<p> Quench-aged low carbon iron specimens, containing various distributions of carbide particles were fatigued in tension-compression under low amplitude strain control. </p> <p> Observations of the influence of second phase particles upon the development of dislocation substructure were made using transmission electron microscopy of thin foils. These observations were correlated with the cyclic mechanical response of the material, and with the response of material containing a fatigue saturation substructure of subsequent tensile overstrain. </p> <p> A rationale for the development of cyclic softening in the material is proposed, based on the requirements of continuity in plastically inhomogeneous materials. A source model for the observed instability of the cyclic substructure in tensile overstrain is described. </p> / Thesis / Master of Science (MS)

No description available.

The built environment puts the greatest pressure on the natural environment out of all human activities, so it has a fundamental obligation to be environmentally sustainable. Carbon dioxide (CO2) or carbon emissions is a significant greenhouse gas that is inevitably associated with energy use when energy is produced via the combustion of fuels. Total life cycle energy, embodied and operational energy over a building's lifetime, creates significant environmental impacts through the production of CO2. By keeping and reusing existing and historic buildings rather than discarding them and building new, the embodied energy, or the energy that is locked up, can help to mitigate future damage. These buildings already exist, which indicates that the energy consumed to build them has been applied and the carbon associated with their construction has been released. The greenest buildings are ones that are already built. They are inherently more sustainable than any new buildings even with green and zero net energy systems and can be retrofitted to become more energy efficient. To demonstrate this thesis specifically, a design project engages with an abandoned late nineteenth-century bank building in Philadelphia and transforms it into a high-performance building that is prepared for long-term use. For the immediate next use, the project creates a work environment and a new vertical expansion of residential units. The preservation field always confronts the challenge of bridging the gap between embodied energy and operational energy. In the abandoned bank, there are some aspects of this building that are near permanent and define its character, such as brick walls with masonry ornament, two bank vaults, Wissahickon Schist foundation wall, and ceiling trusses. This thesis explores new approaches to leverage the embodied energy of the permanent parts of the abandoned bank and transform it into a high-performance building. A lot of energy of the abandoned bank, the building's material, and thermal mass is still actively performing. The building's envelope, the thick masonry wall, provides a moderately good insulating effect that will temper the indoor air that also preserves its historical character both inside and outside. The embodied energy of the building's envelope is leveraged by pairing it with localized heating and cooling using a radiation and conduction system. Other approaches that increase energy performance in the existing building, include the use of phase-change material for cooling the process water, solar hot water, creating drinking water via a solar still in the skylight, and distilled water from radiant cooling surfaces. In the new construction, a thermal switch facade and double-skin facade for the residential units are proposed, along with providing flexible space with thick mobile interior wall units. / Master of Architecture / Global warming as a problem of the twenty-first-century increase concentrations of greenhouse gases in the atmosphere due to human actions like burning fossil fuels. The built environment puts the greatest pressure on the natural environment of all industrial parts, and it has a fundamental role to manage the environment sustainably. Total life cycle energy, embodied and operational energy over the lifetime of the buildings, creates significant environmental impacts through the production of CO2. Embodied energy is the whole amount of energy applied to extract the raw materials, manufacture, transport, install, and use the product across its life cycle. Assessments of the embodied energy of historic and existing buildings are helping to mitigate future damage to resources. These buildings already exist, which indicates that the energy consumed to build them has been applied and the carbon associated with their construction has been released. The greenest buildings are ones that are already built. They are inherently sustainable and can be retrofitted to become more energy efficient. Specifically, this design engages with an abandoned late nineteenth-century bank building in Philadelphia and transforms it into a high-performance building that is prepared for long-term use. For the immediate next use, the project creates a work environment and in a new vertical expansion, residential units. In the abandoned bank, there are some aspects of this building that are near-permanent and define its characters, such as brick walls with masonry ornament, two bank vaults, Wissahickon Schist wall, and ceiling trusses. This thesis explores the new approaches to leverage the embodied energy of the permanent parts of the abandoned bank and transform it into a high-performance building. This is achieved through various means such as providing localized heating and cooling by using a radiation and conduction system, the use of phase-change material for cooling the process water, solar hot water, creating drinking water via a solar still in the skylight and distilled water from radiant cooling surfaces. In the new construction, a thermal switch facade and double-skin facade for the residential units are proposed, along with providing flexible space with thick mobile interior wall units.

Yes / The UK faces the joint economic policy challenges of raising productivity and tackling climate change. This report challenges prevailing narrow market-based views of productivity, by examining the £4bn UK early stage Cleantech innovation finance market. We find that Cleantech innovation is frequently capital intensive and long horizon (5-10+ years), measured by shorterterm technology readiness level (TRL) and intellectual property (IP) progression. Longer-term sustainable productivity impacts remain little understood and, where applied, narrowly relate to customer adoption. This leads to Cleantech environmental impact investor logics that primarily relate to end user financial value (customer sales). There is little consideration for non-market values from, for example, circular economy (CE) and wider environmental spillover impacts (e.g. supply chains). Whilst few Cleantechs currently successfully commercialise, a small proportion exhibit high employment and sales growth and global environmental impact. Improved understanding of the broader environmental impacts of Cleantechs, through the adoption of environmental impact metrics (EIMs) can (i) add to a more holistic notion of productivity and (ii) improve the efficiency of the finance escalator, enabling more Cleantechs to contribute significantly to establishing the UK as a globally leading low carbon economy. / ESRC

Ongoing modification and change is core to how domestic and built environments function. Thus occupants domestication and development of home heating practices around low-carbon technologies is likely to exceed what building engineering sciences have the ability to plan ahead for. Yet, environmental policies and low -carbon industry approaches to sustainable energy consumption are characterised by a high degree of technological determinism. Disciplinary approaches to sustainable energy consumption tend to separate home heating into stable, routine interaction with control points, environmental factors and socio-demographic drivers. Framing low-carbon technical change in isolation from domestic environments often leads to a gap between intended and actual use of technologies. By focusing on TRVs (thermostatic radiators valve) and radiators, this thesis takes an interdisciplinary turn to jointly examine the social and environmental elements of households energy use. A turn to sensory ethnography and practice-place relationships offers a way to better understand how people use energy for space heating in relation to the buildings they live in and how improvisatory uses of technologies emerge from flows of material, domestic, sensory and physical contingencies of the home. Combining home video tours with building energy monitoring in eight homes, the thesis demonstrates that home heating is a place-event of the home because heating systems and energy consumption are woven into the fabric of everyday life. Environmental elements show that the social and technical are inseparable in energy used for space heating and individual elements imply that the domestication of technologies is highly unpredictable. The thesis synthesises findings into a taxonomy table of irregular radiator and TRV use. On the one hand, irregularities indicate that improvisatory uses of technologies are productive sources of sustainable change because they can be potential sites for co-design. On the other hand, the interwoven character of the social and technical in households energy use critically challenges how environmental policy, low-carbon industry and disciplinary approaches frame intervention into sustainable energy consumption. The thesis argues for the value of logic of intervention and sustainable change that is collaborative, system-focused and gradually uncovers interrelationships.

都市CO2的過量排放，是造成全球氣候暖化與環境變異的主因之一。低碳都市的發展成為目前永續發展的核心議題，亦是抑制氣候暖化的關鍵。低碳都市的概念，包括空間和非空間維度。空間維度探討了都市型態、土地利用與運輸系統，非空間維度則著眼於經濟、能源使用和節能產品。然而過去低碳方面的研究，多聚焦於非空間維度之探討上，甚少關注空間維度面向，但面對全球氣候暖化與低碳發展，都市不僅可落實低碳發展政策，其規劃更在低碳都市的建設與發展過程中扮演關鍵角色。因此，本研究依循「全球考量，在地行動」之概念及方式，以低碳都市為主軸，並以空間規劃及環境經濟之角度切入，針對低碳都市衡量指標建構及分析、縣市低碳效率評估及低碳政策影響效果之探討、都市發展及空間結構與碳量間關係之探討等三項研究主題，進行實證分析與探討，企圖補強低碳都市在空間維度之論述，使都市的低碳化有所依循，亦使都市能藉此更達低碳與永續之目標。 在「低碳都市衡量指標系統之建構及探討」主題上，以台灣為實證案例，根據低碳都市的內涵、理念與目標，研撰適宜之衡量指標系統，透過因子分析定權法進行衡量指標的擇取，藉此評估台灣各縣市的低碳發展狀態。根據實證結果，顯示台灣的低碳都市評估指標系統，包括「環境品質及資源消耗」、「經濟及建設」、「財政及資源循環」、「社會狀態」等4構面，共22個指標；而台灣各縣市在低碳發展的綜合表現上，以台北市的狀態最佳，而以彰化縣表現最差。 而在「縣市低碳發展效率評估及低碳政策影響效果之探討」主題上，以台灣各縣市作為實證案例，在考量非意欲產出下(碳排放威脅、環境污染衝擊)，透過DEA中的不良產出模型(Bad Outputs Model)評估縣市低碳發展效率，並藉由Tobit模型，釐清低碳政策對縣市低碳發展效率之影響效果。依據不良產出模型之效率評估結果，顯示臺北市、新竹市、臺東縣、花蓮縣在低碳發展效率上相對具有效率，且已達最適規模水準；而高雄縣是目前亟待改善的首要縣市。此外，藉由Tobit模式的實證分析，其結果顯示工廠家數、資源回收量、市區公車系統路線總長、具綠建築標章的建物數、綠地面積等變數，對縣市低碳發展效率有顯著影響，其中，除工廠家數對縣市低碳發展效率有負向影響外，其餘變數皆呈正向影響效果。而由此亦得知產業結構、資源循環利用、低碳運輸、低碳建築、碳匯規劃等低碳政策，對於縣市低碳發展效率是顯著有效的。 在「都市發展及空間結構與碳量關係之探討」主題上，以台灣各縣市作為實證案例，透過偏最小平方法的分析，實證都市發展及空間結構對碳量之影響關係與影響程度，並找出低碳都市發展中關鍵的空間規劃要素。而根據偏最小平方法的實證結果，顯示都市混合度、都市發展強度及密度與都市綠化對碳淨存量產生負向影響，亦即都市混合度、都市緊密度及綠化程度愈高，愈能減少碳淨存量；而都市工業機能、都市交通狀態對碳淨存量有正向影響，亦即都市工業機能與都市交通狀態愈高，愈會增加碳淨存量，其中又以都市交通狀態的影響效果最大。 綜合上述，本研究之研究成果包括：「釐清低碳都市模糊且紛雜的概念及內涵」、「建構適宜台灣本土的低碳都市衡量指標系統」、「評估台灣各縣市低碳發展之整體狀態」、「評估台灣各縣市之低碳發展效率」、「檢視台灣現行低碳政策對於縣市低碳發展效率之影響效果」及「找出低碳都市發展中關鍵的空間規劃要素」，期待此些成果，能作為地方政府或規劃單位於低碳目標下，進行低碳都市發展及規劃開發時之參考。 / Excessive CO2 emission is one of the main causes of causing global warming and climate change. Therefore, low-carbon urban development is currently the core issue in sustainable development, and it is also the key to curb climate warming. The concept of the low-carbon city includes spatial dimension and non-spatial dimension. The former contains the issues of urban form, transportation system, and land use planning, the latter contains the issues of economy, energy consuming, and energy saving product. The spatial dimension plays the important role in the construction and development of the low-carbon city, but only the few studies focused on. Therefore, this paper takes the spatial dimension of the low-carbon city as the main scope, and discusses the topics of “research on low-carbon city indicator system”, “evaluating the low-carbon efficiency of city and analyzing its influential policies”, and “the effects of urban development and spatial structure on carbon emissions”. In the topics of “research on low-carbon city indicator system”, this paper takes cities and counties of Taiwan as the empirical cases, and uses factor analysis to establish the appropriate low-carbon city indicator system for Taiwan. Furthermore, this paper evaluates the cities'/counties' status of low-carbon developments by this low-carbon city indicator system. According to the empirical results, there are four evaluating aspects of the low-carbon city: 1) environmental quality and resource consumption, 2) economy and construction, 3) finance and resource recycling and 4) social status. Based on the comprehensive performance of the low-carbon city indicator system, Taipei City shows the best performance, whereas Changhua County shows the worst performance. In the topics of “evaluating the low-carbon efficiency of the city and analyzing its influential policies”, this paper takes cities and counties of Taiwan as the empirical cases, and assesses low-carbon efficiency of the city by Bad Outputs Model. Moreover, this paper uses Tobit Model to analyze the influence of low-carbon policies on the low-carbon efficiency of the city. According to the result of Bad Outputs Model, Taipei City, Hsinchu City, Taitung County, and Hualien County are efficiency, and achieve the optimal scale level. Moreover, Kaohsiung County is the county in the most urgent need of improvement. Another result of Tobit model indicates that the industrial unit has the negative impact on the low-carbon efficiency of the city. Moreover, resource recovery, the total length of the urban bus route, the number of green buildings, and green area all have the positive impact on the low-carbon efficiency of the city. In the topics of “the effects of urban development and spatial structure on carbon emissions”, this paper takes cities and counties of Taiwan as the empirical cases, and uses partial least squares method (PLS) to identify the impact of urban development and spatial structure on carbon emissions. The empirical results show that the mixed land use, urban intensity and density, and urban greening all have the negative impact on carbon emissions. Moreover, industrial function and urban transportation all have a positive impact on carbon emissions. Finally, these results can be used as reference for future low-carbon urban planning and policy.

India's electricity system is faced with the challenges of meeting the growing demand for electricity, managing recurring shortages in supply and addressing concerns of global warming. India is adopting a two-pronged approach to address these challenges – (i) making huge investments in new technologies, and (ii) enacting new policies to promote low carbon initiatives. Together, they are believed to help in achieving energy security as well as mitigation of global warming. Such low carbon initiatives can alter the traditional electricity planning and provide with a wide set of supply options to achieve a transition in to a low carbon electricity planning (LCEP). At the outset, one has to explore the supply options for an optimal supply-demand matching of electricity. While finding out various alternatives to meet the demand on a continuous basis using existing supply, non-supply and future supply options, the technology challenges of low carbon options, renewable energy policies and emissions policies need to be studied in detail from the perspective of a developing country keeping India as a focus. The effectiveness of renewable energy and emissions policy interventions such as Renewable Purchase Obligation (RPO), Renewable Energy Certificate (REC), Renewable Energy Certificate Excess (RECX), Emission Tax and Emission Cap-and-Trade and emission policies need to be assessed. Based on the analysis of the literature review, it appears that there is no mathematical model for optimally matching the supply with electricity demand simultaneously considering all the complexities for LCEP discussed in this study. The overall objective of the research is to develop, validate and apply a set of mathematical models to address a complex research problem of "LCEP of existing supply, non-supply and future supply options in the presence of technology and policy interventions to achieve a least-cost, low carbon and sustainable electricity system". This complex research problem is decomposed into five independent LCEP problems based on real-life situations. For each of these five LCEP problems, a mathematical model is proposed. For generating the five proposed mathematical models for any given data, LINGO Set Codes have been developed. In order to validate the proposed mathematical models, data was collected from the Karnataka state electricity system. For the collected data, the proposed mathematical models are generated using the LINGO Set Codes and solved using LINGO. From the optimal solutions, insights are drawn on the impact and effectiveness of low carbon interventions on the present electricity system which is in a transition towards a low carbon electricity system. It is our belief that the proposed mathematical models can act as a basis for introducing any new low carbon interventions such as energy efficiency certificates, auction based tariff mechanisms for renewable energy pricing, and other new REC interventions in the future scope.

The manner in which socioeconomic forces direct environmentally unsustainable behaviour is largely unseen and unappreciated. North American cultural beliefs, norms and values reinforce the economic system and constitute significant barriers to large-scale societal ecological behaviour change. Overlooked in the degrowth literature, even by researchers who have examined the importance of socioeconomic barriers (materialism and consumption), is the role occupation plays in dictating the ecological footprint and forming our socioeconomic identities. We have gained some understanding of the motivation of those individuals who have chosen to pursue a low-carbon lifestyle, but are lacking information about those who go one step further and adopt a low-carbon livelihood. Fifteen individuals who successfully adopted low-carbon livelihoods were interviewed to examine socioeconomic barriers they may have experienced and learn how those challenges were met. To assume a low-carbon livelihood at present is likely to require forming a new social status identity, adopting new metrics for judging oneself, and creating a new social network supportive of that identity and its values. A four-quadrant framework was used to examine the systemic nature of emergent themes regarding socioeconomic barriers and how those were overcome. Themes that emerged revealed many similarities to individuals committed to a low-carbon lifestyle with some critical differences in terms of both inhibiting and enabling factors. A core finding was that motivational and personality characteristics of the low-carbon livelihood individuals mimic the attributes of moral exemplars that drive a deep sense of ethical obligation to create a pro- social occupation that can function in a low-carbon manner. Clear values, coupled with a strong sense of personal responsibility, overpowered the socioeconomic barriers participants encountered. Implications regarding interventions for fostering the adoption of low-carbon livelihoods and fortifying the Degrowth movement are examined. / Graduate

Published Article / Selective laser micro-welding (SLMW) is a recent rapid manufacturing technique that produces metal parts through the use of a laser beam that selectively scans over the powder layers and fully melts and micro-welds the metallic particles. The advantage of SLMW is that any type of commercial steel alloys or other metal powders can be used to build parts in a single step without the need to add low melting point additives to join the particles as in the former SLS process. In this study, two types of low cost general purpose powders were evaluated as the raw materials for the selective laser micro-welding (SLMW): one powder is AISI304 stainless steel powder from Hoganas, Belgium (cost = $11/kg) and the other isAISI100510w carbon steel locally produced in-house from scrap steel using gas atomizing then de-oxidizing techniques (cost = $1.2/kg). Twelve sample parts were fabricated using two different laser speeds, 70 and 100 mm/s. Dimensions, density, hardness, tensile and microstructure properties were evaluated. Results showed that both powders successfully produced complete parts with accurate dimensions and fine details. Both microstructure phases were austenite due to the rapid heating and cooling cycles. At the higher speed of 100 mm/s mechanical properties deteriorated because of the porosities inside the structure. Using low cost powders gives more potential for the SLMW to spread as an economical manufacturing process in the near future.

The UK’s policy commitment to an 80% reduction in CO₂ levels over 1990 levels by 2050 has framed much recent research and debates between policy-makers and industry about whether and how a transition to a low-carbon future can be achieved. The technical potential for improved energy efficiency and installation of low- and zero-carbon generation technologies in the built environment is, in theory, large enough to achieve the emissions reduction targets in this economic sector but it requires a step-change in technology deployment, with less well studied implications for the industry actors who predominate in the existing markets for housing refurbishment. A socio-technical approach is taken to investigating this problem, drawing on the academic traditions of Actor-Network Theory and Transitions to frame the problem: how can a policy-driven change be brought about in a highly diffuse system of actors, where large outcomes emerge as the result of millions of small-scale decisions? Parallels are drawn with the history of Market Transformation policies that have achieved improved energy efficiency of stocks of electrical appliances over time. In order to explore how a Market Transformation approach might work in the rather different context of housing refurbishment, three key aspects of this particular socio-technical system need to be explored: the technical potential and workings of technology deployment; the operation of several implicated markets; the nature of innovation in the relevant industry sectors. A review of the practical, technical issues encountered in pioneering low-carbon refurbishment projects reveals certain risks of under-performance and unintended consequences of poor implementation. Managing these risks requires a level of underpinning knowledge as well as good-quality workmanship, raising the question of how such knowledge can best be introduced into the fragmented roles and contractual relationships that characterise the industry. The market opportunities for the work are complicated by the number and interdependence of the markets involved, including markets for property transactions and markets for refurbishment work and technology installation. Information systems already exist at the point of property transactions in the form of the Energy Performance Certificate, but the greatest potential for change exists in the mainstream repair, maintenance and improvement market. Interviews with mainstream SME construction managers explain the reasons why the industry’s custom and practice is essentially conservative, but also provide insights into the situations in which innovation can thrive, rather than being resisted or subverted. A proposal for systemic change has at its core the coordination of monitoring information and learning experiences from a range of innovative demonstration projects, with implications for change at an institutional level as well as within the practices of the industry itself. The findings of the research are discussed in terms of the strategic implications they hold for industry and policy-making.