Adsorption behavior of hydrophobin and hydrophobin/surfactant mixtures at the air-water interface

The adsorption of the surface-active protein hydrophobin, HFBII, and the competitive adsorption of HFBII with the cationic, anionic, and nonionic surfactants hexadecyltrimethylammonium bromide, CTAB, sodium dodecyl sulfate, SDS, and hexaethylene monododecyl ether, C(12)E(6), has been studied using neutron reflectivity, NR. HFBII adsorbs strongly at the air-water interface to form a dense monolayer ～30 ? thick, with a mean area per molecule of ～400 ?(2) and a volume fraction of ～0.7, for concentrations greater than 0.01 g/L, and the adsorption is independent of the solution pH. In competition with the conventional surfactants CTAB, SDS, and C(12)E(6) at pH 7, the HFBII adsorption totally dominates the surface for surfactant concentrations less than the critical micellar concentration, cmc. Above the cmc of the conventional surfactants, HFBII is displaced by the surfactant (CTAB, SDS, or C(12)E(6)). For C(12)E(6) this displacement is only partial, and some HFBII remains at the surface for concentrations greater than the C(12)E(6) cmc. At low pH (pH 3) the patterns of adsorption for HFBII/SDS and HFBII/C(12)E(6) are different. At concentrations just below the surfactant cmc there is now mixed HFBII/surfactant adsorption for both SDS and C(12)E(6). For the HFBII/SDS mixture the structure of the adsorbed layer is more complex in the region immediately below the SDS cmc, resulting from the HFBII/SDS complex formation at the interface.     

The search for neutrino bursts from core collapse Supernovae at the Baksan Underground Scintillation Telescope

The current status of the experiment on recording neutrino bursts from core collapse stars is presented. The actual observational time T (from June 30, 1980 until December 31, 2009) is 25.58 years. An upper bound of the mean frequency of gravitational collapse in our Galaxy f _col < 0.090 year^?1 at a 90% confidence level. The results of studying single events at the facility in the case of muon inelastic interaction of cosmic rays with the matter of the detector are presented.     

Antiwear,Antiseize and Antioxidising Properties of Operation‐Conservation Oils Modified with Organometal Oil‐Soluble Additives Containing Nitrogen and Oxygen

The present work aims at studying the antiwear, antiseize and antioxidising properties of anode‐shielding corrosion inhibitors. The physicochemical properties of the inhibitors and those of the operation‐conservation motor oils modified with them were determined. It was found that these inhibitors improve the antiwear, antiseize and antioxidising properties of the motor oils obtained. Real‐life experiments were carried out with a four‐stroke four‐cylinder engine (“Skoda” Czech Republic) mounted on a 30‐ton fishing barge which uses diesel fuel containing up to 1,4% sulphur. The antiwear and antioxidising properties of the oils obtained were determined, and a probable action mechanism of the complex corrosion inhibitors was suggested.     

3D structure of dendritic and hyper-branched macromolecules by X-ray diffraction

The atomic ordering in dendritic and hyper-branched macromolecules has been determined by X-ray diffraction. The approach of the atomic pair distribution function technique has been used due to the lack of 3D periodicity in these polymeric materials. Dendrimers are found to possess a semi-regular structure riddled with nanosize cavities. The cavities are joined into channels connecting dendrimer's surface and core. In contrast, hyper-branched polymers are rather irregular at the atomic scale and with less accessible interior.     

Solvent Vapor Annealing of Block Copolymers in Confined Topographies: Commensurability Considerations for Nanolithography

The directed self‐assembly of block copolymer (BCP) materials in topographically patterned substrates (i.e., graphoepitaxy) is a potential methodology for the continued scaling of nanoelectronic device technologies. In this Communication, an unusual feature size variation in BCP nanodomains under confinement with graphoepitaxially aligned cylinder‐forming poly(styrene)‐block‐poly(4‐vinylpyridine) (PS‐b‐P4VP) BCP is reported. Graphoepitaxy of PS‐b‐P4VP BCP line patterns (C_II) is accomplished via topo­graphy in hydrogen silsequioxane (HSQ) modified substrates and solvent vapor annealing (SVA). Interestingly, reduced domain sizes in features close to the HSQ guiding features are observed. The feature size reduction is evident after inclusion of alumina into the P4VP domains followed by pattern transfer to the silicon substrate. It is suggested that this nano­domain size perturbation is due to solvent swelling effects during SVA. It is proposed that using a commensurability value close to the solvent vapor annealed periodicity will alleviate this issue leading to uniform nanofins.

     

Far field measurement of optodynamic source size

A micro-explosion occurring after pulsed laser-induced breakdown in water can be effectively described as an optodynamic phenomenon. It is a source of shock waves that propagate into the surrounding medium. We present a measurement of the source size based on far field detection of the propagating waves using a beam deflection probe technique. By taking into consideration the moving breakdown model the relation between the size of the breakdown region and the apparent size of the optodynamic source is shown. An energy dependent enlargement parameter d is introduced which describes the relation. PACS 42.62.-b; 52.50.Jm; 52.35.Dm     

Lifetime measurements and particle-core coupling calculations in144Sm

Applying the generalized centroid shift method in the¹⁴²Nd(α, 2n)¹⁴⁴Sm reaction the following half-lives have been measured:T _1/2(3,376 keV)=(1.6±0.2) ns,T _1/2(3,460 keV) =(0.5±0.2) ns andT _1/2(5,150 keV)≦0.3 ns. Level energies and electromagnetic transition rates have been calculated within a particle-core coupling approach that is based on the shell model with configuration mixing. The persistence ofl-forbiddenness of M1 transitions between rather complex configurations could be confirmed.