Biodiversity of sponges (Phylum: Porifera) off Tuticorin, India

The present study deals with 18 new records of sponges found at Kayalpatnam area and a checklist of sponges reported off Tuticorin in the Gulf of Mannar. The new records are Aiolochoria crassa, Axinella damicornis, Clathria (Clathria) prolifera, Clathrina sororcula, Clathrina sinusarabica, Clathrina coriacea, Cliona delitrix, Colospongia auris, Crella incrustans, Crambe crambe, Hyattella pertusa, Plakortis simplex, Petrosia (Petrosia) ficiformis, Phorbas plumosus, Spheciospongia vesparium, Spirastrella cunctatrix, Xestospongia muta and Sycon ciliatum. Details about the species diversity of common sponges, invasive sponges,massive sponges and boring sponges of the area are discussed and presented

Structural singularities in GexTe100−x\mathrm{Ge_{x}Te_{100−x}} films

Structural and calorimetric investigation of Ge$_{x}$Te$_{100−x}$ films over wide range of concentration 10 < x < 50 led to evidence two structural singularities at x ~ 22 at. % and x ~ 33-35 at. %. Analysis of bond distribution, bond variability, and glass thermal stability led to conclude to the origin of the first singularity being the flexible/rigid transition proposed in the framework of rigidity model and the origin of the second one being the disappearance of the undercooled region resulting in amorphous materials with statistical distributions of bonds. While the first singularity signs the onset of the Ge–Ge homopolar bonds, the second is related to compositions where enhanced Ge–Ge correlations at intermediate lengthscales (7.7 Å) are observed. These two threshold compositions correspond to recently reported resistance drift threshold compositions, an important support for models pointing the breaking of homopolar Ge–Ge bonds as the main phenomenon behind the ageing of phase change materials