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 40 freely available and openly licensed textbooks are among our most downloaded items.
Communities in VTechWorks
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Recent Submissions
Housing the Richmond Region: Needs, Impediments, and Strategies
Virginia Center for Housing Research; Center for Urban and Regional Analysis (The Partnership for Housing Affordability, 2015)
On behalf of the Capital Region Collaborative, the Partnership for Housing Affordability commissioned this report to determine how we can work together to ensure adequate housing quality for Richmond residents of all incomes and circumstances.
Design and thermal analysis for a novel EMCCD camera payload in a 1U CubeSat form factor
Angle, Nicholas Blake (Virginia Tech, 2024-06-24)
Nüvü Camēras, a Canadian company that designs a range of CCD and EMCCD cameras and controllers, recently began development on a miniaturized EMCCD controller for a CubeSat form factor. The detector for this payload requires near-cryogenic temperatures, approximately 188K, for performance operation. A temperature requirement of that magnitude for a CubeSat form factor is challenging given the low thermal mass, volume, surface area, and power availability for heat storage, dissipation and control systems that would typically be available for larger form factor spacecraft. The goal of this project is to design and per- form thermal analysis for the Nüvü Camēras CubeSat EMCCD Controller that allows for cold-biased active temperature control of both the controller electronics and detector. The EMCCD controller had an operational temperature range of −35◦C to +60◦C while the detector had a performance range of −110◦C to −85◦C with a desire to maintain a resolu- tion of ±0.25◦C. To meet these requirements, a system was designed within 3D modeling software Autodesk Inventor and imported into Thermal Desktop for thermal analysis and iteration. Models were updated based on thermal analysis results, adjusted by hand, and then tested again until a passive cooling and active heating system that met the require- ments was achieved. The final control system was shown to be capable of cooling from 20◦C (293.15K) to −85◦C (188.15K) and beyond given a Sun Synchronous orbit at 600km with attitude control and operational requirements. It was also shown to be capable of heating up, using resistive heaters on key components, beyond the thermal inertia of the system and environment, indicating viable control on orbit. In the future a PID control method can be implemented, and its use is being investigated by Nüvü Camēras for achieving the desired resolution of ±0.25◦C in the future.
Climate Change Vulnerabilities in Loíza: The Role of Transportation in Enhancing Resilience
Gonzalez-Velez, Justine Ivan (Virginia Tech, 2024-06-24)
Climate change-related vulnerabilities in Loíza are prevalent in both physical and social dimensions. The social-ecological systems indicate that a change in one component will trigger an effect in the other regardless if physical or not, suggesting that the examination of vulnerabilities cannot be done overlooking one dimension. Such is the case of transportation, as climate change vulnerabilities in Puerto Rico are exacerbated due to the capacity of the Island to recover from a disaster, mainly because there are nearly no options for mobility aside from a private vehicle. This research intended to describe the social vulnerabilities of the population and asses the physical vulnerabilities of the transportation infrastructure of Loíza to understand how resilience is threatened using the social-ecological systems approach. This study found that the transportation infrastructure is exposed and sensitive to sea level rise, flooding, and strong winds, mainly because these climate stressors cause damage to the roadways and inhibit the flow and traffic of people throughout the main roadway and evacuation route, the PR-187. The study also identified that Loíza is socially vulnerable. Many people belong to one of the described vulnerable groups, indicating that its population may experience hurdles in preparing for and recovering after a natural disaster primarily because the available resources greatly condition the level of preparedness and capacity to cope. It was evidenced that transportation plays an enormous role in decreasing or increasing resilience in Loíza, as it will determine how fast people can access supplies and necessary services to reconstruct and recover from a natural disaster. Adaptation strategies should be outlined alongside the community to ensure an equitable and inclusive approach, as well as ensure assertive and effective outcomes for all the residents of Loíza.
Load Flow Study for Utility-Scale Wind Farm Economic Operation and Reactive Power Grid Compliance
Moon, Christopher Michael (Virginia Tech, 2024-06-24)
With environmental and policy pressure to move towards cleaner fuel sources, wind energy is a proven technology that can be successfully implemented at the utility-scale and provide clean energy to the grid. Wind energy consists of many distributed wind turbines that are paralleled and connected to inject power to one location on the transmission grid. There are real power losses and reactive power drops that must be taken into consideration for these projects for plant performance and compliance. The better the performance of each new and operating wind farm installed, the more efficiently the grid operates as well as the less greenhouse gases generated. This thesis will first review the creation of an Excel tool to perform a load flow study given inputs for a wind farm using Newton-Raphson algorithms.
Next, the results of the load flow analysis will be compared to an actual operating wind farm located in Texas to review the accuracy of the scenarios. Finally, alternative design and operating states for the wind farm are proposed and cases are simulated to review the impact on wind farm energy generation and reactive power provided to the grid. Finally, preferred improvements for future design and operational considerations are provided along with future areas of research and development.
Multiplicity of Experiences
Shagul Hameed, Kamar Shafeeha (Virginia Tech, 2024-06-24)
In the bustling heart of Chicago's LaSalle Street, the 111 West Monroe site presents a unique narrative of adaptive reuse, encapsulating the thesis of 'Multiplicity of Experiences.' This thesis ventures beyond the conventional restoration, aspiring to reinvigorate and repurpose two distinct architectural forms — a robust brick structure and its transparent steel and glass counterpart — through strategic cuts that foster gathering and community interaction. The manipulation of light at varying intensities becomes the silent choreographer of space, delineating zones of activity and orchestrating the human experience within these revitalized edifices.
The old brick building, a testament to historical solidity, now breathes anew as student housing, offering challenges turned opportunities through its dense facade and muted interiors. In contrast, the steel and glass structure, with its morning light and open vistas, evolves into a sanctuary for families, children, and the elderly, promoting a sense of openness and interconnectivity. This architectural duality harmonizes to form a living, dynamic tableau that captures the multiplicity of human experiences, enabled by horizontal and vertical incisions that carve out communal and private spheres.
The groundwork of the thesis is the concept of gathering — initiating with the public's allure into the retail and amenity spaces on the lower levels, ascending to the private residences above, and culminating in the shared terraces that bridge different age groups and backgrounds. This thesis demonstrates how spatial intervention, particularly through the nuanced application of light and the deliberate choreography of openings, can script diverse experiences from serendipitous encounters to orchestrated communal activities. It presents a model of adaptive reuse that not only conserves the structural essence but also injects a new pulse into the urban fabric, championing a symbiosis between the old and the new, the individual and the collective, the built and the unbuilt.
Through the transformative act of cutting and layering, this study sheds light on the potency of architectural intervention in shaping human and spatial experiences. The result is a rich mosaic of life, where every stratum, every incision, every ray of light adds a verse to the narrative of gathering, from dawn's first light to the tranquil hum of evening, offering a blueprint for reactivating spaces that reach beyond their walls to touch the human soul.