Time filter

Source Type

Fahmy R.A.,Egyptian Nuclear and Radiological Regulatory Authority ENRRA | Badr R.I.,Cairo University | Ralmian F.A.,Egyptian Nuclear and Radiological Regulatory Authority ENRRA
Mediterranean Journal of Measurement and Control | Year: 2015

The Proportional-Integral-Derivative (PID) is widely used in industrial control systems due to its simplicity. For Single-Input Single-Output (SISO) systems, choosing the PID gain values is a difficult task especially that in most applications systems parameter variations and changes in operating conditions occur. Thus, there is necessity to find parameters tuning method in which PED gains should be adapted to handle such changes. This paper is concerned with the design of an Adaptive PID (APID) controller in which Recursive Least Square (RLS) algorithm is used as adaptation mechanism. Meaning that RLS algorithm is used to tune the PID gains online forcing the system to behave like a desired reference model. Since stability is a vital issue in the evaluation of control systems, therefore stability analysis of the proposed technique is developed. Controlling the temperature of Fluidized Bed Reactor (FBR) system is used as an example of an unstable SISO system to examine the effectiveness of the proposed APID controller. Computer simulations show the superiority of the proposed APID controller over the conventional fixed gains PED controller in stabilizing the system and tracking the setpoint changes even when some variations in the system parameters occur. © 2015 SoftMotor Ltd. ISSN: 1743-9310.


Gomaa R.,Egyptian Nuclear and Radiological Regulatory Authority ENRRA | Adly I.,The British University in Egypt | Sharshar K.,National Center for Radiation Research And Technology | Safwat A.,Cairo University | Ragai H.,Ain Shams University
IEEE Radiation Effects Data Workshop | Year: 2014

WSN deployment for monitoring nuclear environment has recently addressed as incremental and experimental networks. The work objective is to determine dose tolerance of commercially wireless Zigbee modules in nuclear embedded applications, with gamma irradiation fluxes. © 2014 IEEE.


Shaban S.E.,Egyptian Nuclear and Radiological Regulatory Authority ENRRA | Ibrahiem N.M.,Egyptian Nuclear and Radiological Regulatory Authority ENRRA | El-Mongy S.A.,Egyptian Nuclear and Radiological Regulatory Authority ENRRA | Elshereafy E.E.,Menoufia University
Journal of Radioanalytical and Nuclear Chemistry | Year: 2013

Ten ore samples, two unpurified yellow cake samples and natural uranyl nitrate hexahydrate sample were analyzed by Scanning Electron Microscope (SEM) and Energy Dispersive X-ray (EDX) method to verify source nuclear material. Samples represent source nuclear material as possible. All samples were scanned at ideal conditions; working distance = 10 mm, voltage = 30 kV, magnification value = × 100, spot size = 50 to screen samples for the presence of uranium and thorium, Also Hyper pure germanium (HPGe) gamma spectrometers were applied to estimate the uranium and thorium contents in Bq/kg (ppm). For the ore samples uranium-238 ranges from 1,049.23 Bq/kg (85.30 ppm) to 2,096.06 Bq/kg (170.41 ppm), uranium-235 ranges from 47.51 to 105.61 Bq/kg and thorium-232 ranges from 22.84 Bq/kg (5.65 ppm) to 41.78 Bq/kg (10.34 ppm). For the yellow cake samples and uranyl nitrate hexahydrate uranium-238 ranges from 42.99 Bq/kg (3.50 ppm) to 71,887.2 Bq/kg (5,844.49 ppm) and thorium-232 is 4.78 Bq/kg (1.83 ppm) and the other two samples are lower than the detection limit. © 2012 Akadémiai Kiadó, Budapest, Hungary.


Zidan W.I.,Egyptian Nuclear and Radiological Regulatory Authority ENRRA | Abo-Aly M.M.,Ain Shams University | Elhefnawy O.A.,Egyptian Nuclear and Radiological Regulatory Authority ENRRA | Bakier E.,Ain Shams University
Journal of Radioanalytical and Nuclear Chemistry | Year: 2015

A novel sorbent 4XADMnO (Amberlite XAD-4 modified with nano-flakes of manganese dioxide) was synthesized for improving UO2 2+ ions sorption in aqueous medium from low radioactive waste. The new sorbent was characterized using EDX, XRD and FTIR analyses. Uranium sorption was investigated in both batch and column studies at different operating conditions. Different kinetics, isothermal and dynamic models were applied for the results of the carried experiments. The developed sorbent was successfully utilized for UO2 2+ ions sorption in safeguards application. © 2014, Akadémiai Kiadó, Budapest, Hungary.


Elhefnawy O.A.,Egyptian Nuclear and Radiological Regulatory Authority ENRRA | Zidan W.I.,Egyptian Nuclear and Radiological Regulatory Authority ENRRA | Abo-Aly M.M.,Ain Shams University | Bakier E.M.,Ain Shams University | Elsayed G.A.,Ain Shams University
Journal of Radioanalytical and Nuclear Chemistry | Year: 2014

A new sorbent Amberlite-7HP modified by the nanoFe3O4 (7HPNFeO) formed by surface modification of Amberlite-7 HP using iron oxide magnetic nano-particles which was prepared by precipitation of iron(II) and iron(III) ions in an aqueous solution. The prepared particles have been characterized with transmission electron microscopy, energy dispersive X-ray/scanning electron microscope, X-ray diffraction, and infrared techniques. The sorption kinetics of U(VI) obeyed pseudo second-order and fitted to the intra-particle diffusion model. The sorption isotherms can be correlated to Langmuir isotherm with monolayer capacity of 47.169 mg/g. The breakthrough data obtained by column studies then utilized to model it with Thomas model and to estimate the loading capacity of U(VI) under the specified column conditions. The interfering effect of various anion and cations on the sorption process was examined. Oxalic acid was found suitable for U(VI) separation from the interfering ions Co(II), Cd(II), and Zr(IV) in aqueous solution. Results obtained showed that 7HPNFeO is a promising and effective sorbent and could be used in real samples for safeguard verification purposes. © 2013 Akadémiai Kiadó, Budapest, Hungary.


Elhefnawy O.A.,Egyptian Nuclear and Radiological Regulatory Authority ENRRA | Zidan W.I.,Egyptian Nuclear and Radiological Regulatory Authority ENRRA | Abo-Aly M.M.,Ain Shams University | Bakier E.M.,Ain Shams University | Al-Magid G.A.,Ain Shams University
Spectroscopy Letters | Year: 2014

In this work, a commercially available Amberlite 7HP has been modified using nano-flakes MnO2 prepared by a simple reduction method. The characterization of the new sorbent impregnated by nano manganese dioxide was performed by scanning electron microscope, transmission electron microscope, energy-dispersive X-ray, X-ray diffraction, and Fourier transformation infrared spectrometric analyses. The performance of the new sorbent for ion separation in aqueous medium was studied in detail by varying the pH, contact time, initial concentration, bed height, and flow rate. The maximum sorption has been achieved at a solution of pH 3.1. Sorbed ions were desorbed with 10 mL of 1.5 M HCl solution. The kinetics and isothermal parameters of the sorption of ions onto the new sorbent have been studied. The kinetic experimental data properly correlate with the second-order kinetic model and the time required to reach sorption equilibrium is 240 min. The sorption data could be well interpreted by the Langmuir sorption isotherm and the monolayer sorption capacity was found to be 56.3 mg · g-1. The sorption data were fitted to two well-established fixed-bed sorption models, namely, Thomas and Yoon-Nelson models, with a correlation coefficient, R2, ≥0.993. The separation performance of the new sorbent was demonstrated by using different real samples. Consequently, the developed sorbent resin was successfully utilized for the separation of uranyl ions in safeguard applications. © 2014 Copyright Taylor and Francis Group, LLC.


Atta A.M.,King Saud University | Atta A.M.,Egyptian Petroleum Research Institute | Akl Z.F.,Egyptian Nuclear and Radiological Regulatory Authority ENRRA
Materials Chemistry and Physics | Year: 2015

The present study describes synthesis and characterization of diacrylamidoxime triaethylenetetralevopimaramide (DPAO) and its use in surface modification of Fe3O4 magnetic nanoparticles to obtain DPAO-based magnetic nanoparticles (DPAO-MNPs). The prepared composite was characterized by FTIR, 1HNMR, XRD, DLS, TEM, SEM and EDX. Vibrating sample magnetometer is used to determine the magnetic properties of DPAO-MNPs. Results of analyses indicate that the surface of Fe3O4 was successfully capped with DPAO. The adsorption features of the prepared composite towards thorium ions were investigated in a batch system. Kinetic study of Th(IV) adsorption on DPAO-MNPs indicate the adsorption equilibrium achieved within 150 min and is pH dependent. The adsorption results were described mathematically using Langmuir and Freundlich sorption models. The composite showed a maximum Th(IV) loading capacity of 666 mg/g at 25 °C and pH 4. The thermodynamic results indicated that the adsorption process was thermodynamically favorable, spontaneous and endothermic nature. The obtained results suggest that DPAO-MNPs composite may be considered as a potential fast, effective and simple adsorbent for sorption thorium(IV) from water. © 2015 Elsevier B.V. All rights reserved.


Akl Z.F.,Egyptian Nuclear and Radiological Regulatory Authority ENRRA | El-Saeed S.M.,Egyptian Petroleum Research Institute | Atta A.M.,Egyptian Petroleum Research Institute | Atta A.M.,King Saud University
Journal of Industrial and Engineering Chemistry | Year: 2016

A new in-situ magnetite nanoparticles inserted into crosslinked poly (acrylamido-amineamidoxime-co-2-acrylamido-2-methylpropane sulfonic acid (AO/AMPS) were prepared and used as novel uranium adsorbents. The prepared composites were applied as adsorbents to remove U(VI) from aqueous solutions that could be separated by a simple magnetic separation method. The removal of U(VI) was evaluated by spectrophotometric method using arsenazo-III as complexing agent. The results showed that, the sorption process strongly depended on pH and the sorption equilibrium can be reached within 150 min. The Langmuir sorption isotherm model correlated well with the uranium sorption equilibrium data for the concentration range of 50-500 mg/L. © 2015 The Korean Society of Industrial and Engineering Chemistry.


Abdeen Z.,Egyptian Petroleum Research Institute | Akl Z.F.,Egyptian Nuclear and Radiological Regulatory Authority ENRRA
RSC Advances | Year: 2015

Poly(vinyl alcohol)/multiwalled carbon nanotubes (PVA/MWCNTs) composite hydrogels were prepared by a dispersion method and their ability to adsorb and remove uranyl ions from aqueous solutions was investigated. The prepared composites were characterized by XRD, TEM, SEM and FTIR. The effect of contact time, solution pH, initial UO22+ ion concentration and temperature on UO22+ ion adsorption from aqueous solution onto the prepared hydrogels was studied. The obtained results illustrated that, dispersion of MWCNTs into the PVA matrix enhanced the removal efficiency of UO22+ ions compared to PVA only. The Langmuir and Freundlich adsorption models have been applied to evaluate the adsorption efficiency and the data correlated well with the Langmuir model. Thermodynamic parameters (ΔH°, ΔS°, ΔG°) were determined which indicated that the UO22+ ion adsorption process onto the prepared hydrogels was exothermic and spontaneous. The adsorbed UO22+ can be desorbed effectively by 0.1 M EDTA. © The Royal Society of Chemistry 2015.


Fahmy R.A.,Egyptian Nuclear and Radiological Regulatory Authority ENRRA | Badr R.I.,Cairo University | Rahman F.A.,Egyptian Nuclear and Radiological Regulatory Authority ENRRA
Journal of Fusion Energy | Year: 2016

Nuclear fusion is one of the newest and most promising clean and safe energies hence, it imposes a new research area of control. In this paper, the design of a multivariable adaptive proportional-integral-derivative (PID) controller for the control of the plasma current, shape and position to ensure the safe operation of the fusion reactor is successfully developed. The recursive least square algorithm is used in an alternative way as an adaptation mechanism for tuning PID controller gains. Since stability is a vital issue in the evaluation of control systems, therefore stability analysis of the proposed controller is developed using the Lyapunov stability theory. The main objective of plasma current, shape and position controller in fusion reactors is to improve the stability and the performance of tokamak magnetic systems without contravening the limits imposed by the actuating coils voltages physical limitations. The proposed APID (adaptive PID) controller tunes online its parameters to cope with the presence of the disturbance or any parameters changes occur during the operation. The results of the proposed APID on a simulation code of a tokamak show a noteworthy improvement with respect to those obtained with other control techniques in the cases of changing the initial controller gains, adding disturbance signal and variation in the reactor model parameters. © 2016 Springer Science+Business Media New York

Loading Egyptian Nuclear and Radiological Regulatory Authority ENRRA collaborators
Loading Egyptian Nuclear and Radiological Regulatory Authority ENRRA collaborators