Lattice Gas Model in Random Medium and Open Boundaries: Hydrodynamic and Relaxation to the Steady State

We consider a lattice gas interacting by the exclusion rule in the presence of a random field given by i.i.d. bounded random variables in a bounded domain in contact with particles reservoir at different densities. We show, in dimensions d≥3, that the rescaled empirical density field almost surely, with respect to the random field, converges to the unique weak solution of a quasilinear parabolic equation having the diffusion matrix determined by the statistical properties of the external random field and boundary conditions determined by the density of the reservoir. Further we show that the rescaled empirical density field, in the stationary regime, almost surely with respect to the random field, converges to the solution of the associated stationary transport equation.     

Homogenization of rectangular cross-section fibre-reinforced materials: bending–torsion effects

We study the homogenization of an elastic material in contact with periodic parallel elastic rectangular cross-section fibres of higher rigidity. The interactions between the matrix and the fibres are described by a local adhesion contact law with interfacial adhesive stiffness parameter depending on the period. Assuming that the Lamé constants in the fibres and the stiffness parameter have appropriate orders of magnitude, we derive a class of energy functionals involving extension, flexure and torsion terms.     

Strong gravitational lensing by a charged Kiselev black hole

We study the gravitational lensing scenario where the lens is a spherically symmetric charged black hole (BH) surrounded by quintessence matter. The null geodesic equations in the curved background of the black hole are derived. The resulting trajectory equation is solved analytically via perturbation and series methods for a special choice of parameters, and the distance of the closest approach to black hole is calculated. We also derive the lens equation giving the bending angle of light in the curved background. In the strong field approximation, the solution of the lens equation is also obtained for all values of the quintessence parameter \(w_q\). For all \(w_q\), we show that there are no stable closed null orbits and that corrections to the deflection angle for the Reissner–Nordström black hole when the observer and the source are at large, but finite, distances from the lens do not depend on the charge up to the inverse of the distances squared. A part of the present work, analyzed, however, with a different approach, is the extension of Younas et al. (Phys Rev D 92:084042, 2015) where the uncharged case has been treated.     

Energy harvesting from quasi-periodic vibrations using electromagnetic coupling with delay

In this paper, we study quasi-periodic vibrational energy harvesting in a delayed self-excited oscillator with a delayed electromagnetic coupling. The energy harvester system consists in a delayed van der Pol oscillator with delay amplitude modulation coupled to a delayed electromagnetic coupling mechanism. It is assumed that time delay is inherently present in the mechanical subsystem of the harvester, while it is introduced in the electrical circuit to control and optimize the output power of the system. A double-step perturbation method is performed near a delay parametric resonance to approximate the quasi-periodic solutions of the harvester which are used to extract the quasi-periodic vibration-based power. The influence of the time delay introduced in the electromagnetic subsystem on the performance of the quasi-periodic vibration-based energy harvesting is examined. In particular, it is shown that for appropriate values of amplitudes and frequency of time delay the maximum output power of the harvester is not necessarily accompanied by the maximum amplitude of system response.     

Ultrasound-Assisted Extraction of Carotenoids from Carrot Pomace and Their Optimization through Response Surface Methodology

Ultrasound-assisted extraction (UAE) was used to extract carotenoids from the carrot pomace. To investigate the effect of independent variables on the UAE, the response surface methodology (RSM) with central-composite design (CCD) was employed. The study was conducted with three independent variables including extraction time (min), temperature (°C), and ethanol concentration (%). The results showed that the optimal conditions for UAE were achieved with an extraction time of 17 min, temperature of 32 °C, and ethanol concentration of 51% of total carotenoids (31.82 ± 0.55); extraction time of 16 min, temperature of 29 °C, and ethanol concentration of 59% for a combination of β-carotene (14.89 ± 0.40), lutein (5.77 ± 0.19), and lycopene (2.65 ± 0.12). The non-significant (p > 0.05) correlation under optimal extraction conditions between predicted and experimental values suggested that UAE is the more productive process than conventional techniques for the extraction of carotenoids from the carrot pomace.     

Stereoselective synthesis of (2E) 3‐amino‐2‐(1H‐benzimidazol‐2‐yl)acrylate and symmetric bisacrylates by transamination reactions

A range of various amines 2(a–i) was tested in transamination reactions using ethyl 2‐(1H‐benzimidazol‐2‐yl)‐3‐dimethylamino‐acrylate 1a. The (E)‐s‐cis/trans conformation of some representative products 4 was analyzed by ¹H and ¹³C NMR spectra. The C‐2/C‐3 bond of the compounds 3(a–i) is strongly polarized by a push‐pull effect. In the same manner, reactions of ethyl 2‐(benzoxazol‐2‐yl)‐3‐dimethylamino‐acrylate 1c with 1,4‐diaminobenzene 2i, ethylenediamine 2i, and 1,5‐diaminomaphthalene 2k have been investigated and gave directly the corresponding symmetric bis‐acrylates 4(a–c) in good yields. © 1999 John Wiley & Sons, Inc. Heteroatom Chem 10: 446–454, 1999     

Mesoporous γ‐Iron Oxide Nanoparticles for Magnetically Triggered Release of Doxorubicin and Hyperthermia Treatment

Mesoporous iron‐oxide nanoparticles (mNPs) were prepared by using a modified nanocasting approach with mesoporous carbon as a hard template. mNPs were first loaded with doxorubicin (Dox), an anticancer drug, and then coated with the thermosensitive polymer Pluronic F108 to prevent the leakage of Dox molecules from the pores that would otherwise occur under physiological conditions. The Dox‐loaded, Pluronic F108‐coated system (Dox@F108‐mNPs) was stable at room temperature and physiological pH and released its Dox cargo slowly under acidic conditions or in a sudden burst with magnetic heating. No significant toxicity was observed in vitro when Dox@F108‐mNPs were incubated with noncancerous cells, a result consistent with the minimal internalization of the particles that occurs with normal cells. On the other hand, the drug‐loaded particles significantly reduced the viability of cervical cancer cells (HeLa, IC₅₀=0.70 μm ), wild‐type ovarian cancer cells (A2780, IC₅₀=0.50 μm ) and Dox‐resistant ovarian cancer cells (A2780/AD, IC₅₀=0.53 μm ). In addition, the treatment of HeLa cells with both Dox@F108‐mNPs and subsequent alternating magnetic‐field‐induced hyperthermia was significantly more effective at reducing cell viability than either Dox or Dox@F108‐mNP treatment alone. Thus, Dox@F108‐mNPs constitute a novel soft/hard hybrid nanocarrier system that is highly stable under physiological conditions, temperature‐responsive, and has chemo‐ and thermotherapeutic modes of action.