Particle size, compaction characteristic and tablet strength of spray-dried fermented jackfruit pulp - microcrystalline cellulose binary powder mixture

The tableting properties for fermented spray dried jackfruit (FJP) and microcrystalline cellulose (MCC) powders were studied. 25% FJP + 75% MCC, 50% FJP + 50% MCC and 75% FJP + 25% MCC binary powder mixtures were compacted into tablet form at various compaction pressures ranging from 15.1 to 73.8 MPa. The properties were compared to pure FJP and MCC tablets. The addition of MCC resulted in a higher particle size and the increased in the plastic work of the tablet. The best ratio of FJP-MCC binary tablet was found to be at 25% FJP + 75% MCC where the tablet showed the highest tensile strength. In conclusion, the addition of MCC to FJP improved the compaction characteristics and the tablet mechanical strength.

Tuneable Magneto-Resistance by Severe Plastic Deformation

Bulk metallic samples were synthesized from different binary powder mixtures consisting of elemental Cu, Co, and Fe using severe plastic deformation. Small particles of the ferromagnetic phase originate in the conductive Cu phase, either by incomplete dissolution or by segregation phenomena during the deformation process. These small particles are known to give rise to granular giant magneto-resistance. Taking advantage of the simple production process, it is possible to perform a systematic study on the influence of processing parameters and material compositions on the magneto-resistance. Furthermore, it is feasible to tune the magneto-resistive behavior as a function of the specimens’ chemical composition. It was found that specimens of low ferromagnetic content show an almost isotropic drop in resistance in a magnetic field. With increasing ferromagnetic content, percolating ferromagnetic phases cause an anisotropy of the magneto-resistance. By changing the parameters of the high pressure torsion process, i.e., sample size, deformation temperature, and strain rate, it is possible to tailor the magnitude of giant magneto-resistance. A decrease in room temperature resistivity of ~3.5% was found for a bulk specimen containing an approximately equiatomic fraction of Co and Cu.