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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 …

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 …

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 …

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.

An Improved Approach For "Optimization" Of Multiple Policy Objectives, Perihan Soliman Tawfik

Dissertations and Theses

This thesis involved three categories of activity; development and testing of an expanded version of ELECTRE II, also the development of a computer software program for ELECTRE II.

The expanded version of ELECTRE II took the form of an input aiding questionnaire along with a tailored structure to suit a particular problem. The contents of the questionnaire were based on geueral problem solving concepts (techniques, strategies) gleaned from the systems science literature. This questionnaire assumed a programmed instruction format in contrast to that of an interactive computer software package, so that it would not be prohibitive in terms of expenses …

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.

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.

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, …

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

Mathematics Technical Papers - Archive

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 …

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

Mathematics Technical Papers - Archive

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. …

Differential Energy-Loss Cross Sections For Ionization Of Atomic Hydrogen By 25-200-Kev Protons, John T. Park, John 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 …

Middle And Upper Eocene Biostratigraphy (Foraminifera) Of The Cascade Head Area, Lincoln And Tillamook Counties, Oregon, Arden D. Callender Jr.

Dissertations and Theses

An almost complete sequence of middle and upper marine strata, informally designated in this study as the "Strata of Cascade Head", has yielded 334 species and varieties of fossil Foraminifera. The Foraminifera were collected from 38 localities in four stratigraphic sections measured along the Salmon River, Neskowin Creek, Cascade Head Road, and near the town of Three Rocks in the central Oregon Coast Range.

Software For Numerical Computation, John R. Rice

Department of Computer Science Technical Reports

No abstract provided.

Convex Cones And Dentability, J. C. Hankins, R. (Roy) M. Rakestraw

Mathematics and Statistics Faculty Research & Creative Works

No abstract provided.

On The Mann Iteration Process In A Hilbert Space, Troy L. Hicks, John D. Kubicek

Mathematics and Statistics Faculty Research & Creative Works

No abstract provided.

A Class Of Singular Neutral-Differential Systems, W. J. Fitzpatrick, L. J. Grimm

Mathematics and Statistics Faculty Research & Creative Works

Noetherian operator theory is used to prove an existence theorem for a singular functional-differential system. An analogue of the standard existence and uniqueness results at an ordinary point follows as a corollary. © 1977 American Mathematical Society.

Regular Singular Differential Equations Whose Conjugate Equation Has Polynomial Solutions, Leon M. Hall

Mathematics and Statistics Faculty Research & Creative Works

Consider the n -dimensional singular differential system defined by the operator $L:(Ly)(z) = z^p y'(z) + A(z)y(z)$, where z is a complex variable and p is a positive integer. The solvability of the nonhomogeneous system $Ly = g$ depends on the solutions of the homogeneous conjugate system, $L^ * f = 0$, where $L^ * $ is the operator conjugate to L. We show that $L^ * f = 0$ has polynomial solutions if the constant matrix in the series expansion of $A(z)$ has at least one nonpositive integer eigenvalue. Also, we show that if $L^ * f = 0$ …

Mathematics In America: The First Hundred Years, Judith V. Grabiner

Pitzer Faculty Publications and Research

There are two main questions I shall discuss in this paper. First, why was American mathematics so weak from 1776 to 1876? Second, and much more important, how did what happened from 1776-1876 produce an American mathematics respectable by international standards by the end of the nineteenth century? We will see that the "weakness" -at least as measured by the paucity of great names- co-existed with the active building both of mathematics education and of a mathematical community which reached maturity in the 1890's.

Systems Analysis Of The Presaharan Ecosystem Of Southern Tunisia, George Novikoff, Frederic H. Wagner, Mohamed S. Hajjaj

Progress reports

No abstract provided.

Estimation Of The Guarantee Time In A Two-Parameter Exponential Failure Model, Danny D. Dyer

Mathematics Technical Papers - Archive

There are available several classical point estimators of the guarantee time (location parameter) in a two-parameter exponential failure model. For the purpose of making a pairwise comparison of the estimators, a two-fold technique is introduced which essentially examines (a) the "odds" in favor of an estimator being closer to the true value than is a competing estimator and (b) an estimator's average closeness given that it is closer to the true value as well as given that it is not. Closeness to the true value is measured through an absolute error loss function. Joint consideration of these concepts is discussed …

Runoff Estimates For Small Rural Watersheds And Development Of A Sound Design Method: Volume I. Research Report, Joel E. Fletcher, A. Leon Huber, Frank W. Haws, Calvin G. Clyde

Reports

Foreword: This report is composed of thee volumes; Volume I is the Research Report; Volume II consists of recommendations for establishing design manuals and Appendices B, C, D, E, F, G, and H, which are the design aids required for establishing design manuals; Volume III consists of Appendix A, and accumulation of the data base used in the study, FHWA chose to arrange the report as described to facilitate distribution of the results. The methods reported herein are designated as the Federal Highway Administration Methods are designed to be applied to watersheds smaller than 50 square miles but may be …

Runoff Estimates For Small Rural Watersheds And Development Of A Sound Design Method. Volume Ii, Recommendations For Preparing Design Manuals And Appendices B, C, D, E, F, G, & H, Joel E. Fletcher, A. Leon Huber, Frank W. Haws, Calvin G. Clyde

Reports

Frequency analyses of more than 1,000 small watersheds in the United States and Puerto Rico were used to develop the estimation method for design of peak flow for ungaged watersheds. This method, called the Federal highway Administration (FHWA) method, is conceptually similar to the Bureau of Public Roads (BRP) method developed by W. D. Potter. The FHWA method relates the runoff peak to easily determined hydrophysiographic parameters and is intended for use on watersheds smaller than 50 square miles. The concept of risk is incorporated inot the design procedure. The risk is the probability that one or more events will …

Mixed Integer Programming Models For Water Resources Management, Brad A. Finney, William J. Grenney, A. Bruce Bishop, Trevor C. Hughes

Reports

A regional water quality control model is developed by linking a steady-state water quality simulation model with an optimization model. The water quality simulation model can be applied to complex river systems with both point and nonpoint loads using multiple interdependent pollution parameters described by either linear or nonlinear equations. Twelve water quality parameters can be modeled simultaneously: four non conservative constituents (or conservative constituents if the decay rate is set equal to zero); coliform bacteria (MPN); phosphorus; biochemical oxygen demand (BOD); ammonia (NH3); nitrate (NO3); dissolved oxygen (DO); temperature (°C); and algae. The water quality model is used to …

Proposal To Technology Transfer Office Of Water Research And Technology U.S. Department Of Interior, C. Earl Israelsen, Frank W. Haws, Donna H. Falkenborg, L. Douglas James

Reports

Executive Summary:

Existence Of Solutions In A Closed Set For Delay Differential Equations In Banach Spaces, V. Moauro, S. Leela

Mathematics Technical Papers - Archive

The study of the Cauchy problem for ordinary differential equations in a Banach space has been extensive [1,3-7,9-12]. The two main directions that are followed in such a study are (i) finding monotonicity type conditions which guarantee the existence as well as uniqueness of solutions and (ii) finding compactness type conditions which assure only the existence of solutions [3,4]. It is also known [10,12] that in order to prove the existence of solutions in a closed subset F of the Banach space, a boundary condition of the type [see pdf for notation] is required.

Asymptotic Properties Of A Nonlinear Diffusion Process Arising In Articular Cartilage, Van C. Mow, Jerome Eisenfeld

Mathematics Technical Papers - Archive

There has been considerable effort put forth to analyse degenerative Joint diseases in terms of the principles of mechanics and hydrodynamics [8]. This effort has led to mathematical models which are systems of nonlinear partial differential equations (see e.g., [6] and [7]). The mathematical models are based on assumptions concerning the nature of the physical system which are not a priori known. Therefore laboratory experiments are performed with an eye towards validating the mathematical models. This paper deals with a particular mathematical model, a nonlinear diffusion equation, which has been proposed by Mow and Monsour [4], [5] to describe the …

A Model For Solid Waste Collection Costs, Bruce Anderson

Retrospective Theses and Dissertations

No abstract provided.

General Moment Methods For A Class Of Nonlinear Models, Stephen W. Cheng, Jerome Eisenfeld

Mathematics Technical Papers - Archive

This paper deals with the following problems: (i) the development of a general theory which incorporates several methods as special cases; (ii) the applicability of moment methods to a class of nonlinear problems, (iii) the specification of the class of admissible weighting functions; (iv) the estimation of the number of parameters; (v) the elimination of the cut-off error in the analysis of fluorescence decay data.

Stability Of Differential Systems With Impulsive Perturbations In Terms Of Two Measures, S. Leela

Mathematics Technical Papers - Archive

The study of differential systems of the form (1.1) [see pdf for notation] where [see pdf for notation] denotes the distributional derivative of [see pdf for notation], a function of bounded variation (that is, differential systems with impulsive perturbations, also called measure differential equations), is both interesting and important because most models for biological neural nets,pulse frequency modulation systems, automatic control problems with impulsive inputs and many physical processes are best described by such equations [1-3,8,10,12,13]. Since the solutions of (1.1) are discontinuous (that is, functions of bounded variation), the investigation of the stability properties of (1.1) by the usual …