Margaret Pinnell

An Examination of the Effect of Composite Constituent Properties on the Notched-Strength Performance of Composite Materials

The effect of matrix and fiber properties on the strengths and failure processes of notched, continuous-fiber composite specimens has been investigated. Bearing, open and filled hole tension and compression tests were conducted on AS-4/3501-6, IM-8/3501-6, AS-4/APC-2 and IM-8/APC-2 specimens. Failure characteristics of tested specimens were studied by fractographic techniques. Failure progression was tracked by means of incremental loading, radiography and fractographic inspection.

Can service-learning in K-12 math and science classes affect a student’s perception of engineering and their career interests

The objective of a National Science Foundation (NSF) sponsored grant entitled, ldquoMaking Connections: Resources for K-12 Service-learning and Experiential Learning in STEM Disciplinesrdquo was to encourage K-12 educators to incorporate service-learning into the science and math curriculum by providing an easy-to-use resource. It was hoped that the use of service-learning in the science and math curriculum would help promote the entry of women and minorities into the Science, Technology, Engineering and Mathematics (STEM) fields, increase the potential pool of engineers and scientists in the United States, contribute to the development of STEM educators and enhance cultural sensitivity, ethics and social responsibility in future STEM workers. As part of this grant, 60 local K-12 teachers were asked to use the website, facilitate an activity identified on the website and assess the usefulness of the website as well as the perceived affect the activity had on the students. All participants were asked to fill out a survey to assess the usefulness of the website as well as the perceived impact of service-learning in enhanced student interest in STEM. A subset of this group facilitated well developed career interest inventory tools prior to and after facilitating the activity in an effort to determine if the activity had an affect on the students perception of engineering or the resultant career choices. This paper will focus on the survey, assessment tools and will present the results obtained from the survey.

Mechanical Test Methods for Assessing Porcine Carotid and Uterine Artery Burst Pressure Following Ex Vivo Ultrasonic Ligature Seal and Transection

A test method was developed to identify those variables important for assessing the performance of ultrasonic surgical devices in ex vivo ligature sealing of porcine carotid and uterine arteries. Ruggedness testing using a small sample size in pilot experiments was conducted using a newly developed test method in an effort to assess the usefulness of this methodology and to identify test variables that might warrant further testing. The development of this test method included the use of a custom-designed prototypic tension device for load-controlled ex vivo vessel stretching during saline perfusion and subsequent seal and transection of porcine arteries with an advanced energy surgical device. The quality of the seal was evaluated as a burst pressure (mmHg). The experimental set-up allowed for either monitoring or controlling specific test conditions, including blood vessel tension during cutting and sealing, saline infusion rate, cutting time, pressure generated in the vessel during cutting, and burst pressure. Both muscular-type uterine and elastic-type carotid arteries were investigated, since energy based devices are most frequently used on muscular-type arteries but are developed and tested using elastic-type arteries. Although confounded with the age of the animal, in the ruggedness test pilot, it was observed that porcine carotid arteries yielded a comparatively lower burst strength seal as compared to porcine uterine arteries. The data generated during ruggedness testing suggests that the artery type and saline infusion rate during transection may be important variables in ex vivo vessel seal testing.

A different path to internationalization of engineering education

The collaborative team of Engineers in Technical, Humanitarian Opportunities of Service Learning (ETHOS, formed by students and staff at Iowa State University, University of Dayton, and Seattle University), has taken a new path to internationalizing engineering education. ETHOS has helped students gain awareness of the social and cultural fabric of the poorest nations in the world and has allowed them to perform research and design focused on improving the ability of people living in these nations to meet their basic needs. These activities are being implemented via on-campus curricular and immersion service experiences. Collaborations between these universities have been focused on helping two international nongovernmental organizations improve the efficiency and durability of the wood-burning stoves typically used for cooking by the worlds poor This paper discusses the initial successes of and lessons learned from this collaboration, as well as its future activities.

Student perspectives of curriculum integrated international service-learning internships

The engineers in Technical, Humanitarian Opportunities of Service-learning (ETHOS) program at the University of Dayton is founded on the belief that engineers are more apt and capable to serve our world more appropriately when they have experienced opportunities that increase their understanding of technologys global linkage with values, culture, society, politics and economy. ETHOS seeks to provide these opportunities by means of curriculum integrated service-learning program. These opportunities include international technical immersion volunteer internships, student organization activities, collaborative research and classroom projects, which support appropriate technologies for the developing world, locally and globally. Over the course of three years, 27 students have participated in service-learning internships, working with development organizations and communities throughout Central and South America. Students live in the community which they volunteer and together, with the community, work to appropriately and creatively solve technical challenges. Such experiences expose students to alternative, nontraditional technologies that are based on fundamental science and engineering principles, thus allowing higher comprehension of curriculum material in a hands-on, practical and humanitarian manner. Furthermore, such exposure allows students to recognize the far-reaching effects, positive and negative, of engineering and technology and thus the responsibilities of being an engineer in our ever-increasing global society. Students are awarded credit via a multidisciplinary engineering elective, coordinated by the ETHOS program, for preparing for and participating in an international service-learning internship. The preparation, prior to the six to sixteen week international technical immersion, includes a semester-long technical, cultural, language and travel instructional class. Student development and progress is monitored through technical reporting and reflection before, during and after travels. This paper examines in detail, one students experience in his international service-learning internship and how this experience has affected his educational objectives

Design of a factorial experiment with randomization restrictions to assess medical device performance on vascular tissue

BackgroundEnergy-based surgical scalpels are designed to efficiently transect and seal blood vessels using thermal energy to promote protein denaturation and coagulation. Assessment and design improvement of ultrasonic scalpel performance relies on both in vivo and ex vivo testing. The objective of this work was to design and implement a robust, experimental test matrix with randomization restrictions and predictive statistical power, which allowed for identification of those experimental variables that may affect the quality of the seal obtained ex vivo.MethodsThe design of the experiment included three factors: temperature (two levels); the type of solution used to perfuse the artery during transection (three types); and artery type (two types) resulting in a total of twelve possible treatment combinations. Burst pressures of porcine carotid and renal arteries sealed ex vivo were assigned as the response variable.ResultsThe experimental test matrix was designed and carried out as a split-plot experiment in order to assess the contributions of several variables and their interactions while accounting for randomization restrictions present in the experimental setup. The statistical software package SAS was utilized and PROC MIXED was used to account for the randomization restrictions in the split-plot design. The combination of temperature, solution, and vessel type had a statistically significant impact on seal quality.ConclusionsThe design and implementation of a split-plot experimental test-matrix provided a mechanism for addressing the existing technical randomization restrictions of ex vivo ultrasonic scalpel performance testing, while preserving the ability to examine the potential effects of independent factors or variables. This method for generating the experimental design and the statistical analyses of the resulting data are adaptable to a wide variety of experimental problems involving large-scale tissue-based studies of medical or experimental device efficacy and performance.

Summer Research and Collaborative Professional Development Experience for NSF RET Teachers in Advanced Manufacturing and Materials

The current collaborative National Science Foundation Research Experience for Teachers (NSF-RET) site placed seventeen in-service and pre-service teachers with research mentors at one of the three regional universities WSU, CSU, and UD to work on engineering research projects. These research projects were chosen in such a way so that they were relevant to regional strengths in advanced manufacturing and materials. In addition to research, the RET teachers participated in various professional development (PD) activities such as “boot camp” facilitated by ASM Materials Education Foundation prior to the start of their research experience, field trips, seminars given by guest speakers and group work that produced K-12 curriculum related to the teams’ research experience. The teacher groups also presented the developed STEM curriculum and the final laboratory project results, and provided regular guided reflections regarding their efforts during the six-week program. This paper presents a brief overview of the collaborative RET project and details the achievement during the first project year. Emphasis is given to the collaborative PD activities of all seventeen teachers and the research projects performed by the two WSU RET groups comprised of four in-service and two pre-service teachers.Copyright

Making Connections Between Service and Engineering in K-12 Education

This paper will summarize the findings obtained through the work of a National Science Foundation (NSF) sponsored grant entitled, “Making Connections: Resources for K-12 Service-learning and Experiential Learning in STEM Disciplines.” The objective of this grant was to encourage K-12 educators to incorporate service-learning into the science and math curriculum by providing an easy-to-use resource. It was hoped that the use of service-learning in the science and math curriculum would help promote the entry of women and minorities into the Science, Technology, Engineering and Mathematics (STEM) fields, increase the potential pool of engineers and scientists in the United States, contribute to the development of STEM educators and enhance cultural sensitivity, ethics and social responsibility in future STEM workers. The methodology used to develop, assess and refine the web based resource will be discussed. Additionally, the research design and inferential statistics used to assess the impact of service-learning on K-12 students’ perceptions of STEM careers will be presented.Copyright

Innovation, Entrepeneurship and International Experience

The University of Dayton (UD) Engineers in Technical Humanitarian Opportunities for Service-Learning (ETHOS), in collaboration with UD’s School of Business, UD’s Design Clinic, Grupo Fenix (Nicaragua), and the local Nicaraguan community, is currently working on an 18 month project to research and develop a solar medical device sterilizer (sterilizer) that can be used in rural areas of Nicaragua. Engineering and business students are working in a variety of capacities with the local community and Grupo Fenix in Nicaragua to research, design and develop the device. Once developed, the engineering and business students will continue to work with the community and Grupo Fenix to establish a micro-business for the manufacture and distribution of the device. Although this project will address a particular technical need, the infrastructure and unique partnerships that are being developed and optimized through its facilitation will serve as a model for other projects and programs that will be shared within the University of Dayton and with other universities.Copyright

Teaching Sustainable Engineering Throughout the Mechanical Engineering Curriculum

The natural world has long been impacted by technological society; however, in recent years environmental impacts and constraints are increasingly on the global, rather than local or regional, scale. Moreover, the interconnectivity of biological systems with energy and material flows is increasingly evident. Today, it is well understood that climate change, energy constraints and biological degradation are largely a consequence of technological production and energy use. In this context, one would expect engineering education to have evolved to prepare engineers to be capable of addressing these issues. Rather, excluding the resurgence in design education, we see a curriculum that remains largely unchanged. In this context, we propose an integrated mechanical engineering curriculum that emphasizes sustainable engineering and whole-system design. The curriculum provides mechanical engineering students with a deeper understanding of the broader impact of the products and processes they design, the tools to assess that impact, and the system level thinking to design technologies for a sustainable future.© 2008 ASME