Phase transitions are abrupt changes in the macroscopic properties of a system. Examples of the phenomenon are familiar: freezing, condensation, magnetization. Often these transitions are particularly dramatic, as when solid objects composed of the silvery metal gallium vanish into puddles when picked up (the temperature of the hand is just enough to raise gallium’s temperature past its melting...

b An electroanalytical method for studying electrode reactions, called cyclic chronopotenticmetry, in which the applied current is successively reversed a t each t,*ansition, is proposed. A circuit for carrying out automatic current reversals is described. T h e equations for the successive transition times for linear diffusion in a singie clmponent system have been derived and solved, and t h ...

A [Co(24)] metallamacrocycle with a [36-MC(Co)-12] periphery and an inner [24-MC(Co)-6] rim is constructed by linking six Co(4)-thiacalixarene shuttlecock-like SBUs with twelve 1,2,4-triazole molecules.

introduction: congenital hypothyroidism (ch) is one of the most common preventable causes of mental retardation. its worldwide incidence is estimated to be one in 2500-5500 births. assessment of thyroid gland in neonates is critical. the aims of this study were to demonstrate the incidence of ch in neonates born in yazd province, iran in 1389 (2010) and compare the results with other reported s...

introduction: the aim of this in vitro study was to evaluate the effect of calcium hydroxide (ch) on push-out bond strength of white mineral trioxide aggregate (wmta) and calcium-enriched mixture (cem) cement in simulated furcation perforations. methods and materials: furcation perforations, measuring 1.3 mm in diameter and 2 mm in height, were created in 80 human mandibular first molars. the t...

The β-Z selectivity in the hydrosilylation of terminal alkynes has been hitherto explained by introduction of isomerisation steps in classical mechanisms. DFT calculations and experimental observations on the system [M(I)2{κ-C,C,O,O-(bis-NHC)}]BF4 (M=Ir (3a), Rh (3b); bis-NHC=methylenebis(N-2-methoxyethyl)imidazole-2-ylidene) support a new mechanism, alternative to classical postulations, based...