All Faculty Deposits

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The "All Faculty Deposits" collection contains works deposited by faculty and appointed delegates from the Elements (EFARs) system. For help with Elements, see Frequently Asked Questions on the Provost's website. In general, items can only be deposited if the item is a scholarly article that is covered by Virginia Tech's open access policy, or the item is openly licensed or in the public domain, or the item is permitted to be posted online under the journal/publisher policy, or the depositor owns the copyright. See Right to Deposit on the VTechWorks Help page. If you have questions email us at vtechworks@vt.edu.

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The Elk River MCHM spill: A case study on managing environmental risks
Scaggs, Meredith; Sarver, Emily A.; Mendoza, Lucas Rojas (Society for Mining, Metallurgy and Exploration, 2015-04)
On January 9, 2014, a large chemical spill occurred on the bank of the Elk River near Charleston, WV. Within hours, the potable water supply for more than 300,000 people was contaminated, and the incident captured national headlines for weeks. Although the primary chemical, crude 4-methylcyclohexanemethanol, or MCHM, is considered nonhazardous, the impacts of the spill are significant – with all stakeholders, including the public, members of industry, and relevant government agencies experiencing losses. More than a year later, this case continues to garner significant attention, with many still questioning just how it could have happened given the complex regulatory system in the US. In retrospect, the Elk River spill highlights the need for a more proactive approach to environmental protection, shifting from prescriptive regulation to comprehensive risk management. The lessons learned are particularly important for “gray” areas within regulatory framework, such as the vast area of nonhazardous chemicals.
Towards Sustainable Development: Conflict Management Practice and Education
McCullough, Erin; Sarver, Emily A. (Society for Mining, Metallurgy and Exploration, 2016-02-22)
Fostering positive community relations is a principal tenet of sustainable development, but conflict can test even the strongest of relationships. While conflict surrounding resource development projects has the potential to be destructive, it may actually pose opportunities for partnership and collaboration when managed effectively. It is therefore not only important for mineral resource professionals to recognize the financial and social costs associated with legal disputes among project stakeholders, but also for them to prioritize resolving social conflict using alternative channels that allow for win-win outcomes. A variety of dispute prevention and resolution techniques do exist, but successful practice is not yet the norm. Here we review the sources and consequences of social conflict in the context of mining projects, and discuss typical and alternative approaches to conflict management in light of their respective benefits and drawbacks. We also suggest implementation of conflict resolution lessons into resource-related university curricula as a critical step in the continued shift of the mining industry towards sustainable development.
"There Should Be No Life": Environmental Perspectives on Genocide in Northern Iraq
Ahram, Ariel I. (Routledge, 2023-09-07)
This article examines the natural environment during the Kurdish genocide in northern Iraq. The genocide killed between 50,000 and 180,000 people and destroyed some 4,500 Kurdish villages from the 1960s to 1980s, reach peak violence during the Iran-Iraq War (1980–88). The paper uses American, British, and Iraqi archival documents to analyse how the violence affected the natural landscape and how ecological conditions constrained the violence. Iraqi leaders regarded dams and other modes of environmental engineering as levers to facilitate agricultural modernization and social integration. Protecting and projecting hydraulic power justified greater military exertion. Iraqi leaders, frustrated by the lack of progress in development and hostile to the claims of Kurdish nationalism, resorted to more coercive options to combat guerrillas. But the inadequacies of military exertion prompted the government to redouble efforts to tame unruly nature and those who dwelled in it. This escalation contributed significantly to the lethal violence against rural Kurdish society. At a theoretical level, these findings highlight the troubling ways in which policies aimed to improve environmental conditions fold into campaigns of mass violence. The article also adds to understanding of violence in Iraq, showing how Iraq’s attempts to use environmental engineering for development intersected with security concerns and ethnic marginalization to create more intensive repression.
In Search of a Middle East and North Africa Peace System
Ahram, Ariel I. (SAGE Publications, 2024-04-11)
This article examines the strengths and weaknesses of the peace system in the Middle East and North Africa (MENA). It views peace not merely as the absence of direct violence but as the result of institutions and systems that mitigate, defuse, and diminish conflict. The peace system of MENA operates at multiple scales and deals with multiple kinds of violent conflict. Different system components produce different forms of positive and negative peace through both formal and informal institutional channels. Consequently, peace in MENA is often uneven and unstable, with progress in one dimension coming at the expense of another. Understanding the gaps and inconsistencies within the MENA peace system can help devise a more realistic and feasible approach to conflict resolution rather than abstract and ultimately impractical ideals. The article identifies shortcomings in the current explanations for the frequency of war, explores the idea of a regional peace system that operates in regional and domestic arenas both formally and informally, and examines policy measures that might bolster or undercut the MENA peace system.
Niche partitioning and the storage effect facilitate coexistence in an amphibian community
Brooks, George C.; Caruso, Nicholas M.; Chandler, Houston C.; Haas, Carola A. (Wiley, 2023-10-18)
Virtually all natural community assemblages are dominated by a handful of common species. Dominant species can exert negative impacts on biodiversity through competitive exclusion, and thus there is a strong incentive to understand imbalances in community composition, changes in dominance hierarchies through time, and mechanisms of coexistence. Pond-breeding amphibians that utilize ephemeral wetlands provide an excellent opportunity to evaluate theoretical predictions of community composition in stochastic environments. One of the most striking features of pond-breeding amphibians is the marked stochastic fluctuations in abundance across years. Given strong theoretical and empirical links between evenness and biomass, one would expect community evenness to change from year to year. Moreover, if different species exhibit different boom-and-bust reproductive cycles, then a storage effect may help to explain why one species does not outcompete all others. Here, we explore the interplay between biotic and abiotic conditions in shaping amphibian communities at two ephemeral wetlands on Eglin Air Force Base, Florida. We document consistent community composition over 6 years of monitoring, resulting from a lack of species turnover and similar responses of all community members to environmental conditions. The similar dynamics of species argues against a storage effect as the sole mechanism for coexistence and instead points to niche partitioning as a more important factor. In support of this conclusion, we show that the degree of synchrony in breeding migrations only correlates with environmental conditions within species, not between species. The lack of pattern seen between species implies that individuals are somewhat constrained in the timing of breeding migrations, perhaps owing in part to competition with other community members. We hope that our work reinvigorates interest in amphibian communities and highlights ephemeral wetlands as model systems to study community dynamics in stochastic environments.
Forecasting the flooding dynamics of flatwoods salamander breeding wetlands under future climate change scenarios
Chandler, Houston C.; Caruso, Nicholas M.; McLaughlin, Daniel L.; Jiao, Yan; Brooks, George C.; Haas, Carola A. (PeerJ, 2023-09-19)
Ephemeral wetlands are globally important systems that are regulated by regular cycles of wetting and drying, which are primarily controlled by responses to relatively short-term weather events (e.g., precipitation and evapotranspiration). Climate change is predicted to have significant effects on many ephemeral wetland systems and the organisms that depend on them through altered filling or drying dates that impact hydroperiod. To examine the potential effects of climate change on pine flatwoods wetlands in the southeastern United States, we created statistical models describing wetland hydrologic regime using an approximately 8-year history of water level monitoring and a variety of climate data inputs. We then assessed how hydrology may change in the future by projecting models forward (2025–2100) under six future climate scenarios (three climate models each with two emission scenarios). We used the model results to assess future breeding conditions for the imperiled Reticulated Flatwoods Salamander (Ambystoma bishopi), which breeds in many of the study wetlands. We found that models generally fit the data well and had good predictability across both training and testing data. Across all models and climate scenarios, there was substantial variation in the predicted suitability for flatwoods salamander reproduction. However, wetlands with longer hydroperiods tended to have fewer model iterations that predicted at least five consecutive years of reproductive failure (an important metric for population persistence). Understanding potential future risk to flatwoods salamander populations can be used to guide conservation and management actions for this imperiled species.
Wearing a back-support exoskeleton alters lower-limb joint kinetics during single-step recovery following a forward loss of balance
Park, Jang-Ho; Madigan, Michael L.; Kim, Sunwook; Nussbaum, Maury A.; Srinivasan, Divya (Elsevier, 2024-03-31)
We assessed the effects of a passive, back-support exoskeleton (BSE) on lower-limb joint kinetics during the initiation and swing phases of recovery from a forward loss of balance. Sixteen (8M, 8F) young, healthy participants were released from static forward-leaning postures and attempted to recover their balance with a single-step while wearing a BSE (backX^TM) with different levels of support torque and in a control condition. The BSE provided ∼ 15-20 Nm of external hip extension torque on the stepping leg at the end of initiation and beginning of swing phases. Participants were unable to generate sufficient hip flexion torque, power, and work to counteract this external torque, although they sustained hip flexion torque for a more prolonged period, resulting in slightly increased hip contribution to positive leg work (compared to control). However, net positive leg work, and the net contribution of hip joint (human + BSE) to total leg work decreased with BSE use. While all participants had changes in hip joint kinetics, a significant compensatory increase in ankle contribution to positive leg work was observed only among females. Our results suggest that BSE use adversely affects reactive stepping by decreasing the stepping leg kinetic energy for forward propulsion, and that the relative contributions of lower-limb joints to total mechanical work done during balance recovery are altered by BSE use. BSEs may thus need to be implemented with caution for dynamic tasks in occupational settings, as they may impair balance recovery following a forward loss of balance.
Narrows, VA: Mill Creek Nature Park Trailhead Conceptual Site Master Plan
Harrington, Hayley (2024-03-29)
Narrows, Virginia is a small community of about 2,000 people located in Giles County off of Route 460 and near the narrowing of the New River. Within the mountains of Narrows is Mill Creek Nature Park, a park of about 145-acres. The park, which adjoins Jefferson National Forest, includes several trails of varying lengths for hiking and mountain biking as well as two waterfalls. The park also offers the opportunity to fish for native trout. The trailhead for the park is about 1-acre and includes two parking areas, one of which is bordered by boulders on one side to keep vehicles away from overhead power lines, a picnic shelter with 4 picnic tables, a kiosk, a porta potty, and a gate for maintenance vehicle access. The town would like improve the trailhead to make it more visually appealing, plan for additional parking in the future, and make the trailhead more functional. Initial ideas for improvements included park entry signage, wayfinding signage and branding for trails, installing a new single stall restroom in a different location than the porta potty, creating a formal path from the parking areas to the trails and the new restroom, landscaping with native plant materials, expanded parking for in the future, and the ability for one or two buses to be able to park and turn around.
Castlewood, VA: Conceptual Redevelopment Plan for the Mudhole Store
Harrington, Hayley (2024-02-29)
Castlewood is an unincorporated community located in northwest Russell County with approximately 1,700 residents (U.S. Census Bureau, 2020). The community was originally named Castle’s Woods after Jacob Castle, who first arrived in the area around 1750. Castlewood was the first settlement in Russell County, and its first permanent residents arrived in 1769. Daniel Boone and his family also lived in Castle’s Woods between 1773 and 1775. The Mudhole Store site is located at 776 Red Oak Ridge Road at the intersection of Red Oak Ridge Road and Reeds Valley Road. The site consists of several properties owned by Charles Bickley “Bick” and Judith “Judy” Gibson amounting to approximately 13 acres. The former filling station located onsite was built in the 1950s and is located on a parcel of about .31 acres. There were two pumps and the tanks are likely still located underground. The station also served as a convenience store. The historic egg house, located about 120 feet east of the current gas station building, was built between 1930 and 1950 and historically used to store and trade eggs.
Castlewood, VA: Conceptual Redevelopment Plan for the Mudhole Store Executive Summary
Harrington, Hayley (2024-02-29)
Castlewood is an unincorporated community located in northwest Russell County with approximately 1,700 residents (U.S. Census Bureau, 2020). The community was originally named Castle’s Woods after Jacob Castle, who first arrived in the area around 1750. Castlewood was the first settlement in Russell County, and its first permanent residents arrived in 1769. Daniel Boone and his family also lived in Castle’s Woods between 1773 and 1775. The Mudhole Store site is located at 776 Red Oak Ridge Road at the intersection of Red Oak Ridge Road and Reeds Valley Road. The site consists of several properties owned by Charles Bickley “Bick” and Judith “Judy” Gibson amounting to approximately 13 acres. The former filling station located onsite was built in the 1950s and is located on a parcel of about .31 acres. There were two pumps and the tanks are likely still located underground. The station also served as a convenience store. The historic egg house, located about 120 feet east of the current gas station building, was built between 1930 and 1950 and historically used to store and trade eggs.
The Virginia Tech Honors Minor: Mapping a guided path for students to take risks in collaborative discovery
Budowle, Rachael; Velez, Anne-Lise; Lewis, Nikki (2023-12-08)
Optimal distinctiveness of short-term rental property design
Zhang, Huihui; Zach, Florian J.; Xiang, Zheng (Elsevier, 2024-07)
The short-term rental market remains highly competitive, requiring that hosts should identify effective strategies to position their products for desirable performance. This study investigates the optimal balance beyond dyadic choice between differentiating from or conforming to competitors, in the dimensions of properties’ functional and aesthetic design. We hypothesize U-shaped distinctiveness-performance relationships considering high legitimacy pressure and low strategy effectiveness in the short-term rental context. Moreover, the moderating effects of factors including online review volume and listing age are examined. Analyzing a sample of 99,757 Airbnb listings in Texas, the findings reveal different patterns of product positioning between functionality and aesthetics. The moderate degree of distinctiveness in functionalities leads to the worst performance while in aesthetics generating the best outcome. This study contributes to the hospitality literature by introducing and testing optimal distinctiveness within the short-term rental market. The findings also provide positioning guidance for short-term rental listings under different conditions.
Big Data, Smart Buildings, Post-Covid Office Real Estate Decision Making, and Multi-Disciplinary Undergraduate Learning: A Case Study in Discovery Thinking
Kretser, Michael; Cherbaka, Natalie (2024-02-22)
Application of Distributed Ledger Technology in Distribution Networks
Zhou, Yue; Manea, Andrei Nicolas; Hua, Weiqi; Wu, Jianzhong; Zhou, Wei; Yu, James; Rahman, Saifur (IEEE, 2022-06-24)
In the transition to a society with net-zero carbon emissions, high penetration of distributed renewable power generation and large-scale electrification of transportation and heat are driving the conventional distribution network operators (DNOs) to evolve into distribution system operators (DSOs) that manage distribution networks in a more active and flexible way. As a radical decentralized data management technology, distributed ledger technology (DLT) has the potential to support a trustworthy digital infrastructure facilitating the DNO-DSO transition. Based on a comprehensive review of worldwide research and practice, as well as the engagement of relevant industrial experts, the application of DLT in distribution networks is identified and analyzed in this article. The DLT features and DSO needs are first summarized, and the mapping relationship between them is identified. Detailed DSO functions are identified and classified into five categories (i.e., 'planning,' 'operation,' 'market,' 'asset,' and 'connection') with the potential of applying DLT to various DSO functions assessed. Finally, the development of seven key DSO functions with high DLT potential is analyzed and discussed from the technical, legal, and social perspectives, including peer-to-peer energy trading, flexibility market facilitation, electric vehicle charging, network pricing, distributed generation register, data access, and investment planning.
Optimal Scheduling of Integrated Energy Systems With Multiple CCHPs for High Efficiency and Low Emissions
Xie, Haimin; Liu, Hui; Wan, Can; Goh, Hui Hwang; Rahman, Saifur (IEEE, 2023-08-14)
In order to reach carbon neutrality, there is growing interest in reducing greenhouse gas (GHG) and improving energy efficiency. One way to address this issue is the optimal scheduling of the integrated energy system (IES) with multiple combined cooling heating and power (CCHP) systems as proposed in this article. We model IES as a device with multiple input/output ports by the energy hub (EH) framework and propose a multiobjective optimal model to improve energy efficiency and reduce GHG emissions. The proposed model is constructed as a mixed-integer nonlinear programming (MINLP) due to considering nonlinear couplings of multiple energy flows and the unit commitment of multiple CCHP systems. To improve the computational efficiency, the proposed MINLP model is transformed into a nonlinear programming (NLP) model by a fast unit commitment technique based on the approximation of the aggregated online capacity. Finally, simulation results show the effectiveness of the proposed approach in reducing GHG emissions and improving energy efficiency as well as computational efficiency.
A Comparative Performance Analysis of ANN Algorithms for MPPT Energy Harvesting in Solar PV System
Roy, Rajib Baran; Rokonuzzaman, Md; Amin, Nowshad; Mishu, Mahmuda Khatun; Alahakoon, Sanath; Rahman, Saifur; Mithulananthan, Nadarajah; Rahman, Kazi Sajedur; Shakeri, Mohammad; Pasupuleti, Jagadeesh (IEEE, 2021-07-13)
In this paper, artificial neural network (ANN) based Levenberg-Marquardt (LM), Bayesian Regularization (BR) and Scaled Conjugate Gradient (SCG) algorithms are deployed in maximum power point tracking (MPPT) energy harvesting in solar photovoltaic (PV) system to forge a comparative performance analysis of the three different algorithms. A comparative analysis among the algorithms in terms of the performance of handling the trained dataset is presented. The MATLAB/Simulink environment is used to design the maximum power point tracking energy harvesting system and the artificial neural network toolbox is utilized to analyze the developed model. The proposed model is trained with 1000 dataset of solar irradiance, temperature, and voltages. Seventy percent data is used for training, while 15% data is employed for validation, and 15% data is utilized for testing. The trained datasets error histogram represents zero error in the training, validation, and test phase of data matching. The best validation performance is attained at 1000 epochs with nearly zero mean squared error where the trained data set is converged to the best training results. According to the results, the regression and gradient are 1, 1, 0.99 and 0.000078, 0.0000015739 and 0.26139 for Levenberg-Marquardt, Bayesian Regularization and Scaled Conjugate Gradient algorithms, respectively. The momentum parameters are 0.0000001 and 50000 for Levenberg-Marquardt and Bayesian Regularization algorithms, respectively, while the Scaled Conjugate Gradient algorithm does not have any momentum parameter. The Scaled Conjugate Gradient algorithm exhibit better performance compared to Levenberg-Marquardt and Bayesian Regularization algorithms. However, considering the dataset training, the correlation between input-output and error, the Levenberg-Marquardt algorithm performs better.
An Assessment of Multistage Reward Function Design for Deep Reinforcement Learning-Based Microgrid Energy Management
Goh, Hui Hwang; Huang, Yifeng; Lim, Chee Shen; Zhang, Dongdong; Liu, Hui; Dai, Wei; Kurniawan, Tonni Agustiono; Rahman, Saifur (IEEE, 2022-06-01)
Reinforcement learning based energy management strategy has been an active research subject in the past few years. Different from the baseline reward function (BRF), the work proposes and investigates a multi-stage reward mechanism (MSRM) that scores the agent's step and final performance during training and returns it to the agent in real time as a reward. MSRM will also improve the agent's training through expert intervention which aims to prevent the agent from being trapped in sub-optimal strategies. The energy management performance considered by MSRM-based algorithm includes the energy balance, economic cost, and reliability. The reward function is assessed in conjunction with two deep reinforcement learning algorithms: double deep Q-learning network (DDQN) and policy gradient (PG). Upon benchmarking with BRF, the numerical simulation shows that MSRM tends to improve the convergence characteristic, reduce the explained variance, and reduce the tendency of the agent being trapped in suboptimal strategies. In addition, the methods have been assessed with MPC-based energy management strategies in terms of relative cost, self-balancing rate, and computational time. The assessment concludes that, in the given context, PG-MSRM has the best overall performance.
Celebrate the 10th Anniversary of IEEE Electrification Magazine and Embrace a New Era
Rahman, Saifur (IEEE, 2023-09)
Optimizing dynamic electric ferry loads with intelligent power management
Roy, Rajib Baran; Alahakoon, Sanath; Arachchillag, Shantha Jayasinghe; Rahman, Saifur (Elsevier, 2023-12)
In recent years, there has been an increasing shift towards using environmentally friendly renewable resources in marine vessels, replacing traditional diesel generators. However, one of the main challenges faced in renewable energy-driven marine vessels is dynamic load management. The feasibility of a renewable-powered electric marine vessel largely depends on the optimal utilization of renewable resources, and storage is an essential component of the marine electric vessel. This paper proposes a two-stage power management system (PMS) for an electric ferry powered by the fuel cell and battery energy storage systems (BESS). The primary objective of the proposed PMS is to ensure a balance between the generated power and the ferry load by minimizing the consumption of hydrogen (H2) fuel. The first stage of the PMS employs particle swarm optimization (PSO), bacterial foraging optimization (BFO), and a hybrid PSO-BFO algorithm to optimize the fuel cell and battery capacity. This is done so that the generated power can follow the load demand. The second stage of the PMS utilizes the Mamdani rule-based fuzzy logic system (FLS) to match the load demand with the generated power. The hybrid PSO-BFO algorithm optimizes the fuzzy control parameters to meet the dynamic load by ensuring optimal H2 fuel consumption and battery state of charge (SOC). To obtain optimal values, the load profile of a conventional ferry is used for the proposed PMS. Based on the optimization results, the optimal capacities are found to be 318 kWh and 317.64 kWh for the fuel cell and BESS, respectively, which are obtained using the hybrid PSO-BFO algorithm. The optimal value of H2 fuel consumption during cruising is found to be 18 kg. A simulated model-based approach validates the operation of the proposed PMS. The proposed PMS ensures optimal H2 fuel consumption and battery SOC while meeting the dynamic load demands of the ferry. The results obtained demonstrate the effectiveness of the proposed PMS in optimizing the renewable energy-driven marine vessel power system.
"This is not a scam!!" A mixed methods evaluation of findings of an interactive theatre production about scams victimizing older people
Parti, Katalin (2024-03-26)
In 2021-23, this interdisciplinary collaborative project investigated the needs of older scam victims. The report is an assessment of the interactive theatre program "This is not a scam!!" showcased in the Spring of 2023. Implications and recommendations are included.

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