The Experts below are selected from a list of 2946 Experts worldwide ranked by ideXlab platform
Tianzhu Zhang - One of the best experts on this subject based on the ideXlab platform.
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Sustainable Urban Solid Waste Management from both Life Cycle and Urban Metabolism Perspectives
2012 Third International Conference on Digital Manufacturing & Automation, 2012Co-Authors: Lili Qu, Tianzhu Zhang, Sai LiangAbstract:Urban solid waste management is an important component of urban sustainability. The concept of evaluating technologies from both life cycle and urban metabolism perspectives is proposed in this study. The analysis from life cycle perspective (using physical input-output life cycle assessment model) provides support for determining the priority of technologies, and the analysis from urban metabolism perspective (using physical input-output model) provides support for identifying the acceptability of technologies. Suzhou City in China is taken as an example. From urban metabolism perspective, sludge recycling is regarded as an accepted method, while current fly ash recycling method is unsatisfying. Technical levels of Scrap Tire recycling and food waste recycling should be improved to reduce their negative effects on Suzhou's urban metabolism. From life cycle perspective, sludge recycling has the smallest environmental impacts, and Scrap Tire recycling has larger environmental impacts than food waste recycling does. Thus, more concerns should be paid to technical improvements of Scrap Tire recycling than to that of food waste recycling. The concept of evaluating technologies from both life cycle and urban metabolism perspectives in this study provides foundations for evaluating technologies in other countries and cities.
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Comparing urban solid waste recycling from the viewpoint of urban metabolism based on physical input-output model: A case of Suzhou in China
Waste Management, 2012Co-Authors: Sai Liang, Tianzhu ZhangAbstract:Investigating impacts of urban solid waste recycling on urban metabolism contributes to sustainable urban solid waste management and urban sustainability. Using a physical input-output model and scenario analysis, urban metabolism of Suzhou in 2015 is predicted and impacts of four categories of solid waste recycling on urban metabolism are illustrated: Scrap Tire recycling, food waste recycling, fly ash recycling and sludge recycling. Sludge recycling has positive effects on reducing all material flows. Thus, sludge recycling for biogas is regarded as an accepted method. Moreover, technical levels of Scrap Tire recycling and food waste recycling should be improved to produce positive effects on reducing more material flows. Fly ash recycling for cement production has negative effects on reducing all material flows except solid wastes. Thus, other fly ash utilization methods should be exploited. In addition, the utilization and treatment of secondary wastes from food waste recycling and sludge recycling should be concerned. © 2011 Elsevier Ltd.
Sai Liang - One of the best experts on this subject based on the ideXlab platform.
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Sustainable Urban Solid Waste Management from both Life Cycle and Urban Metabolism Perspectives
2012 Third International Conference on Digital Manufacturing & Automation, 2012Co-Authors: Lili Qu, Tianzhu Zhang, Sai LiangAbstract:Urban solid waste management is an important component of urban sustainability. The concept of evaluating technologies from both life cycle and urban metabolism perspectives is proposed in this study. The analysis from life cycle perspective (using physical input-output life cycle assessment model) provides support for determining the priority of technologies, and the analysis from urban metabolism perspective (using physical input-output model) provides support for identifying the acceptability of technologies. Suzhou City in China is taken as an example. From urban metabolism perspective, sludge recycling is regarded as an accepted method, while current fly ash recycling method is unsatisfying. Technical levels of Scrap Tire recycling and food waste recycling should be improved to reduce their negative effects on Suzhou's urban metabolism. From life cycle perspective, sludge recycling has the smallest environmental impacts, and Scrap Tire recycling has larger environmental impacts than food waste recycling does. Thus, more concerns should be paid to technical improvements of Scrap Tire recycling than to that of food waste recycling. The concept of evaluating technologies from both life cycle and urban metabolism perspectives in this study provides foundations for evaluating technologies in other countries and cities.
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Comparing urban solid waste recycling from the viewpoint of urban metabolism based on physical input-output model: A case of Suzhou in China
Waste Management, 2012Co-Authors: Sai Liang, Tianzhu ZhangAbstract:Investigating impacts of urban solid waste recycling on urban metabolism contributes to sustainable urban solid waste management and urban sustainability. Using a physical input-output model and scenario analysis, urban metabolism of Suzhou in 2015 is predicted and impacts of four categories of solid waste recycling on urban metabolism are illustrated: Scrap Tire recycling, food waste recycling, fly ash recycling and sludge recycling. Sludge recycling has positive effects on reducing all material flows. Thus, sludge recycling for biogas is regarded as an accepted method. Moreover, technical levels of Scrap Tire recycling and food waste recycling should be improved to produce positive effects on reducing more material flows. Fly ash recycling for cement production has negative effects on reducing all material flows except solid wastes. Thus, other fly ash utilization methods should be exploited. In addition, the utilization and treatment of secondary wastes from food waste recycling and sludge recycling should be concerned. © 2011 Elsevier Ltd.
Ni Bin Chang - One of the best experts on this subject based on the ideXlab platform.
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economic and policy instrument analyses in support of the Scrap Tire recycling program in taiwan
Journal of Environmental Management, 2008Co-Authors: Ni Bin ChangAbstract:Understanding the cost-effectiveness and the role of economic and policy instruments, such as the combined product tax-recycling subsidy scheme or a tradable permit, for Scrap Tire recycling has been of crucial importance in a market-oriented environmental management system. Promoting product (Tire) stewardship on one hand and improving incentive-based recycling policy on the other hand requires a comprehensive analysis of the interfaces and interactions in the nexus of economic impacts, environmental management, environmental valuation, and cost-benefit analysis. This paper presents an assessment of the interfaces and interactions between the implementation of policy instruments and its associated economic evaluation for sustaining a Scrap Tire recycling program in Taiwan during the era of the strong economic growth of the late 1990s. It begins with an introduction of the management of the co-evolution between technology metrics of Scrap Tire recycling and organizational changes for meeting the managerial goals island-wide during the 1990s. The database collected and used for such analysis covers 17 major Tire recycling firms and 10 major Tire manufacturers at that time. With estimates of Scrap Tire generation and possible scale of subsidy with respect to differing Tire recycling technologies applied, economic analysis eventually leads to identify the associated levels of product tax with respect to various sizes of new Tires. It particularly demonstrates a broad perspective of how an integrated econometric and engineering economic analysis can be conducted to assist in implementing policy instruments for Scrap Tire management. Research findings indicate that different subsidy settings for collection, processing, and end use of Scrap Tires should be configured to ameliorate the overall managerial effectiveness. Removing the existing boundaries between designated service districts could strengthen the competitiveness of Scrap Tires recycling industry, helping to reduce the required levels of product tax and subsidy. With such initial breakthroughs at hand to handle the complexity of Scrap Tire recycling technologies, there remains unique management and policy avenues left to explore if a multi-dimensional solution is to be successful in the long run.
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Economic and policy instrument analyses in support of the Scrap Tire recycling program in Taiwan
Journal of Environmental Management, 2008Co-Authors: Ni Bin ChangAbstract:Understanding the cost-effectiveness and the role of economic and policy instruments, such as the combined product tax-recycling subsidy scheme or a tradable permit, for Scrap Tire recycling has been of crucial importance in a market-oriented environmental management system. Promoting product (Tire) stewardship on one hand and improving incentive-based recycling policy on the other hand requires a comprehensive analysis of the interfaces and interactions in the nexus of economic impacts, environmental management, environmental valuation, and cost-benefit analysis. This paper presents an assessment of the interfaces and interactions between the implementation of policy instruments and its associated economic evaluation for sustaining a Scrap Tire recycling program in Taiwan during the era of the strong economic growth of the late 1990s. It begins with an introduction of the management of the co-evolution between technology metrics of Scrap Tire recycling and organizational changes for meeting the managerial goals island-wide during the 1990s. The database collected and used for such analysis covers 17 major Tire recycling firms and 10 major Tire manufacturers at that time. With estimates of Scrap Tire generation and possible scale of subsidy with respect to differing Tire recycling technologies applied, economic analysis eventually leads to identify the associated levels of product tax with respect to various sizes of new Tires. It particularly demonstrates a broad perspective of how an integrated econometric and engineering economic analysis can be conducted to assist in implementing policy instruments for Scrap Tire management. Research findings indicate that different subsidy settings for collection, processing, and end use of Scrap Tires should be configured to ameliorate the overall managerial effectiveness. Removing the existing boundaries between designated service districts could strengthen the competitiveness of Scrap Tires recycling industry, helping to reduce the required levels of product tax and subsidy. With such initial breakthroughs at hand to handle the complexity of Scrap Tire recycling technologies, there remains unique management and policy avenues left to explore if a multi-dimensional solution is to be successful in the long run. © 2007 Elsevier Ltd. All rights reserved.
Youngkeun Hong - One of the best experts on this subject based on the ideXlab platform.
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friction and wear properties of Scrap Tire potassium hexatitanate whisker composites
Journal of Industrial and Engineering Chemistry, 2013Co-Authors: Kyungho Chung, Youngkeun HongAbstract:Abstract As a way of solving the environmental problem of waste Tires, we developed a new type of friction material made of Scrap Tire composites with potassium hexatitanate in which rubber formed a continuous phase. The tribological behaviors of the Scrap Tire rubber composites were investigated by a friction and wear tester under dry conditions. According to the results, the optimum amounts of potassium hexatitanate were 5 phr in terms of the friction and wear properties up to 200 °C. The specimen containing other ingredients showed 0.72 of friction coefficient and 1.03 of wear rate which are highly compatible to those of the commercial ‘Sonata’ motor brake pad when it contains 5, 20, 10, 20, 10 phr of potassium hexatitanate, phenol, cashew, barium sulfate, and copper, respectively.
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Friction and wear properties of Scrap Tire/potassium hexatitanate whisker composites
Journal of Industrial and Engineering Chemistry, 2013Co-Authors: Kyungho Chung, Youngkeun HongAbstract:Abstract As a way of solving the environmental problem of waste Tires, we developed a new type of friction material made of Scrap Tire composites with potassium hexatitanate in which rubber formed a continuous phase. The tribological behaviors of the Scrap Tire rubber composites were investigated by a friction and wear tester under dry conditions. According to the results, the optimum amounts of potassium hexatitanate were 5 phr in terms of the friction and wear properties up to 200 °C. The specimen containing other ingredients showed 0.72 of friction coefficient and 1.03 of wear rate which are highly compatible to those of the commercial ‘Sonata’ motor brake pad when it contains 5, 20, 10, 20, 10 phr of potassium hexatitanate, phenol, cashew, barium sulfate, and copper, respectively.
Nemkumar Banthia - One of the best experts on this subject based on the ideXlab platform.
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value added reuse of Scrap Tire polymeric fibers in cement based structural applications
Journal of Cleaner Production, 2019Co-Authors: Obinna Onuaguluchi, Nemkumar BanthiaAbstract:Abstract Presently, Scrap Tire polymeric fibers (STF) have limited reuse value in most countries of the world, hence it is largely land filled or used as an eco-unfriendly Tire derived fuel (TDF). Unfortunately, toxic gases and acids could be released from these aforementioned STF management strategies. Therefore, in this study, an alternative reuse approach for the STF was explored; the possibility that it could enhance the flexural post-crack residual strength and wear resistance of cement composites were examined. Furthermore, the likelihood of improving the aforementioned properties through the hybridization of the STF with commercial macro fibers such as steel hook-end (HE) and polypropylene (PP) fibers was also evaluated. The cement composites investigated consist of a set of 0.50 water-to-cement (w/c) ratio mortar and two sets of concrete batches corresponding to 0.50 and 0.40 w/c ratios. Results indicate that the post-crack residual strengths of mortar and concrete mixtures singly reinforced with the STF was about 0.10 MPa and 0.10 – 0.20 MPa, respectively. Hence, these STF reinforced cement composites have no useful structural application value. However, with the hybridization of 0.35% STF with 0.2 – 0.5% macro fibers, mortar mixtures with post-crack residual strengths ranging from 1.4 to 3.1 MPa were attained as a result of the positive synergy between the STF and the HE fibers. Hybrid 0.35% STF and 0.35% HE fiber reinforcement of concrete also led to a positive synergy and improvement in post-crack residual strength capacity, especially for the 0.50 w/c ratio mixture. Relative to the plain concrete, 0.35% STF or hybrid combination of 0.35% STF and 0.35% PP had no impact on concrete abrasion resistance. Conversely, cumulative volume loss of concrete reinforced with hybrid 0.35% STF and 0.35% HE fibers decreased by approximately 8.9% and 16.1% for 0.50 and 0.40 w/c ratio concrete mixtures, respectively. All-in-all, these results suggest that in lieu of its present use as a TDF, the STF hybridized with HE fibers could actually be used as a sustainable, discrete fiber reinforcement for cement-based repair applications where slightly enhanced flexural post-crack performance and resistance to abrasive wear are desired.
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Scrap Tire steel fiber as a substitute for commercial steel fiber in cement mortar engineering properties and cost benefit analyses
Resources Conservation and Recycling, 2018Co-Authors: Obinna Onuaguluchi, Nemkumar BanthiaAbstract:Abstract Utilization of recyclates in the construction industry is hamstrung by perceptions of lower quality, uncertain performance benefits and high cost. Thus, in this study, the mechanical performance and cost implications of using Scrap Tire steel fiber (SSF) with a hitherto limited reuse value as a partial or full substitute for virgin commercial macro hooked-end (HE) steel fibers in cement mortar are investigated. Mechanical properties, especially the post-crack average residual strength (ARS) and abrasion resistance of mixtures reinforced with 0.35% and 0.5% total fiber volumes were evaluated. Cost-benefit analyses based on derived ARS/abrasion performance enhancements and HE: SSF material cost ratios ranging from 1:0.2 to 1:0.7 were also performed. Results indicate comparable compressive and splitting tensile strength for all the mixtures investigated. However, fifty percent replacement of HE fiber with the SSF yielded a 39% increase in ARS relative to that of the 0.35% singly reinforced HE mortar. Similarly, the abrasion resistance of mortar mixtures singly reinforced with the SSF or fifty-fifty combination of the SSF and HE fibers was higher than those of mixtures reinforced with just HE fibers. Cost – benefit analyses indicate that for both ARS and Abrasion resistance, mortar mixtures singly reinforced with 0.35% SSF gave the best performance – cost benefit, up to four times that of the HE fiber at HE: SSF cost ratio of 1:0.2. Conversely, once HE: SSF cost ratio exceeds 1:0.5, the use of the SSF as a fiber reinforcement in mortar gave only marginal cost benefits, especially for 30% substitution of HE fibers with the SSF.
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Performance of Scrap Tire steel fibers in OPC and alkali-activated mortars
Materials and Structures, 2017Co-Authors: Obinna Onuaguluchi, Paulo H. R. Borges, Aamer Bhutta, Nemkumar BanthiaAbstract:In this study, the mechanical strength, total porosity and corrosion performance of ordinary Portland cement (OPC), class F fly ash (PFA) and metakaolin (MK) alkali-activated mortars (AAM) reinforced with 1 and 2% mass fraction of Scrap Tire steel fibers (SSF) were investigated. The accelerated corrosion test comprised of immersion of specimens in a 5% NaCl solution and specimen electrical resistivity measurements over a three-month period. Thereafter, surface and internal corrosion of SSF in these matrices were also characterized using image analyses. Compressive and the four-point flexural strength were assessed before (28-day cured specimens) and after accelerated corrosion testing. The results indicate that SSF may be employed as discrete fiber reinforcement for OPC and AAM mixtures, as the former improves deformation and toughness of the mortars even after the accelerated corrosion testing. Nonetheless AAM presented higher porosity and reduced electrical resistivity than OPC mortars, probably due to alkali leaching. While the surface and internal corrosion performance of the SSF-reinforced MK-based AAM was poor, PFA-based AAM presented internal corrosion comparable to that of the OPC mortar, as well as the lowest surface corrosion among the mortars studied.
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durability performance of polymeric Scrap Tire fibers and its reinforced cement mortar
Materials and Structures, 2017Co-Authors: Obinna Onuaguluchi, Nemkumar BanthiaAbstract:In this study, cement-based application for polymeric Scrap Tire fibers (STF) which are hitherto used either as Tire derived fuel or are disposed in landfills is explored. STF was characterized; surface morphology, organic and elemental composition of STF/crumb rubber inclusions were examined. Alkaline stability of the STF, the effects of STF on plastic shrinkage cracking, mortar microstructure and long-term durability were also analyzed. Results indicate that STF which consists mainly of polyester fiber was more stable in alkaline environment compared to commercial polyethylene terephthalate (PET) fibers. Relative to the plain reference mixture, 0.4% STF and 0.3% PET fibers reduced the plastic shrinkage crack area of mortar by 97.5 and 99.4%, respectively. While inductively-coupled plasma mass spectrometer test showed that the sulfur content of the alkaline degradation test solution filtrate was <10 mg/L, scanning electron microscope–energy dispersive X-ray spectroscopy analyses revealed slight increases in the S/Ca and (Al + Fe)/Ca ratios of the specimens containing STF. However, these increased atomic ratios were insignificant; hence no degradation of the hardened properties of the STF reinforced specimens in terms of length expansion and loss of mechanical strength under accelerated curing condition and external sulfate attack were observed.