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Browsing by Author "McGinnis, Sean"

Now showing 1 - 17 of 17
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    Chloride Penetration Resistance and link to Service Life Design of Virginia Bridge Decks
    Bales, Elizabeth Rose (Virginia Tech, 2016-06-19)
    Reinforced concrete (RC) bridge decks are exposed to chlorides from deicing salts. Chloride ingress in RC initiates corrosion of the reinforcing steel. The high costs of corrosion have sparked interest in service life design of bridge decks. This thesis characterized the exposure conditions of Virginia, including temperature and surface chloride concentration, as well as Virginia concrete mix properties, including initial chloride concentration and chloride migration coefficient. The service life estimations for a case study bridge in Virginia from three service life models were compared. The first model is based on the fib Bulletin 34 Model Code for Service Life Design, the second is a finite element solution of the fib Bulletin, and the third accounts for a time-, temperature-, moisture-, and concentration-dependent apparent diffusion coefficient. A sensitivity analysis was completed on the three models showing that the most important variables in these models are the aging coefficient and surface chloride concentration. Corresponding life cycle cost analyses were completed for plain and corrosion resistant reinforcing steel. This thesis showed that the error function solution underestimates chloride ingress. The life cycle cost analysis of plain and corrosion resistant reinforcing steels show that overestimation of service life leads to underestimation of life cycle costs.
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    Condition Assessment, Indices, and Risk-based Decision-making for Public School Infrastructure Managment
    Ackerman Jr, Paul J. (Virginia Tech, 2014-09-04)
    The Asbestos Hazard Emergency Response Act (AHERA) requires public schools to manage asbestos containing materials. Twenty five years after AHERA was enacted public schools continue to struggle with documenting and managing asbestos containing material assets. In addition, the manufacturing of lead based paint (LBP) was banned over thirty years ago yet public schools continue to have to manage LBP assets with no guidelines specific to public schools. When compared to current civil infrastructure asset management systems, AHERA and the HUD guidelines lack a rating system based on visual inspection data. The development of a condition index algorithm and risk of failure model would provide school planners an efficient management tool to predict the future condition of asbestos containing material and lead based paint assets. As a result, school planners would be able to prioritize maintenance, repair, and abatement projects based on the risk to the indoor air quality of their facilities and more efficiently utilize their limited resources to mitigate such risks. This paper presents initial work toward the development of a visual condition index algorithm and a risk of failure model to support prioritization of maintenance, repair, and abatement projects. The condition assessment categories provided by AHERA and HUD were adapted and incorporated in an evaluation form created to assist in rating the various stages of accessibility, deterioration, and detection of typical ACM and LBP building components. The evaluation form can be utilized by inspection and school personnel when reclassifying ACM and LBP components during semi-annual inspections of their facilities and also ensure the repeatability of the condition assessment and risk of failure methodologies. A risk of failure model was developed utilizing the FMEA process, specifically the calculation of a risk priority number (RPN). Three schools were selected for a field pilot study to develop the accessibility, deterioration, detection, and RPN algorithms and evaluate for repeatability. The algorithms will provide a quantitative and consistent means for documenting the condition and RPN of asbestos containing material and lead based paint assets and allow the condition of these assets to be monitored and reclassified over a period of time.
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    A Decision-Support Framework for Design of Non-Residential Net-Zero Energy Buildings
    Tiwari, Railesha (Virginia Tech, 2015-04-28)
    Designing Net-Zero Energy Buildings (NZEB) is a complex and collaborative team process involving knowledge sharing of experts leading to the common goal of meeting the Net-Zero Energy (NZE) project objectives. The decisions made in the early stages of design drastically affect the final outcome of design and energy goals. The Architecture, Engineering and Construction (AEC) industry is pursuing ways to improve the current building design process and project delivery methods for NZEBs. To enable the building industry to improve the building design process, it is important to identify the gaps, ways of improvement and potential opportunities to structure the decision-making process for the purpose of NZE performance outcome. It is essential to identify the iterative phases of design decisions between the integrated team of experts for the design processes conducted in these early stages to facilitate the decision-making of NZEB design. The lack of a structured approach to help the AEC industry in making informed decisions for the NZEB context establishes the need to evaluate the argumentation of the NZEB design decision process. The first step in understanding the NZEB design decision process is to map the current processes in practice that have been successful in achieving the NZE goal. Since the energy use performance goal drives the design process, this research emphasizes first the need to document, in detail, and investigate the current NZEB design process with knowledge mapping techniques to develop an improved process specific to NZEB context. In order to meet this first objective, this research qualitatively analyzed four NZEB case studies that informed decision-making in the early design phases. The four components that were studied in the early design phases included (1) key stakeholders involved (roles played), (2) phases of assessments (design approach, (3) processes (key processes, sub-processes and design activities affecting performance) and (4) technology (knowledge type and flow). A series of semi-structured, open-ended interviews were conducted with the key decision-makers and decision facilitators to identify their roles in the early design processes, the design approach adopted, rationale for decision-making, types of evaluations performed, and tools used for analysis. The qualitative data analysis was performed through content analysis and cognitive mapping techniques. Through this process, the key phases of decision-making were identified that resulted in understanding of the path to achieving NZE design goal and performance outcome. The second objective of this research was to identify the NZE decision nodes through a comparative investigation of the case studies. This research also explored the key issues specific to each stakeholder group. The inter-relationships between the project objectives, decision context, occupants usage patterns, strategies and integrated systems, building operation and renewable energy production was identified through a series of knowledge maps and visual process models leading to the identification of the key performance indicators. This research reviewed the similarities and differences in the processes to identify significant opportunities that can improve the early building design process for NZEBs. This research identifies the key decision phases used by the integrated teams and describes the underlying structure that can change the order of key phases. A process mapping technique was adapted to capture the practice-based complex NZEB design approach and draw insights of the teamwork and interdisciplinary communication to enable more comprehensive understanding of linkages between processes, sub-processes and design activities, knowledge exchange, and decision rationale. Ket performance indicators identified for early design of NZEBs resulted in developing a decision-support process model that can help the AEC industry in making informed decisions. This dissertation helps improve understanding of linkages between processes, decision nodes and decision rationale to enable industry-wide NZEB design process assessment and improvement. This dissertation discusses the benefits the proposed NZEB design process model brings to the AEC industry and explores future development efforts.
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    Development and Deployment of Renewable and Sustainable Energy Technologies
    Jung, Jae Sung (Virginia Tech, 2014-03-06)
    Solar and wind generation are one of the most rapidly growing renewable energy sources, and is regarded as an appealing alternative to conventional power generated from fossil fuel. This is leading to significant levels of distributed renewable generation being installed on distribution circuits. Although renewable generation brings many advantages, circuit problems are created due to its intermittency, and overcoming these problems is a key challenge to achieving high penetration. It is necessary for utilities to understand the impacts of Photovoltaic (PV) generation on distribution circuits and operations. An impact study is intended to quantify the extent of the issues, discover any problems, and investigate alternative solutions. In this manner, system wide and local impact study are proposed in the dissertation. 1) System wide impact study This study considers system effects due to the addition of Plug-in Hybrid Vehicles (PHEV) and Distributed Energy Resource (DER) generation. The DER and PHEV are considered with energy storage technology applied to the residential distribution system load. Two future year scenarios are considered, 2020 and 2030. The models used are of real distribution circuits located near Detroit, Michigan, and every customer load on the circuit and type of customer are modeled. Monte Carlo simulations are used to randomly select customers that receive PHEV, DER, and/or storage systems. The Monte Carlo simulations provide not only the expected average result, but also its uncertainty. 2) Local impact study Analysis of high PV penetration in distribution circuits using both steady-state and quasi steady-state impact studies are presented. The steady-state analysis evaluates impacts on the distribution circuit by comparing conditions before and after extreme changes in PV generation at three extreme circuit conditions, maximum load, maximum PV generation, and when the difference between the PV generation and the circuit load is a maximum. The quasi steady-state study consists of a series of steady-state impact studies performed at evenly spaced time points for evaluating the spectrum of impacts between the extreme impacts. Results addressing the impacts of cloud cover and various power factor control strategies are presented. PV penetration levels are limited and depend upon PV generation control strategies and the circuit design and loading. There are tradeoffs in PV generation control concerning circuit voltage variations, circuit losses, and the motion of automated utility control devices. The steady state and quasi steady-state impact studies provide information that is helpful in evaluating the effect of PV generation on distribution circuits, including circuit problems that result from the PV generation. In order to fully benefit from wind power, accurate wind power forecasting is an essential tool in addressing this challenge. This has motivated researchers to develop better forecast of the wind resources and the resulting power. As a solution for wind generation, frequency domain approach is proposed to characterize and analyze wind speed patterns in the dissertation. 3) Frequency Domain Approach This study introduces the frequency domain approach to characterize and analyze wind speed patterns. It first presents the technique of and the prerequisite conditions for the frequency domain approach. Three years of wind speed data at 10 different locations have been used. This chapter demonstrates that wind speed patterns during different times and at different locations can be well characterized by using the frequency domain approach with its compact and structured format. We also perform analysis using the characterized dataset. It affirms that the frequency domain approach is a useful indicator for understanding the characteristics of wind speed patterns and can express the information with superior accuracy. Among the various technical challenges under high PV penetration, voltage rise problems caused by reverse power flows are one of the foremost concerns. The voltage rises due to the PV generation. Furthermore, the need to limit the voltage rise problem limits PV generators from injecting more active power into the distribution network. This can be one of the obstacles to high penetration of PVs into circuits. As a solution for solar generation, coordinated control of automated devices and PV is proposed in the dissertation. 4) Coordinated Automated Device and PV Control A coordinating, model-centric control strategy for mitigating voltage rise problems due to PV penetration into power distribution circuits is presented. The coordinating control objective is to maintain an optimum circuit voltage distribution and voltage schedule, where the optimum circuit operation is determined without PV generation on the circuit. In determining the optimum circuit voltage distribution and voltage schedule, the control strategy schedules utility controls, such as switched capacitor banks and voltage regulators, separate from PV inverter controls. Optimization addresses minimizing circuit losses and motion of utility controls. The coordinating control action provides control setpoints to the PV inverters that are a function of the circuit loading or time-of-day and also the location of the PV inverter. Three PV penetration scenarios are considered, 10%, 20%, and 30%. Baselines with and without coordinating controls for circuit performance without PV generation are established, and these baselines are compared against the three PV penetration scenarios with and without coordinating control. Simulation results are compared and differences in voltage variations and circuit losses are considered along with differences in utility control motion. Results show that the coordinating control can solve the voltage rise problem while minimizing circuit losses and reducing utility control motion. The coordinating control will work with existing PV inverter controls that accept control setpoints without having to modify the inverter controls. 5) Coordinated Local and Centralized PV Control Existing distribution systems and their associated controls have been around for decades. Most distribution circuits have capacity to accommodate some level of PV generation, but the question is how much can they handle without creating problems. It proposes a Configurable, Hierarchical, Model-based, Scheduling Control (CHMSC) of automated utility control devices and photovoltaic (PV) generators. In the study here the automated control devices are assumed to be owned by the utility and the PV generators and PV generator controls by another party. The CHMSC, which exists in a hierarchical control architecture that is failure tolerant, strives to maintain the voltage level that existed before introducing the PV into the circuit while minimizing the circuit loss and reducing the motion of the automated control devices. This is accomplished using prioritized objectives. The CHMSC sends control signals to the local controllers of the automated control devices and PV controllers. To evaluate the performance of the CHMSC, increasing PV levels of adoption are analyzed in a model of an actual circuit that has significant existing PV penetration and automated voltage control devices. The CHMSC control performance is compared with that of existing, local control. Simulation results presented demonstrate that the CHMSC algorithm results in better voltage control, lower losses, and reduced automated control device motion, especially as the penetration level of PV increases.
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    The Effect of Uncertain End-of-Life Product Quality and Consumer Incentives on Partial Disassembly Sequencing in Value Recovery Operations
    Rickli, Jeremy Lewis (Virginia Tech, 2013-08-19)
    This dissertation addresses gaps in the interaction between End-of-Life (EoL) product acquisition systems and disassembly sequencing. The research focuses on two remanufacturing research problems; 1) modeling uncertain EoL product quality, quantity, and timing in regards to EoL product acquisition and disassembly sequencing and 2) designing EoL product acquisition schemes considering EoL product uncertainty. The main research objectives within these areas are; analyzing, predicting, and controlling EoL product uncertainty, and incorporating EoL product uncertainty into operational and strategic level decisions. This research addresses these objectives by researching a methodology to determine optimal or near-optimal partial disassembly sequences using infeasible sequences while considering EoL product quality uncertainty. Consumer incentives are integrated into the methodology to study the effect of EoL product take-back incentives, but it also allows for the study of EoL product quantity uncertainty. EoL product age distributions are key to integrating the disassembly sequence method with EoL product acquisition management, acting both as an indicator of quality and as a basis for determining return quantity when considering incentives. At a broader level, this research makes it possible to study the impact of EoL product quality, and to an extent quantity, uncertainty resulting from strategic level (acquisition scheme) decisions, on operational (disassembly sequencing) decisions. This research is motivated by the rising importance of value recovery and sustainability to manufacturers. Extended Producer Responsibility (EPR) and Product Stewardship (PS) policies are, globally, changing the way products are treated during their use-life and EoL. Each new policy places a greater responsibility on consumers and manufacturers to address the EoL of a product. Manufacturers, in particular, may have to fulfill these obligations by such means as contracting 3rd parties for EoL recovery or performing recovery in-house. The significance of this research is linked to the growing presence of remanufacturing and recovery in the US and global economy, either via profitable ventures or environmental regulations. Remanufacturing, in particular, was surveyed by the US International Trade Commission in 2011-2012, where it was determined that remanufacturing grew by 15% to $43 billion, supported 180,000 full-time jobs from 2009-2011, and is continuing to grow. A partial disassembly sequence, multi-objective genetic algorithm (GA) is used a solution procedure to address the problem of determining the optimal or near-optimal partial disassembly sequence considering a continuous age distribution of EoL or available consumer products, with and without a consumer take-back incentive. The multi-objective GA, novel to the presented approach, relies on infeasible sequences to converge to optimal or near-optimal disassembly sequences. It is verified with a discrete economic and environmental impact case prior to incorporating EoL product age distributions. Considering the age distribution of acquired EoL products allows for decisions to be made based not only on expected profit, but also on profit variance and profit probability per EoL product, which was not observed in previous literature. As such, the research presented here within provides three contributions to disassembly and EoL product acquisition research: 1) integrating EoL product age distributions into partial disassembly sequencing objective functions, 2) accounting for partial disassembly sequence expected profit, profit variation, and profit probability as compared to disassembly sequencing methods that have, historically, only considered expected profit, and 3) studying the impact of EoL product age distributions and consumer take-back incentives on optimal or near-optimal partial disassembly sequences. Overall, this doctoral research contributes to the body of knowledge in value recovery, reverse logistics, and disassembly research fields, and is intended to be used, in the future, to develop and design efficient EoL product acquisition systems and disassembly operations.
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    A Framework to Support the Development of Manually Adjustable Light Shelf Technologies
    Javed, Shamim (Virginia Tech, 2014-06-30)
    Active daylight harvesting technologies that are currently available in the market have often suffered from wide-spread market acceptability due to their high cost and imperfect performance. Passive systems, though simple and affordable, typically cannot harvest higher potentials of daylight, which is dynamic over days, months, and seasons, due to their static nature. There is a research and market gap that calls for investigation towards the development of low-tech, manually adjustable, high-performance daylighting mechanisms to be used as an alternative to active daylighting solutions, which are often controlled by building automation systems. This research proposes a framework to support the development of daylight harvesting mechanisms, which will allow for low-tech yet temporary adjustable systems, merging some of the advantages of active systems with passive ones. The hybrid of the above two categories will be a manually adjustable light harvesting device that will allow for quick adjustment through mechanical means to few predefined positions. These positions will be customized to each location to achieve optimum daylight harvesting. The resulting device will allow for flexible adjustment to daily and seasonal variations of the sun's path, while retaining a level of simplicity and elegance towards low-cost installation and operation. Significant effort was made in the initial phase of this research to use experimental studies as the primary method of investigation. However, given the nature of daylight and practical constraints in the field, the experimental method was found to be not productive enough for extent of this research. As a result, simulation studies were ultimately used to generate the necessary data for the development of this framework. For the simulation phase 'DIVA4Rhino,' a climate-based daylighting software and 'Grasshopper,' a graphical programming tool for Rhino, was used to first construct a parametric simulation loop. Next, a reduced set of parameters for a manually adjustable light shelf system were tested for daylight performance, as a 'proof of concept'. Finally, based on the previous two steps, a framework to help the development of manually adjustable light shelf systems has been defined. This research shows that light shelves, even when kept fixed at a single optimum configuration for the whole year, can increase interior daylight performance in most locations and orientations. It also shows that indoor daylight harvesting can be further enhanced if the light shelf is manually adjusted on a seasonal basis. Amongst the variations tested, rotational adjustability has been found to contribute most to the increase in performance. Segmented adjustability, e.g. where the inner and outer sections of a light shelf are manipulated separately, was found to extend performance of light shelves even further though not by significant amounts.
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    Life Cycle Analysis of a Ceramic Three-Way Catalytic Converter
    Belcastro, Elizabeth Lynn (Virginia Tech, 2012-04-23)
    The life cycle analysis compares the environmental impacts of catalytic converters and the effects of not using these devices. To environmentally evaluate the catalytic converter, the emissions during extraction, processing, use of the product are considered. All relevant materials and energy supplies are evaluated for the catalytic converter. The goal of this life cycle is to compare the pollutants of a car with and without a catalytic converter. Pollutants examined are carbon monoxide (CO), carbon dioxide (CO2), hydrocarbons (HC), and nitrogen oxides (NOx). The main finding is that even considering materials and processing, a catalytic converter decreases the CO, HC and NOx pollutant emissions. The CO2 emissions are increased with a catalytic converter, but this increase is small relative to the overall CO2 emissions. The majority of catalytic converter pollutants are caused by the use phase, not extraction or processing. The life cycle analysis indicates that a catalytic converter decreases damage to human health by almost half, and the ecosystem quality damage is decreased by more than half. There is no damage to resources without a converter, as there are no materials or energy required; the damages with a converter are so small that they are not a significant factor. Overall, catalytic converters can be seen as worthwhile environmental products when considering short term effects like human health effects of smog, which are their design intent. If broader environmental perspectives that include climate change are considered, then the benefits depend on the weighting of these different environmental impacts.
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    Life Cycle Impact Assessment of Iron Oxide (Fe3O4/γ-Fe2O3) Nanoparticle Synthesis Routes
    Rahman, Asifur; Kang, Seju; McGinnis, Sean; Vikesland, Peter J. (2022)
    The synthesis of superparamagnetic iron oxide nanoparticles (FeOx-NPs) has rapidly developed over the past decade due to their wide-ranging applications in research and technology. However, at present there exists very limited knowledge about the environmental impacts of the various input materials and the energy required for different FeOx-NP synthesis approaches. In this study, we used cradle-to-gate life cycle assessment (LCA) to analyze and compare the environmental impacts of FeOx-NPs produced via seven common synthesis routes. Four different functional units (i.e., mass, mean particle size, specific surface area, and saturation magnetization) were used to normalize the environmental impacts and evaluate the corresponding changes. Overall, physical and biological synthesis routes exhibited high environmental impacts due to their higher input material and energy requirements. Interestingly, biological syntheses had the highest environmental impacts due to their reliance on bacterial culture media. All of the chemical synthesis routes had lower environmental impacts except the thermal decomposition method, which had higher environmental impacts due its use of non-polar organic solvents during synthesis. The lab-scale LCA inventory data and analysis presented here addresses the existing data gaps and helps guide future research for FeOx-NP synthesis under industrial conditions. The information generated by this effort aids in the identification of environmentally friendly and sustainable production pathways for FeOx-NPs.
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    Nanotechnology in the real world: Redeveloping the nanomaterial consumer products inventory
    Vance, Marina; Kuiken, Todd; Vejerano, Eric P.; McGinnis, Sean; Hochella, Michael F. Jr.; Rejeski, David; Hull, Matthew S. (Beilstein-Institut, 2015)
    To document the marketing and distribution of nano-enabled products into the commercial marketplace, the Woodrow Wilson International Center for Scholars and the Project on Emerging Nanotechnologies created the Nanotechnology Consumer Products Inventory (CPI) in 2005. The objective of this present work is to redevelop the CPI by leading a research effort to increase the usefulness and reliability of this inventory. We created eight new descriptors for consumer products, including information pertaining to the nanomaterials contained in each product. The project was motivated by the recognition that a diverse group of stakeholders from academia, industry, and state/federal government had become highly dependent on the inventory as an important resource and bellweather of the pervasiveness of nanotechnology in society. We interviewed 68 nanotechnology experts to assess key information needs. Their answers guided inventory modifications by providing a clear conceptual framework best suited for user expectations. The revised inventory was released in October 2013. It currently lists 1814 consumer products from 622 companies in 32 countries. The Health and Fitness category contains the most products (762, or 42% of the total). Silver is the most frequently used nanomaterial (435 products, or 24%); however, 49% of the products (889) included in the CPI do not provide the composition of the nanomaterial used in them. About 29% of the CPI (528 products) contain nanomaterials suspended in a variety of liquid media and dermal contact is the most likely exposure scenario from their use. The majority (1288 products, or 71%) of the products do not present enough supporting information to corroborate the claim that nanomaterials are used. The modified CPI has enabled crowdsourcing capabilities, which allow users to suggest edits to any entry and permits researchers to upload new findings ranging from human and environmental exposure data to complete life cycle assessments. There are inherent limitations to this type of database, but these modifications to the inventory addressed the majority of criticisms raised in published literature and in surveys of nanotechnology stakeholders and experts. The development of standardized methods and metrics for nanomaterial characterization and labelling in consumer products can lead to greater understanding between the key stakeholders in nanotechnology, especially consumers, researchers, regulators, and industry.
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    A New Business Process Model for Enhancing BIM Implementation in Architectural Design
    Abdelhady, Ibrahim A I. (Virginia Tech, 2013-12-04)
    During the past few years, Building Information Modeling (BIM) started to gain acceptance within the AEC industry. But, as with many software products for project management, BIM currently faces significant issues and obstacles that hinder its widespread use. The broad goal of this study is to improve BIM implementation in mid-size firms during the Schematic Design (SD) and Design Development (DD) phases. The study has four main objectives. First, mapping the existing BIM related process model in mid-size firms, and modeling the flow of information between BIM users inside these firms. Second, identifying the challenges that are currently facing BIM users during the Schematic Design (SD) and Design Development (DD) phases, because of the importance of these phases in making critical decisions that directly affect the building life cycle. Then, linking these challenges to a BIM related business process model in order to identify when and how these issues occur. Third, exploring the structural conditions that may change or affect the BIM workflow. Fourth, the study proposes a new business process model that can enhance BIM implementation in mid-size firms. The study is qualitative in nature, and based on interviews with a sample of BIM users involved in mid-size firms in the USA. The researcher attempted to capture BIM issues and the flow of information between BIM users through case studies and interviews inside their firms. Also, the researcher involved a new group of BIM users in the research to seek their feedback, in order to generalize the research results.
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    Performance Assessment of Alternative Composite Earth Wall Panels
    Gowda, Vidya (Virginia Tech, 2008-09-08)
    The American Society of Heating, Refrigerating and Air conditioning Engineers suggests that the building sector represents over 30 percent of our national energy consumption (Parsons, R., 2001). Embodied energy in components of building construction can represent as much as five to ten years of operating energy. Building materials such as concrete, steel and glass require significant amounts of energy for production, and therefore are important when calculating embodied energy in buildings (Keable, 2007; Rypkema, 2007). Because of the relatively large area and volume of related components, the building enclosure system represents a major factor when calculating embodied energy. Alternative materials could be incorporated by adapting traditional and vernacular building approaches to today's standards, for example, compressing soil blocks for use as external walls in buildings that can be applicable to almost any climate including rainforests and cold climates. As an alternative to high-embodied energy materials used for enclosure systems, compacted earth-based enclosure systems may be a viable option, particularly if developed and applied as a pre-manufactured modular system. This study seeks to both quantitatively and qualitatively explore the potential development of earth-based building curtain wall systems. Using modified ASTM test protocols for building enclosure systems and components, alternative earth-based panels were compared. The results suggest that earth-based panels may be a viable option for curtain wall systems but its performance is highly dependent on the composition of the panels. The results of the tests are summarized.
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    Quantitative Approach to Select Energy Benchmarking Parameters for Drinking Water Utilities
    Chanpiwat, Pattanun (Virginia Tech, 2014-06-04)
    Energy efficiency is currently a hot topic on all regional, national, and global stages. Accurate measurements on how energy is being used over a period of time can improve performance of the drinking water utility substantially and reduce energy consumption. Nevertheless, the drinking water industry does not have a specific benchmarking practice to evaluate its energy performance of the system. Therefore, there are no standards to compare energy use between water utilities that have a variety of system characteristics. The goal of this research is to develop quantitative approach to select energy benchmarking parameters of the water system, so the drinking water utilities can use those parameters to improve their energy efficiency. In addition to a typical benchmarking of drinking water utilities, the energy benchmarking can specifically compare energy efficiency of a utility with other utilities nationwide. The research developed a regression model based on the statistical representation of the energy use and descriptive characteristics of the drinking water utilities data throughout the U.S. Methodologies to eliminate singularity and multicollinearity from collinear survey dataset are discussed. The all possible regressions were chosen as parameters selection methodology to identify a subset of most significant parameters, i.e. system characteristics, that can mathematically correspond to energy use across different utilities. As a result, the energy benchmarking would be able to calculate the predicted total energy use of the system from given system characteristics.
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    Re-defining the Architectural Design Process Through Building a Decision Support Framework for Design with Reused Building Materials and Components
    Ali, Ahmed Kamal (Virginia Tech, 2012-12-07)
    Waste from construction and demolition-building activities is increasing every day. Landfills have almost reached their capacity. When thinking about the negative impact of demolishing activities on the environment it becomes very necessary to think about reusing and recycling building materials in new construction or perhaps better recycling our thoughts on how to make use of waste materials. In Kevin Lynch's book, Wasting Away, he wrote: "Architects must begin to think about holes in the ground and about flows of materials." Studies show that construction and demolition activities are the primary source of solid waste worldwide. For example construction and demolition wastes constitute about 40% of the total solid waste stream in the United States. The growing interest in materials and resource conservation in the United States is inherent in the growth of green building practices. The USGBC identifies six categories in the Materials and Resources (MR) section of LEED. One of these six categories is Resource Reuse (RR). Interestingly enough, a recent study about the cost of green buildings indicated that RR was the category credits least often achieved in most LEED certified projects. Literature suggests that there are a number of constraints and barriers to resource reuse primarily due to the complexity of buildings but perhaps the most important barrier, according to many architects, is the lack of easily accessible information to the design team on resource reuse. Therefore, as we promote the idea of building material reuse to a wider audience of designers and architects, we mus not forget that in the Architecture, Engineering and Construction (AEC) industry, both Reuse and Recycle terms are used interchangeably without yet a clear distinction between them. The use of arbitrary descriptions to distinguish reuse from recycle has caused nothing but more confusion to the public. This study argues that the real distinction between reuse and recycle exists in Knowledge and Information. This suggests that design with reuse requires a paradigm shift in the required knowledgebase and the way information flows within the design process. Unfortunately, the structure of this paradigm shift is not known and has not been well defined. Since knowledge forms the core of building a Decision Support Systems (DSS) for a design team in order to consider reuse, it is necessary to capture the required knowledge and information from the industry experts through a Knowledge Acquisition (KA) process. This knowledge can then be used to 1) identify the building material reuse criteria and 2) to build a prescriptive decision model and 3) to map the process design of the current traditional architectural design workflow and the proposed one. The overarching goal of this study is to use the building material reuse knowledgebase for 1) building a Unified Virtual Repository database to be connected to all available physical repositories and share a unified standard of information. 2) When the unified virtual repository is integrated with the Building Information Modeling (BIM) database, the DSS can work as a feedback and feed forward support for architects and designers as they consider building material reuse in new designs and constructions.
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    Sustainable Nanotechnology: Life Cycle Thinking in Gold Nanoparticle Production and Recycling
    Pati, Paramjeet (Virginia Tech, 2015-09-01)
    Nanotechnology has enormous potential to transform a wide variety of sectors, e.g., energy, electronics, healthcare, and environmental sustainability. At the same time, there are concerns about the health and environmental impacts of nanotechnology and uncertainties about the fate and toxicity of nanomaterials. Life cycle assessment (LCA), a quantitative framework for evaluating the cumulative environmental impacts associated with all stages of a material or process, has emerged as a decision-support tool for analyzing the environmental burdens of nanotechnology. The objective of this research was to combine laboratory techniques with LCA modeling to reduce the life cycle impacts of gold nanoparticle (AuNP) production. The LCA studies were focused on three aspects of AuNP synthesis: 1) the use of bio-based ("green") reducing agents; 2) the potential for recycling gold from nanomaterial waste; and, 3) the reduction of the life cycle impacts of AuNP production by conducting the synthesis at reduced temperature. The LCA models developed for AuNPs can inform future nanotechnology-focused LCA studies. Comparative LCA showed that in some cases, the environmental impacts associated with green synthesis methods may be worse than those of conventional synthesis approaches. The main driver of the environmental burdens associated with AuNP synthesis is the large embodied energy of gold, and so-called green synthesis methods do not offset those impacts. In addition, the reaction yield, which is seldom reported in the literature for green synthesis of nanomaterials, was found to greatly influence the life cycle impacts of AuNP synthesis. Gold from nanomaterial waste was successfully recovered by using host-guest inclusion complex formation facilitated by alpha-cyclodextrin. This recycling approach involved room temperature conditions and did not require the toxic cyanide or mercury commonly used in the selective recovery of gold. A major advantage offered by this approach for selective gold recovery over conventional approaches is that the recovery does not involve the use of toxic cyanide or mercury. To reduce the energy footprint of citrate-reduced AuNP synthesis, the synthesis was conducted at room temperature. LCA models showed significant reduction in the energy footprint. The findings of this research can inform future LCAs of other nanomaterials.
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    Sustainable provision of food and water using an interdisciplinary, system-of-systems framework
    Bosch, Darrell J.; Clark, Susan F.; Cobourn, Kelly M.; Easton, Zachary M.; Godrej, Adil N.; Hession, W. Cully; Hester, Erich T.; Hull, Robert Bruce IV; Little, John C.; Marathe, Achla; McGinnis, Sean; O'Rourke, Megan E.; Schmale, David G. III; Schoenholtz, Stephen H.; Shortridge, Julie; Swecker, Terry; Thomason, Wade E.; Vullikanti, Anil; White, Robin R. (Virginia Tech, 2017-05-15)
    Although sustainability is an essential concept to ensuring the future of humanity and integrity of the resources and ecosystems on which we depend, identification of a comprehensive approach to assess and enhance sustainability is another grand challenge. Fortuitously, in a groundbreaking re-conceptualization of the problem, we identified the collective limitations of the current suite of approaches used to assess sustainability and instead proposed a computational, system-of-systems framework that is causal, modular, tiered, and scalable. Our approach incorporates a comprehensive definition of sustainability as well as new educational structures to systematically and computationally connect across the disciplines. It also aspires to address the political, economic, and decision-making challenges that limit the applicability of science and technical solutions to wicked problems...
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    Waste not want not: life cycle implications of gold recovery and recycling from nanowaste
    Pati, Paramjeet; McGinnis, Sean; Vikesland, Peter J. (Royal Society of Chemistry, 2016-08-24)
    Commercial-scale applications of nanotechnology are rapidly increasing. Enhanced production of nanomaterials and nano-enabled products and their resultant disposal lead to concomitant increases in the volume of nanomaterial wastes (i.e., nanowaste). Many nanotechnologies employ resource-limited materials, such as precious metals and rare earth elements that ultimately end up as nanowaste. To make nanotechnology more sustainable it is essential to develop strategies to recover these high-value, resource-limited materials. To address this complex issue, we developed laboratory-scale methods to recover nanowaste gold. To this end, α-cyclodextrin facilitated host–guest inclusion complex formation involving second-sphere coordination of [AuBr4]− and [K(OH2)6]+ was used for gold recovery and the recovered gold was then used to produce new nanoparticles. To quantify the environmental impacts of this gold recycling process we then produced life cycle assessments to compare nanoparticulate gold production scenarios with and without recycling. The LCA results indicate that recovery and recycling of nanowaste gold can significantly reduce the environmental impacts of gold nanoparticle synthesis.