MRAC based speed regulation of an excitation controlled quickresponse induction motor

Speed regulation of a voltage decoupled induction motor which provides optimal efficiency and quick response is discussed. A robust first-order model reference adaptive control (MRAC)-based speed controller whose stability has been proved via Lyapunov's second method is proposed. Computer simulation results for a 100-hp squirrel-cage motor show that the proposed MRAC controller has remarkably good tracking and regulation characteristic

MRAC based speed regulation of an excitation controlled quickresponse induction motor

Speed regulation of a voltage decoupled induction motor which provides optimal efficiency and quick response is discussed. A robust first-order model reference adaptive control (MRAC)-based speed controller whose stability has been proved via Lyapunov's second method is proposed. Computer simulation results for a 100-hp squirrel-cage motor show that the proposed MRAC controller has remarkably good tracking and regulation characteristic

Hepatic Hilar Lymph Node Reactivity at Kasai Portoenterostomy for Biliary Atresia: Correlations With Age, Outcome, and Histology of Proximal Biliary Remnant

We hypothesized that if infection is the proximate cause of congenital biliary atresia, an appropriate response to antigen would occur in lymph nodes contiguous with the biliary remnant. We compared the number of follicular germinal centers (GC) in 79 surgically excised hilar lymph nodes (LN) and 27 incidentally discovered cystic duct LNs in 84 subjects at the time of hepatic portoenterostomy (HPE) for biliary atresia (BA) to autopsy controls from the pancreaticobiliary region of non-septic infants >3 months old at death. All 27 control LN lacked GC, a sign in infants of a primary response to antigenic stimulation. GC were found in 53% of 106 LN in 56 of 84 subjects. Visible surgically excised LN contiguous with the most proximal biliary remnants had 1 or more well-formed reactive GC in only 26/51 subjects. Presence of GC and number of GC/LN was unrelated to age at onset of jaundice or to active fibroplasia in the biliary remnant but was related to older age at HPE. Absent GC in visible and incidentally removed cystic duct LNs predicted survival with the native liver at 2 and 3 years after HPE, P = .03, but significance was lost at longer intervals. The uncommon inflammatory lesions occasionally found in remnants could be secondary either to bile-induced injury or secondary infection established as obstruction evolves. The absence of consistent evidence of antigenic stimulation in LN contiguous with the biliary remnant supports existence of at least 1 major alternative to infection in the etiology of biliary atresia

Histological criteria for the identification of acute cellular rejection in human small bowel allografts: results of the pathology workshop at the VIII International Small Bowel Transplant Symposium

Acute cellular rejection remains a serious and frequent complication during the posttransplant course of small bowel allograft recipients. Currently, small bowel biopsies are the optimal method to identify this form of rejection. The morphological criteria for this diagnosis have been known for some time; however, no consensus study has classified these changes. To address issues in bowel transplant pathology, several pathologists experienced in this particular subdiscipline participated in a Pathology Workshop preceding the VIIIth International Small Bowel Transplant Symposium in Miami, Florida. Among the results of this workshop was the development a standardized grading scheme for acute cellular rejection in small bowel transplants