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Articles 31801 - 31830 of 34224

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Three-State Model Driven By Two Laser Beams, C. E. Carroll, Foek T. Hioe Jul 1987

Three-State Model Driven By Two Laser Beams, C. E. Carroll, Foek T. Hioe

Physics Faculty/Staff Publications

We use a three-state model for an atom or molecule in which two transitions are simultaneously driven by the oscillating electric fields of two laser beams. The amplitudes and detunings of the applied oscillating fields vary during the optical pulse, which can cause transitions from one state to another. For some special cases not previously known, the transition probabilities and probabilities of no transition are obtained analytically. We give conditions for complete transfer of the atomic population from one state to another, and for complete return to the initial state.

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Theoretical Studies Of Electron Transfer In Metal Dimers: Xy+→X+Y, Where X, Y=Be, Mg, Ca, Zn, Cd, Robert J. Cave, David V. Baxter, William A. Goddard Iii, John D. Baldeschwieler Jul 1987

Theoretical Studies Of Electron Transfer In Metal Dimers: Xy+→X+Y, Where X, Y=Be, Mg, Ca, Zn, Cd, Robert J. Cave, David V. Baxter, William A. Goddard Iii, John D. Baldeschwieler

All HMC Faculty Publications and Research

The electronic matrix element responsible for electron exchange in a series of metal dimers was calculated using ab initio wave functions. The distance dependence is approximately exponential for a large range of internuclear separations. A localized description, where the two nonorthogonal structures characterizing the electron localized at the left and right sites are each obtained self‐consistently, is found to provide the best description of the electron exchange process. We find that Gaussian basis sets are capable of predicting the expected exponential decay of the electronic interactions even at quite large internuclear distances.

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Surface Conductance Of A Copper Wire In A Fluid At High Pressure, Daniel L. Decker Jul 1987

Surface Conductance Of A Copper Wire In A Fluid At High Pressure, Daniel L. Decker

Faculty Publications

The three-dimensional flow of heat in a wire carrying a current and immersed in a liquid is solved in detail. Using this exact result the surface conductance of copper in petroleum ether has been measured as a function of pressure to 40 kbars. The measured surface conductance for copper in a fluid is very small, justifying approximations which yield results that are in agreement with a simplified one-dimensional heat-flow problem. Surprisingly, even at 40 kbars pressure a very large fraction of the joule heating within a wire with a length-to-diameter ratio of ~100 is dissipated through the ends of the …

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Molecular Lifetimes In The Presence Of Periodically Roughened Metallic Surfaces, P.T. Leung, Z. C. Wu, Daniel A. Jelski, Thomas F. George Jul 1987

Molecular Lifetimes In The Presence Of Periodically Roughened Metallic Surfaces, P.T. Leung, Z. C. Wu, Daniel A. Jelski, Thomas F. George

Physics Faculty Publications and Presentations

The lifetimes of molecules located close to a sinusoidal grating surface are studied within a classical phenomenological model. The contribution of surface roughness to the molecular decay rate is attributed to the discrepancy between the experiments of Rossetti and Brus and the theory of Chance, Prock, and Silbey. It is found that surface roughness can either enhance or diminish the flat-surface value for the decay rate depending on the emitting frequency, molecule-surface distance, and the molecular orientation.

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Observation Of Possible Supercondictivity At 230 K, C. Y. Huang, L. J. Dries, P. H. Hor, R. L. Meng, C. W. Chu, Richard B. Frankel Jul 1987

Observation Of Possible Supercondictivity At 230 K, C. Y. Huang, L. J. Dries, P. H. Hor, R. L. Meng, C. W. Chu, Richard B. Frankel

Physics

Recently, Chu announced the observation of sharp drops of up to two orders of magnitude in the resistance of several Y-, Sc- and La-based multi-phase Ba–Cu oxide samples at temperatures as high as 240 K. The resistance drops reported did not survive the thermal cyclings for magnetic measurements. Later, M. H. Cohen (personal communication) reported similar anomalies in some Y-based oxides. In the absence of zero resistivity and evidence for the Meissner effect, the sharp resistance drops have been taken only as an indication of the possible existence of superconductivity at these unusually high temperatures. More recently, Chen et al. …

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Saddle-Point Electrons In Ionizing Ion-Atom Collisions, R. E. Olson, Timothy J. Gay, H. G. Berry, V. D. Irby Jul 1987

Saddle-Point Electrons In Ionizing Ion-Atom Collisions, R. E. Olson, Timothy J. Gay, H. G. Berry, V. D. Irby

Timothy J. Gay Publications

We have studied H++He ionizing collisions, and find that electrons stranded between the two postcollision Coulomb centers dominate the ejected-electron spectra for intermediate (~100 keV) projectile energies. The importance of these electrons is clearly established by our classical calculations which are in qualitative agreement, in both shape and magnitude, with experimental spectra taken by us, and with earlier measurements. These ‘‘saddle-point’’ electrons are produced by a classically understandable mechanism, and are unambiguously observed at nonzero scattering angles.

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The Stability And Decomposition Of Gaseous Chloroferrocenes, S. Barfuss, M. Grade, W. Hirschwalde, W. Rosinger, N.M. Boag, D.C. Driscoll, Peter A. Dowben Jul 1987

The Stability And Decomposition Of Gaseous Chloroferrocenes, S. Barfuss, M. Grade, W. Hirschwalde, W. Rosinger, N.M. Boag, D.C. Driscoll, Peter A. Dowben

Peter Dowben Publications

The ionic and neutral decomposition of gaseous ferrocene, 1, 1'-dichloroferrocene and 1, 1', 2,2'- tetrachloroferrocene, has been investigated via photon and electron induced ionization mass spectroscopy. The thermodynamic cycle incorporating the ionic and neutral fragments of ferrocene has been constructed. Elimination reactions in the decomposition of the dichloroferrocene and tetrachloroferrocenes have been identified.

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Measurement Of The Condensation Coefficient Of Water In The Umr Cloud Simulation Chamber, Daniel R. White, James L. Kassner, John C. Carstens, Donald E. Hagen, John L. Schmitt, Darryl J. Alofs, A. R. Hopkins, Max B. Trueblood, M. W. Alcorn Jun 1987

Measurement Of The Condensation Coefficient Of Water In The Umr Cloud Simulation Chamber, Daniel R. White, James L. Kassner, John C. Carstens, Donald E. Hagen, John L. Schmitt, Darryl J. Alofs, A. R. Hopkins, Max B. Trueblood, M. W. Alcorn

Physics Faculty Research & Creative Works

Measurements of the condensation coefficient of water under conditions closely approximating those in natural atmospheric cloud have been made in the cooled-wall UMR cloud simulation chamber. Current measurements disclose a value of condensation coefficient near unity at the outset of the experiment, generally decreasing to lower values (~ .01) as the experiment progresses. The significance of the magnitude of condensation coefficient in atmospheric cloud is briefly discussed.

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Superconductivity At 155 K, David D. Allred, S. R. Ovshinsky, R. T. Young, G. Demaggio, G. A. Van Der Leeden Jun 1987

Superconductivity At 155 K, David D. Allred, S. R. Ovshinsky, R. T. Young, G. Demaggio, G. A. Van Der Leeden

Faculty Publications

Transition to a superconducting zero-resistance state at 155 K is observed for the first time in bulk material. A new five-element compound has been synthesized with nominal composition Y1Ba2Cu3F2Oy. Fluorine plays a critical role in achieving this effect. X-ray diffraction and electron microprobe analysis indicate that the samples are multiphasic. Evidence is presented that the samples contain superconducting phases with onset temperatures considerably above 155 K. Magnetic measurements suggest a flux-trapping effect below 260 K, and diamagnetic deviations from Curie-Weiss behavior in the range from 250 K≤T≤100 K indicate that Meissner effect in a small superconducting volume fraction.

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Antiphase Domain Boundaries In The Superconducting Phase Of The Y-Ba-Cu-O System, C.H. Chen, J. Werder, Sy_Hwang Liou, M. Hong Jun 1987

Antiphase Domain Boundaries In The Superconducting Phase Of The Y-Ba-Cu-O System, C.H. Chen, J. Werder, Sy_Hwang Liou, M. Hong

Sy-Hwang Liou Publications

Transmission-electron-microscopy examination of the superconducting phase of the Y-Ba-Cu-O system reveals the presence of dense antiphase boundaries. The structure of the superconducting phase was determined to be orthorhombic with space group Pm2m. The orthorhombic a and b axes are found to alternate across the antiphase boundary which runs parallel to the [110] direction.

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Break-Junction Tunneling Measurements Of The High-TC Superconductor Y1Ba2Cu3O9- Δ , J. Moreland, J.W. Ekin, L.F. Goodrich, T.E. Capobianco, A.F. Clark, J. Kwo, M. Hong, Sy_Hwang Liou Jun 1987

Break-Junction Tunneling Measurements Of The High-TC Superconductor Y1Ba2Cu3O9- Δ , J. Moreland, J.W. Ekin, L.F. Goodrich, T.E. Capobianco, A.F. Clark, J. Kwo, M. Hong, Sy_Hwang Liou

Sy-Hwang Liou Publications

Current-voltage tunneling characteristics in a high-critical-temperature superconducting material containing predominately Y1Ba2Cu3O9- δ have been measured using the break-junction technique. Sharp gap structure was observed, with the largest superconductive energy gap measured to be Δ=19.5±1 meV, assuming a superconductor-insulator-superconductor junction. This energy gap corresponds to 2Δ/kBTc=4.8 at T=4 K, for a critical temperature of 93 K (midpoint of the resistive transition).

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Length-Independent Voltage Fluctuations In Small Devices, A. Benoit, C. P. Umbach, R. B. Laibowitz, Richard A. Webb Jun 1987

Length-Independent Voltage Fluctuations In Small Devices, A. Benoit, C. P. Umbach, R. B. Laibowitz, Richard A. Webb

Faculty Publications

Conductance fluctuations in one-dimensional lines of length L shorter than the phase-coherence length Lφ are not universal but diverge as L-2. Using the Onsager relations and voltage additivity, we show that the voltage fluctuations are independent of the distance between voltage probes. The antisymmetric (Hall-type) contribution to the voltage fluctuations is constant for all values of L. Measurements of the voltage fluctuations and correlation function between different regions in Au and Sb lines confirm these results.

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Some Aspects Of The Isogroup Of The Self-Dual Yang-Mills System, C. J. Papachristou, B. Kent Harrison Jun 1987

Some Aspects Of The Isogroup Of The Self-Dual Yang-Mills System, C. J. Papachristou, B. Kent Harrison

Faculty Publications

A generalized isovector formalism is used to derive the isovectors and isogroup of the self-dual Yang-Mills (SDYM) equation in the so-called J formulation. In particular, the infinitesimal "hidden symmetry'' transformation, a linear system, and a well-known Backlund transformation of the SDYM equation are derived in the process. Thus symmetry and integrability aspects of the SDYM system appear in natural relationship to each other within the framework of the isovector approach.

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Simulation Of Normal Rb2Zncl4 Near The Incommensurate Transition, P. J. Edwardson, V. Katkanant, John R. Hardy, L. L. Boyer Jun 1987

Simulation Of Normal Rb2Zncl4 Near The Incommensurate Transition, P. J. Edwardson, V. Katkanant, John R. Hardy, L. L. Boyer

John R. Hardy Papers

The purposes of the reported computer simulation of the normal (high-temperature) phase of rubidium tetrachlorozincate are to understand the disordered structure in that phase and to investigate the possibility that the transition, upon cooling, from the normal phase to one with an incommensurate modulation is associated with a change from the disordered structure to an ordered one. The simulation of the dynamics of 168 ions in a periodic structure begins from a slight perturbation of a structure that is determined by minimization of the potential energy within the constraints of the experimentally determined average symmetry. Rigid ions with short-range interactions …

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Comment On "Molecular Description Of Two-Electron Atoms", Anthony F. Starace, Joseph H. Macek Jun 1987

Comment On "Molecular Description Of Two-Electron Atoms", Anthony F. Starace, Joseph H. Macek

Anthony F. Starace Publications

Molecular Description of Two-Electron Atoms

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Synthetic Aperture Multi-Telescope Tracker Apparatus, Richard A. Carreras, Salvatore J. Cusumano, Morton B. Jenks, Robert I. Suizu May 1987

Synthetic Aperture Multi-Telescope Tracker Apparatus, Richard A. Carreras, Salvatore J. Cusumano, Morton B. Jenks, Robert I. Suizu

AFIT Patents

A plurality of telescopes provide output return signals which are applied both directly and in sampled form to a photo-detector cell. The detected signals from the photo-detector will represent the constant and transient errors of the telescope system. A low pass filter insures that the tracker provides only the constant or D.C. component of the error, while a high pass filter insures that the existing measuring devices for each telescope beam provide only the transient or A.C. component of the error. The A.C. and D.C. error signals are summed together with the appropriate applied gains on each channel such that …

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Variational Principles Of Fluid Mechanics And Electromagnetism: Imposition And Neglect Of The Lin Constraint, Ross Roundy Allen Jr. May 1987

Variational Principles Of Fluid Mechanics And Electromagnetism: Imposition And Neglect Of The Lin Constraint, Ross Roundy Allen Jr.

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Variational principles in classical fluid mechanics and electromagnetism have sprinkled the literature since the eighteenth century. Even so, no adequate variational principle in the Eulerian description of matter was had until 1968 when an Eulerian variational principle was introduced which reproduces Euler's equation of fluid dynamics. Although it successfully produces the appropriate equation of motion for a perfect fluid, the variational principle requires imposition of a constraint which was not fully understood at the time the variational principle was introduced. That constraint is the Lin constraint. The Lin constraint has subsequently been utilized by a number of authors who have …

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University Of Missouri--Rolla Cloud Simulation Facility: Proto Ii Chamber, Daniel R. White, James L. Kassner, John C. Carstens, Donald E. Hagen, John L. Schmitt, Darryl J. Alofs, Alfred Raymond Hopkins, Max B. Trueblood, Max W. Alcorn, William L. Walker May 1987

University Of Missouri--Rolla Cloud Simulation Facility: Proto Ii Chamber, Daniel R. White, James L. Kassner, John C. Carstens, Donald E. Hagen, John L. Schmitt, Darryl J. Alofs, Alfred Raymond Hopkins, Max B. Trueblood, Max W. Alcorn, William L. Walker

Physics Faculty Research & Creative Works

The Graduate Center for Cloud Physics Research at UMR has developed a cloud simulation facility to study phenomena occurring in terrestrial clouds and fogs. The facility consists of a pair of precision cooled-wall expansion chambers along with extensive supporting equipment. The smaller of these chambers, described in this article, is fully operational, and is capable of simulating a broad range of in-cloud thermodynamic conditions. It is currently being used to study water drop growth and evaporation for drops nucleated (activated) on well-characterized aerosol particles. Measurements have been made not only for continuous expansions (simulated updraft) but also for cyclic conditions, …

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Reduced-Mass Fock-Tani Representations For A+ + (B+C-) --> (A+C-) + B+ And First-Order Results For {Abc} = {Ppe, Epe, Μpμ, Μdμ, And Μtμ}, Jack C. Straton May 1987

Reduced-Mass Fock-Tani Representations For A+ + (B+C-) --> (A+C-) + B+ And First-Order Results For {Abc} = {Ppe, Epe, Μpμ, Μdμ, And Μtμ}, Jack C. Straton

Physics Faculty Publications and Presentations

The Fock-Tani transformation in the Jacobi three ⟶ two-body reduced-mass system is carried out and the first-order T matrix is found to be identical to that for the full three-body transformation. The Fock-Tani transformation in the reduced-mass system in which particle b is fixed at the origin is found to give a first-order T matrix with an error of mc /mb in the initial momentum wave function. First-order differential and total cross sections are calculated for a+ + (b+c-)⟶(a+c-) + b+ where |abc|= { …

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Enhanced Magnetism In Amorphous Fe-Based Alloys, Sy_Hwang Liou, S.H. Ge, J.N. Taylor, C.L. Chien Apr 1987

Enhanced Magnetism In Amorphous Fe-Based Alloys, Sy_Hwang Liou, S.H. Ge, J.N. Taylor, C.L. Chien

Sy-Hwang Liou Publications

Systematic investigations of binary amorphous Fe–T alloys (T=an early transition-metal elements Ti, Zr, Nb, Hf, Ta...) over wide composition ranges reveal depressed magnetic properties with anomalously low magnetic ordering temperature and magnetization. We show in this work, via a prototype amorphous Fe70Ti30 alloy, the substitution of Fe by Co, Ni, or Cu greatly enhances the magnetic ordering temperature and the magnetization. Our results indicate that this is primarily caused by the increased Fe moment upon alloying.

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Magnetic Properties Of Fe/Nd Multilayer Films, David J. Sellmyer, Z.R. Zhao, Z.S. Shan, S. Nafis Apr 1987

Magnetic Properties Of Fe/Nd Multilayer Films, David J. Sellmyer, Z.R. Zhao, Z.S. Shan, S. Nafis

David Sellmyer Publications

Measurements are reported on the relationship between magnetic properties and microstructure in thin amorphous and crystalline Fe/Nd multilayer films. The samples, denoted by (XÅFe/YÅNd) ( X/Y), were prepared in a multiple-gun sputtering chamber with a microprocessor-controlled rotating table. For X and Y values less than about 20 Å an amorphous compositionally modulated structure is obtained, with magnetic properties characterized by speromagnetic ordering associated with strong Nd random anisotropy. The net magnetization in general lies in the plane of the film. The temperature and composition dependence of the coercivity, magnetization, and transition temperatures are …

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Magnetism And Microstructure Of Compositionally Modulated Disordered Fe/Ta Films, Z.S. Shan, Z.R. Zhao, J.G. Zhao, David J. Sellmyer Apr 1987

Magnetism And Microstructure Of Compositionally Modulated Disordered Fe/Ta Films, Z.S. Shan, Z.R. Zhao, J.G. Zhao, David J. Sellmyer

David Sellmyer Publications

Results are presented on compositionally modulated disordered magnetic films of the form (XÅFe/YÅTa), as a function of the modulation wavelength λ≡X+Y. Magnetization, ac susceptibility, torque magnetometry, x-ray diffraction, and Mössbauer measurements are used to probe magnetic transitions and microstructure. For X and Y values less than about 12 Å the structure is amorphous within the layers and compositionally modulated in the direction perpendicular to the film. Films with ultrathin individual layers (1–3 atomic diameters) exhibit perpendicular anisotropy while the thicker ones have in-plane magnetization. Spin-glass and ferromagnetic transitions are observed and are …

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Magnetic Transitions And Scaling In Anisotropic Rare-Earth Glasses, Kevin M. Lee, Michael J. O'Shea, David J. Sellmyer Apr 1987

Magnetic Transitions And Scaling In Anisotropic Rare-Earth Glasses, Kevin M. Lee, Michael J. O'Shea, David J. Sellmyer

David Sellmyer Publications

We report studies of the magnetic critical behavior as a function of anisotropy strength in rare-earth-rich glasses. Anisotropy is induced in Gd-Co by alloying with Tb. The system studied is Gd65-xTbxCo35 and the random magnetic anisotropy (RMA) strength may be increased by increasing x. The x=0 alloy of this series has been shown to exhibit standard critical behavior expected for a second-order phase transition. With increasing x we find deviations from this behavior due to the presence of RMA. We present detailed results for the alloy with composition x=50 at. % and …

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Magnetic Granular Fe-(Sio2) Solids, C.L. Chien, Gang Xiao, Sy_Hwang Liou, J.N. Taylor, A. Levy Apr 1987

Magnetic Granular Fe-(Sio2) Solids, C.L. Chien, Gang Xiao, Sy_Hwang Liou, J.N. Taylor, A. Levy

Sy-Hwang Liou Publications

We have synthesized a series of granular Fe-SiO2 solids consisting of Fe metal granules of nanometer sizes embedded in an insulating SiO2 matrix. The ultrafine microstructures, revealed by TEM, are achieved by using a high-rate magnetron sputtering system. The magnetic properties of such solids are determined by the granular size and the metal volume fraction. Below the percolation threshold, isolated single-domain particles having large magnetic coercivity in the blocked state exhibit superparamagnetic relaxation, which has been studied by using SQUID magnetometry and Mössbauer spectroscopy. Above the percolation threshold, magnetic coercivity drops dramatically and the magnetic properties approach that …

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Mössbauer Study Of Spin Reorientation In Y1.8Er0.2Fe14B, M. Abe , Sy_Hwang Liou, C.L. Chien, N.C. Koon, B.N. Das, E. Callen Apr 1987

Mössbauer Study Of Spin Reorientation In Y1.8Er0.2Fe14B, M. Abe , Sy_Hwang Liou, C.L. Chien, N.C. Koon, B.N. Das, E. Callen

Sy-Hwang Liou Publications

Fe57 Mössbauer spectra were taken from 300 K down to 4.2 K for two single-crystal samples of Y1.8Er0.2Fe14B, one cut with its [001] axis normal to the surface, the other with its diagonal of [100], [010], and [001] axes normal to the surface. The former sample has shown that the angle between the Fe spin and the [001] increases continuously below ~90 K. This qualitatively agrees with the spin reorientation (i.e., the easy axis of magnetization rotates away from the [001] toward [100] on cooling below ~90 K) which have already been observed …

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Magnetic Characteristics Of Ultrafine Fe Particles Reduced From Uniform Iron Oxide Particles, K. Bridger, J. Watts, M. Tadros, Gang Xiao, Sy_Hwang Liou, C.L. Chien Apr 1987

Magnetic Characteristics Of Ultrafine Fe Particles Reduced From Uniform Iron Oxide Particles, K. Bridger, J. Watts, M. Tadros, Gang Xiao, Sy_Hwang Liou, C.L. Chien

Sy-Hwang Liou Publications

Uniform, cubic 0.05-µm iron oxide particles were formed by forced hydrolysis of ferric perchlorate. These particles were reduced to α-Fe by heating in hydrogen at temperatures between 300 and 500 °C. The effect of reduction temperature and various prereduction treatments on the microstructure of the iron particles will be discussed. Complete reduction to α-Fe was established by 57Fe Mössbauer spectroscopy and x-ray diffraction. Magnetic measurements on epoxy and polyurethane films containing these particles with various mass fractions gave coercivities as high as 1000 Oe. The relationship between the magnetic measurements and the microstructure will be discussed. Na2SiO …

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Radiosensitivity Parameters For Neoplastic Transformations In C3h10t1/2 Cells, M. P. R. Waligorski, G. L. Sinclair, Robert Katz Apr 1987

Radiosensitivity Parameters For Neoplastic Transformations In C3h10t1/2 Cells, M. P. R. Waligorski, G. L. Sinclair, Robert Katz

Robert Katz Publications

We have evaluated radiosensitivity parameters for cellular transformation from published experimental data on neoplastic transformations induced in C3H10T1/2 cells by BEVALAC ions. The measured RBE values are well reproduced by a track theory calculation using sets of m-target parameters with either m = 2 or m = 3, suggesting a quadratic or cubic extrapolation to low doses of γ rays. Using track theory one is thus able to predict transformation frequencies in those cells after an arbitrary radiation field, under known or assumed conditions of exposure, in a manner shown earlier for cellular survival. Extension of these calculations to interpret …

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The Breakdown Of Hund's Rule In Systems Of Fourfold Symmetry, Gordon A. Gallup Apr 1987

The Breakdown Of Hund's Rule In Systems Of Fourfold Symmetry, Gordon A. Gallup

Gordon Gallup Publications

The lowest energies of molecular systems with fourfold symmetry can violate Hund's multiplicity rule. We derive relationships between two electron integrals that in favorable cases allow one to predict when this will happen. These relationships result in a fairly simple inequality as a criterion. The systematics of the phenomenon are illustrated with a series of calculations on model systems consisting of hydrogen atoms. These are rings of three, four, five, six, seven, and eight members as well as octahedral and square planar arrangements. These show how the results and simple ideas of molecular orbital theory can be qualitatively modified when …

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Excitation Of The Isobaric Analog State Of ¹⁶⁵Ho By Pion Single-Charge Exchange, William J. Fickinger Apr 1987

Excitation Of The Isobaric Analog State Of ¹⁶⁵Ho By Pion Single-Charge Exchange, William J. Fickinger

Faculty Scholarship

Forward-angle differential cross sections for the 165Ho(π+,π0)165Er(IAS) reaction have been measured at Tπ=98.0, 163.2, and 228.3 MeV in the angular range & ≲14°. The shapes of the angular distributions at 98.0 and 163.2 MeV are compared to predictions arising from the strong absorption model of pion single-charge exchange scattering. Extrapolated 0° cross sections are compared with trends previously established with mostly spherical and near-spherical nuclei. The measurement demonstrates the possibility of using the (π+,π0) reaction for studying neutron density deformations in oriented 165Ho.

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Testing Of Beam Line For Charge Exchange Measurements, Mohd. Noor Ali Apr 1987

Testing Of Beam Line For Charge Exchange Measurements, Mohd. Noor Ali

Masters Theses

The atomic physics beam line in the Western Michigan University accelerator laboratory was tested for the first time for making atomic charge-exchange experiments. Cross sections obtained for single electron capture and loss for 25 MeV oxygen ions incident on a helium gas target are in reasonable agreement with previous measurements. These results indicate that the system is operating properly. An attempt to observe a nuclear resonance effect on electron capture and/or loss was not successful. However, it was determined that additional collimation is necessary for such measurements.

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