Two new relationships for slip velocity and characteristic velocity in a non-center rotating column

Torkaman Rezvan,Heydari Mehran,Cheshmeh Javad Najafi,Heydari Ali,Asadollahzadeh Mehdi 한국원자력학회 2022 Nuclear Engineering and Technology Vol.54 No.8

In this investigation work, liquid-liquid extraction (L.L.E) through three distinctive frameworks have been examined for assurance of slip velocity (S.V), and characteristic velocity (C.V) in a non-center rotating column (N.C.R.C) with a wide extend of factors. Three double frameworks with distinctive interfacial tension comprising of toluene-water (high interfacial tension), n-butyl acetateewater (medium interfacial tension), and n-butanolewater (low interfacial tension) were investigated for tests. Two common relationships for the expectation of S.V and C.V, including phase stream rates, rotor speed, column geometry additionally physical properties, are displayed. The recommended relationships were compared with test information gotten from the writing and the display examination. Findings of this study, the present proposed correlations are more accurate than those previously reported.

Novel Method of ACO and Its Application to Rotor Position Estimation in a SRM under Normal and Faulty Conditions

Torkaman, Hossein,Afjei, Ebrahim,Babaee, Hossein,Yadegari, Peyman The Korean Institute of Power Electronics 2011 JOURNAL OF POWER ELECTRONICS Vol.11 No.6

In this paper a novel method of the Ant Colony Optimization algorithm for rotor position estimation in Switched Reluctance Motors is presented. The data provided by the initial assumptions is one of the important aspects used to solve the problems relative to an Ant Colony algorithm. Considering the nature of a real ant colony, it was found that the ants have no primary data for deducing which is the shortest path in their initial iteration. They also do not have the ability to see the food sources at a distance. According to this point of view, a novel method is presented in which the rotor pole position relative to the corresponding stator pole in a switched reluctance motor is estimated with high accuracy using the active and inactive phase parameters. This new method gives acceptable results such as a desirable convergence together with an optimized and stable response. To the best knowledge of the authors, such an analysis has not been carried out previously.

ELECTROCHEMICAL SYNTHESIS AND CHARACTERIZATION OF DIFFERENT MORPHOLOGIES NANORAMSDELLITE-MnO2

MADJID TORKAMAN,AZIZAN AZIZ,MOHAMAD ABU BAKAR,SULAIMAN AB GHANI 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2012 NANO Vol.7 No.4

In this work manganese dioxide (Ramsdellite-MnO2) was synthesized at room temperature using a facile electrochemical method. X-ray di®raction (XRD) was used to identify the type and the size of the crystal particle, while ¯eld emission scanning electron microscopy (FESEM) and energy ¯ltered transmission electron microscopy (EFTEM) were used to show and identify the morphology of the particles and changes of their morphologies with the increase of reaction times. Fourier transform infrared (FTIR) spectroscopy con¯rmed the Mn?O bond. Results from XRD showed that optimum time for synthesis Ramsdellite-MnO2 was 9 h. The results of EFTEM showed a mixture of nanospheres and nanorods after 9 h reaction time while a homogenous morphology of nanospheres was detected at 12 h reaction time. Results con¯rmed on the existence of a correlation between the reaction time and the resulting nanostructures. Moreover, the EFTEM result showed that average particle size for 12 h was (25 ? 7nm). The variation of calculated speci¯c capacitance (F/g) versus the di®erent scan rate has indicated that the e±-ciency of synthesized Ramsdellite-MnO2 nanostructures in 12 h reaction time was superior to 9 h.

Novel Method of ACO and Its Application to Rotor Position Estimation in a SRM under Normal and Faulty Conditions

Hossein Torkaman,Ebrahim Afjei,Hossein Babaee,Peyman Yadegari 전력전자학회 2011 JOURNAL OF POWER ELECTRONICS Vol.11 No.6

In this paper a novel method of the Ant Colony Optimization algorithm for rotor position estimation in Switched Reluctance Motors is presented. The data provided by the initial assumptions is one of the important aspects used to solve the problems relative to an Ant Colony algorithm. Considering the nature of a real ant colony, it was found that the ants have no primary data for deducing which is the shortest path in their initial iteration. They also do not have the ability to see the food sources at a distance. According to this point of view, a novel method is presented in which the rotor pole position relative to the corresponding stator pole in a switched reluctance motor is estimated with high accuracy using the active and inactive phase parameters. This new method gives acceptable results such as a desirable convergence together with an optimized and stable response. To the best knowledge of the authors, such an analysis has not been carried out previously.

Feasibility of pilot-scale disc-donut column for continuous cadmium extraction with the perspective of droplet size distribution

Asadollahzadeh Mehdi,Torkaman Rezvan,Torab-Mostaedi Meisam,Heydari Ali 한국자원공학회 2021 Geosystem engineering Vol.24 No.6

Heavy metal removal is a significant problem in various industries. Liquid-liquid extraction is a practical process in recovering these elements. In this study, the behavior of pilot-scale disc-donut column in the extraction of cadmium ions was evaluated. The effects of droplets with the variation size distributions are significant in describing performance and characteristics of an extractor for removing the substrate from aqueous or organic phases. The size distribution of droplets is relative to the interfacial area under steady conditions. To match the size distribution of droplets, the experiments are carried out in reaction and non-reaction conditions. In emulsion regime (pulsing intensity (Af), inlet organic and aqueous phase flow rate (Vc, Vd) equal to 3.3 cm/s, 2.22 mm/s, and 2.22 mm/s, respectively) and under the optimized conditions, 99.7% of the cadmium can be recovered from the aqueous solution. It was found that Weibull distribution gives the best fit at each operation mode while inverse Gaussian distribution gives the most inferior fit. According to a series of statistical analyses, it is shown that the pulsation intensity imposed more influence on drop sizes, and superficial flow rates of both phases are less able to the successful prediction of size distribution of droplets.

Testing the Implementation of a Pilot-Scale Kühni Column in Reactive and non-Reactive Condition

Asadollahzadeh Mehdi,Torkaman Rezvan,Torab-Mostaedi Meisam 한국자원공학회 2021 Geosystem engineering Vol.24 No.2

In this study, the primary efforts focused on using the Kühni extraction column with optimal energy and extraction efficiency for the removal of zinc ions from aqueous solution. The implementation of the extractive column was investigated in the reactive and non-reactive conditions. The experimental works illustrate that the extraction efficiency and hydrodynamic parameters, particularly depend on the energy input, phase flow rates as well as on the physical properties of the aqueous and organic phases. Among the operating parameters, the choice of the appropriate range for rotation speed plays a significant role for the removal of zinc ions in the pilot-scale Kühni column. The results showed that in the optimal condition for rotation speed, aqueous phase flow rate, and dispersed phase flow rate equal to 181 rpm, 33 L/h, and 21 L/h, respectively, the amount of zinc extraction reaches a maximum of 99.58%.

Study on the feasibility of using a pilot plant Scheibel extraction column for the extraction and separation of lanthanum and cerium from aqueous solution

Mehdi Asadollahzadeh,Rezvan Torkaman,Meisam Torab-Mostaedi 한국화학공학회 2020 Korean Journal of Chemical Engineering Vol.37 No.2

Batch and continuous experiments were carried out in a Scheibel extraction column to separate La(III) from Ce(III). Central composite design was used to evaluate the influence of pH, extractant concentration in the batch experiments, and the influence of rotor speed, phase flow rates in the continuous experiments. At optimum conditions (pH 3.5, D2EHPA extractant concentration 0.05 M, rotor speed 128 rpm, dispersed phase flow rate 32 L/h and continuous phase flow rate 18 L/h), high extraction efficiency and separation factor equal to 88.12% and 4.89, respectively, for cerium separation from lanthanum were reasonably well predicted by the model. At higher rotor speed, La(III) and Ce(III) ions move faster from aqueous to the organic phase, which retards the higher interaction between ions and D2EHPA extractant. The results showed that this extraction column could be a potential candidate for the extraction and separation of La(III) and Ce(III) ions or other industrial wastewater.

Optimization of lanthanum extraction in asymmetric rotation pilot plant column by using central composite methodology

Mehdi Asadollahzadeh,Rezvan Torkaman,Meisam Torab-Mostaedi 한국자원공학회 2020 Geosystem engineering Vol.23 No.2

The present work aimed to optimize the lanthanum extraction efficiency in the pilot-scale asymmetric rotating disc contactor. Optimal batch-scale extraction conditions were determined for the preparation of feed for extraction column (D2EHPA 0.08 mol/L; pH~8). In continuous mode, the optimization with the central composite design approach was performed by using three main parameters, such as continuous phase flow rate, agitation intensity, dispersed phase flow rate. Three responses studied were slip velocity, dispersed phase holdup, and extraction efficiency. The higher value of extraction efficiency for lanthanum extraction shows the main effect of agitation intensity on the dispersed phase holdup, slip velocity, and rate of mass transfer. The optimum conditions for extraction efficiency equal 98.5% were obtained at a rotation speed equal to 7.75 1/s, and phase flow rates equal to 1.25 × 10−5 m3/s. The new correlations are estimated to describe the holdup of the dispersed phase and the slip velocity with high accuracy and R-square values equal to 0.9734 and 0.9670, respectively. The results showed that the pilot plant asymmetric rotating disc column could be used as an appropriate column for the lanthanum extraction from aqueous solution as an example of rare earth metals.

Extraction of dysprosium from waste neodymium magnet solution with ionic liquids and ultrasound irradiation procedure

Mehdi Asadollahzadeh,Rezvan Torkaman 한국화학공학회 2022 Korean Journal of Chemical Engineering Vol.39 No.1

This study investigated imidazolium ionic liquids’ capability under ultrasonic irradiation conditions for dysprosium extraction from the aqueous nitrate solution. The main objective was to evaluate the feasibility of ultrasoundassisted extraction techniques compared to conventional solvent extraction. The extraction process was investigated as a function of the ionic liquids and organic extractant, organic/aqueous phase volume ratio, the acidity of the aqueous phase, contact time, ion concentration, temperature, and stripping condition. The outcomes demonstrated that the combination of C6MIM.PF6 and TOPO extractant is more extractable than the mixture of C6MIM.NTf2 and TOPO. The effects of ultrasonic irradiation on the Dy(III) ions show that ion transfer occurs with high extraction efficiency. The variation of logD versus temperature demonstrated that temperature had little impact on the extraction procedure. The recovery of dysprosium ions from the organic phase using 0.5M nitric acid is achieved in stripping studies. The results showed that the extraction and recovery under ultrasonic irradiation and with the presence of ionic liquids proposed a simple and environmentally friendly approach for the purification and separation of rare-earth ions from the permanent magnet wastewater.

Design, Modeling and Prototyping a Flat Switched Reluctance Machine for Direct‑Drive Systems

Majid Asgar,Hossein Torkaman,Ebrahim Afei 대한전기학회 2020 Journal of Electrical Engineering & Technology Vol.15 No.1

In this paper, a fat-type 24 by 16 SRM, is considered for the application of direct-drive washing machine. Firstly, the structure is introduced and using the nonlinear equivalent circuit, the researchers present a design for the SRM. Then, using the three-dimensional fnite element method, the electromagnetic characteristics of the proposed confguration are analyzed to evaluate the motor’s performance. The motor prototype is fabricated and tested experimentally to authenticate the theoretical and simulation analysis, and subsequently to prove the applicability. Finally, the performance of this proposed motor is compared with an SRM that has the same condition. Since a direct drive motor does not require a reduction gear, the drive system can be made simple without harmonic gears, and therefore it can be used in high-precision, more reliable, and low cost appliances.