Todd Schweisinger

Introduction to hydromechanical well tests in fractured rock aquifers.

This article introduces hydromechanical well tests as a viable field method for characterizing fractured rock aquifers. These tests involve measuring and analyzing small displacements along with pressure transients. Recent developments in equipment and analyses have simplified hydromechanical well tests, and this article describes initial field results and interpretations during slug and constant-rate pumping tests conducted at a site underlain by fractured biotite gneiss in South Carolina. The field data are characterized by displacements of 0.3 microm to more than 10 microm during head changes up to 10 m. Displacements are a hysteretic function of hydraulic head in the wellbore, with displacements late in a well test always exceeding those at similar wellbore pressures early in the test. Displacement measurements show that hydraulic aperture changes during well tests, and both scaling analyses and field data suggest that T changed by a few percent per meter of drawdown during slug and pumping tests at our field site. Preliminary analyses suggest that displacement data can be used to improve estimates of storativity and to reduce nonuniqueness during hydraulic well tests involving single wells.

Removable Borehole Extensometers for Measuring Axial Displacements During Well Tests

Fractures in rock hold important stores of water and petroleum, and slight changes in fracture aperture accompanying drawdown from pumping wells play a key role in recovering these resources. Two removable borehole extensometers were designed to measure small displacements in order to improve the characterization of fractured rock aquifers using hydraulic well tests. The extensometers consist of four major components: (1) a pair of anchors, (2) a temperature-compensated reference rod, (3) a registration system, and (4) a displacement transducer. One extensometer uses an axial reference rod with multiple, low-profile anchors, whereas another uses an offset reference rod with a single pair of anchors. Both designs can be readily mobilized and are capable of resolving submicron displacements in boreholes.

An Improved Undergraduate Mechanical Engineering Laboratory Structure and Curriculum: Design and Assessment

The mechanical engineering department at Clemson University reevaluated its undergraduate laboratory experience and focused on improving various aspects of the three required laboratory courses. The faculty believe that these laboratory courses are a defining feature of the bachelor of science degree, as many graduates accept entry-level manufacturing positions or pursue graduate studies. The mechanical engineering laboratory courses at Clemson are stand-alone offerings in the undergraduate program, in contrast those schools which attach the labs to select courses. This structure allows a variety of experiments to be offered during each course, which can encompass various scientific and engineering topics. This paper reviews various changes to the laboratories, describes their implementation and presents evidence of their effectiveness. Examples of the improvements were: the development of printed manuals for both students and teaching assistants, the development of a unified training program for the teaching assistants, the introduction of new laboratory equipment and experiments, and revision of the current laboratory documentation. To evaluate the effectiveness of the implemented changes, survey results were analyzed. Overall, student satisfaction with the course improved significantly, as evidenced by the survey results.

A Mechatronics and Material Handling Systems Laboratory: Experiments and Case Studies

Industrial mechatronic systems integrate technologies from a variety of engineering disciplines to create solutions to challenging manufacturing problems. The material handling industry utilizes mechatronics to move, track, and manipulate items in factories and distribution centers. Material handling systems are a logical choice of study, due to their use of multiple mechatronic elements. This article describes mechatronic experiments and projects in a new course. Topical coverage includes sensors, actuators, PLCs, robotics, pneumatics, hydraulics, human factors, teamwork, leadership, and project management. A series of eight laboratory experiments have been created to introduce PLCs, robotics, electric circuits, and data acquisition fundamentals. In-depth case studies synthesize the technologies and interpersonal skills together to create a flexible material handling system. The most significant student outcome is the successful completion of a course project that required individuals to apply mechatronics concepts and technology in a multi-disciplinary team setting to solve industrial material handling tasks.