Vortex activity

During Stage 1 both piles burned independently, ambient indrafts were controlled by each pile separately with no evidence of gross vortex activity. 

Lee, S.L., and Otto, F.W. (1975) Gross Vortex Activities in a Simple Simulated Urban Fire, 15th International Symposium on Combustion, 25-31 August 1974, Plant Engineering, 157-161. 

Figure 4.11 Flow patterns of LDPE and HDPE melts flowing through a 20 1 axisymmetric contraction before unstable conditions set in. Note the big vortex for LDPE and the absence of any vortex activity for HDPE [55],...

Determination of Optimal pH for SC-PEG Reactivity. To triethanolamine-borate buffer (0.3 M, 1 mL) at the appropriate pH, a stock solution of N,a-acetyl-lysine (NAL) in water (50 mM, 0.1 mL) was added followed by a stock solution of SC-activated mPEG-5000 in CH3CN (50 mM active acyl, 0.1 mL). The resultant solution was vortexed and incubated at 28 °C for 1 h. A mixture of the same components but leaving out SC-PEG was used as a control. The TNBS assay version of Snyder and Sobocinski (18) was used to determine the unreacted NAL. 

There are various ways how this huge field strength could be used to produce a GRB. The fields in the vortex rolls (see Fig. 8 in Rosswog and Davies 2002) will wind up the magnetic field fastest. Once the field reaches a strength close to the local equipartition value it will become buoyant, float up, break through the surface and possibly reconnect in an ultra-relativistic blast (Kluzniak and Ruderman 1998). The time structure imprinted on the sequence of such blasts would then reflect the activity of the fluid instabilities inside the central object. The expected lightcurve of the GRB would therefore be an erratic sequence of sub-bursts with variations on millisecond time scales. 

The analysis of human plasma for acetaminophen, the active ingredient in some pain relievers, involves a unique extraction procedure. Small-volume samples (approximately 200 fiL) of heparinized plasma, which is plasma that is treated with heparin, a natural anticoagulant found in biological tissue, are first placed in centrifuge tubes and treated with 1 N HC1 to adjust the pH. Ethyl acetate is then added to extract the acetaminophen from the samples. The tubes are vortexed, and after allowed to separate, the ethyl acetate layer containing the analyte is decanted. The resulting solutions are evaporated to dryness and then reconstituted with an 18% methanol solution, which is the final sample preparation step before HPLC analysis. The procedure is a challenge because the initial sample size is so small. 

Eddies are turbulent instabilities within a flow region (Fig. 2). These vortices might already be present in a turbulent stream or can be generated downstream by an object presenting an obstacle to the flow. The latter turbulence is known as Karman vortex streets. Eddies can contribute a considerable increase of mass transfer in the dissolution process under turbulent conditions and may occur in the GI tract as a result of short bursts of intense propagated motor activity and flow gushes. ... 

The reason why the currents are smaller than those expected from the Levich equation is because turbulent flow results in the entrapment of air within the vortex around the electrode. In effect, the active area (the area in contact with solution) of the electrode decreases in a random way. 

Working on experimental data at Edgewood drew me relentlessly into a deepening vortex of mathematics and other abstract domains, such as electronic circuits. I would often visit the Biostatistics Office and talk to John Atkinson about his LGP-30 computer, and how I could learn to use it. It was a monstrous device, one end taking in long ribbons of paper punched with holes that told it what to do and the other end typing answers without fingers on another role of paper, like the tapes that activate a player piano. 

Figure 21.4 Vortex dynamics manipulation by actively controlling relative phase of fuel injection with respect to air vortex shedding...

Figure 21.10 shows the transient behavior of the combustor pressure as the proper phase-delay was applied at time t = 0 and the comparison of the pressure spectra. The high-amplitude oscillations were quickly brought under control and all of the harmonics, as well as the fundamental, were effectively suppressed in this case. The RMS pressure amplitude under active control was maintained well below 0.5% of the combustor pressure. It should also be noted, however, that oscillations at a very small level are still needed to maintain the phase-lock and vortex-synchronized fuel injection. 

Yu, K.H., T. P. Parr, K. J. Wilson, K.C. Schadow, and E. J. Gutmark. 1996. Active control of liquid-fueled combustion using periodic vortex-droplet interaction. 26th Symposium (International) on Combustion Proceedings. Pittsburgh, PA The Combustion Institute. 

Experimenters who have observed asymmetry of internal circulation patterns have generally attributed this to accumulation of surface-active materials at the rear, causing a stagnant cap (see Chapter 3). It seems likely that at least part of the asymmetry results from the forward shift of the internal vortex at nonzero Re, as predicted numerically. 

Surface-active contaminants play an important role in damping out internal circulation in deformed bubbles and drops, as in spherical fluid particles (see Chapters 3 and 5). No systematic visualization of internal motion in ellipsoidal bubbles and drops has been reported. However, there are indications that deformations tend to decrease internal circulation velocities significantly (MI2), while shape oscillations tend to disrupt the internal circulation pattern of droplets and promote rapid mixing (R3). No secondary vortex of opposite sense to the prime internal vortex has been observed, even when the external boundary layer was found to separate (Sll). 

Through a variety of studies, it is now generally accepted that the observed losses are associated with chlorine derived from CFCs and that heterogeneous chemistry on polar stratospheric clouds plays a major role. The chemistry in this region is the result of the unique meteorology. As described in detail by Schoeberl and Hartmann (1991) and Schoeberl et al. (1992), a polar vortex develops in the stratosphere during the winter over Antarctica. The air in this vortex remains relatively isolated from the rest of the stratosphere, allowing photochemically active products to build up... 

Evidence for the contribution of the CIO + BrO interaction is found in the detection and measurement of OCIO that is formed as a major product of this reaction, reaction (31a). This species has a very characteristic banded absorption structure in the UV and visible regions, which makes it an ideal candidate for measurement using differential optical absorption spectrometry (see Chapter 11). With this technique, enhanced levels of OCIO have been measured in both the Antarctic and the Arctic (e.g., Solomon et al., 1987, 1988 Wahner and Schiller, 1992 Sanders et al., 1993). From such measurements, it was estimated that about 20-30% of the total ozone loss observed at McMurdo during September 1987 and 1991 was due to the CIO + BrO cycle, with the remainder primarily due to the formation and photolysis of the CIO dimer (Sanders et al., 1993). The formation of OCIO from the CIO + BrO reaction has also been observed outside the polar vortex and attributed to enhanced contributions from bromine chemistry due to the heterogeneous activation of BrONOz on aerosol particles (e.g., Erie et al., 1998). 

Support for the importance of aerosols in maintaining chlorine in an active form during the maintenance period is found in Fig. 12.34. This shows the satellite-derived average total O, in the vortex as a function of... 

Muller, R., P. J. Crutzen, J.-U. GrooB, C. Briihl, J. M. Russell III, and A. F. Tuck, Chlorine Activation and Ozone Depletion in the Arctic Vortex Observations by the Halogen Occultation Experiment on the Upper Atmosphere Research Satellite, J. Geophys. Res., 101, 12531-12554 (1996). 

F. S. Rowland, Chlorofluorocarbons and the depletion of stratospheric ozone Am. Sci. 77, 36-45 (1989) T.-L. Tso, L. T. Molina, and F. C.-Y. Wang, Antarctic stratospheric chemistry of chlorine nitrate, hydrogen chloride and ice release of active chlorine. Science 238, 1253-1260 (1987) J. G- Anderson, D. W. Toohey, and W. H. Brune, Free radicals within the Antarctic vortex the role of CFCs in Antarctic ozone loss. Science 251, 39-46 (1991) P. S. Zurer, Complexities of ozone loss continue to challenge scientists. Chem. Eng. News June 12, 20-23 (1995). 

The sequence of operations is as follows Azimuth and range to the target are determined. Hie primary fuze is set and the correct amount of propint charge is loaded into the gun to deliver the round to the area above the target. Launch setback activates the safe and arm device. As the projectile continues on its ballistic path, the pre-set primary fuze initiates when the round passes into the desired delivery area. Primary fuze initiation causes an expl pusher charge to eject the three submunitions from the aft end of the round, which continues on its trajectory. After ejection, a de-spin mechanism slows the speed to allow for parachute deployment. Once de-spin occurs, the vortex ring parachute is deployed, initiating... 

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