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Engineering Calculations (engineering + calculation)

Distribution by Scientific Domains
Engineering75%

Selected Abstracts

Spreadsheet-based interactive modules for control education

COMPUTER APPLICATIONS IN ENGINEERING EDUCATION, Issue 1 2010
Nourdine Aliane
Abstract In the last few years, spreadsheets have become a popular computational tool and a powerful platform for performing engineering calculations. The simplicity of spreadsheet programming in addition to their plotting capabilities, and other provided utilities, make them a powerful didactic tool. This paper describes the development of interactive tools based on Excel spreadsheets for basic control education. The motivation for developing these tools was to give students special learning modules focused on transmitting the essence of dynamics of systems to achieve an accurate mental model as well as helping them understand how feedback works. © 2009 Wiley Periodicals, Inc. Comput Appl Eng Educ 18: 166,174, 2010; Published online in Wiley InterScience (www.interscience.wiley.com); DOI 10.1002/cae.20221 [source]

A Practical Approach to the Design, Monitoring, and Optimization of In Situ MTBE Aerobic Biobarriers

GROUND WATER MONITORING & REMEDIATION, Issue 1 2010
Paul C. Johnson
A paradigm for the design, monitoring, and optimization of in situ methyl tert -butyl ether (MTBE) aerobic biobarriers is presented. In this technology, an oxygen-rich biologically reactive treatment zone (the "biobarrier") is established in situ and downgradient of the source of dissolved MTBE contamination in groundwater, typically gasoline-impacted soils resulting from leaks and spills at service station sites or other fuel storage and distribution facilities. The system is designed so that groundwater containing dissolved MTBE flows to, and through, the biobarrier treatment zone, ideally under natural gradient conditions so that no pumping is necessary. As the groundwater passes through the biobarrier, the MTBE is converted by microorganisms to innocuous by-products. The system also reduces concentrations of other aerobically degradable chemicals dissolved in the groundwater, such as benzene, toluene, xylenes, and tert -butyl alcohol. This design paradigm is based on experience gained while designing, monitoring, and optimizing pilot-scale and full-scale MTBE biobarrier systems. It is largely empirically based, although the design approach does rely on simple engineering calculations. The paradigm emphasizes gas injection,based oxygen delivery schemes, although many of the steps would be common to other methods of delivering oxygen to aquifers. [source]

Computability in non-linear solid mechanics

INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING, Issue 1-2 2001
T. Belytschko
Abstract The computability of non-linear problems in solid and structural mechanics problems is examined. Several factors which contribute to the level of difficulty of a simulation are discussed: the smoothness and stability of the response, the required resolution, the uncertainties in the load, boundary conditions and initial conditions and inadequacies and uncertainties in the constitutive equation. An abstract measure of the level of difficulty is proposed, and some examples of typical engineering simulations are classified by this measure. We have put particular emphasis on engineering calculations, where many of the factors that diminish computability play a prominent role. Copyright © 2001 John Wiley & Sons, Ltd. [source]

PERMEABILITY ANISOTROPY DISTRIBUTIONS IN AN UPPER JURASSIC CARBONATE RESERVOIR, EASTERN SAUDI ARABIA

JOURNAL OF PETROLEUM GEOLOGY, Issue 2 2007
A. Sahin
Most classical reservoir engineering concepts are based on homogeneous reservoirs despite the fact that homogeneous reservoirs are the exception rather than the rule. This is especially true of carbonate reservoirs in the Middle East which are known to be highly heterogeneous. The realistic petrophysical characterization of these kinds of reservoirs is not an easy task and must include the study of directional variations of permeability. Such variation can be incorporated into engineering calculations as the square root of the ratio of horizontal to vertical permeability, a parameter known as the anisotropy ratio. This paper addresses the distribution of anisotropy ratio values in an Upper Jurassic carbonate reservoir in the Eastern Province of Saudi Arabia. Based on whole core data from a number of vertical wells, statistical distributions of horizontal and vertical permeability measurements as well as anisotropy ratios were determined. The distributions of both permeability measurements and anisotropy ratios have similar patterns characterized by considerable positive skewness. The coefficients of variation for these distributions are relatively high, indicating their very heterogeneous nature. Comparison of plots of anisotropy ratios against depth for the wells and the corresponding core permeability values indicate that reservoir intervals with lower vertical permeability yield consistently higher ratios with considerable fluctuations. These intervals are represented by lower porosity mud-rich and/or mud-rich/granular facies. Granular facies, on the other hand, yielded considerably lower ratios without significant fluctuations. [source]