An improved variant known as the asymmetrical CHB (ACHB) inverter uses H-bridges of different
sizes and then needs fewer isolated power sources than the CHB. However, in battery-powered EVs, only one power supply (fuel cell or battery pack) is desirable. This work presents a solution to solve the problem, operating some of the small H-bridges (Aux-bridges) as series active filters and using a small high-frequency link (HFL). With this solution, only one dc source is required to feed the inverter, and if the control Transmembrane Transporters inhibitor is adjusted to work at particular switching points, more than 98% of power is transferred through the larger H-bridges (MAIN bridges). The proposed ACHB topology can produce any number of levels, and the MAIN bridges always commutate at fundamental frequency. As
the number of levels must remain constant for all output voltages, a variable dc source is required to control the amplitude of the motor voltage. This work shows some simulations and experiments on a 2-kW 27-level ACHB working with only 23 levels. The concept is being implemented in a small EV with an ACHB drive of 18 kW.”
“Background: Competency in the management of acutely unwell patients has not previously been formally assessed as part of an objective structured clinical examination (OSCE).\n\nAim: The reliability of the paediatric 3-deazaneplanocin A mw postgraduate OSCE was calculated. An objective structured video examination was designed to assess candidates’ clinical decision making ability when managing acutely unwell children.\n\nMethods: The performance of 3522 postgraduate paediatric trainees was assessed (2006-2008). OSCE reliability was determined using Cronbach’s alpha and mean inter-item correlation. Performance in the video station was compared with overall performance (not including video station; Mann-Whitney U) and video station scores correlated with individual station scores (Spearman’s Rho correlation coefficient).\n\nResults: Clinical examination pass rates for the 684 UK graduates, 1608 overseas candidates training in the UK and 1104 overseas candidates training overseas
were 69.7%, 28% and 22.3%, respectively (graduation information not available for 126 candidates). Cronbach’s alpha was 0.62. Mean inter-item correlation was 0.15. Candidates selleck kinase inhibitor who passed the OSCE overall had significantly higher scores on the video station (t (3520) = 14.48); p < 0.001). There was significant positive correlation between scores on the video station, individual stations and overall total score (r’s=0.300; p=0.001).\n\nConclusions: The postgraduate paediatric OSCE provides a sound and valid means of assessing clinical skills at the postgraduate level. The video station provides an important new method of assessment. Its use in other postgraduate clinical examinations should be explored.