A Stochastic Subgradient Method for Distributionally Robust Non-convex and Non-smooth Learning

Journal of Optimization Theory and Applications - We consider a distributionally robust formulation of stochastic optimization problems arising in statistical learning, where robustness is with...     

An infeasible-start framework for convex quadratic optimization,with application to constraint-reduced interior-point and other methods

Mathematical Programming - A framework is proposed for solving general convex quadratic programs (CQPs) from an infeasible starting point by invoking an existing feasible-start algorithm tailored...     

Formation of Hydrophobic and Superhydrophobic Coatings on Track-Etched Membrane Surfaces to Create Composite Membranes for Water Desalination

Colloid Journal - Different methods have been considered for the formation of coatings on the surface of a hydrophilic poly(ethylene terephthalate) track-etched membrane with the help of...     

Stacking Aggregation and Photodimerization of Thymine Chromophores in Aqueous Solutions of Polythymidylic Acid

Optics and Spectroscopy - Heterogeneity of aqueous solutions of polythymidylic acid (poly-T) at room temperature is established by luminescence and absorption spectroscopy. It is found that there...     

Portable single-sided NMR measurements at variable temperatures: Implementation of a thermo-controlled device and application to the heating of bread dough

A temperature control unit was implemented to vary the temperature of samples studied on a commercial Mobile Universal Surface Explorer nuclear magnetic resonance (MOUSE-NMR) apparatus. The device was miniaturized to fit the maximum MOUSE sampling depth (25 mm). It was constituted by a sample holder sandwiched between two heat exchangers placed below and above the sample. Air was chosen as the fluid to control the temperature at the bottom of the sample, at the interface between the NMR probe and the sample holder, in order to gain space. The upper surface of the sample was regulated by the circulation of water inside a second heat exchanger placed above the sample holder. The feasibility of using such a device was demonstrated first on pure water and then on several samples of bread dough with different water contents. For this, T1 relaxation times were measured at various temperatures and depths and were then compared with those acquired with a conventional compact closed-magnet spectrometer. Discussion of results was based on biochemical transformations in bread dough (starch gelatinization and gluten heat denaturation). It was demonstrated that, within a certain water level range, and because of the low magnetic field strength of the MOUSE, a linear relationship could be established between T1 relaxation times and the local temperature in the dough sample.     

Aggregation Behavior and Catalytic Action of Carbamate-Bearing Surfactants in Aqueous Solutions

Kinetics and Catalysis - The aggregation behavior of new cationic hexadecyl surfactants with one or two alkylcarbamate fragments in the head group in water was studied using conductometry,...     

Stereodivergent Desymmetrization of Simple Dicarboxylates via Branch-Selective Pd/Cu Catalyzed Allylic Substitution

Asymmetric desymmetrization has been demonstrated to be a powerful strategy for building stereocenters in asymmetric synthesis. Herein, a Pd/Cu catalyzed asymmetric desymmetrization reaction with a simple geminal dicarboxylate is reported. A wide scope of imino esters bearing an aryl or heteroaromatic group were compatible with this bimetallic catalytic system. The reactions proceeded smoothly, giving the desired products in good yields with high to excellent regio-, diastereo-, and enantioselectivity (up to 20 : 1 branched:linear, >20 : 1 dr, >99 % ee). Notably, the reaction favored branched selectivity, which is unusual for the Pd-catalyzed allylic alkylation reaction. In addition, the standard product could be easily transformed to other valuable molecules such as chiral allylic alcohols, carbamates, and organic boron compounds. Furthermore, DFT calculations were conducted to explain the origin of the branched selectivity.     

Present-Day Practice of Non-Target Chemical Analysis

Journal of Analytical Chemistry - We review the main techniques, procedures, and information products used in non-target analysis (NTA) to reveal the composition of substances. Sampling and sample...     

Study of Sorption Properties of Bog Ores for Extraction of Manganese and Iron Ions from Ground Water

Russian Journal of Applied Chemistry - Results are presented of a study of the sorption properties of iron-manganese bog ores, aimed to assess the possibility of using these ores to purify natural...