Study the Effect of Absorption Solution for Same Composite Polymeric Material
In this paper concerns an investigation of absorption solution in materials of polymeric composite were prepared two types of the matrix material were used (PE,PVC). Also two types of fiber were used (woven and short glass fiber ).with volume fraction 20%. The sample were immersed in different solution (NaCO3-KOH –HCL , Normality 0.5 N) for equal time at constant temperature (room temperature ±20C ) . The result show that the relative mass gain increased with increasing the immersion time till they tend saturation moisture mass after that the relative mass gain decreased . The result show that sample in (KOH)solution had higher mass gain while the sample immersed in (HCL) had lower mass gain .Also the results show that the sample immersed in (NaCO3) has maximum diffusion coefficient which means minimum absorption resistance, while the sample immersed in (HCL) has minimum diffusion coefficient which means maximum absorption resistance.
Liquid Transport Through Polymer Nanocomposites
Transport of molecules through polymer is a controlling factor in several applications such as protective coating and membrane separation process. This chapter provides a detailed study of liquid transport in polymer composites. Topics covered include liquid transport in elastomers, thermoplastics, thermosets, and blend composites. Effect of filler loading and applications of transport in polymer composites are also discussed here. Diffusion through composites/elastomers follows generally follows Fick's law. In natural rubber/carbon black composites, the nature of carbon black plays an important role. Transport properties vary with different factors like temperature, nature of thermoplastic, and fiber. On the basis of different experimental studies on liquid transport through polymer composites are discussed.
Studies on root enamel (2). Enamel pearls. A review of their morphology, localization, nomenclature, occurrence, classification, histogenesis and incidence.
Enamel pearls are one of a number of different enamel structures that can be found on the roots of deciduous and permanent teeth. They have a distinct predilection for the furcation areas of molar teeth, particularly the maxillary third and second molars. They can consist primarily of enamel, but in most instances, a core of dentin is contained within them. On rare occasions, even pulpal tissues can be found. Enamel pearls usually occur singularly, but up to 4 enamel pearls have been observed on the same tooth. Depending on the study, enamel pearls on permanent molar teeth have an incidence rate of between 1.1%-9.7% with distinct differences among racial and national groups. The incidence of enamel pearls increases greatly in histological studies, suggesting that they are often obscured by a covering of cementum.