Engineering Commons^™

The Great Falls Zinc Plant, Donald Edward Macknight

Bachelors Theses and Reports, 1928 - 1970

This paper will be confined to the processes by which zinc is recovered. In discussing the unit processes and operations, I shall first give a general view of the process and why it is necessary. Next, I shall analyze the process in terms of metallurgy and thermodynamics, showing by calculation, where necessary, certain facts that could not be suitably explained without a knowledge of the fundamental principles of extractive metallurgy.

Temperature Stabilized Transistor Direct Current Amplifier, William Lewis Metcalf Jr.

Masters Theses

"A stable direct current transistor amplifier is difficult to design for use at elevated temperatures. The above is true since transistor parameters and bias conditions are affected by temperature. When transistors are incorporated in direct coupled amplifier circuits, these variations in parameters and bias conditions usually result in unstable operation. It is the purpose of this thesis to investigate this problem and to design a stable direct current transistor amplifier which will operate satisfactorily at elevated temperatures.

This problem is of importance as such direct current amplifier circuits are found in airborne or missile servo systems. In such systems the …

Test 632: John Deere 830 Diesel, Nebraska Tractor Test Lab

Nebraska Tractor Tests

No abstract provided.

Test 613: Case 311 Gasoline, Nebraska Tractor Test Lab

Nebraska Tractor Tests

EXPLANATION OF TEST REPORT:

TEST A: The manufacturer's representative operates the tractor for a minimum of 12 hours using light to heavy drawbar loads in each gear.

This serves as a period for limber up, general observation and adjustments. Adjustments that are permissible include valve tappet clearance, breaker, point gap, spark plug gaps, clutch and others of a similar nature. No new parts or accessories can be installed without having mention made of it in the report. No data' are recorded during this preliminary run except the time that the engine is operated.

BELT HORSEPOWER TESTS

TEST B: The throttle …

Servomechanism Compensation With An Active Phase-Lead Network, Robert T. Dewoody

Masters Theses

"The problem is to develop a phase-lead compensation network for a servomechanism which will not reduce the low-frequency gain and thus decrease the velocity-lag error. The principal part of this thesis deals with the design of such an active phase-lead network. The active network does not have d-c coupling; this eliminates drift problems.

To illustrate an active phase-lead network a simple second order servomechanism is used as a basis for comparing three methods of compensation.

The first method is compensation with a conventional phase-lead network with a gain decrease. The second method is compensation with a conventional phase-lead network with …

Investigation Of Plastic Deformation In Prestressed Concrete Slabs From Long Time Loading, Joe B. Roberts

Masters Theses

"It is the purpose of this research to investigate the creep in a thin concrete slab under a long-time prestress load with the compressive load being applied to the edge of the slab through a bearing plate of small dimensions.

Seven plain concrete slabs, 3' x 4' x 4", approximately one year old, made of normal cement and approved aggregate were subjected to the following loading conditions: (1) Three slabs loaded at the center of the greater dimension with a prestress load or 20,000 pounds applied over an area of eight square inches, (2) Three slabs loaded symmetrically at six …

The Stability Of Rectangular Plates With Built-In Supports At The Edges, John Bruce Miles

Masters Theses

"The purpose of this investigation is to derive an expression for the critical stress for a thin rectangular plate with compressive edge loading. The load is applied on two opposite edges with the remaining two edges built-in. (See Fig. 1) This is essentially a stability problem.

Rectangular plates with compressive edge loading and various edge restraints appear in a number of engineering structures. Bulkheads of ships could be so classified, as could certain components of fabricated beams and columns. The new supersonic B-58 bomber developed by Convair has a honeycomb wing structure dictated by heat conduction requirements. This, too, involves …

Filter Materials For Emergency Use In Diatomite Type Water Filters, Robert Wassell Mcleane

Masters Theses

"A completely different type of filter, using diatomaceous earth as the filter media, had been in use for many years for filtration of industrial liquids, however, the use of diatomaceous earth for water filtration purposes had been discouraged due to the rapid clogging of the filter material. "As late as 1930 it was reported that the very excellence of filtration with diatomite prevented its extensive use in water filtration except where complete elimination of bacteria and suspended matter is essential.”

Diatomaceous earth, however, seemed to exhibit the general properties the research groups were seeking; in the refined state it exhibited …

Influence Of Some Metals On The Rate Of Corrosion And Deposition Of Titanium In Molten Salt Baths, Yu-Pu Huang

Masters Theses

"2. The purpose of this investigation. The substances obtained by corrosion of titanium in fused salts, if leached with water and dried, are composed of three kinds of products, namely of black, gray and yellowish ones. The black product was identified by X-ray diffraction as titanium-oxygen alloy with 9-10% by weight oxygen which later was used as coating material instead of the titanium sheet for deposition experiments described previously. The yellowish product was identified as rutile. The grayish product was also rutile but containing some titanium powder. Of these three products only the black one possessed the ability to deposit …

Investigation Of Length Changes In Prestressed Concrete Slabs With Outside Exposures, John Best

Masters Theses

"In general, pavements may be classed as being either rigid or flexible. The term “rigid pavement”, as commonly used in the United States, is applied only to wearing surfaces constructed of portland-cement concrete. All other types of pavements are classed as “flexible”. A pavement constructed of portland-cement concrete is assumed to possess considerable flexural strength which will permit it to act as a beam and allow it to bridge any minor irregularities which may occur in the base on which it rests, hence the term “rigid”….

In view of the experience and information gathered in over 50 years of road …

Physical Properties Of Concrete At Early Ages, Curtis E. Weddle Jr.

Masters Theses

"The introduction of the motor vehicle and the subsequent rapid expansion of the highway systems of the United States have brought with them many problems.

The Civil Engineer, in his attempts to provide adequate safe avenues of travel for the populace, has been faced with many problems. Handicapped by the need for speed in design and lack of information of the trends in motor vehicle design, the engineer has been forced at times to utilize design methods inconsistent with good engineering practices.

Of the many types of pavement sections which have been designed in an effort to provide structurally and …

Separation Of Iron-Tin Alloys Using Gas-Solid Reactions, Carl Richard Bieling

Masters Theses

"For years it has been a problem to the tin smelting, plating, and detinning industries to be able to separate iron from tin once they were associated together as described above. Due to the lack of a tin smelter in the United States in the past, and the abundance of tin scrap available, which had little value either for the iron content or the tin content in their untreated state, most interest was concentrated on seeking methods of separating this tin scrap into its two useful components, iron and tin, rather than deal with the problems of smelting tin from …

Creep Characteristics Of Thin Prestressed Concrete Slabs, Wayne F. Alch

Masters Theses

"Prestressed concrete as a structural material is finding wider usage in the United States today. Until recently, economic factors have precluded the use of prestressed concrete in this country, while Europe became the leader in discovering new uses and applications in construction for the material. As new methods are developed in this country, more engineers and contractors are discovering that prestressed concrete is, in many ways, far superior to plain or reinforced concrete. In line with this awakening the Missouri Highway Department is carrying on research to determine the feasibility of prestressed concrete for highway slabs. This study is a …

Investigation Of Length Changes And Warping In Thin Prestressed Pavements, Wilbur D. Stites

Masters Theses

"The present growth of the American highway system presents a staggering problem to the highway designer. The increased and urgent demand for more highways, capable of accommodating traffic loads that are constantly increasing, combined with the increased construction cost of highways, behooves the present day highway designer to envision future highway problems that will arise. These future problems are numerous and complex; however, it seems the primary problem is the selection of a surfacing material that will withstand projected traffic loads with a maximum economy of construction and future maintenance costs. Concrete at the present time is the most satisfactory …

An Investigation Of The Dissolution Of Hafnium-Free Zirconium In Hydrofluoric Acid And The Effect Of Fluoride Additions, Alfred S. Neiman

Masters Theses

"Hafnium-free zirconium has assumed great importance in commercial use in recent years. When economical methods were developed in 1950 to remove hafnium from Zr, a metal was produced which not only exhibited good corrosion resistance and desirable physical properties, but also had a very low absorption cross section for thermal neutrons. Such a metal could obviously be utilized to advantage as a structural material for nuclear reactors. This application is the most important one for Zr at present.

Good corrosion resistance to most mineral acids is one of the outstanding non-nuclear properties of Zr. Hf-free Zr has good corrosion resistance …

The Correlation Of Kelly Ball Penetration Readings With Standard Slump Cone Readings For Concrete Made From Missouri Aggregates, James Claude Rives

Masters Theses

"The ASTM standard slump test as set forth in ASTM Designation: C143-52, has been used for many years in concrete construction tor measuring the consistency of plastic concrete. Slump tests taken in the laboratory are considered reasonably accurate; however, there are numerous disadvantages in performing these tests in the field; the most serious being the time required to make a test on pavement work. The standard slump cone method is also subject to personal differences in sampling, rigidity and smoothness of base, dampening the apparatus, filling the cone, rodding, raising the cone, freedom from jarring and selection of point to …

The Magnitude And Directions Of Strains And Stresses In Edge Loaded Concrete Slabs, William M. Baldwin

Masters Theses

"The concrete industry in the United States represents one of the fastest growing segments of the national economy. Many reasons for this may be given, among which are, the durability of concrete structures, the local availability of a large portion of the materials used in concrete, and its wide range of adaptability to the designs of engineers and architects.

One of the most recent changes in concrete usage is the change from reinforced concrete to prestressed concrete. The term prestressed as used herein refers to any type of reinforced concrete in which the reinforcing material has a stress prior to …

Development Of Rating Curves For Concrete Rebound Hammer On Concrete Specimens From Local Aggregates, Rolla Smith Lush

Masters Theses

"Frequently engineers find it imperative to determine the compressive strength of concrete as it exists in a structure. There are two methods of making this determination, either by a destructive or a non-destructive test. The destructive test has the disadvantage of being costly, time consuming, and detrimental to the appearance of the concrete surface. The non-destructive, pulse-velocity, sonic measuring devices used to determine the compressive strength of concrete in the field also have the disadvantage of high cost due to the large initial cost of the equipment.

A relatively new non-destructive testing device has been developed which may replace the …

A Simplified Mathematical Method For Petroleum Property Evaluation, Charles G. Edwards

Masters Theses

"The economic evaluation of a petroleum reservoir involves two fundamental operations; 1) predicting future production behaviour, 2) determining the present worth or this future production. This thesis purposes to eliminate the necessity of repeated calculation which is required in performing the second operation under existing methods.

Because the first operation, that of predicting future behaviour, is necessarily an estimate, there is an apparent tendency to employ approximate methods in the determination of present worth. The evaluation method developed in this paper confines estimation to the first operation, where it rightly belongs, and treats all subsequent work with mathematical exactness.The estimation …

Statistical Analysis Of X-40 (Stellite-31) Production Blends., Edward P. Patterson

Masters Theses

"An investigation was undertaken to statistically analyze the data obtained on X-40 (Stellite 31) production blends which were tested to the requirements of AMS 5382. For our purpose a blend is one or more furnace heats, the shot of which has been thoroughly mixed to produce greater uniformity of product. The mixed shot is charged to the arc furnaces and cast into parts, and test specimens. A great range of test results have been obtained in testing blends, and it was felt that a statistical analysis of a few of the variables might yield information which could be applied toward …

Determination Of Lattice Constants, And Thermal Expansion Coefficients Of Ti₂O₃ And Of Its Solid Solutions With Ti, Tatsuhiko Ejima

Masters Theses

"For the determination of the precise lattice constants of Ti₂O₃, it is very important to use a Ti₂O₃ as pure as possible.

Due to the formation of solid solution with titanium or oxygen, ranging from 32.5 to. 34.5% O₂ by weight in the Ti-O binary system, it is very difficult to get a pure Ti₂O₃ (33.8% O₂ by weight) in the laboratory.

To determine the precise lattice constants of pure Ti₂O₃, therefore, the extrapolation method was used.

This method computes the respective constants for pure Ti₂O₃ from the values obtained With Ti₂O₃-Ti solid solutions by extrapolation. To carry out such …

Physical Properties Of Concrete At Early Ages, Karl H. Dunn

Masters Theses

"There are well over 100,000 miles of concrete pavements existing today on our United States highway system. The development of these pavements during the first half of this century has been a process of learning from construction applications and mistakes. However, the unexpected increase in traffic load has brought highway designers to experiment with relatively new types and designs of concrete pavement construction.

Some designers, in an effort to reduce temperature warping stresses, have used short slabs 10 to 15 feet in length, generally unreinforced. Another type of construction is the definitely jointed slabs, the slabs being from 20 to …

A Determination Of The Sonic Modulus Of Early Age Concrete, William Dale Nelson

Masters Theses

"The problem which the writer is analyzing in this thesis was suggested by Professor E. W. Carlton of the Civil Engineering Department. It is a determination, by use of sonic testing equipment, of the growth in the sonic modulus of early age concrete.

Since 1938 when T. C. Powers published his paper, "Measuring Young's Modulus of Elasticity by Means of Sonic Vibrations", in the proceedings of the American Society of Testing Materials, Vol. 38, Part II, a great deal of work has been done on the applications of sonic testing of concrete. It began a new era in concrete testing, …

A Comparative Determination Of Weld Shearing Values In Welded Wire Reinforcement Fabric, Ernest Charles Kobs

Masters Theses

"At the suggestion of Professor E. W. Carlton, Chairman, Civil Engineering Department, Missouri School of Mines and Metallurgy, the author selected as subject for research thesis, “A Comparative Determination of Weld Shear Values in Welded Wire Reinforcement Fabric”.

In 1948, the Wire Reinforcement Institute initiated a research program to measure the actual stresses, including weld shear stresses, that occur in Welded Wire Fabric when used as reinforcement in a concrete slab. A great majority of this research was under the supervision of Professor Carlton.

The results of these investigations indicated a wide variation in strength of welds. As a means …

The Strength Of Bituminous Mixtures And Their Behavior Under Repeated Loads, Part 2, Leonard E. Wood, William Harner Goetz

JTRP Technical Reports

No abstract provided.

A Literature Survey On Soil Stabilization Lime-Flyash Admixtures : Informational Report, F. Kocataskin

JTRP Technical Reports

No abstract provided.

Pumping Of Highway And Airfield Pavements: Technical Paper, Eldon J. Yoder

JTRP Technical Reports

No abstract provided.

Power Augers And Earth Resistivity Units As Supplements To Drilling Machines, D. G. Shurig

JTRP Technical Reports

No abstract provided.

Summary Report On State Highway Needs In Indiana, Donald O. Covault, Harold L. Michael, Arthur K. Branham

JTRP Technical Reports

No abstract provided.

Selection And Retention Of Civil Engineer Employees : Technical Paper, Arthur K. Branham

JTRP Technical Reports

No abstract provided.