Numerical analysis of magnetohydrodynamics Casson nanofluid flow with activation energy, Hall current and thermal radiation.

In this study we analyzed the flow, heat and mass transfer behavior of Casson nanofluid past an exponentially stretching surface under the impact of activation energy, Hall current, thermal radiation, heat source/sink, Brownian motion and thermophoresis. Transverse magnetic field with the assumption of small Reynolds number is implemented vertically. The governing partial nonlinear differential equations of the flow, heat and mass transfer are transformed into ordinary differential equations by using similarity transformation and solved numerically by using Matlab bvp4c package. The impact of each of the Hall current parameter, thermal radiation parameter, heat source/sink parameter, Brownian motion parameter, Prandtl number, thermophoresis parameter and magnetic parameter on velocity, concentration and temperature, is discussed through graphs. The skin friction coefficient along the x-and z-directions, the local Nusselt number and the Sherwood number are calculated numerically to look into the inside behavior of the emerging parameters. It is witnessed that the flow velocity is a diminishing function of the thermal radiation parameter and the behavior has observed in the case of Hall parameter. Moreover, mounting values of Brownian motion parameter reduce the nanoparticle concentration profile.

Influence of Tin Doped TiO2 Nanorods on Dye Sensitized Solar Cells.

The one-step hydrothermal method was used to synthesize Sn-doped TiO2 (Sn-TiO2) thin films, in which the variation in Sn content ranged from 0 to 7-wt % and, further, its influence on the performance of a dye-sensitized solar cell (DSSC) photoanode was studied. The deposited samples were analyzed by X-ray diffraction (XRD) and Raman spectroscopy, which confirmed the existence of the rutile phase of the synthesized samples with crystallite size ranges in between 20.1 to 22.3 nm. In addition, the bare and Sn-TiO2 thin films showed nanorod morphology. A reduction in the optical band gap from 2.78 to 2.62 eV was observed with increasing Sn content. The X-ray photoelectron spectroscopy (XPS) analysis confirmed Sn4+ was successfully replaced at the Ti4+ site. The 3-wt % Sn-TiO2 based DSSC showed the optimum efficiency of 4.01%, which was superior to 0.87% of bare and other doping concentrations of Sn-TiO2 based DSSCs. The present work reflects Sn-TiO2 as an advancing material with excellent capabilities, which can be used in photovoltaic energy conversion devices.

Composite Pheochromocytoma Presenting as Severe Lactic Acidosis and Back Pain: A Case Report.

Pheochromocytoma is a rare, catecholamine secreting tumor arising from chromaffin cells. Presentation of this tumor is highly variable, the most common being hypertension, tachycardia, sweating, and headache. Lactic acidosis and back pain are rare complications of this tumor. We report a 51-year-old gentleman with composite pheochromocytoma, which is rarer than pheochromocytoma, presenting as severe back pain and lactic acidosis.

Immobilization of trypsin on alginic acid-poly (glycidyl methacrylate) graft copolymer.

Trypsin was immobilized onto alginic acid-poly(glycidyl methacrylate) graft copolymer (AAGMA). The resulting immobilized enzyme showed 65% of the soluble enzymatic activity. The temperature optimum was shifted by 5 degrees C to a higher value. The pH optimum of immobilized enzyme has also been shifted by 0.5 units toward the alkaline side when compared to that of soluble enzyme. The pH stability and thermal stability are better than that of soluble enzyme.

Some characteristics of collagen-heparin complex.

In various forms of purified collagen (powder of insoluble collagen from bovine skin, fibers from rat tail tendons, membrane from bovine gut), carboxyl groups were activated by carbodiimide to allow covalent binding of heparin. Collagen powder and collagen fibers from rat tail tendons were also incubated in a heparin solution under the same reaction conditions but without carbodiimide present to account for other forms of collagen-heparin interaction. It was found that the linkage of heparin to collagen formed in the presence of carbodiimide is stable, as heparin was minimally extractable by 0.2M buffers with a pH ranging from 5 to 9. Collagen powder incubated with heparin in the absence of carbodiimide released heparin almost completely into Tris buffer of pH 9.0. As a consequence of covalent binding of heparin to collagen, the collagen fibers became more stable as shown by their significantly reduced swelling capacity and significantly increased shrinkage temperature. Collagen fibers interacted with heparin in the absence of carbodiimide also showed some stabilization of their structure, which was, however, significantly less than with carbodiimide reaction. By two independent methods it was shown that heparin linked to collagen by a stable bond retains its anticoagulant activity. It is concluded that, in the presence of carbodiimide, heparin covalently binds to collagen thus forming an antithrombogenic surface. At the same time, collagen is crosslinked. Incubation of collagen in the solution of heparin without carbodiimide also stabilizes collagen structure, but to a significantly lesser degree. Such a linkage is unstable as heparin dissociates and is readily extractable into 0.2M Tris buffers with pH 7-9.