Stirring effect

Solidification. The heat of the electric arc melts a portion of the base metal and any added filler metal. The force of the arc produces localized flows within the weld pools, thus providing a stirring effect, which mixes the filler metal and that portion of the melted base metal into a fairly homogeneous weld metal. There is a very rapid transfer of heat away from the weld to the adjacent, low temperature base metal, and solidification begins nearly instantaneously as the welding heat source moves past a given location. 

The checkers found that the heavy suspension could not be stirred effectively with a magnetic stirring bar and recommend that a mechanical stirrer be used. 

The glycocalyx and the mucus layer make up the structure of the unstirred water layer (UWL) [73]. The thickness of the UWL is estimated to be 30-100 pm in vivo, consistent with very efficient stirring effects [74]. In isolated tissue (in the absence of stirring), the mucus layer is 300-700 pm thick [73]. The pH in the unstirred water layer is 5.2-6.2, and might be regulated independently of the luminal pH (Section 2.3). The mucus layer may play a role in regulating the epithelial cell surface pH [73]. 

In Section III, emphasis was placed on flux kinetics across the cultured monolayer-filter support system where the passage of hydrophilic molecular species differing in molecular size and charge by the paracellular route was transmonolayer-controlled. In this situation, the mass transport barriers of the ABLs on the donor and receiver sides of the Transwell inserts were inconsequential, as evidenced by the lack of stirring effects on the flux kinetics. In this present section, the objective is to give quantitative insights into the permeability of the ABL as a function of hydrodynamic conditions imposed by stirring. The objective is accomplished with selected corticosteroid permeants which have been useful in rat intestinal absorption studies to demonstrate the interplay of membrane and ABL diffusional kinetics (Ho et al., 1977 Komiya et al., 1980). 

Ultrasonic irradiation of a liquid leads to the generation of cavitation phenomenon which comprised of unique reaction fields in addition to physical and mechanical effects the formation of micro-meter sized bubbles, formation of bubbles with high temperature and high pressure conditions, formation of shock waves, and strong micro-stirring effects are produced. Table 5.1 shows representative ultrasound techniques to synthesize inorganic and metal nanoparticles and nanostructured materials. 

Hirata, T., Ishikawa, M., and Anezaki, S., Stirring Effect in Bath-Smelting Furnace with Combined Blowing of Top and Side Blown Oxygen and Bottom Blown Nitrogen, /.S /,/ Int., 32 182 (1992)... 

Schwertmann, U. Stanjek, H (1998) Stirring effects on properties of A1 goethite formed from ferrihydrite. Clays Clay Miner. 46 317-321... 

S. Colombie, A. Gaunand, and B. Lindet, Lysozyme inactivation under mechanical stirring effect of physical and molecular interfaces, Enz. Microb. Technol. 2001, 28, 820-826. 

Modeling of the Stirring Effect in the Autocatalytic Step of the Belousov—Zhabotinsky Reaction. 

The lid is provided with a rectangular opening (1) (35 x20 cm) for feeding in the naphthalene. After the nitrator has been charged the opening is closed with a sheet iron lid. The nitrator lid is also equipped with pipe (2), connected with a ventilator by means of a stoneware pipe the ventilator itself is connected with an absorption tower for absorption of nitrogen dioxide in water. In addition the nitrator is equipped with stirrer (3) (85-90 r. p. m) and with two baffles (4) located opposite to each other to increase the stirring effect. 

The next experiment is very useful to compare the stirring effect (which is a weak thermodynamic effect) with a stronger thermodynamic effect, such as that exerted by the presence of high concentrations of chiral templates. The next system, in our design, has to behave differently to the previous ones and helps in delineating a model. 

Scheme 5 Schematic representation of the possible stirring effect on a J-aggregate solution in which a thermodynamic unbalancing factor is present throughout its formation (A-[Ru(Phen)3]2+ in this case). Stirring is unable to overcome the initial unbalancing. Modified from [62]...

It is essential that the zinc dust be stirred effectively or the reaction may become violent. 

The cake porosity, obtained from the steady-state flux, is shown with the surface charge density in Fig. 2. It was observed that the porosity of a cake layer tended to increase as the surface charge density increased. The stirring effect was investigated with monodisperse microspheres of different surface charge density. It was observed that the stirrer speed was proportional to the porosity of a cake layer. 

Hydrogen bubble evolution can provide a stirring effect and lead to a substantial bubble raft at the free surface of the solution. 

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