On a property of the stable or conditionally stable solutions of systems of non-linear differential equations

Summary Qualitatively expressed me assert the following. If the equation (1.1)·(1.2) fulfills the restriction(1.6)·(1.7)·(1.8) whic are less restrictive than usual, then all solutions with norms tending to O with1/t cannot be ?to small? in an arbitrary interval in t ≧ 0 with fixed length. A Giovanni Sansone nel suo 70° compleanno.     

Revised multi-choice goal programming for multi-period,multi-stage inventory controlled supply chain model with popup stores in Guerrilla marketing

In this paper, we consider a supply chain network design problem with popup stores which can be opened for a few weeks or months before closing seasonally in a marketplace. The proposed model is multi-period and multi-stage with multi-choice goals under inventory management constraints and formulated by 0–1 mixed integer linear programming. The design tasks of the problem involve the choice of the popup stores to be opened and the distribution network design to satisfy the demand with three multi-choice goals. The first goal is minimization of the sum of transportation costs in all stages; the second is to minimization of set up costs of popup stores; and the third goal is minimization of inventory holding and backordering costs. Revised multi-choice goal programming approach is applied to solve this mixed integer linear programming model. Also, we provide a real-world industrial case to demonstrate how the proposed model works.     

A numerical study of rotation effects on jets effusing from inclined holes into a cross-flow

In this work, the complexity of the flow field arising from the impact of the interaction of coolant jets with a hot cross-flow under rotation conditions was numerically simulated using large eddy simulation with artificial inflow boundary condition. The finite-volume method and the unsteady PISO (Pressure Implicit with Splitting of Operators) algorithm were applied on a non-uniform staggered grid. The simulations were performed for four different values of rotation number (Ro) of 0.0, 0.03021, 0.06042, and 0.12084, a jet Reynolds number of 4700, based on the hole width and the jet exit velocity. The air jet was injected at 30° and 90° in the streamwise direction with a density ratio of 1.04 and a velocity ratio of 0.5. The flow fields of the present study were compared with experimental data in order to validate the reliability of the LES technique. It was shown that the rotation has a strong impact on the jet trajectory behaviour and the film cooling effectiveness. The film trajectory always inclines centrifugally. Under rotating conditions, the film trajectory departs from the centreline to the left boundary. The deflection becomes greater as Ro increases. Furthermore, it was also found that the injection angle has a strong impact on separation and reattachment behaviour as well as the strength of the penetration into the cross-flow. As it increases, the distribution of the film cooling downstream the jet exit is more non-uniform and the film cooling effectiveness level slightly decreases.     

Synthesis of highly functionalized BEDT-TTF analogues incorporating 1,4-dithiin rings from 1,8-diketones

Employment of 1,8-diketone ring formation reaction led to the synthesis of tetrathiafulvalene derivatives having diphenyl-1,4-dithiin ring together with dihydroxyl, dimethyl, MEM and diphenylthiophene groups. Spectroelectrochemistry of ET and its fully unsaturated analogue 4 was compared. While both displayed nearly similar behaviours, ET started to precipitate as the second oxidation potential is reached. CV studies indicated that the fully unsaturated 4 and tetraphenyldithiophene 20 have the highest oxidation potentials, while diphenyldithiindimethylthio 16 displayed the lowest oxidation potentials. CV measurements indicated that the combination of dithiin and hydroxyl groups help lowering the oxidation potentials. It is surprising that while the presence of dithiin ring results in higher oxidation potentials, hydroxyl groups lower the potentials. Single crystal structure of 13, having both dithiin and 1,4-dithiepine rings, was examined and it was observed that dithiin and dithiepine rings form angles of 20.52° and 25.65° with the planar TTF core in cis form as both rings bent about their S?S axis to give a boat conformation.     

Persistence of undercompressive phase boundaries for isothermal Euler equations including configurational forces and surface tension

The persistence of subsonic phase boundaries in a multidimensional Van der Waals fluid is analyzed. The phase boundary is considered as a sharp free boundary that connects liquid and vapor bulk phase dynamics given by the isothermal Euler equations. The evolution of the boundary is driven by effects of configurational forces as well as surface tension. To analyze this problem, the equations and trace conditions are linearized such that one obtains a general hyperbolic initial boundary value problem with higher‐order boundary conditions. A global existence theorem for the linearized system with constant coefficients is shown. The proof relies on the normal mode analysis and a linear form in suitable spaces that is defined using an associated adjoint problem. Especially, the associated adjoint problem satisfies the uniform backward in time Kreiss–Lopatinski? condition. A new energy‐like estimate that also includes surface energy terms leads finally to the uniqueness and regularity for the found solutions of the problem in weighted spaces. Copyright © 2016 John Wiley & Sons, Ltd.     

Electrical properties of nitrogen implanted GaSe single crystal

N‐implantation to GaSe single crystals was carried out perpendicular to c‐axis with ion beam of 6 × 10¹⁵ ions/cm² dose having energy values 30 keV and 60 keV. Temperature dependent electrical conductivities and Hall mobilities of implanted samples were measured along the layer in the temperature range of 100‐320 K. It was observed that N‐implantation decreases the resistivity values down to 10³ Ω‐cm depending on the annealing temperature, from the room temperature resistivity values of as‐grown samples lying in the range 10⁶‐10⁷ Ω‐cm. The temperature dependent conductivities exhibits two regions (100‐190 and 200‐320 K) with the activation energies of 234‐267 meV and 26‐74 meV, for the annealing temperatures of 500 and 700 °C, respectively. The temperature dependence of Hall mobility for the sample annealed at 500 °C shows abrupt increase and decrease as the ambient temperature increases. The analysis of the mobility‐temperature dependence in the studied temperature range showed that impurity scattering and lattice scattering mechanisms are effective at different temperature regions with high temperature exponent. Annealing of the samples at 700 °C shifted impurity scattering mechanism toward higher temperature regions. In order to obtain the information about the defect produced by N‐implantation, the carrier density was analyzed by using single donor‐single acceptor model. We found acceptor ionization energy as E_a = 450 meV, and acceptor and donor concentration as 1.3 × 10¹³ and N_d = 3.5 × 10¹⁰ cm⁻³, respectively. (© 2003 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)