Results 341 to 350 of about 107,176 (359)

Void formation in short‐fiber thermoplastic composites

Polymer Composites, 1989
AbstractVoids, or bubbles, are formed in short‐fiber thermoplastic composites because of entrapment of air in the compounding and melt flow processing steps and as a result of uneven shrinkage due to temperature gradients involved in the solidification step by cooling.
S. Kenig, Moshe Narkis, Anita Vaxman, Arnon Siegmann   +3 more
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STRUCTURAL METHODS FOR COMPOSITES IN THE PRESENCE OF POROSITY/VOIDS

2013
Porosity/void locations and shapes obtained by X-Ray Computed Tomography are essential for accurate predictions of strength and fatigue life by structural analysis models of curved-beam ...
Guillaume Seon, Yuri G Nikishkov, Andrew Makeev   +2 more
openaire   +1 more source

Characterisation of voids in fibre reinforced composite materials

NDT & E International, 2012
Abstract Voids and porosity are critical imperfections in fibre reinforced composite materials. The aim of this study is to assess the comparative accuracy and reliability of conventional and novel void characterisation techniques for analysing voids within carbon fibre reinforced composite (CFRC) laminates.
Xiaowen Yuan, Mark I. Jones, John Eric Little   +2 more
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Effective properties of composite materials containing voids

Proceedings of the Royal Society of London. Series A: Mathematical and Physical Sciences, 1993
Recent results of theoretical and practical importance prove that the two-dimensional (in-plane) effective (average) Young’s modulus for an isotropic elastic material containing voids is independent of the Poisson’s ratio of the matrix material.
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The Porosities or Voids Included in Composite Resin Restorations

Advanced Materials Research, 2013
Purpose: The aim of this in vitro study was to investigate effects of consistency of resin composite and insertion techniques on the formation of porosity or inclusion of air bubbles in resin composite restorations. Materials and Methods: Three resin composites (Tetric Ceram HB, Tetric EvoCeram and Prodigy) were selected to represent high, intermediate
Wu Zhang, Clyde L. Roggenkamp, Sean S Lee, Xin Yi Zhao   +3 more
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Do vesical and voided urine have identical compositions?

Scandinavian Journal of Urology and Nephrology, 2004
In view of the concept that the urothelium is a functioning epithelium, we investigated the hypothesis that the composition of urine is modified as it passes through the urethra from the urinary bladder to the exterior.The study was performed in 22 healthy volunteers (13 males, 9 females; mean age 44.6+/-6.2 years).
Olfat El Sibai, Ali A. Shafik, Ahmed Shafik, Ismail Ahmed   +3 more
openaire   +3 more sources

Does the composition of voided urine reflect that of the renal pelvis?

Urological Research, 2006
Studies have shown that the urothelium has a transport function and that urine composition changes on its way through the urinary tract. In this study, we investigated the hypothesis that the composition of voided urine differs from and does not reflect that of the renal pelvis.
Olfat El Sibai, Ismail Ahmed, Ali A. Shafik, Ahmed Shafik   +3 more
openaire   +3 more sources

Measurement of voids in composites by X-ray Computed Tomography

Composites Science and Technology, 2013
Abstract Manufacturing defects often lead to significant degradation of structural behavior in composite parts. Recent advances in X-ray Computed Micro-Tomography were shown to improve non-destructive assessment of defects in composites. Current methods of porosity/void detection by X-ray Computed Tomography use qualitative techniques prone to large ...
Yuri Nikishkov, Luca Airoldi, Andrew Makeev   +2 more
openaire   +2 more sources

Void Formation in Metal Matrix Composites

2000
The mechanisms of void nucleation, growth and coalescence in discontinuously-reinforced metal-matrix composites are critically reviewed. Starting from experimental observations, mechanical models are presented to predict the influence of microstructural factors (reinforcement size, shape, volume fraction, spatial distribution and strength, interface ...
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Void formation in composite prepregs – Effect of dissolved moisture

Composites Science and Technology, 2010
Abstract Void formation as a function of resin moisture content was investigated to better understand and control process defects in composite parts made from prepreg. In this study, uncured prepreg was conditioned at 70%, 80% and 90% relative humidity and at 35 °C. Conditioned prepreg was laid up into quasi-isotropic laminates and cured using vacuum
Steven Nutt, Lessa Kay Grunenfelder
openaire   +2 more sources