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The purpose of this paper is to present a methodological approach to support qualitative analysis of waste flows in food supply chains. The methodological framework introduced allows the identification of circular food waste flows that can maximise the sustainability of food supply chains.

Following a qualitative approach, circular economy perspectives are combined with core industrial ecology concepts in the specification of a standardised analytical method to map food waste flows and industrial synergies across a supply chain.

The mapped waste flows and industrial linkages depict two time-related scenarios: (1) current scenarios showing the status quo of existing food waste flows, and (2) future scenarios pointing out circular flows along the supply chain. The future scenarios inform potential alternatives to take waste flows up the food waste hierarchy.

The qualitative approach does not allow generalisations of findings out of the scope of the study. The framework is intended for providing focussed analysis, case by case. Future research involving mixed methods where quantitative approaches complement the qualitative perspectives of the framework would expand the analytical perspective.

The framework provides a relatively low-cost and pragmatic method to identify alternatives to minimise landfill disposals and improve the sustainability of food supply chains. Its phased methodology and standardised outcomes serve as a referential basis to inform not only comparative analysis, but also policymaking and strategic decisions aimed at transforming linear food supply chains into circular economy ecosystems.

In the present scenario of high-speed machines, the use of non-circular hole-entry bearing configuration, i.e. two-lobe, multi-lobe, lemon bore, etc., has becomes unavoidable, as the journal bearings with non-circular configurations provide better stability at high operating speed and heavy dynamic loading. Further, this research aims to show that the presence of micro particles in the lubricants greatly affects performance of the bearings, as their presence leads to non-Newtonian behaviors of the lubricant. Therefore, to consider the effect of these micro particles, the lubricant is modeled as a micropolar lubricant. The present work analyzes the effect of these micropolar lubricants on the performance of hole-entry circular and non-circular (two-lobe) hybrid journal bearings compensated with constant flow valve restrictor and compares with that of Newtonian lubricants.

The modified Reynolds equation governing the laminar flow of iso-viscous, incompressible micropolar lubricant in the clearance space of a journal bearing system has been solved using finite element method and appropriate boundary conditions. Further, a comparative analysis between circular and non-circular (two-lobe) hybrid journal bearing compensated with constant flow valve restrictor operating with Newtonian and micropolar lubricant has been presented.

The numerically simulated results reveal that the non-circular bearing configuration provides better performance vis-à-vis the circular bearing configuration. Further, the increase in the micropolar effect of the lubricant enhances the performance of circular and the non-circular bearing configurations compared with the Newtonian lubricant. Also, in the case of the non-circular bearing configuration with an offset factor (δ = 1.5), the bearing performance improved compared with (δ = 1.25).

Many research studies have been done in the area of non-circular hybrid journal bearing with Newtonian lubricants with different types of restrictors, but the non-circular hole-entry constant flow valve-compensated hybrid journal bearing operating with the micropolar lubricant has not been analyzed. Therefore, in the present work, an effort has been made to fill this research gap.

The purpose of this paper is to simulate the flow of a conducting fluid past a circular cylinder placed centrally in a channel subjected to an imposed transverse magnetic field to study the effect of a magnetic field on vortex shedding at different Reynolds numbers varying from 50 to 250.

The two‐dimensional incompressible laminar viscous flow equations are solved using a second‐order implicit unstructured collocated grid finite volume method.

An imposed transverse magnetic field markedly reduces the unsteady lift amplitude indicating a reduction in the strength of the shed vortices. It is observed that the periodic vortex shedding at the higher Reynolds numbers can be completely suppressed if a sufficiently strong magnetic field is imposed. The required magnetic field strength to suppress shedding increases with Reynolds number. The simulation shows that the separated zone behind the cylinder in a steady flow is reduced as the magnetic field strength is increased.

In this paper, due attention is given to resolve and study the unsteady cylinder wake and its interaction with the shear‐layer on the channel wall in the presence of a magnetic field. A critical value of the Hartmann number for complete suppression of the shedding at a given Reynolds number is found.

This paper aims to investigate the aerodynamic sound generated from flow over bluff bodies at a high Reynolds number. By taking circular and square cylinders as two representative geometries for the cross-section of bluff bodies, this study aims to clarify the difference in flow formation and sound generation between the two types of bluff bodies. Furthermore, the possibility for a downstream flat plate to be used as sound cancellation passive mechanism is also discussed in this study.

Sound source from the near field is numerically solved by using the Unsteady Reynolds-Averaged Navier Stokes equations. While for the sound at far-field, the compact sound theory of Curle’s analogy is used.

Magnitude of the generated sound is dominant by the aerodynamic forcer fluctuations, i.e. lift and drag, where the lift fluctuation gives the strongest influence on the sound generation. The square cylinder emits 4.7 dB higher than the sound emitted from flow over the circular cylinder. This relates to the longer vortex formation length for the case of square cylinder that provides space for more vortex to dissipate. It is suggested that downstream flat plate is possible to be applied for a sound cancellation mechanism for the case of circular cylinder, but it would be more challenging for the case of square cylinder.

This study include implications for the development of noise reduction study especially in high-speed vehicles such as the aircrafts and high-speed trains.

This study identified that there is possible method for sound cancellation in flow over bluff body cases by using passive control method, even in flow at high Reynolds number.

In the research work on blocking flow, the concept of minimum flow of a two‐terminal network was introduced. In this paper, a kind of special blocking flow – the concept of minimum spanning flow in the network is introduced and its construction method studied. Here, we show that it is easy to determine whether there is a minimum spanning flow in a network in polynomial time, but it is hard to determine whether there is a non‐circuit minimum spanning flow in one step. Fortunately, the latter problem can be solved in two steps, and its self‐organizing principle is put forward. The feasibility of the algorithm developed on this principle was proved by about 4,500 examples. The significance of this research work is pointed at last.

The purpose of this paper is to identify requirements and tradeoffs on logistics services for enhanced circularity of materials and resources.

Based on multiple case study design and abductive reasoning, the study investigates 13 different product categories. The data were analyzed based on theoretical, a priori codes from the literature review. Inductive, emerging codes were added to the coding scheme during the analysis.

Requirements of logistics services to support slowing of resource flows are categorized with respect to initiator, location of the service, single or multiple actors, and transportation of parts, products and people. Moreover, the study identifies new logistics tradeoffs: material and people, knowledge and people, and information and knowledge. Transportation of product, people and parts can be reduced by increasing local knowledge and improve information sharing.

This review contributes to the understanding of the relationship between logistics services and enhancement of circularity by highlighting requirements on logistics services in the aftermarket supply chain that support slowing of resource flows. To enhance circularity, logistics services must extend the traditional material information flow with the flow of people and knowledge, respectively.

The categorization provides practitioners and researchers with an overview of requirements and tradeoffs on logistics services to enhance circularity of a particular circular cycle. The implications will provide an opportunity to address environmental impact of transportation and improve the utilization of scarce materials.

Variety of tradeoffs in logistics services can enhance slowing and hence circularity of scarce materials.

First, the authors illustrate how traditional tradeoffs in logistics such as flow of materials, resources and people need to be addressed to enhance circularity through slowing. Second, the authors identify two new tradeoffs in logistics services: knowledge flow and degree of customer involvement.

A computational procedure based on a hybrid Lagrangian‐Eulerian discrete‐vortical element formulation and conformal transformation schemes are employed in this study to simulate the interaction of an air jet with swirling air flow inside a two‐dimensional cylinder. Such an investigation is of importance to many flow‐related industrial and environmental problems, such as mixing, cooling, combustion and dispersion of air‐borne or water‐borne contaminants because of the role of vortices in the global transport of matter and heat. The basis for the simulation is discussed and numerical results compared with theoretical results for the velocity field and streamfunction obtained by the method of images. The swirling air motion and the features of a real jet are well simulated and numerical results are validated by predictions of theory to within 20 per cent. To illustrate the merging and interaction processes of vortices and the formation of large eddies, velocity vectors, particle trajectories and streamline contours are presented.

The earth’s carrying capacity cannot withstand the pace of consumption resulting from current economic models, mainly the linear economy (LE) built on a throwaway culture. In the last few decades, the concept of a circular economy (CE), aiming to design waste out of the economy and mimic ecosystems, emerged as a strong alternative to LE. Being at the heart of the economic landscape, supply chains (SCs) need to respond to the necessary shift to CE. In so doing, the planning and execution of circular supply chains (CSCs) require a broader comprehension of CE and more sophisticated and large-scale analytical decision models. This chapter surveys extant literature on available best practices and quantitative models for sustainable supply chains (SSCs) and offers a new definition of CSC. Mapping on the knowledge extracted from this classification, potential gaps and strengths in the literature are identified. Key research papers on the “closed-loop” and “open-loop” ends of CSCs are highlighted. Challenges in developing CSC performance indicators and prescriptive models are emphasized.

The purpose of this paper is to outline more computational schemes which provide a low computational cost approach to analyze flow characteristics through tube bundles. Flow through tube bundles has been numerically simulated by means of an alternative approach so as to assess flow behavior and its characteristics.

A Cartesian‐staggered grid based finite‐volume solver has been implemented. Furthermore, the ghost‐cell method in conjunction with Great‐Source‐Term technique has been employed in order to directly enforce no‐slip condition on the tubes boundaries. Before giving a solution for flow field through tube bundles, the accuracy of the solver is validated by simulation of flow in the cavity and also over a single circular cylinder. The results are completely compatible with the experiments reported in the literature.

Eventually, the flow through two types of tube bundles in in‐line square and general staggered arrangements in Re = 100 are simulated and analyzed. For these tube bundles that are being studied, the maximum drag and lift coefficients and maximum gap velocities have been numerically obtained. The same simulations have been also performed for the cases where the tube bundles are confined by two lateral walls.

These configurations are frequently used in heat exchangers, steam boilers, nuclear reactors, and many mechanical structures.

The adapted method is firstly implemented to simulate flow through tube bundles and the analyzed simulations have not previously been presented by other researches.

The circular economy (CE) approach has been acknowledged as key for manufacturing organizations wishing to overcome sustainability challenges. However, the transition has been slow. Stakeholder engagement is a driver of the transition, but there is limited knowledge on stakeholder engagement practices in a CE context. The purpose of this paper is thus to explore with whom, on what and how organizations engage with stakeholders to implement CE as part of sustainability efforts.

This study is situated at the intersection of CE, stakeholder theory and supply chain literature. A case study with three Swedish manufacturing organizations was conducted to explore stakeholder engagement practices that facilitate the implementation of CE in organizational practice and the supply chain, considering conceptual differences between stakeholder engagement for sustainability and CE.

This study provides empirical evidence on how manufacturing organizations engage stakeholders to implement CE as part of organizations' sustainability efforts. The study highlights that manufacturing organizations have to move not only from linear to circular resource flows, but also from linear to circular stakeholder engagement. Such engagement can be achieved by extending with whom, expanding on what and leveling up how stakeholders are engaged.

This study provides an enhanced conceptual understanding of stakeholder engagement in the CE context and discusses differences regarding stakeholder engagement based on linear thinking. The study emphasizes the role of circular stakeholder engagement practices for the transition toward CE in manufacturing organizations.