Synthesis of 1,3-aminonaphthols by diastereoselective Betti-type aminoalkylation of dihydroxy naphthalenes; diastereoselectivity,absolute configuration,and application

Dihydroxy naphthalenes have been applied in Betti-type solventless condensation between aldehydes and (S)-phenylethylamine as a chiral auxiliary. A series of chiral 1,3-aminonaphthols has been synthesized and isolated in diastereoisomerically pure form. The absolute configurations of the aminonaphthols synthesized have been determined by means of advanced NMR experiments and confirmed by X-ray crystallography. The new chiral aminonaphthols have been tested as pre-catalysts for the addition of diethyl zinc and alkynyl-Zn-reagents to aldehydes with enantioselectivities of up to 98% ee.     

Removal of Methylene Blue from Aging Water Solutions Treated by a Submerged Arc

Low voltage, low energy submerged pulsed arcs with a pulse repetition rate of 100 Hz, energies of 2.6–192 mJ and durations of 10–40 μs, followed by aging in the dark, were used to decompose 10 mg/l methylene blue (MB) dissolved in 40 ml of water, with the addition of 0.5 % H₂O₂. Electrode pairs composed of Fe/Fe, Ti/Ti, Cu/Cu, Cu/Fe, Fe/Cu, Ti/Fe, Fe/Ti, Cu/Ti and Ti/Cu were used. MB degraded during arc treatment, and during post arc treatment aging. The aging degraded MB faster (by a factor of ~2–3) when the MB solution was subjected to arcing with dissimilar electrodes when one of them was Cu, than for arcing with other used electrode pairs. The impact of the arc treatment time and the electrode materials on the MB removal ratio (C₀–C_ta)/C₀ was determined as a function of aging time t_a, where C₀ and C_ta are the MB concentrations initially and after t_a. For a pulse duration of 10 μs and pulse energies of 2–20 mJ, the MB removal rate increased linearly with treatment time and its growth rate increased with pulse energy. The linear dependence of the MB removal rate on treatment time was violated with pulse duration of 40 μs and pulse energies of 30–200 mJ. Kinetics of the MB degradation during aging of the arc treated solution was well described by the 1st order linear rate equation.     

Direct contact free real-time acquisition of temperature profiles in adsorbent bed during vacuum swing adsorption

Real-time temperature co-axial profiles in a bed of mesoporous alumosilicate were recorded by means of FPA-based infrared thermography during air drying vacuum swing adsorption cycles. The good correlation between experimentally measured temperature profiles and profiles simulated on the basis of linear driving force model of mass and heat transfer in nonadiabatic regime is observed.     

Special elements of the lattice of epigroup varieties

We describe right-hand skew Boolean algebras in terms of a class of presheaves of sets over Boolean algebras called Boolean sets, and prove a duality theorem between Boolean sets and étalé spaces over Boolean spaces.     

Why Does Monte Carlo Fail to Work Properly in High-Dimensional Optimization Problems?

The paper presents a quantitative explanation of failure of generic Monte Carlo techniques as applied to optimization problems of high dimensions. Deterministic grids are also discussed.