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2002

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Articles 601 - 630 of 3435

Full-Text Articles in Physical Sciences and Mathematics

Decoding Of Images Using Soft-Bits And Markov Random Field Modeling, Alfred Mertins, O. Jamart Sep 2002

Decoding Of Images Using Soft-Bits And Markov Random Field Modeling, Alfred Mertins, O. Jamart

Faculty of Informatics - Papers (Archive)

We combine soft-bit decoding with Markov random field modeling of source signals and apply the proposed technique to image communication over noisy channels. No redundancy is added by the encoder in the form of channel codes. For error correction and concealment, the decoder relies only on the bit-reliability information extracted at the channel output and the random field modeling of natural images. The results obtained show that the proposed method yields excellent performance even under extremely noisy conditions.

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Edge To Edge Measurement-Base Distributed Network Monitoring, Ahsan Habib, Maleq Khan, Bharat Bhargava Sep 2002

Edge To Edge Measurement-Base Distributed Network Monitoring, Ahsan Habib, Maleq Khan, Bharat Bhargava

Department of Computer Science Technical Reports

No abstract provided.

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Representation Of A Quantum Ensemble As A Minimal Set Of Pure States, Thomas E. Skinner, Steffen J. Glaser Sep 2002

Representation Of A Quantum Ensemble As A Minimal Set Of Pure States, Thomas E. Skinner, Steffen J. Glaser

Physics Faculty Publications

The density matrix ρ for an n-level system is decomposed into the minimum number of pure states necessary to calculate physical observables. The corresponding physical system is first represented by a set B of n pure states |βi〉, together with their statistical weights. The time evolution of the system is therefore calculated as B(t)=UB(t0), with the propagator U operating on each member of the set, in contrast to the more laborious ρ(t)=Uρ(t0)U†. At least one of the states can be eliminated from the set by reducing its weight to zero via a …

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Characterization Of Homoepitaxial P-Type Zno Grown By Molecular Beam Epitaxy, David C. Look, D. C. Reynolds, C. W. Litton, R. L. Jones, D. B. Eason, G. Cantwell Sep 2002

Characterization Of Homoepitaxial P-Type Zno Grown By Molecular Beam Epitaxy, David C. Look, D. C. Reynolds, C. W. Litton, R. L. Jones, D. B. Eason, G. Cantwell

Physics Faculty Publications

An N-doped, p-type ZnO layer has been grown by molecular beam epitaxy on an Li-diffused, bulk, semi-insulating ZnO substrate. Hall-effect and conductivity measurements on the layer give: resistivity = 4×101 Ω cm; hole mobility = 2 cm2/V s; and hole concentration = 9×1016 cm−3. Photoluminescence measurements in this N-doped layer show a much stronger peak near 3.32 eV (probably due to neutral acceptor bound excitons), than at 3.36 eV (neutral donor bound excitons), whereas the opposite is true in undoped ZnO. Calibrated, secondary-ion mass spectroscopy measurements show an N surface concentration of about …

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Holographic Analysis Of Diffraction Structure Factors, S. Marchesini, N. Mannella, C. S. Fadley, M. A. Van Hove, J. J. Bucher, D. K. Shuh, L. Fabris, M. J. Press, M. W. West, Wayne C. Stolte, Z. Hussain Sep 2002

Holographic Analysis Of Diffraction Structure Factors, S. Marchesini, N. Mannella, C. S. Fadley, M. A. Van Hove, J. J. Bucher, D. K. Shuh, L. Fabris, M. J. Press, M. W. West, Wayne C. Stolte, Z. Hussain

Chemistry and Biochemistry Faculty Research

We combine the theory of inside-source/inside-detector x-ray fluorescence holography and Kossel lines/x ray standing waves in kinematic approximation to directly obtain the phases of the diffraction structure factors. The influence of Kossel lines and standing waves on holography is also discussed. We obtain partial phase determination from experimental data obtaining the sign of the real part of the structure factor for several reciprocal lattice vectors of a vanadium crystal.

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Two-Dimensional Ds/Cft Correspondence, Mariano Cadoni, P. Carta, Marco Cavaglia, S. Mignemi Sep 2002

Two-Dimensional Ds/Cft Correspondence, Mariano Cadoni, P. Carta, Marco Cavaglia, S. Mignemi

Physics Faculty Research & Creative Works

We investigate de Sitter/conformal field theory (dS/CFT) correspondence in two dimensions. We define the conserved mass of de Sitter spacetime and formulate the correspondence along the lines of the anti–de Sitter/conformal field theory duality. The asymptotic symmetry group, mass, and central charge of de Sitter spacetime are equal to those of anti–de Sitter spacetime. The entropy of two-dimensional de Sitter spacetime is evaluated by applying the Cardy formula. We calculate the boundary correlators induced by the propagation of the dilaton in two-dimensional de Sitter space. Although the dilaton is a tachyonic perturbation in the bulk, boundary conformal correlators have a …

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The Liouville-Bratu-Gelfand Problem For Radial Operators, Jon T. Jacobsen, Klaus Schmitt Sep 2002

The Liouville-Bratu-Gelfand Problem For Radial Operators, Jon T. Jacobsen, Klaus Schmitt

All HMC Faculty Publications and Research

We determine precise existence and multiplicity results for radial solutions of the Liouville–Bratu–Gelfand problem associated with a class of quasilinear radial operators, which includes perturbations of k-Hessian and p-Laplace operators.

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Effect Of Grain Growth Inhibitors On The Hysteresis Properties Of Nd10Fe82C6B2Melt-Spun Alloys, M. Daniil, Y. Zhang, H. Okumura, George C. Hadjipanayis, David J. Sellmyer Sep 2002

Effect Of Grain Growth Inhibitors On The Hysteresis Properties Of Nd10Fe82C6B2Melt-Spun Alloys, M. Daniil, Y. Zhang, H. Okumura, George C. Hadjipanayis, David J. Sellmyer

David Sellmyer Publications

An effort has been made to improve the coercivity of nanocomposite Nd10Fe82C6B2 alloys, using small amounts (up to 1 at%) of Cr, Ti, Nb, Zr, and Ga. X-ray studies revealed that the amount of –Fe phase in both as-spun and annealed ribbons was significantly reduced for Nb and Zr substitutions, but increased for all the other substitutions. From the magnetic properties point of view, Zr (1 at%) was proven to be the most advantageous of all, since it increased the coercivity of annealed ribbons from 3.2 to 4.8 kOe and the maximum energy …

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Permanent-Magnet Properties Of Thermally Processed Fept And Fept–Fe Multilayer Films, Jian Zhou, Ralph Skomski, Xingzhong Li, Wei Tang, George C. Hadjipanayis, David J. Sellmyer Sep 2002

Permanent-Magnet Properties Of Thermally Processed Fept And Fept–Fe Multilayer Films, Jian Zhou, Ralph Skomski, Xingzhong Li, Wei Tang, George C. Hadjipanayis, David J. Sellmyer

David Sellmyer Publications

FePt single-layer and FePt–Fe multilayer thin films are prepared by magnetron sputtering. By varying the Pt content, FePt, Fe3Pt, or a mixture of FePt and Fe3Pt can be obtained in Fe–Pt single layers. In annealed FePt–Fe multilayers, the coercivities decrease with the introduction of Fe layers compared to FePt single layers, while the magnetization increases. The single-phase behavior of the hysteresis loops of FePt–Fe multilayers indicates the existence of exchange coupling in these materials. For one FePt–Fe sample with optimized exchange coupling, the intrinsic properties correspond to an energy product of 19 MGOe. The texture of …

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The Microbial And Metazoan Community Associated With Colonies Of Trichodesmium Spp.: A Quantitative Survey, Cc Sheridan, Deborah K. Steinberg, Gw Kling Sep 2002

The Microbial And Metazoan Community Associated With Colonies Of Trichodesmium Spp.: A Quantitative Survey, Cc Sheridan, Deborah K. Steinberg, Gw Kling

VIMS Articles

Association with resource-rich particles may benefit a number of planktonic species in oligotriphic, open-ocean regimes. This study examined communities of microbes and Zooplankton associated with colonies of the cyanobacterium Trichodesmium spp. in the Sargasso Sea. Trichodesmium colonies and seawater controls were collected near Bermuda using SCUBA during September 1995, and June, July and August 1996. Organisms associated with the colonies and those in the surrounding seawater were enumerated using light and fluorescence microscopy. We found that 85% of the Trichodesmium puff and tuft colonies examined harbored associated organisms. Associated organisms included bacteria (rod and coccoid),fungi, pennate diatoms, centric diatoms, heterotrophic …

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Wiyn Open Cluster Study. Xi. Wiyn 3.5 Meter Deep Photometry Of M35 (Ngc 2168), Ted Von Hippel, Aaron Steinhauer, Ata Sarajedini, Constantine P. Deliyannis Sep 2002

Wiyn Open Cluster Study. Xi. Wiyn 3.5 Meter Deep Photometry Of M35 (Ngc 2168), Ted Von Hippel, Aaron Steinhauer, Ata Sarajedini, Constantine P. Deliyannis

Publications

We present deep BVI observations of the core of M35 and a nearby comparison field obtained at the WIYN 3.5 m telescope under excellent seeing conditions. These observations probe to V > 26 and display the lower main sequence in BV and VI CMDs down to V = 23.3 and 24.6, respectively. At these faint magnitudes the background Galactic field stars are far more numerous than the cluster stars, yet by using a smoothing technique and CMD density distribution subtraction we are able to recover the cluster fiducial main sequence and luminosity function to V = 24.6. We find the location …

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Analysis Of The N-Card Version Of The Game Le Her, Arthur T. Benjamin, Alan J. Goldman Sep 2002

Analysis Of The N-Card Version Of The Game Le Her, Arthur T. Benjamin, Alan J. Goldman

All HMC Faculty Publications and Research

We present a complete solution to a card game with historical origins. Our analysis exploits the convexity properties in the payoff matrix, allowing this discrete game to be resolved by continuous methods.

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Infinitely Many Nonradial Solutions To A Superlinear Dirichlet Problem, Hugo Aduén, Alfonso Castro Sep 2002

Infinitely Many Nonradial Solutions To A Superlinear Dirichlet Problem, Hugo Aduén, Alfonso Castro

All HMC Faculty Publications and Research

In this article we provide sufficient conditions for a superlinear Dirichlet problem to have infinitely many nonradial solutions. Our hypotheses do not require the nonlinearity to be an odd function. For the sake of simplicity in the calculations we carry out details of proofs in a ball. However, the proofs go through for any annulus.

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The Nadca Probe, Issue 224 Sep 2002

The Nadca Probe, Issue 224

The Probe: Newsletter of the National Animal Damage Control Association


Development of Training Curricula for the Private I Wildlife Control Industry
What is catnip and are all cats attracted to it?
CALENDAR OF UPCOMING EVENTS
Damage Control, Springfield, Massachusetts
"Comprehensive Guide to Professional Mole Control" by Bob Jameson
Big-Ticket Mice
Free-Ranging Cats Publication Available
Graduate Student Opportunities at the Berryman Institute
A Review of the Impact of Predation on Sage-Grouse Populations

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Polarized Neutron Diffraction And Mössbauer Spectral Study Of Short-Range Magnetic Correlations In The Ferrimagnetic Layered Compounds (Pph₄) [FeIiFeIii(Ox)₃] And (Nbu₄) [FeIiFeIii(Ox)₃], Simon G. Carling, Dirk W. Visser, Dimitri Hautot, Ian D. Watts, Peter Day, Jürgen Ensling, Phillip Gütlich, Gary J. Long, Fernande Grandjean Sep 2002

Polarized Neutron Diffraction And Mössbauer Spectral Study Of Short-Range Magnetic Correlations In The Ferrimagnetic Layered Compounds (Pph₄) [FeIiFeIii(Ox)₃] And (Nbu₄) [FeIiFeIii(Ox)₃], Simon G. Carling, Dirk W. Visser, Dimitri Hautot, Ian D. Watts, Peter Day, Jürgen Ensling, Phillip Gütlich, Gary J. Long, Fernande Grandjean

Chemistry Faculty Research & Creative Works

Short-range antiferromagnetic correlations have been studied in the layered compounds (PPh4) [FeIIFeIII(ox)3] and (NBu4) [FeIIFeIII(ox)3] by neutron polarization analysis and Mössbauer spectroscopy. Polarized neutron diffraction profiles obtained between 2 and 50 K on (d20-Pph4) [FeIIFeIII(ox)3] show no magnetic Bragg scattering; the lack of such scattering indicates the absence of long-range magnetic order. However, a broad asymmetric feature observed at a Q of ca. 0.8 Å-1 is attributed to two-dimensional short-range magnetic correlations, which …

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Morphologic And Magnetic Properties Of Pd₁₀₀₋ₓfeₓ Nanoparticles Prepared By Ultrasound Assisted Electrochemistry, Maribel Guzman, Jean Luc Delplancke, Gary J. Long, Jacques P. Delwiche, Marie Jeanne Hubin-Franskin, Fernande Grandjean Sep 2002

Morphologic And Magnetic Properties Of Pd₁₀₀₋ₓfeₓ Nanoparticles Prepared By Ultrasound Assisted Electrochemistry, Maribel Guzman, Jean Luc Delplancke, Gary J. Long, Jacques P. Delwiche, Marie Jeanne Hubin-Franskin, Fernande Grandjean

Chemistry Faculty Research & Creative Works

Nanopowdered alloys of Pd100-xFex, with x=4, 6, 8, and 12, have been prepared by ultrasound assisted electrochemistry. The composition of the individual particles, as determined by x-ray fluorescence, and the bulk composition, as determined by atomic absorption, are in agreement within experimental error. Transmission electron microscopy indicates that the nanopowders consist of agglomerates of small grains with a radius of approximately 5 nm, a radius which is confirmed by the broadening of the reflections in the x-ray powder diffraction patterns. X-ray fluorescence analysis of individual grains indicates a homogeneous distribution of palladium and iron throughout the …

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An Environment For Mobile Context-Based Hypermedia Retrieval, James Carswell Sep 2002

An Environment For Mobile Context-Based Hypermedia Retrieval, James Carswell

Conference papers

This paper proposes a novel solution to querying hyperlinked multimedia cultural heritage datasets based on the user's context. Context in this sense is defined as the user's location in virtual space and the particular mobile device being modeled together with user preferences or profile. The purpose is to automatically push relevant data from the database server to the client based on this comprehensive definition of the user's context. Consideration in regard to which mobile device is currently being modeled is a primary filter for determining what data will be sent and in what format. For example, image data will not …

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Normal Mode Mixing And Ferromagnetic Resonance Linewidth, Andrew Kunz, R. D. Mcmichael Sep 2002

Normal Mode Mixing And Ferromagnetic Resonance Linewidth, Andrew Kunz, R. D. Mcmichael

Physics Faculty Research and Publications

The normal modes of an inhomogeneous thin film are obtained by diagonalization of the perturbed Hamiltonian. The resulting modes are mixtures of the spin-wave modes and the uniform mode. We find that the ferromagnetic resonance intensity spectrum of the diagonalized system has a Lorentzian profile, and that the results correspond to the two-magnon model for weak perturbations. For stronger perturbations, the density of states is smoothed, and the spectrum becomes asymmetric due to the low-frequency cutoff of the spin-wave manifold. The technique is expected to be valid for perturbation amplitudes that are large enough to invalidate the assumptions of the …

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Rangeways - Community Based Planning For Ecologically Sustainable Land Use In The Western Australian Goldfields, Alec Holm, Margaret H. Friedel, Donald Burnside, Jennifer Duffecy, David Fitzgerald, Greg Brennan Sep 2002

Rangeways - Community Based Planning For Ecologically Sustainable Land Use In The Western Australian Goldfields, Alec Holm, Margaret H. Friedel, Donald Burnside, Jennifer Duffecy, David Fitzgerald, Greg Brennan

Agriculture reports

Ways to identity and reconcile opportunities tor different land uses while protecting biologically sensitive areas were researched within the Western Australian rangeland from1995 to 2000. The research was undertaken within a framework of community-based regional planning and was underpinned by policies of ecological sustainable development.The research and community structures arising from the work were collectively named the Rangeways project. The purpose was to resolve land use problems through a structural approach to land use planning and the development of processes rather than to devise 'The Plan'.

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Discovery Of A Substellar Companion To The K2 Iii Giant Ɩ Draconis, Sabine Frink, David Mitchell, Andreas Quirrenbach, Debra A. Fischer, Geoffrey W. Marcy, R. Paul Butler Sep 2002

Discovery Of A Substellar Companion To The K2 Iii Giant Ɩ Draconis, Sabine Frink, David Mitchell, Andreas Quirrenbach, Debra A. Fischer, Geoffrey W. Marcy, R. Paul Butler

Physics

We report precise radial velocity measurements of the K giant ɩ Dra (HD 137759, HR 5744, HIP 75458), carried out at Lick Observatory, which reveal the presence of a substellar companion orbiting the primary star. A Keplerian fit to the data yields an orbital period of about 536 days and an eccentricity of 0.70. Assuming a mass of 1.05 M8 for ɩ Dra, the mass function implies a minimum companion mass m2 sin i of 8.9 MJ, making it a planet candidate. The corresponding semimajor axis is 1.3 AU. The nondetection of the orbital motion by Hipparcos …

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Preliminary Geochemical Evaluation Of Groundwaters From Wells Of The Nye County Early Warning Drilling Program, Irene Farnham, Klaus J. Stetzenbach, Amy J. Smiecinski Sep 2002

Preliminary Geochemical Evaluation Of Groundwaters From Wells Of The Nye County Early Warning Drilling Program, Irene Farnham, Klaus J. Stetzenbach, Amy J. Smiecinski

Publications (YM)

As part of the Yucca Mountain Oversight program, the Nye County Nuclear Waste Repository Project Office (NWRPO) has established a groundwater monitoring program to protect groundwater resources for the residents of Nye County in Amargosa and Pahrump Valleys. This groundwater monitoring program, referred to as the Nye County Early Warning Drilling Program (NCEWDP), involves drilling a series of wells down-gradient from Yucca Mountain for long term groundwater monitoring and also to provide much needed geologic and hydrologic information in this area. A comprehensive database of aquifer parameters in the alluvial, volcanic, and carbonate aquifers down-gradient hydrogeologically of Yucca Mountain is …

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Illinois River 2001 Pollutant Loads At Arkansas Highway 59 Bridge, Marc A. Nelson, Thomas S. Soerens Sep 2002

Illinois River 2001 Pollutant Loads At Arkansas Highway 59 Bridge, Marc A. Nelson, Thomas S. Soerens

Technical Reports

Automatic water samplers and a U. S. Geological Survey gauging station were established in 1995 on the main stem of the Illinois River at the Arkansas Highway 59 Bridge. Since that time, continuous stage and discharge measurements and water quality sampling have been used to determine pollutant concentrations and loads in the Arkansas portion of the Illinois River. This report represents the results from the measurement and sampling for January 1, 2001 to December 31, 2001.

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3-D Seismic Exploration Project, Ute Indian Tribe, Uintah & Ouray Reservation, Uintah County, Utah, Marc T. Eckels Sep 2002

3-D Seismic Exploration Project, Ute Indian Tribe, Uintah & Ouray Reservation, Uintah County, Utah, Marc T. Eckels

All U.S. Government Documents (Utah Regional Depository)

No abstract provided.

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On The Area Of Hypercube Layouts, Ronald I. Greenberg, Lee Guan Sep 2002

On The Area Of Hypercube Layouts, Ronald I. Greenberg, Lee Guan

Computer Science: Faculty Publications and Other Works

This paper precisely analyzes the wire density and required area in standard styles for the hypercube. It shows that the most natural, regular layout of a hypercube of N^2 nodes in the plane, in a NxN grid arrangement, uses floor(2N/3)+1 horizontal wiring tracks for each row of nodes. (In the process, we see that the number of tracks per row can be reduced by 1 with a less regular design, as can also be seen from an independent argument of Bezrukov et al.) This paper also gives a simple formula for the wire density at any cut position and a …

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Finite Extinction Time For Non-Linear Absorption-Diffusion Equations, Jacob B. Goldberg Sep 2002

Finite Extinction Time For Non-Linear Absorption-Diffusion Equations, Jacob B. Goldberg

Theses and Dissertations

In this thesis, we develop a numerical method in order to approximate the solutions of one-dimensional, non-linear absorption-diffusion equations. We test our method for accuracy against a linear diffusion equation with a solution that can be written in closed form. We then test various types of diffusion and absorption terms to determine which ones produce extinction in finite time. We also develop a numerical method to computationally solve diffusion-free equations. We compare the numerical solutions of the one-dimensional, non-linear absorption-diffusion equation and the diffusion-free equation and we find that for the cases tested, the numerical absorption-diffusion solutions are always less …

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Branching Ratio Measurements Of Exclusive B+ Decays To Charmonium With The Collider Detector At Fermilab, Darin Acosta, Kenneth A. Bloom, Collider Detector At Fermilab Collaboration Sep 2002

Branching Ratio Measurements Of Exclusive B+ Decays To Charmonium With The Collider Detector At Fermilab, Darin Acosta, Kenneth A. Bloom, Collider Detector At Fermilab Collaboration

Kenneth Bloom Publications

We report on measurements of the branching ratios of the decays B+→χc10 (1P)K+ and B+→J/ψK+π+π-, where χc10(1P)→J/ψγ and J/ψ→μ+μ- in pp̅ collisions at √s=1.8 TeV. Using a data sample from an integrated luminosity of 110 pb-1 collected by the Collider Detector at Fermilab we measure the branching ratios to be BR(B+→ χc10(1P)K+)=15.5±5.4(stat)±1.5(syst)±1.3(br)×10-4 and BR(B+→J/ψK+π+π-)=6.9±1.8(stat)±1.1(syst)±0.4(br)×10-4 where (br) is due …

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The Fourier Transform And Some Applications, Christopher Zion Sep 2002

The Fourier Transform And Some Applications, Christopher Zion

Masters Theses & Specialist Projects

none

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Fisheries Research Report No. 141 - A Guide To Good Otolith Cutting, Jerry Jenke Sep 2002

Fisheries Research Report No. 141 - A Guide To Good Otolith Cutting, Jerry Jenke

Fisheries research reports

This is a guide for embedding and sectioning fish otoliths. It is based on many years of otolith sectioning experience and is written as a recipe book for novice and expert alike. Included is a method for the enhancement of the clarity of small otoliths for improved sectioning, development of custom made tools, as well as a list of do’s and don’ts and hints to make the job easier. Use of this guide will assist in the most reliable interpretation of an otolith's internal structure, thereby improving ageing studies in general.

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Mass Profile Of The Infall Region Of The Abell 2199 Supercluster, K. Rines, M. J. Geller, A. Diaferio, A. Mahdavi, J. J. Mohr, G. Wegner Sep 2002

Mass Profile Of The Infall Region Of The Abell 2199 Supercluster, K. Rines, M. J. Geller, A. Diaferio, A. Mahdavi, J. J. Mohr, G. Wegner

Dartmouth Scholarship

Using a redshift survey of 1323 galaxies (1092 new or remeasured) in a region of 95 deg2 centered on the nearby galaxy cluster Abell 2199, we analyze the supercluster containing A2199, A2197, and an X-ray group. The caustic technique accurately reproduces the true mass profiles of simulated simple superclusters (i.e., superclusters for which the virial mass of one cluster is 2–10 times the virial mass of all other clusters in the supercluster). We calculate the masses of the two main components of A2197 (A2197W and A2197E) by using archival X-ray observations and demonstrate that the A2199 supercluster is simple (the …

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Adaptive Harmonic Balance Method For Unsteady, Nonlinear, One-Dimensional Periodic Flows, Raymond C. Maple Sep 2002

Adaptive Harmonic Balance Method For Unsteady, Nonlinear, One-Dimensional Periodic Flows, Raymond C. Maple

Theses and Dissertations

A new adaptive split-domain harmonic balance computational fluid dynamics (CFD) method is developed to solve highly nonlinear time-periodic flows such as those found in turbomachinery. The basic harmonic balance CFD method transforms an unsteady time-periodic problem into a steady-state problem by assuming a solution in the form of a Fourier series in time. The new method employs a unique multi-domain split-operator solution technique to remove a large-series stability restriction present in previous harmonic balance CFD approaches. In addition, the new method adapts the frequency content to the flow, starting with a small number of Fourier frequencies and augmenting the frequency …

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