INTRODUCTION Secondary hyperparathyroidism in end-stage renal disease patients has protean musculoskeletal manifestations. Some of our dialysis patients spontaneously vocalized that they had lost the ability to crack their knuckles and then experienced gratifying restoration after surgical parathyroidectomy. We propose that the physiology and mechanical basis of knuckle cracking would be affect...

In this work, Slow Strain Rate Test (SSRT) testing, Light Optical Microscopy (LOM) and Scanning Electron Microscopy (SEM) were used to study the effect of microstructure, corrosive environments and cathodic polarisation on stress corrosion cracking (SCC) of two grades of high strength steels, Type A and Type B. Type A is manufactured by quench and tempered (Q&T) method. Type B, a normalize stee...

Understanding the mechanism of cracking during the drying of aqueous colloidal dispersions is important to preventing film failure. While most of the reported work has dealt with stable aqueous dispersions, a few studies have focused on flocculated systems. The latter especially assumes importance because the role of particle packing in the mechanism of cracking is not completely understood. In...

When colloidal suspensions dry, stresses build up and cracks often occur -a phenomenon undesirable for important industries such as paint and ceramics. We demonstrate an effective method which can completely eliminate cracking during drying: by adding emulsion droplets into colloidal suspensions, we can systematically decrease the amount of cracking, and eliminate it completely above a critical...

Concrete and cracking are nearly synonymous despite our best efforts and intentions. Relationships between cracking and the stress states that lead to cracking can be instructive. In an effort to better understand these relationships, X-ray microtomography was used to make high-resolution three-dimensional digital images of small concrete specimens under load. Using 3D image analysis, quantitat...

The interaction of laser radiation with dielectrics and metals is detected with femtosecond resolution by pump&probe techniques (t = 80 fs or 3 ps, λ = 810 nm). Even with femtosecond laser radiation melt ejection dynamics can be observed by irradiating metals like copper or aluminium using time-resolved shadowgraphy. Laser-induced melt ejection has been observed in the time range of 100 ns to 1...

Culture extends biology in that the setting of development shapes the traditions that individuals learn, and over time, traditions evolve as occasional variations are learned by others. In humans, interactions with others impact the development of cognitive processes, such as sustained attention, that shape how individuals learn as well as what they learn. Thus, learning itself is impacted by c...