Analytical and numerical fluid–structure interaction study of a microscale piezoelectric wind energy harvester

In this paper, an analytical approach and two numerical models have been developed to study an energy‐harvesting device for micropower generation. This device uses wind energy to oscillate a cantilevered beam attached to a piezoelectric layer for generating electric energy output. The analytical approach and the first numerical model consider the fluid–structure interaction phenomenon in the harvester performance. The equations governing beam oscillations and airflow have been coupled to a set of four differential equations in the analytical approach. This set of equations has been solved to determine the beam deflection and the air pressure variation with time. The numerical methods have been conducted by employing a commercial software. The results of the analytical method and the first numerical model have been compared in different working conditions, and their credibility has been discussed. In the second numerical model, the electromechanical performance of the piezoelectric material has also been incorporated in the harvester device analysis. This model has been verified against experimental data for the output voltage and power of the device available in the literature. Finally, the effect of different geometrical parameters has been studied on the harvester performance, and suggestions have been made to improve the harvester efficiency.     

Inhibition Studies on Carbonic Anhydrase Isoforms I,II, IX,and XII with a Series of Sulfaguanidines

Two novel sulfaguanidine series, six N-(N,N′-dialkyl/dibenzyl-carbamimidoyl) benzenesulfonamide derivatives and nine N-(N-alkyl/benzyl-carbamimidoyl) benzenesulfonamide derivatives, were obtained by desulfidative amination of easily accessible dimethyl arylsulfonylcarbonimidodithioates under catalyst- and base-free conditions. The newly synthesized compounds were tested for the inhibition of four different isozymes of human carbonic anhydrase (hCA I, II, IX and XII, EC 4.2.1.1). Both series reported here were inactive against the off-target isozymes hCA I and II (K_i>100 μM). Interestingly, all investigated compounds inhibited both target isozymes hCA IX and XII in the submicromolar to micromolar ranges in which K_i values spanned from 0.168 to 0.921 μM against hCA IX and from 0.335 to 1.451 μM against hCA XII. The results indicated that N-(N-alkyl/benzyl-carbamimidoyl) benzenesulfonamides were slightly more potent inhibitors than N-(N,N′-dialkyl/dibenzyl-carbamimidoyl) benzenesulfonamides. Among the evaluated compounds, N-n-octyl-substituted N-carbamimidoylbenzenesulfonamide showed the most significant activity with a K_i value of 0.168 μM against hCA IX, which was four-fold more selective toward this isozyme versus hCA XII. Again, another derivative from N-(N-alkyl/benzyl-carbamimidoyl) benzenesulfonamide series, N-p-methylbenzyl-substituted N-carbamimidoylbenzenesulfonamide, demonstrated superior inhibitory activity against hCA XII with a K_i value of 0.335 μM.     

Computational analysis of citric acid pertraction in emulsion liquid membranes

Citric acid is one of the most widely used acids in industry, and its recovery from waste streams is critical. Emulsion liquid membrane (ELM) is one of the most effective recovery methods that has been investigated in recent years. Numerous transport phenomena parameters affect the efficiency of this process. From the process equipment design point of view, optimization based on overall cost is of great importance, and important equipment sizing decisions/constraints must be considered. A physics-based model for a full-scale simulation of ELM systems is very useful. This work is focused on developing and verifying such a model. A coupled particle/mixture simulation was carried out in this work, and the modelling results were fitted on the experimental data. The novelty of this modelling work is physics-based results based on the system's geometry and its effects on the mass transfer resistances. Since the model is physics-based, the model is capable of simulating similar systems with any geometry or experimental conditions.     

Band gap tuning of oxygen vacancy-induced Al2O3-TiO2 ceramics processed by spark plasma sintering

Journal of Electroceramics - Optical and photocatalytic applications of Al2O3 and TiO2 ceramics are limited, especially under visible light, due to their wide bandgap; so, this parameter plays an...     

A new analytical model to predict heavy oil production rate in the SAGD process

An analytical model for predicting the oil production rate in the steam-assisted gravity drainage (SAGD) process is presented in this article. The suggested correlation is found based on Butler's original work. It considers the most effective parameters of the process that emphasize the influence of gravity drainage and that are grouped together in the form of the Rayleigh's number. The present model introduces three coefficients (i, j, and k) into the equation, which are determined by minimizing an objective function based on the difference between the six experimental SAGD datasets and the calculated results. The tool chosen for the minimization is the genetic algorithm (GA). After the initial evaluation, the same approach is used for other reservoir characteristics to ensure the robustness of the new equation. Having considered various simulation outcomes with an average error of 8.9% makes this model a credible one for predicting the SAGD production rates. The novelty of the new predictive model lies within its unique approach, making it quite fast and applicable to a wide range of reservoirs with low associated estimation inaccuracies.     

Semi-analytical SPICE-compatible ballistic I–V model for 5 nm channel MoS2 FETs

Journal of Computational Electronics - An analytical I–V model for a double-gate ballistic monolayer molybdenum disulfide (MoS2) field-effect transistor (FET) with 5 nm channel...     

Facile route for synthesis of strontium hexaborate crystalline powders

In this paper, a solid-state reaction route was developed to synthesize SrB₆O₁₀ crystalline powders. Regarding the last preparation methods, a short process time of synthesis was achieved that has not reported before. The prepared sample was characterized using various methods, such as X-ray diffraction, Raman spectroscopy, field emission scanning electron microscopy, transmission electron microscopy, and diffuse reflection spectroscopy. The obtained results proved that the prepared sample at temperature 840°C with 2.5 h duration consists of SrB₆O₁₀ crystalline powders with 4.96 eV bandgap.