151 |
Tracing mantle structure and chemical evolution using noble gas isotopesBroadley, Michael Ward January 2015 (has links)
The mantle is the largest reservoir of many of the Earth’s volatile species. Detailed isotopic studies of noble gases within the mantle volatiles have demonstrated that they are of a primordial origin, which have been trapped in the mantle since the Earth’s accretion. This original volatile signature has continually evolved over time, due to the production of in situ radiogenic isotopes and through the recycling of surface volatiles back into the mantle (Lupton and Craig, 1975; Holland and Ballentine, 2006). The study of noble gases within magmatic samples has enabled the composition and structure of the mantle to be determined and has distinguished the multiple volatile reservoirs (primordial, crustal, marine etc.) that have contributed to the mantle composition sampled. Together with the halogens (Cl, Br and I) they represent key tracers of volatile transport processes in the Earth. Therefore a combined analytical approach including the halogens and noble gases is not only be able to track the influx of surface volatile into the mantle, but also provide a greater understanding to the fundamental controls of transport, storage and partitioning of volatiles within the mantle. A combined noble gas and halogen study was undertaken on three different geological samples sets to determine how surface volatiles interact with the mantle on a variety of different scales. Firstly continental xenoliths from the Western Antarctic Rift were analysed to establish the role of subduction volatiles in the creation of the rifts volcanic products. The xenoliths have 3He/4He ratios of 7.5RA indicating that the rift is dominated by the rising asthenospheric mantle. However the Br/Cl and I/Cl ratio and heavy noble gases within the xenoliths indicate that marine derived volatiles have been incorporated into the mantle beneath the rift and may have provided and fundamental control on the formation of the rift itself. Secondly the role of surface contamination on mantle samples has been evaluated. A transect along a MOR pillow basalt has been analysed for its halogen concentrations in conjunction with the previously determined noble gases. The outer sections are enriched in Cl relative to Br and I due to the assimilation of a high salinity brine during eruption. In contrast the crystalline interior of the pillow has MORB like Br/Cl and I/Cl ratios but elevated 132Xe/36Ar ratios indicative of the incorporation of pelagic sediments. This small scale analytical approach has shown that submarine pillow basalts are prone to contamination from the surrounding marine environment and provides a method for the identification and quantification of marine contamination. Finally the halogens within olivine phenocrysts from three Emperor Seamounts have been analysed to determine the distribution of the halogens within the lower mantle. The I/Cl ratio of the samples evolves from a MORB-like ratio in the oldest seamount to elevated values similar to sedimentary pore fluids and chondrites in the younger seamounts. This indicates that the Hawaiian mantle plume contains isolated pockets of subducted or primordial material which have been isolated from whole mantle mixing and have therefore retained a halogen signature distinct from the average mantle values.
|
152 |
The economics of resource recovery : the case of lubrication oilKing, Janice Ilene Norman January 1981 (has links)
Environmental concern and the possibility of energy shortages have drawn attention to means for recovering material and energy resources from waste products. The focus of this thesis is on the application of cost-benefit analysis as a methodological technique for evaluating the economics of resource recovery: namely used lubrication oil.
The study initially focuses on the general concern of the economics of resource recovery. This is undertaken primarily by a review of existing literature. An investigation of cost-benefit analysis as advanced by Pearce, Pearce and Dasgupta, Canadian Treasury Board Secretariat, Winch, Nath, Anderson, and Settle, to name a few, reveal a comprehensive and systematic framework for the evaluation of public investment alternatives.
Items for inclusion in the analysis are all costs and benefits to every member of, a defined society whose welfare would be affected by the project if implemented. Many goods and services do not enter into the market system, causing difficulty in deriving monetary values for some of the components, especially environmental concerns. For example, the case study reveals two areas:
1) benefit of pollution abatement stemming from resource recovery of used lubrication oil, and
2) costs associated with the improper disposal of the waste products from the recycling process of used lubrication oil.
An attempt is made to apply the cost-benefit framework to the case of lubrication oil recycling in the province of British Columbia. Adequate quantitative data were not available, particularly on the social costs and benefits, to fully employ the cost-benefit technique, therefore restricting the analysis in that only an identification of costs and benefits was prepared.
When quantification of costs and benefits is not possible, a detailed description of the unquantifiable items indicates to the decision maker the extent of the components. Included in this study is a presentation of the environmental impacts of used oil disposal.
The limitations of the cost-benefit analysis as an evaluation technique arise because of limited information and data needed to evaluate, in monetary terms, environmental improvement. Future research could involve a "simulation" of the market to determine a plausible shadow price that gives an indication of what the market price of the item would have been if it had been normally traded. A determination of the price that consumers would be willing to pay for the benefits of pollution control with the knowledge that some pollution would be produced by the recycling activity would aid the analyst in placing values on the costs and benefits. / Applied Science, Faculty of / Community and Regional Planning (SCARP), School of / Graduate
|
153 |
Recycling - a Marabastad community developmentKunz, Barend Mattheus 28 July 2008 (has links)
The theme of this dissertation is recycling and recycling-awareness to the users of the city on a physical and non-physical level. In this the user of the city will be introduced to the effect of recycling on a city and how it can change a city positively from the inside out. The theme includes physical recycling of building material, the recycling of existing dilapidated buildings on the site and the recycling of the existing informal functions and activities on the site. The added programming of the development supporting the building material recycling centre, consist of an existing ZCC, community centre, training facility and taxi mechanic facility. / Dissertation (MArch(Prof))--University of Pretoria, 2008. / Architecture / unrestricted
|
154 |
Low cost fencing material for a pre-school in Lavender HillMazwai, Konke 07 1900 (has links)
This project has been proposed by the UCT Knowledge Partnership Project. This institution is aimed at providing assistance to under-privileged communities in the Western Cape. A pre-school fence material which is low cost is to be investigated. The following criterions were set to be met for the material: -The material is to have no fuel usage value such as wood, which can be burnt for space heating -The material is to have no scrap metal value such as steel and wire fencing material as this easily gets stolen. -The material is not to block visibility which harbors criminal activity in the area. Fences such as concrete slabs and brick block visibility. The materials considered in this project are: -Various plastic polymer materials -Plastic Lumber composite material -Recycled Plastic -Rubber reinforced concrete Plastic lumber and recycled plastic HDPE were considered for use in the fence material. After considering the available fence components and loading on the fence, 100 x 100 mm cross section plastic lumber and recycled plastic section were chosen to be used. The fence design was based on existing patents which were modified. A design showing the meter of the fence was designed and is shown in the document.
|
155 |
Two-phase anaerobic digestion of high-solid food waste for energy recoveryXu, Suyun 01 January 2012 (has links)
No description available.
|
156 |
Getting to zero: A case for new Greywater policy in New OrleansJanuary 2015 (has links)
This directed research project explores the benefits of implementing a policy change to allow greywater recycling in New Orleans. Throughout history, New Orleans has had a tenuous relationship with water. Current practices of pumping water both into and out of the city place enormous amounts of strain on the aging water infrastructure system that New Orleans utilizes to keep the city dry and provide potable water to its citizens. The use of greywater recycling systems could dramatically reduce the stress on the city's infrastructure; however this practice is presently prohibited by the city's current plumbing code. This paper presents a case for the adoption of new legislation and changes to the city's policy to allow for greywater recycling. / 0 / SPK / specialcollections@tulane.edu
|
157 |
Recycling Procurement Strategies with Variable Yield SuppliersRowe, Paul David 13 December 2014 (has links)
Companies are no longer judged on financial performance alone, but rather on their “Triple-Bottom Line”, which accounts for social and environmental measures as well. This leads companies to investigate the sustainability of their operations and their products. Between the increasing cost of virgin raw materials and customers demanding post-consumer product content, manufacturers have begun looking at recycled material options. This paper addresses a procurement issue facing a polystyrene packaging manufacturer considering its optimal purchasing strategies between two suppliers – one providing virgin material, the other offering recycled material. A single-period scenario is modeled where each supplier sells product with a known yield distribution at market pricing. The manufacturer must choose whether to sole-source or dual-source, as well as determine how much material to purchase from each supplier to meet deterministic demand. Our results indicate that there is a range of prices from the recycled material supplier where dual-sourcing will lead to higher manufacturer profits compared to sole-sourcing. We show, based on the procurement strategy, the optimal quantities to purchase to maximize manufacturer’s expected profit. We then investigate the area of supplier development and how the manufacturer can improve their expected profit by investing in their supplier’s quality improvement effort. The questions addressed are how much the manufacturer would be willing to invest and how they ensure the proper return on their investment. This paper determines the expected increase in profit for the manufacturer from yield improvement projects at a supplier, which therefore becomes the upper threshold for investment. We also find that a company can err in their project acceptance criteria if they have an approval process that views project acceptance myopically rather than holistically. Lastly, we develop a systematic and comprehensive approach to the supplier selection process. We utilize the fundamental concepts behind W. Edwards Deming’s Plan-Do-Study-Act improvement cycle and apply them to the supplier selection process. We also present analytic and numerical study results that can be used in conjunction with contractual mechanisms to not only overcome issues such as free riding, but to also incentivize suppliers to engage in supplier development projects they may not have otherwise undertaken.
|
158 |
Cold In-Place Recycling Characterization Framework for Single or Multiple Component Binder SystemsCox, Ben C 11 December 2015 (has links)
Cold in-place recycling (CIR) is a pavement rehabilitation technique which has gained momentum in recent years. This momentum is due partly to its economic and sustainability characteristics, which has led to CIR market expansion. When pavement network deterioration is considered alongside increasing material costs, it is not beyond reason to expect demands on CIR to continue to increase. Historically, single component binder (SCB) systems, those with one stabilization binder (or two if the secondary binder dosage is 1% or less), have dominated the CIR market and could be considered the general state of practice. Common stabilization binders are either bituminous or cementitious. Two example SCB systems would be: 1) 3% portland cement, or 2) 3% asphalt emulsion with 1% hydrated lime. While traditional SCB systems have demonstrated positive economic and sustainability impacts, this dissertation focuses on multiple component binder (MCB) systems (bituminous and cementitious combined) which exhibit the potential to provide better overall economics and performance. Use of MCBs has the potential to alleviate SCB issues to some extent (e.g. cracking with cementitious SCBs, rutting with bituminous SCBs). Furthermore, to fairly represent both binders in an MCB system a universal design method which can accommodate multiple binder types is needed. The main objectives of this dissertation are to develop a universal CIR design framework and, using this framework, characterize multiple SCB and MCB systems. Approximately 1500 CIR specimens were tested herein along with approximately 300 asphalt concrete specimens which serve as a reference data set for CIR characterization. A case study of a high-traffic Mississippi CIR project which included cement SCB and emulsion SCB sections is also presented to support laboratory efforts. Individual components needed to comprise a universal design framework, such as curing protocols, were developed. SCB and MCB characterization indicated that cement SCBs yielded low cracking resistance, high rutting resistance, and lower costs. Emulsion SCBs yielded the opposite. MCBs demonstrated the ability to balance rutting, cracking, and economics. Overall, the universal framework presented appears promising as it could offer agencies flexibility and, in some cases, improved overall performance beyond that of current SCB design methods.
|
159 |
j u x t a p o s e d: A Revelatory Appraoch to Reconcile Past and PresentDawson, Michele Renee 28 September 2005 (has links)
Carlo Scarpa, Italian architect, designer, painter, had a vision of a deliberate juxtaposition of the presence of the past against the backdrop of the present. Such are the conditions that describe various palimpsests, partially legible windows into the past. Reconstructing the Ca'Foscari (1935-37), Scarpa's first real commission marked the realized reconciliation between the old and the new. The finished work of the Ca'Foscari reflects the poetic manner in which the presence of the history and the present moment are allowed to be what they are no more, no less; yet the two operate in ethereal symbiosis. A perforated semi-transparency and sophisticated manipulation of light evolved to become the governing strategies for future projects. Revelatory changes in materials establish a relationship with an evolving fabric. Scarpa believed that arranging such exhibits as the Ca'Foscari project kept these delicate reconciliations at the forefront of one's mind.
In an era of placelessness, Niall Kirkwood states that history's failures are repeating themselves. In efforts to "Hold Our Ground" he make the revelation that spaces built from the 1990's on may deteriorate faster than expected as landscapes evolve. Spaces are redesigned with new forms masking what was.
Kirkwood proposes a working paradigm, similar to a palimpsest, to provide legible insight into a site's past.
This thesis investigation is intended to explore possible reconfigurations of history's artifacts, lending themselves to a dialogue between the past and the present as applied to a conceptual palimpsest. This is possible taking Scarpa's ability of weaving a new work into the ongoing dialogue of an evolving fabric paired with the fusions of modern/historical impulses of sculptor Isamu Noguchi strung with Walter Hood's improvisational analysis whereas the site informs the design.
This design project will take form as a revelatory unveiling of Love Plaza's history, one of Philadelphia's many reused canvasses. / Master of Landscape Architecture
|
160 |
Sustainable Nanotechnology: Life Cycle Thinking in Gold Nanoparticle Production and RecyclingPati, Paramjeet 01 September 2015 (has links)
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. / Ph. D.
|
Page generated in 0.0804 seconds