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2002

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Articles 2911 - 2940 of 3435

Full-Text Articles in Physical Sciences and Mathematics

Animated Vehicle Turning Path Simulation System On An Internet/Intranet Browser, Yuwen Deng Jan 2002

Animated Vehicle Turning Path Simulation System On An Internet/Intranet Browser, Yuwen Deng

Theses Digitization Project

The animated vehicle turning path simulation system on Internet/Intranet web browser presented in this project is intended to provide civil engineers with an easy-to-use, all functional simulation system that could help them with highway and street design.

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Study Of Relative Effectiveness Of Features In Content-Based Image Retrieval, S. R. Subramanya, Jui Che Teng, Yongjian Fu Jan 2002

Study Of Relative Effectiveness Of Features In Content-Based Image Retrieval, S. R. Subramanya, Jui Che Teng, Yongjian Fu

Electrical and Computer Engineering Faculty Research & Creative Works

Content-based retrieval in image databases requires appropriate features of images to be derived and used in the indexing and searching process. Fast and accurate retrieval is crucial from a user point of view. The kinds of features used, their organization in suitable data structures, and the similarity search scheme, directly affect the speed and quality of content-based retrieval. In this paper, we evaluate the relative significance of three different image features - geometry, moments, and Fourier descriptors in the context of content-based retrieval, and present experimental results. The evaluation metrics are retrieval quality and search time. These could be used …

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On The Existence Of Nontrivial Solutions To Some Elliptic Variational Inequalities, Vy Khoi Le, Klaus Schmitt Jan 2002

On The Existence Of Nontrivial Solutions To Some Elliptic Variational Inequalities, Vy Khoi Le, Klaus Schmitt

Mathematics and Statistics Faculty Research & Creative Works

The paper is concerned with the existence of nontrivial solutions of the obstacle problem: u ε K: ∫Ω ▽u▽ (v - u) dx - λ ∫ Ω u (v - u) dx ≥ ∫ Ω p (x, u) (v - u) dx ∀x ε K, where K = {v ε Ho1(Ω): v ≤ Ψ a.e. on Ω}. By using a generalized mountain pass theorem for inequalities, we prove, subject to some restrictions on the obstacle Ψ, the existence of nontrivial solutions of the above inequality.

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Time-Dependent Current-Density-Functional Theory For The Linear Response Of Weakly Disordered Systems, Carsten A. Ullrich, G. Vignale Jan 2002

Time-Dependent Current-Density-Functional Theory For The Linear Response Of Weakly Disordered Systems, Carsten A. Ullrich, G. Vignale

Physics Faculty Research & Creative Works

Time-dependent density-functional theory (TDFT) provides a way of calculating, in principle exactly, the linear response of interacting many-electron systems, and thus allows one to obtain their excitation energies. For extended systems, there exist excitations of a collective nature, such as bulk and surface plasmons in metals or intersubband plasmons in doped semiconductor quantum wells. This paper develops a quantitatively accurate first-principles description for the frequency and the linewidth of such excitations in inhomogeneous weakly disordered systems. A finite linewidth in general has intrinsic and extrinsic sources. At low temperatures and outside the region where electron-phonon interaction occurs, the only intrinsic …

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Technical Assistance Providers' Guide To Extending Your Reach Through Local Economic Development, Iowa Waste Reduction Center Jan 2002

Technical Assistance Providers' Guide To Extending Your Reach Through Local Economic Development, Iowa Waste Reduction Center

Iowa Waste Reduction Center Book Gallery

The Guide to Extending Your Reach through Local Economic Developers was prepared as a step-by-step work plan for technical assistance providers to extend their targeted promotional efforts through local economic developers. Building on existing relationships that the economic developers have with area businesses, the Guide provides advice, support material, and insight into the process of partnering with a local, trusted entity to build a strong foundation in the community with regard to utilizing the provider’s technical assistance program to fill the environmental niche in the business community.

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Observational Limits On Quantum Geometry Effects, Tomasz J. Konopka '02, Seth Major Jan 2002

Observational Limits On Quantum Geometry Effects, Tomasz J. Konopka '02, Seth Major

Articles

Using a form of modified dispersion relations derived in the context of quantum geometry, we investigate limits set by current observations on potential corrections to Lorentz invariance. We use a phenomological model in which there are separate parameters for photons, leptons and hadrons. Constraints on these parameters are derived using thresholds for the processes of photon stability, photon absorption, vacuum Cerenkov radiation, pion stability and the GZK cutoff. Although the allowed region in parameter space is tightly constrained, non-vanishing corrections to Lorentz symmetry due to quantum geometry are consistent with current astrophysical observations.

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Small-Angle Neutron Scattering Of Soot Formed In Laminar Premixed Ethylene Flames, Hai Wang, Bin Zhao, Barbara E. Wyslouzil, Kiril A. Streletzky Jan 2002

Small-Angle Neutron Scattering Of Soot Formed In Laminar Premixed Ethylene Flames, Hai Wang, Bin Zhao, Barbara E. Wyslouzil, Kiril A. Streletzky

Physics Faculty Publications

We used small-angle neutron scattering (SANS) to measure soot development in one-dimensional, laminarpremixed flames. Scattering spectra were collected for two sooting ethylene/oxygen/argon flames at six positions above the burner surface. A detailed analysis of the scattering signals yielded the basic properties of the soot size distributions as a function of position. The experiments demonstrate that SANS can be used to extract spatially resolved, quantitative information about incipient soot formation and growth with better particle size resolution than light scattering and extinction.

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Determination Of Magnetic Exchange Stiffness And Surface Anisotropy Constants In Epitaxial Ni_ {1-X} Co_ {X}(001) Films, P. Talagala, Petru S. Fodor, Haddad R. Naik, Lowell E. Wenger, P. P. Vaishnava, V. M. Naik Jan 2002

Determination Of Magnetic Exchange Stiffness And Surface Anisotropy Constants In Epitaxial Ni_ {1-X} Co_ {X}(001) Films, P. Talagala, Petru S. Fodor, Haddad R. Naik, Lowell E. Wenger, P. P. Vaishnava, V. M. Naik

Physics Faculty Publications

Magnetic characteristics of epitaxial Ni1-xCox(001) (x=0, 0.16, and 0.50) films with nominal 200 nm thickness on Cu(001)/Si(100) substrates have been investigated by magnetization and ferromagnetic resonance measurements in order to better clarify the rationale for the large variation in the magnetic exchange stiffness constant A, previously determined from different measurements. The exchange constant as well as the saturation magnetization, effective demagnetizing field, fourth-order magnetocrystalline, and second-order perpendicular uniaxial magnetic anisotropy fields has been determined. The analyses of low-temperature saturation magnetization data on these films yield A values that increase from 0.82×10-6erg/cm for a pure Ni film to 2.27×10-6erg/cm for the …

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A Simple Demonstration Of Mie Scattering Using An Overhead Projector, Charles L. Adler, James A. Lock Jan 2002

A Simple Demonstration Of Mie Scattering Using An Overhead Projector, Charles L. Adler, James A. Lock

Physics Faculty Publications

No abstract provided.

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Rethinking Mechanistic Explanation, Stuart Glennan Jan 2002

Rethinking Mechanistic Explanation, Stuart Glennan

Scholarship and Professional Work - LAS

Philosophers of science typically associate the causal-mechanical view of scientific explanation with the work of Railton and Salmon. In this paper I shall argue that the defects of this view arise from an inadequate analysis of the concept of mechanism. I contrast Salmon's account of mechanisms in terms of the causal nexus with my own account of mechanisms, in which mechanisms are viewed as complex systems. After describing these two concepts of mechanism, I show how the complex-systems approach avoids certain objections to Salmon's account of causal-mechanical explanation. I conclude by discussing how mechanistic explanations can provide understanding by unification.

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Mixed Signals: Rational-Choice Theories Of Social Norms And The Pragmatics Of Explanation, W. Bradley Wendel Jan 2002

Mixed Signals: Rational-Choice Theories Of Social Norms And The Pragmatics Of Explanation, W. Bradley Wendel

Cornell Law Faculty Publications

The question of how societies secure cooperation and order in the absence of state enforced sanctions has long vexed law and economics scholars. Recently the concept of social norms--informally enforced rules of behavior--has occupied the attention of a large number of these theorists, who are concerned with understanding why economically rational actors would bother to follow rules whose costs seem to outweigh their benefits. Because of the prestige (or at least trendiness) of law and economics, it seems that now everyone in the legal academy is talking about social norms. This burgeoning scholarship is closely related to a wider concern …

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Generalized Moonshine And Orbifold Constructions, Michael Tuite, Rossen Ivanov Jan 2002

Generalized Moonshine And Orbifold Constructions, Michael Tuite, Rossen Ivanov

Conference papers

A brief review is given of some of our recent work on Generalised Monstrous Moonshine using abelian orbifoldings of the Moonshine Module.

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Electrochemical Investigation Of 4'-Haloderivatives Of N,N-Dimethyl-4-Aminoazobenzene, Mustafa Uçar, Ali̇ Osman Solak, M. Levent Aksu, Mehmet Toy Jan 2002

Electrochemical Investigation Of 4'-Haloderivatives Of N,N-Dimethyl-4-Aminoazobenzene, Mustafa Uçar, Ali̇ Osman Solak, M. Levent Aksu, Mehmet Toy

Turkish Journal of Chemistry

In this study, the electrochemical behaviour of 4' -halogene-N,N-dimethyl-4-aminoazobenzene derivatives were investigated using various polarographic and voltammetric methods. The peak potentials of these derivatives were observed to shift towards negative values with increase in pH. The standard rate constants were determined with (Laviron technique) or without (Nicholson and Klingler-Kochi techniques) taking the adsorption phenomena into account. The diffusion coefficients were calculated from the cyclic voltammetric data using the method developed by Garrido. The amount of adsorbed substances (surface excess values) and transfer coefficients for the electron transfer were also determined. These compounds can be quantitatively determined between 1 x 10^{-5} …

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2002 File Geodatabase Containing Photo Point Locations, Aerial Photos, And Flight Maps, City Of Tampa Department Of Sanitary Sewers Bay Study Group, Pete Reehling, Richard Mckenzie Jan 2002

2002 File Geodatabase Containing Photo Point Locations, Aerial Photos, And Flight Maps, City Of Tampa Department Of Sanitary Sewers Bay Study Group, Pete Reehling, Richard Mckenzie

Data Sets

The Bay Study Group was created by the City of Tampa in 1976 to monitor the effects of pollution abatement that occurred in Hillsborough Bay when the city’s wastewater treatment plant was upgraded from primary to advanced treatment in 1979. The Bay Study Group documented a remarkable restoration of water quality parameters and biological indicators in Hillsborough Bay from the mid 1980s until 2009, when it was disbanded. This zip Geodatabase file contains the photo point locations, aerial photos, and flight maps for the year 2002.

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บรรณาธิการแถลง Jan 2002

บรรณาธิการแถลง

Thai Environment

No abstract provided.

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สารบัญ Jan 2002

สารบัญ

Thai Environment

No abstract provided.

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ข่าวกิจกรรมสิ่งแวดล้อม Jan 2002

ข่าวกิจกรรมสิ่งแวดล้อม

Thai Environment

No abstract provided.

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การใช้น้ำอย่างมีประสิทธิภาพ, เผชิญโชค จินตเศรณี Jan 2002

การใช้น้ำอย่างมีประสิทธิภาพ, เผชิญโชค จินตเศรณี

Thai Environment

No abstract provided.

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สิทธิและหน้าที่ของผู้บริโภค, เทวี โพธิผละ Jan 2002

สิทธิและหน้าที่ของผู้บริโภค, เทวี โพธิผละ

Thai Environment

No abstract provided.

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การคุ้มครองสิทธิผู้บริโภค, วินัย ดะห์ลัน Jan 2002

การคุ้มครองสิทธิผู้บริโภค, วินัย ดะห์ลัน

Thai Environment

No abstract provided.

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แนวทางการจัดการและพัฒนาสวนสัตว์ดุสิตในทัศนะของผู้บริหาร, ศศิธร จั่นลา Jan 2002

แนวทางการจัดการและพัฒนาสวนสัตว์ดุสิตในทัศนะของผู้บริหาร, ศศิธร จั่นลา

Thai Environment

No abstract provided.

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ความคิดเห็นของประชาชน : ปัญหาสิ่งแวดล้อม บริเวณพื้นที่อุตสาหกรรมจังหวัดขอนแก่น, ธนพรรณ สุนทระ Jan 2002

ความคิดเห็นของประชาชน : ปัญหาสิ่งแวดล้อม บริเวณพื้นที่อุตสาหกรรมจังหวัดขอนแก่น, ธนพรรณ สุนทระ

Thai Environment

No abstract provided.

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บทสัมภาษณ์ : ผู้ช่วยศาสตราจารย์ ดร.ทวีวงศ์ ศรีบุรี โครงการวิจัย "การพัฒนาและจัดการแหล่งน้ำในพื้นที่ลุ่มน้ำจันทบุรี เพื่อการเกษตรและบริโภคอย่างพอเพียง", สิริพร แก่นสียา, กรชนก รักษาเสรี Jan 2002

บทสัมภาษณ์ : ผู้ช่วยศาสตราจารย์ ดร.ทวีวงศ์ ศรีบุรี โครงการวิจัย "การพัฒนาและจัดการแหล่งน้ำในพื้นที่ลุ่มน้ำจันทบุรี เพื่อการเกษตรและบริโภคอย่างพอเพียง", สิริพร แก่นสียา, กรชนก รักษาเสรี

Thai Environment

No abstract provided.

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สร้างโลกสวย Jan 2002

สร้างโลกสวย

Thai Environment

No abstract provided.

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Negative-Parity Baryon Masses Using An O(A)-Improved Fermion Action, M. Göckeler, R. Horsley, D. Pleiter, P. E. L. Rakow, G. Schierholz, C. M. Maynard, D. G. Richards Jan 2002

Negative-Parity Baryon Masses Using An O(A)-Improved Fermion Action, M. Göckeler, R. Horsley, D. Pleiter, P. E. L. Rakow, G. Schierholz, C. M. Maynard, D. G. Richards

Physics Faculty Publications

We present a calculation of the mass of the lowest-lying negative-parity J=1/2− state in quenched QCD. Results are obtained using a non-perturbatively O(a)-improved clover fermion action, and a splitting is found between the mass of the nucleon, and its parity partner. The calculation is performed on two lattice volumes and at three lattice spacings, enabling a study of both finite-volume and finite lattice-spacing uncertainties. A comparison is made with results obtained using the unimproved Wilson fermion action.

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Η Photoproduction On The Proton For Photon Energies From 0.75 To 1.95 Gev, M. Bektasoglu, K. V. Dharmawardane, G. E. Dodge, C. E. Hyde-Wright, A. Klein, S. E. Kuhn, S. Stepanyan, J. Yun, Et Al., Clas Collaboration Jan 2002

Η Photoproduction On The Proton For Photon Energies From 0.75 To 1.95 Gev, M. Bektasoglu, K. V. Dharmawardane, G. E. Dodge, C. E. Hyde-Wright, A. Klein, S. E. Kuhn, S. Stepanyan, J. Yun, Et Al., Clas Collaboration

Physics Faculty Publications

Differential cross sections for γp→ηp have been measured with tagged real photons for incident photon energies from 0.75 to 1.95 GeV. Mesons were identified by missing mass reconstruction using kinematical information for protons scattered in the production process. The data provide the first extensive angular distribution measurements for the process above W = 1.75  GeV. Comparison with preliminary results from a constituent quark model support the suggestion that a third S11 resonance with mass ∼1.8  GeV couples to the ηN channel.

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Publisher's Note: Η Photoproduction On The Proton For Photon Energies From 0.75 To 1.95 Gev [Phys. Rev. Lett. 89, 222002 (2002)], M. Bektasoglu, K. V. Dharmawardane, G. E. Dodge, C. E. Hyde-Wright, A. Klein, S. E. Kuhn, R. A. Niyazov, S. Stepanyan, L. B. Weinstein, Et Al., Clas Collaboration Jan 2002

Publisher's Note: Η Photoproduction On The Proton For Photon Energies From 0.75 To 1.95 Gev [Phys. Rev. Lett. 89, 222002 (2002)], M. Bektasoglu, K. V. Dharmawardane, G. E. Dodge, C. E. Hyde-Wright, A. Klein, S. E. Kuhn, R. A. Niyazov, S. Stepanyan, L. B. Weinstein, Et Al., Clas Collaboration

Physics Faculty Publications

No abstract provided.

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Phase And Absorption Gratings For Electrons, Hong Gao, Glen Gronniger, Daniel Friemund, Alex Cronin Jan 2002

Phase And Absorption Gratings For Electrons, Hong Gao, Glen Gronniger, Daniel Friemund, Alex Cronin

Department of Physics and Astronomy: Faculty Publications

We report the experimental realization of phase and absorption gratings for electrons. Phase gratings made with standing waves of light with a periodicity of 266 nm are used to diffract 380 eV electrons [1]. Material gratings of 100 and 200 nm periodicity are used to diffract 500 eV electrons. We are exploring the possibility to use these gratings for low energy electron interferometry.

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Chemical Composition Of Particles Of D < 0.20 Mu In The Lower Stratospheric Aerosol, Spring 1993, Joseph D. Scott, David M. Chittenden Ii Jan 2002

Chemical Composition Of Particles Of D < 0.20 Mu In The Lower Stratospheric Aerosol, Spring 1993, Joseph D. Scott, David M. Chittenden Ii

Journal of the Arkansas Academy of Science

The majority of the mass of stratospheric aerosol collected during the spring of 1993 consisted principally of particles of d >0.20 mu containing a mixture of H2SO4 and (NaK)2SO4. However, the composition of the more numerous particles with d< 0.2 mu was very different. X-ray emission spectra (EDS) of individual particles indicated that there were three different chemical populations of small particles. The most numerous population was almost all C with only traces of S and Na. The second population contained metal sulfates and chlorides, possibly accreted to a C-containing matrix. The third population consisted of S- and Cl- containing species and trace amounts of Na and K ions. The number of equivalents of metal ion was much less than that of S and Cl species, indicating that most of the S and Cl was not ionic, but was covalently bonded, perhaps to a C matrix.

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Land-Use Effects On Soil-Water Retention Characteristic, Naomi Colton, Kristofor Brye Jan 2002

Land-Use Effects On Soil-Water Retention Characteristic, Naomi Colton, Kristofor Brye

Discovery, The Student Journal of Dale Bumpers College of Agricultural, Food and Life Sciences

Tillage can negatively affect soil physical properties such as bulk density, organic matter content, and soil hydraulic properties, which in turn affect how plants grow. The objective of this study was to evaluate water retention characteristics of a Jay silt loam soil under cultivated agriculture and native tallgrass prairie in northwest Arkansas. Air-dry soil samples collected from 0-10 cm depth were re-wet with varying amounts of distilled water to create a range of water contents. After overnight equilibration, the water potential was measured on the re-wet soil samples using a dewpoint potentiameter. The relationship between water potential (Ψ) and water …

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