Digitized by Kansas Correctional Industries

No description available.

Thesis (M. S.)--Civil and Environmental Engineering, Georgia Institute of Technology, 2008. / Committee Chair: Kurtis, Kimberly; Committee Member: Kahn, Lawrence; Committee Member: Sobecky, Patricia.

This project researched the fungal and bacterial communities (i.e. biofilms) found on concrete infrastructure in Georgia. Various microbial communities were sampled from four geographically separated sites. The species present in these biofilms were identified through DNA analysis and cultured for testing. A new, rapid test method was developed to accurately simulate field growth conditions in a laboratory environment. Using the newly developed test method, these communities were grown on small mortar tiles, which varied in w/cm, surface roughness, cement type (including photocatalytic cement), and supplementary cementing materials. This research determined that photocatalytic cement was the most effective in decreasing biofilm growth under artificial daylight, but did not increase or decrease growth when not exposed to light. The next most effective ways to decrease growth were lowering w/cm and decreasing surface roughness. The supplementary cementing materials examined did not increase or decrease biofilm growth.

Thesis (M.S.)--University of Wisconsin--Madison, 1969. / eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.

Thesis (M.S. in engineering)--Washington State University. / Includes bibliographical references.

Automated techniques to acquire weight and traffic data are indispensable to effective management and maintenance of the vast network of highways. Weigh-In-Motion (WIM) systems have the potential to greatly reduce the cost and improve the accuracy associated with weight data collection. The existing WIM systems utilizing piezoelectric cables have been shown to result in rather large random errors of up to 12% and need to be installed at permanent sites. In addition, the exponential decay of the output signal of the piezoelectric cable with time can cause complications in signal processing and possibly further errors. In this thesis, a fiber-optic sensor is proposed which measures the pressure generated by the weight of a vehicle. The system consists of a pneumatic tube filled with an incompressible fluid, a rubber pad embedding the tube, a diaphragm to convert pressure into displacement, and an optical displacement sensor. A prototype of the proposed sensor is designed, manufactured and tested in the laboratory. Both piezoelectric cable and the optical sensor are tested under varying load-frequencies~ It is shown that the piezoelectric cable sensor shows considerable dependence on the load frequency, whereas the response of the proposed system is much less frequency dependent and, unlike the piezoelectric cable has a waveform similar to that of the applied load. This latter property can significantly reduce the difficulties associated with signal processing. Besides, the linearity of response over the range of loads applied is better than that of the piezoelectric cable. This implies that the proposed fiber-optic sensor with its high rate of accuracy can be implemented under conditions where piezoelectric sensor does not deliver accurate results. For example, when equally loaded axles at different vehicle speeds and axle configurations are used. / Master of Science

No description available.

The system dynamics methodology is used to develop a computer simulation model to determine whether to add lanes to a congested highway or build a new, more direct, facility. Fundamental to this evaluation is the incorporation of non-user measures of effectiveness to go with the traditional highway user measures of effectiveness, such as the Benefit-Cost Ratio. In the system dynamics methodology three alternative forms of the model of a system are used: verbal, visual, and mathematical. The verbal description is diagrammatic and shows cause-and-effect relationships between many variables in a simple, concise manner. The visual model or "causal diagram" is translated into a mathematical model and system equations. The model is comprised of four sectors: 1. population sector 2. economic sector 3. university sector 4. transportation sector The model applies to the area of Blacksburg, Christiansburg and Roanoke (city and county). with special treatment to Virginia Tech through the university model. The simulation results of the non-user benefits along with user benefits is used to evaluate the alternatives in the Blacksburg-Christiansburg-Roanoke corridor. / Ph. D.

The dissertation gives the background to the need for management of roads and transportation research in the Republic of South Africa. The close co-operation between researcher and end-user of research findings in the above-mentioned fields and its application into practice, is described. The advent of autonomy of research institutions in 1986, highlighted the need for a structured approach for the management of road and transportation research. Tasks, previously undertaken mainly by the Division for Road and Transport Research of the Council for Scientific and Industrial Research on behalf of the South African road and transportation authorities, had to be taken over by the Department of Transport. A transition period of five years was given (from 1987 to 1992) to implement a suitable scientifically sound system. Details towards co-ordination and formalising of needs such as determination, prioritisation, allocation, funding and control of transportation research are given. / Public Administration and Management / M.A. (Public Administration)