Thermoluminescence characteristics of different phase transitions from nanocrystalline alumina

Journal of Radioanalytical and Nuclear Chemistry - Nanocrystalline boehmite material was synthesized using the hydrothermal method. Different annealing temperatures have been used to transform...     

Sustainable use of eggshell powder in the composite based on recycled polystyrene and virgin polystyrene mixture

One of the ideas to recycle plastic waste is to mix it with virgin plastic in order to produce sustainable material. In this study, recycled polystyrene (R-PS) is used as a mixing component with virgin polystyrene (PS). Besides, eggshell powder (ESP) was also incorporated to reduce the compounding cost of the composite. Effects of R-PS/PS weight percentage on properties of composites were studied. Increasing PS content has increased tensile properties and impact strength of composites. Results obtained from these properties are in good relation to SEM micrographs. More surprisingly, R-PS plays a crucial role in enhancing the thermal stability of composites. This is simply due to the impurities contained in R-PS.     

Catalytic and biological valorization of a supramolecular mononuclear copper complex based 4‐aminopyridine

Hydrothermal reaction of copper bromide with 4‐aminopyridine in DMF solution yields a new mononuclear copper complex [Cu(C₅H₆N₂)₄]2Br.2(C₃H₇NO) abbreviated Cu‐4AP‐Br . The product was characterized, structurally, by single‐crystal X‐ray diffraction analysis and, thermally, by DSC‐ATG measurement. The inorganic–organic hybrid compound Cu‐4AP‐Br crystallizes in the centrosymmetric space group Pbcn, exhibiting a supramolecular network. Simultaneous DSC‐ATG analysis shows that this compound remains stable up to 100 °C and then performs a successive decompositions accompanied with endothermic peaks. The complex Cu‐4AP‐Br was applied as a catalyst in the Heck coupling reaction under ultrasonic irradiation in various reaction conditions. The yields, obtained for a short period of time, allow us to consider this complex, generating selectivity on the external position of styrene with a preference of the trans form over cis, as an excellent catalyst for this type of reaction. Interestingly, Cu‐4AP‐Br displayed important antibacterial (Gram‐positive and Gram‐negative) and antioxidant activities (β‐carotene bleaching inhibition, scavenging effect on DPPH free radical, and reducing power).     

A Closed Chemobrionic System as a Biochemical Delivery Platform

Inorganic cells bearing calcium silicate membranes were prepared and resembled closed chemical gardens. It was demonstrated that these inorganic cells can successfully be loaded with natural products, proteins and plasmid DNA, and their cargo can be released in a controlled manner. These cells demonstrated the ability of chemical gardens to act as platforms for the sustained delivery of biomolecules and are expected to introduce chemical gardens in the field of biosciences.     

Control of the nonlinear dynamics of a truck and trailer combination

Nonlinear Dynamics - The directional instability problem of a truck and trailer combination in a forward motion has been investigated by developing a dynamic model of the planar rigid-body dynamics...     

A three-level time-split MacCormack method for two-dimensional nonlinear reaction-diffusion equations

A three-level explicit time-split MacCormack method is proposed for solving the two-dimensional nonlinear reaction-diffusion equations. The computational cost is reduced thank to the splitting and the explicit MacCormack scheme. Under the well-known condition of Courant-Friedrich-Lewy (CFL) for stability of explicit numerical schemes applied to linear parabolic partial differential equations, we prove the stability and convergence of the method in L^∞(0,T;L²)-norm. A wide set of numerical evidences which provide the convergence rate of the new algorithm are presented and critically discussed.     

Multiband small zeroth-order metamaterial antenna

A novel resonant metamaterial antenna based on the Composite Right/Left-Handed (CRLH) transmission line (TL) model is presented. The proposed small antenna is designed to operate simultaneously over multiple wireless services (UMTS-WLAN-WIMAX)     

Robust sensor fault estimation for fractional-order systems with monotone nonlinearities

Nonlinear Dynamics - This paper investigates the problem of sensor fault estimation for systems with monotone nonlinearities and unknown inputs. To the best of our knowledge, such a particular...