In composite propellant processing, propellant mixing and casting are the most complex and important operations. A solid propellant mixer must be capable of blending a mixture of solid/liquid ingredients with weight ratios as high as 90% solids and 10% liquids and resultant bulk viscosities ranging up to several kilopoise. Propellant mixing and casting processes are affected significantly by the rheological properties of the uncured propellant. 1 Sometimes too short potlife is a great problem in propellant manufacturing particulary when the solid content is up to 87%. The often used iron compounds generally even in small amounts also catalyze the curing reaction and shorten the pot life. 2 many papers discused the developed methods for improving the composite propellant process by extending its pot life using some affected chemical materials. This work concentrated on a method for improving the manufacturing of the composite propellants dynamically, i.e without adding chemical materials to the propellant formula. This was done by delaying the addition of the curing agent to some hours. During this period a second standared mixing was carrying out. The comparison between the tow kinds of mixing was done to study the effect of the delaying of addition of the curing agent. It was found that viscosity build up test give similar reading for both kinds, which means that the propellant viscocity was not affected by this delaying. It was also found that, the mechanical and performance properties not affected by this step. It confirmed that delaying of the addition of the curing agent in the mixing process can be applied successfully.

A Plastic Bonded Explosives (type PU/RDX) was prepared and cured by casting technique. This aimed for producing a new generation of warheads with high performance and low sensitivity. The obtained PBXs were characterized by determination of melting point, and measurement of some explosive characteristics (Sensitivity to impact and ignition temperature). Properties of this explosive were compared with those of RDX and comp-B by using a computer program. An autodyne program was used to compare the terminal ballistic parameters of 122 mm warhead for different types of explosives (Inert PBXs, energetic PBXs, RDX, and Comp-B). Results show advantages of using energetic PBXs over the other explosives.

Slaughter house waste contains high levels of organic matter and pollutants. These pollutants can affect the ecosystem and public health negatively, to minimize the effects of these pollutants many treatments are used, one of these is biological treatment methods.  In this study potential of biogas production from cattle paunch manure (stomach digestion content) was investigated using a batch process laboratory scale of liters digester size. Three replicate of total solid concentration of (5%, 7%) of cattle paunch manure were mixed with (10%v/v) inoculums with control units for each concentrations at room temperature. The total amount of biogas produced   after 49 days of experiments were, 12.678 L, 11.544 L, 8.154 and 5.724 L for,  7% ,5% TS seeded sample, 7%  and 5% total solid control  respectively.

No abstract

Composite propellant properties are directly affected by many processing parameters, particle size of aluminum is one of these parameters. It affects both mechnical properties and performance parameters of propellants. This research is mainly foucused on the experimental study of the effect of using different particle sizes of aluminum on density, tensile strengh, elongation, burning rate, burning time, average pressure, average thrust, specific impulse, and thrust coefficient of a typical rocket propellant. This was achieved by using the same weight percent of ingredients in the propellant and changing only the particle size of aluminum. In addition, different computer programs were used to determine the probable effect of changing particle size of aluminum on the propellant properties.