Stine R.,Nova Research Inc. |
Lee W.-K.,U.S. Navy |
Whitener Jr. K.E.,U.S. Navy |
Robinson J.T.,Washington Technology |
Sheehan P.E.,U.S. Navy
Nano Letters | Year: 2013
Fluorination can alter the electronic properties of graphene and activate sites for subsequent chemistry. Here, we show that graphene fluorination depends on several variables, including XeF2 exposure and the choice of substrate. After fluorination, fluorine content declines by 50-80% over several days before stabilizing. While highly fluorinated samples remain insulating, mildly fluorinated samples regain some conductivity over this period. Finally, this loss does not reduce reactivity with alkylamines, suggesting that only nonvolatile fluorine participates in these reactions. © 2013 American Chemical Society.
Nova Research Inc. | Date: 2011-07-27
A dual mode amplifier for photodiode output reads a photodiode providing a current input. An integration capacitor is connected to receive the current input and connected to a voltage output node. An input capacitor is also connected to receive the voltage input and drives an operational amplifier having an output connect to the voltage output node. A correlated double-sample (CDS) capacitor is connected to the voltage output node and a sample and hold circuit incorporating a sample and hold capacitor for sampling the CDS capacitor. A log function on (LOGON) switch is connected between the operational amplifier output and the voltage output node and a reset switch connected to short the photodiode. The LOGON switch sequentially operates in conjunction with the reset switch at the end of an integration time allowing the integration capacitor to retain an integrated current plus a log voltage by closing of the reset switch shorting the detector photodiode and offsetting the voltage on the integration capacitor into the negative voltage direction.
Nova Research Inc. | Date: 2010-09-28
A Read-In Integrated Circuit scene generator incorporates an array of unit cells, with each cell having a switching control circuit. An array of emitting elements is associated with the unit cells and each element is connected with a lead to the switching control circuit of the associated cell. A first electrically conducting overlayer is deposited substantially covering the array of unit cells and connected for current supply. Each emitting element is connected to the first conducting overlayer and the first conducting overlayer includes vias through which each connecting lead from the emitting element to the switching control circuit extends. A second electrically conducting overlayer is deposited substantially covering the array of unit cells and connected for current return. Each switching control circuit is connected to the second conducting overlayer. The second conducting overlayer also has vias through which each lead from the emitting element extends to the switching circuit.
Nova Research Inc. | Date: 2011-10-27
A dual speed Read-Out Integrated Circuit employs a native pixel array with associated high resolution integration circuits for each pixel and a superpixel array created within the native pixel array by combination of native pixels for charge sharing integration in reduced resolution integration circuits simultaneously with the integration of the high resolution integration circuits. Switching control for readout of the high resolution integration circuits is accomplished at a first frame rate and switching control for readout of the reduced resolution integration circuits is accomplished at a second higher frame rate.
Nova Research Inc. | Date: 2011-11-04
A method for super resolution enhancement of infrared imaging data employing an image array having simultaneous, high speed, randomly addressable windows of pixels for small regions of interest (ROI) within a large imaging sensor field of view. Data is retrieved from the ROI window pixels at an increased data rate and the array is dithered to produce sub-pixel motion consistent with the increased data rate. A selected super resolution (SR) algorithm is then applied to the data retrieved from the ROT window pixels at the increased data rate. The reduced data set substantially relieves the computational load on the processor compared with the requirement of performing SR processing on the entire frame of image data. The output from the SR algorithm is either used to replace the LR frame data in the image or is displayed as a separate image to the user.
Nova Research Inc. | Date: 2010-02-19
An armor plate includes at least four layers configured to generate a compression wave that is dissipated in a fracture player. The armor plate includes a deformable layer of a material having an elongation before failure of 20% or more; a transparent ceramic layer adjacent the deformable layer; a transparent fracture layer adjacent the ceramic layer; and a transparent spall liner backing the fracture layer.
Nova Research Inc. | Date: 2011-02-23
An infrared camera system for low contrast employs a focal plane array (FPA) of a plurality of detector diodes. A read out integrated circuit (ROIC) including a plurality of integration switches is connected to the plurality of detector diodes. A frame mean calculator receives raw data from the FPA and an integration time servo receives a frame mean from the frame mean calculator and a preprogrammed target mean. The integration time servo compares the frame mean and target mean and provides an integration time output to the ROIC responsive to the comparison for control of the integration switches.
Nova Research Inc. | Date: 2010-06-24
A unit cell for a Read-In Integrated Circuit employs a signal sampling circuit with a voltage input controlled by a first switch, a capacitor charged by the voltage input and a linear amplifier connected to the capacitor. An output through a second switch samples the capacitor as the input signal for a transistor cascade for emitter current supply incorporating a first transistor receiving the input signal and a second transistor serially connected to the first transistor with a parallel resistor. The second transistor is maintained in saturation for a first portion of the input signal range with the first transistor acting as a source follower for that range. Linear current flow through the resistor results allowing high resolution control in the low current range. The second transistor departs saturation in a second portion of the range for the input signal resulting in saturation mode square-law behavior dominating the first transistor which, in turn, causes a rapid increase in current through its channel in response to higher input signal level thereby allowing a lower resolution but higher current for emitter drive at higher temperatures.
Sutto T.E.,U.S. Navy |
Duncan T.T.,Nova Research Inc.
Electrochimica Acta | Year: 2012
The electrochemical behavior of magnesium perchlorate in ionic liquids is characterized using Co 3O 4 as the working electrode and Mg foil as the anode material. The cations of the ionic liquids were 1,2-dimethyl-3-R-imidazolium with R = butyl (MMBI) or octyl (MMOI), and the anion was bis(trifluoromethanesulfonyl)imide (TFSI). The TFSI ionic liquids exhibited large electrochemical windows, with MMOITFSI possessing an electrochemical window of 5 V. Ionic conductivity studies indicated a higher ionic conductivity of 3.67 mS/cm for 1.0 M Mg(ClO 4) 2 in MMBITFSI when compared to 2.16 mS/cm for 1.0 M Mg(ClO 4) 2. MMOITFSI was selected as the electrolyte for the electrochemical characterizations of Co 3O 4, due to its larger electrochemical window and its inability to intercalate, and therefore degrade, graphitic material added to the Co 3O 4 electrode. Electrochemical results indicated that the maximum attainable value for x in Mg xCo 3O 4 was 0.33, with an initial capacity of only 78 mAh/g. X-ray diffraction studies of the Mg intercalated Co 3O 4 indicated a 20% expansion of the unit cell and a decrease in the symmetry of the metal oxide from cubic to orthorhombic symmetry. Charge/discharge experiments at a C/3 rate were performed vs. Mg metal. Results indicated that after 10 cycles, the capacity decreased linearly with cycling, most likely due to the inability to deintercalate the more strongly interacting Mg ++. © 2012 Elsevier Ltd.
Nova Research Inc. | Date: 2011-03-14
A composite armor plate includes a fracture layer placed adjacent to a ceramic layer. The ceramic layer provides a ballistic resistant layer that receives a ballistic impact and propagates a compression wave. The fracture layer is placed behind the ceramic layer and absorbs a portion of the compression wave propagating out in front of the ballistic impact. The absorbed compression wave causes the fracture layer to at least partially disintegrate into fine particles, which dissipates energy in the process. To cause a higher degree of fracturing (and thus larger dissipation of compression wave energy) the fracture layer includes a plurality of resonators embedded in a fracture material.