Digital Commons Network^™

Evidence For Uncorrelated Electron Capture And K-Shell Excitation In S13++He Collisions, J. A. Tanis, E. M. Bernstein, M. W. Clark, W. G. Graham, Robert H. Mcfarland, T. J. Morgan, B. M. Johnson, K. W. Jones, M. Meron

Physics Faculty Research & Creative Works

Evidence is presented for a two-step process in ion-atom collisions in which two independent interactions occur in a single encounter. Measurements for 15200-MeVS13++He collisions indicate that uncorrelated projectile K-shell excitation and capture of a target electron occur in a single collision with one target atom. The results are in reasonable qualitative agreement with theoretical predictions of this two-step process. © 1985 The American Physical Society.

Raman Studies Of Heavily Implanted, Dye-Laser-Annealed Gaas, H. D. Yao, A. Compaan, Edward Boyd Hale

Physics Faculty Research & Creative Works

Raman scattering is used to study the annealing behavior produced by 10 nsec, 565 nm dye laser pulses in high dose ion-implanted GaAs. Samples were prepared with Sn and Cd implantations of 2, 5, and 10 x 1015 cm2. The Raman spectra indicate that the threshold for epitaxial growth lies between 0.2 - 0.3 J cm2. Best carrier activation (∼ 2%), however, is achieved at ∼1.6 J cm2 for the Sn-implanted sample (n-type). For Cd implantation the electrical activation appears to be very high ({greater-than or approximate} 50%) for low pulse energies({less-than or approximate} 0.3 J cm2) but decreases for …

Erratum: Normalized Line Shapes For Far-Wing Continuum Spectra: The Rb-Xe Satellite Band (Physical Review A(1985) 32, 5 (3150-3152)), Ronald James Bieniek

Physics Faculty Research & Creative Works

Recent advances in experimental spectroscopy offer the promise of yielding much detailed information about molecular potentials and collisional interactions from a study of the light emitted or absorbed in the far wings of atomic lines. However, readily manipulable, accurate theoretical expressions and methods are needed to extract such knowledge. Straightforward formulas, based on the distorted-wave approximation, for the normalized emission intensity in the far wing of a pumped atomic line are given here. By normalizing theoretical spectra with respect to the strength of the atomic line, one obtains a convenient form for the analysis of experimental differential spectra that are …

Middle And Late Wisconsinan (Pleistocene) Insect Assemblages From Illinois, Kristine D. Carter

Theses and Dissertations

Two highly organic sediment sequences from central and western Illinois (the Athens North Quarry and Biggsville sites, respectively) of Middle and Late Wisconsinan age were studied to gain knowledge about the environment and climate of this area during the time immediately prior to the maximum extent of the last glaciation. Paleoenvironmental and paleoclimatic inferences are based principally upon knowledge of the habitat preferences and geographic distributions of extant species of beetles that are represented as fossils. These data are supplemented by information from sedimentological and taphonomic studies and from previously published palynological and plant-macrofossil studies.

The Athens North Quarry site …

Petrology Of The Sentinel Butte Formation (Paleocene), North Dakota, Nels F. Forsman

Theses and Dissertations

Sedimentary materials of the Sentinel Butte Formation have been petrographically examined using optical and scanning electron micro scope/microprobe techniques. The formation consists of fine-grained materials which generally are classified mineralogically as volcanic litharenites or feldspathic litharenites. Most rock units in the formation are siltstones and mudstones. Multiple source rock types, including volcanic, metamorphic, and sedimentary, are represented by mineralogic constituents, but volcanic rock fragments are most abundant. Petrographic distinctions between basal and uppermost sandstone units suggest that a change in sediment supply took place near the end of Sentinel Butte time. Authigenic cement development appears concentrated in more porous and …

A Quantitative Analysis Of Shoreline Erosion Processes, Lake Sakakawea, North Dakota, Mark D. Millsop

Theses and Dissertations

Shoreline erosion is a problem at Lake Sakakawea and Lake Audubon, North Dakota. Land is lost, water quality is adversely affected, and reservoir storage capacity is decreased.

Instrumentation of the eastern shores of both lakes began in 1983 to quantify bank erosion by process (e.g., wave erosion, rainsplash and runoff, and frost-thaw failure). Other data gathered included: pool level fluctuations; wind velocity, direction, and duration; precipita tion; soil moisture; frost penetration; freeze-thaw cycles; and geology (e.g., texture, clay mineralogy and structure).

The magnitude of shoreline erosion is highly variable, especially within Lake Sakakawea. For the interval of May 1983 through …

Metamorphism And Migmatization Of Metasediments In The Precambrian English River Subprovince, Western Ontario, Rodney M. Baumann

Theses and Dissertations

Metasediments of the Precambrian English River subprovince, a subdivision of the Superior province, are conspicuously migmatized by 'bands of light-colored, igneous-appearing material. The metasediments themselves consist of alternating layers of pelite and wacke lithologies, which represent original mudstones and graywackes respectively. Their deposition is thought to represent subaqueous turbidity flows.

For the metasediments of the study area, a 250 square kilometer portion of the English River subprovince, metamorphic grade increases southward from the English River subprovince's northern border. Two isograds have been mapped: the disappearance of muscovite and the disappearance of stable sillimanite. Geothermometry studies are consistent with the trend …

Metamorphism In The Eastern Lac Seul Region Of The English River Subprovince, Ontario, Steve J. Chipera

Theses and Dissertations

The English River subprovince of the Superior Province, Canada, is a linear, east-west trending high-grade metamorphic belt which extends from Lake Winnipeg in the west, to the James Bay lowlands in the east. It is composed of two prominent lithologic domains: a northern sedimentary gneiss-migmatite domain, and a southern plutonic domain. The northern domain consists primarily of alternating migmatized layers of garnet-biotite "wacke" and garnet-cordierite-biotite "pelitic" metasediments. The southern domain is composed mainly of intermediate granitic to trondhjemitic plutons. Bordering to the north and south are the lower grade Uchi and Wabigoon greenstone belts. Metamorphism and migmatization occurred during the …

Racial Differences In The Distribution Of Posterior Circulation Occlusive Disease, Philip B. Gorelick, Louis R. Caplan, Daniel B. Hier, Dushyant Patel, Patricia Langenberg, Michael S. Pessin, Jose Biller, David Kornack

Chemistry Faculty Research & Creative Works

We Compared Clinical and Arteriographic Features in 27 White and 24 Black Patients with Symptomatic Posterior Circulation Occlusive Disease. the Degree of Arterial Stenosis Was Measured Independently by Two Examiners at 12 Sites within the Vertebrobasilar Territory. Racial Comparisons Were Made based Upon the Distribution of Extra- and Intracranial Occlusive Lesions and Symptomatic Sites of the Lesions. White Patients Had Significantly More Angina Pectoris, More Lesions of the Origin of the Left Vertebral Artery and More High-Grade Lesions of the Extracranial Vertebral Arteries. Black Patients Had Significantly Higher Mean Diastolic Blood Pressure, More Diabetes Mellitus, More Lesions of the Distal …

Interobserver Variability In The Assessment Of Neurologic History And Examination In The Stroke Data Bank, David Shinar, Cynthia R. Gross, Jay P. Mohr, Louis R. Caplan, Thomas R. Price, Philip A. Wolf, Daniel B. Hier, Carlos S. Kase, Irene G. Fishman, Christine L. Wolf, Selma C. Kunitz

Chemistry Faculty Research & Creative Works

Interobserver Reliability in Obtaining Neurologic Histories and Examinations Was Investigated among Neurologists Collaborating in the Stroke Data Bank (SDB). Seventeen In-Hospital Stroke Patients Were Examined by Six Neurologists Experienced in Stroke over the Course of Three Days. Patients Were Examined Twice a Day for Two Successive Days, with Each Patient Seen by Four Different Neurologists. Data Were Recorded on SDB Forms, According to Definitions and Procedures Established for the SDB. Percent Agreement and Κ Coefficients Were Calculated to Assess the Levels of Agreement for Each Item. Important Differences in Levels of Agreement Were Found among Items on Both Neurologic History …

Plasma Polymerization Investigated By The Substrate Temperature Dependence., H. Yasuda, Cheng Wang

Chemistry Faculty Research & Creative Works

In the reported experiments, plasma polymerization of tetrafluoroethylene (TFE), perfluoro-2-butyl-tetrahydrofuran (PFBTHF), ethylene, and styrene were investigated in various combinations of monomer flow rates and discharge wattages for the substrate temperature range of minus 50 to 80 degree C. The polymer deposition rates can be generally expressed by k//o equals Ae** minus **b**t, where k//o is the specific deposition rate given by k//o equals (deposition rate)/(mass flow rate of monomer), A is the preexponential factor representing the extrapolated value of k//o at zero absolute temperature, and b is the temperature-dependence coefficient. It was found that the value of b is not …

A Model For Orientation Effects In Electron‐Transfer Reactions, Paul Siders, Robert J. Cave, R.A. Marcus

All HMC Faculty Publications and Research

A method for solving the single‐particle Schrödinger equation with an oblate spheroidal potential of finite depth is presented. The wave functions are then used to calculate the matrix element T_BA which appears in theories of nonadiabatic electron transfer. The results illustrate the effects of mutual orientation and separation of the two centers on T_BA. Trends in these results are discussed in terms of geometrical and nodal structure effects. Analytical expressions related to T_BA for states of spherical wells are presented and used to analyze the nodal structure effects for T_BA for the spheroidal wells.

(Super)Conformal Symmetry Breaking, Andrew Strominger, V. Parameswaran Nair

Publications and Research

We argue that the only consistent way to break conformal invariance in a quantum theory of gravity is spontaneously in a finite locally conformal supersymmetric theory. This generically occurs whenever scalar fields are present. Covariant surface-integral expressions for the super-charge and four-momentum in terms of asymptotically constant spinor fields are derived. These are used to discuss stability and other aspects of the theory.

Blas, Linear, Algebra Modules And Supercomputers Parvec Workshop #4, John R. Rice

Department of Computer Science Technical Reports

No abstract provided.

An Analysis Of The Effect Of Network Load And Topology On The Performance Of Concurrency Control Algorithm In Distributed Database Systems, Anoop Singhal, Amit P. Sheth, Ming T. Liu

Kno.e.sis Publications

Earlier studies in the performance analysis of concurrency control algorithms in distributed database systems (DDBS) have assumed that the message transmission time between any two nodes of a network is constant. Hence they disregard the effect of communication subnet related parameters such as network traffic, network topology, the capacity of transmission channels and the size of messages transmitted. In this paper an analytical model is used to estimate the delays in transmission channels for a DDBS in a long haul network. The analysis shows that the constant transmission time assumption cannot be justified in many cases and that response time …

Survey Of Routing Algorithms For Computer Networks, Lu Yu, Thomas J. Sager

Computer Science Technical Reports

This thesis gives a general discussion of routing for computer networks, followed by an overview of a number of typical routing algorithms used or reported in the past few years. Attention is mainly focused on distributed adaptive routing algorithms for packet switching (or message switching) networks. Algorithms for major commercial networks (or network architectures) are reviewed as well, for the convenience of comparison.

Artificial Intelligence: Myths And Realities, Hugo D'Alarcao

Bridgewater Review

Artificial intelligence the name conjures images of mechanical monsters, the Golem, Dr. Frankenstein’s creation and the rebellious computer Hal. We have always been fascinated by the possibility of creating a machine in our image, but this fascination is often accompanied by apprehension. We fear losing control of our creation and suspect that it might turn against us. It is this duality, this conflict between the desire to create and the fear of the consequences of the creation that has been so successfully exploited by writers. It is also, in part, this fascination that has recently brought the field of Artificial …

Semiflexible Self-Avoiding Polymers, Rolfe G. Petschek

Faculty Scholarship

A simple two dimensional model for semiflexible polymers is discussed. A rigorous lower bound is obtained for the free energy and a rigorous upper bound is obtained for the energy. These bounds evaluated for infinite systems are shown to be in serious conflict with results obtained by a Monte Carlo simulation of a finite system.

Microprocessor-Based Pressure Controller, E. Redd, John T. Park

Physics Faculty Research & Creative Works

A device for automatic control of pressure in an ion-atom scattering experiment has been constructed. The system was modeled to achieve the minimum time for transition from one pressure to another. The pressure controller "learns" the system response and iterates the parameters used in "profiling" the valve voltage to reduce the transition time. The device has been used with two different scattering chambers and has worked well with both.

The Modified Index Of Severity Scale, Marion Gamundoy

Loma Linda University Electronic Theses, Dissertations & Projects

[No Abstract Included]

Late Tertiary Rodents From The Catamarca Province, Argentina : The Field Museum Collections, Lee A. Schremp

Loma Linda University Electronic Theses, Dissertations & Projects

The rodents collected in the 1920's by the Marshall Field Expedition for the Field Museum of Natural History, Chicago, are systematically reviewed and placed within the stratigraphic framework established at the time of collection. One new genus (Proeuryzygomys) and three new species (Abracoma intermedias, Proeuryzygomys diminutiva, and Cayiodon (Lelongia) catamarcensis) are proposed. Two distinct faunas are recognized corresponding to the Huayquerian and Montehermosan Land Mammal Ages respectively. Several computer programs were developed to aid in character analysis.

Resolution Algorithms In A Parallel Processing Environment, Paula Beth Brandman Hencken

Masters Theses

An ever increasing number of processors are becoming available to the multiprocessor user. For faster response and efficient utilization of parallel processing systems it is necessary to develop parallel algorithms to solve a single problem.

This paper evaluates the complexity of resolution algorithms run in a parallel processing environment. An overview of parallel processing is presented along with a discussion of general resolution and resolution-refutation systems. An analysis of the complexity required by different control strategies to perform resolution programing is presented using both uniprocessor and multiprocessor systems.

The Tilde Project, Douglas E. Comer, John T. Korb, Thomas Murtagh, Walter Tichy

Department of Computer Science Technical Reports

No abstract provided.

Statistical Consulting In A Geographically Dispersed Organization, Richard M. Engeman, William E. Dusenberry

United States Department of Agriculture Wildlife Services: Staff Publications

There has been much discussion in the recent statistical literature concerning the optimal manner for a consulting statistician to operate within a larger organization. Marquardt (1979) described the "total involvement" approach, involving a statistician from conceptualization of a project to the final report; Finney (1982) discussed the questions a statistician should ask for effective consulting; and Bishop, Peterson, and Tragser (1982) argued that a statistician's most substantive contributions are made during the planning stages of a study. McCulloch et al. (1982) described a program for training statistical consultants, and Hunter (1981) discussed the roles a statistician may assume.

Absence Of Minimum Metallic Conductivity In Gd(3-X)Vxs4 At Very Low Temperature And Evidence For A Coulomb Gap, S. Washburn, Richard A. Webb, S. Von Molnar, F. Holtzberg

Faculty Publications

Gd_(3-x)v_xS₄ provides a convenient analog of a compensated semiconductor in which, for x≃0.3, the mobility edge can be tuned smoothly through the Fermi energy by the application of a magnetic field. The results of a search for a minimum metallic conductivity demonstrate that, down to T=6 mK, the metal-insulator transition is smooth. In the insulating regime, the temperature dependence of the conductivity was more consistent with the theory of mutual interactions than with the theory of pure localization.

Civilian Space Stations And The U.S. Future In Space, U.S. Office Of Technology Assessment

Space Law Documents

After the expenditure of some $200 billion (1984$) since the launch of its first spacecraft in early 1958, the United States has obtained the scientific knowledge and developed the technological capability and professional expertise to succeed in virtually any theoretically possible civilian space venture that it may choose to undertake, But America’s second quarter-century of space activities promises to differ markedly from the first, almost wholly exploratory, era. If space is to be successfully developed in roughly the same fashion as have other, more familiar natural resources and environments, the next stage will be characterized by establishing and securing the …

J. P. Finley: The First Severe Storms Forecaster, Joseph G. Galway

National Oceanographic and Atmospheric Administration: Technical Reports and Related Materials

During the 19th century, while others were debating about the theory and morphology of tornadoes, Finley set out to prove that tornadoes, like other weather phenomena, could be forecast. He developed forecast rules and made experimental forecasts. His forecasting and analysis activities made him the center of controversy during most of his professional life and led to open debate in the literature, but he set precedents in meteorological forecasting that are still valid today. His career as a meteorologist started while he was a private in the United States Army. His interest continued even when he had achieved the rank …

Sulfur Dioxide And Particles In Quiescent Volcanic Plumes From Poás, Arenal, And Colima Volcanos, Costa Rica And Mexico, T. Casadevall, William I. Rose, William H. Fuller, William H. Hunt, Mark A. Hart, Jarvis L. Moyers, David C. Woods, Raymond L. Chuan, James P. Friend

Department of Geological and Mining Engineering and Sciences Publications

Measurements of SO₂ emission rates and concentrations and of particle distribution, size, shape, and composition were made in quiescent volcanic plumes emitted into the troposphere from Poás and Arenal volcanos, Costa Rica, and Colima volcano, Mexico. SO₂ emission rates were 700±180 metric tons per day (t/d) for Poás, 210±30 t/d for Arenal, and 320±50 t/d for Colima. The concentrations of SO₂ calculated from the COSPEC/lidar data were 5–380 ppb. Concentrations of SO₂measured directly by flame photometry were 10–250 ppb. Particles collected in the plumes with a quartz crystal microbalance impactor were mostly less than 3 …

Multiple Determination Of The Optical Constants Of Thin-Film Coating Materials, D. P. Arndt, R. M.A. Azzam, J. M. Bennett, J. P. Borgogno, C. K. Carniglia, W. E. Case, J. A. Dobrowolski, U. J. Gibson, T. Tuttle Hart, F. C. Ho, V. A. Hodgkin, W. P. Klapp, H. A. Macleod, E. Pelletier, M. K. Purvis, D. M. Quinn, D. H. Strome, R. Swenson, P. A. Temple, T. F. Thonn

Electrical Engineering Faculty Publications

The seven participating laboratories received films of two different thicknesses of Sc₂O₃ and Rh. All samples of each material were prepared in a single deposition run. Brief descriptions are given of the various methods used for determination of the optical constants of these coating materials. The measurement data are presented, and the results are compared. The mean of the variances of the Sc₂O₃refractive-index determinations in the 0.40–0.75-nm spectral region was 0.03. The corresponding variances for the refractive index and absorption coefficient of Rh were 0.35 and 0.26, respectively.

Magnetoresistance Of Small, Quasi-One-Dimensional, Normal-Metal Rings And Lines, C. P. Umbach, S. Washburn, R. B. Laibowitz, Richard A. Webb

Faculty Publications

The magnetoresistance of sub-0.4-μm-diam Au and Au₆₀Pd₄₀ rings was measured in a perpendicular magnetic field at temperatures as low as 5 mK in search of simple, periodic resistance oscillations that would be evidence of flux quantization in normal-metal rings. However, instead of simple oscillations, a very complex structure developed in the magnetoresistance at low temperatures. Fourier analysis of all the data did not reveal convincing evidence for flux quantization in the rings. Complex structure similar to that observed in the rings was also found in the magnetoresistance of short, narrow, Au and Au₆₀Pd …