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U.S. Navy research on extremely low-light (ELL) cameras in nighttime underwater operations is limited. This study aims to address this limitation in capability by quantifying the Teledyne Bowtech Limited Explorer Pro Low Light Monochrome Camera’s performance in the field as a function of water depth at night in the coastal ocean. To reach this goal, proven techniques like modulation transfer function (MTF) and contrast transfer function (CTF) analyses were applied to modified target patterns for lower-quality images. The new target pattern was tested on land using commercial cameras against a commercial test pattern chart for high-resolution cameras. The ELL camera vertical casts, including measures of surface lux and the water column characteristics, were performed at California’s Monterey Harbor and Bay in the presence of bioluminescence. The MTF results from the target pattern showed a steady MTF as the spatial frequency increased; the MTF decayed with increasing depth and decreasing lux. Furthermore, the MTFs showed that bioluminescence improves the MTF at depths > 24.5 m versus the MTF with no bioluminescence. The target pattern was detected at a maximum depth of 37 m. However, predicted maximum depths using a linear regression model were > 37 m with and without bioluminescence. The new ideal target pattern for the ELL video camera provides a foundation for nighttime underwater operations and the future development of underwater night vision goggles for the U.S. Navy., Office of Naval Research (Arlington, VA 22203-1995), Lieutenant Commander, United States Navy, Approved for public release. Distribution is unlimited.

This research presents an application of Charge-Coupled Device (CCD) linear sensor and laser diode in an optical tomography system. Optical tomography is a non-invasive and non-intrusive method of capturing a cross-sectional image of multiphase flow. The measurements are based on the final light intensity received by the sensor and this approach is limited to detect solid objects only. The aim of this research is to analyse and demonstrate the capability of laser with a CCD in an optical tomography system for detecting objects with different clarity in crystal clear water. Experiments for detecting transparent objects were conducted. The object’s diameter and image reconstruction can also be observed. As a conclusion, this research has successfully developed a non-intrusive and non-invasive optical tomography system that can detect objects in crystal clear water.

This paper describes the design and simulation of a radiation detector system for diagnostic measurements of photon beams produced by Thomson or Compton Scattering. The photon beam is Compton scattered in a thin passive converter, and the resulting electrons are analyzed using a charge-coupled device-based tracker and classification algorithms. The flux of the scattered electrons is much lower than that of the photon beam and is additionally dispersed. This dispersal enables measurements while avoiding pileup, which is important in order to provide diagnostic information from intense 'shot’ based pulsed systems, such as those being built to leverage laser wakefield accelerators. Simulations indicate that the designed system is capable of resolving beam parameters from a single shot. The fidelity to which various beam parameters can be resolved is presented as are methods that could result in further improvement to diagnostic resolution.

This paper describes the design and simulation of a radiation detector system for diagnostic measurements of photon beams produced by Thomson or Compton Scattering. The photon beam is Compton scattered in a thin passive converter, and the resulting electrons are analyzed using a charge-coupled device-based tracker and classification algorithms. The flux of the scattered electrons is much lower than that of the photon beam and is additionally dispersed. This dispersal enables measurements while avoiding pileup, which is important in order to provide diagnostic information from intense 'shot’ based pulsed systems, such as those being built to leverage laser wakefield accelerators. Simulations indicate that the designed system is capable of resolving beam parameters from a single shot. The fidelity to which various beam parameters can be resolved is presented as are methods that could result in further improvement to diagnostic resolution.

This research presents an application of Charge-Coupled Device (CCD) linear sensor and laser diode in an optical tomography system. Optical tomography is a non-invasive and non-intrusive method of capturing a cross-sectional image of multiphase flow. The measurements are based on the final light intensity received by the sensor and this approach is limited to detect solid objects only. The aim of this research is to analyse and demonstrate the capability of laser with a CCD in an optical tomography system for detecting objects with different clarity in crystal clear water. Experiments for detecting transparent objects were conducted. The object’s diameter and image reconstruction can also be observed. As a conclusion, this research has successfully developed a non-intrusive and non-invasive optical tomography system that can detect objects in crystal clear water.

Tomography is a method to capture a cross sectional image based on the data obtained by sensors, distributed around the periphery of the analyzed system. Optical tomography is one of the tomography methods which are non-invasive and non-intrusive system, consisting of emitter with detectors. Combinations of Charge-Coupled Device and low intensity laser diode are used in this research. Experiments on air bubbles detecting in non-flowing crystal clear water are conducted. Cross-sectional image of two phase flow; air and liquid are captured using this optical hardware construction and the information on air diameter, shape and path are observed using LabVIEW programming.

Tomography is a method to capture a cross sectional image based on the data obtained by sensors, distributed around the periphery of the analyzed system. Optical tomography is one of the tomography methods which are non-invasive and non-intrusive system, consisting of emitter with detectors. Combinations of Charge-Coupled Device and low intensity laser diode are used in this research. Experiments on air bubbles detecting in non-flowing crystal clear water are conducted. Cross-sectional image of two phase flow; air and liquid are captured using this optical hardware construction and the information on air diameter, shape and path are observed using LabVIEW programming.

Gene transcription is regulated in response to environmental changes and developmental cues. In mammalian cells subjected to stress conditions such as heat shock, transcription of most protein-coding genes decreases, while the transcription of heat shock protein genes increases. Repression involves direct binding to RNA polymerase II (Pol II) of certain noncoding RNAs (ncRNAs) that are upregulated upon heat shock. Another class of ncRNAs is also upregulated and binds to Pol II but does not inhibit transcription. Incorporation of repressive ncRNAs into pre-initiation complexes prevents transcription initiation, while non-repressive ncRNAs are displaced from Pol II by TFIIF. Here, we present cryo-electron microscopy reconstructions of human Pol II in complex with six different ncRNAs from mouse and human. Our structures show that both repressive and non-repressive ncRNAs bind to a conserved binding site within the cleft of Pol II. The site, which is also shared with a previously characterized yeast aptamer, is close to the active center and, thus, in an ideal position to regulate transcription. Importantly, additional RNA elements extend flexibly beyond the docking site. We propose that the differences concerning the repressive activity of the ncRNAs analyzed must be due to the distinct character of these more unstructured, flexible segments of the RNA that emanate from the cleft.

Gene transcription is regulated in response to environmental changes and developmental cues. In mammalian cells subjected to stress conditions such as heat shock, transcription of most protein-coding genes decreases, while the transcription of heat shock protein genes increases. Repression involves direct binding to RNA polymerase II (Pol II) of certain noncoding RNAs (ncRNAs) that are upregulated upon heat shock. Another class of ncRNAs is also upregulated and binds to Pol II but does not inhibit transcription. Incorporation of repressive ncRNAs into pre-initiation complexes prevents transcription initiation, while non-repressive ncRNAs are displaced from Pol II by TFIIF. Here, we present cryo-electron microscopy reconstructions of human Pol II in complex with six different ncRNAs from mouse and human. Our structures show that both repressive and non-repressive ncRNAs bind to a conserved binding site within the cleft of Pol II. The site, which is also shared with a previously characterized yeast aptamer, is close to the active center and, thus, in an ideal position to regulate transcription. Importantly, additional RNA elements extend flexibly beyond the docking site. We propose that the differences concerning the repressive activity of the ncRNAs analyzed must be due to the distinct character of these more unstructured, flexible segments of the RNA that emanate from the cleft.

The operation of a two-phase charge-coupled shift register is discussed and analyzed. A parametric study for simultaneous operation with more than one input signal is presented. The output circuit is analyzed for its contribution to nonlinearity. An analog signal processing linear model of the charge-coupled device is proposed., http://archive.org/details/chargecoupleddev1094517687, Lieutenant Commander, United States Navy, Approved for public release; distribution is unlimited.

For the development and improvement of multi-pinhole SPECT systems, high-resolution gamma cameras can be essential. Electron-multiplying charge-coupled devices (EMCCDs) have a high resolution and sensitivity and therefore can be extremely useful for application in photon-counting scintillation gamma cameras. The scintillation crystal captures the gamma photons and converts their energy into (visible) light photons, which are detected by the EMCCD. A very low readout noise and a high sensitivity (over 90% for the visible spectrum) enable these devices to detect individual gamma interactions in the crystal. Algorithms have been developed to analyze the EMCCD images for the presence of the scintillation events and provide estimates of their position and energy content. The first photon-counting gamma camera based on EMCCDs was demonstrated in our group in 2005. Subsequently, during the course of this PhD project all elements of this gamma camera have been investigated and improved. This thesis will introduce the essential components of a CCD-based gamma camera, and subsequent chapters demonstrate improvements that have been implemented. These improvements range from the gamma photon-detection algorithm, the readout mode of the CCD, the optical coupling between scintillator and CCD, the scintillator material itself to the inclusion of side detectors for a priori indication of the number of interactions in the scintillation crystal. The thesis concludes with some future investigations and prospects., Radiation, Radionuclides & Reactors, Applied Sciences

For the development and improvement of multi-pinhole SPECT systems, high-resolution gamma cameras can be essential. Electron-multiplying charge-coupled devices (EMCCDs) have a high resolution and sensitivity and therefore can be extremely useful for application in photon-counting scintillation gamma cameras. The scintillation crystal captures the gamma photons and converts their energy into (visible) light photons, which are detected by the EMCCD. A very low readout noise and a high sensitivity (over 90% for the visible spectrum) enable these devices to detect individual gamma interactions in the crystal. Algorithms have been developed to analyze the EMCCD images for the presence of the scintillation events and provide estimates of their position and energy content. The first photon-counting gamma camera based on EMCCDs was demonstrated in our group in 2005. Subsequently, during the course of this PhD project all elements of this gamma camera have been investigated and improved. This thesis will introduce the essential components of a CCD-based gamma camera, and subsequent chapters demonstrate improvements that have been implemented. These improvements range from the gamma photon-detection algorithm, the readout mode of the CCD, the optical coupling between scintillator and CCD, the scintillator material itself to the inclusion of side detectors for a priori indication of the number of interactions in the scintillation crystal. The thesis concludes with some future investigations and prospects., Radiation, Radionuclides & Reactors, Applied Sciences

Thesis (B.S.)--University of Rochester. Dept. of Physics and Astronomy, 1994., A charge-coup led device (CCD ) is used, in replacement of photographic plates, in the Meinel spectrograph ( figure 1-1 ) mounted on the 24" telescope of the C.E.K. Mees observatory ( figure 1-2 I. This thesis describes the development of the CCD system presently in use with the Meinel spectrograph, data acquistion and analysis, and overall system performance. All work was completed, over a period of four years, as part of a series of advanced laboratory and independent study courses with Professor Fulbright as advisor.

Thesis (B.S.)--University of Rochester. Dept. of Physics and Astronomy, 1994., A charge-coup led device (CCD ) is used, in replacement of photographic plates, in the Meinel spectrograph ( figure 1-1 ) mounted on the 24" telescope of the C.E.K. Mees observatory ( figure 1-2 I. This thesis describes the development of the CCD system presently in use with the Meinel spectrograph, data acquistion and analysis, and overall system performance. All work was completed, over a period of four years, as part of a series of advanced laboratory and independent study courses with Professor Fulbright as advisor.

This is a review of our recent work in the use of a CCD-based digital imaging system for the shadow spectral digital imaging (SSDI) of boron, aluminium (spike formation), and condensation of vapour of selected analytes, matrices, and chemical modifiers in graphite furnace atomic absorption spectrometry (GFAAS). The use of a charge-coupled device (CCD) camera has enabled a number of processes in the Massmann-type GFAAS to be more thoroughly investigated than has been previously possible. The SSDI technique has been used to obtain spatially and temporally resolved distributions of atoms, molecules and condensed-phase species generated in a graphite furnace as a result of processes such as vaporization, atomization and condensation. The application of this technique to the investigation of atomic and molecular species of boron has helped in elucidating the mechanism of vaporization and atomization of boron. Thermal dissociation of boron oxide species results in the formation of BO(g) and its loss from a graphite furnace at temperatures below the atomization temperature of boron. The atomic boron signal is the result of desorption of boron atoms from the decomposition of condensed-phase boron carbide. Studies using the CCD imaging of atomic and molecular species of aluminium in a graphite furnace have resulted in a mechanism being proposed for aluminium atom spike formation and for dissipation of aluminium atoms in the graphite furnace, aluminium atom spikes formed from gaseous Al2O precursors, this reaction being triggered by the formation of a condensed-phase Al4C3 melt. Finally, the SSDI technique has been used to further our knowledge and understanding of light-scattering of microparticles produced by condensation of vapours of selected analytes, matrices and chemical modifiers. The spatial and temporal non-uniformity of condensed-phase particle clouds are attributed to thermal expansion of gas, gas flow patterns and temperature gradients in the vapour phase and in

This is a review of our recent work in the use of a CCD-based digital imaging system for the shadow spectral digital imaging (SSDI) of boron, aluminium (spike formation), and condensation of vapour of selected analytes, matrices, and chemical modifiers in graphite furnace atomic absorption spectrometry (GFAAS). The use of a charge-coupled device (CCD) camera has enabled a number of processes in the Massmann-type GFAAS to be more thoroughly investigated than has been previously possible. The SSDI technique has been used to obtain spatially and temporally resolved distributions of atoms, molecules and condensed-phase species generated in a graphite furnace as a result of processes such as vaporization, atomization and condensation. The application of this technique to the investigation of atomic and molecular species of boron has helped in elucidating the mechanism of vaporization and atomization of boron. Thermal dissociation of boron oxide species results in the formation of BO(g) and its loss from a graphite furnace at temperatures below the atomization temperature of boron. The atomic boron signal is the result of desorption of boron atoms from the decomposition of condensed-phase boron carbide. Studies using the CCD imaging of atomic and molecular species of aluminium in a graphite furnace have resulted in a mechanism being proposed for aluminium atom spike formation and for dissipation of aluminium atoms in the graphite furnace, aluminium atom spikes formed from gaseous Al2O precursors, this reaction being triggered by the formation of a condensed-phase Al4C3 melt. Finally, the SSDI technique has been used to further our knowledge and understanding of light-scattering of microparticles produced by condensation of vapours of selected analytes, matrices and chemical modifiers. The spatial and temporal non-uniformity of condensed-phase particle clouds are attributed to thermal expansion of gas, gas flow patterns and temperature gradients in the vapour phase and in