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An Attributional Life Cycle Assessment of Hemcrete

Description

Hemcrete is an alternative, environmentally‐friendly building material gaining adherents in Great Britain and other European countries. It is an attractive choice as a building material because it is made from a renewable resource, hemp, a hardy plant that is a close, but

Hemcrete is an alternative, environmentally‐friendly building material gaining adherents in Great Britain and other European countries. It is an attractive choice as a building material because it is made from a renewable resource, hemp, a hardy plant that is a close, but non‐hallucinogenic relative of marijuana. This plant is relatively easy to cultivate, requires little in the way of pesticides or fertilizers, and almost all parts can be used for various products from paper to textiles to food.

Hemcrete is made from a mixture of lime, water, and the fibrous outer portion of the hemp plant called the “hurd” or “shive”. When mixed, it is worked and placed much like conventional concrete ‐ hence the name. However, that is where the similarities with concrete end. Hemcrete is not comparable to concrete on a strength basis, and is better described as an alternative insulation product. When built into walls of sufficient thickness, Hemcrete offers high thermal efficiency, and has strong claims to being carbon negative. The purpose of this study
was to evaluate this claim of carbon negativity, and to compare these environmentally friendly qualities against conventional fiberglass batt insulation.

Our model was constructed using two identically sized “walls” measuring eight feet square by one foot in depth, one insulated using Hemcrete, and the other using fiberglass. Our study focused on three areas: water usage, cost, and carbon dioxide emissions. We chose water
usage because we wanted to determine the feasibility of using Hemcrete in the Phoenix metropolitan region where water is a troubled resource. Secondly, we wished to evaluate the claim on carbon negativity, so CO2 equivalents throughout the production process were measured. Finally, we wished to know whether Hemcrete could compete on a cost basis with more conventional insulation methods, so we also built in a price comparison.

Since the cultivation of hemp is currently unlawful in the United States, this study can help determine whether these restrictions should be relaxed in order to allow the construction of buildings insulated with Hemcrete.

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2013-05

Finding Your Dog's Ecological 'Pawprint': A Hybrid EIO-LCA of Dog Food Manufacturing

Description

Many relationships exist between humans and their animal companions. Regardless of the relationship, the costs of pet ownership are more than just veterinary bills and the purchase of pet food. The purpose of this study is to examine the environmental

Many relationships exist between humans and their animal companions. Regardless of the relationship, the costs of pet ownership are more than just veterinary bills and the purchase of pet food. The purpose of this study is to examine the environmental impacts associated with ownership of canus lupus familiaris, more commonly known as the domesticated dog. Since dogs are carnivorous by nature, there has already been significant interest in the ecological ‘pawprint’ of pet food, or the pressure that dog food production exerts on the environment.

This study utilizes Life Cycle Assessment (LCA) to determine the environmental impacts of industrial pet food production and furthermore, pet ownership through nutritional requirements. Additionally, this study aims to examine how pet food type—beef or lamb—can influence greenhouse gas (GHG) emissions. The approach taken by this study is that of a hybrid input-output LCA, combining Economic Input Output (EIO-LCA) data and process-level data to examine how supply chain decisions made by pet food manufactures can affect the ecological ‘pawprint’ of the domestic dog. The EIO-LCA provides an economy-wide lens, whereas, process-based LCAs provide data relevant to specific materials and processes. This approach was used to compare the environmental impacts associated with environmentally friendly supply chain decisions compared to the typical environmental impact of dog food.

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Date Created
2013-05

Life Cycle Assessment of Two End-of-Life Scenarios for Glass Bottles on a Micro Level: Arizona State University, Tempe Campus

Description

This paper applies LCA methodology using local variables to assess the environmental impacts of the food grade glass containers that are disposed of on Arizona State University’s Tempe campus throughout their two distinct end-of-life scenarios: glass to be recycled or glass to be sent to the landfill as refuse.

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Date Created
2013-05

Attributional Life Cycle Assessment: Emissions, Greenhouse Gas, and Costs for Palm Fronds Attributed to the City of Phoenix

Description

Urban landscaping palm tree waste in the form of palm frond trimmings and bark shavings that is currently handled as municipal solid waste by the City of Phoenix and other major municipalities can be handled in more cost effective ways and lead to

Urban landscaping palm tree waste in the form of palm frond trimmings and bark shavings that is currently handled as municipal solid waste by the City of Phoenix and other major municipalities can be handled in more cost effective ways and lead to reductions in emissions and greenhouse gases. While many cities have green organics collection and diversion programs, they always exclude palm tree waste due to its unique properties. As a result, an unknown tonnage of palm tree waste is annually landfilled as municipal solid waste. Additionally, as the tonnage is unknown, so are the associated emissions, greenhouse gases, and costs. An attributional lifecycle assessment was conducted in the City of Phoenix from the perspective responsibility of the City of Phoenix’s Public Works Department.

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2013-05

Worrying About Our (Neuro) Image: How Much Does fMRI Really Reveal About Us?

Description

After a brief introduction to Functional Magnetic Resonance Imaging (fMRI), this paper presents some common misunderstandings and problems that are frequently overlooked in the application of the technology. Then, in three progressively more involved examples, the paper demonstrates (a) how

After a brief introduction to Functional Magnetic Resonance Imaging (fMRI), this paper presents some common misunderstandings and problems that are frequently overlooked in the application of the technology. Then, in three progressively more involved examples, the paper demonstrates (a) how use of fMRI in pre-surgical mapping shows promise, (b) how its use in lie detection seems questionable, and (c) how employing it in defining personhood is useless and pointless. Finally, in making a case for emergentism, the paper concludes that fMRI cannot really tell us as much about ourselves as we had hoped. Since we are more than our brains, even if fMRI were perfect, it is not enough.

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My Kingdom for a Toolsmith! The IRIDIUM System Specification Through the Lens of Actor-Network Theory

Description

Most would agree that telecommunications systems are socially constructed. Since communication tends to involve people, it seems obvious that people should impact the creation of such systems. But it is far less obvious that the specifications for such systems should be

Most would agree that telecommunications systems are socially constructed. Since communication tends to involve people, it seems obvious that people should impact the creation of such systems. But it is far less obvious that the specifications for such systems should be noted for their social construction. As marvelous and technical as the system is, we must not forget the important technological artifact known as the specification that came before it. This paper tells the story of the social construction of the IRIDIUM system specification as viewed through the eyes of a popular socio-technical systems (STS) analysis tool. Actor-Network Theory (ANT) is employed to elucidate the culture of the Motorola requirements engineering process while describing some of the primary actors and their lively interactions as they strove diligently to produce the “perfect” specification. Throughout, it will become obvious that just as the kingdom was lost “for want of a nail,” so the IRIDIUM system specification was nearly lost for want of a toolsmith.

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Life Cycle Assessment & Public Policy: Supporting Precautionary Principle Decision-Making

Description

This paper’s intent is to explore the environmental gap analysis tool, Life Cycle Assessment (LCA), as it pertains to the decision-making process.

As LCA is more frequently utilized as a measurement of environmental impact, it is prudent
to understand

This paper’s intent is to explore the environmental gap analysis tool, Life Cycle Assessment (LCA), as it pertains to the decision-making process.

As LCA is more frequently utilized as a measurement of environmental impact, it is prudent
to understand the historical and potential impact that LCA has had or can have on its inclusion in public policy domain - specifically as it intersects the anticipatory governance framework and the supporting decision-making precautionary principle framework. For that purpose, LCA will be examined in partnership with the Precautionary Principle in order to establish practical
application.

LCA and Precautionary Principle have been used together in multiple functions. In two
case studies, the California Green Chemistry Initiative and in Nanotechnology uncertainty, there is a notion that these practices can create value for one another when addressing complex issues.

The recommendations presented in this paper are ones that recognize the current
dynamics of the LCA field along with the different sectors of decision makers. For effective
catalytic initiatives, adoptions of these recommendations are best initially leveraged by
government entities to lead by example. The proposed recommendations are summarized into
the following categories and explored in further detail later in the paper:
       1. Improvement in data sharing capabilities for LCA purposes.
       2. Common consensus on standards and technical aspects of LCA structure.
       3. Increased investment of resource allocation for LCA use and development.

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Date Created
2013-05

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 practice, the dental bur is a commonly used instrument that

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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Date Created
2013-05

The Comparative Life Cycle Assessment of Structural Retrofit Techniques

Description

The current study conducts a comparative LCA of two alternative structural retrofit/ strengthening techniques - steel jacketing, and the carbon fiber reinforced polymer (CFRP) retrofit. A cradle-to-gate system boundary is used for both techniques. The results indicated that the CFRP

The current study conducts a comparative LCA of two alternative structural retrofit/ strengthening techniques - steel jacketing, and the carbon fiber reinforced polymer (CFRP) retrofit. A cradle-to-gate system boundary is used for both techniques. The results indicated that the CFRP retrofit technique has merits over the conventional steel jacketing in all three impact categories covered by this study. This is primarily attribute to the much less material consumption for CFRP retrofit as compared to steel jacketing for achieving the same load carrying capability of the retrofitted bridge structures. Even though the transoceanic transportation of carbon fiber has been taken into account in this study, the energy consumption and environmental impacts of CFRP transportation is still much smaller than steel due to it light weight property. The impacts of CFRP retrofit are mainly focused in the material manufacturing phase, which implies that the improvements in the carbon fiber manufacturing technology could potentially further reduce the environmental impacts of CFRP retrofit.

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Date Created
2013-05