Every spring the Graduate School Association sponsors a research symposium to present graduate research work to the VCU and local Richmond community. The event is an excellent opportunity for graduate students to present their original research and creative projects in a professional but relaxed environment. This is the only opportunity for many graduate students to showcase their work at VCU. Participation in this event has nearly doubled every year and attracts not only VCU students and faculty, but local media, legislators, and respected members of the Richmond business community.
Nazanin R. Ghavamabadi
Between 20% to 50% of industrial energy input is lost as waste heat in the form of hot exhaust gases, cooling water and energy loss from generating equipment. Vibrations and variable heating are a common form of waste energy in motors, generators, power cables exposed to ambient temperatures, fuel exhausts from vehicles, and various types of heavy machinery. The recovery of even a fraction of this lost energy would have a transformational impact on the utility industry since the demand for energy is increasing and the impact of this demand on the environment is significant. Recent technical breakthroughs in new composite materials and energy storage devices make waste energy harvesting a practical alternative energy source. An energy harvesting system or harvester consists of a material such as a piezoelectric or pyroelectric composite to convert wasted heat or kinetic energy into electricity and the electronics and components for voltage conversion and energy storage.
In the current research we investigate and develop hybrid piezoelectric and pyroelectric systems to harvest waste energy. For this reason, six different experimental set up have been prepared to maximize the harvested energy for the hybrid case. Based on this work we provide a comprehensive review of the opportunities, potential scalability and practical limitations of energy harvesters as a new and potentially transformational alternative energy source. So, the wide-scale incorporation of energy harvesting systems to recover wasted heat and kinetic energy could have a dramatic impact on energy and environmental conservation efforts.
Negar Ghochaghi and Adetoun Taiwo
Electrospinning is a widely applicable technique that generates non-woven fibers in the micro and nano range. In this project two of its applications are highlighted namely filtration media and enhancement of wettability. The first project demonstrates that electrospinning can be used to produce new fiber filtration media with controlled microstructure. The bimodal and unimodal orthogonal and random filters were made and characterized against their filtration efficiency and pressure drop. Figure of Merit (FOM) was also calculated and discussed. It is shown that the FOM increases when the electrospun fibers are arranged into alternating layers of aligned course and fine fibers.
Secondly, surfaces were prepared by electrospinning thin, aligned polystyrene fibers onto a piezoelectric unimorph substrate. Results showed electric field induced changes in substrate curvature, which produced corresponding changes in surface wettability. From experiments, an average change in water contact angle of 7.2° ± 1.2° with 90% confidence was observed in ~2μm diameter fiber coatings electrospun for 5 minutes with applied electric field. In addition, fiber coatings electrospun with equivalent deposition showed average electric field induced changes in WCA of 2.5° ± 0.92° for lower diameter fibers (~1μm) and 3.5° ± 1.37° for higher diameter fibers (~2μm) with 90% confidence.