Material voids in elastic solids with anisotropic surface energies

This work discusses the role of highly anisotropic interfacial energy for problems involving a material void in a linearly elastic solid. Using the calculus of variations it is shown that important qualitative features of the equilibrium shape of the void may be deduced from smoothness and convexity properties of the interfacial energy.     

Entire Solutions to Equivariant Elliptic Systems with Variational Structure

We consider the system Δu ? W _u (u) = 0, where \({u : \mathbb{R}^n \to \mathbb{R}^n}\) , for a class of potentials \({W : \mathbb{R}^n \to \mathbb{R}}\) that possess several global minima and are invariant under a general finite reflection group G. We establish existence of nontrivial G-equivariant entire solutions connecting the global minima of W along certain directions at infinity.     

Hexafluorobenzene: a powerful solvent for a noncovalent stereoselective organocatalytic Michael addition reaction

A dramatic enhancement of the diastereo- and enantioselectivity in the nitro-Michael addition reaction organocatalysed by a commercially available α,α-L-diaryl prolinol was disclosed when performing the reaction in unconventional hexafluorobenzene as a medium. DFT calculations were performed to clarify the origin of stereoselectivity and the role of C(6)F(6).     

Radiation effects on viscosimetry of protein based solutions

Due to their good functional properties allied to their excellent nutritional value, milk protein isolates and soy protein concentrates have gained a crescent interest. These proteins could have their structural properties improved when some treatments are applied, such as gamma irradiation, alone or in presence of other compounds, as a plasticizer. In this work, solutions of those proteins were mixed with a generally recognized as safe plasticizer, glycerol. These mixtures (8% protein (w/v) base) at two ratios 1:1 and 2:1 (protein:glycerol) were submitted to a gamma irradiation treatment (⁶⁰Co), at doses 0, 5, 15 and 25 kGy, and their rheological performance was studied. As irradiation dose increased viscosity measurements decayed significantly (p<0.05) for mixture soy/glycerol and calcium caseinate/glycerol. The mixture sodium caseinate/glycerol showed a trend to form aggregation of macromolecules with dose of 5 kGy, while the apparent viscosity for dispersions containing whey/glycerol remained almost constant as irradiation dose increases. In the case of soy protein isolate and sodium caseinate, a mixture of 2:1 showed a significant higher viscosity (p<0.05) than a mixture of 1:1.     

The Use of Real-World Computer Models for Computer-Aided Design of Tracking Control Schemes for Induction Motors

The design of tracking controllers for induction motors is usually developed by neglecting the presence of power-supply devices, such as inverters, and measurement apparatuses, e.g., encoders. However, these components represent unmodeled dynamics that are present during the real operating conditions of the induction motor. Since the development of a numerical simulation study represents a low-cost, safe, and fast test to validate the design of tracking control schemes, the need arises to build a computer model of the overall system (i.e., motor, power supply, measurement devices, and tracking controller) as realistic as possible. In this context, the paper describes a computer model for simulation of an induction motor under a tracking control scheme including many real-world effects; namely, encoder's quantization, current sensors' noise, stator current dynamics, presence of a current-controlled voltage-source inverter within a stator current regulator loop, flux observer dynamics, saturation of the control signal, and discrete-time implementation of the control algorithm. The developed computer model is finally used in a case study and the simulation results obtained for an induction motor driving a single-link robotic arm under an H8 tracking control scheme are reported.     

Measurement of separate cosmic-ray electron and positron spectra with the fermi large area telescope

We measured separate cosmic-ray electron and positron spectra with the Fermi Large Area Telescope. Because the instrument does not have an onboard magnet, we distinguish the two species by exploiting Earth's shadow, which is offset in opposite directions for opposite charges due to Earth's magnetic field. We estimate and subtract the cosmic-ray proton background using two different methods that produce consistent results. We report the electron-only spectrum, the positron-only spectrum, and the positron fraction between 20 and 200?GeV. We confirm that the fraction rises with energy in the 20-100?GeV range. The three new spectral points between 100 and 200?GeV are consistent with a fraction that is continuing to rise with energy.     

Stability of Pólya–Szegő inequality for log-concave functions

A quantitative version of Pólya–Szeg? inequality is proven for log-concave functions in the case of Steiner and Schwarz rearrangements.     

Functions of Bounded Variation¶and Rearrangements

The action of the symmetric rearrangement of functions of bounded variation is investigated. In particular, pointwise regularizing effects are established. Pólya-Szeg? type inequalities, with a characterization of equality cases, are also proved.     

Non conventional syntheses of heterocyclic compounds. 2. Synthesis of 1H-4,5-dihydro-1,3,4-benzotriazepine derivatives

Arylazoanils carrying aromatic methyl or ethyl groups in the position ortho to the imine function thermally cyclize to give 1H-4,5-dihydro-1,3,4-benzotriazepine derivatives in fairly good yields. A study of the effect of the substituents on both the aryl rings is reported. The reaction is interpreted as an internal oxo-reduction process.