Different concentrations of fillers such as manganese dioxide (MnO 2 ) and magnetite (Fe 3 O 4 ) were incorporated into acrylonitrile butadiene rubber (NBR)-interlinked composites. The prepared composite systems were irradiated by electrons at a constant dose of 50 kGy to induce radiation cross-linking under atmospheric conditions. The effect of different contents of fillers and temperature variations on direct current (DC) electrical conductivity, DC , in NBR/MnO 2 and NBR/Fe 3 O 4 mixture systems was investigated. The calculated activation energy, ÁE DC , from DC was found to be highly affected by both the type and concentration of the fillers, while the dielectric properties namely dielectric constant, dielectric loss, and the alternating current (AC) electrical conductivity ( AC ), were measured as functions of frequency and temperature and for different filler concentrations of MnO 2 and Fe 3 O 4 . The AC value was calculated from dielectric measurements and by employing a simple relationship. The analysis of the AC results shows that the conductivity increases up to a temperature of about 330 K. Further increase of temperature reduces the conductivity of Fe 3 O 4 samples, while the conductivity of MnO 2 samples tends to show almost constant values after this temperature. Mechanical properties, tensile strength (TS), tensile modulus at 100% elongation, and hardness were established as a function of different concentrations of fillers MnO 2 and Fe 3 O 4 . It was found that filler incorporation into the NBR matrix is one of the major factors that enhance the TS as well as hardness resistance, while the elongation at break shows an adverse behavior by increasing the content of MnO 2 and Fe 3 O 4 fillers.

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Simulation approach has been widely utilized for design and planning of a warehouse logistic system. As technology advances, better simulation tools have been developed. This enables decision makers to create more realistic models to represent the actual scenario. As a result, better evaluation could be made especially regarding dynamic factors within system. Thus, complex logistic problems could be solved. This paper reviews the fundamentals of warehouse logistic and the simulation tools available to analyze logistic problems.

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