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

Physical Sciences and Mathematics Commons™

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

Faculty Publications

Discipline
Institution
Keyword
Publication Year
File Type

Articles 3721 - 3750 of 3783

Full-Text Articles in Physical Sciences and Mathematics

Tip-Angle-Dependent Magnetic Relaxation In Superfluid 3he, Richard A. Webb Mar 1978

Tip-Angle-Dependent Magnetic Relaxation In Superfluid 3he, Richard A. Webb

Faculty Publications

Using a pulsed superconducting-quantum-interference-device (SQUID) NMR technique, relaxation of the longitudinal magnetization in superfluid 3He has been measured in magnetic fields of 31, 102, 180, and 306 Oe in the pressure range 16-26 bar. It is observed that in both superfluid phases there is a temperature-dependent, well-defined spin-tipping angle, θc, for which the relaxation of the magnetization changes from an exponential to a nonexponential behavior.

Go to article

The Stephen F. Austin Traveling Science Show, James C. Dennis Jan 1978

The Stephen F. Austin Traveling Science Show, James C. Dennis

Faculty Publications

No abstract provided.

Go to article

Compact Compacts: Models: A Simple (And Tasty) Model For Electron Clouds, John T. Moore Jan 1978

Compact Compacts: Models: A Simple (And Tasty) Model For Electron Clouds, John T. Moore

Faculty Publications

A simple (and tasty) model for demonstrating the electron cloud concept; and a classroom visualization of ethylene II and II* molecular orbitals.

Go to article

Ferromagneticlike Resonance Behavior In Superfluid 3he-B, Richard A. Webb Oct 1977

Ferromagneticlike Resonance Behavior In Superfluid 3he-B, Richard A. Webb

Faculty Publications

Nonlinear cw NMR behavior, similar to that observed on ferromagnets at high rf powers, has been observed in superfluid 3He-B using a superconducting quantum interference device (SQUID) magnetometer in fields of 31, 102, 180, and 308 Oe and at a pressure of 21 bar. It is observed that beyond some threshold value of the transverse H1 field the z component of magnetization anomalously decreases and is followed by a rapid increase back to the normal resonance curve as the frequency of the H1 field is swept through resonance.

Go to article

The Use Of Nuclear Reactions And Sims For Quantitative Depth Profiling Of Hydrogen In Amorphous Silicon, David D. Allred, G. J. Clark, C. W. White, B. R. Appleton, C. W. Magee, D. E. Carlson Aug 1977

The Use Of Nuclear Reactions And Sims For Quantitative Depth Profiling Of Hydrogen In Amorphous Silicon, David D. Allred, G. J. Clark, C. W. White, B. R. Appleton, C. W. Magee, D. E. Carlson

Faculty Publications

Depth profiles for hydrogen in amorphous silicon have been determined by the use of resonant nuclear reactions [1H(15N,αγ)12C and 1H(19F,αγ)16O] and by secondary ion mass spectroscopy (SIMS). Independent calibration procedures were used for the two techniques. Measurements were made on the same amorphous silicon film to provide a direct comparison of the two hydrogen analysis techniques. The hydrogen concentration in the bulk of the film was determined to be about 9 at % H. The SIMS results agree with the resonant nuclear reaction results to within 10%, which demonstrates that quantitative hydrogen depth profiles can be obtained by SIMS analysis …

Go to article

Fragments Of 1st-Order Logic, I: Universal Horn Logic, George F. Mcnulty Jun 1977

Fragments Of 1st-Order Logic, I: Universal Horn Logic, George F. Mcnulty

Faculty Publications

No abstract provided.

Go to article

Measurement Of The Difference Between The Dynamic Nmr And Static Susceptibilites Of Superfluid 3he-B Using An Rf-Biased Superconducting Quantum-Interference Device, Richard A. Webb May 1977

Measurement Of The Difference Between The Dynamic Nmr And Static Susceptibilites Of Superfluid 3he-B Using An Rf-Biased Superconducting Quantum-Interference Device, Richard A. Webb

Faculty Publications

The temperature-dependent susceptiblity of superfluid 3He-B has been measured both statically and via a pulse technique in a field of 309 G using an rf-biased superconducting quantum-interference device (SQUID). In the pressure range 26.5 to 18 bar, the dynamic NMR susceptiblity agrees qualitatively with the theoretical weak-coupling predictions for the Balian-Werthamer state. However, the static susceptiblity, measured using the same rf-biased SQUID and detection system, is significantly smaller thatn the dynamic susceptibility.

Go to article

A Random Differential-Equation Approach To Probability Distribution Of Bod And Do In Streams, William J. Padgett, G Schultz, Chris P. Tsokos Mar 1977

A Random Differential-Equation Approach To Probability Distribution Of Bod And Do In Streams, William J. Padgett, G Schultz, Chris P. Tsokos

Faculty Publications

No abstract provided.

Go to article

Intermolecular Potential Surfaces From Electron Gas Methods. Ii. Angle And Distance Dependence Of The A’ And A” Ar–No(X^2ii) Interactions, Glen C. Nielson, Gregory A. Parker, Russell T. Pack Feb 1977

Intermolecular Potential Surfaces From Electron Gas Methods. Ii. Angle And Distance Dependence Of The A’ And A” Ar–No(X^2ii) Interactions, Glen C. Nielson, Gregory A. Parker, Russell T. Pack

Faculty Publications

Angle dependent intermolecular potential energy surfaces for the two states (2A’ and 2A”) that arise from the interaction of ground (X^2II) state NO with Ar are calculated using the electron gas model to obtain the short range interactions. The average and difference of the two interaction energies are fit to analytic forms convenient for use in scattering calculations and joined smoothly onto the long range van der Waals potential previously determined. The results, which appear to be of useful accuracy, and the applicability of the electron gas model to such open shell–closed shell interactions are discussed.

Go to article

Computer Model Of A Fast Toroidal Plasma Compression, With Application To The Topolotron, H. Mark Nelson, Keith H. Brown, Charles A. Hart Nov 1976

Computer Model Of A Fast Toroidal Plasma Compression, With Application To The Topolotron, H. Mark Nelson, Keith H. Brown, Charles A. Hart

Faculty Publications

The method is developed for a comuputer sequence which models a fast toroidal theta or screw pinch for a highly conducting axially symmetric plasma. The computer sequence takes into account the self-inductances of the plasma and the external conductors which drive the compression as well as the mutual inductance which electromagnetically couples the two. The computer sequence is divided into three phases: a snowplow compression phase, an adiabatic compression phase, and a crowbarred circuit phase. The computer sequence is applied to a topolotron and an example is given of a magnetohydrodynamic equilibrium geometry for which the plasma surface possesses an …

Go to article

Effect Of Glycosylation On The In Vivo Circulating Half-Life Of Ribonuclease, John W. Baynes, Finn Wold Oct 1976

Effect Of Glycosylation On The In Vivo Circulating Half-Life Of Ribonuclease, John W. Baynes, Finn Wold

Faculty Publications

The circulating half-lives of the four isozymes of bovine pancreatic ribonuclease (RNases A, B, C, and D) have been determined in normal and in nephrectomized rats. The isozymes differ only in their glycosyl content. While A contains no sugars, B has a simple oligosaccharide (GlcNAc, Man,+), and C and D each have a complex oligosaccharide (GlcNAc, Man,., Gal, Fuc NeuAc%, and GlcNAc, Mans Gal, Fuc NeuAc,, respectively) attached to Asn-34 of the polypeptide chain. All four isozymes were cleared rapidly in normal rats (t,,, = 2 to 3 min), as expected on the basis of the established role of the …

Go to article

Behavior Of A Manganin Coil At Elevated Temperatures And Pressures, Jonathan D. Weiss, Daniel L. Decker, H. B. Vanfleet Sep 1976

Behavior Of A Manganin Coil At Elevated Temperatures And Pressures, Jonathan D. Weiss, Daniel L. Decker, H. B. Vanfleet

Faculty Publications

We have determined the temperature dependence in the first-order pressure coefficient of a manganin coil to be dBetaB/dT= (4.2±0.8) ×10^-7 (kbar degrees C)^-1 in the equation R (T,P) =R (T,0)(1+BetaP+GammaP2), where R (T,P) is the coil resistance at temperature T and pressure P. The measurements were performed by simultaneously measuring the coil resistance and temperature at the transitions of mercury and bismuth, which were observed by differential thermal analysis.

Go to article

Undecidable Properties Of Finite Sets Of Equations, George F. Mcnulty Sep 1976

Undecidable Properties Of Finite Sets Of Equations, George F. Mcnulty

Faculty Publications

No abstract provided.

Go to article

Application Of Theorems Of Schur And Albert, Thomas L. Markham Sep 1976

Application Of Theorems Of Schur And Albert, Thomas L. Markham

Faculty Publications

No abstract provided.

Go to article

Esr Study Of Free Radicals In Irradiated Single Crystals Of Potassium Hydroxylamine Disulfonate, B. J. Wilson, Robert W. Holmberg Aug 1976

Esr Study Of Free Radicals In Irradiated Single Crystals Of Potassium Hydroxylamine Disulfonate, B. J. Wilson, Robert W. Holmberg

Faculty Publications

Two free radicals formed when single crystals of potassium hydroxylamine disulfonate are irradiated with gamma rays at 77degrees K were studied by ESR. The ESR spectra result from a predominant center (radical A) exhibiting large 14N and 1H hyperfine splittings and from lesser amounts of Fremy's radical [O-dotN(SO3)2-2]. The g and hyperfine tensors of these radicals have been evaluated and are discussed. Radical A, whose identity remains in doubt, may be regarded as the precursor to Fremy's radical; on warming its lines decay and those of Fremy's radical are formed. Lines from radical A decrease in strength and those of …

Go to article

Van Der Waals Interactions Of Carbon Monoxide, Gregory A. Parker, Russell T. Pack Mar 1976

Van Der Waals Interactions Of Carbon Monoxide, Gregory A. Parker, Russell T. Pack

Faculty Publications

Pade approximant methods and experimental frequency dependent polarizabilities are used to calculate reliable van der Waals C6 coefficients for the interaction of CO with He, Ne, Ar, Kr, Xe, H, Li, Na, K, Rb, Cs, H2, N2, O2, CO2, and CO. Error bounds are given for the C6 coefficients and for the CO oscillator strength sums.

Go to article

Van Der Waals Interactions Of Ii-State Linear Molecules With Atoms. C6 For No(X 2Π) Interactions, Glen C. Nielson, Gregory A. Parker, Russell T. Pack Mar 1976

Van Der Waals Interactions Of Ii-State Linear Molecules With Atoms. C6 For No(X 2Π) Interactions, Glen C. Nielson, Gregory A. Parker, Russell T. Pack

Faculty Publications

Formulas are derived for the van der Waals Cn coefficients for the interaction of a diatomic molecule in a II electronic state with an S-state atom. Two triatomic states arise from the degenerate IIstate. The average of the two energies has the usual Legendre polynomial (PL) angular dependence, but the difference in energies of the two states is shown to have associated Legendre polynomial (PML with M=2) angular dependence. Procedures for including spin orbit coupling are included, and the extension to interactions of Delta- and Phi-state molecules is discussed. Values of the spherical part of the C6 coefficients for the …

Go to article

Comment On ''Inelastic Scattering In Atom-Diatomic Molecule Collisions. I. Rotational Transitions In The Sudden Approximation'', Russell T. Pack Feb 1976

Comment On ''Inelastic Scattering In Atom-Diatomic Molecule Collisions. I. Rotational Transitions In The Sudden Approximation'', Russell T. Pack

Faculty Publications

It is argued that conflicting approximations in a recent paper [J. R. Stallcop, J. Chem. Phys. 61, 5085 (1974)] render the resulting theory invalid.

Go to article

Relaxation Of The Wall-Pinned Magnetization Ringing Mode In Superfluid 3he-B, Richard A. Webb, R. E. Sager, J. C. Wheatley Oct 1975

Relaxation Of The Wall-Pinned Magnetization Ringing Mode In Superfluid 3he-B, Richard A. Webb, R. E. Sager, J. C. Wheatley

Faculty Publications

Observations of the wall-pinned mode in 3He-B allow new magnetic relaxation phenomena to be studied. Excepting the quantitative value of the zero-time ringing frequency, comparison of experiment with theory is satisfactory, including a linear dependence of the square of the ringing period on time and a square-root singularity near Tc in the relaxation parameter.

Go to article

Nonlinear Parallel Ringing Of Magnetization In Superfluid 3he, Richard A. Webb, R. E. Sager, J. C. Wheatley Oct 1975

Nonlinear Parallel Ringing Of Magnetization In Superfluid 3he, Richard A. Webb, R. E. Sager, J. C. Wheatley

Faculty Publications

Experiments based on an analogy to the ac Josephson effect have shown in both 3He-A and 3He-B that a pairing theory of the superfluidity of 3He is essentially correct. Additional observations of parallel ringing are not in agreement with the simple "pendulum models" used to describe nonlinear dynamic magnetic effects.

Go to article

Relationship Between The Linear Ringing Frequencies In 3he-A And 3he-B Near The Polycritical Point, Richard A. Webb, R. E. Sager, J. C. Wheatley Sep 1975

Relationship Between The Linear Ringing Frequencies In 3he-A And 3he-B Near The Polycritical Point, Richard A. Webb, R. E. Sager, J. C. Wheatley

Faculty Publications

New measurements of parallel ringing in a quasi-ideal geometry for 3He-B near the temperature and pressure of the polycritical point suggest fB2/fA2∼5/2, where fB and fA are the linear parallel-ringing frequencies at a given temperature near Tc. This result approaches the prediction of theory using the Anderson-Brinkman-Morel and Balian-Werthamer states to describe 3He-A and 3He-B, respectively, and hence the results of Osheroff at melting pressure, but disagrees with earlier observations at pressures near the polycritical point.

Go to article

Close Coupling Test Of Classical And Semiclassical Cross Sections For Rotationally Inelastic Ar-N2 Collisions, Russell T. Pack Apr 1975

Close Coupling Test Of Classical And Semiclassical Cross Sections For Rotationally Inelastic Ar-N2 Collisions, Russell T. Pack

Faculty Publications

Accurate quantum mechanical close coupling (CC) integral cross sections are reported for rotationally inelastic Ar-N2 collisions at room temperature using an empirical intermolecular potential. These cross sections are used to test the infinite order sudden (IOS) approximation and the results of several methods [classical trajectories (CT), full sudden (SA), generalized phase shift (GPS), and classical limit generalized phase shift (CGPS)] as reported in the preceding paper by Pattengill. The IOS approximation works very well for cross sections involving low rotational states. The CT method works well for all the cross sections examined, justifying the popular belief that the rotational motion …

Go to article

Conifer Wood From The Upper Jurassic Of Utah; I, Xenoxylon Morrisonense Sp. Nov., William D. Tidwell, David A. Medlyn Feb 1975

Conifer Wood From The Upper Jurassic Of Utah; I, Xenoxylon Morrisonense Sp. Nov., William D. Tidwell, David A. Medlyn

Faculty Publications

A new species of conifer wood, Xenoxylon morrisonense, is described from the Morrison Formation on the Colorado Plateau. It is compared with other species of Xenoxylon, with X. latiporosum being the closest. Xenoxylon morrisonense differs from X. latiporosum in its marked indentations, simple pits on the horizontal and tangential walls of ray cells, absence of crassulae, presence of wood parenchyma, and thin borders on podocarpoid type crossfield pits. The origin of the septa in the tracheids is summarized, and the possible affinity of Xenoxylon with the Podocarpaceae is considered.

Go to article

Fluid Mechanics In The Elementary Laboratory, James C. Dennis Jan 1975

Fluid Mechanics In The Elementary Laboratory, James C. Dennis

Faculty Publications

No abstract provided.

Go to article

Application Of Separation Theorem For Hermitian Matrices, Thomas L. Markham Jan 1975

Application Of Separation Theorem For Hermitian Matrices, Thomas L. Markham

Faculty Publications

No abstract provided.

Go to article

Erratum: On Improved Wkb (Uniform Asymptotic) Quantum Conditions, Dunham Corrections, The Langer Modification, And Rkr Potentials, Russell T. Pack Nov 1974

Erratum: On Improved Wkb (Uniform Asymptotic) Quantum Conditions, Dunham Corrections, The Langer Modification, And Rkr Potentials, Russell T. Pack

Faculty Publications

In Eqs. (28) and (29) p should be changed to t.

Go to article

Experiments On Dynamic Parallel Magnetism In Superfluid 3he, Richard A. Webb, R. L. Kleinberg, J. C. Wheatley Jul 1974

Experiments On Dynamic Parallel Magnetism In Superfluid 3he, Richard A. Webb, R. L. Kleinberg, J. C. Wheatley

Faculty Publications

Observations are reported of the ringing of parallel magnetization in superfluid 3He when an incremental magnetic field parallel to a steady field is suddenly turned off.

Go to article

The Role Of A Dolichol-Oligosaccharide As An Intermediate In Glycoprotein Biosynthesis, An-Fei Hsu, John W. Baynes, Edward C. Heath Jun 1974

The Role Of A Dolichol-Oligosaccharide As An Intermediate In Glycoprotein Biosynthesis, An-Fei Hsu, John W. Baynes, Edward C. Heath

Faculty Publications

Incubation of mouse myeloma microsomes with GDP-[(14)C]mannose results in the biosynthesis of [(14)C]mannose phosphoryl dolichol [Baynes, J. W., Hsu, A.-F. & Heath, E. C. (1973) J. Biol. Chem. 248, 5693-5704] and a [(14)C]mannose- and N-acetylglucosamine (GlcNAc)-containing oligosaccharide derivative of dolichol. Thus, [(14)C]mannose phosphoryl dolichol and [(14)C]mannose-labeled oligosaccharide pyrophosphoryl dolichol were isolated from incubation mixtures by solubilization in 2% (w/v) Triton X-100 and the lipids were separated from small molecules by gel filtration fractionation. After removal of radioactive protein from the preparation, the two lipid derivatives were separated quantitatively by fractionation on a concanavalin A-Sepharose column; [(14)C]mannose phosphoryl dolichol was not …

Go to article

Graphs With 1-Factors, David Sumner Jan 1974

Graphs With 1-Factors, David Sumner

Faculty Publications

In this paper it is shown that if G is a connected graph of order 2n (n > 1) not containing a 1-factor, then for each k, 1

Go to article

System Implementation And Evaluation, I. Trotter Hardy Dec 1973

System Implementation And Evaluation, I. Trotter Hardy

Faculty Publications

No abstract provided.

Go to article

First Prev Next Last