The objective of this paper is to provide a comparison among permanent magnet (PM) wind generators of different topologies. Seven configurations are chosen for the comparison, consisting of both radial-flux and axial-flux machines. The comparison is done at seven power levels ranging from 1 to 200 kW. The basis for the comparison is discussed and implemented in detail in the design procedure. The criteria used for comparison are considered to be critical for the efficient deployment of PM wind generators. The design data are optimized and verified by finite-element analysis and commercial generator test results. For a given application, the results provide an indication of the best-suited machine.

Slotted axial-flux machines have excellent power and torque densities. However, it is difficult to reduce their cogging torque due to the complexity associated with implementing classical techniques. In this paper, slot-opening widths and tooth-profiles will be shown to be significant in mitigating cogging torque in these machines. In particular, varying the slot-opening reduced it by 52 %, whereas a paralleltooth (rectangular) profile lowered it by 24 %, when compared to a conventional trapezoidal-tooth profile. An analytical quasi 3-D analysis was formulated and used to analyse and determine cogging torque. It was validated numerically and experimentally. Its versatility is in its ability to analyse different shapes of poles and slot-openings, which can be extended to model airgap nonuniformities. The paper also presents cogging torque minimization techniques that maintain the ease of manufacture of the parallelteeth stator. Experimental results showed a 73 % and 48 % reduction in cogging torque; achieved by the use of alternating pole-arcs and skewed poles. NOMENCLATURE aSlot-opening depth 0278-0046 (c)

Background and Purpose— The Ottawa subarachnoid hemorrhage (SAH) rule identifies patients with headache requiring no testing for SAH, while the 6-hour computed tomography (CT) rule guides when to forgo a lumbar puncture. Our objectives were to: (1) estimate the clinical impact of the Ottawa SAH rule and the 6-hour-CT rule on testing rates (ie, CT, lumbar puncture, CT angiography); (2) validate the 6-hour-CT rule for SAH when applied prospectively in a new cohort of patients. Methods— We conducted a multicenter prospective before/after implementation study from 2011 to 2016 with 6 months follow-up at 6 tertiary-care Canadian Academic Emergency Departments. Consecutive alert, neurologically intact adults with headache were included. For intervention period, physicians were given a 1-hour lecture, pocket cards, posters were installed, and physicians indicated Ottawa SAH rule criteria when ordering CTs. SAH was defined by blood on CT, xanthochromia in cerebrospinal fluid, or >1×10 6 /L red blood cells in cerebrospinal fluid with aneurysm. Results— We enrolled 3672 patients, 1743 before and 1929 after implementation, including 188 with SAH. Proportions undergoing CT was unchanged (88.0% versus 87.5%; P =0.643). Lumbar puncture use decreased (38.9% versus 25.9%; P <0.0001). Additional testing following CT (ie, lumbar puncture or CT angiography) decreased (51.3% versus 42.2%; P <0.0001). Admissions declined (9.8% versus 7.4%; P =0.011). Mean emergency department stay was unchanged (6.3±4.0 versus 6.4±4.2 hours; P =0.685). The Ottawa SAH rule was 100% (95% CI, 98.1%–100%) sensitive, and the 6-hour-CT rule was 95.5% (95% CI, 89.8–98.5) sensitive for SAH. The 6-hour-CT rule missed 5 SAHs: 1 radiology misread, 2 incidental aneurysms, 1 nonaneurysmal cause, and 1 profoundly anemic patient. Conclusions— The Ottawa SAH rule and the 6-hour-CT rule are highly sensitive and can be used routinely when SAH is considered in patients with headache. Implementing both rules was associated with a meaningful decrease in testing and admissions to hospital.

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Herein, we describe the synthesis of 11new thiazolyl coumarin derivatives and evaluation of their potential role as antibacterial and antituberculosis agents. The structures of the synthesized compounds were established by extensive spectroscopic studies (Fourier transform infrared spectroscopy, 1 H-nuclear magnetic resonance, 13 Cnuclear magnetic resonance, 2D-nuclear magnetic resonance and liquid chromatography-mass spectrometry) and elemental analysis.