Results 91 to 100 of about 16,769 (309)
British Educational Research Journal, EarlyView.Abstract Recruiting and retaining school leaders is a challenge in many systems worldwide. Previous research has identified three distinct ways in which succession planning can be conceptualised and approached: a ‘pipeline’ approach seeks to match supply and demand for the posts that need filling; a ‘pool’ strategy involves proactively identifying and ...
Toby Greany +3 more
wiley +1 more source
The Commutation Booster, a New Concept to Aid Commutation in Hybrid DC-Breakers [PDF]
, 2020 SUMMARY The difficulty in interrupting DC currents lies in the lack of a natural current zero crossing. In an ACbreaker, the current is interrupted by separating the contacts to draw an electric arc.
Lars Liljestrand +2 more
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Two-step commutation control of switched reluctance motor based on PWM
The Journal of Engineering, 2019 Aiming at the noise suppression of switched reluctance machine (SRM), the two-step commutation control method is improved. Combining this with pulse width modulation (PWM), the optimisation problem of the switching angle is studied and analysed and given
Chuan Yu +3 more
doaj +1 more source
British Educational Research Journal, EarlyView.Abstract The intersection of economic conditions and early years education has long been debated, particularly where financial constraints shape educational practice and professional realities. Türkiye, characterised by high inflation and structural vulnerabilities in purchasing power parity, provides a critical context for examining how economic ...
Ebru Aydın, Şerif Yüksel
wiley +1 more source
The Journal of Engineering, 2019 The current source converter (CSC)-HVDC system is the key technology for long distance large power transmission. However, the traditional CSC-HVDC has two serious shortcomings: (i) vulnerable to commutation failures; and (ii) not being able to control ...
Haitao Wu +4 more
doaj +1 more source
Addressing racialised awarding gap in higher education: Insights from personal tutors
British Educational Research Journal, EarlyView.Abstract Situated within a wider cross‐institutional research project, this article provides an in‐depth case study of one higher education (HE) institution, focusing on how personal tutors make sense of racialised degree awarding disparities for both undergraduate and postgraduate students, how they perceive their responsibilities, the challenges and ...
Benjamin Ajibade +3 more
wiley +1 more source
Studyonthe CommutationFailureinMulti-infeedHVDCSystem
工程科学与技术, 2014 :Because the accuracy of the traditional minimum voltage drop method used to commutation failure is not high enough, a new commutation failure criterion was proposed.
肖俊, 李兴源, 张英敏, 林桥
doaj
The Journal of Engineering, 2018 This study makes a detailed analysis about the influence of AC system fault moments on commutation process of inverter valves and commutation failures. Taking into account the time-varying characteristic of the commutation voltage effective value after a
Jingqiu Zhang +4 more
doaj +1 more source
Flight of the dragons: a global review of migration in Odonata
Biological Reviews, EarlyView.ABSTRACT Insects are the most abundant and ecologically important animal migrants. Yet, we know relatively little about the patterns and processes underlying insect migration. Dragonflies (Anisoptera) and damselflies (Zygoptera) comprise the ancient insect order Odonata, whose ancestors were the first organisms to fly on Earth.
Johanna S.U. Hedlund +3 more
wiley +1 more source
Synthèse fonctionnelle des interrupteurs dans la cellule de commutation
, 2008 Cet article sur la commutation expose une démarche systématique orientée vers la synthèse des interrupteurs d'une cellule de commutation utilisée pour effectuer un transfert d'énergie contrôlé entre deux sources d'énergie complémentaires.
Foch, Henri +4 more
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