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Articles 292561 - 292590 of 302480

Full-Text Articles in Physical Sciences and Mathematics

Eutrophication Factors In North Central Florida Lakes, H. D. Putnam, Patrick L. Brezonik, Earl E. Shannon Feb 1972

Eutrophication Factors In North Central Florida Lakes, H. D. Putnam, Patrick L. Brezonik, Earl E. Shannon

United States Environmental Protection Agency: Publications

A small Florida lake has been receiving a regimen of nutrient addition equivalent to 500 mg/m3-yr N and 43 mg/m3-yr P since 1967. Data has been accumulated through 1969. The effect on the lacustrine ecosystem of various biogenes includes production by primary producers, species diversity of plankton and certain production estimates at the secondary trophic level using natural populations of planktivorous fish. Plankton production using isotopic carbon is ca. 58 grms/m2-yr; Species diversity is slowly changing to a mixed chlorophycean and yellow-green. Biomass of benthic green filamentous types has increased slightly. Nutrient addition has …


Upper Pennsylvanian Shoreline Deposits Form Iowa And Nebraska: Their Recognition, Variation, And Significance, J. A. Fagerstrom, R. R. Burchett Feb 1972

Upper Pennsylvanian Shoreline Deposits Form Iowa And Nebraska: Their Recognition, Variation, And Significance, J. A. Fagerstrom, R. R. Burchett

Conservation and Survey Division

No abstract provided.


Raman-Active Resonance Modes, Overtones, And Anharmonicity In Nacl:Cu+, B.N. Ganguly, Roger D. Kirby, M.V. Klein, G.P. Montgomery Jr. Jan 1972

Raman-Active Resonance Modes, Overtones, And Anharmonicity In Nacl:Cu+, B.N. Ganguly, Roger D. Kirby, M.V. Klein, G.P. Montgomery Jr.

Roger Kirby Publications

The existence of an impurity-activated Eg resonance mode in NaCl:Cu+ has been suggested by several previous experiments. Raman data presented here reveal this resonance directly and also reveal the three components of the first overtone of the 23.5-cm-1 infrared resonance mode. The frequencies of the Eg resonance and the Eg component of the overtone are shifted as a result of a strong anharmonic coupling. Their line shapes and strengths are considerably altered by an interference between the Raman amplitudes. A reasonable fit to the data has been obtained using a simple theory.


Catechol Effected Dissolution Of Silicate Minerals, James Maurice Kelley Jan 1972

Catechol Effected Dissolution Of Silicate Minerals, James Maurice Kelley

Dissertations and Theses

The chemical properties of guanidinium tris(catecholato)siliconate, [(H₂N)₂C=NH₂]₂[Si(C₆H₄O₂)₃]·XH₂O (0 < X < 1), precipitated from an ammoniacal solution of silica and catechol by adding guanidinium hydrochloride, (H₂N)₂C=NH·HC1, were studied, and infrared, nmr, x-ray powder diffraction, and analytical data were gathered.

This same compound was, upon addition of' (H₂N)₂C=NH·HC1, isolated from 0.25, M aqueous catechol solutions buffered at pH 10 and containing the silicate minerals albite, andradite, muscovite, pyrophyllite, talc, and wollastonite, and also from unbuffered catechol solutions containing wollastonite and andradite.

It is concluded from this work that the formation of an anionic catechol-silicon complex, Si(C₆H₄O₂)₃²⁻, is largely responsible for the dissolution of the minerals mentioned above. From this conclusion, it is proposed that naturally occurring members of the class of organic compounds to which catechol belongs, the aromatic v̲i̲̲c̲-diols, may play …


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 …


A Note On Orders Of Enumeration, John Helm, Albert Meyer, Paul Young Jan 1972

A Note On Orders Of Enumeration, John Helm, Albert Meyer, Paul Young

Department of Computer Science Technical Reports

No abstract provided.


A Methodology For The Design And Optimization Of Information Processing Systems, J. F. Nunamaker Jan 1972

A Methodology For The Design And Optimization Of Information Processing Systems, J. F. Nunamaker

Department of Computer Science Technical Reports

No abstract provided.


Some Quasi-Uniform Space Examples, Troy L. Hicks, J. W. Carlson Jan 1972

Some Quasi-Uniform Space Examples, Troy L. Hicks, J. W. Carlson

Mathematics and Statistics Faculty Research & Creative Works

No abstract provided.


Eigenvalues Of The 2p3pp3 And 2p3dd1,3 Bound States Of The Helium Isoelectronic Sequence, H. Doyle, M. Oppenheimer, Gordon W. F. Drake Jan 1972

Eigenvalues Of The 2p3pp3 And 2p3dd1,3 Bound States Of The Helium Isoelectronic Sequence, H. Doyle, M. Oppenheimer, Gordon W. F. Drake

Physics Publications

The 1Z expansion method is used to calculate the eigenvalues of the 2p3pP3 and 2p3dD1,3 states of the helium isoelectronic sequence. The results are compared to variational calculations for neutral helium. Wavelengths are predicted for a number of transitions originating in doubly excited states of the heliumlike ions up to Fe xxv. The results for neutral helium are compared to recent beam-foil experiments and alternative line identifications are made. The predicted wavelength for the 2p3dD3-2p2P3 transition is 3014, in close agreement with the line observed by Berry et al. at 3012 ± 2. © 1972 The American Physical Society.


Relativistic Corrections To Radiative Transition Probabilities, Gordon W. F. Drake Jan 1972

Relativistic Corrections To Radiative Transition Probabilities, Gordon W. F. Drake

Physics Publications

The rate of spontaneous emission of radiation by a loosely bound composite system is calculated from quantum electrodynamics correct through terms of relative order α2Z2. Recent criticisms by Feinberg and Sucher of the semiclassical method of deriving the higher-order radiation coupling terms are discussed. It is proved that the Breit interaction remains valid in the presence of radiation emission and that the semiclassical and quantum-electrodynamic methods of deriving the higher-order coupling terms always yield the same results to relative order α2Z2. We discuss in particular relativistic corrections to allowed and spin-forbidden electric dipole transitions and the 1s2s S13-1s2 S01 magnetic …


Radiative Transition Rates From The 2p3p P3 And 2p3d D1,3 States Of The Helium Isoelectronic Sequence, Gordon W. F. Drake Jan 1972

Radiative Transition Rates From The 2p3p P3 And 2p3d D1,3 States Of The Helium Isoelectronic Sequence, Gordon W. F. Drake

Physics Publications

The Hylleraas-Scherr-Knight variation-perturbation method is applied to the calculation of oscillator strengths for the dominant transitions from the metastable 2p3p P3 and 2p3d D1,3 states of helium and the heliumlike ions. The results explain the absence of the 1s2pP3-2p3pP3 transition of He i from recent beam-foil excitation spectra. © 1972 The American Physical Society.


Water Resources News, Volume 4, No. 1, January 1972 Jan 1972

Water Resources News, Volume 4, No. 1, January 1972

Water Current Newsletter

House Hearings on Water Pollution Control
New Publications Available from the NWRRI
Coastal Zone Management
Ground Water Pollution
Economic Disclocation from Pollution Control
EPA Regulations
Waste Treatment Plant Guidelines
WRC Policy on Revision of Regional and River Basin Plans
Water Resources Council Outlines New Principles and Standards
Experts Advise on EPA on Sewage Plant Construction
Pollution Prevention Guide for Cottage Owners
Desalting Plant for Orange County, California
US Is Accelerating Desalting Programs
Farm Cleanup is Hindered by EPA Bias for Sewage
Sources Sought


Soil And Plant Analysis For Mineral Deficiencies, M D. Carroll Jan 1972

Soil And Plant Analysis For Mineral Deficiencies, M D. Carroll

Journal of the Department of Agriculture, Western Australia, Series 4

Soil and plant analysis (testing) has its supporters and its critics. Some of the differences are resolved if the distinction is made between the concept and the practice. Most people would agree with the concept of soil and plant analysis but the practice, or service offered, in any agricultural situation can be subject to valid criticism.

This article defines some of the principles involved and illustrates some of the problems, to provide a better understanding of the usefulness and the limitations of soil and plant analysis as a diagnostic aid in plant and animal nutrition.


Long Term Rotation Trials, I C. Rowland Jan 1972

Long Term Rotation Trials, I C. Rowland

Experimental Summaries - Plant Research

LONG TERM ROTATION TRIALS The results shown are the yield of grain harvested from crops grown under various rotations of pasture ley. W56H, 66M29, 67N4, 67BA6, 68E5, 68SG5, 69GE20


The Alfred C. Glassell, Jr.—University Of Miami Argosy Expedition To Ecuador, Donald P. De Sylva Jan 1972

The Alfred C. Glassell, Jr.—University Of Miami Argosy Expedition To Ecuador, Donald P. De Sylva

Studies in Tropical Oceanography

No abstract provided.


Study Of Channel Sediments, Baltimore Harbor, Norfolk Harbor, York Entrance Channel, R. J. Huggett Jan 1972

Study Of Channel Sediments, Baltimore Harbor, Norfolk Harbor, York Entrance Channel, R. J. Huggett

Reports

3ot~om sediment samples were collected from seven channel locations in the Chesapeake Bay and communicating river systems. The sampling format involved. long cores (designated "L") taken at two nautical mile intervals and surface samples (designated "S) taken at one-half mile intervals.


Petrology Of The Nemeiben Lake Ultramafic And Associated Nickel-Sulphide Deposits, Anantaramam Peddada Jan 1972

Petrology Of The Nemeiben Lake Ultramafic And Associated Nickel-Sulphide Deposits, Anantaramam Peddada

Geology Theses and Dissertations

The Nemeiben Lake ultramafic body is located in the center of Saskatchewan, Canada, within the Churchill Province of the Canadian Shield. The ultramafic rocks consist of serpentinites, partly serpentinized and uralitized pyroxenite, and unaltered pyroxenite. Associated sulphide mineralization is of disseminated, net texture, and fracture filling types. The ore minerals present are pyrrhotite, pentlandite, chalcopyrite, pyrite, marcasite, violarite, bravoite and native copper. The sulphides are considered to be initially of magmatic origin formed from a sulphide melt separated at a late stage during crystallization of the ultramafic rocks. Subsequent serpentinization has locally redistributed the ores.
Serpentinization in the Nemeiben Lake …


Taxonomic Note On Fossil Glyptostrobus In Northeastern Arkansas, Eugene B. Whittlake Jan 1972

Taxonomic Note On Fossil Glyptostrobus In Northeastern Arkansas, Eugene B. Whittlake

Journal of the Arkansas Academy of Science

Two papers by Brown (1936, 1962) are reviewed and discussed in relation to the validity of specific names applied to the fossil Glyptostrobus as found in North American deposits. Evidence is presented supporting the contention that G. nordenskioldi Brown n. comb, is the valid name for Glyptostrobus specimens from the Hooker site of northeastern Arkansas.


Frost Injury To Cereals In W.A, M W. Perry, A. G. P. Brown Jan 1972

Frost Injury To Cereals In W.A, M W. Perry, A. G. P. Brown

Journal of the Department of Agriculture, Western Australia, Series 4

Late spring frosts commonly reduce yields and affect the quality of grain in wheat crops, especially in the southern, eastern and north-eastern districts. The damage is usually localised on individual farms, but is sometimes widespread.

Barley, and oats to a lesser extent, are also affected. Average losses of wheat in Western Australia have been estimated at 3 to 5 per cent, per year, or about 2 million bushels on current production figures.


Simultaneous Determination Of Short-Period Photosynthesis And Evapotranspiration (Horticulture And Forestry Progress Report No. 91), Norman J. Rosenberg Jan 1972

Simultaneous Determination Of Short-Period Photosynthesis And Evapotranspiration (Horticulture And Forestry Progress Report No. 91), Norman J. Rosenberg

School of Natural Resources: Faculty Publications

No abstract provided.


Isopiestic Studies Of Some Aqueous Electrolyte Solutions At 80°C, John T. Moore Jan 1972

Isopiestic Studies Of Some Aqueous Electrolyte Solutions At 80°C, John T. Moore

Faculty Publications

No abstract provided.


Observation Of A Broad Resonance In The 23S Excitation Of Helium By Electron Impact, G. B. Crooks, R. D. Dubois, D. E. Golden, M. Eugene Rudd Jan 1972

Observation Of A Broad Resonance In The 23S Excitation Of Helium By Electron Impact, G. B. Crooks, R. D. Dubois, D. E. Golden, M. Eugene Rudd

M. Eugene Rudd Publications

We have observed a broad P-wave resonance at about 50 eV primary energy in the angular distribution of electrons scattered after excitation of the 23S state of helium. The resonance has a width of about 15 eV and affects the differential excitation cross section by more than 3 orders of magnitude. It is suggested that this resonance is associated with the temporary formation of triply excited states of the negative helium ion.


Strong, Quasiperiodic Dependence Of Autoionization Shape Parameters On Projectile Energy In H+ + He Collisions, F. D. Schowengerdt, M. Eugene Rudd Jan 1972

Strong, Quasiperiodic Dependence Of Autoionization Shape Parameters On Projectile Energy In H+ + He Collisions, F. D. Schowengerdt, M. Eugene Rudd

M. Eugene Rudd Publications

Profiles of the 2s2 (1S) autoionizing state in He have been observed in the ejected-electron spectrum of H+ + He for small angles of ejection and for H+ energies of 6 to 150 keV. The shape parameter q shows an increasing dependence on projectile energy as the angle of ejection is decreased, with strong, quasiperiodic oscillations appearing at 10°.


Detection Of Energetic Heavy Ions, Robert Katz, S. C. Sharma, Mehdi Homayoonfar Jan 1972

Detection Of Energetic Heavy Ions, Robert Katz, S. C. Sharma, Mehdi Homayoonfar

Robert Katz Publications

The delta-ray theory of track structure, applied earlier to such 1-or-more hit detection systems as the inactivation of dry enzymes and viruses, the NaI(Tl) scintillation counter, and nuclear emulsion, is extended to the silver activated phosphate glass dosimeter, the LiF thermoluminescent dosimeter, the creation of free radicals in solid biological substances, solid and liquid organic scintillators, and the ferrous sulfate (Fricke) dosimeter. The response of these systems to both gamma-rays and heavy ions is characterized by two parameters: 1) Dγ37, the dose of gamma-rays at which 37% of the sensitive elements remain unaffected by the radiation, and …


An Embryonic Forestry Program In Coastal British Columbia-Preparation For Management, M Crown Jan 1972

An Embryonic Forestry Program In Coastal British Columbia-Preparation For Management, M Crown

Yale School of the Environment Bulletin Series

No abstract provided.


A Simulation Model For The Management Of Sandhill Cranes, Richard S. Miller, George S. Hochbaum, Daniel B. Botkin Jan 1972

A Simulation Model For The Management Of Sandhill Cranes, Richard S. Miller, George S. Hochbaum, Daniel B. Botkin

Yale School of the Environment Bulletin Series

No abstract provided.


A Simulation Model For The Management Of Sandhill Cranes, Richard S. Miller, George S. Hochbaum, Daniel B. Botkin Jan 1972

A Simulation Model For The Management Of Sandhill Cranes, Richard S. Miller, George S. Hochbaum, Daniel B. Botkin

Yale School of the Environment Bulletin Series

No abstract provided.


Radicals And Torsion Theories In Locally Compact Groups, Robert R. Bruner Jan 1972

Radicals And Torsion Theories In Locally Compact Groups, Robert R. Bruner

Mathematics Faculty Research Publications

In this paper we will study the properties of locally compact Abelian Hausdorff topological groups (hereafter known as LCA groups) by means of their mapping properties. The results contained herein are an outgrowth of work done by Professor Armacost [Al] on "sufficiency classes" of LCA groups. The sufficiency class S\textunderscore(H) of an LCA group H is the class of all LCA groups G such that there are sufficiently many continuous homomorphisms from G to H to separate the points of G. This condition is easily seen to be equivalent to the requirement that ∩ker(f)=0, where f ranges over all elements …


The Interpretation Of Lanthanide-Induced Shifts In 1h Nuclear Magnetic Resonance Spectra, Jerry Goodisman, R. S. Matthews Jan 1972

The Interpretation Of Lanthanide-Induced Shifts In 1h Nuclear Magnetic Resonance Spectra, Jerry Goodisman, R. S. Matthews

Chemistry - All Scholarship

Owing to the present accuracy of the data and various other factors, it is easy to obtain agreement with experimental results for lanthanide-induced shifts in 1H n.m.r. spectra; some considerations in the formulation of such models which have been ignored previously are discussed.


Table Of Contents Jan 1972

Table Of Contents

Journal of the Minnesota Academy of Science

No abstract provided.