Physical Sciences and Mathematics Commons^™

Field Emission Based Sensors Using Carbon Nanotubes, Changkun Dong

Physics Theses & Dissertations

A number of sensitive applications would be greatly benefited by the development of better cold cathodes that employ the electron field emission process. Among the many kinds of field emitters that could be tried, carbon nanotubes (CNT) have a number of distinct advantages because of their unique geometrical structure, chemical inertness, mechanical stiffness, and high thermal and electrical conductivities. This dissertation describes research in which CNT cathodes were fabricated and their emission characteristics were measured.

Multi-walled carbon nanotubes (MWNT) were grown by chemical vapor deposition (CVD) on various substrates: Ni and Hastelloy gauze, 304 stainless steel (SS) plates, and Ni-coated …

Measurement Of Proton Transfer Reaction Rates In A Microwave Cavity Discharge Flowing Afterglow, George M. Brooke Iv

Physics Theses & Dissertations

The reaction rate coefficients between the hydronium ion and the molecules ethene (C₂H₄), propene (C₃H₆), 1-butene (C₄H₈) and hydrogen sulfide (H₂S) were measured at 296 K. The measured reaction rates were compared to collision rates calculated using average dipole orientation (ADO) theory. Reaction efficiency depends primarily upon the proton affinity of the molecules. All the measurements were obtained using the newly developed microwave cavity discharge flowing afterglow (MCD-FA) apparatus. This device uses an Asmussen-type microwave cavity discharge ion source that is …

Coherent Backscattering Of Light From An Ultra Cold Gas Of Rubidium-85 Atoms, Pasad B. Kulatunga

Physics Theses & Dissertations

This thesis reports on the experimental study of coherent radiative transport in an ultracold gas of ⁸⁵Rb atoms confined in a magneto-optic trap. Measurements are made of the polarization dependence of the spatial and spectral profile of light backscattered from the sample. The results shows an interferometric enhancement sensitive to coherent multiple scattering in the atomic gas, and strong variations with the polarization of the incident and detected light. Effects due to coherent enhancement of weak non-resonant transitions are also observed. Comparison of the measurements with realistic quantum Monte Carlo simulations of Kupriyanov, et al [1] yield very good …

Measurments Of Correlated Pair Momentum Distributions In 3he(E,E'Pp)N With Clas, Rustam Niyazov

Physics Theses & Dissertations

We have measured the ³He(e,e'pp)n reaction at 2.2 and 4.4 GeV over a wide kinematic range. The kinetic energy distribution for ’fast’ nucleons (p > 250 MeV/c) peaks where two nucleons each have 20% or less and the third or ‘leading’ nucleon carries most of the transferred energy. These fast nucleon pairs (both pp and pn) are back-to-back and carry very little momentum along q, indicating that they are spectators. Experimental and theoretical evidence indicates that we have measured N N correlations in ³He(e,e'pp)n by striking the third nucleon and detecting the spectator correlated pair.

The Tragedy Of The Rivers: Building Authority Over The British Water Environment, Kevin B. Vichcales

Dissertations

"The Tragedy of the Rivers: Building Authority over the British Water Environment" examines the problem of rivers as common public resources in modern Britain. Viewed historically, the enduring problem of environmental pollution control in Britain has been the establishment of regulating authority over aspects of nature that are regarded simultaneously as economic resources, public utilities, and public amenities. Legislators, subject to pressure from industrial polluters, political parties, and advocates for environmental quality, sought at different times to locate authority at local, regional, national and extra-national levels. Each effort failed to resolve the issue of authority over the environment, because administrative …

Multiobjective Optimal Control Problems With Endpoint And State Constraints, Kirsty J. Eisenhart

Dissertations

In this thesis we consider nonsmooth multiobjective optimal control problems in terms of a general preference on [Special characters omitted.]. The optimal control problems considered involve differential inclusion, endpoint constraints and state constraints. No convexity assumption is needed on the differential inclusion. Examples of common preferences are given, and the idea of approximating a preference is introduced. Euler-Lagrange necessary conditions and a form of the maximum principle are developed for closed preferences (and those that can be approximated by closed preferences) in terms of the limiting subdifferential. As a consequence, this is the first result in the literature for lexicographical …

Analysis Of Data Relevant To Establishing Outer Limits Of A Continental Shelf Under Law Of The Sea Article 76, Martin Jakobsson, Larry A. Mayer, Andy Armstrong

Center for Coastal and Ocean Mapping

Coastal states may extend the limits of their juridically defined continental shelf beyond 200 nautical miles from their baselines under the provisions set forth in Article 76 of the United Nations Convention on the Law of the Sea (UNCLOS). In a preparatory desktop study, the University of New Hampshire’s Center for Coastal and Ocean Mapping/Joint Hydrographic Center analysed existing U.S. bathymetric and geophysical data holdings, identified data adequacy, and survey requirements to prepare a U.S. claim beyond the Exclusive Economical Zone (EEZ). In this paper we describe the methodology for our desktop study with particular emphasis on how we assembled …

Paleomagnetic Chronology Of Arctic Ocean Sediment Cores: Reversals And Excursions -The Conundrum, Reidar Lovlie, Martin Jakobsson, Jan Backman

Center for Coastal and Ocean Mapping

Chronologies of Arctic Ocean sediment cores are mainly based on interpretation of paleomagnetic inclination records. The first paleomagnetic chronology assigned zones with negative inclinations to polarity reversals (Steuerwald et al, 1968) because geomagnetic excursions at that time were a novel observation and had only been reported from lavas. Arctic Ocean sedimentation rates were thus established to be in the mm/ka-range. A general recognition of excursions as real features of the geomagnetic field emerged more than three decades later, and presently there is still no consensus regarding the number (or name), duration and age of global synchronous excursions within the Brunhes …

The International Bathymetric Chart Of The Arctic Ocean (Ibcao): An Improved Morphological Framework For Oceanographic Investigations, Ron Macnab, Martin Jakobsson

Center for Coastal and Ocean Mapping

The IBCAO initiative set out in late 1997 to assemble and merge all available bathymetric observations from northern regions, with the intent of constructing a reliable and up-to-date portrayal of the Arctic seabed in digital and printed form. In early 2000, a provisional grid and map were placed in circulation for public review and comment. Available for free downloading from a website hosted by the U.S. National Geophysical Data Center, these products won immediate acceptance from a broad spectrum of Arctic investigators who recognized the potential worth of the new information in a variety of applications ranging from straightforward map …

Study Of Energy Sampling Weights In The Dø Detector Using Multiparameter Fitting Method, Qun Yu

Doctoral Dissertations

The DØ calorimeter at Fermilab is a sampling calorimeter measuring the energy of particles produced in high energy proton-antiproton collisions. A set of accurate sampling weights is of significant importance to DØ research activity. The objective of this work was to obtain a set of optimized sampling weights for the DØ central calorimeter, the Inter-Cryostat Detector (ICD), the Central Calorimeter Massless Gap (CCMG), and the End Calorimeter Massless Gap (ECMG).

The foundation of the optimization method is that, in high energy physics, the ratio of energy E and the corresponding momentum P of a particle is approximately 1, in units …

Machine Learning Approaches For Determining Effective Seeds For K -Means Algorithm, Kaveephong Lertwachara

Doctoral Dissertations

In this study, I investigate and conduct an experiment on two-stage clustering procedures, hybrid models in simulated environments where conditions such as collinearity problems and cluster structures are controlled, and in real-life problems where conditions are not controlled. The first hybrid model (NK) is an integration between a neural network (NN) and the k-means algorithm (KM) where NN screens seeds and passes them to KM. The second hybrid (GK) uses a genetic algorithm (GA) instead of the neural network. Both NN and GA used in this study are in their simplest-possible forms.

In the simulated data sets, I investigate two …

Asymptotic Properties Of Self-Energy Coefficients, Ulrich D. Jentschura, Eric Olivier Le Bigot, Peter J. Mohr, Paul Indelicato, Gerhard Soff

Physics Faculty Research & Creative Works

We investigate the asymptotic properties of higher-order binding corrections to the one-loop self-energy of excited states in atomic hydrogen. We evaluate the historically problematic A₆₀ coefficient for all P states with principal quantum numbers n ≤ 7 and D states with n ≤ 8 and find that a satisfactory representation of the n dependence of the coefficients requires a three-parameter fit. For the high-energy contribution to A₆₀, we find exact formulas. The results obtained are relevant for the interpretation of high-precision laser spectroscopic measurements.

Intensional Logic And Topology, Andrew Scott Buchanan

Student Work

This thesis is concerned with mathematical logic, in particular it is an investigation of a branch of mathematical logic called modal logic. This branch of mathematical logic extends the propositional calculus by adding two unary operators □ and 0 to the standard set of logical operators. This extension of classical logic has many interpretations; traditionally it is said to be the logic of necessity, denoted by the box operator, and possibility, denoted by the diamond operator. The notion of necessity within modal logic is ubiquitous and lends itself to a vast sea of metaphysics. For example, if X is necessarily …

An Efficient Targeting Strategy For Multiobject Spectrograph Surveys: The Sloan Digital Sky Survey “Tiling” Algorithm, Michael R. Blanton, Huan Lin, Robert H. Lupton, F. Miller Maley, Neal Young

Dartmouth Scholarship

Large surveys using multiobject spectrographs require automated methods for deciding how to efficiently point observations and how to assign targets to each pointing. The Sloan Digital Sky Survey (SDSS) will observe around 106 spectra from targets distributed over an area of about 10,000 deg2 , using a multiobject fiber spectrograph that can simultaneously observe 640 objects in a circular field of view (referred to as a ‘‘ tile ’’) 1= 49 in radius. No two fibers can be placed closer than 5500 during the same observation; multiple targets closer than this distance are said to ‘‘ collide.’’ We present here …

Virginia's Capital Jurors, Stephen P. Garvey, Paul Marcus

Cornell Law Faculty Publications

Next to Texas, no state has executed more capital defendants than Virginia. Moreover, the likelihood of a death sentence actually being carried out is greater in Virginia than it is elsewhere, while the length of time between the imposition of a death sentence and its actual execution is shorter. Virginia has thus earned a reputation among members of the defense bar as being among the worst of the death penalty states. Yet insofar as these facts about Virginia's death penalty relate primarily to the behavior of state and federal appellate courts, they suggest that what makes Virginia's death penalty unique …

The Government As Litigant: Further Tests Of The Case Selection Model, Theodore Eisenberg, Henry Farber

Cornell Law Faculty Publications

We develop a model of the plaintiff's decision to file a lawsuit that has implications for how differences between the federal government and private litigants translate into differences in trial rates and plaintiff win rates at trial. Our case selection model generates a set of predictions for relative trial rates and plaintiff win rates, depending on the type of case and whether the government is defendant or plaintiff. To test the model, we use data on about 474,000 cases filed in federal district court between 1979 and 1994 in the areas of personal injury and job discrimination, in which the …

ข่าวกิจกรรมและสิ่งแวดล้อม

Thai Environment

No abstract provided.

แนวความคิดการสร้างเครื่องมือทางเศรษฐศาสตร์ และเครื่องมือทางสังคมในการประเมินผลการอนุรักษ์พลังงาน, เสถียร รุจิรวนิช

Thai Environment

No abstract provided.

การควบคุม ป้องกันกลิ่น จากระบบบำบัดน้ำเสียสำเร็จรูป, นุชนาถ แช่มช้อย

Thai Environment

No abstract provided.

สิ่งแวดล้อมกับรัฐประศาสนโยบาย, วิชาญ กิตติสุขสันต์

Thai Environment

No abstract provided.

การเรียนรู้จากสิ่งแวดล้อมริมทางหลวงแผ่นดิน, พรทิพย์ โภไคยอุดม

Thai Environment

No abstract provided.

แนวทางการจัดเก็บน้ำมันหล่อลื่นใช้แล้ว, สิริพร แก่นสียา

Thai Environment

No abstract provided.

การดำเนินงานตามแผนปฏิบัติการ 21 ของอิสราเอล [Towards Local Agenda 21], กนกธร ดำรงวัฒน

Thai Environment

No abstract provided.

บทสัมภาษณ์ : โครงการธนาคารความดี โรงเรียนธัญญสิทธิศิลป์

Thai Environment

No abstract provided.

กิจกรรม

Thai Environment

No abstract provided.

สร้างโลกสวย

Thai Environment

No abstract provided.

สิ่งแวดล้อมน่ารู้

Thai Environment

No abstract provided.

User Interface Improvement For Mlpq System, Shasha Wu

Department of Computer Science and Engineering: Dissertations, Theses, and Student Research

This thesis describes the experience of migrating the MLPQ constraint database system, a complex standalone Multiple Document Interface (MDI) application, to a server-based remote accessible application. Centralized, standalone MDI application is a common style for personal software products in Windows. For a database management system, server-based, thin-client computing is a more popular infrastructure. Migrating an existing standalone constraint database application to be a web accessible constraint database server is the main goal of this thesis. This migration process provides a method for the constraint database system to collaborate with other specific applications. We rebuild the desktop MLPQ constraint database system …

Regio- And Stereoselective Ruthenium Catalyzed Hydrovinylation Of 1,3-Dienes: Application To The Generation Of A 20s-Steroidal Sidechain, Zhengjie He, Chae S. Yi, William A. Donaldson

Chemistry Faculty Research and Publications

The addition of ethylene to 1,3-dienes and 1-vinylcycloalkenes, catalyzed by two ruthenium complexes, proceeds in a regioselective fashion to afford 3-methyl-1,4-dienes as products. For a steroidal-based 1-vinylcycloalkene, the addition is stereospecific, giving a product with a 20(S) configuration.

Co-Catalytic Metallopeptidases As Pharmaceutical Targets, Richard C. Holz, Krzysztof P. Bzymek, Sabina I. Swierczek

Chemistry Faculty Research and Publications

Understanding the reaction mechanism of co-catalytic metallopeptidases provides a starting point for the design and synthesis of new molecules that can be screened as potential pharmaceuticals. Many of the enzymes that contain co-catalytic metallo-active sites play important roles in cellular processes such as tissue repair, protein maturation, hormone level regulation, cell-cycle control and protein degradation. Therefore, these enzymes play central roles in several disease states including cancer, HIV, stroke, diabetes, bacterial infections, neurological processes, schizophrenia, seizure disorders, and amyotrophic lateral sclerosis. The mechanism of AAP, an aminopeptidase from Aeromonas proteolytica, is one of the best-characterized examples of a metallopeptidase …