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Babaei, Hamid,Khosravi, Morteza,Sovizi, Mohamad Reza,Khorramie, Saeid Abedini The Korean Electrochemical Society 2020 Journal of electrochemical science and technology Vol.11 No.2
The impact of effective parameters on the electrodeposition rate optimization of Au-Cu alloy at high thicknesses on the silver substrate was investigated in the present study. After ensuring the formation of gold alloy deposits with the desired and standard percentage of gold with the cartage of 18K and other standard karats that should be observed in the manufacturing of the gold and jewelry artifacts, comparing the rate of gold-copper deposition by direct and pulsed current was done. The rate of deposition with pulse current was significantly higher than direct current. In this process, the duty cycle parameter was effectively optimized by the "one factor at a time" method to achieve maximum deposition rate. Particular parameters in this work were direct and pulse current densities, bath temperature, concentration of gold and cyanide ions in electrolyte, pH, agitation and wetting agent additive. Scanning electron microscopy (SEM) and surface chemical analysis system (EDS) were used to study the effect of deposition on the cross-sections of the formed layers. The results revealed that the Au-Cu alloy layer formed with concentrations of 6gr·L<sup>-1</sup> Au, 55gr·L<sup>-1</sup> Cu, 24 gr·L<sup>-1</sup> KCN and 1 ml·L<sup>-1</sup> Lauryl dimethyl amine oxide (LDAO) in the 0.6 mA·cm<sup>-2</sup> average current density and 30% duty cycle, had 0.841 ㎛·min<sup>-1</sup> Which was the highest deposition rate. The use of electrodeposition of pure and alloy gold thick layers as a production method can reduce the use of gold metal in the production of hallow gold artifacts, create sophisticated and unique models, and diversify production by maintaining standard karats, hardness, thickness and mechanical strength. This will not only make the process economical, it will also provide significant added value to the gold artifacts. By pulsating of currents and increasing the duty cycle means reducing the pulse off-time, and if the pulse off-time becomes too short, the electric double layer would not have sufficient growth time, and its thickness decreases. These results show the effect of pulsed current on increasing the electrodeposition rate of Au-Cu alloy confirming the previous studies on the effect of pulsed current on increasing the deposition rate of Au-Cu alloy.
( Mohammad Reza Amini ),( Hossein Shahinfar ),( Nadia Babaei ),( Samira Davarzani ),( Mojdeh Ebaditabar ),( Kurosh Djafarian ),( Cain C. T. Clark ),( Sakineh Shab-bidar ) 한국임상영양학회 2020 Clinical Nutrition Research Vol.9 No.2
In the present study, we sought to examine the association between dietary patterns (DPs) and visceral adiposity, lipid accumulation product (LAP), and triglyceride-glucose index. This cross-sectional study was conducted on adults aged between 18-45 years old who lived in Tehran, Iran, between February 2017 and December 2018 (n = 270). DPs were derived using principal component analysis. We used analysis of variance to examine differences in continues variables across tertiles of major DPs. Subsequently, for the modeling of these relationships, and also considering the possible effect of the confounding factors, multivariate regression was used. Three DPs were identified: healthy pattern, mixed pattern, and western pattern, respectively. Compared with individuals in the lowest category of mixed pattern, those in the highest category had lower fasting blood sugar (96.26 ± 11.57 vs. 101 ± 28.66, p = 0.01). A significant association was found between healthy pattern, after adjustment for potential confounders, and odds of LAP; such that individuals in the top category of healthy pattern score were 71% less likely to have a high LAP compared with those in the lowest category (odds ratio, 0.29; 95% confidence interval, 0.10-0.81). We found that adherence to a healthy DP was associated with decreased LAP. To confirm the veracity of these findings, more studies should be conducted.
Large amplitude free vibrations of FGM shallow curved tubes in thermal environment
Hadi Babaei,Yaser Kiani,M. Reza Eslami 국제구조공학회 2020 Smart Structures and Systems, An International Jou Vol.25 No.6
In the current investigation, large amplitude free vibration behavior of shallow curved pipes (tubes) made of functionally graded materials is investigated. Properties of the tube are distributed across the radius of the tube and are obtained by means of a power law function. It is also assumed that all thermo-mechanical properties are temperature dependent. The governing equations of the tube are obtained using a higher order shear deformation tube theory, where the traction free boundary conditions are satisfied on the top and bottom surfaces of the tube. The von Kármán type of geometrical non-linearity is included into the formulation to consider the large displacements and small strains. Uniform temperature elevation of the tube is also included into the formulation. For the case of tubes which are simply supported in flexure and axially immovable, the governing equations are solved using the two-step perturbation technique. Closed form expressions are provided to obtain the small and large amplitude fundamental natural frequencies of the FGM shallow curved tubes in thermal environment. Numerical results are given to explore the effects of thermal environment, radius ratio, and length to thickness ratio of the tube on the fundamental linear and non-linear frequencies.
Nonlocal buckling characteristics of heterogeneous plates subjected to various loadings
Ebrahimi, Farzad,Babaei, Ramin,Shaghaghi, Gholam Reza Techno-Press 2018 Advances in aircraft and spacecraft science Vol.5 No.5
In this manuscript, buckling response of the functionally graded material (FGM) nanoplate is investigated. Two opposite edges of nanoplate is under linear and nonlinear varying normal stresses. The small-scale effect is considered by Eringen's nonlocal theory. Governing equation are derived by nonlocal theory and Hamilton's principle. Navier's method is used to solve governing equation in simply boundary conditions. The obtained results exactly match the available results in the literature. The results of this research show the important role of nonlocal effect in buckling and stability behavior of nanoplates. In order to study the FG-index effect and different loading condition effects on buckling of rectangular nanoplate, Navier's method is applied and results are presented in various figures and tables.
Ganjali, Mohammad Reza,Babaei, Leila Hajiagha,Taghvaei-Ganjali, Saeed,Modjallal, Atoosa,Sahmsipur, Mojtaba,Hosseini, Morteza,Javanbakht, Mehran Korean Chemical Society 2004 Bulletin of the Korean Chemical Society Vol.25 No.2
A PVC membrane electrode for silver ion based on a new cone shaped calix[4]arene (CASCA) as membrane carrier was prepared. The electrode exhibits a Nernstian response for $Ag^+$ over a wide concentration range ($1.0{\times}10^{-1}-8.0{\times}10^{-6}$M) with a slope of 58.2 {\pm}$ 0.5 mV per decade. The limit of detection of the sensor is $5.0{\times}10^{-6}$M. The sensor has a very fast response time (~5 s) in the concentration range of ${\leq}=1.0{\times}10^{-3}$ M, and a useful working pH range of 4.0-9.5. The proposed sensor displays excellent discriminating ability toward $Ag^+$ ion with respect to common alkali, alkaline earth, transition and heavy metal ions. It was used as an indicator electrode in potentiometric titration of $Ag^+$ with EDTA and in direct determination of silver ion in wastewater of silver electroplating.
Forough Gashtasbi,Reza Jalilzadeh Yengejeh,Ali Akbar Babaei 한국화학공학회 2018 Korean Journal of Chemical Engineering Vol.35 No.8
The simultaneous presence of antibiotics and bacteria in aqueous media has been recognized as an environmental threat, due to the enhancement of antibiotic resistance of bacteria. We synthesized an activated carbon impregnated magnetite composite (PAC/Fe3O4) and used it for removal of cephalexin (CEX) from aqueous solution via UV system. A series of batch experiments was carried out under various experimental conditions such as pH of solution (3-11), contact time (0-120 min), catalyst dosages (0.1-2 g/L) and initial CEX concentrations (10, 25, 50 and 100 mg/L). Some common isotherm models were used for study of CEX adsorption and finding the best model. In addition, kinetic studies of CEX photocatalytic removal were performed by fitting the experimental data on first-order and second-order models. Results of comparative studies showed that UV+PAC/Fe3O4 and UV+TiO2 systems, compared to UV/Fe3O4, naked Fe3O4, PAC/Fe3O4 and UV only, had more capability of removing CEX from aqueous solution, indicating PAC/Fe3O4 is effectively catalyzed by UV light. Furthermore, increasing catalyst dosages and decreasing initial CEX concentrations led to the enhancing photocatalytic removal of CEX from solution. The obtained results of kinetic studies also represent that among the studied models, second-order model with significant coefficient of correlation (R2) had higher ability than first-order model to fit the data of CEX removal. Finally, the findings of reusability tests, showed that the applied catalyst would be applicable for CEX removal, even after five consecutive cycles.
Vibration analysis thermally affected viscoelastic nanosensors subjected to linear varying loads
Ebrahimi, Farzad,Babaei, Ramin,Shaghaghi, Gholam Reza Techno-Press 2018 Advances in nano research Vol.6 No.4
Unwanted vibration is an issue in many industrial systems, especially in nano-devices. There are many ways to compensate these unwanted vibrations based on the results of the past researches. Elastic medium and smart material etc. are effective methods to restrain unnecessary vibration. In this manuscript, dynamic analysis of viscoelastic nanosensor which is made of functionally graded (FGM) nanobeams is investigated. It is assumed that, the shaft is flexible. The system is modeled based on Timoshenko beam theory and also environmental condition, external linear varying loads and thermal loading effect are considered. The equations of motion are extracted by using energy method and Hamilton principle to describe the translational and shear deformation's behavior of the system. Governing equations of motion are extracted by supplementing Eringen's nonlocal theory. Finally vibration behavior of system especially the frequency of system is developed by implementation Semi-analytical differential transformed method (DTM). The results are validated in the researches that have been done in the past and shows good agreement with them.