Matching Items (25)

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Valuing lnterdependent Water and Energy Savings ln Arizona

Description

ABSTRACT Water and energy resources are intrinsically linked, yet they are managed separately even in the water scarce America southwest. This study develops a spatially explicit model of water energy

ABSTRACT Water and energy resources are intrinsically linked, yet they are managed separately even in the water scarce America southwest. This study develops a spatially explicit model of water energy inter-dependencies in Arizona and assesses the potential for co beneficial conservation programs. The interdependent benefits of investments in 8 conservation strategies are assessed within the context of legislated renewable energy portfolio and energy efficiency standards. The co- benefits of conservation are found to be significant. Water conservation policies have the potential to reduce statewide electricity demand by 1.0 - 3.0 %, satisfying 3.3 -10 % of the state's mandated energy-efficiency-standard. Adoption of energy -efficiency measures and renewable generation portfolios can reduce non - agricultural water demand by 2.3 - 12 %. The conservation co- benefits are typically not included in conservation plans or benefit cost analyses. Many co-benefits offer negative costs of saved water and energy, indicating that these measures provide water and energy savings at no net cost. Because ranges of costs and savings for water energy conservation measures are somewhat uncertain, future studies should investigate the co-benefits of individual conservation strategies in detail. Although this study focuses on Arizona, the analysis can be extended elsewhere as renewable portfolio and energy efficiency standards become more common nationally and internationally.

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Created

Date Created
  • 2013-12

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A Longitudinal Assessment of U.S. Public Transportation Energy Use and GHG Emissions

Description

While public transit systems are perceived to produce lower GHG emission intensities per passenger miles traveled (PMT) and per vehicle miles traveled (VMT), there is a limited understanding of emissions

While public transit systems are perceived to produce lower GHG emission intensities per passenger miles traveled (PMT) and per vehicle miles traveled (VMT), there is a limited understanding of emissions per PMT/VMT across cities, or of how emissions may change across modes (light, metro, commuter, and bus) and time (e.g., with changing electricity mixes in the future). In order to better understand the GHG emissions intensity of public transit systems, a comparative emissions assessment was developed utilizing the National Transit Database (NTD) which reports energy use from 1997 to 2012 of rail and bus systems across the US. By determining the GHG emission intensities (per VMT or per PMT) for each mode of transit across multiple years, the modes of transit can be better compared between one another. This comparison can help inform future goals to reduce GHG emissions as well as target reductions from the mode of transit that has the highest emissions. The proposed analysis of the NTD and comparison of modal emission intensities will be used to develop future forecasting that can guide public transit systems towards a sustainable future.

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Date Created
  • 2014-12

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Assessing the Potential for Transit-Oriented Development Infill to Reduce Life-Cycle Energy Use and Environmental Impacts: A Case Study of Los Angeles Metro's Gold and Orange Transit Lines

Description

Transit-oriented developments (TODs) are a promising strategy to increase public transit use and, as a result, reduce personal car travel. By using TOD infill to increase urban population density and

Transit-oriented developments (TODs) are a promising strategy to increase public transit use and, as a result, reduce personal car travel. By using TOD infill to increase urban population density and encourage transportation mode-shifting, the potential exists to reduce life-cycle per capita energy use and environmental impacts of the interdependent infrastructure systems. This project specifically examined the Gold Line of light rail and Orange Line of bus rapid transit in Los Angeles, CA.

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Created

Date Created
  • 2013-05

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Water and energy requirements for outdoor algal cultivation in panel and raceway photobioreactors

Description

Recognition of algae as a “Fit for Purpose” biomass and its potential as an energy and bio-product resource remains relatively obscure. This is due to the absence of tailored and

Recognition of algae as a “Fit for Purpose” biomass and its potential as an energy and bio-product resource remains relatively obscure. This is due to the absence of tailored and unified production information necessary to overcome several barriers for commercial viability and environmental sustainability. The purpose of this research was to provide experimentally verifiable estimates for direct energy and water demand for the algal cultivation stage which yields algal biomass for biofuels and other bio-products. Algal biomass productivity was evaluated using different cultivation methods in conjunction with assessment for potential reduction in energy and water consumption for production of fuel and feed. Direct water and energy demands are the major focal sustainability metrics in hot and arid climates and are influenced by environmental and operational variables connected with selected algal cultivation technologies. Evaporation is a key component of direct water demand for algal cultivation and directly related to variations in temperature and relative humidity. Temperature control strategies relative to design and operational variables were necessary to mitigate overheating of the outdoor algae culture in panel photobioreactors and sub-optimal cultivation temperature in open pond raceways. Mixing in cultivation systems was a major component in direct energy demand that was provided by aeration in panel bioreactors and paddlewheels in open pond raceways. Management of aeration time to meet required biological interactions provides opportunities for reduced direct energy demand in panel photobioreactors. However, the potential for reduction in direct energy demand in raceway ponds is limited to hydraulics and head loss. Algal cultivation systems were reviewed for potential integration into dairy facilities in order to determine direct energy demand and nutrient requirements for algal biomass production for animal feed. The direct energy assessment was also evaluated for key components of related energy and design parameters for conventional raceway ponds and a gravity fed system. The results of this research provide a platform for selecting appropriate production scenarios with respect to resource use and to ensure a cost effective product with the least environmental burden.

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Created

Date Created
  • 2015

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Decision analysis for comparative life cycle assessment

Description

Life Cycle Assessment (LCA) quantifies environmental impacts of products in raw material extraction, processing, manufacturing, distribution, use and final disposal. The findings of an LCA can be used to improve

Life Cycle Assessment (LCA) quantifies environmental impacts of products in raw material extraction, processing, manufacturing, distribution, use and final disposal. The findings of an LCA can be used to improve industry practices, to aid in product development, and guide public policy. Unfortunately, existing approaches to LCA are unreliable in the cases of emerging technologies, where data is unavailable and rapid technological advances outstrip environmental knowledge. Previous studies have demonstrated several shortcomings to existing practices, including the masking of environmental impacts, the difficulty of selecting appropriate weight sets for multi-stakeholder problems, and difficulties in exploration of variability and uncertainty. In particular, there is an acute need for decision-driven interpretation methods that can guide decision makers towards making balanced, environmentally sound decisions in instances of high uncertainty. We propose the first major methodological innovation in LCA since early establishment of LCA as the analytical perspective of choice in problems of environmental management. We propose to couple stochastic multi-criteria decision analytic tools with existing approaches to inventory building and characterization to create a robust approach to comparative technology assessment in the context of high uncertainty, rapid technological change, and evolving stakeholder values. Namely, this study introduces a novel method known as Stochastic Multi-attribute Analysis for Life Cycle Impact Assessment (SMAA-LCIA) that uses internal normalization by means of outranking and exploration of feasible weight spaces.

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Created

Date Created
  • 2013

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Comparative life cycle assessment of reused versus disposable dental burs

Description

Healthcare infection control has led to increased utilization of disposable medical devices, which has subsequently led to increased adverse environmental effects attributed to healthcare and its supply chain. In dental

Healthcare infection control has led to increased utilization of disposable medical devices, which has subsequently led to increased adverse environmental effects attributed to healthcare and its supply chain. In dental practice, the dental bur is a commonly used instrument that can either be reused or used once and then disposed. To evaluate the disparities in environmental impacts of disposable and reusable dental burs, a comparative life cycle assessment (LCA) was performed. The comparative LCA evaluated a reusable dental bur (specifically, a 2.00mm Internal Irrigation Pilot Drill) reused 30 instances versus 30 identical burs used as disposables. The LCA methodology was performed using framework described by the International Organization for Standardization (ISO) 14040 series. Sensitivity analyses were performed with respect to ultrasonic and autoclave loading. Findings from this research showed that when the ultrasonic and autoclave are loaded optimally, reusable burs had 40% less of an environmental impact than burs used on a disposable basis. When the ultrasonic and autoclave were loaded to 66% capacity, there was an environmental breakeven point between disposable and reusable burs. Eutrophication, carcinogenic impacts, non-carcinogenic impacts, and acidification were limited when cleaning equipment (i.e., ultrasonic and autoclave) were optimally loaded. Additionally, the bur's packaging materials contributed more negative environmental impacts than the production and use of the bur itself. Therefore, less materially-intensive packaging should be used. Specifically, the glass fiber reinforced plastic casing should be substituted for a material with a reduced environmental footprint.

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Created

Date Created
  • 2013

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Quantum resilience

Description

Quantum resilience is a pragmatic theory that allows systems engineers to formally characterize the resilience of systems. As a generalized theory, it not only clarifies resilience in the literature, but

Quantum resilience is a pragmatic theory that allows systems engineers to formally characterize the resilience of systems. As a generalized theory, it not only clarifies resilience in the literature, but also can be applied to all disciplines and domains of discourse. Operationalizing resilience in this manner permits decision-makers to compare and contrast system deployment options for suitability in a variety of environments and allows for consistent treatment of resilience across domains. Systems engineers, whether planning future infrastructures or managing ecosystems, are increasingly asked to deliver resilient systems. Quantum resilience provides a way forward that allows specific resilience requirements to be specified, validated, and verified.

Quantum resilience makes two very important claims. First, resilience cannot be characterized without recognizing both the system and the valued function it provides. Second, resilience is not about disturbances, insults, threats, or perturbations. To avoid crippling infinities, characterization of resilience must be accomplishable without disturbances in mind. In light of this, quantum resilience defines resilience as the extent to which a system delivers its valued functions, and characterizes resilience as a function of system productivity and complexity. System productivity vis-à-vis specified “valued functions” involves (1) the quanta of the valued function delivered, and (2) the number of systems (within the greater system) which deliver it. System complexity is defined structurally and relationally and is a function of a variety of items including (1) system-of-systems hierarchical decomposition, (2) interfaces and connections between systems, and (3) inter-system dependencies.

Among the important features of quantum resilience is that it can be implemented in any system engineering tool that provides sufficient design and specification rigor (i.e., one that supports standards like the Lifecycle and Systems Modeling languages and frameworks like the DoD Architecture Framework). Further, this can be accomplished with minimal software development and has been demonstrated in three model-based system engineering tools, two of which are commercially available, well-respected, and widely used. This pragmatic approach assures transparency and consistency in characterization of resilience in any discipline.

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Created

Date Created
  • 2015

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High occupancy toll lanes with a refund option: a stated preference survey of the Phoenix-Metropolitan Area

Description

Managed Lanes (MLs) have been increasingly advocated as a way to reduce congestion. This study provides an innovative new tolling strategy for MLs called the travel time refund (TTR). The

Managed Lanes (MLs) have been increasingly advocated as a way to reduce congestion. This study provides an innovative new tolling strategy for MLs called the travel time refund (TTR). The TTR is an “insurance” that ensures the ML user will arrive to their destination within a specified travel time savings, at an additional fee to the toll. If the user fails to arrive to their destination, the user is refunded the toll amount.

To gauge interest in the TTR, a stated preference survey was developed and distributed throughout the Phoenix-metropolitan area. Over 2,200 responses were gathered with about 805 being completed. Exploratory data analysis of the data included a descriptive analysis regarding individual and household demographic variables, HOV usage and satisfaction levels, HOT usage and interests, and TTR interests. Cross-tabulation analysis is further conducted to examine trends and correlations between variables, if any.

Because most survey takers were in Arizona, the majority (53%) of respondents were unfamiliar with HOT lanes and their practices. This may have had an impact on the interest in the TTR, although it was not apparent when looking at the cross-tabulation between HOT knowledge and TTR interest. The concept of the HOT lane and “paying to travel” itself may have turned people away from the TTR option. Therefore, similar surveys implementing new HOT pricing strategies should be deployed where current HOT practices are already in existence. Moreover, introducing the TTR concept to current HOT users may also receive valuable feedback in its future deployment.

Further analysis will include the weighting of data to account for sample bias, an exploration of the stated preference scenarios to determine what factors were significant in peoples’ choices, and a predictive model of those choices based on demographic information.

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Created

Date Created
  • 2015

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Food, a global product: an enhanced FEW nexus approach

Description

Sustainable food systems have been studied extensively in recent times and the Food-Energy-Water (FEW) nexus framework has been one of the most common frameworks used. The dissertation intends to examine

Sustainable food systems have been studied extensively in recent times and the Food-Energy-Water (FEW) nexus framework has been one of the most common frameworks used. The dissertation intends to examine and quantitatively model the food system interaction with the energy system and the water system. Traditional FEW nexus studies have focused on food production alone. While this approach is informative, it is insufficient since food is extensively traded. Various food miles studies have highlighted the extensive virtual energy and virtual water footprint of food. This highlights the need for transport, and storage needs to be considered as part of the FEW framework. The Life cycle assessment (LCA) framework is the best available option to estimate the net energy and water exchange between the food, energy, and water systems. Climate plays an important role in food production as well as food preservation. Crops are very sensitive to temperature changes and it directly impacts a crop’s productivity. Changing temperatures directly impact crop productivity, and water demand. It is important to explore the feasibility of mitigation measures to keep in check increasing agricultural water demands. Conservation technologies may be able to provide the necessary energy and water savings. Even under varying climates it might be possible to meet demand for food through trade. The complex trade network might have the capacity to compensate for the produce lost due to climate change, and hence needs to be established. Re-visualizing the FEW nexus from the consumption perspective would better inform policy on exchange of constrained resources as well as carbon footprints. This puts the FEW nexus research space a step towards recreating the FEW nexus as a network of networks, that is, FEW-e (FEW exchange) nexus.

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Created

Date Created
  • 2019

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Transportation infrastructure and heat vulnerability

Description

In the American Southwest, an area which already experiences a significant number of cooling degree days, anthropogenic climate change is expected to result in higher average temperatures and the increasing

In the American Southwest, an area which already experiences a significant number of cooling degree days, anthropogenic climate change is expected to result in higher average temperatures and the increasing frequency, duration, and severity of heat waves. Climatological forecasts predict heat waves will increase by 150-840% in Los Angeles County, California and 340-1800% in Maricopa County, Arizona. Heat exposure is known to increase both morbidity and mortality and rising temperatures represent a threat to public health. As a result there has been a significant amount of research into understanding existing socio-economic vulnerabilities to extreme heat which has identified population subgroups at greater risk of adverse health outcomes. Additionally, research has shown that man-made infrastructure can mitigate or exacerbate these health risks. However, while recent socio-economic heat vulnerability research has developed geospatially explicit results, research which links it directly with infrastructure characteristics is limited. Understanding how socio-economic vulnerabilities interact with infrastructure systems is a critical component to developing climate adaptation policies and programs which efficiently and effectively mitigate health risks associated with rising temperatures.

The availability of cooled space, whether public or private, has been shown to greatly reduce health risks associated with extreme heat. However, a lack of fine-scale knowledge of which households have access to this infrastructure results in an incomplete understanding of the health risks associated with heat. This knowledge gap could result in the misallocation of resources intended to mitigate negative health impacts associated with heat exposure. Additionally, when discussing accessibility to public cooled space there are underlying questions of mobility and mode choice. In addition to captive riders, a growing emphasis on walking, biking and public transit will likely expose additional choice riders to extreme temperatures and compound existing vulnerabilities to heat.

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Created

Date Created
  • 2016