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Large Eddy Simulation of environmental impacts on mass transport in laboratory-scale vertical farm
No full textPublisher Copyright: © 2025 The Authors.The impact of environmental factors on airflow and mass transport within a laboratory-scale vertical farm is investigated using Computational Fluid Dynamics. Large Eddy Simulation models complex airflow behaviour, while solving enthalpy and mass transport equations yields temperature, humidity, and CO2 concentration. The Eulerian-Lagrangian approach simulates the free-fall of water droplets in the dehumidifier-cooling system. Humidity and CO2 consumption/production by plants and utilities are modelled as volumetric sources/sinks. An experimental campaign is conducted to measure temperature, relative humidity, and CO2 above cultivation beds, validating the numerical setup with mean absolute errors of 0.8%, 2.2%, and 3.9%, respectively. Analysing the airflow shows that the free fall of droplets is the dominant mechanism driving airflow characteristics. We investigate the effects of wall confinement, number of lamps, and location of lamps on the mass transport. Curtains were used to divide each cultivation bed into three regions to assess the wall confinement effect. Results show the overall adverse effect of curtains on mass transport. In more detail, mass transport is enhanced when the curtains and streamlines are aligned parallel, whereas it is reduced when they are perpendicular. Increasing the number of operative lamps improves the uniformity of mass distribution on the upper cultivation beds due to a stronger positive buoyancy. Positioning lamp-induced buoyant flow within the droplet’s lateral momentum injection zone further enhances vertical mass transport. These findings highlight the impact of environmental factors on mass transport, offering insights for more efficient designs of indoor vertical farms.Peer reviewe
Spacing Resistance in a Business School Relocation
No full textIn this paper, we offer an in-depth longitudinal study of a business school relocation. Focusing on the relationship between spatial practices and resistance over time, we show how faculty appropriated, reappropriated, and disappropriated their business school space, and how this “spacing” built, modified, and diluted resistance to the managerially driven relocation. Our contribution is threefold. First, we theorize resistance to managerialism in business schools as processually enacted in and through faculty’s spatial practices. Second, we theorize the contested character of organizational space as it emerges through intertwined spatial practices. Third, we elucidate how combining ethnographic inquiry with collaborative autoethnography offers a meaningful new methodological approach to exploring the business of business schools. Overall, the paper offers insights into how the potentiality of business school spaces as spaces of resistance can be realized, understood, and empirically studied.Peer reviewe
Perspective : Topological photonics in nanoscaled systems with far-field radiation and polarization singularities
No full textPublisher Copyright: © 2025 Author(s).Topology is a powerful framework for controlling and manipulating light, minimizing detrimental perturbations on the photonic properties. Combining nanophotonics with topological concepts presents opportunities for both fundamental physics and technological applications. Although most topological photonic realizations have been inspired by condensed-matter analogue models, new topological ideas have just begun to be realized at the nanoscale. Nanophotonics is characterized by subtle phenomena that are not usually considered in other topological models' realizations, such as nonlocality, strong field confinement, and light radiating to the far-field continuum. In this perspective, we will discuss how standard topological band theory for photonic crystals needs to be extended by a more comprehensive approach that properly treats such nanophotonic intrinsic effects and, in particular, the interplay of polarization and far-field radiation. We highlight the emerging role that polarization singularities might play in defining the topological invariants in the far field, which are not fully captured by bulk observables alone. We conclude by outlining a set of open questions and promising directions for exploring novel concepts in topological nanophotonics and shaping next-generation photonic devices.Peer reviewe
Application of deep dehumidification technology in low-humidity industry : A review
No full textFunding Information: This work was supported by the Fundamental Research Funds for Beijing University of Civil Engineering and Architecture . And sponsored by the Beijing University of Civil Engineering and Architecture Post Graduate Innovation Project [ DG2023010 ]. Publisher Copyright: © 2024 Elsevier LtdHumidity regulation plays a pivotal role in both residential and industrial environments, significantly impacting comfort, health, and process efficiency. The integration of dehumidification systems with air conditioning systems allows for the control of temperature and humidity, resulting in a decrease in carbon dioxide emissions. In order to address the demands of industries with low humidity levels, this study offers a comprehensive review of advanced deep dehumidification systems. The study initially delineates the specific ranges for deep dehumidification as outlined in academic research, as well as the humidity levels in low-humidity industries. Evaluation models are proposed for the analysis of the dehumidification performance, energy efficiency, economic feasibility, and environmental impact of the system. The review focuses on the deep dehumidification technology, which encompasses air compression dehumidification, liquid desiccant dehumidification, solid desiccant dehumidification, membrane dehumidification, and coupled dehumidification, with an emphasis on materials, components, and systems flow. The research provides a comprehensive overview of the various potential applications of dehumidification systems, including air humidification, water collection, air purification, intelligent control, and optimization. Moreover, a comprehensive comparative analysis of different dehumidification technologies is conducted with regard to industrial application humidity requirements, energy performance, economic factors, and environmental considerations. Drawing on advanced studies and findings, this research examines the primary areas for future development in advancing deep dehumidification systems. The objective of this study is to propose optimization techniques aimed at enhancing dehumidification efficiency and reducing energy consumption in low-humidity industrial settings.Peer reviewe
Experimental investigation on flue gas condensation heat recovery system integrated with heat pump and spray heat exchanger
No full textPublisher Copyright: © 2024To deeply recover the flue gas condensation heat, a flue gas condensation heat recovery system that combines a compression heat pump (FGCHR-HP) is proposed. An experimental bench of the FGCHR-HP system was established to explore the thermal properties of the system under variable operating conditions. The experimental results show that when the inlet water temperature of the heat pump condensing heat exchanger is 50 °C and the flow rate is 40 L/min, the optimal experimental conditions are achieved. Under this working condition, the heat efficiency is 13.8 %, and the exhaust gas temperature is 26.9 °C. At the same time, the flue gas moisture recovery is up to 6.5–7.0 kg/hour, which is better than other boilers.The payback period of the FGCHR-HP system is 3.4 years. The system has achieved significant energy-saving and water-saving effects, and has certain promotion and application prospects.Peer reviewe
A modified zeolite (Na2SO4 @zeolite NaA) as a novel adsorbent for radium-226,228 from acidic radioactive wastewater : Synthesis, characterization and testing
No full textPublisher Copyright: © 2024 Elsevier LtdThe radiological contamination with radium in oil and gas production is challenging environmental and health concerns. This study investigated the synthesis of zeolite NaA modified with Na2SO4 (Na2SO4@zeolite NaA) hydrothermal method and subsequent use as an adsorbent along with manganese dioxide (MnO2) for removing radium isotopes (226Ra and 228Ra) from acidic radioactive wastewater (ARW). ARW was generated through acidic sequential leaching of petroleum-based organic soils collected from the South Rumaila fields in the Basra Governorate, Iraq. The optimum adsorption parameters were MnO2: Na2SO4@zeolite NaA mass ratio of 1:0.5 g.g−1 and a pH of 6.3 resulting in maximum removal of 78.7% and 66.7% for 226Ra and 228Ra, respectively. Higher levels of removal were not attainable due to co-elements effect. The adsorption was endothermic with cation exchange of Na+ with Ra2+ being the main mechanism. The incorporation of Na2SO4 increased the exchange sites available for Ra2+ and the surface area and pore size available for facilitating such reactions. The exhausted column was regenerated and subsequently used for five cycles with a small drop in the removal of 226Ra and 228Ra by 11% and 9.5%, respectively highlighting the propitious application of Na2SO4@zeolite NaA and MnO for treating contaminated wastewater in oil fields.Peer reviewe
Disorder- and Interaction-Driven Quantum Criticality in WSe2
No full textPublisher Copyright: © 2025 American Chemical Society. | openaire: EC/H2020/834742/EU//ATOP | openaire: EC/H2020/872049/EU//IPN-BioQuantum fluctuations resulting from strong Coulomb interactions or strong disorders lead to quantum phase transitions (QPTs) in 2D materials. However, understanding of disorder- and interaction-driven QPTs remains a fundamental challenge in 2D materials owing to the presence of strong disorder and strong Coulomb interactions. Here, we study the systematic interplay of strong disorder and strong Coulomb interactions by controlling the thickness of WSe2 to elucidate the disorder- and interaction-driven metal-insulator QPTs. An observation of metal-insulator transitions (MITs) with a conductivity of ∼e2/h in thin-WSe2 agrees with the Mott-Ioffe-Regel limit, excluding bad-metal behavior; conversely, MITs with a conductivity of <e2/h demonstrate the bad-metal behavior in thick-WSe2. We observe the distinct temperature dependences of resistivity, which unveil anomalous metallic transport in WSe2. Furthermore, the emergence of the metallic glass phase (MGP) in thin-WSe2 underscores the significant role of strong disorder and strong Coulomb interactions. Contrarily, the absence of the MGP in thick-WSe2 suggests that the Coulomb interactions dominate over the disorder. Finally, the successful scaling collapse of conductivity reveals the disorder-dominated quantum criticality in thin-WSe2 and interaction-driven Mott quantum criticality in thick-WSe2. This study provides compelling evidence that thickness-dependent WSe2 could be an exciting testbed to understand anomalous metallic transport and metal-insulator QPTs in 2D materials.Peer reviewe
Year-on-year analysis of multi-modal digital travel diaries: Temporal, spatial and modal traveler profiles
No full textUnderstanding multi-modal urban mobility patterns is essential for effective planning and policy-making. Traditional data sources, such as infrequent surveys or smart card records, often lack the temporal, spatial, and modal comprehensiveness required to fully capture the complexity of multi-modal travel behavior. Emerging mobility data sources are instrumental in capturing these patterns and in enabling additional insights. This study leverages a digitally collected trajectory-level dataset (i.e., TravelSense) obtained from a smartphone application operated by the public transport authority of Helsinki, Finland. Unlike conventional public transport data, TravelSense provides insights into modal choices alongside temporal and spatial travel characteristics. In order to analyze mobility patterns and explore the capabilities of this novel dateset, a Latent Profile Analysis is employed to classify travelers based on these attributes over a week-long period, with profiles compared across three consecutive years (2022, 2023, and 2024). Findings reveal that while spatial travel patterns remain relatively stable, temporal and modal patterns exhibit greater variability. A distinct shift is observed between 2022 and subsequent years, likely reflecting post-pandemic behavioral changes. Key traveler groups identified include exclusive active mode users (13 % annually) and non-private car users, whose share declined from 38 % in 2022 to approximately 20 % in 2023 and 2024. Study findings offer valuable input for shaping evidence-based mobility policies, particularly those aiming to support sustainable travel behavior and adapt to evolving urban mobility needs through enhanced multi-modality. TravelSense enables detailed analysis of temporal, spatial, and modal travel patterns, underscoring the value of novel data for multi-modal transport research.Peer reviewe
Experimental comparison of structural and active protective methods against breath- and cough-borne aerosols in a meeting room
No full textPublisher Copyright: © 2024 Elsevier LtdIn this experimental study, the focus is to address the challenges of cross-contamination due to the presence of an infected individual in a meeting room environment. A detailed analysis is performed to identify effective methods to reduce the spread of infectious aerosols generated due to breathing and coughing. Infectious aerosols are simulated using a Paraffin oil-based solution with a respiratory exhalation simulator integrated with a breathing/coughing machine and an atomizer. Filtration-based active strategies such as the room air purifier, personal air purifier, and facemasks (FFP2 and surgical) along their wearing patterns are examined and compared with structural measures such as face shields and partition walls. The impact of the infectors' location on the exposed person is also studied. Facemasks are the most effective protective measure for both examined respiratory activities and provide over 60 % protection. Other mitigating strategies behaved differently for breathing and coughing trials. In the well-mixed room, during breathing, the portable room air purifier designed for clean air delivery rates (CADR) 2.5 times the ventilation rate effectively reduced aerosol spread. A personal air purifier, with a flow rate of 0.02 times the ventilation rate, offered only partial protection to the exposed occupant. Structural partitions showed marginal effectiveness for breathing but were effective during coughing events. The infector's location has little impact on contaminant levels in a well-mixed meeting room, except for a slight increase when seated next to the exposed person. This study provides a valuable reference for using different mitigation strategies in indoor settings.Peer reviewe
Convex body domination for rough singular integrals
No full textPublisher Copyright: © 2025 The AuthorConvex body domination is a technique, where operators acting on vector-valued functions are estimated via certain convex body averages of the input functions. This domination lets one deduce various matrix weighted bounds for these operators and their commutators. In this paper, we extend the sparse domination results for rough singular integrals due to Conde-Alonso, Culiuc, Di Plinio and Ou to the convex body setting. In particular, our methods apply to homogeneous rough singular integrals with unbounded angular part. We also note that convex body domination implies new two weight commutator bounds even in the scalar case.Peer reviewe