Prediction of electropolymerization mechanisms of two substituted phenylene: Poly‐3‐methoxy‐toluenes (P3mt1 and P3mt2)

P3mt₁ and P3mt₂ were electrochemically synthesized using two different electrolyte supports H₂SO₄ and TEABF₄, respectively. First, it was deduced from density functional theory (DFT) calculations that the electronic and steric effects govern polymerization mechanism of the radical monomers. Second, DFT combined with experimental spectroscopic analyses (ESR, Infrared, Raman, and ¹³C NMR) demonstrate that H₂SO₄ or TEABF₄ could generate a homogenous or heterogeneous coupling site, respectively. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 57–64, 2006     

Optical and vibrational studies on single walled carbon nanotubes/short oligo‐para‐methoxy‐toluene composite

In a solution state, an oligophenylene prepared by electrochemical oxidation of para‐methoxy‐toluene exhibited luminescence in the violet‐to‐blue region. However, in a solid state, a clear red shift was observed as a signature of a supramolecular π‐stacking interaction between oligomer chains. In a de‐doped state, by chemical reduction, a fine structure in the form of two peaks was observed and luminescence intensity was strongly improved. When mixed with single walled carbon nanotubes (SWNTs), a quenching in the luminescence intensity accompanied by a slight blue shift of the PL peak of the nanocomposite was observed. This implies the shortening of the oligomer's effective π‐conjugation length caused by the added amount of SWNTs. A charge transfer in the photo‐excited state was also noted. The interaction taking place between the two materials was supported by optical infrared absorption and Raman scattering measurements and then a functionalizing mechanism was proposed. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

A high speed low input impedance current pulse amplifier cell

A high speed CMOS current pulse amplifier cell with low input impedance, devoted to nuclear multichannel detectors where crosstalk is a serious problem, is presented. The symmetry of the circuit achieved with complementary transistors yields both an input and an output with low offset voltage, opening a large field of applications such as transimpedance amplifiers and therefore transimpedance operational amplifiers.     

Proactive and reactive e-government services recommendation

Governmental portals designed to provide electronic services are generally overloaded with information that may hinder the effectiveness of e-government services. This paper proposes a new framework to supply citizens with adapted content and personalized services that satisfy their requirements and fit with their profiles in order to guarantee universal access to governmental services. The proposed reactive and proactive solutions combine several recommendation techniques that use different data sources i.e., citizen profile, social media databases, citizen’s feedback databases and service databases. It is shown that recommender systems provide citizens with accessible personalized e-government services.     

An Evaluation of RetinaNet on Indoor Object Detection for Blind and Visually Impaired Persons Assistance Navigation

Neural Processing Letters - Indoor object detection presents a computer vision task that deals with the detection of specific indoor classes. This task attracts a lot of attention, especially in...     

Elaboration and Characterization of Amorphous Silicon Carbide Thin Films (a-SiC) by Sputerring Magnetron Technique for Photoelectrochemical CO2 Conversion

Silicon - Semiconductors as photoelectric catalysis is recognized as a promising strategy for simultaneous face energy crisis and environmental pollution. In this study, amorphous silicon carbide...     

Investigation of the candesartan cilexetil antihypertensive drug microencapsulation by PLA-PVP K30 biodegradable polymers: Experimental optimization and release kinetics modelling

Candesartan is an angiotensin receptor blocker (ARB) used to treat hypertension. However, its poor aqueous solubility and oral bioavailability have limited its therapeutic applications. In order to increase bioavailability and control the release of candesartan condensation, microspheres containing biodegradable polymers (polyvinylpyrrolidone [PVP K30] and polylactic acid [PLA]) in different ratios were prepared by the o/o solvent evaporation method using Span 80 as a surfactant. In addition, the impact of encapsulation parameters (i.e., PVP K30 and PLA concentrations) on the encapsulation ratio and release percentage was investigated by the mixed factorial design method. The release kinetics of the microspheres was simulated by combining two methods, the Dragonfly algorithm and a support vector machine (DA-SVM). The experimental data were in good agreement with the predicted data, with a coefficient of determination close to unity and a mean square error close to zero. Fourier-transfer infrared spectrometry (FTIR) analysis revealed the presence of condensation in all formulations without reporting distortion in the spectra. Scanning electron microscopy (SEM) confirmed the successful synthesis of microspheres, whose sizes were between 12 and 26 μm. Formulations with a PLA-drug ratio of 6:1 (N15, N17, and N18) showed the highest encapsulation efficiency (68%, 71%, and 70%, respectively), while formulations that do contain PVP K30, such as N5, N4, and N3, showed a higher release (83%, 84%, and 89%, respectively), indicating that the agent (PVP K30) enhanced the bioavailability and release of candesartan. Overall, N3 showed a higher drug release rate at 12 h and important encapsulation efficiency, making it the optimal formulation obtained in this study.