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Rectangular S-duct diffusers are widely used in air-intake system of several military aircrafts. A well-designed diffusing duct should efficiently decelerate the incoming flow, over a wide range of incoming conditions, without the occurrence of streamwise separation. A short duct is desired because of space constraint and aircraft weight consideration, however this results in the formation of a secondary flow to the fluid within the boundary layer. The axial development of these secondary flows, in the form of counter rotating vortices at the duct exit is responsible for flow non-uniformity and flow separation at the engine face. Investigation on S-shaped diffusers reveals that the flow at the exit plane of diffusers is not uniform and hence offers an uneven impact loading to the downstream components of diffuser. Experiments are conducted with an S-shaped diffuser of rectangular cross-section at Re = 1.34 105 to find out the effects of the corners (i.e. sharp 90º, 45º chamfered etc.) on its exit flow pattern. A ‘fishtail’ shaped submerged vortex generators (VG) are designed and introduced at different locations inside the diffusers in multiple numbers to control the secondary flow, thereby improving the exit flow pattern. It is found that the locations of the VG have a better influence on the flow pattern rather than the number of the VG used. The best combination examined in this study is a 45 chamfered duct with 3 3 VG fixed at the top and bottom of the duct inflexion plane. The results exhibit a marked improvement in the performance of S-duct diffusers. Coefficient of static pressure recovery (CSP) and coefficient of total pressure loss (CTL) for the best configuration are reported as 48.57% and 3.54% respectively. With the best configuration of VG, the distortion coefficient (DC60) is also reduced from 0.168 (in case of bare duct) to 0.141.

The arylation of C-H bonds to generate heteroaryl-aryl (Het-Ar) and arylated quinone (Quin-Ar) compounds has received great attention to achieve sustainable goals in synthetic chemistry. Despite significant advances, arylation of a broad range of Het-Ar and Quin-Ar derivatives remains a challenging task. Herein, a variety of heterocycles are arylated by using arylboronic acids in the presence of catalytic amounts of inexpensive Fe(NO3)(3). The C-arylated quinone compounds can be prepared by reacting arylboronic acids with either quinone or hydroquinone. The present method is operationally simple, scalable, does not require prefunctionalization of the heterocycle or quinone, and can tolerate a wide variety of functional groups in the coupling partners. These qualities are expected to render this method attractive for academic and industrial use.

Context Autoimmune pancreatitis is characterized by immune-mediated inflammation, prominent lymphocytic infiltration and fibrosis of pancreas. It accounts for 4.6-6% of chronic pancreatitis but only a few cases from India have been reported. Objective Evaluation of cases of autoimmune pancreatitis diagnosed between July 2006 and June 2009. Design Retrospective analysis of the clinical records of all patients diagnosed as autoimmune pancreatitis between July 2006 and June 2009. Setting Tertiary care centre, northern India. Main outcome measure Clinical records of all patients with autoimmune pancreatitis were analyzed with respect to their initial diagnosis and treatment, imaging, cytology, serology, presence of other organ involvement and response to treatment. Results The 5 cases of autoimmune pancreatitis included 4 men and one woman ranging in age from 48 to 60 years. The interval between initial consultation and diagnosis ranged from 3 months to 7 years. Symptoms included obstructive jaundice (5/5), abdominal pain (3/5) and weight loss (3/5). In 3 cases a presumptive diagnosis of a pancreatic mass with a biliary stricture was made and, in one patient, the diagnosis of primary sclerosing cholangitis was considered. These four patients had received a biliary stent and it was only on follow-up and review of the repeat CT scan that a diagnosis of autoimmune pancreatitis was suggested. In one patient, a diagnosis of autoimmune pancreatitis was considered in the first instance. Radiologically, all 5 patients showed a bulky pancreas with loss of lobulations. Conclusion In this report from India, we highlight the need for a high index of suspicion in diagnosing autoimmune pancreatitis because it responds dramatically to steroids. Image: Pancreatic acinar cell cluster with lymphocytes and plasma cells in the background., JOP. Journal of the Pancreas, Vol 11, No 3 (2010): May - p. 199-298

To study the profile of irritable bowel syndrome (IBS), and the frequency of such symptoms among the general population, in India.In this prospective, multi-center study, data were obtained from 2785 patients with chronic lower gastrointestinal symptoms (complainants) with no alarm feature and negative investigations for organic causes visiting physicians at 30 centers, and from 4500 community subjects (non-complainants), using separate questionnaires.Most complainants were middle-aged (mean age 39.4 years) and male (1891; 68%). The common symptoms were: abdominal pain or discomfort (1958; 70%), abdominal fullness (1951; 70%); subjective feeling of constipation (1404 of 2656; 53%), or diarrhea (1252 of 2656, 47%), incomplete evacuation (2134; 77%), mucus with stools (1506; 54%), straining at stools (1271; 46%), epigastric pain (1364; 49%) and milk intolerance (906; 32%). Median stool frequency was similar in patients who felt they had constipation or those who felt they had diarrhea. Information to subtype symptoms using standard criteria was available in 1301 patients; of these, 507 (39%) had constipation-predominant IBS ( 3or= stools/week), 50 (4%) had diarrhea-predominant IBS (3 stools/day) and 744 (57%) had indeterminate symptoms. Among non-complainants, most subjects reported daily defecation frequency of one (2520 [56%]) or two (1535 [34%]). Among non-complainants, 567 (12.6%) reported abdominal pain, 503 (11%) irregular bowel, 1030 (23%) incomplete evacuation, 167 (4%) mucus and 846 (18%) straining at stools; a combination of abdominal pain or discomfort relieved by defecation, and incomplete evacuation was present in 189/4500 (4.2%) community subjects.Most patients with IBS in India are middle-aged men, and have a sense of incomplete evacuation and mucus with stools. Abdominal pain or discomfort is frequent but not universal. Importantly, stool frequency was similar irrespective of whether the patients felt having constipation or diarrhea. Most (90%) non-complainant subjects had 1 or 2 stools per day; symptoms complex suggestive of IBS was present in 4.2% of community subjects.