In this paper, first the limitations of the ray-based method and the one-way wave-field extrapolation migration (WEM) in imaging steeply dipping structures are discussed by some examples. Then a new method of the reverse time migration (RTM), used in imaging such complex structures is presented. The proposed method uses a new wave-field extrapolator called the Leapfrog-Rapid Expansion Method (L...

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...

Curing is a critical process in the compression molding of carbon fiber reinforced polymer (CFRP). It directly bears on quality molded products. Based curing theory resin-based polymers, thermo-mechanical-chemical multi-field coupling model for CFRP form thermal-chemical subprocess, matrix flow-compaction sub-process and residual stress-deformation sets up its data exchange mutual call relation...

A wood-based prepreg was formed using vacuum assisted resin transfer molding (VARTM) and a low viscosity thermoplastic resin. Wood strands were assembled to make porous mat for injection. The filled most of the cavities inside wood cells resulting in void volume fraction 7%. Young’s modulus strength saturated 38% 124% higher, respectively, than those prior infusion. Flat laminates produced by t...

BACKGROUND Medical researchers often use longitudinal observational studies to examine how risk factors predict change in health over time. Selective attrition and inappropriate modeling of regression toward the mean (RTM) are two potential sources of bias in such studies. METHOD The current study used Monte Carlo simulations to examine bias related to selective attrition and inappropriate mo...

Electrodeposition of a roughened copper coating onto steel was carried out to produce bonding surface for thermoplastic resin (polyphenylenesulfide). The film electrodeposited using sulfate bath containing polyacrylic acid (PAA). Following injection molding the resin, strength evaluated in tensile lap shear test, followed by durability testing at high temperature and humidity (85 ± 2 °C 85 2% r...

In this paper we propose Re-Transport Media (RTM), a peer-to-peer streaming architecture which amortizes the bandwidth costs of serving internet media by cooperatively distributing the streaming load among connected clients. Conventional media streaming architectures typically impose significant bandwidth load on the server’s Internet uplink, requiring the content provider to serve the stream t...

In the pathogenesis of thrombotic thrombocytopenic purpura (TTP), reductions in the enzyme activity of ADAMTS13, which cuts ultralarge von Willebrand multimers, generates shear stress on the microvascular endothelium, leading to platelet aggregation and the formation of a thrombus. ADAMTS13 activity is markedly decreased in typical TTP, but is only mildly reduced in secondary TTP, which concomi...

Background and Aim: Water sorption is one of the most important properties that affects the quality of a prosthesis, and subsequently, the quality of treatment, and pa-tient’s quality of life. The aim of this study was to determine and compare the water sorption of two types of poly methyl methacrylate (PMMA) using the injection-molding systems with a traditional acrylic resin base material. M...