Aquarium test

Dallas Aquarium Tests. In October of 1981, tests were initiated at Zoecon Industries (Dallas, Texas), using three 10 gallon aquariums, each infested with 5 adult male and 5 adult female german lea. 

The results obtained in these chamber and aquarium tests clearly confirmed the potential of hydroprene as a cockroach control agent with consumer oriented application methods. 

Figure 1. Aquarium tests Dallas (1981) Population development over 6 months in aquaria exposed to fogging with hydroprene and methoprene.

The other group of methods includes those that are based on the registration of the state originated after the shock wave reflection from a barrier. For instance, the detonation pressure m be determined on the basis of the measurement of a thin metal plate firee-surface velocity. The plate free-surface velocity can be determined using optical methods or the electrocontact type of probes and oscilloscope technique. The methods based on the determination of the shock wave velocity through an inert material, e.g., the Aquarium test, are also included in this group. The time resolution of these methods may be on a nanoseconds scale, and even less than a nanosecond, e.g., w en laser interferometry technique is used. Since the processes in the shock fi-ont occur on a nanosecond scale, the present-day techniques are still inadequate to study the detonation wave shock front. 

The aquarium test is essentially a modification of the flying plate test in which the metal plate is replaced by a layer of water or some other optically transparent material, such as Plexiglas. Instead of the determination of the plate free-surface velocity, the traveling of the shock wave through an inert and optically transparent material is viewed as a function of time. When having the shock wave velocity vs. distance dependence, and knowing the adiabatic shock equation of the inert material used, the mass velocity behind the shock wave front and the detonation pressure of a tested explosive may be calculated. 

Several methods of calculating the detonation pressure based on aquarium test data are cited in the literature. One method uses the Goranson equation. This calculation is described below ... 

The determination of the detonation wave parameters and its structure on the basis of the determination of the shock wave velocity in an inert and optically transparent material using a laser follows the same principles as in the case of the aquarium test. However, if compared to the standard aquarium test, it is characterised by a better time resolution, on a nanosecond scale. Thus, this technique allows the study of the detonation wave structure, i.e., the chemical reaction zone width and the duration time (Ashaev et al., 1988). 

For studying the effects of underwater shock, the samples in the shape of pressed pellets of 5 mm diameter and one mm thick, were put in teflon plugs and placed at suitable distances from the donor charge in an aquarium test, as described by Liddiard [12]. Shock waves ranging over 4-18 kbars of pressure and a few microseconds duration could be imparted to the samples. 

Vermiculite-bed test - algae mixture Designed to predict field performance but is absolutely matrix specific Trentepholia - specific, direct inoculation of paint film Aquarium-Test ... 

Several photographic exposures are taken of the detonation front, the shock waves in the water, and the expanding tube-water interface (or bubble-water interface if the tube is absent). The optical data, shown schematically in Figure 2.12. are used to infer detonation velocity, detonation pressure (C-J states), and the release isentrope of the detonation products. A collection of aquarium test data is available in the data volume entitled Los Alamos Explosives Performance Data and on the CD-ROM. An animation of a NOBEL calculation of a PBX-9502 aquarium test is on the CD-ROM in the /MOVIE/AQUAR.MVE directory. 

The aquarium test is also particularly attractive for numerical modeling since water behaves as a true fluid and its equation of state is well defined. The shock wave in the water and the interface between the explosive cylinder and the water expand in a smooth manner without distortions, which makes modeling of the flow easy and accurate. The aquarium test has been used to determine the physics and chemistry of ideal and nonideal explosives. 

Figure 2.11 Water tank containing explosive column for aquarium test. The flood lights furnish the back lighting for the image intensifier camera.

Figure 2.12 Schematic diagram of typical aquarium test result. Three exposures (1, 2, and 3) are shown.

A water-gel explosive called WGE-1 consists of approximately 46 wt% ammonium nitrate, 24 wt% TNT, 15 wt% sodium nitrate, 13.2 wt% water, 1.2 wt% ethylene glycol, and 0.6 wt% thickener) and has a density of 1.5 g/cc. In a 20 cm diameter charge, the detonation speed is 0.481 cm//rsec as described in reference 33. This is well below the BKW ideal detonation speed of 0.73 cm/nsec and C-J pressure of 187 kbar. A BKW calculation, under the assumption that no ammonium nitrate reacts, gives a velocity of 0.495 cm/ijLsec and a pressure of 71 kbar. The aquarium test data could be reproduced for WGE-1 with no ammonium nitrate reacting at the C-J plane and all the ammonium nitrate remaining inert behind the detonation wave. 

Detonation performance tests have been performed for many ammonium salts containing propellants and explosives. Some of the propellants and commercial explosives that have been examined and the nature of their nonideality are summarized in Table 2.5. The first two explosives in the table are common commercial explosives. Aquarium tests were performed for both explosives. To reproduce the observed performance, all of the ammonium nitrate and some of the aluminum had to be treated as inert. The aquarium test for the first commercial explosive required no additional reaction of the ammonium nitrate behind the C-J state. The aquarium test for the second commercial explosive required some additional reaction of the aluminum or ammonium nitrate below the C-J state. The ammonium perchlorate containing systems in Table 2.5 are various propellants. As the amount of ammonium perchlorate is increased in the propellants with corresponding decrease in HMX, the degree of nonideality increases. The propellant with 36% ammonium perchlorate also had the air isentrope state determined. The measured air isentrope particle velocity was 0.6 cm/ sec and 0.6 kbar, which is in agreement with the isentrope for all the ammonium nitrate remaining inert. 

Aquarium tests were also performed for a 15-cm and a 20-cm-diameter ANFO charge in clay pipe surrounded by water. The measured detonation velocities and partially reacted ammonium nitrate interpretations obtained from the aquarium tests follow. 

Figure 2.16 The aquarium test image intensifler photograph with three exposures of a detonation proceeding along a 10-cm-diameter cylinder of ANFO confined with plexiglas confinement in water.

The aquarium test was performed by S. Goldstein . Calculations of the aquarium test for a 20.63-mm radius cylinder of X0233 in water were performed using the 2DL code described in Appendix B. 

Figure 2.23 The aquarium test for X0233. Two photographic exposures taken with the image intensifier camera. The shock wave in the water and the interface between the...

To further test the weak detonation model, S. Goldstein measured the water shock velocity in the aquarium test after the detonation wave interacted with the water above the top of the X0233 cylinder. Her experimental water shock velocities, as a function of distance above the top of the explosive cylinder, are shown in Figure 2.28 along with the calculated water shock velocities. They are consistent with a flat top Taylor wave characteristic of a weak detonation and a detonation front pressure of 160 kbars. The initial water shock velocities exhibit behavior characteristic of irregular decomposition of the explosive near the shock front. The 2DL calculated aquarium pressure contours are shown in Figure 2.29. 

Methods for determining an equation of state for these nonideal explosives for use in numerical hydrodynamic codes have been developed. They depend upon extensive experimental calibration of each explosive in the particular geometry of interest. Aquarium test data are crucial for the evaluation of the nature of the nonideal behavior and for the calibration of the equations of state. 

Aquarium Test - NOBEL Calculation AQUAR.MVE - A Cylinder of PBX-9502 in Water... 

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