In this work, the mass transport properties of a neutral solute in a rough microtube with a porous wall under the combined influence of both pressure and electric fields for non-Newtonian power-law fluids are examined. This investigation explores the effect of various microtube roughness patterns, such as sinusoidal, triangular, and rectangular, as well as different flow behavior indices, on solute mass transport behavior. The Poisson–Boltzmann equation, Cauchy momentum equation, and species conservation equation were solved computationally for different roughness profiles to assess the distribution of electric potential, velocity, and concentration fields. Higher relative roughness amplitude (δ = 0.1) and roughness wavenumber (λ = 12) reduced the average cross-sectional velocity by 31% for the dilatant solution, leading to improved permeation. The influence of roughness parameters (δ and λ) and the flow behavior index (n) on solute permeation mass flux was quantified. For the dilatant case, solute mass flux was enhanced by employing rectangular, sinusoidal, and triangular roughness profiles compared to the smooth porous wall by 19%, 9%, and 8% for assisting flow and 16%, 13%, and 11% for opposing flow. In fact, the highest mass flux effectiveness (ξ) for solute delivery was observed for the dilatant fluid with rectangular roughness in assisting flow. It is anticipated that the results of this study will provide valuable insights for the design of specialized drug delivery systems using microfluidic channels and contribute to a better understanding of nutrient transport in physiological systems.

Purpose Supply chain planning (SCP) as an important management intervention is highly relevant to operations and supply chain practice. While SCP processes have developed over time with the use of integrative and advanced analytics tools, the essential foundation and focus on restoring stability remain unchanged and limit the capacity of SCP to adapt to uncertainty. We aim to address this limitation and the way forward in research and practice of SCP through adaptable supply chain planning (ASCP). Design/methodology/approach Drawing on the current discourse on uncertainty regulation and SCP foundations and assumptions, a typology of SCP uncertainty and respective planning strategies are conceptualized. Findings To elevate SCP to account for today's volatile environment, we put forward various forms of uncertainty that organizations face with respect to their awareness and understanding of threats from uncertainty. We also consider how conditions require simultaneously using different planning strategies and navigating between the strategies to regulate the uncertainty, not only to mitigate it but also to create opportunities for progress and growth. Originality/value We propose a new ASCP paradigm with foundational principles, planning strategies and layers of potential research avenues.

PurposeDue to emerging uncertainties, supply chain planning (SCP) has become complex for many companies, and practitioners are unsure how emerging technologies can help. We address this gap by identifying pathways of how digital technologies may aid planned flexibility in SCP.Design/methodology/approachThe research builds on engaged scholarship and co-creation of knowledge. Eight senior managers from two companies participated in three rounds of workshops with us discussing and contrasting their planning challenges and potential solutions using examples of industry 4.0 applications drawn from the literature.FindingsBased on a novel framework for digital transition in SCP, this research shows how emerging technologies may aid SCP in building resilience to emergent uncertainties and open new research avenues through four impact pathways.Research limitations/implicationsThe SCP literature is ruefully short on studies that address technology-aided SC resilience. The research explains why this calls for a paradigm shift in SCP research.Originality/valueThis research argues that resilience-building SCP requires planned flexibility and presents a digital transition framework that allows for it.

Aligning future system design with the ever-increasing compute needs of large language models (LLMs) is undoubtedly an important problem in today’s world. Here, we propose a general performance modeling methodology and workload analysis of distributed LLM training and inference through an analytical framework that accurately considers compute, memory sub-system, network, and various parallelization strategies (model parallel, data parallel, pipeline parallel, and sequence parallel). We validate our performance predictions with published data from literature and relevant industry vendors (e.g., NVIDIA). For distributed training, we investigate the memory footprint of LLMs for different activation re-computation methods, dissect the key factors behind the massive performance gain from A100 to B200 (∼ 35x speed-up closely following NVIDIA’s scaling trend), and further run a design space exploration at different technology nodes (12 nm to 1 nm) to study the impact of logic, memory, and network scaling on the performance. For inference, we analyze the compute versus memory boundedness of different operations at a matrix-multiply level for different GPU systems and further explore the impact of DRAM memory technology scaling on inference latency. Utilizing our modeling framework, we reveal the evolution of performance bottlenecks for both LLM training and inference with technology scaling, thus, providing insights to design future systems for LLM training and inference.

Petroleum and exploration industries employ a hydrofracking process where a large volume of water (fracturing fluid) is injected and a fraction (known as flowback water) is returned to the surface. Froth flotation is a typical process employed for the primary treatment of water. In the present work, froth flotation has been used as a pretreatment method for real flowback water sourced from the petroleum and shale gas exploration industry. In the present work, a first-principle based convective mass transfer model has been developed to describe the froth flotation performance. The resultant equation was solved analytically and compared with the numerical solution, and a parametric sensitivity analysis of the process performance was also undertaken. In addition, a correlation to estimate the flotation rate constant was proposed, thereby circumventing the need to obtain a large number of cumbersome parameters experimentally. Overall, this study proposes froth flotation as an efficient primary treatment method towards the separation of dispersed oil droplets from the flowback water and the corresponding prediction of kinetics using a first-principle based transport model.

Through qualitative case research involving two cases of digital lean implementation projects, we identify and explicate how grit, vision, and pragmatism (as enablers) and technology maturity, implementability, and idiosyncrasy (as barriers) interact with and affect strategic digitalization initiatives. Seemingly-paradoxical strategic approaches to digitalization emerge from the associations between the enablers and barriers with micro-foundations in continuous learning and purposeful implementation—in other words, a lean mindset. Lean thinking changes how firms work with production processes and practices, approach management culture, envision the larger operational landscape, and manage strategy. In today’s business environment, firms need to consider how to make digital technologies fit their own strategic and operational priorities. The contribution of this study is its presentation of strategic digitalization as a lean approach to competitive differentiation.

A number of microfluidic systems of interest essentially consist of micro-scaled channels/tubes, whose walls are inherently rough. The novelty of the current study lies in exploring the impact of the wall roughness on mass transfer in the case of flow through a microtube with porous wall. The current investigation is possibly the first attempt at exploring the effect of mass transfer for a porous-walled, rough microtube, as earlier studies were limited to the analysis of hydrodynamic and thermal effects only in an impervious microtube. In particular, the effects of the corrugation amplitude and the wavenumber on the mass transport have been assessed in detail in this work, via a combination of perturbation approximations and numerical analysis. Several interesting revelations are elicited regarding the effects of these pertinent parameters on the mass transfer coefficient, permeation flux, wall surface concentration, and delivery flux of the neutral solute. It has been unveiled that it is possible to enhance the solute mass flux by 10% via appropriate tuning of corrugation amplitude. The findings of the study can help in better understanding of mass transport for a porous-walled, rough microtube, which has critical relevance in several important applications such as micromixers, targeted drug delivery, and so on.

We posit that the zero-defect mindset from manufacturing is a crucial step in the direction of achieving zerowaste value chains. Using a reflective conversation approach within a food grocery retail case setting, we show how digital twin-supported sales and operations planning (S&OP) may be used as an intervention to predict and detect variabilities across the value chain to prevent and reallocate food surplus, allowing us to bring the zero-waste value chain concept to fruition. The contributions of this study include extending the zero-defect concept to value chains in grocery retail for addressing food waste and proposing the notion of digital twinenabled planning as a means of improving upon the shortcomings of the traditional S&OP process.

Despite the acclaimed potential of industry 4.0 for efficiency and growth, statistics show that the majority of firms’ digital transformation programs fail to meet their objectives. We provide a plausible explanation of this understudied phenomenon through theoretical discussions on the four overlooked paradoxical characteristics found between digitalization activities. Further, using the lens of lean and dynamic capabilities theory, we propose strategies for firms to transcend the paradoxes and in turn, realize their expectations of the transformation initiatives.

The present study is undertaken to analyze the hydrodynamic stability of pressure-driven flow of non-Newtonian fluid-porous systems, where the fluid exhibits the power-law rheology. Such combined fluid-porous flow systems are widely prevalent in diverse geophysical and industrial applications. In the beginning, modal analysis has been performed for comprehending the long-time flow transition characteristics. The plots of the eigenfunctions corresponding to the critical eigenmodes demonstrate the intricate interplay between the non-Newtonian viscosity (quantified by the flow behavior index n) and the porous layer (quantified by depth ratio). It is observed that for a shear-thinning fluid, the flow transition is less sensitive to a variation in depth ratio than that for a shear-thickening fluid. In addition, by exploring the transient energy growth and pseudospectrum in the framework of non-modal stability analysis, the responses to initial conditions and external excitations have been investigated in detail.

The role of the transition layer (existing at the fluid-porous interface) on the hydrodynamic stability of a fluid-porous channel configuration has been investigated, particularly in the context of a non-Newtonian (power-law) fluid. The inherent relationships among the transition layer, the velocity discontinuity at the interface, and the flow criticality are explored in detail. Unlike shear-thickening, the effect of shear-thinning behavior on flow criticality is found to be non-monotonic, owing to an intricate interplay between the transition layer and the fluid rheology. Possible avenues to exploit these flow transition characteristics are also discussed.

This study provides an insider's perspective on why engineering undergraduates at elite Indian universities lack academic motivation. Using interpretive qualitative research (actors approach), we uncover students' perceptions of academic (de)motivation and group them into three broad categories: faculty-related, course-related and cognitive-related, which we then explain through select motivation theories. The study arrives at two alternate explanations for the (lack of) academic motivation (demotivation and amotivation). The findings help guide decision-making by faculty members, academic administrators and planners.

In this study, both modal and non-modal stability analyses are attempted in case of Couette–Poiseuille flow of a Bingham fluid overlying a porous layer. Such a flow configuration is widely encountered in the geophysical context in case of oil drilling. The solution of the modal problem yields no unstable eigenvalue, similar to the flow of a viscoplastic fluid in a non-porous channel configuration. Thus, non-modal analysis is performed to throw light on the short-time characteristics. The primary goal is to unveil the complex interplay between the upper plate velocity (Couette component) and the parameters characterizing the porous layer in dictating the flow transition characteristics. The current study is possibly the first attempt at investigating the effect of the Couette flow on the stability of a fluid–porous system for any kind of non-Newtonian fluid and reveals marked departure from the results reported in the literature for a similar flow configuration involving Newtonian rheology. The reason for the deviation is attributed to the role of yield stress, quantified by the Bingham number, and its complex interaction with the Couette number and porous layer parameters (depth, permeability, anisotropy, inhomogeneity, etc.). The relative interaction between fluid and porous modes in an environment of non-linear viscosity variation (owing to the rheology of the viscoplastic fluid), coupled with enhanced shearing (imparted by the Couette component), is found to demonstrate unique, non-monotonic flow transition characteristics. The possible physical mechanism governing short-time (non-modal) amplifications via interaction between the mean shear flow and the perturbation waves is also explored in detail.

Couette-Poiseuille flow of a Bingham fluid through a channel overlying a porous layer has been investigated in this study. Such flows are relevant in drilling muds for oil recovery, blood flow in biological systems, etc. An analytical solution of the velocity profile was derived from first principles. Effects of various parameters, like, Couette number (Co), Bingham number (Bn), Darcy number, slip coefficient, depth of porous layer on the velocity profile were studied in detail. The phase space plot of Couette-Bingham number was generated to obtain the region of double shear flow desirable for enhanced convective flow. Effects of other operating parameters on Co-Bn phase space were also investigated in order to identify a feasible region to operate for ensuring double shear flow. Locations of both yield surfaces due to asymmetric flow were obtained and effects of operating conditions on them were investigated. Variation of wall shear stress with operating conditions was also quantified. The present analysis will be beneficial for efficient design of flow channels dealing with viscoplastic fluids in real life applications.

•Arsenic-contaminated water is a major public health issue in India and Bangladesh.•Laterite soil provides a novel and cost-efficient way of removing arsenic from water.•A mathematical model determines filter lifetime and an upscaling protocol.•The model captures the filter behaviour through three simple parameters.•The model plays an essential role in the filter deployment and maintenance.

Modal and non-modal stability analyses are performed for Poiseuille flow of a Bingham fluid overlying an anisotropic and inhomogeneous porous layer saturated with the same fluid. In the case of modal analysis, the resultant Orr–Sommerfeld type eigenvalue problem is formulated and solved via the Chebyshev collocation method, using QZ decomposition. It is found that no unstable eigenvalues are present for the problem, indicating that the flow is linearly stable. Therefore, non-modal analysis is attempted in order to observe the short-time response. For non-modal analysis, the initial value problem is solved, and the response of the system to initial conditions is assessed. The aim is to evaluate the effects on the flow stability of porous layer parameters in terms of depth ratio (ratio of the fluid layer thickness $d$ to the porous layer thickness $d_{m}$), Bingham number, Darcy number and slip coefficient. The effects of anisotropy and inhomogeneity of the porous layer on flow transition are also investigated. In addition, the shapes of the optimal perturbations are constructed. The mechanism of transient growth is explored to comprehend the complex interplay of various factors that lead to intermediate amplifications. The present analysis is perhaps the first attempt at analysing flow stability of viscoplastic fluids over a porous medium, and would possibly lead to better and efficient designing of flow environments involving such flow.

In client-provider-customer service triads, direct interactions between the providers and customers result in clients' exposure to various risks. This paper develops a taxonomy of service triads based on four attributes of outsourced services that result in those risks: 1) business impact; 2) customer contact; 3) mode of interaction; and 4) relationship continuity. We conduct a qualitative study to develop a contextually rich understanding of the resulting taxonomy. Characterization of the four taxons, namely, 'low-hazard,' 'easily-monitored,' 'to-be-watched,' and 'vulnerable' service triads, based on agency theory, contributes to the understanding of how these services have traits and risks that are different from one another. It also provides insights into how the providers in each of the four taxons should be contracted and managed.

Purpose Service triads refer to tripartite relationships in which client firms serve their customers through third-party service providers. The purpose of this paper is to systematically review the nascent but fast-growing literature on service triads to explore the broad themes along which the literature has grown, and to identify the gaps and future research opportunities. Design/methodology/approach Systematic literature review (SLR) approach is adopted to retrieve, select, and synthesise relevant service triads studies. A citation network analysis on the corpus resulting from the SLR identified the core articles of the literature. Findings The SLR uncovered ten themes of research along the articles' objectives, theories and methodologies. The classification framework of service triads, the roles of customers and providers, the size of the provider, triadic risks, controlling service delivery and service quality, regulated triads, the stability of the triads, and cross-country, cross-culture triads emerged as significant under-researched areas. Originality/value The paper illustrates research trends and provides insights into the neglected and under-researched problems of service triads. This is the first SLR on service triads.