For nominal 3 and 9 nm FePt nanoparticles coated with oleylamine/oleic acid and having a face-centred-cubic (fcc) structure, temperature variations (5–300 K) of magnetization M, ac susceptibility χ′ and χ″ for the frequency range fm = 0.1–1000 Hz and electron magnetic resonance (EMR) spectra at 9.28 GHz are reported. X-ray diffraction of the samples shows fcc structure with a lattice constant a = 3.84 Å and TEM characterization yields log-normal distributions of the particle sizes with average D = 3.15(0.16) nm and D = 8.70(0.12) nm for the 3 nm and 9 nm samples, respectively. M versus T data for the zero-field-cooled and field-cooled modes yield a blocking temperature TB = 15 K (85 K) for the 3 nm (9 nm) samples whereas the hysteresis loops at 5 K yield a coercivity Hc = 0 Oe (1.4 kOe). Analysis of the data of TB at different fm determined from the peaks in χ″ in ac susceptibility and the temperature variation of the EMR spectra are used to determine the following parameters of the Vogel–Fulcher relaxation for the 3 nm (9 nm) samples respectively: the attempt frequency fo = 8 × 1010 Hz (2 × 1012 Hz); inter-particle interaction temperature To = 3 K (33 K) and anisotropy Ka = 1.96 × 106 ergs cm−3 (4.3 × 105 ergs cm−3). The use of the above parameters for the calculations of the optimum size for magnetic hyperthermia is analysed and discussed.

A lattice model of membrane proteins with a composite energy function is proposed to study their folding dynamics and native structures using Monte Carlo simulations. This model successfully predicts the seven helix bundle structure of sensory rhodopsin I by practicing a three-stage folding. Folding dynamics of a transmembrane segment into a helix is further investigated by varying the cooperativity in the formation of alpha helices for both random folding and assisted folding. The chain length dependence of the folding time of a hydrophobic segment to a helical state is studied for both free and anchored chains. An unusual length dependence in the folding time of anchored chains is observed.

Photo-decomposition of sulfamethazine (SMT) involves photolytic and photo-catalytic reactions, which occur simultaneously.

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