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Full-Text Articles in Engineering

A Simple, Robust, And On-Site Microwave Technique For Determining Water-To-Cement Ratio (W/C) Of Fresh Portland Cement-Based Materials, K. Mubarak, Karl Joseph Bois, R. Zoughi Oct 2001

A Simple, Robust, And On-Site Microwave Technique For Determining Water-To-Cement Ratio (W/C) Of Fresh Portland Cement-Based Materials, K. Mubarak, Karl Joseph Bois, R. Zoughi

Electrical and Computer Engineering Faculty Research & Creative Works

Inspection and evaluation of cement-based materials such as concrete is of great interest to the construction industry. In particular, real-time and on-site evaluation of water-to-cement ratio (w/c) is an important practical issue, since the compressive strength of a concrete structure is significantly influenced by its w/c. Currently, there is no single real-time, on-site, relatively in-expensive, easy-to-implement, and operator friendly technique for evaluating this parameter. Microwave nondestructive testing and evaluation techniques have shown great promise when used for inspection and evaluation of the properties of cement-based materials. In this paper, the optimal design of a monopole antenna probe used to evaluate …


Resilient Modulus Of Kentucky Soils, Tommy C. Hopkins, Tony L. Beckham, Charlie Sun, Bixian Ni Jun 2001

Resilient Modulus Of Kentucky Soils, Tommy C. Hopkins, Tony L. Beckham, Charlie Sun, Bixian Ni

Kentucky Transportation Center Research Report

In recent years, the American Association of State Highway Transportation Officials (AASHTO) has recommended the use of resilient modulus for characterizing highway materials for pavement design. This recommendation evolved as of a result of a trend in pavement design of using mechanistic models, which are based on the theory of elasticity (layered elastic analysis) or linear and non-linear, finite elements (and finite difference methods), or a combination of both of those theoretical approaches. Although much progress has been made in recent years in developing mathematical, mechanistic pavement design models, results obtained from those models are only as good as the …


Design And Fabrication Of On-Chip Inductors, Robert K. Requa Jan 2001

Design And Fabrication Of On-Chip Inductors, Robert K. Requa

Journal of the Microelectronic Engineering Conference

An inductor is a conductor arranged in an appropriate shape (such as a conducting wire wound as a coil) to supply a certain amount of self-inductance. This passive device stores magnetic energy. Simple spiral planar inductors of varying geometry were designed and fabricated on a silicon substrate insolated by silicon oxide. The process chosen for fabrication of the devices was the copper damascene process. Line widths and spaces varied from 5μm to 20μm. Thickness of the copper wire was approximately 1.5 μm. The inductors were isolated from the silicon substrate by 0.5 μm of Si02 and wires were insolated …


Design And Analysis Of A Cmos Based Mems Accelerometer, Matthew A. Zeleznik Jan 2001

Design And Analysis Of A Cmos Based Mems Accelerometer, Matthew A. Zeleznik

Journal of the Microelectronic Engineering Conference

Traditionally, microelectromechanical systems (MEMS) have been fabricated using standard surface micromachining or bulk micromachining processes with prior or subsequent CMOS incorporation. Recently, a new hybrid technique known as CMOS enicromachining has been developed allowing for parallel fabrication of mechanical and electrical components. A single axis and dual axis accelerometer have been designed for submission for an ASIMPS alpha run using the CMOS micromachining process. Electrical and mechanical analysis and simulations for the single axis accelerometer have been performed. The sensitivity of the single axis accelerometer has been calculated to be 19.66mV/g neglecting the effects of parasitic capacitance. The released die …


Cubic Beam Elements In Practical Analysis And Design Of Steel Frames, Lip H. Teh Jan 2001

Cubic Beam Elements In Practical Analysis And Design Of Steel Frames, Lip H. Teh

Faculty of Engineering - Papers (Archive)

This paper discusses various issues in the use of cubic beam elements for computer structural analysis/design of steel frames. It is pointed out that the concern expressed in recent literature regarding the number of cubic elements required to model a steel member is not justified, and that the inaccuracy of one cubic element in Euler buckling analysis of a simply supported column is largely irrelevant to the second-order elastic analysis/design or advanced analysis of steel frames. The sources of inaccuracy of the cubic element are elucidated. It is also explained that the plastic-zone analysis method is not so inefficient as …


Prototype Development For A Leak-Preventive Toilet Flush System- An Met Senior Design (Capstone) Project, Cheng Y. Lin Jan 2001

Prototype Development For A Leak-Preventive Toilet Flush System- An Met Senior Design (Capstone) Project, Cheng Y. Lin

Engineering Technology Faculty Publications

A senior design (Capstone) project for three mechanical engineering technology students at Old Dominion University is described. A prototype design is presented to perform the functional test of a leak-preventive toilet system. There are two major leaks in the toilet water tank. In the first case, leaking occurs when the seal in the water tank becomes aged. The leak is very easy to detect visually, since the outside of the tank and the floor becomes wet. In the second case, leak occurs when the flapper valve can't complete shut off the water, due to corrosion or damage of the rubber …