This paper presents an investigation into the durability of alkali-activated slag (AAS) concrete exposed to acid attack. To study resistance of AAS concrete in acid environments, AAS concrete was immersed in an acetic acid solution of pH=4. The main parameters studied were the evolution of compressive strength, products of degradation, and microstructural changes. It was found that AAS concrete of Grade 40 had a high resistance in acid environment, superior to the durability of Nike Free 3.0 V2
OPC concrete of similar grade.
Following the work of Schur and Coleman, we prove the generalized Laguerre polynomial <img height="26" border="0" style="vertical-align:bottom" width="332" alt="" title="" src="http://origin-ars.els-cdn.com/content/image/1-s2.0-S0022314X04000599-si1.gif"> is irreducible over the rationals for all n⩾1 and has Galois group An if n+1 is an Nike Free Run Black Uk
odd square, and Sn otherwise. We also show that for certain negative integer values of α and certain congruence classes of n modulo 8, the splitting field of Ln(α)(x) can be embedded in a double cover.
An investigation was made to determine whether methane (CH4) could assist with polymer formation during fabrication of amorphous carbon hard masks. The results indicated that when CH4 is added to a simple O2/N2 chemistry superior sidewall profiles are seen. Profiles can be modified by addition of extra methane or by an increase in low frequency RF power. Subsequent tests with the simpler CH4/O2 chemistry showed similar profiles could be obtained suggesting this chemistry may also be suitable for etching carbon.