College of Engineering (COE)
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Note: The Department of Biological Systems Engineering is listed within the College of Agriculture and Life Sciences (CALS).
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Browsing College of Engineering (COE) by Content Type "Book chapter"
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- A Brief History of Aerospace Engineering at the Virginia Polytechnic Institute and State UniversityWalters, Robert W.; Johnston, Jane Echols (American Institute of Aeronautics and Astronautics, 2004)This book chapter provides an historical of Aerospace Engineering at Virginia Tech, covering 1913-2004.
- Compressive Behavior of Concrete under Environmental EffectsFarzampour, Alireza (IntechOpen, 2019)Concrete strength is fairly sensitive to environmental effects. Extreme weather conditions and changes in humidity rates significantly affect the concrete compressive strength development. Concrete as one of the substantial material used in residential buildings and infrastructures is subjected to a massive strength change under extreme weather conditions. For understanding, the different concrete’s behavioral aspects, various commercial cement types under different temperatures, and humidity rates are investigated in this chapter. The experiments are aimed to investigate the concrete strength development over time when the material is cast at lower to mild temperatures and different humidity index rates. Results show that reducing the curing temperature more than 15° could result in 20% reduction in total compressive strength, while decreasing humidity rates by 50% leads to less than 10% drop in ultimate strength. To understand the strength developing process, maturity tests are conducted. It is shown that concrete is not able to reach to the expected ultimate strength if the temperature is significantly low regardless of curing time. The effect of temperature change during the curing process is more tangible on strength development compared to cement type and humidity rate values.
- Effect of Covalent Functionalization on Young’s Modulus of a Single-Wall Carbon NanotubeShah, Priyal H.; Batra, Romesh C. (Springer, 2014)Effective utilization of carbon nanotubes (CNTs) as reinforcements in composites necessitates good interfacial bonding with the surround matrix material. The covalent functionalization of CNTs is an effective method to enhance this bonding. However, covalent bonds introduced by a functional group may alter the pristine structure of the CNT and lower its mechanical properties. Here we study the effect of hydrogen (–H), hydroxyl (–OH), carboxyl (–COOH), and amine (–NH2) functionalization on Young’s modulus of a single-wall CNT (SWCNT) using molecular mechanics (MM) simulations with the MM3 potential and the software TINKER. Both pristine and functionalized SWCNTs have been deformed in simple tension. From the strain energy of deformation vs. the axial strain curves, the value of Young’s modulus has been derived as a function of the functionalization group and the amount of functionalization. It is found that Young’s modulus decreases by about 30 % with 20 % of functionalization, the reduction is essentially proportional to the increase in the percentage of the functionalization material and is nearly the same for each of the four functional groups studied.
- Electronic Theses and Dissertations: Progress, Issues, and ProspectsMcMillan, Gail; Fox, Edward A.; Srinivasan, Venkat (Center for Digital Discourse and Culture, Virginia Tech, 2009)ETDs form an important component of global scholarship and research output. Many universities around the world require, accept, or at least encourage students to submit their theses and dissertations electronically. The Networked Digital Library of Theses and Dissertations (NDLTD), which promotes ETD activities worldwide, now has over 779,000 ETDs accessible through its Union Catalog, run by Online Computer Library Center (OCLC). Other NDLTD partners provide powerful tools for searching, browsing, and visualization...
- Fuel Cells and Their Applications in Energy SystemsLai, Jih-Sheng; Ellis, Michael W. (Wiley, 2019-06-27)
- Healthcare data analyticsReddy, Chandan K.; Aggarwal, C. C. (Chapman and Hall/CRC, 2015)
- Maximizing Local Access to Therapeutic Deliveries in Glioblastoma. Part III: Irreversible Electroporation and High-Frequency Irreversible Electroporation for the Eradication of GlioblastomaLorenzo, Melvin F.; Arena, Christopher B.; Davalos, Rafael V. (2017)Glioblastoma (GBM) is the most common and aggressive primary brain tumor in adults. Approximately 9180 primary GBM tumors are diagnosed in the United States each year, in which median survival is up to 16 months. GBM eludes and resists typical cancer treatments due to the presence of infiltrative cells beyond the solid tumor margin, heterogeneity within the tumor microenvironment, and protection from the blood-brain barrier. Conventional treatments for GBM, such as surgical resection, radiotherapy, and chemotherapy, have shown limited efficacy; therefore, alternate treatments are needed. Tumor chemoresistance and its proximity to critical structures make GBM a prime theoretical candidate for nonthermal ablation with irreversible electroporation (IRE) and high-frequency IRE (H-FIRE). IRE and H-FIRE are treatment modalities that utilize pulsed electric fields to permeabilize the cell membrane. Once the electric field magnitude exceeds a tissue-specific lethal threshold, cell death occurs. Benefits of IRE and H-FIRE therapy include, but are not limited to, the elimination of cytotoxic effects, sharp delineation from treated tissue and spared tissue, a nonthermal mechanism of ablation, and sparing of nerves and major blood vessels. Preclinical studies have confirmed the safety and efficacy of IRE and H-FIRE within their experimental scope. In this chapter, studies will be collected and information extrapolated to provide possible treatment regimens for use in high-grade gliomas, specifically in GBM.
- Multi-Story Buildings Equipped with Innovative Structural Seismic Shear Fuse SystemsFarzampour, Alireza; Mortazavi, Seyed Javad; Mansouri, Iman; Awoyera, Paul Oluwaseun; Wan Hu, Jong (Elsevier, 2022-03-29)Infrastructures could be designed and constructed to resist seismic lateral loads without experiencing a significant amount of damage concentrations in specific area. Having sufficient strength and stiffness to reduce the structural vulnerabilities against serious damages under seismic loading, requires structural elements to have adequate ductility and energy dissipating capability, which could be provided with the use structural dampers. These elements are typically replaceable, and designed to yield and protect the surrounding members from damages, and then be accessible after a major event. In this study, butterfly-shaped links with linearly varying width between larger ends and a smaller middle section are used for redesigning the prototype structures due to substantial ductility and stable energy dissipation capability. The effect of implementation of innovative seismic dampers in multi-story structures is investigated by analyzing multi-story prototype structures with structural seismic shear dampers, and subsequently compared with simple conventional linking beams. The results of the nonlinear response history analysis are summarized for 44 ground motions under maximum considered earthquake (MCE) and designed based earthquake (DBE) hazard levels. It is shown that implementation of the butterfly-shaped dampers in buildings with similar stiffness and strength leads to higher dissipated energy and less pinched curves compared to typical eccentrically braced frame systems. It is determined that the general stiffness and strength of the system with the butterfly-shaped link is close to conventional models; however, the demands on the surrounding boundary elements are lower than the corresponding conventional model, which could be beneficent for improving the seismic performance of the structural systems.
- Perspective Chapter: Blockchain-Enabled Trusted Longitudinal Health RecordDong, Yibin; Mun, Seong K.; Wang, Yue (2022-09)In the United States, longitudinal personal health record (LPHR) adoption rate has been low in the past two decades. Patients’ privacy and security concern is a major roadblock. Patients like to control the privacy and security of their own LPHR distributed across multiple information systems at various facilities. However, little is known how a scalable and interoperable LPHR can be constructed with patient-controlled security and privacy that both patients and providers trust. As an effort to increase LPHR adoption rate and improve the efficiency and quality of care, we propose a blockchain-enabled trusted LPHR (BET-LPHR) design in which security and privacy are protected while patients have full control of the access permissions. Two limitations associated with the proposed design are discussed. Options and practical resolutions are presented to stimulate future research.