Structure Evolution and Thermal Decomposition of Supramolecular and Lamellar Hybrid Sulfates Templated by 4-Aminopyridinium

Journal of Inorganic and Organometallic Polymers and Materials - The aromatic diamine 4-aminopyridine was used for the synthesis of a series of supramolecular metal–organic sulfate salts. The...     

Correction to: “Measuring the Speed of Data Exchange in Memory Cards Using Programmable Logic Integrated Circuits”

Measurement Techniques - The affiliation of the first author, E. V. Kostikova, is incorrect     

Manufacturing and mechanical characterization of Al<Subscript>2</Subscript>O<Subscript>3</Subscript>/β-TCP/TiO<Subscript>2</Subscript> biocomposite as a potential bone substitute

This paper focuses on the mechanical characterization of a bioceramic based on commercial alumina (Al₂O₃) mixed with synthesized tricalcium phosphate (β-TCP) and commercial titania powder (TiO₂). The effect of β-TCP and TiO₂ addition on the mechanical performance was investigated. After a sintering process at 1600 °C for 1 h, various mechanical properties of the samples have been studied, such as compressive strength, flexural strength, tensile strength, elastic modulus, and fracture toughness. The measurements of the elastic modulus (E) and the tensile strength (σ _t ) were conducted using the modified Brazilian test while the compressive strength (σ _c ) was determined through a compression test. Also, semi-circular bending (SCB) specimens were used to evaluate the flexural strength (σ _f ) and the opening mode fracture toughness (K _IC). From the main results, it was found that the best mechanical performance is obtained with the addition of 10 wt.% TCP and 5 wt.% TiO₂. Alumina/10 wt.% tricalcium phosphate/5 wt.% titania composites displayed the highest values of mechanical properties and a good combination of compressive strength (σ _c ?≈?352 MPa), flexural strength (σ _f ?≈?98 MPa), tensile strength (σ _t ?≈?86.65 MPa), and fracture toughness (K _IC?≈?13 MPa m^1/2).     

Nanofibrous nonwovens based on dendritic‐linear‐dendritic poly(ethylene glycol) hybrids

Dendritic‐linear‐dendritic (DLD) hybrids are highly functional materials combining the properties of linear and dendritic polymers. Attempts to electrospin DLD polymers composed of hyperbranched dendritic blocks of 2,2‐bis(hydroxymethyl) propionic acid on a linear poly(ethylene glycol) core proved unsuccessful. Nevertheless, when these DLD hybrids were blended with an array of different biodegradable polymers as entanglement enhancers, nanofibrous nonwovens were successfully prepared by electrospinning. The pseudogeneration degree of the DLDs, the nature of the co‐electrospun polymer and the solvent systems used for the preparation of the electrospinning solutions exerted a significant effect on the diameter and morphology of the electrospun fibers. It is worth‐noting that aqueous solutions of the DLD polymers and only 1% (w/v) poly(ethylene oxide) resulted in the production of smoother and thinner nanofibers. Such dendritic nanofibrous scaffolds can be promising materials for biomedical applications due to their biocompatibility, biodegradability, multifunctionality, and advanced structural architecture. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 45949.     

Effects of thermal annealing on the optical,spectroscopic, and structural properties of tris (8-hydroxyquinolinate) gallium films grown on quartz substrates

In this study we report the optical, spectroscopic, and structural properties of vacuum deposited tris (8-hydroxyquinolinate) gallium film upon thermal annealing in the temperature range from 85 °C to 255 °C under a flowing nitrogen gas for 10 min. The optical UV–vis–NIR and luminescence spectroscopy measurements were performed to estimate the absorption bands, optical energy gap (E_g), and photoluminescence (PL) of the films. Fourier transform infrared (FTIR) spectroscopy and X-ray diffraction (XRD) techniques were used to probe the spectroscopic and structural nature of the films. We show that, by annealing the films from 85 °C to 235 °C, it is possible to achieve an enhanced absorption and increased photoluminescence to five times stronger than that of the pristine film. The PL quenching at 255 °C was attributed to the presence of plainer chains allow easy going for excitons to a long distance due to the crystalline region formation of α-Gaq3 polymorph. The reduction in E_g and infrared absorption bands upon annealing were referred to the enhancement in π–π interchain interaction and conformational changes by re-arrangement of the Gaq3 quinolinate ligands, respectively. Stokes shift for the films were observed and calculated. From the differential scanning calorimetry, DSC measurements, higher glass transition temperature was observed for Gaq3 (T_g = 182 °C) compared to that of Alq3 (T_g = 173 °C), which suggests the existence of stronger dipolar interaction in Gaq3 due to the Ga³⁺ cation effect, in comparison to that of Alq3.     

Towards treatment planning for the embolization of arteriovenous malformations of the brain: intranidal hemodynamics modeling

This paper presents a patient-derived model for the simulation of the hemodynamics of arteriovenous malformations of the brain (BAVM). This new approach is a step toward the simulation of the outcome of the embolization of the BAVM during treatment planning. More specifically, two aspects of the planning are pursued: simulation of the change of blood flow in the brain vasculature after the blocking of the malformation and simulation of the transport of the embolic liquid. The method we propose is tested on 3 BAVM cases of varying complexity. Twenty two out of 24 main BAVM flow paths have been identified well by simulation.     

Magnetic Field Effect on the Evolution of the Magnon Population Properties in the [Co/Ag] Superlattice

In this work, the effect of applied magnetic field on the magnetic properties of [Co/Ag] superlattice is studied in the framework of the theory of spin waves for ferromagnetic Heisenberg systems, where the exchange and the dipolar interactions and the magneto-crystalline and surface anisotropies are all taking into account. The obtained corresponding Hamiltonian is treated using Green’s functions method. The analytical expressions of the excitation spectrum and the magnetization per spin are obtained when the exchange is present alone. While in the case where the above-cited other interactions are also present, a numerical study is done. The adjustment of the results of calculated and measured magnetization per spin obtained for various magnetic layer thickness (t _Co) is good. The deduced values of the exchange integral J are in line of the values usually given for this type of superlattices based on 3d-transition metals. The combined effect of dipolar interactions and surface anisotropy is studied numerically.