The Experts below are selected from a list of 261 Experts worldwide ranked by ideXlab platform
Jian Chen - One of the best experts on this subject based on the ideXlab platform.
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Supply Chain Carbon footprinting and responsibility allocation under emission regulations.
Journal of environmental management, 2016Co-Authors: Jin-xiao Chen, Jian ChenAbstract:Reduction of greenhouse gas emissions has become an enormous challenge for any single enterprise and its supply Chain because of the increasing concern on global warming. This paper investigates Carbon footprinting and responsibility allocation for supply Chains involved in joint production. Our study is conducted from the perspective of a social planner who aims to achieve social value optimization. The Carbon footprinting model is based on operational activities rather than on firms because joint production blurs the organizational boundaries of footprints. A general model is proposed for responsibility allocation among firms who seek to maximize individual profits. This study looks into ways for the decentralized supply Chain to achieve centralized optimality of social value under two emission regulations. Given a balanced allocation for the entire supply Chain, we examine the necessity of over-allocation to certain firms under specific situations and find opportunities for the firms to avoid over-allocation. The comparison of the two regulations reveals that setting an emission standard per unit of product will motivate firms to follow the standard and improve their emission efficiencies. Hence, a more efficient and promising policy is needed in contrast to existing regulations on total production.
Charles J. Corbett - One of the best experts on this subject based on the ideXlab platform.
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The state of supply Chain Carbon footprinting: analysis of CDP disclosures by US firms
Journal of Cleaner Production, 2016Co-Authors: Christian Blanco, Felipe Caro, Charles J. CorbettAbstract:Although collaboration and performance measurement are widely recognized as critical for increasing sustainability in supply Chains, little is known about how comprehensively firms are currently measuring their supply Chain Carbon emissions (or Scope 3). We develop a way to assess how complete firms’ reports of Scope 3 emissions are, by comparing them to benchmarks based on Environmental Input-Output Life-Cycle Assessment models. We use this approach to evaluate Scope 3 Carbon emissions disclosed by many of the largest firms in the United States to CDP (formerly the Carbon Disclosure Project). We estimate that, on average, these firms reported 22% of their full Scope 3 emissions in 2013. Our results show that Scope 3 reporting varies widely across industries. We highlight two firms that are able to capture a significant portion of their Scope 3 Carbon emissions despite having a large number of suppliers. Although firms are beginning to account for an increasing portion of their supply Chain's Carbon emissions, there is substantial room for improvement in their measurement and disclosure of Scope 3 emissions.
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Double Counting in Supply Chain Carbon Footprinting
Manufacturing & Service Operations Management, 2013Co-Authors: Felipe Caro, Charles J. Corbett, Tarkan Tan, Rob ZuidwijkAbstract:Carbon footprinting is a tool for firms to determine the total greenhouse gas GHG emissions associated with their supply Chain or with a unit of final product or service. Carbon footprinting typically aims to identify where best to invest in emission reduction efforts, and/or to determine the proportion of total emissions that an individual firm is accountable for, whether financially and/or operationally. A major and underrecognized challenge in determining the appropriate allocation stems from the high degree to which GHG emissions are the result of joint efforts by multiple firms. We introduce a simple but general model of joint production of GHG emissions in general supply Chains, decomposing the total footprint into processes, each of which can be influenced by any combination of firms. We analyze two main scenarios. In the first scenario, the social planner allocates emissions to individual firms and imposes a cost on them such as a Carbon tax in proportion to the emissions allocated. In the second scenario, a Carbon leader voluntarily agrees to offset all emissions in the entire supply Chain and then contracts with individual firms to recoup part of the costs of those offsets. In both cases, we find that, to induce the optimal effort levels, the emissions need to be overallocated, even if the Carbon tax is the true social cost of Carbon. This is in contrast to the usual focus in the life-cycle assessment LCA and Carbon footprinting literatures on avoiding double counting. Our work aims to lay the foundation for a framework to integrate the economics-and LCA-based perspectives on supply Chain Carbon footprinting.
K.m. Liew - One of the best experts on this subject based on the ideXlab platform.
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Rectifying performance and negative differential behavior in graphite—Chain—Carbon nanotube junctions
Applied Physics Letters, 2014Co-Authors: Ming Qiu, K.m. Liew, Chris YuanAbstract:In this paper, the (5, 5) capped Carbon nanotubes (CNTs) in contact with different lengths of sp monoatomic Chains grown on the surface of graphite substrate are fabricated and its electronic transport properties sandwiched between CNT and graphite electrodes are investigated. The first-principles calculations based on nonequilibrium Green's function in combination with density-functional theory show that their rectifying performance and negative differential resistance behavior are observed under very low biases and obviously are enhanced when the length increases. From our analysis, the charge transfer, transmission spectra, projected density of states and evolutions of molecular orbitals are responsible for these phenomena.
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The first-principles study of oscillating rectifying performance in nanoribbon-Chain-Carbon nanotube junctions
Applied Physics Letters, 2013Co-Authors: Ming Qiu, K.m. LiewAbstract:Electronic transport properties of armchair graphene nanoribbon and capped Carbon nanotube junctions, covalently bridged by Carbon atomic Chains with different numbers of Carbon atoms, are investigated. The first-principles calculations based on non-equilibrium Green's functions with the density-functional theory show that their I-V characteristics display odd-even effects and rectifying behaviors show obvious oscillations, namely, different bond patterns for even- and odd-numbered Carbon Chains affect the contact bonds, charge transfer, density of states, evolutions of molecular orbitals, and rectifying performance.
Ming Qiu - One of the best experts on this subject based on the ideXlab platform.
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Rectifying performance and negative differential behavior in graphite—Chain—Carbon nanotube junctions
Applied Physics Letters, 2014Co-Authors: Ming Qiu, K.m. Liew, Chris YuanAbstract:In this paper, the (5, 5) capped Carbon nanotubes (CNTs) in contact with different lengths of sp monoatomic Chains grown on the surface of graphite substrate are fabricated and its electronic transport properties sandwiched between CNT and graphite electrodes are investigated. The first-principles calculations based on nonequilibrium Green's function in combination with density-functional theory show that their rectifying performance and negative differential resistance behavior are observed under very low biases and obviously are enhanced when the length increases. From our analysis, the charge transfer, transmission spectra, projected density of states and evolutions of molecular orbitals are responsible for these phenomena.
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The first-principles study of oscillating rectifying performance in nanoribbon-Chain-Carbon nanotube junctions
Applied Physics Letters, 2013Co-Authors: Ming Qiu, K.m. LiewAbstract:Electronic transport properties of armchair graphene nanoribbon and capped Carbon nanotube junctions, covalently bridged by Carbon atomic Chains with different numbers of Carbon atoms, are investigated. The first-principles calculations based on non-equilibrium Green's functions with the density-functional theory show that their I-V characteristics display odd-even effects and rectifying behaviors show obvious oscillations, namely, different bond patterns for even- and odd-numbered Carbon Chains affect the contact bonds, charge transfer, density of states, evolutions of molecular orbitals, and rectifying performance.
Eiji Ihara - One of the best experts on this subject based on the ideXlab platform.
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Reactivity of poly(alkoxyCarbonylmethylene)s under basic conditions: alkylation of main Chain Carbon atoms via a ketene silyl acetal-type intermediate and cleavage of the Carbon–Carbon main Chain
Polymer Chemistry, 2021Co-Authors: Hiroaki Shimomoto, Tomomichi Itoh, Shogo Tsunematsu, Eiji IharaAbstract:We report the alkylation of main Chain Carbon atoms and cleavage of the Carbon–Carbon main Chain of poly(alkoxyCarbonylmethylene)s.
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Carbon-Carbon main Chain polymer with accumulated oligo(ethylene glycol)-substituted cyclotriphosphazenes: Study on the LCST-type phase separation of organic-inorganic poly(substituted methylene)s
Polymer Journal, 2019Co-Authors: Hiroaki Shimomoto, Tomomichi Itoh, Tomohiro Yamada, Eiji IharaAbstract:The synthesis and characterization of organic-inorganic thermoresponsive poly(substituted methylene)s are described. Diazoacetates with oligo(ethylene glycol)-substituted cyclotriphosphazenes were synthesized, and the obtained products were employed as monomers for Pd-initiated polymerization to produce Carbon–Carbon main Chain polymers bearing an oligo(ethylene glycol)-substituted cyclotriphosphazene on every main Chain Carbon atom. The resulting polymers with densely accumulated oligo(ethylene glycol) units around the polymer main Chain showed lower critical solution temperature-type phase separation in an aqueous medium. Pd-initiated polymerization of diazoacetates containing oligo(ethylene glycol)-substituted cyclotriphosphazenes was conducted to yield Carbon-Carbon main Chain polymers bearing an oligo(ethylene glycol)-substituted cyclotriphosphazene on every main Chain Carbon atom. The resulting organic–inorganic poly(substituted methylene)s were found to show an LCST-type phase separation in aqueous media, and thus their thermosensitive behavior was evaluated by turbidity measurements.
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lithium ion conductivity of polymers containing n phenyl 2 6 dimethoxybenzamide framework in their side Chains possible role of bond rotation in polymer side Chain substituents for efficient ion transport
Solid State Ionics, 2016Co-Authors: Hiroaki Shimomoto, Takahiro Uegaito, Shohei Yabuki, Soichiro Teratani, Tomomichi Itoh, Eiji Ihara, Naohiro Hoshikawa, Akihiko Koiwai, Naoki HasegawaAbstract:Abstract A new Carbon–Carbon main Chain polymer with N -phenyl-2,6-dimethoxybenzamide on its each main Chain Carbon atom is prepared by Pd-initiated polymerization of diazoacetate containing the benzamide group, and the Li ion conductivity of the polymer doped with lithium bis(trifluoromethylsulfonyl)imide is evaluated along with its vinyl polymer counterparts with the same benzamide substituent. Although the expected high ion conductivity at low temperatures derived from a unique ion transport mechanism based on the bond rotation in the benzamide moiety reported in a literature is not observed, it is revealed that the dense packing of the benzamide group along the polymer main Chain results in the enhanced ion conductivity. In addition, investigation of the correlation between ion conductivity and glass transition temperature of these solid polymer electrolytes (SPEs) reveals that other ion transport mechanism would operate in the benzamide containing SPEs than that derived from segmental motion of polymer Chains observed in PEO-based SPEs.