Structural health monitoring (SHM) is a major component of the vehicle health monitoring (VHM) concept currently considered for the civilian and military aerospace applications. Piezoelectric wafer active sensors (PWAS) are one of the candidate embedded sensors considered for SHM applications. PWAS are inexpensive, non-intrusive, un-obtrusive, devices that can be used in both active and passive...

In this study, experimental work was carried out on reinforced concrete (RC) beams strengthened with carbon fiber polymers (CFRP) plates. This study aims to examine the effect of reinforcement ratio flexural behavior these and propose a new model for predicting debonding moment. Six RC consisting three control CFRP plates were tested. The simply supported loaded four-point bending. test variabl...

BACKGROUND It is unclear whether eczema prevalence is truly increasing worldwide. OBJECTIVE We sought to investigate worldwide secular trends in childhood eczema. METHODS Children (n = 302,159) aged 13 to 14 years in 105 centers from 55 countries and children aged 6 to 7 years (n = 187,943) in 64 centers from 35 countries were surveyed from the same study centers taking part in Phase One an...

Multiwalled carbon nanotubes (MWCNTs) were covalently modified with different molecular weights 400 and 2000 poly(oxyalkylene)-amine bearing DGEBA epoxy (POA400-DGEBA and POA2000-DGEBA) oligomers via a grafting method. The weight-average molecular weights of POA400-DGEBA and POA2000-DGEBA were measured as 1623 and 9231 with polydispersity indices (PDIs) of 2.3 and 1.6, respectively. The oxidize...

background: flexural strength of prosthesis made with dental composite resin materials plays an important role in their survival. the aim of this study was investigating the effect of nanoclay fillers and poly (methyl methacrylate)-grafted (pmma-grafted) nanoclay fillers loading on the flexural strength of fiber-reinforced composites (frcs). materials and methods: standard frc bars (2 × 2 × 25 ...

We demonstrate the experimental realization of a multiresonant metamaterial for Lamb waves, i.e., elastic waves propagating in plates. The metamaterial effect comes from the resonances of long aluminum rods that are attached to an aluminum plate. Using time-dependent measurements, we experimentally prove that this metamaterial exhibits wide band gaps as well as sub- and suprawavelength modes fo...

Dowling-Degos disease (DDD) is a rare genetic disease of the skin (reticulate pigmented anomaly), clinically characterized by flexural brown pigmented reticulate macules, comedo-like papules on the back, neck and pitted perioral or facial scars. We present the case of a 51 year-old man with macrocomedo-like lesions, pitted scars, cysts, hyperpigmented macules in his back, chest, axillae, neck, ...

In this paper a novel method for acoustic emission (AE) source location in dispersive media is presented by processing the low-frequency components of the flexural waves arrived in arbitrary positioning transducers. The accurate location of the source is obtained by minimizing the time-domain square error (TDSE) between a model-based AE source signals arrived at any sensor and the real signals....