Open Access. Powered by Scholars. Published by Universities.®
- Discipline
-
- Engineering (1314)
- Physical Sciences and Mathematics (921)
- Education (400)
- Electrical and Computer Engineering (246)
- Social and Behavioral Sciences (227)
-
- Physics (214)
- Chemical Engineering (208)
- Materials Science and Engineering (207)
- Chemistry (198)
- Mechanical Engineering (192)
- Computer Sciences (190)
- Psychology (165)
- Mathematics (145)
- Civil and Environmental Engineering (138)
- Earth Sciences (135)
- Civil Engineering (108)
- Geology (99)
- Medicine and Health Sciences (95)
- Biomedical Engineering and Bioengineering (90)
- Geophysics and Seismology (86)
- Educational Leadership (78)
- Mining Engineering (70)
- Clinical Psychology (68)
- Operations Research, Systems Engineering and Industrial Engineering (67)
- Petroleum Engineering (64)
- Business (63)
- Nuclear Engineering (62)
- Arts and Humanities (60)
- Nanoscience and Nanotechnology (59)
- Geological Engineering (57)
- Institution
- Keyword
-
- Physics (208)
- Biology (201)
- Education (184)
- Chemistry (170)
- Psychology (151)
-
- Engineering (134)
- Sociology (100)
- General (99)
- Ecology (73)
- Environmental Sciences (69)
- Agriculture (64)
- Applied sciences (58)
- History (57)
- United States (53)
- Pure sciences (49)
- Organic (44)
- Astronomy and Astrophysics (43)
- Literature (43)
- Physical (43)
- Fluid and Plasma (41)
- Mathematics (40)
- Social (40)
- Zoology (40)
- Analytical (39)
- Genetics (38)
- Mechanical (38)
- Biochemistry (37)
- Microbiology (37)
- Women's Studies (32)
- Individual and Family Studies (31)
- Publication Year
- Publication Type
- File Type
Articles 5551 - 5580 of 5718
Full-Text Articles in Entire DC Network
Hot Atom Chemistry Of Phosphorus-32 In Alkali Chlorides And Sodium Silicates, Meral Tayan Ercan
Hot Atom Chemistry Of Phosphorus-32 In Alkali Chlorides And Sodium Silicates, Meral Tayan Ercan
Doctoral Dissertations
No abstract provided.
An Optimization Approach To Well Spacing For Gas Storage Reservoirs, Jagannath Rao Ghole
An Optimization Approach To Well Spacing For Gas Storage Reservoirs, Jagannath Rao Ghole
Doctoral Dissertations
"A finite approximation to the conventional diffusivity equation describing compressible fluid flow through porous media has been developed with a view to apply it to the problems of optimum well spacing. An equilateral grid system has been employed to enable uniform well spacing for any number of wells. A numerical model has been developed on an IBM 360 - Model 50 computer, which simulates the pressure and saturation transience in the reservoir due to production impulses. This model has been used to maximize with respect to number of wells, the minimum well bore pressure reached throughout the specified withdrawal schedule. …
Mass And Heat Transfer Through Nonwettable Porous Membranes, Chung-Liang Yeh
Mass And Heat Transfer Through Nonwettable Porous Membranes, Chung-Liang Yeh
Doctoral Dissertations
"Evaporation of water through nonwettable porous membranes has been studied under various pressures with various membrane thicknesses. The results of previous investigations at 1 atmosphere have been correlated into one equation for mass transfer resistance which has also been found to fit approximately new data obtained of 1.5, 2, and 3 atmospheres in this investigation. In the new data fluxes varied from 0.064 to 0.691 lb./ft.²/hr. through glass fiber-Teflon membrane from 0.02 to 0.08 inch in thickness. Temperatures ranged for 80 to 260°F. A more theoretical equation has been developed to explain variations from the equations based on 1 atmosphere …
A Five Parameter Study Of Spherical Transient Waves In A Generalized Voigt Model, Liang-Juan Tsay
A Five Parameter Study Of Spherical Transient Waves In A Generalized Voigt Model, Liang-Juan Tsay
Doctoral Dissertations
"Transient spherical waves in a generalized Voigt model were investigated in this study. Both Laplace and fourier transform solutions of the spherical wave equation for a generalized Voigt model were obtained by means of the correspondence principle. Laplace transform solutions were inverted numerically into the domain for the study of the characteristics of the wave forms, and Fourier transform solutions were utilized for the analysis of frequency dependency attenuation in the models. Generalized Voigt models A and B in which a dashpot is connected in series with spring and dashpot components were unable to represent a solid which would simulate …
Diffusion Of Iron And Cobalt In Nickel Single Crystals, Charles Frederick Heuer
Diffusion Of Iron And Cobalt In Nickel Single Crystals, Charles Frederick Heuer
Doctoral Dissertations
"Diffusion coefficients of iron-59 in nickel have been determined in the temperature range 815°C to 1200°C. The temperature dependence can be represented by an Arrhenius type relationship,...The effect of the isotopic mass on the diffusion coefficient of cobalt in nickel has also been investigated. The isotope effect parameter, E, was found to vary from .26 to .84 over the temperature range 970.5°C to 1200°C. Both results are consistent with the single vacancy mechanism of diffusion. No evidence of divacancy contributions to the mass transport has been found"--Abstract, Page i.
A Study Of The Energy Loss Spectra Induced By Impact Of 23-125 Kev Protons On Helium Atoms, Franklin Dean Schowengerdt
A Study Of The Energy Loss Spectra Induced By Impact Of 23-125 Kev Protons On Helium Atoms, Franklin Dean Schowengerdt
Doctoral Dissertations
"Results of a study of the inelastic energy loss spectra induced by the impact of protons on gaseous helium at energies of 25 to 125 keV are reported. The spectra were obtained by sending an accelerated beam of protons through a chamber containing the helium target gas, mass-analyzing the forward-scattered beam, then decelerating the beam to a low, well-defined energy for energy analysis and detection. The accelerating potential was varied to produce the spectra. An energy resolution of 2 eV was obtained. Apparent differential cross sections and absolute total cross sections were obtained from the spectra. Total cross sections for …
Spherical Antenna Array, Narong Yoothanom
Spherical Antenna Array, Narong Yoothanom
Doctoral Dissertations
"The far field radiation pattern of an isotropic spherical antenna array with two types of element distributions, a latitude-longitude distribution and an approximately equally-spaced distribution, has been analyzed using Poisson's Sum Formula. Beamwidth expressions of both element distributions are found in various planes. All numerical results are given only for the case of 21 rings"--Abstract, page ii.
The Iron-Holmium Binary System And Related Magnetic Properties, Gerald J. Roe
The Iron-Holmium Binary System And Related Magnetic Properties, Gerald J. Roe
Doctoral Dissertations
"The iron-holmium phase diagram was investigated to determine the alloying behavior of these two metals and to determine the magnetic properties of some of the iron-holmium alloys which formed intermediate phases. The iron-holmium binary system was determined by three experimental techniques, differential thermal analysis (DTA), x-ray diffraction, and metallography. A phase diagram with three eutectic points and four intermediate phases was constructed from the experimental data. The two phases, Ho₆Fe₂₃ and Ho₂Fe₁₇, melted congruently at 1322⁰C and 1343⁰C respectively. HoFe₂ and HoFe₃ melted incongruently at 1288⁰C and 1293⁰C respectively. Neutron diffraction investigations were made on the intermediate phases Ho₆Fe₂₃ and …
Models For The Pn Diode And The Npn And Pnp Transistor For Use In Computer Aided Design And Analysis Programs, Glenn Ronald Case
Models For The Pn Diode And The Npn And Pnp Transistor For Use In Computer Aided Design And Analysis Programs, Glenn Ronald Case
Doctoral Dissertations
"This work is concerned with the problem of developing suitable mathematical representations for the pn junction diode and npn and pnp transistors for use in computer aided design and analysis programs. The Ebers-Moll model as used in the Net-1 program has been considerably improved, particularly regarding base resistance prediction, prediction of high forward current behavior, and the addition of reverse breakdown terms. The resulting models show substantial improvement in representation of d-c and transient characteristics. Some improvement in a-c characteristics has also been obtained. Methods of obtaining parameters for the new model and several of the present models, given measured …
Statistical Inferences For The Cauchy Distribution Based On Maximum Likelihood Estimators, Gerald Nicholas Haas
Statistical Inferences For The Cauchy Distribution Based On Maximum Likelihood Estimators, Gerald Nicholas Haas
Doctoral Dissertations
"Various estimators of the location and scale parameters in the Cauchy distribution are investigated, and the superiority of the maximum likelihood estimators is established. Tables based on maximum likelihood estimators are presented for use in making statistical inferences for the Cauchy distribution. Those areas considered include confidence intervals, tests of hypothesis, power of the tests, and tolerance intervals. Both one- and two-sample problems are considered. Tables for testing the hypothesis of whether a sample came from a normal distribution or a Cauchy distribution are presented. The problems encountered in finding maximum likelihood estimators for the Cauchy parameters are discussed, and …
The Statistics Of Finite, One Dimensional Lattice Fluids, John Roger Glaese
The Statistics Of Finite, One Dimensional Lattice Fluids, John Roger Glaese
Doctoral Dissertations
"A one dimensional lattice fluid in which particles are allowed to assume only discrete positions is proposed. Particles are free to move from one lattice site to another interacting through a variety of potentials, including the Lennard-Jones type. The model allows the partition function to be evaluated as a discrete sum over the allowable configurations. Both the canonical ensemble and grand ensemble are treated by computer and a third, the pressure ensemble, is considered and shown to be useful in the theoretical treatment of lattice systems. The thermodynamic behavior of various systems is investigated in both the canonical and grand …
A Theoretical Study On The Interpretation Of Resistivity Sounding Data Measured By The Wenner Electrode System, Siew Hung Chan
A Theoretical Study On The Interpretation Of Resistivity Sounding Data Measured By The Wenner Electrode System, Siew Hung Chan
Doctoral Dissertations
"This thesis deals with a theoretical study on the interpretation of resistivity sounding data measured by the Wenner electrode system. The objectives of this investigation are twofold: (i) to derive from the apparent resistivity data some suitable functions from which the resistivity and thickness of each member of the sequence of layers composing the earth may be determined, and (ii) to devise suitable methods for analyzing the resulting functions. In this investigation it is shown that the solution of the boundary value problem associated with an n-layered earth model leads to an integral equation for the Wenner electrode system. This …
I A Study Of The Basicities Of Some Aryl Methyl Sulfoxides Ii A Study Of The Hydrolysis Of Arenesulfinamides In Basic Aqueous Ethanol, Joseph Brian Biasotti
I A Study Of The Basicities Of Some Aryl Methyl Sulfoxides Ii A Study Of The Hydrolysis Of Arenesulfinamides In Basic Aqueous Ethanol, Joseph Brian Biasotti
Doctoral Dissertations
No abstract provided.
Purification And Characterization Of Staphylococcal Nuclease, David Gordon Stuart
Purification And Characterization Of Staphylococcal Nuclease, David Gordon Stuart
Doctoral Dissertations
No abstract provided.
The Hot-Atom Chemistry Of Sulfur(35) Produced By The Chlorine-35(Neutron,Proton)Sulfur-35 Reaction In Mixed Crystals Of Potassium Chloride And Potassium Bromide, John Robert Hobbs
The Hot-Atom Chemistry Of Sulfur(35) Produced By The Chlorine-35(Neutron,Proton)Sulfur-35 Reaction In Mixed Crystals Of Potassium Chloride And Potassium Bromide, John Robert Hobbs
Doctoral Dissertations
No abstract provided.
A Conformational Study Of Various 3- And 4-Piperidinols, David Harold Mcmahon
A Conformational Study Of Various 3- And 4-Piperidinols, David Harold Mcmahon
Doctoral Dissertations
No abstract provided.
Seasonal Variation Of Aliphatic And Phenolic Acids And The Relationship Between Titratable Acidity And Percentages Of Calcium, Magnesium And Potassium In The Leaves Of Selected Mcintosh Apple Clones, John Chrysostom Mugwanya Ddungu
Seasonal Variation Of Aliphatic And Phenolic Acids And The Relationship Between Titratable Acidity And Percentages Of Calcium, Magnesium And Potassium In The Leaves Of Selected Mcintosh Apple Clones, John Chrysostom Mugwanya Ddungu
Doctoral Dissertations
No abstract provided.
The Reactions Of Organometallic Reagents With Pyridinium Salts, Edward White V.
The Reactions Of Organometallic Reagents With Pyridinium Salts, Edward White V.
Doctoral Dissertations
No abstract provided.
The Extension Of A Locally Compact Local Group To A Global Group, David Warren Cohen
The Extension Of A Locally Compact Local Group To A Global Group, David Warren Cohen
Doctoral Dissertations
No abstract provided.
Measurement Of Ionospheric Absorption By The Cosmic Radio Noise Method, J Ronald Earhart
Measurement Of Ionospheric Absorption By The Cosmic Radio Noise Method, J Ronald Earhart
Doctoral Dissertations
No abstract provided.
Cell Model Of A Fluid With Hard-Core Repulsive Long-Range Attractive Potential, Ralph G. Tross
Cell Model Of A Fluid With Hard-Core Repulsive Long-Range Attractive Potential, Ralph G. Tross
Doctoral Dissertations
"A model of a one-dimensional fluid is investigated in which the praticles [sic] are embedded in a cellular space grid and interact with a modified Lennart-Jones potential. It is shown that with an appropriate change in the potential function the model is also suitable for a two- or three-dimensional fluid with more restricted interactions. The man-fermion-like nature of the system resulting from the hard-rod repulsive part of the modified Lennard-Jones potential makes possible an isomorphism between occupation numbers (number operators) and spin states (spin operators) of an Ising ferromagnet, permitting a convenient mathematical formulation of the problem in terms of …
A Numerical Simulation Of Pressure Distribution And Radius Of Drainage In Infinite Radial Aquifers - Constant Rate Case, Alton John Nute
A Numerical Simulation Of Pressure Distribution And Radius Of Drainage In Infinite Radial Aquifers - Constant Rate Case, Alton John Nute
Doctoral Dissertations
"The diffusivity equation for the transient flow of slightly-compressible liquids has been solved for infinite radial aquifers, subject to constant terminal rates, by employing a Romberg integration of the Van Everdingen - Hurst explicitly solution over the transformed integral limits for .01̲TD>500, the classical solutions presented by Carslaw and Jaeger, Mortada, Theis, and others are incorporated in the digital analysis to yield dimensionless pressures for 40 selected dimensionless radius (RD) ratios between 1 and 64 for dimensionless time values of .0005 to 1000.0. A new expression for dimensionless pressure-distribution, PD'(RD, TD), as a fraction of well bore pressure drop …
Inferences On The Parameters Of The Weibull Distribution, Darrel Ray Thoman
Inferences On The Parameters Of The Weibull Distribution, Darrel Ray Thoman
Doctoral Dissertations
"For the most part, solutions to the problems of making inferences about the parameters in the Weibull distribution have been limited to providing simple estimators of the parameters. Little has been known about the properties of the estimators. In this paper the small and moderate sample size properties of the maximum likelihood estimators are studied and their superiority is established. The problem of making further inferences which are based on the maximum likelihood estimates of the parameters is then considered. The inferences that are presented can be divided into those based on a single sample and those based on two …
Recombination Statistics For The Neutron-Induced Base Current Component, Ming-Chwan Chow
Recombination Statistics For The Neutron-Induced Base Current Component, Ming-Chwan Chow
Doctoral Dissertations
"This paper presents a derivation of the recombination statistical model for the neutron-induced base current component. The derivation was based on the assumptions: 1) the current equation for the induced current component developed by Goben is valid; 2) the Shockley-Read-Hall statistics for holes and electrons are applicable; and 3) the recombination statistics derived by Sah, Noyce and Shockley, for sites in the bulk space-charge region are valid. Several examples were presented to emphasize accuracy of this derived model for predictions. This paper shows that the recombination process may be described by a mathematical model, recombination statistics which depend on the …
Surface Self-Diffusion On Nickel (111) By Radioactive Tracers, James Ronald Wolfe
Surface Self-Diffusion On Nickel (111) By Radioactive Tracers, James Ronald Wolfe
Doctoral Dissertations
"Surface self-diffusion coefficients have been measured by a radioactive tracer method over the temperature range 614⁰ to 840⁰C on nickel (111) surfaces characterized by LEED. Previously unrecognized tracer evaporation during surface diffusion resulted in restricted spreading of the tracer at higher temperatures. A theoretical treatment of the tracer evaporation phenomenon is presented and subsequently used in the analysis of the data. The temperature dependence of the surface self-diffusion coefficient (Ds) for nickel (111) can be represented, over the experimental temperature range, by a single Arrhenius type relationship...Arguments are presented to justify an adatom surface diffusion mechanism which is …
The Damage Assessment Of Thermally Shocked High Density, High Purity Aluminum Oxide, John H. Ainsworth
The Damage Assessment Of Thermally Shocked High Density, High Purity Aluminum Oxide, John H. Ainsworth
Doctoral Dissertations
"The traditional approach to thermal shock testing in brittle materials has been to determine the temperature difference required to nucleate cracks in these materials. Recent work has indicated that the degree of damage after crack nucleation should be an additional consideration. The degree of damage resulting from cooling thermal shocks has been the primary consideration of the present work. Test specimens of two geometries: long, solid rods and short, solid cylinders were quenched from selected temperatures into ice water. The degree of damage was determined through strength measurements and sonic damping analysis. Initial damage occurred at a temperature difference above …
Signal Theoretic Characterization Of A Function Using Positive Exponential Basis Functions, James Julius Baremore
Signal Theoretic Characterization Of A Function Using Positive Exponential Basis Functions, James Julius Baremore
Doctoral Dissertations
"A signal theory characterization of a time function or signal is a representation of the function throughout a sample interval by an orthogonal basis function expansion. The characterization described here obtains the coefficients in the expansion by processing the input waveform, in real time, through a system of three terminal passive RC filters. The outputs of the filters are sampled periodically and the coefficients of the basis function expansion in that interval are related to these values. The basis functions result from an exponential transformation applied to the Legendre polynomials and are orthogonal in time over the sample interval. The …
Analysis Of A Focus Log Electrode In A Non Homogeneous Medium, John Julian Zenor
Analysis Of A Focus Log Electrode In A Non Homogeneous Medium, John Julian Zenor
Doctoral Dissertations
"The mathematical model presented for the focused logging system is applicable to any resistance logging tool of the electrode type. Horizontal or cylindrical resistance interfaces may be included in any combinations. The tool and its environment are compartmentalized, and the integral form of the condition for continuity of current is applied to each compartment. Acceleration methods are applied to the iterative solution of the resulting large-scale system of linear equations. Two specific models are presented, one for the study of the effects of invasion and the other for the study of the effects of bed thickness on the apparent resistivity …
Hrva - A Velocity Analysis Technique For Seismic Data, John Charles Robinson
Hrva - A Velocity Analysis Technique For Seismic Data, John Charles Robinson
Doctoral Dissertations
"A High-Resolution Velocity Analysis (HRVA) has been developed for the determination of the root-mean-square subsurface-velocity energy spectrum from gated seismic data which has been normal-moveout corrected. All calculations are performed in the frequency-space or frequency-wavenumber domain; seismic gates are transformed from the time-space domain via the Fast Fourier Transform algorithm. HRVA is not restricted to the investigation of apparent horizontal velocities which have associated stepout values that are integral multiples of the time sampling interval, as are the existing correlation techniques. The technique liberally exploits the inexistence of significant energy in the higher frequency harmonies of seismic data, resulting in …
Decomposition Of Cr(Oh)₃ To Form Active Cr₂C₃, Timothy A. Clancy
Decomposition Of Cr(Oh)₃ To Form Active Cr₂C₃, Timothy A. Clancy
Doctoral Dissertations
"This study was concerned with the sinterability of Cr₂C₃ powders produced by the calcination of a Cr(OH)₃ gel. The decomposition of the gel was investigated by thermogravimetric analysis, X-ray analysis and microscopic examination. Comparison was made between the size of crystallites as determined by X-ray line broadening and the size of aggregated particles as determined by independent means. These lineal measurements were compared to surface area measurements on the calcined powders. The degree of sinterability was judged from the density measurements on Cr₂C₃ pellets fired under air, oxygen and nitrogen atmospheres. Energies of activation of 25 and 20 kilocalories per …