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The size effect, namely the change of sheet resistance, Rs as a function of resistor length, has been investigated in layers whose conductive phase evolves from Pb-rich (Ru-deficient pyrochlores) to Pb2Ru206.5 and finally to RuO2 by increasing the firing temperature. It is found that Bi diffusion from the terminations is responsible for lower sheet resistance values in shorter resistors whatever the conductive phase is. On the contrary, Ag diffusion is responsible for lower sheet resistance values in shorter resistors only in the case of ruthenate conductive grains while the reverse is observed in RuO2-based layers. Size effect can be suppressed with Pt/Au-based terminations provided that no Bi is contained and with Au-metallorganic-based contact provided that the peak firing temperature is not too high.

This study presents the appraisal of indentation hardness and flexural modulus of composites prepared by mixing particles of palm kernel shell (PKS), coconut shell (CNS) and mixtures of palm kernel-coconut shell (MPKCNS) of different sizes (35.5 µm, 75 µm and 106 µm) with epoxy and hardener for various applications. The Rockwell hardness tester results showed that PKS particles epoxy filled composites of 35.5 µm had the highest hardness number of 77 while the MPKCNS particles epoxy filled composites of 106 µm had the least hardness number of 43. The CNS particles epoxy filled composites of 35.5 µm and 75 µm had relatively higher flex moduli of 428.66 MPa and 425.55 MPa respectively. The particle size of 106 µm had relatively higher flexure extension than 35.5 µm and 75 µm. The Scanning Electron Microscope (SEM) analysis revealed proper adhesion of the shell particles and epoxy resins with little or no pores in the composites. The PKS particles epoxy filled composites of 35.5 µm can be employed to enhance the mechanical properties of the composites for engineering applications.