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The recent innovations in the field of power electronic industries have led to advancements in high power converters and their usage in the modern grid. This trend focused on the interconnection of power converters with solid-state transformer (SST). Since it is capable of controlling power flow in the power system, it is seen as a potential technology which can replace the conventional transformers that are used today. SST consists of power electronic switches interconnected with a high frequency transformer (HFT). The usage of HFT reduces the size and volume of the SST. A suitable controller can upgrade the performance of SST under different operating conditions. This paper proposes a novel control strategy for SST with a reduced number of converter stages and also discusses the design of the HFT. The results show that the SST will enhance power flow from the source to the grid.

Spontaneous bacterial peritonitis (SBP) is a common serious complication of cirrhosis, and carries a high morbidity and mortality. Rapid diagnosis and prompt treatment of this condition may improve survival of such patients.To validate the diagnostic efficacy of a leukocyte esterase reagent (LER) strip test for rapid, bedside diagnosis of SBP.We prospectively studied 175 patients with liver cirrhosis and ascites [mean age 48 (SD 16.4) years; 146 men] between August 2007 and December 2008. Alcohol was the most common (124 of 175; 70.8%) cause of liver cirrhosis. All patients underwent abdominal paracentesis, and the ascitic fluid was processed for cell count, LER strip (Magistik 10) test and culture. Two different cut-offs for calling the LER strip test positive were tried, namely when the color turned light blue [grade 2:125 polymorphonuclear leucocytes (PMNL)/microL] or it turned purple (grade 3:500 PMNL/microL). Sensitivity, specificity, positive predictive value, negative predictive value were calculated, using PMN count by microscopy exceeding 250 PMNL/microL.LER strip using the more stringent purple-color cut off to diagnose SBP had a sensitivity of 92% and specificity of 100%. The corresponding figures using the light-blue color cut-off were 97% and 89%, respectively.LER strip testing of ascitic fluid is a rapid, cheap and sensitive bed side tool for the diagnosis of SBP.

The utilisation factor for a discrete dam, defined as the stationary probability of non-emptiness of the dam just before release, is obtained for a class of models that includes the Odoom–Lloyd model, the Anis–Lloyd model, the model of Herbert, etc. The method used points to a different approach to measuring dam utilisation via the actual utilisation, which appears to be more fruitful, and this is discussed in the last section.

Let Un be the time between the nth and (n + 1)th arrivals to a single-server queuing system, and Vn the nth arrival's service time. There are quite a few models in which {Un, Vn , n ≥ 1} is a regenerative sequence. In this paper, some light and heavy traffic limit theorems are proved solely under this assumption; some of the light traffic results, and all the heavy traffic results, are new for two such models treated earlier by the author; and all the results are new for the semi-Markov queuing model. In the last three sections, the results are applied to a single-server queue whose input is the output of a G/G/1 queue functioning in light traffic.