A Novel Analytical Beam Formulation and Its Application on Composite Wind Turbine Blades

This paper presents a novel analytical formulation for modelling the mechanics of non-uniform and asymmetrical straight beams made of functionally graded materials (FGMs) and composites. This approach addresses the complexities caused by the asymmetry of the cross-section and those arising from the variations in geometry and material properties along the beam's axis by approximating these variations as stepped changes. It is assumed that each segment of the beam has constant properties, which are determined through the averaging of functions representing the actual property variations. This method enables efficient and accurate modelling/representation of beam structures such as wind turbine blades. The accuracy and reliability of the analytical model are verified through a comparison with the Technical University of Denmark (DTU) 10 MW reference wind turbine blade, considering two representative load cases (bending, BLC1 and torsional, BLC2) and confirming its ability to accurately predict the structural response. Furthermore, the study assesses the computational performance of the model, demonstrating its efficiency. This study contributes to the literature by providing a robust and computationally efficient approach for the analysis of wind turbine blades

Numerical investigation on cooling performance of phase change assisted direct ventilation system for data center

Traditional data centers often use mechanical cooling systems, leading to high energy consumption and waste of natural cooling resources. Thus, a novel phase change ventilation device that combines natural cooling with phase change storage has been designed to maintain continuous natural cooling of the data center by storing cold energy from the natural cold air using phase change plates (PCPs), and eliminate the reliance on mechanical refrigeration in traditional data centers and achieving energy savings. In this study, the cooling performance of the proposed device is numerically analyzed and the feasibility of the model is verified by experiments, filling the research gap in data centers for this method. Considering main effectors, i.e., the inlet air velocity (IAV), inlet air temperature (IAT), phase change plate thickness (PCPT), phase change temperature (PCT), and thermal conductivity of encapsulation material (TCEM) on the cooling performance of the device. The results show that: (1) Phase change ventilation device can reduce the IAT of 34 °C by an average of 2.53 °C within 8 h (2) When the IAV increases from 1 m/s to 4 m/s, the average cooling performance of the phase change ventilation device decreases by 62.93 %. (3) In the phase change latent heat stage, the temperature difference (TD) of phase change ventilation device decreases almost linearly over time. (4) The significance analysis of orthogonal experiment shows the impact of various factors on the cooling performance of phase change ventilation device as follows: IAV > IAT > PCPT > PCT > TCEM

Effect of gas nuclei on the primary stage of shock–droplet interaction

The presence of entrapped gas in liquids is well-documented, arising from gas solubility, surface irregularities, or prior phase-change events. In this study, simulations are carried out replicating an experiment involving a Mach 2.4 Planar shock interacting with a cylindrical water column, and the results are benchmarked against experimental pressure measurements in which the presence of entrapped air is reported. The liquid droplet is modelled as a homogeneous mixture of liquid and gas using a multiphase flow framework, and a novel relaxation approach is introduced to capture non-equilibrium effects within the mixture region. The effects of Gaseous Volume Fraction (GVF) and relaxation rate on shock attenuation, wave propagation speed, and cavitation are explored. The results reveal that increasing GVF enhances shock attenuation and slows down the wave propagation speed due to the mixture’s higher compressibility. A non-monotonic relationship between relaxation rate and pressure peak intensity is observed, governed by the effect of the relaxation rate on shock diffusivity, with maximum attenuation occurring at intermediate rates. At high GVF, the low wave propagation speed leads to an interaction between the shocks formed internally and around the droplet, which suppresses the rarefaction wave formation. Regarding cavitation, results indicate that lower GVF promotes stronger gas growth due to less shock attenuation. Finally, this study provides a physical explanation for the temporal pressure variations reported in prior numerical works and highlights the critical role of entrapped gas in shock–droplet interaction dynamics

The impact of the Great War of 1914-18 on tourism in the UK: Implications for tourism research

This paper examines an overlooked feature of tourism management – the relationship between the state, the population and their holidaytaking habits and behaviour during World War One in the UK. The paper provides a series of important insights into a period of traumatic social and economic change to illustrate how a state anti-tourism policy evolved, utilising various policy sanctions and tools to try and limit the demand for holidays and leisure travel. The research is paradigm shifting in terms of addressing a major research gap and misconceptions that the war led to a cessation of tourism, or constitutes a period of limited research interest. As a study of tourism management and policy, it demonstrates the protracted problem of seeking to change tourist behaviour, even in periods of major crises and global upheaval that offers important lessons for governments and other policymakers in addressing issues such as overtourism and sustainable tourism

Automated novel real-time framework for rainfall data imputation in flood early warning systems

Real-time flood warning systems play a crucial role in mitigating impacts of flooding. However, their performance is highly dependent on input data, which can often contain missing values. While data imputation techniques have been widely applied in pre-processing stages, their integration into real-time operations remains underexplored. This study presents a real-time automated decision support system that integrates a soft-voting stacked data mining ensemble model comprising decision tree, K-nearest neighbour, Naive Bayes, Neural Network, Support Vector Machine, Discriminant Analysis, and Gaussian Regression. The system also incorporates hydrological–hydraulic event identification, external benchmarking, and a multi-data fuzzy weighted spatial imputation framework. The effectiveness of the proposed method was evaluated through a real-world case study involving a flood early warning system in an urban drainage network in London, UK. Comparative analyses were conducted against well-established artificial intelligence model, and a sensitivity analysis was performed for further assessment. Results showed that all types of missing data were correctly identified with a precision exceeding 90 % and were accurately imputed - particularly in situations where other models failed to recognise current rainfall values during the onset, peak, and falling limb of events (with no reduction in accuracy compared to the best-performing benchmark models). For the 3-h-ahead flood forecasting, the proposed method reduced the normalised root mean square error by up to 30 % compared to alternative approaches. To ensure the generalisability of the approach, additional locations across the UK were used for validation, which demonstrates the stability and robustness of the system, with only minor error variations

Inhibition of levodopa-induced abnormal involuntary movements (AIMs) using a selective α7 nicotinic positive allosteric modulator

Chronic administration of nicotine and nicotinic ligands have been shown to reduce levodopa-induced dyskinesia (LID) in rodents and primates. Due to its unique extra-striatal localisation and biochemical signalling properties, the α7 subtype of nicotinic acetylcholine receptors (nAChRs) may represent an important and unique target for drug development for the treatment of dyskinesia, particularly since positive allosteric modulator (PAM) at the α7 nAChRs subtype may provide an opportunity to reduce dyskinesia without side effects. In this study, we report on the anti-dyskinetic actions of a selective α7 PAM, PNU-120596 and compared its action to nicotine and other α7 nAChRs ligands. Unilaterally 6-OHDA lesioned female rats were primed with levodopa to display abnormal involuntary movements (AIMs) to model levodopa-induced dyskinesia. The effects of the α7 PAM, PNU-120596, an α7 agonist, PHA-543613 or the α7 antagonist, methyllycaconitine (MLA), as well as nicotine, a non-selective nAChR agonist were all examined on AIMs. Low doses of PNU-120596 and nicotine dose-dependently reduced AIMs, but combination of the PAM with nicotine produced only an additive effect which surprisingly, could not be demonstrated with the α7 agonist PHA-543613, while MLA dose-dependently reduced AIMS. The effects of PNU-120596 suggests that α7 PAMs may enhance the effect of basal acetylcholine on α7 receptors in the striatum and may provide a new avenue for the treatment of levodopa-induced dyskinesia. Reduction of AIMs by MLA suggests that the mechanism of AIMs reduction may involve the rapid desensitization of the α7 nAChRs subtype

Principles in practice? A policy review of the IOC’s environmental sustainability agenda.

This paper is a policy review focused on the environmental sustainability (ES) agenda of the International Olympic Committee (IOC). This incorporates exploration of IOC documents such as policies, strategies, guidelines, reports, codes, and conference outputs. The IOC's ES agenda is interpreted as both strategy around ES, as a plan of action to achieve desired outcomes, and policies around ES, as matters of practice and principle to be enacted. This review encompasses each of the IOC's three spheres of activity (as an organisation, as owner of the Olympic Games, and as leader of the Olympic Movement). The documentary analysis incorporates inductive thematic analysis and Critical Policy Discourse Analysis (CPDA). This allows for consideration of the role of the IOC as a driver of ES with the power and reach to influence pro-environmental behaviours on a global scale, as well as analysis of the extent to which documentary discourse demonstrates committed leadership in this sphere. Key themes arising from the data are networks and knowledge transfer, leadership and influence, governance and accountability, and opportunities and obstacles. Power relationships between stakeholders are important in terms of facilitating or inhibiting ES, and there are missed opportunities for the IOC both to better demonstrate positive ES outcomes from existing practices and to utilise its power in leveraging ES commitments from stakeholders across the Olympic Movement (OM). The application of CPDA highlights varying levels of commitment across these themes as well as a tendency toward ambiguity and contradiction that engenders the likelihood of unintended consequences including greenwashing. The IOC ES agenda needs to encompass clear and unambiguous policy and strategy with more explicit commitment and accountability across its three spheres of activity

Experimental study on improving thermal management of fan-wall data center by setting baffles in cold aisle

To maintain a stable thermal environment in the data center, the air conditioning system operates at high energy consumption levels annually. The airflow organization within the data center significantly impacts the cooling effectiveness of the air conditioning system. To achieve uniform airflow distribution, this study explores the effects of vertical and horizontal baffles placed between the air supply outlet and rack, both individually and in combination. This study explores the applicability of baffles in fan-wall data centers, analyzing and obtaining the optimal baffle angle, spacing, distance, and their corresponding thermal environment. This research aims to provide an optimized solution for enhancing thermal conditions within server rooms. The results indicate that: (1) Both vertical and horizontal baffles can improve the cold air trajectory from the air supply outlet to the rack, effectively improving the thermal environment of the rack. (2) Implementing a single vertical baffle at a distance of 0 cm and an angle of 75° effectively eliminates heat accumulation and achieves uniform temperature distribution. (3) When vertical or horizontal baffles are arranged individually, distance has a significant impact on airflow organization, however, when both vertical and horizontal baffles are combined, the influence of distance is minimal

Label-free multiplexed detection of diabetic retinopathy biomarkers using fiber optic biosensors: Towards lab-in-the-tear

Diabetic retinopathy is a common disease in diabetic patients accompanied by such complications as edema, formation of hard exudates, hemorrhages, and eventually vision loss. Detection of the disease at an early stage could increase the effectiveness of therapy and preserve the patient's vision. Measuring the levels of diabetic retinopathy-associated biomarkers using more reliable methods is an alternative and promising way of diagnosis. Optical fiber biosensors have gained rising popularity in providing affordable platforms due to their high-performance capabilities, miniature size, and label-free nature of detection. These properties made them a sensor of choice for developing biosensors for a multiplexed in situ detection of biomarkers in this study. Here, we report an optical fiber-based biosensor that is based on simply fabricated semi-distributed interferometry sensors. After fabrication, sensitive sensors were chosen for further functionalization with two antibodies against biomarkers relevant to diabetic retinopathy to produce biosensors. The detection of the biomarkers was evaluated in artificial tear fluid in static conditions and most importantly in dynamic conditions simulating natural tear flow. This method allowed label-free monitoring of the intensity change with the increasing concentrations of analytes specifically binding on the biosensor surface. Namely, it was possible to detect lipocalin 1 protein with a limit of detection of 5.98 ng/mL and vascular endothelial growth factor down to 26.6 fg/mL. The designed biosensors can become the basis for developing a new method for a clinical diagnosis of eye diseases at early stages of development