Conducting copolymers of thiophene-functionalized polystyrene

The syntheses of conducting copolymers of thiophene-functionalized polystyrene and pyrrole (PS/PPy) were achieved using p-toluene sulfonic acid (PTSA) as the supporting electrolyte via constant potential electrolysis technique. Characterization of the samples was performed by a combination of techniques: cyclic voliammetry (CV), thermogravimetric analysis (TGA), differential scanning colorimetry (DSC), scanning electron microscopy (SEM), NMR, and FT-IR analyses. The conductivities were measured by the four-probe technique

POLYMORPHISMS OF THE ANGIOTENSIN CONVERTING ENZYME AND ANGIOTENSINOGEN GENE IN PATIENTS WITH ATRIAL FIBRILLATION

WOS: 000289284500039

Aerodynamic data modeling using support vector machines

Aerodynamic data modeling plays an important role in aerospace and industrial fluid engineering. Support vector machines (SVMs), as a novel type of learning algorithms based on the statistical learning theory, can be used for regression problems and have been reported to perform well with promising results. The work presented here examines the feasibility of applying SVMs to the aerodynamic modeling field. Mainly, the empirical comparisons between the SVMs and the commonly used neural network technique are carried out through two practical data modeling cases – performance-prediction of a new prototype mixer for engine combustors, and calibration of a five-hole pressure probe. A CFD-based diffuser optimization design is also involved in the article, in which an SVM is used to construct a response surface and hereby to make the optimization perform on an easily computable surrogate space. The obtained simulation results in all the application cases demonstrate that SVMs are the potential options for the chosen modeling tasks

MWCNTs/P(St-co-GMA) composite nanofibers of engineered interface chemistry for epoxy matrix nanocomposites

Strengthened nanofiber-reinforced epoxy matrix composites are demonstrated by engineering composite electrospun fibers of multi-walled carbon nanotubes (MWCNTs) and reactive P(St-co-GMA). MWCNTs are incorporated into surface-modified, reactive P(St-co-GMA) nanofibers by electrospinning; functionalization of these MWCNT/P(St-co-GMA) composite nanofibers with epoxide moieties facilitates bonding at the interface of the cross linked fibers and the epoxy matrix, effectively reinforcing and toughening the epoxy resin. Rheological properties are determined and thermodynamic stabilization is demonstrated for MWCNTs in the P(St-co-GMA)-DMF polymer solution. Homogeneity and uniformity of the fiber formation within the electrospun mats are achieved at polymer concentration of 30 wt %. Results show that the MWCNT fraction decreases the polymer solution viscosity, yielding a narrower fiber diameter. The fiber diameter drops from an average of 630 nm to 460 nm, as the MWCNTs wt fraction (1, 1.5, and 2%) is increased. The electrospun nanofibers of the MWCNTs/P(St-co-GMA) composite are also embedded into an epoxy resin to investigate their reinforcing abilities. A significant increase in the mechanical response is observed, up to >20% in flexural modulus, when compared to neat epoxy, despite a very low composite fiber weight fraction (at about 0.2% by a single-layer fibrous mat). The increase is attributed to the combined effect of the two factors the inherent strength of the well-dispersed MWCNTs and the surface chemistry of the electrospun fibers that have been modified with epoxide to enable, cross linking between the polymer matrix and the nanofibers