Dental ceramics are presented within a simplifying framework allowing for understanding of their composition and development. The meaning of strength and details of the fracture process are explored, and recommendations are given regarding making structural comparisons among ceramics. Assessment of clinical survival data is dealt with, and literature is reviewed on the clinical behavior of meta...

A low head recirculating aquaculture system has been designed, constructed, and is being tested at the Vriginia Tech Aquaculture Lab. Each recirculating system contains two grow-out tanks; a filtration vessel containing a microscreen drum filter; and four rotating biological contactor (RBC) biofilters; sixteen airlift pumps (eight per tank); a regenerative blower with air lines, vacuum lines, a...

Two ceramic smoking-pipe bowls, excavated in Lalibela Cave, Begemeder Province, Ethiopia, were radiocarbon dated to 1320 ±2 80 A.D. A modified thin-layer chromatographic technique, applied to the pipe residues, yields positive tests for cannabis-derived compounds. Long-lived cannabinoids, produced by the heat of smoking from short-lived psychoactive ingredients in cannabis, makes identification...

abstract : alumina (al 2 o 3 ) is one of the most practical ceramics used in making ceramic-metal armours. to improve the properties of alumina, some other materials are added to it. in this paper, sic material as nano powder is added to alumina, and four armour samples of this new ceramic with different volume fractions (v.f. ) including 0%, 5%, 10% and 15% of sic particles are made. then, the...

This study is an attempt to investigate the mechanical behavior of proppant packs deforming under compression loading. A generalized confined compression test (CCT) was simulated in the present study to investigate the deformation of walnut/ceramic proppants against compression. In this way, the CCT was simulated using ABAQUS explicit code. Unlike ordinary CCT, we obtained permeability of compr...