Engineering Commons^™

Direct Measurement Of Dynamic Capacitance, Norman G. Dillman

Electrical and Computer Engineering Faculty Research & Creative Works

No abstract provided.

Response Of Steel Frames To Earthquake Forces, M. J. Kaldjian, Wm. R. S. Fan

American Iron and Steel Institute (AISI) Specifications, Standards, Manuals and Research Reports (1946 - present)

No abstract provided.

Response Of Multistory Steel Frames To Earthquake Forces, Subhash C. Goel

American Iron and Steel Institute (AISI) Specifications, Standards, Manuals and Research Reports (1946 - present)

No abstract provided.

Behavior Of Steel Building Connections Subjected To Inelastic Strain Reversals, E. P. Popov, R. B. Pinkney

CCFSS Library (1939 - present)

Inelastic design of steel structures to withstand seismic forces requires a knowledge of the behavior of connections when subjected to cyclically reversed loading. This report contains a description of the design and testing of selected steel beam-to-column connection specimens. The motivations for the choice of connection types and overall geometry of the specimens are discussed, relating them to full-size prototypes used in actual building frames. The characteristics of the test installation are described, including means of loading, type of lateral support provided, etc. The programs of cycling of all tests are presented in terms of the deflection of the tip …

Behavior Of Steel Building Connections Subjected To Inelastic Strain Reversals Experimental Data, E. P. Popov, R. B. Pinkney

CCFSS Library (1939 - present)

No abstract provided.

Design Recommendations For Diaphragm-Braced Beams, Columns And Wall-Studs, T. V. S. R. Apparao, George Winter, S. J. Errera

CCFSS Library (1939 - present)

INTRODUCTION Light gage steel panels are often used as wall sheathing, roof decking or floor covering in steel framed buildings. These panels carry loads normal to their plane by virtue of their bending strength. Also, diaphragms formed by interconnecting such panels can resist shear deformation in their plane. Because of this shear resisting capacity, diaphragms can be very effective in bracing columns and beams of a steel frame against lateral buckling and, thus, increase the load carrying capacity of these members. For wall columns, such diaphragm bracing may be either directly attached or connected to girts which in turn are …

Investigation Of Torsional-Flexural Buckling Of Thin-Walled Open Sections With Unequal End Eccentricities, Nuri Celebi, George Winter

CCFSS Library (1939 - present)

INTRODUCTION Compression members of thin walled open sections may buckle in the torsional-flexural mode at loads lower than the Euler buckling load, because of their low torsional rigidity. Doubly symmetric sections, loaded eccentrically in the plane of symmetry, buckle in the torsional-flexural mode when sufficient strength against flexural yielding is provided in the plane of loading. In singly symmetric sections, the shear center and centroid do not coincide. When such sections are loaded in the plane of symmetry, flexural buckling out of the plane of loading is possible only if the load acts at the shear center. Otherwise, torsional flexural …

Automation In The Design Of Asynchronous Sequential Circuits, Richard T. Smith, James H. Tracey, W. L. Schoeffel, G. K. Maki

Electrical and Computer Engineering Faculty Research & Creative Works

Sequential switching circuits are commonly classified as being either synchronous or asynchronous. Clock pulses synchronize the operations of the synchronous circuit. The operation of an asynchronous circuit is usually assumed to be independent of such clocks. The operating speed of an asynchronous circuit is thus limited only by basic device speed. One disadvantage of asynchronous circuit design has been the complexity of the synthesis procedures for large circuits.

Problems In Structural Diaphragm Bracing 1. Beams Continuously Braced By Diaphragms 2. I-Section Columns Braced By Girts And A Diaphragm, T. V. S. R. Apparao, S. J. Errera, Gordon P. Fisher

CCFSS Library (1939 - present)

Shear-resistant light-gage metal diaphragms can be very effective in increasing the load carrying capacity of beams continuously braced by diaphragms, or of columns braced by girts which in turn are braced by diaphragms, if proper connections are made between the individual elements. In this thesis, behavior of diaphragm-braced I-beams, channel beams, and Z-beams under uniform moments, and the behavior of axially loaded I-section columns braced by girts which in turn are braced by diaphragms are investigated.

Load-deflection relationships of diaphragm-braced beams are obtained taking into consideration the initial imperfections of the beams and using the equilibrium method. Critical moments of …

Structural Behavior Of Small-Scale Steel Models, William A. Litle, David C. Foster, Duke Oakes, Philip A. Falcone, Richard B. Reimer

CCFSS Library (1939 - present)

No abstract provided.

The Dynamic Behavior Of Steel Frame And Truss Buildings, Dixon Rea, Jack G. Bouwkamp, R. W. Clough

CCFSS Library (1939 - present)

This report describes experimental and analytical studies of the dynamic behavior of the East Building of the University of California's new Medical Center at San Francisco, California. It also describes experimental tests conducted on the East Building's mechanical service tower and on an adjacent elevator tower. Experimental tests on the East Building were conducted in the summers of 1964 and 1965. Vibrations were produced by eccentric-masstype vibration generators. Frequency responses, time responses, and mode shapes were observed. In the summer 1964 tests, the first mode east-west had 2% of critical damping and the first mode north-south had 1.8%; the values …

Deformation And Energy Absorption Capacity Of Steel Structures In The Inelastic Range, Theodore V. Galambos

CCFSS Library (1939 - present)

This report summarizes the status of knowledge on the inelastic deformability of steel members and frames. It demonstrates that the inelastic response of planar beams, beamcolumns, connections and frames is well understood and can be adequately, though conservatively, predicted by theory provided the loading is static, proportional and monotonic, and adequate provisions are made to inhibit premature local and lateral-torsional instability. The report reviews the available theoretical work, and examines the experimental evidence. It shows that the inelastic rotation capacity, which defines also the "ductility factor" and the inelastic energy absorption capacity, is both predictable and large enough to meet …

Specification For The Design Of Cold-Formed Steel Structural Members, American Iron And Steel Institute

American Iron and Steel Institute (AISI) Specifications, Standards, Manuals and Research Reports (1946 - present)

No abstract provided.

A Fluidic Liquid Level Control System, Vinod Kumar Verma

Masters Theses

"The prime objective of this investigation was to design and construct a working "Fluidic liquid level control system", and to make a functional study of the characteristics of the devices employed therein. A working model of a "fluidic liquid level control system" is developed and experimental data is collected to describe the functional characteristics of the fluidic circuits employed. The system contains a pressure sensitive, variable frequency oscillator; appropriate demodulation stages to convert the variable frequency alternating signal into a varying non-alternating signal; and on-off control elements in the final stages"--Abstract, page ii.

Cutting Nbs Budget, Norbert J. Kreidl

Materials Science and Engineering Faculty Research & Creative Works

No abstract provided.

Dynamic Capacitance Of Metal-Oxide-Semiconductor Field-Effect Transistors, Marion Wendell Tucker

Masters Theses

"A transient peak was observed for MOSFET devices when measuring the dynamic capacitance versus applied gate voltage for various configurations at low frequencies. This peak is absent in conventional steady-state ac measurements. Since the peak is also absent in high grade devices and at high frequencies a possible explanation in terms of surface state traps is discussed for the observed phenomena"--Abstract, page ii.

Age Hardening In A Mg-9 Wt.% Al Alloy, J. Beverley Clark

Materials Science and Engineering Faculty Research & Creative Works

The precipitation process and age hardening mechanism in a Mg-9 wt.% Al alloy were studied principally by transmission electron microscopy. This alloy age hardens by the general precipitation of plates of the equilibrium Mg₁₇Al₁₂ phase on the basal plane of the magnesium solid solution matrix. No evidence for the formation of either G.P. zones or a transition lattice of the Mg₁₇Al₁₂ precipitate was obtained. Cellular precipitation occurs competitively with the general precipitation at nearly all age hardening temperatures. In the solution treated condition, basal slip and {101̄2} twins are the principal deformation modes. Precipitation …

Interstitial Solute Trapping In Irradiated And Quenched Iron, M. (Manfred) Wuttig, J. T. Stanley, H. K. Birnbaum

Materials Science and Engineering Faculty Research & Creative Works

The interaction of interstitial carbon and nitrogen solutes with defects produced by low temperature neutron irradiation and by quenching was studied in high purity and Ferrovac E iron. Magnetic Dis accommodation techniques were applied to determine the interstitial solute content after irradiation and upon annealing. Doses of about 1017 neutrons/cm2 caused the trapping of about 20 ppm (atomic) interstitial solutes at 65 (carbon) and 40°C (nitrogen). Trapping of carbon in a Ferrovac E iron alloy occurred during a fast quench from 880°C. After trapping, the interstitial solutes reappeared in solid solution at 300 (carbon, neutron irradiation), 200 (nitrogen, neutron irradiation), …

Current Density-Anodic Potential Curves Of Single Crystal Gaas At Low Currents In Koh, Martin E. Straumanis, J. P. Krumme, William Joseph James

Materials Science and Engineering Faculty Research & Creative Works

Single p-type, GaAs crystals of high purity, Zn doped, were used to determine whether or not the inverse octahedral {111} faces show potential differences and various rates of anodic dissolution. The Ga{111}, As{111}, {110}, and {100} faces, were polished, etched, and etch-polished with concentrated H₂SO₄ + H₂O₂, and immersed in IN KOH. The Ga{111} faces were found to be the most noble with respect to rest and anodic dissolution potentials. The potential difference between the inverse {111} faces was as large as 0.14v for the rest and 0.123v for the dissolution potentials. The …

Zener Disaccommodation In Dilute F.C.C. Co-Ti Alloys, H. B. Aaron, M. (Manfred) Wuttig, H. K. Birnbaum

Materials Science and Engineering Faculty Research & Creative Works

The magnetic Dis accommodation, i.e., the time dependence of the low field magnetic permeability, was investigated in cobalt base alloys containing 0-5.1 at.% (0-4.2 wt.%) titanium in the temperature range 400-700°C. A strong temperature dependence of the Dis accommodation observed in the range 430-530°C could be accounted for predominantly by a single first order relaxation process. Analyzing the data in terms of (a) a single exponential relaxation, (b) a lognormal distribution of relaxation times, and (c) a sum of exponential relaxations, it was shown that the relaxation strength varies as the square of the titanium concentration and that the relaxation …

Neutron Radiation Damage In Silicon Transistors, C. A. Goben, F. M. Smits, J. L. Wirth

Electrical and Computer Engineering Faculty Research & Creative Works

In the investigation of base and collector current as a function of the emitter-to-base voltage, previous studies have shown that neutron-induced base current has components originating in the emitter space charge region as well as the neutral base region. This study shows that while the low injection level neutron-induced base current is dominated by the space charge component, the high injection behavior appears to be controlled by recombination in the neutral base region. Additional experiments performed in special tetrode transistors and van der Pauw-type samples indicate that changes in collector current are dominated by recombination in the neutral base, while …

Coupled Transport Of Heat And Mass In Laminar Tube Flow, Lung-Mau Huang

Masters Theses

"The object of this investigation is to study the mutual dependence of heat and mass transport in laminar and hydrodynamically developed tube flow. Consideration is given to gas flow through a tube whose wall is coated with a sublimable materials so that heat and mass transfers take place between the wall and the flowing gas stream. The tube wall is thermally insulated from the external environment, with the result that the latent heat required by the sublimation process at the wall is supplied solely by convective transfer from the gas. The analysis of the problem requires simultaneous solution of the …

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 …

Film Boiling Of Nitrogen From A Spherical Heating Surface At Atmospheric Pressure And Standard Gravity, Juan Jorge MariáNyi

Masters Theses

"A steady state film boiling heat transfer study was conducted at atmospheric pressure, with a heated sphere as the heat transfer surface and liquid nitrogen as the boiling medium. Results indicate that the heat transfer rate in film boiling is not the same around the sphere. For the same heat flux, heat transfer at the sides of the sphere takes place at higher temperatures than at the bottom of the sphere. The data were compared with the equation of Frederking and Clark for spheres (1̲8̲), which was derived to predict steady state conditions at standard, fractional and near zero gravity. …

The Compressibility Of Preconsolidated Till, William H. Koechlein

Masters Theses

"Preconsolidated glacial till was tested "in-situ" with the Geoprobe and in the laboratory on undisturbed soil samples. The two soil testing methods were compared and three tests; consolidation, "thin-cake", and Geoprobe were analyzed to see if a more rapid method for determining the preconsolidation stress of soil could be developed. When comparing Geoprobe results to laboratory results for foundation conditions, it was found the two methods agreed on bearing capacity but differed significantly on settlement. The three tests analyzed for determining the preconsolidation stress indicated they are a function of preconsolidation stress even though there was variation in the test …

A Mechanical Metallurgical Method Of Predicting The Springback Tendencies Of A Bent Metal Strip, Jerrold Myles Alyea

Masters Theses

"Attempted substitution of new solid materials and composite metal strips for those materials presently being used in many applications now being pursued vigorously in industry. A serious problem was created because the newly proposed materials do not exhibit the same springback after bending as did the previously used materials in a particular bend angle and radius situation. Elementary bend theory and mechanical metallurgical techniques have been incorporated into a method which can be used to accurately predict the .2% offset yield strength of any proposed rolled-temper solid metal strip and some composite strips when they must exhibit the same springback …

An Unsteady-State Method For Determining The Thermal Conductivity Of Materials, Richard H. Bulmer

Masters Theses

"Originally this work was initiated to develope [sic] a method for measuring the thermal diffusivity and thermal conductivity of metals. Due to the characteristics of the method and the equipment used, it was concluded that the technique is not suitable for materials of high conductivity. However, results show that the apparatus is valuable for the determination of the thermal diffusivity of relatively poor heat conductors. The favorable characteristics of the method are its rapidity and basic simplicity"--Abstract, page ii.

Semiempirical Determination Of The Differential Fast Flux Spectrum For U-235 Fission With Water Moderator, Henry Anthony Till

Masters Theses

"The differential fast flux spectrum of the UMR Pool Research and Training Reactor core was determined by simultaneous activations of threshold foil detectors by neutron-nucleon reactions. This represents one phase of the composite neutron environment at two sample irradiation locations and the center of a fuel element during a power operation of 200 Kw (th). To accomplish this measurement a semiempirical least-squares approximation fitting activation date to a theoretical Cranberg U-wet fission spectrum was applied. This is a technique designed specifically for water moderated systems and takes into consideration both virgin and down-scatter neutrons. Gamma decay photopeaks were reduced using …

Synchronization Of Pulse Code Modulation Telemetry, Lawrence J. Mueller

Masters Theses

"Pulse Code Modulation (PCM) is one of the most widely utilized radio telemetry techniques for the recovery of test data from aerospace vehicles. Synchronization of the receiver with the transmitted data is perhaps the prime requisite of a PCM telemetry system. In this paper the frame synchronization process is analyzed by developing equations which define the three modes of synchronizer operation (SEARCH, VERIFY, and LOCK) in terms of the relative probabilities of operation. The criteria employed to optimize the synchronization process are the mean time to acquire true synchronization, the probability of true synchronization after verification of the synchronization decision, …

Evaluation Of Methods For Analysis Of Multi-Degree-Of-Freedom Systems With Damping, Brijgopal R. Mohta

Masters Theses

"A general review of various methods for studying the behavior of linear lumped parameter systems with viscous damping is presented. Five methods are discussed. These are: (1) Normal Mode Technique (2) Ho's Method (3) Impedance Method (4) Graphical Technique (5) A Method for Reducing Degrees-of-freedom. For solution of vibration problems by the Normal Mode Technique, the systems are classified as (1) classically damped or (2) non-classically damped. It is shown that the classically damped systems are relatively easy to solve. For non-classically damped systems, the method proposed by K. A. Foss has been employed. This method is quite complex, but …