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Two polymer based sorbents PS-I and PS-II are analyzed for water sorption applications. Adsorption/desorption isotherms of water vapor onto PS-I and PS-II have been experimentally measured using a magnetic suspension adsorption measurement unit for adsorber temperature ranges 20-80°C and evaporator temperature ranges 2-73°C. The equilibrium adsorption uptake of water vapors corresponding to saturation condition at 30°C by PS-I and PS-II was found nearly 2 and 2.5 times higher than the conventional silica-gel, respectively. Adsorption data has been analyzed for various adsorption models which include Brunauer-Emmett-Teller (BET); Freundlich; DubininAstakhov (D-A); Oswin; and Guggenheim-Anderson-de Boer (GAB) model. The GAB and BET model give the good fit for relative pressure range of 0.10-0.90 and 0.05-0.35, respectively. At all adsorption temperatures of both sorbents, the monolayer uptake by the GAB model is found higher than the BET model. Effect of adsorption potential on adsorption uptake is highlighted in relation with water vapor adsorption mechanism. The isosteric heat of water vapor adsorption is determined for both sorbents using Clausius-Clapeyron equation.

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Discrimination between benign and malignant biliary strictures is difficult, with 5.2 to 24.5 per cent of biliary strictures proving to be benign after histological examination of the resected specimen. This study aimed to evaluate the clinicopathological features of benign biliary strictures in patients undergoing resection for presumed biliary malignancy. From January 1990 to August 2010, 5 of 153 (3.3%) patients who had undergone resection after a preoperative diagnosis of biliary malignancy had a final histological diagnosis of benign biliary stricture. The infiltration of immunoglobulin G4-positive plasma cells was evaluated by immunohistochemistry. None of the five patients had a history of trauma or earlier hepatobiliary surgery and all five underwent hemihepatectomy (combined with extrahepatic bile duct resection in three patients). Postoperative morbidity was recorded in two patients (transient cholangitis and biliary fistula), but there was no postoperative mortality. Histological re-examination identified immunoglobulin G4-related sclerosing cholangitis (n = 2) and nonspecific fibrosis/inflammation (n = 3). No preoperative clinical or radiographic features were identified that could reliably distinguish patients with benign biliary strictures from those with biliary malignancies. Although benign biliary strictures are rare, differentiating benign strictures from malignancy remains problematic. Thus, the treatment approach for biliary strictures should remain surgical resection for presumed biliary malignancy.