VTechWorks
VTechWorks provides global access to Virginia Tech scholarship, including journal articles, books, theses, dissertations, conference papers, slide presentations, technical reports, working papers, administrative documents, videos, images, and more by faculty, students, and staff. Faculty can deposit items to VTechWorks from Elements, including journal articles covered by the University open access policy. Email vtechworks@vt.edu for help.
Open Access Policy
Virginia Tech's open access policy enables researchers to deposit the accepted version of scholarly articles with no embargo.
Theses and Dissertations
Virginia Tech was first in the world to require ETDs in 1997, and continues to add scans of older theses and dissertations.
Open Textbooks
More than 50 freely available and openly licensed textbooks are among our most downloaded items.
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Recent Submissions
2025 Jeanne Clery Campus Safety Act Report
(Virginia Tech, 2025-09)
The Virginia Tech Police Department has been designated as the department responsible for compiling and publishing the university’s annual security and fire safety report. This document is intended to serve as the annual security and fire safety report, as required by the Higher Education Opportunity Act and the Jeanne Clery Disclosure of Campus Security Policy and Crime Statistics Act. The purpose of the report is to provide information about security on campus, to include: campus and community crime statistics, fire statistics and safety information, policy information, safety tips, resource phone numbers and a brief overview of the many services the university provides. A map of the campus can be found online at www.maps.unirel.vt.edu/interactive and has been added to this report as Appendix A.
ROPES Hub Research Brief: Strengthening STEM Pathways - Lessons Learned in S-STEM Identity
Rodriguez, Sarah L.; Blaney, Jennifer M.; Richardson, Amy Jo; Knight, David B. (2025-11-11)
Psychological Monitoring: Detecting Real-Time Emotional Changes
McClafferty, Shane R. (Virginia Tech, 2025-08-26)
The present study introduces a novel, real-time emotion (or generalized behavioral) tracking model capable of independently estimating valence, motivation (approach-avoidance), and activation (arousal) through estimations of parasympathetic (PNS), α-adrenergic (α-SNS), and β-adrenergic (β-SNS) sympathetic nervous system activity. These separate autonomic systems correspond to distinct emotional dimensions: valence to the PNS, motivation (approach-avoidance) to the α-SNS, and activation to the β-SNS. This framework enables continuous, real-time, and interpretable estimation of emotion from a single, wearable-compatible signal through photoplethysmography (PPG). The tested model utilizes inter-beat interval (IBI) and pulse wave or pulse volume amplitude (PVA), which are tracked using an extended Kalman filter (EKF) to extract frequencies (VLF-UHF) and standard heart rate variability metrics (HRV). These features were mapped onto emotional dimensions using supervised partial least squares (PLS) regressions from behavioral validation measures: facial electromyograph (EMG) for valence, a joystick for motivation, and eye-tracking (activation). The dimensional predictions reached within-subject accuracy levels comparable to those of traditional physiological models. Additionally, these emotional dimensions can be used to produce reasonable, discrete emotion probabilities based solely on theory (without requiring training data). These findings support a new model of emotion based on separate autonomic systems and dimensions that functionally define emotions in real time. Such an approach enables dynamic emotional inference or generalized behavior across various contexts, including experimental design, clinical monitoring, and ambulatory assessment, utilizing low-cost, wearable technology.
Electrostatic Defrosting
Lolla, Venkata Yashasvi; Zhang, Hongwei; Socha, Beckett Z.; Qiao, Rui; Boreyko, Jonathan B. (Wiley-VCH, 2025-11-11)
Electrification of ice has been studied for over half a century, mostly in the context of atmospheric science. Here, the polarizability and natural thermovoltage of a substrate-bound frost sheet are exploited for frost removal by placing an actively charged electrode overhead. This new technique, which we term electrostatic defrosting (EDF), can remove up to 75% of the frost’s mass from its substrate over a time scale of only minutes. A one-dimensional numerical model is developed to rationalize the effective electrostatic force exerted by the electrode on the warm end of the frost sheet. Experimentally, the effectiveness of EDF is shown to depend on the applied voltage, relative humidity of the ambient air, the gap height between the frosted substrate and the electrode plate, and the type of substrate. Although EDF primarily removes the dendritic frost structures rather than the underlying frozen condensate, this selective removal can still offer significant advantages for applications requiring improved visibility or reduced surface roughness. EDF can effectively remove frost without the application of heat, chemicals, or mechanical forces, rendering it a promising new construct for defrosting.
Polysaccharide-based H2S donors: Thiol-ene functionalization of amylopectin with H2S-releasing N-thiocarboxyanhydrides
Chinn, Abigail F.; Williams, Noah R.; Miller, Kevin M.; Matson, John B. (Wiley, 2024-09-15)
Polymeric donors of gasotransmitters, gaseous signaling molecules such as hydrogen sulfide, nitric oxide, and carbon monoxide, hold potential for localized and extended delivery of these reactive gases. Examples of gasotransmitter donors based on polysaccharides are limited despite the availability and generally low toxicity of this broad class of polymers. In this work, we sought to create a polysaccharide H2S donor by covalently attaching N-thiocarboxyanhydrides (NTAs) to amylopectin, the major component of starch. To accomplish this, we added an allyl group to an NTA, which can spontaneously hydrolyze to release carbonyl sulfide and ultimately H2S via the ubiquitous enzyme carbonic anhydrase, and then coupled it to thiol-functionalized amylopectin of three different molecular weights (MWs) through thiol-ene "click" photochemistry. We also varied the degree of substitution (DS) of the NTA along the amylopectin backbone. H2S release studies on the six samples, termed amyl-NTAs, with variable MWs (three) and DS values (two), revealed that lower MW and higher DS led to faster release. Finally, dynamic light scattering experiments suggested that aggregation increased with MW, which may also have affected H2S release rates. Collectively, these studies present a new synthetic method to produce polysaccharide H2S donors for applications in the biomedical field.