Rayleigh backscattering, optical fiber, optical time reflectometry, OTDR, white light interferometry, optical lowcoherence reflectometry Rayleigh backscattering at a wavelength of 1.55 um is measured in standard single-mode fiber with a spatial resol ution of 32 um and a dynamic range of over 30 dB. A minimum reflection sensitivity of -148 dB is the best reported to date using optical low-coher...

The use of subband coding on image data is discussed. An overviev~ of siibbai~d coding is given. Advantages of subbanding for browsing and progressive resol~itiori ar-e presented. Implementations for lossless and lossy coding are discussed. Algorithn~ considerations and simple implementations of subband systems are given.

The objective of this study is to investigate the ability thermoplastic vulcanizates (TPVs) (materials based on PP/EPDM blend) foam under CO 2 batch conditions. EPDM phase, which dispersed into PP was dynamically crosslinked either by a phenolic resin (Resol) or radical peroxide (dicumyl peroxide). results show an influence crosslinking chemistry extensional viscosity TPV. Regarding chemistry, ...

nanocomposites based on phenolic resol and novolac resins and cloisite 30b were prepared. different kinds of phenolic resins and clay content were studied with respect to the morphology and mechanical properties of the polymer silicate layers. the phenolic resins, namely resol, novolac and their mixture and four different percentages of clay contents, 0.5, 1, 2 and 5 wt% have been considered. x...

This study reports the results of a study aimed at reducing the free formaldehyde content of Phenolformaldehyde resin by using Urea as means for forming a reversible adduct with formaldehyde. The highly volatile formaldehyde has an unpleasant odour and irritates the eyes and nasal passages. The free formaldehyde content (FFC) of the modified resol resin was determined by titration method. With ...

Different resol phenol-formaldehyde prepolymer resins have been synthesized with different formaldehyde / phenol ratios. The phenolic resin composition depends on monomer ratio, catalyst, reaction conditions, and residual free monomers. Temperature and pH conditions under which reactions of phenols with formaldehyde are carried out have a profound effect on the characteristics of the resulting ...