Effects of the nano-tubular anodic TiO2 buffer layer on bioactive hydroxyapatite coating

We studied the effect of nano-tubular anodic TiO2 buffer layers on hydroxyapatite (HA) coating. The pulsed laser deposition (PLD) method was used to deposit HA on a well arranged nano-tubular anodic TiO2 (NT-ATO) buffer layer prepared by an electrochemical anodization technique. The surface morphology and chemical composition of HA coatings were characterized by using scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), and contact angle measurement. We found that crystalline HA coatings show well arranged porous morphologies with a favorable surface wettability. We also found that an anodic nano-tubular TiO2 buffer layer with a relatively short tube length shows a better coating morphology. The deposition process of HA on the nanotubular TiO2 buffer layer was also proposed.     

Gold nanoparticle conjugated poly(p-phenylene-β-cyclodextrin)-graft-poly(ethylene glycol) for theranostic applications

Fluorescent conjugated polymers gained interest in the last decades for both imaging and targeting tumor cells for the purpose of diagnosis and treatment of cancer. In the light of this objective conjugated poly(p-phenylene) possessing β-cyclodextrin (β-CD) units in the main chain and poly(ethylene glycol) side chains is used as an imaging and therapeutic agent to target U87 and Vero cells. Additionally, imaging quality and therapy efficiency of the bare graft copolymer and its gold nanoparticle (AuNP) conjugated form were investigated and compared. It is observed that β-CD is effective not only for the imaging of the tumor cells, but also as a radiotherapy agent. Conjugation of the polymer with the AuNPs provides significant improvement in the therapeutic efficiency. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47250.     

PERFORMANCE OF ACIDIC MCM-LIKE ALUMINOSILICATE CATALYSTS IN PYROLYSIS OF POLYPROPYLENE

Mesoporous aluminosilicate catalysts having different Al/Si ratios were synthesized following a hydrothermal synthesis route and using different aluminum sources, such as aluminum nitrate and aluminum isopropoxide. These mesoporous materials have high surface areas, in the range of 520–1001 m²/g, and exhibit Type IV nitrogen adsorption isotherms. EDS and ²⁷Al MAS NMR results showed that aluminum was incorporated more effectively into the structure of the catalyst forming a tetrahedral framework when aluminum nitrate was used as the aluminum source. The activities of these catalysts in the polypropylene pyrolysis reaction were tested in a TGA apparatus. Results showed a marked reduction in the degradation temperature in the presence of aluminosilicate catalysts. The activation energy of degradation was 172 kJ/mole without any catalyst. However, using the mesoporous aluminosilicate catalysts synthesized by using aluminum nitrate as the aluminum source, activation energy of the degradation reaction decreased to values of about 24–28 kJ/mole.     

Breakthrough Analysis OF H 2 S removal on CU-V-MO,CU-V,and CU-MO mixed oxides

Kinetic studies carried out for the sorption of H 2 S in the presence and absence of hydrogen on Cu-V-Mo, Cu-V, and Cu-Mo mixed oxides gave detailed information about the reaction sequences. Formation of SO 2 even in the presence of hydrogen at the initial stages of the sorption process showed the partial reduction of the metal oxides prior to the sulfidation step. A sorption experiment carried out with Cu-Mo mixed oxide gave incomplete sulfidation of molybdenum, whereas with Cu-V mixed oxide complete sulfidation was obtained. Predictions of the breakthrough curves by the deactivation model showed good agreement with the experimental results.     

Nickel-doped gallium-containing glasses luminescent in the near-infrared spectral range

The heat treatment of glasses synthesized in the M ₂O-Ga₂O₃-GeO₂-SiO₂ (M = Li, Na, K) system results in bulk precipitation of Ga₂O₃ and LiGa₅O₈ nanocrystals and, consequently, in luminescence within the bands with maxima at wavelengths of 1500 and 1300 nm, respectively, with the half-width exceeding 300 nm. In their spectral luminescence properties, the gallium germanium silicate glasses synthesized are similar to the gallium silicate glasses. However, the melting temperature of the former glasses is approximately 100°C lower, which considerably facilitates the preparation of glasses of high optical quality.     

Heat transfer intensification for retrofitting heat exchanger networks with considering exchanger detailed performances

The challenging of this work is to present a thorough study of implementing heat transfer intensification in heat exchanger network (HEN) retrofitting, including all details of exchanger geometry, stream bypassing and splitting, temperature‐variation of properties, LMTD and its correction, and pressure drops. This leads to very complex mixed integer nonlinear programming (MINLP) problems rarely reported before. By adopting the MILP‐based iterative approach proposed in the earlier work (Pan et al., Chem Eng Sci. 2013;104:498–524.), temperature‐variation of properties, LMTD and its correction are initialized to parameters at first, and the rest nonlinear terms are then linearized and expressed as first‐order Taylor series expansions. Finally, two iteration loops are executed to find optimal solutions. A small‐scale motivating problem and an industrial scale problem are presented to demonstrate the validity and efficiency of the proposed methods. © 2018 American Institute of Chemical Engineers AIChE J, 64: 2052–2077, 2018     

Magnetodynamic testing of the thickness of nickel coatings applied under chromium coatings on two-layer (nonferromagnet-ferromagnet) bases

Russian Journal of Nondestructive Testing - The possibility of testing the thicknesses of nickel coatings under chromium coatings on two-layer (nonferromagnetic-ferromagnetic) bases by the...     

Dynamic analysis of adsorption equilibrium and rate parameters of reactants and products in MTBE,ETBE and TAME production

Adsorption equilibrium constants of ethanol, methanol, isobutylene, isoamylenes (2M2B, 2M1B), MTBE and TAME on Amberlyst 15 catalyst were evaluated from the packed bed moment technique. Adsorption equilibrium constants of alcohols were found to be two orders of magnitude greater than the adsorption equilibrium constants of i-olefins and the corresponding tertiary ethers. However, their apparent heat of adsorption values are quite low (-6,7 kJ/mol and ?8.3 kJ/mol for methanol and ethanol, respectively). Among the i-olefins, isobutylene gave the highest adsorption equilibrium constant and the heat of adsorption (-54.2 kJ/mol The adsorption equilibrium constant of 2M2B on a catalyst, which was pretreated with ethanol, was about three times greater than the corresponding value obtained on fresh catalyst. Second moment analysis indicated that diffusion resistance in both macropores and microspheres of the catalyst are equally significant.