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Articles 186991 - 187020 of 193492

Full-Text Articles in Engineering

Solution To Transient Vertical Moisture Movement Based Upon Saturation--Capillary Pressure Data And Modified Burdine Theory, Roland W. Jeppson Jan 1970

Solution To Transient Vertical Moisture Movement Based Upon Saturation--Capillary Pressure Data And Modified Burdine Theory, Roland W. Jeppson

Reports

Using finite differences and the Crank-Nicholson implicit scheme for solving parabolic type partial differential equations, a computer program has been developed for solving the one-dimensional, vertical movement of water in soils. The formulation of the initial boundary value problem is obtained by introducing a new dependent variable through the Kirchoff transformation to replace the hydraulic head. Data relating saturation (or moisture content) to the capillary pressure in the soil are used to define the hydraulilc properties of the soil which are needed in order to obtain a solution. The Burdine Theory has been implemented in the program to obtain the …

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Computer Simulation Of The Hydrologic-Salinity Flow System Within The Upper Colorado River Basin, M. Leon Hyatt, J. Paul Riley, M. Lynn Mckee, Eugene K. Israelsen Jan 1970

Computer Simulation Of The Hydrologic-Salinity Flow System Within The Upper Colorado River Basin, M. Leon Hyatt, J. Paul Riley, M. Lynn Mckee, Eugene K. Israelsen

Reports

Changes in the hydrologic equilibrium of a river basin resulting from resource development also produce changes in the quality pattern. Since the burden of quality maintenance must be shared by users (just as are quantities) predictions are needed for quality changes which might result from contemplated development at any specified location within the river system. This study reports the development of a computer simulation model of the water and salt flow systems within the Upper Colorado River basin. Because of the close relationship between the hydrologic and salinity flow systems, an understanding of the hydrologic system is essential to successful …

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A Hydrologic Model Of The Bear River Basin, Robert W. Hill, Eugene K. Israelsen, A. Leon Huber, J. Paul Riley Jan 1970

A Hydrologic Model Of The Bear River Basin, Robert W. Hill, Eugene K. Israelsen, A. Leon Huber, J. Paul Riley

Reports

As demands upon available water supplies increase, there is an accompanying increase in the need to assess downstream consequences resulting from changes at specific locations within a hydrologic system. The problem is approached in this study by hybrid computer simulation of the hydrologic system. Modeling concepts are based upon the development of basic relationships which describe the various hydrologic processes. Within a system these relationships are linked by the continuity-of-mass priciple which requires a hydrologic balance at all points. Spatial resolution is achieved by considering the modeled areas as a series of subbasins. The time increment adopted for the model …

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A Thermodynamic Analysis Of A Primary Waste Stabilization Pond, David W. Hendricks Jan 1970

A Thermodynamic Analysis Of A Primary Waste Stabilization Pond, David W. Hendricks

Reports

Traditional design practice for waste stabilization ponds is based upon the premise that sufficient photosynthetic oxygen must be produced within the pond to satisfy oxygen requirements of the incoming waste flow. Thus, because algae production is proportional to pond surface area, surface organic loading rate is a principal design criterion (hydraulic detention time is the other) . That a possible adverse energy trade exists in the sequence of coupled reactions (aerobic waste degradation-photosynthesis) has been largely ignored. This work is focused on quantitatively articulating this energy trade, in terms of algae produced vis a vis waste degraded. This is done …

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Final Report: Wasatch Airborne Seeding Program, Geoffrey E. Hill Jan 1970

Final Report: Wasatch Airborne Seeding Program, Geoffrey E. Hill

Reports

No abstract provided.

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Bacterial Absorption On Soils--Thermodynamics, David W. Hendricks, Frederick J. Post, Deorao R. Khairnar, Jerome J. Jurinak Jan 1970

Bacterial Absorption On Soils--Thermodynamics, David W. Hendricks, Frederick J. Post, Deorao R. Khairnar, Jerome J. Jurinak

Reports

Laboratory studies on the adsorption of bacteria onto soils and activated carbon were undertaken to evaluate the role of the process in removal of bacteria from groundwater. It was hypothesized that removal of bacteria from water passing through soil would be primarily due to adsorption in which case the bacteria would behave in a manner similar to colloidal particles or chemical molecules. The basic kinetics of uptake of Staphylococcus aureus were determined on activated carbon, a highly adsorbing material chemically speaking. Once the technique was worked out and adsorption demonstrated to take place, sand, clay, and Mendon silt loam were …

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Systems Analysis Of Hydrologic Problems, J. Paul Riley, Diana Averett Jan 1970

Systems Analysis Of Hydrologic Problems, J. Paul Riley, Diana Averett

Reports

Introduction: Increasing national and international interest in water resources in recent years has stimulated much new activity and progress in hydrology. It is now generally recognized that the science of hydrology is basic to an understanding of water resources problems and to planning for water resources development. Accompanying this demand upon the science of hydrology is an urgent need for improved education at the university level. In resopnse to this need for improved education, the First International Seminar for Hydrology Professors was held at Urbana, Illinois, in July 1969. The Second International Seminar was held at Logan, Utah, during August …

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Computer Simulation Of Water Resource Systems At Utah State University, J. Paul Riley Jan 1970

Computer Simulation Of Water Resource Systems At Utah State University, J. Paul Riley

Reports

Introduction: The problems of managing water-resource systems are basically those of decision making based upon a consideration of the physical, economic, and sociological processes involved. These processes are strongly interrelated and constitute a dynamic and continuous system. Any combination of these interrelated and numerous system variables yields a management solution. At Utah State University the problem of investigating system response to various possible management alternatives is being approached by hybrid computer simulation. The concept of simulation is fundamentally simple. Basically, it is a technique of analysis whereby a model is developed for investigating the behavior or performance of a dynamic …

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An Examination Of Approximately Simultaneous Salt Lake Valley And Cache Valley Clearing (Ventilation) Indexes, George W. Reynolds, William Mcneill, Floyd Johnson, Janet Cleary Jan 1970

An Examination Of Approximately Simultaneous Salt Lake Valley And Cache Valley Clearing (Ventilation) Indexes, George W. Reynolds, William Mcneill, Floyd Johnson, Janet Cleary

Reports

The Clearing Index is a numerical estimate of the contamination dispersal capability of the atmosphere. Between July, 1969, and June, 1970, 192 rawinsonde flights were made in the Cache Valley at approximately the same time as officially scheduled flights at the Salt Lake City Weather Bureau Airport Station. Clearing Indexes were computed from various combinations of Salt Lake Valley and Cache Valley rawinsonde and maximum surface temperature data. These were examined from the viewpoint of recommending a standard procedure for providing Clearing Indexes on a daily basis for Intermountain valleys. The primary conclusions were that: 1. Actual Salt Lake Valley …

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Attitudes For Environmental Planning In The 1970'S, Dean F. Peterson Jan 1970

Attitudes For Environmental Planning In The 1970'S, Dean F. Peterson

Reports

No abstract provided.

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Progress Report On Studies Of Hydraulic Geometry Of Large Bed Element Streams, Dean F. Peterson Jan 1970

Progress Report On Studies Of Hydraulic Geometry Of Large Bed Element Streams, Dean F. Peterson

Reports

This study developed a general method for estimating runoff rates and associated confidence limits of a given recurrence interval for ungaged small urban watersheds. The utility of the method developed was demonstrated through its application to a southeast region of Texas. Some 200 historical rainfall-runoff events from 40 watersheds in the Houston, Austin, Dallas, and Fort Worth urban areas were analyzed. Watershed data such as drainage area, percent of urbanized area channel length, average channel slope, land slope, and soil type are documented. Total rainfall amounts, intensities, durations, and mass-time distributions were determined for each storm and used to develop …

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Statistical Relationships Between Storm And Urban Watershed Characteristics, V. V. Dhruva Narayana, M. Akbar Sial, J. Paul Riley, Eugene K. Israelsen Jan 1970

Statistical Relationships Between Storm And Urban Watershed Characteristics, V. V. Dhruva Narayana, M. Akbar Sial, J. Paul Riley, Eugene K. Israelsen

Reports

Because of the rapid urban development in recent years, hydrologic problems associated with urban watersheds have gained importance. Large sums of money are being spent for the design of urban drainage systems based upon inadequate procedures for predicting peak runoff rates. In this report a procedure is proposed for predicting peak runoff rates from small urban and rural watersheds based upon measurable storm and watersheds characteristics. The technique was tested for a number of runoff events on the Boneyard Creek watershed at Urbana, Illinois, and the results of this test are included. The procedure will be particularly useful for estimating …

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Optimizing Conjunctive Use Of Groundwater And Surface Water, James H. Milligan, Calvin G. Clyde Jan 1970

Optimizing Conjunctive Use Of Groundwater And Surface Water, James H. Milligan, Calvin G. Clyde

Reports

Mathematical models for groundwater and surface-water systems are formulated and solved on a digital computer using linear programming for optimizing the water use of the system. Post-optimal analysis, including sensitivity analysis of the objective function coefficients and right-hand side terms, is also applied to the models. The models which are developed include a general deterministic model, a general stochastic model in which hydrologic inputs are allowed to be probabilistic, and models of two simple, but real, river basins. The advantages of linear programming analysis are demonstrated by the computer solutions which can be obtained by this method of optimization. The …

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Publications Of The Utah Water Research Laboratory, Utah Water Research Laboratory Jan 1970

Publications Of The Utah Water Research Laboratory, Utah Water Research Laboratory

Reports

No abstract provided.

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Subcritical Flow At Open Channel Structures Open Channel Expansions, Lloyd H. Austin, Gaylord V. Skogerboe, Ray S. Bennett Jan 1970

Subcritical Flow At Open Channel Structures Open Channel Expansions, Lloyd H. Austin, Gaylord V. Skogerboe, Ray S. Bennett

Reports

Analyzing the hydraulics of open channel constrictions has been modified to allow the analysis of energy loss in open channel expansions. The modified technique has been compared with previous methods of analysis using data collected in the laboratory on open channel expansions with vertical walls, and triangular-shaped baffles. Also, a design procedure for such baffled outlet structures has been developed.

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The Function Of Social Behavior In Water Resource Development , Wade H. Andrews, Dennis C. Geertsen Jan 1970

The Function Of Social Behavior In Water Resource Development , Wade H. Andrews, Dennis C. Geertsen

Reports

Preface: This report is an analysis of a social survey of the middle and lower Bear River Basin of southeastern Idaho and northern Utah concerning the problem of water resource development in a semiarid region of the Western United States. The survey part of the study, carried out in the summer of 1966, dealt with both general social factors and a specific proposal made by the Bureau of Reclamation for developing water resources of the Bear River. In many respects this proposal and the resulting behavior is typical of other western river basin projects, in some other ways, however, it …

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A Theoretical Study Of Infiltration Into Range And Forest Soils, Joel E. Fletcher, Yehia Z. El-Shafei Jan 1970

A Theoretical Study Of Infiltration Into Range And Forest Soils, Joel E. Fletcher, Yehia Z. El-Shafei

Reports

More than 400 rainfall simulator experiments were examined to detect which soil properties could be used to computer infiltration time relationships. Three theoretical equations were tested to determine their efficacy for calculating infiltration time relationships from soil and site characteristics. It was shown that both the modified Green and Ampt and Fletcher equations could by successfully used. Darcian type equations were developed on laboratory type samples which would show the relations between soil, solution and rainfall properties and infiltration. These latter equations have not been tested on undisturbed soils but give excellent agreement between measured and computed values for time …

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Developing A Hydro-Quality Simulation Model, Neal P. Dixon, David W. Hendricks, A. Leon Huber, Jay M. Bagley Jan 1970

Developing A Hydro-Quality Simulation Model, Neal P. Dixon, David W. Hendricks, A. Leon Huber, Jay M. Bagley

Reports

No abstract provided.

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Binary Molecular Diffusivities In Liquids: Prediction And Comparison With Experimental Data, Ronald Dean Mitchell Jan 1970

Binary Molecular Diffusivities In Liquids: Prediction And Comparison With Experimental Data, Ronald Dean Mitchell

Doctoral Dissertations

"The Eyring rate theory equation has been modified successfully to enable predictions of binary molecular diffusivities for a wide variety of liquid-liquid systems. The activation free energy for binary diffusion has been evaluated in terms of the activation free energies for self diffusion of the solvent and solute. This was accomplished through the use of regular solution theory by relating the bond breaking energy of the jump step to the bond breaking energy in evaporation. Diffusivities estimated by this equation and the equations developed by Olander, by Gainer and Metzner, and by Wilke and Chang were compared with experimental data. …

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A Digital Simulation For Optimum Nonlinear Detection Of Binary Signals In Impulsive Noise, Ralph Bernard Fluchel Jan 1970

A Digital Simulation For Optimum Nonlinear Detection Of Binary Signals In Impulsive Noise, Ralph Bernard Fluchel

Masters Theses

"The problem of reducing the effects of impulsive noise on binary communication systems is considered. A digital simulation of such a system is developed in order to find a nearly optimum (minimum probability of error criterion) nonlinear device to precede detection. The level of the Gaussian noise power is found to be the most important parameter for determining the nearly optimum nonlinear device"--Abstract, page ii.

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Efficiency And Loss Mechanism Of The Electro-Fluid Dynamic Momentum Transfer Process Applied To Propulsion Systems Using Atmospheric Air As The Working Fluid, Roger Coy Crites Jan 1970

Efficiency And Loss Mechanism Of The Electro-Fluid Dynamic Momentum Transfer Process Applied To Propulsion Systems Using Atmospheric Air As The Working Fluid, Roger Coy Crites

Masters Theses

"The general equations governing EFD (electrofluid dynamic) flow are established, simplified, and solved in closed form to provide a mathematical model of an ideal EFD propulsion system. This mathematical model, in conjunction with an analysis of ion-neutral and neutral-neutral molecular collision phenomena, indicates that the cause of inefficiency in the EFD propulsion system is the system entropy increase associated with the diffusion of ion momentum through the neutral fluid. This loss mechanism is shown to be analogous to resistive heating losses in a constant voltage linear electrical network and can be minimized by obtaining minimum ion mobility. It is shown …

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Next-State Equation Generation For Asynchronous Sequential Circuits - Normal Mode, Gregory Martin Bednar Jan 1970

Next-State Equation Generation For Asynchronous Sequential Circuits - Normal Mode, Gregory Martin Bednar

Masters Theses

"This paper describes the known methods of generating next-state equations for asynchronous sequential circuits operating in normal fundamental mode. First, the methods that have been previously developed by other authors are explained and correlated in a simple and uniform language in order that the subtle differences of these approaches can be seen. This review is then followed by a development of a new method for generating minimal next-state equations which has some advantages over the previous methods. From the comparison of the previous known methods, it is noted that any one of these methods may be desirable for certain designs …

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The Design, Construction And Experimental Verification Of A Split Hopkinson Bar, Woosoon Bai Jan 1970

The Design, Construction And Experimental Verification Of A Split Hopkinson Bar, Woosoon Bai

Masters Theses

"This thesis presents the design considerations for a dynamic loading device utilizing a projectile fired from a tube. Also included is a preliminary investigation of the stress-strain relation, under dynamic loading with the device, for a plaster known as Hydrostone. Design of the unit is based on the split Hopkinson pressure bar originally developed by Kolsky and on a similar unit in use at the Lawrence Radiation Laboratory, Livermore, California. The strain pulses along the pressure bars are sensed by resistance wire strain gages and displayed on an oscilloscope. The oscilloscope traces are photographed and manually digitized for insertion into …

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Digital Simulation Of A Signal Conditioner/Bit Synchronizer, Quentin Reed Webb Jan 1970

Digital Simulation Of A Signal Conditioner/Bit Synchronizer, Quentin Reed Webb

Masters Theses

"A bit rate filter type signal conditioner/bit synchronizer used in a split-phase PCM system is modeled digitally in three stages to determine overall system performance. General computer algorithms are developed to approximate independent operation of each major segment within the device. Bit rate effects and signal time-base error are investigated yielding the characteristic G-curves for the phase detector. These characteristics facilitate subsequent analysis of a linear equivalent digital-data-transition tracking phase-locked loop under several typical time-base error input conditions. Using bit error probabilities as performance criteria, the conditioner/synchronizer is found to perform adequately at signal-to-noise ratios exceeding +10dB. For inputs below …

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Bound-Free Continuum Radiation From Non-Gray Nonisothermal Shock Layers, Chu Yih Wang Jan 1970

Bound-Free Continuum Radiation From Non-Gray Nonisothermal Shock Layers, Chu Yih Wang

Masters Theses

"This study investigates the continuum radiative flux from nonisothermal stagnation shock layers composed of atomic gases. The general equations for the composition are derived and the Rankine-Hugoniot equations are simplified and solved to give the thermodynamic conditions of the shock layers. To accurately model the stagnation shock layer, the plasma must be considered to be nonisothermal. In the current study, linear shock layer temperature profiles are assumed. Consequently, the fluid dynamics and the radiation are uncoupled. The radiation model assumes one-dimensional radiative energy transport and considers only continuum processes. The radiative flux is calculated by considereing ground to free state …

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Computer Time-Sharing (T-S) "An Engineering Tool" For The Engineering Applications Of The Small Company, James Binford Summers Jan 1970

Computer Time-Sharing (T-S) "An Engineering Tool" For The Engineering Applications Of The Small Company, James Binford Summers

Masters Theses

"The objectives of this investigation were to illustrate the capabilities of the time-sharing (T-S) industry, identify the means by which the small sized company, with a need to solve engineering problems, can best be served through T-S, and to present T-S to these potential users. Investigation was made of distinctive T-S services to formulate a composite of the T-S industry. Examples of three distinctive T-S services were used within this composite to exemplify the variations of services within the industry. The methods a small company could use to utilize computer services were identified emphasizing T-S as the method best suited …

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The Influence Of A Carbon Ablation Layer On Radiation From A Hydrogen Shock Layer, Birbal Singh Jan 1970

The Influence Of A Carbon Ablation Layer On Radiation From A Hydrogen Shock Layer, Birbal Singh

Masters Theses

"The effect of ablation heat shields on the radiative heat transfer to vehicles entering hydrogen atmospheres at thermo-dynamic conditions similar to those expected in Jovian atmospheres is investigated. The shock layer is assumed to consist of two plane parallel layers, one consisting of pure hydrogen species, and the other consisting of carbon species only. Each layer is assumed to be in local thermodynamic equilibrium at its respective temperature. The thermodynamic conditions in the hydrogen layer are arrived at by solving the Rankine-Hugoniot Equations across the shock. The temperature of carbon layer is taken as (3000, 5000, and 7000ºK) to cover …

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Heat Transfer Through A Spherical Gas Shell, Adel Nassif Saad Jan 1970

Heat Transfer Through A Spherical Gas Shell, Adel Nassif Saad

Masters Theses

"The radiative transfer through an absorbing-emitting gas shell contained within black concentric spheres at uniform but different temperatures was investigated. A close form exact solution and an approximate solution were derived for the case of isothermal gas layer. The two solutions appear to compare well specially at low diameter ratios, and both agree with the radiative equilibrium solution in the thin limit. An approximate method was developed for the radiative equilibrium, non-isothermal gas layer, of the above problem. The method is based on the assumption of a hyperbolic emissive power distribution through the gas shell. The jump boundary conditions were …

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Investigation Of The System Al₂O₃-Teo₂-O₂, Vera Zelenkova Sestak Jan 1970

Investigation Of The System Al₂O₃-Teo₂-O₂, Vera Zelenkova Sestak

Masters Theses

"The system Al₂O₃-TeO₂-O₂ has been investigated by X-ray diffraction and differential thermal analysis in air and in sealed silica ampoules. The tellurate, Al₂TeO₆, with tellurium in the +6 valence state, forms in air but not in vacuum at 1 mm pressure. A second phase, a tellurite, possibly Al₂Te₂O₇, forms in air or vacuum by devitrification. The glass-forming region is wider than previously stated and is more extensive in vacuum--from 50% to 98% TeO₂. Tentative phase boundaries have been placed for the system in air and vacuum"--Abstract, page ii.

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Fracture Surface Energy Determinations Of High Density Polycrystalline Ceramics, Gene Arthur Pahlmann Jan 1970

Fracture Surface Energy Determinations Of High Density Polycrystalline Ceramics, Gene Arthur Pahlmann

Masters Theses

"Values of fracture surface energy were measured for steatite, zircon, mullite and four densities of alumina. Rods of these high density materials were cut into thin rectangular specimens which were notched and broken in three-point loading. The resulting load necessary for fracture of the specimens was used to calculate the fracture surface energy of the materials. The value for the steatite was around 20,000 ergs/cm². The values for the zircon and mullite were on the order of 13,000 ergs/cm², and the values for the aluminas ranged from 17,000 to 24,000 ergs/cm²"--Abstract, page ii.

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