Ballooning effect

Powder C had particles with more and deeper folds or shrinkages and had frequently, as shown in Figure 5, broken hollow particles,possibly due to ballooning effect, as compared to powders A and B. The observed change is further magnified (1800 x) in Figure 4. 

Figure 9.4. Results of melt-spinning a simple bicomponent fiber. Light and dark portions represent different polymer materials. Note the ballooning effect (the die-swell phenomenon) as the blend leaves the common capillary. Since the pressure drop in the common capillary must be the same for each component, careful regulation of the homopolymer capillary diameters is necessary to obtain the desired result.

The biaxial compression tests were carried out on the small scale soil specimens under 100 kPa, 200 kPa, 300 kPa respectively to calculate the macro-mechanical parameters of soil. Figure 2 shows the sample before and after the biaxial compression with confining pressure equals 300 kPa. Through comparison the ballooning effect can be seen obviously that the axial compression... 

The appearance schematic of S-RM specimens contain polygonal rock block with rigid and flexible boundary at an axial strain of 12.10% under 300 kPa confining pressure are shown in Figure 7. The ballooning effect won t appear under the constraint of rigid boundary. The expansion which should be concentrated in the in the middle of the specimen is evenly distributed on the whole sample height so it can t simulate the membrane boundary in physical experiments. 

Summaries of the properties of gases, particularly the variation of pressure with volume and temperature, are known as the gas laws. The first reliable measurements of the properties of gases were made by the Anglo-Irish scientist Robert Boyle in 1662 when he examined the effect of pressure on volume. A century and a half later, a new pastime, hot-air ballooning, motivated two French scientists, Jacques Charles and Joseph-Louis Gay-Lussac, to formulate additional gas laws. Charles and... 

We see that, for a given pressure and temperature, the greater the molar mass of the gas, the greater its density. Equation 10 also shows that, at constant temperature, the density of a gas increases with pressure. When a gas is compressed, its density increases because the same number of molecules are confined in a smaller volume. Similarly, heating a gas that is free to expand at constant pressure increases the volume occupied by the gas and therefore reduces its density. The effect of temperature on density is the principle behind hot-air balloons the hot air inside the envelope of the balloon has a lower density than that of the surrounding cool air. Equation 10 is also the basis for using density measurements to determine the molar mass of a gas or vapor. 

Sigman et al. have optimized their system too [45]. A study of different solvents showed that the best solvent was f-BuOH instead of 1,2-dichloroethane, which increased the conversion and the ee. To ensure that the best conditions were selected, several other reaction variables were evaluated. Reducing the catalyst loading to 2.5 mol % led to a slower conversion, and varying temperature from 50 °C to 70 °C had little effect on the selectivity factor s. Overall, the optimal conditions for this oxidative kinetic resolution were 5 mol % of Pd[(-)-sparteine]Cl2, 20 mol % of (-)-sparteine, 0.25 M alcohol in f-BuOH, molecular sieves (3 A) at 65 °C under a balloon pressure of O2. 

Inoculation of cell cultures with virus-containing material produces characteristic changes in the cells. The replication of many types of viruses produces the cytopathic effect (CPE) in which cells degenerate. This effect is seen as the shrinkage or sometimes ballooning of cells and the disruption of the monolayer by death and detachment of the cells (Fig. 3.6). The replicating virus can then be identified by inoculating a series of cell cultures with mixtures of the virus and different known viral antisera. If the virus is the same as one of the types used to prepare the various antisera, then its activity will be neutralized by that particular antiserum and CPE will not be apparent in that tube. Alternatively viral antisera labelled with a fluorescent dye can be used to identify the virus in the cell culture. 

An explosion occurs when energy previously confined is suddenly released to affect the surroundings. Small explosions, like the bursting of a toy balloon, are familiar and innocuous, but large-scale explosions, like an atomic bomb, are rare and usually disastrous. Between these two extremes lie the commercial and conventional military fields where explosions are produced on a limited scale to cause specific effects. It is with explosions of this intermediate scale that this book is concerned. 

The first term on the right-hand side is known as the buoyant force, the second is known as thrust. If this were just a puff of hot air without the balloon exhaust, we would only have the buoyant force acting. In this case we could not ignore (d/dt) Jjf pvxdV since the puff would rise (vx +) solely due to its buoyancy, with viscous effects retarding it. Buoyancy generated flow is an important controlling mechanism in many fire problems. 

So the reason why the balloon floats is because the air inside its voluminous hood has a lower density than the air outside. The exterior air, therefore, sinks lower than the less-dense air inside. And the sinking of the cold air and the rising of the warm air is effectively the same thing it is movement of the one relative to the other, so the balloon floats above the ground. Conversely, the balloon descends back to earth when the air it contains cools to the same temperature as the air outside the hood. 

Helium, like the other members of its family, is an inert gas often used in balloons on account of its low density, and when inhaled results in a comic transposition of the human voice to a significantly higher register (not a realistic way to mimic counter-tenors, but very effective in well-loved Walt Disney cartoon characters) ... 

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