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A Symmetrical Winding Pattern for Common-Mode Noise Reduction in Inductive Power Transfer Systems
Get PDFIn high-power inductive power transfer (IPT) systems, ferrite layer and grounded shielding layer are usually adopted to mitigate the magnetic- and electric- field exposed to the environment. However, with substantial parasitic capacitance between the planar winding and the shielding layer, severe common-mode (CM) noise is generated with the excitation of high dv/dt along the planar windings. As a result, significant CM electromagnetic interference (EMI) is created, affecting the normal operation of nearby electronic equipment. In this letter, symmetry circuit is applied to mitigate the CM noise in IPT systems. To realize a fully symmetrical propagation path and enhance CM noise cancellation, a symmetrical pattern of planar winding is proposed to reduce the CM noise without additional component. A 3-kW IPT system is built in the lab, and the proposed symmetry circuit with symmetrical pattern of planar winding can achieve 30 dB of CM noise reduction, improving the electromagnetic compatibility of the IPT systems
Flexible authenticity: heritage remaking on modern buildings in Chan Street, Wenzhou, China
Get PDFAuthenticity is a core evaluation criterion in the field of architectural heritage. A review of heritage theories and international conventions shows that this criterion has continuously expanded and diversified over time. This is particularly evident in Western scholarship on heritage in the 1980s and the 1990s, for example, David Lowenthal’s work in “Critical Heritage Studies” argues that the essence of heritage should be regarded as a cultural production and exhibition. Heritage evolves dynamically, and its value is assigned by people, varying from person to person. This paper first discusses the theoretical foundations and implementation methods of heritage remaking. It then analyzes the project of Chan Street in historic Wenzhou, China, including its historical context, orientation, design strategies, and subsequent impacts. Through the case study, it illustrates how Chan Street has been transformed from a purely modern street to a “historical street”. The paper concludes with reflections on the ideas of authenticity, historic streets, historic quarters, and historical city conservation. The intention of this study is to exert a far-reaching influence on the future regeneration process of historical cities
Large-scale analysis of bacterial genomes reveals thousands of lytic phages
Get PDFPhages are typically classified as temperate, integrating into host genomes, or lytic, replicating and killing bacteria; for this reason, lytic phages are not expected in bacterial genome sequences. Here we analyse 3.6 million bacterial genome assemblies from 1,226 species and find 119,510 lytic phage genomes, which we term bacterial assembly-associated phage sequences. This represents a ~5-fold increase in the number of phages with associated hosts and raises questions about fundamental aspects of phage biology. Our analyses of bacterial assembly-associated phage sequences revealed previously undescribed phage clusters, including clusters distantly related to Salmonella Goslarviruses in Escherichia coli and Shigella, while also substantially expanding known genera such as Seoulvirus (from 16 to >300 members). Close relatives of lytic phages used therapeutically were also detected, suggesting clinical isolate sequencing unknowingly archives potential phage candidates. The discovery of complete, lytic phage genomes within bacterial assemblies challenges assumptions about the nature of the lytic lifestyle and reveals an untapped reservoir of phages
PMSM Control via Composite Logarithmic Sliding Mode Control
Get PDFNon-singular fast terminal sliding mode control (NFTSMC) is a promising control method for permanent magnet synchronous motor (PMSM) control due to its fast convergence speed. However, the presence of unknown disturbances poses a significant challenge to its performance. This article focuses on the fast position tracking and improved anti-disturbance performance for PMSM control system. The main contribution is a composite logarithmic sliding mode control (CLnSMC) scheme incorporating a disturbance observer (DOB) based on a novel sliding mode reaching law. This approach effectively mitigates the impact of unknown disturbances on the control system. The proposed scheme stands out by effectively integrating a disturbance observer (DOB) into the traditional LnSMC framework. This integration not only enhances the control performance but also enables the direct estimation and suppression of complex disturbances, thereby improving the robustness and reliability of the control system. Extensive simulation and semi-physical experimental studies have been carried out to verify the effectiveness of the proposed control strategy. The results show that the proposed CLnSMC outperforms NFTSMC in both transient response and steady-state performance
A new viscoelastic-continuum damage model for asphalt concrete with applications to cyclic indirect tensile fatigue tests
No full textThis paper aims to develop a new viscoelastic-continuum damage model for asphalt concrete under cyclic loading and validate its implementation in the finite element (FE) modelling for the cyclic indirect tensile (IDT) fatigue tests. The viscoelastic-continuum damage model and damage evolution law were proposed based on the continuum damage mechanics and pseudo J-integral Paris’ law. The model was then utilised in the experimental characterisations and implemented in the FE modelling. The long-term oven ageing, dynamic modulus, non-destructive cyclic IDT, IDT strength, and cyclic IDT fatigue tests were conducted on both field and laboratory asphalt cores to obtain the model inputs and to validate the FE model. Results show that the proposed model can accurately capture both non-destructive and destructive cycle-by-cycle strain responses of asphalt concrete via FE modelling. The mean absolute values of relative error in most cases are lower than 12% between the FE modelling and non-destructive tests. The FE modelled strain responses in the cyclic IDT fatigue tests match well with the experimental results, distinguishing different stages of strain evolutions. Besides, the present model can effectively characterise the different phases (damage initiation and propagation) of damage growth and different stages (deceleration, acceleration, and instability) of damage growth rate
Advancing asphalt pavement monitoring and prognostics with physics-informed digital twins: a feasibility study
Get PDFAsphalt pavements experience progressive deterioration from repeated traffic loads and environmental exposure, leading to premature failure and increased maintenance costs. Traditional monitoring methods fail to provide real-time insights into pavement health, limiting proactive maintenance strategies. This study establishes a framework for the development of a digital twin-enabled cyber-physical platform for the monitoring of asphalt pavements by leveraging the potential of modern sensors and physics engine software. The study combines embedded ‘smart rock’ sensors capable of capturing real-time mechanical responses of asphalt under varying loads and temperatures with physics informed virtual asphalt models developed using physics engines. Laboratory validation established strong agreement between the virtual model simulations and real asphalt performance data. This alignment provides a foundational breakthrough to correlate changes in mechanical behaviour with emerging distress patterns, enabling early damage detection and failure prediction. Overall, sensor-virtual model fusion can potentially enable proactive, self-updating road performance prediction via cyber-physical systems
Roadmap for Molecular Benchmarks in Nonadiabatic Dynamics
Get PDFSimulating the coupled electronic and nuclear response of a molecule to light excitation requires the application of nonadiabatic molecular dynamics. However, when faced with a specific photophysical or photochemical problem, selecting the most suitable theoretical approach from the wide array of available techniques is not a trivial task. The challenge is further complicated by the lack of systematic method comparisons and rigorous testing on realistic molecular systems. This absence of comprehensive molecular benchmarks remains a major obstacle to advances within the field of nonadiabatic molecular dynamics. A CECAM workshop, Standardizing Nonadiabatic Dynamics: Towards Common Benchmarks, was held in May 2024 to address this issue. This Perspective highlights the key challenges identified during the workshop in defining molecular benchmarks for nonadiabatic dynamics. Specifically, this work outlines some preliminary observations on essential components needed for simulations and proposes a roadmap aiming to establish, as an ultimate goal, a community-driven, standardized molecular benchmark set
A Multidimensional Machine Learning Study of Environmental Innovation and ESG Integration in BRICS Economies
Get PDFEnvironmental, social, and governance (ESG) performance has developed as a critical axis of business strategy, specifically within countries enduring institutional transformation and coping with extreme environmental exposures. This empirical study considers the degree to which environmental innovation improves ESG outcomes in BRICS economies (Brazil, Russia, India, China, and South Africa). Using a dataset from Refinitiv Eikon covering the 2009 to 2023 data, this study applies elastic net regression and a comprehensive stacked ensemble learning framework combining random forest, gradient boosting, ridge regression, and support vector machine (SVM) models to evaluate the predictive capability of environmental innovation with governance and firm-specific determinants. We find that environmental innovation positively influences ESG performance, suggesting environmental innovation is not only strategic, but also an important driver of corporate sustainability initiatives in emerging markets. Results reveal that institutional quality and CEO power moderate the relationship between environmental innovation and ESG. These insights feature the economically significant and contingent value of sustainability investments and offer actionable inferences for corporate leaders and policymakers
Effects of supplemental protein in older people: an overview of meta-analyses
Get PDFBackground Benefits of supplemental protein in older people in different health states and settings are uncertain. This review aimed to determine the effects of supplemental protein on health outcomes in older people. Methods An overview of reviews. Cochrane Library, MEDLINE (Ovid), EMBASE (Ovid), Cumulative Index to Nursing and Allied Health Literature (CINAHL) (EBSCOhost) and Google Scholar were searched from January 1990 to August 2024. Systematic reviews with meta-analyses reporting protein intake’s effect on health outcomes were included. Methodological quality was assessed using the Assessing Methodological Quality of Systematic Reviews 2 critical appraisal tool. Inconsistency between results from different reviews was explored by examining effects by population type [healthy people, living with long-term conditions (LTCs), hospital inpatients] and whether supplementation was given with or without concomitant exercise. Results Thirty-three reviews with meta-analyses collating data from 441 unique studies were included. There was no increase in muscle mass, strength or physical performance from protein supplementation in older people in general, nor in healthy older people. There was medium-certainty evidence of at least small increases in muscle mass and strength in older people with LTCs, and the benefits of protein supplementation were more certain with concomitant exercise. Evidence suggests that protein supplementation in hospital patients with hip fractures reduced the number of medical complications. Conclusion Protein supplementation is effective for improving muscle mass and strength in older people with LTCs and medical complications in older hospitalised patients with hip fractures. The evidence does not support its routine use in other groups of healthy older people
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