Acoustic field patterns from a planar multi-element ultrasonic applicator were determined experimentally and compared with theory. Measurements were obtained from square arrays of 4 and 16 elements. The acoustic fields produced by various configurations of individual square elements (3.6 cm X 3.6 cm) driven at 1 MHz were measured in water. Transverse and axial scans paths were used to characterize the acoustic beam for different aperture sizes and individual element excitations. Unequal power excitation of adjacent elements produced multiple peaked acoustic intensity patterns. While a simple theoretical model was not able to account for all the experimentally determined transverse and axial field patterns, a model including mechanical damping improved the agreement between theory and experiment. However, less ripple in the axial pattern was measured than predicted by either theoretical model. The ability of the applicator to generate acoustic field patterns suitable for local tissue heating was demonstrated by an experimental study in dog thigh muscle.
A rectangular microstrip antenna radiator is investigated for its near-zone radiation characteristics in water. Calculations of a cavity model theory are compared with the electric-field measurements of a miniature nonperturbing diode-dipole E-field probe whose 3 mm tip was positioned by an automatic three-axis scanning system. These comparisons have implications for the use of microstrip antennas in a multielement microwave hyperthermia applicator. Half-wavelength rectangular microstrip patches were designed to radiate in water at 915 MHz. Both low (epsilon r = 10) and high (epsilon r = 85) dielectric constant substrates were tested. Normal and tangential components of the near-zone radiated electric field were discriminated by appropriate orientation of the E-field probe. Low normal to transverse electric-field ratios at 3.0 cm depth indicate that the radiators may be useful for hyperthermia heating with an intervening water bolus. Electric-field pattern addition from a three-element linear array of these elements in water indicates that phase and amplitude adjustment can achieve some limited control over the distribution of radiated power.
College where he has taught since 1993. Over the past 20+ years, he has become known for his work with students on an eclectic mix of practical, hands-on projects involving such things as electric vehicles, aircraft, vehicles for use in developing countries, and methods of finding and removing antipersonnel land mines. Dr. Pratt is a co-founder of the Collaboratory for Strategic Partnerships and Applied Research. He and his wife of 30+ years have two grown children and three grandchildren. An avid pilot and builder, he enjoys flying over the beautiful farms and forests of the Cumberland Valley.c American Society for Engineering Education, 2015 Page 26.362.1 Combining Digital with Analog Circuits in a Core Course for a Multidisciplinary Engineering CurriculumA multidisciplinary engineering curriculum requires certain core courses to provide students with the content they will need to be successful in subsequent coursework, projects and beyond. Circuit Analysis, a common core course, has traditionally emphasized the analog side, leaving digital circuits for electrical or computer specializations. While a number of recent papers [3][4][5][6][7][8] address improved methods of instruction for Circuit Analysis, strategic ordering of topics and selection of content also makes a difference in preparing students for the curriculum as a whole.With the growing infusion of digital technology in contemporary practice, we believe students in all engineering disciplines should have exposure to digital theory, at least at a basic level. Thus, at Messiah College, we have formed a new Circuits I core course combining introductory analog and digital circuit theory. Accordingly, we replaced our Circuit Analysis and Digital Electronics courses with a new Circuits 1, 2 sequence. While the Circuits 2 course takes up more advanced topics required for electrical and computer specializations, the Circuits 1 course covers basic analog and digital theory, including both discrete circuits and selected integrated circuit devices, working knowledge of which is required for competency in all engineering disciplines. Such competency allows multidisciplinary teams to work together more effectively, when deciding how to implement circuit functionality, make digital measurements, analyze and share digitized data, and plan the flow of information through newly designed systems. This paper provides details on course content division, textbook selection, lecture and lab adjustments, student reaction and other lessons learned, for the benefit of those who wish to try this approach. I. IntroductionA course on electric circuits has long been one of the core courses in a traditional engineering curriculum, providing a basic foundation for students specializing in a variety of disciplines. A typical first semester engineering course on electric circuits such as Circuit Analysis emphasizes linear, discrete elements such as the voltage and/or current source, resistor (R), capacitor (C) and inductor (L), focusing on how to find simplified equivalent circu...
Dr. Underwood received his Ph.D. in Electrical Engineering at UIUC in 1989, and has been a faculty member of the Engineering Department at Messiah College since 1992. Besides teaching Circuit Analysis, Electromagnetics, and Communications Systems, he supervises students in the Communications Technology Group on the credited Integrated Projects Curriculum (IPC) track and those participating voluntarily via the Collaboratory for Strategic Parnternships and Applied Research. His ongoing projects include improving Flight Tracking and Messaging for small planes in remote locations, and developing an assistive communication technology involving Wireless Enabled Remote Co-presence for cognitively and behaviorally challenged individuals.
For Social ServicesOrienting projects toward social services introduces and motivates students to real-world problem solving in an engineering curriculum. While service learning has gained traction in recent years, only a few papers in the literature have addressed the development of assistive technologies as a focus for engineering project applications. Over the past eight years, the Collaboratory for Strategic Partnerships and Applied Research at Messiah College has fostered several interdisciplinary undergraduate student and faculty projects, such as the assistive communication technology Wireless-Enabled Remote Co-presence (WERCware) described here. WERCware is designed for those who depend on job-or life-coaching, to ameliorate cognitive and behavioral challenges that affect performance at home or in the workplace. It facilitates remote communication between coach and consumer, for training and/or other support as needed, to increase independence of the consumer. WERCware development, as a collaborative effort between Messiah College and a small company, has gone through several fits and starts including sporadic seed grant funding, angel investor interest, multiple field trials, consultant contributions, and attempted commercialization. These phases have exposed students to technical challenges of electrical and computer engineering outside the formal classroom, but also have required an interdisciplinary mindset to understand the social need and recognize realistic hurdles inherent to getting a product from development to market. Previous papers have addressed the competitive student team member selection process and assessment of the creditbearing project work in our engineering project curriculum at Messiah College. This paper focuses on WERCware as an extended duration example of multidisciplinary undergraduate project work, highlighting lessons learned by both students and faculty from the experience.
supervises engineering students in the Communications Technology Group on credited work in the Integrated Projects Curriculum (IPC) of the Engineering Department, and those who participate voluntarily via the Collaboratory for Strategic Parnternships and Applied Research. His on-going projects include improving flight tracking and messaging systems for small planes in remote locations, and developing assistive communication technology for those with cognitive and behavioral challenges, such as highfunctioning autism, or PTSD.c American Society for Engineering Education, 2017 Formalizing Experiential Learning Requirements In An Existing Interdisciplinary Engineering Project CurriculumIn education, experiential learning has become a best practice, high-impact strategy, because engaging with real life problems heightens students' interest, teaches them career-related skills, and enables them to become more self-aware/mature independent thinkers. While many students engage in experiential learning activities voluntarily, some schools have formalized a credited version as an elective to ensure the learning includes the reflective and conceptual components, as verified by a deliverable outcome. A few schools such as Messiah College have also gone a step further to require an approved experiential learning activity of all students, including engineering majors, to enhance their career preparation and community engagement before graduation. Students matriculating to Messiah College as of 2015 may now opt to fulfill the Experiential Learning Initiative (ELI) by either credited internship, practicum, service learning, leadership, off campus program, or research. While pre-graduation professional preparation may be new for some liberal arts disciplines, engineering has encouraged an experiential approach for some time. Since 2007, the Engineering Department at our institution has required students to complete a multiyear "practicum" which functions as an on-campus credited internship with our Collaboratory for Strategic Partnerships and Applied Research. Junior and senior engineering students receive credit for such project work through a four-semester Engineering Project 1-4 sequence, coupled with a two-semester Engineering Seminar 1-2 sequence as the reflective component. What remains is to incorporate the new features of the ELI mandate. While many engineering students on their own already complete paid internships with off-campus companies before graduation, to avoid extra tuition expense and unneeded credits, few opt for an academically approved internship with its intentional reflective component. Thus, we have decided to embed the specific ELI requirements related to reflection and the deliverable into our existing on-campus required upper divisional project curriculum structure. In our Seminar 1 course, students write four pre-experience learning objectives in stipulated areas; during Seminar 2, they complete correlated post-experience reflective questions, and compose a deliverable. In between Seminar 1 and 2, stu...
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