by which inter-agent communication can be achieved in a more scalable fashion by interpreter based mobile agent systems. The future of the Internet depends on its ability …

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Monitoring And Analyzing Distributed Cluster Performance And Statistics Of Atlas Job Flow, Sreeranjani Ramprakash Aug 2005

Monitoring And Analyzing Distributed Cluster Performance And Statistics Of Atlas Job Flow, Sreeranjani Ramprakash

Computer Science and Engineering Theses

Grid3 is a Grid facility used by many High Energy Physics experiments to enable physicists to process data intensive and CPU intensive jobs more effectively as well as more efficiently. Amongst other things, the highlights of Grid3 are participation by more than 25 sites across the U.S. and Korea which collectively provide more than 2000 CPU's, resources used by seven different scientific applications, including three high energy physics simulations and four data analyses in high energy physics, bio-chemistry, astrophysics and astronomy, more than 100 individuals are currently registered with access to the Grid, a peak throughput of 500-900 jobs running …

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Sql-Based Approach To Significant Interval Discovery In Time-Series Data, Sunit Shrestha Aug 2005

Sql-Based Approach To Significant Interval Discovery In Time-Series Data, Sunit Shrestha

Computer Science and Engineering Theses

With time-series data, events (like turning off a light, opening garage door, turning on TV) occur with a high degree of certainty not at specific time points but within time intervals (sequence of time points). So, it is useful for applications to consider data as contiguous time points. The smallest interval that satisfies the criteria of interval-confidence (i.e., ratio of total support of participating time points and the number of days) is termed as Significant Interval (SI). Significant Interval Discovery (SID) algorithm finds SIs from time-series data. The main focus of this thesis is on the improvement of existing SID …

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Quantitative Comparison Of Two Approaches To Agent Cooperation, Jose Ramon Espino Aug 2005

Quantitative Comparison Of Two Approaches To Agent Cooperation, Jose Ramon Espino

Computer Science and Engineering Theses

Multi-agent systems (MASs) are characterized by collections of autonomous agents that interact with each other in simple ways, but the collection of agents as a whole is characterized by emergent behavior (EB) which will have properties that individual agents do not. Engineers want to design artificial MASs for a variety of reasons including military operations. The idea is for the EB to be carrying out the mission itself. In this scenario, the agents are relatively inexpensive and expendable. A large body of work exists in MAS research for military applications and a variety of different designs have been proposed. Because …

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Structure Based Xml Indexing, Niroj Manandhar Aug 2005

Structure Based Xml Indexing, Niroj Manandhar

Computer Science and Engineering Theses

The increase in the usage and popularity of semi-structured data has received considerable attention, and a lot of research is going on for the efficient retrieval and storage of semi-structured data. A popular model and language for semi-structured data is XML. In this thesis we focus on the structure based indexing of XML. As a part of an ongoing XML indexing project, we study and implement A(k)-index, which is a structure based indexing technique; and propose the use of offset, length pair to retrieve nodes of interest. We record offset and length of every node using the SAX parser, and …

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Integration Of The Sam-Grid Infrastructure To The D0 Data Reprocessing Effort, Anoop Rajendra Aug 2005

Integration Of The Sam-Grid Infrastructure To The D0 Data Reprocessing Effort, Anoop Rajendra

Computer Science and Engineering Theses

The D0 experiment is one of the two high energy physics experiments currently being conducted at Fermi National Accelerator Laboratory, in Batavia, IL, on what is currently the world's highest energy particle accelerator, the Tevatron. The experiment produces vast amounts of raw data of the order of several hundred terabytes. This data needs to be converted from the raw format that comes from the detector, ie. digitized data, to a format that is close to the physics, ie. data that can be subjected to analysis. This process, called reconstruction, is done according to constantly evolving and improving reconstruction algorithms. This …

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Direct Numerical Simulation For Flow Transition Over A Flat Plate, Shutian Deng Aug 2005

Direct Numerical Simulation For Flow Transition Over A Flat Plate, Shutian Deng

Mathematics Dissertations

In this paper, direct numerical simulation (DNS) of flow transition over a flat plate at a free stream Mach number of 0.5 and a Reynolds number of 1000 based on the free stream velocity and inflow displacement thickness has been carried out. The time-dependent Navier-Stokes equations are solved directly by a third-order TVD Runge-Kutta method from Shu(1998). A sixth order central compact scheme from Lele (1992) that facilitates high resolution of the flow field is used for spatial discretization together with a sixth order implicit compact filter. To avoid possible non-physical wave reflection from the boundaries, the non-reflecting boundary conditions …

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Game Theoretical Models And Algorithms For Rate Control In Video Compression, Jiancong Luo Jul 2005

Game Theoretical Models And Algorithms For Rate Control In Video Compression, Jiancong Luo

Computer Science and Engineering Dissertations

This thesis investigates game theory based rate control algorithms for optimizing the bit allocation in video compression. The first algorithm utilizes the cooperative bargaining game in a MB level rate control algorithm to optimize the perceptual quality while guaranteeing "fairness" in bit allocation among macroblocks. The algorithm first allocates the target bits to frames based on their coding complexity; a method to estimate the coding complexity of the remaining frames is proposed. Next, macroblocks of a frame play cooperative games such that each macroblock competes for a share of resources (bits) to optimize its quantization scale while considering the human …

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Automating Inhabitant Interactions In Home And Workplace Environments Through Data-Driven Generation Of Hierarchical Partially-Observable Markov Decision Processes, Gregory Michael Youngblood Jul 2005

Automating Inhabitant Interactions In Home And Workplace Environments Through Data-Driven Generation Of Hierarchical Partially-Observable Markov Decision Processes, Gregory Michael Youngblood

Computer Science and Engineering Dissertations

Markov models provide a useful representation of system behavioral actions and state observations, but they do not scale well. Utilizing a hierarchy and abstraction through hierarchical hidden Markov models (HHMMs) improves scalability, but these structures are usually constructed manually using knowledge engineering techniques. We introduce a new method of automatically constructing HHMMs using the output of a sequential data-mining algorithm, Episode Discovery, and apply it to solving automation problems in the intelligent environment domain. Repetitive behavioral actions in sensor rich environments such as smart homes can be observed and categorized into periodic and frequent episodes through data-mining techniques utilizing the …

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Statistical Analysis Of Rock Fabrics, Boris Avdeev Jul 2005

Statistical Analysis Of Rock Fabrics, Boris Avdeev

Earth & Environmental Sciences Theses

The main goal of the work is to present new procedures for statistical analysis of fabric data for structural geology. After an introduction to the problems of orientation analysis, discussion of different types of the orientation data and a brief review of the existing techniques and statistics for the orientation data, a comprehensive discussion of several proposed methods is given. The first part of the methodology chapter states a general model in terms of a structural frame and introduces some notation. The second part is a detailed description of a pooled estimator, which is intended to assess a structural frame …

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A First-Principles Study On Bulk Cuo: Electronic Structures And Native Point Defects, Dangxin Wu Jul 2005

A First-Principles Study On Bulk Cuo: Electronic Structures And Native Point Defects, Dangxin Wu

Physics Theses

In this thesis, we have performed a first-principles study on strongly correlated monoclinic cupric oxide (CuO) by using the LSDA+U method implemented in the PAW method. Based on the optimized structural parameters, which are in good agreement with the experimental data, the electronic structure and the magnetic properties are obtained. Our calculations show that CuO is a semiconducting material with an indirect gap of about 1.0 eV. The semiconducting nature of CuO from our calculations is consistent with many experiments, but is qualitatively different from the LSDA calculations which incorrectly predict CuO to be metallic. The indirect gap of 1.0 …

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Group Key Distribution Via Local Collaboration In Wireless Sensor Networks, Anuj Chadha Jul 2005

Group Key Distribution Via Local Collaboration In Wireless Sensor Networks, Anuj Chadha

Computer Science and Engineering Theses

Wireless sensor networks have been recognized as one of the most important technologies in the networking world. Security of sensor networks is one of the major concerns today. To this end, a whole suite of protocols have been designed to provide various security features which includes key management. This thesis covers the issue of group key management in wireless sensor networks. Traditional cryptographic techniques can be used to provide communication privacy and integrity, but do not provide scalable solutions to group key management. A group key management scheme for sensor networks has been discussed that targets at fast response to …

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Distributed Streaming For Video On Demand, Shraddha Rumade Jul 2005

Distributed Streaming For Video On Demand, Shraddha Rumade

Computer Science and Engineering Theses

With the advent of digital media, implementing reliable Video on Demand (VoD) systems over the best effort Internet is a potential issue. Distributed streaming for Video on Demand presents a combination of two techniques. The first being Distributed Video Streaming using Multicast (DVSM) [1] involves video streaming from multiple servers to overcome path congestion. The second technique, Asynchronous Hybrid mechanism for Video on Demand [2] implements segmentation-based periodic broadcast to effectively share network bandwidth. In this work we aim at providing path diversity of multiple senders and maximizing bandwidth sharing via multicast. We exploit alternate paths in case of congestion …

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The Least-Squares Finite Element Method For Grid Deformation And Meshfree Applications, Dionisio Laeber Fleitas Jul 2005

The Least-Squares Finite Element Method For Grid Deformation And Meshfree Applications, Dionisio Laeber Fleitas

Mathematics Dissertations

Grid adaptation is often needed to improve the numerical solution of a Partial Differential Equation (PDE), due to, for example, shock waves and boundary layers. In moving boundary problems, the grid needs to be regenerated or adapted to fit the new domain. In this work, a LSFEM deformation method is developed for grid generation on fixed or moving domains. The LSFEM is a finite-elements method which seeks to minimize the PDE residual equation through the least-squares method. A new class of numerical methods currently being researched is the meshfree methods, in which the main goal is to numerically solve PDEs …

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A Framework For Model Checking Object Oriented Security Protocol Implementations, Parikshit Singh Jun 2005

A Framework For Model Checking Object Oriented Security Protocol Implementations, Parikshit Singh

Computer Science and Engineering Theses

With the rapid growth of the Internet, more and more vendors see the Internet as a viable marketplace. Since the Internet is public, providing security in the presence of malicious intruders has become paramount. Security protocols have been proposed to protect systems. These protocols work by exchanging messages, many of which are encrypted. Though it may take a long time for an intruder to break the underlying encryption employed by the protocol, it is possible for the intruder to intervene in the authentication process. It may take years before a crucial loophole is discovered in a security protocol. Until then, …

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Cyclopropylcarbinyl → Homoallyl-Type Ring Opening Of Ketyl Radical Anions. Structure/Reactivity Relationships And The Contribution Of Solvent/Counterion Reorganization To The Intrinsic Barrier, J. M. Tanko, Jason G. Gillmore, Robert Friedline, M'Hamed Chahma May 2005

Cyclopropylcarbinyl → Homoallyl-Type Ring Opening Of Ketyl Radical Anions. Structure/Reactivity Relationships And The Contribution Of Solvent/Counterion Reorganization To The Intrinsic Barrier, J. M. Tanko, Jason G. Gillmore, Robert Friedline, M'Hamed Chahma

Faculty Publications

Following a protocol developed by Mathivanan, Johnston, and Wayner (J. Phys. Chem. 1995, 99, 8190−8195), the radical anions of several cyclopropyl- and oxiranyl-containing carbonyl compounds were generated in an effort to measure the rate constants for their ring opening (ko) by laser flash photolysis. The results of these experiments are compared to those obtained from earlier electrochemical studies, and the combined data set is used to rationalize the kinetics of radical anion ring opening in a general context by using Savéant's theory pertaining to stepwise dissociative electron transfer (Acc. Chem. Res. 1993, 26, 455−461). Compared to cyclopropylcarbinyl → homoallyl rearrangements …

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Two-Neutron Transfer In The 6he + 209bi Reaction Near The Coulomb Barrier, Paul A. Deyoung, Patrick J. Mears, J. J. Kolata, E. F. Aguilera, F. D. Becchetti, Y. Chen, M. Cloughesy, H. Griffin, C. Guess, J. D. Hinnefeld, H. Jiang, Scott R. Jones, U. Khadka, D. Lizcano, E. Martinez-Quiroz, M. Ojaniega, Graham F. Peaslee, A. Pena, J. Reith, S. Vandendriessche, J. A. Zimmerman May 2005

Two-Neutron Transfer In The 6he + 209bi Reaction Near The Coulomb Barrier, Paul A. Deyoung, Patrick J. Mears, J. J. Kolata, E. F. Aguilera, F. D. Becchetti, Y. Chen, M. Cloughesy, H. Griffin, C. Guess, J. D. Hinnefeld, H. Jiang, Scott R. Jones, U. Khadka, D. Lizcano, E. Martinez-Quiroz, M. Ojaniega, Graham F. Peaslee, A. Pena, J. Reith, S. Vandendriessche, J. A. Zimmerman

Faculty Publications

The cross section for α-particle emission in the He6+Bi209 reaction at energies near the Coulomb barrier is remarkably large. Possible reactions that may produce the observed α particles include two-neutron transfer, one-neutron transfer, and direct projectile breakup. Each of these mechanisms results in a distinctive angular correlation between the α particle and the outgoing neutron(s). A neutron-α-particle coincidence experiment was performed to study two-neutron transfer to unbound states of Bi211. It is shown that approximately 55% of the observed α-particle yield at and beyond the grazing angle is because of this process. This is more than 2.5 times the fraction …

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Matlab Code For Bayesian Fitting Of Adaptive P-Splines In Regression, Veera Baladandayuthapani May 2005

Matlab Code For Bayesian Fitting Of Adaptive P-Splines In Regression, Veera Baladandayuthapani

Veera Baladandayuthapani

No abstract provided.

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Isobaric Analog States Of Neutron-Rich Nuclei. Doppler Shift As A Measurement Tool For Resonance Excitation Functions, P. Boutachkov, G. V. Rogachev, V. Z. Goldberg, A. Aprahamian, F. D. Becchetti, J. P. Bychowski, Y. Chen, G. Chubarian, P. A. Deyoung, J. J. Kolata, L. O. Lamm, Graham F. Peaslee, M. Quinn, B. B. Skorodumov, A. Wohr Apr 2005

Isobaric Analog States Of Neutron-Rich Nuclei. Doppler Shift As A Measurement Tool For Resonance Excitation Functions, P. Boutachkov, G. V. Rogachev, V. Z. Goldberg, A. Aprahamian, F. D. Becchetti, J. P. Bychowski, Y. Chen, G. Chubarian, P. A. Deyoung, J. J. Kolata, L. O. Lamm, Graham F. Peaslee, M. Quinn, B. B. Skorodumov, A. Wohr

Faculty Publications

We present a new approach for the measurement of resonance excitation functions of neutron-rich nuclei using Doppler shift information. Preliminary data from the first application of the method is presented in the spectroscopy studies of 7He isobaric analog states in 7Li.

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Maximizing The Chances Of A Color Match, Ramin Naimi, Roberto Pelayo Mar 2005

Maximizing The Chances Of A Color Match, Ramin Naimi, Roberto Pelayo

Ramin Naimi

No abstract provided.

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A Solvent-Free Baeyer–Villiger Lactonization For The Undergraduate Organic Laboratory: Synthesis Of Γ-T-Butyl-Ε-Caprolactone, John J. Esteb, James N. Hohman, Diana E. Schladaminger, Anne M. Wilson Jan 2005

A Solvent-Free Baeyer–Villiger Lactonization For The Undergraduate Organic Laboratory: Synthesis Of Γ-T-Butyl-Ε-Caprolactone, John J. Esteb, James N. Hohman, Diana E. Schladaminger, Anne M. Wilson

Scholarship and Professional Work - LAS

We present an experiment involving the Baeyer–Villiger oxidation reactionfor a first-year organic chemistry class. The Baeyer–Villiger reactionprovides an efficient method to convert ketones to esters or lactones. Most organictextbooks cover the Baeyer–Villiger reaction but owing to a lack of suitableexperiments, students seldom get to explore the reaction in the undergraduateteaching laboratory. In this experiment, m-chloroperoxybenzoic acid(m-CPBA) and4-tert-butylcyclohexanone are mixed together for 30 minutes under solvent-freeconditions to produce γ-t-butyl-ε-caprolactone in 95%yield. The solvent-free nature of this procedure greatly limits the quantityof waste generated by students and keeps costs low by removing the need for solvent.

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