I present an overview of nal coalgebras together with a description of initial algebras, showing the analogies between the two. In particular , I show how initiality of algebras leads to the properties of deenition by recursion and proof by induction. I then show how nal coalgebras have the analogous properties of deenition by corecursion and proof by coinduction, motivating the latter by Peter...

We discuss two themes from Chandra observations of galaxies, groups, and clusters. First, we review the merging process as seen through the high angular resolution of Chandra. We present examples of sharp, edge-like surface brightness structures " cold fronts " , the boundaries of the remaining cores of merger components and the Chandra observations of CL0657, the first clear example of a stron...

Type I (Na8Si46) or type II (Nax?24Si136) silicon clathrates films with a large 15 × 45 mm2 surface have been synthesized from p-type and intrinsic c-Si (001) wafers using two-step process without the need of any glove box. Conditions to selectively obtain either phase finely tuned. Optical absorption coefficients are found much larger in Si than diamond visible light range. provide direct band...

the our main goal of the present research is evaluating the performance of mno2 nanoparticles-agx zeolite composite as a novel adsorbent catalyst for the decontamination reactions of two most known sulfur mustard simulants; 2-chloroethyl phenyl sulfide (2-ceps), 2-chloroethyl ethyl sulfide (2-cees) at room temperature and monitoring by gas chromatography flame ionization detector (gc-fid) and g...