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Inhomogeneous mechanical properties in flash butt welded high-strength low-alloy steel joints via nanoindentation and reverse analysis
Get PDFThis study investigates the inhomogeneous mechanical properties of flash butt welded (FBW) S590LW high-strength low-alloy steel joints in wheel rims and their impact on the flaring process. Nanoindentation tests, complemented by microhardness measurements and microstructural analysis, were conducted to divide the weld joint into four distinct zones: interface zone (IZ), coarse grain zone (CZ), normalizing zone (NZ), and partial normalizing zone (PZ). Each zone exhibited distinct loadpenetration depth behavior, microstructure, and microhardness characteristics. True stress–strain relationships for each zone were determined through finite element (FE) modeling combined with reverse analysis of nanoindentation data. The results revealed significant gradients in yield strength and strain hardening exponent across the weld joint, with IZ showing the highest strength and lowest strain hardening. A three-dimensional FE simulation of the flaring process was developed using the localized mechanical properties of each weld zone. The model revealed nonuniform stress and strain distributions, with IZ experiencing high Von Mises stress, indicating its vulnerability to fracture. These findings underscore the importance of accurately characterizing local mechanical property gradients in welded structures, providing a foundation for improved predictive accuracy and enhanced quality control in rim manufacturing processes
Early‐life hunger experience and dietary behaviors in adulthood: evidence from the Great Chinese Famine
No full textThe impacts of famine are both complicated and constant. This paper provides a pathway from hunger experience to dietary behaviors, which is vital to health and individual development. Using data from four waves in the China Health and Nutrition Survey (2004–2011), a cohort difference-in-differences strategy is applied to estimate the long-term effects of the Great Chinese Famine (1959–1961) on dietary behaviors of middle-aged adults in rural China. Results show that early-life exposure to hunger negatively affects their caloric, carbohydrate, calcium, and manganese intakes but has no significant impact on dietary structure and quality. Food consumption is a direct pathway linking early-life famine to changes in nutrient intake. Mechanism analysis reveals that economic hardship and dietary knowledge act as key channels through which long-term economic hardship constrains access to nutrients, while enhanced dietary knowledge mitigates the reduction of caloric intake, though it cannot offset the economic impacts. Heterogenous effects are observed among different groups based on gender, weight, and income level
Youth, work and housing: a nexus of precarity
Get PDFGlobally, young people’s efforts to secure access to work and housing are characterised by considerable precarity and often impede youth transitions. Contributing to debates in housing studies, labour and youth geographies, this paper conceptualises ‘a nexus of precarity’, analysing young people’s experiences of unattainable and poorly paid work alongside their often unaffordable and poor-quality housing in Ethiopia and South Africa. Policy, particularly across the global south, focuses on youths’ employment challenges leaving access to affordable housing under-addressed. This paper argues that understanding the intimate connections between youths’ home and workspaces, and work and housing circumstances, are critical to youth transitions. It employs a framing of temporalities, spatialities and socio-political dimensions to illustrate the varied historical and multi-scalar processes shaping youth work and housing. The idea of a ‘nexus of precarity’ characterising young people’s lives, is advanced through a comparative analysis focused on Hawassa, Ethiopia and Ekangala, South Africa
From sales exaptation to digital transformation: Value creation from remote selling
Get PDFDigital transformation of sales practices was accelerated during the pandemic as it necessitated a rapid shift to remote selling for many organizations. However, traditional sales' reliance on onsite visits, collaborative sales team meetings, and in-person interactions with customers have raised questions on the viability of remote selling in the B2B sales context. This qualitative study explores how sales organizations rapidly responded to these disruptions to create value for remote buyers. Through in-depth interviews with sales managers engaged in remote selling, we reveal new value creation mechanisms via digital channels, enhancing both sales efficiency and customer relationships, the realization of which is followed by organizations' deliberate efforts to assimilate remote selling. We argue this rapid shift can be better understood through evolutionary concepts of exaptation and subsequent adaptation, providing insights into organizational response to radical environmental changes. More specifically, we propose a processual framework where crisis-induced salesforce exaptation prompts organizations to accelerate technology adoption and capability development, which in turn catalyzes organizational changes to propel businesses into digital transformation trajectories. Our research contributes to the literature on crisis-driven innovation and exaptation theory for analyzing rapid transformations. We offer practical insights to address the challenges of incorporating digital technologies into sales structures
Pentagram maps over rings, Grassmannians, and skewers
Get PDFThe pentagram map is a discrete dynamical system on planar polygons. By definition, the image of a polygon P under the pentagram map is the polygon P’ whose vertices are the intersection points of consecutive shortest diagonals of P. The pentagram map was introduced by R. Schwartz in 1992, and is now one of the most renowned discrete integrable systems. Several authors proposed generalizations of the pentagram map to other geometries, in particular to Grassmannians, where the role of points and lines is played by higher-dimensional subspaces, as well to skewer geometry, where both points and lines are affine lines in the three-dimensional Euclidean space. In the present paper, we develop a common framework for these kinds of generalizations. Specifically, we show that those maps can be viewed as pentagram maps in the projective plane over an appropriate ring. In general, those rings need not be division rings or commutative. We show that the Grassmannian pentagram map corresponds to the ring of matrices, while the skewer map is the pentagram map over the ring of dual numbers. Furthermore, we prove that the pentagram map remains integrable for any stably finite ground ring R
Adaptation of an evidence-based home cardiac rehabilitation programme for people with coronary heart disease in Bangladesh
No full textBackground:
Cardiac rehabilitation (CR) is a clinically proven cost-effective intervention and reduces the risk of hospital readmissions and recurrent cardiac events and improves exercise capacity and health-related quality of life in people. However, access to CR in low and middle-income countries remains scarce and a high unmet need. The purpose of this study was to adapt a home-based CR programme (‘the Heart Manual’) originally developed and evaluated in the United Kingdom (UK) for the people with coronary heart disease (CHD) in Bangladesh.
Methods:
Guided by the 2021 ADAPT methodological framework, a multiphase approach to intervention adaptation was undertaken that included mapping of the Bangladeshi healthcare context and in-depth consultation meetings and workshops with key stakeholders (patients and their families, healthcare professionals, and health service providers).
Results:
In addition to language translation (English to Bangla) and cultural adaptation, the UK Heart Manual content and structure were modified whilst retaining its core interventional components and principles. The resulting Bangla Heart Manual comprises of three main adaptions: (1) combination of the UK Heart Manual post-myocardial infarction and revascularisation manuals into a single document; (2) development of a short version for easy reference for patients; and (3) creation of audiovisual and animated versions of materials to promote patient accessibility.
Conclusion:
Using an evidence-based approach, the UK Heart Manual programme was contextually and culturally adapted for people with CHD in the Bangladesh healthcare setting. The Bangla Heart Manual provides the opportunity for access to home-based CR in a low resource setting. Research is needed to confirm the feasibility and acceptability of the delivery of the adapted Bangla Heart Manual for healthcare practitioners, patients, and their families
Reflexive accountability in water governance: navigating ethical crossroads
No full textPurpose:
This study examines how people involved in river-care initiatives understand and enact accountability when structural accountability systems are influenced by political control. Drawing on Archer's critical realism, it explores how identity and reflexive thinking enable actors to navigate the ethical limits of structural accountability in addressing river pollution and water scarcity.
Design/methodology/approach:
A qualitative approach was adopted, combining reflexive life-history interviews with longitudinal fieldwork involving NGO officers and community members engaged in river-care programmes in Malaysia.
Findings:
River-care commitments are constrained by structural accountability shaped by political intervention and factionalism. Actors employ communicative, autonomous, and collaborative modes of reflexivity, often rooted in identity formation, to reinterpret, adapt, or circumvent imposed accountability demands. We term this reflexive accountability, manifested through human reflexivity grounded in moral judgement, identity, and lived experience, facilitating navigation of ethical limits.
Originality/value:
This study introduces reflexive accountability, illustrating how reflexivity enables actors to navigate the ethical limits of NGO accountability and water governance in politicised settings. It is a nuanced form of subjective accountability that complements structural accountability systems in addressing complex environmental challenges
Towards large-area EELS mapping of precipitates in a steel matrix: comparing low loss and high loss quantification
Get PDFIt is demonstrated that the low loss region of the electron energy loss spectrum can successfully map (V,Ti,Nb)C precipitates in the matrix of a steel including determining their thicknesses, volume, number density, volume fraction and size distribution. A comparison is made of the results obtained using both the low loss (mainly plasmon-type losses and low-lying semi-core-loss edges) and high loss signals (principally more classic core-loss edges) from the same dataset. The agreement between the two sets of results is excellent. While the high loss results are more element specific, the data takes much longer to acquire. When acquiring only the low loss data, the acquisition time is much shorter and would therefore allow mapping of much larger areas of a specimen, with obvious potential for making statistically significant measurements of precipitate size distributions and volume fractions. Provided that an initial study which includes high loss data is made, such large area maps can be quantified. The residual diffraction contrast in the low loss signal also provides a link connecting the precipitates and the microstructure of the matrix. While the approach here is applied to steels, it has potential for much wider applicability
Adaptive and risk recovery strategies for enhancing supply chain network resilience: a cascading failure perspective
No full textThe increasing complexity of global supply chain networks, driven by economic integration, has heightened their susceptibility to cascading failures triggered by various disruptions. Existing studies on risk propagation and response strategies in supply chain networks often model only single failure modes, neglect firm-specific heterogeneity in defining failure characteristics, and treat recovery strategies as discrete interventions rather than continuous adaptive behaviors across varying operational states. To address these shortcomings, this study proposes an extended load-capacity model that integrates the coexistence and interaction of overload and underload failure modes, defines nonlinear functions to capture firm-heterogeneous failure characteristics, and develops a continuous unified framework comprising four distinct node states that integrates proactive and reactive risk recovery strategies for adaptive and risk states. By employing the Barabási–Albert model to construct supply chain networks of varying density and simulating both random and targeted disruptions, the results demonstrate that: (1) firms require a comprehensive risk management framework incorporating forward-looking risk warning mechanisms and dual-track parallel risk response systems, with effective implementation of adaptive recovery strategies focusing on three key dimensions under the equilibrium principle; (2) at the network level, the implementation of adaptive recovery strategies should follow differentiation principles across two critical dimensions—strategic prioritization of core firms and management of inter-firm capability disparities. These insights advance both theoretical understanding and practical approaches for designing resilient supply chain networks capable of preventing and mitigating cascading disruptions
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