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Articles 292471 - 292500 of 302466

Full-Text Articles in Physical Sciences and Mathematics

Methodological And Validation Study Of Seed Reserves In Desert Soils, David W. Goodall, Stuart Childs, Herman Wiebe Apr 1972

Methodological And Validation Study Of Seed Reserves In Desert Soils, David W. Goodall, Stuart Childs, Herman Wiebe

Memorandum

The development of a method for separating seeds from desert soils, and enumerating them, is described.

In the Great Basin desert, species differed greatly in their depth distribution, some having a peak at or just below the surface, while others were still abundant below 5 cm. Much higher seed densities were found beneath the canopies of shrubs and of tussock grasses than in the inter-spaces; no consistent differences were found, however, associated with the species of the canopy plant, or with distance from its center.

Tentative estimates are given of the seed population in the four validation sites in Curlew …


The Major Contribution Of Leibniz To Infinitesimal Calculus, Carolyn Rhodes Apr 1972

The Major Contribution Of Leibniz To Infinitesimal Calculus, Carolyn Rhodes

Honors Theses

A study of the work of Leibniz is of importance for at least two reasons. In the first place, Leibniz was not alone among great men in presenting in his early works almost all the important mathematical ideas contained in his mature work, In the second place, the main ideas of his philosophy are to be attributed to his mathematical work, not vice versa. He was perhaps, the earliest to realize fully and correctly the important influence of a calculus on discovery. The almost mechanical operations which one goes through when one is using a calculus enables one to discover …


The Regular Polyhedra: A Study In Visual Aids For Teaching Geometry, Sammye Halbert Apr 1972

The Regular Polyhedra: A Study In Visual Aids For Teaching Geometry, Sammye Halbert

Honors Theses

Traditionally, mathematics, past simple addition, subtraction, multiplication, and division, has been taught of as being so boring, irrelevant, and in short, one of the unavoidable evils of school. An advertisement in The Mathematics Teacher expressed the general attitude of many students when it said, "mathematics was invented by an old magician in the desert who, with the help of his talking monkey, bakes equations and cupcakes in the hot sun." It seems that many students think mathematics is just one problem after another that has some mystical answer floating around in the air somewhere. The object is to get that …


Convergence Of Bounds In Optimization, Pascal D. Mubenga Apr 1972

Convergence Of Bounds In Optimization, Pascal D. Mubenga

Dissertations

No abstract provided.


Scattering Spin 1/2 Particles By Nuclei, Pui-Wah Cheng Apr 1972

Scattering Spin 1/2 Particles By Nuclei, Pui-Wah Cheng

Masters Theses

No abstract provided.


Kinetics Of Free Radical-Initiated Polymerization Of Α-Methylstyrene In The Region Of The Ceiling Temperature, Fred E. Huang Apr 1972

Kinetics Of Free Radical-Initiated Polymerization Of Α-Methylstyrene In The Region Of The Ceiling Temperature, Fred E. Huang

Masters Theses

No abstract provided.


Discrete Approximations To Continuous Optimal Control Problems, Maurice L. Eggen Apr 1972

Discrete Approximations To Continuous Optimal Control Problems, Maurice L. Eggen

Dissertations

No abstract provided.


The Relationship Between Degree Of Clay Dispersion And The Optical And Pore Properties Of Starch - Clay Coatings, Chinu S. Dalal Apr 1972

The Relationship Between Degree Of Clay Dispersion And The Optical And Pore Properties Of Starch - Clay Coatings, Chinu S. Dalal

Masters Theses

No abstract provided.


Development Of An Ultra High Shear Recording Viscometer, David C. Thornton Apr 1972

Development Of An Ultra High Shear Recording Viscometer, David C. Thornton

Masters Theses

No abstract provided.


Heats Of Combustion Of Alpha-Methylstyrene Oligomers, Dale Keith Humbert Apr 1972

Heats Of Combustion Of Alpha-Methylstyrene Oligomers, Dale Keith Humbert

Masters Theses

Introduction

The heat of polymerization (∆Hp) of α-methylstyrene (AMS) has been a source of study for many years. The structure of AMS is shown in Figure 1.

The first quantitative work was done by Roberts and Jessup.1 Their values were more positive than those theoretically calculated by Flory2 and compared with ∆Hp data of other systems. This was not totally unexpected and could be satisfactorily explained on the basis of steric hindrance and loss of resonance energy of conjugation. This steric hindrance arose from "head-to-tail" polymerization of the 1, 1-disubstituted ethylene structure.3 Their data …


Diurnal Studies At A Station On An Urban Estuary In Norfolk, Virginia, Burton Marc Golue Apr 1972

Diurnal Studies At A Station On An Urban Estuary In Norfolk, Virginia, Burton Marc Golue

Biological Sciences Theses & Dissertations

No abstract.


The Influence Of The Summer Thermocline On Estuarine Classification In The Chesapeake Bay Entrance, William G. Weiss Jr. Apr 1972

The Influence Of The Summer Thermocline On Estuarine Classification In The Chesapeake Bay Entrance, William G. Weiss Jr.

OES Theses and Dissertations

The temperature, salinity, and sigma-t of 397 oceanographic stations taken in the entrance to Chesapeake Bay were plotted using a simple interpolation formula by the lBM 1130 computer. Each station was catalogued by position, tidal stage, season, and estuarine classification. Results indicated increased stratification during the ebb phase of all entrance stations regardless of season. Partially mixed conditions predominate. The influence of the summer thermocline on the stratification caused a slight increase in the summer stratification mean. However, statistical tests showed this summer increase to be insignificant at the 95% level. Detailed classification of tidal stage by estuarine type for …


A Physical Hydrographic Study Of The Lafayette River, E. Glenn White Apr 1972

A Physical Hydrographic Study Of The Lafayette River, E. Glenn White

OES Theses and Dissertations

A basic investigation of the physical ~properties, temperature, density and current velocity, in the Lafayette River is presented. Graphs of the observations indicata a difference in salinity, density and current velocity- distributions after moderate to heavy rains from the graphs during a dry period. The changes in distribution indicate a change in the classification of the estuary from a type B/C, partially mixed estuary, to a type D, sectionally homogeneous estuary. The estuary is predominantly a well-mixed or sectionally homogeneous estuary.

Changes in salinity, temperature, density and current velocity over tidal cycles are discussed as well as tidal height data. …


Continuous Wave Co2 Laser Degradation And Mass Spectrometric Analysis Of Organic Polymers., Stanley G. Coloff Mar 1972

Continuous Wave Co2 Laser Degradation And Mass Spectrometric Analysis Of Organic Polymers., Stanley G. Coloff

Chemistry and Chemical Biology ETDs

Previous laser-mass spectrometer and laser-gas-chromatographic instruments for study of organic polymer degradation have used high power pulsed lasers (ruby, Nd-glass) which limit sample characterization due to extensive fragmentation.

A new experimental technique has been developed for high temperature pyrolysis and rapid analysis of organic polymers. The experimental technique combines a low power continuous wave CO2 laser for sample pyrolysis and a time-of-flight mass spectrometer to analyze degradation products. The laser built for use in this study was a continuous flow CO2 gas-molecular laser excited by high voltage direct current with maximum power of 10 watts at a wavelength of 10600 …


Tolerance Shown By Rattus Rattus To An Anticoagulant Rodenticide, P. J. Deoras, G. C. Chaturvedi, N. E. Vad, D. M. Renapurkar Mar 1972

Tolerance Shown By Rattus Rattus To An Anticoagulant Rodenticide, P. J. Deoras, G. C. Chaturvedi, N. E. Vad, D. M. Renapurkar

Vertebrate Pest Conference Proceedings: 5th (1972)

Apart from using 0.005% concentration, the recommended field dose of 0.025% of the anticoagulant is used along with an alternate food for individual rats for a varying number of days. Those that had survived were taken as tolerant, provided they showed an mg/kg intake beyond the tolerance limit, survived a six days of feeding, exhibited bait-shyness and did not exhibit hemorrhage after death. In determining the criteria for tolerance to an anticoagulant by a rat, one should take into account four composite factors. These are, six days of even 0.025% feeding, bait-shyness when alternate food is given, higher mg/kg intake …


Commensal Rodent Control, D. R. Maddock, H. F. Schoof Mar 1972

Commensal Rodent Control, D. R. Maddock, H. F. Schoof

Vertebrate Pest Conference Proceedings: 5th (1972)

SUMMARY: Federal Urban Rat Control Program grants were awarded to cities in different areas of the United States. Severe problems of rat infestations have been detected in many of the cities by the Environmental Health Service. Approximately 20% of 3.8 million people in the project areas were occupying homes infested with rats. Control operations are now in effect in all cities, and the living conditions of the people have been substantially improved. An increase in interest in rodent control also is evident in countries outside of the United States. The Technical Development Laboratories of the National Communicable Disease Center are …


What’S Ahead In Predator Management, Maynard W. Cummings Mar 1972

What’S Ahead In Predator Management, Maynard W. Cummings

Vertebrate Pest Conference Proceedings: 5th (1972)

Editors note: Because of the great need for exchange of information concerning predator management, I have requested and received permission from the author to include in the Vertebrate Pest Conference Proceedings this paper presented at the Predator Ecology Symposium held in Orland, California, March 1, 1972.

There may not be many things about predators that everyone here agrees upon, but I do believe you all are certain that major changes are about to be made in their management. You all are aware of two recent proclamations of change, the President's Executive Order No. 11643 of February 8, 1972, and the …


Conference Participants, Fifth Vertebrate Pest Conference (1972) Mar 1972

Conference Participants, Fifth Vertebrate Pest Conference (1972)

Vertebrate Pest Conference Proceedings: 5th (1972)

The Fifth Vertebrate Pest Conference drew a registered attendance of 239 with an estimated additional 50-75 persons who attended portions of the conference but did not register. As in past conferences, the attendance was made up of individuals having varying interests in vertebrate pest problems from twenty two states plus the District of Columbia. Participants from Canada, Denmark, England, Germany, India and New Zealand contributed greatly to the success of the conference and provided further exchange of information on an international level.


Closing Remarks - Fifth Vertebrate Pest Conference, Warren V. Johnson Mar 1972

Closing Remarks - Fifth Vertebrate Pest Conference, Warren V. Johnson

Vertebrate Pest Conference Proceedings: 5th (1972)

As this concludes the Fifth Vertebrate Pest Conference, I would like to thank all of you for your attendance and the enthusiasm you have shown throughout the meeting. Any suggestions or comments you may have to improve future meetings will be appreciated. On behalf of the California Vertebrate Pest Committee, I want to thank all speakers for their contributions and the Session Chairmen for a job well done in keeping the program moving smoothly. Also a special thanks to those individuals, organizations and agencies that contributed to the preparation for the success of this Conference, particularly the Chairmen and members …


Digital Video Display System Using Cathode-Ray Tube, George M. Low, Arthur I. Zygielbaum, Warren L. Martin, Alexander Engel Mar 1972

Digital Video Display System Using Cathode-Ray Tube, George M. Low, Arthur I. Zygielbaum, Warren L. Martin, Alexander Engel

School of Natural Resources: Faculty Publications

A digital video display system (DWDS) is disclosed for display of image, alphanumeric and other data on a cathode-ray tube (CRT) with sequential raster scan and two, four or eight gray shades. The DVDS includes a central processing unit for ac tivating the system, selecting the X (horizontal axis) and Z (in tensity modulation) modes, and designating the starting loca tion of two successive rasters of data from a memory accessed by a data multiplexer subsystem (DMS). At the end of each raster, the DMS interrupts the computer for a new starting lo cation of a raster of data to …


Communications Link For Computers, Thomas O. Paine, Arthur I. Zygielbaum, James W. Layland, Warren L. Martin Mar 1972

Communications Link For Computers, Thomas O. Paine, Arthur I. Zygielbaum, James W. Layland, Warren L. Martin

School of Natural Resources: Faculty Publications

A system is disclosed for a computer to communicate with a selected one of a plurality of other computers through two identical communications links associated with the communicating computers. A single channel connects the two links which operate at a clock rate independent of the computers. Binary digits and clock pulses are combined and converted into a three-level signal for serial transmission over the single channel. Both control messages and data words may be transmitted. Each message and word transmitted is checked for error by the receiving link before it is accepted and the receiving computer is interrupted. If error …


Contents, Committees, And Frontmatter Mar 1972

Contents, Committees, And Frontmatter

Vertebrate Pest Conference Proceedings: 5th (1972)

No abstract provided.


Huxley Humus, 1972, Volume 02, Issue 05, Shirley Weston, Huxley College Of The Environment, Western Washington University Mar 1972

Huxley Humus, 1972, Volume 02, Issue 05, Shirley Weston, Huxley College Of The Environment, Western Washington University

Historical Collection of Huxley Newsletters

No abstract provided.


Water Resources News, Volume 4, No. 3, March 1972 Mar 1972

Water Resources News, Volume 4, No. 3, March 1972

Water Current Newsletter

1972 Annual Meeting of UCOWR
Summer Short Course Planned
Simulation of Water Resources Systems
Institute on Applications of Stochastic Methods in Civil Engineering
Institute on River Mechanics
Water Resources Systems - Short Course
International Symposium on Mathematical Modelling Techniques in Water Resources Systems
Seminar on Advances in Practical Hydrology
NWRA Resolutions
EPA to Be Advised By Experts on Sewage Plant Construction
GAO Questions EPA Insistence on Clean Waste Water
Study on Water Subsidies
EPA Bias for Sewage Hinders Farm Cleanup
Land Use Planning
Rural Development Act (HR 12931) Passed by House
Saline Water Bill Goes to House
1973 USGS Budget …


Decoding By Sequential Code Reduction, Luther D. Rudolph, Carlos R.P. Hartmann Mar 1972

Decoding By Sequential Code Reduction, Luther D. Rudolph, Carlos R.P. Hartmann

Electrical Engineering and Computer Science - Technical Reports

A general decoding method for cyclic codes is presented which gives promise of substantially reducing the complexity of decoders at the cost of a modest increase in decoding time (or delay). Significant reductions in decoder complexity for binary cyclic finite-geometry codes are demonstrated, and two decoding options for the Golay code are presented.


The Prairie Naturalist Vol. 4, No.1. March, 1972 Mar 1972

The Prairie Naturalist Vol. 4, No.1. March, 1972

The Prairie Naturalist

EDITORIAL: Advertising by Power Suppliers ▪ William A. Buresh

FIRST FLOWERS OF TREES, SHRUBS AND VINES IN THE FARGO, NORTH DAKOTA AREA ▪ O. A. Stevens

CHRISTMAS BIRD COUNTS FOR NORTH DAKOTA—1971 ▪ Robert N. Randall

ENVIRONMENTAL LEGISLATION IN NORTH DAKOTA—EXPECTATIONS AND REALITIES ▪ Paul B. Kannowski

SEASONAL NOTES ON PLANKTON ALGAE OF EAST STUMP LAKE, NORTH DAKOTA ▪ Dean W. Blinn

A SKUNK WITH A GLASS COLLAR ▪ Peter W. Rakowski

SPRING MIGRATION OF BIRDS IN NORTH DAKOTA IN 1971 ▪ Paul F. Springer, Douglas H. Johnson and John T. Lokemoen

NOTE

Red throated loon observed on Lake Ashtabula, …


Solutions Of The Two-State Potential-Curve-Crossing Problem, John B. Delos, W. R. Thorson Mar 1972

Solutions Of The Two-State Potential-Curve-Crossing Problem, John B. Delos, W. R. Thorson

Arts & Sciences Articles

A general theory of the two-state curve-crossing problem has been developed, with a complete solution of an accurate model for "close" crossings (including numerical computations for strong coupling). Results clarify the position of the Landau-Zener approximation and its improvements by Nikitin and others, provide a general way of extending these approximations into regions often treated incorrectly (including the high-energy limit), and can be readily adapted to simple, rapid calculations.


Opening Remarks - Fifth Vertebrate Pest Conference, Rex E. Marsh Mar 1972

Opening Remarks - Fifth Vertebrate Pest Conference, Rex E. Marsh

Vertebrate Pest Conference Proceedings: 5th (1972)

It is a pleasure to welcome you to the Fifth Vertebrate Pest Conference. It has been 10 years since the first Conference was held in Sacramento in February of 1962. The attendance has grown at each successive conference and, from the looks of the audience this morning, we shall surpass all previous records. It would, however, be wrong to judge the significance of this conference on attendance alone, for we are equally or more concerned with the quality of the conference and its ultimate contribution to the specialized area of wildlife management. The Conference is sponsored by the California Vertebrate …


Keynote Address - Vertebrates: A Resource Needing Management, Donald A. Spencer Mar 1972

Keynote Address - Vertebrates: A Resource Needing Management, Donald A. Spencer

Vertebrate Pest Conference Proceedings: 5th (1972)

A veritable storm of concern for wildlife - approaching biotechnology - is currently sweeping the nation. Some of this concern has a sound basis. But the very best of ideas and programs can be carried so far that they become irrational. We appear to be driving head-on into irrational actions with respect to environmental good housekeeping. The vegetative cover in the United States has changed markedly as the result of Man's occupancy, reducing the habitat on which some wildlife species depend and greatly enhancing that of others. Competition, a no-holds-barred struggle, continues unabated between all living things for the finite …


The Extending Of Cotton Rat Range In California - Their Life History And Control, Dell O. Clark Mar 1972

The Extending Of Cotton Rat Range In California - Their Life History And Control, Dell O. Clark

Vertebrate Pest Conference Proceedings: 5th (1972)

Cotton Rats (Sigmodon hispidus eremicus Mearns) are known to have reached the Imperial Valley in 1921 from the Colorado River along canal banks. Recently (1967-69) cotton rats were found distributed throughout the irrigated portion of the Imperial Valley, Imperial County, California. Limited crop damage has occurred and is described. Life history information is included. Control measures are listed.