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Articles 285901 - 285930 of 303797

Full-Text Articles in Physical Sciences and Mathematics

Analysis Of Population And Price Aspects Of The Virginia Hard Clam (Mercenaria Mercenaria) Fishery, Andre C. Kvaternik Jan 1982

Analysis Of Population And Price Aspects Of The Virginia Hard Clam (Mercenaria Mercenaria) Fishery, Andre C. Kvaternik

Dissertations, Theses, and Masters Projects

No abstract provided.

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Application Of The Genetic Algorithm To A Simplified Form Of The Phase Problem, Byrne Lovell, Martin Zwick Jan 1982

Application Of The Genetic Algorithm To A Simplified Form Of The Phase Problem, Byrne Lovell, Martin Zwick

Systems Science Faculty Publications and Presentations

The Genetic Algorithm, a technique for global optimization which simulates evolutionary adaptation, is applied to a simplified form of the "phase problem" in theoretical crystallography. Results are compared with those of a problem-specific algorithm.

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Two-Dimensional, Intratidal Model Study Of Salinity Intrusion Structure And Motion In Partially-Mixed Estuaries (Virginia), Carl F. Cerco Jan 1982

Two-Dimensional, Intratidal Model Study Of Salinity Intrusion Structure And Motion In Partially-Mixed Estuaries (Virginia), Carl F. Cerco

Dissertations, Theses, and Masters Projects

A two-dimensional, longitudinal-vertical model for partially-mixed estuaries has been developed. The model provides intratidal predictions of surface level, velocity, and salinity through a semi-implicit finite-difference solution to the continuity and momentum equations and an explicit finite-difference solution to the salinity equation. The model was verified through comparison with analytical solutions, laboratory data, and prototype data. Following verification, the model was used to simulate the destratification-stratification cycle which occurs in the James River Estuary, Virginia, coincident with the spring-neap tidal cycle. In a second application to the James, a simulation of the movement of the salinity intrusion following a storm-generated freshwater …

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A Study Of Nutritional Requirements Of The Larvae Of The American Oyster (Crassostrea Virginica), Fu-Lin E. Chu Jan 1982

A Study Of Nutritional Requirements Of The Larvae Of The American Oyster (Crassostrea Virginica), Fu-Lin E. Chu

Dissertations, Theses, and Masters Projects

The purpose of this study is to obtain information for the formulation of artificial diets for larvae of the American oyster (Crassostrea virginica) and to test procedures related to presenting these diets to the oyster larvae. In order to determine the nutrient components usually provided in larval diets, biochemical analyses of lipids and fatty acids, proteins and amino acids and polysaccharide carbohydrates were performed on five algae species used as a food source for oyster larvae. These algae are Chlorella sp., Pyramimonas virginica, Pseudoisochrysis paradoxa, Pavlova (Monochrysis) lutheri and Isochrysis galbana. The biochemical analyses indicate that the nutritional value of …

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Atomic Carbon In The Atmosphere Of Venus, Jane L. Fox Jan 1982

Atomic Carbon In The Atmosphere Of Venus, Jane L. Fox

Physics Faculty Publications

The densities of atomic carbon in the Venusian thermosphere are computed for a model which includes both chemistry and transport. The maximum density of C is 2.8×107 cm−3 near 150 km for an assumed O2 mixing ratio of 1×10−4. Photoionization of atomic carbon is found to be the major source of C+ above 200 km, and resonance scattering of sunlight by atomic carbon may be the major source of the C I emissions at 1561 Å, 1657 Å, and 1931 Å. The computed C+ densities are found to be in substantial agreement with …

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Reconnaissance Of The Bedrock Aquifers And Groundwater Chemistry Of Crawford, Franklin, And Sebastian Counties, Arkansas, Samuel R. Rothermel, Wyndal M. Robison, Julie L. Wanslow, James R. Musgrove, Daryll Saulsberry, Albert E. Ogden Jan 1982

Reconnaissance Of The Bedrock Aquifers And Groundwater Chemistry Of Crawford, Franklin, And Sebastian Counties, Arkansas, Samuel R. Rothermel, Wyndal M. Robison, Julie L. Wanslow, James R. Musgrove, Daryll Saulsberry, Albert E. Ogden

Journal of the Arkansas Academy of Science

A ground water reconnaissance of Crawford, Franklin, and Sebastian counties was performed utilizing 122 wells having drillers' logs from bedrock aquifers. North of the Arkansas River, essentially all bedrock wells produce from the Atoka Formation. There are many low producing aquifers within the Atoka with a range in yield of 0.1 to 55 gpm, but having a median yield of only 2 gpm. Well depths range from 18 to 248 feet with a median of 122 feet. More water is generally obtained from the shale/siltstone aquifers than the sandstones due to more bedding-plane partings and more closely spaced fractures. Greater …

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Synthesis And Evaluation Of Polymeric Ether Glycol Derivatives For Use As Transducer Fluids, Cynthia K. Mccurry Jan 1982

Synthesis And Evaluation Of Polymeric Ether Glycol Derivatives For Use As Transducer Fluids, Cynthia K. Mccurry

Retrospective Theses and Dissertations

A series of end-capped PAG (n-butyl, n-alkyl substituted polypropylene glycol) and PPGs (bis-di-alkyl-,bis-di-halo-, bis-di-fluoroalkylpolypropylene glycol) were synthesized. Optimum reaction conditions were determined in regard to time, temperature, reaction ratios, and solvents for each of the PAG and PPG derivatives. An investigation of the named PAG and PPG derivatives as potentially new sonar transducer fluids was carried out. Density, viscosity and sound speed measurements with regard to temperature, as well as water solubility measurements, were carried out for several of these derivatives. The desirable properties possessed by several of these derivatives make them of potential value in application as transducer fill-fluids.

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1. Doublegee Dormancy 2. Lupins - Chemical Tolerance Of Kiev Mutant 3. Lupins - Simazine And Diuron Plus Mixtures 4. Lupins - Pp009 5. Lupins - New Herbicides 6. Lupins - Ssh 0860, D. J. Gilbey, R. Klemm Jan 1982

1. Doublegee Dormancy 2. Lupins - Chemical Tolerance Of Kiev Mutant 3. Lupins - Simazine And Diuron Plus Mixtures 4. Lupins - Pp009 5. Lupins - New Herbicides 6. Lupins - Ssh 0860, D. J. Gilbey, R. Klemm

Experimental Summaries - Plant Research

Doublegee seed longevity x cultivation - 75WH65, Doublegee seed longevity x depth- Effect of burial on longevity of doublegee achenes - 75WH66, 76C9, 76KA8, 82 N 25, 82 N 24, 82 N 30, 82 LG 30, 82 LG 33, 82 KA 35, 82 KA 36, 82TS38, 82GE33, 82TS37, 82ME62, 82BA42, 82GE35, 82TS36, 82 NO 62, 82 ME 83, 82GE36, 82TS35, 82ME63B, 82M038, 82GE32, 82BA41, 82ME63A,

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Fine Structure Of Rydberg States. V. N=5 And 6f And G States Of He4, John W. Farley, Doreen A. Weinberger, Shin Sheng Tarng, Nancy D. Piltch, William H. Wing Jan 1982

Fine Structure Of Rydberg States. V. N=5 And 6f And G States Of He4, John W. Farley, Doreen A. Weinberger, Shin Sheng Tarng, Nancy D. Piltch, William H. Wing

Physics: Faculty Publications

We have made 17 new high-precision measurements of the nF-nG intervals (n=5,6) of neutral He4 using the microwave-optical method. The rms one-standard-deviation experimental uncertainty for the transitions reported here is 188 kHz (14 ppm). The new measurements agree with the predictions of a least-squares fit to previous experimental data, and are up to 40 times more precise. The nF-nG manifold is now known experimentally to better than 1 MHz for all values of the quantum numbers. The precision of the experimental measurement exceeds that of the best currently available theory by approximately three orders of magnitude.

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Benthic Testacida (Rhizopoda, Protozoa) Of Lake Washington, Brevard County, Florida, Haydee Lena Jan 1982

Benthic Testacida (Rhizopoda, Protozoa) Of Lake Washington, Brevard County, Florida, Haydee Lena

Ocean Engineering and Marine Sciences Faculty Publications

Benthic Testacida from sediments of Lake Washington were studied. The Testacida were extracted using standard foraminiferologic techniques. The determined taxa were photographed using scanning electron microscopy. Twenty-one taxa were found. The majority were cosmopolitan and the most abundant were Difflugia pyriformis and Centropyxis compressa. The Testacida guild was similar to that previously studied in other American and European lakes. However, the type and size of the species were different from those found in soil and mosses.

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Effects Of Disruptive Grazing By The Mud Snail Ilyanassa Obsoleta On Mudflat Nematode Populations, David Ludwig Jan 1982

Effects Of Disruptive Grazing By The Mud Snail Ilyanassa Obsoleta On Mudflat Nematode Populations, David Ludwig

Dissertations, Theses, and Masters Projects

Population densities of the mud snail Ilyanassa obsoleta were manipulated in caging experiments on a salt marsh mudflat and in laboratory microcosms. Mud snails outcompete nematodes for food resources, but may increase resources available to deposit feeding groups. Mud snails reduce annelid (polychaete and oligochaete) populations by substrate disruption. Reduced annelid densities provide the nematode community with some release from predation and competition. In mudflat sediments, the nematode community responds to both primary (predation) and secondary (envirorm1ental release, food competition) interactions. Multiple levels of interactive coupling should be considered in any systems level investigation in this habitat.

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Organic Compound Levels In A Sediment Core From The Elizabeth River Of Virginia, Muzhen Lu Jan 1982

Organic Compound Levels In A Sediment Core From The Elizabeth River Of Virginia, Muzhen Lu

Dissertations, Theses, and Masters Projects

No abstract provided.

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Electron Density Measurements In A Laser Induced Na Plasma, D. J. Krebs, Laird D. Schearer Jan 1982

Electron Density Measurements In A Laser Induced Na Plasma, D. J. Krebs, Laird D. Schearer

Physics Faculty Research & Creative Works

The optical emission spectrum of a recombining Na plasma is observed. The shift and broadening of the spectral line emission due to electron collisions is observed. Electron densities on the order of 5x1014 cm -3 are calculated from the shift measurements. The results agree well with electron densities obtained in the same system from Saha plots of excited state densities. © 1982 American Institute of Physics.

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Determination Of The Absolute Structure Factor For The Forbidden (222) Reflection In Silicon Using 0.12-Γ Rays, R. W. Alkire, W. (William) B. Yelon, J. R. Schneider Jan 1982

Determination Of The Absolute Structure Factor For The Forbidden (222) Reflection In Silicon Using 0.12-Γ Rays, R. W. Alkire, W. (William) B. Yelon, J. R. Schneider

Physics Faculty Research & Creative Works

A room-temperature determination of the absolute structure factor for the forbidden (222) reflection in silicon has been conducted at the University of Missouri Research Reactor with 103-keV gamma rays. The measured structure factor of F(222)=1.456 is in excellent agreement with five of the earlier intensity measurements and is significantly different from any value determined using Pendellösung techniques. An increase in accuracy over previous intensity measurements by a factor of between 2 and 10 has been achieved and is made possible through the use of monoenergetic, short-wavelength gamma rays, which allow absolute measurements to be made in Laue geometry on relatively …

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Phaseautomodulation In Magnesium, Alexander Aning, Tetsuro Suzuki, Manfred Wuttig Jan 1982

Phaseautomodulation In Magnesium, Alexander Aning, Tetsuro Suzuki, Manfred Wuttig

Physics Faculty Research & Creative Works

No abstract provided.

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Electron-Capture Collisions Of H+ With Ground- And Excited-State Na, M. Kimura, Ronald E. Olson, J. Pascale Jan 1982

Electron-Capture Collisions Of H+ With Ground- And Excited-State Na, M. Kimura, Ronald E. Olson, J. Pascale

Physics Faculty Research & Creative Works

Pseudopotential molecular-structure calculations have been used to obtain the low-lying interaction energies for NaH+. The wave functions were used to calculate accurate radial and rotational coupling matrix elements. Scattering calculations which include electron translational factors were performed using up to eight coupled channels for laboratory energies 0.1 to 10 keV. Electron capture from ground-state Na 3s yields cross sections in the 10-15-cm2 range of which the dominant products are H 2s and H 2p. Electron capture from excited Na 3p does not show an enhanced cross section relative to capture from the ground state even though the energy gap E(R=) …

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Octal-Tree Spatial Sorting And Its Applications, Jeffrey L. Posdamer Jan 1982

Octal-Tree Spatial Sorting And Its Applications, Jeffrey L. Posdamer

All Computer Science and Engineering Research

An octal tree subdivision recursively divides a bounded three-dimensional volume into octanta about an internal division point. This scheme has been used to represent cellular or enumerated voxel models of solid objects. Given one or more sets of points sampled from the surface of a solid, an octal tree may be generated in which each leaf node contains m or less points. By specifying the tree traversal rule, the points are accessed in a sorted order. By defining m=3, a divide-and-conquer surface triangulation algorithm may be developed which does not require special sampling conditions (such as co-planarity) on subsets of …

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Measurement Of The Wear Properties Of Metallic Solids With A Falex Lubricant Testing Machine, Edward Boyd Hale, Chun-Ping John Meng, Ronald A. Kohser Jan 1982

Measurement Of The Wear Properties Of Metallic Solids With A Falex Lubricant Testing Machine, Edward Boyd Hale, Chun-Ping John Meng, Ronald A. Kohser

Physics Faculty Research & Creative Works

A modified Falex Lubricant Testing Machine has been used to determine wear properties of metallic solids. In particular, wear mass loss, wear volume loss, wear rates, and other parameters have been determined for a basic steel, as heat treated and after ion implantation. Wear rate improvements of more than an order of magnitude were found in a nickel-chrome steel (SAE 3135) implanted with 2.5x1017 N+2/cm2. Wear tests were conducted with a cylinder-in-groove geometry in a mild lubricating oil with loads greater than 540 N, which corresponded to pressures which exceeded 108N/m2 …

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A Multiobjective Branch-And-Bound Method For Planning Wastewater And Residual Management Systems, Masahisa Nakamura, Suraj M. Alexander, James M. Riley, Robert Simon, Susan Meyer, Kenneth F. Bloemer Jan 1982

A Multiobjective Branch-And-Bound Method For Planning Wastewater And Residual Management Systems, Masahisa Nakamura, Suraj M. Alexander, James M. Riley, Robert Simon, Susan Meyer, Kenneth F. Bloemer

KWRRI Research Reports

A multiobjective branch-and-bound algorithm is proposed for use in analysing multiobjective fixed-charge network-flow problems which are found commonly in water resources planning situations. Also proposed is a multiobjective imputed value analysis which makes use of the branch-and-bound tree structure and allows the comparison of the importance of facilities in the network as represented by individual arcs or sets of arcs. The mathematical formulation and the analysis procedure of the method are described, and the potential usefulness of the method is demonstrated using two hypothetical example problems dealing with regional wastewater treatment and residual management systems. A FORTRAN program for implementing …

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Threshold Friction Velocities And Rupture Moduli For Crusted Desert Soils For The Input Of Soil Particles Into The Air, Dale A. Gillette, John Adams, Daniel R. Muhs, Rolf Kihl Jan 1982

Threshold Friction Velocities And Rupture Moduli For Crusted Desert Soils For The Input Of Soil Particles Into The Air, Dale A. Gillette, John Adams, Daniel R. Muhs, Rolf Kihl

United States Geological Survey: Staff Publications

Desert soils having clay crusts, mostly from the Mojave Desert, were tested for threshold friction velocity (the friction velocity at which soil erosion begins) with an open-bottomed wind tunnel. The soils were also tested for content of clay, water-soluble material, calcium carbonate, organic material, mineralogy of clay and of salts, soil moisture, modulus of rupture, and crust thickness. If no loose material existed on the soil surface, crusts having modulus of rupture greater than 0.7 bar and crust thickness of 0.7 cm to 0.3 cm were effective in protecting against wind erosion. Disturbed clay crusts having modulus of rupture before …

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The Distribution Of Natural Fractures And Joints At Depth In Crystalline Rock, Donald A. Seeburger, Mark D. Zoback Jan 1982

The Distribution Of Natural Fractures And Joints At Depth In Crystalline Rock, Donald A. Seeburger, Mark D. Zoback

United States Geological Survey: Staff Publications

This paper presents the results of studies of the natural fracture distribution encountered in 10 test wells drilled in three areas of the United States. Seven of the wells were drilled to depths of 200-250m, while three were drilled to depths of about 1 km. Using an ultrasonic borehole televiewer, fracture depths, strikes, and dips were determined. Steeply dipping fractures were found throughout each of the wells, and in general, few horizontal fractures were observed. Statistically significant fracture pole concentrations were found for each well which were basically invariant with depth, although some variation of fracture orientation with depth was …

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Seasat Sar Test Of The Virginian Sea Wave Climate Model, John C. Munday Jr., Christopher S. Welch, George R. Mapp Jan 1982

Seasat Sar Test Of The Virginian Sea Wave Climate Model, John C. Munday Jr., Christopher S. Welch, George R. Mapp

Reports

Coastal wave refraction imaged by the Seasat Synthetic Aperture Radar is compared to simulations produced by the Virginian Sea Wave Climate Model. Seasat SAR passes 974 at Cape Hatteras, and 974 and 1404 at Long Island, were examined using OFT and ZTS methods. Results generally confirm the validity of linear wave theory in modeling of shallow-water wave refraction --roughly half the deviations between VSWCM and SAR data for direction and wavelength are within 2 degrees and 10 meters. Convergence of wave orthogonals is found in predicted caustic regions. Available bathymetric data were adequate for the analysis. Some details in the …

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The Biogenic Structure Of Lower Chesapeake Bay Sediments : Epa Chesapeake Bay Program Final Report, Karl J. Nilsen, Robert J. Diaz, Linda C. Schaffner, Donald F. Boesch, Rodney Bertelsen, Michel Kravitz Jan 1982

The Biogenic Structure Of Lower Chesapeake Bay Sediments : Epa Chesapeake Bay Program Final Report, Karl J. Nilsen, Robert J. Diaz, Linda C. Schaffner, Donald F. Boesch, Rodney Bertelsen, Michel Kravitz

Reports

No abstract provided.

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Graduate Bulletin, 1982-1984 (1982), Moorhead State University Jan 1982

Graduate Bulletin, 1982-1984 (1982), Moorhead State University

Graduate Bulletins (Catalogs)

No abstract provided.

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Ci Cygni Since The 1980 Eclipse, R. E. Stencel, Andrew G. Michalitsianos, Menas Kafatos Jan 1982

Ci Cygni Since The 1980 Eclipse, R. E. Stencel, Andrew G. Michalitsianos, Menas Kafatos

Mathematics, Physics, and Computer Science Faculty Books and Book Chapters

Following the 1980 eclipse of the 855 day period symbiotic binary CI Cyg, we were confronted with a data set showing high excitation resonance lines which were largely uneclipsed but brightening on an orbital timescale, and intercombination lines exhibiting pronounced but nontotal eclipses and which were fading on an orbital timescale. Our model invoked a low density dissipating nebula surrounding the hot companion to explain the intercombination lines, and a shock between stellar winds to interpret the resonance lines. Subsequent synoptic observations have revealed continuing changes in the W emission line fluxes, consistent with those described above, except for the …

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Existence Of The Dielectric Constant In Fluids Of Classical Deformable Molecules, John D. Ramshaw Jan 1982

Existence Of The Dielectric Constant In Fluids Of Classical Deformable Molecules, John D. Ramshaw

Physics Faculty Publications and Presentations

The existence of the dielectric constant epsilon is investigated for fluids composed of classical deformable (polarizable) molecules. The development is based upon generalized functional-derivative relations which involve joint distributions in molecular positions r/sub k/ and dipole moments ..mu../sub k/. Sufficient conditions for the existence of epsilon are expressed in terms of the generalized direct correlation function c(12) = c(r/sub 1/, ..mu../sub 1/; r/sub 2/, ..mu../sub 2/). It is found that epsilon exists if -kTc(12) depends only on relative positions and dipole moment directions (in addition to Vertical Bar..mu../sub 1/Vertical Bar and Vertical Bar..mu../sub 2/Vertical Bar), and becomes asymptotic to the …

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Molecular Treatment Of Electron Capture By Protons From The Ground And Excited States Of Alkali-Metal Atoms, M. Kimura, Ronald E. Olson, J. Pascale Jan 1982

Molecular Treatment Of Electron Capture By Protons From The Ground And Excited States Of Alkali-Metal Atoms, M. Kimura, Ronald E. Olson, J. Pascale

Physics Faculty Research & Creative Works

Electron-capture cross sections for H+ plus alkali-metal atom (Na, K, Rb, and Cs) systems have been computed for projectile energies from 10 eV to 10 keV. An impact parameter perturbed-stationary-state theory using molecular states that incorporate electron translation factors was used to calculate the cross sections. The wave functions were generated by employing the pseudopotential method. These yield equilibrium parameters Re and De for the A +2 molecular state that are in good agreement with ab initio results. Interaction energies are also presented for the LiH+ system. Basis sets of up to eight molecular states were used to calculate the …

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The University Of Missouri-Rolla, Absolute Aitken Nucleus Counter, John L. Schmitt, James L. Kassner, Josef Podzimek Jan 1982

The University Of Missouri-Rolla, Absolute Aitken Nucleus Counter, John L. Schmitt, James L. Kassner, Josef Podzimek

Physics Faculty Research & Creative Works

The authors discuss the expansion cloud chamber system known as the University of Missouri-Rolla-absolute Aitken nucleus counter. A review of the properties of an expansion chamber and how it creates a supersaturation are given and a critical examination is made of the assumptions in its operation, e.g. adiabaticity of the expansion. The design of the chamber is described in detail and an analysis of the propagation of errors is given for quantities measured and calculated. A short review of the performance of the chamber and some general comments relative to comparisons with other Aitken nucleus counting instruments are given. The …

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Coloured Monopoles From Fractional Charges In Ocd, A. P. Balachandran, V. Parameswaran Nair, C. G. Trahern Jan 1982

Coloured Monopoles From Fractional Charges In Ocd, A. P. Balachandran, V. Parameswaran Nair, C. G. Trahern

Publications and Research

In a recent paper, Slansky et al. have suggested that SU(3)c may be broken to SO(3) X Z, in order to explain the possible existence of fractionally charged states. We point out that there are low mass monopoles associated with such a symmetry breakdown and discuss their properties. Such states may be observable at LEP if not at PETRA energies.

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Ultraviolet Spectrum Of The Crab Nebula, K. Davidson, T. R. Gull, S. P. Maran, T. P. Stecher, R. A. Fesen, R. A. Parise, C. A. Harvel, Menas Kafatos, V. L. Trimble Jan 1982

Ultraviolet Spectrum Of The Crab Nebula, K. Davidson, T. R. Gull, S. P. Maran, T. P. Stecher, R. A. Fesen, R. A. Parise, C. A. Harvel, Menas Kafatos, V. L. Trimble

Mathematics, Physics, and Computer Science Faculty Articles and Research

Data from 65 hours of observation of the Crab Nebula with the International Ultraviolet Explorer are reported, together with new ground-based spectrophotometry. We have measured the important C IV λ1549, He II λ1640, and C III] λ1908 emission line intensities and placed upper limits on other ultraviolet features for the brightest filamentary region in the nebula. We have also measured some ultraviolet continuum surface brightnesses at two places in the Crab. The emission lines imply an average ionic abundance ratio n(C^+2)/n(O^+2 ) in the range from 0.4 to 1.5 in the observed gaseous condensations. The elemental abundance ratio of carbon …

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