Physical Sciences and Mathematics Commons^™

Homogeneous Nucleation Rate For Water, Donald E. Hagen, James L. Kassner

Physics Faculty Research & Creative Works

Homogeneous nucleation rate data for water extending over an exceptionally large domain of rate (J), supersaturation ratio (S), and temperature (T) was recently published. Because it spans a large J-S-T surface, this data constitutes a good test of nucleation theory. Here classical nucleation theory is used to analyze this data. By adjusting only the sticking coefficient, we are able to obtain a good fit between theory and experiment. It was necessary to include an increase in the water molecular density associated with the finite water compressibility.

Preparation And Characterization Of Composite Hollow Fiber Reverse Osmosis Membranes By Plasma Polymerization. 2. Reproducibility Of The Plasma Polymerization Process And Durability Of The Resulting Coated Membrane, Y. Matsuzawa, H. Yasuda

Chemistry Faculty Research & Creative Works

The reproducibility of the plasma polymerization process was examined in a semicontinuous coating of hollow fibers, 6 fibers in lengths of approximately 12-15 m, by evaluating the performance of reverse osmosis membranes. The uniformity of the coating along the length of hollow fibers, as well as the reproducibility of the process, was found to be satisfactory when electrodes were conditioned in the actual conditions of plasma polymerization to be employed and plasma polymerization conditions were carefully controlled. The durability of the coated hollow fibers was then investigated in the following test media: hot water, low pH, high pH, and 0.1% …

Preparation And Characterization Of Composite Hollow Fiber Reverse Osmosis Membranes By Plasma Polymerization. 1. Design Of Plasma Reactor And Operational Parameters, P. J. Heffernan, K. Yanaglhara, Y. Matsuzawa, E. E. Hennecke, E. W. Hellmuth, H. Yasuda

Chemistry Faculty Research & Creative Works

Composite hollow fiber reverse osmosis membranes were prepared by depositing a thin layer (10-50 nm) of plasma polymers on hollow fibers with porous walls (made of polysulfone). The coating was carried out in a semicontinuous manner with six strands of substrate fibers. Operational parameters which influence reverse osmosis characteristics of composite membranes were investigated. © 1984, American Chemical Society. All rights reserved.

Magnetic Phase Diagram And Spin Glass Behavior Of Fe₁₋ₓmnₓcl₂·2h₂O, Gary C. Defotis, Christoph Pohl, Spencer A. Pugh, Ekkehard Sinn

Chemistry Faculty Research & Creative Works

The magnetic phase diagram of Fe_1-xMn_xCl₂·2H₂O has been determined. A tetracritical point appears to be present at x ≊ 0.74 and T≊2.8 K. The upper paramagnetic-antiferromagnetic phase boundaries exhibit an unusually rapid descent, and the mixed ordered region below the tetracritical point is quite small. Moreover, regions exhibiting spin glass character also occur in the diagram. The unusually complex behavior is presumably due to the unique constitution of this system: A mixture of two antiferromagnets with different periodicities, competing orthogonal spin anisotropics, competing ferromagnetic and antiferromagnetic near neighbor intrachain exchange interactions, and …

Elastic Differential Cross Sections For Small-Angle Scattering Of 25-, 40-, And 60-Kev Protons By Atomic Hydrogen, Eduard P. Rille, Jerry Peacher, E. Redd, Thomas J. Kvale, Denver G. Seely, D. M. Blankenship, Ronald E. Olson, John T. Park

Physics Faculty Research & Creative Works

Elastic angular differential cross sections for small-angle scattering of protons by atomic hydrogen have been measured. The technique utilized unambigously distinguishes the elastically and inelastically scattered ions. The cross sections fall monotonically by 3 orders of magnitude in the angular range from 0.5 to 3.0 mrad, in the center-of-mass system. The experimental data obtained are in very good agreement with a multistate calculation and in fair agreement with both our Glauber-approximation and classical-trajectory Monte Carlo results.

An Improved Algorithm For Generating Minimal Perfect Hash Functions, Thomas J. Sager

Computer Science Technical Reports

A minimal perfect hash function (MPHF) is a function from a set of M objects to the first M non-negative integers. MPHF's are useful for the compact storage and fast retrieval of frequently used objects such as reserved words in a programming language or commonly employed words in a natural language. In this paper we improve on an earlier result and present an algorithm for generating MPHF's with an expected time complexity proportional to M⁴. We also give a MPHF for the 256 most frequently used words in the English language.

Parallelism In The Language, Natural, Thomas J. Sager

Computer Science Technical Reports

Natural is a language designed to provide a vehicle for the expression of abstract programming concepts clearly and precisely in a natural and mathematical form. The concept of parallelism can be expressed both explicitly and implicitly in the language, Natural. Due to relative freedom from side-effects and the use of a special value, undef, subexpressions can often be evaluated in parallel. The for and do statements both allow for a parallel mode of execution. A builtin functional, prlleval, creates functions which can evaluate their arguements in a parallel mode. In addition, the concept of module allows for the definition of …

A New Method For Generating Minimal Perfect Hash Functions, Thomas J. Sager

Computer Science Technical Reports

A perfect hash function, PHF, is an injection, F, from a set, W, of M objects into the set consisting of the first N non-negative integers where N>=M. If N=M then F is a minimal perfect hash function, MPHF. PHFs are useful for the compact storage and fast retrieval of frequently used objects such as reserved words in a programming language or commonly employed words in a natural language.

The mincycle algorithm for finding PHFs executes with an expected time complexity proportional to M⁴ and has been used successfully on sets of cardinality up to 256. The mincycle …

Additional Remarks To The Schrödinger Spin‐Exchange Ferromagnet, Harry A. Brown

Physics Faculty Research & Creative Works

No abstract provided.

Ciegen: A System For Testing Knowledge Base Compilation Heuristics On A Microcomputer, Jayne D. Ward

Masters Theses

"The expert system has proven itself to be a valuable aid in diagnosing and treating problems in domains requiring expertise. The commercial world has been alerted to this fact and the thrust is to make the expert system portable and available on small computers.

The goal of this research has been to lay the groundwork for a domain independent expert system builder on a microcomputer. The result of this effort was CIEGEN, a system consisting of a rule compiler, inference engine, and rule generator developed on the IBM PC. It is domain independent, responsible for transforming a knowledge base of …

Non-Linear Oscillation, Automodulation And Anelasticity, Tetsuro Suzuki, Manfred Wuttig

Physics Faculty Research & Creative Works

The auto modulation observed in the course of internal friction is discussed as a special example of the universal nature of non-linear oscillations. Universal features of non-linear oscillations are the requirement of energy supply or negative damping and the period doubling route to chaos. The negative damping responsible for the auto modulation is described in terms of the soliton model for twinning deformation. © 1984 The Japan Society of Applied Physics.

A Three-Spin Interaction Model, Harry A. Brown

Physics Faculty Research & Creative Works

A three-spin interaction in the form of a box product, σ1 x σ2 · σ3, is considered. The thermodynamic behavior is investigated using an effective field theory. A second-order phase transition is found and the magnetization and energy per spin appear to be very similar to those of an ordinary Heisenberg ferromagnet. © 1984.

Electron-Ion Recombination In Gas Mixtures Of Helium, Nitrogen, And Carbon Dioxide, Ian M. Littlewood, M. C. Cornell, Kaare J. Nygaard

Physics Faculty Research & Creative Works

A study has been conducted to determine the electron-ion recombination rates in gas mixtures of helium, nitrogen, and carbon dioxide. Measurements were made as functions of electric field strength, gas pressure, and gas composition. In gas mixtures containing only nitrogen and carbon dioxide, the rates were dependent on pressure. This dependence is interpreted as being due to the separate effects of two- and three-body recombination processes. No pressure dependence was observed for mixtures containing helium. In such mixtures, two-body recombination appears to be dominant. Moreover, the addition of relatively low concentrations of helium to the discharge leads to a dramatic …

Magnetic And Crystallographic Structure Of Y₆Mn₂₃D₂₃, K. A. Hardman-Rhyne, James J. Rhyne, E. Prince, Cyrus E. Crowder, William Joseph James

Chemistry Faculty Research & Creative Works

The magnetic behavior of Y6Mn23 is dramatically altered upon hydrogenation (or deuteration). In this study it has been found, by means of high-resolution powder diffraction and Rietveld refinement techniques, that the crystallographic structure is distorted from face-centered cubic (Fm3m) at 295 K to a primitive tetragonal structure at 4 K in which deuterium atoms are atomically ordered. Y6Mn23 is a ferromagnetic compound with Tc=486 K, and bulk magnetization of 13.2 Bf.u. (formula unit). After deuteration of Y6Mn23 to the composition Y6Mn23D23, low-temperature scattering data (T<180 K) show that the b and f2 sites in the Fm3m structure are antiferromagnetic and the d and f1 sites have no spontaneous magnetic moment. © 1984 The American Physical Society.

Composition Of Regenerated Cell Walls Of Reverting Aureobasidium Pullulans Protoplasts, D. R. Quigley, Donald J. Siehr

Chemistry Faculty Research & Creative Works

Protoplasts of Aureobasidium pullulans, formed by treating normal blastospores with polysaccharide-hydrolizing enzymes, synthesized glycans when incubated in shallow culture. The polysaccharides formed a loose, thick coating on the cells. The glycans that were formed are similar to the glycans in normal cell walls; however, they lack the branching that is normally found. This result is consistent with the findings of others who have studied the cell wall composition of reverting yeast protoplasts.

Molecular Motion And Phases In An Equimolar Phosphatidylcholine/Ethylene Glycol System, David W. Larsen, Shankar B. Rananavare, Frank E. Stary, Magda Elnokaly, Stig Friberg

Chemistry Faculty Research & Creative Works

An equimolar mixture of phosphatidylcholine and ethylene glycol was studied by pulsed proton NMR at temperatures between 100 and 430 K. Relaxation times T1, T1ρ, and T1D, and second moments, M2, were measured. The system is lamellar liquid crystalline at room temperature, but at least four phases are present within the temperature range studied. Phase transitions were confirmed by DSC. Activation barriers were estimated for methyl reorientation, choline group motion, and chain motion. Models to describe the various motions and the role of spin diffusion are discussed. The relationship of the parameters for the present system to those for the …

A Lamellar Liquid Crystal As An In Situ Surface Balance. I. The Conformation Of 5- (And 6-)Carboxy-4-Hexyl-2-Cyclohexene-1-Yl Octanoic Acid And Its Monosoap, Tony Flaim, Stig Friberg

Chemistry Faculty Research & Creative Works

The interfacial conformation of a dicarboxylic acid, 5- (and 6-)carboxy-4-hexyl-2-cyclohexene-1-yl octanoic acid, and its monosodium soap was determined from the change of liquid crystal dimensions after introduction of the diacid compounds. The results showed that both functional groups of the Mono soap form were present at the interface and that increased water content of the liquid crystal matrix had little effect on the conformation of the Mono soap. On the other hand, the results indicated the conformation of the diacid as such to depend on the water content of the matrix. At low water content, the diacid form was in …

Single Compound Forming A Lyotropic Liquid Crystal At Room Temperature, Stig Friberg, Paul Liang, Frances E. Lockwood, Maher Tadros

Chemistry Faculty Research & Creative Works

The compound triethanolammonium oleate forms a lamellar liquid crystal at room temperature. The basis for the lyotropic mesomorphism is the fact that part of the triethanolammonium oleate has changed to triethanolamine and oleic acid. These two compounds serve as solvents in the liquid crystalline structure. © 1984 American Chemical Society.

Solubilization Of Calcium Dodecyl Sulfate In A Micellar Solution And In Lamellar Liquid Crystal, Stig Friberg, David W. Osborne

Chemistry Faculty Research & Creative Works

Calcium dodecyl sulfate (CDS) was solubilized in the aqueous micellar solution of sodium dodecyl sulfate and in the lamellar liquid crystal obtained from water, sodium dodecyl sulfate and decanal. The solubilization of CDS in the micellar solution was strongly increased with the concentration of sodium dodecyl sulfate while the maximum amount of CDS solubilized in the liquid crystal remained similar. The solubilization in the micellar solution was gradually increased with the alcohol content with a sudden reduction to zero at the decanol/sodium-dodecyl-sulfate ratio marking the end of the micellar region with no calcium soap being present. The dependence of the …

Alignment Of A Nonaqueous Lyotropic Liquid Crystalline Phase With Lecithin, David W. Larsen, Shankar B. Rananavare, Stig Friberg

Chemistry Faculty Research & Creative Works

No abstract provided.

A Focus Of Attention Algorithm For Expert Systems, Kevin W. Whiting

Masters Theses

"This research is primarily concerned with increasing the performance of expert systems. A refined focus of attention strategy and its affect on performance are discussed. Early expert systems used a brute force approach to process the knowledge base. Each production rule in the knowledge base was evaluated each cycle. More recently, processing efficiency has been increased by focusing the attention of the inference engine on a subset of the rules by "filtering" for further testing, only rules that could possibly fire given the current content of the context base. Focus of attention as developed in this research increases performance over …

Lyotropic Liquid Crystals From Lecithin, Water, And Polyethylene Glycol, Magda El Nokaly, Stig Friberg, David W. Larsen

Chemistry Faculty Research & Creative Works

Lyotropic liquid crystals with lecithin as the amphiphile and with water/polyethylene glycol (PEG) solutions as the solvent were prepared with polyethylene glycol/water ratios from 182 to 0. The liquid crystals were lamellar and the interlayer spacing was independent of the solvent content for water/PEG ratios ≤1 but increased strongly with the water/PEG ratio. Higher ratios gave increased interlayer spacing with solvent content similar to the variation for liquid crystals with water as solvent but the absolute values of the spacing were higher. © 1984 Academic Press, Inc. All rights reserved.

Order Parameters Of Hydrocarbons Solubilized In A Lamellar Liquid Crystal, Anthony J.I. Ward, Stig Friberg, David W. Larsen, Shankar B. Rananavare

Chemistry Faculty Research & Creative Works

A preliminary study of the 2H NMR spectrum of n-hexadecane-d34 solubilized in the lamellar phase of tetra ethylene glycol n-dodecyl ether has been made as a function of solubilization content. Complex spectra comprising eight overlapping powder spectra were observed, which showed a complex oil concentration dependence. These spectra were unusually rich in detail and indicate a considerably higher degree of complexity than has earlier been reported for solubilized hydrocarbons. The derived order profile was found to be different from that normally found for amphiphiles in lamellar environments. A tentative model involving some penetration of solubilize molecules between the host amphiphiles …

Approximate Tolerance Limits And Confidence Limits On Reliability For The Gamma Distribution, Lee J. Bain, Max Engelhardt, Wei Kei Shiue

Mathematics and Statistics Faculty Research & Creative Works

No abstract provided.

Aphasia After Left Thalamic Infarction, Philip B. Gorelick, Daniel B. Hier, Louis Benevento, Susan Levitt, Walter Tan

Chemistry Faculty Research & Creative Works

We Examined a 70-Year-Old Woman Who Became Aphasic after a Left Thalamic Infarction. Computed Tomographic Scan Showed Injury that Was Largely Limited to the Ventral Anterior and Rostral Ventral Lateral Thalamic Nuclei. Speech Was Characterized by Reduced Voice Volume, Impaired Auditory and Reading Comprehension, Perseverations, Intermittent Use of Jargon, Fluctuations in the Ability to Perform Confrontation Naming, Extraneous Intrusions, Verbal Paraphasia, Intact Repetition Skills, and Fluent Speech that Was Laconic But Grammatically Correct. We Propose that the Deficits after Left Thalamic Injury Can Be Grouped into the Following Four Large Clusters: Extrapyramidal Deficits (Decreased or Fading Voice Volume), Deficits in …

Dipole Moment And Potential Energy Functions Of The X ¹Σ + And A 1Σ+ States Of Nah, W. T. Zemke, Ronald E. Olson, K. K. Verma, W. C. Stwalley, B. Liu

Physics Faculty Research & Creative Works

Calculated radiative transition probabilities between all vibrational levels in the X 1Σ+ state (υ=0-21) and in the A 1Σ+ state (υ=0-32) of NaH are given. In addition, the calculated spontaneous emission lifetimes for vibrational- rotational levels (J=0,1) and the calculated dipole moments for these same levels are given. The calculations use new hybrid potential energy curves based on Rydberg-Klein-Rees (RKR) and ab initio potential curves. The RKR curve for the X state is new. The calculations use new ab initio dipole moment functions of internuclear distance. © 1984 American Institute of Physics.

Resonant Electron Transfer And Excitation In Two-, Three-, And Four- Electron Caq +20 And Vq +23 Ions Colliding With Helium, J. A. Tanis, E. M. Bernstein, W. G. Graham, M. P. Stockli, M. Clark, Robert H. Mcfarland, T. J. Morgan, K. H. Berkner, A. S. Schlachter, J. W. Stearns

Physics Faculty Research & Creative Works

Significant new evidence is reported for resonant transfer and excitation in ion-atom collisions. This process, which is analogous to dielectronic recombination, occurs when a target electron is captured simultaneously with the excitation of the projectile followed by photon emission. Strong resonant behavior with structure, in agreement with theoretical calculations, is observed in the cross section for projectile K x rays coincident with single electron capture for 100-360-MeV Ca16+,17+,18+20 and 180-460-MeV V19+,20+,21+23 ions colliding with helium. © 1984 The American Physical Society.

Molecular-State Cross-Section Calculations For H+Csh-+Cs+, Ronald E. Olson, M. Kimura, H. Sato

Physics Faculty Research & Creative Works

Pseudopotential molecular-structure calculations have been used to obtain the seven lowest 1 and 1 states of CsH. These states and their associated radial and rotational coupling terms have been used to calculate the cross sections for H-+Cs+ ion-pair production in H+Cs(6s) and H+Cs*(6p) collisions at energies from 0.1 to 10 keV. The ion-ion mutual neutralization cross section, H-+Cs+ H+Cs, is also presented. The cross-section calculations were done with the perturbed-stationary-state method, modified to include two-electron translation factors. The ion-pair production cross section for ground-state reactants is in good agreement with experiment; collisions of H with excited Cs*(6p) show an order-of-magnitude …

The Homogeneous Nucleation Of Nonane, G. W. Adams, John L. Schmitt, R. A. Zalabsky

Physics Faculty Research & Creative Works

The homogeneous nucleation rate of n-nonane has been measured as a function of temperature and supersaturation ratio in a precision fast-expansion chamber. The measured nucleation rate ranges from 102 to 105 drops/cm3 over the temperature range 215-270 K. The results have been compared to the classical theory and to the classical theory with the RKC replacement factor. The RKC theory functional form is the basis for an empirical rate equation to fit the data. A full listing of the thermodynamic constants used for the reduction of the data is given. © 1984 American Institute of Physics.

A Graphical Representation Of An Executing Program, Sherry A. Lile

Masters Theses

"This thesis describes the rationale for a computer program used as a teaching aid, as well as, the design, development, and implementation of that computer program. The program is a prototype that displays, line by line, a graphical depiction of a BASIC program being executed. Icons are used to represent FOR-NEXT loops, the contents of variables, I/O, and other programming elements. The internal logic associated with the Arithmetic-Logic Unit is also represented. The purpose is to produce an environment where the student may visualize the processes occurring in memory by viewing a symbolic portrayal of an executing program. The example …