Experiments with liquids

It was pointed out that measurements of laser-induced breakdown suffer from the same artifacts as DC-breakdown measurements. Impurities of low ionization energy, submicroscopic particles (dust or ice), and microscopic gas bubbles may serve as centers for the initiation of the breakdown process and mask the development of a pure avalanche breakdown (Brueck and Kildal, 1981). Subsequent investigations on the optical breakdown of liquid helium (Abrikosova and Anshukov, 1973  

Hunklinger and Leiderer, 1971) and of organic liquids (Butenin and Kogan, 1972) also demonstrated the governing influence of impurity particles on the breakdown threshold. 

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This equation is based on experience with liquid chromatography of low molecular weight samples displaying single peaks. Its application for the GPC of polymers, however, contains a disadvantage, as it mixes two inseparable properties the retention difference for the separation and the peak width for the contrary effect of band broadening. Such a procedure is acceptable if both effects are accessible for an experimental examination. For the GPC experiment, we do not possess polymer standards, consisting of molecules that are truly monodisperse. Therefore, we cannot determine the real peak width necessary for a reliable and reproducible peak resolution R,. This equation then is not qualified for a sufficient characterization of a GPC column. 

It was also shown in 1983 [11] that lithium can be reversibly inserted into graphite at room temperatures when a polymeric electrolyte is used. Prior experiments with liquid electrolytes were unsuccessful due to co-intercalation of species from the organic electrolytes that were used at that time. This problem has been subsequently solved by the use of other electrolytes. 

Perform experiments with liquid bromine in the presence of your instructor. 

During World War II the Germans experimented with liquid mixtures consisting of tetranitromethane and combustibles as a liquid fuel for the propulsion of the big V2 rockets. 

Paul and Paciotti [19] took this work a step further by measuring the flux of a liquid (hexane) through a membrane both in pervaporation experiments with atmospheric pressure on the feed side of the membrane and a vacuum on the permeate side, and in reverse osmosis experiments with liquid at elevated pressures on the feed side and at atmospheric pressure on the permeate side. The hexane flux obtained in these two sets of experiments is plotted in Figure 2.17 against the hexane concentration difference in the membrane (c o(m) — c,eimi). The concentrations, cio(m) and Cie(m), were calculated from Equations (2.26), (2.36) and (2.72). 

In experiments with liquid solutions laser beam was focused inside the parallelepiped or cylindrical quvettes. The beam had the minimal cross section diameter not lower then 0.2 mm. In experiments with solid samples the beam was stretched in one direction by means of cylindrical lens, so the ellipse projected on a surface had dimensions of about 2x0.2 mm2. In such conditions the density of exciting light power did not excite 65 W/cm2 for the experiments with liquids and was at least 10 times smaller for the... 

Erdmann (Ber., 1904, 37, 4737) describes a convenient apparatus for experiments with liquid ozone. 

Wetting experiments with liquid tin on heterogeneous surfaces composed of oxide glass ceramic (a) and molybdenum (/ ) with 0 = 125° and 0 = 18° were performed using the sessile drop technique (Voitovich 1992, Naidich et al. 1995). 

The result that the coefficient should increase as is equally surprising because it is contrary to our experience with liquids, the viscosity of which decreases as T increases. It is found experimentally that the increase in t) is not given by any simple power of T but does increase faster than T. This may be qualitatively justified by considering not a spherical model for a molecule but one which is also capable of exerting attrac-... 

In order to avoid these drawbacks and following RCH/RP s excellent experiences with liquid recycles, the gas recycle was replaced by the liquid recycle variant (Figure 14) which is used in most modem LPO plants. Combinations of gas and liquid recycle have also been described, claiming an increased propene conversion [203, 204]. 

While in analytical operations, since one generally deals with aqueous solutions, the cleaned vessels may be used even if wet, it frequently happens in organic work, in experimenting with liquids not miscible with water, that dry vessels must be employed. In order to dry small pieces of apparatus rapidly, they should be rinsed first with alcohol and then with ether. To remove the last portions of the easily volatile ether, air from a blast is blown through the vessel for a short time, or the ether vapours are removed by suction. The alcohol and ether used for rinsing can frequently be used again it is convenient to keep two separate bottles for the wash alcohol and wash ether, into which the substances, after being used, may be poured. 

For R —> 0 ( point particles), theories of particle and molecular diffusion are equivalent. Schmidt numbers for particle diffusion are much larger than unity, often of the same order of magnitude as for molecular diffusion in liquids. The principle of dimensional similitude tells us that the results of diflusion experiments with liquids can be used to predict rates of diffusion of point particles in gases, at the same Reynolds number. 

An effort was made to use the same technique for liquid solutes by trapping the liquid in a porous membrane having the shape of a disk. Ward also reported results of some experiments with liquid oils using this method. 

The third form (Fig. 7) differs only in detail from the second it was preferred for the experiments with liquid hydrogen, because it could be made of much smaller dimensions. The platinum wire was wound on the outside of the cylindrical silver vessel and covered, to avoid thermal losses, with silver foil which was soldered at the edges to give a better thermal contact this form has the advantage that the platinum wire docs not have to be introduced vacuum-tight into the inside of the silver vessel. In a small size and at low temperatures this form of calorimeter proved to be excellent. The heat capacity of the silver vessel could be calculated with good accuracy, but it was also directly determined by a series of... 

Adsorption-desorption processes have been very successful with vapor systems. In contrast, the experiences with liquid systems have provided many disappointments, and the hopes once held for large markets remain unfulfilled. Probably research on fundamental aspects could do much to place future applications in this field on a sounder footing. 

The importance of reacting surfaces in liquid and gelatin explosives has long been known from experience with liquid nitroglycerine and gelatin dynamites. Aeration is an important aspect of the sensitivity of these liquid and semiliquid explosives. More recently this has been reemphasized by the observed effects of aeration on the sensitivity of slurry explosives sensitized by aluminum or other nonexplosive fuels. The sensitivity, indeed the propagation of the detonation wave, in these slurry explosives is initially associated with small gas bubbles which act as reaction centers for the essential chemical reactions. 

Neon (from the Greek word neos, meaning new ) is the second lightest of the noble gases. It forms no stable compounds with other elements. Discovered in 1898 by Sir William Ramsay and Morris Travers during their experiments with liquid air, neon accounts for 18 millionths (18 ppm) of the volume of Earth s atmosphere. Trace amounts are also found in the oceans. It is present in the Sun and in the atmosphere of Mars. 

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