Digital Commons Network^™

Intelligent Beam Steering For Wireless Communication Using Programmable Metasurfaces, Nouman Ashraf, Taqwa Saeed, Hamidreza Taghvaee, Sergi Abadal, Vasos Vasos, Christos Liaskos Christos Liaskos, Andreas Pitsillides, Marios Lestas Marios Lestas

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Future generations of wireless communications are envisioned to provide several Gbps data rates per user for billions of users simultaneously [1]. The proliferation of billions of Internet of Things (IoT) devices in various industries has pushed wireless networks to their limits in terms of the required capacity to effectively communicate the vast amounts of data that are generated [2]. Moreover, the increasing number of IoT devices is changing mobile communication services from interpersonal communication to smart interconnection among billions of devices. 6G is expected to fulfill the requirements of a fully connected world and provide ubiquitous wireless connectivity for all …

Metaheuristic Optimization Techniques Used In Controlling Of An Active Magnetic Bearing System For High-Speed Machining Application, Suraj Suraj, Pabitra Kumar Biswas Pabitra Kumar Biswas, Sukanta Debnath, Anumoy Ghosh, Thanikanti Sudhakar Babu, Hossam Zawbaa, Salah Kemal

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Smart control tactics, wider stability region, rapid reaction time, and high-speed performance are essential requirements for any controller to provide a smooth, vibrationless, and efficient performance of an in-house fabricated active magnetic bearing (AMB) system. In this manuscript, three pre-eminent population-based metaheuristic optimization techniques: Genetic algorithm (GA), Particle swarm optimization (PSO), and Cuckoo search algorithm (CSA) are implemented one by one, to calculate optimized gain parameters of PID controller for the proposed closed-loop active magnetic bearing (AMB) system. Performance indices or, objective functions on which these optimization techniques are executed are integral absolute error (IAE), integral square error (ISE), integral …

Performance Improvement Of Hybrid System Based Dfig-Wind/Pv/Batteries Connected To Dc And Ac Grid By Applying Intelligent Control, Younes Sahri, Salah Tamalouzt, Sofia Lalouni Belaid, Mohit Bajaj, Sherif S.M. Ghoneim, Hossam Zawbaa, Salah Kamel

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One of the main causes of CO2 emissions is the production of electrical energy. Therefore, many researchers goal’s is to develop renewable power systems. This paper proposes a new intelligent control development of hybrid PV–Wind-Batteries. Neuro-Fuzzy Direct Power Control (NF-DPC) is invested in order to enhance system performance and generated currents quality. An improved MPPT algorithm based on Fuzzy Controller (FC) is invested for PV power optimization. In addition, a new Modified Fuzzy Direct Power Control (MF-DPC) is developed and applied to the grid side converter to control the active and reactive power by monitoring the involved active power flow …

Local Electricity Market Operation In Presence Of Residential Energy Storage In Low Voltage Distribution Network: Role Of Retail Market Pricing, Aziz Saif, Shafi K. Khadem Shafi K. Khadem, Michael Conlon, Brian Norton

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Local Electricity Market (LEM) appears as a promising consumer-centric market-based approach that extends the self-consumption method, widely implemented in residential households, to collective self-consumption in the local energy communities, enabled through peer-to-peer (P2P) transactions. To facilitate the integration of LEM in the wholesale electricity market (WEM), it is paramount to comprehend the synergy of retail electricity pricing on the LEM operation hosted in the low-voltage distribution network (LVDN). The paper presents a co-simulation framework consisting of a local electricity market model coupled with a three-phase distribution network simulator to perform a holistic case study for a smart energy community in …

Analysis And Design Of Secure Sampled-Data Control Subject To Denial-Of-Service Attacks, Hira Sana, Ghulam Mustafa, Owais Khan, Nouman Ashraf, Abdul Qayyum Khan, Muhammad Abid, Haroom Ur Rashid Khan

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This study addresses the issue of secure control design for cyber-physical systems (CPS) against denial of service (DoS) attacks. We take into account a continuous-time linear system with a convex quadratic performance measure and a sampled linear state feedback control. DoS attacks impose constraints on the CPS, where packets may be jammed between the sensor and controller by a malicious entity, potentially resulting in system instability and performance degradation. We assume that the attacker can perform DoS attacks with a limited time and frequency due to energy restrictions. We devise an efficient procedure using the linear matrix inequality approach to …

Nipuna: A Novel Optimizer Activation Function For Deep Neural Networks, Golla Madhu, Sandeep Kautish, Khalid Abdulaziz Alnowibet, Hossam Zawbaa, Ali Wagdy Mohamed

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In recent years, various deep neural networks with different learning paradigms have been widely employed in various applications, including medical diagnosis, image analysis, self-driving vehicles and others. The activation functions employed in deep neural networks have a huge impact on the training model and the reliability of the model. The Rectified Linear Unit (ReLU) has recently emerged as the most popular and extensively utilized activation function. ReLU has some flaws, such as the fact that it is only active when the units are positive during back-propagation and zero otherwise. This causes neurons to die (dying ReLU) and a shift in …

Collective Relaxation Processes In Nonchiral Nematics, Neelam Yadav, Yuri Panarin, Wanhe Jiang, Georg H. Mehl, Jagdish Vij

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Nematic–nematic transitions in a highly polar nematic compound are studied, in thick cells in which the molecules are aligned parallel to the substrates but perpendicular to the applied electric field, using dielectric spectroscopy in the frequency range 1 Hz to 10 MHz over a wide temperature range. The studied compound displays three nematic phases under cooling from the isotropic phase: ubiquitous nematic N; high polarizability NX; and ferroelectric nematic NF. Two collective processes were observed. The dielectric strength and relaxation frequency of one of the processes P2 showed a dependence on the thickness of the cell. The process P1 is …

Analysis Of Degradation Of Sb2se3 Thin Film Solar Cells Deploying A Time-Dependent Approach Linked With 1d-Amps Simulation, Ming-Lang Tseng, Malek Gassoumi, Nima Ghadiri

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In this paper, we have developed a time-dependent model to study defect growth in the absorber layer of Sb2Se3 thin film solar cells. This model has been integrated with the AMPS-1D simulation platform to investigate the impact of increasing defect density at different positions within the Sb2Se3 layer on the electrical parameters of the solar cell. We adopted the Gloeckler standard model for thin films in AMPS to represent Sb2Se3 materials. The study focuses on tracking the degradation of device performance parameters as donor-like mid-gap states accumulate in the Sb2Se3 layer over time. We monitored the variation of key electrical …

Interpreting Energy Utilisation With Shapley Additive Explanations By Defining A Synthetic Data Generator For Plausible Charging Sessions Of Electric Vehicles, Prasant Kumar Mohanty, Gayadhar Panda, Malabika Basu, Diptendu Sinha Roy

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Electric vehicles (EVs) are an effective solution for reducing reliance on non-renewable energy sources. However, the lack of charging infrastructure and concerns over their range are some of the biggest hurdles to adopting EVs. Charging infrastructure for EVs is, however, on the rise. Proper planning of charging stations vis-`a-vis road networks and related points of interest such as transportation hubs, schools, shopping centres, etc., alongside such roads become vital to laying out a plan for such infrastructure, particularly for developing countries like India where EV adoption is relatively in a nascent stage. Synthetic datasets can help overcome these hurdles and …

Lightnet: A Novel Lightweight Convolutional Network For Brain Tumor Segmentation In Healthcare, Dongyuan Wu, Junyi Tao, Zhen Qin, Rao Asad Mumtaz, Jin Qin, Linfang Yu, Jane Courtney

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Diagnosis, treatment planning, surveillance, and the monitoring of clinical trials for brain diseases all benefit greatly from neuroimaging-based tumor segmentation. Recently, Convolutional Neural Networks (CNNs) have demonstrated promising results in enhancing the efficiency of image-based brain tumor segmentation. Most current work on CNNs, however, is devoted to creating increasingly complicated convolution modules to improve performance, which in turn raises the computing cost of the model. This work proposes a simple and effective feed-forward CNN, LightNet (Light Network). Based on multi-path and multi-level, it replaces traditional convolutional methods with light operations, which reduces network parameters and redundant feature maps. In the …

Optical Properties Of Periodically And Aperiodically Nanostructured P-N Junctions, Z. Taliashvili, E Łusakowska E Łusakowska, S. Chusnutdinow, A. Tavkhelidze, L. Jangidze, S. Sikharulidze, Nima Ghadiri, Z. Chubinidze, R. Melkadze

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Recently, semiconductor nanograting layers have been introduced and their optical properties have been studied. Spectroscopic ellipsometry has shown that nanograting significantly modifies the dielectric function of c-Si layers. Photoluminescence spectroscopy reveals the emergence of an emission band with a remarkable peak structure. It has been observed that nanograting also alters the electronic and magnetic properties. In this study, we investigate the quantum efficiency and spectral response of Si p-n junctions fabricated using subwavelength grating layers and aperiodically nanostructured layers.

Wind Turbine Predictive Fault Diagnostics Based On A Novel Long Short-Term Memory Model, Shuo Zhang, Emma Robinson, Malabika Basu

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The operation and maintenance (O&M) issues of offshore wind turbines (WTs) are more challenging because of the harsh operational environment and hard accessibility. As sudden component failures within WTs bring about durable downtimes and significant revenue losses, condition monitoring and predictive fault diagnostic approaches must be developed to detect faults before they occur, thus preventing durable downtimes and costly unplanned maintenance. Based primarily on supervisory control and data acquisition (SCADA) data, thirty-three weighty features from operational data are extracted, and eight specific faults are categorised for fault predictions from status information. By providing a model-agnostic vector representation for time, Time2Vec …

Laser Structure Based On An Erbium-Doped Fiber Ring And A Whispering Gallery Mode Microbottle Resonator, Anuradha Rout, Zhe Wang, Zhuochen Wang, Yuliya Semenova

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A novel fiber laser structure, to the best of our knowledge, based on an erbium-doped fiber ring (EDFR) and a silica microbottle resonator (MBR) is proposed and investigated experimentally. Two fiber laser samples based on MBRs with different geometries and diameters of 200 and 150 µm are fabricated, and their performance is studied experimentally. Periodic whispering gallery mode spectra of the MBRs are dependent on the position of the fiber taper used for coupling of light into the MBR, and this dependence is explored to achieve lasing at different wavelengths by moving the light coupling point along the axis of …

An Evaluation Study On The Analysis Of People's Domestic Routines Based On Spatial, Temporal And Sequential Aspects, Aitor Arribas Velasco, John Mcgrory, Damon Berry

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The concept of collecting data on people's domestic routines is not novel. However, the methods and processes used to decipher these raw data and transform them into useful and appropriate information (i.e., sequence, duration, and timing derived from monitoring domestic routines) have presented challenges and are the focus of numerous research groups. But how are the results of the decoded transposition received, interpreted and used by the various professionals (e.g., occupational therapists and architects) who consume the information? This paper describes the inclusive evaluation process undertaken, which involved a selected group of stakeholders including health carers, engineers and end-users (not …

Understanding Professional Skills In Engineering Education: A Phenomenographic Study Of Faculty Conceptions, Una Beagon, Brian Bowe

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Abstract Background Globalization and socially complex problems will greatly affect the way engineers work in the future. Therefore, efforts to transform engineering education must focus on professional skills and engagement of faculty as key change agents.

Purpose/Hypotheses For engineering programs to address the needs of society, graduates must have the skills to tackle future challenges. Transformation will only be successful if faculty fully engage in all curriculum design aspects; however, little is known about how faculty view professional skills. This understanding is critical if we wish to support and encourage their participation in the transformation effort. This novel study reveals …

Investigation Of Oleic Acid As A Dispersant For Hydroxyapatite Powders For Use In Ceramic Filled Photo-Curable Resins For Stereolithography, Brendan Kennedy, Eamonn De Barra, Stuart Hampshire, Maura Kelleher

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Stereolithography allows production of porous hydroxyapatite scaffolds for bone regeneration but is limited by the challenging rheology of ceramic filled resins. Oleic acid, a natural fatty acid, was applied in concentrations of 0.0–0.3 wt% to improve the rheological properties of HAp resins for the fabrication of solid cylinders and scaffolds by digital light processing (DLP) printing in a wiperless system. Bonding by chemisorption was confirmed by FTIR analysis. The powders were then incorporated into a photo-curable resin of 1–6 hexanediol diacrylate at 18–30 vol%. The shear viscosity and sedimentation rates of photocurable resins containing HAp powder decreased with increasing concentration …

Thermodynamic Modelling Of Harsh Environments On The Solid Phase Assemblage Of Hydrating Cements Using Phreeqc, Niall Holmes Dr., Mark Tyrer, Denis Kelliher

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Poor durability of reinforced concrete structures can lead to serious structural failures. An accurate model to observe the effects of aggressive agents like carbonation, sulfate ingress, and seawater solutions on the solid phase assemblagewill help designers and specifiers better understand howcement behaves in these environments. This paper presents the first steps in developing such a model using the PHREEQC geochemical software by accounting for alkali binding and dissolution. It also presents the use of discrete solid phases (DSPs) to account for the solid-solution behaviour of siliceous hydrogarnet and magnesium silicate hydrate (M-S-H). A new thermodynamic description of the vaterite phase …

Quantifying Farm-To-Fork Greenhouse Gas Emissions For Five Dietary Patterns Across Europe And North America: A Pooled Analysis From 2009 To 2020, Daniel Burke, Paul Hynds, Anushree Priyadarshini

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Dietary patterns are inherently related to greenhouse (GHG) emissions via agricultural practices and food production systems. As the global population is predicted to increase from 8 billion (current) to 9.6 billion by 2050 added pressure will be placed on existing agricultural systems, resulting in increased GHG emissions thus exacerbating climate change. Therefore, there is an urgent need to understand present-day dietary patterns to shift to sustainable and healthy diets to mitigate GHG emissions and meet future climate targets. However, no review or pooled analyses of dietary pattern emissions from a farm-to-fork perspective has been undertaken to date. The current study …

Groundwater Quality: Global Challenges, Emerging Threats And Novel Approaches, Dan Lapworth, Thomas Boving, Bentje Brauns, Jane Dottridge, Paul Hynds, Seifu Kebede, David Kreamer, Bruce Misstear, Abhijit Mukherjee, Abhijit Mukherjee, Viviana Re, James Sorensen, Claudia Ruz Vargas

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Improving our understanding of groundwater quality threats to human health and the environment is essential to protect and manage groundwater resources effectively. This essay highlights some global groundwater quality challenges, describes key contaminant groups and threats of emerging concern, including antimicrobial resistance, and discusses novel approaches to assessing groundwater quality. Groundwater quality monitoring needs to improve significantly in order to effectively identify and mitigate threats to groundwater from historical, current and future pollution.

Identifying Novel Data-Driven Dietary Patterns Via Dimensionality Reduction And Associations With Socioeconomic Profile And Health Outcomes In Ireland, Daniel Burke, Annemarie E. Bennett, Paul Hynds, Anushree Priyadarshini

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Dietary patterns and body mass index (BMI) play a significant role in the development of noncommunicable diseases (NCDs), which are the leading cause of mortality worldwide, including Ireland. A cross-sectional survey was conducted across Ireland to collate respondents’ socioeconomic profiles, health status, and dietary patterns with a representative sample size of 957 adult respondents. Principal component analysis (PCA) and statistical analyses were subsequently employed. To the author’s knowledge, this is the first study to use recent (2021) nationally representative data to characterise dietary patterns in Ireland via dimensionality reduction. Five distinct dietary patterns (“meat-focused”, “dairy/ovo-focused”, “vegetable-focused”, “seafood-focused”, and “potatofocused”) were …

Wind Energy Harvesting And Conversion Systems: A Technical Review, Sinhara M. H. D. Perera, Ghanim Putrus, Michael Conlon, Mahinsasa Narayana, Keith Sunderland

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Wind energy harvesting for electricity generation has a significant role in overcoming the challenges involved with climate change and the energy resource implications involved with population growth and political unrest. Indeed, there has been significant growth in wind energy capacity worldwide with turbine capacity growing significantly over the last two decades. This confidence is echoed in the wind power market and global wind energy statistics. However, wind energy capture and utilisation has always been challenging. Appreciation of the wind as a resource makes for difficulties in modelling and the sensitivities of how the wind resource maps to energy production results …

Impact Of Distributed Energy Resources In Smart Homes And Community-Based Electricity Market, Aziz Saif, Shafi K. Khadem, Michael Conlon, Brian Norton

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Toward the achievement of decarbonised European smart grid network by 2050, the European Commission (EC) has given high importance to its “Clean Energy for all Europeans Package (CEP)” by empowering individuals and groups of consumers to participate in this energy transition. Such energy transition demands residential households to transform the energy-positive smart homes into energy-active smart homes, thus building a smart community. This transformation will expedite if the residential customers are provided with a better choice of supply, access to reliable energy prices, possibility to produce and sell their own electricity with increased transparency and better regulation for more involvement …

Fostering Spatial Ability Development In And For Authentic Stem Learning, Caiwei Zhu, Chloe Oi-Ying Leung, Eleni Lagoudaki, Mariana Velho, Natalia Segura-Caballero, Dietsje Jolles, Gavin Duffy, Gunter Maresch, Marianna Pagkratidou, Remke Klapwijk

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Empirical interdisciplinary research has explored the role of spatial ability in STEM learning and achievement. While most of this research indicates that fostering spatial thinking in educational contexts has the potential to positively impact students’ enrollment and performance in STEM subjects, there is less agreement on the best approach to do so. This article provides an overview of various types of effective spatial interventions and practices in formal or informal educational contexts, including targeted training of STEM-relevant spatial skills, spatialized curricula embedded in schools, integrated STEM practices addressing students’ use of spatial skills, and spatial activities in informal STEM education. …

An Experimental-Numerical Study Of Heat Transfer Enhancement In A Minichannel Using Asymmetric Pulsating Flows, Parth S. Kumavat, Sajad Alimohammad, Seamus M. O'Sullivan

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The development of current and next-generation high-performance electronic devices has led to miniaturization in more densely packed spaces. The increasing power levels have resulted in ever-increasing heat flux densities which necessitates the evolution of new liquid-based heat exchange technologies. Implementation of single-phase cooling systems using pulsating flow is viewed as a potential solution to the problems involving high energy density electronics. This work involves a combined experimental and numerical analysis of pulsating flows in a rectangular mini channel undergoing asymmetric sinusoidal flow pulsation formats. The mini channel design includes a heated bottom section approximated as a constant heat flux boundary …

The Effect Of Process Parameters On The Properties Of Elastic Melt Blown Nonwovens: Air Pressure And Dcd, Li Change, Yanfen Zhou, Stephen Jerrams, Jianwei Ma, Shaojuan Chen

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An elastic masterbatch and elastic melt blown nonwovens are prepared based successively on styrene-ethylene/butylene-styrene (SEBS) and polypropylene (PP) blend. The phase separation morphology, rheological properties and crystal structure of the elastic masterbatch are investigated. The results show that a compatible and stable structure is obtained in molten SEBS and PP blend with excellent mobility in the temperature range of 210–230C. The crystallization of PP slows down resulting in a finer structure due to the restriction of the SEBS network structure with rarely change of crystalline structure. The relationship between process parameters and properties of the elastic nonwoven is also studied …

Highly Stretchable And Sensitive Sbs/Gr/Cnts Fibers With Hierarchical Structure For Strain Sensors, Mengsui Liu, Yaping Sheng, Chenggang Huang, Chenggang Huang, Yanfen Zhou, Liang Jiang, Mingwei Tian, Shaojuan Chen, Stephen Jerrams, Fenglei Zhou, Jianyong Yu

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Most of the reported flexible strain sensors can only normally sense external stretch in a quite narrow working range and with low sensitivity. In order to overcome these drawbacks, elastomeric fiber based strain sensors incorporating graphene (Gr) and carbon nanotubes (CNTs) were initially fabricated via coaxial wet spinning. The solution etching method was employed for forming a 1D@2D@1D hierarchical structure, with pores and microcracks on fibers, to reconstruct their conductive networks. The solution etched fiber based strain sensors achieved a significant improvement in obtaining a high maximum gauge factor of 1667 and capability of working over a wide strain range …

Color-Changing Reflection Hologram For Quality Assurance Of Therapeutic Ultrasound Systems, Tatsiana Mikulchyk, John Walsh, Jacinta Browne, Izabela Naydenova, Dervil Cody

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The acoustic output of clinical therapeutic ultrasound equipment requires regular quality assurance (QA) testing to ensure the safety and efficacy of the treatment and that any potentially harmful deviations from the expected output power density are detected as soon as possible. A hologram, consisting of a reflection grating fabricated in an acrylate photopolymer film, has been developed to produce an immediate, visible, and permanent change in the color of the reconstructed hologram from red to green in response to incident ultrasound energy. The influence of the therapeutic ultrasound insonation parameters (exposure time, ultrasound power density, and proximity to the point …

Automation, Ai, And Future Skills Needs: An Irish Perspective, Raimunda Bukartaite, Daire Hooper

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This study explores insights from key stakeholders into the skills they believe will be necessary for the future of work as we become more reliant on artificial intelligence (AI) and technology. The study also seeks to understand what human resource policies and educational interventions are needed to support and take advantage of these changes.

Household Electricity Consumption: A Study On The Role Of Micro-Renewable Energy Systems In Vietnam, Luong Vinh Quoc Duy, Damien Cassells, Jim Hanly

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Although nearly all households in Vietnam have connected to the national grid, electricity shortage in the residential sector is still an issue. One measure of residential electricity shortage is the micro-renewable energy system (micro-RES), but little is known about the drivers for household adoption of such system and whether the presence of a micro-RES can help to reduce household energy consumption. This paper examines the characteristics of households that have adopted a micro-RES and investigates whether the presence of micro-RES would result in a decrease in energy demand by using fixed-effects models. Analysis was carried out on the 2016 and …

The Onus On Coal Consumption And The ‘Beautiful China Initiative’: Economic And Policy Implications, Daniel Rajmil, Lucia Morales, Bernadette Andreosso-O'Callaghan

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China’s need for rapid economic growth and its hunger for natural resources significantly challenge its economic and policy vision of sustainability, social stability and economic development. The ‘Beautiful China Initiative’ plans to put China on the path of sustainable development in line with the United Nations’ 2030 Agenda and its Sustainable Development Goals. The Chinese authorities are expected to reconsider traditional economic policy models to integrate environmental protection while ensuring that their economy proliferates. The shift from a traditional and heavy coal-dependent economy towards greener energy and a sustainable economic model brings additional challenges to China due to its historical …