Physical Sciences and Mathematics Commons^™

Scanning Motions Of An Atomic Force Microscope Tip In Water, Kenichiro Koga, Xiao Cheng Zeng

Xiao Cheng Zeng Publications

Integral equation techniques are used to study scanning motions of a single-atom tip of the atomic force microscope (AFM) over a rigid, hydrophobic monolayer substrate in water. The calculated force curve is found to be oscillatory, in agreement with recent AFM experiments, which can lead to multiple scanning trajectories for the tip under a constant load. The unique trajectory along which the system is thermodynamically stable is revealed. This study shows that the tip may take a hopping motion over a defect-free substrate due to layering of water molecules between the tip and substrate.

39th Rocky Mountain Conference On Analytical Chemistry

Rocky Mountain Conference on Magnetic Resonance

Preliminary program and registration information for the 39th annual meeting of the Rocky Mountain Conference on Analytical Chemistry, co-sponsored by the Colorado Section of the American Chemical Society and the Rocky Mountain Section of the Society for Applied Spectroscopy. Held in Denver, Colorado, August 3-7, 1997.

The John Muir Newsletter, Fall 1997, The John Muir Center For Regional Studies

Muir Center Newsletters (1981-2015)

Fall 1997 NEWSLETTER Intimacies of a New England Trip: John Muir's 1898 Excursion by j. Parker Huber (Editor's note: Parker Huber, a regular contributor to these ■pages, here excerpts and discusses a few days of John Muir's life from the pages of Muir's journal of 1898 and from his letters.) ohn Muir's extensive travels included five trips to New England, finch occurred in 1893,1896,1898,1903 and 1911. His longest fxposure to New England came in late summer and autumn of 1898. This visit had three phases: first an overnight on Cape Cod, ; which is considered here, followed by a tour …

Seasonal Adjustment Of Naira Exchange Rate Statistics 1970-1995, O M. Akinuli

CBN Occasional Papers

This paper uses a current statistical approach to examine and adjust the seasonalities in the Naira exchange rate statistics, vis-a-vis the U.S. Dollar and the pound sterling for a period of twenty-five (25) years. Such study is necessary as it helps to understand the behavioural pattern of a trend in an attempt to predict the future. An investigation like this also helps to expose both the short and long run tendencies of a series which may require urgent or new policy measures to be taken sooner than expected. This paper reviews the regimes of exchange rate under the period, the …

A Generalized Mahonian Statistic On Absorption Ring Mappings, Don Rawlings

Mathematics

Based on a coin-tossing scheme, a generalized Mahonian statistic is defined on absorption ring mappings and applied in obtaining combinatorial interpretations of the coefficient ofq^jin the expansion of ∏^k_i=1 (1+q+q²+…+q^m_i). In the permutation case, the statistic coincides with one studied by Han that specializes many known Mahonian statistics.

A Study Of The Volatile Matter Of Coal As A Function Of The Heating Rate, Enrique Santos

Masters Theses & Specialist Projects

A study of volatile matter yields as a function of the heating rate was conducted. A suite of 21 coal and coke samples varying in rank from anthracitic to lignitic and heating rates from 10°C/min to about 450°C/min were used in the study. Heating rates up to 60°C per minute, which are typically used in ASTM Test Method 5142 (instrumental Proximate Analysis), were achieved in a macro thermogravimetric analysis (TGA) system. Heating rates of 50-200°C/min were obtained in a micro TGA system. All measurements were made in a nitrogen atmosphere. The results of the study illustrate the dependance of the …

The Probe, Issue 179 - August 1997

The Probe: Newsletter of the National Animal Damage Control Association

Contents:
The Uneasy Conscience of the Animal Rights Movement
Calendar of Upcoming Events
NADCA Officers' Nominations Needed
Berryman Institute Announces Fellows
Reviews of the Video: “Balancing Nature – Trapping in Today’s World”
New Product Available: “Scarecrow” by Contech Deters Mammals, Birds
Garlic Repellent Device for Deer, Rabbits

Magneto-Aerotaxis In Marine Coccoid Bacteria, Richard B. Frankel, Dennis A. Bazylinski, Mark S. Johnson, Barry L. Taylor

Physics

Magnetotactic cocci swim persistently along local magnetic field lines in a preferred direction that corresponds to downward migration along geomagnetic field lines. Recently, high cell concentrations of magnetotactic cocci have been found in the water columns of chemically stratified, marine and brackish habitats, and not always in the sediments, as would be expected for persistent, downward-migrating bacteria. Here we report that cells of a pure culture of a marine magnetotactic coccus, designated strain MC-1, formed microaerophilic bands in capillary tubes and used aerotaxis to migrate to a preferred oxygen concentration in an oxygen gradient. Cells were able to swim in …

Spurious Electrons In Electron Spectrometers And Their Effect On Differential Electron Impact Ionization Cross-Section Measurements, M. Eugene Rudd

M. Eugene Rudd Publications

The effect of the nonideal response characteristics of electrostatic analyzers is described and equations are derived, which allow a calculation of the distortion that this causes in measurements of angular and energy distributions of electrons from atomic collisions, especially in electron impact. Examples are given that show how a contamination as small as 10^-5 from spurious electrons generated inside an analyzer can explain the peak seen at zero angle in some angular distribution measurements and the filling in of the minimum in the energy distributions in others.

Hypersurfaces In R-D And The Variance Of Exit Times For Brownian Motion, Kimberly Kinateder, Patrick Mcdonald

Mathematics and Statistics Faculty Publications

Using the first exit time for Brownian motion from a smoothly bounded domain in Euclidean space, we define two natural functionals on the space of embedded, compact, oriented, unparametrized hypersurfaces in Euclidean space. We develop explicit formulas for the first variation of each of the functionals and characterize the critical points.

The Eclipsing Double-Lined Spectroscopic Binary System V505 Persei, Laurence A. Marschall, Robert P. Stefanik, Claud H. Lacy, Guillermo Torres, David B. Williams, Franz Agerer

Physics and Astronomy Faculty Publications

The recently-discovered eclipsing double-lined spectroscopic binary V505 Persei (SAO 23229) consists of two nearly identical F5 main sequence stars in a 4.2 day orbit. We have obtained both spectroscopic and photometric observations of the binary that densely sample the complete cycle of radial velocity and light variations. These observations have been used to determine the elements of the orbit, to determine individual masses of the stars in the system to a precision of better than 1%, and to estimate an age for the system. The derived properties agree well with current stellar structure models and provide fundamental data for tests …

Infinite-Dimensional Hamilton-Jacobi-Bellman Equations In Gauss-Sobolev Spaces, Pao-Liu Chow, Jose-Luis Menaldi

Mathematics Faculty Research Publications

We consider the strong solution of a semi linear HJB equation associated with a stochastic optimal control in a Hilbert space H: By strong solution we mean a solution in a L²(μ,H)-Sobolev space setting. Within this framework, the present problem can be treated in a similar fashion to that of a finite-dimensional case. Of independent interest, a related linear problem with unbounded coefficient is studied and an application to the stochastic control of a reaction-diffusion equation will be given.

Quasi-Steady Monopole And Tripole Attractors In Relaxing Vortices, Louis F. Rossi, Joseph F. Lingevitch, Andrew J. Bernoff

All HMC Faculty Publications and Research

Using fully nonlinear simulations of the two-dimensional Navier–Stokes equations at large Reynolds number (Re), we bracket a threshold amplitude above which a perturbed Gaussian monopole will relax to a quasi-steady, rotating tripole, and below which will relax to an axisymmetric monopole. The resulting quasi-steady structures are robust to small perturbations. We propose a means of measuring the decay rate of disturbances to asymptotic vortical structures wherein streamlines and lines of constant vorticity correspond in some rotating or translating frame. These experiments support the hypothesis that small or moderate deviations from asymptotic structures decay through inviscid and viscous mixing.

Performing Out-Of-Core Ffts On Parallel Disk Systems, Thomas H. Cormen, David M. Nicol

Computer Science Technical Reports

The Fast Fourier Transform (FFT) plays a key role in many areas of computational science and engineering. Although most one-dimensional FFT problems can be solved entirely in main memory, some important classes of applications require out-of-core techniques. For these, use of parallel I/O systems can improve performance considerably. This paper shows how to perform one-dimensional FFTs using a parallel disk system with independent disk accesses. We present both analytical and experimental results for performing out-of-core FFTs in two ways: using traditional virtual memory with demand paging, and using a provably asymptotically optimal algorithm for the Parallel Disk Model (PDM) of …

Water Current, Volume 29, No. 4, August 1997

Water Current Newsletter

Fifth Annual Festival of Color Highlights Landscaping, Youth Activities Near Mead
From the Director: Retirement, New Staff Welcomed, USGS Funds Nebraska Proposals
Unicameral Moves Quickly on Changes to Instream Appropriations Process with LB877
Schulze One of Three Extension Staff Honored
Native Plants Help Clean-Up Toxins
Spalding Recognized for EPA Superfund Cleanup Technique
Education and Action Join Forces
Water News Briefs
42nd Annual Midwest Groundwater Conference
Symposium Focused on Water Act and Groundwater
Nineteen Attend Groundwater U
Environment97
AWWA Research RFPs
Ground Water Protection Council Annual Forum in Cleveland, Ohio
National Drought Planning Center Headquarters at UNL

Biology Of Shovelnose Sturgeon, Scaphirhynchus Platorynchus, In The Lower Platte River, Nebraska, Robin L. Hofpar

School of Natural Resources: Dissertations, Theses, and Student Research

No abstract provided.

Cheetahs Are Fast, But Nearly Irrelevant, Calton Pu, Jonathan Walpole, Charles Consel

Computer Science Faculty Publications and Presentations

A brief paper submitted to the NSF Workshop on New Challenges and Directions for Systems Research, held in St. Louis, Mo., July 31-August 1, 1997. Outlines the case for more cooperation among software system architects, and a less reductionistic approach to software development.

Systematics Of Stable Isotopes And Radionuclides In Precipitation At Kalamazoo, Michigan, Usa, Madhav V. Machavaram

Dissertations

Precipitation samples were collected at Kalamazoo from June 1992 to March 1995. The samples were analyzed for their 8D and 8lgO values. The 5D - 5I80 relationship is comparable to that of Meteoric Water Line (MWL). The monthly mean isotopic values in precipitation exhibited strong seasonality, being higher in summer and lower in winter months. This behavior is apparently a direct consequence of the temperature effect on isotope fractionation.

The summer precipitation at Kalamazoo is derived predominantly from the water vapor originated in the Gulf of Mexico. A box model calculation showed that a Rayleigh type distillation with Gulf moisture …

Generating, Visualizing And Evaluating High Quality Clusters For Information Organization, Javed Aslam, Katya Pelekhov, Daniela Rus

Computer Science Technical Reports

We present and analyze the star clustering algorithm. We discuss an implementation of this algorithm that supports browsing and document retrieval through information organization. We define three parameters for evaluating a clustering algorithm to measure the topic separation and topic aggregation achieved by the algorithm. In the absence of benchmarks, we present a method for randomly generating clustering data. Data from our user study shows evidence that the star algorithm is effective for organizing information.

The Self-Organizing Desk, Daniela Rus, Peter De Santis

Dartmouth Scholarship

The self-organizing desk is a system that enhances a physical desk-top with electronic information. It can remember, organize, update, and manipulate the information contained in the documents on a desk. The system consists of a simple robot eye that can survey the desk, a module for smart extraction of information from the images taken by the robot, a module for representing this information in multiple views, and a module that allows a user to interact with this information.

Fast Discrete Polynomial Transforms With Applications To Data Analysis For Distance Transitive Graphs, J. R. Driscoll, D. M. Healy, D. N. Rockmore

Dartmouth Scholarship

Let $\poly = \{P_0,\dots,P_{n-1}\}$ denote a set of polynomials with complex coefficients. Let $\pts = \{z_0,\dots,z_{n-1}\}\subset \cplx$ denote any set of {\it sample points}. For any $f = (f_0,\dots,f_{n-1}) \in \cplx^n$, the {\it discrete polynomial transform} of f (with respect to $\poly$ and $\pts$) is defined as the collection of sums, $\{\fhat(P_0),\dots,\fhat(P_{n-1})\}$, where $\fhat(P_j) = \langle f,P_j \rangle = \sum_{i=0}^{n-1} f_iP_j(z_i)w(i)$ for some associated weight function w. These sorts of transforms find important applications in areas such as medical imaging and signal processing.

In this paper, we present fast algorithms for computing discrete orthogonal polynomial transforms. For a system …

Parallel 3d Reconstruction Of Spherical Virus Particles From Digitized Images Of Entire Electron Micrographs Using Cartesian Coordinates And Fourier Analysis, Robert E. Lynch, Dan C. Marinescu

Department of Computer Science Technical Reports

No abstract provided.

Building Multi-Discipline, Multi-Format Digital Libraries Using Clusters And Buckets, Michael L. Nelson

Computer Science Theses & Dissertations

Our objective was to study the feasibility of extending the Dienst protocol to enable a multi-discipline, multi-format digital library. We implemented two new technologies: cluster functionality and publishing buckets. We have designed a possible implementation of clusters and buckets, and have prototyped some aspects of the resultant digital library.

Currently, digital libraries are segregated by the disciplines they serve ( computer science, aeronautics, etc.), and by the format of their holdings (reports, software, datasets, etc.). NCSTRL+ is a multi-discipline, multi-format digital library (DL) prototype created to explore the feasibility of the design and implementation issues involved with created a …

Extraction Of Premafloxacin Radiolabeled With Carbon Fourteen From Loam Soil, Steven Gregory Staskiewicz

Masters Theses

Premafloxacin is a fluoroquinolone antibiotic being developed by Pharmacia & Upjohn for veterinary indications. Since the parent drug and possibly metabolites will be applied to soil through the deposition of animal excreta, many regulatory agencies will require environmental assessment testing. In order to determine if ¹⁴C-premafloxacin would biodegrade in the soil, loam soil was extracted with solvents and C18 solid phase columns were used to isolate the compound after three weeks of incubation. In addition to extracting the soil, production of ¹⁴CO₂ was monitored by trapping the degradation by-product in 2 N NaOH. Liquid scintillation counting of …

Learning Recursive Functions From Approximations, John Case, Susanne Kaufmann, Martin Kummer, Efim Kinber

School of Computer Science & Engineering Faculty Publications

This article investigates algorithmic learning, in the limit, of correct programs for recursive functionsffrom both input/output examples offand several interesting varieties ofapproximateadditional (algorithmic) information aboutf. Specifically considered, as such approximate additional information aboutf, are Rose's frequency computations forfand several natural generalizations from the literature, each generalization involving programs for restricted trees of recursive functions which havefas a branch. Considered as the types of trees are those with bounded variation, bounded width, and bounded rank. For the case of learning final correct programs for recursive functions, EX-learning, …

A Cephalometric Study Of The Class Ii Correction Effects Of The Eureka Spring, Ernest L. Stromeyer

Loma Linda University Electronic Theses, Dissertations & Projects

The effect of the Eureka Spring appliance, was investigated on 37 consecutively treated, non compliant, bilateral Class II malocclusions, requiring at least 3 mm or more of additional molar correction. The mean pretreatment age of this sample was 13.9 years. All patients were treated by a single clinician utilizing the Eureka Spring. Lateral cephalographs were taken at start of orthodontic treatment (T1), at insertion of Eureka Springs (T2), and at removal of the Eureka Springs (T3). The average treatment interval between T2 and T3 was 4 months. Class II correction occurred almost entirely by dentoalveolar movement, 33% in the maxilla …

Phosphorus And Nitrate Loss From Horticulture On The Swan Coastal Plain, Neil Clifton Lantzke

Agriculture reports

(En) The extent of nutrient loss from nine horticultural properties located on the sandy soils of the Swan Coastal Plain was examined. On three of the properties phosphorus (P) loss was measured by monitoring nutrient loads in shallow drains. On the other six properties networks of monitoring bores were installed and both P and nitrate nitrogen (NO3-N) concentrations were monitored. All of the properties except one were located on the low phosphate fixing Bassendean sands. The level of nutrient loss was depend l production areas. High to very high N03-N concentrations were found in the shallow groundwater beneath the production …

A Bayesian Nonlinear Inversion Of Seismic Body-Wave Attenuation Factors, Stephen S. Gao

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

It is a well-known fact that the uncertainties in measuring relative attenuation factors within a local or regional seismic network are usually high, due to noise of different kinds and unrealistic assumptions. Numerical experiments using nine synthetic seismograms, created using t* values ranging from 0.1 to 0.9 sec, reveal that the commonly used spectral ratio method is strongly affected by the selection of data processing parameters such as width of the spectral smoothing window, reference station, and so on. The numerical experiments demonstrate that a Bayesian nonlinear inversion approach that directly matches the spectra is better at finding the correct …

Lyapunov Exponents, Singularities, And A Riddling Bifurcation, Lora Billings, James H. Curry, Eric Phipps

Department of Mathematics Faculty Scholarship and Creative Works

There are few examples in dynamical systems theory which lend themselves to exact computations of macroscopic variables of interest. One such variable is the Lyapunov exponent which measures the average attraction of an invariant set. This article presents .a family of noninvertible transformations of the plane for which such computations are possible. This model sheds additional insight into the notion of what it can mean for an attracting invariant set to have a riddled basin of attraction.

Experimental Investigation Of Nonlinear Dynamics In Single Mode Semiconductor Laser Diodes With Phase Conjugate Feedback, Gordon T. Hengst

Theses and Dissertations

The semiconductor laser diode offers a unique system to investigate nonlinear dynamics when optical feedback is applied. Although there is extensive research of laser diodes with optical feedback from normal dielectric mirrors, very little has been done experimentally to analyze the effects of degenerate phase conjugate feedback from a BaTiO₃ crystal. This research experimentally investigated the dynamics of a single-mode laser diode with weak phase conjugate feedback using both the self-pumped and double phase conjugate geometries. The experimental results validated a mathematical model which numerically evaluates the Lang-Kobayahsi coupled differential equations. The model simulated the nonlinear behavior of a …