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Articles 3661 - 3690 of 3691

Full-Text Articles in Physical Sciences and Mathematics

New Thin-Film Tunnel Triode Using Amorphous Semiconductors, Pavel Smejtek, R. F. Shaw, H. Fritzsche, M. Silver, S. Holmberg, S. R. Ovshinsky Apr 1972

New Thin-Film Tunnel Triode Using Amorphous Semiconductors, Pavel Smejtek, R. F. Shaw, H. Fritzsche, M. Silver, S. Holmberg, S. R. Ovshinsky

Physics Faculty Publications and Presentations

A new thin‐film tunnel triode is discussed which uses a p‐type amorphous film to achieve amplification of injected current from a tunnel cathode. It is not only the basis for a new semiconductor device but also suggests a novel method for measuring electrical properties of semiconductors.


Studies Of Bistable Fluid Devices For Particle Flow Control, Gerald H. Hogland Feb 1972

Studies Of Bistable Fluid Devices For Particle Flow Control, Gerald H. Hogland

Dissertations and Theses

This study was directed toward the development of a bistable wall attachment Flip-Flop device which was capable of directionally controlling particle flow. The particles were transported by a fluid stream which under the influence of wall attachment. The dominant criteria in the development of the device was the achievement of the highest recovery of particles at the active output, without destroying the wall attachment of the fluid stream The experiment was conducted in several distinct stages; each of which was concerned with at least one aspect of wa1l attachment or particle flow. Results derived from one test were used to …


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

Catechol Effected Dissolution Of Silicate Minerals, James Maurice Kelley

Dissertations and Theses

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

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

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


A Review Of "Longitudinal Study" In Developmental Psychology, Emily H. Finley Jan 1972

A Review Of "Longitudinal Study" In Developmental Psychology, Emily H. Finley

Dissertations and Theses

The purpose of this library research thesis is to review the "longitudinal study" in terms of problems and present use. A preliminary search of the literature on longitudinal method revealed problems centering around two areas: (1) definition of "longitudinal study" and (2) practical problems of method itself. The purpose of this thesis then is to explore through a search of books and journals the following questions:

1. How can “longitudinal study” be defined?

2. What problems are inherent in the study of the same individuals over time and how can these problems be solved?

A third question which emerges from …


Reaction Of Aqueous Catechol Solutions With Minerals, Boonthong Poocharoen Jan 1972

Reaction Of Aqueous Catechol Solutions With Minerals, Boonthong Poocharoen

Dissertations and Theses

The effectiveness of catechol, an aromatic vic-diol, in dissolving silicate minerals was studied. A synthetic amorphous magnesium trisilicate, Mg₂Si₃O₈∙5H₂O, as well as the minerals olivine, sepiolite, diopside, augite, and enstatite were used to react with catechol in slightly acidic, basic, and neutral solutions. It was found, depending on the solvent used, that 33-52, 8-17, 14-30, 5-11, 3-6, and 0.5-1 % of the minerals dissolved, respectively.

The reaction with Mg₂Si₃0₈·5H₂0 resulted in the formation of crystals of magnesium tris (catecholato) siliconate nonahydrate Mg[Si(Cat)₃]∙9H₂0. Dehydration of the crystals at room temperature resulted in the loss of 6 moles of water to form …


The Geology Of The Southeast Quarter Of The Bone Mountain Quadrangle, Oregon, Richard Cortland Kent Jan 1972

The Geology Of The Southeast Quarter Of The Bone Mountain Quadrangle, Oregon, Richard Cortland Kent

Dissertations and Theses

This thesis is a study of the geology of the southeast quarter of the Bone Mountain Quadrangle. The bedrock geology mapped includes about 56 square miles.The Klamath Mountain and Coast Range Provinces of southwestern Oregon are represented in the area. Rocks in the area include the Rogue, Dothan Riddle, Days Creek, upper member of the Umpqua and Tyee Formations. The ages of these rocks range from Late Jurassic to middle Eocene. Late Jurassic ultramafic and mafic intrusive rocks associated with the Rogue Formation occur in the Klamath Province. The metavolcanics of the Rogue Format ion and an associated linear belt …


Kinetics Of The Cope Rearrangement Of 3,4-Diphenylhexa-1,5-Diene, Harlan Albert Jerome Berg Jan 1972

Kinetics Of The Cope Rearrangement Of 3,4-Diphenylhexa-1,5-Diene, Harlan Albert Jerome Berg

Dissertations and Theses

Kinetics investigations of the thermal Cope rearrangement of meso-and d1-3,4-diphenylhexa-1,5-dienes were undertaken in order to gain information about the transition states for these reactions by determining the appropriate enthalpies and entropies of activation. Of particular interest were the activation parameters for the meso compounds' rearrangement as it represents the only known example in which both four-and six-centered transition states are of comparable energy.

Kinetics of the dl isomers' rearrangement in the temperature range 90-110⁰were determined using 5 X 10¯⁵M solutions of the olefin in heptane contained within sealed Pyrex ampules. Extents of reaction were determined from UV absorbance measurements at …


On The Mechanism Of The Diels-Alder Reaction--Dimerization Of Trans-Phenylbutadiene, Michael Ward Mcnicholas Jan 1972

On The Mechanism Of The Diels-Alder Reaction--Dimerization Of Trans-Phenylbutadiene, Michael Ward Mcnicholas

Dissertations and Theses

The Diels-Alder dimerization of trans-1-substituted butadienes is expected to yield a cyclohexene adduct with the substituents in the 3 and 4 positions cis to one another. This prediction is based on past observations of other Diels-Alder additions. The cis-isomer is the only one consistent with a two-stage mechanism proposed by Woodward and Katz.

In the case of trans-phenylbutadiene, the expected adduct is cis-3-phenyl 1-4-(trans-styry1) cyclohexene. Alder, Haydn and Vogt, however, reported that the corresponding trans-isomer is the dimerization product. There is reason to believe that the observation of the trans-isomer may have been the result of product isomerization during purification. …


Adsorption Of Sulfur Dioxide On Douglas Fir Woodchips, Uen-Ping David Wang Dec 1971

Adsorption Of Sulfur Dioxide On Douglas Fir Woodchips, Uen-Ping David Wang

Dissertations and Theses

In recent years, people have raised their alertness to the hazard of air pollution. Sulfur dioxide is one of the most dangerous chemical compounds among those air pollutants. A study on removing sulfur dioxide from an air stream by adsorption using wood chips as the adsorbent is presented in this thesis. The reason for using wood as an adsorbent is that wood is a porous material and possesses a large surface of cell cavities which can hold a great amount of moisture. As sulfur dioxide gas is passed through the wood bed, it would be either condensed in the cell …


Comment On Electron Scattering In The Image Potential Well, Pavel Smejtek, M. Silver Oct 1971

Comment On Electron Scattering In The Image Potential Well, Pavel Smejtek, M. Silver

Physics Faculty Publications and Presentations

Comments are made on the model of electron injection into SiO₂ proposed by Berglund and Powell. Their assumptions on electron scattering, disregarding the change of the escape cone with the distance from the emitter, lead to serious underestimation of the injected current. Two alternative models of electron injection, based solely on elastic scattering are discussed and do not predict the experimental results. We suggest that observed field dependence of the injected current into SiO₂ indicates that energy relaxation associated with the injected electrons is responsible for the voltage dependence of the current.


Evidence For The Existence Of Two Stable Sites For Cobalt Impurity Atoms In Aluminum, Arun Venkatachar Aug 1971

Evidence For The Existence Of Two Stable Sites For Cobalt Impurity Atoms In Aluminum, Arun Venkatachar

Dissertations and Theses

Using Fe57Mössbauer spectroscopy, two alternative sites occupied by cobalt (10-4 at. % ) impurity atoms in aluminum have been isolated. The substitutional site A is the stable position after annealing the sample above 840 K, followed by a rapid quench. The impurity atoms in site A are characterized by a single line Mössbauer spectrum (indicative of a cubic environment), a room-temperature f = 0.502 (r. m. s. displ. 0.071 A) and an I. S. (reI. to Fe) = -0.421 mm/sec. For anneals below 770 K the cobalt atoms migrate to site B, which is characterized by a …


On The Molecular Theory Of Dielectric Polarization In Rigid‐Dipole Fluids, John D. Ramshaw Aug 1971

On The Molecular Theory Of Dielectric Polarization In Rigid‐Dipole Fluids, John D. Ramshaw

Physics Faculty Publications and Presentations

A molecular theory is developed for the polarization P(r) produced by a weak position‐dependent external electric field E0(r) in a finite fluid system, of arbitrary shape, composed of rigid polar molecules. The theory differs from earlier work in that no assumption is made concerning the form of the electrostatic constitutive relation. [The usual assumption in this regard is that P(r) = (ε–1) E(r) / 4π, where E(r) is the total Maxwell electric field. The “dielectric constant” ε is well defined only if the relation between P(r) and E(r) …


Crystal Structure Determination Of Β-Lactoglobulin From Electron Micrographs, Richard Roeter Jul 1971

Crystal Structure Determination Of Β-Lactoglobulin From Electron Micrographs, Richard Roeter

Dissertations and Theses

Often electron micrographs exhibit a repeating structure. Sometimes this repeating structure satisfies the definition of a crystal in that it has a three dimensional repeating structure. If the unit cell structure of this repeating structure can be determined it can be used to help categorize different sections of a particular sample. In some cases, the use of optical diffraction analysis of electron micrographs with repeating structure is a method of determining the unit cell structure.

Samples of β-Lactoglobulin were prepared for viewing in the electron microscope using both the crystalline material and carbon replicas of the crystal surface. Because the …


Dielectric Polarization And Alignment And The Structure Of Polar Fluids, John D. Ramshaw, D. W. Schaefer, John S. Waugh, J. M. Deutsch Feb 1971

Dielectric Polarization And Alignment And The Structure Of Polar Fluids, John D. Ramshaw, D. W. Schaefer, John S. Waugh, J. M. Deutsch

Physics Faculty Publications and Presentations

An analysis is made of the information about the structure of dense polar fluids which resides in the dielectric constant, the Kerr constant, and the nuclear magnetic resonance (NMR) quadratic electric field effect. The inadequacy of the "local-field" model for liquids is discussed. The existence of a nonzero molecular hyperpolarizability is shown to destroy an equivalence which would otherwise exist between the Kerr and NMR experiments, and can easily account for apparent discrepancies between the reported Kerr and NMR data for nitrobenzene and nitromethane. A method is presented for removing dielectric boundary effects from statistical averages, so that the averages …


Geophysical And Geological Analysis Of A Fault-Like Linearity In The Lower Clackamas River Area, Clackamas County, Oregon, Ronald Jay Schmela Jan 1971

Geophysical And Geological Analysis Of A Fault-Like Linearity In The Lower Clackamas River Area, Clackamas County, Oregon, Ronald Jay Schmela

Dissertations and Theses

A fault-like linearity along the lower Clackamas River is evaluated by analysis of physiographic and structural alignments, geological relationships, and by gravity and magnetic data. The study has resulted in the verification of a structural feature extending along the Clackamas River and the eastern front of the Portland Hills. Physiographic alignments were examined in twelve 15 minute and two 7-1/2 minute quadrangle maps. A significant northeasterly morphologic trend, N. 20⁰ W. and N. 40° W., and other secondary trends, namely, the N-S, E-W, and N. 50-60° E., has developed in the Portland area. The consistent northwest trend is observed throughout …


MöSsbauer Studies Of Stable Interstitial And Substitutional Sites Of Cobalt In Gold, Charles Freeland Steen Jan 1971

MöSsbauer Studies Of Stable Interstitial And Substitutional Sites Of Cobalt In Gold, Charles Freeland Steen

Dissertations and Theses

Precision measurements of the Debye-Waller factor of Fe57 in Au using the wide black absorber technique have been made in the temperature range from room temperature to 830 K. The major source of error arises from Au Ly x-rays which are unresolved by the radiation detection system from the 14.4 KeV gamma ray. The K absorption edge of Br has been used to correct for the presence of x-rays.

These measurements have revealed the existence of two nonequivalent lattice sites which the Co57 impurity (parent of Fe57) may occupy. One of the sites has been …


"Remarks On The Motion Picture No Blade Of Grass", Cornel Wilde Nov 1970

"Remarks On The Motion Picture No Blade Of Grass", Cornel Wilde

Special Collections: Oregon Public Speakers

No abstract provided.


Electron Optical Study Of A Secondary Electron Multiplier, Chang Min Shen Jul 1970

Electron Optical Study Of A Secondary Electron Multiplier, Chang Min Shen

Dissertations and Theses

Electron orbital theory was applied to the design of the geometrical structure of an electron multiplier for an image intensifier. A special structure satisfying production requirements was studied. Electron optical calculations consisted of determining the potential distribution and tracing the electron trajectories. Liebmann's procedure was used to solve Laplace's equation with constant potentials on the multiplier electrodes as boundary conditions. The trajectories were determined by solving the equation of motion in an electrostatic field using a Runge-Kutta procedure. The initial conditions for the trajectories were the initial energies, initial positions, and the initial directions of the secondary electrons. The plotted …


Distribution Of The Sum Of Independent Unity-Truncated Logarithmic Series Variables, Russell James Wayland May 1970

Distribution Of The Sum Of Independent Unity-Truncated Logarithmic Series Variables, Russell James Wayland

Dissertations and Theses

Let X1, X2, ..., Xn be n independent and identically distributed random variables having the unity-truncated logarithmic series distribution with probability function given by f(x;θ) = αθX/x x ε T where α = [-log(1-θ) - θ]-1, 0 < θ < 1, and T = {2,3,...,∞}. Define their sum as Z = X1 + X2 + ... + Xn.

We derive here the distribution of Z, denoted by p(z;n,θ), using the inversion formula for characteristic functions, in an explicit form in terms of a linear combination of Stirling numbers of the first kind. A recurrence relation for the probability function p(z;n,θ) is obtained …


The Chemistry Of Trifluorothiolacetic Acid, Patricia Diane Weeks May 1970

The Chemistry Of Trifluorothiolacetic Acid, Patricia Diane Weeks

Dissertations and Theses

Addition reactions of perfluorothiolacetic acid (TFTAA) with organic and inorganic substrates were studied and six new compounds containing the trifluoroacetyl group have been prepared. Two types of reactions were observed, free radical and nucleophilic addition. Under the influence of ultraviolet light, TFTAA (CF₃COSH) adds to olefins to form 1:1 adducts. The CF₃COS• radical appears to be the adding species. Three new olefin adducts were prepared: CF₃COSCFHCF₂H, CF₃COSCH₂CF₂H, and CF₃COSCH₂CFH₂. In addition, this was found to be a new way to prepare CF₃COSCH₂CH₃, which had been previously prepared by another route. Physical constants, analytical data, infrared, ultraviolet, nmr and mass spectra …


Hot Electron Injection Into Liquid Argon From A Tunnel Cathode, Pavel Smejtek, David G. Onn, M. Silver, P. Kumbhare May 1970

Hot Electron Injection Into Liquid Argon From A Tunnel Cathode, Pavel Smejtek, David G. Onn, M. Silver, P. Kumbhare

Physics Faculty Publications and Presentations

Hot electrons from a tunnel cathode have been injected into liquid argon (99.998% pure) at 87°K. The current vs voltage characteristics indicate that the injected hot electrons thermalize very slowly, losing their energy only by elastic scattering processes and finally by capture by the dilute impurities. The deduced thermalization time and distance are very long compared with that in helium, where bubble formation is responsible for energy loss.


Investigation Of The Alpha-Sub-Gamma Phase In Alnico 6, Cortez Samuel Jan 1970

Investigation Of The Alpha-Sub-Gamma Phase In Alnico 6, Cortez Samuel

Dissertations and Theses

The purpose of this research project was to study the αᵧ phase in Alnico 6. Other phases were studies for comparison. Also the effect of an applied magnetic field on the formation of the αᵧ phase was investigated.

Three single crystals of Alnico 6 were heat treated for one hour—one at 1250°C, one at 1000°C, and one at 800°C—and water-quenched. The microstructure of each sample was observed with the optical microscope, and X-ray diffraction patterns were taken to determine the crystal structure of the phases present.

Several single crystal samples of Alnico 6 were heat treated at 1000°C and furnace-cooled. …


Cyclization Studies Involving The Synthesis Of 5-Substituted-1-Naphthol, Clark Keelock Chow Jun 1969

Cyclization Studies Involving The Synthesis Of 5-Substituted-1-Naphthol, Clark Keelock Chow

Dissertations and Theses

The γ-o-substituted-phenylparaconic acids were prepared by a method patterned after that of Fuson. These paraconic acids were prepared in good yield. A re-investigation of the Perkin and Fittig methods of preparing γ-phenylisocrotonic acid was carried out without success.

The synthesis of γ-o-halophenylisocrotonic acids by thermal, and catalyzed decarboxylation of γ-o-halophenylparaconic acid, have been carried out in good yield. An effective catalyst, optimum temperature and reaction period of decarboxylation of the γ-o-halophenylparaconic acids have been determined. Infrared absorptions have characterized the γ-o-halophenylisocrotonic acids formed to be in the stable trans form. …


A Comparison Of The Effects Of Fluoride And Chloride Ions Upon The Activity Of Yeast Alcohol Dehydrogenase, Ellen J. Hannan May 1969

A Comparison Of The Effects Of Fluoride And Chloride Ions Upon The Activity Of Yeast Alcohol Dehydrogenase, Ellen J. Hannan

Dissertations and Theses

Very little is known about the effect of hydrofluoric acid and of the fluoride ion on enzyme systems. The purpose of this work was to determine the effect of hydrofluoric acid and of the fluoride ion on the enzyme, yeast alcohol dehydrogenase and to distinguish between the effect of the fluoride ion and of hydrofluoric acid. The rate of the enzyme reaction was followed spectrophotometrically at 340 mμ on the Cary 14 Model spectrophotometer according to the method of Racker. The data taken from the instrument recordings were plotted on two types of graphs, the Lineweaver-Burk plot and the Hanes …


Directional Correlation Of The 346-136 Kev Gamma-Gamma Cascade In Ta¹⁸¹, Robert Allan Wilson May 1969

Directional Correlation Of The 346-136 Kev Gamma-Gamma Cascade In Ta¹⁸¹, Robert Allan Wilson

Dissertations and Theses

The directional correlation of the 346-136 Kev gamma-gamma cascade in Ta¹⁸¹ was measured using the delayed coincidence method with a source of Hf¹⁸¹ in 27 N HF. The contributions to the composite delayed coincidence spectrum of the interfering 133-482 Kev and 133-346 Kev cascades were removed by the subtraction from this spectrum of appropriate 133-482 Kev pure delayed coincidence data. The extracted 346-136 Kev coincidence data then yielded the correlation coefficients A₂₂ = 0.190±0.011 and A₄₄. = -0.025±0.024 that are consistent with the established spin sequence 5/2(E2)9/2(M1 + E2)7/2 and with an admixture of 16.2%±1. 2% E2 radiation in the …


Steady-State And Transient Currents In Organic Liquids By Injection From A Tunnel Cathode, Pavel Smejtek, David G. Onn, M. Silver Apr 1969

Steady-State And Transient Currents In Organic Liquids By Injection From A Tunnel Cathode, Pavel Smejtek, David G. Onn, M. Silver

Physics Faculty Publications and Presentations

Experimental data are presented on the currents induced in organic liquids by injection from a tunnel cathode. The injection level was varied over a wide range resulting in almost no space‐charge limitation to almost complete space‐charge limitation. Results were different from that usually observed in solids, in that at low fields, the steady‐state current was proportional to V², while at high fields the current was proportional to V. By proper choice of electrode spacing and applied voltage, space‐charge‐limited current transients as low as 10⁻¹¹ A∕cm² and 5 sec transit times were observed. A smooth transition between the electrode‐limited and the …


Applications Of Modified Wittig Reaction To Butatriene Synthesis, John Pearson Oct 1968

Applications Of Modified Wittig Reaction To Butatriene Synthesis, John Pearson

Dissertations and Theses

The preparation of allenes by the condensation of an acyl chloride with a phosphonium ylid and subsequent elimination of an acid salt and a phosphonium oxide has been established by Bestmann and Hartung. It was felt that this process could be expanded to include the synthesis of butatrienes. Butatrienes are stabilized by aromatic substituents while aromatic substituents decrease the nucleophilicity and reactivity of the phosphonium ylids to be used in the synthesis of the butatrienes. The ylids employed were carbomethoxyphenylmethylenetriphenyl phosphorane, and a new compound, carbethoxyphenylmethylenetriphenyl phosphorane, both of which failed to form alkylated condensation products. Both ylids were prepared …


Bacterial Degradation Of Methyl Dehydroabietate, Burl C. Carter May 1968

Bacterial Degradation Of Methyl Dehydroabietate, Burl C. Carter

Dissertations and Theses

Bacteria (Arthrobacter sp.), isolated from lodgepole pine (Pinus contortus), are capable of utilizing methyl dehydroabietate as the sole source of carbon. Degradation products of methyl dehydroabietate have been obtained by manually extracting the cell-free supernatant solution of a liquid growth medium with methylene chloride. Gas chromatography (G. L. C.) was used for separation of the neutral products. The acid products were converted to their methyl esters diazomethane and then separated by gas chromatography. Structures have been proposed for two G. L. C. fractions (V, II) on the basis of infrared (I.R.) and mass spectral (M. S.) data. …


"Planetary Exploration (Lecture Two)", Carl Sagan Mar 1968

"Planetary Exploration (Lecture Two)", Carl Sagan

Special Collections: Oregon Public Speakers

Requested by: "Standing order from Science" "Planetary Exploration"


"Planetary Exploration (Lecture One)", Carl Sagan Mar 1968

"Planetary Exploration (Lecture One)", Carl Sagan

Special Collections: Oregon Public Speakers

No abstract provided.