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Full-Text Articles in Engineering
Mathematical Model For Estimating Transient Pressure Surges In Cryogenic Liquid-Vapor Systems, Philippe Pfister
Mathematical Model For Estimating Transient Pressure Surges In Cryogenic Liquid-Vapor Systems, Philippe Pfister
Retrospective Theses and Dissertations
Numerical treatments have become the most accurate methods for transient liquid flows analysis. Based on a computer code provided by NASA/KSC, this paper presents two simulations of cryogenic transfer systems. Experimental data originated from the Space Shuttle Liquid Oxygen Servicing were obtained during drain flows. Two sets of data (pressure at various locations versus time) corresponding to a drain stop and a drain initiation were used for a comparison with the predicted pressures. The first test case was a single-phase flow whereas the second one was associated with liquid-column separation and vapor cavity collapse. Major modifications were made to the …
Personal Computer Simulation Program For Step Motor Drive Systems, William M. Koos
Personal Computer Simulation Program For Step Motor Drive Systems, William M. Koos
Retrospective Theses and Dissertations
A system of equations modeling a class of step motors known as the permanent magnet rotor step motor is presented. The model is implemented on a APPLE personal computer in a version of BASIC. Measurements are then made on an existing motor and input to the program for validation. A special test fixture is utilized to take performance data on the motor to facilitate comparisons with the predictions of the program. The comparisons show the model is indeed valid for design of step motor drive systems and emphasize the practical nature of using personal computers and simulations for design.
A Comparative Study Of Forecasting Techniques For The Us Air Force Medical Material Management System, Phillip John Van Ess
A Comparative Study Of Forecasting Techniques For The Us Air Force Medical Material Management System, Phillip John Van Ess
Retrospective Theses and Dissertations
A computer simulation experiment was conducted to evaluate and compare five individual forecasting models across nine different demand patterns. The models were based on the Medical Materiel Management System used by the US Air Force hospitals. Results indicated the best model varied depending on the demand pattern, the safety stock level, the noise level of the demand pattern, and the measure of forecast error. Across all demand patterns, exponential smoothing and 12-month moving average were best for the short term forecast used by the system, regardless of noise level in the demand patterns. Analysis of models within a single demand …
An Application Of "Storm" Mathematical Modeling For Evaluation Of Nonpoint Source Water Pollution For A Nonurban Watershed, John T. Izzo
An Application Of "Storm" Mathematical Modeling For Evaluation Of Nonpoint Source Water Pollution For A Nonurban Watershed, John T. Izzo
Retrospective Theses and Dissertations
Today, the engineer is faced with the task of predicting and evaluating the extent of the Nonpoint Sources that pollute our waterways. A mathematical model may be an extremely useful tool in helping the engineer solve problems in the area of water resources. During the course of this investigation, a literature survey related to the Econlockhatchee River Basin and to the "STORM" mathematical modeling technique for runoff evaluation has been conducted. The latter part of this report deals with an application of the "STORM" mathematical model for predicting quantity and quality of surface runoff for the Econlockhatchee River Basin located …
A Study Of Assimilative Capacities For Receiving Streams, Hadi. Elmi
A Study Of Assimilative Capacities For Receiving Streams, Hadi. Elmi
Retrospective Theses and Dissertations
Literature reviews on various stream processes which contribute to reoxygenation and deoxygenation was presented. These processes include atmospheric reaeration, photosynthesis-respiration, biochemical oxygen consumption, and benthic demand. Measuring these parameters in a selected stream is a complex and costly operation. On the other hand, prediction models developed are specific to particular location and environmental conditions and can only be applied to similar situations. Computer models such as "RIVER" are available and could be used to predict dissolved oxygen concentrations along a waterway for a specified set of stream conditions. The model "RIVER" was calibrated by using the existing conditions of flow …
An Application Of A Computerized Mathematical Model For Estimating The Quantity And Quality Of Nonpoint Sources Of Pollution From Small Urban And Nonurban Watersheds., Charles John Ingraham
An Application Of A Computerized Mathematical Model For Estimating The Quantity And Quality Of Nonpoint Sources Of Pollution From Small Urban And Nonurban Watersheds., Charles John Ingraham
Retrospective Theses and Dissertations
The problem of "Total Water Management" is reviewed; particular emphasis is given to the magnitude and intensity of pollution from nonpoint sources. The relationship between land usage in south Florida and subsequent effects upon receiving water bodies is discussed. Basic factors effecting hydrological and ecological subsystems are illustrated. The U.S. Army Corps of Engineers Urban Storm Water Runoff Mathematical Model, "STORM," is introduced. Model parameters and methodology are discussed. The mathematical relationships and modeling processes are reviewed and the model is exercised using a "new generation" southeast Florida community (The City of Palm Beach Gardens) as the subject of study. …
A System Dynamics Model To Test Urban Transportation Policy Alternatives, John Paul Burtle
A System Dynamics Model To Test Urban Transportation Policy Alternatives, John Paul Burtle
Retrospective Theses and Dissertations
This study investigates the structure of urban transportation systems, the bases of commuter mode selection, and the effects of alternate transportation system management policies. The study was based on the hypothesis that changes in transportation system management policies are possible which will significantly increase the demand for public transportation in urban areas.
A Dynamic Simulation Of The Gasoline Distribution System During Periods Of Normal And Restricted Availability, Sheriar R. Bamasi
A Dynamic Simulation Of The Gasoline Distribution System During Periods Of Normal And Restricted Availability, Sheriar R. Bamasi
Retrospective Theses and Dissertations
No abstract provided.
A Military Training System Perspective And Model For Training Program Management, Alvin J. Boudreaux
A Military Training System Perspective And Model For Training Program Management, Alvin J. Boudreaux
Retrospective Theses and Dissertations
A perspective of the Naval Education and Training System (NETS) is developed and utilized as a framework on which a simulation model of general training system activities is constructed. The simulation model, which is based on functional activities, emphasizes the interdependent consequences of decisions and actions created through management planning, analysis, and control of training programs. A simulation experiment was conducted using a test situation description (scenario) to reflect the impact of management decisions and actions on the resulting allocation of resources and timeliness of training program activities. Conclusions are drawn regarding the utility and implications of the system dynamics …
A Mathematical Model For Determining The Thermal Distribution Resulting From Discharge Of A Heated Effluent, Alan H. Epstein
A Mathematical Model For Determining The Thermal Distribution Resulting From Discharge Of A Heated Effluent, Alan H. Epstein
Retrospective Theses and Dissertations
A mathematical model is presented for the problem of determining the two-dimensional temperature distribution resulting from the discharge of a heated effluent into a shallow, quiescent receptacle. The physical model of the problem is the two-dimensional jet augmented by an imposed condition of viscous drag due to bottom friction effects. By virtue of the assumption that the physical properties of the effluent are independent of temperature over the operational temperature range of the plume, the analysis separates the total problem into a flow problem and a temperature problem. Solution of the temperature distribution is accomplished both analytically and numerically. Analytically, …