A crossover multi-fluid nonrandom lattice fluid model for pure hydrocarbons and carbon dioxide near to and far from the critical region

The multi-fluid nonrandom lattice fluid model with the local composition concept is capable of describing thermodynamic properties for complex systems, but this model cannot represent the singular behavior of fluids near the critical region. In this research, the multi-fluid nonrandom lattice fluid model for pure fluids is combined with a crossover theory to obtain a crossover multi-fluid nonrandom lattice fluid model which incorporates the critical scaling laws valid asymptotically close to the critical point and reduces to the original classical multi-fluid nonrandom model far from the critical point. The crossover multi-fluid nonrandom lattice fluid model shows a great improvement in prediction of the thermodynamic properties of pure compounds near the critical region.     

Mechanical and barrier properties of MOCVD processed alumina coatings on Ti6Al4V titanium alloy

This study focuses on the implementation of different aluminum oxide coatings processed by metal-organic chemical vapor deposition from aluminum tri-isopropoxide on commercial Ti6Al4V titanium alloy to improve its high temperature corrosion resistance. Films grown at 350 °C and at 480 °C are amorphous and correspond to formulas AlOOH, and Al₂O₃, respectively. Those deposited at 700 °C are composed of γ-Al₂O₃ nanocrystals dispersed in a matrix of amorphous alumina. Their mechanical properties and adhesion to the substrates were investigated by indentation, scratch and micro tensile tests. Hardness and rigidity of the films increase with increasing deposition temperature. The hardness of the coatings prepared at 350 °C and 480 °C is 5.8 ± 0.7 GPa and 10.8 ± 0.8 GPa respectively. Their Young's modulus is 92 ± 8 GPa (350 °C) and 155 ± 6 GPa (480 °C). Scratch tests cause adhesive failures of the films grown at 350 °C and 480 °C whereas cohesive failure is observed for the nanocrystalline one, grown at 700 °C. Micro tensile tests show a more progressive cracking of the latter films than on the amorphous ones. The films allow maintaining good mechanical properties after corrosion with NaCl deposit during 100 h at 450 °C. After corrosion test only the film deposited at 700 °C yields an elongation at break comparable to that of the as processed samples without corrosion. The as established processing–structure–properties relation paves the way to engineer MOCVD aluminum oxide complex coatings which meet the specifications of the high temperature corrosion protection of titanium alloys with regard to the targeted applications.     

Self‐Healing Reduced Graphene Oxide Films by Supersonic Kinetic Spraying

The industrial scale application of graphene and other functional materials in the field of electronics has been limited by inherent defects, and the lack of simple deposition methods. A simple spray deposition method is developed that uses a supersonic air jet for a commercially available reduced graphene oxide (r‐GO) suspension. The r‐GO flakes are used as received, which are pre‐annealed and pre‐hydrazine‐treated, and do not undergo any post‐treatment. A part of the considerable kinetic energy of the r‐GO flakes entrained by the supersonic jet is used in stretching the flakes upon impact with the substrate. The resulting “frozen elastic strains” heal the defects (topological defects, namely Stone‐Wales defect and C₂ vacancies) in the r‐GO flakes, which is reflected in the reduced ratio of the intensities of the D and G bands in the deposited film. The defects can also be regenerated by annealing.     

丝滑从手中陷落

“心随心动，愉悦丝滑。愉悦随时随地，尽享心灵随时随地的愉悦。”——原本巧克力的广告语此时借来形容nendo办公室并不为过，原木的清新，手中的陷落，让这“丝滑”充斥放大，办公室游戏在设计中展开。     

半开放式的负体积设计

当你在网络上搜索“负体积”这个词条的时候也许会出现这样的说法：“负体积是由于元素本身产生很大的变形而造成自我体积的内面跑到外面，或是外面跑到内面。”如何在负体积的承载方式上建立不一样的生活姿态，这是h2o的建筑师要告诉我们的。     

Nanocrystalline scheelite SrWO4: a low temperature co-fired ceramic optical material-synthesis and properties

Nanocrystalline strontium tungstate (SrWO₄) is synthesized through a single step modified combustion process. The X-ray diffraction, Fourier transform Raman and Infrared spectroscopy studies reveal that the as-prepared powder is single phase and possess tetragonal structure. The transmission electron microscopic investigations have shown that the particle size of the as prepared powder is in the range 18–22 nm. The optical constants are estimated from the UV–Visible studies and calculated optical band gap is 4.28 eV. The sample showed maximum transmission in the visible regions but poor transmittance in the ultraviolet region. The photoluminescence spectra recorded at different temperatures showed intense blue emission. The nanocrystalline SrWO₄ obtained by the present combustion method was sintered to 95 % density at a relatively lower temperature of 810 °C for 3 h. The dielectric constant (ε_r) and loss factor (tan δ) of the sintered SrWO₄ pellets at 5 MHz measured at room temperature were 9.9 and 6.29 × 10^?3 respectively. The experimental results obtained in this work demonstrate the application of SrWO₄ as UV filters, transparent films for window layers on solar cells, anti-reflection coatings, scintillators, detectors and for low-temperature co-fired ceramic applications.     

Shift From Coke to Coal Using Direct Reduction Method and Challenges

 Ironmaking involves the separation of iron ores. It not only represents the first step in steelmaking but also is the most capital intensive and energy intensive process in the production of steel. The main route for producing iron for steelmaking is to use the blast furnace, which uses metallurgical coke as the reductant. Concerns over the limited resources, the high cost of coking coals, and the environmental impacts of coking and sinter plants have driven steelmakers to develop alternative ironmaking processes that can use non coking coals to reduce iron ores directly. Since the efficiency and productivity of modern large capacity blast furnaces will be difficult to surpass, blast furnaces will continue to retain their predominant position as the foremost ironmaking process for some time to come. The alternative ironmaking processes are therefore expected to play an increasingly significant role in the iron and steel industry, especially in meeting the needs of small sized local and regional markets. It is likely that the importance of direct reduced iron (DRI) and hot metal as sources of virgin iron will continue to increase, especially in the developing countries where steelmaking is, and will be, primarily based on electric arc furnace (EAF) minimills. Consequently, the challenges that are faced by the new technology have to be embraced.     

Rebound and disinvestment effects in refined oil consumption and supply resulting from an increase in energy efficiency in the Scottish commercial transport sector

In this paper, we use an energy–economy–environment computable general equilibrium (CGE) model of the Scottish economy to examine the impacts of an exogenous increase in energy augmenting technological progress in the domestic commercial Transport sector on the supply and use of energy. We focus our analysis on Scottish refined oil, as the main type of energy input used in commercial transport activity. We find that a 5% increase in energy efficiency in the commercial Transport sector leads to rebound effects in the use of oil-based energy commodities in all time periods, in the target sector and at the economy-wide level. However, our results also suggest that such an efficiency improvement may cause a contraction in capacity in the Scottish refined oil supply sector. This ‘disinvestment effect’ acts as a constraint on the size of rebound effects. However, the magnitude of rebound effects and presence of the disinvestment effect in the simulations conducted here are sensitive to the specification of key elasticities of substitution in the nested production function for the target sector, particularly the substitutability of energy for non-energy intermediate inputs to production.