Growth and structure of TiC coatings chemically vapour deposited on graphite substrates

TiC coatings were grown on graphite substrates by the chemical vapour deposition technique, using gas mixtures of CH₄-TiCl₄-H₂ at a total pressure of 10.7 kPa and at temperatures of 1400 and 1425 K. The growth rate and structure of the TiC coatings were investigated as a function of CH₄ and H₂ concentrations. The deposition rate of TiC increased with increasing CH₄ flow rate, but did not change with H₂ flow rate. This behaviour was explained by a mass transport theory. Thermodynamic analyses based on minimization of Gibbs' free energy predicted carbon codeposition with TiC. X-ray diffraction and Auger electron spectroscopy (AES) studies and microstructural observations, however, suggested that free carbon did not form. Textural analyses indicated that the growth of TiC coatings was initiated as randomly oriented crystallites, and as the thickness of the coatings increased, preferentially oriented columnar grains developed. The textures of TiC coatings with the same thickness changed from the 110 orientation to the 100 orientation with decreasing H₂ flow rate for a constant CH₄ flow rate. The CH₄ concentration also greatly influenced the preferred orientation of the coatings.     

Quantum Henry gas solubility optimization algorithm for global optimization

Engineering with Computers - In this article, the lightweight design problems of Timoshenko composite beams with and without considering the uncertainties of input data (i.e., the geometry of beam,...     

HDI trimer based fluorine containing urethane methacrylates for hydrophobic photocured coatings

In this work, hexamethylene diisocyanate (HDI) trimer based two urethane methacrylates were synthesized by reacting 2-hydroxyethyl methacrylate (HEMA) and a fluoroalcohol with HDI trimer. Due to the high viscosity of the fluorinated methacrylates, they were applied onto glass substrates after mixing with tripropylene glycol diacrylate (TPGDA). The performance of the fluorinated resins were compared to a fluorine free HDI trimer based trimethacrylate. The TPGDA diluted formulations were better in terms of surface wettability than the neat resins. TPGDA diluted fluorinated resins exhibited a water contact angle of 109°± 2. All coatings exhibited high surface hardness (4H and 5H) and good adhesion.     

B-Phase solid solutions in Er- and Y-SiAlON glass–ceramics

Glasses with cation composition of M:Si:Al = 3.45:3:2 (where M = Er and Y) with varying nitrogen contents (0, 5, 8, 15 and 22 eq.%) have been prepared by ball milling in alcohol media. These Er- and Y-sialon glasses were heat-treated at temperatures in the range of 950–1200 °C for 10 h to study the crystal phase(s) obtained. Samples were characterised by SEM and XRD and obtained data from XRD were further analysed to obtain unit cell parameters of some phases. It is shown that it is possible to obtain B-phase (Y₂SiAlO₅N) from these glass compositions with relatively low nitrogen contents (5 and 8 eq.%N) but with different unit cell parameters (i.e. a = 3.77–3.81 Å and c = 9.83–9.97 Å) to those reported previously in the literature, suggesting that there are some compositional differences between B-phases obtained from different nitrogen content glasses as well as different modifier cations. Long-term heat treatment studies revealed that the stability range of temperature for Er–B-phase is more extensive than its Y–B-phase equivalent.     

Novel approach with polyfluorene/polydisulfide copolymer binder for high-capacity silicon anode in lithium-ion batteries

In this study, as a novel design with the collaboration of a fluorene and sulfide-based copolymer for Li-ion battery application is presented. Polyfluorene-co-polydisulfide is prepared with desired functional groups to yield a conductivity and good adhesion. These critical and important features are performed by preparing polymers with proper functional groups. The preparation process is accomplished via Suzuki coupling process under Pd catalyst by combining separately synthesized 4,4′-dibromodiphenyl disulfide in combination with 9,9-dioctylfluorene-2,7-bis(trimethylborate). The fully obtained capacity of the silicon particles, that is, at C/10 with the capacity of 1250 mAh g⁻¹ after the 500th cycle, approves the good performance by preserving capacity stability till 600th cycles. The designed and synthesized polymer binder with different functionalities and carbon nanotube additive show better characteristics such as conductivity, high polarity, and binding adhesion. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 48303.     

Anaerobic mesophilic co-digestion of sugar-beet processing wastewater and beet-pulp in batch reactors

In this study, biochemical methane potential (BMP) assay was conducted to investigate the effect of waste mixing and F/M ratio on the co-digestion of wastewater and beet-pulp, in addition to the digestion of the wastes separately. In the studied F/M range (0.51–2.56 g COD/g VSS), observed treatment efficiencies (63.7–87.3% COD removal and 69.6–89.3% VS reduction) were indications of high biodegradability for both wastewater and beet-pulp, which decreased with increasing F/M. It was evident that the extent of biomethanation of wastewater was higher than beet-pulp, owing to the inherent soluble carbohydrates in wastewater. When the co-digestion of the wastes was evaluated, it came up with the result that, major outcome of wastewater addition was to increase methane production rate of beet-pulp, rather than increasing its ultimate biodegradability. Indeed, modeled first-order rate functions indicated that rate constants (k values) differentiated in the ranges between 0.081 and 0.143 day^?1 and 0.028–0.050 day^?1 respectively for wastewater added and non-added reactors. These results indicated that anaerobic co-digestion of wastewater and beet-pulp is promising since wastewater addition significantly increases the rate of biomethanation of beet-pulp.