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The samples of Cu 0.9 Mg 0.1 R y Fe 2-y O 4, where y = 0.01 and R = Sm , Dy , Ho and Hf , were prepared by standard ceramic method. All investigated samples were sintered at 1150°C with a heating rate of 4°C/min and sintering time of 8 h. X-ray diffraction study of the compositions revealed the formation of cubic spinel structure with the appearance of small peaks indicating the presence of secondary phases. Seebeck coefficient was obtained from thermo-electromotive force (emf) measurements. The alternation of the Seebeck coefficient sign between (+)ve and (-)ve means that the two conduction mechanisms take place simultaneously. The dielectric parameters such as dielectric constant, quality factor were determined as a function of temperature and at different frequencies. The decrease in Fe 3+ ions on the octahedral site decreased the polarization of the system, through the dielectric transition point.

DESCRIPTION Blending of elastomer is often used to enhance the performance characteristics of rubber products. Compatibilizer is used for the improvement of interfacial interaction, processability, mechanical & chemical properties of the investigated blends. In this study, the effect of acrylonitrile-butadiene-styrene (ABS) compatibilizer in vulcanizable compositions of mixed acrylonitrile butadiene rubber (NBR) and styrene butadiene rubber (SBR) is investigated. Silica and carbon black improve the properties the obtained blends. The effects of blend ratio on the physico –chemical and mechanical properties such as tensile strength, Hardness and swelling of SBR/NBR blend are studied. Addition of NBR decreases the maximum degree of swelling, and the cross link density. It is argued that the compatible blend 50/50 NBR/SBR with the optimum nano white filler has higher durability of the physico-mechanical properties, than the other blend loaded with carbon black.

Temperature changes resulting from application of periodic strain (deformation) with strain amplitudes up to 60% are reported for vulcanized styrene-butadiene rubber loaded with different parts of fast extrusion furnace carbon black at room temperature. The method used involves determination of the thermoelastic coefficient, change in entropy, enthalpy per unit length and Gruneisen constant. Thermal effects were found to be dependent

Nanostructure ferrite of composition Ni0.5Zn0.5Cr0.1Fe1.9O4 was prepared by sol–gel, co-precipitation, citrate-gel, flash and oxalate precursor methods. Structural and micro structural analysis of the investigated samples were carried out by X-rays diffractometer (XRD), infrared spectroscopy, transmission electron microscopy (TEM) and atomic force microscope. It was observed that the lattice parameter of cubic spinel was constant, and the positions of both tetrahedral and the octahedral bands had the fixed positions for all methods except flash and oxalate precursor methods. These results were explained on the basis of theoretical calculation of cation distribution for Ni–Zn–Cr ferrite. The average crystalline sizes of the investigated samples deduced by TEM were in good agreement with the one estimated by XRD. The above results were correlated to the results of magnetic measurements of the investigated samples.

ABSTRACT Different concentrations of super abrasion furnace black filler [SAF (N 115)] and white filler [Silica (Hi-Sil 233D)] were mixed with styrene-butadiene rubber [SBR-1502] cured by conventional sulfur system. Rheometer characteristics, the physico-mechanical behavior, abrasion resistance, hardness and swelling measurements were performed and studied. Comparison between black and white fillers was established and it was found that, filler incorporation into the rubber matrix is one of the major factors that improve the tensile strength, abrasion resistances, hardness and swelling resistance. The increase in tensile strength as well as Young's modulus was attributed to improve interfacial bonding between filler and SBR matrix. The results reveal that vulcanizates containing 30 phr of carbon black and 50 phr of silica ;respectively exhibit the better overall physico-mechanical properties.

Blending of elastomer is often used to enhance the performance characteristics of rubber products. Compatibilizer is used for the
improvement of interfacial interaction, processability, mechanical & chemical properties of the investigated blends. In this study,
the effect of acrylonitrile-butadiene-styrene (ABS) compatibilizer in vulcanizable compositions of mixed acrylonitrile butadiene
rubber (NBR) and styrene butadiene rubber (SBR) is investigated. Silica and carbon black improve the properties the obtained
blends. The effects of blend ratio on the physico –chemical and mechanical properties such as tensile strength, Hardness and
swelling of SBR/NBR blend are studied. Addition of NBR decreases the maximum degree of swelling, and the cross link density.
It is argued that the compatible blend 50/50 NBR/SBR with the optimum nano white filler has higher durability of the
physico-mechanical properties, than the other blend loaded with carbon black.

The samples of Cu0.9Mg0.1RyFe2−yO4, where y = 0.01 and R=Sm, Dy, Ho and Hf, were
prepared by standard ceramic method. All investigated samples were sintered at 1150◦C
with a heating rate of 4◦C/min and sintering time of 8h. X-ray diffraction study of the
compositions revealed the formation of cubic spinel structure with the appearance of
small peaks indicating the presence of secondary phases. Seebeck coefficient was obtained
from thermo-electromotive force (emf) measurements. The alternation of the Seebeck
coefficient sign between (+)ve and (−)ve means that the two conduction mechanisms
take place simultaneously. The dielectric parameters such as dielectric constant, quality
factor were determined as a function of temperature and at different frequencies. The
decrease in Fe3+ions on the octahedral site decreased the polarization of the system,
through the dielectric transition point.

Nanostructure ferrite of composition Ni0.5Zn0.5
Cr0.1Fe1.9O4 was prepared by sol–gel, co-precipitation,
citrate-gel, flash and oxalate precursor methods. Structural
andmicrostructuralanalysisoftheinvestigatedsampleswere
carried out by X-rays diffractometer (XRD), infrared spec-
troscopy, transmission electron microscopy (TEM) and
atomic force microscope. It was observed that the lattice
parameter of cubic spinel was constant, and the positions of
both tetrahedral and the octahedral bands had the fixed posi-
tions for all methods except flash and oxalate precursor
methods. These results were explained on the basis of theo-
retical calculation of cation distribution for Ni–Zn–Cr ferrite.
The average crystalline sizes of the investigated samples
deduced by TEM were in good agreement with the one esti-
mated by XRD. The above results were correlated to the
resultsofmagneticmeasurementsoftheinvestigatedsamples.

Different concentrations of super abrasion furnace black filler [SAF (N 115)] and white filler [Silica (Hi-Sil
233D)] were mixed with styrene-butadiene rubber [SBR-1502] cured by conventional sulfur system. Rhe-
ometer characteristics, the physico-mechanical behavior, abrasion resistance, hardness and swelling
measurements were performed and studied. Comparison between black and white fillers was established
and it was found that, filler incorporation into the rubber matrix is one of the major factors that improve
the tensile strength, abrasion resistances, hardness and swelling resistance. The increase in tensile
strength as well as Young’s modulus was attributed to improve interfacial bonding between filler and
SBR matrix. The results reveal that vulcanizates containing 30 phr of carbon black and 50 phr of silica
respectively exhibit the better overall physico-mechanical properties.