Acetic acid exists as dimers in organic solvents like benzene, toluene and xylene. Adsorption of dimeric acetic acid on activated charcoal (AC) at various temperatures from benzene, toluene and xylene solutions have been studied. The system obeys Langmuir isotherm, thus signifying a monolayer adsorption of dimers. Corrections on AC-solvent pore volume fillings, molecular cross sectional surface area of acetic acid dimers, the adsorption equilibrium constants, the free energy change and the enthalpy change values are computed at different temperatures for the three solvents. The adsorption process has been found to be physisorption type. The FTIR measurements show that the adsorbed acetic acid dimer seems to retain the cyclic structure against the open chain non-cyclic structure.

Initial growth stages of the ultra thin films of germanium (Ge) prepared by ion beam sputter deposition have been studied using atomic force microscope (AFM) and interference enhanced Raman scattering. The growth of the films follows Volmer-Weber growth mechanism. Analysis of the AFM images shows that Ostwald ripening of the grains occurs as the thickness of the film increases. Raman spectra of the Ge films reveal phonon confinement along the growth direction and show that the misfit strain is relieved for film thickness greater than 4 nm.

In this paper, seventeen different fish Antifreeze Proteins (AFPs) retrieved from Swiss-Prot database are analysed and characterized using In silico tools. Primary structure analysis shows that most of the AFPs are hydrophobic in nature due to the high content of non-polar residues. The presence of 11 cysteines in the rainbow smelt fish and sea raven fish AFPs infer that these proteins may form disulphide (SS) bonds, which are regarded as a positive factor for stability. The aliphatic index computed by Ex-Pasy’s ProtParam infers that AFPs may be stable for a wide range of temperature. Secondary structure analysis shows that most of the fish AFPs have predominant α-helical structures and rest of the AFPs have mixed secondary structure. The very high coil structural content of rainbow smelt fish and sea raven fish AFPs are due to the rich content of more flexible glycine and hydrophobic proline amino acids. Proline has a special property of creating kinks in polypetide chains and disrupting ordered secondary structure. SOSUI server predicts one transmembrane region in winter flounder fish and atlantic cod and two transmembrane regions in yellowtail flounder fish AFP. The predicted transmembrane regions were visualized and analysed using helical wheel plots generated by EMBOSS pepwheel tool. The presence of disulphide (SS) bonds in the AFPs Q01758 and P05140 are predicted by CYS_REC tool and also identified from the three-dimensional structure using Rasmol tool. The disulphide bonds identified from the three-dimensional structure using the Rasmol tool might be correct as the evaluation parameters are within the acceptable limits for the modelled 3D structures.