Engineering Commons^™

Paper Recycling : Recovery Of Secondary Fibers By Selective Wettability, Gary Keith Welshans

Dissertations

A separation process has been developed which recovers similar paper grades from a mixed stock by selective wettability. This process capitalizes on the various paper additives which are intended to resist water wetting and result in paper flotation. While water can be used to achieve many desirable paper separations, the detention times required are excessive, and therefore, limit any industrial application. Surface-active agents, in low concentrations, can be used advantageously by reducing the detention times for all paper while the structure of the surfactant can be used to selectively recover similar papers over a controlled time period. Detention times have …

Possible Efficiency Improvements In Residential, Gas Fired Furnances, Philip Louis Rinaldi

Theses

This project examines the problem of how to improve energy utilization in a residential space heating environment. Techniques for lowering unit energy consumption are developed and the feasibility of their implementation is discussed.

The project development first establishes the magnitude of the energy wastage problem for the individual consumer and its impact on the national scale. It must be emphasized that these represent two, sometimes distinctly different justifications for reducing energy use in the home. What may be considered only a small personal waste of $50 to $100 per year may indeed--when viewed in aggregate--represent a significant burden on the …

A Kinetic Study Of The Reactions Of Poly-L-Lysine With 1-Halo-2, 4-Dinitrobenzenes, Raymond K. Rakowitz

Theses

The kinetics of the reactions of poly-L-lysine with 1-Fluoro, 1-Chloro, 1-Bromo, and 1-Iodo-2,4-Dinitrobenzenes have been studied. The investigation was done at 25°C as a function of pH and concentration. In all cases the rate of reaction increased as pH increased. In the reactions of Chloro, Bromo, and Iododinitrobenzenes with Polylysine the reaction rate is the composite of two rates; one associated with the random coil and one associated with the helical conformation. For the reaction of Fluorodinitrobenzene with Polylysine the reaction rate is the composite of four rates; two associated with the random coil and two associated with the helical …

Management Of Manpower Planning In A Job Shop, John E. Yadlon

Theses

The object of any system of manpower planning is to provide a means to optimize manpower utilization. Within this base there is the normal requirement to provide effective utilization of equipment, materials and manpower. In a production type of environment, studies, statistics, research and supervisory manpower are readily available to best optimize manpower planning. In a job shop environment only fragments of these elements are available. Also, the available supervisory time for studies and implementation of research into statistics is usually very small. The net result is that manpower management in a job shop is all too often guessed at. …

The Introduction Of A Computerized Production Control System In A Small Manufacturing Company, Harry Leroy Zimmerly

Theses

The purpose of this thesis is to acquaint the reader with the intricacies of introducing a computerized production control system into a small manufacturing company. To do this a hypothetical company was described as it existed with a manual production control system. The information flow of the manual system was described in detail.

Potential computerized production control systems with a shop data collection system were then investigated. A computerized system would expedite information flow, allow rapid assembly tracking, take accurate data and reveal the actual cost (including labor cost) of an assembly. This was done first by examining technical publications. …

The Countercurrent Multistage Desorption Of The Acetic Acid/Water Solution With An Inert Vapor, Michael John Danko

Theses

The desorption of a acetic acid and water solution with an inert gas was experimentally investigated using a perforated plate distillation column having 17 actual trays. An inert air stream flowing countercurrent was used to strip the water from the acetic acid and water solution.

The feed composition was 0.2509 mole fraction acetic acid. The experimental results showed the best obtainable separation to be 0.16118 and 0.3965 mole fraction acetic acid in the overhead condensate and bottoms respectively, at an average column operating temperature of 56.0 degrees centigrade. The concentration of acetic acid predicted by calculation is 0.003917 and 0.9860 …

The Slow Settling Of A Sphere In A Viscous Fluid In The Proximity Of A Corner, Joseph Kisutcza

Theses

Experimental settling velocities for three different sizes of Delrin spheres in Ucon lubricant were determined at 20.2 degrees Celsius in order to confirm the validity of a theoretically derived equation for the settling of a sphere in the proximity of a corner. The experiments were conducted in a wedge shaped column with a circular sector base, filled with the viscous fluid, where the angle of the wedge was varied for experimental purposes. The distance from the wedge apex to the particle was also changed for the different runs.

The experimental data gave a good approximation of the values evaluated by …

Semicontinous Ph-Parametric Pump : Experimental Study, Hsien-Chih Lee

Theses

Voidage of SP Sephadex (C-50) ion exchanger at different aqueous buffer concentration and the pH have been estimated from draining the interstitial aqueous. Experimental results of the SP Sephadex (C-50) voidage at pH cycling zone are in quantitative agreement with previous test method, so the voidage estimated from draining the interstital aqueous can be used in pH-parametric pumping. The optional displacement volume in semicontinuous pH-parametric pump of different buffer concentration can be predicted from voidage. A semicontinuous pH-parametric pump for separating proteins has been experimentally investigated using the model system haemoglobin and albumin on a. SP Sephadex (C-50) ion exchanger. …

Numerical Control Milling, Roger Schroeder

Graduate Research Papers

This research paper centers on two general problems:

1) Development of machine angles on the point-to-point NC mill by utilizing different combinations of feed rates on the X and Y axes.

2) Developing a learning activity package which includes a product to be produced by students on the numerical control milling machine that is safe, fast and inexpensive. The experiences gained in this activity will give the students a good working knowledge of numerical control principles.

Test 1276: White Field Boss 2-155 Dsl 18-Speed, Nebraska Tractor Test Lab

Nebraska Tractor Tests

EXPLANATION OF THE TEST PROCEDURE General Tractors are tested at the University of Nebraska according to the Agricultural Tractor Test Code approved by the American Society of Agricultural Engineers and the Society of Automotive Engineers or official Nebraska test procedure. The manufacturer selects the tractor to be tested and certifies that it is a stock model. Each tractor is equipped with the common power consuming accessories such as power steering, power lift pump, generator, etc., if available. Power consuming accessories may be disconnected only when the means for disconnecting can be reached from the operating station. An official representative of …

Test 1275: White Field Boss 2-135 Diesel 18-Speed, Nebraska Tractor Test Lab

Nebraska Tractor Tests

EXPLANATION OF THE TEST PROCEDURE General Tractors are tested at the University of Nebraska according to the Agricultural Tractor Test Code approved by the American Society of Agricultural Engineers and the Society of Automotive Engineers or official Nebraska test procedure. The manufacturer selects the tractor to be tested and certifies that it is a stock model. Each tractor is equipped with the common power consuming accessories such as power steering, power lift pump, generator, etc., if available. Power consuming accessories may be disconnected only when the means for disconnecting can be reached from the operating station. An official representative of …

A Comprehensive Study Of Excimer Laser Systems, Robert Ray Butcher

Electrical and Computer Engineering ETDs

Rare gas halogen lasers are finding increasing usage as an intense source of ultraviolet energy. Many applications require a high energy laser capable of operation at reasonably high repetition rates. Elec­trical discharge pumping satisfies these requirements quite nicely, however to date little has been reported on the discharge character­istics of this class of laser. This paper describes a parametric study done on electrical discharge excimer laser systems.

We have designed and tested a flashboard pre-ionized excimer laser utilizing a cable pulse forming network (PFN) for the main discharge. Extensive voltage and current data were taken with various gas mixtures at …

Acuta Enews May 1978, Vol. 7, No.5

ACUTA Newsletters

In This Issue

PRESIDENT'S MESSAGE

PARTY LINE

BITS & PIECE

S SNOWBOARD CONFERENCE '78

MOUTH OF THE SOUTH

POTPOURRI

VIRGINIA VIEW

GETTING THERE FROM HERE--- AT A DISCOUNT

A Design Study For A Wavy Hydrodynamic Mechanical Face Seal, Raymond Edward Pierce

Mechanical Engineering ETDs

A desirable objective of mechanical face seal design is to achieve the maximum hydrodynamic load support possible while main­taining an acceptable leakage. In this way, mechanical face seal life can be greatly extended as the wear of the seal faces is significantly reduced. It has been shown that circumferentially varying waviness of one of the faces of a mechanical face seal causes such hydrodynamic lubrication.

The objective of this investigation is to examine the performance characteristics of the wavy mechanical face seal by studying the effects of certain design parameters. Seal performance is measured by leakage and wear rate. The …

Rayleigh-Debye Scattering With Focused Laser Beams, Lee W. Casperson, Cavour W. Yeh

Electrical and Computer Engineering Faculty Publications and Presentations

A focused beam technique has been developed for diagnosing the characteristics of individual particles within a polydisperse ensemble. In the Rayleigh-Debye approximation the scattered fields are related to the orientation and properties of a scatterer by means of explicit analytic formulas. The results simplify when the particle size is small compared to the minimum beam diameter.

A Mathematical Model Of Stratified Bi-Directional Flow Through The Railroad Causeway Embankment Of Great Salt Lake, James T. Cameron

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A two-dimensional, finite-element, porous-media flow model is developed to simulate stratified bi-directional flow of brine through the earth embankment carrying the Southern Pacific Railroad across Great Salt Lake. The model is part of a two-year research program whose objective is to develop a computer model of circulation in Great Salt Lake. This overall model is to be used as a predictive device for salinity distributions and circulation patterns in the lake. The porous media flow model is designed to establish flow rates through the Southern Pacific Railroad causeway embankment which traverses the north central part of the lake and divides …

Engineering Properties, And Slope Stability And Settlement Analysis Related To Phosphate Mine Spoil Dumps In Southeastern Idaho, Richard Ellsworth Riker

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The engineering properties of waste spoil from phosphate mines in Southeastern Idaho were determined through field and laboratory testing. The testing included compaction tests, grain size analysis, powder x-ray defraction tests, permeability tests, compression tests, triaxial and direct shear strength tests, and nutrient analyses. Based on these tests, the slope stability and settlement characteristics of phosphate spoil dumps were investigated.

The study showed that the foundation is an important component of the stability of a spoil dump. Hypothetical examples were used to illustrate possible modes of foundation failures. Such failures might occur when weak foundation soils exist or when there …

A Mathematical Model Of The Dispersion Of A Concentrated Substance For Use In The Great Salt Lake's South Arm, Anthony O. Rughellis

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The ability to predict the dispersion of substances in the Great Salt Lake is a requisite towards making responsible management decisions relating to uses of the lake. The lake is a complex terminal body of water and will require a fairly sophisticated mathematical model to properly simulate the dispersion process in the lake. This finite element convection-dispersion model is a first step towards developing a comprehensive model.

The model provides a finite element solution to the two-dimensional convection-dispersion equation and is capable of simulating steady or unsteady-state situations. It utilizes a known velocity field, dispersion coefficients, an introduced substance concentration, …

Irish H & V News

Building Services Engineering

No abstract provided.

Geothermal Energy: Heat Extraction From Hot-Dry-Rock Masses In The Presence Of Secondary Thermal Cracks, Yaw-Min Lu

Mechanical Engineering ETDs

Additional heat extraction from geothermal energy reservoirs depends on the feasibility to extend the main, hydraulic fracture through secondary thermal cracks of the adjacent hot rock. When the main, hydraulic fracture is cooled sufficiently, these secon­dary thermal cracks are produced normal to the main fracture surface, As such, both the heat transfer surface area and heat energy available to the fluid circulating through the main, hydraulic fracture system increase.

An Investigation Into The Transport Properties And Kinetic Parameters Of Single Coal Particles During Devolatilization, Gregory Forrest Roach

Chemical and Biological Engineering ETDs

This study focuses on the devolatilization step that occurs in the process of coal gasification. This is a key economic step for both the Lurgi synthetic natural gas process and the in-situ gasification that are being proposed for New Mexican coals. The findings of this study may be used by industry to improve the design and operation of these processes.

The work presented is an investigation into the transport properties and kinetic parameters that govern the extent of pyrolysis for single particles of subbituminous coal from the San Juan Basin in north-west New Mexico. The unique feature of this work …

Axisymmetric Air Jet Impinging On A Hemispherical Concave Plate, Stefan Jachna

Dissertations

This experimental study was conducted on an axisymmetric air jet impinging normally on a smooth, hemispherical, concave plate. The jet Reynolds numbers, based on bulk nozzle velocity and nozzle exit air properties, were between 14,000 and 75,000.

The impingement plate used in this work was a hemispherical surface with the radius of 94 mm.

Calibrated Pitot tubes and a micromanometer were used for pressure and velocity measurements. The Pitot tubes were mounted on precision positioning mechanisms permitting the accurate traversing of any direction in space. The test air flow rate was measured with calibrated rotometers.

The following results of this …

Desublimation Of Water Vapor At Low Pressure And Evaporative Freezing Of Seawater, Sun Sea Pao

Chemical and Biological Engineering ETDs

The Vacuum-Freezing Vapor-Desublimation and High Pressure Ice-Melting Process has been developed since 1972. In 1976, Mr. T. C. Chung finished a theoretical study of Low Pressure Water Vapor Desublimation Operation. The writer was a co-worker of Mr. Chung, and had worked with him for the study for four months. The information collected in Mr. Chung's thesis was borrowed and edited as Chapters 1 and 2 in the present thesis. Mr. Chung's theory predicts the rate of water vapor desublimation as a function of the difference between operating temperature and desublimer wall temperature. In the present thesis, experimental rates of desublimation …

A Simple, Inexpensive Spinning-Drop Interfacial Tensiometer, Humoud S. Al-Rabiah

Chemical and Biological Engineering ETDs

A spinning-drop interfacial tensiometer was designed, built, and tested. The device is very simple, inexpensive to build, and easy to operate compared with other spinningdrop tensiometers.

The tensiometer measures the interfacial tension of liquid-liquid or liquid-vapor systems. Interfacial tensions of three systems were measured to test the device: water-heptane, glycerol-heptane, and glycerol-air.

Experimental results agree with literature values within one percent for the glycerol-heptane system. The variations among the values for the liquid-liquid systems at different rotational speeds are within six percent. Repeated experiments with different drop sizes show that drop size of the glycerol-air system may affect the results. …

Dielectric Strength Of Sio₂ In A Cmos Transistor Structure, Jerry Malin Soden

Electrical and Computer Engineering ETDs

The maximum dielectric strength distribution of SiO₂ in a CMOS structure is shown to be composed of a primary, normal distribution of high dielectric strength and a low dielectric strength group spread through the lower electric field region. The maximum dielectric strength in the primary distribution is within about 0.5 MV/cm of the dielectric strength reported for uniform thickness SiO₂ in capacitor studies. This indicates the maximum dielectric strength of SiO₂ in a properly fabricated CMOS structure can be nearly as high as the maximum obtainable dielectric strength of uniform SiO₂. The primary dielectric strength …

Charge Storage Nonvolatile Semiconductor Memory Device, Dae Yeong Joh

Electrical and Computer Engineering ETDs

Semiconductor memory elements have been fabricated on silicon utilizing reactively evaporated TiO₂ as the charge storage insulator medium. The dielectric and charge storage properties of TiO₂ films have been characterized as a function of TiO₂ deposition conditions and post-deposition heat-treatment. Experimental results indicate a strong dependence of the film properties on fabrication process parameter such as oxygen pressure during deposition, substrate temperature, and post-deposition heat-treatment temperature and time. Data taken on the test devices show that both dielectric constant and charge storage properties are enhanced by reactive evaporation of TiO₂ in an oxygen ambient and substrate …

Structural Design Of Built-Up Plywood Box Beams, Michael J. Sneddon

Graduate Research Papers

The purpose of this study, given the background mentioned above, is to investigate the structural design of built-up plywood box beams and to develop an instructional unit based on their design.

The scope shall be limited to statically determinate beams with either uniformly distributed loads or typical girder loadings.

The resulting instructional unit will be designed as an addition to a course in structural wood design at the vocational-technical/community college level.

Microwave Transmission Through Laser Irradiated Dielectrics, Ronald Robert Delyser

Electrical and Computer Engineering ETDs

An investigation is made of microwave transmission through two types of dielectrics while being irradiated by a 15 Kw, CO₂ continuous wave laser. The two materials, a high silica ceramic and a fiber­glass laminate, present two different problems for solution of their microwave transmission characteristics while being subjected to high intensity continuous wave irradiation.

The high silica ceramic was found to exhibit a slightly reduced transmission coefficient with an accompanying change in phase delay due to ablation of the material during laser irradiation. As much as -4db loss with a phase delay of +30° is observed at an intensity …

Buckling Of Stiffened Plates And Shells, William De La Garza

Civil Engineering ETDs

The emphasis in this dissertation is the determination of buckling loads on many types of structures. The available solutions are usually written in a complex form that requires large amounts of time in order to find the buckling loads. For stiffened structures the use of finite difference calculus will provide a vehicle for obtaining solutions that are not as complex. In addition, the use of a reasonable approximation for the stiffener behavior allows the solution to be written in closed from. Direct substitution of the elastic and geometric properties of the stiffeners gives the buckling loads. The application of finite …

Cpacs Happenings (April 1978 Newsletter), College Of Public Affairs And Community Service, University Of Nebraska At Omaha

CPACS Newsletters

The College of Public Affairs and Community Service (CPACS) newsletter that reported on the news, collaborations, events, and general happenings of the UNO College of Public Affairs and Community Service. This newsletter has had many names and variations over the years including SPACS Newsletter (1973); Newsletter of the College of Public Affairs and Community Service (1973-1974): Happenings (1974-1980s); and the current e-newsletter titled the CPACS Collective (2021-)