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

Digital Commons Network™

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

Brigham Young University

Discipline
Keyword
Publication Year
Publication
Publication Type
File Type

Articles 28441 - 28470 of 29588

Full-Text Articles in Entire DC Network

Three New Species Of Petrified Wood From The Upper Jurassic Morrison Formation Of Southern Utah, David Arthur Medlyn May 1972

Three New Species Of Petrified Wood From The Upper Jurassic Morrison Formation Of Southern Utah, David Arthur Medlyn

Theses and Dissertations

The petrified wood for this study was collected from the Upper Jurassic Morrison Formation in the south central part of Utah on the Colorado Plateau. The study area, located near Clay Point, Garfield County, Utah, is south of the Henry Mountains. The site is relatively undisturbed containing many well preserved specimens. This study constitutes the first detailed study of fossil coniferous woods of the Morrison Formation. Although this formation contains abundant petrified wood, its floral composition has been virtually unknown. Three genera have been identified in this study: Protopiceoxylon Gothan, Mesembrioxylon Seward, and Taxaceoxylon (Unger) Krausel. Protopiceoxylon has only been …

Go to article

Electrolytic Synthesis Of [Gamma]-Diketones, Leon F. Pahler May 1972

Electrolytic Synthesis Of [Gamma]-Diketones, Leon F. Pahler

Theses and Dissertations

Four γ-diketones were synthesized by using a modification of the Kolbe electrolytic condensation of β-ketocarboxylic acids. [--see equation in thesis--] The following γ-diketones were synthesized in moderate yields: 2,5-hexanedione, 4,7-decanedione, 2,2,7,7-tetramethyl- 3,6-octanedione, and 1,4-diphenyl-1,4-butanedione (34, 39, 23, and 27, respectively). However, attempted preparation of the following γ-diketones failed: 3,4-dimethyl- 2,5-hexanedione, 3,3,4,4-tetramethyl-2,5-hexanedione, and 1,4-di(2-thienyl)-1,4-butanedione. Attempts to electrolytically condense α-alkyl and α, α-dialkyl substituted monocarboxylic acids have been reported and all attempts have ended in failure; similarly, the attempts to synthesize 3,4-dimethyl and 3,3,4,4-tetramethyl- 2,5-hexanedione from 2-methyl and 2,2-dimethyl-3- oxobutanoic acid, respectively, failed. The preparation of 1,4-di(2-thienyl)-l,4-butanedione failed because the product or …

Go to article

A New Method For The Preparation Of Alkylnaphthyl Ethers And Sulfides, Edward Ying-Shih Chen May 1972

A New Method For The Preparation Of Alkylnaphthyl Ethers And Sulfides, Edward Ying-Shih Chen

Theses and Dissertations

The reaction of monohalonaphthalenes with metal alkoxides and mercaptides in a solvent mixture of the corresponding alcohol and dimethyl sulfoxide (DMSO) has been studied. These reactions are convenient methods for the preparation of alkylnaphthyl ethers and sulfides. Only direct nucleophilic substitution was observed in the reactions of bromonaphthalenes with sodium methoxide and sodium nbutyl mercaptide. The reaction of fluoronaphthalene with potassium t-butoxide also proceeded by way of direct nucleophilic substitution rather than the 1,2-dehydronaphthalene intermediate as in the reactions of bromonaphthalene with potassium t-butoxide. The use of a base which is weaker than t-butoxide can change the apparent reaction mechanism …

Go to article

Rhenium Catalyzed Hydrogenation Of Maleic Anhydride And Crotonaldehyde, William Russel Dixon May 1972

Rhenium Catalyzed Hydrogenation Of Maleic Anhydride And Crotonaldehyde, William Russel Dixon

Theses and Dissertations

The preparation of a number of supported rhenium catalysts is reported. The determination of their activity and selectivity and of optimal reaction parameters for the reduction of maleic anhydride and crotonaldehyde is reported. Optimal time of hydrogenation was chosen as one hour and pressures were chosen as 2000 psig for crotonaldehyde and 3000 psig for maleic anhydride. Quantitative reduction of maleic anhydride to tetrahydrofuran occurred at 275° with charcoal supported rhenium catalysts. Lower temperatures (ca. 200°) produce quantitative amounts of butyrolactone. Unsupported catalysts at low temperatures (100°) selectively reduce crotonaldehyde to crotyl alcohol, but at very low conversion rates. Temperatures …

Go to article

The Reproductive Biology Of The Leech Helobdella Stagnalis (Linnaeus) In Utah Lake, David L. Tillman May 1972

The Reproductive Biology Of The Leech Helobdella Stagnalis (Linnaeus) In Utah Lake, David L. Tillman

Theses and Dissertations

The reproductive biology of the brooding leech Helobdella stagnalis (Linnaeus) in Utah Lake was studied for an 18 month period from June 1970 to December 1971. In determining the annual reproductive cycle, the number of adult leeches carrying eggs or young were counted at weekly intervals during the reproductive season and monthly during the rest of the year. Gonadal staging data from histological sections were correlated with the field collection data. It was found that two broods of young were produced by the adult animals during the reproductive season. Continuous water temperatures were recorded at the study site throughout the …

Go to article

Toward Hydrogen Bonds Of Predictable Geometry, Robert Shao-Chih Hsu May 1972

Toward Hydrogen Bonds Of Predictable Geometry, Robert Shao-Chih Hsu

Theses and Dissertations

A literature review on the geometry of hydrogen bonding showed that the geometry is often de-emphasized or even ignored, probably because of the inherent flexibility of many systems studied. Examination of molecular models suggested the geometrically constrained bicyclo [2, 2, 1] heptane system wherein hydrogen bond distances and angles might be more easily predicted. Dihydroboration-oxidation of norbornadiene was shown to yield exo, exo-2,5-norbornadiol, thus clarifying uncertainties in the literature. 2, 5-Norbornadiol was oxidized to the corresponding dione, heretofore inadequately characterized. Several derivatives of the dione were prepared, and spectral data were accumulated for the dione, its precursor, and its derivatives. …

Go to article

The Optimum Design Of A Shock Absorber To Minimize The Force Transmitted To The Supporting Base Of A Vibrating Equipment, J. P. Singh May 1972

The Optimum Design Of A Shock Absorber To Minimize The Force Transmitted To The Supporting Base Of A Vibrating Equipment, J. P. Singh

Theses and Dissertations

The present study involved two types of analyses as a part of the investigation leading to the design of a shock absorber providing optimal vibration control and minimum transmissibility. Those two types of analyses were the following.

Go to article

A Taxonomic Study Of The Western Collared Lizard (Crotaphytus Collaris), Nathan M. Smith May 1972

A Taxonomic Study Of The Western Collared Lizard (Crotaphytus Collaris), Nathan M. Smith

Theses and Dissertations

The marked pattern and coloration which distinguish members of Crotaphytus collaris baileyi in its western range indicated a need to compare it to the collaris-complex consisting of C.c. auriceps, C.c. baileyi, and C.c. fuscus. Thirty-two external and sixteen cranial characters were measured on preserved specimens. Blood serum proteins were compared by disc gel electrophoresis. Cluster, canonical, and discriminant analyses were used to define population characteristics and areas of intergradation. Disc electrophoresis did not reveal consistent population differences. The western range of C.c. baileyi is restricted to Central Arizona. The Great Basin form from western Arizona, western Utah, southern Idaho, southeastern …

Go to article

Synthesis And Metal Coordination Properties Of Some Cyclic Polyethers And Polythioethers, Barry Lant Haymore May 1972

Synthesis And Metal Coordination Properties Of Some Cyclic Polyethers And Polythioethers, Barry Lant Haymore

Theses and Dissertations

Thermodynamic values for cation-cyclic polyether interactions for several systems are reported and discussed in light of ligand geometry, cation selectivity, solvent effects, structure, stoichiometry and the nature of the coordinate bond. Cyclic polyethers are shown to be remarkably good ligands even in water and to have marked selectivity for d0, d10 and d10 s2 cations. Syntheses of one new cyclic polyether and several new mixed cyclic polyether-thioethers are reported. Cyclic chelates with smaller rings are shown to prefer smaller cations, but this selectivity is masked by the hydration energy of the cation. Except for thiophillic cations such as Hg2+ and …

Go to article

Determination Of Drag And Lift Coefficients For A Spinning Baseball, M. B. Parekh May 1972

Determination Of Drag And Lift Coefficients For A Spinning Baseball, M. B. Parekh

Theses and Dissertations

Few experiments have been carried out in the past to deter mine the effect of the lift and the drag forces on the trajectory of a ball used in any game. In a baseball game, it was reported that sometimes the ball took a sharp turn aburptly in the region of 15 to 20 feet from the home plate. This indicated a sudden change of the forces acting on the ball. The principal forces acting w ere as fol lows: 1. Weight of the ball. 2. Drag force acting in the direction parallel to the relative wind. 3. Lift force …

Go to article

Vegetation Changes Following Fire In The Pinyon-Juniper Type Of West Central Utah, Milo Arnel Barney May 1972

Vegetation Changes Following Fire In The Pinyon-Juniper Type Of West Central Utah, Milo Arnel Barney

Theses and Dissertations

A total of 28 burn areas, that varied in age from 3-100+- years, were analyzed in a study of succession following fire, in the pin yon-juniper woodlands of west central Utah. Data were collected by means of the line-point and quadrat methods. These data were subjected to a multiple regression analysis. Canopy cover, basal area (sq. ft./acre) and density (trees/acre) of juniper were highly correlated with age of burn. Percentage dead sagebrush was found to be positively correlated with density of junipers. The stages of succession following fire began with weedy annuals, that reached a peak within 3-4 years. Juniper …

Go to article

A Common Garden Study Of North American Chokecherries, R. Max Butler May 1972

A Common Garden Study Of North American Chokecherries, R. Max Butler

Theses and Dissertations

Three species or varieties of chokecherry reportedly grow in North America. Data were collected to determine if the varieties could be distinguished by morphological characteristics of the seedling. Seeds, collected from 20 locations in North America, were grown in a greenhouse where gross environmental factors could be controlled. For two growing seasons, data were collected on (1) height, (2) leaf thickness, (3) rate of root growth, (4) number of teeth, (5) number of leaves, and (6) the ratio of leaf length to width. The resulting data were subjected to analysis of variance and group means, and correlation studies. For the …

Go to article

The Dynamic Characteristics Of A Beam Whose Material Is Represented By A Three-Parameter Viscoelastic Solid, Vishnurao K. Devkar May 1972

The Dynamic Characteristics Of A Beam Whose Material Is Represented By A Three-Parameter Viscoelastic Solid, Vishnurao K. Devkar

Theses and Dissertations

Man observes many phenomena occurring in nature which he can use to his benefit. He observes how physical quantities vary as a function of their environment in order to predict how these variations will affect a system he wishes to design. For this purpose, he must establish a model that is representative of the relation between those physical quantities and certain environments to which they are subjected.

Go to article

Application Of The Maximum Deformation Theory Of Failure To The Torsional Failure Due To Fracture Of 4140 Steel, C. V. Krishna Kumar May 1972

Application Of The Maximum Deformation Theory Of Failure To The Torsional Failure Due To Fracture Of 4140 Steel, C. V. Krishna Kumar

Theses and Dissertations

Forming is the fastest way of changing the shape of a piece of metal. It is the most economical process to use for high-volume mass production when the shape of a part is such that it can be made by one of the forming operations

Go to article

A Revision Of The Phacelia Crenulatae Group (Hydrophyllaceae) For North America, N. Duane Atwood May 1972

A Revision Of The Phacelia Crenulatae Group (Hydrophyllaceae) For North America, N. Duane Atwood

Theses and Dissertations

This study is a taxonomic monograph of the Phacelia Crenulatae group for North America and recognizes thirty-three species and six varieties. A brief discussion of the history, general morphology, phylogeny and cytology is given. All entities are separated by a comprehensive key, followed by a list of types, synonyms, descriptions and general habitat. Distribution maps and illustrations are included. The body of this work is based on herbarium specimens and extensive field observations and collections made throughout much of western North America. These studies have resulted in the description of five new species and several nomenclatural changes.

Go to article

Enzymatic Synthesis Of Oligoribonucleotides Of Defined Base Sequence, Mark J. Rowe May 1972

Enzymatic Synthesis Of Oligoribonucleotides Of Defined Base Sequence, Mark J. Rowe

Theses and Dissertations

The synthetic reaction of ribonuclease T_1 has been studied as to its potential for the synthesis of oligoribonucleotides of defined base sequence. Conditions have been determined for maximum synthesis with respect to percentage incorporation of both guanosine 2',3'-cyclic phosphate (donor), and cytidine (acceptor). With regard to maximum acceptor incorporation, a donor blocked at the 5'-hydroxyl has been used to drive the reaction. It has also been shown that acceptor incorporation decreases as the chain-length increases up to the hexanucleotide. Synthesis of a 3'-blocked substrate for polynucleotide phosphorylase for use in chain termination studies was attempted using adenylate kinase. In this …

Go to article

The Bottom Fauna Of Fish Lake, Utah And Its Relationship To The Trout Fishery, Dennis L. Shirley Apr 1972

The Bottom Fauna Of Fish Lake, Utah And Its Relationship To The Trout Fishery, Dennis L. Shirley

Theses and Dissertations

One-hundred and three bottom samples taken at Fish Lake, Utah from July, 1969 to June, 1970 were analyzed to determine the abundance, distribution, and standing crop of the bottom fauna species and to relate their availability to the amount of food eaten by the trout. Twenty-three taxa, representing three phyla and 19 families were collected. An amphipod, Gammarus limnaeus, in the littoral zone, and a tubificid worm, Rhyacodrilus coccineus, in the sublittoral and profundal zones, were the most abundant species. All 23 species were unevenly distributed in the littoral zone, whereas, only eight were found in the sublittoral and five …

Go to article

Analysis Of Asexual Reproduction Dugesia Dorotocephala, Harvey Dee Mecham Apr 1972

Analysis Of Asexual Reproduction Dugesia Dorotocephala, Harvey Dee Mecham

Theses and Dissertations

Genetic control of decapitation-induced fission in planaria is mediated by stimulator and inhibitor molecules. Resolution of the two factors was accomplished by filtration chromatography of whole planaria extract. The stimulator (M.W. 2500 to 3500) was purified with ion exchange chromatography and increases the multiple fission rate. The inhibitor (M.W. 20,000 to 50,000) is non-dialyzable, heat labile and is inactivated unless kept frozen. Storage at 4°C results in a loss of inhibitory capacity with a concomitant stimulator increase, suggesting a protein-stimulator complex as the inhibitor. In light of a demonstrated animal intercommunication system, the inhibitor-stimulator complex is hypothesized as part of …

Go to article

Nesting Of The White-Faced Ibis (Plegadis Chihi) Of Utah Lake, Kenichi David Kaneko Apr 1972

Nesting Of The White-Faced Ibis (Plegadis Chihi) Of Utah Lake, Kenichi David Kaneko

Theses and Dissertations

Information on the nesting of the White-faced Ibis (Plegadis chihi) in Utah County is presented for the first time. Nests built in hardstem bulrush (Sciprus acutus) settled from an average height of 120.8cm on June 9 to 93.6cm on June 27, 1971. Nest spacing ranged from 2m to 9m, averaging 4.6m. Invertebrates of the class Arachnida and the insect orders Coleoptera, Homoptera, Lepidoptera, and Thysanoptera were collected in a Berlese funnel. Average clutch size was 3.17. Egg length and width averaged 51.40mm X 36.75mm. Average volume was 36.93cc. In 21 study nests, 45.8 percent of the eggs hatched, beginning on …

Go to article

Introductory Pages, Byu Studies Apr 1972

Introductory Pages, Byu Studies

BYU Studies

No abstract provided.

Go to article

The Christian Commitment: C.S. Lewis And The Defense Of Doctrine, William Clayton Kimball Apr 1972

The Christian Commitment: C.S. Lewis And The Defense Of Doctrine, William Clayton Kimball

BYU Studies

No abstract provided.

Go to article

End Matter, Vol. 32 No. 1 Mar 1972

End Matter, Vol. 32 No. 1

Great Basin Naturalist

No abstract provided.

Go to article

The Contributions Of The 1822 Works Of Jarocki And Fleming To Herpetological Nomenclature, Robert C. Feuer, Hobart M. Smith Mar 1972

The Contributions Of The 1822 Works Of Jarocki And Fleming To Herpetological Nomenclature, Robert C. Feuer, Hobart M. Smith

Great Basin Naturalist

No abstract provided.

Go to article

Small Rodent Populations And Biomass In Three Sagebrush Communities Of Rush Valley, Utah, David W. Nichols Feb 1972

Small Rodent Populations And Biomass In Three Sagebrush Communities Of Rush Valley, Utah, David W. Nichols

Theses and Dissertations

Three desert Artemisia tridentata communities in Rush Valley, Utah were trapped for small rodents during the summer of 1970 in a mark-recapture study. Population densities were estimated using several indices for each population category. Animals were weighed and rodent biomass calculated for each species throughout the summer. Populations, biomass, and other data were then analyzed to gain a better understanding of A. tridentata community types of the Great Basin. Peromyscus maniculatus, Eutamias minimus, and Reithrodontomys megalotis were common to area 1. Peromyscus maniculatus, E. minimus, and Perognathus parvus were common to areas 2 and 3. The peak estimated standing crops …

Go to article

Book Reviews: Notes In Brief Feb 1972

Book Reviews: Notes In Brief

Swiss American Historical Society Newsletter

A collection of short book reviews.

Go to article

Full Issue Feb 1972

Full Issue

Swiss American Historical Society Newsletter

No abstract provided.

Go to article

Electron Cyclotron Radiation Measurements To Determine Relative Electron Temperatures In A Low-Density Magnetic-Mirror Plasma System, Andrew L. Gardner Feb 1972

Electron Cyclotron Radiation Measurements To Determine Relative Electron Temperatures In A Low-Density Magnetic-Mirror Plasma System, Andrew L. Gardner

Faculty Publications

Measurements of the electron cyclotron radiation emitted from the plasma of the Alice system were made using a synchronous detection microwave radiometer in the range of 10.2 - 11.6 GHz. Both sidebands were used to sample radiation from two nested closed shells within the plasma. For a tenuous plasma this radiation is proportional to the product of the electron density and the electron temperature. Since measurements of the plasma density were available from other detectors, relative values of the electron temperature were obtained using the measured radiation intensity.

Go to article

On The Mechanism Of Low-Temperature Termolecular Atomic Recombination, Russell T. Pack, Richard L. Snow, Wesley D. Smith Jan 1972

On The Mechanism Of Low-Temperature Termolecular Atomic Recombination, Russell T. Pack, Richard L. Snow, Wesley D. Smith

Faculty Publications

A simple theory of gas-phase termolecular atomic recombination kinetics is presented which treats the bound-complex (BC) mechanism in a fashion which parallels the Roberts, Bernstein, and Curtiss resonance theory of the energy-transfer (ET) mechanism. The ET rate constant has a low temperature maximum, but the BC rate constant does not. The contributions of the two mechanisms to the low-temperature recombination of hydrogen atoms, with He, Ar, and H2 as third bodies, are estimated and compared. The presence (absence) of a low-temperature maximum in the observable total rate constant is determined by absence (presence) of bound vibrational levels of the hydrogen-third …

Go to article

An Analysis Of The Speaking Style Of Charles W. Penrose, Kent Shelley Davis Jan 1972

An Analysis Of The Speaking Style Of Charles W. Penrose, Kent Shelley Davis

Theses and Dissertations

The purpose of this thesis was to determine the public speaking style of Charles W. Penrose. The problem was investigated by using the elements of a speaking situation, the speaker, the speech, the audience, and the occasion. Three speeches were used; namely, "Remarks on Union" given on January 19, 1879, "Women Suffrage" given on June 3, 1889, and "Graphic Glimpses of Pioneer Life" given on February 4, 1924. Seven selected criteria were used as guidelines for the evaluation of the speeches; namely, accuracy, clarity, propriety, economy, force, striking quality, and liveliness.

The following conclusions resulted from the evaluation of the …

Go to article

Introductory Pages, Byu Studies Jan 1972

Introductory Pages, Byu Studies

BYU Studies

No abstract provided.

Go to article

First Prev Next Last