Magnesium hydroxide (Mg(OH) 2 ) micro-and nanostructures have been synthesized by a single step h... more Magnesium hydroxide (Mg(OH) 2 ) micro-and nanostructures have been synthesized by a single step hydrothermal route. Surface morphology analysis reveals the formation of micro-and nanostructures with varying shape and size at different synthesis conditions. Structural investigations by X-ray diffraction (XRD) and transmission electron microscopy (TEM) confirm that the synthesized material is Mg(OH) 2 with hexagonal crystal structure. An optical band gap of 5.7 eV is determined for Mg(OH) 2 nanodisks from the UV-vis absorption spectrum. A broad emission band with maximum intensity at around 400 nm is observed in the photoluminescence (PL) spectra of Mg(OH) 2 nanodisks at room temperature depicting the violet emission, which can be attributed to the ionized oxygen vacancies in the material. Furthermore, Mg(OH) 2 has been converted to MgO by calcination at 450 8C. Optical studies of the MgO nanodisks have shown an optical band gap of 3.43 eV and a broadband PL emission in the UV region. Mg(OH) 2 and MgO nanostructures with wide-band gap and short-wavelength luminescence emission can serve as a better luminescent material for photonic applications. #
Strong blue-green light emitting Eu doped SrAl 2 O 4 phosphor was synthesized by a low-temperatur... more Strong blue-green light emitting Eu doped SrAl 2 O 4 phosphor was synthesized by a low-temperature initiated, self-propagating and gas producing combustion process in a very short time (<5 min). The prepared powder was characterized by X-ray diffraction, Fourier-transform infrared spectrometry and scanning electron microscopy. The excitation spectrum shows a peak at 397 nm. Upon excitation at 397 nm, the emission spectrum exhibits a well defined broad band with maximum at 493 nm corresponding to 4f 6 5d ? 4f 7 transition. Electron paramagnetic resonance (EPR) measurements at X-band showed low field signals due to Eu 2+ ions in SrAl 2 O 4 :Eu.
Recently, many aluminate materials have been extensively studied as phosphors for the next genera... more Recently, many aluminate materials have been extensively studied as phosphors for the next generation of display and lighting devices. Synthesis of aluminate oxide phosphors has been achieved by a variety of routes: solid-state reactions, sol-gel techniques, microwave processing, hydrothermal synthesis and combustion synthesis. In the present investigation, we have successfully employed low temperature combustion method for the preparation of BaAl 2 O 4 :Cr 3+ . Powder X-ray diffraction analysis was used to characterize the as-prepared combustion products, while the optical properties were studied using photoluminescence. The morphological aspect of the resulting powders was examined by scanning electronic microscopy, which showed crystallites with irregular morphology in the form of plates. PL excitation spectrum revealed two broad intense bands located at 421 nm and 552 nm due to Cr 3+ ions, while emission spectrum showed peaks due to Cr 3+ ions at 705 nm. EPR spectrum of undoped BaAl 2 O 4 showed signals attributable to unintentional Fe 3+ impurity ions, while EPR spectrum of BaAl 2 O 4 :Cr 3+ contained an additional signal around 3450 G. corresponding to g ≅ 1.98, typical of Cr 3+ ions.
Characterization of microscopic deformation in polymeric thin films using particle image velocimetry
The effectiveness of a technique based on particle image velocimetry (PIV) for measuring the inst... more The effectiveness of a technique based on particle image velocimetry (PIV) for measuring the instantaneous deformation field in planar polymeric films is investigated. Detailed deformation of polymeric films under complex stretching conditions will be very useful in characterization as well as optimization of mechanical properties. PIV is a method for measuring velocity fields in many fluid mechanics applications. In this technique, light scattering from glass micro-particles is used for estimating flow fields. In this work, the particles are spread on the surface of a polymeric film. The film is kept in a laser sheet while the deformation takes place. Two consecutive images of areas as large as 100 cm2 are taken, separated by small time interval Δt. Displacement of seed particles over this time interval is estimated using cross-correlation. The polymer film was stretched uniaxially at constant rates. The deformation fields in the thin films over the time of stretching were evaluated. Films with introduced defects were also investigated for the measurement of the planar deformation fields. It is shown that the technique has potential to quantify the instantaneous deformation rate and strain fields for a large area in the plane of a film.
We describe R-GMA (Relational Grid Monitoring Architecture) which has been developed within the E... more We describe R-GMA (Relational Grid Monitoring Architecture) which has been developed within the European DataGrid Project as a Grid Information and Monitoring System. Is is based on the GMA from GGF, which is a simple Consumer-Producer model. The special strength of this implementation comes from the power of the relational model. We offer a global view of the information as if each Virtual Organisation had one large relational database. We provide a number of different Producer types with different characteristics; for example some support streaming of information. We also provide combined Consumer/Producers, which are able to combine information and republish it. At the heart of the system is the mediator, which for any query is able to find and connect to the best Producers for the job. We have developed components to allow a measure of inter-working between MDS and R-GMA. We have used it both for information about the grid (primarily to find out about what services are available at any one time) and for application monitoring. R-GMA has been deployed in various testbeds; we describe some preliminary results and experiences of this deployment.
We describe R-GMA (Relational Grid Monitoring Architecture) which is being developed within the E... more We describe R-GMA (Relational Grid Monitoring Architecture) which is being developed within the European DataGrid Project as an Grid Information and Monitoring System. Is is based on the GMA from GGF, which is a simple Consumer-Producer model. The special strength of this implementation comes from the power of the relational model. We offer a global view of the information as if each VO had one large relational database. We provide a number of different Producer types with different characteristics; for example some support streaming of information. We also provide combined Consumer/Producers, which are able to combine information and republish it. At the heart of the system is the mediator, which for any query is able to find and connect to the best Producers to do the job. We are able to invoke MDS info-provider scripts and publish the resulting information via R-GMA in addition to having some of our own sensors. APIs are available which allow the user to deploy monitoring and information services for any application that may be needed in the future. We have used it both for information about the grid (primarily to find what services are available at any one time) and for application monitoring. R-GMA has been deployed in Grid testbeds, we describe the results and experiences of this deployment.
Computational Grids are distributed systems that provide access to computational resources in a t... more Computational Grids are distributed systems that provide access to computational resources in a transparent fashion. Collecting and providing information about the status of the Grid itself is called Grid monitoring.
We describe how the R-GMA (Relational Grid Monitoring Architecture) can be used to allow for inst... more We describe how the R-GMA (Relational Grid Monitoring Architecture) can be used to allow for instrument monitoring in a Grid environment. The R-GMA has been developed within the European DataGrid Project (EDG) as a Grid Information and Monitoring System. It is based on the Grid Monitoring Architecture (GMA) from the Global Grid Forum (GGF), which is a simple Consumer-Producer model. The special strength of this implementation comes from the power of the relational model. It offers a global view of the information as if each Virtual Organisation had one large relational database. It provides a number of different Producer types with different characteristics; for example some support streaming of information. We describe the R-GMA component that allows for instrument monitoring, the CanonicalProducer. We also describe an example use of this approach in the European CrossGrid project, SANTA-G, a network monitoring tool.
We describe how the R-GMA (Relational Grid Monitoring Architecture) can be used to allow for inst... more We describe how the R-GMA (Relational Grid Monitoring Architecture) can be used to allow for instrument monitoring in a Grid environment. The R-GMA has been developed within the European DataGrid Project (EDG) as a Grid Information and Monitoring System. It is based on the Grid Monitoring Architecture (GMA) from the Global Grid Forum (GGF), which is a simple Consumer-Producer model. The special strength of this implementation comes from the power of the relational model. It offers a global view of the information as if each Virtual Organisation had one large relational database. It provides a number of different Producer types with different characteristics; for example some support streaming of information. We describe the R-GMA component that allows for instrument monitoring, the CanonicalProducer. We also describe an example use of this approach in the European CrossGrid project, SANTA-G, a network monitoring tool.
We describe R-GMA (Relational Grid Monitoring Architecture) which is being developed within the E... more We describe R-GMA (Relational Grid Monitoring Architecture) which is being developed within the European DataGrid Project as a Grid Information and Monitoring System for both the grid itself and for use by applications. Is is based on the GMA from GGF, which is a simple Consumer-Producer model. The special strength of this implementation comes from the power of the relational model. We offer a global view of the information as if each VO had one large relational database. We provide a number of different Producer types with different characteristics; for example some support streaming of information. We also provide combined Consumer/Producers, which are able to combine information and republish it. At the heart of the system is the mediator, which for any query is able to find and connect to the best Producers to do the job. In addition to having some of our own sensors able to publish information, we are able to invoke MDS info-provider scripts and publish the resulting information via R-GMA.
Magnesium hydroxide (Mg(OH) 2 ) micro-and nanostructures have been synthesized by a single step h... more Magnesium hydroxide (Mg(OH) 2 ) micro-and nanostructures have been synthesized by a single step hydrothermal route. Surface morphology analysis reveals the formation of micro-and nanostructures with varying shape and size at different synthesis conditions. Structural investigations by X-ray diffraction (XRD) and transmission electron microscopy (TEM) confirm that the synthesized material is Mg(OH) 2 with hexagonal crystal structure. An optical band gap of 5.7 eV is determined for Mg(OH) 2 nanodisks from the UV-vis absorption spectrum. A broad emission band with maximum intensity at around 400 nm is observed in the photoluminescence (PL) spectra of Mg(OH) 2 nanodisks at room temperature depicting the violet emission, which can be attributed to the ionized oxygen vacancies in the material. Furthermore, Mg(OH) 2 has been converted to MgO by calcination at 450 8C. Optical studies of the MgO nanodisks have shown an optical band gap of 3.43 eV and a broadband PL emission in the UV region. Mg(OH) 2 and MgO nanostructures with wide-band gap and short-wavelength luminescence emission can serve as a better luminescent material for photonic applications. #
Strong blue-green light emitting Eu doped SrAl 2 O 4 phosphor was synthesized by a low-temperatur... more Strong blue-green light emitting Eu doped SrAl 2 O 4 phosphor was synthesized by a low-temperature initiated, self-propagating and gas producing combustion process in a very short time (<5 min). The prepared powder was characterized by X-ray diffraction, Fourier-transform infrared spectrometry and scanning electron microscopy. The excitation spectrum shows a peak at 397 nm. Upon excitation at 397 nm, the emission spectrum exhibits a well defined broad band with maximum at 493 nm corresponding to 4f 6 5d ? 4f 7 transition. Electron paramagnetic resonance (EPR) measurements at X-band showed low field signals due to Eu 2+ ions in SrAl 2 O 4 :Eu.
Recently, many aluminate materials have been extensively studied as phosphors for the next genera... more Recently, many aluminate materials have been extensively studied as phosphors for the next generation of display and lighting devices. Synthesis of aluminate oxide phosphors has been achieved by a variety of routes: solid-state reactions, sol-gel techniques, microwave processing, hydrothermal synthesis and combustion synthesis. In the present investigation, we have successfully employed low temperature combustion method for the preparation of BaAl 2 O 4 :Cr 3+ . Powder X-ray diffraction analysis was used to characterize the as-prepared combustion products, while the optical properties were studied using photoluminescence. The morphological aspect of the resulting powders was examined by scanning electronic microscopy, which showed crystallites with irregular morphology in the form of plates. PL excitation spectrum revealed two broad intense bands located at 421 nm and 552 nm due to Cr 3+ ions, while emission spectrum showed peaks due to Cr 3+ ions at 705 nm. EPR spectrum of undoped BaAl 2 O 4 showed signals attributable to unintentional Fe 3+ impurity ions, while EPR spectrum of BaAl 2 O 4 :Cr 3+ contained an additional signal around 3450 G. corresponding to g ≅ 1.98, typical of Cr 3+ ions.
Characterization of microscopic deformation in polymeric thin films using particle image velocimetry
The effectiveness of a technique based on particle image velocimetry (PIV) for measuring the inst... more The effectiveness of a technique based on particle image velocimetry (PIV) for measuring the instantaneous deformation field in planar polymeric films is investigated. Detailed deformation of polymeric films under complex stretching conditions will be very useful in characterization as well as optimization of mechanical properties. PIV is a method for measuring velocity fields in many fluid mechanics applications. In this technique, light scattering from glass micro-particles is used for estimating flow fields. In this work, the particles are spread on the surface of a polymeric film. The film is kept in a laser sheet while the deformation takes place. Two consecutive images of areas as large as 100 cm2 are taken, separated by small time interval Δt. Displacement of seed particles over this time interval is estimated using cross-correlation. The polymer film was stretched uniaxially at constant rates. The deformation fields in the thin films over the time of stretching were evaluated. Films with introduced defects were also investigated for the measurement of the planar deformation fields. It is shown that the technique has potential to quantify the instantaneous deformation rate and strain fields for a large area in the plane of a film.
We describe R-GMA (Relational Grid Monitoring Architecture) which has been developed within the E... more We describe R-GMA (Relational Grid Monitoring Architecture) which has been developed within the European DataGrid Project as a Grid Information and Monitoring System. Is is based on the GMA from GGF, which is a simple Consumer-Producer model. The special strength of this implementation comes from the power of the relational model. We offer a global view of the information as if each Virtual Organisation had one large relational database. We provide a number of different Producer types with different characteristics; for example some support streaming of information. We also provide combined Consumer/Producers, which are able to combine information and republish it. At the heart of the system is the mediator, which for any query is able to find and connect to the best Producers for the job. We have developed components to allow a measure of inter-working between MDS and R-GMA. We have used it both for information about the grid (primarily to find out about what services are available at any one time) and for application monitoring. R-GMA has been deployed in various testbeds; we describe some preliminary results and experiences of this deployment.
We describe R-GMA (Relational Grid Monitoring Architecture) which is being developed within the E... more We describe R-GMA (Relational Grid Monitoring Architecture) which is being developed within the European DataGrid Project as an Grid Information and Monitoring System. Is is based on the GMA from GGF, which is a simple Consumer-Producer model. The special strength of this implementation comes from the power of the relational model. We offer a global view of the information as if each VO had one large relational database. We provide a number of different Producer types with different characteristics; for example some support streaming of information. We also provide combined Consumer/Producers, which are able to combine information and republish it. At the heart of the system is the mediator, which for any query is able to find and connect to the best Producers to do the job. We are able to invoke MDS info-provider scripts and publish the resulting information via R-GMA in addition to having some of our own sensors. APIs are available which allow the user to deploy monitoring and information services for any application that may be needed in the future. We have used it both for information about the grid (primarily to find what services are available at any one time) and for application monitoring. R-GMA has been deployed in Grid testbeds, we describe the results and experiences of this deployment.
Computational Grids are distributed systems that provide access to computational resources in a t... more Computational Grids are distributed systems that provide access to computational resources in a transparent fashion. Collecting and providing information about the status of the Grid itself is called Grid monitoring.
We describe how the R-GMA (Relational Grid Monitoring Architecture) can be used to allow for inst... more We describe how the R-GMA (Relational Grid Monitoring Architecture) can be used to allow for instrument monitoring in a Grid environment. The R-GMA has been developed within the European DataGrid Project (EDG) as a Grid Information and Monitoring System. It is based on the Grid Monitoring Architecture (GMA) from the Global Grid Forum (GGF), which is a simple Consumer-Producer model. The special strength of this implementation comes from the power of the relational model. It offers a global view of the information as if each Virtual Organisation had one large relational database. It provides a number of different Producer types with different characteristics; for example some support streaming of information. We describe the R-GMA component that allows for instrument monitoring, the CanonicalProducer. We also describe an example use of this approach in the European CrossGrid project, SANTA-G, a network monitoring tool.
We describe how the R-GMA (Relational Grid Monitoring Architecture) can be used to allow for inst... more We describe how the R-GMA (Relational Grid Monitoring Architecture) can be used to allow for instrument monitoring in a Grid environment. The R-GMA has been developed within the European DataGrid Project (EDG) as a Grid Information and Monitoring System. It is based on the Grid Monitoring Architecture (GMA) from the Global Grid Forum (GGF), which is a simple Consumer-Producer model. The special strength of this implementation comes from the power of the relational model. It offers a global view of the information as if each Virtual Organisation had one large relational database. It provides a number of different Producer types with different characteristics; for example some support streaming of information. We describe the R-GMA component that allows for instrument monitoring, the CanonicalProducer. We also describe an example use of this approach in the European CrossGrid project, SANTA-G, a network monitoring tool.
We describe R-GMA (Relational Grid Monitoring Architecture) which is being developed within the E... more We describe R-GMA (Relational Grid Monitoring Architecture) which is being developed within the European DataGrid Project as a Grid Information and Monitoring System for both the grid itself and for use by applications. Is is based on the GMA from GGF, which is a simple Consumer-Producer model. The special strength of this implementation comes from the power of the relational model. We offer a global view of the information as if each VO had one large relational database. We provide a number of different Producer types with different characteristics; for example some support streaming of information. We also provide combined Consumer/Producers, which are able to combine information and republish it. At the heart of the system is the mediator, which for any query is able to find and connect to the best Producers to do the job. In addition to having some of our own sensors able to publish information, we are able to invoke MDS info-provider scripts and publish the resulting information via R-GMA.
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Papers by Manish Soni