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 75961 - 75990 of 78603

Full-Text Articles in Entire DC Network

"Toxic Chemicals In The Environment", William E. Cooper Jun 1978

"Toxic Chemicals In The Environment", William E. Cooper

Special Collections: Oregon Public Speakers

Presented and recorded with Arbib, M. A., "Environmental Simulation and Long-Term Planning."


"Ecosystems", William E. Cooper Jun 1978

"Ecosystems", William E. Cooper

Special Collections: Oregon Public Speakers

From a lecture series with M.A. Arbib, "Environmental simulation and long-term planning."


"Space Settlements", John Billingham Jun 1978

"Space Settlements", John Billingham

Special Collections: Oregon Public Speakers

No abstract provided.


The Kinetics Of Solvent Reorientation In Hydroxylated Solvents From The Exciting-Wavelength Dependence Of Chromophore Emission Spectra, John Milton, Robert M. Purkey, William C. Galley Jun 1978

The Kinetics Of Solvent Reorientation In Hydroxylated Solvents From The Exciting-Wavelength Dependence Of Chromophore Emission Spectra, John Milton, Robert M. Purkey, William C. Galley

WM Keck Science Faculty Papers

The disappearance of the exciting-wavelength dependence of the phosphorescence spectra of polar, aromatic chromophores in supercooled glycol–water mixtures is utilized to monitor the kinetics of solvent reorientation. Reorientation times in the nanosecond to second range are obtained for (3:2 v/v) glycerol–water and (1:1 v/v) ethylene glycol–water at 140–240 °K. The results suggest that the process is one involving a cluster of solvent molecules and in which the chromophore plays a relatively passive role. Steady-state data and direct measurements of phosphorescence shifts as a function of time indicate that the solvent reorientation process is nonexponential in nature. The decay function derived …


Terminal Talk - The Wofford Connection - June 1978, Wofford College Computer Center Jun 1978

Terminal Talk - The Wofford Connection - June 1978, Wofford College Computer Center

Terminal Talk

No abstract provided.


A Primary Ecological Survey Of Dardanelle Reservoir Prior To Nuclear Facility Effluent Discharge, Clarence B. Sinclair, Robert L. Watson Jun 1978

A Primary Ecological Survey Of Dardanelle Reservoir Prior To Nuclear Facility Effluent Discharge, Clarence B. Sinclair, Robert L. Watson

Arkansas Water Resources Center Technical Reports

A preliminary ecological survey of Dardanelle Reservoir during the construction phase of Arkansas Power and Light Company's nuclear generating facility was conducted from January 1970 through June 1974. The reservoir is characterized by relatively shallow depths and a high flow-thru rate. A number of features were associated with these characteristics. The reservoir carried a great deal of suspended material and exhibited high turbidities throughout most of the year. Typical thermal stratification and oxygen depletion were only rarely observed. Many of the physico-chemical parameters exhibited relatively high values in comparison to other Arkansas lakes and reservoirs, but due to absence of …


Dredge Spoil Disposal With Particular Reference To Management Practices In Southern New England, Lynne A. Melville Jun 1978

Dredge Spoil Disposal With Particular Reference To Management Practices In Southern New England, Lynne A. Melville

Marine Affairs Theses and Major Papers

One-half million acres of U.S. coastal wetlands have been destroyed by dredging and filling operations since 1956. They are being destroyed at the rate of 0.5-1.0% each year. In one ten year period, Rhode Island lost 5% of its 2000 acres of wetlands to urban development, and Connecticut lost 12% of its marsh lands. Less than 1500 acres of marsh remain in Connecticut. During the course of this research project, I examined one aspect of wetland destruction - the dredging and disposal of spoil materials onto wetlands and into the coastal waters of Southern New England. What follows is a …


The Prairie Naturalist Vol. 10, No. 2. June 1978 Jun 1978

The Prairie Naturalist Vol. 10, No. 2. June 1978

The Prairie Naturalist

ANALYSIS OF THE FLEHMEN DISPLAY IN AMERICAN BISON (BISON BISON) ▪ B. R. Mahan, M. P. Munger and H. L. Gunderson

AVIAN MORTALITY CAUSED BY A SEPTEMBER WIND AND. HAIL STORM ▪ K. F. Higgins and M. A. Johnson

DISTRIBUTION OF TWO SPECIES OF LONG-EARED BATS OF THE GENUS MYOTIS ON THE NORTHERN GREAT PLAINS ▪ J. K. Jones, Jr. and J. R. Choate

ALFALFA AND THE OCCURRENCE OF FISSURES ON THE NORTH DAKOTA PRAIRIES ▪ J. P. Bluemle, A. E Kehew, E. A. Brostuen and K. L. Harris

NOTES

An Observation of Badger Predation on Richardson Ground Squirrels ▪ …


Stress Analysis Of Post And Crown Restorations Of Endodontically Treated Teeth, Ronald C. Hansen Jun 1978

Stress Analysis Of Post And Crown Restorations Of Endodontically Treated Teeth, Ronald C. Hansen

Loma Linda University Electronic Theses, Dissertations & Projects

Forty-four similar sized maxillary lateral incisor teeth were randomly divided into four equal groups to test their resistance to fracture. Group 1 teeth were the controls, no treatment was done. Group 2 teeth consisted of endodontically treated teeth, restored with composite resin in the access opening. Group 3 teeth were endodontically treated and restored with a post and flat surface standardized aluminum crown. The teeth in Group 4 were endodontically treated and restored with a post and composite resin core buildup with a cast gold crown. The metal collar of gold incorporated 1.5 mm of tooth structure below the core …


Calculated Yields And Slowing-Down Spectra For Electrons In Liquid Water: Implications For Electron And Photon Rbe, R. N. Hamm, H. A. Wright, Robert Katz, J. E. Turner, R. H. Ritchie Jun 1978

Calculated Yields And Slowing-Down Spectra For Electrons In Liquid Water: Implications For Electron And Photon Rbe, R. N. Hamm, H. A. Wright, Robert Katz, J. E. Turner, R. H. Ritchie

Robert Katz Publications

Detailed Monte Carlo calculations have been carried out of slowing-down spectra and yields for a number of end-points for electrons in liquid water. These investigations were made to study differences in physical effects of different low-LET radiations and implications for RBE. Initial electron energies from 1 keV to 1 MeV were used, and all secondary electrons were followed in the computations until their energies fell below 10 eV. Though there are substantial differences in the slowing-down spectra at energies near and above the K-shell ionization potential of oxygen, the energy spectrum of electrons at lower energies is found to be …


Chemiluminescence Studies Of Silicon Fluoride And Uranium Oxide, Russell A. Armstrong May 1978

Chemiluminescence Studies Of Silicon Fluoride And Uranium Oxide, Russell A. Armstrong

Chemistry and Chemical Biology ETDs

Spectroscopic studies of the reactions of fluorine with silicon, silane and deuterated silane, and of oxygen with uranium are reported. Chemiluminescence and atomic absorption techniques have been employed to determine the kinetics, photon yields and branching ratios of the chemistry leading to the excited states of the radical SiF. The reaction of silicon vapor with fluorine occurs at nearly a gas kinetic rate (k2=1.3 x 10-10 cc molecule-1 sec-1). The overall system photon yield from the reaction of silane and fluorine to produce SiF(A➔X) and SiF(a➔X) emission were 5 x 10-2% and …


The Natural Growth Records Of Reef-Building Corals, Richard E. Dodge May 1978

The Natural Growth Records Of Reef-Building Corals, Richard E. Dodge

Oceanography Faculty Theses and Dissertations

Through analysis of hermatypic coral incremental growth features, it is possible to determine the response of recent corals to their environments. In this way I have attempted to obtain a tool not only to gain knowledge of recent growth processes but also for reconstructing aspects of past environmental conditions associated with fossil coral growth. The procedure has been first to determine time relationships and characteristics of coral skeletal density bands and to next use banding for investigations into areal growth rate patterns, coral population age distributions, and coral-climate interactions.

Density band couplets, visible X-radiographically in medial sections of coral skeletons, …


Zooplankton Limnology Of Beaver And Degray Reservoirs In Arkansas, Eugene H. Schmitz May 1978

Zooplankton Limnology Of Beaver And Degray Reservoirs In Arkansas, Eugene H. Schmitz

Arkansas Water Resources Center Technical Reports

Research during the year 1975-76 continued to emphasize studies of seasonal changes in patterns of zooplankton abundance and biomass in Beaver and DeGray Reservoirs. Zooplankton samples were taken monthly from three stations on Beaver Reservoir (Figure 1) during the period May 1975 through May 1976. Collections from DeGray Reservoir were made weekly from a single station (Station 1) during the period April 1975 through December 1975. Beaver collections were obtained by taking oblique tows using a Miller sampler equipped with no. 10 mesh. The DeGray program entailed stratified vertical samples taken at 5 intervals to 20 a and 20 m …


Present Trends In The Development Of Marine Fisheries By Coastal States Of The East Central Atlantic, Ethman T. A. Golley-Morgan May 1978

Present Trends In The Development Of Marine Fisheries By Coastal States Of The East Central Atlantic, Ethman T. A. Golley-Morgan

Marine Affairs Theses and Major Papers

In order to create an incentive for a rapid development of the rural-based artisanal fisheries of coastal states, that can actively compete with large scale industrial fisheries of non-coastal states as well as coastal states of the region, some states are now moving towards an integrated approach in their development efforts. Such integrated projects will take into consideration rural development, provision of infrastructural facilities for fish handling and processing, vessel servicing, repairs and boat building. Socio-economic factors such as organization of fishermen's cooperatives, financing and marketing institutions are also vital inputs.


The Effect Of Selenium On The Toxicity Of Methyl Mercury In Medaka Embryos, Peter H. Krauth May 1978

The Effect Of Selenium On The Toxicity Of Methyl Mercury In Medaka Embryos, Peter H. Krauth

All-Inclusive List of Electronic Theses and Dissertations

The purpose of this research was to investigate the effect of selenium upon methyl mercury poisoning in Medaka fish (Oryzias latipes) embryos. Selenium has been shown to provide a protective mechanism against mercury poisoning in some adult animals. Three experiments were done. In the first, selenium and methyl mercury were put directly in the growing medium of the eggs. In the second experiment, selenium was included in the diet of the parent fish. In the third part, methyl mercury exposure was delayed three days. The results of the first experiment were quite dramatic and showed a significant difference when selenium …


Water Current, Volume 10, No. 3, May/June 1978 May 1978

Water Current, Volume 10, No. 3, May/June 1978

Water Current Newsletter

From the Desk of the Director
Grantsmanship Training Program Planned
Dee Creek Project Funded
Area of Excellence Review
Odgaard New Director of NWRA
National Water Policy Revealed
OWRT Appropriations
Research Review: Region-Wide Irrigation Scheduling by Local Evapotranspiration Measurement


Conflict In Outdoor Recreation, Gerald R. Jacob May 1978

Conflict In Outdoor Recreation, Gerald R. Jacob

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The causes of conflict among users of outdoor recreation resources have received little attention from recreation researchers. Knowledge of factors responsible for conflict might assist recreation planners' attempts to reduce future instances of conflict and help management focus its conflict resolution efforts. A theory of conflict is offered as the first step in systematically procuring such knowledge. A definition and characteristics of outdoor recreation conflicts are presented; four comprehensive causes of user conflicts are proposed. Ten propositions are used to link these factors to conflict and suggest future research hypotheses. The social psychological dynamics of conflict, as described here, have …


Multicollinearity And The Estimation Of Regression Coefficients, John Charles Teed May 1978

Multicollinearity And The Estimation Of Regression Coefficients, John Charles Teed

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The precision of the estimates of the regression coefficients in a regression analysis is affected by multicollinearity. The effect of certain factors on multicollinearity and the estimates was studied. The response variables were the standard error of the regression coefficients and a standarized statistic that measures the deviation of the regression coefficient from the population parameter.

The estimates are not influenced by any one factor in particular, but rather some combination of factors. The larger the sample size, the better the precision of the estimates no matter how "bad" the other factors may be.

The standard error of the regression …


Studies Toward The Synthesis Of A- And B- Mercapto Alanine Derivatives, And Of A,B- And B, B- Dimercapto Alanine Derivatives, Aldean James Kolar May 1978

Studies Toward The Synthesis Of A- And B- Mercapto Alanine Derivatives, And Of A,B- And B, B- Dimercapto Alanine Derivatives, Aldean James Kolar

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A convenient, economical, large scale synthesis of N-acetyldehydro-alanine (a-acetamidoacrylic acid) and its methyl ester was developed via a sequence of N-chlorination-dehydrochlorination. The method was extended to the synthesis of the corresponding N-benzoyl, N-phenylacetyl and N-benzyloxycarbonyl derivatives.

The conversion of a-methoxy-N-acetyl alanine derivatives to the corresponding a-mercapto alanine derivatives, using zinc chloride and an appropriate mercaptan, was investigated. Methyl a-methoxy-N-acetyl-D, L-alaninate was successfully converted to the a-acetylthio derivative, in 24% yield; however, a 90% yield could be obtained by treatment of the dehydroalanine derivative with hydrogen chloride gas in neat thiolacetic acid.

A facile conversion of the a-acetylthio derivative to the …


Organochlorine Pesticide Residue, Physico-Chemical, And Bacteriological Profile Of The Lower Rio Grande River Of Texas, Juan H. Gonzalez May 1978

Organochlorine Pesticide Residue, Physico-Chemical, And Bacteriological Profile Of The Lower Rio Grande River Of Texas, Juan H. Gonzalez

Theses and Dissertations - UTB/UTPA

An investigation was conducted to determine if the widespread and abundant use of organochlorine pesticides in the Lower Rio Grande Valley of Texas has had any effect on the microbial flora in the water and in the bottom sediments of the Lower Rio Grande River of Texas.

Rio Grande River water and bottom sediments were cultured for microbial flora, were analyzed for pesticide residues, and the physicochemical properties of the water were determined. Samples were taken at four different sites during a ten month sampling period in 1974.

Traces of organochlorine residues were found in the water, and higher concentrations …


A Discriminant Function Model Of Gray-Headed Junco Habitat, Andrew R. Grainger May 1978

A Discriminant Function Model Of Gray-Headed Junco Habitat, Andrew R. Grainger

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This paper presents a description of gray-headed junco habitat in the form of a model based on discriminant function analysis. Junco nests were found by searching randomly located grids on a 7.8 km2 study area in central Utah. Vegetation data was gathered on 500 m2 circular plots surrounding nests and contrasted with similar data from searched grids where nests were not found. The model explains 28 percent of the between-groups variance and correctly classifies 68 percent of the plots.

Plant cover types are good predictors of areas where gray-headed juncos nest, while plant community type descriptions do not …


Adaptive Significance Of Lactate Dehydrogenase B2 Isozymes In Rainbow Trout, Salmo Gairdneri And A Biochemical Genetic Comparison Of Cutthroat Trout (Salmo Clarki) Populations, Gerald Thomas Klar May 1978

Adaptive Significance Of Lactate Dehydrogenase B2 Isozymes In Rainbow Trout, Salmo Gairdneri And A Biochemical Genetic Comparison Of Cutthroat Trout (Salmo Clarki) Populations, Gerald Thomas Klar

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Rainbow trout lactate dehydrogenase (LDH) B2' B2' , B2' B2" and B2" B2" phenotypes were tested under a variety of conditions for swimming endurance, oxygen consumption rates, and blood pH, pO2, and lactate. The B2" B2" phenotype exhibited a lower swimming endurance, under a limited oxygen supply, than the B2' B2' and B2' B2" phenotypes. Blood pH at fatigue did not differ among the LOH phenotypes that swam under low oxygen conditions (2 mg/1). …


Plant Succession Studies On Subalpine Acid Mine Spoils In The Beartooth Mountains, Patricia Lea Howard May 1978

Plant Succession Studies On Subalpine Acid Mine Spoils In The Beartooth Mountains, Patricia Lea Howard

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Large areas within alpine and subalpine tundra have been by disturbed by mining during this century. The most promising method for retarding deterioration of these areas is revegetation with native species through both seeding and transplants. One natural process of revegetation which occurs on portions of many existing disturbances seems to be the establishment of a few species that expand with time to form matts of plants.

At the McLaren Mine, located at 3000 m elevation in the Beartooth Mountains, Montana, active succession is occurring and is dominated by Carex species. Seed viability and successional patterns studies were conducted on …


Population Dynamics And Net Production Of Brown Trout (Salmo Trutta) In Two Areas Of A High Gradient Mountain Stream, Jeffrey C. Gosse May 1978

Population Dynamics And Net Production Of Brown Trout (Salmo Trutta) In Two Areas Of A High Gradient Mountain Stream, Jeffrey C. Gosse

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Estimates of the brown trout (Salmo trutta) population were made in two areas of the Blacksmith Fork River, Cache County, Utah, from June 1972 to June 1973. Additional data were obtained on movement, growth, mortality, biomass, production, and yield.

Population density was highly variable in the area where habitat alterations had occurred, but was relatively uniform where the habitat was undisturbed. The brown trout exhibited little movement except during spawning season. Instantaneous growth and mortality rates are provided for each age group.

Mean annual biomass in the two areas was 12.0 and 10.2 grams per square meter and …


Abstracts Of Contributed Papers, Iowa Academy Of Science [90th Meeting], April 21-22, 1978, Iowa Academy Of Science Apr 1978

Abstracts Of Contributed Papers, Iowa Academy Of Science [90th Meeting], April 21-22, 1978, Iowa Academy Of Science

Iowa Academy of Science Documents

Presentation abstracts from the annual meeting of the Iowa Academy of Science


The Annual Meeting Of The Iowa Academy Of Science April 21-22, 1978 [Program, 90th Meeting], Iowa Academy Of Science Apr 1978

The Annual Meeting Of The Iowa Academy Of Science April 21-22, 1978 [Program, 90th Meeting], Iowa Academy Of Science

Iowa Academy of Science Documents

No abstract provided.


Microhabitat Selection In Two Species Of Heteromyid Rodents, Cliff A. Lemen, Michael L. Rosenzweig Apr 1978

Microhabitat Selection In Two Species Of Heteromyid Rodents, Cliff A. Lemen, Michael L. Rosenzweig

School of Natural Resources: Faculty Publications

An experiment was conducted to determine the microhabitat preferences of two heteromyid rodents, Dipodomys ordi and Perognathus flavus. This experiment used marked seeds and the atomic absorption spectrophotometer in order to study the environment as a mosaic of microhabitats. The results of our analysis indicate that these two heteromyids are microhabitat selectors. The preferences of the rodents are, D. ordi: grass habitat 0.0%, near grass habitat 22.5%, open habitat 77.4%, and P. flavus: grass habitat 46.2%, near grass habitat 32.2%, open habitat 21.4%. The overlap between the two species is only 0.43.


Volume 2, Number 4 (April 1978), The Otec Liaison Apr 1978

Volume 2, Number 4 (April 1978), The Otec Liaison

The OTEC Liaison

No abstract provided.


Science In The Sea-Can The Scientists Endure 200 Mile Jurisdiction?: A Case Study Of The R/V Trident 1973-1975, Barbara Ray Apr 1978

Science In The Sea-Can The Scientists Endure 200 Mile Jurisdiction?: A Case Study Of The R/V Trident 1973-1975, Barbara Ray

Marine Affairs Theses and Major Papers

Before the 1958 Continental Shelf Convention scientists were free to do their research anywhere in the oceans except within a narrow band of territorial waters. Since that time national jurisdiction has closed off increasing amounts of the sea. Most coastal areas and continental shelf areas now require coastal state consent prior to commencing work. Possible reasons for this closure include 1) fear of natural resource exploitation, 2) fear of military exploitation, or 3) growing feelings of nationalism among the developing countries. This paper is divided into two parts. The first deals at length with the development of the issue of …


Shallow Water High-Magnesium Calcite Mud Production And Dispersal, St. Croix, U.S. Virgin Islands, Jonathan A. Fuller Apr 1978

Shallow Water High-Magnesium Calcite Mud Production And Dispersal, St. Croix, U.S. Virgin Islands, Jonathan A. Fuller

Masters Theses

Boiler Bay, on the northeast coast of St. Croix, is 200 m wide, 800 m long, and about 3-5 m. deep. The hay is separated from the open Caribbean by a barrier reef. Winds from the east drive currents westward across a narrow carbonate platform (where they entrain platform-derived carbonate mud) and into the east end of the bay. Longshore currents continue westward through the bay, and the entrained platform- derived suspended load is combined with bay-produced carbonate mud and swept northwestward off the platform after passing through a 6 km complex of bays along the northeastern shore. The suspended …