Brett Gunnink

Writing, critical thinking, and engineering curricula

Writing-across-the-curriculum and critical thinking approaches have gained favor in higher education. However, while these movements have sprouted and grown roots in colleges of arts and science across the country, they have found the ground less fertile in colleges of engineering. These movements certainly influenced changes in the philosophy and approach to the accreditation of engineering programs, manifest in ABET Engineering Criteria 2000. Several ABET program outcomes are difficult to achieve using traditional approaches to engineering education. For example, it seems particularly difficult to show that graduate engineers will have the broad education necessary to understand the impact of civil engineering solutions in a global and societal context, and knowledge of contemporary issues as they relate to engineering problems. We believe that there is much to be gained from broader application of the philosophies and techniques of these movements to the education of engineers. This paper presents examples of assignments that promote these goals.

Compaction of binderless coal for coal log pipelines

Abstract Coal log pipelines transport compacted coal cylinders (logs) through a water-filled pipeline. To develop fully this technology and make it ready for commercial use, it is necessary to investigate means for fabricating coal logs. This paper describes the experimental tests and results that were completed to investigate and quantify the significance of various compaction conditions, determine optimal compaction conditions, and evaluate the technical feasibility of making durable coal logs without binders. Included are the results of three parametric studies. The first investigated the effect of loading rate, unloading rate and peak load application duration on the strength of coal logs, the second investigated the effect of moisture content on the strength of coal logs, and the third investigated the effect of compaction temperature on the strength of coal logs. In addition, the authors report and discuss preliminary results concerning the significance of other compaction parameters and the tensile strength characteristics of coal logs. The authors conclude that the strength of coal logs is highly dependent on the loading and log removal method, compaction temperature, compaction moisture content, and maximum particle size and that logs of adequate strength can be formed under many different sets of conditions. However, the water adsorption characteristics of the coal logs need to be improved in order for the logs to be suitable for transport in hydraulic freight pipelines.

Binderless compaction of hot water formed coal logs for pipeline transport

Abstract Coal log pipelines will transport compacted coal through a water filled pipeline. To fully develop this technology and make it ready for commercial use it is necessary to make high strength, water resistant coal compacts. Means for making coal compacts without binders that are strong and water resistant enough for pipeline transport are not currently available. It is possible to make high strength coal compacts by several means. However, these compacts suffer from an excessive loss of strength when exposed to water. If logs are formed at a moisture content equal to the equilibrium moisture content for the coal, water absorption is minimal, and there is little loss of strength. However, for many coals, that equilibrium moisture content is high and logs formed at that moisture content have low mechanical strength. The moisture content of the coal compact can be lowered when the compact is formed under appropriate conditions. If the appropriate moisture, temperature and pressure conditions are created during the formation of a coal compact, the resultant coal compacts moisture content is also lowered. These compacts adsorb little water and retain their mechanical strength when exposed to high-pressure water. We refer to compacts formed in this manner as hot water formed coal compacts or HWF compacts. HWF compacts have performed very well in durability and strength tests and are belived to be suitable for coal log pipeline transport.

Field Testing of Major Trenchless Technology Methods For Road Crossings

Ground displacements and borehole stability are always of prime concern during trenchless technology installations under pavements, and in close proximity to existing buried utilities and structures. Stable boreholes also relate to successful completion of the projects. The Missouri Department of Transportation (MoDOT), University of Missouri -- Columbia, Michigan State University, and several industry participants have joined forces to conduct a research program to evaluate borehole stability. The objective of this research is to study the ground movements caused by pipe jacking, auger and guided boring and horizontal directional drilling methods. The soil displacement in the vicinity of the cutterhead, reamer and at the ground surface will be examined. To conduct the research, several field installations were conducted at the University of Missouri’s Capsule Pipeline Research Center during the summer of 2002. In addition, an actual road crossing with pipe jacking method was closely monitored. The results of these unique field evaluations will be incorporated in the MoDOT specifications and guidelines and a summary will be presented in this paper. This will bring cost saving information for future MoDOT projects.

Optimal moisture for rapid compaction of coal logs for freight pipelines

The cost of producing coal logs and thus the economic competitiveness of coal log pipelines is directly related to the compaction time necessary to make the coal logs. Previous research has demonstrated the ability to make laboratory scale coal logs with a 5-s compaction time. It was also observed that for rapidly compacted coal logs, coal log circulation performance (resistance to abrasion in a commercial pipeline) is maximized, if the logs are compacted from a coal mixture at optimal moisture content. For the bituminous Mettiki coal that has been studied, this optimal moisture content is about 9%, if the compaction time is 5 s. The practical application of this is that if stockpiled coal is wetter than optimum, it would require drying of the coal to compact it at the optimum moisture content. Obviously, this would effect the cost of coal log fabrication. The authors hypothesize that an alternative to drying coal exists. If the coal logs are to be made at mix moisture contents that are above the optimum value, then it is hypothesized that coal log quality can be maintained if the compaction time is increased. In fact, we believe that if compaction time is increased such that the bulk density and moisture content of the compacted coal logs are the same, then the circulation performance of the coal logs will be the same. In this paper, the results of experiments designed to test this hypothesis are presented. The experimental data show that there is a range of mix moisture contents over which rapidly compacted quality coal logs can be formed. This range could be determined experimentally for any coal. For the Mettiki coal studied here, the range is 6% to 9%. For mix moisture contents above the optimum (high end of the range or 9% for the Mettiki coal), logs can be made with optimal dry bulk densities and log moisture contents if the compaction time is sufficiently slow. Logs with the same dry bulk density will have the same circulation performance. These results indicate that the hypothesis is valid.