Search results for "IPM"
showing 10 items of 1361 documents
Effect of operating conditions and feedstock composition on the properties of manganese oxide or quartz charcoal pellets for the use in ferroalloy in…
2020
peer-reviewed The full text of this article will not be available until the embargo expires on the 26/12/2021 This study investigates the effect of heat treatment temperature on the properties of charcoal composite pellets used for the reduction of ferroalloys. The heavy fraction of biooil was used as a binder for the charcoal ore pellet preparation. The effect of heat treatment temperature on the pellet shrinkage was related to the degree of reduction which varied with feedstock and ore composition. The results showed that the size and shape of the charcoal pellets were not affected by the biooil devolatilization. Manganese charcoal pellets showed higher electrical resistance during pyroly…
Back EMF Sensorless-Control Algorithm for High-Dynamic Performance PMSM
2010
In this paper, a low-time-consuming and low-cost sensorless-control algorithm for high-dynamic performance permanent-magnet synchronous motors, both surface and internal permanent-magnet mounted for position and speed estimation, is introduced, discussed, and experimentally validated. This control algorithm is based on the estimation of rotor speed and angular position starting from the back electromotive force space-vector determination without voltage sensors by using the reference voltages given by the current controllers instead of the actual ones. This choice obviously introduces some errors that must be vanished by means of a compensating function. The novelties of the proposed estima…
Field Oriented Control of IPMSM Fed by Multilevel Cascaded H-Bridges Inverter with NI-SOM sbRIO-9651 FPGA controller
2022
Electrical drives fed by Multilevel Inverters (MIs) are of considerable interest for traction and e-mobility applications. In detail, Cascaded H-Bridge Multilevel Inverter (CHBMI) is a promising solution for electrical drive optimization purposes in terms of efficiency, safety, integration and flexible use of energy sources. The aim of this paper is the experimental implementation of the field-oriented control strategy of Interior Permanent Magnet Synchronous Machine (IPMSM) fed by CHBMI by use of NI-SOM sbrRIO-9651 FPGA controller. This FPGA controller can be programmable in the LabVIEW programming environment with the consequent benefits of graphical programming. The paper address the acq…
Head and neck cancer surgery during the COVID-19 pandemic: An international, multicenter, observational cohort study
2020
Background The aims of this study were to provide data on the safety of head and neck cancer surgery currently being undertaken during the coronavirus disease 2019 (COVID-19) pandemic. Methods This international, observational cohort study comprised 1137 consecutive patients with head and neck cancer undergoing primary surgery with curative intent in 26 countries. Factors associated with severe pulmonary complications in COVID-19-positive patients and infections in the surgical team were determined by univariate analysis. Results Among the 1137 patients, the commonest sites were the oral cavity (38%) and the thyroid (21%). For oropharynx and larynx tumors, nonsurgical therapy was favored in…
A critical appraisal of capillary electrochromatography.
2002
Although still in its infancy, CEC promises some advantages over competitive techniques for separating charged analytes including biomolecules.
Destination Therapy with Left Ventricular Assist Devices in Non-transplant Centres: The Time is Right
2020
For almost half a century, cardiac transplant has been the only long-term treatment for patients with end-stage heart failure. Implantable left ventricular assist devices (LVADs) have emerged as a new treatment option for advanced heart failure as destination therapy for patients either too old or not suitable for transplant. A meta-analysis presenting head-to-head comparisons of cardiac transplant versus LVAD as destination therapy (LVAD-DT) found no difference in 1-year mortality rates between LVAD-DT and cardiac transplant (OR 1.49; 95% CI [0.48–4.66]; I2=82.8%). Moreover, a recent subanalysis from the Interagency Registry for Mechanically Assisted Circulatory Support found similar outco…
External stenting with a new polyester mesh reduces neointimal hyperplasia of vein grafts in a sheep model.
2007
Objective External stents placed around vein grafts have demonstrated effectiveness in reducing neointimal hyperplasia by preventing distension of the thin-walled vein grafts when exposed to arterial pressure. However, the ideal stent material has yet to be defined. The following study investigates the short- and long-term effects of an innovative polyester mesh stent designed with optimized adaptation of circumferential compliance. Methods Following in vitro definition of the ideal macro-porous polyester stent material, a total of 12 sheep underwent implantation of bilateral carotid artery vein graft bypasses. In six sheep, the short-term outcome (four weeks of implantation) was investigat…
Enhanced Modelling for Extended Performance Analysis of Interior Permanent Magnet Synchronous Machine Drive fed with Cascaded H-Bridges Multilevel In…
2021
This paper presents a comparative simulation analysis of an Interior Permanent Magnet Synchronous Machine (IPMSM) performance once fed by a traditional three-phase two-level inverter and then using a three-phase five-level Cascaded H-Bridges Multilevel Inverter (CHBMI). For this purpose, an enhanced mathematical model of the IPMSM, that take into account simultaneously saturation, cross-coupling, spatial harmonics and iron loss effects, has been employed. Furthermore, two different PWM modulation strategies have been considered. The study was conducted for several working conditions, evaluating the impact of CHBMI adoption on the IPMSM performance in terms of improved efficiency and torque …
Comparison of heparin to citrate as a catheter locking solution for non-tunneled central venous hemodialysis catheters in patients requiring renal re…
2014
Background The incidence of acute kidney injury (AKI) is estimated at 10 to 20% in patients admitted to intensive care units (ICU) and often requires renal replacement therapy (RRT). ICU mortality in AKI patients can exceed 50%. Venous catheters are the preferred vascular access method for AKI patients requiring RRT, but carry a risk of catheter thrombosis or infection. Catheter lock solutions are commonly used to prevent such complications. Heparin and citrate locks are both widely used for tunneled, long-term catheters, but few studies have compared citrate versus heparin for patients with short-term, non-tunneled catheters. We aim to compare citrate 4% catheter lock solution versus hepar…
Comparison of central venous catheterization with and without ultrasound guide
2003
Purpose: To compare the effectiveness, safety and time needed to perform central venous catheterization (CVC) in the presence or absence of an ultrasound (US) guide. Methods: Between January 1999 and February 2002 we performed CVCs in 196 patients: 105 patients received US guided CVC (group I) and 91 patients had CVC without US guide (group II). Results: The average time to perform CVC was shorter with US guide (4 vs 7min). The utilization of the US guide was also associated with improved success (98.09% vs 91.2%, p < 0.025) and lack of major complications (0% vs 9.8%, p < 0.001). Conclusions: US-guided CVC affords an easier, safer and more rapid cannulation of a central vein. It is especia…