Ultra Flow

To improve the delivery, 13-mm-diameter rate-controlling membranes held in a Swinnex filter chamber (Millipore Corp.) were inserted in the delivery line between the insulin reservoir and the micropump. The effective membrane area was 0.7 cm2. Membranes investigated were l- xm and 8- xm pore size polycarbonate filters (Nucle-pore Corp.), 0.45- xm cellulosic microporous filters (Amicon Corp.), Cuprophane PT-150 (from Ultra-Flow 145 Dialyser, Travenol Laboratories), and 0.2- xm and 1.2- xm pore size cellulose acetate filters (Schleicher and Schuell OE 66 and ST 69). 

Property/Temperature (°C) Toughest Medium Flow High Flow Ultra Flow... 

Mudawar I, Bowers MB (1999) Ultra-high critical heat flux (CHF) for subcooled water flow boiling. I CHF data and parametric effects for small diameter tubes. Int J Heat Mass Transfer 42 1405-1428... 

Since the middle of the 1990s, another computation method, direct simulation Monte Carlo (DSMC), has been employed in analysis of ultra-thin film gas lubrication problems [13-15]. DSMC is a particle-based simulation scheme suitable to treat rarefied gas flow problems. It was introduced by Bird [16] in the 1970s. It has been proven that a DSMC solution is an equivalent solution of the Boltzmann equation, and the method has been effectively used to solve gas flow problems in aerospace engineering. However, a disadvantageous feature of DSMC is heavy time consumption in computing, compared with the approach by solving the slip-flow or F-K models. This limits its application to two- or three-dimensional gas flow problems in microscale. In the... 

The last category is the pressure-driven gas flows, which are typical in micro gas fluidic and micro heat transfer systems. Because the channel diameter or width in micro gas fluidic systems is in the scale of sub-micrometer or less, ultra-thin gas lubrication theory plays an important role in... 

Mitsuya, Y., Modified Reynolds Equation for Ultra-thin Film Gas Lubrication Using 1.5-order Slip-Flow Model and Considering Surface Accommodation Coefficient," ASME J. Tri- [25] fcoZ.,Vol. 115,1993, pp. 289-294. 

PFPE, AI2O3, and X-IP were 500 mg, 200 mg, and 100 mg, respectively. The materials in Samples 2 to 4 were sufficiently mixed to ensure that the liquid PFPE and X-IP completely wet the alumina powders. These specimens were put in a closed space hlled with inert nitrogen. The flow rate of the nitrogen gas was kept at 20 milliliters per minute. The environmental temperature of the system was set at 220 ° C and the duration time was 250 minutes per sample for each individual operation procedure. PFPE used in the experiment was Z-dol and the alumina was in ultra-fine powders with chemical analytic grade purity. 

The flow of liquid hydrocarbons can be enhanced by introducing into the stream a nonagglomerating suspension of ultra-high molecular weight polyethylene [490,1647] in water with small amounts of surfactant. The finely divided polyethylene is prepared by polymerization and then cryogrinded below the glass-transition temperature. 

The current status of chromatography is shown in Table 10.25. Since reducing separation time is a major issue, there is a pronounced trend toward shorter columns filled with small particles. The current trends for lower flow (micro- and nano-LC) columns, and great strides to achieve (ultra-) fast chromatographic... 

Ma Y, Zhou M, Jin X et al (2004) Flow-injection chemiluminescence assay for ultra-trace determination of DNA using rhodamine B-Ce(IV)-DNA ternary system in sulfuric acid media. Anal Chim Acta 501 25-30... 

An alternative method to position two electrodes at nanometer distances apart is the mechanically-controlled, break junction (MCBJ) technique. An ultra-thin, notched Au wire on a flexible substrate can be broken reliably by pushing on the Au with a piezoelectric piston, cracking the Au (Fig. 4). This produces a gap between the Au shards whose size can be finely varied to 1 A by a piston or control rod [46, 47]. When UE molecules with thiol groups on both ends are present in a surrounding solution, the gap can be adjusted until the molecules can span it. A dilute solution means the number of spanning molecules will be small, and the least-common-multiple of current flow among many junctions indicates those spanned by a single molecule [47]. 

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