LiveWell Initiative LWI, a self funded nonprofit social enterprise (www.livewellng.org) has, for ... more LiveWell Initiative LWI, a self funded nonprofit social enterprise (www.livewellng.org) has, for 5 years, supervised MPH and DrPH Practicums for the Harvard T. H. Chan School of Public Health, Harvard University, Boston USA. It also supervises PhD thesis at University of Helsinki, Finland. The organization has repurposed quinine for use in moderate to severe coronavirus disease (COVID-19) by compiling three sets of STUDY PROTOCOLS in response to the COVID-19 RESPONSE with a goal to arriving at a practical and affordable solution to the pandemic. The protocols underwent debates and hypothesis testing among physicians, researchers, pharmacists and virologists. The protocols, still undergoing random Physician–Patient Trials at the discretion of prescribing clinicians and clinical researchers, are as recommended in a compilation of recent findings by LiveWell Initiative LWI on COVID-19. It is a study protocol designed to ‘evolve’ as a solution to COVID-19 response. The protocols strongl...
High-speed trains have become one of the most leading transportation means, where each year the m... more High-speed trains have become one of the most leading transportation means, where each year the manufacture companies reach a new speed record. This progressive speed records increase the handover (HO) rate which makes it very difficult for high speed railway (HSR) mobile communication to sustain a reliable communication link. Utilizing distributed antenna systems (DASs) along with the two-hop architecture, this paper analyzes the conventional handover scheme based on this architecture and proposes a faster HO strategy. The proposed scheme reduces the HO latency and failure probability which could greatly improve the end-users quality of services (QoS). The analytical results show that the proposed scheme performs better than the conventional HO scheme.
Background: LiveWell Initiative LWI is a self-funded nonprofit social enterprise that thrives on ... more Background: LiveWell Initiative LWI is a self-funded nonprofit social enterprise that thrives on innovation.The organization has, for 5 years, supervised MPH and DrPH Practicums for the Harvard T. H. Chan School of Public Health, Harvard University, Boston USA. It also supervises the PhD thesis at the University of Helsinki, Finland. At the inception of COVID-19, LWI designed and compiled three (3) sets of study protocols in response to the COVID-19 response in Africa with a goal to arrive at a practical and affordable solution to the pandemic using 4-aminoquinolines. Method: A concurrent cohort/descriptive study of observation in patients exposed to HCQ/CQ prophylaxis and treatment with HCQ/CQ and quinine with categorization as specified as not critically ill, critically ill but not on a ventilator and critically ill on a ventilator. One hundred and twenty-three (123) subjects were categorized into shelter-in-place, self-quarantine and self-isolation (not critically ill, critically...
In this work, a pioneering study on the electrical properties of composite carbon nanofibres (CNF... more In this work, a pioneering study on the electrical properties of composite carbon nanofibres (CNFs) using current-sensitive atomic force microscopy (CS-AFM) has been demonstrated. CNFs are highly interesting materials which are usable in a wide array of applications e.g. electrode materials for biosensors, lithium ion batteries, fuel cells and supercapacitors. CNFs offer a high specific surface area and thus have a high contact area for charge transfer. CNFs can be produced using spinnable polyacrylonitrile (PAN) as a precursor for carbonisation. For the purpose of developing efficient CNFs with high conductivity and power density, silver nanoparticle (AgNPs)-containing PAN solutions were electrospun to form composite nanofibres which was followed by heat treatment. The applied voltage of the spinning setup and the content of both PAN and the silver nanoparticles in the spinning solution were varied in order to study their influence on the morphology and the electrical properties of...
High-speed railway (HSR) has witnessed a huge growth all over the globe reaching a maximum speed ... more High-speed railway (HSR) has witnessed a huge growth all over the globe reaching a maximum speed of 575 km/h. This record of speed makes mobile communications difficult for HSR since the handover (HO) frequency increases which frequently results in a loss of connectivity. This paper proposes a specialized network architecture based on distributed antenna systems (DAS) for HSR broadband wireless communication systems along with the two- hop architecture. Further, a frequency switch (FSW) scheme is proposed aiming to eliminate the need for HO between the successive small coverage remote antenna units (RAUs) that fall under the same central unit (CU) control. The analytical results show that the proposed scheme outperforms traditional HO schemes and can support the application with high quality of services (QoS) requirement.
GLOBECOM 2017 - 2017 IEEE Global Communications Conference, 2017
The version in the Kent Academic Repository may differ from the final published version. Users ar... more The version in the Kent Academic Repository may differ from the final published version. Users are advised to check http://kar.kent.ac.uk for the status of the paper. Users should always cite the published version of record.
Konventionelle Techniken zur Trink- und Abwasseraufbereitung zur Entfernung von perfluorierten Te... more Konventionelle Techniken zur Trink- und Abwasseraufbereitung zur Entfernung von perfluorierten Tensiden (PFC) funktionieren eher ungenügend. Daher sind neue Adsorber für PFCs erforderlich. Im Forschungsprojekt wurden textilbasierte Adsorber auf Basis beschichteter Polyesterfasern mit verschiedenen Polyelektrolyten entwickelt. Die textilbasierten Adsorber wurden per Foulard-Ausrüstungsmethode hergestellt, was zu langlebigen, leistungsstarken und kostengünstigen Adsorbentien für die Entfernung von PFCs aus Wasser führt. Aus dem kontaminierten Grundwasser aus Düsseldorf und eines ehemaligen Textilveredlungsbetriebs in Bielefeld wurden ~95 bzw. 85 % der lang- und kurzkettigen PFCs reduziert. Dagegen zeigte das stark mit kurzkettigen PFC belastete Grundwasser aus der Papierschlammentsorgung aus Rastatt eine geringere Elimination für kurzkettige PFC. Der daraus resultierende amphiphile Charakter bewirkt eine starke Reduzierung der Oberflächenspannung von Wasser, wobei die hydrophile Kopfg...
Im IGF-Projekt Nr. 19617 N wurden stickstoff- und phosphorsubstituierte Alkoxysilane hergestellt ... more Im IGF-Projekt Nr. 19617 N wurden stickstoff- und phosphorsubstituierte Alkoxysilane hergestellt und ihre flammhemmenden Eigenschaften für Textilien untersucht. Die Synthesen erfolgten nach unterschiedlichen Strategien wie der Klick-Chemie und der nukleophilen Substitution kommerziell erhältlicher Organophosphorverbindungen mit aminobasierten Trialkoxysilanen und/oder Cyanurchlorid. Diese neuartigen, halogen- und aldehydfreien Flammschutzmittel wurden auf Stoffe aus Baumwolle (BW), Polyethylenterephthalat (PET), Polyamid (PA), sowie Mischgeweben daraus mit der industriell etablierten Pad-Dry-Cure-Technik und mittels Sol-Gel-Verfahren aufgetragen. Die flammhemmenden Eigenschaften wurden mit den Prüfverfahren nach EN ISO 15025 (Schutzkleidung – Schutz gegen Hitze und Flammprüfverfahren für begrenzte Flammenausbreitung) bewertet. Eine gute Schwerentflammbarkeit der hybriden organisch-anorganischen Materialien wurde bei einer geringen Menge von 3-5 Gew.-% auf Baumwollgeweben erreicht. D...
A spectrum-sensing algorithm is used to detect the available and the occupied frequency bands. Th... more A spectrum-sensing algorithm is used to detect the available and the occupied frequency bands. The wideband antenna design approach is used for a microstrip fed monopole antenna that can be used for various wireless technologies such as GSM, UMTS, LTE, and WiFi operating at different frequencies from 1.25 to 3 GHz. The antenna is constructed from two copper layers of rectangular radiator and a partial ground plane. These layers are printed on an RO4003 substrate with dimensions 60 x 80 mm2. The antenna is experimentally fabricated to verify the simulation predictions and good matching between simulated and measured results is achieved. The wide-band antenna is tested by connecting it to the receiver of the Blade-RF Software Defined Radio (SDR) platform. A matlab script is then used to control the SDR board and to perform Spectrum Sensing for Cognitive Radio Applications.
On the basis of the major application for block copolymers to use them as separation membranes, l... more On the basis of the major application for block copolymers to use them as separation membranes, lithographic mask, and as templates, the preparation of highly oriented nanoporous thin films requires the selective removal of the minor phase from the pores. In the scope of this study, thin film of polystyrene-block-poly(ethylene oxide) block copolymer with a photocleavable junction groups based on ortho-nitrobenzylester (ONB) (PS-hν-PEO) was papered via the spin coating technique followed by solvent annealing to obtain highly-ordered cylindrical domains. The polymer blocks are cleaved by means of a mild UV exposure and then the pore material is washed out of the polymer film by ultra-pure water resulting in arrays of nanoporous thin films to remove one block. The removal of the PEO materials from the pores was proven using the grazing-incidence small-angle X-ray scattering (GISAXS) technique. The treatment of the polymer film during the washing process was observed in real time after ...
Although current desalination technologies are mature enough and advanced, the shortage of freshw... more Although current desalination technologies are mature enough and advanced, the shortage of freshwater is still considered as one of the most pressing global issues. Therefore, there is a strong incentive to explore and investigate new potential methods with low energy consumption. We have previously reported that reversible thermally induced sorption/desorption process using polymeric hydrogels hold promise for water desalination with further development. In order to develop a more effective hydrogels architecture, polyelectrolyte moieties were introduced in this work as pendent chains and a thermally responsive polymer as network backbone using reversible addition-fragmentation chain transfer (RAFT) polymerisation. The ability of the comb-type polymeric hydrogels to desalinate water was evaluated. These hydrogels were proved to absorb water with low salinity from brine solution of 2 g L −1 NaCl and release the absorbed water at relatively low temperature conditions of 50 • C. The fraction of the grafted polyacrylic acid and the comb-chain length were varied to understand their influence on the swelling/deswelling behaviour for these hydrogels. The ionic fraction in the hydrogels and the resulting hydrophilic/hydrophobic balance are crucial for the proposed desalination process. In contrast, the comb-chain length impacted the swelling behaviour of hydrogels but showed relatively little influence on the dewatering process.
In this article, a size miniaturized ultra-wideband (UWB) monopole antenna with dual band-notched... more In this article, a size miniaturized ultra-wideband (UWB) monopole antenna with dual band-notched is presented. By inserting a rectangular slot on the bottom plane, the operation bandwidth of the required antenna is increased by 7%, so that the required antenna can achieve a wide applicable fractional bandwidth of 137.01% (2.85-15.25 GHz). Moreover, a band notch located at 7.6 GHz is generated by cutting a defected microstrip structure (DMS) consisting of circular head dumbbell on the metallic patch. Meanwhile, by introducing a defected ground structure (DGS) consisting of metallic circular head dumbbell shaped in the ground plane, the second band-notch created at 5.6 GHz. Experimental results of the required antenna agree with the simulations quite well, with a miniaturized size of 32 9 25 mm 2 , which illustrates that the required antenna is suitable for UWB applications.
In this work, we explore the ability of utilizing hydrogels synthesized from a temperature-sensit... more In this work, we explore the ability of utilizing hydrogels synthesized from a temperature-sensitive polymer and a polyelectrolyte to desalinate salt water by means of reversible thermally induced absorption and desorption. Thus, the influence of the macromolecular architecture on the swelling/deswelling behavior for such hydrogels was investigated by tailor-made network structures. To this end, a series of chemically cross-linked polymeric hydrogels were synthesized via free radical-initiated copolymerization of sodium acrylate (SA) with the thermoresponsive comonomer N-isopropylacrylamide (NIPAAm) by realizing different structural types. In particular, two different polyNIPAAm macromonomers, either with one acrylate function at the chain end or with additional acrylate functions as side groups were synthesized by controlled polymerization and subsequent polymer-analogous reaction and then used as building blocks. The rheological behaviors of hydrogels and their estimated mesh size...
Langmuir : the ACS journal of surfaces and colloids, Jan 10, 2015
Highly ordered block copolymer thin films have been studied extensively during the last years bec... more Highly ordered block copolymer thin films have been studied extensively during the last years because they afford versatile self assembled morphologies via a bottom-up approach. They promise to be used in applications such as polymeric membranes or templates for nanostructured materials. Among the block copolymer structures, perpendicular cylinders have received strong attention due to their ability to fabricate highly ordered nanopores and nanowires. Nanopores can be created from a thin block copolymer film upon removal of one block by selective etching or by dissolution of one polymer block. Here, we demonstrate the utilization of polystyrene-block-poly(ethylene oxide) diblock copolymer (PS-hν-PEO) with an ortho-nitrobenzyl ester (ONB) as the photocleavable block-linker to create highly ordered thin films. Removal of the PEO block by choosing an appropriate solvent upon photo cleavage is expected to yield arrays of nanopores decorated with functional groups thus lending itself to ...
2010 International Symposium on Signals, Systems and Electronics, 2010
Page 1. Space Time Adaptive Processing (STAP) Using Two Dimensional Array of Real Elements Based ... more Page 1. Space Time Adaptive Processing (STAP) Using Two Dimensional Array of Real Elements Based on Direct Data Domain Least Squares (D 3 LS) Approach Hassan M. Elkamchouchi#1, Darwish AE Mohamed*2, Wael AE Ali*3 ...
2010 International Symposium on Signals, Systems and Electronics, 2010
Page 1. Multiple Constraint Space-Time Direct Data Domain Approach Using Nonuniformly, Semicircul... more Page 1. Multiple Constraint Space-Time Direct Data Domain Approach Using Nonuniformly, Semicircular and Sinusoidal Spaced Arrays of Real Elements Hassan M. Elkamchouchi#1, Darwish AE Mohamed*2, Wael AE Ali*3 ...
International Journal of Computer Applications, 2011
In this paper, Space Time Adaptive Processing (STAP) applied on wideband signals from uniformly s... more In this paper, Space Time Adaptive Processing (STAP) applied on wideband signals from uniformly spaced real elements using Direct Data Domain Least Squares (D 3 LS). Two antenna configurations are used: an array of dipole antenna (narrowband antenna) and an array of patch antenna (wideband antenna). A frequency transformation technique is used only for the case of narrowband antenna which transforms the steering vector at a wideband frequency to another steering vector at the desired frequency. The mutual coupling between elements will affect on the estimation of complex amplitude of Signal of Interest (SOI). It is necessary to compensate for the strong mutual coupling that exists between the real antenna elements. This is done by using coupling transformation matrix which converts the voltages that are induced at the real antenna elements to an equivalent set of voltages that will be induced by the same incident wave in uniform linear virtual array (ULVA). Then, we will apply STAP D 3 LS on the compensated voltages. Numerical simulations are done using the three main methods of D 3 LS namely the forward, backward, and the forward-backward methods.
LiveWell Initiative LWI, a self funded nonprofit social enterprise (www.livewellng.org) has, for ... more LiveWell Initiative LWI, a self funded nonprofit social enterprise (www.livewellng.org) has, for 5 years, supervised MPH and DrPH Practicums for the Harvard T. H. Chan School of Public Health, Harvard University, Boston USA. It also supervises PhD thesis at University of Helsinki, Finland. The organization has repurposed quinine for use in moderate to severe coronavirus disease (COVID-19) by compiling three sets of STUDY PROTOCOLS in response to the COVID-19 RESPONSE with a goal to arriving at a practical and affordable solution to the pandemic. The protocols underwent debates and hypothesis testing among physicians, researchers, pharmacists and virologists. The protocols, still undergoing random Physician–Patient Trials at the discretion of prescribing clinicians and clinical researchers, are as recommended in a compilation of recent findings by LiveWell Initiative LWI on COVID-19. It is a study protocol designed to ‘evolve’ as a solution to COVID-19 response. The protocols strongl...
High-speed trains have become one of the most leading transportation means, where each year the m... more High-speed trains have become one of the most leading transportation means, where each year the manufacture companies reach a new speed record. This progressive speed records increase the handover (HO) rate which makes it very difficult for high speed railway (HSR) mobile communication to sustain a reliable communication link. Utilizing distributed antenna systems (DASs) along with the two-hop architecture, this paper analyzes the conventional handover scheme based on this architecture and proposes a faster HO strategy. The proposed scheme reduces the HO latency and failure probability which could greatly improve the end-users quality of services (QoS). The analytical results show that the proposed scheme performs better than the conventional HO scheme.
Background: LiveWell Initiative LWI is a self-funded nonprofit social enterprise that thrives on ... more Background: LiveWell Initiative LWI is a self-funded nonprofit social enterprise that thrives on innovation.The organization has, for 5 years, supervised MPH and DrPH Practicums for the Harvard T. H. Chan School of Public Health, Harvard University, Boston USA. It also supervises the PhD thesis at the University of Helsinki, Finland. At the inception of COVID-19, LWI designed and compiled three (3) sets of study protocols in response to the COVID-19 response in Africa with a goal to arrive at a practical and affordable solution to the pandemic using 4-aminoquinolines. Method: A concurrent cohort/descriptive study of observation in patients exposed to HCQ/CQ prophylaxis and treatment with HCQ/CQ and quinine with categorization as specified as not critically ill, critically ill but not on a ventilator and critically ill on a ventilator. One hundred and twenty-three (123) subjects were categorized into shelter-in-place, self-quarantine and self-isolation (not critically ill, critically...
In this work, a pioneering study on the electrical properties of composite carbon nanofibres (CNF... more In this work, a pioneering study on the electrical properties of composite carbon nanofibres (CNFs) using current-sensitive atomic force microscopy (CS-AFM) has been demonstrated. CNFs are highly interesting materials which are usable in a wide array of applications e.g. electrode materials for biosensors, lithium ion batteries, fuel cells and supercapacitors. CNFs offer a high specific surface area and thus have a high contact area for charge transfer. CNFs can be produced using spinnable polyacrylonitrile (PAN) as a precursor for carbonisation. For the purpose of developing efficient CNFs with high conductivity and power density, silver nanoparticle (AgNPs)-containing PAN solutions were electrospun to form composite nanofibres which was followed by heat treatment. The applied voltage of the spinning setup and the content of both PAN and the silver nanoparticles in the spinning solution were varied in order to study their influence on the morphology and the electrical properties of...
High-speed railway (HSR) has witnessed a huge growth all over the globe reaching a maximum speed ... more High-speed railway (HSR) has witnessed a huge growth all over the globe reaching a maximum speed of 575 km/h. This record of speed makes mobile communications difficult for HSR since the handover (HO) frequency increases which frequently results in a loss of connectivity. This paper proposes a specialized network architecture based on distributed antenna systems (DAS) for HSR broadband wireless communication systems along with the two- hop architecture. Further, a frequency switch (FSW) scheme is proposed aiming to eliminate the need for HO between the successive small coverage remote antenna units (RAUs) that fall under the same central unit (CU) control. The analytical results show that the proposed scheme outperforms traditional HO schemes and can support the application with high quality of services (QoS) requirement.
GLOBECOM 2017 - 2017 IEEE Global Communications Conference, 2017
The version in the Kent Academic Repository may differ from the final published version. Users ar... more The version in the Kent Academic Repository may differ from the final published version. Users are advised to check http://kar.kent.ac.uk for the status of the paper. Users should always cite the published version of record.
Konventionelle Techniken zur Trink- und Abwasseraufbereitung zur Entfernung von perfluorierten Te... more Konventionelle Techniken zur Trink- und Abwasseraufbereitung zur Entfernung von perfluorierten Tensiden (PFC) funktionieren eher ungenügend. Daher sind neue Adsorber für PFCs erforderlich. Im Forschungsprojekt wurden textilbasierte Adsorber auf Basis beschichteter Polyesterfasern mit verschiedenen Polyelektrolyten entwickelt. Die textilbasierten Adsorber wurden per Foulard-Ausrüstungsmethode hergestellt, was zu langlebigen, leistungsstarken und kostengünstigen Adsorbentien für die Entfernung von PFCs aus Wasser führt. Aus dem kontaminierten Grundwasser aus Düsseldorf und eines ehemaligen Textilveredlungsbetriebs in Bielefeld wurden ~95 bzw. 85 % der lang- und kurzkettigen PFCs reduziert. Dagegen zeigte das stark mit kurzkettigen PFC belastete Grundwasser aus der Papierschlammentsorgung aus Rastatt eine geringere Elimination für kurzkettige PFC. Der daraus resultierende amphiphile Charakter bewirkt eine starke Reduzierung der Oberflächenspannung von Wasser, wobei die hydrophile Kopfg...
Im IGF-Projekt Nr. 19617 N wurden stickstoff- und phosphorsubstituierte Alkoxysilane hergestellt ... more Im IGF-Projekt Nr. 19617 N wurden stickstoff- und phosphorsubstituierte Alkoxysilane hergestellt und ihre flammhemmenden Eigenschaften für Textilien untersucht. Die Synthesen erfolgten nach unterschiedlichen Strategien wie der Klick-Chemie und der nukleophilen Substitution kommerziell erhältlicher Organophosphorverbindungen mit aminobasierten Trialkoxysilanen und/oder Cyanurchlorid. Diese neuartigen, halogen- und aldehydfreien Flammschutzmittel wurden auf Stoffe aus Baumwolle (BW), Polyethylenterephthalat (PET), Polyamid (PA), sowie Mischgeweben daraus mit der industriell etablierten Pad-Dry-Cure-Technik und mittels Sol-Gel-Verfahren aufgetragen. Die flammhemmenden Eigenschaften wurden mit den Prüfverfahren nach EN ISO 15025 (Schutzkleidung – Schutz gegen Hitze und Flammprüfverfahren für begrenzte Flammenausbreitung) bewertet. Eine gute Schwerentflammbarkeit der hybriden organisch-anorganischen Materialien wurde bei einer geringen Menge von 3-5 Gew.-% auf Baumwollgeweben erreicht. D...
A spectrum-sensing algorithm is used to detect the available and the occupied frequency bands. Th... more A spectrum-sensing algorithm is used to detect the available and the occupied frequency bands. The wideband antenna design approach is used for a microstrip fed monopole antenna that can be used for various wireless technologies such as GSM, UMTS, LTE, and WiFi operating at different frequencies from 1.25 to 3 GHz. The antenna is constructed from two copper layers of rectangular radiator and a partial ground plane. These layers are printed on an RO4003 substrate with dimensions 60 x 80 mm2. The antenna is experimentally fabricated to verify the simulation predictions and good matching between simulated and measured results is achieved. The wide-band antenna is tested by connecting it to the receiver of the Blade-RF Software Defined Radio (SDR) platform. A matlab script is then used to control the SDR board and to perform Spectrum Sensing for Cognitive Radio Applications.
On the basis of the major application for block copolymers to use them as separation membranes, l... more On the basis of the major application for block copolymers to use them as separation membranes, lithographic mask, and as templates, the preparation of highly oriented nanoporous thin films requires the selective removal of the minor phase from the pores. In the scope of this study, thin film of polystyrene-block-poly(ethylene oxide) block copolymer with a photocleavable junction groups based on ortho-nitrobenzylester (ONB) (PS-hν-PEO) was papered via the spin coating technique followed by solvent annealing to obtain highly-ordered cylindrical domains. The polymer blocks are cleaved by means of a mild UV exposure and then the pore material is washed out of the polymer film by ultra-pure water resulting in arrays of nanoporous thin films to remove one block. The removal of the PEO materials from the pores was proven using the grazing-incidence small-angle X-ray scattering (GISAXS) technique. The treatment of the polymer film during the washing process was observed in real time after ...
Although current desalination technologies are mature enough and advanced, the shortage of freshw... more Although current desalination technologies are mature enough and advanced, the shortage of freshwater is still considered as one of the most pressing global issues. Therefore, there is a strong incentive to explore and investigate new potential methods with low energy consumption. We have previously reported that reversible thermally induced sorption/desorption process using polymeric hydrogels hold promise for water desalination with further development. In order to develop a more effective hydrogels architecture, polyelectrolyte moieties were introduced in this work as pendent chains and a thermally responsive polymer as network backbone using reversible addition-fragmentation chain transfer (RAFT) polymerisation. The ability of the comb-type polymeric hydrogels to desalinate water was evaluated. These hydrogels were proved to absorb water with low salinity from brine solution of 2 g L −1 NaCl and release the absorbed water at relatively low temperature conditions of 50 • C. The fraction of the grafted polyacrylic acid and the comb-chain length were varied to understand their influence on the swelling/deswelling behaviour for these hydrogels. The ionic fraction in the hydrogels and the resulting hydrophilic/hydrophobic balance are crucial for the proposed desalination process. In contrast, the comb-chain length impacted the swelling behaviour of hydrogels but showed relatively little influence on the dewatering process.
In this article, a size miniaturized ultra-wideband (UWB) monopole antenna with dual band-notched... more In this article, a size miniaturized ultra-wideband (UWB) monopole antenna with dual band-notched is presented. By inserting a rectangular slot on the bottom plane, the operation bandwidth of the required antenna is increased by 7%, so that the required antenna can achieve a wide applicable fractional bandwidth of 137.01% (2.85-15.25 GHz). Moreover, a band notch located at 7.6 GHz is generated by cutting a defected microstrip structure (DMS) consisting of circular head dumbbell on the metallic patch. Meanwhile, by introducing a defected ground structure (DGS) consisting of metallic circular head dumbbell shaped in the ground plane, the second band-notch created at 5.6 GHz. Experimental results of the required antenna agree with the simulations quite well, with a miniaturized size of 32 9 25 mm 2 , which illustrates that the required antenna is suitable for UWB applications.
In this work, we explore the ability of utilizing hydrogels synthesized from a temperature-sensit... more In this work, we explore the ability of utilizing hydrogels synthesized from a temperature-sensitive polymer and a polyelectrolyte to desalinate salt water by means of reversible thermally induced absorption and desorption. Thus, the influence of the macromolecular architecture on the swelling/deswelling behavior for such hydrogels was investigated by tailor-made network structures. To this end, a series of chemically cross-linked polymeric hydrogels were synthesized via free radical-initiated copolymerization of sodium acrylate (SA) with the thermoresponsive comonomer N-isopropylacrylamide (NIPAAm) by realizing different structural types. In particular, two different polyNIPAAm macromonomers, either with one acrylate function at the chain end or with additional acrylate functions as side groups were synthesized by controlled polymerization and subsequent polymer-analogous reaction and then used as building blocks. The rheological behaviors of hydrogels and their estimated mesh size...
Langmuir : the ACS journal of surfaces and colloids, Jan 10, 2015
Highly ordered block copolymer thin films have been studied extensively during the last years bec... more Highly ordered block copolymer thin films have been studied extensively during the last years because they afford versatile self assembled morphologies via a bottom-up approach. They promise to be used in applications such as polymeric membranes or templates for nanostructured materials. Among the block copolymer structures, perpendicular cylinders have received strong attention due to their ability to fabricate highly ordered nanopores and nanowires. Nanopores can be created from a thin block copolymer film upon removal of one block by selective etching or by dissolution of one polymer block. Here, we demonstrate the utilization of polystyrene-block-poly(ethylene oxide) diblock copolymer (PS-hν-PEO) with an ortho-nitrobenzyl ester (ONB) as the photocleavable block-linker to create highly ordered thin films. Removal of the PEO block by choosing an appropriate solvent upon photo cleavage is expected to yield arrays of nanopores decorated with functional groups thus lending itself to ...
2010 International Symposium on Signals, Systems and Electronics, 2010
Page 1. Space Time Adaptive Processing (STAP) Using Two Dimensional Array of Real Elements Based ... more Page 1. Space Time Adaptive Processing (STAP) Using Two Dimensional Array of Real Elements Based on Direct Data Domain Least Squares (D 3 LS) Approach Hassan M. Elkamchouchi#1, Darwish AE Mohamed*2, Wael AE Ali*3 ...
2010 International Symposium on Signals, Systems and Electronics, 2010
Page 1. Multiple Constraint Space-Time Direct Data Domain Approach Using Nonuniformly, Semicircul... more Page 1. Multiple Constraint Space-Time Direct Data Domain Approach Using Nonuniformly, Semicircular and Sinusoidal Spaced Arrays of Real Elements Hassan M. Elkamchouchi#1, Darwish AE Mohamed*2, Wael AE Ali*3 ...
International Journal of Computer Applications, 2011
In this paper, Space Time Adaptive Processing (STAP) applied on wideband signals from uniformly s... more In this paper, Space Time Adaptive Processing (STAP) applied on wideband signals from uniformly spaced real elements using Direct Data Domain Least Squares (D 3 LS). Two antenna configurations are used: an array of dipole antenna (narrowband antenna) and an array of patch antenna (wideband antenna). A frequency transformation technique is used only for the case of narrowband antenna which transforms the steering vector at a wideband frequency to another steering vector at the desired frequency. The mutual coupling between elements will affect on the estimation of complex amplitude of Signal of Interest (SOI). It is necessary to compensate for the strong mutual coupling that exists between the real antenna elements. This is done by using coupling transformation matrix which converts the voltages that are induced at the real antenna elements to an equivalent set of voltages that will be induced by the same incident wave in uniform linear virtual array (ULVA). Then, we will apply STAP D 3 LS on the compensated voltages. Numerical simulations are done using the three main methods of D 3 LS namely the forward, backward, and the forward-backward methods.
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Papers by Wael Ali