Balloon experiments

In all of these tests, flame acceleration was minimal or absent. Acceleration, when it occurred, was entirely due to intrinsic flame instability, for example, hydrodynamic instability (Istratov and Librovich 1969) or instability due to selective diffusion (Markstein 1964). To investigate whether the flame would accelerate when allowed to propagate over greater distances, tests were carried out in an open-sided test apparatus 45 m long (Harris and Wickens 1989). Flame acceleration was found to be no greater than in the balloon experiments (Table 4.1a). 

This refrigerator has been tested in a balloon experiment [42] and will be used in the Plank satellite experiment [43],... 

Table I, provided yet another instrumental approach for balloon experiments intended to measure the extinction of solar radiation by stratospheric aerosol. Spectrometer 4, Table I, based on the use of a pyroelectric vidicon image device, was developed to measure the strong absorption bands of non-isonuclear molecules ( 2-5 ym range). Recently we have developed spectrometer 5, Table I, based on the use of a self-scanned solid state pyroelectric array sensor. The main advantages of this sensor, over the pyroelectric vidicon, are its improved sensitivity and reduced channel-to-channel cross-talk.

Figure 14. Solar occultation spectra measured in this balloon experiment. Solar zenith angle a, 76.6° and b, 92.0°. (Reproduced with permission from Ref. 6. Copyright 1983, American Geophysical Union.)...

Similarly, divergence will also occur if we have an infinitely precise computer to solve the chaotic problem, but the balloon experiences an unaccounted-for, infinitesimal fluctuation between finite time steps of the trajeaory calculation. The accumulation of errors resulting from the extreme sensitivity of a chaotic trajectory to its instantaneous environment was called the butterfly effect by Lorenz. The butterfly effect arises from the fact that the balloon s trajectory is dynamically unstable, which means that it is so sensitive to changes in its instantaneous environment that the perturbations caused by the fluttering of a butterfly s wing thousands of miles away are sufficient to cause the trajectory of the balloon to change from what it would otherwise have been. 

The feasibility of this kind of modulation imaging has been confirmed by a balloon experiment (Lu Z.G. et al, 1994). The hard X-ray telescope HAPI-4, constructed in collaboration of IHEP/Beijing, MEPI/Moscow and AIT/Tuebingen, consists of multiwire proportional counter and phoswish scintillators with a sensitive area 1600 cm and slat coUimator of 3° X 3°... 

McMahon, T. A., Clark, C., Murthy, V. S., and Shapiro, A. H., Intra-aratic balloon experiments in a lumped-element hydraulic model of the circulation, 7. Biomech., 4 335-350,1971. 

Bom in France, Joseph Louis Proust was the second son of an apothecary. (We have seen—and will continue to see— that apothecaries produce fine chemists.) Proust was initially apprenticed to his father, but when he was 20, despite his father s objection, he moved to Paris. He continued his education in chemistry and physics and participated in some of the first piloted balloon experiments. He eventually found a permanent teaching position in Spain, though he was reportedly an indifferent teacher. He married a Spanish woman of French descent. 

At the present time approximately thirty groups around the world are actively pursuing a variety of balloon-borne infrared observing programs. Table I is a list of groups which have flown an infrared astronomical balloon experiment during the 1970 s. 

Gamma rays are produced in copious quantities in the upper atmosphere of the Earth as a consequence of cosmic-ray interactions. Balloon experiments rely typically on the growth curve technique to estimate the contribution of atmospheric gamma rays to the observed event count rate. In this method, the total count rate of the detector is determined as a function of the residual atmosphere remaining... 

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