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Lubrication and friction are the core processes in cold strip rolling, which are the key links to realizing the stable production of high‐quality strips, reflecting country advanced level in rolling technology. This review investigates the crucial properties of lubrication and friction in cold strip rolling by analyzing the mechanism, characterization methods, and influencing factors. The lubricant forms an oil film on the surface of rolls and strips based on the lubrication dynamics and tribology theory, changing the asperity contact state in the loaded roll gap, leading to changes in friction characteristics. Oil film thickness and coefficient of friction (COF) are crucial parameters for characterizing and judging the characteristics of lubrication and friction, theoretical calculations have become the core analytical method, and the study of the measurement method is still a great challenge. Parameters like rolling speed and oil viscosity affect the lubricant distribution and asperity contact in the loaded roll gap, changing the lubrication and friction state. The influence of parameters is strongly linked to the experimental or rolling environment. Prospective research trends on lubrication and friction in cold strip rolling are presented based on the status of research on lubrication and friction characterization. [ABSTRACT FROM AUTHOR]

The glides of curling stones to the button on curling-sheet ice are composed of three segments: (i) an initial high-speed travel characterized by mild decelerations (and minor curls); (ii) a slower-speed segment with visibly greater rates of deceleration (and curl); and (iii) an abrupt end-of-travel. It is proposed here that these three travel segments correlate with the three well-known frictional regimes of tribology's Stribeck curve: (i) a hydrodynamic (wet) frictional regime in which, at high speeds, the generation of frictional heat from shearing stress within a lubricating water film is sufficient to melt ice and fully isolate the rock's running-band from the ice surface, i.e., from mutually abrasive contact; (ii) a mixed frictional regime where, with ever-more severe friction and ever-stronger deceleration and thus ever-lower speeds, the generation of frictional heat is progressively less and the lubricating water film becomes ever-thinner, allowing rock and ice asperities to cut ever-more abrasively into their opposing surfaces; and (iii) a totally dry, highly abrasive frictional regime in which, at very low speeds, lubrication ends because of the lack of sufficient frictional heat to maintain a water film and thus the rock's advance comes to an abrupt end. [ABSTRACT FROM AUTHOR]

The collective volume stands as pivotal research in recent pastoralism studies. Using a multisituated and pluridisciplinary perspective, it addresses the need to understand integratively the dynamic responses of grazing communities across Europe in the context of the new “heritage turn,” in conjunction with environmental stresses, social transformations, global institutions and their policies. Providing in-depth descriptions of the numerous challenges that transhumance in Europe faces today—security of land holding, new market relations, the growing pressures of governments, processes of social change and modernization—it reveals the complex interplay of these drivers of change and analyzes numerous examples of loss and adaptations of grazing practices to the new heritage scenario. In its attempt to ground a more holistic view on mobile pastoralism under global frictions, it proposes reframing it as biocultural heritage.

The behavioral literature suggests that minor frictions can elicit desirable behavior without obvious coercion. Using closures of ATMs in a densely populated city as an instrument for small frictions to physical banking access, we find that customers affected by ATM closures increase their usage of the bank's digital platform. Other spillover effects of this adoption of financial technology include increases in point-of-sale transactions, electronic funds transfers, automatic bill payments and savings, and a reduction in cash usage. Our results show that minor frictions can help overcome the status quo bias and facilitate significant behavior change. This paper was accepted by David Sraer, finance. Supplemental Material: Data and the online appendix are available at https://doi.org/10.1287/mnsc.2023.4972. [ABSTRACT FROM AUTHOR]

Behavioral scientists have begun to research 'sludge,' excessive frictions that make it harder for people to do what they want to do. Friction is also an important concept in transaction-cost economics. Nevertheless, sludge has been discussed without explicit referral to transaction costs. Several questions arise from this observation. Is the analogy to friction used differently in both literatures? If so, what are the key differences? If not, should we develop the concept of sludge when the well-established literature on transaction costs already exists? This conceptual article shows that sludge and transaction costs are related, but distinct, concepts, and that the literature on sludge can benefit from incorporating elements from transaction-cost research. For example, we suggest defining sludge as aspects of the choice architecture that lead to the experience of costs, organize sludges using a typology inspired by the transaction-cost literature, highlight specificity, uncertainty, and frequency as important determinants of the 'sludginess' of choice architecture, and show that sludge audits can be conducted using methods developed in the transaction-cost literature. [ABSTRACT FROM AUTHOR]

This paper studies the implications of business cycle frictions for the diffusion of permanent changes in automation. Incorporating task‐based production in different versions of the New Keynesian model reveals considerable short‐run implications. Price‐distorting nominal rigidities amplify the labor displacement and attenuate the productivity and welfare gains of automation during the transition to the new equilibrium. They exacerbate the falls in the labor income share, the job finding probability, the value of long‐term contracts, and labor market tightness. The inflation response follows a J‐curve. Frictions in capital supply and wage rigidities amplify the labor displacement and attenuate the productivity gains too. [ABSTRACT FROM AUTHOR]

The reflective article examines the nature of contemporary humanities in the context of the digital and globalized era. Emphasis is placed on their ability to integrate diverse cultural and technological perspectives, reflecting their significance in constructing a critical and contextualized understanding of reality. Despite facing challenges such as utilitarian pressure and the prioritization of disciplines, contemporary humanities can leverage these pressures as opportunities to address ethical and social issues. Additionally, the shift towards a transdisciplinary approach in contemporary humanities is highlighted, breaking traditional barriers to address complex problems that transcend conventional academic boundaries. Furthermore, the crucial role of the humanities today is underscored by providing a profound understanding of the human condition and its complexities, fostering empathy and cross-cultural understanding. Finally, the transgressive and undisciplined nature of the humanities is emphasized as a driving force to maintain their dynamism and relevance by challenging existing norms and expanding the boundaries of knowledge. [ABSTRACT FROM AUTHOR]

We develop a new housing search index (HSI) extracted from online search activity on a limited set of keywords related to the house-buying process. We show that HSI has strong predictive power over subsequent changes in house prices, both in-sample and out-of-sample and after controlling for the effect of commonly used predictors, and relate our findings to models of search-induced frictions. Our results imply that search data can be used as an early indicator of where the market is going. This paper was accepted by David Sraer, finance. Funding: We acknowledge support from the Danish Finance Institute and from the Independent Research Fund Denmark [Grants DFF 7024-00020B and DFF 7015-00017B]. Supplemental Material: The online appendix and data are available at https://doi.org/10.1287/mnsc.2023.4672. [ABSTRACT FROM AUTHOR]

In practice, firms face a number of scarce innovation projects. They choose one towards which to direct their effort, but do not coordinate these choices. This gives rise to coordination frictions. This paper develops an expanding-variety endogenous growth model to study the implications of these frictions for growth and welfare. We find that the coordination failure generates a number of foregone innovations and reduces the economy-wide research intensity. Both effects decrease the growth rate. This creates a general equilibrium effect that endogenously amplifies the fraction of wasteful simultaneous innovation. Furthermore, formalizing the coordination frictions uncovers a novel link between the "stepping on toes" and "standing on shoulders" externalities—their magnitudes are endogenously determined through the ratio of firms to innovation projects. We find that the "stepping on toes" externality is larger for all parameter values. [ABSTRACT FROM AUTHOR]

This paper combines an input–output model and a novel regional labour market matching model in order to identify potential bottlenecks in regional labour markets resulting from shocks in demand caused by the energy transition. Identifying these bottlenecks provides relevant information for policymakers to determine in which regions and industries policy intervention in labour markets may be needed to ensure a smooth transformation. We analyse the effects of a shock that is illustrative for the energy transition in the Netherlands. Our results indicate that the aim of the Dutch government to substantially reduce greenhouse gas emissions may, at least in the short run, be hampered by bottlenecks in labour markets. [ABSTRACT FROM AUTHOR]

Although leveraged exchange-traded funds (ETFs) are popular products for retail investors, how to hedge them poses a great challenge to financial institutions. We develop an optimal rebalancing (hedging) model for leveraged ETFs in a comprehensive setting, including overnight market closure and market frictions. The model allows for an analytical optimal rebalancing strategy. The result extends the principle of "aiming in front of target" introduced by Gârleanu and Pedersen (2013) from a constant weight between current and future positions to a time-varying weight because the rebalancing performance is monitored only at discrete time points, but the rebalancing takes place continuously. Empirical findings and implications for the weekend effect and the intraday trading volume are also presented. This paper was accepted by Agostino Capponi, finance. Funding: M. Dai acknowledges support from the National Natural Science Foundation of China [Grant 12071333], the Hong Kong Polytechnic University [Grant P0039114], and the Singapore Ministry of Education [Grants R-146-000-243/306/311-114 and R-703-000-032-112]. H. M. Soner acknowledges partial support from the National Science Foundation [Grant DMS 2106462]. C. Yang acknowledges support from the Chinese University of Hong Kong [Grant 4055132 and a University Startup Grant]. Supplemental Material: Data and the online supplement are available at https://doi.org/10.1287/mnsc.2022.4407. [ABSTRACT FROM AUTHOR]

It has been about three decades since Mozambique transitioned from a brutal civil war and one-party rule to peace and democracy. Although Mozambique has not relapsed into another large-scale civil war, sustainable peace and democracy in the country have become ever more elusive. In 2013, military clashes between Renamo and the Frelimo-led government resumed and prompted a new peace process, whilst poverty and inequalities are rampant, authoritarianism is on the rise, and an Islamic insurgency erupted in the northern region. Accordingly, while some scholars still praise Mozambique's post-war peacebuilding as successful, others have claimed that peacebuilding failed. This article evades the binary of successful or failed liberal peacebuilding in Mozambique. Instead, it applies the concepts of friction and hybridity to offer an alternative way of reading the 30 years of peace (building) in Mozambique. The article argues that frictions in values and interests between the international/liberal peacebuilders and local (non-liberal) elites have resulted in a negative and unstable hybrid peace, that is, a precarious peace in Mozambique. [ABSTRACT FROM AUTHOR]

This paper proposes a generalized high-order observer for estimating total disturbance of permanent magnet synchronous motors (PMSMs). This total disturbance is dominated by load torque but also includes many other terms such as frictions, viscous force, Eddy and flux pulling forces, and noises. Comprehensive experimental results and analyses under various scenarios will be presented to find the appropriate order of the observer. We will compare the performance of zero-order observer (ZDO), first-order observer (FDO), and second-order observer (SDO) under three different scenarios of load torque. Additionally, the results of an state observer (ESO) under the same conditions are also presented. The experimental results show that FDO and SDO achieve similar performance and both of them are notably better than the ZDO and ESO. However, during the severe conditions of load torque, the SDO-based controller can achieve better performance compared to that of FDO-based controller. Moreover, fuzzy algorithm is applied to online tune the PI gains in the speed loop. The results also show that the SDO-based fuzzy-PI control scheme is effective in disturbance rejection and high-performance speed tracking. All of the experiments are carried out on a 300-W PMSM testbed with a digital signal processor (DSP).

This paper engages with the translation of the abstract concept of Responsible Research and Innovation (RRI) into practice. Our investigation is situated within a large-scale European project seeking to develop a citizen-centered digital health data platform. We specifically engage with co-creation practices and their potential for creating and maintaining inclusive environments generative of critique and empowerment. Critique for us means questioning practices and the modes of thought they rest on, both of ourselves and participants in the co-creation process. We combine a narrative analysis of EU funding calls framing the project with a reflection on our experiences as STS scholars during the co-creation process and on how citizens formulated their critique regarding the health data infrastructure. We end discussing the possibilities and limits of such a co-creation approach and the spaces and modes of critique made possible and, thus, how it lives up to the promises of responsible innovation.

Abstract With the closure of the border with then-Macedonia in early 2016, it was foreseeable that Greece would become the “last station” for a large number of refugees. Flanked by the agreement between Turkey and the European Union of March 2016, Greece underwent a profound transformation from a transit country to a recipient country. Through a new regulation, the Emergency Support Instrument, initially activated by the European Commission 2016–2019, international humanitarian aid operations were supported for the first time in the EU. The article analyzes the resulting frictions on the basis of empirical field research and a broad literature review. While frictions similar to those in other non-European humanitarian operations exist, specific peculiarities due to the operation taking place in an austerity-ridden member state of the EU must also be noted.

Several structural results for the set of competitive equilibria in trading networks with frictions are established: The lattice theorem, the rural hospitals theorem, the existence of side‐optimal equilibria, and a group‐incentive‐compatibility result hold with imperfectly transferable utility and in the presence of frictions. While our results are developed in a trading network model, they also imply analogous (and new) results for exchange economies with combinatorial demand and for two‐sided matching markets with transfers. [ABSTRACT FROM AUTHOR]

This paper studies arbitrage-free financial markets with bid-ask spreads whose super-hedging prices are submodular. The submodular assumption on the super-hedging price, or the supermodularity usually assumed on utility functions, is the formal expression of perfect complementarity, which dates back to Fisher, Pareto, and Edgeworth, according to Samuelson (J Econ Lit 12:1255–1289, 1974). Our main contribution provides several characterizations of financial markets with frictions that are submodular as a consequence of a more general study of submodular pricing rules. First, a market is submodular if and only if its super-hedging price is a Choquet integral and if and only if its set of risk-neutral probabilities is representable as the core of a submodular non-additive probability that is uniquely defined, called risk-neutral capacity. Second, a market is representable by its risk neutral capacity if and only if it is equivalent to a market, only composed of bid-ask event securities. [ABSTRACT FROM AUTHOR]

This article explores how experiences related to daily mobility negatively impact and shape the way women in Accra engage with and perceive the city they live in and the opportunities it provides for them. In Accra, being mobile is crucial for women's ability to work and provide for their families and for their identity as modern and hardworking women. However, when traveling through the city women are faced with severe traffic congestion, a volatile public transport system and gendered confrontations, which create frictions in their daily mobility. These frictions make it difficult for women to plan their everyday lives and their immediate futures, they reduce their ability to move alone or after dark and challenge their conceptions of gender equality and rights to the city. Underscoring the socio-material structures that shape mobility, I argue that women's everyday mobility in Accra is circumscribed by these frictions, which impact their lives on multiple levels and ultimately construct a mistrust of, and disillusionment with, the city's ability to provide for its citizens. This perspective on mobility contributes to an improved understanding of urban life and urban identities as shaped through mobility and the circumstances created by the specific transport system. [ABSTRACT FROM AUTHOR]

With the closure of the border with then-Macedonia in early 2016, it was foreseeable that Greece would become the "last station" for a large number of refugees. Flanked by the agreement between Turkey and the European Union of March 2016, Greece underwent a profound transformation from a transit country to a recipient country. Through a new regulation, the Emergency Support Instrument, initially activated by the European Commission 2016–2019, international humanitarian aid operations were supported for the first time in the EU. The article analyzes the resulting frictions on the basis of empirical field research and a broad literature review. While frictions similar to those in other non-European humanitarian operations exist, specific peculiarities due to the operation taking place in an austerity-ridden member state of the EU must also be noted. [ABSTRACT FROM AUTHOR]

We construct experimental economies, populated with human subjects, with different institutional features that have a structure and incentives similar to a dynamic stochastic general equilibrium model. An experimental economy with monopolistic competition and no menu costs generates empirical patterns that are closer to the U.S. economy than simulations or the other experimental environments. We observe greater welfare and output in a setting where goods are perfect substitutes compared to treatments with monopolistic competition. Discretionary human central bankers produce lower output and welfare compared to an automated instrumental rule. Menu costs reduce inflation volatility. [ABSTRACT FROM AUTHOR]

We investigate the links between firm-level total factor productivity (TFP) growth and technical efficiency change, and their implications on firm-level stock returns. We estimate TFP growth of US firms between 1966 and 2015 and decompose TFP growth into returns to scale, technical progress, and technical efficiency change components. We show that most of the variation in TFP growth is explained by variation in technical efficiency change. Moreover, we examine the effects of important macro- and micro-level factors on inefficiency as well as its asset pricing implications. We find that low-efficiency firms are more vulnerable to a wide class of aggregate economic shocks, and the well-known five stock return anomalies (Fama and French in J Financ Econ 116(1):1–22, 2015) are more pronounced among those firms. Our results also emphasize the role of macroeconomic determinants of efficiency, and the stability effects of many useful policy targets on firm-level TFP. [ABSTRACT FROM AUTHOR]

The essay focuses on local conflicts related to the presence of an oil refining plant in Milazzo, north-western Sicily. On the basis of an ethnographic research led in close contact with some refinery workers and some members of environmental justice movements, this paper highlights how the public assessments on the interweaving of industrial presence, environment and health, defined in conflicting “causation fields” produce real frictions inside the workers families. From this perspective, the families and the biographies of the workers themselves are spaces of friction useful for the understanding of the more complex system that connects global instances of environmental risk to local specificities and the experiences of the people who live and work in industrial areas.

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This article uses networks to study price dispersion in seller-buyer markets where buyers with unit demand interact with multiple, but not all, sellers; and buyers and sellers compete on prices after they meet. The central finding of this article is that price dispersion is determined by the structure of the network. First, for any given network we characterize the pairwise stable matchings and the prices that support them. Second, we characterize the set of all graphs where price dispersion is precluded. Third, we use a theorem from Frieze (1985) to show that the graphs where price dispersion is precluded arise asymptotically with probability one in random Poisson networks, even as the probability of each individual link goes to zero. Finally, we calibrate our model to the documented price dispersion at the online trading platform eBay and show how counterfactual network structures at eBay would substantially decrease price dispersion. [ABSTRACT FROM AUTHOR]

We investigate the effects of banks' operating costs on allocations and welfare in a low interest rate environment. We introduce an explicit production function for banks in a microfounded model where banks employ labor resources, hired on a competitive market, to run their operations. In equilibrium, this generates a spread between interest rates on loans and deposits, which reflects the underlying monetary policy and the efficiency of financial intermediation. In a deflation or low‐inflation environment, equilibrium deposits yield zero returns. Hence, banks soak up labor resources to offer deposits that do not outperform idle balances, thus reducing aggregate efficiency. [ABSTRACT FROM AUTHOR]

Global political economists have highlighted how states and corporations enact environmentally destructive practices and create commodities that legitimate those same activities. Linking macroeconomic systems to situated micropractices, how a by-product of US ethanol production, distillers' grains, has been transformed into a global animal feed commodity is explored in this study. The effect of this transformation is to legitimate both biofuel production and intensive livestock operations, while delegitimating the resistant 'food vs. fuel' argument proposed by critics of biofuel production. Yet the process of creating an animal feed commodity from industrial waste is also problematic, characterized by the creation of multiple 'frictions of consumption', concerning the product's storability, flowability and digestibility. Bioscience experts work to overcome these frictions; yet these frictions may also offer opportunities for those seeking to resist these environmentally destructive industries. [ABSTRACT FROM AUTHOR]

We show how frictions and continuous transfers jointly affect equilibria in a model of matching in trading networks. Our model incorporates distortionary frictions such as transaction taxes and commissions. When contracts are fully substitutable for firms, competitive equilibria exist and coincide with outcomes that satisfy a cooperative solution concept called trail stability. However, competitive equilibria are generally neither stable nor Pareto‐efficient. [ABSTRACT FROM AUTHOR]