Loading density

Loading density in terms of required burning characteristics... 

Propellants cast into rockets are commonly case-bonded to the motors to achieve maximum volumetric loading density. The interior of the motor is thoroughly cleaned, coated using an insulating material, and then lined with a composition to which the propellant binder adheres under the environmental stresses of the system. The insulation material is generally a mbber-type composition, filled with siUca, titanium dioxide, or potassium titanate. SiUca-filled nitrate mbber and vulcanizable ethylene—propylene mbber have been used. The liner generally consists of the same base polymer as is used in the propellant. It is usually appHed in a thin layer, and may be partially or fully cured before the propellant is poured into the rocket. 

The mechanical design of the idler roUs is a function of the particular service under which the conveyor operates. Minimum industrial standards for roU dimensions, bearings, and appHcation criteria for different service conditions have been estabHshed (14). Idler life is deterrnined by a combination of factors such as bearings, seals, shell thickness, load density, and the operating environment. 

Empty bags are ordinarily shipped compressed (to obtain high load density) and on pallets, the most common of which measure 1220 by 1065 mm (48 by 42 in), 1220 by 1015 mm (48 by 40 in), and 1270 by 1115 mm (50 by 44 in). The number of empty bags per pallet varies with size, 1500 to 2000 being common. A typical tilled pallet weighs about 907 kg (2000 lb). Pallet loads are often triple-tiered in warehouses. 

Explosive D is approx 80% as brisant as TNT, as indicated by sand tests, but fragmentation tests in shell have shown it to be about 95% as brisant. Both expls have about the same rate of detonation at a d of 1.56g/cc hence, approx equality of brisance would be expected. The rate of detonation of Explosive D has been found to be somewhat affected, particularly at lower loading densities, by the granulation of the material, but this effect is not pronounced. Its expl strength is 98% that of TNT, as evidenced by the ballistic pendulum test (see below)... 

Effect of Base Separation and Loading Density on the Setback Sensitivity of Composition A-3 , PATR 4147 (1970) 5) V.F. DeVost, Pre-... 

Silicon substrate diameter, thickness too mm 500 pm Catalyst loading density 0.8-1.0 g cm ... 

GL 16] [R 12] [P 15] As excess of cyclohexene was used, the kinetics were zero order for this species concentration and first order with respect to hydrogen [11]. For this pseudo-first-order reaction, a volumetric rate constant of 16 s was determined, considering the catalyst surface area of 0.57 m g and the catalyst loading density of1g cm. ... 

As the loading density of a powdered solid explosive is reduced the detonation velocity becomes less. This follows from equation (5) of Chapter 2, asp2 is smaller the lower the density. Calculation shows that at the lowest densities the detonation velocity tends towards a limiting lower value, typically about 2000 m s-1. This is also the detonation velocity in a dust explosion of these substances. 

As well as the normal addition reaction, an extremely exothermic decomposition reaction may occur, particularly at high vessel loadings. At loadings of 0.8 ml of 1 1 mixture per ml, the violent reaction, catalysed by iron(III) chloride, initiates at —40°C and will attain pressures above 0.7 kbar at the rate of 14 kbar/s. At 0.5 ml loading density, a maximum pressure of 68 bar, attained at 114 bar/s, was observed. 

Iwama, G.K. and G.L. Greer. 1979. Toxicity of sodium pentachlorphenate to juvenile chinook salmon under conditions of high loading density and continuous-flow exposure. Bull. Environ. Contam. Toxicol. 23 711-716. 

Herrera, Vargas, et al. (2) report experimental measurements of the behavior of energetic materials burning in a compartment. The results indicate that as the critical loading density, Mc (kg/m3) Increases, the mass burning rate inside the compartment reaches a steady state condition and unburned material is carried out in the plume. Burning of the unburned material then takes place outside the compartment, thereby contributing to the destructive potential of the fire in adjacent spaces. 

The theory behind the method to measure the burning rate was not explicitly presented by Lamb et al. Obviously, the mathematical model must be based on the bed properties, such as packing ratio, loading density, bed height, as well as the trolley speed. No discussion is presented about the limitations and assumptions of the method. 

Figure 6.12 Antigen array signal intensity vs. spot size and loading density. (From Joos, T.O. et al.. Electrophoresis, 21, 2641-2650, 2000. With permission.)...

Azide polymers such as GAP and BAMO are also used to formulate AP composite propellants in order to give improved specific impulses compared with those of the above-mentioned AP-HTPB propellants. Since azide polymers are energetic materials that burn by themselves, the use of azide polymers as binders of AP particles, with or without aluminum particles, increases the specific impulse compared to those of AP-HTPB propellants. As shown in Fig. 4.15, the maximum of 260 s is obtained at (AP) = 0.80 and is approximately 12 % higher than that of an AP-HTPB propellant because the maximum loading density of AP particles is obtained at about (AP) = 0.86 in the formulation of AP composite propellants. Since the molecular mass of the combustion products. Mg, remains relatively unchanged in the region above (AP) = 0.8, decreases rapidly as (AP) increases. 

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