Practical Configurations Research Articles

Flashback Prevention in a Hydrogen-Fueled Reheat Combustor by Water Injection Optimized With Global Sensitivity Analysis

Abstract This paper investigates water injection effects in a simplified Ansaldo GT36 reheat system under realistic conditions of 20 atm using large eddy simulation (LES) coupled with thickened flame modeling and adaptive mesh refinement. The water injection conditions are optimized by performing a parametric study based on global sensitivity analysis (GSA) with a surrogate model based on Gaussian process (GP) to reduce computational cost. In particular, the influence of four design parameters, namely, Sauter mean diameter (SMD), water mass flow, and the angles of the spray's hollow cone, is tested to achieve an optimized solution. In the “dry” case, the LES simulations show several flashback events attributed to compressive pressure waves resulting from auto-ignition in the core flow near the crossover temperature. The use of water injection is found to be effective in suppressing the flashback occurrence. In particular, the global sensitivity analysis shows that the external angle of the spray cone and the mass flow of water are the most important design parameters for flashback prevention. NOx emissions are reduced by about 17% with water injection. Once an optimized condition with water injection is found, a recently proposed method to downscale the combustor to lower pressures is applied and tested. Additional LESs are performed for this purpose at the dry, unstable condition and the “wet,” stable condition. Results show that similar dynamics are predicted at 1 atm, validating the method's robustness. This provides avenues for experimentally testing combustion dynamics at simplified conditions which are still representative of high-pressure practical configurations.

(Re)configurations of public education: marketisation, teacher professionalism, and individual rights of students and educators in Norway and Sweden

ABSTRACT This article studies the (re)configurations of ‘public education’ in Norway and Sweden by empirically unpacking connections between marketisation, teacher professionalism and schools’ mandate to secure the individual rights of students and teachers. These countries share considerable common cultural and political history; however, they display varying trajectories and configurations in both educational policy and practice. This makes these cases particularly useful for comparing how ‘publicness’ and ‘public education’ are (re)configured in the two Nordic welfare states. This comparative exploration is framed by four dimensions of public schooling regarding national policy set-ups expressed through control, access, funding, and teaching. The data includes official policy documents, such as legislation and government reports. We unpack and discuss commonalities and differences by relating them to multiple issues of (re)configured ‘publicness’ and its implications. Moreover, we argue that the differences in the degrees to which inflows have shaped the Norwegian and Swedish education systems (despite their similarities) offer valuable opportunities for exploring (re)configurations of the notion of publicness.

Water-Mediated Surface Engineering Enhances High-Voltage Stability of Fast-Charge LiCoO2 Cathodes.

Maintaining the surface structure stability of LiCoO2 (LCO) during rapid charge-discharge processes (>5C) and under high-voltage conditions (>4.2 V) is challenging due to interfacial side reactions, cobalt dissolution, and oxygen redox activity at deeply delithiated states, all of which contribute to performance degradation. Herein, different from traditional surface coating methods, we report a water-mediated strategy that modifies the surface architecture of LCO, creating a passivating layer to inhibit surface degradation and enhance cycling stability under fast charging conditions. The surface etching of LCO by H2O is accompanied by a concurrent Li+/H+ cation exchange, which passivates surface oxygen with H+ ions, thereby enhancing both the hydrophobicity and structural stability. Consequently, the modified LCO exhibits superior capacity retention, which is 2.5 times that of the pristine LCO, after 100 cycles at a current density of 1000 mA g-1 (∼6C at 4.5 V). Even at an elevated temperature of 45 °C, it maintains impressive cycling stability at a current density of 500 mA g-1 (∼3C), as demonstrated in practical full-cell configurations. Investigation with multiple samples confirmed that the water-mediated strategy demonstrated broad applicability. We emphasize that the water-mediated modification of the surface architecture on cathode materials offers significant insights into enhancing the stability of high-energy-density lithium-ion batteries (LIBs).

Practical Configuration of a Discrete RIS With Phase-Dependent Amplitude Response

Practical Configuration of a Discrete RIS With Phase-Dependent Amplitude Response

Comparative study of zinc sulfide, tin selenide, and their composite electrocatalysts for oxygen evolution reaction: Towards efficient and stable water splitting

Oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) are critical processes in electrochemical water splitting, driving demand for efficient and durable electrocatalysts. This study presents a comprehensive evaluation of water splitting performance of ZnS@SnSe2 nano–composite in 1.0 M KOH solution. With ZnS nanoparticles decorated on SnSe2, exhibited remarkable catalytic activity for both HER and OER. ZnS@SnSe₂ composite demonstrated an low overpotential of 22 mV to reach a current density of 10 mA cm-2, outperforming ZnS (245 mV) and SnSe2 (280 mV). Furthermore, it achieved a Tafel slope of 25 mV dec‑1 and a charge transfer resistance (Rct) of 5.2 Ω, reflecting its enhanced kinetics compared to ZnS (101 mV dec‑1, Rct = 35 Ω) and SnSe2 (230 mV dec‑1, Rct = 7.5 Ω). These results are even competitive with benchmark Pt/C catalyst (30 mV overpotential, 46 mV dec‑1, and 2.2 Ω Rct), highlighting efficiency of composite for hydrogen production. For OER, ZnS@SnSe2 composite required an overpotential of 234 mV to reach 10 mA cm⁻², a substantial improvement over ZnS (361 mV) and SnSe2 (375 mV). Composite showcased a low Tafel slope of 48 mV dec‑1 and an Rct of 1.5 Ω, comparable to commercial RuO2 catalyst (44 mV dec‑1, Rct = 2.2 Ω), further underscoring its superior oxygen evolution capabilities. In practical device configuration, ZnS@SnSe₂/NF electrode achieved a Tafel slope of 21.335 mV dec‑1 for HER and 58.028 mV dec‑1 for OER, demonstrating its bifunctional efficiency in a two-electrode system. The device exhibited exceptional long-term stability over 50 h of continuous operation, highlighting its potential for scalable and sustainable water splitting applications.

Theoretical Procedure for Precise Evaluation of Chemical Enhancement in Molecular Surface-Enhanced Raman Scattering.

The enhancement of the molecular Raman signal in plasmon-assisted surface-enhanced Raman scattering (SERS) results from electromagnetic and chemical mechanisms, the latter determined to a large extent by the chemical interaction between the molecules and the hosting plasmonic nanoparticles. A precise quantification of the chemical mechanism in SERS based on quantum chemistry calculations is often challenging due to the interplay between the chemical and electromagnetic effects. Based on an atomistic description of the SERS signal, which includes the effect of strong field inhomogeneities, we introduce a comprehensive approach to evaluate the chemical enhancement in SERS, which conveniently removes the electromagnetic contribution inherent to any quantum calculation of the Raman polarization. Our approach uses density functional theory (DFT) and time-dependent DFT to compute the total SERS signal, together with the electromagnetic and chemical enhancement factors. We apply this framework to study the chemical enhancement of biphenyl-4,4'-dithiol embedded between two gold clusters. Although we find that for small clusters the total SERS enhancement is mainly determined by the chemical mechanism, our procedure enables removal of the electromagnetic contribution and isolation of the contribution of the bare chemical effect. This approach can be applied to reproduce and understand Raman line activation and strength in practical and challenging SERS configurations such as in plasmonic nano- and pico-cavities.

A Serious Game for the Digital Transformation of Organizations

To aid human resource management professionals design a configuration of human resource management practices that facilitates the employee behaviour needed for the digital transformation, a serious game was created. The serious game challenges human resource management professionals to combine and design human resource management practices that align to the organizational strategy and optimize employee digital transformation behaviour over multiple simulated years. In this paper, the underlying rationale, design, and outcomes of the first test rounds of the game are presented. Organizational change shaped by the diffusion of technology is labelled the digital transformation (Hanelt et al., 2021). Employees can accelerate or slow down the digital transformation. Hence, organizations are looking to facilitate digital transformation enhancing employee behaviours: adaptive performance and proactive agility behaviour (Collou and Bruinsma, 2022). Aligned human resource management configurations (i.e., combination of human resource management practices such as recruitment, selection, and job design) can shape that employee behaviour (Gratton and Truss, 2003; Delery and Doty, 1996). Designing such a human resource management configuration however is challenging. There are many human resource management practices that need to be designed over multiple years and effects on employee behaviour vary. Serious games are well suited tools to enhance understanding of challenges such as strategic human resource management design. They allow professionals to experiment with choices and gauge the outcomes of their selection without the need to test these decisions in real life. Prior work (Collou and Bruinsma, 2022, 2019) illustrated that a serious game can aid human resource management professionals in their quest to design human resource management configurations that align to the organizational strategy. In the current game an additional challenge was added: shaping digital transformation behaviour. Tested in multiple rounds the game shows great promise for professionals and students to experiment with human resource management configuration design. First evaluations illustrate that responders are positive in terms of their learning experience. Balancing the need to align the human resource management configuration and affecting the employee behaviour simultaneously has proven to be challenging for players of the game. Future steps are focused on this balance and empirically validating the serious game.

Harnessing dysprosium telluride/GPE as an effective electrode for energy storage and conversion

Hydrogen stands out as a clean alternative to fossil fuels, and its production via water electrolysis is promising, although the slow kinetics of the oxygen evolution reaction (OER) pose a significant challenge. Alongside energy conversion, the quest for effective energy storage remains critical. This study explores the potential of dysprosium telluride (Dy2Te3) as a highly efficient catalyst for OER and a supercapacitor electrode. The hydrothermally synthesized Dy2Te3 exhibits exceptional OER activity, characterized by an overpotential of 294 mV at 1.48 V vs. RHE, a low Tafel slope of 48 mV dec−1, and minimal interfacial resistance of 13 Ω. In a 1.0 M KOH solution, Dy2Te3 nanoparticles demonstrate outstanding supercapacitor performance, achieving a power density of 283.5 W kg−1, specific capacitance of 645.33 F g−1, and energy density of 22.8 Wh kg−1 at 1 A g−1. The high performance is attributed to enhanced electrical conductivity and a low impedance of 0.352 Ω in a three-electrode system. In a practical two-electrode configuration, Dy2Te3 nanoparticles deliver a specific capacitance of 479 F g−1, energy density of 94 Wh kg−1, and power density of 0.32 kW kg−1, with a reduced interfacial resistance of 1.03 Ω. These results underscore the potential of Dy2Te3 as a viable electrode material for both supercapacitors and water splitting, offering valuable insights into the application of lanthanide-based metal chalcogenides in energy technologies.

Everyday practices and needs as entry points for an operationalisation of more collective approaches to sufficiency

When it comes to grappling with both the environmental and social dimensions of energy transitions, sustainable wellbeing can be seen as a normative aim to be achieved through the satisfaction of human needs. This article exposes an engaging conceptual framework that describes the reduction of consumption through social practice theory, combined with a eudaimonic approach to wellbeing. Drawing on individual interviews with people who declare themselves as ‘living degrowth’ in French-speaking Switzerland, the article discusses everyday practices of consumption reduction that inform the actualisation of fundamental needs. The article proposes an operationalisation of Max-Neef’s approach of needs satisfaction, showing that an emphasis can be placed on sustainable practices representing synergic satisfiers. To support social change towards sufficiency, the article discusses that synergic satisfiers must be planned for collectively. Synergic collective changes are discussed in relation to synergic configurations of practices towards consumption reduction and needs satisfaction – or sufficiency.

Open-cycle thermochemical energy storage for building space heating: Practical system configurations and effective energy density

Salt-hydrate thermochemical materials (TCM) are promising candidates for energy storage systems for building space heating due to their high theoretical energy density and the need for low regeneration temperature. However, water vapor is required to drive the hydration process of the TCM reactor, which poses a challenge during winter when water vapor is typically scarce. Using indoor air directly lowers the building's humidity to an unconformable level in practice, while the cold outdoor air contains limited moisture. Here we consider different integration strategies for open-cycle TCM reactors in buildings and develop a model to simulate their thermal performance across diverse buildings and climates, specifically for building space heating. The potential energy densities and the levelized cost of storage of the TCM reactor are evaluated in practical scenarios to demonstrate the load-shifting potential of TCM systems for heating applications. We use a strontium chloride (SrCl2)-based composite as the baseline and explore the impact of various reactor and material changes to the energy density and levelized cost of storage.

Damage identification of reinforced concrete slabs using experimental modal testing and finite element model updating

Condition assessment and health monitoring of reinforced concrete structures is an essential part of their effective maintenance throughout their service life. Vibration-based damage detection and health monitoring is one of the most popular global approaches where experimentally measured modal parameters, such as frequencies, mode shapes, etc. are compared to their corresponding finite element counterparts to estimate possible stiffness loss. The present investigation implements a vibration-based parameter estimation algorithm for updating a finite-element (FE) model for damage assessment of reinforced concrete slabs using measured frequency response functions (FRF) data through a mixed numerical-experimental technique. An inverse eigen-sensitivity algorithm has been implemented to minimize the error function realized as the weighted differences in the mode shapes and frequencies of the FE model and the modal test data. Three reinforced concrete slabs were subjected to real physical damage conditions to verify the efficacy of the proposed methodology. The technique is found to be resilient in the presence of modal and coordinate sparsity. In general, damage can be assessed even if the portions of the structure are inaccessible to the users, thereby extending the possibility of its application to most of the practical configurations of reinforced concrete slabs.

Holistic development of rechargeable Metal-CO2-Mars battery chemistry for Mars exploration

The development of metal-CO2 batteries is a promising technology due to their high energy density and, more importantly, their ability to utilize the greenhouse gas carbon dioxide (CO2) as an energy carrier and, therefore, to combat the climate change effects. Furthermore, the metal-CO2 battery can offer great benefits in terms of energy storage and in-situ resource utilization for the interplanetary Mars mission, reducing overall mission cost, weight, and complexity. This work is a novel attempt to realize the feasible development of a metal-CO2Mars battery for Mars exploration. To the best of our knowledge, we hereby report the practical configuration of metal (X)-CO2Mars batteries (X = Li, Na and K) which is operated in a simulated Martian atmosphere for the first time. To develop a better fundamental understanding, we investigate the effective reversibility and discharge-reaction product formation of these metal-CO2Mars batteries. Further, the electrochemical performance and underlying mechanism of metal-CO2Mars batteries are evaluated using electrochemical testing (galvanic discharge-charge, cyclic voltammetry), potentiodynamic polarization, and Raman spectroscopy analysis, which are then later supported by first-principle calculation based on density functional theory. Thus, we believe that this work provide a rational design strategy for the practical development of metal-CO2Mars and metal-CO2 batteries.

Musical activity, show business and post-colonial politics in socialist Maputo, or ‘the multiple sides of a full circle’ (1975–1994)

ABSTRACT This article evaluates the configuration of musical practices in Mozambique’s capital city, Maputo, during the ‘socialist single-party period’ (1975–1994), focusing on changes in dancing venues and entertainment shows organized by companies like Produções 1001, Delta Produções, and the state-owned Empresa Moçambicana de Entretenimento (EME), which aimed to centralize all aspects related to música ligeira (literally ‘light music’) in the country. Through fieldwork interviews with politicians, producers, musicians, and archival research, this article elucidates the significance of musical activity and the entertainment industry in shaping the ‘sonorous construction’ of the ‘new Mozambican man’, as envisioned by FRELIMO. It explores numerous topics, including the initial prohibition of many venues in the early years of independence and the subsequent informal reversal of such decisions by 1994.

Anode-Free Lithium-Sulfur Batteries with a Rare-Earth Triflate as a Dual-Function Electrolyte Additive.

Anode-free lithium-sulfur batteries feature a cell design with a fully lithiated cathode and a bare current collector as an anode to control the total amount of lithium in the cell. The lithium stripping and deposition are key factors in designing an anode-free full cell to realize a practical cell configuration. To realize effective anode protection and achieve a good performance of the anode-free full cell, manipulation of the electrolyte chemistry toward the modification of the solid-electrolyte interphase on the anode is considered a feasible approach. In this study, the use of neodymium triflate, Nd(OTf)3, as a dual-function electrolyte additive is demonstrated to promote homogeneous catalysis on the cathode conversion reactions and the anode stabilization. Nd(OTf)3 not only facilitates the conversion reaction by promoting the polysulfide adsorption but also effectively protects the lithium-metal anode and stabilizes the lithium stripping and deposition during cycling. With this electrolyte modification, both Li∥Li2S half cells and Ni∥Li2S anode-free full cells support a high areal capacity of 5.5-7.0 mA h cm-2 and maintain a high Coulombic efficiency of 94-95% during cycling.

Can the best management practices resist the combined effects of climate and land-use changes on non-point source pollution control?

Climate and land-use changes have an overlying impact on non-point source (NPS) pollution in river basins. However, the control effect of Best Management Practices (BMPs) for NPS pollution is not yet clear under future scenarios. The Soil and Water Assessment Tool (SWAT) model was coupled with the entropy-weighted method, global climate patterns and land-use data to explore the dynamic variations in total nitrogen (TN) and total phosphorus (TP) loads in the Jing River Basin during the baseline (2000−2020) and future periods (2021–2065), evaluate the pollution reduction effectiveness of individual and combined BMPs, and propose practical BMP configurations. Results indicate that a future trend of urban land expansion, particularly in the economic scenario (LU_SSP585), leads to weakened environmental ecosystems, while the sustainable scenario (LU_SSP126) exhibits more balanced land development. The MIROC-ES2L model demonstrates higher Taylor skill scores, forecasted significant increases in precipitation, maximum, and minimum temperatures under the SSP585 scenario. Spatial heterogeneity in TN and TP loads is notable, showing an upward trajectory in the future. The interaction between land-use and climate change has complex effects on TN and TP loads, with land-use-induced TN changes being relatively small (4.6 %) and TP changes substantial (24.3 %). The spatial distribution, under overlying effects, leans towards the influence of climate change, emphasizing its dominant role in TN and TP load variations. Distinct differences exist in the reduction of NPS pollution loads among different BMPs, with combined BMPs demonstrating superior effectiveness. The environmental-cost effectiveness trends of BMPs remain consistent across various future scenarios. RG (Return agricultural land to grass), RG + TT (Terracing), and RG + FR10 (Fertilizer reduction: 10 %) + GW (Grassed waterway) + FS (Filter strip) + TT emerge as the most effective single, double, and multiple BMP combinations, respectively. The results offer valuable insights for preventing and mitigating future NPS pollution risks, optimizing land-use layouts, and enhancing watershed management decisions.

Piecewise nonlinear materials and Monotonicity Principle

This paper deals with the Monotonicity Principle (MP) for nonlinear materials with piecewise growth exponent. The results obtained are relevant because they enable the use of a fast imaging method based on MP, applied to a wide class of problems with two or more materials, at least one of which is nonlinear. The treatment is very general and makes it possible to model a wide range of practical configurations such as superconducting (SC), perfect electrical conducting (PEC) or perfect electrical insulating (PEI) materials. A key role is played by the average Dirichlet-to-Neumann operator, introduced in Corbo Esposito et al (2021 Inverse Problems 37 045012), where the MP for a single type of nonlinearity was treated. Realistic numerical examples confirm the theoretical findings.

Modelling circular economy capabilities and sustainable manufacturing practices for environmental performance: Assessing linear (PLS-SEM) and non-linear (fsQCA) effects

With the rising need to protect and preserve the environment coupled with pressure from stakeholders, businesses are looking for ways to minimise the harmful effects of their operations on the environment by enhancing their circular economy capabilities and implementing sustainable manufacturing practices. Most prior research has investigated how circular economy and sustainable manufacturing enhance environmental performance, but scant research has explored the configurational effects of circular economy capabilities and sustainable manufacturing practices on environmental performance. This study employs a multi-method approach on a sample of 285 manufacturing firms, to examine the effects of circular economy capabilities and sustainable manufacturing practices on environmental performance from the theoretical lenses of resource orchestration theory. First, the study uses PLS-SEM to determine the symmetric effects of circular economy capabilities and sustainable manufacturing practices on environmental performance. Second, the study adopts fsQCA to unravel the best permutation of circular economy capabilities, sustainable manufacturing practices, or (3) a combination of both circular economy capabilities and sustainable manufacturing practices to enhance or diminish environmental performance. We found that Sensing capabilities, Seizing capabilities, and Reconfiguring capabilities, as well as Sustainable product design, Sustainable manufacturing process, Sustainable Supply chain management, and Sustainable end-of-life management, have substantial effects on environmental performance. The finding further highlights that the configurations of circular economy capabilities and sustainable manufacturing practices rather than individual capabilities or practices strongly affect environmental performance. The findings support the value of circular economy capabilities and sustainable manufacturing practices for the manufacturing sector.

Beyond tree planting: Mobilizing a global production network for savanna restoration in Brazil

Emerging global production networks innovate the supply of restoration products and services to reverse degraded ecosystems globally. Yet, savanna restoration interventions often neglect diverse plant life forms and planting techniques in implementing large-scale pledges. Drawing on global production network analysis, we examine how the configuration of savanna restoration practices in Brazil influences decision-making processes and outcomes. Our assessment of a case study in Central Brazil reveals a myriad of forces affecting the interconnections between institutional drivers, markets, and supply systems for restoration actions across multiple scales. Prevailing policies and regulations often disregard diverse expertise, economic strategies, and socio-cultural perspectives when setting savanna restoration priorities and incentives. While we identify different buyers influencing market demands to meet mandatory or voluntary environmental compliance, a wide range of suppliers remakes savanna restoration actions according to regional contexts. The experiences of community-led plant material supply systems in Central Brazil showcase collective organization that enables situated socio-technical innovations to link a high diversity of non-tree species with livelihood outcomes. This study contributes to revealing how institutional drivers and restoration markets assert political authority and commercial objectives in multifaceted decisions, while community partnerships catalyze place-based savanna restoration innovations.

Investigation of GeSe Photovoltaic Device Performance via 1-Dimensional Computational Modelling

Germanium selenide (GeSe) is a potential absorber material for thin film solar cells. However, many physical, electronic parameters and practical defect configurations that result in different effects on the performance of GeSe solar cells are not fully understood. In this study, a baseline of a GeSe thin film solar cell was designed and simulated using SCAPS-1D simulator. The physical and electronic parameters of the absorber layer is varied to investigate their effect on the performance of the solar cell. The simulation uses absorption files extracted from Xue et al. 2016 and the SCAPS-1D absorption model. Practical defect configurations are also introduced in GeSe thin film solar cells to optimize solar cell performance. Simulation results show that baseline GeSe solar cells had obtained Voc 0.62 V, Jsc 39.52 mA/cm<sup>2</sup>, FF 79.34 and ƞ 19.48%. Simulation using the SCAPS-1D absorption model achieved a more accurate JSC contour graph compared to simulation using absorption files extracted from Xue et al. 2016. The highest efficiency of 26.13% was achieved at 1.40 eV bandgap, 4.27 eV electron affinity, 10 cm2/Vs hole mobility, 1E+18 1/cm<sup>3</sup> hole concentration and 2000 nm GeSe layer thickness. For bulk defect, an increase in defect concentrations or capture cross section hole and electron (σ) reduce efficiency. For interfacial defect GeSe/CdS, total density of 1E+12 1/cm<sup>2</sup> with σ of 1E-13 cm<sup>2</sup>, total density of 1E+18 1/cm2 with σ of 1E-19 cm<sup>2</sup>, total density of 1E+16 1/cm<sup>2</sup> and 1E+18 1/cm<sup>2</sup> with σ of 1E-16 cm<sup>2</sup> have critical impact to solar cell.

Towards greener hospitals: The effect of green organisational practices on climate change mitigation performance

Healthcare organisations have a significant carbon footprint due to their substantial energy consumption and waste generation. The existing literature has mostly focused on examining the isolated impact of specific green organisational practices on individual dimensions of environmental performance. Hence, policy makers and practitioners still lack a holistic view of how combinations of green organisational practices can mitigate the impact on climate change of healthcare organisations. Drawing on the practice-based view (PBV) of strategy, the study first examines the extent to which the adoption of imitable, individual green organisational practices impacts on the whole climate change mitigation performance of publicly owned hospitals. Second, it explores possible combinations of green organisational practices that can lead to high levels of climate change mitigation performance. Focusing on the illustrative case of publicly owned acute care hospitals in the English National Health Service and employing a two-stage Data Envelopment Analysis and a fuzzy set Qualitative Comparative Analysis (fsQCA), the analysis shows that the adoption of the practice of green energy procurement can, in isolation, positively lead to high climate change mitigation outcomes. Moreover, high performance levels can be achieved through multiple configurations of green organisational practices. Therefore, the findings suggest that the effectiveness of green organisational practices on climate change mitigation performance of hospitals depends on how practices are combined, rather than on their single effects, and indicate the presence of a complementary as well as a substitution effect between practices.