Dynamic stall phenomena bring risk for negative damping and instability in wind turbine blades. It is crucial to model these phenomena accurately to reduce inaccuracies in predicting design driving (fatigue) loads. Inaccuracies in currentdynamic stall models may be due to the facts that they are not properly designed for high angles of attack, and that they do not 10 specifically describe vortex shedding behaviour. The Snel second order dynamic stall model attempts to explicitly model unsteady vortex shedding. This model could therefore be a valuable addition to DNV GL’s turbine design software Bladed. In this thesis the model has been validated with oscillating airfoil experiments and improvements have been proposed for reducing inaccuracies. The proposed changes led to an overall reduction in error between the model and experimental data. Furthermore the vibration frequency prediction improved significantly. The improved model has been implemented in Bladed and tested 15 against small scale turbine experiments at parked conditions. At high angles of attack the model looks promising for reducing mismatches between predicated and measured (fatigue) loading. Leading to possible lower safety factors for design and more cost efficient designs for future wind turbines.
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Dynamic stall phenomena carry the risk of negative damping and instability in wind turbine blades. It is crucial to model these phenomena accurately to reduce inaccuracies in predicting design driving (fatigue and extreme) loads. Some of the inaccuracies in current dynamic stall models may be due to the fact that they are not properly designed for high angles of attack and that they do not specifically describe vortex shedding behaviour. The Snel second-order dynamic stall model attempts to explicitly model unsteady vortex shedding. This model could therefore be a valuable addition to a turbine design software such as Bladed. In this paper the model has been validated with oscillating aerofoil experiments, and improvements have been proposed for reducing inaccuracies. The proposed changes led to an overall reduction in error between the model and experimental data. Furthermore the vibration frequency prediction improved significantly. The improved model has been implemented in Bladed and tested against small-scale turbine experiments at parked conditions. At high angles of attack the model looks promising for reducing mismatches between predicted and measured (fatigue and extreme) loading, leading to possible lower safety factors for design and more cost-efficient designs for future wind turbines.
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Horizontal axis wind turbines (HAWTs) experience three-dimensional rotational and unsteady aerodynamic phenomena at the rotor blades sections. These highlyunsteady three-dimensional effects have a dramatic impact on the aerodynamic load distributions on the blades, in particular, when they occur at high angles of attack due to stall delay and dynamic stall. Unfortunately, there is no complete understanding of the flow physics yet at these unsteady 3D flow conditions, and hence, the existing published theoretical models are often incapable of modelling the impact on the turbine response realistically. The purpose of this paper is to provide an insight on the combined influence of the stall delay and dynamic stall on the blade load history of wind turbines in controlled and uncontrolled conditions. New dynamic stall vortex and nonlinear tangential force coefficient modules, which integrally take into account the three dimensional rotational effect, are also proposed in this paper. This module along with the unsteady influence of turbulent wind speed and tower shadow is implemented in a blade element momentum (BEM) model to estimate the aerodynamic loads on a rotating blade more accurately. This work presents an important step to help modelling the combined influence of the stall delay and dynamic stall onthe load history of the rotating wind turbine blades which is vital to have lighter turbine blades and improved wind turbine design systems.
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Urban tourism increasingly focuses on the role of hospitality in cities, evolving from a means to strengthen tourism as a ‘product’, towards a focus on tourism as an opportunity for revitalization and transformation of destinations. In this context, cities are considered dynamic communities in which ‘hosts’ (entrepreneurs, residents, municipalities) and ‘guests’ (visitors, tourists) co-habitate and co-create multisensorial experiences. This shift in focus comes hand in hand with increasing awareness of competitiveness and sustainability of destinations, expressed by a harmonious relationship between city residents and visitors and a balanced usage of the city as a shared resource. This is of great importance, given the intense usage of urban spaces – the city center of Amsterdam being an illustrative example – and the multiple purposes that these spaces represent for different stakeholders. This paper presents the outcome of a review study into city hospitality experience indicators. We integrate these indicators as a basis for the development of a new scale for measuring the effectiveness of hospitality interventions in relation to outcome variables such as satisfaction and net promotor score (NPS). We thereby provide an important means for scholars and practitioners to develop sustainable tourism actions inclusive of local community interests, in support of efforts toward more balanced city experiences among all stakeholders.
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The transition to an inclusive society through design Inclusive design can play a critical role in shaping a more equitable society. When products and services are intentionally created to be inclusive, they become more accessible to a wide audience, including people who might otherwise struggle to engage with them. In this way, designers become agents of social transformation. The project Active Inclusive Design (AID) addresses this challenge directly. It aims to enhance the capabilities of professional and future designers to create inclusive products and services, both digital and non-digital. In doing so, it supports a responsible and digital society central to the Expertise network Systemic Co-design (ESC) agenda, and is closely connected to all ESC Dynamic Learning Agenda (DLA) themes: Systemic Co-Design (SCD) in me, SCD with others, SCD in reality and SCD in time.
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The COVID-19 global pandemic has raised once more the spectre of world governance, demonstrating in one fell swoop, the intricate entanglement of nation-states and the challenges they face when confronted with a global threat. The pandemic has produced an array of problems, from the deaths of millions, the desecration of health care systems all over the world, to the disruption of the economic and social lives of most of the worlds citizens and the emergence of vaccine politics. While not addressing the pandemic directly, this dossier examines the pandemic moment as both an opportunity and a crisis for the UN and the idea of global governance. The articles in this dossier, drawn from a selection of established academics and younger scholars, highlight the expanding array of issues and challenges the UN faces as its competencies increase in the face of multiplying threats to the global system. The organisation has gained new areas of expertise, consolidated its competencies in some areas while expanding its agency in others. In addressing global challenges, the UN has increased its relevance, normative power and connection to humanity but at the same time its lacklustre performance on a lot of issues has revealed that leadership is lacking, and the organisation has in many cases been found wanting. This dossier examines some of the new challenges facing the UN with a view towards assessing the ability of the organisation to effectively respond to global crises, and whether or not it has the capacity for institutional learning and adaptation in the face of adversity and anarchy. Originally published: https://nvvn.nl/governing-the-world-united-or-divided-nations/
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Background: Interprofessional collaboration (IPC) among health and social care providers is crucial to effectively implement community-based fall prevention. Several factors hinder successful and sustainable IPC, highlighting the need to both design and evaluate context-specific implementation strategies. However, there remains a fundamental gap in the detailed description and evaluation of such strategies. Therefore, this study aims to (1) monitor the implementation process over time and (2) evaluate the impact of a multifaceted implementation strategy aimed at improving interprofessional collaboration among health and social care professionals in community-based fall prevention. Methods: This study was conducted in two districts and one municipality in the Netherlands. We conducted a longitudinal mixed-methods study with a convergent design, emphasizing qualitative methodology. Over 24 months, qualitative (focus groups and regular meetings) and quantitative (questionnaires) data were collected semi-annually from three working groups of health and social care professionals (HSCPs). Qualitative and quantitative data were initially analyzed separately, followed by an integrated analysis for comprehensive insights on themes influencing the implementation process and the impact of the strategy on IPC and implementation outcomes. Results: In total, 32 HSCPs originating from three communities participated in this study. Monitoring and evaluation of the multifaceted implementation strategy revealed four overarching themes: (1) “Network building”, including aspects and activities that contribute to network building; (2) “Team dynamics”, referring to interactions within the working groups; (3) “Coordination”, addressing the coordination of implementation and establishment of protocols and work flows; and (4) “Implementation dynamics” highlighting aspects that influence the implementation process and outcomes. Conclusions This study identified four key themes influencing the implementation process and impact of a multifaceted implementation strategy aimed at improving IPC among HSCPs in community-based fall prevention: network building, team dynamics, coordination and implementation dynamics. Monitoring and evaluation are crucial.
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tract Micro wind turbines can be structurally integrated on top of the solid base of noise barriers near highways. A number of performance factors were assessed with holistic experiments in wind tunnel and in the field. The wind turbines underperformed when exposed in yawed flow conditions. The theoretical cosθ theories for yaw misalignment did not always predict power correctly. Inverter losses turned out to be crucial especially in standby mode. Combination of standby losses with yawed flow losses and low wind speed regime may even result in a net power consuming turbine. The micro wind turbine control system for maintaining optimal power production underperformed in the field when comparing tip speed ratios and performance coefficients with the values recorded in the wind tunnel. The turbine was idling between 20%–30% of time as it was assessed for sites with annual average wind speeds of three to five meters per second without any power production. Finally, the field test analysis showed that inadequate yaw response could potentially lead to 18% of the losses, the inverter related losses to 8%, and control related losses to 33%. The totalized loss led to a 48% efficiency drop when compared with the ideal power production measured before the inverter. Micro wind turbine’s performance has room for optimization for application in turbulent wind conditions on top of noise barriers. https://doi.org/10.3390/en14051288
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Depression is a highly prevalent and seriously impairing disorder. Evidence suggests that music therapy can decrease depression, though the music therapy that is offered is often not clearly described in studies. The purpose of this study was to develop an improvisational music therapy intervention based on insights from theory, evidence and clinical practice for young adults with depressive symptoms. The Intervention Mapping method was used and resulted in (1) a model to explain how emotion dysregulation may affect depressive symptoms using the Component Process Model (CPM) as a theoretical framework; (2) a model to clarify as to how improvisational music therapy may change depressive symptoms using synchronisation and emotional resonance; (3) a prototype Emotion-regulating Improvisational Music Therapy for Preventing Depressive symptoms (EIMT-PD); (4) a ten-session improvisational music therapy manual aimed at improving emotion regulation and reducing depressive symptoms; (5) a program implementation plan; and (6) a summary of a multiple baseline study protocol to evaluate the effectiveness and principles of EIMT-PD. EIMT-PD, using synchronisation and emotional resonance may be a promising music therapy to improve emotion regulation and, in line with our expectations, reduce depressive symptoms. More research is needed to assess its effectiveness and principles.
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From the article : "Based on a review of recent literature, this paper addresses the question of how urban planners can steer urban environmental quality, given the fact that it ismultidimensional in character, is assessed largely in subjective terms and varies across time. A novel perspective of urban environmental quality is proposed, simultaneously exploring three questions that are at the core of planning and designing cities: ‘quality of what?’, ‘quality for whom?’ and ‘quality at what time?’. The dilemmas that urban planners face in answering these questions are illustrated using secondary material. This approach provides perspectives for action. Rather than further detailing the exact nature of urban quality, it calls for sustainable urban environmental quality planning that is integrated, participative and adaptive" ( wileyonlinelibrary.com ) DOI: 10.1002/eet.1759 - Preprint available for free download.
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