Open Access. Powered by Scholars. Published by Universities.®
- Discipline
-
- Electrical and Computer Engineering (754)
- Mechanical Engineering (696)
- Civil and Environmental Engineering (597)
- Materials Science and Engineering (533)
- Chemical Engineering (505)
-
- Civil Engineering (454)
- Metallurgy (278)
- Operations Research, Systems Engineering and Industrial Engineering (194)
- Mining Engineering (184)
- Aerospace Engineering (156)
- Petroleum Engineering (153)
- Ceramic Materials (120)
- Computer Engineering (120)
- Nuclear Engineering (108)
- Physical Sciences and Mathematics (108)
- Geological Engineering (80)
- Manufacturing (74)
- Biomedical Engineering and Bioengineering (53)
- Engineering Science and Materials (49)
- Industrial Engineering (48)
- Construction Engineering and Management (43)
- Electromagnetics and Photonics (38)
- Earth Sciences (32)
- Social and Behavioral Sciences (30)
- Engineering Mechanics (29)
- Environmental Engineering (29)
- Life Sciences (28)
- Systems Engineering (28)
- Explosives Engineering (27)
- Institution
- Keyword
-
- Additive Manufacturing (17)
- CFD (17)
- Optimization (14)
- Additive manufacturing (13)
- Simulation (12)
-
- Steel (10)
- Modeling (9)
- Aerodynamics (8)
- Concrete (8)
- Electric filters (7)
- MCNP (7)
- Machine Learning (7)
- PDN (7)
- Pedestrian (7)
- 3D printing (6)
- Epilepsy (6)
- Explosives (6)
- FPGA (6)
- Glass (6)
- Image processing (6)
- Machine learning (6)
- Nanoparticles (6)
- Power (6)
- Safety (6)
- Autonomous vehicles (5)
- Characterization (5)
- Corrosion (5)
- Data Analysis (5)
- Design (5)
- EEG (5)
- Publication Year
- Publication Type
Articles 2521 - 2550 of 3914
Full-Text Articles in Engineering
Triangular Signal Stabilization Of Nonlinear Systems, Kamaleddin Yadavar Nikravesh
Triangular Signal Stabilization Of Nonlinear Systems, Kamaleddin Yadavar Nikravesh
Masters Theses
"Many nonlinear systems display self-sustained oscillations which are often undesirable. The stabilizing effect of a high frequency input signal on an oscillating system with one nonlinearity is determined by the characteristics of the nonlinear element in the system, the linear portion of the system and the amplitude of the signal. This investigation has been concerned with the effect of a triangular wave stabilizing signal on these self oscillations. The equivalent gains for several common nonlinearities are derived. The pseudo describing function introduced by Oldenburger and Boyer for sinusoidal stabilization has been extended to the triangular wave case, and it is …
An Experimental Determination Of The Effect Of The Axisymmetric Turbulent Wake On The Pressure Distribution On A Sphere, Martin Gardner Bowin
An Experimental Determination Of The Effect Of The Axisymmetric Turbulent Wake On The Pressure Distribution On A Sphere, Martin Gardner Bowin
Masters Theses
"A study of the effect of the turbulent wake of a water drop on the motion of a smaller droplet is essential in order to gain an understanding of the behavior associated with the collision coalescence phenomena. The use of spheres of macroscopic size proves to be a valuable method in observing these effects. This experimental investigation centers on (1) a check on the validity of the instrumented sphere as a device to measure normal static pressure, and (2) the study of the effect of the turbulent wake of the test model sphere upon the instrumented sphere. Measurements were made …
Irradiation Enhanced Decomposition Of A Nickel-Carbon Solid Solution, Bryce Linn Shriver
Irradiation Enhanced Decomposition Of A Nickel-Carbon Solid Solution, Bryce Linn Shriver
Masters Theses
"This investigation was performed to determine the effects of room temperature neutron irradiation on the distribution of carbon in a nickel--0.3 wt. % carbon alloy. The experiment consisted of comparing the amount of carbon in solid solution and the internal stresses of both unirradiated and irradiated (10¹³ fn-cm⁻² < ΦF < 10¹⁸ fn-cm⁻²) samples following isochronal anneals between 100ºC and 1200ºC by using the magnetic disaccommodation technique. The results indicate that the amount of carbon remaining in solid solution decreases with increasing neutron dose. At temperatures below 200ºC this is due to the trapping of carbon by mobile irradiation-produced defects. Between 200ºC and 600ºC the formation of metastable carbides is enhanced by the presence of irradiation-produced defects. No differences are observed in irradiated and unirradiated samples above 600ºC"--Abstract, page iii.
Phase Equilibrium And Thermodynamic Study Of Lime-Iron Oxide Solid Solutions, Shin Suk Kang
Phase Equilibrium And Thermodynamic Study Of Lime-Iron Oxide Solid Solutions, Shin Suk Kang
Masters Theses
"The solubility limits of iron oxide in solid lime were determined as a function of oxygen pressure at 1300º and 1400ºG in the system CaO-iron oxide. The stability region of dicalcium ferrite was determined with respect to formation of lime-iron oxide solid solution and liquid oxide. In addition, the hydration behavior in moist air of pure lime and sintered mixtures of lime and iron oxide was also observed. Pelletized samples were equilibrated under known oxygen partial pressures and quenched. Phases present in the quenched samples were identified by microscopy. The solubility limit of iron oxide in CaO is strongly dependent …
Quenching Defects In Aluminum Plus Ten Atomic Per Cent Zinc, James Thomas Grider
Quenching Defects In Aluminum Plus Ten Atomic Per Cent Zinc, James Thomas Grider
Masters Theses
"This study was undertaken to resolve the conflict which has recently arisen as to the as-quenched microstructure in the Al-Zn system as revealed by thin film transmission electron microscopy. The composition range of most active study has been that from 5 to 15 atomic per cent Zn in superpurity AL. Consequently a composition of 10 atomic per cent Zn was chosen for this study. There are no discontinuties in the phase diagram in this composition range which would influence the above choice. It exists as a single phase solid solution at high temperatures and as a two phase alloy at …
The Design Of A High Temperature Thermoelectric Generator Element Using Silicon Carbide, John Talmage Barrow Jr.
The Design Of A High Temperature Thermoelectric Generator Element Using Silicon Carbide, John Talmage Barrow Jr.
Masters Theses
"This report presents the design of an optimum, high temperature silicon carbide thermoelectric generator element. The analytical efforts have been divided into three basic parts, the development of the theory, the accumulation of the data, and the optimization of the design. The first step in the theory development was the derivation of accurate design equations. With this done, the design philosophy and computer program were constructed, the latter utilizing a subroutine to contain the design equations. The data was obtained from a survey of many references and, for the most part, was found to be inexact, requiring the consideration of …
Effects Of Flat And Elongated Particles Upon Properties Of Mixtures Containing Glass Aggregates, John Dean Doyle
Effects Of Flat And Elongated Particles Upon Properties Of Mixtures Containing Glass Aggregates, John Dean Doyle
Masters Theses
"As a possible solution for the rapidly proliferating problem of waste glass disposal in the United States, glass is being considered for use as aggregate in bituminous concrete mixtures. Crushed waste glass particles, and crushed bottle glass particles in particular, are more angular, much smoother, and contain a higher percentage of flat and/or elongated particles than conventional rock aggregate particles. Because of the differences in shape and surface texture, glass aggregate may require different gradations than those found suitable for conventional rock aggregate. Objectives of this research were to determine gradations which result in maximum density for aggregates consisting entirely, …
A Study Of Early-Late Type S0-Pcm Signal Bit Synchronizers, Kuang-Cheng Hu
A Study Of Early-Late Type S0-Pcm Signal Bit Synchronizers, Kuang-Cheng Hu
Masters Theses
"The steady-state phase noise performances of an absolute value type and a squaring loop type of early-late gate S0-PCM signal bit synchronizers are developed using the Fokker-Planck method. The results are compared on the basis of the performance of two configurations with equal loop bandwidth at each input signal-to-noise ratio Rs. The probabilities of bit-detection error of the two configurations are compared. These comparisons are made as a function of Rs. The absolute value type of early-late gate S0-PCM signal bit synchronizater yields better performance than that of the squaring loop type of early-late gate S0-PCM …
Final Sintering Of Cr₂O₃ With Minor Additions Of Mgo And Sintering Of Mgo With Minor Additions Of Cr₂O₃, Gordon E. Jungquist
Final Sintering Of Cr₂O₃ With Minor Additions Of Mgo And Sintering Of Mgo With Minor Additions Of Cr₂O₃, Gordon E. Jungquist
Masters Theses
"The effect of oxygen activity on the sintering of Cr₂O₃ with minor additions of MgO, and of MgO with minor additions of Cr₂O₃ at 1600ºC was investigated. A peak density (99.4% of theoretical) was obtained for high purity Cr₂O₃ by maintaining the equilibrium oxygen partial pressure needed to maintain the Cr₂O₃ phase. The addition of 0.1 wt. % MgO increased the sintered density at the same oxygen pressure to 99.8%. Further MgO additions decreased the density. The density of pure MgO was independent of the PO₂ over the range investigated. Addition of Cr₂O₃ to MgO decreased the density at …
Alkali Mobility And Mechanical Relaxation In Mixed-Alkali Silicate Glasses, James W. Fleming Jr.
Alkali Mobility And Mechanical Relaxation In Mixed-Alkali Silicate Glasses, James W. Fleming Jr.
Masters Theses
"Internal friction and sodium and potassium self-diffusion coefficients for (1-X)Na₂O · XK₂O· 3SiO₂ glasses were measured. Alkali diffusion was measured between 300 and 500ºC using radioactive isotopes and a thin-sectioning technique. Internal friction was measured from room temperature to 500ºC, 0.1 to 2000 Hz. Comparison between alkali diffusion and internal friction data for Na-K glasses with those for other mixed-alkali glasses shows that the mixed-alkali peak is related to alkali mobility. It is concluded that the mechanism for mixed-alkali internal friction is a cooperative rearrangement of dissimilar alkali ions, with the slower moving ion controlling the rate of reorientation"--Abstract, page …
Reservoir Design: Simulation Techniques, Larry W. Mays
Reservoir Design: Simulation Techniques, Larry W. Mays
Masters Theses
"A simulation model is developed to aid in the analysis of small dams to reduce the possibility of inadequate spillway designs. Basic assumptions concerning the geometric aspects of the natural reservoir are made to develop the model which is based upon describing the timing and magnitude of a design flood passing through a reservoir. Simulation equations are derived from the basic continuity equation and describe reservoir outflow and storage as functions of reservoir depth. Newton's Iteration Technique is utilized to solve the simulation equations for the reservoir depth. The resulting simulation model determines an optimum size auxiliary spillway having a …
A Study Of The Effects Of Mixing On The Accelerated Anaerobic Digestion Of Concentrated Municipal Sludges, Victor Darryl Orr
A Study Of The Effects Of Mixing On The Accelerated Anaerobic Digestion Of Concentrated Municipal Sludges, Victor Darryl Orr
Masters Theses
"Most domestic sewage treatment plants today practice anaerobic digestion of sludge. The purpose of this investigation was to determine if thorough mechanical mixing of concentrated sludge would improve its digestion. The simulated digesters consisted of six 1 gallon anaerobic reactors which were operated in the laboratory for 78 days. The contents of three digesters were continually mixed and their responses were compared with those of the similarly loaded remaining three unmixed units. Raw sludge with solids concentrations of 7.5, 15 and 30 per cent was digested for detention periods of 30, 15 and 7.5 days at 33º C. Various analyses …
The Thermal Contact Resistance Of Lubricant Films In Vacuum, Garry A. Heizer
The Thermal Contact Resistance Of Lubricant Films In Vacuum, Garry A. Heizer
Masters Theses
"This paper presents the results of an experimental investigation on the thermal contact resistance of lubricant films and bare interfaces. The apparatus and procedure used in the determination of these resistances are described. Twelve series of tests were performed to evaluate the effects of temperature and contact pressure on the thermal resistance of lubricant films. Variations of thermal contact resistance with temperature and contact pressure for four lubricants and for bare interfaces are presented graphically. The thermal resistances of the four lubricants tested in vacuum conditions: lithium grease, graphite grease, molykote grease, and silicone lubricant, were found to lie in …
The Effect Of Solvents On The Desorption Of Phenol From Carbon In A Water Free System, William W. Knickmeyer
The Effect Of Solvents On The Desorption Of Phenol From Carbon In A Water Free System, William W. Knickmeyer
Masters Theses
"The desorption of phenol from active carbon was studied using a continuous flow desorber. The system used was nearly water free to reduce water-phenol interactions. The ten solvents used in this study exhibited a wide difference in their desorption capabilities. An attempt to correlate the desorption data with the physical properties of phenol and solvents, in addition to regular solution theory, proved unsuccessful. A thermodynamic approach using the linear free energy-enthalpy relationship produced a general trend by using the heat of solution for phenol in solution and a reasonable correlation using the heat of formation of the phenol-solvent hydrogen bond …
Anodic Oxidation Of Ethylenediaminetetraacetic Acid On Pt In Acid Sulfate Solutions, Howard Ho-Wei Jiang
Anodic Oxidation Of Ethylenediaminetetraacetic Acid On Pt In Acid Sulfate Solutions, Howard Ho-Wei Jiang
Masters Theses
"The anodic oxidation of EDTA was studied in acid sulfate solutions on platinized-Pt at 25ºC. Polarization relationships were obtained for the EDTA concentration range 3. 42 x 10⁻⁵ to 3. 42 x 10⁻³ M and pH range 0. 35 to 3. 80. Numerous reaction products were identified that indicated a sequential removal of acetate groups from the EDTA, each by an initial decarboxylation followed by a reverse Schiff-type reaction, that produced formaldehyde and the corresponding amine. A reaction sequence which correlated the experimental data involved Frumkin-type adsorption of the EDTA species through an unionized acetate group followed by a rate-determining …
An Energy Solution For Vibration Characteristics Of Free Thin Cylinders, Dale Elmer Leanhardt
An Energy Solution For Vibration Characteristics Of Free Thin Cylinders, Dale Elmer Leanhardt
Masters Theses
"In this report the flexural vibrations of the walls of free, thin, circular cylinders are considered. Theoretical expressions are developed for the natural frequencies by extending the approximate energy method of Arnold and Warburton to the free-free case. Furthermore, the developed expressions are shown to apply, as special cases, to the fixed-fixed and simply-supported cylinders analyzed by Arnold and Warburton. The energy solution for free-free cylinders is checked both experimentally using a 3500 pound-force, 5 to 2000 hertz, vibration exciter and numerically using the well documented SABOR IV-DYNAL finite element program. While the derived energy method accounts for any prescribed …
Electrolytic Reduction Of Zinc From Acidic Sulfate Solutions, Kenneth Dale Gielow
Electrolytic Reduction Of Zinc From Acidic Sulfate Solutions, Kenneth Dale Gielow
Masters Theses
"Cathode polarization curves were obtained for the electrodeposition of zinc from sulfate solutions with pH 2 and zinc concentrations of 10.0, 40.0, 80.0, and 100.0 gpl zinc. Both pure zinc and pure aluminum were used as cathodes with some difference in results noted. The effect of animal glue additions of 0.01, 0.10, and 0.50 gpl of solution on the cathodic polarization curves and the resulting deposit morphologies were determined. These glue additions correspond to 0.20, 2.0, and 10.0 pounds of glue per ton of zinc deposited, respectively. The slope of the Tafel region of the polarization curves was found to …
A Study Of Radiative Heat Transfer From A Spherical Layer, Hakimuddin Kalimuddin Khalil
A Study Of Radiative Heat Transfer From A Spherical Layer, Hakimuddin Kalimuddin Khalil
Masters Theses
"The problem of radiative heat transfer from a spherical layer of absorbing-emitting gas has been studied. First, the medium is assumed to be gray and then nongray. A thorough survey of literature from fields other than heat transfer, such as astrophysics and neutron transport has been made to stimulate further interest in this important area. To gain some insight into the effect of various parameters on the heat transfer, simple physical situations involving isothermal medium are considered. Comparison of the results obtained for the flux from the spherical and planar layers reveal that the curvature becomes increasingly important as the …
Hydrostatic Extrusion Of Tubular Products, John Lester Roth
Hydrostatic Extrusion Of Tubular Products, John Lester Roth
Masters Theses
"The production of quality tubular products by hydrostatic extrusion has been demonstrated to be a highly satisfactory method. The forming of tubes by the floating mandrel method has been accomplished on mild steel, aluminum alloy, and brass. This thesis describes the method, equipment design and operation, and the results obtained in the hydrostatic tube extrusion. A discussion on the advantages of the use of hydrostatic over conventional extrusion is included. The hydrostatic extrusion system designed for this study is described in detail"--Abstract, page ii.
A Statistical Hydrologic Simulation Model, Ronald L. Wycoff
A Statistical Hydrologic Simulation Model, Ronald L. Wycoff
Masters Theses
"Simulation of a physical system requires knowledge of all components of the system and their interactions. A probabilistic simulation model of a hydrologic system is developed from short term continuous, sychronized rainfall-runoff records. The individual components of the system area the time between and duration of storms, the depth of rain occurring in each time period of the storm, precipitation excess relations, and the watersheds unit hydrograph. The available data is used to define or develop the probabilistic models involved. The only nonprobabilistic model employed is the watersheds unit hydrograph. It is found that the time between and duration of …
A Study Of The Void-Strengthening Of Aluminum And Its Nature, Purushottam G. Manusmare
A Study Of The Void-Strengthening Of Aluminum And Its Nature, Purushottam G. Manusmare
Masters Theses
"Strengthening of aluminum by formation of the voids and the nature of resultant strengthening, viz., the temperature and the strain rate dependence of its yield strength were studied. Aluminum wires with 99.999% purity and of 3.1 mm diameter were quenched and heat treated to form voids of the approximate density 10¹³-10¹⁴ voids/cm³ and were tested for their yield strength. Voids in selected samples were observed by transmission electron microscopy using the Hitachi HU-11A microscope. The yield strength of the void strengthened samples was measured at various temperatures from 77ºK to 593ºK using two strain rates, 3.33 x 10⁻²/sec and 1.67 …
Calculation Of Eddy Current Loss Of A Disc, Kou Quen Chang
Calculation Of Eddy Current Loss Of A Disc, Kou Quen Chang
Masters Theses
"A method is presented to calculate the eddy current losses of a uniform disc with an opening in the center and excited by a circular current loopage First, the disc is subdivided into smaller concentric rings, then the self-inductances, the mutual inductances between these smaller rings, the mutual inductances between the excitation coil and the smaller rings, and the resistance of the rings are calculated. Next, the eddy current flowing in each ring is obtained by solving a complex matrix equation of the form [X] [I] = [V] where X is the impedance matrix, I is the eddy current matrix, …
Two Component Heat Pipe, Surapol Chandsawangbhuvana
Two Component Heat Pipe, Surapol Chandsawangbhuvana
Masters Theses
"A two component heat pipe with water and ethanol as the working fluid was investigated at different angles of inclination and various ethanol concentration for two power loads. The heat pipe was 15 inches long and 0.75 inches in diameter with a 100 mesh stainless steel screen wick. The wall and the vapor temperatures were measured at different stations along the length of the heat pipe by copper-constantan thermocouples. The results were used to evaluate an existing model which includes the constraint of thermodynamic phase equilibrium of the solution on the governing equations. Based on the measured pressure and temperature …
Factors Affecting The Ductility And Microstructure Of Ti-6al-6v-2sn Titanium Alloy Weldments, Michael John Ball
Factors Affecting The Ductility And Microstructure Of Ti-6al-6v-2sn Titanium Alloy Weldments, Michael John Ball
Masters Theses
"The purpose of the investigation was to study the effect of material thickness, weld heat input and post weld heat treatment on the tensile properties and microstructure of Ti-6Al-6V-2Sn Titanium, and obtain a practical weld/thermal treatment cycle. The objectives were accomplished by electron beam and gas tungsten arc welding 0.060, 0.125 and 0.250 inch thick material and then heat treating at various temperatures and times. Electron beam and gas tungsten arc welding enabled an approximate 4:1 ratio of heat inputs to be utilized. Resultant welded and heat treated material was tensile tested and metallographically examined. Heat treatments involved both air …
Radiant Interchange In A Non-Isothermal Rectangular Cavity, Tilak Raj Sawheny
Radiant Interchange In A Non-Isothermal Rectangular Cavity, Tilak Raj Sawheny
Masters Theses
"Radiant interchange between non-isothermal, gray diffuse surfaces with non-uniform radiosity has been determined for a rectangular cavity. Temperature distribution and heat flux as thermal specifications for the parallel surfaces of the cavity have been considered separately. Ambarzumian's method has been used for the first time to solve a radiant interchange problem. According to the method, the integral equation for the radiosity is first transformed into an integro-differential equation and then into a system of ordinary differential equations. Initial conditions required to solve the differential equations are the H-functions. The H-functions represent the radiosity at the edge of the cavity for …
The Use Of Scattering Parameters In Amplifier Design, Yousef Neman-Ebrahim
The Use Of Scattering Parameters In Amplifier Design, Yousef Neman-Ebrahim
Masters Theses
"The scattering-parameter formulation of an active two-port device is developed from the compensation theorem. The use of scattering parameters in graphical developments of forward operating power gain and tunability is considered in detail. Finally, two design examples show the application of the graphical procedures"--Abstract, page ii.
Digested Sludge Dewatering On Drying Beds Under Controlled Environmental Conditions, Daniel James Harris
Digested Sludge Dewatering On Drying Beds Under Controlled Environmental Conditions, Daniel James Harris
Masters Theses
"The dewatering characteristics of anaerobically digested primary and activated sludge were investigated under eight selected combinations of laboratory controlled air temperature and relative humidity using three open, drained model beds, as well as a closed, drained and an open, nondrained bed. The evaporation rate from a free water surface was also determined. Moisture content, drainage, evaporative weight loss, and sludge surface recession were measured and recorded periodically throughout the two week period of each of the eight experiments. Relationships were shown to exist between sludge moisture content, evaporation rate from a free water surface, and the parameters 6T (the difference …
Evaporation And Condensation Of Zinc, Shailesh Bhanuprasad Vora
Evaporation And Condensation Of Zinc, Shailesh Bhanuprasad Vora
Masters Theses
"Evaporation rates of liquid zinc were determined experimentally within the temperature range of 450º C to 575º C and at argon pressures ranging from 730mm Hg to 130mm Hg. Extrapolated values of these rates are found to be consistent with the previously reported rates obtained by St. Clair and Spendlove at lower pressures. Between 100 microns and one atmosphere pressure rates of evaporation seem to vary according to an equation of the form W = APᴮ, where Pis pressure and, A and B are constants. Similar experiments were performed with brass powders in atmospheres of argon and helium at temperatures …
Simulation Of Digital Computer Simcom, Ming-Te Hsieh
Simulation Of Digital Computer Simcom, Ming-Te Hsieh
Masters Theses
"SIMCOM(SIMulated COMputer) is a hypothetical small general-purpose digital computer. It has a core memory of 4096 12-bit words and has been modeled after the Scientific Control Corporation SCC 650. The instructions of SIMCOM are completely compatible with the SCC 650, any SIMCOM program can be run on the SCC 650. The logical organization is similar but not identical to the SCC 650, the mnemonics that are used to represent all instructions are identical to those used on the SCC 650 except the Input/Output instructions. This computer can be simulated on any available commercial computer. If such a simulation is available, …
A Step-Wise Gray Approximation Of The Radiative Absorption Coefficient For An Isothermal Hydrogen Plasma, Keith Harlan Browne
A Step-Wise Gray Approximation Of The Radiative Absorption Coefficient For An Isothermal Hydrogen Plasma, Keith Harlan Browne
Masters Theses
"The radiative absorption coefficient of an isothermal hydrogen plasma is calculated using a step-wise gray approximation. The approximation retains a high degree of accuracy while significantly reducing the numerical computer time. The accuracy of the approximation depends on the spacing of the steps taken in the frequency spectrum as well as the number or steps used; 135 steps are used in this study. Plasma conditions of interest in this study are for temperatures between 5000 and 60,000ºK, densities between 10⁻⁵ and 10⁻⁷ gm/cm³, and thicknesses between 0.1 and 100 cm. Flux and intensity calculations are made for each case using …