An onsite demonstration and validation of LiDAR technology for wind energy resource assessment

The investigation of wind resource at higher heights is very crucial in planning wind power project. Normally, this involves the installation of a high and costly meteorological mast with a cup anemometer and wind vanes. This investigation uses the new ground-based remote-sensing technique Light Detection and Ranging (LiDAR) to investigate the wind resource at higher heights. This paper describes the LiDAR technology principle and examines the potential of LiDAR measurement to estimate the wind resource at higher heights by conducting a measurement campaign at Tamil Nadu, India. The wind statistics were determined using the 10?min average time-series wind data monitored by ZephIR LiDAR. These include the Weibull parameters, daily mean wind speed, wind power density, wind energy density, vertical wind speed profile and capacity factor. The investigation reveals that the vertical wind speed profile measured from the LiDAR system has approximate closer values to the standard meteorological measurement.     

Fuzzy-modeling with Particle Swarm Optimization for enhancing the production of biodiesel from Microalga

Biodiesel is one of the promising energy sources that could replace petroleum oil in the near future. Microalgae is occupying a distinguished position among the promising sources for biodiesel production. Enhancement of the lipids production during the pretreatment is a key factor for the biodiesel production. High-pressure homogenizer is a better pretreatment procedure to enhance the lipid extraction from microalgae. In this research, a robust model of biodiesel system using fuzzy logic is built based on the experimental data for biodiesel system. Then, Particle Swarm Optimization (PSO) optimizer is applied for determining the best operating parameters of biodiesel system. The decision variables used in the optimization process are; pressure, number of passes, and reaction time that maximizes the percentage of recovery lipids of biodiesel. A comparison study was carried out between the optimized results thought PSO algorithm and those obtained by the experimental results and the optimized results through the Response Surface Methodology (RMS). Results demonstrated that using the proposed optimization methodology is significantly better than RSM, a nearly 78.7% increase in lipids extraction could be achieved according to the current model.     

Saliency-based framework for facial expression recognition

This article proposes a novel framework for the recognition of six universal facial expressions. The framework is based on three sets of features extracted from a face image: entropy, brightness, and local binary pattern. First, saliency maps are obtained using the state-of-the-art saliency detection algorithm “frequency-tuned salient region detection”. The idea is to use saliency maps to determine appropriate weights or values for the extracted features (i.e., brightness and entropy).We have performed a visual experiment to validate the performance of the saliency detection algorithm against the human visual system. Eye movements of 15 subjects were recorded using an eye-tracker in free-viewing conditions while they watched a collection of 54 videos selected from the Cohn-Kanade facial expression database. The results of the visual experiment demonstrated that the obtained saliency maps are consistent with the data on human fixations. Finally, the performance of the proposed framework is demonstrated via satisfactory classification results achieved with the Cohn-Kanade database, FG-NET FEED database, and Dartmouth database of children’s faces.     

The Tail Effect of Some Prepared Cationic Surfactants on Silver Nanoparticle Preparation and Their Surface,Thermodynamic Parameters,and Antimicrobial Activity

The surface parameters of some cationic surfactants having different hydrophobic alkyl chains were assessed in aqueous solution using different techniques; surface tension, ultraviolet-Visible (UV–Vis) spectroscopy, and conductivity measurements. The obtained critical micelle concentration (CMC) for N-(2-((3,4-dimethoxybenzylidene)amino)ethyl)-N,N-dimethyloctan-1-aminium bromide (DBAO), N-(2-((3,4-dimethoxybenzylidene)amino)ethyl)-N,N-dimethyldodectan-1-aminium bromide (DBAD), and N-(2-((3,4-dimethoxybenzylidene)amino)ethyl)-N,N-dimethylhexadectan-1-aminium bromide (DBAH) in aqueous solution using three techniques are nearly the same. Increasing the hydrophobic chain length enhances micelle formation. Raising the solution temperature from 25 to 65 °C also shows the same trend. The thermodynamic calculations outlined the adsorption propensity of the surfactants at the surface compared to their affinity to form micelles. Both micellization and adsorption processes are enhanced with both the hydrocarbon elongation and with raising the solution temperature. The effect of the surfactant tail on the preparation process of the silver nanoparticles (AgNP) was assessed and confirmed using transmission electron microscope (TEM), dynamic light scattering (DLS), and UV–Vis spectra. Increasing the surfactant tail leads to a smaller particle size with a narrow distribution. The stability of the prepared AgNP is enhanced with hydrophobic surfactant tail elongation as proved with increasing the zeta-potential of the prepared AgNP colloid. The foaming power, interfacial tension, and emulsification stability of the DBAO, DBAD, and DBAH surfactants were determined. The DBAO, DBAD, and DBAH surfactants showed good antimicrobial activities against both bacteria (Gram positive and negative) and fungi, which have been enhanced because of incorporation of AgNP.     

Synthesis,complexation and biological effects studies of new thiacrown ethers derived quinoline: part I

A series of new thiacrown ethers derived quinoline 7–9 were synthesized in good yield and in a simple way. Their transition metal ions complexation was studied using a conductometric method in acetonitrile at 25°C. Crowns 7 and 8 showed a continuous decrease in the molar conductances in their complexation with Ag⁺, Cu²⁺, Hg²⁺ and Zn²⁺ which begins to level off at a molar ratio of 1:1 crown to metal, indicating the formation of 1 stable 1:1 complex. On the other hand, crown 9 showed the formation of 1:1 complexes only with Ag⁺, Cu²⁺, Hg²⁺. The in vitro, a preliminary antimicrobial, antioxidant and cytotoxic effects on breast tumor cells were also reported. Five bacterial test strains were included in the present study. Antioxidant activity was measured in terms of the radical scavenging ability and decolorization of 1,1-Diphenyl-2-picrylhydrazyl (DPPH) radicals. Cytotoxic effect of thiacrown was evaluated using MDA MB-231 cell line (human breast adenocarcinoma, ATCC HTB-26).     

Glass microparticle- versus microsphere-filled experimental dental adhesives

This study aimed to formulate antibacterial dental adhesives. Phosphate-substituted methacrylate adhesives were modified with 0–20 wt % copper-doped glass microparticles. Two shapes of microparticles were used: regular shaped (microspheres) and irregular shaped (microparticles). The morphology/composition, roughness, monomer conversion (DC%), thermogravimetric analysis, and antibacterial action against S. mutans and P. aeruginosa and ion release were investigated. The results showed that microspheres produced adhesives with a relatively smoother surface than microparticles did. The DC% of adhesives increased with increasing glass filler content. Filled adhesives showed polymer decomposition at ~315 °C and glass melting at 600–1000 °C. The weight loss percent of adhesives decreased with increasing weight percent of fillers. Glass microparticles at 0–20 wt % significantly increased the antibacterial action of adhesives against both bacteria. Glass microspheres at 0–5 wt % significantly increased the antibacterial action of adhesives against both bacteria. Only 20 wt % microparticle-filled adhesive showed an inhibition zone similar to tobramycin (positive control). Microparticle-filled adhesives (with >5 wt % filler) significantly reduced S. mutans more than their microsphere counterparts. Microsphere-filled adhesives (with ≤5 wt % filler) significantly reduced P. aeruginosa more than their microparticle counterparts. Microsphere-filled adhesives showed higher Cu release than their microparticle counterparts. Accordingly, phosphate-substituted methacrylate filled with glass could be used as an antibacterial adhesive. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47832.     

Designing zinc oxide nanostructures (nanoworms,nanoflowers, nanowalls,and nanorods) by pulsed laser ablation technique for gas-sensing application

In this study, pulsed laser ablation technique, also known as pulsed laser deposition (PLD), is used to design and grow zinc oxide (ZnO) nanostructures (nanoworms, nanowalls, and nanorods) by template/seeding approach for gas-sensing applications. Conventionally, ZnO nanostructures used for gas-sensing have been usually prepared via chemical route, where the 3D/2D nanostructures are chemically synthesized and subsequently plated on an appropriate substrate. However, using pulsed laser ablation technique, the ZnO nanostructures are structurally designed and grown directly on a substrate using a two-step temperature-pressure seeding approach. This approach has been optimized to design various ZnO nanostructures by understanding the effect of substrate temperature in the 300-750°C range under O₂ gas pressure from 10-mTorr to 10 Torr. Using a thin ZnO seed layer as template that is deposited first at substrate temperature of ~300°C at background oxygen pressure of 10 mTorr on Si(100), ZnO nanostructures, such as nanoworms, nanowalls, and nanorods (with secondary flower-like growth) were grown at substrate temperatures and oxygen background pressures of (550°C and 2 Torr), (550°C and 0.5 Torr), and (650°C and 2 Torr), respectively. The morphology and the optical properties of ZnO nanostructures were examined by Scanning Electron Microscope (SEM-EDX), X-ray Diffraction (XRD), and photoluminescence (PL). The PLD-grown ZnO nanostructures are single-crystals and are highly oriented in the c-axis. The vapor-solid (VS) model is proposed to be responsible for the growth of ZnO nanostructures by PLD process. Furthermore, the ZnO nanowall structure is a very promising nanostructure due to its very high surface-to-volume ratio. Although ZnO nanowalls have been grown by other methods for sensor application, to this date, only a very few ZnO nanowalls have been grown by PLD for this purpose. In this regard, ZnO nanowall structures are deposited by PLD on an Al₂O₃ test sensor and assessed for their responses to CO and ethanol gases at 50 ppm, where good responses were observed at 350 and 400°C, respectively. The PLD-grown ZnO nanostructures are very excellent materials for potential applications such as in dye-sensitized solar cells, perovskite solar cells and biological and gas sensors.     

Novel sulfonated multi-walled carbon nanotubes filled chitosan composite membrane for fuel-cell applications

In the present study, multi-walled carbon nanotubes (MWCNTs) were sulfonated by 1,3-propane sultone and distillation–precipitation polymerization, respectively, and then incorporated into chitosan (CS) to prepare CS/MWCNTs composite membranes for fuel cell applications. CS/MWCNTs membranes show better thermal and mechanical stability than pure CS membrane due to the strong electrostatic interaction between the  SO₃H groups of MWCNTs and the  NH₂ groups of CS, which can restrict the mobility of CS chain. The sulfonated MWCNTs provide efficient proton hopping sites ( SO₃H,  SO₃⁻ …. ₃⁺HN ), thereby resulting in the formation of continuous proton conducting channels. The composite membranes with 5 wt % of MWCNTs modified by two different ways show a proton conductivity of 0.026 and 0.025 S·cm⁻¹, respectively. In conclusion, CS/MWCNTs membrane is a promising proton exchange membrane for fuel-cell applications. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47603.