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1998

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Articles 151 - 180 of 2339

Full-Text Articles in Physical Sciences and Mathematics

Environmental Assessment For The Designation Of The Continental Divide National Scenic Trail, United States Department Of The Interior, Bureau Of Land Management Nov 1998

Environmental Assessment For The Designation Of The Continental Divide National Scenic Trail, United States Department Of The Interior, Bureau Of Land Management

Environmental Assessments (WY)

On October 2, 1968, Congress passed the National Trails System Act. This Act called for the establishment of a system of national scenic trails "which will be extended trails so located as to provide for maximum outdoor recreation potential and for the conservation and enjoyment of the nationally significant scenic, historic, natural, or cultural qualities of the areas through which such trails may pass." As a result of the 1978 amendment to this Act, Congress designated the Continental Divide National Scenic Trail (CDNST) as part of the National Scenic Trail system. The CDNST is a trail route traversing the length …


Dynamics Of Biomolecules: Assignment Of Local Motions By Fluorescence Anisotropy Decay, Carl N. Bialik, Barnabas Wolf, Edward L. Rachofsky, J. B. A. Ross, William Laws Nov 1998

Dynamics Of Biomolecules: Assignment Of Local Motions By Fluorescence Anisotropy Decay, Carl N. Bialik, Barnabas Wolf, Edward L. Rachofsky, J. B. A. Ross, William Laws

Chemistry and Biochemistry Faculty Publications

Many biological systems have multiple fluorophores that experience multiple depolarizing motions, requiring multiple lifetimes and correlation times to define the fluorescence intensity and anisotropy decays, respectively. To simplify analyses, an assumption often made is that all fluorophores experience all depolarizing motions. However, this assumption usually is invalid, because each lifetime is not necessarily associated with each correlation time. To help establish the correct associations and recover accurate kinetic parameters, a general kinetic scheme that can examine all possible associations is presented. Using synthetic data sets, the ability of the scheme to discriminate among all nine association models possible for two …


Santa Clara Magazine, Volume 40 Number 3, November 1998, Santa Clara University Nov 1998

Santa Clara Magazine, Volume 40 Number 3, November 1998, Santa Clara University

Santa Clara Magazine

8 - EARTHBOUND IN TUSCANY By Susan Vogel. Cultivating the soil and restoring a Tuscan farmhouse became regenerative physically and spiritually for SCU English professor Edward Kleinschmidt.

14 - PREMIES By Sue Frey. Kathy (Straus) VandenBerg '66 pioneers a rule-defying path, as she puts tenderness and love above tubes and isolation in caring for premature newborns.

18 - SEA HUNT By Connie Hinckley. SCU SCREEM team members probe the blue-black waters of the Arctic Ocean for historic bounty using high-tech robotics.

26 - THE VILLAGE PEOPLE By Kathleen (Nino) Castello '88. Some 40 years ago a community of ex-GIs and …


Parity Nonconservation In Neutron Capture On 113cd, S J. Seestrom, J D. Bowman, Bret E. Crawford, P P J. Delheij, C M. Frankle, C R. Gould, D G. Haase, M Iinuma, J N. Knudsen, P E. Koehler, L Y. Lowie, A Masaike, Y Matsuda, G E. Mitchell, S I. Penttila, Y P. Popov, H Postma, N R. Roberson, E I. Sharapov, H M. Shimizu, D A. Smith, Sharon L. Stephenson, Y-F Yen, V W. Yuan Nov 1998

Parity Nonconservation In Neutron Capture On 113cd, S J. Seestrom, J D. Bowman, Bret E. Crawford, P P J. Delheij, C M. Frankle, C R. Gould, D G. Haase, M Iinuma, J N. Knudsen, P E. Koehler, L Y. Lowie, A Masaike, Y Matsuda, G E. Mitchell, S I. Penttila, Y P. Popov, H Postma, N R. Roberson, E I. Sharapov, H M. Shimizu, D A. Smith, Sharon L. Stephenson, Y-F Yen, V W. Yuan

Physics and Astronomy Faculty Publications

Parity nonconservation was studied for 23 p-wave resonances in 113Cd up to En=500eV at the LANSCE pulsed neutron source using a longitudinally polarized neutron beam and the time-of-flight method. The helicity dependence of the total neutron capture cross section was measured with an enriched 113Cd target and with a target of natural cadmium. Parity violating effects were observed for several resonances in 113Cd and 111Cd. A root-mean-square value of the parity nonconserving matrix element MJ=1=2.9-0.9+1.3meV was obtained for the spin J=1 levels in the compound nucleus 114Cd. This …


Monte Carlo Simulation Of An Ion-Dipole Mixture As A Model Of An Electrical Double Layer, Douglas Henderson, Dezso Boda, Kwong-Yu Chan Nov 1998

Monte Carlo Simulation Of An Ion-Dipole Mixture As A Model Of An Electrical Double Layer, Douglas Henderson, Dezso Boda, Kwong-Yu Chan

Faculty Publications

Canonical Monte Carlo simulations were performed for a nonprimitive model of an electrical double layer. The ions and the solvent molecules are modeled as charged and dipolar hard spheres, respectively, while the electrode as a hard, impenetrable wall carrying uniform surface charge. We found that the ion-dipole model gives a reasonable description of the double layer for partially charged ions with small to moderate dipole moments, or equivalently for an "effective" dielectric constant. Density, polarization and mean electrostatic potential profiles are reported. Strong layering structure, and at higher charges, charge inversion in the second layer were found. With appropriate choices …


Development Of A Hard X-Ray Polarimeter For Astrophysics, Mark L. Mcconnell, John R. Macri, M Mcclish, James M. Ryan, D J. Forrest, W T. Vestrand Nov 1998

Development Of A Hard X-Ray Polarimeter For Astrophysics, Mark L. Mcconnell, John R. Macri, M Mcclish, James M. Ryan, D J. Forrest, W T. Vestrand

Space Science Center

We have been developing a Compton scatter polarimeter for measuring the linear polarization of hard X-rays (100-300 keV) from astrophysical sources. A laboratory prototype polarimeter has been used to successfully demonstrate the reliability of our Monte Carlo simulation code and to demonstrate our ability to generate a polarized photon source in the lab. Our design concept places a self-containedpolarimeter module on the front-end of a a 5-inch position sensitive PMT (PSPMT). We are currently working on the fabrication of a science model based on this PSPMT concept. Although the emphasis of our development effort is towards measuring hard X-rays from …


Center For Sustainable Agricultural Systems Newsletter, November/December 1998 Nov 1998

Center For Sustainable Agricultural Systems Newsletter, November/December 1998

Center for Sustainable Agricultural Systems: Newsletter (1993–2000)

Contents:

Grants to Teach Sustainable Agriculture

Spring CSAS Seminar Series: Re-Integrating Agriculture and Community in the Midwest

Highlights of Upcoming New Book: Under the Blade (Part 4)

Watershed Information Flows Along the Internet

Nordic Agroecology Program Begins August 1999

Beef Home Study Courses Begin Fifth Year

Two On-farm Assessment Tools


Quasars As Cosmological Probes: The Ionizing Continuum, Gas Metallicity, And The WΛ-L Relation, Kirk Korista, Jack Baldwin, Gary J. Ferland Nov 1998

Quasars As Cosmological Probes: The Ionizing Continuum, Gas Metallicity, And The WΛ-L Relation, Kirk Korista, Jack Baldwin, Gary J. Ferland

Physics and Astronomy Faculty Publications

Using a realistic model for line emission from the broad emission line regions of quasars, we are able to reproduce the previously observed correlations of emission-line ratios with the shape of the spectral energy distribution (SED). In agreement with previous studies, we find that the primary driving force behind the Baldwin effect (Wλ ~ Lβ, β < 0) is a global change in the SED with quasar luminosity, in that more luminous quasars must have characteristically softer ionizing continua. This is completely consistent with observations that show (1) a correlation between Luv, αox, and αuvx (2) correlations of SED shape-sensitive line ratios with αox, αuvx, and Luv; and (3) correlations between line equivalent widths and αox, αuvx …


Inhibition Of The Aminopeptidase From Aeromonas Proteolytica By L-Leucinephosphonic Acid, A Transition State Analogue Of Peptide Hydrolysis, Brian Bennett, Richard C. Holz Nov 1998

Inhibition Of The Aminopeptidase From Aeromonas Proteolytica By L-Leucinephosphonic Acid, A Transition State Analogue Of Peptide Hydrolysis, Brian Bennett, Richard C. Holz

Physics Faculty Research and Publications

No abstract provided.


Simple Model For Linear And Nonlinear Mixing At Unstable Fluid Interfaces With Variable Acceleration, John D. Ramshaw Nov 1998

Simple Model For Linear And Nonlinear Mixing At Unstable Fluid Interfaces With Variable Acceleration, John D. Ramshaw

Physics Faculty Publications and Presentations

A simple model is described for predicting the time evolution of the half-width h of a mixing layer between two initially separated immiscible fluids of different density subjected to an arbitrary time-dependent variable acceleration history a(t). The model is based on a heuristic expression for the kinetic energy per unit area of the mixing layer. This expression is based on that for the kinetic energy of a linearly perturbed interface, but with a dynamically renormalized wavelength which becomes proportional to h in the nonlinear regime. An equation of motion for h is then derived from Lagrange's equations. This model reproduces …


A Theory Of Satisficing Decisions And Control, Richard L. Frost, Michael A. Goodrich, Wynn C. Stirling Nov 1998

A Theory Of Satisficing Decisions And Control, Richard L. Frost, Michael A. Goodrich, Wynn C. Stirling

Faculty Publications

The existence of an optimal control policy and the techniques for finding it are grounded fundamentally in a global perspective. These techniques can be of limited value when the global behavior of the system is difficult to characterize, as it may be when the system is nonlinear, when the input is constrained, or when only partial information is available regarding system dynamics or the environment. Satisficing control theory is an alternative approach that is compatible with the limited rationality associated with such systems. This theory is extended by the introduction of the notion of strong satisficing to provide a systematic …


High-Resolution Electron Time-Of-Flight Apparatus For The Soft-X-Ray Region, Oliver Hemmers, S. B. Whitfield, P. Glans, H. Wang, Dennis W. Lindle, R. Wehlitz, I. A. Sellin Nov 1998

High-Resolution Electron Time-Of-Flight Apparatus For The Soft-X-Ray Region, Oliver Hemmers, S. B. Whitfield, P. Glans, H. Wang, Dennis W. Lindle, R. Wehlitz, I. A. Sellin

Environmental Studies Faculty Publications

A gas-phase time-of-flight (TOF) apparatus, capable of supporting as many as six electron-TOF analyzers viewing the same interaction region, has been developed to measure energy- and angle-resolved electrons with kinetic energies up to 5 keV. Each analyzer includes a newly designed lens system that can retard electrons to about 2% of their initial kinetic energy without significant loss of transmission; the analyzers can thus achieve a resolving power (E/ΔE) greater than 104 over a wide kinetic-energy range. Such high resolving power is comparable to the photon energy resolution of state-of-the-art synchrotron–radiation beamlines in the soft …


Photofragmentation Of Third-Row Hydrides Following Photoexcitation At Deep-Core Levels, D. Hansen, M. E. Arrasate, J. Cotter, G. R. Fisher, Oliver Hemmers, K. T. Leung, Jon C. Levin, R. Martin, Paul Neill, Rupert C. Perera, I. A. Sellin, Marc Simon, Y. Uehara, B. Vanderford, S. B. Whitfield, Dennis W. Lindle Nov 1998

Photofragmentation Of Third-Row Hydrides Following Photoexcitation At Deep-Core Levels, D. Hansen, M. E. Arrasate, J. Cotter, G. R. Fisher, Oliver Hemmers, K. T. Leung, Jon C. Levin, R. Martin, Paul Neill, Rupert C. Perera, I. A. Sellin, Marc Simon, Y. Uehara, B. Vanderford, S. B. Whitfield, Dennis W. Lindle

Environmental Studies Faculty Publications

The relaxation dynamics of HCl, DCl, H2S, and D2S following photoexcitation in the vicinities of the Cl and S K-shell thresholds (∼2.8keV for Cl, ∼2.5 keV for S) were studied by means of ion time-of-flight mass spectroscopy. In all cases, the onset of pre-edge core-shell photoionization precedes the formation on resonance of a significant amount of neutral hydrogen as well as postcollision-interaction effects above threshold. Examination of the width of the H+ peak in spectra taken with the analyzer parallel and perpendicular to the polarization vector of the incident light indicates that on resonance, the …


Photofragmentation Of Third-Row Hydrides Following Photoexcitation At Deep-Core Levels, D. L. Hansen, M. E. Arrasate, J. Cotter, G. R. Fisher, Oliver Hemmers, K. T. Leung, Jon C. Levin, R. Martin, Paul Neill, Rupert C. Perera, I. A. Sellin, Marc Simon, Y. Uehara, B. Vanderford, S. B. Whitfield, Dennis W. Lindle Nov 1998

Photofragmentation Of Third-Row Hydrides Following Photoexcitation At Deep-Core Levels, D. L. Hansen, M. E. Arrasate, J. Cotter, G. R. Fisher, Oliver Hemmers, K. T. Leung, Jon C. Levin, R. Martin, Paul Neill, Rupert C. Perera, I. A. Sellin, Marc Simon, Y. Uehara, B. Vanderford, S. B. Whitfield, Dennis W. Lindle

X-Ray Atomic and Molecular Science Program

The relaxation dynamics of HCl, DCl, H2S, and D2S following photoexcitation in the vicinities of the Cl and S K-shell thresholds (~2.8 keV for Cl, ~2.5 keV for S) were studied by means of ion time-of-flight mass spectroscopy. In all cases, the onset of pre-edge core-shell photoionization precedes the formation on resonance of a significant amount of neutral hydrogen as well as postcollision-interaction effects above threshold. Examination of the width of the H+ peak in spectra taken with the analyzer parallel and perpendicular to the polarization vector of the incident light indicates that on resonance, …


Information Coupling In Web Databases, Sourav S. Bhowmick, Wee-Keong Ng, Ee Peng Lim Nov 1998

Information Coupling In Web Databases, Sourav S. Bhowmick, Wee-Keong Ng, Ee Peng Lim

Research Collection School Of Computing and Information Systems

Web information coupling refers to an association of topically related web documents. This coupling is initiated explicitly by a user in a web warehouse specially designed for web information. Web information coupling provides the means to derive additional, useful information from the WWW. In this paper, we discuss and show how two web operators, i.e., global web coupling and local web coupling, are used to associate related web information from the WWW and also from multiple web tables in a web warehouse. This paper discusses various issues in web coupling such as coupling semantics, coupling-compability, and coupling evaluation.


Comparison Of Water And Temperature Distribution Profiles Under Sand Tube Irrigation, Masoud Meshkat, Richard C. Warner, Stephen R. Workman Nov 1998

Comparison Of Water And Temperature Distribution Profiles Under Sand Tube Irrigation, Masoud Meshkat, Richard C. Warner, Stephen R. Workman

Biosystems and Agricultural Engineering Faculty Publications

Drip irrigation is one of the most efficient systems in delivering water to the plant root zone. Research has shown that the saturated, or nearly saturated, surface beneath the emitter may increase evaporation thereby reducing the irrigation efficiency. To increase the efficiency of surface applied drip irrigation on permanent tree crops a sand tube irrigation (STI) method was developed and tested. The sand tube method consists of removing a soil core beneath the emitter and filling the void with coarse sand. A weighing lysimeter was designed and instrumented to directly measure temporal evaporation during irrigation and for a period of …


Conserved Geometrical Base-Pairing Patterns In Rna, Neocles B. Leontis, Eric Westhof Nov 1998

Conserved Geometrical Base-Pairing Patterns In Rna, Neocles B. Leontis, Eric Westhof

Chemistry Faculty Publications

RNA molecules fold into a bewildering variety of complex 3D structures. Almost every new RNA structure obtained at high resolution reveals new, unanticipated structural motifs, which we are rarely able to predict at the current stage of our theoretical understanding. Even at the most basic level of specific RNA interactions – base-to-base pairing – new interactions continue to be uncovered as new structures appear. Compilations of possible non-canonical base-pairing geometries have been presented in previous reviews and monographs (Saenger, 1984; Tinoco, 1993). In these compilations, the guiding principle applied was the optimization of hydrogen-bonding. All possible pairs with two standard …


Stability And Reconstruction For An Inverse Problem For The Heat Equation, Kurt Bryan, Lester Caudill Nov 1998

Stability And Reconstruction For An Inverse Problem For The Heat Equation, Kurt Bryan, Lester Caudill

Department of Math & Statistics Faculty Publications

We examine the inverse problem of determining the shape of some unknown portion of the boundary of a region Ω from measurements of the Cauchy data for solutions to the heat equation on Ω. By suitably linearizing the inverse problem we obtain uniqueness and continuous dependence results. We propose an algorithm for recovering estimates of the unknown portion of the surface and use the insight gained from a detailed analysis of the inverse problem to regularize the inversion. Several computational examples are presented.


Uniqueness For A Boundary Identification Problem In Thermal Imaging, Kurt Bryan, Lester Caudill Nov 1998

Uniqueness For A Boundary Identification Problem In Thermal Imaging, Kurt Bryan, Lester Caudill

Department of Math & Statistics Faculty Publications

An inverse problem for an initial-boundary value problem is considered. The goal is to determine an unknown portion of the boundary of a region in ℝn from measurements of Cauchy data on a known portion of the boundary. The dynamics in the interior of the region are governed by a differential operator of parabolic type. Utilizing a unique continuation result for evolution operators, along with the method of eigenfunction expansions, it is shown that uniqueness holds for a large and physically reasonable class of Cauchy data pairs.


A Photometric And Kinematic Study Of Awm 7, Daniel M. Koranyi, Margaret Geller, Joseph J. Mohr, Gary Wegner Nov 1998

A Photometric And Kinematic Study Of Awm 7, Daniel M. Koranyi, Margaret Geller, Joseph J. Mohr, Gary Wegner

Dartmouth Scholarship

We have measured redshifts and Kron-Cousins R-band magnitudes for a sample of galaxies in the poor cluster AWM 7. We have measured redshifts for 172 galaxies; 106 of these are cluster members. We determine the luminosity function (LF) from a photometric survey of the central 1.2 × 1.2 h-1 Mpc. The LF has a bump at the bright end and a faint-end slope of α = -1.37 ± 0.16, populated almost exclusively by absorption-line galaxies. The cluster velocity dispersion is lower in the core (~530 km s-1) than at the outskirts (~680 km s-1), …


Sciagents Tool: User's Guide, John R. Rice, P. Tsompanopoulou, E. Vavalis Nov 1998

Sciagents Tool: User's Guide, John R. Rice, P. Tsompanopoulou, E. Vavalis

Department of Computer Science Technical Reports

No abstract provided.


Molding Best-Effort Bandwith Into Graded Services: The Sbs Approach, Kihong Park, Shaogang Chen Nov 1998

Molding Best-Effort Bandwith Into Graded Services: The Sbs Approach, Kihong Park, Shaogang Chen

Department of Computer Science Technical Reports

No abstract provided.


Decoupled Delay And Rate Guarantees For Cross Domain Thread Scheduling, David K.Y. Yau Nov 1998

Decoupled Delay And Rate Guarantees For Cross Domain Thread Scheduling, David K.Y. Yau

Department of Computer Science Technical Reports

No abstract provided.


A Knowledge Discovery Methodology For The Performance Evaluation Of Scientific Software, Vassilios S. Verykios, Elias N. Houstis, John R. Rice Nov 1998

A Knowledge Discovery Methodology For The Performance Evaluation Of Scientific Software, Vassilios S. Verykios, Elias N. Houstis, John R. Rice

Department of Computer Science Technical Reports

No abstract provided.


An Aspect-Oriented Approach To Distributed Object Security, Riubing Hao, Ladislau Bölöni, Kyungkoo Jun, Dan C. Marinescu Nov 1998

An Aspect-Oriented Approach To Distributed Object Security, Riubing Hao, Ladislau Bölöni, Kyungkoo Jun, Dan C. Marinescu

Department of Computer Science Technical Reports

No abstract provided.


Parallel Algorithms For 3d Reconstruction Of Asymmetric Objects From Electron Micrographs, Robert E. Lynch, Dan C. Marinescu, Hong Lin, Timothy S. Baker Nov 1998

Parallel Algorithms For 3d Reconstruction Of Asymmetric Objects From Electron Micrographs, Robert E. Lynch, Dan C. Marinescu, Hong Lin, Timothy S. Baker

Department of Computer Science Technical Reports

No abstract provided.


Partial Redundancy Elimination For Access Path Expressions, Antony L. Hosking, National Nystrom, David Whitlock, Quintin Cutts, Amer Diwan Nov 1998

Partial Redundancy Elimination For Access Path Expressions, Antony L. Hosking, National Nystrom, David Whitlock, Quintin Cutts, Amer Diwan

Department of Computer Science Technical Reports

No abstract provided.


Measuring The Deterrent Effect Of Punitive Damages, Theodore Eisenberg Nov 1998

Measuring The Deterrent Effect Of Punitive Damages, Theodore Eisenberg

Cornell Law Faculty Publications

Professor Viscusi's article differs from the dominant mode of law and economics scholarship on punitive damages. The usual punitive damages article contains purely theoretical considerations about when punitive damages are appropriate and about their optimal level; no effort is made to ascertain whether the existing pattern of punitive awards corresponds with the theory. This is part of a larger problem: the dearth of empirical evidence in law and economics scholarship. Viscusi, on the other hand, provides empirical tests of whether punitive damages accomplish their goals, and he makes creative use of publicly available data sources. For the goal of his …


Robust Course-Boundary Extraction Algorithms For Autonomous Vehicles, Chris Roman, Charles Reinholtz Nov 1998

Robust Course-Boundary Extraction Algorithms For Autonomous Vehicles, Chris Roman, Charles Reinholtz

Graduate School of Oceanography Faculty Publications

Practical autonomous robotic vehicles require dependable methods for accurately identifying course or roadway boundaries. The authors have developed a method to reliably extract the boundary line using simple dynamic thresholding, noise filtering, and blob removal. This article describes their efforts to apply this procedure in developing an autonomous vehicle.


Tga–Fti.R. Investigation Of The Thermal Degradation Of Nafion® And Nafion®/[Silicon Oxide]-Based Nanocomposites, Q. Deng, Charles Wilkie, R. B. Moore, Kenneth A. Mauritz Nov 1998

Tga–Fti.R. Investigation Of The Thermal Degradation Of Nafion® And Nafion®/[Silicon Oxide]-Based Nanocomposites, Q. Deng, Charles Wilkie, R. B. Moore, Kenneth A. Mauritz

Chemistry Faculty Research and Publications

The integrated TGA–FTi.r. technique probed the thermal degradation of: (1) a Nafion®–H+ membrane; (2) this membrane as modified by incorporation of a SiO2[1-x/4] (OH)x phase via in situ sol–gel reactions for tetraethoxysilane; and (3) this modified membrane as further modified, organically, via post-reaction with diethoxydimethylsilane. Gravimetric loss is multistep for (1) and (2), but occurs in a single step for (3) which has the greatest thermal degradative stability. The considerable inhibition of SO2 evolution for (2) and (3) is rationalized in terms of side-chains that are immobilized within silicon oxide cages …