Physical Sciences and Mathematics Commons^™

Biota Of Lake Mead: Annotated Checklist And Bibliography, Wesley E. Niles, Charles L. Douglas, National Park Service

Publications (WR)

In 1935 construction was completed on the Bureau of Reclamation's Hoover Dam, located near the bend of the historic Colorado River. Rising 726 feet within the rugged walls of Black Canyon, the structure is still recognized today as the highest concrete dam in the western hemisphere. Impoundment of water above Hoover Dam created Lake Mead, some 110 miles long, having a shoreline of 84 miles when the lake is at its maximum elevation of 1229 feet - this country's largest man-made reservoir. Below the dam, in Black Canyon and southward, the wild aspect of the Colorado River was altered by …

On The Existence Of Weak Solutions Of Differential Equations In Nonreflexive Banach Spaces, V. Lakshmikantham, Evin Bronson, A. Richard Mitchell

Mathematics Technical Papers

The study of the Cauchy problem for differential equations in a Banach space relative to the strong topology has attracted much attention in recent years [2,4,5,7]. This study has taken two different directions. One direction is to impose compactness type conditions that guarantee only existence and the corresponding results are extensions of the classical Peano's Theorem. The other approach is to utilize dissipative type conditions that assure existence and uniqueness of solutions, and the corresponding results are extensions of the classical Picard's Theorem. However, a similar study of the Cauchy problem in a Banach space relative to the weak topology …

Existence Of Solutions Of Boundary Value Problems For Nonlinear Second Order Systems In A Banach Space, A. Richard Mitchell, V. Chandra

Mathematics Technical Papers

This paper is concerned with the existence of solutions of boundary value problems (BVP, for short) for nonlinear second order ordinary differential equations of the type (1.1) [see pdf for notation] (1.2) [see pdf for notation] where [see pdf for notation] is a real Banach space. In case [see pdf for notation], existence was proved by first obtaining a priori bounds for [see pdf for notation] of a solution of (1.1) and (1.2) and then employing a theorem of Scorza-Dragoni [3,7,16]. The methods involve assuming inequalities in terms of the second derivative of Lyapunov-like functions relative to H, using comparison …

Apical Closure Induction Using Bone Growth Factors And Mineral Trioxide Aggregate, Kenneth W. Tittle

Loma Linda University Electronic Theses, Dissertations & Projects

This study compared the ability of three different bone growth factor combinations with that of Ca(OH)₂ to stimulate apical closure as well as the effectiveness of Mineral Trioxide Aggregate (MTA) as an apical barrier. Fifty-six roots of second and fourth mandibular premolars of seven six- month old beagle dogs were used. Periradicular lesions were created over a four week period. The canals were cleaned and shaped and filled with Ca(OH)₂ for one week. They were then irrigated and received one of seven different treatments in a balanced design. Growth factors were placed in a carboxymethylcellulose carrier and delivered …

A Random Differential-Equation Approach To Probability Distribution Of Bod And Do In Streams, William J. Padgett, G Schultz, Chris P. Tsokos

Faculty Publications

No abstract provided.

Characterization Of A Historically Nutrient Enriched Marsh Ecosystem : Yorktown Creek, Yorktown, Virginia, R. L. Wetzel, M. S. Kowalski, W. M. Rizzo, A. Thompson, K. L. Webb

Reports

In this report, we summarize our initial findings of a nutrient enriched aquatic ecosystem prior to relaxation of sewage input. The studies reported were directed toward characterizing the system prior to relaxation and to begin 􀌣xperimental studies to accomplish our general objectives.

Application Of Numerical Classification In Ecological Investigations Of Water Pollution, Donald F. Boesch

Reports

No abstract provided.

Certain Edaphic And Biotic Factors Affecting Vegetation In The Shadscale Community Of The Kaiparowits Area, Vane Orlan Campbell

Theses and Dissertations

A study area on the southern extensions of the Great Basin cold desert (Kaiparowits Basin, Utah) was selected which has had varying amounts of disturbance. Areas with similar slope and exposure in the Shadscale community were sampled. At each site, soil samples were collected and percent sand, percent clay, percent silt, soluble salts, and hydrogen ion concentrations were measured. Cluster analysis based on percent frequency of the perennial species showed that eight groups or sub-communities were definable within the area sampled. Patterns within the vegetation were shown to be independent with the use of cluster analysis. Discriminant analysis on soil …

High Accuracy Finite Difference Approximation To Solutions Of Elliptic Partial Differential Equations, Robert E. Lynch, John R. Rice

Department of Computer Science Technical Reports

No abstract provided.

O(H^6) Accurate Finite Difference Approximation To Solutions Of The Poisson Equation In Three Variables, Robert E. Lynch

Department of Computer Science Technical Reports

No abstract provided.

Intermolecular Potential Surfaces From Electron Gas Methods. Ii. Angle And Distance Dependence Of The A’ And A” Ar–No(X^2ii) Interactions, Glen C. Nielson, Gregory A. Parker, Russell T. Pack

Faculty Publications

Angle dependent intermolecular potential energy surfaces for the two states (2A’ and 2A”) that arise from the interaction of ground (X^2II) state NO with Ar are calculated using the electron gas model to obtain the short range interactions. The average and difference of the two interaction energies are fit to analytic forms convenient for use in scattering calculations and joined smoothly onto the long range van der Waals potential previously determined. The results, which appear to be of useful accuracy, and the applicability of the electron gas model to such open shell–closed shell interactions are discussed.

Fermi-Surface Topology Of 2h-Tase2 At 4.2k, Paul D. Hambourger

Physics Faculty Publications

The magnetoresistance of single-crystal 2H-TaSe₂ in the commensurate charge-density-wave state has been measured at 4.2 K in magnetic fields up to 48 kG. The results indicate that the Fermi surface supports open orbits parallel to the [0001] direction for all orientations of magnetic field in the (0001) plane. No evidence of open orbits in other directions was observed.

Mare Basalt Thickness In Sinus Aestuum And Sinus Medii, J. B. Sharp, N. Gilbert, R. A. De Hon

Journal of the Arkansas Academy of Science

No abstract provided.

Natural Areas Preservation In Arkansas, Mina Austin Marsh

Journal of the Arkansas Academy of Science

No abstract provided.

Scs 32: The Spectral Theory Of Distributive Continuous Lattices, Karl Heinrich Hofmann, Jimmie D. Lawson

Seminar on Continuity in Semilattices

No abstract provided.

Devonian-Mississippian Boundary, Batesville District, Northeast Arkansas, Steven H. Terry, Deborah E. Coogan

Journal of the Arkansas Academy of Science

The total record of the Devonian System in the Batesville district, northeast Arkansas is represented by the Penters Chert. Conodonts recovered from a thin limestone near the top of the Penters confirm a Lower Devonian age assignment, making this the oldest Devonian formation in northern Arkansas. The contact of the Penters Chert and the overlying Mississippian section is a marked disconformity. Excellent exposures in the bluffs along the east side of the White River exhibit unpredictable distributions of lower Mississippian strata. The most complete representation of the Mississippian sequence includes a basal sandstone of the Bachelor Formation, overlain by several …

A Time- And Space-Efficient Garbage Compaction Algorithm, F. Lockwood Morris

Electrical Engineering and Computer Science - Technical Reports

Given an area of storage containing scattered marked nodes, one may wish to rearrange them into a compact mass at one end of the area, meanwhile revising all pointers to marked nodes to show their new locations. An algorithm is here described which accomplishes this task in Iinear time relative to the size of the storage area, and in space of the order of one bit for each pointer. The algorithm operates by reversibly encoding the situation that a collection of locations point to a single location by a linear list, emanating from the pointed-to location, passing through the pointing …

Dual-Mode Combinational Logic For Function-Independent Fault Testing, Sumit Dasgupta

Electrical Engineering and Computer Science - Technical Reports

This paper presents a method of using hardware redundancy to ease the problem of fault testing in combinational logic networks. Combinational logic networks are constructed using dual-mode logic gates. Initially, it is shown that these networks can be tested for all single stuck-at-faults using just two function-independent tests. This method is then extended to detect a large class of multiple faults with the same two function-independent tests.

Software For Linear Elliptic Problems On General Two Dimensional Domains, Elias N. Houstis, John R. Rice

Department of Computer Science Technical Reports

No abstract provided.

Heuristics For Trie Index Minimization, Douglas E. Comer

Department of Computer Science Technical Reports

No abstract provided.

A Compiler Extension Theorem For Lucid, Christoph M. Hoffmann

Department of Computer Science Technical Reports

No abstract provided.

Can Physics Develop Reasoning?, Robert Fuller, Robert Karplus, Anton E. Lawson

Robert G. Fuller Publications

The life of every physicist is punctuated by events that lead him to discover that the way physicists see natural phenomena is different from the way non-physicists see them. Certain patterns of reasoning appear to be more common among physicists than in other groups. These include:
• focusing on the important variables (such as the force that accelerates the apple, rather than the lump it makes on your head);
• propositional logic ("if heat were a liquid it would occupy space and a cannon barrel could only contain a limited amount of heat, but this is contrary to my observations, …

Differential Energy-Loss Cross Sections For Ionization Of Atomic Hydrogen By 25-200-Kev Protons, John T. Park, Judith E. Aldag, Jacob M. George, Jerry Peacher, Jim H. Mcguire

Physics Faculty Research & Creative Works

Ionization continuum cross sections, differential in energy loss, have been determined from the energy-loss spectra of 25-, 50-, 75-, 145-, and 200-keV protons scattered from atomic hydrogen. The theoretical differential cross sections in the Glauber and Born approximations that are presented show that the theory and the experimental results for 200-keV proton impact agree very well, but below 200 keV there are differences. These differences, which are more pronounced at the lower projectile energies, may be explained in terms of charge transfer to the continuum, which is not treated in our Born and Glauber calculations of direct Coulomb ionization. The …

Environmental Effects Of James River Sewage Treatment Plant Outfall Construction, Dexter S. Haven, Paul C. Kendall, Robert J. Diaz, Donald F. Boesch, Michael E. Bender

Reports

In the spring of 1975 the Institute began a program to determine whether significant environmental changes would occur in the area of the new James River Plant outfall that might be related to its construction and/or initial operation. Parameters measured in the study were benthic animal and oyster populations, coliform levels and chlorine residuals. The primary emphasis of the study centered on the estimation of the impact of the construction activity on shellfish beds in the area. The results of the investigation are presented in three segments, the first dealing with shellfish populations, the second with other benthic animals and …

Generalization Of The Rosen-Zener Model Of Noncrossing Interactions. Ii. Differential Cross Sections., T. R. Dinterman, John B. Delos

Arts & Sciences Articles

The generalized Rosen-Zener model developed in the accompanying paper is used to calculate differential cross sections for a model noncrossing system, and the structure of the cross sections is explained in terms of the deflection functions. It is found that the angular threshold effects that are typical of potential-curve crossings do not appear in this noncrossing system.

Interval Estimation Of Reliability Characteristics Of A K-Identical Unit Standby Redundant System, Danny D. Dyer

Mathematics Technical Papers

Standby redundancy is a method for increasing the reliability of a system through the use of additional "backup" units. Assuming perfect failure-sensing and switch-over, we consider such a system when the units are identical, non-repairable, and their lifetimes follow a two-parameter exponential distrubution. Based on unit Type II censored data, interval estimates of the system threshold parameter, mean time to failure, and reliability at time [see pdf for notation], are made through structural inference (a group theoretic approach to fiducial theory). A discussion of n-content structural tolerance intervals for the distribution of the lifetime of the system is also given. …

Mathematical Analysis Of Stress Relaxation In Articular Cartilage During Compression, Jerome Eisenfeld, Harold Lipshitz, Van C. Mow

Mathematics Technical Papers

Articular cartilage is the avascular bearing material covering the articulating ends of the mating bony segments of synovial joints. Functionally articular cartilage provides a near frictionless surface, whose coefficient of friction 0.002, which is tough and wear resistant. These biomechanical functions of the tissue are preserved so long as the tissue is maintained in a normal physiological state. The destruction and subsequent loss of articular cartilage as a result of degenerative joint diseases would lead to joint stiffness, pain and deformities. An abnormal state of mechanical stress exerted upon the tissue is an initiating factor or at least a precursor …

Generalization Of The Rosen-Zener Model Of Noncrossing Interactions. I. Total Cross Sections, T. R. Dinterman, John B. Delos

Arts & Sciences Articles

The formalism developed previously to study electronic transitions by the curve-crossing mechanism is used to obtain a general model for transitions which take place due to the strong coupling of curves which do not cross. This exactly solvable model is a generalization of a model developed by Rosen and Zener. The model is shown to give respectable agreement with exact calculations at low velocities, and to go to the correct resonant-charge-exchange limit at high velocities. Predictions of the model are shown to give good agreement with the measured total cross sections for charge exchange in the sytem Li+ + Na⇄Li+Na+.

Petroleum Hydrocarbons From Effluents: Detection In Marine Environment, John T. Tanacredi Ph.D.

Faculty Works: CERCOM (1977-2016)

The marine environment has become the primary disposa ground for an increasing quantity of petroleum wastes. Mushrooming demands for petroleum products and the lack of economic incentive to recycle waste oil will increase the concentrations of detrimental petroleum hydrocarbons in the marine environment

Although a continuous, low-level discharge of waste petroleum hydrocarbons into the marine environment may not be as dramatic as a major oil spill, the consequences could be more devastating over an extended period. As noted by Blumer, earlier interpretations of the environmental effects of oil must not be reevaluated in the light of recent evidence of its …

Conformational Analysis Of 1-Tertiarybutyl-1, 4-Dihydronaphthalene A Turnover From Srni To Sni Mechanism, Su-Jen Huang

Masters Theses & Specialist Projects

The cyclohexadiene porition of 1-tertiarybutyl-1, 4-dihydronaphthalene exists in a puckered rather than planar conformation at room temperature, with approximately equal populations of the isomer with the t-butyl group “axial” and “equatorial.” Analysis of chemical shifts and coupling constants was aided by use of a LAOCOON III program.