Open Access. Powered by Scholars. Published by Universities.®

Digital Commons Network™

Open Access. Powered by Scholars. Published by Universities.®

Physical Sciences and Mathematics

Institution
Keyword
Publication Year
Publication
Publication Type
File Type

Articles 88531 - 88560 of 91805

Full-Text Articles in Entire DC Network

A Blocked Orthogonalization Method For Nonlinear Regression, Daniel C. St. Clair Jan 1975

A Blocked Orthogonalization Method For Nonlinear Regression, Daniel C. St. Clair

Doctoral Dissertations

"The blocked orthogonalization algorithm for nonlinear regression developed in this work results from a study of matching problems having certain identifiable characteristics with algorithms which exploit those characteristics. The new algorithm represents an extension of an earlier algorithm by D. S. Grey using a blocked orthogonalization technique proposed by R. E. von Holdt. The result is a generalization of the Grey and the Gauss-Hartley algorithms which maintains the desirable properties of these algorithms while avoiding their more serious limitations. The new algorithm was found to be quite effective for solving problems in which the parameters in the model under consideration …


The Ecology Of A Predaceous Troglobitic Beetle, Neaphaenops Tellkampfii (Coleoptera: Carabidae, Trechinae) I. Seasonality Of Food Input And Early Life History Stages, Thomas C. Kane, Russell M. Norton, Thomas L. Poulson Jan 1975

The Ecology Of A Predaceous Troglobitic Beetle, Neaphaenops Tellkampfii (Coleoptera: Carabidae, Trechinae) I. Seasonality Of Food Input And Early Life History Stages, Thomas C. Kane, Russell M. Norton, Thomas L. Poulson

International Journal of Speleology

The adaptations in the life history of the Carabid beetle Neaphaenops tellkampfii has been investigated in respect to seasonal food input. The following characters have been studied: copulations, egg production, larvae and pupae.


Three New Troglobitic Asellids From Western North America (Crustaces: Isopoda: Asellidae), Thomas E. Bowman Jan 1975

Three New Troglobitic Asellids From Western North America (Crustaces: Isopoda: Asellidae), Thomas E. Bowman

International Journal of Speleology

Fleming’s arguments (1973) for reducing Conasellus to a synonym of Asellus are considered inadequate, but the name Conasellus is replaced by its senior synonym Caecidotea. Two new troglobitic species of Caecidotea are described, C. chiapas from caves in Chiapas, Mexico, and C. sequoiae from Liburn Cave, Tulare County, California. Asellus califomicus is reported from springs in Napa and Santa Clara Counties; the male pleopod 2 is redescribed, and the species is assigned to the subgenus Phreatoasellus. A new genus and species, Salmasellus steganothrix, is described from Horseshoe Lake, Alberta, Canada.


1975 Field Experiments And Cereal Disease Surveys, A. G. P. Brown Jan 1975

1975 Field Experiments And Cereal Disease Surveys, A. G. P. Brown

Experimental Summaries - Plant Research

1. Septoria disease of wheat - 75BA17. 2. Fungicide seed dressing on lupins 3. Cereal Disease survey - Table 7 - Zone l. Beverley R.S. B3 2. Badgingarra A2 3. Chapman Bl 4. Gibson A5 5. Merredin C3 6. Mt Barker A5 7. Newdegate B4 8. Salmon Gums C5 9. Wongan Hills B2 10. Woodgenellup A5 11. Chowerup A5 12. Neradup A5 13. W. Grass Patch B5 14. E. Salmon Gums C5 15. Mellewa Cl 16. Yuna Cl 17. N. Mingenew Bl 18. Mingenew Bl 19. Gairdner River A5 20. Jerramungup B5 21. Ravensthorpe B5 22. N. Kojonup A4 23. …


1975 Mn Drilled And Sprayed On Unicrop, J. W. Gartrell Jan 1975

1975 Mn Drilled And Sprayed On Unicrop, J. W. Gartrell

Experimental Summaries - Plant Research

75AL25 (with Trevenen) Mn Drilled and Sprayed on Unicrop, 75AL26, 75ES28, 785ES29, 75GE32, 75MO31, 75MO33, 75TS24, 75TS25.


Computational Models Of Learning., Kenneth Jesse Marse Jan 1975

Computational Models Of Learning., Kenneth Jesse Marse

Masters Theses

"An investigation is made into the use of techniques which would normally be described as learning if encountered in a human being. A literature review of several subject areas including game-playing computer programs, automatic control systems, pattern recognition methods, and biological modeling is performed, with the purpose of extracting and examining those processes which exhibit learning. A general model of the type of learning most widely utilized in these areas is constructed and used to compare and contrast specific models which describe the learning techniques employed. Some specific models which do not exhibit learning as described by the general model …


Can Psi Help Him? Jan 1975

Can Psi Help Him?

Personalized System of Instruction (PSI), or Keller Plan, Materials

PSI (Personalized System of Instruction) can help students learn!

If the lecture-taught course has you meeting the students as adversaries, continually answering redundant questions, haggling over half credit for half correct answers, and generally finding your students being inhibited by the lock-step timing of a lecture course, then PSI is an alternative.

It is also the title of a film, PSI: An Alternative, that imaginatively and graphically outlines an intriguing and dynamic system for learning.

PSI (also known as the Keller Plan) is self-paced, mastery oriented, student tutored for junior college and college level instruction with classes of all sizes …


A Comparison Between Direct Waves And Head Waves In A Seismic Refraction Profile., Nelson Jose Aboud Garcia Jan 1975

A Comparison Between Direct Waves And Head Waves In A Seismic Refraction Profile., Nelson Jose Aboud Garcia

Masters Theses

"The purpose of this investigation was to experimentally verify the theoretical prediction that the particle velocity of a head wave is the time integral of the particle velocity of a direct wave.

The procedure was to use small explosions in the field to generate direct waves and head waves in a surface layer of low compressional velocity overlying a higher velocity medium. The direct waves were distinguished by the ratio of frequencies and by the slopes in a time distance plot.

The result of comparing the particle velocity of the head waves with the integral of the particle velocity of …


A Study Of Several Substitution Ciphers Using Mathematical Models., Wanda Louise Garner Jan 1975

A Study Of Several Substitution Ciphers Using Mathematical Models., Wanda Louise Garner

Masters Theses

"This paper will consider vector and matrix representations for several polyalphabetical substitution ciphers. Classical ciphers such as the Vigenère, the True Beaufort, the Variant Beaufort, and the autokey will be included. We shall also discuss ways to mathematically vary a substitution cipher. In addition, we shall employ our mathematical representations to decipher a fixed matrix substitution cipher"--Abstract, p. ii


The Intramolecular Torsional Potential And Dielectric Properties Of 2,3-Butanedione, Gevert H. Meyer Jan 1975

The Intramolecular Torsional Potential And Dielectric Properties Of 2,3-Butanedione, Gevert H. Meyer

Masters Theses

Dipole moment measurements have been carried out on 2,3-butanedione in solution, pure liquid, and the vapor phase. A dipole moment of 1.03 ± .01 Debye was observed for dilute solutions of 2,3-butanedione in carbon tetrachloride. Pure liquid samples exhibit an anomalous dipole of 1.56 ± .01 Debye. The following results were obtained for vapor phase measurements: 1.04, 1.07, 1.08, 1.11, and 1.17 ± .01 Debye at 310.15, 350.15, 370.15, 431.70 and 472.10 ± .02°K respectively.

The acetyl torsional potential was characterized from the observed temperature dependence of dipole moment. This torsional mode was described by a two-parameter potential function: V(Ø) …


Nutrient Dynamics And Gas Production In Aquatic Ecosystems: The Effects And Utilization Of Mercury And Nitrogen In Sediment-Water Microcosms, D. B. Porcella, V. D. Adams, P. A. Cowan, S. Austrheim-Smith, W F. Holmes, J. Hill Iv, W. J. Grenney, E. J. Middlebrooks Jan 1975

Nutrient Dynamics And Gas Production In Aquatic Ecosystems: The Effects And Utilization Of Mercury And Nitrogen In Sediment-Water Microcosms, D. B. Porcella, V. D. Adams, P. A. Cowan, S. Austrheim-Smith, W F. Holmes, J. Hill Iv, W. J. Grenney, E. J. Middlebrooks

Reports

Sixteen sediment-water microcosms designed to allow complete gas, liquid, and solid mass balances of gases, nutrients, and mercury were studies under dark conditions or varying light intensity for a period of 189 days. Results indicated that the microcosm technique is a very sensitive method of analyzing microbial dynamics in sediment water systems. Gas quantity and composition changes were easy to monitor and were especially sensitive to light and nutrient variations. Nitrogen fixation occurred in all lighted systems (blue-green algae nitrogen fixers, Anabaena, and others) and was adequate to insure that no nitrogen limitation occurred even though nitrogen limitation was imposed …


Regionalization As An Effect Of Offshore Oil And Gas Exploitation: A Case Study Of The North Sea, Mark J. Chittum Jan 1975

Regionalization As An Effect Of Offshore Oil And Gas Exploitation: A Case Study Of The North Sea, Mark J. Chittum

Marine Affairs Theses and Major Papers

This study attempts to analyze whether oil and gas exploitation in a semi-enclosed sea will result in closer relations being developed in the region leading to the establishment of a special regime for that sea. The study area is Northwestern Europe which is centered on the North Sea. All the littoral states of Northwestern Europe have major interests in the North Sea, one of which is oil and gas exploitation. This study is developed through the examination of the activities in the North Sea, related to oil and gas production, which tend to join the region together followed by an …


77-4 Hydrographic And Biological Observations At An Anchor Station Off St. Augustine, Florida (Eastward Cruise E-1g-75), Larry P. Atkinson, Gustav A. Paffenhofer, William M. Dunstan Jan 1975

77-4 Hydrographic And Biological Observations At An Anchor Station Off St. Augustine, Florida (Eastward Cruise E-1g-75), Larry P. Atkinson, Gustav A. Paffenhofer, William M. Dunstan

CCPO Publications

The intrusion of deep, nutrient-rich Gulf Stream water into the shelf waters off the southeastern United States is probably the major source of nutrients in the shelf waters and consequently intrusions have a major impact on the biota. This particular cruise was one of the first to be designed to find the front that represents the interface between intruding Gulf Stream waters and normal shelf water. Once the front was delineated an anchor station was occupied to observe the time change at a particular location as the front moved back and forth past the station.

The methods used and resultant …


Strain Effects On The Esr Spectrum From Antimony Donors In Germanium, Edward Boyd Hale, John R. Dennis, Shih Hua Pan Jan 1975

Strain Effects On The Esr Spectrum From Antimony Donors In Germanium, Edward Boyd Hale, John R. Dennis, Shih Hua Pan

Physics Faculty Research & Creative Works

The electron-spin-resonance spectra from surface-strained (but not externally stressed) antimony-doped germanium are investigated in detail. Experimental data are given for the linewidth, line asymmetry, and line-shape reversal feature as well as for the changes in donor concentration, temperature, and surface conditions. The donors of interest occur in a surface layer several microns thick. A theoretical analysis is based on the Kohn-Luttinger formulation for a shallow donor electron, which is forced by surface strain to predominately occupy a [111] conduction-band valley minimum. A substantial distribution in strain among the donor sites is necessary to account for the line-structure features. These features …


Photoionization Of The 6p32,122 Fine-Structure Levels In Cesium, Kaare J. Nygaard, Robert E. Hebner, James A. Jones, Robert J. Corbin Jan 1975

Photoionization Of The 6p32,122 Fine-Structure Levels In Cesium, Kaare J. Nygaard, Robert E. Hebner, James A. Jones, Robert J. Corbin

Physics Faculty Research & Creative Works

The relative photoionization cross sections for cesium atoms selectively excited to the 6P32,122 states have been measured in a triple-crossed-beam experiment. A cesium discharge lamp produced resonant wavelengths of 8521 and 8944 for the excitation process. A Hg-Xe lamp combined with a grating monochromator was used for the actual ionization in the wavelength region from 2500 to 5000. Background counts due to photoionization of ground-state cesium atoms and dimers as well as various surface effects were discriminated against by chopping the excitation light source. The data are compared with results from radiative-recombination measurements in which the fine-structure levels are not …


Double Reflection Dips From Grating Ruled Semiconductors, L. F. Teng, Ralph William Alexander, Robert John Bell, B. Fischer Jan 1975

Double Reflection Dips From Grating Ruled Semiconductors, L. F. Teng, Ralph William Alexander, Robert John Bell, B. Fischer

Physics Faculty Research & Creative Works

The Double Reflectivity Dips, Previously Observed by Fischer Et Al. and Anderson Et Al., Which Appeared in the Reflection Spectra of Grating Surfaces On, the Te‐doped Semiconductors GaAs and InSb Around Both the Plasmon and Phonon Frequencies Have Been Measured in More Detail. in the Plasmon Region, Several Possible Explanations of the Phenomenon Are Discussed, But the Favored Explanation Involves Surface Damage. a Simple Two‐region Reflectivity Equation Checked with a Rigorous Grating Theory is Proposed and is Shown to Fit the Data Well. Copyright © 1975 WILEY‐VCH Verlag GmbH & Co. KGaA


Seasonal Changes In A Population Of Pseudanopthalmus Tenuis (Coleoptera, Carabidae) In Murray Spring Cave, Indiana: A Preliminary Report, James H. Keith Jan 1975

Seasonal Changes In A Population Of Pseudanopthalmus Tenuis (Coleoptera, Carabidae) In Murray Spring Cave, Indiana: A Preliminary Report, James H. Keith

International Journal of Speleology

A study of a population of Pseudanophthalmus tenuis is being conducted in Murray Spring Cave, Orange County, Indiana as one facet of a larger research project encompassing the entire terrestrial community of that cave. Changes in behaviour and abundance determined by census and mark-recapture methods and physiological changes determined from field-collected beetles indicates that these animals exhibit a seasonal reproductive rhythm probably mediated or controlled by winter and spring flooding of the cave.


Interaction Between Competition And Predation In Cave Stream Communities, David C. Culver Jan 1975

Interaction Between Competition And Predation In Cave Stream Communities, David C. Culver

International Journal of Speleology

Predation by salamander larvae (Gyrinophilus porphyriticus) reduces the density of one of its prey (the isopod Asellus recurvatus) but increases the density of the other (the amphipod Crangonyx antennatus in a Virginia cave stream. This happens because predation on the isopod reduces its competitive effect on the amphipod. Both prey populations tend to occur more frequently in refugia when predators are present. In another cave where there are no prey refugia, the predator reduces the density of both species. It appears that it is easier for a predator to invade a community than to reach a stable …


Reductive Cleavage Of N-Substituted Benzenesulfonamides And P-Sulfamylbenzoic Acid, Robert E. Davenport Jan 1975

Reductive Cleavage Of N-Substituted Benzenesulfonamides And P-Sulfamylbenzoic Acid, Robert E. Davenport

University of the Pacific Theses and Dissertations

The objective of the present work was to study further the effect of varying substituents on the nitrogen atom and on the ring of sulfonamides in the Birch reduction of aromatic sulfonamides, especially with respect to the amount of thiol formed, in the hope that information concerning the initial cleavage step might be discerned.


Multivalue Methods, Clayton V. Henrie Jan 1975

Multivalue Methods, Clayton V. Henrie

All Graduate Plan B and other Reports, Spring 1920 to Spring 2023

Methods of solving ordinary differential equations with initial conditions are of a great importance to engineers and scientists. Many of these equations can be solved by well-known analytical techniques, but a greater number of physically significant differential equations cannot be so solved. Thus, the solutions of these equations must be approximated numerically. It is the purpose of this paper to investigate the techniques used in solving differential equations with initial conditions by "multivalue methods."


Multivariate Analysis Of Variance For Simple Designs, Yin-Yin Chen Jan 1975

Multivariate Analysis Of Variance For Simple Designs, Yin-Yin Chen

All Graduate Plan B and other Reports, Spring 1920 to Spring 2023

The analysis of variance is a well known tool for testing how treatments change the average response of experimental units. The essence of the procedure is to compare the variation among means of groups of units subjected to the same treatment with the within treatment variation. If the variation among means is large with respect to the within group variation we are likely to conclude that the treatments caused the variation and hence we say the treatments cause some change in the group means.

The usual analysis of variance checks how far apart the group means are in a single …


An Evaluation Of Bartlett's Chi-Square Approximation For The Determinant Of A Matrix Of Sample Zero-Order Correlation Coefficients, Stephen M. Hattori Jan 1975

An Evaluation Of Bartlett's Chi-Square Approximation For The Determinant Of A Matrix Of Sample Zero-Order Correlation Coefficients, Stephen M. Hattori

All Graduate Plan B and other Reports, Spring 1920 to Spring 2023

The single equation least-squares regression model has been extensively studied by economists and statisticians alike in order to determine the problems which arise when particular assumptions are violated. Much literature is available in terms of the properties and limitations of the model. However, on the multicollinearity problem, there has been little research, and consequently, limited literature is available when the problem is encountered. Farrar & Glauber (1967) present a collection of techniques to use in order to detect or diagnose the occurrence of multicollinearity within a regression analysis. They attempt to define multicollinearity in terms of departures from a hypothesized …


The Noble Gas Record Of Terrestrial And Meteoritic Samples, Edward W. Hennecke Jan 1975

The Noble Gas Record Of Terrestrial And Meteoritic Samples, Edward W. Hennecke

Doctoral Dissertations

"Analyses of tellurium and xenon in a telluride ore from Kalgoorlie, Australia resulted in the following conclusions:

  1. The ratio of the double beta-decay half-life of 128Te relative to that of 130Te is 1.6 x 103
  2. The double beta-decay half-life of 130Te is 1.0 x 1021 years.
  3. The measured half-lives are consistent with values predicted for a second order process of ordinary beta-decay that occurs with the emission of two neutrinos.

A study of noble gases in Thailand tektites provided the following information on the history of these objects:

  1. The isotopic compositions of nonradiogenic Ne, Ar, …


Reflected Surface Waves From A Vertical Discontinuity., Jesus Manuel Aboud Jan 1975

Reflected Surface Waves From A Vertical Discontinuity., Jesus Manuel Aboud

Masters Theses

"Surface waves generated in the field by small explosions were observed along lines parallel and perpendicular to a vertical discontinuity in a surface layer. Three types of wave particle motion were observed in waves incident on the discontinuity: retrograde, progressive, and shear (SH). Waves of the last two types were intense enough to observe a reflection, permitting calculation of reflection coefficients. The results demonstrate the feasibility of using reflection measurements to locate a discontinuity such as a fault zone"-- Abstract, p. ii


Thermal Instability In Supernova Shells, R. Mccray, R. F. Stein, Menas Kafatos Jan 1975

Thermal Instability In Supernova Shells, R. Mccray, R. F. Stein, Menas Kafatos

Mathematics, Physics, and Computer Science Faculty Articles and Research

Thermal instability in the radiative cooling region behind a shock will cause upstream density fluctuations to collapse into thin sheets aligned parallel to the shock front. A linearized calculation demonstrates the development of this instability. Thermal conduction suppresses the development of small-scale perturbations. Estimates of the scale sizes for the fully developed condensations agree roughly with the scale sizes of fine structure observed in supernova shells such as the Cygnus Loop.


Sources Of Excitation Of The Interstellar Gas And Galactic Structure, J. J. Cowan, Menas Kafatos, W. K. Rose Jan 1975

Sources Of Excitation Of The Interstellar Gas And Galactic Structure, J. J. Cowan, Menas Kafatos, W. K. Rose

Mathematics, Physics, and Computer Science Faculty Articles and Research

The excitation of the interstellar gas. is discussed in the light of recent evidence from γ-ray, molecular, and 21-cm line observations. Previous studies of the excitation of the interstellar gas have not taken into account the substantial density contrast that exists between spiral arms and interarm regions. We examine the role played by the galactic distribution of three sources of excitation (supernovae, OB stars, and ultraviolet stars) in determining the physical state of the interstellar gas in arm and interarm regions.


Late Pleistocene And Holocene Geology Of The Moe Site, New Town, North Dakota, Richard W. Kornbrath Jan 1975

Late Pleistocene And Holocene Geology Of The Moe Site, New Town, North Dakota, Richard W. Kornbrath

Theses and Dissertations

Eight stratigraphic units of Late Cenoioic age are present around the Moe Archeological Site near New Town, North Dakota. Unit Zero is a layer of glacial sediment consisting of grayish brown pebbly clay loam. Unit One consists of fluvial and beach sand and gravel. Unit Two consists of light yellowish brown, offshore lake silt that was deposited into a glacial lake in Late Wisconsinan time. Unit Three is a layer of glacial sediment consisting of grayish brown pebbly clay loam (Late Wisconsinan). Unit Four consists of fluvial sand and gravel (Late Wisconsinan}. Unit Five is a layer of slough sediment …


The Keller Plan In College Introductory Physical Geology : A Comparison With The Conventional Teaching Method, Robert G. Walsh Sr. Jan 1975

The Keller Plan In College Introductory Physical Geology : A Comparison With The Conventional Teaching Method, Robert G. Walsh Sr.

Theses and Dissertations

The purpose of this study is to compare the learning and attitudinal changes that took place in a college introductory physical geology class between a self-paced method of instruction called the Keller Plan and the conventional lecture-laboratory method.

The sample population was 56 students enrolled in Earth Science 120, an introductory physical geology course at Minot State College ·~ during the fall quarter, 1973. An experimental section of 20 students experienced the Keller Plan treatment and two control groups consisting of 18 students each received the conventional method of instruction.

Four specific areas of investigation were tested: (1) knowledge of …


Methyl Proton Nmr Shifts Of Coordinated Methanol In A Series Of Co(Ch,0h),X2+ Compounds, J.R Vriesenga, Jerry Goodisman Dec 1974

Methyl Proton Nmr Shifts Of Coordinated Methanol In A Series Of Co(Ch,0h),X2+ Compounds, J.R Vriesenga, Jerry Goodisman

Chemistry - All Scholarship

The isotropic contact NMR shifts of the coordinated cis and tram methanol methyl proton resonances of a series of Co(CH30H)5X2+ complexes were measured, where the ligand X was pyridine, /I- and a-picoline, DMF, DMSO, acetonitrile, and water. The question of how to separate the observed shifts into their respective Fermi contact and dipolar (pseudocontact) contributions was examined in detail with the result that a new procedure for carrying out the separation was proposed. The dipolar shifts for these complexes were found to vary widely, with the acetonitrile complex exhibiting the largest dipolar shift. For the DMSO and water complexes the …


Syntheses And Characterizations Of Vanadyl (Iv) Complexes With Dihydroxydicarboxylate Ligands, Sharon K. Hahs Dec 1974

Syntheses And Characterizations Of Vanadyl (Iv) Complexes With Dihydroxydicarboxylate Ligands, Sharon K. Hahs

Chemistry and Chemical Biology ETDs

Binuclear complexes of the vanadyl(IV) tartrates have already been shown to exist both in the solid state and in solution. These complexes consist of two vanadyl(IV) ions bridged by two tartrato(4-) ligands, either of the same--DD (or LL)-- or opposite--DL--enantiomeric configuration. (The meso isomer of tartaric acid will not form binuclear complexes with vanadyl(IV).) The DL complex is more stable than the DD complex due to a greater degree of staggering between the vicinal hydrogen atoms on each tartrate chain. Investigations of vanadyl(IV) complexes with substituted tartaric acid ligands--specifically, (±)-dimethyltartaric acid and (±)-threomethyltartaric acid--have been undertaken to determine whether this …