OBJECTIVE To validate preoperative dynamic CT and fecal elastase-1 level in predicting the development of pancreatic fistulae after pancreatoduodenectomy. MATERIALS AND METHODS For 146 consecutive patients, CT attenuation values of the nontumorous pancreatic parenchyma were retrospectively measured on precontrast, arterial and equilibrium phase images for calculation of enhancement ratios. CT...

The Gibbs Thomson effect modifies the pressure and temperature at which clathrates occur, hence altering the depth at which they occur in the sea-bed. NMR measurements as a function of temperature are being conducted for water/ice/hydrate systems in a range of pore geometries, including templated SBA-15 silicas, controlled pore glasses and sol-gel silicas. Rotator-phase plastic ice is shown to ...

We consider a simplified model of methane hydrates which we cast as a nonlinear evolution problem. For its well-posedness we extend the existing theory to cover the case in which the problem involves a measurable family of graphs. We represent the nonlinearity as a subgradient and prove a useful comparison principle, thus optimal regularity results follow. For the numerical solution we apply a ...

With the increasing use of different types of auctions in market designing, modeling of participants’ behaviors to evaluate the market structure is one of the main discussions in the studies related to the deregulated power industries. In this article, we apply an approach of the optimal bidding behavior to the Iran wholesale electricity market as a restructured electric power industry and mode...

Gas hydrates form at relatively high pressures in near-surface, organic-rich marine sediments, with the base of hydrate stability field and onset partial gas saturation determined by temperature increases depth. Because pore-scale curvature wetting effects, transition between free occurrence need not take place a distinct depth or boundary, but instead can be characterized zone finite thickness...

Crystal structure prediction studies indicated the existence of an unknown high density monohydrate structure (Hy1B°) as global energy minimum for 4-aminoquinaldine (4-AQ). We thus performed an interdisciplinary experimental and computational study elucidating the crystal structures, solid form inter-relationships, kinetic and thermodynamic stabilities of the stable anhydrate (AH I°), the kinet...

We calculate structures and thermochemical parameters for H2SO4•(H2O)n, HSO4 •(H2O)n, H2SO4•NH3•(H2O)m and HSO4 •NH3•(H2O)m clusters (with n = 0 ... 4 and m = 0 ... 1) using the MP2/aug-cc-pV(D + d)Z quantum chemical method, with higher-order corrections computed at the MP2/aug-cc-pV(T + d)Z and MP4/aug-cc-pV(D + d)Z levels. Equilibrium constants for hydrate formation at different temperatures ...

The equilibrium as well as nonequilibrium phase behaviors of colloidal dispersions have been investigated using statistical-mechanical theories of fluids and solids in complement with the renormalization-group (RG) theory. It is shown that the osmotic second virial coefficient at the critical point of the fluid-fluid transition varies with the range of attractions and is sensitive to specific f...

gas hydrate formation in production and transmission pipelines and consequent plugging of these lines have been a major flow-assurance concern of the oil and gas industry for the last 75 years. gas hydrate formation rate is one of the most important topics related to the kinetics of the process of gas hydrate crystallization. the main purpose of this study is investigating phenomenon of gas hyd...