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SynopsisThe rheological behavior of the two-phase systems consisting of a polystyrene-irtstyrene phase distributed in a rubber-in-styrene phase is shown to exhibit increasing IIOIINewtouiari behavior up to the phase inversion point, as a consequence of its two phase nature. The equation is recommended for the prediction of the viscosity of the polymerizing mass up to phase inversion during the production of HIPS by the in situ bulk polymerization of styrene in the presence of dissolved rubber.

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1 Introduction Recently, we reported a magnetic field sensor based on a piezoelectric transformer with a ring-dot electrode pattern [1,2]. A piezoelectric transformer is a two port device, where on one port the input voltage is converted into a stress through the converse piezoelectric effect, and where on the other port this stress is then converted into voltage through the direct piezoelectric effect [3]. In this prior design, a voltage is applied to the ring section at the resonance frequency which induces a magnetic field in the dot section. If an external magnetic object is then brought in the vicinity of the dot section, the change in magnetic field will induce a change in the voltage gain of the transformer via the magnetoelectric (ME) effect. Particulate ME composites of composition 0.8Pb(Zr 0.52 Ti 0.48 )O 3 -0.2Ni 0.8 Zn 0.2 Fe 2 O 4 were used in this prior design. In sintered ceramics, an applied magnetic field generates a strain by magnetostrictive coupling to the ferrite grains, which is then elastically transferred to the piezoelectric grains where it is converted to electric charge [4,5]. It is well-known that the ME effect in sintered composites is small because of: (i) reduced piezoelectric and magnetostrictive constants due to inter-diffusion, (ii) interfacial defects, and (iii) low resistivity. Various investigations have shown that the ME effect is an order of magnitude or more higher in laminate composites, in particular those consisting of magnetostrictive metal alloys [6][7][8]. Here, we report on a magnetic field sensor design with a laminate geometry. Our findings demonstrate enhanced sensitivity to small changes in DC magnetic

This study reports the design, fabrication, and characterization of a tachometer utilizing magnetoelectric (ME) laminate composites with sandwich structure consisting of Pb(Zr,Ti)O3 (PZT) and Galfenol. High temperature characterization of Galfenol shows that it can sustain the magnetic property over 500°C. The Curie temperature of PZT compositions was in the range of 325–340°C. The magnitude of the ME coefficient was found to scale with the dimensionless ratio (d g/S), where d is the piezoelectric strain constant, g is the piezoelectric voltage constant, and S is the elastic compliance. The tachometer design is based on the principle that when ME composite is exposed to oscillating magnetic field, it generates voltage with the same frequency.