Mansour Ahmed - Academia.edu (original) (raw)
Papers by Mansour Ahmed
Arabian Journal for Science and Engineering
Forward osmosis (FO) is considered an emerging and energy-efficient technology for seawater desal... more Forward osmosis (FO) is considered an emerging and energy-efficient technology for seawater desalination. Future research should focus on the large-scale exploration of efficient membranes and draw solutions to assess the real feasibility of the technology. This study explores the performance of a commercial-scale cellulose triacetate-based hollow fibre FO membrane in a pilot-scale FO desalination system of 10 m3/d capacity assisted by a polyelectrolyte draw solution. The large-scale membrane was divided into ten equivalent portions to evaluate the performance of the FO membrane more effectively. The study revealed that maximum water recovery was achieved at the centre and least towards the axial directions of the module, influenced by draw solution (DS) concentration distribution. Higher flow rates of both feed solution (FS) and DS have a higher potential to extract product water throughout the membrane configuration due to the reduced concentration polarization effect and the enhanced mass transfer coefficient. The stable performance of the FO membrane was verified over the long run to produce freshwater with high rejection towards toxic boron. An optimized overall water recovery of 40.0% was achieved with a permeate flow of 6.0 L/min by maintaining FS and DS flow rates of 15.0 L/min and 20 L/min, respectively. The FO system has low capital cost consumption considering the less energy of 0.15 kW/m3 consumed by the system; however, integration of the system with a low-energy DS recovery system will effectively reduce the overall energy cost of the system.
DESALINATION AND WATER TREATMENT, 2020
Multistage flash (MSF) and reverse osmosis (RO) are the two major desalination technologies curre... more Multistage flash (MSF) and reverse osmosis (RO) are the two major desalination technologies currently serving the needs of freshwater in Kuwait. MSF is energy intensive and suffer from low water recovery, while RO desire energy to fulfil its pressure requirement for the process. Thus, globally the scientists are focusing on the innovative desalination technologies which could be operated at low cost and environmentally friendly. In this regard, forward osmosis (FO) is one such emerging technology which can be operated under "Non-Pressure" requirement conditions to reduce the energy/cost of the desalination process. The principle of FO involves flow of the pure water across the semipermeable membrane by maintaining an osmotic pressure gradient between the feed solution (low concentration solution) and draw solution (high concentration solution). Related to this concept, a project was conducted at Kuwait Institute for Scientific Research to fabricate potential and fouling control membranes for the FO desalination. The aim of this paper is to present the important outcomes of the project in fabricating different types of membranes and results related to the high-performance thin film nanocomposite (TFN) membranes obtained in the project compared with commercial FO membranes. The TFN membrane with 0.05 wt.% nanoparticle composition resulted in high flux of vs. the commercial CTA membrane. Therefore, this work concluded that a suitable selection of nanoparticles and their proper modification is essential to fabricate potential membranes for FO application. Further, a nano-based FO membrane showed a potential application in FO desalination compared with commercial FO membranes.
DESALINATION AND WATER TREATMENT, 2020
To enhance the permeation and salt rejection properties of polysulfone membrane, novel TiO 2 nano... more To enhance the permeation and salt rejection properties of polysulfone membrane, novel TiO 2 nanoparticle incorporated acriflavine thin film composite (TFC) was fabricated. Fabricated TFC membranes were characterized thoroughly using Fourier transform infra red (FT-IR), atomic force microscope, field emission scanning electron microscope and contact angle (CA). The signature peaks in FT-IR spectra were identified to confirm the interfacial polymerization (IP) of acriflavine and TMC. TiO 2 nanoparticle incorporation in the TFC layer was analysed using elemental mapping analysis and EDX. The addition of TiO 2 nanoparticle in acriflavine TFC layer resulted change in morphology of membrane and contact angle. The highest pure water flux was reached up to 67.1 Lm-2 h-1 with 0.1 weight percentage of TiO 2 nanoparticle dosage (TFC 4). The water flux of 53.0, and 44.5 Lm-2 h-1 were achieved for TFC 4 membrane using Arabian Gulf Seawater, and reverse osmosis (RO) brine, respectively. Most importantly, TFC 4 membrane showed less fouling with more than 99% of ionic rejection for magnesium, calcium, and sulfate ions. From the studies, it was concluded that, novel TiO 2 nanoparticle incorporated acriflavine TFC membranes are having high capability of rejecting divalent ions and suitable for seawater treatment and RO brine concentration applications.
Miskolc Mathematical Notes, 2017
The aim of this paper is to introduce and analyze chaotic and hyperchaotic conservative complex n... more The aim of this paper is to introduce and analyze chaotic and hyperchaotic conservative complex nonlinear systems. These systems appear in several branches of applied sciences. Lyapunov exponents are calculated to observe chaotic and hyperchaotic behaviors. The wide range of systems parameters at which chaotic and hyperchaotic solutions exist is calculated. The modules for complex variables are computed and plotted. The projections of chaotic and hyperchaotic solutions are shown in 3-spaces and 2-planes. The systems of this paper leave rooms for further studies in the near future, e.g. control and several types of synchronization of the solutions of these systems.
International Journal of Modern Physics C, 2008
This paper introduces and analyzes new hyperchaotic complex Lorenz systems. These systems are 6-d... more This paper introduces and analyzes new hyperchaotic complex Lorenz systems. These systems are 6-dimensional systems of real first order autonomous differential equations and their dynamics are very complicated and rich. In this study we extend the idea of adding state feedback control and introduce the complex periodic forces to generate hyperchaotic behaviors. The fractional Lyapunov dimension of the hyperchaotic attractors of these systems is calculated. Bifurcation analysis is used to demonstrate chaotic and hyperchaotic behaviors of our new systems. Dynamical systems where the main variables are complex appear in many important fields of physics and communications.
Arabian Journal for Science and Engineering
Forward osmosis (FO) is considered an emerging and energy-efficient technology for seawater desal... more Forward osmosis (FO) is considered an emerging and energy-efficient technology for seawater desalination. Future research should focus on the large-scale exploration of efficient membranes and draw solutions to assess the real feasibility of the technology. This study explores the performance of a commercial-scale cellulose triacetate-based hollow fibre FO membrane in a pilot-scale FO desalination system of 10 m3/d capacity assisted by a polyelectrolyte draw solution. The large-scale membrane was divided into ten equivalent portions to evaluate the performance of the FO membrane more effectively. The study revealed that maximum water recovery was achieved at the centre and least towards the axial directions of the module, influenced by draw solution (DS) concentration distribution. Higher flow rates of both feed solution (FS) and DS have a higher potential to extract product water throughout the membrane configuration due to the reduced concentration polarization effect and the enhanced mass transfer coefficient. The stable performance of the FO membrane was verified over the long run to produce freshwater with high rejection towards toxic boron. An optimized overall water recovery of 40.0% was achieved with a permeate flow of 6.0 L/min by maintaining FS and DS flow rates of 15.0 L/min and 20 L/min, respectively. The FO system has low capital cost consumption considering the less energy of 0.15 kW/m3 consumed by the system; however, integration of the system with a low-energy DS recovery system will effectively reduce the overall energy cost of the system.
DESALINATION AND WATER TREATMENT, 2020
Multistage flash (MSF) and reverse osmosis (RO) are the two major desalination technologies curre... more Multistage flash (MSF) and reverse osmosis (RO) are the two major desalination technologies currently serving the needs of freshwater in Kuwait. MSF is energy intensive and suffer from low water recovery, while RO desire energy to fulfil its pressure requirement for the process. Thus, globally the scientists are focusing on the innovative desalination technologies which could be operated at low cost and environmentally friendly. In this regard, forward osmosis (FO) is one such emerging technology which can be operated under "Non-Pressure" requirement conditions to reduce the energy/cost of the desalination process. The principle of FO involves flow of the pure water across the semipermeable membrane by maintaining an osmotic pressure gradient between the feed solution (low concentration solution) and draw solution (high concentration solution). Related to this concept, a project was conducted at Kuwait Institute for Scientific Research to fabricate potential and fouling control membranes for the FO desalination. The aim of this paper is to present the important outcomes of the project in fabricating different types of membranes and results related to the high-performance thin film nanocomposite (TFN) membranes obtained in the project compared with commercial FO membranes. The TFN membrane with 0.05 wt.% nanoparticle composition resulted in high flux of vs. the commercial CTA membrane. Therefore, this work concluded that a suitable selection of nanoparticles and their proper modification is essential to fabricate potential membranes for FO application. Further, a nano-based FO membrane showed a potential application in FO desalination compared with commercial FO membranes.
DESALINATION AND WATER TREATMENT, 2020
To enhance the permeation and salt rejection properties of polysulfone membrane, novel TiO 2 nano... more To enhance the permeation and salt rejection properties of polysulfone membrane, novel TiO 2 nanoparticle incorporated acriflavine thin film composite (TFC) was fabricated. Fabricated TFC membranes were characterized thoroughly using Fourier transform infra red (FT-IR), atomic force microscope, field emission scanning electron microscope and contact angle (CA). The signature peaks in FT-IR spectra were identified to confirm the interfacial polymerization (IP) of acriflavine and TMC. TiO 2 nanoparticle incorporation in the TFC layer was analysed using elemental mapping analysis and EDX. The addition of TiO 2 nanoparticle in acriflavine TFC layer resulted change in morphology of membrane and contact angle. The highest pure water flux was reached up to 67.1 Lm-2 h-1 with 0.1 weight percentage of TiO 2 nanoparticle dosage (TFC 4). The water flux of 53.0, and 44.5 Lm-2 h-1 were achieved for TFC 4 membrane using Arabian Gulf Seawater, and reverse osmosis (RO) brine, respectively. Most importantly, TFC 4 membrane showed less fouling with more than 99% of ionic rejection for magnesium, calcium, and sulfate ions. From the studies, it was concluded that, novel TiO 2 nanoparticle incorporated acriflavine TFC membranes are having high capability of rejecting divalent ions and suitable for seawater treatment and RO brine concentration applications.
Miskolc Mathematical Notes, 2017
The aim of this paper is to introduce and analyze chaotic and hyperchaotic conservative complex n... more The aim of this paper is to introduce and analyze chaotic and hyperchaotic conservative complex nonlinear systems. These systems appear in several branches of applied sciences. Lyapunov exponents are calculated to observe chaotic and hyperchaotic behaviors. The wide range of systems parameters at which chaotic and hyperchaotic solutions exist is calculated. The modules for complex variables are computed and plotted. The projections of chaotic and hyperchaotic solutions are shown in 3-spaces and 2-planes. The systems of this paper leave rooms for further studies in the near future, e.g. control and several types of synchronization of the solutions of these systems.
International Journal of Modern Physics C, 2008
This paper introduces and analyzes new hyperchaotic complex Lorenz systems. These systems are 6-d... more This paper introduces and analyzes new hyperchaotic complex Lorenz systems. These systems are 6-dimensional systems of real first order autonomous differential equations and their dynamics are very complicated and rich. In this study we extend the idea of adding state feedback control and introduce the complex periodic forces to generate hyperchaotic behaviors. The fractional Lyapunov dimension of the hyperchaotic attractors of these systems is calculated. Bifurcation analysis is used to demonstrate chaotic and hyperchaotic behaviors of our new systems. Dynamical systems where the main variables are complex appear in many important fields of physics and communications.