The purpose of this paper is to establish links between supply chain disturbances and corresponding strategies of resilience to counter them. To this end, an inductive research approach is used, examining a sample of 38 cases. Secondary data from the cases is used to identify disturbances which affected the corresponding supply chains and the resilience strategies used by managers. The empirical evidences shows that the negative effects of supply chain disturbances can be categorised into a number of supply chain failure modes. In addition, a set of resilience strategies was identified that could be used to overcome those failure modes. A conceptual model, with links between supply chain disturbances, failures and resilience strategies, is proposed. The limitations of this research result from the use of secondary data sources. The findings are only valid for the selected case studies and, consequently, may not be applicable in other scenarios. Future research should focus on detailed case studies that investigate cross-functional applications across the organisation and the supply chain.

The potential advantage of using superconducting materials in electrical devices is well described in the literature. The electromagnetic properties of these materials make them unique for several applications, such as, e.g. electrical machines and drives, fault current applications, or superconducting magnetic energy storage. In the development of electromechanical conversion devices, superconducting materials are used foreseeing mainly a decrease in the device dimensions or a performance improvement for the same active volume. To guarantee a good application of this kind of materials it is important to describe and model the phenomena that characterize their operation under different regimes. In this paper, a study based in FEM simulations of a motor with bulk superconductor in the rotor is carried out, with the purpose of understand, quantify and qualify which phenomena are present in the different regimes of the motor, leading to obtaining an equivalent electrical circuit with lumped parameters.

Respiratory nitric oxide reductase (NOR) was purified from membrane extract of Pseudomonas (Ps.) nautica cells to homogeneity as judged by polyacrylamide gel electrophoresis. The purified protein is a heterodimer with subunits of molecular masses of 54 and 18 kDa. The gene encoding both subunits was cloned and sequenced. The amino acid sequence shows strong homology with enzymes of the cNOR class. Iron/heme determinations show that one heme c is present in the small subunit (NORC) and that approximately two heme b and one non-heme iron are associated with the large subunit (NORB), in agreement with the available data for enzymes of the cNOR class. Mossbauer characterization of the as-purified, ascorbate-reduced, and dithionite-reduced enzyme confirms the presence of three heme groups (the catalytic heme b(3) and the electron transfer heme b and heme c) and one redox-active non-heme Fe (Fe(B)). Consistent with results obtained for other cNORs, heme c and heme b in Ps. nautica cNOR were found to be low-spin while Fe(B) was found to be high-spin. Unexpectedly, as opposed to the presumed high-spin state for heme b(3), the Mossbauer data demonstrate unambiguously that heme b(3) is, in fact, low-spin in both ferric and ferrous states, suggesting that heme b(3) is six-coordinated regardless of its oxidation state. EPR spectroscopic measurements of the as-purified enzyme show resonances at the g approximately 6 and g approximately 2-3 regions very similar to those reported previously for other cNORs. The signals at g = 3.60, 2.99, 2.26, and 1.43 are attributed to the two charge-transfer low-spin ferric heme c and heme b. Previously, resonances at the g approximately 6 region were assigned to a small quantity of uncoupled high-spin Fe(III) heme b(3). This assignment is now questionable because heme b(3) is low-spin. On the basis of our spectroscopic data, we argue that the g = 6.34 signal is likely arising from a spin-spin coupled binuclear center comprising the low-spin Fe(III) heme b(3) and the high-spin Fe(B)(III). Activity assays performed under various reducing conditions indicate that heme b(3) has to be reduced for the enzyme to be active. But, from an energetic point of view, the formation of a ferrous heme-NO as an initial reaction intermediate for NO reduction is disfavored because heme [FeNO](7) is a stable product. We suspect that the presence of a sixth ligand in the Fe(II)-heme b(3) may weaken its affinity for NO and thus promotes, in the first catalytic step, binding of NO at the Fe(B)(II) site. The function of heme b(3) would then be to orient the Fe(B)-bound NO molecules for the formation of the N-N bond and to provide reducing equivalents for NO reduction.

Purpose – This paper aims to explore the divergences and commitments between the lean, agile, resilient and green paradigms while investigating the effect of paradigms' practices within supply chain attributes.
Design/methodology/approach – A conceptual model with lean, agile, resilient and green practices and supply chain management attributes is proposed. Causal diagrams were used to represent the relationships between paradigm practices and supply chain attributes. The four diagrams were aggregated to build the conceptual model.
Findings – The conceptual model allows for the identification of synergies and divergences resulting from the paradigms practices implementation. The synergies between paradigms are related to “information frequency” and “integration level” increasing as well as reduction of “production lead time” and “transportation lead time”. However, other supply chain attributes such as “capacity surplus”, “inventory level” and “replenishment frequency” are affected in opposite directions by some paradigms creating divergences.
Research limitations/implications – The model relationships were established using an anecdotal approach derived from the literature review, reflecting only a partial view of supply chain dynamics. More research related to other supply chain attributes and/or paradigm practices, and validation of the proposed relationships is suggested.
Practical implications – The proposed model can be the basis for further research in lean, agile, resilient and green paradigms, contributing to a more sustainable and competitive lean supply chain with the necessary agility toward a quick response, resiliency to disruptions, and harmonization with the ecologic and environmental aspects. Originality/value – To the authors' knowledge this paper is the first to provide an understanding about the tradeoffs among lean, agile, resilient and green supply chain paradigms.

Purpose - This paper aims to explore the divergences and commitments between the lean, agile, resilient and green paradigms while investigating the effect of paradigms’ practices within supply chain attributes. Design/methodology/approach - A conceptual model with lean, agile, resilient and green practices and supply chain management attributes is proposed. Causal diagrams were used to represent the relationships between paradigm practices and supply chain attributes. The four diagrams were aggregated to build the conceptual model. Findings - The conceptual model allows for the identification of synergies and divergences resulting from the paradigms practices implementation. The synergies between paradigms are related to “information frequency” and “integration level” increasing as well as reduction of “production lead time” and “transportation lead time”. However, other supply chain attributes such as “capacity surplus”, “inventory level” and “replenishment frequency” are affected in opposite directions by some paradigms creating divergences. Research limitations/implications - The model relationships were established using an anecdotal approach derived from the literature review, reflecting only a partial view of supply chain dynamics. More research related to other supply chain attributes and/or paradigm practices, and validation of the proposed relationships is suggested. Practical implications - The proposed model can be the basis for further research in lean, agile, resilient and green paradigms, contributing to a more sustainable and competitive lean supply chain with the necessary agility toward a quick response, resiliency to disruptions, and harmonization with the ecologic and environmental aspects. Originality/value - To the authors’ knowledge this paper is the first to provide an understanding about the tradeoffs among lean, agile, resilient and green supply chain paradigms.

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The mechanism proposed by Evans to justify the selectivity obtained in Lewis acid catalyzed Diels-Alder reactions of cyclopentadiene with acyloxazolidinones has been generalized and used in the rationalization of selectivities obtained in many other systems. However, we recently proposed an alternative mechanism, on the basis of open-chain mono- and bicomplexes, that avoids the need for chelates and explains the selectivity obtained by Evans. In this manuscript we apply our proposal to the catalyzed conjugated addition of amines to acylimidazolidinones, reported by Cardillo, and we clearly show that aluminum chelates are not involved in the reaction, as they induce no selectivity, while Cardillo observed high experimental selectivities. Our data equally show that bicomplexes with carbonyl parallel orientation, proposed by Cardillo to justify the experimental selectivity with nonchelating Lewis acids, indeed induce the opposite selectivity and have also to be dismissed. On the other hand, our mechanistic proposal allows for the full rationalization of the data obtained by Cardillo with aluminum, boron, or zinc Lewis acids and supports our previous proposal on DA cycloadditions of dienes to Evans chiral auxiliary derivatives.