Effects of SiC particles codeposition and ultrasound agitation on the electrocrystallisation of nickel-based composite coatings

This study analysed the influence of the codeposition of SiC particles with different sizes: 50 nm, 500 nm and 5 μm, and the type of bath agitation (stirring or ultrasonic) on the electrocrystallisation of nickel coatings. The composites matrix microstructure was analysed by means of SEM, EBSD and XRD, to evaluate the grain size, crystal orientation, and internal stresses and was benchmarked against pure nickel samples electrodeposited in equivalent conditions. The codeposition of nano- and microsize particles with an approximate content of 0.8 and 4 vol.%, respectively, caused only a minor grain refinement and did not vary the dominant?<?100?>?crystal orientation observed in pure Ni. The internal stress was, however, increased by particles codeposition, up to 104 MPa by nanoparticles and 57 MPa by microparticles, compared to the values observed in pure nickel (41 MPa). The higher codeposition rate (11 vol.%) obtained by the addition of submicron-size particles caused a change in the grain growth from columnar to equiaxial, resulting in deposits with a fully random crystal orientation and pronounced grain refinement. The internal stress was also increased by 800% compared to pure nickel. The ultrasound (US) agitation during the deposition caused grain refinement and a selective particle inclusion prompting a decrease in the content of the particles with the larger particles. The deposits produced under US agitation showed an increase in the internal stresses, with double values compared to stirring. The increase in the deposits microhardness, from 280 HV in pure Ni to 560 HV in Ni/SiC submicron-US, was linked to the microstructural changes and particles content.

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Effects of Agaricus bisporus on gel properties of chicken myofibrillar protein

The gel-forming ability of myofibrillar protein (MP) is highly correlated with the characteristics of emulsified meat products. Incorporation of Agaricus bisporus (Ab) powder into MP gels may enhance its gel properties to facilitate the development of a novel and safe meat product. Therefore, this study investigated the effects of Ab powder on gel strength, water holding capacity (WHC), texture, rheological behaviour, LF-NMR spin–spin relaxation (T₂), microstructure and protein secondary structure of the MP gel system. The results indicated that the gel strength, WHC, G' value and G" value were significantly improved when the addition of Ab powder increased from 0% to 6% (P < 0.05). Meanwhile, the T₂ relaxation time was shortened, and free water was transformed into immobilised water. The texture of the gel was improved when 1%–4% Ab powder was added compared to the control. Furthermore, Ab filled in the gel network and promoted the unfolding of MP α-helix and the formation of MP β-sheet during the thermal denaturation of MP, leading to a dense aggregated network structure. The study suggested that Ab could be a promising ingredient in improving chicken MP's gel properties and developing fat-reduced meat products.     

Mine inonoations

The paper describes the types of inundations affecting underground mining operations together with their safety, operational, and stability implications. A critical analysis has highlighted three major causes of inundations. These have been classified as event controlled, accidental or spontaneous. The event controlled inundations are associated with the development of fracture zones around a longwall working and followed by main and periodic roof falls in caved mine workings, particularly in coal mines. An approximate theory to predict the event of main and periodic roof falls in the goaf behind the long wall face is given. These types of inundations have been illustrated with several case histories.     

Formation of new functional materials and device heterostructures on the basis of nanosystems of superionic conductors

Search for conditions of conservation of fast ionic transport (FIT) in nanosystems of advanced superionic conductors (ASIC)[1-4] and synthesis of new types of device thin-film heterostructures on this basis is a fundamental scientific problem. ASICs (α-AgI, solid electrolytes of the family RbAg4I5, etc. ) are crystals with a record high level of ionic conductivity and a low value of activation energy E～0. 1 eV.