A Novel Approach for Prediction of Monthly Ground Water Level Using a Hybrid Wavelet and Non-Tuned Self-Adaptive Machine Learning Model

Water Resources Management - In recent decades, due to groundwater withdrawal in the Kabodarahang region, Iran, Hamadan, hazardous events such as sinkholes, droughts, water scarcity, etc., have...     

Effect of hexagonal structure nanoparticles on the morphological performance of the ceramic scaffold using analytical oscillation response

Porous bony scaffolds are utilized to manage the growth and migration of cells from adjacent tissues to a defective position. In the current investigation, the effect of titanium oxide (TiO₂) nanoparticles on mechanical and physical properties of porous bony implants made of polymeric polycaprolactone (PCL) is studied. The bio-nanocomposite scaffolds are prepared with composition of nanocrystalline hydroxyapatite (HA) and TiO₂ powder using the freeze-drying technique for different weight fractions of TiO₂ (0 wt%, 5 wt%, 10 wt%, and 15 wt%). In order to identify the microstructure and morphology of the fabricated porous bio-nanocomposites, the X-ray diffraction (XRD), atomic force microscope (AFM) and scanning electron microscopy (SEM) are employed. Also, the biocompatibility and biodegradability of the manufactured scaffolds are examined by placing them in a simulated body fluid (SBF) for 21 days, their weight and pH changes are measured. The rate of degradation of the PCL-HA scaffold can be controlled by varying the percentage of its constituent components. Due to an increasing growth and activity of bone cells and the apatite formation on the free surface of the fabricated bio-nanocomposite implants as well as their reasonable mechanical properties, they have the potential to be used as a bone substitute. Additionally, with the aid of the experimentally extracted mechanical properties of the scaffolds, the vibrational characteristics of a beam-type implant made of the proposed porous bio-nanocomposites are explored. The results obtained from SEM image indicate that the scaffolds produced by the employed method have high total porosity (70%–85%) and effective porosity. The pore size is obtained between 60 and 200 μm, which is desirable for the growth and propagation of bone cells. Also, it is revealed that the addition of TiO₂ nanoparticles leads to reduce the rate of dissolution of the fabricated bio-nanocomposite scaffolds.     

A new hybrid chaotic atom search optimization based on tree-seed algorithm and Levy flight for solving optimization problems

Engineering with Computers - Optimizing the high computational real-world problems is a challenging task that has taken a great deal of efforts in the last decade. The meta-heuristic algorithms...     

Fuzzy modeling of the forced convection heat transfer from a V‐shaped plate exposed to an air slot jet

This paper focuses on the application of fuzzy logic (FL) to predict the forced convection heat transfer from V‐shaped plate internal surfaces exposed to an air impingement slot jet. The aim of the present paper is to consider the effects of the angle of a V‐shaped plate (Φ), slot‐to‐plate spacing ratio (Z/W), and Reynolds number (Re) variation on average heat transfer from the V‐shaped plate internal surfaces. The data used for developing the FL structure was obtained experimentally by a Mach‐Zehnder interferometer. The proposed FL was developed using MATLAB functions. It was observed that the average Nusselt number will be decreased with an increase in jet spacing and be increased with an increase in Reynolds number and angle of V‐shaped plate. Moreover, it is also shown that fuzzy logic is a powerful technique to use for predicting heat transfer due to its low error rate. The average error of the fuzzy predictions compared with experimental data was found to be 0.33% for this study. © 2012 Wiley Periodicals, Inc. Heat Trans Asian Res; Published online in Wiley Online Library ( wileyonlinelibrary.com/journal/htj ). DOI 10.1002/htj.21009     

Copper-poly (2-aminodiphenylamine) composite as catalyst for electrocatalytic oxidation of formaldehyde in alkaline media

The present work describes the electrocatalytic oxidation of formaldehyde on a copper-polymer modified electrode. The deposition of polymeric film on the surface of carbon paste electrode (CPE) was carried out using consecutive cyclic voltammetry in an aqueous solution of 2-aminodiphenylamine (2ADPA). The transition metal of copper is incorporated into the polymer by electrodeposition of Cu(??) from CuCl₂ acidic solution using potentiostatic technique. Characterization of different modified electrodes was studied using SEM technique and electron probe microanalyzer (EPMA). Cyclic voltammetry experiment of copper-poly(2-aminodiphenylamine) modified carbon paste electrode (Cu/P(2ADPA)/MCPE) in alkaline solution exhibited a number of well-defined anodic and cathodic peaks that are attributed to the Cu/Cu(I), Cu/Cu(II), Cu(I)/Cu(II) and Cu(II)/Cu(III) redox couples. The electrocatalytic oxidation of formaldehyde at the surface of Cu/P(2ADPA)/MCPE was studied by cyclic voltammetry and chronoamperometry methods. This new modified electrode found to be highly active and stable for electrooxidation of the formaldehyde so that the electrocatalytic current density of 25.56 mA cm⁻² was obtained at the potential of 0.63 V. The effects of various parameters such as the copper loading, scan rate and formaldehyde concentration on the electrocatalytic oxidation of formaldehyde were also investigated. Finally, using a chronoamperometric method, the catalytic rate constant (k) for oxidation of formaldehyde was found to be 7.16 × 10⁶ cm³ mol⁻¹ s⁻¹.