Investigation of high-temperature-resistant rhenium–boron neutron shields by experimental studies and Monte Carlo simulations

In this study,novel rhenium–boron neutronshielding high-temperature-resistant materials were designed.The considered samples,Re60–B40,Re58–B42,Re50–B50,and Re40–B60,with different concentrations of rhenium and boron were investigated to elucidate their neutron-shielding performances,and compare them with well-known neutron-shielding materials such as the 316 LN quality nuclear steel.In addition to the experimental studies,Monte Carlo simulations were performed using the FLUKA and GEANT4 codes,where 4.5-MeV neutrons emitted by a ^(241)Am–Be source were employed.Experimental equivalent dose rates,simulated track lengths,energy balances,and neutron mass absorption cross sections were discussed in detail.

Hydrophobic coating of surfaces by plasma polymerization in an RF plasma reactor with an outer planar electrode:synthesis,characterization and biocompatibility

This paper presents the plasma polymerization of poly（hexafluorobutyl acrylate）（PHFBA） thin films on different substrates in an RF plasma reactor with an outer planar electrode. This reactor configuration allows？large area uniformity and fast processing times. Deposition rates of up to60 nm min-1were observed. The influence？of plasma power and substrate temperature on the？deposition rate, structure and wettability of the as-deposited films was？investigated. It was observed that better hydrophobicity was obtained at high plasma power and in low temperature conditions. PHFBA thin films deposited on electrospun poly（acrylonitrile） fiber mats under such conditions resulted in superhydrophobic surfaces with？contact angle values greater than 150°.In？vitro cell studies using human epithelial cells demonstrated the non-toxic nature of the？plasma-polymerized PHFBA films.

Thermoelectric transport behaviours of n-type Mg2 (Si,Sn,Ge) quaternary solid solutions

Mg2X(X=Si,Sn,and Ge)based systems have attracted widespread attention owing to their various benefits in thermoelectric applications.In particular,to date,ternary Mg2X based solid solutions have become one of the most widely investigated thermoelectric systems.However,the investigation of temperature varied thermoelectric properties of Mg2X based quaternary systems is rather limited both theoretically and experimentally.Therefore,here,we report a rigorous theoretical work of thermoelectric properties for n-type Mg2Si0.55-z;Sn0.4Ge0.05Biz quaternary solid solutions(z=0.02,0.025,0.03,and 0.035)from 300 K to 850 K.By using nearly-free-electron model together with Fermi-Dirac statistics we define Fermi level both in extrinsic and intrinsic regimes as a function o f temperature.We follow Hicks and Dresselhaus,approach to calculate electronic transport properties.By performing the Debye's isotropic continuum model a detailed theoretical investigation of lattice thermal conductivity is presented among with various phonon relaxation rates.From our theoretical analysis the highest ZT is attained for Mg2Si0.53Sn0.4Ge0.05Bi0.02 solid solution as 1.14 at 850 K.

Facile Synthesis Route of Au-Ag Nanostructures Soaked in PEG

A nanostructured gold-silver soaked in polyethylene glycol 400 (Au-Ag@PEG) is designed using gold(I) chloride and silver nitrate (AgNO3) as precursors and, polyethylene glycol 400 (PEG) as capping agent. The result of the structure characterization using Selected Area Electron Diffraction (SAED) has showed that the synthesized nanomaterial has a good crystallinity while Transmission Electron Microscopy (TEM), energy dispersive X-ray spectrometry (EDX) and Dynamic Light Scattering (DLS) measurements suggest mixed Au-Ag nanoparticles with an average diameter size of around 7 nm and 30 nm for Au and Ag respectively.