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Full-Text Articles in Physics
Volume Holographic Optical Elements, Ching-Cherng Sun, Partha P. Banerjee
Volume Holographic Optical Elements, Ching-Cherng Sun, Partha P. Banerjee
Partha Banerjee
The final two papers are concerned with the analysis of novel holograms. Banerjee et al. investigate holographic recording and reconstruction for edge-lit holograms recorded in a 90-degree geometry. Various cases of recording and readout that incorporate propagational diffraction have been modeled. It is shown that the 90-degree geometry can result in beam shaping, as evidenced through preliminary experimental results with photorefractive lithium niobate. Nguyen et al. propose a new approach for designing computer-generated holograms. An artificial neural network is used to initiate the genetic algorithm so that the high computation cost of genetic algorithms for synthesizing holograms is significantly reduced …
Chemical Dynamics Of Aluminum Nanoparticles In Ammonium Nitrate And Ammonium Perchlorate Matrices: Enhanced Reactivity Of Organically Capped Aluminum, William K. Lewis, Barbara A. Harruff-Miller, Joseph R. Gord, Andrew T. Rosenberger, Thomas M. Sexton, Elena A. Guliants, Christopher E. Bunker
Chemical Dynamics Of Aluminum Nanoparticles In Ammonium Nitrate And Ammonium Perchlorate Matrices: Enhanced Reactivity Of Organically Capped Aluminum, William K. Lewis, Barbara A. Harruff-Miller, Joseph R. Gord, Andrew T. Rosenberger, Thomas M. Sexton, Elena A. Guliants, Christopher E. Bunker
Elena A. Guliants
Aluminum nanoparticles have been a subject of active investigation in recent years because of their potential to enhance the energy content of energetic materials. The associated kinetics of the chemical reaction and energy release are, in many cases, governed by the properties of the passivation layer protecting the particle rather than those of the underlying metal core. The passivation layer of Al particles is typically an oxide shell several nanometers thick, but other possibilities are now available. We have previously developed synthesis routes to produce air-stable Al nanoparticles that are capped by oleic acid. In the present study, we examine …
Carbon Nanoparticles As Visible-Light Photocatalysts For Efficient Co2 Conversion And Beyond, Li Cao, Sushant Sahu, Parambath Anilkumar, Christopher E. Bunker, Juan Xu, K. A. Shiral Fernando, Ping Wang, Elena A. Guliants, Kenneth N. Tackett Ii, Ya-Ping Sun
Carbon Nanoparticles As Visible-Light Photocatalysts For Efficient Co2 Conversion And Beyond, Li Cao, Sushant Sahu, Parambath Anilkumar, Christopher E. Bunker, Juan Xu, K. A. Shiral Fernando, Ping Wang, Elena A. Guliants, Kenneth N. Tackett Ii, Ya-Ping Sun
Elena A. Guliants
Increasing atmospheric CO2 levels have generated much concern, driving the ongoing carbon sequestration effort. A compelling CO2 sequestration option is its photocatalytic conversion to hydrocarbons, for which the use of solar irradiation represents an ultimate solution. Here we report a new strategy of using surface-functionalized small carbon nanoparticles to harvest visible photons for subsequent charge separation on the particle surface in order to drive the efficient photocatalytic process. The aqueous solubility of the catalysts enables photoreduction under more desirable homogeneous reaction conditions. Beyond CO2 conversion, the nanoscale carbon-based photocatalysts are also useful for the photogeneration of H2 from water under …
Spatio-Spectral Sampling And Color Filter Array Design, Keigo Hirakawa, Patrick Wolfe
Spatio-Spectral Sampling And Color Filter Array Design, Keigo Hirakawa, Patrick Wolfe
Keigo Hirakawa
Owing to the growing ubiquity of digital image acquisition and display, several factors must be considered when developing systems to meet future color image processing needs, including improved quality, increased throughput, and greater cost-effectiveness. In consumer still-camera and video applications, color images are typically obtained via a spatial subsampling procedure implemented as a color filter array (CFA), a physical construction whereby only a single component of the color space is measured at each pixel location. Substantial work in both industry and academia has been dedicated to post-processing this acquired raw image data as part of the so-called image processing pipeline, …
Partition-Based Weighted Sum Filters For Image Restoration, Kenneth Barner, Ahmad Sarhan, Russell Hardie
Partition-Based Weighted Sum Filters For Image Restoration, Kenneth Barner, Ahmad Sarhan, Russell Hardie
Russell C. Hardie
We develop the concept of partitioning the observation space to build a general class of filters referred to as partition-based weighted sum (PWS) filters. In the general framework, each observation vector is mapped to one of M partitions comprising the observation space, and each partition has an associatedfiltering function. We focus on partitioning the observation space utilizing vector quantization and restrict the filtering function within each partition to be linear. In this formulation, a weighted sum of the observation samples forms the estimate, where the weights are allowed to be unique within eachpartition. The partitions are selected and weights tuned …
Risk-Based Critical Infrastructure Protection Priorities For Emp And Solar Storms, George H. Baker Iii
Risk-Based Critical Infrastructure Protection Priorities For Emp And Solar Storms, George H. Baker Iii
George H Baker
The Commission to Assess the Threat to the United States from Electromagnetic Pulse Attack has provided a compelling case for protecting civilian infrastructure against the effects of EMP. As with protecting infrastructure against any hazard, it will be important to take a risk-based priority approach for EMP, recognizing that it is fiscally impracticable to protect everything. In this regard, EMP is particularly challenging in that it interferes with electrical and electronic data, control, transmission, and communication systems organic to nearly all infrastructures in a simultaneous and wide-scale manner. And, for nuclear burst altitudes of 100s of kilometers, the exposed geography …