Superdecomposable Pure-Injective Modules and Integral Group Rings

We prove that if G is a non-trivial finite group, then the integralgroup ring ZG possesses a superdecomposable pure-injective module.     

Affinity liquid chromatography and capillary electrophoresis of seminal plasma proteins

Interactions of boar, bull, and human seminal plasma proteins with heparin and phosphorylcholine were studied by affinity LC using heparin immobilized to a Toyopearl support. A step gradient elution from 0.15 to 1.50 M NaCl was employed to elute the seminal plasma proteins. Relative amounts of the heparin-binding fraction of seminal plasma proteins (H+) in seminal plasma of three species were determined. Further on, the fraction of seminal plasma proteins interacting with phosphorylcholine-binding proteins (P+) was evaluated. P+ proteins were not found in human seminal plasma and their highest amount was present in bull seminal plasma. A CE method was developed for separation of seminal plasma proteins. Various capillaries and separation conditions were tested; the best resolution was obtained in a bare-silica capillary, with a micellar system consisting of a 0.02 M borate buffer and 0.05 M SDS pH 10.0. The optimized conditions were applied to the identification of the components in boar plasma.     

A robust optimization approach to wine grape harvesting scheduling

Optimization models are increasingly being used in agricultural planning. However, the inherent uncertainties present in agriculture make it difficult. In recent years, robust optimization has emerged as a methodology that allows dealing with uncertainty in optimization models, even when probabilistic knowledge of the phenomenon is incomplete. In this paper, we consider a wine grape harvesting scheduling optimization problem subject to several uncertainties, such as the actual productivity that can be achieved when harvesting. We study how effective robust optimization is solving this problem in practice. We develop alternative robust models and show results for some test problems obtained from actual wine industry problems.     

Co-Jacobian for Lipschitzian Maps

The notion of co-Jacobian is introduced for locally Lipschitz functions acting between arbitrary normed spaces. The main results of this paper provide a characterization, calculus rules, a mean value theorem, as well as the computation of the co-Jacobian of piecewise smooth functions. Comparisons with known differentiability notions and Mordukhovich’s co-derivatives are derived.     

Potassium Doped Single Wall Carbon Nanotubes: Resistance under Pressure

Abstract

We report in situ measurements of four-probe de resistance (R) of K-doped purified single wall carbon nanotube (SWNT) “buckypaper” as a function of quasi-hydrostatic pressure. Doped samples show completely different behavior compared to that of pristine nanotubes in the pressure range up to 90 kbar. The characteristic increase in the resistance of pristine buckypaper above 10 kbar, associated with the formation of kinks or/and twists of tubes, is not observed in K-doped samples. This may originate from 1) a substantial change in electronic band structure of donor intercalated nanotubes, 2) completely different transport properties of defect structures, or 3) higher stiffness of doped SWNT's which prevents formation of kinks and twists in this pressure range. On deintercalation, the pristine behavior of R(P) is restored, establishing the reversibility of potassium vapor-transport doping.     

Synthesis of Novel 3‐Aryl‐5‐dichloromethyl‐Δ2‐1,2,4‐oxadiazolines

The first synthetic approach to hitherto unknown 3‐aryl‐5‐dichloromethyl‐Δ²‐1,2,4‐oxadiazolines, of synthetic and biological interest, has been developed involving high‐yield reactions between N‐(2,2‐dichlorovinyl)benzimidoyl chlorides and hydroxylamine. The molecular structure of one member of this new family of compounds—5‐dichloromethyl‐3‐(4‐fluorophenyl)‐1,2,4‐oxadiazoline—has been determined by X‐ray crystallography. Density functional theory calculations supporting the proposed reaction pathway for the formation of these products have been carried out.     

A structural study of new tetrakis(1H-pyrazol-1-yl)methanes

Tetrakis(1H-pyrazol-1-yl)methanes are very rare compounds of which only two are known: the unsubstituted 1 obtained classically by Hückel in 1937 from carbon tetrachloride and prepared again several times and the 3,5-dimethyl substituted 2 obtained serendipitously by Pombeiro in 2009. We have now extended this group to include four new derivatives 8, 9, 11 and 12 bearing methyl groups. The X-ray crystal structure of the four compounds has been determined. They have been studied by NMR both in solution (¹H, ¹³C, ¹⁵N) and in the solid state (¹³C and ¹⁵N). DFT calculations of the six compounds (geometries, energies and absolute shieldings) have been used to discuss the experimental observations.     

Oxidative sulfamidation of vinyl silanes: A route to diverse silylated N-Heterocycles

The reaction of trimethyl(vinyl)silane 1 and dimethyl(divinyl)silane 2 with various sulfonamides in the oxidative system (tert-BuOCl + NaI) has been studied and shown to be an efficient approach for the synthesis of silylated N-heterocycles. Triflamide demonstrated the reactivity principally different from that of arenesulfonamides. With silane 1, it afforded the products of iodochlorination and bis(triflamidation) (major), whereas arenesulfonamides gave N-arenesulfonylaziridines in up to 91% yield. Silane 2 with arenesulfonamides yielded the products of mono and bis(iodochlorination), mono and bis(aziridination), and 3,5-diiodo-4,4-dimethyl-1-(arylsulfonyl)-1,4-azasilinanes. By contrast, triflamide, apart from the products of halogenation and iodotriflamidation, unexpectedly gave 3-(trifluoromethylsulfonyl)-5-(triflamido)oxazolidine as the main product. The structure of most heterocyclic products is proved by X-ray analysis. The effect of the silyl group in the substrate and of the substituent in the reagent on the course of oxidative sulfamidation is discussed by comparing with all-carbon analogues.