Engineering Commons^™

The Monopole Antenna With A Small Number Of Radials, S. H. Durrani

Electrical and Computer Engineering ETDs

This paper reports a study of an antenna system consisting of a vertical monopole and a small number of insulated horizontal radials lying lightly on the ground.

The monopole antenna has long been popular for medium frequency broadcasting because of its inherent simplicity and economy. Although quarter-wavelength resonant structures were used in the early days, it was shown by Ballantine (1924) that for a given power, the strongest field strength at the radio horizon was produced by an antenna about 0.6 wavelength long. This ignored the sky wave and was based on the assumption of a perfectly conducting (and reflecting) …

Hypersonic Plasma Thermionic Generator, Andre R. Leblanc

Electrical and Computer Engineering ETDs

The Langmuir two-probe system is extended to cover the case of electron emission from one of the probes. The contact potential difference between the two probes is also included as part of the equations. One of the probes, known as the emitter, operates at sufficiently high temperatures such that electron emission occurs, while the other probe, known as the collector, operates at low enough temperatures such that its electron emission can be neglected.

Linear Side-Loaded Transmission-Line Antennas, Robert W. Kulterman

Electrical and Computer Engineering ETDs

A need has arisen in recent years for a mobile transmitting antenna capable of radiating large amounts of power as efficiently as possible in the frequency range from 10 to 40 kc. Several mechanical and electrical problems are encountered in building and operating such an antenna.

Unm Snail Programming Manual, Paul Edward Presson

Electrical and Computer Engineering ETDs

The purpose of this thesis is to provide an introduction at the high school level to the principles of programming digital computers and to serve as a programming manual for the UNM SNAIL. The thesis is self-contained; that is, it may be read without reference material to provide a general background knowledge of computer programming.

Electromagnetic Radiation In Magneto-Ionic Media For Vlf And Vhf Spectra, Kenneth R. Cook

Electrical and Computer Engineering ETDs

The interaction of electromagnetic fields and magneto-ionic media has received considerable attention in the last few years. In rather general terms, the investigation of these phenomena can be categorized into two basic classes. In one class of investigation the primary interest is the dynamic nature of the plasma when subjected to specialized forms of electromagnetic fields. This branch of science has various nomenclatures such as hydromagnetics, magnetohydrodynamics, plasma physics and numerous others implying the use of high density ionized gases interacting with electromagnetic fields. Controlled fusion processes for transforming energy states is an example of this branch of electromagnetics and …

A Multistory Structure Concept, Wybe J. Van Der Meer

Civil Engineering ETDs

It is the objective of this thesis to investigate the feasibility of a multistoried structural concept in which the principal structural elements are hollow girders and chambered hollow columns. The scope will be directed towards the general conceptions, assumptions and design procedures for the system. Only such specific design of a particular example will be accomplished as is necessary to provide correlation and justification for the general assumptions. A detailed investigation and design is not intended since this thesis is oriented towards establishing a general concept not merely a particular example.

Experimental Investigation Of The Interaction Of An Oblique Shock Wave With A Turbulent Boundary Layer, Amado Arthur Trujillo

Mechanical Engineering ETDs

The purpose of the investigation was to accurately describe the interaction of a shock wave and a turbulent boundary layer based upon the measurement and subsequent analysis of both static and impact pressure throughout the interaction region.

Some Design Criteria For Open-Ended Microwave Cavities, Richard O. Gilmer

Electrical and Computer Engineering ETDs

Primarily this paper describes the electromagnetic problems involved in determining a proper waveguide size for the ^TE11N cavity and its terminations. Also, one chapter is devoted to construction techniques used in the construction of open-ended sampling cavities. The approach one may use for aerodynamic improvements of the cavities is discussed, but no conclusions can be drawn about the design's validity since no experimental tests were taken.

This paper will describe the design, construction, and testing of a microwave cavity, the end plates which are replaced by terminations which allow up to 93% of the cross-sectional area of the terminations …

A Study Of Temperature Measurement Precision In Debye-Scherrer Specimens During High Temperature X-Ray Diffraction Measurement Of Thermal Expansion, Roy Glenn Merryman

Mechanical Engineering ETDs

The literature cited covers a comprehensive survey on temperature measurement methods in thermal expansion determination utilizing X-ray diffraction from 1921 through 1961 and a compilation of all published data on the thermal expansion of gold from 1916 through 1960 and magnesium oxide from 1906 through 1961. References for comparison of the MgO results with those of the Bureau of Mines Interlaboratory Program of Thermal Expansion Measurements on MgO are also presented. The literature on temperature measurement was limited to those articles featuring camera design or temperature conditions, since to examine publications on all phases of thermal expansion was found to …

Determination Of Thermal Stresses At Interior Points, Siegfried Thunborg Jr.

Mechanical Engineering ETDs

Existing theory was used to determine the thermal stresses and strains throughout a long thick walled cylinder under equilibrium thermal conditions when the thermal gra­dient through the wall is dependent on radial position only.

A thick walled cylindrical model, made of a plastic material, was constructed and strain gages were imbedded in and mounted on the cylinder to determine strains at interior and surface locations. The cylinder was subjected to equi­librium and transient thermal conditions and thermal strains were measured. In the equilibrium thermal condition the measured strains were compared with those predicted by theory.

The results show that imbedded …

An Automatic Standard Cell Comparator, D. W. Braudaway

Electrical and Computer Engineering ETDs

No abstract provided.

Sediment Transport Parameters, Rio Puerco Near Bernardo, New Mexico., Carl F. Nordin Jr.

Civil Engineering ETDs

Preliminary findings of a study of sediment transport in streams with high concentrations of suspended fine sediment indicate that for Rio Puerco near Bernardo, New Mexico the velocity varies logarithmically with depth, and the concentration distribution for several size classes of sand may be described by a conventional distribution equation if the fall velocity of the sand is corrected for the influence of the fine sediment. A corrected fall velocity, empirically defined for a temperature of 24°C and for concentrations up to about 150,000 ppm, is given.

The purpose of this study was to investigate some aspects of the sediment …

The Sand Equivalent As An Acceptance And Control Test For Asphaltic Concrete In New Mexico, Delmar E. Calhoun

Civil Engineering ETDs

The research reported in this thesis was sponsored by the New Mexico State Highway Department and was directed at evaluating the efficacy of the sand equivalent test when used on New Mexico aggregates used for asphaltic concrete pavements.

Conduction Phenomena Of Reduced Titanium Dioxide With An Oxide Surface Layer, Richard Bechtel

Electrical and Computer Engineering ETDs

No abstract provided.

Counter Circuits Using Gaseous Discharge Tubes And Rectifiers, Robert Creveling

Electrical and Computer Engineering ETDs

This thesis pertains to an electric circuit consisting of gaseous discharge tubes and rectifiers arranged to comprise a counting or integrating device for electric impulses impressed on the system. The ideas presented herewith are wholly those of the author and were submitted in the form of a patent application via the New Mexico School of Mines in June 1950. The basic idea for such a circuit was conceived on November 14, 1949.

Compressive And Flexural Strength Of Portland Cement Concrete As Affected By Fractured Particles Of Coarse Aggregate, Russell L. Vesper

Civil Engineering ETDs

Although a great deal of experimental data are available on many of the factors involved in a concrete mix design, a limited amount of work has been done to determine the effect of the surface characteristics of the concrete aggregates. Some research has been done in this connection by the New Mexico Highway Department. Some of the results of this research are included in a later section of this thesis.

Linear Time Base Precision And The Compound Sweep Concept, William W. Steger

Electrical and Computer Engineering ETDs

This paper is a monograph on general precision criteria for feedback linear time base circuits. The linearity and stability performance of these devices is evaluated in terms of deviation from an ideal ramp function.

In its entirety, the paper attempts to provide a complete reference for the most commonly encountered aspects of time base precision. Attention is centered on what could be called the "low frequency" case, which most often is valid in applications requiring a high precision time base.

The subject is developed in a number of progressive, cumulative stages. The end products at each stage of the analysis …

Radial Dislocations In Plane Stress., William J. Sieger

Mechanical Engineering ETDs

The elastic dislocation theory was used to obtain stress potentials for the dual dislocation problem. These solutions give the stress field for an infinite plane region containing a centrally located circular hole with two radial dislocations originating from opposite sides of the hole and extending into the region along a line perpendicular to the axis of applied load. Solutions were obtained for both the case of a linear dislocation relation along the cuts and for a parabolic relation.

A Prototype Transmitter For A Microwave Refractometer, John C. Jordan

Electrical and Computer Engineering ETDs

A study of the design, development and fabrication details of a transmitter for a microwave refractometer is presented. Atmospheric, radio frequency, refractive index is to be measured rapidly and directly up to altitudes of the order of 200,000 feet. Requirements for the transmitter with regard to its weight, volume and environment are indeed stringent since it is proposed to package the transmitter in a ogive configuration and elevate it to these altitudes utilizing a rocket propulsion system.

Complementary Transistor Memory Circuit And Logic Applications, Lee M. Bossart

Electrical and Computer Engineering ETDs

No abstract provided.

An Approach To Azimuth Angle Refraction Corrections, Wallis R. Cramond

Electrical and Computer Engineering ETDs

In the past, analyses of tropospheric reactions of electromagnetic waves propagating in the atmosphere have been based on spherically symmetric medium. However, this applies only to ray bending in a vertical plane (elevation angles). Numerous methods have been developed to correct for elevation angle errors. In 1961, the presentation of a new method for use in a nonsymmetric atmosphere revived interest in horizontal (azimuth angle) bending. In order to use this method to test significance of azimuth angle errors, the spacial distribution of index of refraction must be known.

The primary objective of this paper is to propose a model …

A Theory Of Self-Evaluating Discrete Communication Systems, Samuel D. Sterns

Electrical and Computer Engineering ETDs

No abstract provided.

Radar Back-Scatter Theories For Near-Vertical Incidence And Their Application To An Estimate Of The Lunar Surface Roughness, Harbhajan S. Hayre

Electrical and Computer Engineering ETDs

This work, after the critical examination of the theoretical background on back-scattering from rough surfaces, offers a new approach to its theory. Various back-scatter theories, as well as the statistical models of terrain and moon assumed therein, are critically reviewed and correlated. A new approach which uses a simple statistical model is then presented for the description of scattering of electromagnetic waves from a rough surface. The statistics of a rough surface are discussed in terms of certain parameters which can be easily associated the surface features, and a new expression for the back-scattering radar cross section per unit area …

Plastic Models For The Study Of Thermal Stresses, Carl W. Theisen

Mechanical Engineering ETDs

The purpose of this thesis was to determine and evaluate an experimental method for accurately measuring thermal stresses in structural shapes subjected to large transient thermal gradients, without introducing the problems of high temperature instrumentation, or expensive and elaborate test facilities. Most experimental methods consist of mounting high temperature strain gages on the prototype or model of the metal structure to be evaluated, thermal shocking the structure and then recording the accompanying strains. This method is used quite extensively in the aircraft field, and in others, where the effects of thermal stresses must be considered. However, problems are encountered when …

A System For Recording Electromagnetic Atmospheric Noise In 30-50 Cps Region, James F. White

Electrical and Computer Engineering ETDs

The electromagnetic noise spectrum extends from below 1 cps to above 3,000 mcs. Within this spectrum many phenomena of atmospheric noise have been observed. Those atmospherics which occur in the audio frequency region of the spectrum have been given not only descriptive but also subjective names by many different investigators. As a result, it is often difficult to determine from the literature what aspect of the noise phenomenon is being considered. In addition, references to low frequencies involved in certain experiments are vague. A brief history of atmospherics research is presented here in order to explain the terminology, to show …

A Study Of Gamma-Ray Photoconductivity In Organic Dielectric Materials, Stanley E. Harrison

Electrical and Computer Engineering ETDs

The gamma-ray photoconductivities of polyethylene, polystyrene, polyvinylchloride, polypropylene, Teflon, Nylon, Kel-F, and three thermosetting resins denoted as Epoxy 1478-1, 1478-3, and 1478-22 have been measured. The measurements were made at steady-state gamma-ray intensities ranging from 1.0rad(H₂O)/min to 3.0 x 10⁵ rads(H₂o)/min and at controlled temperatures ranging from 90 degrees Fahrenheit to 140 degrees Fahrenheit. Conductivity changes resulting from the steady-state gamma-ray exposures were measured continuously throughout the exposure and after the exposure. The exposure period was of sufficient duration to allow all samples to achieve an equilibrium conductivity value.

The Development Of A Static Pressure Probe For The Interaction Region Of Shock Waves And Boundary Layers, John Rode

Mechanical Engineering ETDs

The purpose of this investigation was to develop a static pressure probe for measuring static pressures in the region of interaction of a shock wave and a boundary layer. Requirements of such a probe are: small size to permit measurement of pressure variations within the thin boundary layer, pressure coefficient close to unity to permit precise static pressure measurements in regions of unknown and varying velocity and proper response to large pressure gradients.

An Evaluation Of Concrete Making Properties Of Scoria Lightweight Aggregate Based On Compressive Strength, Khurshid Ahmad Chaudhry

Civil Engineering ETDs

Compressive strength of scoria-aggregate concrete was examined by introducing controlled variables into the mix proportions. A mix design method for accurate mix design was formulated and was analyzed for consistency and feasibility.

A Qualitative Study On An Exploding Wire Fuse, W.D. Lacoss

Electrical and Computer Engineering ETDs

This study was undertaken in an effort to develop basic concepts of normal operating fuse criteria that will apply to capacitor energy storage systems. To develop ideas germane to normal fuse operating limits, it was necessary to consider certain principles that preceded this development: (1) A review had to be made of some of the experimental work on the exploding wire phenomenon to indicate a possible application as a fuse; (2) A typical circuit requiring such a fuse had to be described schematically and analyzed to show the dependency between the circuit parameters and the necessary conditions for obtaining fusing …