Direct Synthesis of 1-Butanol from Ethanol in a Plug Flow Reactor: Reactor and Reaction Kinetics Modeling

Bio-ethanol is well known for its use as a gasoline additive. However, it can be blended in low portions to traditional gasoline although it has a corrosive nature. By taking advantage of modern continuous reactor technology and heterogeneous alumina catalysts, ethanol can be upgraded to 1-butanol in fixed beds. Butanol has more feasible properties as fuel component in comparison to ethanol. Mathematical modeling of reaction kinetics revealed a simple kinetic model could be used to describe the complex reaction process on a Cu/alumina catalyst. The reaction kinetics model is based on five parallel reactions in which ethanol reacts to 1-butanol, acetealdehyde, ethyl acetate, diethyl ether and diethoxyethane, respectively.

     

Synthesis of hyperbranched conjugated polymers based on 3-hexylthiophene,triphenylamine and benzo [c] [1,2,5] thiadiazole moieties: convenient synthesis through suzuki polymerization and impact of structures on optical properties

Novel 3-hexylthiophene-based hyperbranched conjugated polymers containing triphenylamine and benzo [c] [1, 2, 5] thiadiazole moieties were synthesized by Suzuki coupling polymerization of tris (4-bromophenyl) amine, 2,2′-(3-hexylthiophene-2,5-diyl) bis(4,4,5,5-tetramethyl-1,3,2-dioxaborolane) and 4,7-dibromobenzo [c] [1, 2, 5] thiadiazole. Organic solvent-soluble polymers with number-average molecular weights of 24,000 and 42,000 g/mol were obtained in 54–57 % yields. Their structures, molecular weights and thermal properties were characterized via proton nuclear magnetic resonance (¹H NMR) and Fourier transform infrared (FT-IR) spectroscopies, gel permeation chromatography (GPC), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and wide-angle powder X-ray diffraction (XRD) measurements. Optical investigation by UV–vis and fluorescence spectroscopies revealed that the incorporation of the benzo [c] [1, 2, 5] thiadiazole moiety in the hyperbranched polymer structure resulted in a red-shift of the maximum absorption wavelength and an increase in the solution-photoluminescence quantum yield, indicating an extension of the conjugation length. The UV–vis, DSC and XRD results demonstrated that the aggregation of conjugated polymer chains could effectively be reduced by the hyperbranched structures and that conjugation length extension via the introduction of benzo [c] [1, 2, 5] thiadiazole units led to the coexistence of both crystalline and amorphous phases in the solid state and in solution upon addition of a non-solvent.     

Copper(I) Bromide‐Dimethyl Sulfide‐Catalyzed Direct Sulfanylation of 4‐Hydroxycoumarins and 4‐Hydroxyquinolinones with Arylsulfonylhydrazides and Selective Fluorescence Switch‐ On Sensing of Cadmium(II) Ion in Water

An efficient protocol for the direct sulfanylation of various 4‐hydroxycoumarins and 4‐hydroxyquinolinones in good yield with arylsulfonylhydrazides as sulfanylating agents was developed via copper(I) bromide⋅dimethyl sulfide‐catalyzed S–O, S–N bond cleavage and C–S cross‐coupling reactions. A highly selective fluorescence turning‐on sensing of cadmium(II) ions in water using the synthesized 3‐sulfanyl‐4‐hydroxycoumarin derivative was also investigated.

     

Core–Shell Nanoarchitectonics of CoFe2O4 Encapsulated La2Fe2O6 Nanoparticles for Their Use in Various Applications

It would be helpful to achieve appropriate synthetic routes to attain larger-scale production at industrial levels of nanocomposites at low costs. In the present work, diphasic composites with core–shell nanostructures formed by La₂Fe₂O₆/CoFe₂O₄ are investigated. The core–shell structure is fabricated via different preparation methods. The advantages and the demerits of the synthesis techniques are discussed. The presence of both the spinel CoFe₂O₄ nano ferrite and orthorhombic La₂Fe₂O₆ perovskite phases is revealed by X-ray diffraction. XPS spectroscopy is utilized to investigate the chemical composition of the prepared samples. The hysteresis loops of the prepared samples exhibit a smooth loop that is resulted from the existence of two homogeneous magnetic phases. For the first time, it has been found that the preparation conditions have the advantage of reducing the switching field distribution value for the core–shell nanoparticles. Exchange coupled core–shell nanoparticles present a high potential to regulate the magnetic properties for numerous applications such as heavy metal removal and/or data storage devices. The maximum adsorption capacity (qm) of Cr III on the core–shell (S3) is higher compared to other adsorbents previously testified in the literature. The cost-effective and eco-friendly prepared core–shell samples with good metal removal capacity have great potential for commercialization.

     

Experimental investigation of lift enhancement by suction-assisted delayed separation of the boundary layer on NACA 0012 airfoil

In the aerodynamic industry, one of the major problems of interest is the lift enhancement without any increase in the drag. In this paper, an attempt is made to increase the lift coefficient by delayed boundary layer separation using suction at various points, also the study is carried out to identify the optimum location for suction which provides maximum lift augmentation. The experiment is conducted with selected suction pressures of 60, 70, 80, 90?kN/m² at different locations in the range of 40–75% of the chord length of the airfoil. Among the selected pressures, the lowest one at the 70% length provides maximum performance. The critical Reynolds number occurs at around 95% of the length instead of 45% of the length when the same experiment is conducted without suction. The suction also assists in the heat transfer enhancement over the airfoil surface.     

Absolute Isotherms of Adsorption of Components of Binary Liquid Solutions of Macro- and Microporous Adsorbents

Protection of Metals and Physical Chemistry of Surfaces - The methods of describing absolute adsorption isotherms of binary nonelectrolyte solutions components on macro- and microporous adsorbents...     

Peculiarities of Sorption of Copper(II) Ions by Modified Wool Keratin

Protection of Metals and Physical Chemistry of Surfaces - The results of studying the equilibrium and kinetics of Cu2+ ions’ sorption from aqueous solutions by the initial and modified wool...     

The Effect of Organosilanes on Protective Properties of Polymer Coatings for Underground Pipelines. Inhibition of Cathodic Peeling-off of Polymer Coatings from Metal

Protection of Metals and Physical Chemistry of Surfaces - Protective properties of polymer coatings are mainly determined by their adhesion properties. Organosilanes represent the most commonly...     

Structural Phase State and Thermal Cyclic Stability of the Thermal Barrier Zr–Si–O Coatings Deposited on a Copper Substrate by the Microplasma Method

Protection of Metals and Physical Chemistry of Surfaces - In this work, preparation of thermal barrier coatings based on zirconium oxide is shown. The phased treatment of the copper substrate is...     

Revealing the Phenotypic and Genomic Background for PHA Production from Rapeseed-Biodiesel Crude Glycerol Using Photobacterium ganghwense C2.2

Polyhydroxyalkanoates (PHA) are promising biodegradable and biocompatible bioplastics, and extensive knowledge of the employed bacterial strain’s metabolic capabilities is necessary in choosing economically feasible production conditions. This study aimed to create an in-depth view of the utilization of Photobacterium ganghwense C2.2 for PHA production by linking a wide array of characterization methods: metabolic pathway annotation from the strain’s complete genome, high-throughput phenotypic tests, and biomass analyses through plate-based assays and flask and bioreactor cultivations. We confirmed, in PHA production conditions, urea catabolization, fatty acid degradation and synthesis, and high pH variation and osmotic stress tolerance. With urea as a nitrogen source, pure and rapeseed-biodiesel crude glycerol were analyzed comparatively as carbon sources for fermentation at 20 °C. Flask cultivations yielded 2.2 g/L and 2 g/L PHA at 120 h, respectively, with molecular weights of 428,629 g/mol and 81,515 g/mol. Bioreactor batch cultivation doubled biomass accumulation (10 g/L and 13.2 g/L) in 48 h, with a PHA productivity of 0.133 g/(L·h) and 0.05 g/(L·h). Thus, phenotypic and genomic analyses determined the successful use of Photobacterium ganghwense C2.2 for PHA production using urea and crude glycerol and 20 g/L NaCl, without pH adjustment, providing the basis for a viable fermentation process.