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.
Communities in VTechWorks
Select a community to browse its collections.
Recent Submissions
Influence of Mesh Design and Surface Treatments on Particle Transport and Fate in a Vibration-Enhanced Flooded Bed Dust Scrubber
Uluer, Mahmud Esad; Noble, Aaron (Springer, 2024-06-01)
Respirable coal mine dust (RCMD) is one of the biggest occupational health hazards for underground coal miners. Dusty mining environments can cause long-term health problems, including pneumoconiosis and progressive massive fibrosis. The Mine Safety and Health Administration (MSHA) has recently revised regulations promoting enhanced dust mitigation technologies, which have sparked renewed interest in the development of dust mitigation technologies. The flooded bed dust scrubber (FBS) is one of the most widely used technologies; however, it is limited by technical challenges, the most notable being the potential to clog. Recent studies have shown that applying vibration to filter mesh can improve the overall efficiency of the scrubber and that the system can be readily integrated to existing continuous mining equipment using an energy harvesting approach. In this follow-up study, the impact of mesh design and surface modification on system efficiency was examined using different vibrating liquid-coated stainless-steel mesh panels in a laboratory-scale FBS. Based on the two-way interaction data from a multi-factor experimental design, the results show that the performance of the system can be optimized by using hydrophilic 20- or 30-layer filters and by excitation frequencies between 67 and 134 Hz. This laboratory study suggests that a 20-layer mesh screen with hydrophilic surface applications and optimized vibration parameters can perform similar to that of a 30-layer static mesh, which is typically used in industrial units.
Hydrothermally Assisted Conversion of Switchgrass into Hard Carbon as Anode Materials for Sodium-Ion Batteries
Li, Yilin; Xia, Dawei; Tao, Lei; Xu, Zhiyuan; Yu, Dajun; Jin, Qing; Lin, Feng; Huang, Haibo (American Chemical Society, 2024-05-23)
Sodium-ion batteries (SIBs) are emerging as a viable alternative to lithium-ion batteries, reducing the reliance on scarce transition metals. Converting agricultural biomass into SIB anodes can remarkably enhance sustainability in both the agriculture and battery industries. However, the complex and costly synthesis and unsatisfactory electrochemical performance of biomass-derived hard carbon have hindered its further development. Herein, we employed a hydrothermally assisted carbonization process that converts switchgrass to battery-grade hard carbon capable of efficient Na-ion storage. The hydrothermal pretreatment effectively removed hemicellulose and impurities (e.g., lipids and ashes), creating thermally stable precursors suitable to produce hard carbon via carbonization. The elimination of hemicellulose and impurities contributes to a reduced surface area and lower oxygen content. With the modifications, the initial Coulombic efficiency (ICE) and cycling stability are improved concurrently. The optimized hard carbon showcased a high reversible specific capacity of 313.4 mAh g(-1) at 100 mA g(-1), a commendable ICE of 84.8%, and excellent cycling stability with a capacity retention of 308.4 mAh g(-1) after 100 cycles. In short, this research introduces a cost-effective method for producing anode materials for SIBs and highlights a sustainable pathway for biomass utilization, underscoring mutual benefits for the energy and agricultural sectors.
Design, Development, and Formative Evaluation of a Hybrid Remote Quantum Laboratory Supporting HBCU Partnerships
Clark-Stallkamp, Rebecca; Reis, Nikita (Springer, 2024-06-01)
Quantum information science and engineering are expanding and scaling worldwide. As government and industry push to expand quantum applications around the world, education institutions scramble to train the next generation of quantum-aware engineers in the Quantum pipeline. However, as educational institutions seek to expand the pipeline, not all learners have access to Quantum training or equipment. Quantum laboratories, an expensive component of STEM education, often remain exclusively accessible to institutions with affluence and funding, thus creating systemic barriers for underrepresented learners to the Quantum pipeline. This design-based case study describes the three-year design and development of a hybrid remote online Quantum laboratory in partnership with historically black colleges and universities across the US with the goal of expanding access for underrepresented learners to Quantum training. The study describes the prototypical design, development, and formative evaluation of the prototype's iterations and reflects on design decisions made resulting from formative feedback during the design process.
Mechanistic Diversity in the Hydrolysis of Sarin by Single Transition-Metal Atoms on MOF-808
Fossum, Carl; Troya, Diego (American Chemical Society, 2024-05-24)
Zr-based metal-organic frameworks (Zr-MOFs) are one of the most promising materials for the decomposition of chemical warfare nerve agents. We present a study of the hydrolysis reaction mechanism of nerve agent sarin catalyzed by Zn(II) and Ti(IV) single atoms on the Zr-MOF MOF-808. We reveal that upon binding of the nerve agent to the catalyst, conformational isomerism leads to a great diversity of hydrolysis reaction mechanisms. Each mechanism follows an addition-elimination sequence but differs markedly in the way the elimination step is accomplished and its energetics. Moreover, while most of the prior work has focused on the HF elimination channel, this work shows that the addition-elimination steps can also lead to isopropanol formation through barriers comparable to those of the HF channel. Additional insight is achieved by high-level electronic structure calculations, including coupled-cluster theory, which allow us to benchmark more efficient DFT techniques commonly used in mechanistic studies of catalytic processes involving transition-metal atoms. Overall, this work reveals new reaction pathways for nerve-agent hydrolysis with lower-lying transition-state energies than previously reported, highlighting the importance of conformational sampling in mechanistic studies of catalytic processes.
Interacting impacts of hydrological changes and air temperature warming on lake temperatures highlight the potential for adaptive management
Olsson, Freya; Mackay, Eleanor B.; Spears, Bryan M.; Barker, Philip; Jones, Ian D. (Springer, 2025-03-01)
Globally, climate warming is increasing air temperatures and changing river flows, but few studies have explicitly considered the consequences for lake temperatures of these dual effects, or the potential to manage lake inflows to mitigate climate warming impacts. Using a one-dimensional model, we tested the sensitivity of lake temperatures to the separate and interacting effects of changes in air temperature and inflow on a small, short-residence time (annual average approximate to 20 days), temperate lake. Reducing inflow by 70% increased summer lake surface temperatures 1.0-1.2 degrees C and water column stability by 11-19%, equivalent to the effect of 1.2 degrees C air temperature warming. Conversely, similar increases in inflow could result in lake summer cooling, sufficient to mitigate 0.75 degrees C air temperature rise, increasing to more than 1.1 degrees C if inflow temperature does not rise. We discuss how altering lake inflow volume and temperature could be added to the suite of adaptation measures for lakes.