Burst sampling

The data show that the specific activity is generally not a simple function of particle size, confirming the composite nature of the samples. The sharp decrease of the 147Pm specific activities in coral burst samples toward large particle sizes is particularly significant. Systematic differences as a function of yield or soil type between refractory 147Pm behavior and semivolatile 90Sr behavior are not apparent. Uranium behaves very much like "Sr. 

The statistics of the detected photon bursts from a dilute sample of cliromophores can be used to count, and to some degree characterize, individual molecules passing tlirough the illumination and detection volume. This can be achieved either by flowing the sample rapidly through a narrow fluid stream that intersects the focused excitation beam or by allowing individual cliromophores to diffuse into and out of the beam. If the sample is sufficiently dilute that... 

Liquids examined by FAB are introduced into the mass spectrometer on the end of a probe inserted through a vacuum lock in such a way that the liquid lies in the target area of the fast atom or ion beam. There is a high vacuum in this region, and there would be little point in attempting to examine a solution of a sample in one of the commoner volatile solvents such as water or dichloromethane because it would evaporate extremely quickly, probably as a burst of vapor when introduced into the vacuum. Therefore it is necessary to use a high-boiling solvent as the matrix material, such as one of those listed in Table 13.1. 

In this section, three examples of blast calculations of BLEVEs and pressure vessel bursts will be given. The first example is designed to illustrate the use of all three methods described in Section 6.3.2. The second is a continuation of sample problem 9.1.5, the BLEVE of a tank truck. A variation in the calculation method is presented instead of determination of the blast parameters at a given distance from the explosion, the distance is calculated at which a given overpressure is reached. The third example is a case study of a BLEVE in San Juan Ixhuatepec (Mexico City). 

Sample problem 9.1.S demonstrated the calculation of thermal radiation from the BLEVE of a tank truck. This 6000-gallon (22.7 m ) tank was 90% filled with propane, and burst due to fire engulfment at an overpressure of 1.8 MPa (18 bar). The resulting thermal radiation was sufficient to cause third degree bums to a distance of 300 to 360 m. 

It is seen from Fig. 20 that the injection flux significantly affects the critical burst time. If the samples are... 

Figure 20 Calculated critical burst time /< as function of the halved sample thickness.

The Code requires that the disks be burst on test by one of three methods using four sample disks, but not less than 5% from each lot. Figure 7-32 illustrates test results for burst pressure versus temperature of a disk design, all fabricated from the same material, and of the same diameter. 

If a sample of red blood cells is added to pure water, osmosis carries water into the cells. This process would continue until the internal pressure of the cell was 6.9 atm higher than the pressure on the outside of the cell. However, 6.9 atm is much more than the cell membrane can tolerate. Consequently, red blood cells burst when immersed in pure water. 

A pulse is a burst of radiofrequency energy that may be applied by switching on the Rf transmitter. As long as the pulse is on, a constant force is exerted on the sample magnetization, causing it to process about the Rf vector. 

A 7 year old screw capped sample burst in storage. Peroxide formation seems a less likely cause than slow hydrolysis and carbon dioxide evolution, though both are possibilities. 

In the late stage of work up of a sample prepared from acrylonitrile and hydrazine hydrate and stripped of water by a procedure involving dichloromethane, the distillation flask pressurised and burst, shattering the front of the fume cupboard. Previously, slight pressurisation had once been observed. Involving both a nitrile and a hydrazino moiety, this molecule cannot be thermodynamically stable but it has not given previous problems. 

Inhibited monomer was transferred from a steel drum into a 4 1 clear glass bottle exposed to sunlight in a laboratory in which the ambient temperature was temporarily higher than usual. Exothermic polymerisation set in and caused the bottle to burst. Precautions recommended included increase in inhibitor concentration tenfold (to 200 ppm) for laboratory-stored samples, and use of metal or brown glass containers. See Other POLYMERISATION INCIDENTS... 

A 9 g sample of the freshly prepared hydroperoxide decomposed after 20 min at ambient temperature, bursting the 20 ml glass container. A 30% solution of the hydroperoxide in ethylbenzene is stable. 

A micro-bomb calorimeter exploded when the wrong proportions of sample and oxidants were used. Instead of 4 g of peroxide and 0.2 g of nitrate for 0.2 g of the sugar sample, 0.35 g of peroxide and 2.6 g of dextrose were used. The deficiency of peroxide to absorb the decomposition gases and excess of organic matter led to a rapid rise in temperature and pressure, which burst the bomb calorimeter. 

After the chromium (II) chloride solution has been transferred to flask B, the flow of ammonia through the reaction vessel should be started. The ammonia delivery tube should approach but not dip below the liquid level in flask B. If tank ammonia is used, the tank should be opened carefully to avoid spattering of liquids by a sudden burst of gas. If ammonia is to be generated, the ammonium sulfate solution should be added carefully to the potassium hydroxide in flask C. It may be necessary to cool flask C with ice at first, then to warm the generator later in order to maintain a reasonably constant flow of ammonia. The use of tank ammonia avoids these problems. If zinc was used in the reduction, a precipitate of zinc hydroxide forms first and redissolves. The violet-blue solution stirred at 0° is saturated with ammonia, then a 2- to 3-g. sample of the platinum catalyst is added rapidly to flask B. A strong countercurrent of nitrogen is used to prevent entrance of air into the system when the catalyst is added. The reaction mixture is allowed to stir for one hour while the flask is cooled with ice. 

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