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This paper presents the design of an ELC to control the frequency of the MHPP for a purely resistive unbalanced 3-phase load. This is necessary since most of the researches done on ELC in MHPPs considered the design using balanced 3-phase load. However, in real world the 3-phase load at each phase varies due to the different consumers connected to each phase. In this work, a fuzzy-PI controller was designed to reduce the steady state error of the frequency variations and also optimize the gains of the conventional PI controller. These gains were then used to generate equivalent Pulse Width Modulation (PWM) signals to control the firing of Insulated Gate Bipolar Transistors (IGBTs) to dump excess power to the damper loads when the consumer loads change to maintain the power at the generator output constant. Simulation results of the MHPP under varying unbalanced loads showed that the designed ELC was efficient in maintaining the frequency of the MHPP at 50 Hz with a tolerance of ±2. The ELC also maintained the output power of the generator by ensuring the balance of power between the consumer and damper loads.

This paper presents the design of an ELC to control the frequency of the MHPP for a purely resistive unbalanced 3-phase load. This is necessary since most of the researches done on ELC in MHPPs considered the design using balanced 3-phase load. However, in real world the 3-phase load at each phase varies due to the different consumers connected to each phase. In this work, a fuzzy-PI controller was designed to reduce the steady state error of the frequency variations and also optimize the gains of the conventional PI con- troller. These gains were then used to generate equivalent Pulse Width Modulation (PWM) signals to control the firing of Insulated Gate Bipolar Transistors (IGBTs) to dump excess power to the damper loads when the consumer loads change to maintain the power at the generator output con- stant. Simulation results of the MHPP under varying unbalanced loads showed that the designed ELC was efficient in maintaining the frequency of the MHPP at 50 Hz with a tolerance of ±2. The ELC also maintained the output power of the generator by ensuring the balance of power between the consumer and damper loads. [ABSTRACT FROM AUTHOR]

The role of pronunciation in teaching spoken English has come in for renewed praise from some quarters and criticism in others. While proponents of linguistic human rights such as Philipson (1992,1998), Suresh Canagarajah ( 1994,1999,2002), Pennycook (1994) speak in favour of teaching pronunciation which is comprehensible, others, such as Stern ( 1983), Quirk( 1998), Hahn (2004), favour the teaching of native speaker norms to ensure mutual intelligibility among and between native and non-native speaker users of English. In India, which has been a generous host to English language, there appear traces of support for the native speaker principle when teachers are advised to teach R.P. to students to remove any trace of mother tongue influence (M.T.I). At a time when Communicative Language Teaching (henceforth CLT) is still holding forth, textbooks recommend the teaching of phonetics where students are put through a battery of tests to check them for proper pronunciation, leading to a situation where students find it rather difficult to cope with the challenges of spoken English. While the syllabus and materials prescribe RP as norm, the onus is on teachers to teach only those aspects of pronunciation that learners have use for. To determine teacher views on teaching RP, a question was asked that established the prevailing view about the necessity of teaching English with stress, rhythm and accent. This was deemed necessary because any method or ideology is promoted or dispensed with depending on the powers and logic the followers have in them. The study revealed that we have come a long way since the time native speaker norms were endorsed as the only way to teach or look at pedagogical practices. [ABSTRACT FROM AUTHOR]

Objective: Extracorporeal life support (ECLS) is a widely accepted modality for the treatment of postoperative low cardiac output syndrome (LCOS) after major cardiac surgery by providing temporary circulatory support for the stunned myocardium. We sought to identify the factors that affect outcomes of ECLS for postoperative LCOS., Methods: From 2005 to 2011, of a total of 9267 adult patients underwent major cardiac surgery, 93 patients (aged, 60.6 ± 13.8 years; 47 women) underwent ECLS to treat postoperative LCOS., Results: Thirty-nine (41.9%) patients were weaned off ECLS successfully, and 1 patient underwent heart transplantation. A final total of 23 patients (24.3%), including 1 heart transplantation recipient, survived until the end of the follow-up period (median, 611 days; range, 125-2247 days). On logistic regression analysis, old age (P = .001), a high blood lactate level before ECLS initiation (P < .001), cardiopulmonary bypass weaning failure after surgery (P < .001), and postoperative bleeding (P = .012) were independent factors associated with mortality. In contrast, administration of anticoagulant nafamostat mesilate (P = .040) was found to be associated with improved outcomes of ECLS. When the predictive value of pre-ECLS blood lactate level for mortality was assessed using the receiver operating characteristic curve, the greatest accuracy was obtained at the cutoff value of 7.9 mmol/L, with 63% sensitivity and 68% specificity., Conclusions: High lactate level before ECLS is an independent predictor of mortality after ECLS, necessitating earlier ECLS implementations before profound lactic acidosis develops. Moreover, nafamostat mesilate should be considered as alternative to heparin to reduce the risk of bleeding in these high-risk patients., (Crown Copyright © 2014. Published by Mosby, Inc. All rights reserved.)