Wilmsmeyer A.R.,Virginia Polytechnic Institute and State University |
Gordon W.O.,Research and Technology Directorate |
Davis E.D.,OptiMetrics, Inc. |
Troya D.,Virginia Polytechnic Institute and State University |
And 3 more authors.
Journal of Physical Chemistry C | Year: 2013
The fundamental interactions of a series of chemical warfare agent (CWA) simulants on amorphous silica particulates have been investigated with transmission infrared spectroscopy and temperature-programmed desorption (TPD). The simulants methyl dichlorophosphate (MDCP), dimethyl cholorophosphate (DMCP), trimethyl phosphate (TMP), dimethyl methylphosphonate (DMMP), and diisopropyl methylphosphonate (DIMP) were chosen to help develop a comprehensive understanding for how the structure and functionality of CWA surrogate compounds affect uptake and hydrogen-bond strengths at the gas-surface interface. Each simulant was found to adsorb molecularly to silica through the formation of strong hydrogen bonds primarily between isolated surface silanol groups and the oxygen atom of the P=O moiety in the adsorbate. The TPD data revealed that the activation energy for desorption of a single simulant molecule from amorphous silica varied slightly with coverage. In the limit of zero coverage and the absence of significant surface defects, the activation energies for desorption were found to follow the trend MDCP < DMCP < TMP < DMMP < DIMP. This trend demonstrates the critical role of electron-withdrawing substituents in determining the adsorption energies through hydrogen-bonding interactions. The infrared spectra for each adsorbed species, recorded during uptake, showed a significant shift in the frequency of the ν(SiO-H) mode as the hydrogen bonds formed. A clear linear relationship between the desorption energy and the shift of the surface ν(SiO-H) mode across this series of adsorbates demonstrates that the Badger-Bauer relationship, established origninally for solute-solvent interactions, effectively extends to gas-surface interactions. High-level electronic structure calculations, including extrapolation to the complete basis set limit, reproduce the experimental energies of all simulants with high levels of accuracy and have been employed to provide insight into the molecular-level details of adsorption geometries for the simulants and to predict the interaction energies for the CWA isopropyl methylphosphonofluoridate (sarin). © 2013 American Chemical Society.
OptiMetrics, Inc. | Date: 2011-06-10
An estimate of random error in an eye-tracking system is done directly from eye-tracker outputs during a trial, without the need for an explicit calibration process. The distances traveled between adjacent user observations are computed, and the random error
Agency: Department of Defense | Branch: Defense Advanced Research Projects Agency | Program: SBIR | Phase: Phase II | Award Amount: 749.99K | Year: 2004
This project will produce a Multitask Training-Game Engine Component (MT-GEC) that can be used for developing Vision Centered-Multitask Training Environments (VC-MTEs). The game engine component will support routine development of scalable, 3D training applications that use metrics based on workload, interaction events, and simulation state to focus training activities at measured deficiencies. The computed measures will capture the subtle strategies that are used by expert performers in multitasking applications and enable the development of high precision training strategies. During the final year of this project, a training application will be developed using the game engine component to establish the applicability of this technology to military training. Phase III is expected to further extend this technology and apply it to mainstream training applications. During this commercialization phase, the technology will be licensed to game and training system developers that are building applications that require cognitive feedback. This phase is also expected to develop training applications for cognitive researchers that can be used to explore the methods that experts use to meet the computational demands of complex, information-intense, multitask decision-making.
Agency: Department of Defense | Branch: Defense Advanced Research Projects Agency | Program: SBIR | Phase: Phase I | Award Amount: 98.97K | Year: 2004
Quantum cryptography will likely play a key role in the future of secure communications. An effective Quantum Key Distribution (QKD) system is the central requirement for a successful quantum cryptographic system. Current QKD systems use a limited and incomplete set of standards to define the interfaces between the quantum system components and the necessary digital components and networks. This document proposes to develop Interface Definition Documents (IDDs) and eventually software tools utilizing those interface standards to control the physical interfaces and management and analysis software of QKD systems. IDDs will be developed for multiple interface layers including: physical interface, management interface and analysis interfaces. As a unique feature of this approach, two analysis components are considered: blue analysis interface, addressing countermeasure factors that can be monitored internally, and a red (threat-side) analysis interface, addressing vulnerability factors that can be monitored externally. Through consulting and teaming arrangements, it is planned to work closely with two organizations developing prototype QKD systems and standards, BBN and NIST.
Agency: Department of Defense | Branch: Navy | Program: SBIR | Phase: Phase I | Award Amount: 149.93K | Year: 2008
OptiMetrics proposes to design a sensor system to provide situational awareness for rotary wing aircraft pilots in visually degraded environments (VDE). The design will capitalize on ten years of experience in the development of algorithms to process LADAR and passive sensor imagery which enhance range resolution, image resolution, image quality and support generation of wide field-of-view images. The technology proposed supports high update rates and has suitable size, weight and power requirements for helicopters and tilt-rotor aircraft applications.