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• 311. [Article] Self-Assembled Epitaxial BaFe12O19 Nano-Island Film Grown on Al2O3 Substrate by Pulsed Laser Deposition

  M-type hexagonal barium ferrite is one of the most favorable ferrite materials, whose functional properties such as ferroelectric polarity alignment and the interaction between electron spins could be ...

  Citation × Citation Citation Abstract Copy Title: Self-Assembled Epitaxial BaFe12O19 Nano-Island Film Grown on Al2O3 Substrate by Pulsed Laser Deposition Author: Wei, Guodong, Wei, Lin, Chen, Yanxue, Yan, Shishen, Mei, Liangmo, Jiao, Jun Year: 2016 M-type hexagonal barium ferrite is one of the most favorable ferrite materials, whose functional properties such as ferroelectric polarity alignment and the interaction between electron spins could be controlled by manipulating its stoichiometry or microstructure. In this letter, BaFe12O19 films have been prepared on Al2O3 substrate by pulsed laser deposition at different temperature. AFM and SEM results show that under optimal preparation condition, the films change into self-assembled triangular shaped nano-islands with highly regulated orientation. Interesting magnetic and optical properties have been observed in these BaFe12O19 nanostructures. We believe this work may provide a unique opportunity to investigate anomalous phenomenons associated with nanostructured magnetic oxides and the growth dynamics of ferrite films. Title: Self-Assembled Epitaxial BaFe12O19 Nano-Island Film Grown on Al2O3 Substrate by Pulsed Laser Deposition Author: Wei, Guodong, Wei, Lin, Chen, Yanxue, Yan, Shishen, Mei, Liangmo, Jiao, Jun Year: 2016 M-type hexagonal barium ferrite is one of the most favorable ferrite materials, whose functional properties such as ferroelectric polarity alignment and the interaction between electron spins could be controlled by manipulating its stoichiometry or microstructure. In this letter, BaFe12O19 films have been prepared on Al2O3 substrate by pulsed laser deposition at different temperature. AFM and SEM results show that under optimal preparation condition, the films change into self-assembled triangular shaped nano-islands with highly regulated orientation. Interesting magnetic and optical properties have been observed in these BaFe12O19 nanostructures. We believe this work may provide a unique opportunity to investigate anomalous phenomenons associated with nanostructured magnetic oxides and the growth dynamics of ferrite films. Close

• 312. [Article] ZnO Nanosheet Arrays Constructed on Weaved Titanium Wire for CdS-Sensitized Solar Cells

  Ordered ZnO nanosheet arrays were grown on weaved titanium wires by a low-temperature hydrothermal method. CdS nanoparticles were deposited onto the ZnO nanosheet arrays using the successive ionic layer ...

  Citation × Citation Citation Abstract Copy Title: ZnO Nanosheet Arrays Constructed on Weaved Titanium Wire for CdS-Sensitized Solar Cells Author: Wu, Cuncun, Wei, Lin, Li, Yitan, Liu, Chang, Jiao, Jun, Chen, Yanxue, Mei, Liangmo Year: 2014 Ordered ZnO nanosheet arrays were grown on weaved titanium wires by a low-temperature hydrothermal method. CdS nanoparticles were deposited onto the ZnO nanosheet arrays using the successive ionic layer adsorption and reaction method to make a photoanode. Nanoparticle-sensitized solar cells were assembled using these CdS/ZnO nanostructured photoanodes, and their photovoltaic performance was studied systematically. The best light-to-electricity conversion efficiency was obtained to be 2.17% under 100 mW/cm/cm2 illumination, and a remarkable shortcircuit photocurrent density of approximately 20.1 mA/cm2 was recorded, which could attribute to the relatively direct pathways for transportation of electrons provided by ZnO nanosheet arrays as well as the direct contact between ZnO and weaved titanium wires. These results indicate that CdS/ZnO nanostructures on weaved titanium wires would open a novel possibility for applications of low-cost solar cells. Title: ZnO Nanosheet Arrays Constructed on Weaved Titanium Wire for CdS-Sensitized Solar Cells Author: Wu, Cuncun, Wei, Lin, Li, Yitan, Liu, Chang, Jiao, Jun, Chen, Yanxue, Mei, Liangmo Year: 2014 Ordered ZnO nanosheet arrays were grown on weaved titanium wires by a low-temperature hydrothermal method. CdS nanoparticles were deposited onto the ZnO nanosheet arrays using the successive ionic layer adsorption and reaction method to make a photoanode. Nanoparticle-sensitized solar cells were assembled using these CdS/ZnO nanostructured photoanodes, and their photovoltaic performance was studied systematically. The best light-to-electricity conversion efficiency was obtained to be 2.17% under 100 mW/cm/cm2 illumination, and a remarkable shortcircuit photocurrent density of approximately 20.1 mA/cm2 was recorded, which could attribute to the relatively direct pathways for transportation of electrons provided by ZnO nanosheet arrays as well as the direct contact between ZnO and weaved titanium wires. These results indicate that CdS/ZnO nanostructures on weaved titanium wires would open a novel possibility for applications of low-cost solar cells. Close

• 313. [Article] Supplementary Balance Laws for Cattaneo Heat Propagation

  In this work we determine for the Cattaneo heat propagation system all the supplementary balance laws (conservation laws ) of the same order (zero) as the system itself and extract the constitutive relations ...

  Citation × Citation Citation Abstract Copy Title: Supplementary Balance Laws for Cattaneo Heat Propagation Author: Preston, Serge Year: 2013 In this work we determine for the Cattaneo heat propagation system all the supplementary balance laws (conservation laws ) of the same order (zero) as the system itself and extract the constitutive relations (expression for the internal energy) dictated by the Entropy Principle. The space of all supplementary balance laws (having the functional dimension 8) contains four original balance laws and their deformations depending on 4 functions of temperature (λ0(ϑ),KA (ϑ), A = 1, 2, 3). The requirements of the II law of thermodynamics leads to the exclusion of three functional degrees (KA= 0, A = 1, 2, 3) and to further restriction to the form of internal energy. In its final formulation, entropy balance represent the deformation of the energy balance law by the functional parameter λ0(ϑ). Title: Supplementary Balance Laws for Cattaneo Heat Propagation Author: Preston, Serge Year: 2013 In this work we determine for the Cattaneo heat propagation system all the supplementary balance laws (conservation laws ) of the same order (zero) as the system itself and extract the constitutive relations (expression for the internal energy) dictated by the Entropy Principle. The space of all supplementary balance laws (having the functional dimension 8) contains four original balance laws and their deformations depending on 4 functions of temperature (λ0(ϑ),KA (ϑ), A = 1, 2, 3). The requirements of the II law of thermodynamics leads to the exclusion of three functional degrees (KA= 0, A = 1, 2, 3) and to further restriction to the form of internal energy. In its final formulation, entropy balance represent the deformation of the energy balance law by the functional parameter λ0(ϑ). Close

• 314. [Article] Oregon Natural Areas Plan

  The rich diversity of ecosystems and native plants and animals is one of Oregon's most distinctive and valued qualities. Our state contains rain forests, dry forests, oak woodlands, alpine meadows, prairies, ...

  Citation × Citation Citation Abstract Copy Title: Oregon Natural Areas Plan Author: Oregon Natural Heritage Advisory Council Year: 2010 The rich diversity of ecosystems and native plants and animals is one of Oregon's most distinctive and valued qualities. Our state contains rain forests, dry forests, oak woodlands, alpine meadows, prairies, deserts, marshes, estuaries, dunes, rocky headlands, lakes and streams. There are a number of reasons it is so diverse. First are the extremes of climate, with rainfall ranging from over 200 inches a year along Oregon’s north coast, to less than 7 inches a year in the Alvord Desert, and temperatures from the very mild banana belt along the coast near the California border to the extremes of the high alpine areas of the Wallowa Mountains. Secondly, Oregon is diverse geographically and geologically, having ancient serpentine landscapes in the Siskiyou Mountains and recent volcanics in the Cascades and the deepest gorge in North America at Hells Canyon. Lastly, Oregon is a floristic crossroads, with arctic boreal species finding their southern limit, Rocky Mountain species common in northeastern Oregon, Great Basin species in southeastern Oregon, and California coastal and Sierra species in the southwest, all mixing with native northwestern taxa to create a wide array of habitats. Title: Oregon Natural Areas Plan Author: Oregon Natural Heritage Advisory Council Year: 2010 The rich diversity of ecosystems and native plants and animals is one of Oregon's most distinctive and valued qualities. Our state contains rain forests, dry forests, oak woodlands, alpine meadows, prairies, deserts, marshes, estuaries, dunes, rocky headlands, lakes and streams. There are a number of reasons it is so diverse. First are the extremes of climate, with rainfall ranging from over 200 inches a year along Oregon’s north coast, to less than 7 inches a year in the Alvord Desert, and temperatures from the very mild banana belt along the coast near the California border to the extremes of the high alpine areas of the Wallowa Mountains. Secondly, Oregon is diverse geographically and geologically, having ancient serpentine landscapes in the Siskiyou Mountains and recent volcanics in the Cascades and the deepest gorge in North America at Hells Canyon. Lastly, Oregon is a floristic crossroads, with arctic boreal species finding their southern limit, Rocky Mountain species common in northeastern Oregon, Great Basin species in southeastern Oregon, and California coastal and Sierra species in the southwest, all mixing with native northwestern taxa to create a wide array of habitats. Close

• 315. [Article] Changing Climate, Changing Behavior: An Interview with Angus Duncan

  In a 2010 report, the Oregon Legislature-created Oregon Global Warming Commission (OGWC) stated "with confidence" that human activities were primarily responsible for a 1.5 degree Fahrenheit increase in ...

  Citation × Citation Citation Abstract Copy Title: Changing Climate, Changing Behavior: An Interview with Angus Duncan Author: Burnham, Michael Year: 2012 In a 2010 report, the Oregon Legislature-created Oregon Global Warming Commission (OGWC) stated "with confidence" that human activities were primarily responsible for a 1.5 degree Fahrenheit increase in 20th century temperatures in the Pacific Northwest. Transportation and electricity were responsible for about 70 percent of Oregon's greenhouse gas emissions during the 2003-2007 period of study, while agriculture, waste, combustion, leakage, and other sources were responsible for the balance of emissions. Metroscape's Michael Burnham sat down with OGWC Chairman Angus Duncan recently to discuss the commission's work and how a warming world might affect the metropolitan Portland area economically, socially, and environmentally. Title: Changing Climate, Changing Behavior: An Interview with Angus Duncan Author: Burnham, Michael Year: 2012 In a 2010 report, the Oregon Legislature-created Oregon Global Warming Commission (OGWC) stated "with confidence" that human activities were primarily responsible for a 1.5 degree Fahrenheit increase in 20th century temperatures in the Pacific Northwest. Transportation and electricity were responsible for about 70 percent of Oregon's greenhouse gas emissions during the 2003-2007 period of study, while agriculture, waste, combustion, leakage, and other sources were responsible for the balance of emissions. Metroscape's Michael Burnham sat down with OGWC Chairman Angus Duncan recently to discuss the commission's work and how a warming world might affect the metropolitan Portland area economically, socially, and environmentally. Close

• 316. [Article] Computational Approach to Dark Current Spectroscopy in CCDs as complex systems. II. Numerical Analysis of the Uniqueness Parameters Evaluation

  The evaluation of the uniqueness parameters of the temperature dependence in CCDs is difficult to the considerable number of input parameters and to the strongly nonlinear (exponential) theoretical relations. ...

  Citation × Citation Citation Abstract Copy Title: Computational Approach to Dark Current Spectroscopy in CCDs as complex systems. II. Numerical Analysis of the Uniqueness Parameters Evaluation Author: Tunaru, Ionel, Widenhorn, Ralf, Iordache, Dan A., Bodegom, Erik Year: 2011 The evaluation of the uniqueness parameters of the temperature dependence in CCDs is difficult to the considerable number of input parameters and to the strongly nonlinear (exponential) theoretical relations. For this reason, the elaborated computer programs are very sensitive to the choice of the zero-order approximations of the effective (Si) energy gap, and of the weights associated to the experimentally determined dark current. The main goal of this work was to study the rather narrow stability domains of the zero-order approximations, which lead to attractors with physical meaning. It was found that the stability domains are surrounded by (usually in this order): other fields leading to oscillations, pseudo-convergence (false attractors, described by non-physical values of the studied parameters) or instability fields, which were studied also in detail. Title: Computational Approach to Dark Current Spectroscopy in CCDs as complex systems. II. Numerical Analysis of the Uniqueness Parameters Evaluation Author: Tunaru, Ionel, Widenhorn, Ralf, Iordache, Dan A., Bodegom, Erik Year: 2011 The evaluation of the uniqueness parameters of the temperature dependence in CCDs is difficult to the considerable number of input parameters and to the strongly nonlinear (exponential) theoretical relations. For this reason, the elaborated computer programs are very sensitive to the choice of the zero-order approximations of the effective (Si) energy gap, and of the weights associated to the experimentally determined dark current. The main goal of this work was to study the rather narrow stability domains of the zero-order approximations, which lead to attractors with physical meaning. It was found that the stability domains are surrounded by (usually in this order): other fields leading to oscillations, pseudo-convergence (false attractors, described by non-physical values of the studied parameters) or instability fields, which were studied also in detail. Close

• 317. [Article] Dark Current Measurements in a CMOS Imager

  We present data for the dark current of a commercially available CMOS image sensor for different gain settings and bias offsets over the temperature range of 295 to 340 K and exposure times of 0 to 500 ...

  Citation × Citation Citation Abstract Copy Title: Dark Current Measurements in a CMOS Imager Author: Porter, William C., Kopp, Bradley, Dunlap, Justin Charles, Widenhorn, Ralf, Bodegom, Erik Year: 2008 We present data for the dark current of a commercially available CMOS image sensor for different gain settings and bias offsets over the temperature range of 295 to 340 K and exposure times of 0 to 500 ms. The analysis of hot pixels shows two different sources of dark current. One source results in hot pixels with high but constant count for exposure times smaller than the frame time. Other hot pixels exhibit a linear increase with exposure time. We discuss how these hot pixels can be used to calculate the dark current for all pixels. Finally, we show that for low bias settings with universally zero counts for the dark frame one still needs to correct for dark current. The correction of thermal noise can therefore result in dark frames with negative pixel values. We show how one can calculate dark frames with negative pixel count. Title: Dark Current Measurements in a CMOS Imager Author: Porter, William C., Kopp, Bradley, Dunlap, Justin Charles, Widenhorn, Ralf, Bodegom, Erik Year: 2008 We present data for the dark current of a commercially available CMOS image sensor for different gain settings and bias offsets over the temperature range of 295 to 340 K and exposure times of 0 to 500 ms. The analysis of hot pixels shows two different sources of dark current. One source results in hot pixels with high but constant count for exposure times smaller than the frame time. Other hot pixels exhibit a linear increase with exposure time. We discuss how these hot pixels can be used to calculate the dark current for all pixels. Finally, we show that for low bias settings with universally zero counts for the dark frame one still needs to correct for dark current. The correction of thermal noise can therefore result in dark frames with negative pixel values. We show how one can calculate dark frames with negative pixel count. Close

• 318. [Article] Measurements of dark current in a CCD imager during light exposures

  Thermal excitation of electrons is a major source of noise in Charge-Coupled Device (CCD) imagers. Those electrons are generated even in the absence of light, hence the name dark current. Dark current ...

  Citation × Citation Citation Abstract Copy Title: Measurements of dark current in a CCD imager during light exposures Author: Widenhorn, Ralf, Hartwig, Ines, Dunlap, Justin Charles, Bodegom, Erik Year: 2008 Thermal excitation of electrons is a major source of noise in Charge-Coupled Device (CCD) imagers. Those electrons are generated even in the absence of light, hence the name dark current. Dark current is particularly important for long exposure times and elevated temperatures. The standard procedure to correct for dark current is to take several pictures under the same condition as the real image, except with the shutter closed. The resulting dark frame is later subtracted from the exposed image. We address the question of whether the dark current produced in an image taken with a closed shutter is identical to the dark current produced in an exposure in the presence of light. In our investigation, we illuminated two different CCD chips to different intensities of light and measured the dark current generation. A surprising conclusion of this study is that some pixels produce a different amount of dark current under illumination. Finally, we discuss the implications that this has for dark frame image correction. Title: Measurements of dark current in a CCD imager during light exposures Author: Widenhorn, Ralf, Hartwig, Ines, Dunlap, Justin Charles, Bodegom, Erik Year: 2008 Thermal excitation of electrons is a major source of noise in Charge-Coupled Device (CCD) imagers. Those electrons are generated even in the absence of light, hence the name dark current. Dark current is particularly important for long exposure times and elevated temperatures. The standard procedure to correct for dark current is to take several pictures under the same condition as the real image, except with the shutter closed. The resulting dark frame is later subtracted from the exposed image. We address the question of whether the dark current produced in an image taken with a closed shutter is identical to the dark current produced in an exposure in the presence of light. In our investigation, we illuminated two different CCD chips to different intensities of light and measured the dark current generation. A surprising conclusion of this study is that some pixels produce a different amount of dark current under illumination. Finally, we discuss the implications that this has for dark frame image correction. Close

• 319. [Article] Correction of dark current in consumer cameras

  A study of dark current in digital imagers in digital singlelens reflex (DSLR) and compact consumer-grade digital cameras is presented. Dark current is shown to vary with temperature, exposure time, and ...

  Citation × Citation Citation Abstract Copy Title: Correction of dark current in consumer cameras Author: Dunlap, Justin Charles, Bodegom, Erik, Widenhorn, Ralf Year: 2010 A study of dark current in digital imagers in digital singlelens reflex (DSLR) and compact consumer-grade digital cameras is presented. Dark current is shown to vary with temperature, exposure time, and ISO setting. Further, dark current is shown to increase in successive images during a series of images. DSLR and compact consumer cameras are often designed such that they are contained within a densely packed camera body, and therefore the digital imagers within the camera frame are prone to heat generated by the sensor as well as nearby elements within the camera body. It is the scope of this work to characterize the dark current in such cameras and to show that the dark current, in part due to heat generated by the camera itself, can be corrected by using hot pixels on the imager. This method generates computed dark frames based on the dark current indicator value of the hottest pixels on the chip. We compare this method to standard methods of dark current correction. Title: Correction of dark current in consumer cameras Author: Dunlap, Justin Charles, Bodegom, Erik, Widenhorn, Ralf Year: 2010 A study of dark current in digital imagers in digital singlelens reflex (DSLR) and compact consumer-grade digital cameras is presented. Dark current is shown to vary with temperature, exposure time, and ISO setting. Further, dark current is shown to increase in successive images during a series of images. DSLR and compact consumer cameras are often designed such that they are contained within a densely packed camera body, and therefore the digital imagers within the camera frame are prone to heat generated by the sensor as well as nearby elements within the camera body. It is the scope of this work to characterize the dark current in such cameras and to show that the dark current, in part due to heat generated by the camera itself, can be corrected by using hot pixels on the imager. This method generates computed dark frames based on the dark current indicator value of the hottest pixels on the chip. We compare this method to standard methods of dark current correction. Close

• 320. [Article] Metamorphic Systems: A Schema for Adaptive Autonomous Systems

  Chapter 11. Unmanned vehicles (UVs) are taking on increasing roles in military and space missions. These UVs operate in radically different domains, yet they have several common features: (1) they must ...

  Citation × Citation Citation Abstract Copy Title: Metamorphic Systems: A Schema for Adaptive Autonomous Systems Author: Greenwood, Garrison W., Tyrrell, Andy M. Year: 2015 Chapter 11. Unmanned vehicles (UVs) are taking on increasing roles in military and space missions. These UVs operate in radically different domains, yet they have several common features: (1) they must survive in harsh domains for extended time periods, (2) they must adapt their behaviour to accommodate changing circumstances and (3) they must operate autonomously, which means they must perform assigned tasks with little or no human intervention. For instance, since August 2012 NASA’s scientific laboratory rover Curiosity has been exploring the Martian surface searching for signs of life (NASA, 2012). Martian surface temperatures average –63°C. As another example, the U.S. Navy is currently developing the Anti-submarine Continuous Trail Unmanned Vessel (ACTUV) to track quiet diesel-electric submarines. The goal is to have a UV that can autonomously interact with an intelligent adversary over ranges spanning thousands of kilometers while enduring harsh ocean environmental conditions for months at a time (DARPA, 2012). Title: Metamorphic Systems: A Schema for Adaptive Autonomous Systems Author: Greenwood, Garrison W., Tyrrell, Andy M. Year: 2015 Chapter 11. Unmanned vehicles (UVs) are taking on increasing roles in military and space missions. These UVs operate in radically different domains, yet they have several common features: (1) they must survive in harsh domains for extended time periods, (2) they must adapt their behaviour to accommodate changing circumstances and (3) they must operate autonomously, which means they must perform assigned tasks with little or no human intervention. For instance, since August 2012 NASA’s scientific laboratory rover Curiosity has been exploring the Martian surface searching for signs of life (NASA, 2012). Martian surface temperatures average –63°C. As another example, the U.S. Navy is currently developing the Anti-submarine Continuous Trail Unmanned Vessel (ACTUV) to track quiet diesel-electric submarines. The goal is to have a UV that can autonomously interact with an intelligent adversary over ranges spanning thousands of kilometers while enduring harsh ocean environmental conditions for months at a time (DARPA, 2012). Close