Application of off-line image processing for optimization in chest computed radiography using a low cost system.

PubMed

Muhogora, Wilbroad E; Msaki, Peter; Padovani, Renato

2015-03-08

 The objective of this study was to improve the visibility of anatomical details by applying off-line postimage processing in chest computed radiography (CR). Four spatial domain-based external image processing techniques were developed by using MATLAB software version 7.0.0.19920 (R14) and image processing tools. The developed techniques were implemented to sample images and their visual appearances confirmed by two consultant radiologists to be clinically adequate. The techniques were then applied to 200 chest clinical images and randomized with other 100 images previously processed online. These 300 images were presented to three experienced radiologists for image quality assessment using standard quality criteria. The mean and ranges of the average scores for three radiologists were characterized for each of the developed technique and imaging system. The Mann-Whitney U-test was used to test the difference of details visibility between the images processed using each of the developed techniques and the corresponding images processed using default algorithms. The results show that the visibility of anatomical features improved significantly (0.005 ≤ p ≤ 0.02) with combinations of intensity values adjustment and/or spatial linear filtering techniques for images acquired using 60 ≤ kVp ≤ 70. However, there was no improvement for images acquired using 102 ≤ kVp ≤ 107 (0.127 ≤ p ≤ 0.48). In conclusion, the use of external image processing for optimization can be effective in chest CR, but should be implemented in consultations with the radiologists.

Application of off‐line image processing for optimization in chest computed radiography using a low cost system

PubMed Central

Msaki, Peter; Padovani, Renato

2015-01-01

The objective of this study was to improve the visibility of anatomical details by applying off‐line postimage processing in chest computed radiography (CR). Four spatial domain‐based external image processing techniques were developed by using MATLAB software version 7.0.0.19920 (R14) and image processing tools. The developed techniques were implemented to sample images and their visual appearances confirmed by two consultant radiologists to be clinically adequate. The techniques were then applied to 200 chest clinical images and randomized with other 100 images previously processed online. These 300 images were presented to three experienced radiologists for image quality assessment using standard quality criteria. The mean and ranges of the average scores for three radiologists were characterized for each of the developed technique and imaging system. The Mann‐Whitney U‐test was used to test the difference of details visibility between the images processed using each of the developed techniques and the corresponding images processed using default algorithms. The results show that the visibility of anatomical features improved significantly (0.005≤p≤0.02) with combinations of intensity values adjustment and/or spatial linear filtering techniques for images acquired using 60≤kVp≤70. However, there was no improvement for images acquired using 102≤kVp≤107 (0.127≤p≤0.48). In conclusion, the use of external image processing for optimization can be effective in chest CR, but should be implemented in consultations with the radiologists. PACS number: 87.59.−e, 87.59.−B, 87.59.−bd PMID:26103165

In-line monitoring technique with visible light from 1.3 microm-band SHG module for optical access systems.

PubMed

Kubo, Takahiro; Taniguchi, Tomohiro; Tadanaga, Osamu; Sakurai, Naoya; Kimura, Hideaki; Hadama, Hisaya; Asobe, Masaki

2010-02-01

We propose an in-line monitoring technique that uses 650 nm visible light for performing maintenance work on Fiber-to-the-home (FTTH) network quickly without the need for measuring skills or external devices. This technique is characterized by visible light (650 nm) generated by an SHG module from the 1.3 microm-band line signal. We fabricate a 1.3 microm-band quasi phase matched LiNbO(3) (QPM-LN) module, and the measure the 650 nm second harmonic (SH) power to test the proposed short-pulse modulation method. The results confirm the feasibility of the short-pulse modulation method with different peak factors (PFs) (1.0-7.3). We also examine the effect of short-pulse modulation on system performance at the optical receiver by measuring the bit error rate (BER) of received data (1.25 Gb/s). The BER is basically unaffected by the PF (1.0-5.5). This means that the proposed technique has little influence on data reception as regards PF (1.0-5.5).

Road Lane Detection Robust to Shadows Based on a Fuzzy System Using a Visible Light Camera Sensor.

PubMed

Hoang, Toan Minh; Baek, Na Rae; Cho, Se Woon; Kim, Ki Wan; Park, Kang Ryoung

2017-10-28

Recently, autonomous vehicles, particularly self-driving cars, have received significant attention owing to rapid advancements in sensor and computation technologies. In addition to traffic sign recognition, road lane detection is one of the most important factors used in lane departure warning systems and autonomous vehicles for maintaining the safety of semi-autonomous and fully autonomous systems. Unlike traffic signs, road lanes are easily damaged by both internal and external factors such as road quality, occlusion (traffic on the road), weather conditions, and illumination (shadows from objects such as cars, trees, and buildings). Obtaining clear road lane markings for recognition processing is a difficult challenge. Therefore, we propose a method to overcome various illumination problems, particularly severe shadows, by using fuzzy system and line segment detector algorithms to obtain better results for detecting road lanes by a visible light camera sensor. Experimental results from three open databases, Caltech dataset, Santiago Lanes dataset (SLD), and Road Marking dataset, showed that our method outperformed conventional lane detection methods.

An Adaptive Low-Cost GNSS/MEMS-IMU Tightly-Coupled Integration System with Aiding Measurement in a GNSS Signal-Challenged Environment.

PubMed

Zhou, Qifan; Zhang, Hai; Li, You; Li, Zheng

2015-09-18

The main aim of this paper is to develop a low-cost GNSS/MEMS-IMU tightly-coupled integration system with aiding information that can provide reliable position solutions when the GNSS signal is challenged such that less than four satellites are visible in a harsh environment. To achieve this goal, we introduce an adaptive tightly-coupled integration system with height and heading aiding (ATCA). This approach adopts a novel redundant measurement noise estimation method for an adaptive Kalman filter application and also augments external measurements in the filter to aid the position solutions, as well as uses different filters to deal with various situations. On the one hand, the adaptive Kalman filter makes use of the redundant measurement system's difference sequence to estimate and tune noise variance instead of employing a traditional innovation sequence to avoid coupling with the state vector error. On the other hand, this method uses the external height and heading angle as auxiliary references and establishes a model for the measurement equation in the filter. In the meantime, it also changes the effective filter online based on the number of tracked satellites. These measures have increasingly enhanced the position constraints and the system observability, improved the computational efficiency and have led to a good result. Both simulated and practical experiments have been carried out, and the results demonstrate that the proposed method is effective at limiting the system errors when there are less than four visible satellites, providing a satisfactory navigation solution.

An Adaptive Low-Cost GNSS/MEMS-IMU Tightly-Coupled Integration System with Aiding Measurement in a GNSS Signal-Challenged Environment

PubMed Central

Zhou, Qifan; Zhang, Hai; Li, You; Li, Zheng

2015-01-01

The main aim of this paper is to develop a low-cost GNSS/MEMS-IMU tightly-coupled integration system with aiding information that can provide reliable position solutions when the GNSS signal is challenged such that less than four satellites are visible in a harsh environment. To achieve this goal, we introduce an adaptive tightly-coupled integration system with height and heading aiding (ATCA). This approach adopts a novel redundant measurement noise estimation method for an adaptive Kalman filter application and also augments external measurements in the filter to aid the position solutions, as well as uses different filters to deal with various situations. On the one hand, the adaptive Kalman filter makes use of the redundant measurement system’s difference sequence to estimate and tune noise variance instead of employing a traditional innovation sequence to avoid coupling with the state vector error. On the other hand, this method uses the external height and heading angle as auxiliary references and establishes a model for the measurement equation in the filter. In the meantime, it also changes the effective filter online based on the number of tracked satellites. These measures have increasingly enhanced the position constraints and the system observability, improved the computational efficiency and have led to a good result. Both simulated and practical experiments have been carried out, and the results demonstrate that the proposed method is effective at limiting the system errors when there are less than four visible satellites, providing a satisfactory navigation solution. PMID:26393605

48. MAIN WAREHOUSE THIRD LEVEL Elevator drive mechanism is ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

48. MAIN WAREHOUSE - THIRD LEVEL Elevator drive mechanism is seen to the right, while drive wheels, belt wheels and chain drives are visible in the wooden wall framing. The horizontal metal conveyor (at the top of the wall Just under the inverted 'V' brace) is part of the empty can supply system connected to the external can conveyor. See Photo No. 28. - Hovden Cannery, 886 Cannery Row, Monterey, Monterey County, CA

Internal vs. external on-premise sign lighting : visibility and safety in the real world.

DOT National Transportation Integrated Search

2009-02-01

Poorly visible on-premise commercial signs have been associated with reduced safety, as drivers trying to locate : and make sense of these signs may drive slower than the rest of traffic and perform erratic, last-second maneuvers. One of the : main r...

Water used to visualize and remove hidden foreign bodies from the external ear canal.

PubMed

Peltola, T J; Saarento, R

1992-02-01

Small foreign bodies lodged anteriorly in the tympanic sulcus are usually not visible, due to the curve of the external ear canal. Such objects can be seen with the aid of an otomicroscope and micromirror or with an endoscope, and removed by irrigation. If irrigation fails, epithelial migration on the tympanic membrane may remove lodged foreign bodies, although this may take months. Our new method, which uses water to locate small objects lodged in the tympanic sulcus, includes irrigation of the ear, adjustment of the water level to the middle curve of the external ear canal, and use of the water surface as a concave lens, making the tympanic sulcus visible. With otomicroscopy a curved ear probe can then be used to remove lodged foreign bodies from behind the curve.

Teaching about Arab Americans: What Social Studies Teachers Should Know.

ERIC Educational Resources Information Center

Suleiman, Mahmoud

External influences in the universal culture have significantly affected the image of Arab Americans and their children. Although Arab Americans are less visible than other minorities, the anti-Arab perception in the media makes them more visible in a negative way. Based on an ethnographic study investigating the experiences of Arabic-speaking…

Road Lane Detection Robust to Shadows Based on a Fuzzy System Using a Visible Light Camera Sensor

PubMed Central

Hoang, Toan Minh; Baek, Na Rae; Cho, Se Woon; Kim, Ki Wan; Park, Kang Ryoung

2017-01-01

Recently, autonomous vehicles, particularly self-driving cars, have received significant attention owing to rapid advancements in sensor and computation technologies. In addition to traffic sign recognition, road lane detection is one of the most important factors used in lane departure warning systems and autonomous vehicles for maintaining the safety of semi-autonomous and fully autonomous systems. Unlike traffic signs, road lanes are easily damaged by both internal and external factors such as road quality, occlusion (traffic on the road), weather conditions, and illumination (shadows from objects such as cars, trees, and buildings). Obtaining clear road lane markings for recognition processing is a difficult challenge. Therefore, we propose a method to overcome various illumination problems, particularly severe shadows, by using fuzzy system and line segment detector algorithms to obtain better results for detecting road lanes by a visible light camera sensor. Experimental results from three open databases, Caltech dataset, Santiago Lanes dataset (SLD), and Road Marking dataset, showed that our method outperformed conventional lane detection methods. PMID:29143764

20-Gbps optical LiFi transport system.

PubMed

Ying, Cheng-Ling; Lu, Hai-Han; Li, Chung-Yi; Cheng, Chun-Jen; Peng, Peng-Chun; Ho, Wen-Jeng

2015-07-15

A 20-Gbps optical light-based WiFi (LiFi) transport system employing vertical-cavity surface-emitting laser (VCSEL) and external light injection technique with 16-quadrature amplitude modulation (QAM)-orthogonal frequency-division multiplexing (OFDM) modulating signal is proposed. Good bit error rate (BER) performance and clear constellation map are achieved in our proposed optical LiFi transport systems. An optical LiFi transport system, delivering 16-QAM-OFDM signal over a 6-m free-space link, with a data rate of 20 Gbps, is successfully demonstrated. Such a 20-Gbps optical LiFi transport system provides the advantage of a free-space communication link for high data rates, which can accelerate the visible laser light communication (VLLC) deployment.

Flight Deck Technologies to Enable NextGen Low Visibility Surface Operations

NASA Technical Reports Server (NTRS)

Prinzel, Lawrence (Lance) J., III; Arthur, Jarvis (Trey) J.; Kramer, Lynda J.; Norman, Robert M.; Bailey, Randall E.; Jones, Denise R.; Karwac, Jerry R., Jr.; Shelton, Kevin J.; Ellis, Kyle K. E.

2013-01-01

Many key capabilities are being identified to enable Next Generation Air Transportation System (NextGen), including the concept of Equivalent Visual Operations (EVO) . replicating the capacity and safety of today.s visual flight rules (VFR) in all-weather conditions. NASA is striving to develop the technologies and knowledge to enable EVO and to extend EVO towards a Better-Than-Visual operational concept. This operational concept envisions an .equivalent visual. paradigm where an electronic means provides sufficient visual references of the external world and other required flight references on flight deck displays that enable Visual Flight Rules (VFR)-like operational tempos while maintaining and improving safety of VFR while using VFR-like procedures in all-weather conditions. The Langley Research Center (LaRC) has recently completed preliminary research on flight deck technologies for low visibility surface operations. The work assessed the potential of enhanced vision and airport moving map displays to achieve equivalent levels of safety and performance to existing low visibility operational requirements. The work has the potential to better enable NextGen by perhaps providing an operational credit for conducting safe low visibility surface operations by use of the flight deck technologies.

Wave and Current Observations in a Tidal Inlet Using GPS Drifter Buoys

DTIC Science & Technology

2013-03-01

right panel). ............17  Figure 10.  DWR-G external sensor configuration (left panel). GT-31 GPS receiver is visible on the bottom left. Two GoPro ...receiver is visible on the bottom left. Two GoPro cameras are attached to the top of the buoy. DWR-G internal sensor configuration (right panel

Enhancing the visibility of injuries with narrow-banded beams of light within the visible light spectrum.

PubMed

Limmen, Roxane M; Ceelen, Manon; Reijnders, Udo J L; Joris Stomp, S; de Keijzer, Koos C; Das, Kees

2013-03-01

The use of narrow-banded visible light sources in improving the visibility of injuries has been hardly investigated, and studies examining the extent of this improvement are lacking. In this study, narrow-banded beams of light within the visible light spectrum were used to explore their ability in improving the visibility of external injuries. The beams of light were induced by four crime-lites(®) providing narrow-banded beams of light between 400 and 550 nm. The visibility of the injuries was assessed through specific long-pass filters supplied with the set of crime-lites(®) . Forty-three percent of the examined injuries improved in visibility by using the narrow-banded visible light. In addition, injuries were visualized that were not visible or just barely visible to the naked eye. The improvements in visibility were particularly marked with the use of crime-lites(®) "violet" and "blue" covering the spectrum between 400-430 and 430-470 nm. The simple noninvasive method showed a great potential contribution in injury examination. © 2012 American Academy of Forensic Sciences.

On-off keying transmitter design for navigation by visible light communication

NASA Astrophysics Data System (ADS)

Louro, P.; Vieira, M.; Costa, J.; Vieira, M. A.

2018-02-01

White LEDS revolutionized the field of illumination technology mainly due to the energy saving effects. Besides lighting purposes LEDs can also be used in wireless communication systems when integrated in Visible Light Communication (VLC) systems. Indoor positioning for navigation in large buildings is currently under research to overcome the difficulties associated with the use of GPS in such environments. The motivation for this application is also supported by the possibility of taking advantage of an existing lighting and WiFi infrastructure. In this work it is proposed an indoor navigation system based on the use of VLC technology. The proposed system includes trichromatic white LEDs with the red and blue chips modulated at different frequencies and a pinpin photodetector with selective spectral sensitivity. Optoelectronic features of both optical sources and photodetector device are analyzed. The photodetector device consists two pin structures based on a-SiC:H and a-Si:H with geometrical configuration optimized for the detection of short and large wavelengths in the visible range. Its sensitivity is externally tuned by steady state optical bias. The localization algorithm makes use of the Fourier transform to identify the frequencies present in the photocurrent signal and the wavelength filtering properties of the sensor under front and back optical bias to detect the existing red and blue signals. The viability of the system was demonstrated through the implementation of an automatic algorithm to infer the photodetector cardinal direction. A capacitive optoelectronic model supports the experimental results and explains the device operation.

STS-45 external tank (ET) falls back to Earth after jettisoning from OV-104

NASA Image and Video Library

1992-03-24

STS045-71-001 (24 March 1992) --- This 70mm photograph of the external fuel tank (ET) for STS-45 was photographed 4 1/2 minutes after having been jettisoned from Space Shuttle Atlantis. The excellent view of the starboard side of the ET shows both top and bottom attach points to the two solid rocket boosters (SRB). NASA engineers studying the STS-45 onboard photography deem the visible burn scars, caused by the SRBs, to be normal. The long thin pipe visible is the liquid oxygen line. At the bottom end of the large tank, both the liquid oxygen (nearest camera) and liquid hydrogen orbiter-to-ET attach hardware can be seen.

KSC-99pp0514

NASA Image and Video Library

1999-05-12

At Launch Pad 39B, the top of the external tank (ET) mated to Space Shuttle Discovery is dotted with nearly a dozen visible dings from recent hail storms. Workers are investigating the damage and potential problems for launch posed by ice forming in the holes, which may number as many as 150 over the entire tank. The average size of the dings is one-half inch in diameter and one-tenth inch deep. The external tank contains the liquid hydrogen fuel and liquid oxygen oxidizer and supplies them under pressure to the three space shuttle main engines in the orbiter during liftoff and ascent. The ET thermal protection system consists of sprayed-on foam insulation. The Shuttle Discovery is targeted for launch of mission STS-96 on May 20 at 9:32 a.m

KSC-99pp0517

NASA Image and Video Library

1999-05-12

At Launch Pad 39B, two holes caused by hail on Space Shuttle Discovery's external tank (ET) are visible. Left of the tank is one of the solid rocket boosters. Workers are investigating the damage and potential problems for launch posed by ice forming in the holes, which may number as many as 150 over the entire tank. The average size of the holes is one-half inch in diameter and one-tenth inch deep. The external tank contains the liquid hydrogen fuel and liquid oxygen oxidizer and supplies them under pressure to the three space shuttle main engines in the orbiter during liftoff and ascent. The ET thermal protection system consists of sprayed-on foam insulation. The Shuttle Discovery is targeted for launch of mission STS-96 on May 20 at 9:32 a.m

A comparison of visual statistics for the image enhancement of FORESITE aerial images with those of major image classes

NASA Astrophysics Data System (ADS)

Jobson, Daniel J.; Rahman, Zia-ur; Woodell, Glenn A.; Hines, Glenn D.

2006-05-01

Aerial images from the Follow-On Radar, Enhanced and Synthetic Vision Systems Integration Technology Evaluation (FORESITE) flight tests with the NASA Langley Research Center's research Boeing 757 were acquired during severe haze and haze/mixed clouds visibility conditions. These images were enhanced using the Visual Servo (VS) process that makes use of the Multiscale Retinex. The images were then quantified with visual quality metrics used internally within the VS. One of these metrics, the Visual Contrast Measure, has been computed for hundreds of FORESITE images, and for major classes of imaging-terrestrial (consumer), orbital Earth observations, orbital Mars surface imaging, NOAA aerial photographs, and underwater imaging. The metric quantifies both the degree of visual impairment of the original, un-enhanced images as well as the degree of visibility improvement achieved by the enhancement process. The large aggregate data exhibits trends relating to degree of atmospheric visibility attenuation, and its impact on the limits of enhancement performance for the various image classes. Overall results support the idea that in most cases that do not involve extreme reduction in visibility, large gains in visual contrast are routinely achieved by VS processing. Additionally, for very poor visibility imaging, lesser, but still substantial, gains in visual contrast are also routinely achieved. Further, the data suggest that these visual quality metrics can be used as external standalone metrics for establishing performance parameters.

A Comparison of Visual Statistics for the Image Enhancement of FORESITE Aerial Images with Those of Major Image Classes

NASA Technical Reports Server (NTRS)

Johnson, Daniel J.; Rahman, Zia-ur; Woodell, Glenn A.; Hines, Glenn D.

2006-01-01

Aerial images from the Follow-On Radar, Enhanced and Synthetic Vision Systems Integration Technology Evaluation (FORESITE) flight tests with the NASA Langley Research Center's research Boeing 757 were acquired during severe haze and haze/mixed clouds visibility conditions. These images were enhanced using the Visual Servo (VS) process that makes use of the Multiscale Retinex. The images were then quantified with visual quality metrics used internally with the VS. One of these metrics, the Visual Contrast Measure, has been computed for hundreds of FORESITE images, and for major classes of imaging--terrestrial (consumer), orbital Earth observations, orbital Mars surface imaging, NOAA aerial photographs, and underwater imaging. The metric quantifies both the degree of visual impairment of the original, un-enhanced images as well as the degree of visibility improvement achieved by the enhancement process. The large aggregate data exhibits trends relating to degree of atmospheric visibility attenuation, and its impact on limits of enhancement performance for the various image classes. Overall results support the idea that in most cases that do not involve extreme reduction in visibility, large gains in visual contrast are routinely achieved by VS processing. Additionally, for very poor visibility imaging, lesser, but still substantial, gains in visual contrast are also routinely achieved. Further, the data suggest that these visual quality metrics can be used as external standalone metrics for establishing performance parameters.

Recovering faces from memory: the distracting influence of external facial features.

PubMed

Frowd, Charlie D; Skelton, Faye; Atherton, Chris; Pitchford, Melanie; Hepton, Gemma; Holden, Laura; McIntyre, Alex H; Hancock, Peter J B

2012-06-01

Recognition memory for unfamiliar faces is facilitated when contextual cues (e.g., head pose, background environment, hair and clothing) are consistent between study and test. By contrast, inconsistencies in external features, especially hair, promote errors in unfamiliar face-matching tasks. For the construction of facial composites, as carried out by witnesses and victims of crime, the role of external features (hair, ears, and neck) is less clear, although research does suggest their involvement. Here, over three experiments, we investigate the impact of external features for recovering facial memories using a modern, recognition-based composite system, EvoFIT. Participant-constructors inspected an unfamiliar target face and, one day later, repeatedly selected items from arrays of whole faces, with "breeding," to "evolve" a composite with EvoFIT; further participants (evaluators) named the resulting composites. In Experiment 1, the important internal-features (eyes, brows, nose, and mouth) were constructed more identifiably when the visual presence of external features was decreased by Gaussian blur during construction: higher blur yielded more identifiable internal-features. In Experiment 2, increasing the visible extent of external features (to match the target's) in the presented face-arrays also improved internal-features quality, although less so than when external features were masked throughout construction. Experiment 3 demonstrated that masking external-features promoted substantially more identifiable images than using the previous method of blurring external-features. Overall, the research indicates that external features are a distractive rather than a beneficial cue for face construction; the results also provide a much better method to construct composites, one that should dramatically increase identification of offenders.

International Space Station Data Collection for Disaster Response

NASA Technical Reports Server (NTRS)

Stefanov, William L.; Evans, Cynthia A.

2015-01-01

Remotely sensed data acquired by orbital sensor systems has emerged as a vital tool to identify the extent of damage resulting from a natural disaster, as well as providing near-real time mapping support to response efforts on the ground and humanitarian aid efforts. The International Space Station (ISS) is a unique terrestrial remote sensing platform for acquiring disaster response imagery. Unlike automated remote-sensing platforms it has a human crew; is equipped with both internal and externally-mounted remote sensing instruments; and has an inclined, low-Earth orbit that provides variable views and lighting (day and night) over 95 percent of the inhabited surface of the Earth. As such, it provides a useful complement to autonomous sensor systems in higher altitude polar orbits. NASA remote sensing assets on the station began collecting International Disaster Charter (IDC) response data in May 2012. The initial NASA ISS sensor systems responding to IDC activations included the ISS Agricultural Camera (ISSAC), mounted in the Window Observational Research Facility (WORF); the Crew Earth Observations (CEO) Facility, where the crew collects imagery using off-the-shelf handheld digital cameras; and the Hyperspectral Imager for the Coastal Ocean (HICO), a visible to near-infrared system mounted externally on the Japan Experiment Module Exposed Facility. The ISSAC completed its primary mission in January 2013. It was replaced by the very high resolution ISS SERVIR Environmental Research and Visualization System (ISERV) Pathfinder, a visible-wavelength digital camera, telescope, and pointing system. Since the start of IDC response in 2012 there have been 108 IDC activations; NASA sensor systems have collected data for thirty-two of these events. Of the successful data collections, eight involved two or more ISS sensor systems responding to the same event. Data has also been collected by International Partners in response to natural disasters, most notably JAXA and Roscosmos/Energia through the Urugan program.

ZnSe quantum dots modified with a Ni(cyclam) catalyst for efficient visible-light driven CO2 reduction in water.

PubMed

Kuehnel, Moritz F; Sahm, Constantin D; Neri, Gaia; Lee, Jonathan R; Orchard, Katherine L; Cowan, Alexander J; Reisner, Erwin

2018-03-07

A precious metal and Cd-free photocatalyst system for efficient CO 2 reduction in water is reported. The hybrid assembly consists of ligand-free ZnSe quantum dots (QDs) as a visible-light photosensitiser combined with a phosphonic acid-functionalised Ni(cyclam) catalyst, NiCycP. This precious metal-free photocatalyst system shows a high activity for aqueous CO 2 reduction to CO (Ni-based TON CO > 120), whereas an anchor-free catalyst, Ni(cyclam)Cl 2 , produced three times less CO. Additional ZnSe surface modification with 2-(dimethylamino)ethanethiol (MEDA) partially suppresses H 2 generation and enhances the CO production allowing for a Ni-based TON CO of > 280 and more than 33% selectivity for CO 2 reduction over H 2 evolution, after 20 h visible light irradiation ( λ > 400 nm, AM 1.5G, 1 sun). The external quantum efficiency of 3.4 ± 0.3% at 400 nm is comparable to state-of-the-art precious metal photocatalysts. Transient absorption spectroscopy showed that band-gap excitation of ZnSe QDs is followed by rapid hole scavenging and very fast electron trapping in ZnSe. The trapped electrons transfer to NiCycP on the ps timescale, explaining the high performance for photocatalytic CO 2 reduction. With this work we introduce ZnSe QDs as an inexpensive and efficient visible light-absorber for solar fuel generation.

Tetra-2,3-pyrazinoporphyrazines with externally appended pyridine rings. 15. Effects of the pyridyl substituents and fused exocyclic rings on the UV-visible spectroscopic properties of Mg(II)-porphyrazines: a combined experimental and DFT/TDDFT study.

PubMed

Donzello, Maria Pia; De Mori, Giorgia; Viola, Elisa; Ercolani, Claudio; Ricciardi, Giampaolo; Rosa, Angela

2014-08-04

Two new Mg(II) porphyrazine macrocycles, the octakis(2-pyridyl)porphyrazinato-magnesium(II), [Py8PzMg(H2O)], and the tetrakis-[6,7-di(2-pyridyl)quinoxalino]porphyrazinato-magnesium(II), [Py8QxPzMg(H2O)], were prepared by Mg-template macrocyclization processes, and their general physicochemical properties were examined. The previously reported porphyrazine analog, the tetrakis-2,3-[5,6-di(2-pyridyl)-pyrazino]porphyrazinato-magnesium(II), [Py8PyzPzMg(H2O)], has been also considered in the present work. The UV-visible solution spectra in nonaqueous solvents of this triad of externally octapyridinated Mg(II) complexes exhibit the usual profile observed for phthalocyanine and porphyrazine macrocycles, with intense absorptions in the Soret (300-450 nm) and Q band (600-800 nm) regions. It is observed that the Q band maximum sensibly shifts toward the red with peak values at 635 → 658 → 759 nm along the series [Py8PzMg(H2O)], [Py8PyzPzMg(H2O)], and [Py8QxPzMg(H2O)], as the extension of the macrocycle π-system increases. TDDFT calculations of the electronic absorption spectra were performed for the related water-free model compounds [Py8PzMg], [Py8PyzPzMg], and [Py8QxPzMg] to provide an interpretation of the UV-visible spectral changes occurring upon introduction of the pyrazine and quinoxaline rings at the periphery of the Pz macrocycle. To discriminate the electronic effects of the fused exocyclic rings from those of the appended 2-pyridyl rings, the UV-visible spectra of [PzMg] and [PyzPzMg] were also theoretically investigated. The theoretical results prove to agree very well with the experimental data, providing an accurate description of the UV-visible spectra. The observed spectral changes are interpreted on the basis of the electronic structure changes occurring along the series.

Automatic illumination compensation device based on a photoelectrochemical biofuel cell driven by visible light

NASA Astrophysics Data System (ADS)

Yu, You; Han, Yanchao; Xu, Miao; Zhang, Lingling; Dong, Shaojun

2016-04-01

Inverted illumination compensation is important in energy-saving projects, artificial photosynthesis and some forms of agriculture, such as hydroponics. However, only a few illumination adjustments based on self-powered biodetectors that quantitatively detect the intensity of visible light have been reported. We constructed an automatic illumination compensation device based on a photoelectrochemical biofuel cell (PBFC) driven by visible light. The PBFC consisted of a glucose dehydrogenase modified bioanode and a p-type semiconductor cuprous oxide photocathode. The PBFC had a high power output of 161.4 μW cm-2 and an open circuit potential that responded rapidly to visible light. It adjusted the amount of illumination inversely irrespective of how the external illumination was changed. This rational design of utilizing PBFCs provides new insights into automatic light adjustable devices and may be of benefit to intelligent applications.Inverted illumination compensation is important in energy-saving projects, artificial photosynthesis and some forms of agriculture, such as hydroponics. However, only a few illumination adjustments based on self-powered biodetectors that quantitatively detect the intensity of visible light have been reported. We constructed an automatic illumination compensation device based on a photoelectrochemical biofuel cell (PBFC) driven by visible light. The PBFC consisted of a glucose dehydrogenase modified bioanode and a p-type semiconductor cuprous oxide photocathode. The PBFC had a high power output of 161.4 μW cm-2 and an open circuit potential that responded rapidly to visible light. It adjusted the amount of illumination inversely irrespective of how the external illumination was changed. This rational design of utilizing PBFCs provides new insights into automatic light adjustable devices and may be of benefit to intelligent applications. Electronic supplementary information (ESI) available. See DOI: 10.1039/c6nr00759g

Soft Lithographic Procedure for Producing Plastic Microfluidic Devices with View-ports Transparent to Visible and Infrared Light.

PubMed

Suryana, Mona; Shanmugarajah, Jegan V; Maniam, Sivakumar M; Grenci, Gianluca

2017-08-17

Infrared (IR) spectro-microscopy of living biological samples is hampered by the absorption of water in the mid-IR range and by the lack of suitable microfluidic devices. Here, a protocol for the fabrication of plastic microfluidic devices is demonstrated, where soft lithographic techniques are used to embed transparent Calcium Fluoride (CaF2) view-ports in connection with observation chamber(s). The method is based on a replica casting approach, where a polydimethylsiloxane (PDMS) mold is produced through standard lithographic procedures and then used as the template to produce a plastic device. The plastic device features ultraviolet/visible/infrared (UV/Vis/IR) -transparent windows made of CaF2 to allow for direct observation with visible and IR light. The advantages of the proposed method include: a reduced need for accessing a clean room micro-fabrication facility, multiple view-ports, an easy and versatile connection to an external pumping system through the plastic body, flexibility of the design, e.g., open/closed channels configuration, and the possibility to add sophisticated features such as nanoporous membranes.

Fully Integrated Optical Spectrometer in Visible and Near-IR in CMOS.

PubMed

Hong, Lingyu; Sengupta, Kaushik

2017-12-01

Optical spectrometry in the visible and near-infrared range has a wide range of applications in healthcare, sensing, imaging, and diagnostics. This paper presents the first fully integrated optical spectrometer in standard bulk CMOS process without custom fabrication, postprocessing, or any external optical passive structure such as lenses, gratings, collimators, or mirrors. The architecture exploits metal interconnect layers available in CMOS processes with subwavelength feature sizes to guide, manipulate, control, diffract light, integrated photodetector, and read-out circuitry to detect dispersed light, and then back-end signal processing for robust spectral estimation. The chip, realized in bulk 65-nm low power-CMOS process, measures 0.64 mm 0.56 mm in active area, and achieves 1.4 nm in peak detection accuracy for continuous wave excitations between 500 and 830 nm. This paper demonstrates the ability to use these metal-optic nanostructures to miniaturize complex optical instrumentation into a new class of optics-free CMOS-based systems-on-chip in the visible and near-IR for various sensing and imaging applications.

On a suspected ring external to the visible rings of Saturn

NASA Technical Reports Server (NTRS)

Feibelman, W. A.; Beebe, R. F.; Smith, B. A.; Cook, A. F., II

1974-01-01

The reexamination of a photograph of Saturn taken on 15 November 1966 when the earth was nearly in the ring plane is investigated which indicates that ring material does exist outside the visible rings, extending to more than 6 Saturnian radii. The observed brightness in blue light was estimated per linear arc second, implying a normal optical thickness, for ice-covered particles.

Lithium Visibility in Rat Brain and Muscle in Vivoby 7Li NMR Imaging

NASA Astrophysics Data System (ADS)

Komoroski, Richard A.; Pearce, John M.; Newton, Joseph E. O.

1998-07-01

The apparent concentration of lithium (Li)in vivowas determined for several regions in the brain and muscle of rats by7Li NMR imaging at 4.7 T with inclusion of an external standard of known concentration and visibility. The average apparent concentrations were 10.1 mM for muscle, and 4.2-5.3 mM for various brain regions under the dosing conditions used. The results were compared to concentrations determinedin vitroby high-resolution7Li NMR spectroscopy of extracts of brain and muscle tissue from the same rats. The comparison provided estimates of the7Li NMR visibility of the Li cation in each tissue region. Although there was considerable scatter of the calculated visibilities among the five rats studied, the results suggested essentially full visibility (96%) for Li in muscle, and somewhat reduced visibility (74-93%) in the various brain regions.

Interdigitation Zone Band Restoration After Treatment of Diabetic Macular Edema.

PubMed

Serizawa, Satoshi; Ohkoshi, Kishiko; Minowa, Yuko; Soejima, Kumiko

2016-09-01

To investigate whether the integrity of the interdigitation zone band, the ellipsoid zone band, and the external limiting membrane are reliable markers of treatment outcome in diabetic macular edema (DME). In this retrospective study, we examined 41 treatment-naïve eyes (38 patients) with DME that were treated with laser therapy, pharmacotherapy, and/or vitrectomy. Best-corrected visual acuity and the integrity of the interdigitation zone band, the ellipsoid zone band, and the external limiting membrane were assessed before treatment and at 3, 6, and 12 months after DME treatment. One year after treatment, the external limiting membrane, ellipsoid zone band, and interdigitation zone band were completely visible in 30 (73.2%), 24 (58.5%), and 2 (4.9%) eyes, respectively. Interdigitation zone band status improved significantly (P = 0.005) 1 year after treatment. The interdigitation zone did not improve in the absence of the ellipsoid zone band. Likewise, ellipsoid zone status did not improve in the absence of the external limiting membrane at any time after treatment. The results of this study show that restoration of the interdigitation zone band constitutes a very sensitive marker of DME treatment outcome when the ellipsoid zone band is visible before treatment.

7 CFR 51.1584 - Internal discoloration.

Code of Federal Regulations, 2011 CFR

2011-01-01

... STANDARDS) United States Consumer Standards for Potatoes Definitions § 51.1584 Internal discoloration..., stem-end browning, internal brown spot, or other similar types of discoloration not visible externally. ...

7 CFR 51.1584 - Internal discoloration.

Code of Federal Regulations, 2012 CFR

2012-01-01

... STANDARDS) United States Consumer Standards for Potatoes Definitions § 51.1584 Internal discoloration..., stem-end browning, internal brown spot, or other similar types of discoloration not visible externally. ...

Highly Transparent, Visible-Light Photodetector Based on Oxide Semiconductors and Quantum Dots.

PubMed

Shin, Seung Won; Lee, Kwang-Ho; Park, Jin-Seong; Kang, Seong Jun

2015-09-09

Highly transparent phototransistors that can detect visible light have been fabricated by combining indium-gallium-zinc oxide (IGZO) and quantum dots (QDs). A wide-band-gap IGZO film was used as a transparent semiconducting channel, while small-band-gap QDs were adopted to absorb and convert visible light to an electrical signal. Typical IGZO thin-film transistors (TFTs) did not show a photocurrent with illumination of visible light. However, IGZO TFTs decorated with QDs showed enhanced photocurrent upon exposure to visible light. The device showed a responsivity of 1.35×10(4) A/W and an external quantum efficiency of 2.59×10(4) under illumination by a 635 nm laser. The origin of the increased photocurrent in the visible light was the small band gap of the QDs combined with the transparent IGZO films. Therefore, transparent phototransistors based on IGZO and QDs were fabricated and characterized in detail. The result is relevant for the development of highly transparent photodetectors that can detect visible light.

Hematological indices of injury to lightly oiled birds from the Deepwater Horizon oil spill

USGS Publications Warehouse

Fallon, Jesse A.; Smith, Eric P.; Schoch, Nina; Paruk, James D.; Adams, Evan A.; Evers, David C.; Jodice, Patrick G. R.; Perkins, Christopher; Schulte, Shiloh A.; Hopkins, William A.

2018-01-01

Avian mortality events are common following large‐scale oil spills. However, the sublethal effects of oil on birds exposed to light external oiling are not clearly understood. We found that American oystercatchers (area of potential impact n = 42, reference n = 21), black skimmers (area of potential impact n = 121, reference n = 88), brown pelicans (area of potential impact n = 91, reference n = 48), and great egrets (area of potential impact n = 57, reference n = 47) captured between 20 June 2010 and 23 February 2011 following the Deepwater Horizon oil spill experienced oxidative injury to erythrocytes, had decreased volume of circulating erythrocytes, and showed evidence of a regenerative hematological response in the form of increased reticulocytes compared with reference populations. Erythrocytic inclusions consistent with Heinz bodies were present almost exclusively in birds from sites impacted with oil, a finding pathognomonic for oxidative injury to erythrocytes. Average packed cell volumes were 4 to 19% lower and average reticulocyte counts were 27 to 40% higher in birds with visible external oil than birds from reference sites. These findings provide evidence that small amounts of external oil exposure are associated with hemolytic anemia. Furthermore, we found that some birds captured from the area impacted by the spill but with no visible oiling also had erythrocytic inclusion bodies, increased reticulocytes, and reduced packed cell volumes when compared with birds from reference sites. Thus, birds suffered hematologic injury despite no visible oil at the time of capture. Together, these findings suggest that adverse effects of oil spills on birds may be more widespread than estimates based on avian mortality or severe visible oiling.

Demonstration and Validation of a Fractured Rock Passive Flux Meter

DTIC Science & Technology

2015-04-01

Thick continuous lines are stream lines and thin dashed lines are potential lines. Green lines are isochrones, i.e., dye , tracer or contaminant...layer of cloth material impregnated with a visible dye . The core inflates separately from the two end packers to provide a mechanism for holding the one...leaches visible dyes and tracers from the internal and external sorbent layers and produces residual dye and tracer distributions. Visual

Siting a municipal solid waste disposal facility, part II: the effects of external criteria on the final decision.

PubMed

Korucu, M Kemal; Karademir, Aykan

2014-02-01

The procedure of a multi-criteria decision analysis supported by the geographic information systems was applied to the site selection process of a planning municipal solid waste management practice based on twelve different scenarios. The scenarios included two different decision tree modes and two different weighting models for three different area requirements. The suitability rankings of the suitable sites obtained from the application of the decision procedure for the scenarios were assessed by a factorial experimental design concerning the effect of some external criteria on the final decision of the site selection process. The external criteria used in the factorial experimental design were defined as "Risk perception and approval of stakeholders" and "Visibility". The effects of the presence of these criteria in the decision trees were evaluated in detail. For a quantitative expression of the differentiations observed in the suitability rankings, the ranking data were subjected to ANOVA test after a normalization process. Then the results of these tests were evaluated by Tukey test to measure the effects of external criteria on the final decision. The results of Tukey tests indicated that the involvement of the external criteria into the decision trees produced statistically meaningful differentiations in the suitability rankings. Since the external criteria could cause considerable external costs during the operation of the disposal facilities, the presence of these criteria in the decision tree in addition to the other criteria related to environmental and legislative requisites could prevent subsequent external costs in the first place.

Flight Deck-Based Delegated Separation: Evaluation of an On-Board Interval Management System with Synthetic and Enhanced Vision Technology

NASA Technical Reports Server (NTRS)

Prinzel, Lawrence J., III; Shelton, Kevin J.; Kramer, Lynda J.; Arthur, Jarvis J.; Bailey, Randall E.; Norman, Rober M.; Ellis, Kyle K. E.; Barmore, Bryan E.

2011-01-01

An emerging Next Generation Air Transportation System concept - Equivalent Visual Operations (EVO) - can be achieved using an electronic means to provide sufficient visibility of the external world and other required flight references on flight deck displays that enable the safety, operational tempos, and visual flight rules (VFR)-like procedures for all weather conditions. Synthetic and enhanced flight vision system technologies are critical enabling technologies to EVO. Current research evaluated concepts for flight deck-based interval management (FIM) operations, integrated with Synthetic Vision and Enhanced Vision flight-deck displays and technologies. One concept involves delegated flight deck-based separation, in which the flight crews were paired with another aircraft and responsible for spacing and maintaining separation from the paired aircraft, termed, "equivalent visual separation." The operation required the flight crews to acquire and maintain an "equivalent visual contact" as well as to conduct manual landings in low-visibility conditions. The paper describes results that evaluated the concept of EVO delegated separation, including an off-nominal scenario in which the lead aircraft was not able to conform to the assigned spacing resulting in a loss of separation.

GLCF: Gallery

Science.gov Websites

UMD Land Cover Classification Product External Galleries * ASTER at JPL * AVHRR at JHU * Earth Observatory at NASA * Landsat 7 at USGS * MODIS at NASA * Visible Earth at NASA e-link 4321 Hartwick Building

Active mode locking of quantum cascade lasers in an external ring cavity.

PubMed

Revin, D G; Hemingway, M; Wang, Y; Cockburn, J W; Belyanin, A

2016-05-05

Stable ultrashort light pulses and frequency combs generated by mode-locked lasers have many important applications including high-resolution spectroscopy, fast chemical detection and identification, studies of ultrafast processes, and laser metrology. While compact mode-locked lasers emitting in the visible and near infrared range have revolutionized photonic technologies, the systems operating in the mid-infrared range where most gases have their strong absorption lines, are bulky and expensive and rely on nonlinear frequency down-conversion. Quantum cascade lasers are the most powerful and versatile compact light sources in the mid-infrared range, yet achieving their mode-locked operation remains a challenge, despite dedicated effort. Here we report the demonstration of active mode locking of an external-cavity quantum cascade laser. The laser operates in the mode-locked regime at room temperature and over the full dynamic range of injection currents.

Active mode locking of quantum cascade lasers in an external ring cavity

PubMed Central

Revin, D. G.; Hemingway, M.; Wang, Y.; Cockburn, J. W.; Belyanin, A.

2016-01-01

Stable ultrashort light pulses and frequency combs generated by mode-locked lasers have many important applications including high-resolution spectroscopy, fast chemical detection and identification, studies of ultrafast processes, and laser metrology. While compact mode-locked lasers emitting in the visible and near infrared range have revolutionized photonic technologies, the systems operating in the mid-infrared range where most gases have their strong absorption lines, are bulky and expensive and rely on nonlinear frequency down-conversion. Quantum cascade lasers are the most powerful and versatile compact light sources in the mid-infrared range, yet achieving their mode-locked operation remains a challenge, despite dedicated effort. Here we report the demonstration of active mode locking of an external-cavity quantum cascade laser. The laser operates in the mode-locked regime at room temperature and over the full dynamic range of injection currents. PMID:27147409

Comprehensive analyses of core-shell InGaN/GaN single nanowire photodiodes

NASA Astrophysics Data System (ADS)

Zhang, H.; Guan, N.; Piazza, V.; Kapoor, A.; Bougerol, C.; Julien, F. H.; Babichev, A. V.; Cavassilas, N.; Bescond, M.; Michelini, F.; Foldyna, M.; Gautier, E.; Durand, C.; Eymery, J.; Tchernycheva, M.

2017-12-01

Single nitride nanowire core/shell n-p photodetectors are fabricated and analyzed. Nanowires consisting of an n-doped GaN stem, a radial InGaN/GaN multiple quantum well system and a p-doped GaN external shell were grown by catalyst-free metal-organic vapour phase epitaxy on sapphire substrates. Single nanowires were dispersed and the core and the shell regions were contacted with a metal and an ITO deposition, respectively, defined using electron beam lithography. The single wire photodiodes present a response in the visible to UV spectral range under zero external bias. The detector operation speed has been analyzed under different bias conditions. Under zero bias, the  -3 dB cut-off frequency is ~200 Hz for small light modulations. The current generation was modeled using non-equilibrium Green function formalism, which evidenced the importance of phonon scattering for carrier extraction from the quantum wells.

Fenestration obscuration techniques

NASA Astrophysics Data System (ADS)

Smalley, Michael

2007-10-01

There are situations where it is advantageous to visually obscure through glass, to an external observer, the movement of people within a well lit room. It may be that the building use has changed or existing measures which had provided obscuration such as 'Bomb-blast' curtains have been discontinued. Recognising that implemented solutions must create the minimum disruption to outward visibility and involve the least procedural effort (be simple to use), the Centre for Protection of National Infrastructure, CPNI, commissioned this study, defining key requirements including: (a) Automatic or simple manual operation (b) Obscuration of movement within the building from outside (c) Varying levels of obscuration depending on the difference in internal and external light levels. (d) Minimum disruption to outward visibility (e) Acceptable for use on heritage and iconic sites (f) Easy to retrofit (g) Low cost This report reviews earlier work carried out into the protection of Guardrooms by the use of lighting techniques coupled with the use of reflective and screen printed films. Other innovative solutions including Electrochromatic controllable glazing which may prove more appropriate to office and commercial buildings are also considered. It is seen that some measures, (window films or blinds), are cost effective and unsophisticated while more complex automatic systems using reactive glazing can offer critical design advantages. It must be noted however that some of the key requirements are mutually exclusive and any solution chosen will always be a compromise based on client needs and circumstances.

Low Velocity Blunt Impact on Lightweight Composite Sandwich Panels

NASA Astrophysics Data System (ADS)

Chan, Monica Kar

There is an increased desire to incorporate more composite sandwich structures into modern aircrafts. Because in-service aircrafts routinely experience impact damage during maintenance due to ground vehicle collision, dropped equipment, or foreign object damage (FOD) impact, it is necessary to understand their impact characteristics, particularly when blunt impact sources create internal damage with little or no external visibility. The objective of this investigation is to explore damage formation in lightweight composite sandwich panels due to low-velocity impacts of variable tip radius and energy level. The correlation between barely visible external dent formation and internal core damage was explored as a function of impact tip radius. A pendulum impactor was used to impact composite sandwich panels having honeycomb core while held in a 165 mm square window fixture. The panels were impacted by hardened steel tips with radii of 12.7, 25.4, 50.8, and 76.2 mm at energy levels ranging from 2 to 14 J. Experimental data showed little dependence of external dent depth on tip radius at very low energies of 2 to 6 J, and thus, there was also little variation in visibility due to tip radius. Four modes of internal core damage were identified. Internal damage span and depth were dependent on impact tip radius. Damage depth was also radius-dependent, but stabilized at constant depth independent of kinetic energy. Internal damage span increased with increasing impact energy, but not with increasing tip radius, suggesting a relationship between maximum damage tip radius with core density/size.

Active Multimodal Sensor System for Target Recognition and Tracking

PubMed Central

Zhang, Guirong; Zou, Zhaofan; Liu, Ziyue; Mao, Jiansen

2017-01-01

High accuracy target recognition and tracking systems using a single sensor or a passive multisensor set are susceptible to external interferences and exhibit environmental dependencies. These difficulties stem mainly from limitations to the available imaging frequency bands, and a general lack of coherent diversity of the available target-related data. This paper proposes an active multimodal sensor system for target recognition and tracking, consisting of a visible, an infrared, and a hyperspectral sensor. The system makes full use of its multisensor information collection abilities; furthermore, it can actively control different sensors to collect additional data, according to the needs of the real-time target recognition and tracking processes. This level of integration between hardware collection control and data processing is experimentally shown to effectively improve the accuracy and robustness of the target recognition and tracking system. PMID:28657609

KSC-99pasparklers

NASA Image and Video Library

1999-07-20

Moments before launch, sparks from the external ignitors are visible below the engines of Space Shuttle Columbia. The ignitors burn off a hydrogen concentration outside the orbiter near the main engines. A cloud effect behind the Shuttle's solid rocket booster and access arm to the left is created by spray from the water deluge system. The launch of STS-93 was scrubbed at the T-7 second mark in the countdown due to an indication of a high concentration of hydrogen in an aft engine compartment. The reading was proven to be a false alarm. The launch is rescheduled for July 22 at 12:28 a.m

Hail damage on Atlantis' external tank is inspected

NASA Image and Video Library

2007-04-13

In the Vehicle Assembly Building, Mike Ravenscroft, with United Space Alliance, points to some of the foam repair done on the external tank of Space Shuttle Atlantis. Holes filled with foam are sanded flush with the adjacent area. In late February, Atlantis' external tank received hail damage during a severe thunderstorm that passed through the Kennedy Space Center Launch Complex 39 area. The hail caused visible divots in the giant tank's foam insulation as well as minor surface damage to about 26 heat shield tiles on the shuttle's left wing. The launch now is targeted for June 8.

Aerophytic Cyanobacteria as a Factor in the Biodegradation of Technical Materials on External Building Walls

NASA Astrophysics Data System (ADS)

Piontek, Marlena; Lechów, Hanna

2014-12-01

A study conducted at the Institute of Environmental Engineering, University of Zielona Góra showed the presence of 4 species of aerophytic cyanobacteria in the biological material sampled from the external building wall with visible biocorrosion: Gloeocapsa montana Kützing, Phormidium calcareum Kützing, Aphanothece saxicola Nägeli, Gloeothece caldariorum (P. Richter) Hollerbach. High levels of moisture were detected in the places of biofilm occurrence.

Genes involved in prostate cancer progression determine MRI visibility

PubMed Central

Li, Ping; You, Sungyong; Nguyen, Christopher; Wang, Yanping; Kim, Jayoung; Sirohi, Deepika; Ziembiec, Asha; Luthringer, Daniel; Lin, Shih-Chieh; Daskivich, Timothy; Wu, Jonathan; Freeman, Michael R; Saouaf, Rola; Li, Debiao; Kim, Hyung L.

2018-01-01

MRI is used to image prostate cancer and target tumors for biopsy or therapeutic ablation. The objective was to understand the biology of tumors not visible on MRI that may go undiagnosed and untreated. Methods: Prostate cancers visible or invisible on multiparametric MRI were macrodissected and examined by RNAseq. Differentially expressed genes (DEGs) based on MRI visibility status were cross-referenced with publicly available gene expression databases to identify genes associated with disease progression. Genes with potential roles in determining MRI visibility and disease progression were knocked down in murine prostate cancer xenografts, and imaged by MRI. Results: RNAseq identified 1,654 DEGs based on MRI visibility status. Comparison of DEGs based on MRI visibility and tumor characteristics revealed that Gleason score (dissimilarity test, p<0.0001) and tumor size (dissimilarity test, p<0.039) did not completely determine MRI visibility. Genes in previously reported prognostic signatures significantly correlated with MRI visibility suggesting that MRI visibility was prognostic. Cross-referencing DEGs with external datasets identified four genes (PHYHD1, CENPF, ALDH2, GDF15) that predict MRI visibility, progression free survival and metastatic deposits. Genetic modification of a human prostate cancer cell line to induce miR-101 and suppress CENPF decreased cell migration and invasion. As prostate cancer xenografts in mice, these cells had decreased visibility on diffusion weighted MRI and decreased perfusion, which correlated with immunostaining showing decreased cell density and proliferation. Conclusions: Genes involved in prostate cancer prognosis and metastasis determine MRI visibility, indicating that MRI visibility has prognostic significance. MRI visibility was associated with genetic features linked to poor prognosis. PMID:29556354

Photonic water dynamically responsive to external stimuli

PubMed Central

Sano, Koki; Kim, Youn Soo; Ishida, Yasuhiro; Ebina, Yasuo; Sasaki, Takayoshi; Hikima, Takaaki; Aida, Takuzo

2016-01-01

Fluids that contain ordered nanostructures with periodic distances in the visible-wavelength range, anomalously exhibit structural colours that can be rapidly modulated by external stimuli. Indeed, some fish can dynamically change colour by modulating the periodic distance of crystalline guanine sheets cofacially oriented in their fluid cytoplasm. Here we report that a dilute aqueous colloidal dispersion of negatively charged titanate nanosheets exhibits structural colours. In this ‘photonic water', the nanosheets spontaneously adopt a cofacial geometry with an ultralong periodic distance of up to 675 nm due to a strong electrostatic repulsion. Consequently, the photonic water can even reflect near-infrared light up to 1,750 nm. The structural colour becomes more vivid in a magnetic flux that induces monodomain structural ordering of the colloidal dispersion. The reflective colour of the photonic water can be modulated over the entire visible region in response to appropriate physical or chemical stimuli. PMID:27572806

The effect of external visible light on the breakdown voltage of a long discharge tube

NASA Astrophysics Data System (ADS)

Shishpanov, A. I.; Ionikh, Yu. Z.; Meshchanov, A. V.

2016-06-01

The breakdown characteristics of a discharge tube with a configuration typical of gas-discharge light sources and electric-discharge lasers (a so-called "long discharge tube") filled with argon or helium at a pressure of 1 Torr have been investigated. A breakdown has been implemented using positive and negative voltage pulses with a linear leading edge having a slope dU/ dt ~ 10-107 V/s. Visible light from an external source (halogen incandescent lamp) is found to affect the breakdown characteristics. The dependences of the dynamic breakdown voltage of the tube on dU/ dt and on the incident light intensity are measured. The breakdown voltage is found to decrease under irradiation of the high-voltage anode of the tube in a wide range of dU/ dt. A dependence of the effect magnitude on the light intensity and spectrum is obtained. Possible physical mechanisms of this phenomenon are discussed.

TH-E-17A-01: Internal Respiratory Surrogate for 4D CT Using Fourier Transform and Anatomical Features

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hui, C; Suh, Y; Robertson, D

Purpose: To develop a novel algorithm to generate internal respiratory signals for sorting of four-dimensional (4D) computed tomography (CT) images. Methods: The proposed algorithm extracted multiple time resolved features as potential respiratory signals. These features were taken from the 4D CT images and its Fourier transformed space. Several low-frequency locations in the Fourier space and selected anatomical features from the images were used as potential respiratory signals. A clustering algorithm was then used to search for the group of appropriate potential respiratory signals. The chosen signals were then normalized and averaged to form the final internal respiratory signal. Performance ofmore » the algorithm was tested in 50 4D CT data sets and results were compared with external signals from the real-time position management (RPM) system. Results: In almost all cases, the proposed algorithm generated internal respiratory signals that visibly matched the external respiratory signals from the RPM system. On average, the end inspiration times calculated by the proposed algorithm were within 0.1 s of those given by the RPM system. Less than 3% of the calculated end inspiration times were more than one time frame away from those given by the RPM system. In 3 out of the 50 cases, the proposed algorithm generated internal respiratory signals that were significantly smoother than the RPM signals. In these cases, images sorted using the internal respiratory signals showed fewer artifacts in locations corresponding to the discrepancy in the internal and external respiratory signals. Conclusion: We developed a robust algorithm that generates internal respiratory signals from 4D CT images. In some cases, it even showed the potential to outperform the RPM system. The proposed algorithm is completely automatic and generally takes less than 2 min to process. It can be easily implemented into the clinic and can potentially replace the use of external surrogates.« less

0D-2D Quantum Dot: Metal Dichalcogenide Nanocomposite Photocatalyst Achieves Efficient Hydrogen Generation.

PubMed

Liu, Xiao-Yuan; Chen, Hao; Wang, Ruili; Shang, Yuequn; Zhang, Qiong; Li, Wei; Zhang, Guozhen; Su, Juan; Dinh, Cao Thang; de Arquer, F Pelayo García; Li, Jie; Jiang, Jun; Mi, Qixi; Si, Rui; Li, Xiaopeng; Sun, Yuhan; Long, Yi-Tao; Tian, He; Sargent, Edward H; Ning, Zhijun

2017-06-01

Hydrogen generation via photocatalysis-driven water splitting provides a convenient approach to turn solar energy into chemical fuel. The development of photocatalysis system that can effectively harvest visible light for hydrogen generation is an essential task in order to utilize this technology. Herein, a kind of cadmium free Zn-Ag-In-S (ZAIS) colloidal quantum dots (CQDs) that shows remarkably photocatalytic efficiency in the visible region is developed. More importantly, a nanocomposite based on the combination of 0D ZAIS CQDs and 2D MoS 2 nanosheet is developed. This can leverage the strong light harvesting capability of CQDs and catalytic performance of MoS 2 simultaneously. As a result, an excellent external quantum efficiency of 40.8% at 400 nm is achieved for CQD-based hydrogen generation catalyst. This work presents a new platform for the development of high-efficiency photocatalyst based on 0D-2D nanocomposite. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Rare Ultra-blue Stars Found in Neighboring Galaxy's Hub

NASA Image and Video Library

2017-12-08

Image release January 11, 2012 A new Hubble Space Telescope image centers on the 100-million-solar-mass black hole at the hub of the neighboring spiral galaxy M31, or the Andromeda galaxy, one of the few galaxies outside the Milky Way visible to the naked eye and the only other giant galaxy in the Local Group. This is the sharpest visible-light image ever made of the nucleus of an external galaxy. The Hubble image is being presented today at the meeting of the American Astronomical Society in Austin, Texas. To read more go to: www.nasa.gov/mission_pages/hubble/science/ultra-blue.html NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

Influence of bedding type on mucosal immune responses.

PubMed

Sanford, Amy N; Clark, Stephanie E; Talham, Gwen; Sidelsky, Michael G; Coffin, Susan E

2002-10-01

The mucosal immune system interacts with the external environment. In the study reported here, we found that bedding materials can influence the intestinal immune responses of mice. We observed that mice housed on wood, compared with cotton bedding, had increased numbers of Peyer's patches (PP) visible under a dissecting microscope. In addition, culture of lymphoid organs revealed increased production of total and virus-specific IgA by PP and mesenteric lymph node (MLN) lymphocytes from mice housed on wood, compared with cotton bedding. However, bedding type did not influence serum virus-specific antibody responses. These observations indicate that bedding type influences the intestinal immune system and suggest that this issue should be considered by mucosal immunologists and personnel at animal care facilities.

Solar corona/prominence seen through the White Light Coronograph

NASA Technical Reports Server (NTRS)

1974-01-01

The solar corona and a solar prominence as seen through the White Light Coronograph, Skylab Experiment S052, on January 17, 1974. This view was reproduced from a television transmission made by a TV camera aboard the Skylab space station in Earth orbit. The bright spot is a burn in the vidicon. The solar corona is the halo around the Sun which is normally visible only at the time of solar eclipse by the Moon. The Skylab coronography uses an externally-mounted disk system which occults the brilliant solar surface while allowing the fainter radiation of the corona to enter an annulus and be photographed. A mirror system allows either TV viewing of the corona or photographic recording of the image.

KSC-07pd0928

NASA Image and Video Library

2007-04-25

KENNEDY SPACE CENTER, FLA. -- In the Vehicle Assembly Building, workers check foam repairs on Atlantis' external tank. In late February, Atlantis' external tank received hail damage during a severe thunderstorm that passed through the Kennedy Space Center Launch Complex 39 area. The hail caused visible divots in the giant tank's foam insulation as well as minor surface damage to about 26 heat shield tiles on the shuttle's left wing. The launch now is targeted for June 8. Photo credit: NASA/Jack Pfaller

Hybrid Molecule-Nanocrystal Photon Upconversion Across the Visible and Near-Infrared

DTIC Science & Technology

2015-07-10

applications in solar energy, biological imaging , and data storage. In this Letter, CdSe and PbSe semiconductor nanocrystals are combined with molecular...Goldschmidt, J. C. Absolute Upconversion Quantum Yield of β-NaYF4 Doped with Er3+ and External Quantum Efficiency of Upconverter Solar Cell Devices...C. Peak External Photocurrent Quantum Efficiency Exceeding 100% via MEG in a Quantum Dot Solar Cell . Science 2011, 334, 1530−1533. (37) Choi, J.-H

A filterless, visible-blind, narrow-band, and near-infrared photodetector with a gain

NASA Astrophysics Data System (ADS)

Shen, Liang; Zhang, Yang; Bai, Yang; Zheng, Xiaopeng; Wang, Qi; Huang, Jinsong

2016-06-01

In many applications of near-infrared (NIR) light detection, a band-pass filter is needed to exclude the noise caused by visible light. Here, we demonstrate a filterless, visible-blind, narrow-band NIR photodetector with a full-width at half-maximum of <50 nm for the response spectrum. These devices have a thick (>4 μm) nanocomposite absorbing layers made of polymer-fullerene:lead sulfide (PbS) quantum dots (QDs). The PbS QDs yield a photoconductive gain due to their hole-trapping effect, which effectively enhances both the responsivity and the visible rejection ratio of the external quantum efficiency by >10 fold compared to those without PbS QDs. Encouragingly, the inclusion of the PbS QDs does not increase the device noise. We directly measured a noise equivalent power (NEP) of 6.1 pW cm-2 at 890 nm, and a large linear dynamic range (LDR) over 11 orders of magnitude. The highly sensitive visible-blind NIR narrow-band photodetectors may find applications in biomedical engineering.

Visible light guided manipulation of liquid wettability on photoresponsive surfaces

PubMed Central

Kwon, Gibum; Panchanathan, Divya; Mahmoudi, Seyed Reza; Gondal, Mohammed A.; McKinley, Gareth H.; Varanasi, Kripa K.

2017-01-01

Photoresponsive titania surfaces are of great interest due to their unique wettability change upon ultraviolet light illumination. However, their applications are often limited either by the inability to respond to visible light or the need for special treatment to recover the original wettability. Sensitizing TiO2 surfaces with visible light-absorbing materials has been utilized in photovoltaic applications. Here we demonstrate that a dye-sensitized TiO2 surface can selectively change the wettability towards contacting liquids upon visible light illumination due to a photo-induced voltage across the liquid and the underlying surface. The photo-induced wettability change of our surfaces enables external manipulation of liquid droplet motion upon illumination. We show demulsification of surfactant-stabilized brine-in-oil emulsions via coalescence of brine droplets on our dye-sensitized TiO2 surface upon visible light illumination. We anticipate that our surfaces will have a wide range of applications including microfluidic devices with customizable wettability, solar-driven oil–water clean-up and demulsification technologies. PMID:28440292

The Use of Magnetic Orientation as a Pinning Modality for Investigation of Photon-Magnon Interactions in Magnetic Nanoparticle Systems.

PubMed

Cuong, Giap Van; Su, Luong Van; Tue, Nguyen Anh; Khanh, Hoang Quoc; Tuan, Nguyen Anh

2018-06-01

In this work, an experimental setup to study the dependence of a visible-light transmission through a magnetic granular film on the magnetic field direction was presented. The results measured the transmission (T) of the visible light, with the wavelengths λ were in the range from 560 to 695 nm, by the magnetic nanogranular films Cox-(Al2O3)100-x system, with Co compositions are x = 10 ÷ 45 at.%, as a function of the magnetic field direction were reported. These investigations were carried out under an external magnetic field of H = 400 Oe, which directs to the normal of the sample surface by an angle varied in the range of φ = 0° ÷ 45°, to magnetize the magnetization direction of all the Co particles following this direction. Consequently, the angle φ between the magnetization direction with the incident-light direction, which sets as the optical axis of the system and always keeps fixedly to the normal of the sample surface, is established. The experimental results showed the different dependencies of T on the angle φ, the magnetic field H, the Co composition x, and the wavelength λ. These dependencies attributed to a behavior that relates to so-called photon-magnon interaction.

New biometric modalities using internal physical characteristics

NASA Astrophysics Data System (ADS)

Mortenson, Juliana (Brooks)

2010-04-01

Biometrics is described as the science of identifying people based on physical characteristics such as their fingerprints, facial features, hand geometry, iris patterns, palm prints, or speech recognition. Notably, all of these physical characteristics are visible or detectable from the exterior of the body. These external characteristics can be lifted, photographed, copied or recorded for unauthorized access to a biometric system. Individual humans are unique internally, however, just as they are unique externally. New biometric modalities have been developed which identify people based on their unique internal characteristics. For example, "BoneprintsTM" use acoustic fields to scan the unique bone density pattern of a thumb pressed on a small acoustic sensor. Thanks to advances in piezoelectric materials the acoustic sensor can be placed in virtually any device such as a steering wheel, door handle, or keyboard. Similarly, "Imp-PrintsTM" measure the electrical impedance patterns of a hand to identify or verify a person's identity. Small impedance sensors can be easily embedded in devices such as smart cards, handles, or wall mounts. These internal biometric modalities rely on physical characteristics which are not visible or photographable, providing an added level of security. In addition, both the acoustic and impedance methods can be combined with physiologic measurements such as acoustic Doppler or impedance plethysmography, respectively. Added verification that the biometric pattern came from a living person can be obtained. These new biometric modalities have the potential to allay user concerns over protection of privacy, while providing a higher level of security.*

KSC-07pd0927

NASA Image and Video Library

2007-04-25

KENNEDY SPACE CENTER, FLA. -- In the Vehicle Assembly Building, foam repairs on Atlantis' external tank include sanding and inspection, as seen here. In late February, Atlantis' external tank received hail damage during a severe thunderstorm that passed through the Kennedy Space Center Launch Complex 39 area. The hail caused visible divots in the giant tank's foam insulation as well as minor surface damage to about 26 heat shield tiles on the shuttle's left wing. The launch now is targeted for June 8. Photo credit: NASA/Jack Pfaller

KSC-07pd0929

NASA Image and Video Library

2007-04-25

KENNEDY SPACE CENTER, FLA. -- In the Vehicle Assembly Building, a worker carefully sands foam repairs on Atlantis' external tank. In late February, Atlantis' external tank received hail damage during a severe thunderstorm that passed through the Kennedy Space Center Launch Complex 39 area. The hail caused visible divots in the giant tank's foam insulation as well as minor surface damage to about 26 heat shield tiles on the shuttle's left wing. The launch now is targeted for June 8. Photo credit: NASA/Jack Pfaller

Rubber band as external assist device to provide simple grip for quadriplegic patients.

PubMed

Pham, H N; Noble, C N; Hentz, V R

1988-08-01

The rubber band as an external assist device provides an effective grip for the hand of high spinal cord injury quadriplegic patients. This technique can also be useful for preoperative patients who are undergoing physical and occupational therapy or to assess patients' needs for surgery. The rubber band as an adaptive device is preferred because of its availability, low visibility, and ease of application. We attempt to provide a more standardized method of the rubber band technique and to popularize it.

Direct endoscopic video registration for sinus surgery

NASA Astrophysics Data System (ADS)

Mirota, Daniel; Taylor, Russell H.; Ishii, Masaru; Hager, Gregory D.

2009-02-01

Advances in computer vision have made possible robust 3D reconstruction of monocular endoscopic video. These reconstructions accurately represent the visible anatomy and, once registered to pre-operative CT data, enable a navigation system to track directly through video eliminating the need for an external tracking system. Video registration provides the means for a direct interface between an endoscope and a navigation system and allows a shorter chain of rigid-body transformations to be used to solve the patient/navigation-system registration. To solve this registration step we propose a new 3D-3D registration algorithm based on Trimmed Iterative Closest Point (TrICP)1 and the z-buffer algorithm.2 The algorithm takes as input a 3D point cloud of relative scale with the origin at the camera center, an isosurface from the CT, and an initial guess of the scale and location. Our algorithm utilizes only the visible polygons of the isosurface from the current camera location during each iteration to minimize the search area of the target region and robustly reject outliers of the reconstruction. We present example registrations in the sinus passage applicable to both sinus surgery and transnasal surgery. To evaluate our algorithm's performance we compare it to registration via Optotrak and present closest distance point to surface error. We show our algorithm has a mean closest distance error of .2268mm.

Effectiveness evaluation of STOL transport operations

NASA Technical Reports Server (NTRS)

Hitt, E. F.; Bruckner, J. M. H.; Drago, V. J.; Brown, R. A.; Rea, F. G.; Porter, R. F.

1973-01-01

A short-takeoff and landing (STOL) systems simulation model has been developed and implemented in a computer code (known as STOL OPS) which permits evaluation of the operation of a STOL aircraft and its avionics in a commercial airline operating environment. STOL OPS concentrated on the avionics functions of navigation, guidance, control, communication, hazard aviodance, and systems management. External world factors influencing the operation of the STOL aircraft include each airport and its geometry, air traffic at each airport, air traffic control equipment and procedures, weather (including winds and visibility), and the flight path between each airport served by the route. The development of the STOL OPS program provides NASA a set of computer programs which can be used for detailed analysis of a STOL aircraft and its avionics and permit establishment of system requirements as a function of airline mission performance goals.

jsc2003e15407

NASA Image and Video Library

2000-01-09

JSC2003-E-15407 (9 Jan. 1990) --- A 35mm still camera located in the umbilical well of the Space Shuttle Columbia took this photograph of the external fuel tank (ET) after it was dropped from the launch stack as the shuttle headed for Earth-orbit on Jan. 9, 1990 for the STS-32 mission. Several large divots are visible near the forward ET/orbiter bipod and smaller divots are visible on the H2 tank acreage. The vertical streak and the horizontal bands were the results of repairs done prior to launch.

Topological insulator infrared pseudo-bolometer with polarization sensitivity

DOEpatents

Sharma, Peter Anand

2017-10-25

Topological insulators can be utilized in a new type of infrared photodetector that is intrinsically sensitive to the polarization of incident light and static magnetic fields. The detector isolates single topological insulator surfaces and allows light collection and exposure to static magnetic fields. The wavelength range of interest is between 750 nm and about 100 microns. This detector eliminates the need for external polarization selective optics. Polarization sensitive infrared photodetectors are useful for optoelectronics applications, such as light detection in environments with low visibility in the visible wavelength regime.

Predicting round window niche visibility via the facial recess using high-resolution computed tomography.

PubMed

Kashio, Akinori; Sakamoto, Takashi; Karino, Shotaro; Kakigi, Akinobu; Iwasaki, Shinichi; Yamasoba, Tatsuya

2015-01-01

To predict round window niche (RWN) visibility using high-resolution computed tomography (HRCT). Case series with chart review. Academic tertiary care center. We retrospectively reviewed 70 cochlear implant ears that underwent presurgical axial HRCT with a surgical video recorder. The visibility of the RWN was classified into three types: 17 as invisible or nearly invisible, 22 as partially visible, and 31 as fully visible. Next, we measured the following three radiologic parameters: 1) the angle of the external auditory canal (EAC) relative to the cochlear basal turn, 2) the width of the facial recess, and 3) the relative location of the facial nerve (FN) to the cochlear basal turn. These were compared with the RWN visibility. Subsequently, to predict the RWN visibility, a line was created parallel to the EAC line and along the anterior lateral FN. The location of the line relative to the round window membrane was compared with the RWN view. In cases that had poor RWN visibility, the angle of the posterior canal wall portion of the EAC relative to the cochlear basal turn was significantly smaller and the location of the FN to the cochlear basal turn was closer. The location of the prediction line to the round window membrane highly predicted the RWN view during the surgery. The RWN visibility and the preoperative HRCT findings showed a high correlation. Drawing the prediction line is a simple and useful way for preoperatively predicting the RWN visibility in cochlear implant surgery.

Luminescence upconversion under hydrostatic pressure in the 3d-metal systems Ti2+:NaCl and Ni2+:CsCdCl3

NASA Astrophysics Data System (ADS)

Wenger, Oliver S.; Salley, G. Mackay; Valiente, Rafael; Güdel, Hans U.

2002-06-01

We present a study of upconversion materials and processes under external hydrostatic pressure. The near-infrared to visible photon upconversion properties of Ti2+-doped NaCl and Ni2+-doped CsCdCl3 at 15 K are studied as a function of external hydrostatic pressure. It is found that in Ti2+:NaCl pressure can be used to switch on an efficient upconversion mechanism, which is inactive at ambient pressure, leading to an order-of-magnitude enhancement of the overall upconversion efficiency of this material. For Ni2+:CsCdCl3 it is demonstrated that upconversion luminescence excitation spectroscopy can be used to study the pressure dependence of excited state absorption transitions. The results demonstrate the ability to tune upconversion properties by altering the local crystal field of active ions, in addition to probing the pressure dependence of excited state absorption transitions via upconversion spectroscopy.

Towards a complete caracterisation of Ganymede's environnement

NASA Astrophysics Data System (ADS)

Cessateur, Gaël; Barthélémy, Mathieu; Lilensten, Jean; Dudok de Wit, Thierry; Kretzschmar, Matthieu; Mbemba Kabuiku, Lydie

2013-04-01

In the framework to the JUICE mission to the Jovian system, a complete picture of the interaction between Ganymede's atmosphere and external forcing is needed. This will definitely allow us to constrain instrument performances according to the mission objectives. The main source of information regarding the upper atmosphere is the non LTE UV-Visible-near IR emissions. Those emissions are both induce by the incident solar UV flux and particle precipitations. This work aims at characterizing the impact from those external forcing, and then at deriving some key physical parameters that are measurable by an orbiter, namely the oxygen red line at 630 nm or the resonant oxygen line at 130 nm for example. We will also present the 4S4J instrument, a proposed EUV radiometer, which will provides the solar local EUV flux, an invaluable parameter for the JUICE mission. Based on new technologies and a new design, only two passbands are considered for reconstructing the whole EUV spectrum.

5 CFR 831.642 - Marriage duration requirements.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 5 Administrative Personnel 2 2014-01-01 2014-01-01 false Marriage duration requirements. 831.642 Section 831.642 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT (CONTINUED) CIVIL SERVICE... infection of and through a visible wound sustained solely through violent, external, and accidental means...

5 CFR 831.642 - Marriage duration requirements.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 5 Administrative Personnel 2 2013-01-01 2013-01-01 false Marriage duration requirements. 831.642 Section 831.642 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT (CONTINUED) CIVIL SERVICE... infection of and through a visible wound sustained solely through violent, external, and accidental means...

5 CFR 831.642 - Marriage duration requirements.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 5 Administrative Personnel 2 2011-01-01 2011-01-01 false Marriage duration requirements. 831.642 Section 831.642 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT (CONTINUED) CIVIL SERVICE... infection of and through a visible wound sustained solely through violent, external, and accidental means...

5 CFR 831.642 - Marriage duration requirements.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 5 Administrative Personnel 2 2012-01-01 2012-01-01 false Marriage duration requirements. 831.642 Section 831.642 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT (CONTINUED) CIVIL SERVICE... infection of and through a visible wound sustained solely through violent, external, and accidental means...

Impact of Grain Shape and Multiple Black Carbon Internal Mixing on Snow Albedo: Parameterization and Radiative Effect Analysis

NASA Astrophysics Data System (ADS)

He, Cenlin; Liou, Kuo-Nan; Takano, Yoshi; Yang, Ping; Qi, Ling; Chen, Fei

2018-01-01

We quantify the effects of grain shape and multiple black carbon (BC)-snow internal mixing on snow albedo by explicitly resolving shape and mixing structures. Nonspherical snow grains tend to have higher albedos than spheres with the same effective sizes, while the albedo difference due to shape effects increases with grain size, with up to 0.013 and 0.055 for effective radii of 1,000 μm at visible and near-infrared bands, respectively. BC-snow internal mixing reduces snow albedo at wavelengths < 1.5 μm, with negligible effects at longer wavelengths. Nonspherical snow grains show less BC-induced albedo reductions than spheres with the same effective sizes by up to 0.06 at ultraviolet and visible bands. Compared with external mixing, internal mixing enhances snow albedo reduction by a factor of 1.2-2.0 at visible wavelengths depending on BC concentration and snow shape. The opposite effects on albedo reductions due to snow grain nonsphericity and BC-snow internal mixing point toward a careful investigation of these two factors simultaneously in climate modeling. We further develop parameterizations for snow albedo and its reduction by accounting for grain shape and BC-snow internal/external mixing. Combining the parameterizations with BC-in-snow measurements in China, North America, and the Arctic, we estimate that nonspherical snow grains reduce BC-induced albedo radiative effects by up to 50% compared with spherical grains. Moreover, BC-snow internal mixing enhances the albedo effects by up to 30% (130%) for spherical (nonspherical) grains relative to external mixing. The overall uncertainty induced by snow shape and BC-snow mixing state is about 21-32%.

Non-radiation induced signals in TL dosimetry.

PubMed

German, U; Weinstein, M

2002-01-01

One source of background signals, which are non-radiation related, is the reader system and it includes dark current, external contaminants and electronic spikes. These factors can induce signals equivalent to several hundredths of mSv. Mostly, the effects are minimised by proper design of the TLD reader, but some effects are dependent on proper operation of the system. The other main group of background signals originates in the TL crystal and is due to tribothermoluminescence, dirt, chemical reactions and stimulation by visible or UV light. These factors can have a significant contribution, equivalent to over several mSv, depending on whether the crystal is bare or protected by PTFE. Working in clean environments, monitoring continuously the glow curves and performing glow curve deconvolution are suggested to minimise non-radiation induced spurious signals.

Solar corona/prominence seen through the White Light Coronograph

NASA Image and Video Library

1974-01-17

S74-15697 (17 Jan. 1974) --- The solar corona and a solar prominence as seen through the White Light Coronograph, Skylab Experiment S052, on Jan. 17, 1974. This view was reproduced from a television transmission made by a TV camera aboard the Skylab space station in Earth orbit. The bright spot is a burn in the vidicon. The solar corona is the halo around the sun which is normally visible only at the time of solar eclipse by the moon. The Skylab coronography uses an externally-mounted disk system which occults the brilliant solar surface while allowing the fainter radiation of the corona to enter an annulus and be photographed. A mirror system allows either TV viewing of the corona or photographic recording of the image. Photo credit: NASA

Visible light alters yeast metabolic rhythms by inhibiting respiration.

PubMed

Robertson, James Brian; Davis, Chris R; Johnson, Carl Hirschie

2013-12-24

Exposure of cells to visible light in nature or in fluorescence microscopy often is considered to be relatively innocuous. However, using the yeast respiratory oscillation (YRO) as a sensitive measurement of metabolism, we find that non-UV visible light has a significant impact on yeast metabolism. Blue/green wavelengths of visible light shorten the period and dampen the amplitude of the YRO, which is an ultradian rhythm of cell metabolism and transcription. The wavelengths of light that have the greatest effect coincide with the peak absorption regions of cytochromes. Moreover, treating yeast with the electron transport inhibitor sodium azide has similar effects on the YRO as visible light. Because impairment of respiration by light would change several state variables believed to play vital roles in the YRO (e.g., oxygen tension and ATP levels), we tested oxygen's role in YRO stability and found that externally induced oxygen depletion can reset the phase of the oscillation, demonstrating that respiratory capacity plays a role in the oscillation's period and phase. Light-induced damage to the cytochromes also produces reactive oxygen species that up-regulate the oxidative stress response gene TRX2 that is involved in pathways that enable sustained growth in bright visible light. Therefore, visible light can modulate cellular rhythmicity and metabolism through unexpectedly photosensitive pathways.

29 CFR 1910.181 - Derricks.

Code of Federal Regulations, 2010 CFR

2010-07-01

..., working means the external load, in pounds, applied to the derrick, including the weight of load attaching... securely affixed where it is visible to personnel responsible for the safe operation of the equipment. The... of service, and environment, or as specifically indicated below. These inspections shall include the...

The changing phenomenology of drug death over the years.

PubMed

Bohnert, M; Hafezi, M; Pollak, S

2001-12-27

When inspecting the scene the circumstances under which a body is found and the findings on the body surface may give first clues to premortal drug abuse. Besides fresh and/or old injection marks tattoos, underweight and signs of physical neglect, especially after long-term abuse, are mentioned in literature. The incidence of such externally visible physical signs of drug abuse was systematically investigated in 100 consecutive drug deaths occurring from 1995 to 1997. Sixty-eight percent of the bodies were found in the apartments of the deceased or those of friends, 11% in public restrooms or the washrooms of restaurants. The so-called body dumping was seen in three cases. In 61% externally visible, fresh injection marks were found; on dissection of the subcutaneous veins, residues of previous injections were found in 95% of the cases. Tattoos were present in 63%. In 8% there was clear evidence of physical neglect. Eighty-six percent of the drug victims had a normal nutritional status.

Preparation of Cu2O modified TiO2 nanopowder and its application to the visible light photoelectrocatalytic reduction of CO2 to CH3OH

NASA Astrophysics Data System (ADS)

Li, Bin; Niu, Wenchao; Cheng, Yongwei; Gu, Junjie; Ning, Ping; Guan, Qingqing

2018-05-01

Cu2O/TiO2 nanopowders were prepared and used as thin film electrode raw materials for CO2 photoelectroreduction. Characterization results from XRD, TEM, UV-Vis and BET show that Cu2O/TiO2 composites have regular morphology, narrow band gap, excellent textural properties, and exhibits marked response of visible light. The photoelectrocatalytic results show that CO2 can be reduced to formaldehyde (i.e., intermediate) and finally methanol (i.e., end product). In addition, the CO2 photoelectroreduction pathway and the mechanism of photoelectrocatalysis are discussed. In summary, the work reports a potential method of CO2 reduction by visible-light photocatalysis without an external bias.

Flagellated Magnetotactic Bacteria as Controlled MRI-trackable Propulsion and Steering Systems for Medical Nanorobots Operating in the Human Microvasculature.

PubMed

Martel, Sylvain; Mohammadi, Mahmood; Felfoul, Ouajdi; Lu, Zhao; Pouponneau, Pierre

2009-04-01

Although nanorobots may play critical roles for many applications in the human body such as targeting tumoral lesions for therapeutic purposes, miniaturization of the power source with an effective onboard controllable propulsion and steering system have prevented the implementation of such mobile robots. Here, we show that the flagellated nanomotors combined with the nanometer-sized magnetosomes of a single Magnetotactic Bacterium (MTB) can be used as an effective integrated propulsion and steering system for devices such as nanorobots designed for targeting locations only accessible through the smallest capillaries in humans while being visible for tracking and monitoring purposes using modern medical imaging modalities such as Magnetic Resonance Imaging (MRI). Through directional and magnetic field intensities, the displacement speeds, directions, and behaviors of swarms of these bacterial actuators can be controlled from an external computer.

The design and evaluation of grazing incidence relay optics

NASA Technical Reports Server (NTRS)

Davis, John M.; Chase, R. C.; Silk, J. K.; Krieger, A. S.

1989-01-01

X-ray astronomy, both solar and celestial, has many needs for high spatial resolution observations which have to be performed with electronic detectors. If the resolution is not to be detector limited, plate scales in excess of 25 microns arc/sec, corresponding to focal lengths greater than 5 m, are required. In situations where the physical size is restricted, the problem can be solved by the use of grazing incidence relay optics. A system was developed which employs externally polished hyperboloid-hyperboloid surfaces to be used in conjunction with a Wolter-Schwarzschild primary. The secondary is located in front of the primary focus and provides a magnification of 4, while the system has a plate scale of 28 microns arc/sec and a length of 1.9 m. The design, tolerance specification, fabrication and performance at visible and X-ray wavelengths of this optical system are described.

DNA-assisted swarm control in a biomolecular motor system.

PubMed

Keya, Jakia Jannat; Suzuki, Ryuhei; Kabir, Arif Md Rashedul; Inoue, Daisuke; Asanuma, Hiroyuki; Sada, Kazuki; Hess, Henry; Kuzuya, Akinori; Kakugo, Akira

2018-01-31

In nature, swarming behavior has evolved repeatedly among motile organisms because it confers a variety of beneficial emergent properties. These include improved information gathering, protection from predators, and resource utilization. Some organisms, e.g., locusts, switch between solitary and swarm behavior in response to external stimuli. Aspects of swarming behavior have been demonstrated for motile supramolecular systems composed of biomolecular motors and cytoskeletal filaments, where cross-linkers induce large scale organization. The capabilities of such supramolecular systems may be further extended if the swarming behavior can be programmed and controlled. Here, we demonstrate that the swarming of DNA-functionalized microtubules (MTs) propelled by surface-adhered kinesin motors can be programmed and reversibly regulated by DNA signals. Emergent swarm behavior, such as translational and circular motion, can be selected by tuning the MT stiffness. Photoresponsive DNA containing azobenzene groups enables switching between solitary and swarm behavior in response to stimulation with visible or ultraviolet light.

Concatenated logic circuits based on a three-way DNA junction: a keypad-lock security system with visible readout and an automatic reset function.

PubMed

Chen, Junhua; Zhou, Shungui; Wen, Junlin

2015-01-07

Concatenated logic circuits operating as a biocomputing keypad-lock security system with an automatic reset function have been successfully constructed on the basis of toehold-mediated strand displacement and three-way-DNA-junction architecture. In comparison with previously reported keypad locks, the distinctive advantage of the proposed security system is that it can be reset and cycled spontaneously a large number of times without an external stimulus, thus making practical applications possible. By the use of a split-G-quadruplex DNAzyme as the signal reporter, the output of the keypad lock can be recognized readily by the naked eye. The "lock" is opened only when the inputs are introduced in an exact order. This requirement provides defense against illegal invasion to protect information at the molecular scale. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

An Overview of the Computational Physics and Methods Group at Los Alamos National Laboratory

DOE Office of Scientific and Technical Information (OSTI.GOV)

Baker, Randal Scott

CCS Division was formed to strengthen the visibility and impact of computer science and computational physics research on strategic directions for the Laboratory. Both computer science and computational science are now central to scientific discovery and innovation. They have become indispensable tools for all other scientific missions at the Laboratory. CCS Division forms a bridge between external partners and Laboratory programs, bringing new ideas and technologies to bear on today’s important problems and attracting high-quality technical staff members to the Laboratory. The Computational Physics and Methods Group CCS-2 conducts methods research and develops scientific software aimed at the latest andmore » emerging HPC systems.« less

Assessment of the hydrogen external tank pressure decay anomaly on Space Transportation System (STS) 51-L

NASA Technical Reports Server (NTRS)

Buckley, Theresa M.

1988-01-01

Following the Challenger tragedy, an evaluation of the integrated main propulsion system flight data revealed a premature decay in the hydrogen external tank ullage pressure. A reconstruction of predicted ullage pressure versus time indicated an inconsistency between predicted and measured ullage pressure starting at approximately 65.5 seconds into the flight and reaching a maximum value between 72 and 72.9 seconds. This discrepancy could have been caused by a hydrogen gas leak or by a liquied hydrogen leak that occurred either in the pressurization system or in the external tank. The corresponding leak rates over the time interval from 65.5 to 72.9 seconds were estimated to range from 0.28 kg/s (0.62 lbm/s) + or - 41 percent to between 0.43 and 0.51kg/s (0.94 and 1.12lbs/s) + or - 1 percent for a gas leak and from 72.9 kg/s (160.5 lbs/s) + or - 41 percent to between 111.6 and 133.2 kg/s (245.8 and 293.3 lbs/s) + or - 1 percent for a liquid leak. No speculation is made to ascertain whether the leak is liquid or gas, as this cannot be determined from the analysis performed. Four structural failures in the hydrogen external tank were considered to explain the leak rates. A break in the 5-cm (2 in) pressurization line, in the 13-cm (5 in) vent line, or in the 43-cm (17 in) feedline is not likely. A break in the 10-cm (4 in) recirculation line with a larger structural failure occurring in the 72 to 73-second time period, the time of the visibly identified premature pressure decay, does seem plausible and the most likely of the four modes considered. These modes are not all-inclusive and do not preclude the possibility of a leak elsewhere in the tank.

Photoinitiated Polymerization-Induced Self-Assembly (Photo-PISA): New Insights and Opportunities.

PubMed

Yeow, Jonathan; Boyer, Cyrille

2017-07-01

The polymerization-induced self-assembly (PISA) process is a useful synthetic tool for the efficient synthesis of polymeric nanoparticles of different morphologies. Recently, studies on visible light initiated PISA processes have offered a number of key research opportunities that are not readily accessible using traditional thermally initiated systems. For example, visible light mediated PISA (Photo-PISA) enables a high degree of control over the dispersion polymerization process by manipulation of the wavelength and intensity of incident light. In some cases, the final nanoparticle morphology of a single formulation can be modulated by simple manipulation of these externally controlled parameters. In addition, temporal (and in principle spatial) control over the Photo-PISA process can be achieved in most cases. Exploitation of the mild room temperature polymerizations conditions can enable the encapsulation of thermally sensitive therapeutics to occur without compromising the polymerization rate and their activities. Finally, the Photo-PISA process can enable further mechanistic insights into the morphological evolution of nanoparticle formation such as the effects of temperature on the self-assembly process. The purpose of this mini-review is therefore to examine some of these recent advances that have been made in Photo-PISA processes, particularly in light of the specific advantages that may exist in comparison with conventional thermally initiated systems.

Photoinitiated Polymerization‐Induced Self‐Assembly (Photo‐PISA): New Insights and Opportunities

PubMed Central

Yeow, Jonathan

2017-01-01

The polymerization‐induced self‐assembly (PISA) process is a useful synthetic tool for the efficient synthesis of polymeric nanoparticles of different morphologies. Recently, studies on visible light initiated PISA processes have offered a number of key research opportunities that are not readily accessible using traditional thermally initiated systems. For example, visible light mediated PISA (Photo‐PISA) enables a high degree of control over the dispersion polymerization process by manipulation of the wavelength and intensity of incident light. In some cases, the final nanoparticle morphology of a single formulation can be modulated by simple manipulation of these externally controlled parameters. In addition, temporal (and in principle spatial) control over the Photo‐PISA process can be achieved in most cases. Exploitation of the mild room temperature polymerizations conditions can enable the encapsulation of thermally sensitive therapeutics to occur without compromising the polymerization rate and their activities. Finally, the Photo‐PISA process can enable further mechanistic insights into the morphological evolution of nanoparticle formation such as the effects of temperature on the self‐assembly process. The purpose of this mini‐review is therefore to examine some of these recent advances that have been made in Photo‐PISA processes, particularly in light of the specific advantages that may exist in comparison with conventional thermally initiated systems. PMID:28725534

Avionic Pictorial Tunnel-/Pathway-/Highway-In-The-Sky Workshops

NASA Technical Reports Server (NTRS)

Parrish, Russell V. (Compiler)

2003-01-01

In 1994-96, Langley Research Center held a series of interactive workshops investigating highway-in-the-sky concepts, which enable precise flight path control. These workshops brought together government and industry display designers and pilots to discuss and fly various concepts in an iterative manner. The primary emphasis of the first workshops was the utility and usability of pathways and the pros and cons of various features available. The final workshops were focused on the specific applications to the eXternal Visibility System (XVS) of the NASA High-speed Research Program, which was concerned with replacement of the forward windows in a High-speed Civil Transport with electronic displays and high resolution video cameras to enable a "No-Droop" configuration. The primary concerns in the XVS application were the prevention of display clutter and obscuration of hazards, as the camera image was the primary means of traffic separation in clear visibility conditions. These concerns were not so prominent in the first workshops, which assumed a Synthetic Vision System application in which hazard locations are known and obscuration is handled easily. The resulting consensus concept has been used since in simulation and flight test activities of many Government programs. and other concepts have been influenced by the workshop discussions.

SU-E-I-23: Design and Clinical Application of External Marking Body in Multi- Mode Medical Images Registration and Fusion

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chen, Z; Gong, G

2014-06-01

Purpose: To design an external marking body (EMB) that could be visible on computed tomography (CT), magnetic resonance (MR), positron emission tomography (PET) and single-photon emission computed tomography (SPECT) images and to investigate the use of the EMB for multiple medical images registration and fusion in the clinic. Methods: We generated a solution containing paramagnetic metal ions and iodide ions (CT'MR dual-visible solution) that could be viewed on CT and MR images and multi-mode image visible solution (MIVS) that could be obtained by mixing radioactive nuclear material. A globular plastic theca (diameter: 3–6 mm) that mothball the MIVS and themore » EMB was brought by filling MIVS. The EMBs were fixed on the patient surface and CT, MR, PET and SPECT scans were obtained. The feasibility of clinical application and the display and registration error of EMB among different image modalities were investigated. Results: The dual-visible solution was highly dense on CT images (HU>700). A high signal was also found in all MR scanning (T1, T2, STIR and FLAIR) images, and the signal was higher than subcutaneous fat. EMB with radioactive nuclear material caused a radionuclide concentration area on PET and SPECT images, and the signal of EMB was similar to or higher than tumor signals. The theca with MIVS was clearly visible on all the images without artifact, and the shape was round or oval with a sharp edge. The maximum diameter display error was 0.3 ± 0.2mm on CT and MRI images, and 1.0 ± 0.3mm on PET and SPECT images. In addition, the registration accuracy of the theca center among multi-mode images was less than 1mm. Conclusion: The application of EMB with MIVS improves the registration and fusion accuracy of multi-mode medical images. Furthermore, it has the potential to ameliorate disease diagnosis and treatment outcome.« less

KAMEDIN: a telemedicine system for computer supported cooperative work and remote image analysis in radiology.

PubMed

Handels, H; Busch, C; Encarnação, J; Hahn, C; Kühn, V; Miehe, J; Pöppl, S I; Rinast, E; Rossmanith, C; Seibert, F; Will, A

1997-03-01

The software system KAMEDIN (Kooperatives Arbeiten und MEdizinische Diagnostik auf Innovativen Netzen) is a multimedia telemedicine system for exchange, cooperative diagnostics, and remote analysis of digital medical image data. It provides components for visualisation, processing, and synchronised audio-visual discussion of medical images. Techniques of computer supported cooperative work (CSCW) synchronise user interactions during a teleconference. Visibility of both local and remote cursor on the conference workstations facilitates telepointing and reinforces the conference partner's telepresence. Audio communication during teleconferences is supported by an integrated audio component. Furthermore, brain tissue segmentation with artificial neural networks can be performed on an external supercomputer as a remote image analysis procedure. KAMEDIN is designed as a low cost CSCW tool for ISDN based telecommunication. However it can be used on any TCP/IP supporting network. In a field test, KAMEDIN was installed in 15 clinics and medical departments to validate the systems' usability. The telemedicine system KAMEDIN has been developed, tested, and evaluated within a research project sponsored by German Telekom.

50 CFR 32.34 - Iowa.

Code of Federal Regulations, 2010 CFR

2010-10-01

... may possess only approved nontoxic shot while hunting for any allowed birds or other small game. C... regulations subject to the following conditions: 1. You may only possess approved nontoxic shot (see § 32.2(k... with one or more of the following articles of visible, external, solid-blaze-orange clothing: a hat...

External view of ISS

NASA Image and Video Library

2014-09-02

ISS040-E-123171 (2 Sept. 2014) --- A portion of the International Space Station’s Russian segment is pictured in this image photographed by an Expedition 40 crew member onboard the station. A portion of the "Georges Lemaitre" Automated Transfer Vehicle-5 (ATV-5) docked to the Zvezda Service Module is visible at right background.

External view of ISS

NASA Image and Video Library

2014-09-02

ISS040-E-123168 (2 Sept. 2014) --- A portion of the International Space Station’s Russian segment is pictured in this image photographed by an Expedition 40 crew member onboard the station. A portion of the "Georges Lemaitre" Automated Transfer Vehicle-5 (ATV-5) docked to the Zvezda Service Module is visible at right background.

Early warning of footpad dermatitis and hockburn in broiler chicken flocks using optical flow, bodyweight and water consumption.

PubMed

Dawkins, M S; Roberts, S J; Cain, R J; Nickson, T; Donnelly, C A

2017-05-20

Footpad dermatitis and hockburn are serious welfare and economic issues for the production of broiler (meat) chickens. The authors here describe the use of an inexpensive camera system that monitors the movements of broiler flocks throughout their lives and suggest that it is possible to predict, even in young birds, the cross-sectional prevalence at slaughter of footpad dermatitis and hockburn before external signs are visible. The skew and kurtosis calculated from the authors' camera-based optical flow system had considerably more power to predict these outcomes in the 50 flocks reported here than water consumption, bodyweight or mortality and therefore have the potential to inform improved flock management through giving farmers early warning of welfare issues. Further trials are underway to establish the generality of the results. British Veterinary Association.

Photo-controllable thermoelectric properties with reversibility and photo-thermoelectric effects of tungsten trioxide accompanied by its photochromic phenomenon

DOE Office of Scientific and Technical Information (OSTI.GOV)

Azuma, Chiori; Kawano, Takuto; Kakemoto, Hirofumi

2014-11-07

The addition of photo-controllable properties to tungsten trioxide (WO{sub 3}) is of interest for developing practical applications of WO{sub 3} as well as for interpreting such phenomena from scientific viewpoints. Here, a sputtered crystalline WO{sub 3} thin film generated thermoelectric power due to ultraviolet (UV) light-induced band-gap excitation and was accompanied by a photochromic reaction resulting from generating W{sup 5+} ions. The thermoelectric properties (electrical conductivity (σ) and Seebeck coefficient (S)) and coloration of WO{sub 3} could be reversibly switched by alternating the external stimulus between UV light irradiation and dark storage. After irradiating the film with UV light, σmore » increased, whereas the absolute value of S decreased, and the photochromic (coloration) reaction was detected. Notably, the opposite behavior was exhibited by WO{sub 3} after dark storage, and this reversible cycle could be repeated at least three times. Moreover, photo-thermoelectric effects (photo-conductive effect (photo-conductivity, σ{sub photo}) and photo-Seebeck effect (photo-Seebeck coefficient, S{sub photo})) were also detected in response to visible-light irradiation of the colored WO{sub 3} thin films. Under visible-light irradiation, σ{sub photo} and the absolute value of S{sub photo} increased and decreased, respectively. These effects are likely attributable to the excitation of electrons from the mid-gap visible light absorption band (W{sup 5+} state) to the conduction band of WO{sub 3}. Our findings demonstrate that the simultaneous, reversible switching of multiple properties of WO{sub 3} thin film is achieved by the application of an external stimulus and that this material exhibits photo-thermoelectric effects when irradiated with visible-light.« less

Implementation of Strategies to Improve the Reliability of III-Nitride Photodetectors towards the Realization of Visible and Solar-Blind Imaging Arrays

NASA Astrophysics Data System (ADS)

Bulmer, John J.

Ultraviolet (UV) radiation detectors are being heavily researched for applications in non-line-of-sight (NLOS) communication systems, flame monitoring, biological detection, and astronomical studies. These applications are currently being met by the use of Si-based photomultiplier tubes (PMTs), which are bulky, fragile, expensive and require the use of external filters to achieve true visible-blind and solar-blind operation. GaN and AlxGa1-xN avalanche photodiodes have been of great interest as a replacement for PMT technology. III-Nitride materials are radiation hard and have a wide, tunable bandgap that allows devices to operate in both visible and solar-blind regimes without the use of external filters. The high price and relative unavailability of bulk substrates demands heteroepitaxy of III-Nitride films on lattice-mismatched substrates, which leads to large dark current and premature breakdown in GaN and AlGaN avalanche photodiodes. While significant advances have been made towards the development of III-Nitride UV photodetectors using a variety of device designs, GaN-based avalanche photodiodes typically demonstrate poor device performance, low yield, and breakdown that results in permanent device damage. To address these challenges, a novel implantation technique was used to achieve edge termination and electric field redistribution at the contact edges in GaN and AlGaN p-i-n photodiode structures to enhance reliability. This process was successful at significantly reducing the levels of dark current over two orders of magnitude and resulted in improved device reliability. Further improvement in reliability of III-Nitride devices was also proposed and explored by a technique for isolation of electrically conductive structural defects. The large number of dislocations induced by the lattice and thermal mismatch with the substrate are known to be leakage current pathways and non-radiative recombination centers in III-Nitride films. This process selectively isolates conductive pathways in III-Nitrides using an electrochemical etch and novel foam passivation technique. Establishing improved photodiode performance and device reliability, 4x4 and 8x8 arrays of GaN p-i-n photodiodes were demonstrated and integrated with external circuitry to generate image patterns using 360nm illumination. This work represents significant progress towards the realization of reliable III-Nitride UV detectors arrays and future directions are proposed in order to demonstrate large-scale arrays for high-resolution ultraviolet imaging.

A COTS-MQS shipborne EO/IR imaging system

NASA Astrophysics Data System (ADS)

Hutchinson, Mark A.; Miller, John L.; Weaver, James

2005-05-01

The Sea Star SAFIRE is a commercially developed, off the shelf, military qualified system (COTS-MQS) consisting of a 640 by 480 InSb infrared imager, laser rangefinder and visible imager in a gyro-stabilized platform designed for shipborne applications. These applications include search and rescue, surveillance, fire control, fisheries patrol, harbor security, and own-vessel perimeter security and self protection. Particularly challenging considerations unique to shipborne systems include the demanding environment conditions, man-machine interfaces, and effects of atmospheric conditions on sensor performance. Shipborne environmental conditions requiring special attention include electromagnetic fields, as well as resistance to rain, ice and snow, shock, vibration, and salt. Features have been implemented to withstand exposure to water and high humidity; anti-ice/de-ice capability for exposure to snow and ice; wash/wipe of external windows; corrosion resistance for exposure to water and salt spray. A variety of system controller configurations provide man-machine interfaces suitable for operation on ships. EO sensor developments that address areas of haze penetration, glint, and scintillation will be presented.

KSC-07pd0886

NASA Image and Video Library

2007-04-13

KENNEDY SPACE CENTER, FLA. -- In the Vehicle Assembly Building, Mike Ravenscroft, with United Space Alliance, points to some of the foam repair done on the external tank of Space Shuttle Atlantis. Holes filled with foam are sanded flush with the adjacent area. In late February, Atlantis' external tank received hail damage during a severe thunderstorm that passed through the Kennedy Space Center Launch Complex 39 area. The hail caused visible divots in the giant tank's foam insulation as well as minor surface damage to about 26 heat shield tiles on the shuttle's left wing. The launch now is targeted for June 8. Photo credit: NASA/George Shelton

Cassini observations of Io's visible aurorae

USGS Publications Warehouse

Geissler, P.; McEwen, A.; Porco, C.; Strobel, D.; Saur, J.; Ajello, J.; West, R.

2004-01-01

More than 500 images of Io in eclipse were acquired by the Cassini spacecraft in late 2000 and early 2001 as it passed through the jovian system en route to Saturn (Porco et al., 2003, Science 299, 1541-1547). Io's bright equatorial glows were detected in Cassini's near-ultraviolet filters, supporting the interpretation that the visible emissions are predominantly due to molecular SO2. Detailed comparisons of laboratory SO2 spectra with the Cassini observations indicate that a mixture of gases contribute to the equatorial emissions. Potassium is suggested by new detections of the equatorial glows at near-infrared wavelengths from 730 to 800 nm. Neutral atomic oxygen and sodium are required to explain the brightness of the glows at visible wavelengths. The molecule S2 is postulated to emit most of the glow intensity in the wavelength interval from 390 to 500 nm. The locations of the visible emissions vary in response to the changing orientation of the external magnetic field, tracking the tangent points of the jovian magnetic field lines. Limb glows distinct from the equatorial emissions were observed at visible to near-infrared wavelengths from 500 to 850 nm, indicating that atomic O, Na, and K are distributed across Io's surface. Stratification of the atmosphere is demonstrated by differences in the altitudes of emissions at various wavelengths: SO2 emissions are confined to a region close to Io's surface, whereas neutral oxygen emissions are seen at altitudes that reach up to 900 km, or half the radius of the satellite. Pre-egress brightening demonstrates that light scattered into Jupiter's shadow by gases or aerosols in the giant planet's upper atmosphere contaminates images of Io taken within 13 minutes of entry into or emergence from Jupiter's umbra. Although partial atmospheric collapse is suggested by the longer timescale for post-ingress dimming than pre-egress brightening, Io's atmosphere must be substantially supported by volcanism to retain auroral emissions throughout the duration of eclipse. ?? 2004 Elsevier Inc. All rights reserved.

Architecture, development and implementation of a SWIR to visible integrated up-conversion imaging device

NASA Astrophysics Data System (ADS)

Sarusi, Gabby; Templeman, Tzvi; Hechster, Elad; Nissim, Nimrod; Vitenberg, Vladimir; Maman, Nitzan; Tal, Amir; Solodar, Assi; Makov, Guy; Abdulhalim, Ibrahim; Visoly-Fisher, Iris; Golan, Yuval

2016-04-01

A new concept of short wavelength infrared (SWIR) to visible upconversion integrated imaging device is proposed, modeled and some initial measured results are presented. The device is a hybrid inorganic-organic device that comprises six nano-metric scale sub-layers grown on n-type GaAs substrates. The first layer is a ~300nm thick PbSe nano-columnar absorber layer grown in (111) orientation to the substrate plan (100), with a diameter of 8- 10nm and therefore exhibit quantum confinement effects parallel to the substrate and bulk properties perpendicular to it. The advantage of this structure is the high oscillator strength and hence absorption to incoming SWIR photons while maintaining the high bulk mobility of photo-excited charges along the columns. The top of the PbSe absorber layer is coated with 20nm thick metal layer that serves as a dual sided mirror, as well as a potentially surface plasmon enhanced absorption in the PbSe nano-columns layer. The photo-excited charges (holes and electrons in opposite directions) are drifted under an external applied field to the OLED section (that is composed of a hole transport layer, an emission layer and an electron transport layer) where they recombine with injected electron from the transparent cathode and emit visible light through this cathode. Due to the high absorption and enhanced transport properties this architecture has the potential of high quantum efficiency, low cost and easy implementation in any optical system. As a bench-mark, alternative concept where InGaAs/InP heterojunction couple to liquid crystal optical spatial light modulator (OSLM) structure was built that shows a full upconversion to visible of 1550nm laser light.

The Physics of Intelligence

ERIC Educational Resources Information Center

Escultura, E. E.

2012-01-01

This paper explores the physics of intelligence and provides an overview of what happens in the brain when a person is engaged in mental activity that we classify under thought or intelligence. It traces the formation of a concept starting with reception of visible or detectable signals from the real world by and external to the sense organs,…

Two-Laser Interference Visible to the Naked Eye

ERIC Educational Resources Information Center

Kawalec, Tomasz; Bartoszek-Bober, Dobroslawa

2012-01-01

An experimental setup allowing the observation of two-laser interference by the naked eye is described. The key concept is the use of an electronic phase lock between two external cavity diode lasers. The experiment is suitable both for undergraduate and graduate students, mainly in atomic physics laboratories. It gives an opportunity for…

Sociogenomics of cooperation and conflict during colony foundation in the fire ant Solenopsis invicta

USDA-ARS?s Scientific Manuscript database

The genomic state of an individual results from the interplay between its internal condition and the external environment, which may include the social environment. The link between genes and social environment is clearly visible during the process of colony founding in the fire ant Solenopsis invic...

Practice as Prize: Citizenship Education in Two Primary Classrooms in Ireland

ERIC Educational Resources Information Center

Waldron, Fionnuala; Ruane, Brian; Oberman, Rowan

2014-01-01

While citizenship education forms part of the formal curriculum at primary level in Ireland, its inclusion as a strand unit of Social, Personal and Health Education, rather than as a discrete subject, tends to make it less visible. In practice, citizenship education is strongly influenced by external agencies and non-governmental organisations…

75 FR 4067 - Release of Draft Documents Related to the Review of the National Ambient Air Quality Standards...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-01-26

... for public comment a second draft assessment document titled, Quantitative Health Risk Assessment for... quantitative analyses that are being conducted as part of the review of the national ambient air quality...-Focused Visibility Assessment--Second External Review Draft and Quantitative Health Risk Assessment for...

16 CFR 1205.3 - Definitions.

Code of Federal Regulations, 2010 CFR

2010-01-01

...: (1) Blade means any rigid or semi-rigid device or means that is intended to cut grass during mowing operations and includes all blades of a multi-bladed mower. (2) Blade tip circle means the path described by the outermost point of the blade as it moves about its axis. (3) Crack means a visible external...

16 CFR 1205.3 - Definitions.

Code of Federal Regulations, 2012 CFR

2012-01-01

...: (1) Blade means any rigid or semi-rigid device or means that is intended to cut grass during mowing operations and includes all blades of a multi-bladed mower. (2) Blade tip circle means the path described by the outermost point of the blade as it moves about its axis. (3) Crack means a visible external...

16 CFR 1205.3 - Definitions.

Code of Federal Regulations, 2011 CFR

2011-01-01

...: (1) Blade means any rigid or semi-rigid device or means that is intended to cut grass during mowing operations and includes all blades of a multi-bladed mower. (2) Blade tip circle means the path described by the outermost point of the blade as it moves about its axis. (3) Crack means a visible external...

16 CFR § 1205.3 - Definitions.

Code of Federal Regulations, 2013 CFR

2013-01-01

...: (1) Blade means any rigid or semi-rigid device or means that is intended to cut grass during mowing operations and includes all blades of a multi-bladed mower. (2) Blade tip circle means the path described by the outermost point of the blade as it moves about its axis. (3) Crack means a visible external...

16 CFR 1205.3 - Definitions.

Code of Federal Regulations, 2014 CFR

2014-01-01

...: (1) Blade means any rigid or semi-rigid device or means that is intended to cut grass during mowing operations and includes all blades of a multi-bladed mower. (2) Blade tip circle means the path described by the outermost point of the blade as it moves about its axis. (3) Crack means a visible external...

Dual mode cobaloxime crystals: Acceleration of trans-cis photochromic reaction rate by photoisomerization

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sekine, Akiko, E-mail: asekine@chem.titech.ac.jp

2016-08-26

Our recent results on the photochromic reactions in dual mode cobaloxime crystals containing azobenzene derivatives are briefly reviewed. This work represents the first step toward the design of functional materials which can be controlled by two independent external stimuli, one by visible light and the other by UV radiation.

10 CFR 32.15 - Same: Quality assurance, prohibition of transfer, and labeling.

Code of Federal Regulations, 2014 CFR

2014-01-01

.... (2) For ionization chamber smoke detectors, label or mark each detector and its point-of-sale package so that: (i) Each detector has a durable, legible, readily visible label or marking on the external surface of the detector containing: (A) The following statement: “CONTAINS RADIOACTIVE MATERIAL”; (B) The...

10 CFR 32.15 - Same: Quality assurance, prohibition of transfer, and labeling.

Code of Federal Regulations, 2010 CFR

2010-01-01

... can be identified. (2) For ionization chamber smoke detectors, label or mark each detector and its point-of-sale package so that: (i) Each detector has a durable, legible, readily visible label or marking on the external surface of the detector containing: (A) The following statement: “CONTAINS...

10 CFR 32.15 - Same: Quality assurance, prohibition of transfer, and labeling.

Code of Federal Regulations, 2012 CFR

2012-01-01

... can be identified. (2) For ionization chamber smoke detectors, label or mark each detector and its point-of-sale package so that: (i) Each detector has a durable, legible, readily visible label or marking on the external surface of the detector containing: (A) The following statement: “CONTAINS...

10 CFR 32.15 - Same: Quality assurance, prohibition of transfer, and labeling.

Code of Federal Regulations, 2011 CFR

2011-01-01

... can be identified. (2) For ionization chamber smoke detectors, label or mark each detector and its point-of-sale package so that: (i) Each detector has a durable, legible, readily visible label or marking on the external surface of the detector containing: (A) The following statement: “CONTAINS...

10 CFR 32.15 - Same: Quality assurance, prohibition of transfer, and labeling.

Code of Federal Regulations, 2013 CFR

2013-01-01

.... (2) For ionization chamber smoke detectors, label or mark each detector and its point-of-sale package so that: (i) Each detector has a durable, legible, readily visible label or marking on the external surface of the detector containing: (A) The following statement: “CONTAINS RADIOACTIVE MATERIAL”; (B) The...

Assistance and Accountability in Externally Managed Schools: The Case of Edison Schools, Inc.

ERIC Educational Resources Information Center

Marsh, Julie; Hamilton, Laura; Gill, Brian

2008-01-01

Edison Schools, Inc., is the largest and most visible among a growing number of Education Management Organizations that have entered into contracts to manage public schools, including both conventional and charter schools. Edison's approach to managing schools is comprehensive, and it distinguishes itself from most other school improvement…

Thermal radiation scanning tunnelling microscopy

NASA Astrophysics Data System (ADS)

de Wilde, Yannick; Formanek, Florian; Carminati, Rémi; Gralak, Boris; Lemoine, Paul-Arthur; Joulain, Karl; Mulet, Jean-Philippe; Chen, Yong; Greffet, Jean-Jacques

2006-12-01

In standard near-field scanning optical microscopy (NSOM), a subwavelength probe acts as an optical `stethoscope' to map the near field produced at the sample surface by external illumination. This technique has been applied using visible, infrared, terahertz and gigahertz radiation to illuminate the sample, providing a resolution well beyond the diffraction limit. NSOM is well suited to study surface waves such as surface plasmons or surface-phonon polaritons. Using an aperture NSOM with visible laser illumination, a near-field interference pattern around a corral structure has been observed, whose features were similar to the scanning tunnelling microscope image of the electronic waves in a quantum corral. Here we describe an infrared NSOM that operates without any external illumination: it is a near-field analogue of a night-vision camera, making use of the thermal infrared evanescent fields emitted by the surface, and behaves as an optical scanning tunnelling microscope. We therefore term this instrument a `thermal radiation scanning tunnelling microscope' (TRSTM). We show the first TRSTM images of thermally excited surface plasmons, and demonstrate spatial coherence effects in near-field thermal emission.

Low-cost, digital lock-in module with external reference for coating glass transmission/reflection spectrophotometer

NASA Astrophysics Data System (ADS)

Alonso, R.; Villuendas, F.; Borja, J.; Barragán, L. A.; Salinas, I.

2003-05-01

A versatile, low-cost, digital signal processor (DSP) based lock-in module with external reference is described. This module is used to implement an industrial spectrophotometer for measuring spectral transmission and reflection of automotive and architectonic coating glasses over the ultraviolet, visible and near-infrared wavelength range. The light beams are modulated with an optical chopper. A digital phase-locked loop (DPLL) is used to lock the lock-in to the chop frequency. The lock-in rejects the ambient radiation and permits the spectrophotometer to work in the presence of ambient light. The algorithm that implements the dual lock-in and the DPLL in the DSP56002 evaluation module from Motorola is described. The use of a DSP allows implementation of the lock-in and DPLL by software, which gives flexibility and programmability to the system. Lock-in module cost, under 300 euro, is an important parameter taking into account that two modules are used in the system. Besides, the algorithms implemented in this DSP can be directly implemented in the latest DSP generations. The DPLL performance and the spectrophotometer are characterized. Capture and lock DPLL ranges have been measured and checked to be greater than the chop frequency drifts. The lock-in measured frequency response shows that the lock-in performs as theoretically predicted.

Tailored surface-enhanced Raman nanopillar arrays fabricated by laser-assisted replication for biomolecular detection using organic semiconductor lasers.

PubMed

Liu, Xin; Lebedkin, Sergei; Besser, Heino; Pfleging, Wilhelm; Prinz, Stephan; Wissmann, Markus; Schwab, Patrick M; Nazarenko, Irina; Guttmann, Markus; Kappes, Manfred M; Lemmer, Uli

2015-01-27

Organic semiconductor distributed feedback (DFB) lasers are of interest as external or chip-integrated excitation sources in the visible spectral range for miniaturized Raman-on-chip biomolecular detection systems. However, the inherently limited excitation power of such lasers as well as oftentimes low analyte concentrations requires efficient Raman detection schemes. We present an approach using surface-enhanced Raman scattering (SERS) substrates, which has the potential to significantly improve the sensitivity of on-chip Raman detection systems. Instead of lithographically fabricated Au/Ag-coated periodic nanostructures on Si/SiO2 wafers, which can provide large SERS enhancements but are expensive and time-consuming to fabricate, we use low-cost and large-area SERS substrates made via laser-assisted nanoreplication. These substrates comprise gold-coated cyclic olefin copolymer (COC) nanopillar arrays, which show an estimated SERS enhancement factor of up to ∼ 10(7). The effect of the nanopillar diameter (60-260 nm) and interpillar spacing (10-190 nm) on the local electromagnetic field enhancement is studied by finite-difference-time-domain (FDTD) modeling. The favorable SERS detection capability of this setup is verified by using rhodamine 6G and adenosine as analytes and an organic semiconductor DFB laser with an emission wavelength of 631.4 nm as the external fiber-coupled excitation source.

Taxonomic description and 3D modelling of a new species of myzostomid (Annelida, Myzostomida) associated with black corals from Madagascar.

PubMed

Terrana, Lucas; Eeckhaut, Igor

2017-03-19

Eenymeenymyzostoma nigrocorallium n. sp. is the first species of myzostomid worm associated with black corals to be described. Endoparasitic specimens of E. nigrocorallium were found associated with three species of antipatharians on the Great Reef of Toliara. Individuals inhabit the gastrovascular ducts of their hosts and evidence of infestation is, most of the time, not visible externally. Phylogenetic analyses based on 18S rDNA, 16S rDNA and COI data indicate a close relation to Eenymeenymyzostoma cirripedium, the only other species of the genus. The morphology of E. nigrocorallium is very unusual compared to that of the more conventional E. cirripedium. The new species has five pairs of extremely reduced parapodia located on the body margin and no introvert, cirri or lateral organs. Individuals are hermaphroditic, with the male and female gonads both being located dorsally in the trunk. It also has a highly developed parenchymo-muscular layer on the ventral side, and the digestive system lies in the middle part of the trunk. A three-dimensional digital model of this worm's body plan has been constructed whereby the external morphology and in toto views of the observed organ systems (nervous, digestive and reproductive) can be viewed on-screen: http://doi.org/10.13140/RG.2.2.17911.21923.

A Post-synthetic Modification of II–VI Nanoparticles to Create Tb3+ and Eu3+ Luminophores

PubMed Central

Mukherjee, Prasun; Sloan, Robin F.; Shade, Chad M.; Waldeck, David H.; Petoud, Stéphane

2013-01-01

We describe a novel method for creating luminescent lanthanide-containing nanoparticles in which the lanthanide cations are sensitized by the semiconductor nanoparticle’s electronic excitation. In contrast to previous strategies, this new approach creates such materials by addition of external salt to a solution of fully formed nanoparticles. We demonstrate this post-synthetic modification for the lanthanide luminescence sensitization of two visible emitting lanthanides (Ln), Tb3+ and Eu3+ ions, through ZnS nanoparticles in which the cations were added post-synthetically as external Ln(NO3)3·xH2O salt to solutions of ZnS nanoparticles. The post-synthetically treated ZnS nanoparticle systems display Tb3+ and Eu3+ luminescence intensities that are comparable to those of doped Zn(Ln)S nanoparticles, which we reported previously (J. Phys. Chem. A, 2011, 115, 4031–4041). A comparison with the synthetically doped systems is used to contrast the spatial distribution of the lanthanide ions, bulk versus surface localized. The post-synthetic strategy described in this work is fundamentally different from the synthetic incorporation (doping) approach and offers a rapid and less synthetically demanding protocol for Tb3+:ZnS and Eu3+:ZnS luminophores, thereby facilitating their use in a broad range of applications. PMID:23997842

Pbte Nanostructures for Spin Filtering and Detecting

NASA Astrophysics Data System (ADS)

Grabecki, G.

2005-08-01

An uniqueness of lead telluride PbTe relies on combination of excellent semiconducting properties, like high electron mobility and tunable carrier concentration, with paraelectric behavior leading to huge dielectric constant at low temperatures. The present article is a review of our experimental works performed on PbTe nanostructures. The main result is observation of one-dimensional quantization of the electron motion at much impure conditions than in any other system studied so far. We explain this in terms of dielectric screening of Coulomb potentials produced by charged defects. Furthermore, in an external magnetic field, the conductance quantization steps show very pronounced spin splitting, already visible at several kilogauss. This indicates that PbTe nanostructures have a potential as local spin filtering devices.

Nanofibrillated Cellulose-Assisted Synthesis of Fiber-Like ZnO-ZnFe2O4 Composites with Enhanced Visible-Light-Driven Photocatalytic Activity

NASA Astrophysics Data System (ADS)

Cai, Aijun; Guo, Aiying; Du, Liqiang; Chang, Yongfang; Wang, Xiuping

2018-05-01

In this article, fiber-like ZnO-ZnFe2O4 composites are obtained by using nanofibrillated cellulose as a biotemplate. The as-prepared composites exhibit strong absorbance in the visible-light region. The ZnO-ZnFe2O4 composites exhibit a similar bandgap (1.88 eV) compared with the ZnFe2O4 (1.85 eV). The ZnO-ZnFe2O4 composites can be easily collected by an external magnet, which contributes to improving the utilization efficiency of the photocatalysts. The photocatalytic activity of the ZnO-ZnFe2O4 catalysts was evaluated by photodegrading rhodamine B (RhB) under visible-light irradiation. Compared with ZnO and ZnFe2O4, the ZnO-ZnFe2O4 catalysts show higher photocatalytic activity due to the efficient electron-hole separation.

Evaluation of growth disturbances of Picea abies (L.) Karst. to disturbances caused by landslide movements

NASA Astrophysics Data System (ADS)

Šilhán, Karel

2017-01-01

Dendrogeomorphic methods are frequently used in landslide analyses. Although methods of landslide dating based on tree rings are well developed, they still indicated many questions. The aim of this study was to evaluate the frequently used theoretical scheme based on the event-response relationship. Seventy-four individuals of Norway spruce (Picea abies (L.) Karst.) exhibiting visible external disturbance, were sampled on the Girová landslide (the largest historical flow-like landslide in the Czech Republic). This landslide reactivated in May 2010, and post-landslide tree growth responses were studied in detail. These growth responses were compared with the intensity and occurrence of visible external tree disturbance: tilted stems, damaged root systems, and decapitation. Twenty-nine trees (39.2%) died within one to four years following the 2010 landslide movement. The trees that died following the landslide movement were significantly younger and displayed significantly greater stem tilting than the live trees. Abrupt growth suppression was a more-frequent response among the dead trees, whereas growth release dominated among the live trees. Only two trees (2.7%) created no reaction wood in response to the landslide movement. Forty-four percent of the trees started to produce reaction wood structure after a delay, which generally spanned one year. Some eccentric growth was evident in the tree rings of the landslide year and was significant in the first years following the landslide movement. Missing rings were observed only on the upper sides of the stems, and no false tree rings were observed. The results confirm the general validity of event-response relationship, nevertheless this study points out the limitations and uncertainties of this generally accepted working scheme.

Synthesis of visibility detection systems.

DOT National Transportation Integrated Search

2012-10-01

Visibility is a critical component to the task of driving on all types of roads. The visibility detection and warning systems provide real-time, automated detection as well as appropriate responses to counteract reduced visibility conditions due to f...

Facile fabrication of an efficient BiVO4 thin film electrode for water splitting under visible light irradiation.

PubMed

Jia, Qingxin; Iwashina, Katsuya; Kudo, Akihiko

2012-07-17

An efficient BiVO(4) thin film electrode for overall water splitting was prepared by dipping an F-doped SnO(2) (FTO) substrate electrode in an aqueous nitric acid solution of Bi(NO(3))(3) and NH(4)VO(3), and subsequently calcining it. X-ray diffraction of the BiVO(4) thin film revealed that a photocatalytically active phase of scheelite-monoclinic BiVO(4) was obtained. Scanning electron microscopy images showed that the surface of an FTO substrate was uniformly coated with the BiVO(4) film with 300-400 nm of the thickness. The BiVO(4) thin film electrode gave an excellent anodic photocurrent with 73% of an IPCE at 420 nm at 1.0 V vs. Ag/AgCl. Modification with CoO on the BiVO(4) electrode improved the photoelectrochemical property. A photoelectrochemical cell consisting of the BiVO(4) thin film electrode with and without CoO, and a Pt counter electrode was constructed for water splitting under visible light irradiation and simulated sunlight irradiation. Photocurrent due to water splitting to form H(2) and O(2) was confirmed with applying an external bias smaller than 1.23 V that is a theoretical voltage for electrolysis of water. Water splitting without applying external bias under visible light irradiation was demonstrated using a SrTiO(3)Rh photocathode and the BiVO(4) photoanode.

Enhancement of external quantum efficiency and quality of heterojunction white LEDs by varying the size of ZnO nanorods.

PubMed

Bano, N; Hussain, I; Sawaf, S; Alshammari, Abeer; Saleemi, F

2017-06-16

The size of ZnO nanorods (NRs) plays an important role in tuning the external quantum efficiency (EQE) and quality of light generated by white light emitting diodes (LEDs). In this work, we report on the enhancement of EQE and the quality of ZnO NR-based hetrojunction white LEDs fabricated on a p-GaN substrate using a low temperature solution method. Cathodoluminescence spectra demonstrate that ultraviolet (UV) emission decreases and visible deep band emission increases with an increase in the length of the ZnO NRs. The UV emission could be internally reabsorbed by the ZnO NR excitation, thus enhancing the emission intensity of the visible deep band. Photocurrent measurements validated the fact that the EQE depends on the size of ZnO NRs, increasing by 87% with an increase in the length of the ZnO NRs. Furthermore, the quality of white light was measured and clearly indicated an increase in the color rendering indices of the LEDs with an increase in the length of the ZnO NRs, confirming that the quality of light generated by LEDs can be tuned by varying the length of the ZnO NRs. These results suggest that the EQE and visible deep band emission from n-ZnONRs/p-GaN heterojunction LEDs can be effectively controlled by adjusting the length of the ZnO NRs, which can be useful for realizing tunable white LEDs.

Enhancement of external quantum efficiency and quality of heterojunction white LEDs by varying the size of ZnO nanorods

NASA Astrophysics Data System (ADS)

Bano, N.; Hussain, I.; Sawaf, S.; Alshammari, Abeer; Saleemi, F.

2017-06-01

The size of ZnO nanorods (NRs) plays an important role in tuning the external quantum efficiency (EQE) and quality of light generated by white light emitting diodes (LEDs). In this work, we report on the enhancement of EQE and the quality of ZnO NR-based hetrojunction white LEDs fabricated on a p-GaN substrate using a low temperature solution method. Cathodoluminescence spectra demonstrate that ultraviolet (UV) emission decreases and visible deep band emission increases with an increase in the length of the ZnO NRs. The UV emission could be internally reabsorbed by the ZnO NR excitation, thus enhancing the emission intensity of the visible deep band. Photocurrent measurements validated the fact that the EQE depends on the size of ZnO NRs, increasing by 87% with an increase in the length of the ZnO NRs. Furthermore, the quality of white light was measured and clearly indicated an increase in the color rendering indices of the LEDs with an increase in the length of the ZnO NRs, confirming that the quality of light generated by LEDs can be tuned by varying the length of the ZnO NRs. These results suggest that the EQE and visible deep band emission from n-ZnONRs/p-GaN heterojunction LEDs can be effectively controlled by adjusting the length of the ZnO NRs, which can be useful for realizing tunable white LEDs.

Quantification of the memory effect of steady-state currents from interaction-induced transport in quantum systems

NASA Astrophysics Data System (ADS)

Lai, Chen-Yen; Chien, Chih-Chun

2017-09-01

Dynamics of a system in general depends on its initial state and how the system is driven, but in many-body systems the memory is usually averaged out during evolution. Here, interacting quantum systems without external relaxations are shown to retain long-time memory effects in steady states. To identify memory effects, we first show quasi-steady-state currents form in finite, isolated Bose- and Fermi-Hubbard models driven by interaction imbalance and they become steady-state currents in the thermodynamic limit. By comparing the steady-state currents from different initial states or ramping rates of the imbalance, long-time memory effects can be quantified. While the memory effects of initial states are more ubiquitous, the memory effects of switching protocols are mostly visible in interaction-induced transport in lattices. Our simulations suggest that the systems enter a regime governed by a generalized Fick's law and memory effects lead to initial-state-dependent diffusion coefficients. We also identify conditions for enhancing memory effects and discuss possible experimental implications.

Visibility and coping with minority stress: a gender-specific analysis among lesbians, gay men, and bisexuals in Flanders.

PubMed

Dewaele, Alexis; Van Houtte, Mieke; Vincke, John

2014-11-01

The role of visibility management strategies, as an extended measure of outness related to sexual orientation, has been rarely studied with the aim of explaining the experience of external stressors (i.e., experiences of everyday discrimination and perceived sanctioning of cross-gender behavior) and internal stressors (i.e., internalized homonegativity and general mental distress). In this study, we examined gender differences within these relationships. A non-representative sample of 2,378 lesbians, gay men, and bisexuals was recruited. We found that lesbian and bisexual women scored significantly higher on perceived cross-gender sanctioning and general mental distress compared to gay and bisexual men. Multivariate analysis showed that visibility management was significantly related to the experience of internalized homonegativity in both men and women. Visibility management mediated the relationship between experiences of every day discrimination on the one hand and internalized homonegativity and general mental distress on the other. Finally, we found that compared to gay and bisexual men, lesbian and bisexual women who maintained relatively closed visibility management strategies, reported lower scores on internalized homonegativity but higher scores on general mental distress. We found fewer gender differences related to visibility management than expected and those that we did find were relatively small. Flemish lesbian and bisexual women and gay and bisexual men appear to more alike than different.

A Fast Visible Camera Divertor-Imaging Diagnostic on DIII-D

DOE Office of Scientific and Technical Information (OSTI.GOV)

Roquemore, A; Maingi, R; Lasnier, C

2007-06-19

In recent campaigns, the Photron Ultima SE fast framing camera has proven to be a powerful diagnostic when applied to imaging divertor phenomena on the National Spherical Torus Experiment (NSTX). Active areas of NSTX divertor research addressed with the fast camera include identification of types of EDGE Localized Modes (ELMs)[1], dust migration, impurity behavior and a number of phenomena related to turbulence. To compare such edge and divertor phenomena in low and high aspect ratio plasmas, a multi-institutional collaboration was developed for fast visible imaging on NSTX and DIII-D. More specifically, the collaboration was proposed to compare the NSTX smallmore » type V ELM regime [2] and the residual ELMs observed during Type I ELM suppression with external magnetic perturbations on DIII-D[3]. As part of the collaboration effort, the Photron camera was installed recently on DIII-D with a tangential view similar to the view implemented on NSTX, enabling a direct comparison between the two machines. The rapid implementation was facilitated by utilization of the existing optics that coupled the visible spectral output from the divertor vacuum ultraviolet UVTV system, which has a view similar to the view developed for the divertor tangential TV camera [4]. A remote controlled filter wheel was implemented, as was the radiation shield required for the DIII-D installation. The installation and initial operation of the camera are described in this paper, and the first images from the DIII-D divertor are presented.« less

Reflex cardioventilatory responses to hypoxia in the flathead gray mullet (Mugil cephalus) and their behavioral modulation by perceived threat of predation and water turbidity.

PubMed

Shingles, A; McKenzie, D J; Claireaux, G; Domenici, P

2005-01-01

In hypoxia, gray mullet surface to ventilate well-oxygenated water in contact with air, an adaptive response known as aquatic surface respiration (ASR). Reflex control of ASR and its behavioral modulation by perceived threat of aerial predation and turbid water were studied on mullet in a partly sheltered aquarium with free surface access. Injections of sodium cyanide (NaCN) into either the bloodstream (internal) or ventilatory water stream (external) revealed that ASR, hypoxic bradycardia, and branchial hyperventilation were stimulated by chemoreceptors sensitive to both systemic and water O2 levels. Sight of a model avian predator elicited bradycardia and hypoventilation, a fear response that inhibited reflex hyperventilation following external NaCN. The time lag to initiation of ASR following NaCN increased, but response intensity (number of events, time at the surface) was unchanged. Mullet, however, modified their behavior to surface under shelter or near the aquarium edges. Turbid water abolished the fear response and effects of the predator on gill ventilation and timing of ASR following external NaCN, presumably because of reduced visibility. However, in turbidity, mullet consistently performed ASR under shelter or near the aquarium edges. These adaptive modulations of ASR behavior would allow mullet to retain advantages of the chemoreflex when threatened by avian predators or when unable to perceive potential threats in turbidity.

Spatial walk-off compensated beta-barium borate stack for efficient deep-UV generation

NASA Astrophysics Data System (ADS)

Li, Da; Lee, Huai-Chuan; Meissner, Stephanie K.; Meissner, Helmuth E.

2018-02-01

Beta-Barium Borate (β-BBO) crystal is commonly used in nonlinear frequency conversion from visible to deep ultraviolet (DUV). However, in a single crystal BBO, its large spatial walk-off effect will reduce spatial overlap of ordinary and extraordinary beam, and thus degrade the conversion efficiency. To overcome the restrictions in current DUV conversion systems, Onyx applies adhesive-free bonding technique to replace the single crystal BBO with a spatial Walk-off Compensated (WOC) BBO stack, which is capable of correcting the spatial walk-off while retaining a constant nonlinear coefficient in the adjacent bonding layers. As a result, the β-BBO stack will provide good beam quality, high conversion efficiency, and broader acceptance angle and spectral linewidth, when compared with a single crystal of BBO. In this work, we report on performance of a spatial walk-off compensated β-BBO stack with adhesive-free bonding technique, for efficiently converting from the visible to DUV range. The physics behind the WOC BBO stack are demonstrated, followed by simulation of DUV conversion efficiency in an external resonance cavity. We also demonstrate experimentally the beam quality improvement in a 4-layer WOC BBO stack over a single BBO crystal.

[Measurement of soil organic matter and available K based on SPA-LS-SVM].

PubMed

Zhang, Hai-Liang; Liu, Xue-Mei; He, Yong

2014-05-01

Visible and short wave infrared spectroscopy (Vis/SW-NIRS) was investigated in the present study for measurement of soil organic matter (OM) and available potassium (K). Four types of pretreatments including smoothing, SNV, MSC and SG smoothing+first derivative were adopted to eliminate the system noises and external disturbances. Then partial least squares regression (PLSR) and least squares-support vector machine (LS-SVM) models were implemented for calibration models. The LS-SVM model was built by using characteristic wavelength based on successive projections algorithm (SPA). Simultaneously, the performance of LSSVM models was compared with PLSR models. The results indicated that LS-SVM models using characteristic wavelength as inputs based on SPA outperformed PLSR models. The optimal SPA-LS-SVM models were achieved, and the correlation coefficient (r), and RMSEP were 0. 860 2 and 2. 98 for OM and 0. 730 5 and 15. 78 for K, respectively. The results indicated that visible and short wave near infrared spectroscopy (Vis/SW-NIRS) (325 approximately 1 075 nm) combined with LS-SVM based on SPA could be utilized as a precision method for the determination of soil properties.

Doomed to Be Entrepreneurial: Institutional Transformation or Institutional Lock-Ins of "New" Universities?

ERIC Educational Resources Information Center

Stensaker, Bjørn; Benner, Mats

2013-01-01

Universities worldwide are facing enormous strains as a result of increased external expectations where global visibility should be mixed with local and regional utility. In debates on the future of higher education, becoming an entrepreneurial university has been highlighted as a novel--although perhaps a more hybrid--way to deal with this…

A Sociological Approach to Institutional Communication: The Public Image in Organizational Administration in Education

ERIC Educational Resources Information Center

Serpa, Sandro

2016-01-01

Acknowledging that the external context visibly affects any organization, this investigation seeks to constitute a specific contribution to the study of the importance of public image in organizational administration. To that end, a collection and documentary analysis of news stories from the newspaper "O Fayalense on the Asylum for the…

Use of Precast Concrete Walls for Blast Protection of Steel Stud Construction Preprint

DTIC Science & Technology

2007-11-01

Side Elevation Front Elevation Front Elevation Side Elevation a) Sandwich Wall b) Solid Wall I I---6’-10" " 11.. Exterior Face - Form finish 2------C...damage to the interior drywall was visible. The instnunentation consisted of three external reflected pressure gages at the front face of the test

Magnetically separable {gamma}-Fe{sub 2}O{sub 3}-SiO{sub 2}-Ce-doped TiO{sub 2} core-shell nanocomposites: Fabrication and visible-light-driven photocatalytic activity

DOE Office of Scientific and Technical Information (OSTI.GOV)

He, Minqiang, E-mail: jbmwgkc@126.com; Li, Di; Jiang, Deli

2012-08-15

Novel visible-light-induced {gamma}-Fe{sub 2}O{sub 3}-SiO{sub 2}-Ce-doped-TiO{sub 2} core-shell nanocomposite photocatalysts capable of magnetic separation have been synthesized by a facile sol-gel and after-annealing process. The as-obtained core-shell nanocomposite is composed of a central {gamma}-Fe{sub 2}O{sub 3} core with a strong response to external fields, an interlayer of SiO{sub 2}, and an outer layer of Ce-doped TiO{sub 2} nanocrystals. UV-vis spectra analysis indicates that Ce doping in the compound results in a red-shift of the absorption edge, thus offering increased visible light absorption. We show that such a {gamma}-Fe{sub 2}O{sub 3}-SiO{sub 2}-Ce-doped-TiO{sub 2} core-shell nanocomposite with appreciated Ce doping amount exhibitsmore » much higher visible-light photocatalytic activity than bare TiO{sub 2} and undoped {gamma}-Fe{sub 2}O{sub 3}-SiO{sub 2}-TiO{sub 2} core-shell nanocomposite toward the degradation of rhodamine B (RhB). Moreover, the {gamma}-Fe{sub 2}O{sub 3}-SiO{sub 2}-Ce-doped-TiO{sub 2} core-shell nanocomposite photocatalysts could be easily separated and reused from the treated water under application of an external magnetic field. - Graphical abstract: Novel {gamma}-Fe{sub 2}O{sub 3}-SiO{sub 2}-Ce-doped-TiO{sub 2} core/shell nanocomposite photocatalysts with enhanced photocatalytic activity and fast magnetic separability were prepared. Highlights: Black-Right-Pointing-Pointer Novel {gamma}-Fe{sub 2}O{sub 3}-SiO{sub 2}-Ce-doped TiO{sub 2} core/shell composite photocatalysts were prepared. Black-Right-Pointing-Pointer The resulting core/shell composite show high visible light photocatalytic activity. Black-Right-Pointing-Pointer The nanocomposite photocatalysts can be easily recycled with excellent durability.« less

Filler bar heating due to stepped tiles in the shuttle orbiter thermal protection system

NASA Technical Reports Server (NTRS)

Petley, D. H.; Smith, D. M.; Edwards, C. L. W.; Patten, A. B.; Hamilton, H. H., II

1983-01-01

An analytical study was performed to investigate the excessive heating in the tile to tile gaps of the Shuttle Orbiter Thermal Protection System due to stepped tiles. The excessive heating was evidence by visible discoloration and charring of the filler bar and strain isolation pad that is used in the attachment of tiles to the aluminum substrate. Two tile locations on the Shuttle orbiter were considered, one on the lower surface of the fuselage and one on the lower surface of the wing. The gap heating analysis involved the calculation of external and internal gas pressures and temperatures, internal mass flow rates, and the transient thermal response of the thermal protection system. The results of the analysis are presented for the fuselage and wing location for several step heights. The results of a study to determine the effectiveness of a half height ceramic fiber gap filler in preventing hot gas flow in the tile gaps are also presented.

Mental states inside out: switching costs for emotional and nonemotional sentences that differ in internal and external focus.

PubMed

Oosterwijk, Suzanne; Winkielman, Piotr; Pecher, Diane; Zeelenberg, René; Rotteveel, Mark; Fischer, Agneta H

2012-01-01

Mental states-such as thinking, remembering, or feeling angry, happy, or dizzy-have a clear internal component. We feel a certain way when we are in these states. These internal experiences may be simulated when people understand conceptual references to mental states. However, mental states can also be described from an "external" perspective, for example when referring to "smiling." In those cases, simulation of visible outside features may be more relevant for understanding. In a switching costs paradigm, we presented semantically unrelated sentences describing emotional and nonemotional mental states while manipulating their internal or external focus. The results show that switching costs occur when participants shift between sentences with an internal and an external focus. This suggests that different forms of simulation underlie understanding these sentences. In addition, these effects occurred for emotional and nonemotional mental states, suggesting that they are grounded in a similar way-through the process of simulation.

Repairing the damage to Atlantis' External Tank

NASA Image and Video Library

2007-03-07

In high bay 1 of the Vehicle Assembly Building, a technician marks off an area for inspection on Atlantis' external tank. A severe thunderstorm with golf ball-sized hail caused visible divots in the giant tank's foam insulation and minor surface damage to about 26 heat shield tiles on the shuttle's left wing. Further evaluation of the tank is necessary to get an accurate accounting of foam damage and determine the type of repair required and the time needed for that work. A new target launch date has not been determined, but teams will focus on preparing Atlantis for liftoff in late April on mission STS-117.

Repairing the damage to Atlantis' External Tank

NASA Image and Video Library

2007-03-07

Technicians in the Vehicle Assembly Building prepare materials that will be used during repair of the nose cone on Atlantis' external tank. A severe thunderstorm with golf ball-sized hail caused visible divots in the giant tank's foam insulation and minor surface damage to about 26 heat shield tiles on the shuttle's left wing. Further evaluation of the tank is necessary to get an accurate accounting of foam damage and determine the type of repair required and the time needed for that work. A new target launch date has not been determined, but teams will focus on preparing Atlantis for liftoff in late April on mission STS-117.

KSC-07pd0884

NASA Image and Video Library

2007-04-13

KENNEDY SPACE CENTER, FLA. -- In the Vehicle Assembly Building, the repair work of hail damage on Atlantis' external tank is inspected. At left is Brian Miller, with NASA Quality Assurance; at right is Mike Ravenscroft, with United Space Alliance. In the front is Sabrena Yedo, with NASA Safety. In late February, Atlantis' external tank received hail damage during a severe thunderstorm that passed through the Kennedy Space Center Launch Complex 39 area. The hail caused visible divots in the giant tank's foam insulation as well as minor surface damage to about 26 heat shield tiles on the shuttle's left wing. The launch now is targeted for June 8. Photo credit: NASA/George Shelton

Coupling mediated by photorefractive phase grating between visible radiation and surface plasmon polaritons in iron-doped LiNbO3 crystal slabs coated with indium-tin oxide

NASA Astrophysics Data System (ADS)

Wang, Hao; Zhao, Hua; Xu, Chao; Li, Liang; Hu, Guangwei; Zhang, Jingwen

2014-10-01

Photorefractive (PR) phase gratings were used in coupling energy between visible light and surface plasmon polaritons in indium-tin oxide (ITO)-coated iron-doped lithium niobate (Fe:LN) crystal slabs via electrostatic modification at the ITO/LN interface based on a strong photovoltaic effect. The energy coupling is considered to be responsible for several interesting observations: (1) dynamic reflectivity change from 3.25 to 37.0% of the very first reflection at the entrance slab interface, (2) total light reflectivity as high as 89%, and (3) two-dimensional diffraction patterns without external feedback needed.

Proposed control tower and cockpit visibility readouts based on an airport-aircraft information flow system

DOT National Transportation Integrated Search

1971-07-01

The problem of displaying visibility information to both : controller and pilot is discussed in the context of visibility : information flow in the airport-aircraft system. : The optimum amount of visibility information, as well as its : rate of flow...

Final Report: Non-Visible, Automated Target Acquisition and Tracking

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ziock, Klaus-Peter; Fabris, Lorenzo; Goddard, James K.

The Roadside Tracker (RST) represents a new approach to radiation portal monitors. It uses a combination of gamma-ray and visible-light imaging to localize gamma-ray radiation sources to individual vehicles in free-flowing, multi-lane traffic. Deployed as two trailers that are parked on either side of the roadway (Fig. 1); the RST scans passing traffic with two large gamma-ray imagers, one mounted in each trailer. The system compensates for vehicle motion through the imager’s fields of view by using automated target acquisition and tracking (TAT) software applied to a stream of video images. Once a vehicle has left the field of view,more » the radiation image of that vehicle is analyzed for the presence of a source, and if one is found, an alarm is sounded. The gamma-ray image is presented to the operator together with the video image of the traffic stream when the vehicle was approximately closest to the system (Fig. 2). The offending vehicle is identified with a bounding box to distinguish it from other vehicles that might be present at the same time. The system was developed under a previous grant from the Department of Homeland Security’s (DHS’s) Domestic Nuclear Detection Office (DNDO). This report documents work performed with follow-on funding from DNDO to further advance the development of the RST. Specifically, the primary thrust was to extend the performance envelope of the system by replacing the visible-light video cameras used by the TAT software with sensors that would allow operation at night and during inclement weather. In particular, it was desired to allow operation after dark without requiring external lighting. As part of this work, the system software was also upgraded to allow the use of 64-bit computers, the current generation operating system (OS), software development environment (Windows 7 vs. Windows XP, and current Visual Studio.Net), and improved software version controls (GIT vs. Source Safe.) With the upgraded performance allowed by new computers, and the additional memory available in a 64-bit OS, the system was able to handle greater traffic densities, and this also allowed addition of the ability to handle stop-and-go traffic.« less

International Space Station Data Collection for Disaster Response

NASA Technical Reports Server (NTRS)

Stefanov, William L.; Evans, Cynthia A..

2014-01-01

Natural disasters - including such events as tropical storms, earthquakes, floods, volcanic eruptions, and wildfires -effect hundreds of millions of people worldwide, and also cause billions of dollars (USD) in damage to the global economy. Remotely sensed data acquired by orbital sensor systems has emerged as a vital tool to identify the extent of damage resulting from a natural disaster, as well as providing near-real time mapping support to response efforts on the ground and humanitarian aid efforts. The International Space Station (ISS) is a unique terrestrial remote sensing platform for acquiring disaster response imagery. Unlike automated remote-sensing platforms it has a human crew; is equipped with both internal and externally-mounted remote sensing instruments; and has an inclined, low-Earth orbit that provides variable views and lighting (day and night) over 95 percent of the inhabited surface of the Earth. As such, it provides a useful complement to free-flyer based, sun-synchronous sensor systems in higher altitude polar orbits. While several nations have well-developed terrestrial remote sensing programs and assets for data collection, many developing nations do not have ready access to such resources. The International Charter, Space and Major Disasters (also known as the "International Disaster Charter", or IDC; http://www.disasterscharter.org/home) addresses this disparity. It is an agreement between agencies of several countries to provide - on a best-effort basis - remotely sensed data of natural disasters to requesting countries in support of disaster response. The lead US agency for interaction with the IDC is the United States Geological Survey (USGS); when an IDC request or "activation" is received, the USGS notifies the science teams for NASA instruments with targeting information for data collection. In the case of the ISS, the Earth Sciences and Remote Sensing (ESRS) Unit, part of the Astromaterials Research and Exploration Science Directorate and supporting the ISS Program Science Office at NASA's Johnson Space Center, receives notification from the USGS and coordinates targeting and data collection with the NASA ISS sensor teams. If data is collected, it is passed back to the USGS for posting on their Hazards Data Distribution System and made available for download. The ISS International Partners (CSA, ESA, JAXA, Roscosmos/Energia) have their own procedures for independently supporting IDC activations using their assets on ISS, and there is currently no joint coordination with NASA ISS sensor teams. Following completion of ISS assembly, NASA remote sensing assets began collecting IDC response data in May 2012. The initial NASA ISS sensor systems available to respond to IDC activations included the ISS Agricultural Camera (ISSAC), an internal multispectral visible-near infrared wavelength system mounted in the Window Observational Research Facility, or WORF; the Crew Earth Observations (CEO) Facility, where the crew collects imagery through Station windows using off-the-shelf handheld digital visible-wavelength cameras; and the Hyperspectral Imager for the Coastal Oceans (HICO), a visible to near-infrared system mounted externally on the Japan Experiment Module Exposed Facility. The ISSAC completed its primary mission and was removed from the WORF in January 2013. It was replaced by the very high resolution ISS SERVIR Environmental Research and Visualization System (ISERV) Pathfinder, a visible-wavelength digital camera, telescope, and pointing system. Since the start of IDC response by NASA sensors on the ISS in May 2012 and as of this report, there have been eighty IDC activations; NASA sensor systems have collected data for twenty-three of these events. Of the twenty-three successful data collections, five involved 2 or more ISS sensor systems responding to the same event. Data has also been collected by International Partners in response to natural disasters, most notably JAXA and Roscosmos/Energia through the Urugan program. Data collected in response to IDC activations is delivered by the ISS sensor teams to the ESRS for quality review and transfer to the USGS, where it is ingested into the Hazards Data Distribution System, or HDDS (https://hdds.usgs.gov/hdds2/; figure 1). This system allows the local agencies that issued the IDC activation request to review and download data. The data is then used to develop secondary products useful for humanitarian response such as flood maps. As of this report, approximately 1000 images collected by NASA ISS sensor systems have been downloaded from the HDDS, indicating that the ISS has assumed a valuable role in disaster response efforts. The ISS is also a unique platform in that it will have multiple users over its lifetime, and that no single remote sensing system has a permanent internal or external berth. This scheduled turnover provides for development of new remote sensing capabilities relevant to disaster response -as well as both research and applied science-and represents a significant contribution to continuance and enhancement of the NASA mission to investigate changes on our home planet.

Development of a visible light transmission (VLT) measurement system using an open-path optical method

NASA Astrophysics Data System (ADS)

Nurulain, S.; Manap, H.

2017-09-01

This paper describes about a visible light transmission (VLT) measurement system using an optical method. VLT rate plays an important role in order to determine the visibility of a medium. Current instrument to measure visibility has a gigantic set up, costly and mostly fails to function at low light condition environment. This research focuses on the development of a VLT measurement system using a simple experimental set-up and at a low cost. An open path optical technique is used to measure a few series of known-VLT thin film that act as sample of different visibilities. This measurement system is able to measure the light intensity of these thin films within the visible light region (535-540 nm) and the response time is less than 1s.

Limitations in 4-Year-Old Children's Sensitivity to the Spacing among Facial Features

ERIC Educational Resources Information Center

Mondloch, Catherine J.; Thomson, Kendra

2008-01-01

Four-year-olds' sensitivity to differences among faces in the spacing of features was tested under 4 task conditions: judging distinctiveness when the external contour was visible and when it was occluded, simultaneous match-to-sample, and recognizing the face of a friend. In each task, the foil differed only in the spacing of features, and…

RAYSAW: a log sawing simulator for 3D laser-scanned hardwood logs

Treesearch

R. Edward Thomas

2013-01-01

Laser scanning of hardwood logs provides detailed high-resolution imagery of log surfaces. Characteristics such as sweep, taper, and crook, as well as most surface defects, are visible to the eye in the scan data. In addition, models have been developed that predict interior knot size and position based on external defect information. Computerized processing of...

10 CFR 32.29 - Conditions of licenses issued under § 32.26: Quality control, labeling, and reports of transfer.

Code of Federal Regulations, 2014 CFR

2014-01-01

... standards approved by the Commission; (b) Label or mark each detector and its point-of-sale package so that: (1) Each detector has a durable, legible, readily visible label or marking on the external surface of the detector containing: (i) The following statement: “CONTAINS RADIOACTIVE MATERIAL”; (ii) The name...

10 CFR 32.29 - Conditions of licenses issued under § 32.26: Quality control, labeling, and reports of transfer.

Code of Federal Regulations, 2010 CFR

2010-01-01

... standards approved by the Commission; (b) Label or mark each detector and its point-of-sale package so that: (1) Each detector has a durable, legible, readily visible label or marking on the external surface of the detector containing: (i) The following statement: “CONTAINS RADIOACTIVE MATERIAL”; (ii) The name...

10 CFR 32.29 - Conditions of licenses issued under § 32.26: Quality control, labeling, and reports of transfer.

Code of Federal Regulations, 2011 CFR

2011-01-01

... standards approved by the Commission; (b) Label or mark each detector and its point-of-sale package so that: (1) Each detector has a durable, legible, readily visible label or marking on the external surface of the detector containing: (i) The following statement: “CONTAINS RADIOACTIVE MATERIAL”; (ii) The name...

10 CFR 32.29 - Conditions of licenses issued under § 32.26: Quality control, labeling, and reports of transfer.

Code of Federal Regulations, 2013 CFR

2013-01-01

... standards approved by the Commission; (b) Label or mark each detector and its point-of-sale package so that: (1) Each detector has a durable, legible, readily visible label or marking on the external surface of the detector containing: (i) The following statement: “CONTAINS RADIOACTIVE MATERIAL”; (ii) The name...

Hidden in plain sight: a crowdsourced public art contest to make automated external defibrillators more visible.

PubMed

Merchant, Raina M; Griffis, Heather M; Ha, Yoonhee P; Kilaru, Austin S; Sellers, Allison M; Hershey, John C; Hill, Shawndra S; Kramer-Golinkoff, Emily; Nadkarni, Lindsay; Debski, Margaret M; Padrez, Kevin A; Becker, Lance B; Asch, David A

2014-12-01

We sought to explore the feasibility of using a crowdsourcing study to promote awareness about automated external defibrillators (AEDs) and their locations. The Defibrillator Design Challenge was an online initiative that asked the public to create educational designs that would enhance AED visibility, which took place over 8 weeks, from February 6, 2014, to April 6, 2014. Participants were encouraged to vote for AED designs and share designs on social media for points. Using a mixed-methods study design, we measured participant demographics and motivations, design characteristics, dissemination, and Web site engagement. Over 8 weeks, there were 13 992 unique Web site visitors; 119 submitted designs and 2140 voted. The designs were shared 48 254 times on Facebook and Twitter. Most designers-voters reported that they participated to contribute to an important cause (44%) rather than to win money (0.8%). Design themes included: empowerment, location awareness, objects (e.g., wings, lightning, batteries, lifebuoys), and others. The Defibrillator Design Challenge engaged a broad audience to generate AED designs and foster awareness. This project provides a framework for using design and contest architecture to promote health messages.

Hidden in Plain Sight: A Crowdsourced Public Art Contest to Make Automated External Defibrillators More Visible

PubMed Central

Griffis, Heather M.; Kilaru, Austin S.; Sellers, Allison M.; Hershey, John C.; Hill, Shawndra S.; Kramer-Golinkoff, Emily; Nadkarni, Lindsay; Debski, Margaret M.; Padrez, Kevin A.; Becker, Lance B.; Asch, David A.

2014-01-01

Objectives. We sought to explore the feasibility of using a crowdsourcing study to promote awareness about automated external defibrillators (AEDs) and their locations. Methods. The Defibrillator Design Challenge was an online initiative that asked the public to create educational designs that would enhance AED visibility, which took place over 8 weeks, from February 6, 2014, to April 6, 2014. Participants were encouraged to vote for AED designs and share designs on social media for points. Using a mixed-methods study design, we measured participant demographics and motivations, design characteristics, dissemination, and Web site engagement. Results. Over 8 weeks, there were 13 992 unique Web site visitors; 119 submitted designs and 2140 voted. The designs were shared 48 254 times on Facebook and Twitter. Most designers–voters reported that they participated to contribute to an important cause (44%) rather than to win money (0.8%). Design themes included: empowerment, location awareness, objects (e.g., wings, lightning, batteries, lifebuoys), and others. Conclusions. The Defibrillator Design Challenge engaged a broad audience to generate AED designs and foster awareness. This project provides a framework for using design and contest architecture to promote health messages. PMID:25320902

Design of a colorimetric sensing platform using reflection mode plasmonic colour filters

NASA Astrophysics Data System (ADS)

Mudachathi, Renilkumar; Tanaka, Takuo

2017-08-01

Plasmonic nano structures fabricated using inexpensive and abundant aluminum metal shows intense narrow reflection peaks with strong response to the external stimuli, provides a simple yet powerful detection mechanism that is well suited for the development of low cost and low power sensors, such as colorimetric sensors, which transduces external stimuli or environmental changes in to visible colour changes. Such low cost and disposable sensors have huge demands in the point-of-care and home health care diagnostic applications. We present the design of a colorimetric sensing platform based on reflection mode plasmonic colour filters on both silicon and glass substrate, which demonstrate a sharp colour change for varying ambient refractive index. The sensor is essentially a plasmonic metamaterial in which the aluminum square plate hovering on a PMMA nano pillar in the background of a perforated aluminum reflector forms the unit cell which is arranged periodically in a 2D square lattice. The meta-surface has two distinct absorption peaks in the visible region leaving a strong reflection band, which strongly responds to the ambient refractive index change, provides a means for the realization of low cost colorimetric sensing platform.

From dynamic measurements of photosynthesis in a living plant to sunlight transformation into electricity.

PubMed

Flexer, Victoria; Mano, Nicolas

2010-02-15

We propose here a new method for the direct and continuous measurement of O(2) and glucose generated during photosynthesis. Our system is based on amperometric enzyme biosensors comprising immobilized redox enzymes (glucose oxidase (GOx) and bilirubin oxidase (BOD)) and redox hydrogels "wiring" the enzyme reaction centers to electrodes. We found that these electrodes, implanted into a living plant, responded in real time to visible light as an external stimulus triggering photosynthesis. They proved to be highly selective and fast enough and may be a valuable tool in understanding photosynthesis kinetics. Furthermore, we demonstrate that with our electrodes we could harvest glucose and O(2) produced during photosynthesis to produce energy, transforming sunlight into electricity in a simple, green, renewable, and sustainable way.

Construction of a Visible Diode Laser Source for Free Radical Photochemistry and Spectroscopy Experiments

NASA Technical Reports Server (NTRS)

Newman, Bronjelyn; Halpern, Joshua B.

1997-01-01

Tunable diode lasers are reliable sources of narrow-band light and comparatively cheap. Optical feedback simplifies frequency tuning of the laser diodes. We are building an inexpensive diode laser system incorporating optical feedback from a diffraction grating. The external optical cavity can be used with lasers that emit between 2 and 100 mW, and will also work if they are pulsed, although this will significantly degrade the bandwidth. The diode laser output power and bandwidth are comparable to CW dye lasers used in kinetics and dynamics experiments. However, their cost and maintenance will be much less as will alignment time. We intend to use the diode lasers to investigate CN and C2 kinetics as well as to study dissociation dynamics of atmospherically important molecules.

An estimated method of visibility for a remote sensing system based on LabVIEW and Arduino

NASA Astrophysics Data System (ADS)

Chen, Xiaochuan; Ruan, Chi; Zheng, Hairong

2017-02-01

Visibility data have long needed to traffic meteorological monitoring and warning system, but visibility data have monitored with expensive special equipment. Visibility degradation in fog is due to the light scattering of fog droplets, which are transit from aerosols via activation. Considering strong correlation between PM2.5 (Particulate matter with diameters less than 2.5μm) mass concentration and visibility, regression models can be useful tools for retrieving visibility data from available PM2.5 data. In this study, PM2.5 is measured by low cost and commercial equipment. The results of experiment indicate that relative humidity is the key factor to impact accuracy correlation between PM2.5 and visibility, the strongest correlation locates in the RH (<60%). Results of the studies suggest that visibility decreases with increases of PM2.5 mass concentration; however, it has been found the decrease rate tapers off gradually. In order to capture the real-time visibility data, to grasp the process of low visibility events, the design of remote monitoring system is put forward. Using the GPRS network to link to cloud as a server, proposed the Arduino as the controller, design and implements a wireless serial acquisition and control system based LabVIEW and Arduino, this system can achieve the function of real-time synchronization Web publishing. The result of the test indicates that this system has typical characteristics of friendly interface, high levels of reliability and expansibility, moreover it can retrieve visibility data from available PM2.5 data that can easy to access by low-cost sensor along the highway.

First clinical use of the EchoTrack guidance approach for radiofrequency ablation of thyroid gland nodules.

PubMed

Franz, Alfred Michael; Seitel, Alexander; Bopp, Nasrin; Erbelding, Christian; Cheray, Dominique; Delorme, Stefan; Grünwald, Frank; Korkusuz, Hüdayi; Maier-Hein, Lena

2017-06-01

Percutaneous radiofrequency ablation (RFA) of thyroid nodules is an alternative to surgical resection that offers the benefits of minimal scars for the patient, lower complication rates, and shorter treatment times. Ultrasound (US) is the preferred modality for guiding these procedures. The needle is usually kept within the US scanning plane to ensure needle visibility. However, this restricts flexibility in both transducer and needle movement and renders the procedure difficult, especially for inexperienced users. Existing navigation solutions often involve electromagnetic (EM) tracking, which requires placement of an external field generator (FG) in close proximity of the intervention site in order to avoid distortion of the EM field. This complicates the clinical workflow as placing the FG while ensuring that it neither restricts the physician's workspace nor affects tracking accuracy is awkward and time-consuming. The EchoTrack concept overcomes these issues by combining the US probe and the EM FG in one modality, simultaneously providing both real-time US and tracking data without requiring the placement of an external FG for tracking. We propose a system and workflow to use EchoTrack for RFA of thyroid nodules. According to our results, the overall error of the EchoTrack system resulting from errors related to tracking and calibration is below 2 mm. Navigated thyroid RFA with the proposed concept is clinically feasible. Motion of internal critical structures relative to external markers can be up to several millimeters in extreme cases. The EchoTrack concept with its simple setup, flexibility, improved needle visualization, and additional guidance information has high potential to be clinically used for thyroid RFA.

Characteristics of a Signal Data Converter for a Multi-runway Visibility Measuring System

DOT National Transportation Integrated Search

1971-10-01

The characteristics of a signal data converter (SDC) are developed with application to airport visibility measuring systems. The SDC is discussed in the context of an evolutionary growth of the visibility measuring system stemming from the present FA...

External quantum efficiency exceeding 100% in a singlet-exciton-fission-based solar cell

NASA Astrophysics Data System (ADS)

Baldo, Marc

2013-03-01

Singlet exciton fission can be used to split a molecular excited state in two. In solar cells, it promises to double the photocurrent from high energy photons, thereby breaking the single junction efficiency limit. We demonstrate organic solar cells that exploit singlet exciton fission in pentacene to generate more than one electron per incident photon in the visible spectrum. Using a fullerene acceptor, a poly(3-hexylthiophene) exciton confinement layer, and a conventional optical trapping scheme, the peak external quantum efficiency is (109 +/-1)% at λ = 670 nm for a 15-nm-thick pentacene film. The corresponding internal quantum efficiency is (160 +/-10)%. Independent confirmation of the high internal efficiency is obtained by analysis of the magnetic field effect on photocurrent, which determines that the triplet yield approaches 200% for pentacene films thicker than 5 nm. To our knowledge, this is the first solar cell to generate quantum efficiencies above 100% in the visible spectrum. Alternative multiple exciton generation approaches have been demonstrated previously in the ultraviolet, where there is relatively little sunlight. Singlet exciton fission differs from these other mechanisms because spin conservation disallows the usual dominant loss process: a thermal relaxation of the high-energy exciton into a single low-energy exciton. Consequently, pentacene is efficient in the visible spectrum at λ = 670 nm because only the collapse of the singlet exciton into twotriplets is spin-allowed. Supported as part of the Center for Excitonics, an Energy Frontier Research Center funded by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences under Award Number DE-SC0001088.

Visible-light responsive photocatalytic fuel cell based on WO(3)/W photoanode and Cu(2)O/Cu photocathode for simultaneous wastewater treatment and electricity generation.

PubMed

Chen, Quanpeng; Li, Jinhua; Li, Xuejin; Huang, Ke; Zhou, Baoxue; Cai, Weimin; Shangguan, Wenfeng

2012-10-16

A visible-light driven photocatalytic fuel cell (PFC) system comprised of WO(3)/W photoanode and Cu(2)O/Cu photocathode was established for organic compounds degradation with simultaneous electricity generation. The central idea for its operation is the mismatched Fermi levels between the two photoelectrodes. Under light illumination, the Fermi level of WO(3)/W photoanode is higher than that of Cu(2)O/Cu photocathode. An interior bias can be produced based on which the electrons of WO(3)/W photoanode can transfer from the external circuit to combine with the holes of Cu(2)O/Cu photocathode then generates the electricity. In this manner, the electron/hole pairs separations at two photoelectrodes are facilitated to release the holes of WO(3)/W photoanode and electrons of Cu(2)O/Cu photocathode. Organic compounds can be decomposed by the holes of WO(3)/W photoanode due to its high oxidation power (+3.1-3.2 V(NHE)). The results demonstrated that various model compounds including phenol, Rhodamine B, and Congo red can be successfully decomposed in this PFC system, with the degradation rate after 5 h operation were obtained to be 58%, 63%, and 74%, respectively. The consistent operation for continuous water treatment with the electricity generation at a long time scale was also confirmed from the result. The proposed PFC system provides a self-sustained and energy-saving way for simultaneous wastewater treatment and energy recovery.

Highly Efficient and Facile Photocatalytic Recycling System Suitable for ICAR ATRP of Hydrophilic Monomers.

PubMed

Jiang, Xiaowu; Zhang, Lifen; Cheng, Zhenping; Zhu, Xiulin

2016-08-01

Photoinduced initiators for continuous activator regeneration atom transfer radical polymerization (ATRP) of hydrophilic monomers in heptane/ethanol latent-biphasic system for copper catalyst separation and recycling have been realized for the first time at room temperature with different wavelengths of visible light LED (green, blue, purple, and white LED) as external stimulus, using 2-bromophenylacetate as the ATRP initiator and camphorquinone/triethylamine as the photoinitiator. In this system, hybrid catalyst complex (HCc) is synthesized as a novel nonpolar catalyst, which is preferentially dissolved in heptane. The hydrophilic polymers obtained catalyzed by HCc in heptane/ethanol mixture solvent show typical "living" features, for example, the values of Mn,GPC increase linearly with monomer conversion up to quantitative level (>96%) and the molecular weight distributions were kept narrow (Mw /Mn < 1.20) throughout the polymerization process. It should be noted that the excellent controllability of this novel polymerization system can be achieved even after 5 catalyst recycling experiments under LED irradiation. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

A simple model of hysteresis behavior using spreadsheet analysis

NASA Astrophysics Data System (ADS)

Ehrmann, A.; Blachowicz, T.

2015-01-01

Hysteresis loops occur in many scientific and technical problems, especially as field dependent magnetization of ferromagnetic materials, but also as stress-strain-curves of materials measured by tensile tests including thermal effects, liquid-solid phase transitions, in cell biology or economics. While several mathematical models exist which aim to calculate hysteresis energies and other parameters, here we offer a simple model for a general hysteretic system, showing different hysteresis loops depending on the defined parameters. The calculation which is based on basic spreadsheet analysis plus an easy macro code can be used by students to understand how these systems work and how the parameters influence the reactions of the system on an external field. Importantly, in the step-by-step mode, each change of the system state, compared to the last step, becomes visible. The simple program can be developed further by several changes and additions, enabling the building of a tool which is capable of answering real physical questions in the broad field of magnetism as well as in other scientific areas, in which similar hysteresis loops occur.

A B-C-N hybrid porous sheet: an efficient metal-free visible-light absorption material.

PubMed

Lu, Ruifeng; Li, Feng; Salafranca, Juan; Kan, Erjun; Xiao, Chuanyun; Deng, Kaiming

2014-03-07

The polyphenylene network, known as porous graphene, is one of the most important and widely studied two-dimensional materials. As a potential candidate for photocatalysis and photovoltaic energy generation, its application has been limited by the low photocatalytic activity in the visible-light region. State-of-the-art hybrid density functional theory investigations are presented to show that an analogous B-C-N porous sheet outperforms the pristine polyphenylene network with significantly enhanced visible-light absorption. Compared with porous graphene, the calculated energy gap of the B-C-N hybrid crystal shrinks to 2.7 eV and the optical absorption peak remarkably shifts to the visible light region. The redox potentials of water splitting are well positioned in the middle of the band gap. Hybridizations among B_p, N_p and C_p orbitals are responsible for these findings. Valence and conduction band calculations indicate that the electrons and holes can be effectively separated, reducing charge recombination and improving the photoconversion efficiency. Moreover, the band gap and optical properties of the B-C-N hybrid porous sheet can be further finely engineered by external strain.

Hail damage on Atlantis' external tank is inspected

NASA Image and Video Library

2007-04-13

In the Vehicle Assembly Building, markers show the hail damage being repaired on the external tank of Space Shuttle Atlantis. The white hole with a red circle around it is a hole prepared for molding and material application. The red material is sealant tape so the mold doesn't leak when the foam rises against the mold. The white/ translucent square mold is an area where the foam has been applied and the foam has risen and cured against the mold surface. The area will be de-molded and sanded flush with the adjacent area. In late February, Atlantis' external tank received hail damage during a severe thunderstorm that passed through the Kennedy Space Center Launch Complex 39 area. The hail caused visible divots in the giant tank's foam insulation as well as minor surface damage to about 26 heat shield tiles on the shuttle's left wing. The launch now is targeted for June 8.

Illusions of having small or large invisible bodies influence visual perception of object size

PubMed Central

van der Hoort, Björn; Ehrsson, H. Henrik

2016-01-01

The size of our body influences the perceived size of the world so that objects appear larger to children than to adults. The mechanisms underlying this effect remain unclear. It has been difficult to dissociate visual rescaling of the external environment based on an individual’s visible body from visual rescaling based on a central multisensory body representation. To differentiate these potential causal mechanisms, we manipulated body representation without a visible body by taking advantage of recent developments in body representation research. Participants experienced the illusion of having a small or large invisible body while object-size perception was tested. Our findings show that the perceived size of test-objects was determined by the size of the invisible body (inverse relation), and by the strength of the invisible body illusion. These findings demonstrate how central body representation directly influences visual size perception, without the need for a visible body, by rescaling the spatial representation of the environment. PMID:27708344

Synthetic Vision Systems - Operational Considerations Simulation Experiment

NASA Technical Reports Server (NTRS)

Kramer, Lynda J.; Williams, Steven P.; Bailey, Randall E.; Glaab, Louis J.

2007-01-01

Synthetic vision is a computer-generated image of the external scene topography that is generated from aircraft attitude, high-precision navigation information, and data of the terrain, obstacles, cultural features, and other required flight information. A synthetic vision system (SVS) enhances this basic functionality with real-time integrity to ensure the validity of the databases, perform obstacle detection and independent navigation accuracy verification, and provide traffic surveillance. Over the last five years, NASA and its industry partners have developed and deployed SVS technologies for commercial, business, and general aviation aircraft which have been shown to provide significant improvements in terrain awareness and reductions in the potential for Controlled-Flight-Into-Terrain incidents/accidents compared to current generation cockpit technologies. It has been hypothesized that SVS displays can greatly improve the safety and operational flexibility of flight in Instrument Meteorological Conditions (IMC) to a level comparable to clear-day Visual Meteorological Conditions (VMC), regardless of actual weather conditions or time of day. An experiment was conducted to evaluate SVS and SVS-related technologies as well as the influence of where the information is provided to the pilot (e.g., on a Head-Up or Head-Down Display) for consideration in defining landing minima based upon aircraft and airport equipage. The "operational considerations" evaluated under this effort included reduced visibility, decision altitudes, and airport equipage requirements, such as approach lighting systems, for SVS-equipped aircraft. Subjective results from the present study suggest that synthetic vision imagery on both head-up and head-down displays may offer benefits in situation awareness; workload; and approach and landing performance in the visibility levels, approach lighting systems, and decision altitudes tested.

Synthetic vision systems: operational considerations simulation experiment

NASA Astrophysics Data System (ADS)

Kramer, Lynda J.; Williams, Steven P.; Bailey, Randall E.; Glaab, Louis J.

2007-04-01

Synthetic vision is a computer-generated image of the external scene topography that is generated from aircraft attitude, high-precision navigation information, and data of the terrain, obstacles, cultural features, and other required flight information. A synthetic vision system (SVS) enhances this basic functionality with real-time integrity to ensure the validity of the databases, perform obstacle detection and independent navigation accuracy verification, and provide traffic surveillance. Over the last five years, NASA and its industry partners have developed and deployed SVS technologies for commercial, business, and general aviation aircraft which have been shown to provide significant improvements in terrain awareness and reductions in the potential for Controlled-Flight-Into-Terrain incidents / accidents compared to current generation cockpit technologies. It has been hypothesized that SVS displays can greatly improve the safety and operational flexibility of flight in Instrument Meteorological Conditions (IMC) to a level comparable to clear-day Visual Meteorological Conditions (VMC), regardless of actual weather conditions or time of day. An experiment was conducted to evaluate SVS and SVS-related technologies as well as the influence of where the information is provided to the pilot (e.g., on a Head-Up or Head-Down Display) for consideration in defining landing minima based upon aircraft and airport equipage. The "operational considerations" evaluated under this effort included reduced visibility, decision altitudes, and airport equipage requirements, such as approach lighting systems, for SVS-equipped aircraft. Subjective results from the present study suggest that synthetic vision imagery on both head-up and head-down displays may offer benefits in situation awareness; workload; and approach and landing performance in the visibility levels, approach lighting systems, and decision altitudes tested.

A radiopaque polymer hydrogel used as a fiducial marker in gynecologic-cancer patients receiving brachytherapy

PubMed Central

Bair, Ryan J.; Bair, Eric; Viswanathan, Akila N.

2016-01-01

PURPOSE We assessed a novel Food and Drug Administration–approved hydrogel, synthesized as absorbable iodinated particles, in gynecologic-cancer patients undergoing computed tomography (CT) or magnetic resonance (MR) based brachytherapy after external beam radiation. METHODS AND MATERIALS Nineteen patients underwent CT-guided (n = 13) or MR-guided (n = 6) brachytherapy for gynecologic cancers. Seventy-seven hydrogel injections were placed. The hydrogel material was injected into gross residual disease and/or key anatomic landmarks in amounts ranging from 0.1 to 0.4 mL. The visibility of the tracer was scored on CT and on MR images using a 5-point scoring scale. A Cohen’s kappa statistic was calculated to assess interobserver agreement. To assess the unadjusted effects of baseline parameters on hydrogel visibility, we modeled visibility using a linear mixed-effect model. RESULTS Injections were without complication. The kappa statistic was 0.77 (95% confidence interval [CI], 0.68–0.87). The volume of hydrogel injected was significantly associated with visibility on both CT (p = 0.032) and magnetic resonance imaging (p = 0.016). We analyzed visibility by location, controlling for amount. A 0.1-cc increase in volume injected was associated with increases of 0.54 (95% CI = 0.05–1.03) in the CT visibility score and 0.83 (95% CI = 0.17–1.49) in the MR visibility score. Injection of 0.4 cc or more was required for unequivocal visibility on CT or MR. No statistically significant correlation was found between tumor type, tumor location, or anatomical location of injection and visibility on either CT or magnetic resonance imaging. CONCLUSIONS In this first report of an injectable radiopaque hydrogel, targets were visualized to assist with three-dimensional–based brachytherapy in gynecologic malignancies. This marker has potential for several applications, is easy to inject and visualize, and caused no acute complications. PMID:26481393

Repairing the damage to Atlantis' External Tank

NASA Image and Video Library

2007-03-07

On an upper level of high bay 1 of the Vehicle Assembly Building, technicians prepare the area around the nose cone (left) of Atlantis' external tank that will undergo repair for hail damage. A severe thunderstorm with golf ball-sized hail caused visible divots in the giant tank's foam insulation and minor surface damage to about 26 heat shield tiles on the shuttle's left wing. Further evaluation of the tank is necessary to get an accurate accounting of foam damage and determine the type of repair required and the time needed for that work. A new target launch date has not been determined, but teams will focus on preparing Atlantis for liftoff in late April on mission STS-117.

Repairing the damage to Atlantis' External Tank

NASA Image and Video Library

2007-03-07

On an upper level of high bay 1 of the Vehicle Assembly Building, technicians place protective material around the nose cone of Atlantis' external tank. The nose cone will undergo repair for hail damage. A severe thunderstorm with golf ball-sized hail caused visible divots in the giant tank's foam insulation and minor surface damage to about 26 heat shield tiles on the shuttle's left wing. Further evaluation of the tank is necessary to get an accurate accounting of foam damage and determine the type of repair required and the time needed for that work. A new target launch date has not been determined, but teams will focus on preparing Atlantis for liftoff in late April on mission STS-117.

Repairing the damage to Atlantis' External Tank

NASA Image and Video Library

2007-03-07

On an upper level of high bay 1 of the Vehicle Assembly Building, technicians prepare the area around the nose cone (foreground) of Atlantis' external tank that will undergo repair for hail damage. A severe thunderstorm with golf ball-sized hail caused visible divots in the giant tank's foam insulation and minor surface damage to about 26 heat shield tiles on the shuttle's left wing. Further evaluation of the tank is necessary to get an accurate accounting of foam damage and determine the type of repair required and the time needed for that work. A new target launch date has not been determined, but teams will focus on preparing Atlantis for liftoff in late April on mission STS-117.

Measuring atmospheric visibility cavity attenuated phase shift spectroscopy

NASA Astrophysics Data System (ADS)

Jie, Guo; Ye, Shan-Shan; Yang, Xiao; Han, Ye-Xing; Tang, Huai-Wu; Yu, Zhi-Wei

2016-10-01

In the paper, an accurate and sensitive cavity attenuated phase shift spectroscopy (CAPS) system was used to monitor the atmospheric visibility coefficient in urban areas. The CAPS system, which detects the atmospheric visibility within a 10 nm bandpass centered at 532 nm, comprises a green LED with center wavelength in 532nm, a resonant optical cavity (36 cm length), a Photo Multiplier Tube detector and a lock in amplifier. The performance of the CAPS system was evaluated by measuring of the stability and response of the system. The minima ( 0.06 Mm-1) in the Allan plots show the optimum average time( 80s) for optimum detection performance of the CAPS system. The 2L/min flow rate, the CAPS system rise and fall response time is about 15 s, so as to realize the fast measurement of visibility. By comparing the forward scatter visibility meter measurement results, the CAPS system measurement results are verified reliably, and have high precision measurement. These figures indicate that this method has the potential to become one of the most sensitive on-line analytical techniques for atmospheric visibility detection.

A Comprehensive Investigation of Visibility Problems on Highways: Developing Real Time Monitoring and Prediction System for Reduced Visibility and Understanding Traffic and Human Factors Implications

DOT National Transportation Integrated Search

2015-10-01

Visibility is one of the most important impacts weather can have on road systems; weather-related visibility reduction is most often due to fog. Florida is among the top-rated states in the United States with regards to traffic safety problems result...

Optimal design of an earth observation optical system with dual spectral and high resolution

NASA Astrophysics Data System (ADS)

Yan, Pei-pei; Jiang, Kai; Liu, Kai; Duan, Jing; Shan, Qiusha

2017-02-01

With the increasing demand of the high-resolution remote sensing images by military and civilians, Countries around the world are optimistic about the prospect of higher resolution remote sensing images. Moreover, design a visible/infrared integrative optic system has important value in earth observation. Because visible system can't identify camouflage and recon at night, so we should associate visible camera with infrared camera. An earth observation optical system with dual spectral and high resolution is designed. The paper mainly researches on the integrative design of visible and infrared optic system, which makes the system lighter and smaller, and achieves one satellite with two uses. The working waveband of the system covers visible, middle infrared (3-5um). Dual waveband clear imaging is achieved with dispersive RC system. The focal length of visible system is 3056mm, F/# is 10.91. And the focal length of middle infrared system is 1120mm, F/# is 4. In order to suppress the middle infrared thermal radiation and stray light, the second imaging system is achieved and the narcissus phenomenon is analyzed. The system characteristic is that the structure is simple. And the especial requirements of the Modulation Transfer Function (MTF), spot, energy concentration, and distortion etc. are all satisfied.

Efficient resource allocation scheme for visible-light communication system

NASA Astrophysics Data System (ADS)

Kim, Woo-Chan; Bae, Chi-Sung; Cho, Dong-Ho; Shin, Hong-Seok; Jung, D. K.; Oh, Y. J.

2009-01-01

A visible-light communication utilizing LED has many advantagies such as visibility of information, high SNR (Signal to Noise Ratio), low installation cost, usage of existing illuminators, and high security. Furthermore, exponentially increasing needs and quality of LED have helped the development of visible-light communication. The visibility is the most attractive property in visible-light communication system, but it is difficult to ensure visibility and transmission efficiency simultaneously during initial access because of the small amount of initial access process signals. In this paper, we propose an efficient resource allocation scheme at initial access for ensuring visibility with high resource utilization rate and low data transmission failure rate. The performance has been evaluated through the numerical analysis and simulation results.

A new visibility measurement system based on a black target and a comparative trial with visibility instruments

NASA Astrophysics Data System (ADS)

Tang, Fanjie; Ma, Shuqing; Yang, Ling; Du, Chuanyao; Tang, Yingjie

2016-10-01

According to Koschmieder's law, a mathematical model of contrast between a single black object and the sky background is established. Based on this principle, we built a black target visiometer system using a photograph of a black object taken with an industrial camera, that has a relatively simple structure and automated operation. In this study, three commercial visibility instruments-a forward scatter meter (CJB-3A) and two atmospheric transmission meters (LT31, VM100)-were compared to the black target visiometer system. Our results show that, within visibility ranges of up to 10 km, 1) all of the instruments agree well at low visibility and agree poorly at a visibility exceeding 5 km; 2) the forward scattering instrument has high bias at low visibility because particle absorption is not included; and 3) the best agreement with the black target method was obtained with the simple transmissometer rather than the forward scatter instrument or the hybrid transmissometer for a visibility range of up to 10 km.

Optimization of the occulter for the Solar Orbiter/METIS coronagraph

NASA Astrophysics Data System (ADS)

Landini, Federico; Vivès, Sébastien; Romoli, Marco; Guillon, Christophe; Pancrazzi, Maurizio; Escolle, Clement; Focardi, Mauro; Antonucci, Ester; Fineschi, Silvano; Naletto, Giampiero; Nicolini, Gianalfredo; Nicolosi, Piergiorgio; Spadaro, Daniele

2012-09-01

METIS (Multi Element Telescope for Imaging and Spectroscopy investigation), selected to fly aboard the Solar Orbiter ESA/NASA mission, is conceived to perform imaging (in visible, UV and EUV) and spectroscopy (in EUV) of the solar corona, by means of an integrated instrument suite located on a single optical bench and sharing the same aperture on the satellite heat shield. As every coronagraph, METIS is highly demanding in terms of stray light suppression. Coronagraphs history teaches that a particular attention must be dedicated to the occulter optimization. The METIS occulting system is of particular interest due to its innovative concept. In order to meet the strict thermal requirements of Solar Orbiter, METIS optical design has been optimized by moving the entrance pupil at the level of the external occulter on the S/C thermal shield, thus reducing the size of the external aperture. The scheme is based on an inverted external-occulter (IEO). The IEO consists of a circular aperture on the Solar Orbiter thermal shield. A spherical mirror rejects back the disk-light through the IEO. A breadboard of the occulting assembly (BOA) has been manufactured in order to perform stray light tests in front of two solar simulators (in Marseille, France and in Torino, Italy). A first measurement campaign has been carried on at the Laboratoire d'Astrophysique de Marseille. In this paper we describe the BOA design, the laboratory set-up and the preliminary results.

Airport Visibility Measuring Systems Elements of Deployment Cost Analysis

DOT National Transportation Integrated Search

1976-09-01

This report analyzes the deployment cost for different visibility measuring systems necessary to satisfy CAT I, II, and II operations. The analysis is based on airport operational requirements and data for commercially available visibility measuring ...

Increased short circuit current in an azafullerene-based organic solar cell.

PubMed

Cambarau, Werther; Fritze, Urs F; Viterisi, Aurélien; Palomares, Emilio; von Delius, Max

2015-01-21

We report the synthesis of a solution-processable, dodecyloxyphenyl-substituted azafullerene monoadduct (DPC59N) and its application as electron acceptor in bulk heterojunction organic solar cells (BHJ-OSCs). Due to its relatively strong absorption of visible light, DPC59N outperforms PC60BM in respect to short circuit current (JSC) and external quantum efficiency (EQE) in blends with donor P3HT.

Visible light driven mineralization of spiramycin over photostructured N-doped TiO2 on up conversion phosphors.

PubMed

Sacco, Olga; Vaiano, Vincenzo; Sannino, Diana; Ciambelli, Paolo

2017-04-01

A novel visible light-active photocatalyst formulation (NdT/OP) was obtained by supporting N-doped TiO 2 (NdT) particles on up-conversion luminescent organic phosphors (OP). The photocatalytic activity of such catalysts was evaluated for the mineralization process of spiramycin in aqueous solution. The effect of NdT loading in the range 15-60wt.% on bulk and surface characteristics of NdT/OP catalysts was investigated by several chemico-physical characterization techniques. The photocatalytic performance of NdT/OP catalysts in the removal of spyramicin from aqueous solution was assessed through photocatalytic tests under visible light irradiation. Total organic carbon (TOC) of aqueous solution, and CO and CO 2 gas concentrations evolved during the photodegradation were analyzed. A dramatic enhancement of photocatalytic activity of the photostructured visible active NdT/OP catalysts, compared to NdT catalyst, was observed. Only CO 2 was detected in gas-phase during visible light irradiation, proving that the photocatalytic process is effective in the mineralization of spiramycin, reaching very high values of TOC removal. The photocatalyst NdT/OP at 30wt.% of NdT loading showed the highest photocatalytic activity (58% of TOC removed after 180min irradiation against only 31% removal after 300min of irradiation of NdT). We attribute this enhanced activity to the high effectiveness in the utilization of visible light through improved light harvesting and exploiting. OP particles act as "photoactive support", able to be excited by the external visible light irradiation, and reissue luminescence of wavelength suitable to promote NdT photomineralization activity. Copyright © 2016. Published by Elsevier B.V.

Predicting catastrophes of non-autonomous networks with visibility graphs and horizontal visibility

NASA Astrophysics Data System (ADS)

Zhang, Haicheng; Xu, Daolin; Wu, Yousheng

2018-05-01

Prediction of potential catastrophes in engineering systems is a challenging problem. We first attempt to construct a complex network to predict catastrophes of a multi-modular floating system in advance of their occurrences. Response time series of the system can be mapped into an virtual network by using visibility graph or horizontal visibility algorithm. The topology characteristics of the networks can be used to forecast catastrophes of the system. Numerical results show that there is an obvious corresponding relationship between the variation of topology characteristics and the onset of catastrophes. A Catastrophe Index (CI) is proposed as a numerical indicator to measure a qualitative change from a stable state to a catastrophic state. The two approaches, the visibility graph and horizontal visibility algorithms, are compared by using the index in the reliability analysis with different data lengths and sampling frequencies. The technique of virtual network method is potentially extendable to catastrophe predictions of other engineering systems.

A Lean Approach to Improving SE Visibility in Large Operational Systems Evolution

DTIC Science & Technology

2013-06-01

large health care system of systems. To enhance both visibility and flow, the approach utilizes visualization techniques, pull-scheduling processes...development processes. This paper describes an example implementation of the concept in a large health care system of systems. To enhance both visibility...and then provides the results to the requestor as soon as available. Hospital System Information Support Development The health care SoS is a set

[Based on the LS-SVM modeling method determination of soil available N and available K by using near-infrared spectroscopy].

PubMed

Liu, Xue-Mei; Liu, Jian-She

2012-11-01

Visible infrared spectroscopy (Vis/SW-NIRS) was investigated in the present study for measurement accuracy of soil properties,namely, available nitrogen(N) and available potassium(K). Three types of pretreatments including standard normal variate (SNV), multiplicative scattering correction (MSC) and Savitzky-Golay smoothing+first derivative were adopted to eliminate the system noises and external disturbances. Then partial least squares (PLS) and least squares-support vector machine (LS-SVM) models analysis were implemented for calibration models. Simultaneously, the performance of least squares-support vector machine (LS-SVM) models was compared with three kinds of inputs, including PCA(PCs), latent variables (LVs), and effective wavelengths (EWs). The results indicated that all LS-SVM models outperformed PLS models. The performance of the model was evaluated by the correlation coefficient (r2) and RMSEP. The optimal EWs-LS-SVM models were achieved, and the correlation coefficient (r2) and RMSEP were 0.82 and 17.2 for N and 0.72 and 15.0 for K, respectively. The results indicated that visible and short wave-near infrared spectroscopy (Vis/SW-NIRS)(325-1 075 nm) combined with LS-SVM could be utilized as a precision method for the determination of soil properties.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Guensch, Gregory R.; Mueller, Robert P.; McKinstry, Craig A.

As part of the research supported by U.S. Department of Energy (DOE) Advanced Hydropower Turbine System (AHTS) Program, the Pacific Northwest National Laboratory (PNNL) conducted a study where age-0 and age-1 Chinook salmon, as well as several other types of fish, were released into a submerged water jet to quantify injuries caused by shear stresses and turbulence (Neitzel et al. 2000). The fish releases were videotaped. These videotape records were digitized and analyzed using new methods to identify the injury mechanisms and the stresses involved. Visible external injuries sustained by fish in this study generally occurred during the initial contactmore » with the jet and not during the tumbling that occurred after the fish fully entered the turbulent flow. The inertial stresses of tumbling, however, may cause temporary or even permanent vestibular and neurological injuries. Such injuries can result in disorientation and loss of equilibrium, which are life threatening in the “natural” environment. Operculum injuries predominated at moderate water jet speeds (12 and 15 m/s). At the highest speed, eye, operculum, isthmus, and gill injuries were equally common, and disorientation was most common. Bruising and descaling were relatively rare, especially for age-0 fish. Age-0 fish were less susceptible than the larger age-1 fish to all visible injury types, especially at lower speeds.« less

Space Shuttle Projects

NASA Image and Video Library

2005-08-03

Launched on July 26, 2005 from the Kennedy Space Center in Florida, STS-114 was classified as Logistics Flight 1. Among the Station-related activities of the mission were the delivery of new supplies and the replacement of one of the orbital outpost's Control Moment Gyroscopes (CMGs). STS-114 also carried the Raffaello Multi-Purpose Logistics Module and the External Stowage Platform-2. A major focus of the mission was the testing and evaluation of new Space Shuttle flight safety, which included new inspection and repair techniques. Upon its approach to the International Space Station (ISS), the Space Shuttle Discovery underwent a photography session in order to assess any damages that may have occurred during its launch and/or journey through Space. The mission’s third and final Extra Vehicular Activity (EVA) included taking a close-up look and the repair of the damaged heat shield. Gap fillers were removed from between the orbiter’s heat-shielding tiles located on the craft’s underbelly. Never before had any repairs been done to an orbiter while still in space. This particular photo was taken by astronaut Stephen K. Robinson, STS-114 mission specialist, whose shadow is visible on the thermal protection tiles, and a portion of the Canadian built Remote Manipulator System (RMS) robotic arm and the Nile River is visible at the bottom.

Close-up of Shuttle Thermal Tiles in Space

NASA Technical Reports Server (NTRS)

2005-01-01

Launched on July 26, 2005 from the Kennedy Space Center in Florida, STS-114 was classified as Logistics Flight 1. Among the Station-related activities of the mission were the delivery of new supplies and the replacement of one of the orbital outpost's Control Moment Gyroscopes (CMGs). STS-114 also carried the Raffaello Multi-Purpose Logistics Module and the External Stowage Platform-2. A major focus of the mission was the testing and evaluation of new Space Shuttle flight safety, which included new inspection and repair techniques. Upon its approach to the International Space Station (ISS), the Space Shuttle Discovery underwent a photography session in order to assess any damages that may have occurred during its launch and/or journey through Space. The mission's third and final Extra Vehicular Activity (EVA) included taking a close-up look and the repair of the damaged heat shield. Gap fillers were removed from between the orbiter's heat-shielding tiles located on the craft's underbelly. Never before had any repairs been done to an orbiter while still in space. This particular photo was taken by astronaut Stephen K. Robinson, STS-114 mission specialist, whose shadow is visible on the thermal protection tiles, and a portion of the Canadian built Remote Manipulator System (RMS) robotic arm and the Nile River is visible at the bottom.

Development of low-cost meteorological observation system based on wireless network for poor-visibility occurred by snowstorm

NASA Astrophysics Data System (ADS)

Kobayashi, Y.; Watanabe, K.; Imai, M.; Watanabe, K.; Naruse, N.; Takahashi, Y.

2016-12-01

Hyper-densely monitoring for poor-visibility occurred by snowstorm is needed to make an alert system, because the snowstorm is difficult to predict from the observation only at a representative point. There are some problems in the previous approaches for the poor-visibility monitoring using video analyses or visibility meters; these require a wired network monitoring (a large amount of data: 10MB/sec at least) and the system cost is high (10,000 at each point). Thus, the risk of poor-visibility has been mainly measured at specific point such as airport and mountain pass, and estimated by simulation two dimensionally. To predict it two dimensionally and accurately, we have developed a low-cost meteorological system to observe the snowstorm hyper-densely. We have developed a low-cost visibility meter which works as the reduced intensity of semiconducting laser light when snow particles block off. Our developed system also has a capability of extending a hyper-densely observation in real-time on wireless network using Zigbee; A/D conversion and wireless data sent from temperature and illuminance sensors. We use a semiconducting laser chip (5) for the light source and a reflection mechanism by the use of three mirrors so as to send the light to a non-sensitive illuminance sensor directly. Thus, our visibility detecting system ($500) becomes much cheaper than previous one. We have checked the correlation between the reduced intensity taken by our system and the visibility recorded by conventional video camera. The value for the correlation coefficient was -0.67, which indicates a strong correlation. It means that our developed system is practical. In conclusion, we have developed low-cost meteorological detecting system to observe poor-visibility occurred by snowstorm, having a potential of hyper-densely monitoring on wireless network, and have made sure the practicability.

LANDSAT 3 return beam vidicon response artifacts: A report on RBV photographic product characteristics and quality coding system

NASA Technical Reports Server (NTRS)

Clark, B. P.

1981-01-01

Analysis of large volumes of LANDSAT 3 RBV digital data that were converted to photographic form led to the firm identification of several visible artifacts (objects or structures not normally present, but producted by an external agency or action) in the imagery. These artifacts were identified, categorized, and traced directly to specific sensor response characteristics. None of these artifacts is easily removed and all cases remain under active study of possible future enhancement. The seven generic categories of sensor response artifacts identified to date include: (1) shading and stairsteps; (2) corners out of focus; (3) missing reseaus; (4) reseau distortion and data distortion; (5) black vertical line; (6) grain effect; and (7) faceplate contamination. An additional category under study, but not yet determined to be caused by sensor response, is a geometric anomaly. Examples of affected imagery are presented to assist in distinguishing between image content and innate defects caused by the sensor system.

Visualization of Penile Suspensory Ligamentous System Based on Visible Human Data Sets

PubMed Central

Chen, Xianzhuo; Wu, Yi; Tao, Ling; Yan, Yan; Pang, Jun; Zhang, Shaoxiang; Li, Shirong

2017-01-01

Background The aim of this study was to use a three-dimensional (3D) visualization technology to illustrate and describe the anatomical features of the penile suspensory ligamentous system based on the Visible Human data sets and to explore the suspensory mechanism of the penis for the further improvement of the penis-lengthening surgery. Material/Methods Cross-sectional images retrieved from the first Chinese Visible Human (CVH-1), third Chinese Visible Human (CVH-3), and Visible Human Male (VHM) data sets were used to segment the suspensory ligamentous system and its adjacent structures. The magnetic resonance imaging (MRI) images of this system were studied and compared with those from the Visible Human data sets. The 3D models reconstructed from the Visible Human data sets were used to provide morphological features of the penile suspensory ligamentous system and its related structures. Results The fundiform ligament was a superficial, loose, fibro-fatty tissue which originated from Scarpa’s fascia superiorly and continued to the scrotal septum inferiorly. The suspensory ligament and arcuate pubic ligament were dense fibrous connective tissues which started from the pubic symphysis and terminated by attaching to the tunica albuginea of the corpora cavernosa. Furthermore, the arcuate pubic ligament attached to the inferior rami of the pubis laterally. Conclusions The 3D model based on Visible Human data sets can be used to clarify the anatomical features of the suspensory ligamentous system, thereby contributing to the improvement of penis-lengthening surgery. PMID:28530218

Visualization of Penile Suspensory Ligamentous System Based on Visible Human Data Sets.

PubMed

Chen, Xianzhuo; Wu, Yi; Tao, Ling; Yan, Yan; Pang, Jun; Zhang, Shaoxiang; Li, Shirong

2017-05-22

BACKGROUND The aim of this study was to use a three-dimensional (3D) visualization technology to illustrate and describe the anatomical features of the penile suspensory ligamentous system based on the Visible Human data sets and to explore the suspensory mechanism of the penis for the further improvement of the penis-lengthening surgery. MATERIAL AND METHODS Cross-sectional images retrieved from the first Chinese Visible Human (CVH-1), third Chinese Visible Human (CVH-3), and Visible Human Male (VHM) data sets were used to segment the suspensory ligamentous system and its adjacent structures. The magnetic resonance imaging (MRI) images of this system were studied and compared with those from the Visible Human data sets. The 3D models reconstructed from the Visible Human data sets were used to provide morphological features of the penile suspensory ligamentous system and its related structures. RESULTS The fundiform ligament was a superficial, loose, fibro-fatty tissue which originated from Scarpa's fascia superiorly and continued to the scrotal septum inferiorly. The suspensory ligament and arcuate pubic ligament were dense fibrous connective tissues which started from the pubic symphysis and terminated by attaching to the tunica albuginea of the corpora cavernosa. Furthermore, the arcuate pubic ligament attached to the inferior rami of the pubis laterally. CONCLUSIONS The 3D model based on Visible Human data sets can be used to clarify the anatomical features of the suspensory ligamentous system, thereby contributing to the improvement of penis-lengthening surgery.

Skin aging: molecular pathology, dermal remodelling and the imaging revolution.

PubMed

Newton, V L; Mcconnell, J C; Hibbert, S A; Graham, H K; Watson, R E

2015-12-01

Skin is a multifunctional organ but, alongside every other organ system, is subject to both intrinsic (chronological) and extrinsic (environmental) aging, resulting in a loss of functional capacity. Cutaneous aging manifests as an observable change in the external appearance of the skin, the major accelerator of the aging process being our interactions with our environment, such as chronic exposure to solar irradiation (UV, IR or visible wavelengths of light). The aim of this contribution, therefore, was to provide a review of the pathological mechanisms which may play roles in the development of extrinsic, mainly photo-, aging and to review how these molecular changes impact on the structure of the organ as a whole, resulting in loss of function. Finally, we will describe the advances which are occurring in imaging techniques which may allow further characterisation of aged skin.

Insights into the Cell Shape Dynamics of Migrating Dictyostelium discoideum

NASA Astrophysics Data System (ADS)

Driscoll, Meghan; Homan, Tess; McCann, Colin; Parent, Carole; Fourkas, John; Losert, Wolfgang

2010-03-01

Dynamic cell shape is a highly visible manifestation of the interaction between the internal biochemical state of a cell and its external environment. We analyzed the dynamic cell shape of migrating cells using the model system Dictyostelium discoideum. Applying a snake algorithm to experimental movies, we extracted cell boundaries in each frame and followed local boundary motion over long time intervals. Using a local motion measure that corresponds to protrusive/retractive activity, we found that protrusions are intermittent and zig-zag, whereas retractions are more sustained and straight. Correlations of this local motion measure reveal that protrusions appear more localized than retractions. Using a local shape measure, curvature, we also found that small peaks in boundary curvature tend to originate at the front of cells and propagate backwards. We will review the possible cytoskeletal origin of these mechanical waves.

Polyelectrolyte Multilayer Film Coated Silver Nanorods: An Effective Carrier System for Externally Activated Drug Delivery

NASA Astrophysics Data System (ADS)

Paramasivam, Gokul; Sharma, Varsha; Sundaramurthy, Anandhakumar

2017-08-01

Nanoparticle anisotropy offers unique functions and features in comparison with spherical nanoparticles (NPs) and makes anisotropic nanoparticles (ANPs) promising candidates in applications like drug delivery, imaging, biosensing and theranostics. Presence of surface active groups (e.g. amine, and carboxylate groups) on their surface provides binding sites for ligands or other biomolecules, and hence, this could be targeted for specific part or cells in our body. In the quest of such surface modification, functionalization of ANPs along Layer-by-Layer (LbL) coating of oppositely charged polyelectrolytes (PE) reduces cellular toxicity and promotes easy encapsulation of drugs. In this work, we report the silver nanorods (AgNRs) synthesis by adsorbate directed synthetic approach using cetyltrimethyl ammonium bromide (CTAB). The formed ANPs is investigated by scanning electron microscopy (SEM) and UV-Visible (UV-Vis) spectroscopy revealing the shaping of AgNRs of 3-16 nm aspect ratio with some presence of triangles. These NRs were further coated with bio polymers of chitosan (CH) and dextran sulphate (DS) through LbL approach and used for encapsulation of water soluble anti-bacterial drugs like ciprofloxacin hydrochloride (CFH). The encapsulation of drugs and profiles of drug release were investigated and compared to that of spherical silver nanoparticles (AgNPs). The added advantages of the proposed drug delivery system (DDS) can be externally activated to release the loaded drug and used as contrast agents for biological imaging under exposure to NIR light. Such system shows unique and attractive characteristics required for drug delivery and bioimaging thus offering the scope for further development as theranostic material.

Orbital docking system centerline color television camera system test

NASA Technical Reports Server (NTRS)

Mongan, Philip T.

1993-01-01

A series of tests was run to verify that the design of the centerline color television camera (CTVC) system is adequate optically for the STS-71 Space Shuttle Orbiter docking mission with the Mir space station. In each test, a mockup of the Mir consisting of hatch, docking mechanism, and docking target was positioned above the Johnson Space Center's full fuselage trainer, which simulated the Orbiter with a mockup of the external airlock and docking adapter. Test subjects viewed the docking target through the CTVC under 30 different lighting conditions and evaluated target resolution, field of view, light levels, light placement, and methods of target alignment. Test results indicate that the proposed design will provide adequate visibility through the centerline camera for a successful docking, even with a reasonable number of light failures. It is recommended that the flight deck crew have individual switching capability for docking lights to provide maximum shadow management and that centerline lights be retained to deal with light failures and user preferences. Procedures for light management should be developed and target alignment aids should be selected during simulated docking runs.

On-patient see-through augmented reality based on visual SLAM.

PubMed

Mahmoud, Nader; Grasa, Óscar G; Nicolau, Stéphane A; Doignon, Christophe; Soler, Luc; Marescaux, Jacques; Montiel, J M M

2017-01-01

An augmented reality system to visualize a 3D preoperative anatomical model on intra-operative patient is proposed. The hardware requirement is commercial tablet-PC equipped with a camera. Thus, no external tracking device nor artificial landmarks on the patient are required. We resort to visual SLAM to provide markerless real-time tablet-PC camera location with respect to the patient. The preoperative model is registered with respect to the patient through 4-6 anchor points. The anchors correspond to anatomical references selected on the tablet-PC screen at the beginning of the procedure. Accurate and real-time preoperative model alignment (approximately 5-mm mean FRE and TRE) was achieved, even when anchors were not visible in the current field of view. The system has been experimentally validated on human volunteers, in vivo pigs and a phantom. The proposed system can be smoothly integrated into the surgical workflow because it: (1) operates in real time, (2) requires minimal additional hardware only a tablet-PC with camera, (3) is robust to occlusion, (4) requires minimal interaction from the medical staff.

Photoredox-catalyzed Direct Reductive Amination of Aldehydes without an External Hydrogen/Hydride Source.

PubMed

Alam, Rauful; Molander, Gary A

2018-05-04

The direct reductive amination of aromatic aldehydes has been realized using a photocatalyst under visible light irradiation. The single electron oxidation of an in situ formed aminal species generates the putative α-amino radical that eventually delivers the reductive amination product. This method is operationally simple, highly selective, and functional group tolerant, which allows the direct synthesis of benzylic amines by a unique mechanistic pathway.

In0.15Ga0.85N visible-light metal-semiconductor-metal photodetector with GaN interlayers deposited by pulsed NH3

NASA Astrophysics Data System (ADS)

Wang, Hongxia; Zhang, Xiaohan; Wang, Hailong; Lv, Zesheng; Li, Yongxian; Li, Bin; Yan, Huan; Qiu, Xinjia; Jiang, Hao

2018-05-01

InGaN visible-light metal-semiconductor-metal photodetectors with GaN interlayers deposited by pulsed NH3 were fabricated and characterized. By periodically inserting the GaN thin interlayers, the surface morphology of InGaN active layer is improved and the phase separation is suppressed. At 5 V bias, the dark current reduced from 7.0 × 10-11 A to 7.0 × 10-13 A by inserting the interlayers. A peak responsivity of 85.0 mA/W was measured at 420 nm and 5 V bias, corresponding to an external quantum efficiency of 25.1%. The insertion of GaN interlayers also lead to a sharper spectral response cutoff.

Collisional desorption of NO by fast O atoms

NASA Technical Reports Server (NTRS)

Sonnenfroh, David M.; Caledonia, George E.

1993-01-01

Surface-adsorbed NO figures largely in the mechanism that produces visible glow around spacecraft in low Earth orbit (LEO). In view of the potential interference to optical observations such a glow represents, we have investigated the collision-induced desorption of NO from Al, Ni, and Z306 Chemglaze-coated surfaces at 96 K by hyperthermal (8 km/s) oxygen atoms. The removal of surface NO was followed by the monitoring of the visible fluorescence of electronically excited NO2 produced through the surface-mediated reaction O + NO. A variability in collisional desorption rate with material was observed. The limited data suggest a removal efficiency of 4 to 8% of the impinging O atom flux. Implications for the atmospheric scouring of contaminants from external surfaces of LEO spacecraft are discussed.

Planar optics with patterned chiral liquid crystals

NASA Astrophysics Data System (ADS)

Kobashi, Junji; Yoshida, Hiroyuki; Ozaki, Masanori

2016-06-01

Reflective metasurfaces based on metallic and dielectric nanoscatterers have attracted interest owing to their ability to control the phase of light. However, because such nanoscatterers require subwavelength features, the fabrication of elements that operate in the visible range is challenging. Here, we show that chiral liquid crystals with a self-organized helical structure enable metasurface-like, non-specular reflection in the visible region. The phase of light that is Bragg-reflected off the helical structure can be controlled over 0-2π depending on the spatial phase of the helical structure; thus planar elements with arbitrary reflected wavefronts can be created via orientation control. The circular polarization selectivity and external field tunability of Bragg reflection open a wide variety of potential applications for this family of functional devices, from optical isolators to wearable displays.

Fabrication of Worm-Like Nanorods and Ultrafine Nanospheres of Silver Via Solid-State Photochemical Decomposition

PubMed Central

2009-01-01

Worm-like nanorods and nanospheres of silver have been synthesized by photochemical decomposition of silver oxalate in water by UV irradiation in the presence of CTAB and PVP, respectively. No external seeds have been employed for the synthesis of Ag nanorods. The synthesized Ag colloids have been characterized by UV-visible spectra, powder XRD, HRTEM, and selected area electron diffraction (SAED). Ag nanospheres of average size around 2 nm have been obtained in the presence of PVP. XRD and TEM analyses revealed that top and basal planes of nanorods are bound with {111} facets. Williamson–Hall plot has revealed the presence of defects in the Ag nanospheres and nanorods. Formation of defective Ag nanocrystals is attributed to the heating effect of UV-visible irradiation. PMID:20596513

Repairing the damage to Atlantis' External Tank

NASA Image and Video Library

2007-03-07

On an upper level of high bay 1 of the Vehicle Assembly Building, technicians secure protective material around the base of the nose cone of Atlantis' external tank. The nose cone will undergo repair for hail damage. A severe thunderstorm with golf ball-sized hail caused visible divots in the giant tank's foam insulation and minor surface damage to about 26 heat shield tiles on the shuttle's left wing. Further evaluation of the tank is necessary to get an accurate accounting of foam damage and determine the type of repair required and the time needed for that work. A new target launch date has not been determined, but teams will focus on preparing Atlantis for liftoff in late April on mission STS-117.

Repairing the damage to Atlantis' External Tank

NASA Image and Video Library

2007-03-07

On an upper level of high bay 1 of the Vehicle Assembly Building, technicians move protective material toward the nose cone (foreground) of Atlantis' external tank. The nose cone will undergo repair for hail damage. A severe thunderstorm with golf ball-sized hail caused visible divots in the giant tank's foam insulation and minor surface damage to about 26 heat shield tiles on the shuttle's left wing. Further evaluation of the tank is necessary to get an accurate accounting of foam damage and determine the type of repair required and the time needed for that work. A new target launch date has not been determined, but teams will focus on preparing Atlantis for liftoff in late April on mission STS-117.

Repairing the damage to Atlantis' External Tank

NASA Image and Video Library

2007-03-07

On an upper level of high bay 1 of the Vehicle Assembly Building, technicians secure protective material around Atlantis' external tank. The preparations are for future repair work of the hail damage that happened Feb. 27. A severe thunderstorm with golf ball-sized hail caused visible divots in the giant tank's foam insulation and minor surface damage to about 26 heat shield tiles on the shuttle's left wing. Further evaluation of the tank is necessary to get an accurate accounting of foam damage and determine the type of repair required and the time needed for that work. A new target launch date has not been determined, but teams will focus on preparing Atlantis for liftoff in late April on mission STS-117.

Urethroscopy and urethral cytology in men with external genital condyloma.

PubMed

Fralick, R A; Malek, R S; Goellner, J R; Hyland, K M

1994-03-01

To develop guidelines as to which asymptomatic male patients with genital human papillomavirus (HPV) infection need further evaluation of the urethra, we studied two screening methods: urethroscopy and voided urethral cytology. In a four-year period, 135 asymptomatic men underwent complete screening for HPV infection. They were evaluated because of HPV-related genital disease in their female sex partners or visible genital lesions, or both. Of the 135 patients, 21 (16%) had no clinical, subclinical, cytologic, or urethroscopic evidence of disease, and 114 (84%) had biopsy-proven HPV infection. Of these 114 patients, only 14 (12.3%) had intraurethral condyloma. All of these 14 patients had current or historical evidence of meatal or perimeatal "sentinel" lesions. They constituted 29.8 percent of 47 such patients with sentinel lesions. In 5 patients (4%), results of voided urine cytology were positive for condyloma cells, but only 1 of these had visible intraurethral disease. Of the 14 patients with urethral disease, only 1 (7%) had positive results of urine cytology. These observations suggest that any asymptomatic male patient undergoing screening for condyloma acuminatum who has a history of or demonstrable subclinical or grossly visible perimeatal or meatal HPV infection should undergo urethroscopy and that voided urine cytology is not a reliable or cost-effective test for the detection of visible intraurethral disease.

Dual-Band Modulation of Visible and Near-Infrared Light Transmittance in an All-Solution-Processed Hybrid Micro-Nano Composite Film.

PubMed

Liang, Xiao; Chen, Mei; Guo, Shumeng; Zhang, Lanying; Li, Fasheng; Yang, Huai

2017-11-22

Smart windows with controllable visible and near-infrared light transmittance can significantly improve the building's energy efficiency and inhabitant comfort. However, most of the current smart window technology cannot achieve the target of ideal solar control. Herein, we present a novel all-solution-processed hybrid micronano composite smart material that have four optical states to separately modulate the visible and NIR light transmittance through voltage and temperature, respectively. This dual-band optical modulation was achieved by constructing a phase-separated polymer framework, which contains the microsized liquid crystals domains with a negative dielectric constant and tungsten-doped vanadium dioxide (W-VO 2 ) nanocrystals (NCs). The film with 2.5 wt % W-VO 2 NCs exhibits transparency at normal condition, and the passage of visible light can be reversibly and actively regulated between 60.8% and 1.3% by external applied voltage. Also, the transmittance of NIR light can be reversibly and passively modulated between 59.4% and 41.2% by temperature. Besides, the film also features easy all-solution processability, fast electro-optical (E-O) response time, high mechanical strength, and long-term stability. The as-prepared film provides new opportunities for next-generation smart window technology, and the proposed strategy is conductive to engineering novel hybrid inorganic-organic functional matters.

46 CFR 112.45-1 - Visible indicators.

Code of Federal Regulations, 2012 CFR

2012-10-01

... COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING EMERGENCY LIGHTING AND POWER SYSTEMS Visible Indicators § 112.45-1 Visible indicators. There must be visible indicators in the... controlled emergency power source is supplying the emergency loads. ...

46 CFR 112.45-1 - Visible indicators.

Code of Federal Regulations, 2013 CFR

2013-10-01

... COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING EMERGENCY LIGHTING AND POWER SYSTEMS Visible Indicators § 112.45-1 Visible indicators. There must be visible indicators in the... controlled emergency power source is supplying the emergency loads. ...

46 CFR 112.45-1 - Visible indicators.

Code of Federal Regulations, 2011 CFR

2011-10-01

... COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING EMERGENCY LIGHTING AND POWER SYSTEMS Visible Indicators § 112.45-1 Visible indicators. There must be visible indicators in the... controlled emergency power source is supplying the emergency loads. ...

46 CFR 112.45-1 - Visible indicators.

Code of Federal Regulations, 2010 CFR

2010-10-01

... COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING EMERGENCY LIGHTING AND POWER SYSTEMS Visible Indicators § 112.45-1 Visible indicators. There must be visible indicators in the... controlled emergency power source is supplying the emergency loads. ...

46 CFR 112.45-1 - Visible indicators.

Code of Federal Regulations, 2014 CFR

2014-10-01

... COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING EMERGENCY LIGHTING AND POWER SYSTEMS Visible Indicators § 112.45-1 Visible indicators. There must be visible indicators in the... controlled emergency power source is supplying the emergency loads. ...

Preparation, characterization and photocatalytic activity of visible-light-driven plasmonic Ag/AgBr/ZnFe{sub 2}O{sub 4} nanocomposites

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, Xiaojuan, E-mail: lixiaojuan@fzu.edu.cn; Tang, Duanlian; Tang, Fan

2014-08-15

Highlights: • A plasmonic Ag/AgBr/ZnFe{sub 2}O{sub 4} photocatalyst has been successfully synthesized. • Ag/AgBr/ZnFe{sub 2}O{sub 4} nanocomposites exhibit high visible light photocatalytic activity. • Ag/AgBr/ZnFe{sub 2}O{sub 4} photocatalyst is stable and magnetically separable. - Abstract: A visible-light-driven plasmonic Ag/AgBr/ZnFe{sub 2}O{sub 4} nanocomposite has been successfully synthesized via a deposition–precipitation and photoreduction through a novel one-pot process. X-ray diffraction spectroscopy, X-ray photoelectron spectroscopy, scanning electron microscopy, transmission electron microscopy and UV–vis diffuse reflectance spectroscopy were employed to investigate the crystal structure, chemical composition, morphology, and optical properties of the as-prepared nanocomposites. The photocatalytic activities of the nanocomposites were evaluated by photodegradationmore » of Rhodamine B (RhB) and phenol under visible light. The results demonstrated that the obtained Ag/AgBr/ZnFe{sub 2}O{sub 4} nanocomposites exhibited higher photocatalytic activity as compared to pure ZnFe{sub 2}O{sub 4}. In addition, the sample photoreduced for 20 min and calcined at 500 °C achieved the highest photocatalytic activity. Furthermore, the Ag/AgBr/ZnFe{sub 2}O{sub 4} nanocomposite has high stability under visible light irradiation and could be conveniently separated by using an external magnetic field.« less

Toward a new information infrastructure in health technology assessment: communication, design, process, and results.

PubMed

Neikter, Susanna Allgurin; Rehnqvist, Nina; Rosén, Måns; Dahlgren, Helena

2009-12-01

The aim of this study was to facilitate effective internal and external communication of an international network and to explore how to support communication and work processes in health technology assessment (HTA). STRUCTURE AND METHODS: European network for Health Technology Assessment (EUnetHTA) connected sixty-four HTA Partner organizations from thirty-three countries. User needs in the different steps of the HTA process were the starting point for developing an information system. A step-wise, interdisciplinary, creative approach was used in developing practical tools. An Information Platform facilitated the exchange of scientific information between Partners and with external target groups. More than 200 virtual meetings were set up during the project using an e-meeting tool. A Clearinghouse prototype was developed with the intent to offering a single point of access to HTA relevant information. This evolved into a next step not planned from the outset: Developing a running HTA Information System including several Web-based tools to support communication and daily HTA processes. A communication strategy guided the communication effort, focusing on practical tools, creating added value, involving stakeholders, and avoiding duplication of effort. Modern technology enables a new information infrastructure for HTA. The potential of information and communication technology was used as a strategic tool. Several target groups were represented among the Partners, which supported collaboration and made it easier to identify user needs. A distinctive visual identity made it easier to gain and maintain visibility on a limited budget.

Photoactive and self-sensing P3HT-based thin films for strain and corrosion monitoring

NASA Astrophysics Data System (ADS)

Ryu, Donghyeon; Loh, Kenneth J.

2014-03-01

Structural systems deteriorate due to excessive deformation and corrosive environments. If damage is left undetected, they can propagate to cause sudden collapse. However, one of the main difficulties of monitoring damage progression is that, for example, excessive/plastic deformation and corrosion are drastically different physical processes. Strain is a mechanical phenomenon, whereas corrosion is a complex electrochemical process. The current strategy for structural health monitoring (SHM) is to use either different types of sensors or to employ system identification for quantifying overall changes to the structure. In this study, an alternative SHM paradigm is proposed in that a single, multifunctional material would be able to selectively sense different but simultaneously occurring structural damage. In particular, a photoactive and self-sensing thin film was developed for monitoring strain and corrosion. Another unique aspect was that the films were self-sensing and did not depend on external electrical energy for operations. First, the thin films were fabricated using photoactive poly(3-hexylthiophene) (P3HT) and other functional polymers using spin-coating and layerby- layer assembly. Second, the fabricated thin films were interrogated using an ultraviolet-visible (UV-Vis) spectrophotometer for quantifying their optical response to applied external stimuli, such as strain and exposure to pH buffer solutions. Lastly, the multifunctional thin films were tested and validated for strain and pH sensing. Interrogation of these separate responses was achieved by illuminating the thin films different wavelengths of light and then measuring the corresponding electrical current generated.

Motion-Base Simulator Evaluation of an Aircraft Using an External Vision System

NASA Technical Reports Server (NTRS)

Kramer, Lynda J.; Williams, Steven P.; Arthur, J. J.; Rehfeld, Sherri A.; Harrison, Stephanie

2012-01-01

Twelve air transport-rated pilots participated as subjects in a motion-base simulation experiment to evaluate the use of eXternal Vision Systems (XVS) as enabling technologies for future supersonic aircraft without forward facing windows. Three head-up flight display concepts were evaluated -a monochromatic, collimated Head-up Display (HUD) and a color, non-collimated XVS display with a field-of-view (FOV) equal to and also, one significantly larger than the collimated HUD. Approach, landing, departure, and surface operations were conducted. Additionally, the apparent angle-of-attack (AOA) was varied (high/low) to investigate the vertical field-of-view display requirements and peripheral, side window visibility was experimentally varied. The data showed that lateral approach tracking performance and lateral landing position were excellent regardless of AOA, display FOV, display collimation or whether peripheral cues were present. However, the data showed glide slope approach tracking appears to be affected by display size (i.e., FOV) and collimation. The monochrome, collimated HUD and color, uncollimated XVS with Full FOV display had (statistically equivalent) glide path performance improvements over the XVS with HUD FOV display. Approach path performance results indicated that collimation may not be a requirement for an XVS display if the XVS display is large enough and employs color. Subjective assessments of mental workload and situation awareness also indicated that an uncollimated XVS display may be feasible. Motion cueing appears to have improved localizer tracking and touchdown sink rate across all displays.

49 CFR 236.515 - Visibility of cab signals.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 4 2010-10-01 2010-10-01 false Visibility of cab signals. 236.515 Section 236.515..., MAINTENANCE, AND REPAIR OF SIGNAL AND TRAIN CONTROL SYSTEMS, DEVICES, AND APPLIANCES Automatic Train Stop, Train Control and Cab Signal Systems Standards § 236.515 Visibility of cab signals. The cab signals...

49 CFR 236.515 - Visibility of cab signals.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 49 Transportation 4 2011-10-01 2011-10-01 false Visibility of cab signals. 236.515 Section 236.515..., MAINTENANCE, AND REPAIR OF SIGNAL AND TRAIN CONTROL SYSTEMS, DEVICES, AND APPLIANCES Automatic Train Stop, Train Control and Cab Signal Systems Standards § 236.515 Visibility of cab signals. The cab signals...

49 CFR 236.515 - Visibility of cab signals.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 49 Transportation 4 2014-10-01 2014-10-01 false Visibility of cab signals. 236.515 Section 236.515..., MAINTENANCE, AND REPAIR OF SIGNAL AND TRAIN CONTROL SYSTEMS, DEVICES, AND APPLIANCES Automatic Train Stop, Train Control and Cab Signal Systems Standards § 236.515 Visibility of cab signals. The cab signals...

49 CFR 236.515 - Visibility of cab signals.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 49 Transportation 4 2012-10-01 2012-10-01 false Visibility of cab signals. 236.515 Section 236.515..., MAINTENANCE, AND REPAIR OF SIGNAL AND TRAIN CONTROL SYSTEMS, DEVICES, AND APPLIANCES Automatic Train Stop, Train Control and Cab Signal Systems Standards § 236.515 Visibility of cab signals. The cab signals...

49 CFR 236.515 - Visibility of cab signals.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 49 Transportation 4 2013-10-01 2013-10-01 false Visibility of cab signals. 236.515 Section 236.515..., MAINTENANCE, AND REPAIR OF SIGNAL AND TRAIN CONTROL SYSTEMS, DEVICES, AND APPLIANCES Automatic Train Stop, Train Control and Cab Signal Systems Standards § 236.515 Visibility of cab signals. The cab signals...

Scaling view by the Virtual Nature Systems

NASA Astrophysics Data System (ADS)

Klenov, Valeriy

2010-05-01

The Actual Nature Systems (ANS) continually are under spatial-temporal governing external influences from other systems (Meteorology and Geophysics). This influences provide own spatial temporal patterns on the Earth Nature Systems, which reforms these influences by own manner and scales. These at last three systems belong to the Open Non Equilibrium Nature Systems (ONES). The Geophysics and Meteorology Systems are both governing for the ANS on the Earth. They provide as continual energetic pressure and impacts, and direct Extremes from the both systems to the ANS on Earth surface (earthquakes, storms, and others). The Geodynamics of the ANS is under mixing of influence for both systems, on their scales and on dynamics of their spatial-temporal structures, and by own ANS properties, as the ONES. To select influences of external systems on the Earth systems always is among major tasks of the Geomorphology. Mixing of the Systems scales and dynamics provide specific properties for the memory of Earth system. The memory of the ANS has practical value for their multi-purpose management. The knowledge of these properties is the key for research spatial-temporal GeoDynamics and Trends of Earth Nature Systems. Selection of the influences in time and space requires for special tool, requires elaboration and action of the Virtual Nature Systems (VNS), which are enliven computer doubles for analysis Geodynamics of the ANS. The Experience on the VNS enables to assess influence of each and both external factors on the ANS. It is source of knowledge for regional tectonic and climate oscillations, trends, and threats. Research by the VNS for spatial-temporal dynamics and structures of stochastic regimes of governing systems and processes results in stochastic GeoDynamics of environmental processes, in forming of false trends and blanks in natural records. This ‘wild dance' of 2D stochastic patterns and their interaction each other and generates acting structures of river nets, and of river basins, in multi-layer, multi-scale, and multi-driven structures of surface processes. It results in the Information Loss Law for observed memory of the VNS (and of external drivers) which gradually cut off own Past and distort own history. This view on the GeoDynamics appeared after long time field measurements thousand of terrace levels, hundreds of terrace ranks, and many terrace complexes in river basins of all scales - for the purpose to recognize their deforming by climatic and tectonic spatial-temporal influences. The method for following up of terrace levels along valleys was used in the Geomorphology and Geology for a long time, by linking fragments of level to ‘cycles'. It gradually linked them by heights above riverbed. The understanding of this logical mistake was happened (as insight) during observing from upstream a valley. All fragmental levels downstream were good visible, without chances for their correlation ‘by height' or ‘by number'. Instead of link of fragments, this explains process of river valleys' stochastic GeoDynamics by properties of the ONES (I. Prigogine et al., 1984) to generate oscillations. Is only first view, but later it turned to simple mechanic of Information Loss Law action in the GeoInformatics for Nature Systems (Klenov, 1980, et al.). The Information Loss distorts and destroys natural records (sources for data on the Past exogenous and endogenous rivers). This simple equation was received by multiple measures of terrace rank, and other natural records. It explains origin of false trend in natural records, destroys most own history by stochastic dynamics of the ONES. It prevents to restore of nature records as a memory of the Past. Non-disturbed is only small time between the Past and the Future, which looks like a peak between two non-linear losses. The history of Past (of the ANS, and of external drivers) are destroyed by the ANS. The Future becomes none determined due unknown 2D data of future external influences. However, the effect is the reliable Outstripping Monitoring for impending disasters and of other processes with satisfactory exactness. It was proved by direct validations (by use observed records). The conclusions are as follows: The ILL is mechanics for dissipation the Past and indeterminism the Future of the Nature. Moving back along the VNS' Phase Trajectory changes a view on natural records, and is chance to restore history of the ANS and its external drivers.

Visible light-induced OH radicals in Ga2O3: an EPR study.

PubMed

Tzitrinovich, Zeev; Lipovsky, Anat; Gedanken, Aharon; Lubart, Rachel

2013-08-21

Reactive oxygen species (ROS) were found to exist in water suspensions of several metal oxide nanoparticles (NPs), such as CuO, TiO2 and ZnO. Visible light irradiation enhanced the capability of TiO2 and ZnO NPs to generate ROS, thus increasing their antibacterial effects. Because of the possible toxic effects on the host tissue it is desired to find nano-metal oxides which do not produce ROS under room light, but only upon a strong external stimulus. Using the technique of electron-spin resonance (ESR) coupled with spin trapping, we examined the ability of Ga2O3 submicron-particle suspensions in water to produce reactive oxygen species with and without visible light irradiation. We found that in contrast to ZnO and TiO2 NPs, no ROS are produced by Ga2O3 under room light. Nevertheless blue light induced hydroxyl radical formation in Ga2O3. This finding might suggest that NPs of Ga2O3 could be used safely for infected skin sterilization.

Application of visible/near-infrared reflectance spectroscopy for predicting internal and external quality in pepper.

PubMed

Toledo-Martín, Eva María; García-García, María Carmen; Font, Rafael; Moreno-Rojas, José Manuel; Gómez, Pedro; Salinas-Navarro, María; Del Río-Celestino, Mercedes

2016-07-01

The characterization of internal (°Brix, pH, malic acid, total phenolic compounds, ascorbic acid and total carotenoid content) and external (color, firmness and pericarp wall thickness) pepper quality is necessary to better understand its possible applications and increase consumer awareness of its benefits. The main aim of this work was to examine the feasibility of using visible/near-infrared reflectance spectroscopy (VIS-NIRS) to predict quality parameters in different pepper types. Commercially available spectrophotometers were evaluated for this purpose: a Polychromix Phazir spectrometer for intact raw pepper, and a scanning monochromator for freeze-dried pepper. The RPD values (ratio of the standard deviation of the reference data to the standard error of prediction) obtained from the external validation exceeded a value of 3 for chlorophyll a and total carotenoid content; values ranging between 2.5 < RPD < 3 for total phenolic compounds; between 1.5 < RPD <2.5 for °Brix, pH, color parameters a* and h* and chlorophyll b; and RPD values below 1.5 for fruit firmness, pericarp wall thickness, color parameters C*, b* and L*, vitamin C and malic acid content. The present work has led to the development of multi-type calibrations for pepper quality parameters in intact and freeze-dried peppers. The majority of NIRS equations obtained were suitable for screening purposes in pepper breeding programs. Components such as pigments (xanthophyll, carotenes and chlorophyll), glucides, lipids, cellulose and water were used by modified partial least-squares regression for modeling the predicting equations. © 2015 Society of Chemical Industry. © 2015 Society of Chemical Industry.

Space Shuttle Atlantis' external tank repairs from Hail Damage

NASA Image and Video Library

2007-04-09

In the Vehicle Assembly Building, markers show the hail damage being repaired on the external tank of Space Shuttle Atlantis. The white hole with a red circle around it is a hole prepared for molding and material application. The red material is sealant tape so the mold doesn't leak when the foam rises against the mold. The white/ translucent square mold is an area where the foam has been applied and the foam has risen and cured against the mold surface. The area will be de-molded and sanded flush the with adjacent area. In late February, Atlantis' external tank received hail damage during a severe thunderstorm that passed through the Kennedy Space Center Launch Complex 39 area. The hail caused visible divots in the giant tank's foam insulation as well as minor surface damage to about 26 heat shield tiles on the shuttle's left wing. The March launch was postponed and has not yet been rescheduled due to the repair process.

Adolescent Defense Style as Correlate of Problem Behavior.

PubMed

Huemer, Julia; Shaw, Richard J; Prunas, Antonio; Hall, Rebecca; Gross, James; Steiner, Hans

2015-09-01

Adolescent problem behaviors are often the visible results of intrapsychic distress. Defensive reactions are the unconscious means of managing intrapsychic distress. This cross-sectional study examines the strength of defensive style as measured by self-report on the Response Evaluation Measure (REM-71) relative to age, sex, and SES, as a correlate of internalizing and externalizing problem behaviors, as assessed by the Youth Self Report (YSR). A sample of 1,487 students from two suburban high schools completed self-report measures of defense style, self-esteem, and internalizing and externalizing problem behaviors. Demographic variables (age, sex, and SES) were included as covariates. Mature and immature defense style correlated as expected with problem behaviors. Demographic variables contributed minimally to the variance in the outcome variable. Defense style, as assessed by the REM-71, is a significant correlate of clinically elevated internalizing and externalizing problem behaviors in youth as in adults. This study adds to the convergent validity of the REM-71.

Space Shuttle Atlantis' external tank repairs from Hail Damage

NASA Image and Video Library

2007-04-09

In the Vehicle Assembly Building, United Space Alliance technicians Brenda Morris and Brian Williams are applying foam and molds on Space Shuttle Atlantis' external tank to areas damaged by hail. The white hole with a red circle around it (upper right) is a hole prepared for molding and material application. The red material is sealant tape so the mold doesn't leak when the foam rises against the mold. The white/ translucent square mold is an area where the foam has been applied and the foam has risen and cured against the mold surface. In late February, Atlantis' external tank received hail damage during a severe thunderstorm that passed through the Kennedy Space Center Launch Complex 39 area. The hail caused visible divots in the giant tank's foam insulation as well as minor surface damage to about 26 heat shield tiles on the shuttle's left wing. The March launch was postponed and has not yet been rescheduled due to the repair process.

Automated Visibility & Cloud Cover Measurements with a Solid State Imaging System

DTIC Science & Technology

1989-03-01

GL-TR-89-0061 SIO Ref. 89-7 MPL-U-26/89 AUTOMATED VISIBILITY & CLOUD COVER MEASUREMENTS WITH A SOLID-STATE IMAGING SYSTEM C) to N4 R. W. Johnson W. S...include Security Classification) Automated Visibility & Cloud Measurements With A Solid State Imaging System 12. PERSONAL AUTHOR(S) Richard W. Johnson...based imaging systems , their ics and control algorithms, thus they ar.L discussed sepa- initial deployment and the preliminary application of rately

Magnetooptics of the luminescent transitions in Tb3+:Gd3Ga5O12

NASA Astrophysics Data System (ADS)

Valiev, Uygun V.; Gruber, John B.; Ivanov, Igor'A.; Burdick, Gary W.; Liang, Hongbin; Zhou, Lei; Fu, Dejun; Pelenovich, Oleg V.; Pelenovich, Vasiliy O.; Lin, Zhou

2015-08-01

The spectra of the luminescence and magnetic circular polarization of luminescence in terbium-gadolinium gallium garnet Tb3+:Gd3Ga5O12 (Tb3+:GGG) were studied within the visible spectral range at temperatures T = 90 and 300 K in an external magnetic field of 0.45 T. The Zeeman effect in the luminescence "green" band associated with 4f → 4f transition 5D4 → 7F5 of Tb3+:GGG was also studied at T = 90 K in an external field of 0.55 T. Measurement of the Zeeman effect in Tb3+:GGG carried out for some doublet lines of the luminescence band 5D4 → 7F5 at T = 90 K shows that a magnetooptical effect of the intensity change of the emitted light is observed on these lines, in contrast to pure Zeeman splitting of the emission lines measured in the luminescence band 5D4 → 7F6. For the systems we have studied, the maximal value of the magnetooptical effect of the intensity change of the luminescence line at low temperatures has been achieved in paramagnetic garnet Tb0.2Y2.8Al5O12 at comparatively low magnetic fields.

Optical detection system for MEMS-type pressure sensor

NASA Astrophysics Data System (ADS)

Sareło, K.; Górecka-Drzazga, A.; Dziuban, J. A.

2015-07-01

In this paper a special optical detection system designed for a MEMS-type (micro-electro-mechanical system) silicon pressure sensor is presented. The main part of the optical system—a detection unit with a perforated membrane—is bonded to the silicon sensor, and placed in a measuring system. An external light source illuminates the membrane of the pressure sensor. Owing to the light reflected from the deflected membrane sensor, the optical pattern consisting of light points is visible, and pressure can be estimated. The optical detection unit (20   ×   20   ×   20.4 mm3) is fabricated using microengineering techniques. Its dimensions are adjusted to the dimensions of the pressure sensor (5   ×   5 mm2 silicon membrane). Preliminary tests of the optical detection unit integrated with the silicon pressure sensor are carried out. For the membrane sensor from 15 to 60 µm thick, a repeatable detection of the differential pressure in the range of 0 to 280 kPa is achieved. The presented optical microsystem is especially suitable for the pressure measurements in a high radiation environment.

Supporting BPMN choreography with system integration artefacts for enterprise process collaboration

NASA Astrophysics Data System (ADS)

Nie, Hongchao; Lu, Xudong; Duan, Huilong

2014-07-01

Business Process Model and Notation (BPMN) choreography modelling depicts externally visible message exchanges between collaborating processes of enterprise information systems. Implementation of choreography relies on designing system integration solutions to realise message exchanges between independently developed systems. Enterprise integration patterns (EIPs) are widely accepted artefacts to design integration solutions. If the choreography model represents coordination requirements between processes with behaviour mismatches, the integration designer needs to analyse the routing requirements and address these requirements by manually designing EIP message routers. As collaboration scales and complexity increases, manual design becomes inefficient. Thus, the research problem of this paper is to explore a method to automatically identify routing requirements from BPMN choreography model and to accordingly design routing in the integration solution. To achieve this goal, recurring behaviour mismatch scenarios are analysed as patterns, and corresponding solutions are proposed as EIP routers. Using this method, a choreography model can be analysed by computer to identify occurrences of mismatch patterns, leading to corresponding router selection. A case study demonstrates that the proposed method enables computer-assisted integration design to implement choreography. A further experiment reveals that the method is effective to improve the design quality and reduce time cost.

Aviation Fuel Exposure Resulting in Otitis Externa with Vertigo.

PubMed

Long, Robert J; Charles, Reese A

2018-07-01

Otitis externa secondary to irritant or chemical exposure is well documented; however, specifically secondary to jet fuel exposure and its associated toxicology is not. Over 2 million military and civilian personnel per year are occupationally exposed to aviation fuels. An aircraft maintainer presented with noninfectious acute otitis externa secondary to external ear canal exposure to JP-5 jet fuel. Proper exposure guidelines were followed, but it was not realized that the external ear canal was involved. The first symptoms to emerge were vertigo, dizziness, and disequilibrium; however, on physical exam it appeared that there was no middle ear involvement. Otitis externa normally does not present with vestibular symptoms as the pathology affects the external ear canal dermal tissue. Upon review of JP-5's toxicology profile, dermal absorption is a route of entry and can cause general neurological symptoms, including loss of coordination. This case highlights potential deficiencies in the standardized safety data sheets that are used after exposure. Without mention of possible auricular exposure one may focus on the logical protection of the eyes, mouth, and visible skin. This is concerning due to potential delayed exposure symptoms, dermal absorption, high level of dermal destruction, and the close proximity to the sensory system. The goal of this case report is to improve the knowledge of providers caring for personnel who may be exposed and to suggest possible revisions to the Safety Data Sheets for jet fuel.Long RJ, Charles RA. Aviation fuel exposure resulting in otitis externa with vertigo. Aerosp Med Hum Perform. 2018; 89(7):661-663.

HandSight: Supporting Everyday Activities through Touch-Vision

DTIC Science & Technology

2015-10-01

switches between IR and RGB o Large, low resolution, and fixed focal length > 1ft • Raspberry PI NoIR: https://www.raspberrypi.org/products/ pi -noir...camera/ o Raspberry Pi NoIR camera with external visible light filters o Good image quality, manually adjustable focal length, small, programmable 11...purpose and scope of the research. 2. KEYWORDS: Provide a brief list of keywords (limit to 20 words). 3. ACCOMPLISHMENTS: The PI is reminded that

An ultraviolet-visible spectrophotometer automation system. Part 3: Program documentation

NASA Astrophysics Data System (ADS)

Roth, G. S.; Teuschler, J. M.; Budde, W. L.

1982-07-01

The Ultraviolet-Visible Spectrophotometer (UVVIS) automation system accomplishes 'on-line' spectrophotometric quality assurance determinations, report generations, plot generations and data reduction for chlorophyll or color analysis. This system also has the capability to process manually entered data for the analysis of chlorophyll or color. For each program of the UVVIS system, this document contains a program description, flowchart, variable dictionary, code listing, and symbol cross-reference table. Also included are descriptions of file structures and of routines common to all automated analyses. The programs are written in Data General extended BASIC, Revision 4.3, under the RDOS operating systems, Revision 6.2. The BASIC code has been enhanced for real-time data acquisition, which is accomplished by CALLS to assembly language subroutines. Two other related publications are 'An Ultraviolet-Visible Spectrophotometer Automation System - Part I Functional Specifications,' and 'An Ultraviolet-Visible Spectrophotometer Automation System - Part II User's Guide.'

Multi-channel medical imaging system

DOEpatents

Frangioni, John V

2013-12-31

A medical imaging system provides simultaneous rendering of visible light and fluorescent images. The system may employ dyes in a small-molecule form that remain in the subject's blood stream for several minutes, allowing real-time imaging of the subject's circulatory system superimposed upon a conventional, visible light image of the subject. The system may provide an excitation light source to excite the fluorescent substance and a visible light source for general illumination within the same optical guide used to capture images. The system may be configured for use in open surgical procedures by providing an operating area that is closed to ambient light. The systems described herein provide two or more diagnostic imaging channels for capture of multiple, concurrent diagnostic images and may be used where a visible light image may be usefully supplemented by two or more images that are independently marked for functional interest.

Multi-channel medical imaging system

DOEpatents

Frangioni, John V.

2016-05-03

A medical imaging system provides simultaneous rendering of visible light and fluorescent images. The system may employ dyes in a small-molecule form that remain in a subject's blood stream for several minutes, allowing real-time imaging of the subject's circulatory system superimposed upon a conventional, visible light image of the subject. The system may provide an excitation light source to excite the fluorescent substance and a visible light source for general illumination within the same optical guide used to capture images. The system may be configured for use in open surgical procedures by providing an operating area that is closed to ambient light. The systems described herein provide two or more diagnostic imaging channels for capture of multiple, concurrent diagnostic images and may be used where a visible light image may be usefully supplemented by two or more images that are independently marked for functional interest.

Documenting the doable and doing the documented: bridging strategies at the UK Stem Cell Bank.

PubMed

Stephens, Neil; Atkinson, Paul; Glasner, Peter

2011-12-01

We explore the local negotiation of regulatory practice at the UK Stem Cell Bank, the first Bank of its type in the world. Basing our empirical work on a detailed analysis of one aspect of the Bank's regulatory commitment--the completion of the Cell Line Information form--we make visible the necessary judgements and labour involved in interpreting and operationalizing externally imposed regulation. The discussion opens by detailing the problems encountered when the Bank completes the form: reconciling a bureaucratic system of accountability with craft-like laboratory skills involving multiple kinds of tacit knowledge. We follow this by explicating the emergent 'bridging strategies' pursued by the Bank to address these issues, highlighting their reliance upon the formation of trust and social networks. The closing discussion emphasizes the contingent assembly of regulatory practices that emerge in the local setting.

Developmental effects of the protein kinase inhibitor kenpaullone on the sea urchin embryo.

PubMed

Anello, Letizia; Cavalieri, Vincenzo; Di Bernardo, Maria

2018-01-01

The selection and validation of bioactive compounds require multiple approaches, including in-depth analyses of their biological activity in a whole-animal context. We exploited the sea urchin embryo in a rapid, medium-scale range screening to test the effects of the small synthetic kinase inhibitor kenpaullone. We show that sea urchin embryos specifically respond to this molecule depending on both dose and timing of administration. Phenotypic effects of kenpaullone are not immediately visible, since this molecule affects neither the fertilization nor the spatial arrangement of blastomeres at early developmental stages. Nevertheless, kenpaullone exposure from the beginning of embryogenesis profoundly perturbs specification, detachment from the epithelium, and migration of the primary mesenchyme cells, thus affecting the whole embryonic epithelial mesenchymal transition process. Our results reaffirm the sea urchin embryo as an excellent and sensitive in vivo system, which provides straightforward and rapid response to external stimuli. Copyright © 2017 Elsevier Inc. All rights reserved.

Aspidoras mephisto, new species: The first troglobitic Callichthyidae (Teleostei: Siluriformes) from South America

PubMed Central

Bichuette, Maria Elina

2017-01-01

Aspidoras mephisto n. sp. is described from the Anésio-Russão cave system, upper Tocantins River basin, Goiás, Brazil. The species can be readily distinguished from its congeners by troglomorphic features and also by presenting the following combination of features: infraorbital 1 generally with well-developed ventral laminar; or moderately developed; poorly-developed serrations on posterior margin of pectoral spine; nuchal plate not externally visible; dorsal fin, even in conspicuously colored specimens, with only dark brown or black chromatophores concentrated on rays, forming spots in some specimens; membranes hyaline; or sparse dark brown or black chromatophores on membranes, not forming any conspicuous pattern; and inner laminar expansion of infraorbital 1 moderately developed. Information about its habitat, ecology, behaviour and conservation status are provided and also a brief description of the juvenile stage. PMID:28248959

Linnehan during Expedition 16/STS-123 EVA 3

NASA Image and Video Library

2008-03-18

ISS016-E-033024 (17/18 March 2008) --- Astronaut Rick Linnehan, STS-123 mission specialist, uses a digital camera to expose a photo of his helmet visor during the mission's third scheduled session of extravehicular activity (EVA) as construction and maintenance continue on the International Space Station. Also visible in the reflections in the visor are various components of the station, the docked Space Shuttle Endeavour and a blue and white portion of Earth. During the 6-hour, 53-minute spacewalk, Linnehan and astronaut Robert L. Behnken (out of frame), mission specialist, installed a spare-parts platform and tool-handling assembly for Dextre, also known as the Special Purpose Dextrous Manipulator (SPDM). Among other tasks, they also checked out and calibrated Dextre's end effector and attached critical spare parts to an external stowage platform. The new robotic system is scheduled to be activated on a power and data grapple fixture located on the Destiny laboratory on flight day nine.

The pioneer projects: Economical exploration of the solar system

NASA Technical Reports Server (NTRS)

Spahr, J. R.; Hall, C. F.

1975-01-01

The interplanetary Pioneer missions are reviewed in terms of management implications and cost control. The responsibilities, organizational structure, and management practices of the Pioneer Projects are presented. The lines of authority and areas of responsibility of the principal organizational elements supporting the Pioneer missions are identified, and the methods employed for maintaining effective and timely interactions among these elements are indicated. The technical and administrative functions of the various organizational elements of the Pioneer Project Office at Ames Research Center are described in terms of their management responsibilities and interactions with other elements of the Project Office and with external organizations having Pioneer Project responsibilities. The management and control of activities prior to and during the hardware procurement phase are described to indicate the basis for obtaining visibility of the technical progress, utilization of resources, and cost performance of the contractors and other institutions supporting the Pioneer projects.

External versus Internal Distraction Devices in Treatment of Obstructive Sleep Apnea in Craniofacial Anomalies.

PubMed

Rachmiel, Adi; Nseir, Saleh; Emodi, Omri; Aizenbud, Dror

2014-07-01

Obstructive sleep apnea is often associated with congenital craniofacial malformations due to hypoplastic mandible and decreased pharyngeal airway. In this study, we will compare external and internal distraction devices for mandibular lengthening in terms of effectiveness, results, patient comfort, and complications. Thirty-seven patients were treated by bilateral mandibular distraction osteogenesis for obstructive sleep apnea: 20 with external and 17 with internal distraction devices. Lengthening of the mandible and increase of the pharyngeal airway were obtained in all patients. Using the external devices, the average mandibular elongation was 30 mm versus 22 mm with the internal devices; however, after 1 year, the results were more stable with internal devices. External devices carried greater risk for pin tract infection than the internal devices (27.5% vs 5.88%). In addition, pin loosening in 22.5% required pin replacement or led to reduced retention period. Internal devices had a precise and predictable vector of lengthening and left less visible scars at the submandibular area but carried the disadvantage of requiring a second operation for device removal. In very young children with severe micrognathia, it was impossible to place internal devices, and external devices were used. Internal devices should be the first choice because they are more comfortable to the patients, more predictable vector of lengthening, are less vulnerable to dislodgement, and leave reduced scarring, with the great disadvantage of second operation for removal. However, external devices still should be considered mainly in severely hypoplastic cases, and the surgeon should be prepared for both options.

Detector arrays for photometric measurements at soft X-ray, ultraviolet and visible wavelengths

NASA Technical Reports Server (NTRS)

Timothy, J. G.; Mount, G. H.; Bybee, R. L.

1979-01-01

The construction and modes of operation of the Multi-Anode Microchannel Array (MAMA) detectors are described, and the designs of spectrometers utilizing them are outlined. MAMA consists of a curved microchannel array plate, an opaque photocathode (peak quantum efficiency of 19% at 1216 A), and a multi-anode (either discrete- or coincidence-anode) readout array. Designed for use in instruments on spaceborne telescopes, MAMA can be operated in a windowless configuration in extreme-ultraviolet and soft X-ray wavelengths, or in a sealed configuration at UV and visible wavelengths. Advantages of MAMA include low applied potential (less than 3.0 kV), high gain (greater than 10 to the 6th electrons/pulse), low sensitivity to high-energy charged particles, and immunity to external magnetic fields of less than 500 Gauss

Non-invasive biomonitoring for PFRs and PBDEs: new insights in analysis of human hair externally exposed to selected flame retardants.

PubMed

Kucharska, Agnieszka; Covaci, Adrian; Vanermen, Guido; Voorspoels, Stefan

2015-02-01

In this study, we investigated the hypothesis whether externally adsorbed and internally deposited flame retardants (FRs) in hair could be distinguished. To this extent, hair samples collected from one volunteer were exposed under controlled conditions to phosphate FR (PFR) and polybrominated diphenyl ether (PBDE) standards to mimic external contamination. Afterwards, suitable washing procedures to selectively remove contaminants from the hair surface were investigated. The samples were measured by GC-(ECNI)-MS for PBDEs and LC-(ESI+)-MS/MS for PFRs. All investigated compounds were transferred onto the hair surface. One of the most important finding was that dust particles are not mandatory to transfer compounds on the hair surface and to be able to measure high levels of compounds in human hair. To assess different protocols to selectively remove external contamination, the exposed hair samples were washed in different media before analysis: water, methanol, hexane:dichloromethane (1:1, v/v), acetone and shampoo. Results indicated that there is no washing medium able to entirely and exclusively remove external contamination. Among investigated media, methanol removed a meaningful part of the external contamination (42-105%), but the removal efficiencies differed among compounds. We therefore concluded that hair should not be washed prior to analysis and in case of visible contamination (e.g. with cosmetic products), water would be the recommended agent. Organic solvents should not be used for the washing step. Although it is impossible to distinguish external from internal exposure, hair samples may be used as valuable biomarker of human exposure, providing a measure of integral exposure. To the best of our knowledge, this is the first study which has used externally exposed hair samples to PBDEs and PFRs. Copyright © 2014 Elsevier B.V. All rights reserved.

Transit visibility zones of the Solar system planets

NASA Astrophysics Data System (ADS)

Wells, R.; Poppenhaeger, K.; Watson, C. A.; Heller, R.

2018-01-01

The detection of thousands of extrasolar planets by the transit method naturally raises the question of whether potential extrasolar observers could detect the transits of the Solar system planets. We present a comprehensive analysis of the regions in the sky from where transit events of the Solar system planets can be detected. We specify how many different Solar system planets can be observed from any given point in the sky, and find the maximum number to be three. We report the probabilities of a randomly positioned external observer to be able to observe single and multiple Solar system planet transits; specifically, we find a probability of 2.518 per cent to be able to observe at least one transiting planet, 0.229 per cent for at least two transiting planets, and 0.027 per cent for three transiting planets. We identify 68 known exoplanets that have a favourable geometric perspective to allow transit detections in the Solar system and we show how the ongoing K2 mission will extend this list. We use occurrence rates of exoplanets to estimate that there are 3.2 ± 1.2 and 6.6^{+1.3}_{-0.8} temperate Earth-sized planets orbiting GK and M dwarf stars brighter than V = 13 and 16, respectively, that are located in the Earth's transit zone.

Auto-locking waveguide amplifier system for lidar and magnetometric applications

NASA Astrophysics Data System (ADS)

Pouliot, A.; Beica, H. C.; Carew, A.; Vorozcovs, A.; Carlse, G.; Kumarakrishnan, A.

2018-02-01

We describe a compact waveguide amplifier system that is suitable for optically pumping rubidium magnetometers. The system consists of an auto-locking vacuum-sealed external cavity diode laser, a semiconductor tapered amplifier and a pulsing unit based on an acousto-optic modulator. The diode laser utilises optical feedback from an interference filter to narrow the linewidth of an inexpensive laser diode to 500 kHz. This output is scannable over an 8 GHz range (at 780 nm) and can be locked without human intervention to any spectral marker in an expandable library of reference spectra, using the autolocking controller. The tapered amplifier amplifies the output from 50 mW up to 2 W with negligible distortions in the spectral quality. The system can operate at visible and near infrared wavelengths with MHz repetition rates. We demonstrate optical pumping of rubidium vapour with this system for magnetometric applications. The magnetometer detects the differential absorption of two orthogonally polarized components of a linearly polarized probe laser following optical pumping by a circularly polarized pump laser. The differential absorption signal is studied for a range of pulse lengths, pulse amplitudes and DC magnetic fields. Our results suggest that this laser system is suitable for optically pumping spin-exchange free magnetometers.

Electrochromic optical switching device

DOEpatents

Lampert, C.M.; Visco, S.J.

1992-08-25

An electrochromic cell is disclosed which comprises an electrochromic layer, a polymerizable organo-sulfur layer which comprises the counter electrode of the structure, and an ionically conductive electronically insulating material which comprises the separator between the electrodes. In a preferred embodiment, both the separator and the organo-sulfur electrode (in both its charged and uncharged states) are transparent either to visible light or to the entire solar spectrum. An electrochromic device is disclosed which comprises such electrodes and separator encased in glass plates on the inner surface of each of which is formed a transparent electrically conductive film in respective electrical contact with the electrodes which facilitates formation of an external electrical connection or contact to the electrodes of the device to permit electrical connection of the device to an external potential source. 3 figs.

Electrochromic optical switching device

DOEpatents

Lampert, Carl M.; Visco, Steven J.

1992-01-01

An electrochromic cell is disclosed which comprises an electrochromic layer, a polymerizable organo-sulfur layer which comprises the counter electrode of the structure, and an ionically conductive electronically insulating material which comprises the separator between the electrodes. In a preferred embodiment, both the separator and the organo-sulfur electrode (in both its charged and uncharged states) are transparent either to visible light or to the entire solar spectrum. An electrochromic device is disclosed which comprises such electrodes and separator encased in glass plates on the inner surface of each of which is formed a transparent electrically conductive film in respective electrical contact with the electrodes which facilitates formation of an external electrical connection or contact to the electrodes of the device to permit electrical connection of the device to an external potential source.

Low visibility operations/surface movement guidance and control system (LVO/SMGCS) chart usability : an examination of flightcrew position awareness in homogeneous 300 ft/75 m RVR conditions

DOT National Transportation Integrated Search

2014-09-01

Two studies were conducted to identify best practices for the design of Low Visibility Operations/Surface Movement Guidance and Control System (LVO/SMGCS) paper charts and flightcrew use of them in extremely low visibility surface conditions. In the ...

Two decades of external peer review of cancer care in general hospitals; the Dutch experience.

PubMed

Kilsdonk, Melvin J; Siesling, Sabine; Otter, Rene; van Harten, Wim H

2016-03-01

External peer review was introduced in general hospitals in the Netherlands in 1994 to assess and improve the multidisciplinary team approach in cancer care. This paper aims to explore the value, perceived impact, and (future) role of external peer review in cancer care. Semistructured interviews were held with clinicians, oncology nurses, and managers from fifteen general hospitals that participated in three rounds of peer review over a period of 16 years. Interviewees reflected on the goals and expectations, experiences, perceived impact, and future role of external peer review. Transcriptions of the interviews were coded to discover recurrent themes. Improving clinical care and organization were the main motives for participation. Positive impact was perceived on multiple aspects of care such as shared responsibilities, internal prioritization of cancer care, improved communication, and a clear structure and position of cancer care within general hospitals. Establishing a direct relationship between the external peer review and organizational or clinical impact proved to be difficult. Criticism was raised on the content of the program being too theoretical and organization-focussed after three rounds. According to most stakeholders, external peer review can improve multidisciplinary team work in cancer care; however, the acceptance is threatened by a perceived disbalance between effort and visible clinical impact. Leaner and more clinically focused programs are needed to keep repeated peer reviews challenging and worthwhile. © 2015 The Authors. Cancer Medicine published by John Wiley & Sons Ltd.

Vertical Field of View Reference Point Study for Flight Path Control and Hazard Avoidance

NASA Technical Reports Server (NTRS)

Comstock, J. Raymond, Jr.; Rudisill, Marianne; Kramer, Lynda J.; Busquets, Anthony M.

2002-01-01

Researchers within the eXternal Visibility System (XVS) element of the High-Speed Research (HSR) program developed and evaluated display concepts that will provide the flight crew of the proposed High-Speed Civil Transport (HSCT) with integrated imagery and symbology to permit path control and hazard avoidance functions while maintaining required situation awareness. The challenge of the XVS program is to develop concepts that would permit a no-nose-droop configuration of an HSCT and expanded low visibility HSCT operational capabilities. This study was one of a series of experiments exploring the 'design space' restrictions for physical placement of an XVS display. The primary experimental issues here was 'conformality' of the forward display vertical position with respect to the side window in simulated flight. 'Conformality' refers to the case such that the horizon and objects appear in the same relative positions when viewed through the forward windows or display and the side windows. This study quantified the effects of visual conformality on pilot flight path control and hazard avoidance performance. Here, conformality related to the positioning and relationship of the artificial horizon line and associated symbology presented on the forward display and the horizon and associated ground, horizon, and sky textures as they would appear in the real view through a window presented in the side window display. No significant performance consequences were found for the non-conformal conditions.

AN ULTRAVIOLET-VISIBLE SPECTROPHOTOMETER AUTOMATION SYSTEM. PART III: PROGRAM DOCUMENTATION

EPA Science Inventory

The Ultraviolet-Visible Spectrophotometer (UVVIS) automation system accomplishes 'on-line' spectrophotometric quality assurance determinations, report generations, plot generations and data reduction for chlorophyll or color analysis. This system also has the capability to proces...

Electron microscopy, histochemistry, and microbiology of bacterial adhesion in trichomycosis axillaris.

PubMed

Shelley, W B; Miller, M A

1984-06-01

Study of a case of trichomycosis axillaris by electron microscopy revealed a specific encapsulated Corynebacterium adhering to but not penetrating the hair shaft. External to this were two other biochemically distinctive pleomorphic Corynebacteria shown to be incapable of direct adherence to the hair. All three types were entrapped in a virtually insoluble cement substance, which they elaborate and which is responsible for the grossly visible colonization that is so characteristic of this disease.

KSC-03pd0077

NASA Image and Video Library

2003-01-15

KENNEDY SPACE CENTER, FLA. -- The late afternoon sun highlights the external tank and solid rocket booster on Space Shuttle Columbia after rollback of the Rotating Service Structure on Launch Pad 39A. Visible are the orbiter access arm with the White Room extended to Columbia's cockpit, and at the top, the gaseous oxygen vent arm and cap, called the "beanie cap." Columbia is scheduled for launch Jan. 16 at 10:39 a.m. EST on mission STS-107, a research mission.

KSC-03pd0074

NASA Image and Video Library

2003-01-15

KENNEDY SPACE CENTER, FLA. -- The late afternoon sun highlights the external tank and solid rocket booster on Space Shuttle Columbia after rollback of the Rotating Service Structure on Launch Pad 39A. Visible are the orbiter access arm with the White Room extended to Columbia's cockpit, and at the top, the gaseous oxygen vent arm and cap, called the "beanie cap." Columbia is scheduled for launch Jan. 16 at 10:39 a.m. EST on mission STS-107, a research mission.

KSC-07pd0600

NASA Image and Video Library

2007-03-09

KENNEDY SPACE CENTER, FLA. -- In Highbay 1 inside the Vehicle Assembly Building, technicians look at hail damage on the external tank. A severe thunderstorm with golf ball-sized hail caused visible divots in the giant tank's foam insulation and minor surface damage to about 26 heat shield tiles on the shuttle's left wing. A new target launch date has not been determined, but teams will focus on preparing Atlantis for liftoff in late April on mission STS-117. Photo credit: NASA/Jim Grossmann

Liftoff of shuttle Challenger and mission STS 51-B

NASA Technical Reports Server (NTRS)

1985-01-01

Liftoff of shuttle Challenger and mission STS 51-B. The shuttle orbiter, its external tank and one of the solid rocket boosters (SRB) are still visible as it leaves the pad. This photo was taken from across the water over the top of a grove of trees (051); Photo taken from camera on the launch complex, showing the orbiter just clearing the tower (052); Side view of the liftoff as the SRBs begin to fire (053).

Marginal Integrity of Glass Ionomer and All Ceramic Restorations

DTIC Science & Technology

2016-06-01

from ceramic blocks, and cemented with a dual-cured resin cement . Following thennocycling (10,000 cycles, 5°/55°C), the restorations were examined...final result by using resin cements .26 There is an increasing range of shades in resin cements that can be used to modify the shade and value of the...restoration. The resin cement can also block out any potential imperfections present in the prepared tooth from being externally visible.27 Modern

Visible and Near-Infrared Photothermal Catalyzed Hydrogenation of Gaseous CO2 over Nanostructured Pd@Nb2O5.

PubMed

Jia, Jia; O'Brien, Paul G; He, Le; Qiao, Qiao; Fei, Teng; Reyes, Laura M; Burrow, Timothy E; Dong, Yuchan; Liao, Kristine; Varela, Maria; Pennycook, Stephen J; Hmadeh, Mohamad; Helmy, Amr S; Kherani, Nazir P; Perovic, Doug D; Ozin, Geoffrey A

2016-10-01

The reverse water gas shift (RWGS) reaction driven by Nb 2 O 5 nanorod-supported Pd nanocrystals without external heating using visible and near infrared (NIR) light is demonstrated. By measuring the dependence of the RWGS reaction rates on the intensity and spectral power distribution of filtered light incident onto the nanostructured Pd@Nb 2 O 5 catalyst, it is determined that the RWGS reaction is activated photothermally. That is the RWGS reaction is initiated by heat generated from thermalization of charge carriers in the Pd nanocrystals that are excited by interband and intraband absorption of visible and NIR light. Taking advantage of this photothermal effect, a visible and NIR responsive Pd@Nb 2 O 5 hybrid catalyst that efficiently hydrogenates CO 2 to CO at an impressive rate as high as 1.8 mmol gcat -1 h -1 is developed. The mechanism of this photothermal reaction involves H 2 dissociation on Pd nanocrystals and subsequent spillover of H to the Nb 2 O 5 nanorods whereupon adsorbed CO 2 is hydrogenated to CO. This work represents a significant enhancement in our understanding of the underlying mechanism of photothermally driven CO 2 reduction and will help guide the way toward the development of highly efficient catalysts that exploit the full solar spectrum to convert gas-phase CO 2 to valuable chemicals and fuels.

Improved spring model-based collaborative indoor visible light positioning

NASA Astrophysics Data System (ADS)

Luo, Zhijie; Zhang, WeiNan; Zhou, GuoFu

2016-06-01

Gaining accuracy with indoor positioning of individuals is important as many location-based services rely on the user's current position to provide them with useful services. Many researchers have studied indoor positioning techniques based on WiFi and Bluetooth. However, they have disadvantages such as low accuracy or high cost. In this paper, we propose an indoor positioning system in which visible light radiated from light-emitting diodes is used to locate the position of receivers. Compared with existing methods using light-emitting diode light, we present a high-precision and simple implementation collaborative indoor visible light positioning system based on an improved spring model. We first estimate coordinate position information using the visible light positioning system, and then use the spring model to correct positioning errors. The system can be employed easily because it does not require additional sensors and the occlusion problem of visible light would be alleviated. We also describe simulation experiments, which confirm the feasibility of our proposed method.

Medical imaging systems

DOEpatents

Frangioni, John V [Wayland, MA

2012-07-24

A medical imaging system provides simultaneous rendering of visible light and fluorescent images. The system may employ dyes in a small-molecule form that remains in a subject's blood stream for several minutes, allowing real-time imaging of the subject's circulatory system superimposed upon a conventional, visible light image of the subject. The system may also employ dyes or other fluorescent substances associated with antibodies, antibody fragments, or ligands that accumulate within a region of diagnostic significance. In one embodiment, the system provides an excitation light source to excite the fluorescent substance and a visible light source for general illumination within the same optical guide that is used to capture images. In another embodiment, the system is configured for use in open surgical procedures by providing an operating area that is closed to ambient light. More broadly, the systems described herein may be used in imaging applications where a visible light image may be usefully supplemented by an image formed from fluorescent emissions from a fluorescent substance that marks areas of functional interest.

Statistical Determination of the Gating Windows for Respiratory-Gated Radiotherapy Using a Visible Guiding System.

PubMed

Oh, Se An; Yea, Ji Woon; Kim, Sung Kyu

2016-01-01

Respiratory-gated radiation therapy (RGRT) is used to minimize the radiation dose to normal tissue in lung-cancer patients. Although determining the gating window in the respiratory phase of patients is important in RGRT, it is not easy. Our aim was to determine the optimal gating window when using a visible guiding system for RGRT. Between April and October 2014, the breathing signals of 23 lung-cancer patients were recorded with a real-time position management (RPM) respiratory gating system (Varian, USA). We performed statistical analysis with breathing signals to find the optimal gating window for guided breathing in RGRT. When we compared breathing signals before and after the breathing training, 19 of the 23 patients showed statistically significant differences (p < 0.05). The standard deviation of the respiration signals after breathing training was lowest for phases of 30%-70%. The results showed that the optimal gating window in RGRT is 40% (30%-70%) with respect to repeatability for breathing after respiration training with the visible guiding system. RGRT was performed with the RPM system to confirm the usefulness of the visible guiding system. The RPM system and our visible guiding system improve the respiratory regularity, which in turn should improve the accuracy and efficiency of RGRT.

Orbital Angular Momentum Multiplexing over Visible Light Communication Systems

NASA Astrophysics Data System (ADS)

Tripathi, Hardik Rameshchandra

This thesis proposes and explores the possibility of using Orbital Angular Momentum multiplexing in Visible Light Communication system. Orbital Angular Momentum is mainly applied for laser and optical fiber transmissions, while Visible Light Communication is a technology using the light as a carrier for wireless communication. In this research, the study of the state of art and experiments showing some results on multiplexing based on Orbital Angular Momentum over Visible Light Communication system were done. After completion of the initial stage; research work and simulations were performed on spatial multiplexing over Li-Fi channel modeling. Simulation scenarios which allowed to evaluate the Signal-to-Noise Ratio, Received Power Distribution, Intensity and Illuminance were defined and developed.

Interaction of Pyrrolobenzodiazepine (PBD) Ligands with Parallel Intermolecular G-Quadruplex Complex Using Spectroscopy and ESI-MS

PubMed Central

Raju, Gajjela; Srinivas, Ragampeta; Santhosh Reddy, Vangala; Idris, Mohammed M.; Kamal, Ahmed; Nagesh, Narayana

2012-01-01

Studies on ligand interaction with quadruplex DNA, and their role in stabilizing the complex at concentration prevailing under physiological condition, has attained high interest. Electrospray ionization mass spectrometry (ESI-MS) and spectroscopic studies in solution were used to evaluate the interaction of PBD and TMPyP4 ligands, stoichiometry and selectivity to G-quadruplex DNA. Two synthetic ligands from PBD family, namely pyrene-linked pyrrolo[2,1-c][1,4]benzodiazepine hybrid (PBD1), mixed imine-amide pyrrolobenzodiazepine dimer (PBD2) and 5,10,15,20-tetrakis(N-methyl-4-pyridyl)porphyrin (TMPyP4) were studied. G-rich single-stranded oligonucleotide d(5′GGGGTTGGGG3′) designated as d(T2G8), from the telomeric region of Tetrahymena Glaucoma, was considered for the interaction with ligands. ESI-MS and spectroscopic methods viz., circular dichroism (CD), UV-Visible, and fluorescence were employed to investigate the G-quadruplex structures formed by d(T2G8) sequence and its interaction with PBD and TMPyP4 ligands. From ESI-MS spectra, it is evident that the majority of quadruplexes exist as d(T2G8)2 and d(T2G8)4 forms possessing two to ten cations in the centre, thereby stabilizing the complex. CD band of PBD1 and PBD2 showed hypo and hyperchromicity, on interaction with quadruplex DNA, indicating unfolding and stabilization of quadruplex DNA complex, respectively. UV-Visible and fluorescence experiments suggest that PBD1 bind externally where as PBD2 intercalate moderately and bind externally to G-quadruplex DNA. Further, melting experiments using SYBR Green indicate that PBD1 unfolds and PBD2 stabilizes the G-quadruplex complex. ITC experiments using d(T2G8) quadruplex with PBD ligands reveal that PBD1 and PBD2 prefer external/loop binding and external/intercalative binding to quadruplex DNA, respectively. From experimental results it is clear that the interaction of PBD2 and TMPyP4 impart higher stability to the quadruplex complex. PMID:22558271

A review of astronomical science with visible light adaptive optics

NASA Astrophysics Data System (ADS)

Close, Laird M.

2016-07-01

We review astronomical results in the visible (λ<1μm) with adaptive optics. Other than a brief period in the early 1990s, there has been little (<1 paper/yr) night-time astronomical science published with AO in the visible from 2000-2013 (outside of the solar or Space Surveillance Astronomy communities where visible AO is the norm, but not the topic of this invited review). However, since mid-2013 there has been a rapid increase visible AO with over 50 refereed science papers published in just 2.5 years (visible AO is experiencing a rapid growth rate very similar to that of NIR AO science from 1997-2000 Close 2000). Currently the most productive small (D < 2 m) visible light AO telescope is the UV-LGS Robo-AO system (Baranec, et al. 2016) on the robotic Palomar D=1.5 m telescope (currently relocated to the Kitt Peak 1.8m; Salama et al. 2016). Robo-AO uniquely offers the ability to target >15 objects/hr, which has enabled large (>3000 discrete targets) companion star surveys and has resulted in 23 refereed science publications. The most productive large telescope visible AO system is the D=6.5m Magellan telescope AO system (MagAO). MagAO is an advanced Adaptive Secondary Mirror (ASM) AO system at the Magellan 6.5m in Chile (Morzinski et al. 2016). This ASM secondary has 585 actuators with < 1 msec response times (0.7 ms typically). MagAO utilizes a 1 kHz pyramid wavefront sensor. The relatively small actuator pitch ( 22 cm/subap) allows moderate Strehls to be obtained in the visible (0.63-1.05 microns). Long exposures (60s) achieve <30mas resolutions, 30% Strehls at 0.62 microns (r') with the VisAO camera in 0.5" seeing with bright R <= 9 mag stars. These capabilities have led to over 22 MagAO refereed science publications in the visible. The largest (D=8m) telescope to achieve regular visible AO science is SPHERE/ZIMPOL. ZIMPOL is a polarimeter fed by the 1.2 kHz SPHERE ExAO system (Fusco et al. 2016). ZIMPOL's ability to differentiate scattered polarized light from starlight allows the sensitive detection of circumstellar disks, stellar surfaces, and envelopes of evolved AGB stars. Here we review the key steps to having good performance in the visible and review the exciting new AO visible science opportunities and science results in the fields of: exoplanet detection; circumstellar and protoplanetary disks; young stars; AGB stars; emission line jets; and stellar surfaces. The recent rapid increase in the scientific publications and power of visible AO is due to the maturity of the next-generation of AO systems and our new ability probe circumstellar regions with very high (10-30 mas) spatial resolutions that would otherwise require much larger (>10m) diameter telescopes in the infrared.

White LED visible light communication technology research

NASA Astrophysics Data System (ADS)

Yang, Chao

2017-03-01

Visible light communication is a new type of wireless optical communication technology. White LED to the success of development, the LED lighting technology is facing a new revolution. Because the LED has high sensitivity, modulation, the advantages of good performance, large transmission power, can make it in light transmission light signal at the same time. Use white LED light-emitting characteristics, on the modulation signals to the visible light transmission, can constitute a LED visible light communication system. We built a small visible optical communication system. The system composition and structure has certain value in the field of practical application, and we also research the key technology of transmitters and receivers, the key problem has been resolved. By studying on the optical and LED the characteristics of a high speed modulation driving circuit and a high sensitive receiving circuit was designed. And information transmission through the single chip microcomputer test, a preliminary verification has realized the data transmission function.

A Cu-Zn nanoparticle promoter for selective carbon dioxide reduction and its application in visible-light-active Z-scheme systems using water as an electron donor.

PubMed

Yin, Ge; Sako, Hiroshi; Gubbala, Ramesh V; Ueda, Shigenori; Yamaguchi, Akira; Abe, Hideki; Miyauchi, Masahiro

2018-04-17

Selective carbon dioxide photoreduction to produce formic acid was achieved under visible light irradiation using water molecules as electron donors, similar to natural plants, based on the construction of a Z-scheme light harvesting system modified with a Cu-Zn alloy nanoparticle co-catalyst. The faradaic efficiency of our Z-scheme system for HCOOH generation was over 50% under visible light irradiation.

Current status of visibility sensors for aviation

NASA Technical Reports Server (NTRS)

Burnham, D. C.

1983-01-01

The development of a new increased range higher visibility was investigated. The visibility sensor that is currently is the Transmissometer. Current transmissometer technology provides only a factor of 10 dynamic range with a single base line. The FAA is preparing to install automated weather observing systems (AWOS) at many locations. These systems require visibilities up to approximately 5 miles. To use a transmissometer for this type of measurement, the base line must be about 1,000 feet; where alignment becomes very difficult to maintain. New technologies were developd for measuring visibility. Improved transmissometers, forward-scatter meters and back-scatter meters have become available. A current practical issue for visibility sensors is how to specify one that is good enough to meet the needs of aviation. The first question is what performance is required; how accurately must the sensor measure? Visibility sensors do not actually measure the visibility directly. The purpose of measuring the visibility is to predict what the pilot will see a considerable distance away from the sensor location. The atmosphere introduces considerable variation in the measurement and the basic sensor accuracy needed is difficult to define. The second question for high visibilities is what to use as the standard reference sensor. The third question pertains to the competitive procurement of visibility sensors, which is mandated at present. Two acceptance test procedures to be used to insure satisfactory sensor performance is examined.

Development and evaluation of a new digital photography visiometer system for automated visibility observation

NASA Astrophysics Data System (ADS)

Wang, Jingli; Liu, Xulin; Yang, Xihua; Lei, Ming; Ruan, Shunxian; Nie, Kai; Miao, Yupeng; Liu, Jincheng

2014-04-01

Visibility information is fundamental in aviation, navigation, land transportation, air quality and dust storm monitoring, and military activities which often require frequent and accurate real-time observation of visibility. The traditional manual observation, the primary means to obtain visibility information by human eyes, is subjective, inconsistent and costly. Instrumental observation (or traditional optical instrument) has overcome some of these limitations, but it is difficult to obtain correct visibility information in a complicated atmospheric (e.g. rainy and foggy) environment. We developed a new visibility instrument, digital photography visiometer system (DPVS), equipped with advanced digital photographic technology including high-resolution charge-coupled-device camera and computer. The new DPVS imitates the human eye observation and accurately calculates the visibility based on its definition and observational principles. We compared the results of the new DPVS with those from a forward scattering visibility instrument (FD12) and manual visibility observations in various (rainy, non-rainy, foggy) weather conditions. The comparative results show that the new DPVS, FD12, and manual observation have the same trend of change, but the observation from the new DPVS is closer to that from the manual observations in rainy days or complicated weather conditions. Our study demonstrates that the new DVPS is superior to the optical visibility instrument and can be used for automated visibility observations under all weather conditions.

Closed-Loop Estimation of Retinal Network Sensitivity by Local Empirical Linearization

PubMed Central

2018-01-01

Abstract Understanding how sensory systems process information depends crucially on identifying which features of the stimulus drive the response of sensory neurons, and which ones leave their response invariant. This task is made difficult by the many nonlinearities that shape sensory processing. Here, we present a novel perturbative approach to understand information processing by sensory neurons, where we linearize their collective response locally in stimulus space. We added small perturbations to reference stimuli and tested if they triggered visible changes in the responses, adapting their amplitude according to the previous responses with closed-loop experiments. We developed a local linear model that accurately predicts the sensitivity of the neural responses to these perturbations. Applying this approach to the rat retina, we estimated the optimal performance of a neural decoder and showed that the nonlinear sensitivity of the retina is consistent with an efficient encoding of stimulus information. Our approach can be used to characterize experimentally the sensitivity of neural systems to external stimuli locally, quantify experimentally the capacity of neural networks to encode sensory information, and relate their activity to behavior. PMID:29379871

Flexible Wing Base Micro Aerial Vehicles: Vision-Guided Flight Stability and Autonomy for Micro Air Vehicles

NASA Technical Reports Server (NTRS)

Ettinger, Scott M.; Nechyba, Michael C.; Ifju, Peter G.; Wazak, Martin

2002-01-01

Substantial progress has been made recently towards design building and test-flying remotely piloted Micro Air Vehicle's (MAVs). We seek to complement this progress in overcoming the aerodynamic obstacles to.flight at very small scales with a vision stability and autonomy system. The developed system based on a robust horizon detection algorithm which we discuss in greater detail in a companion paper. In this paper, we first motivate the use of computer vision for MAV autonomy arguing that given current sensor technology, vision may he the only practical approach to the problem. We then briefly review our statistical vision-based horizon detection algorithm, which has been demonstrated at 30Hz with over 99.9% correct horizon identification. Next we develop robust schemes for the detection of extreme MAV attitudes, where no horizon is visible, and for the detection of horizon estimation errors, due to external factors such as video transmission noise. Finally, we discuss our feed-back controller for self-stabilized flight, and report results on vision autonomous flights of duration exceeding ten minutes.

High-fidelity entanglement between a trapped ion and a telecom photon via quantum frequency conversion.

PubMed

Bock, Matthias; Eich, Pascal; Kucera, Stephan; Kreis, Matthias; Lenhard, Andreas; Becher, Christoph; Eschner, Jürgen

2018-05-21

Entanglement between a stationary quantum system and a flying qubit is an essential ingredient of a quantum-repeater network. It has been demonstrated for trapped ions, trapped atoms, color centers in diamond, or quantum dots. These systems have transition wavelengths in the blue, red or near-infrared spectral regions, whereas long-range fiber-communication requires wavelengths in the low-loss, low-dispersion telecom regime. A proven tool to interconnect flying qubits at visible/NIR wavelengths to the telecom bands is quantum frequency conversion. Here we use an efficient polarization-preserving frequency converter connecting 854 nm to the telecom O-band at 1310 nm to demonstrate entanglement between a trapped 40 Ca + ion and the polarization state of a telecom photon with a high fidelity of 98.2 ± 0.2%. The unique combination of 99.75 ± 0.18% process fidelity in the polarization-state conversion, 26.5% external frequency conversion efficiency and only 11.4 photons/s conversion-induced unconditional background makes the converter a powerful ion-telecom quantum interface.

Collective hydrodynamic communication through ultra-fast contractions

NASA Astrophysics Data System (ADS)

Bhamla, Saad; Mathijssen, Arnold; Prakash, Manu

2017-11-01

The biophysical relationships between physiological sensors and actuators were fundamental to the development of early life forms, as responding to external stimuli promptly is key to survival. We study an unusual protist Spirostomum ambiguum, a single-celled organism that can grow up to 4mm in size, visible to the naked eye, as a model system for impulsive systems. Coiling its cytoskeleton, this ciliate can contract its long body within milliseconds, one of the fastest accelerations known in cell biology. We demonstrate that these rapid contractions generate long-ranged vortex flows that can trigger other cells to contract, repeatedly, which collectively leads to an ultra-fast hydrodynamic signal transduction across a colony that moves hundreds of times faster than the swimming speed. By combining high-speed PIV experiments and analytical modelling we determine the critical rheosensitivity required to sustain these signal waves. Whereas the biological motive is not fully understood, contractions are known to release toxins from membrane-bound extrusomes, thus we hypothesize that synchronised discharges could facilitate the repulsion of large-scale predators cooperatively. Please also see our other talk ``Rheosensing by impulsive cells at intermediate Reynolds numbers''.

Remotely detected differential pulse transit time as a stress indicator

NASA Astrophysics Data System (ADS)

Kaur, Balvinder; Tarbox, Elizabeth; Cissel, Marty; Moses, Sophia; Luthra, Megha; Vaidya, Misha; Tran, Nhien; Ikonomidou, Vasiliki N.

2015-05-01

The human cardiovascular system, controlled by the autonomic nervous system (ANS), is one of the first sites where one can see the "fight-or-flight" response due to the presence of external stressors. In this paper, we investigate the possibility of detecting mental stress using a novel measure that can be measured in a contactless manner: Pulse transit time (dPTT), which refers to the time that is required for the blood wave (BW) to cover the distance from the heart to a defined remote location in the body. Loosely related to blood pressure, PTT is a measure of blood velocity, and is also implicated in the "fight-or-flight" response. We define the differential PTT (dPTT) as the difference in PTT between two remote areas of the body, such as the forehead and the palm. Expanding our previous work on remote BW detection from visible spectrum videos, we built a system that remotely measures dPTT. Human subject data were collected under an IRB approved protocol from 15 subjects both under normal and stress states and are used to initially establish the potential use of remote dPPT detection as a stress indicator.

High-Speed Research Surveillance Symbology Assessment Experiment

NASA Technical Reports Server (NTRS)

Kramer, Lynda J.; Norman, R. Michael

2000-01-01

Ten pilots flew multiple approach and departure scenarios in a simulation experiment of the High-Speed Civil Transport to evaluate the utility of different airborne surveillance display concepts. The primary eXternal Visibility System (XVS) display and the Navigation Display (ND) were used to present tactical and strategic surveillance information, respectively, to the pilot. Three sensors, the Traffic Alert and Collision Avoidance System, radar, and the Automatic Dependent Surveillance-Broadcast system, were modeled for this simulation and the sensors surveillance information was presented in two different symbology sets to the pilot. One surveillance symbology set used unique symbol shapes to differentiate among the sensors, while the other set used common symbol shapes for the sensors. Surveillance information in the form of escape guidance from threatening traffic was also presented to the pilots. The surveillance information (sensors and escape guidance) was either presented head-up on the primary XVS display and head-down on the ND or head-down on the ND only. Both objective and subjective results demonstrated that the display concepts having surveillance information presented head-up and head-down have surveillance performance benefits over those concepts having surveillance information displayed head-down only. No significant symbology set differences were found for surveillance task performance.

Orbiter Camera Payload System

NASA Technical Reports Server (NTRS)

1980-01-01

Components for an orbiting camera payload system (OCPS) include the large format camera (LFC), a gas supply assembly, and ground test, handling, and calibration hardware. The LFC, a high resolution large format photogrammetric camera for use in the cargo bay of the space transport system, is also adaptable to use on an RB-57 aircraft or on a free flyer satellite. Carrying 4000 feet of film, the LFC is usable over the visible to near IR, at V/h rates of from 11 to 41 milliradians per second, overlap of 10, 60, 70 or 80 percent and exposure times of from 4 to 32 milliseconds. With a 12 inch focal length it produces a 9 by 18 inch format (long dimension in line of flight) with full format low contrast resolution of 88 lines per millimeter (AWAR), full format distortion of less than 14 microns and a complement of 45 Reseau marks and 12 fiducial marks. Weight of the OCPS as supplied, fully loaded is 944 pounds and power dissipation is 273 watts average when in operation, 95 watts in standby. The LFC contains an internal exposure sensor, or will respond to external command. It is able to photograph starfields for inflight calibration upon command.

Optical properties of selected components of mineral dust aerosol processed with organic acids and humic material

NASA Astrophysics Data System (ADS)

Alexander, Jennifer M.; Grassian, V. H.; Young, M. A.; Kleiber, P. D.

2015-03-01

Visible light scattering phase function and linear polarization profiles of mineral dust components processed with organic acids and humic material are measured, and results are compared to T-matrix simulations of the scattering properties. Processed samples include quartz mixed with humic material, and calcite reacted with acetic and oxalic acids. Clear differences in light scattering properties are observed for all three processed samples when compared to the unprocessed dust or organic salt products. Results for quartz processed with humic acid sodium salt (NaHA) indicate the presence of both internally mixed quartz-NaHA particles and externally mixed NaHA aerosol. Simulations of light scattering suggest that the processed quartz particles become more moderate in shape due to the formation of a coating of humic material over the mineral core. Experimental results for calcite reacted with acetic acid are consistent with an external mixture of calcite and the reaction product, calcium acetate. Modeling of the light scattering properties does not require any significant change to the calcite particle shape distribution although morphology changes cannot be ruled out by our data. It is expected that calcite reacted with oxalic acid will produce internally mixed particles of calcite and calcium oxalate due to the low solubility of the product salt. However, simulations of the scattering for the calcite-oxalic acid system result in rather poor fits to the data when compared to the other samples. The poor fit provides a less accurate picture of the impact of processing in the calcite-oxalic acid system.

Development of a Signal Data Converter for an Airport Visibility Measuring System

DOT National Transportation Integrated Search

1975-08-01

This report briefly describes the evolution of the FAA/NBS Runway Visual Range RVR transmissometer system into a breadboard Airport Visibility Measuring System (ARVIS) which has been laboratory tested and which will undergo field tests at the Nationa...

Thermochromic halide perovskite solar cells.

PubMed

Lin, Jia; Lai, Minliang; Dou, Letian; Kley, Christopher S; Chen, Hong; Peng, Fei; Sun, Junliang; Lu, Dylan; Hawks, Steven A; Xie, Chenlu; Cui, Fan; Alivisatos, A Paul; Limmer, David T; Yang, Peidong

2018-03-01

Smart photovoltaic windows represent a promising green technology featuring tunable transparency and electrical power generation under external stimuli to control the light transmission and manage the solar energy. Here, we demonstrate a thermochromic solar cell for smart photovoltaic window applications utilizing the structural phase transitions in inorganic halide perovskite caesium lead iodide/bromide. The solar cells undergo thermally-driven, moisture-mediated reversible transitions between a transparent non-perovskite phase (81.7% visible transparency) with low power output and a deeply coloured perovskite phase (35.4% visible transparency) with high power output. The inorganic perovskites exhibit tunable colours and transparencies, a peak device efficiency above 7%, and a phase transition temperature as low as 105 °C. We demonstrate excellent device stability over repeated phase transition cycles without colour fade or performance degradation. The photovoltaic windows showing both photoactivity and thermochromic features represent key stepping-stones for integration with buildings, automobiles, information displays, and potentially many other technologies.

Thermochromic halide perovskite solar cells

NASA Astrophysics Data System (ADS)

Lin, Jia; Lai, Minliang; Dou, Letian; Kley, Christopher S.; Chen, Hong; Peng, Fei; Sun, Junliang; Lu, Dylan; Hawks, Steven A.; Xie, Chenlu; Cui, Fan; Alivisatos, A. Paul; Limmer, David T.; Yang, Peidong

2018-03-01

Smart photovoltaic windows represent a promising green technology featuring tunable transparency and electrical power generation under external stimuli to control the light transmission and manage the solar energy. Here, we demonstrate a thermochromic solar cell for smart photovoltaic window applications utilizing the structural phase transitions in inorganic halide perovskite caesium lead iodide/bromide. The solar cells undergo thermally-driven, moisture-mediated reversible transitions between a transparent non-perovskite phase (81.7% visible transparency) with low power output and a deeply coloured perovskite phase (35.4% visible transparency) with high power output. The inorganic perovskites exhibit tunable colours and transparencies, a peak device efficiency above 7%, and a phase transition temperature as low as 105 °C. We demonstrate excellent device stability over repeated phase transition cycles without colour fade or performance degradation. The photovoltaic windows showing both photoactivity and thermochromic features represent key stepping-stones for integration with buildings, automobiles, information displays, and potentially many other technologies.

Solar Extreme UV radiation and quark nugget dark matter model

NASA Astrophysics Data System (ADS)

Zhitnitsky, Ariel

2017-10-01

We advocate the idea that the surprising emission of extreme ultra violet (EUV) radiation and soft x-rays from the Sun are powered externally by incident dark matter (DM) particles. The energy and the spectral shape of this otherwise unexpected solar irradiation is estimated within the quark nugget dark matter model. This model was originally invented as a natural explanation of the observed ratio Ωdark ~ Ωvisible when the DM and visible matter densities assume the same order of magnitude values. This generic consequence of the model is a result of the common origin of both types of matter which are formed during the same QCD transition and both proportional to the same fundamental dimensional parameter ΛQCD. We also present arguments suggesting that the transient brightening-like "nanoflares" in the Sun may be related to the annihilation events which inevitably occur in the solar atmosphere within this dark matter scenario.

Signal-to-noise optimization and evaluation of a home-made visible diode-array spectrophotometer

PubMed Central

Raimundo, Jr., Ivo M.; Pasquini, Celio

1993-01-01

This paper describes a simple low-cost multichannel visible spectrophotometer built with an RL512G EGG-Reticon photodiode array. A symmetric Czerny-Turner optical design was employed; instrument control was via a single-board microcomputer based on the 8085 Intel microprocessor. Spectral intensity data are stored in the single-board's RAM and then transferred to an IBM-AT 3865X compatible microcomputer through a RS-232C interface. This external microcomputer processes the data to recover transmittance, absorbance or relative intensity of the spectra. The signal-to-noise ratio and dynamic range were improved by using variable integration times, which increase during the same scan; and by the use of either weighted or unweighted sliding average of consecutive diodes. The instrument is suitable for automatic methods requiring quasi-simultaneous multiwavelength detections, such as multivariative calibration and flow-injection gradient scan techniques. PMID:18924979

Glass-Based Transparent Conductive Electrode: Its Application to Visible-to-Ultraviolet Light-Emitting Diodes.

PubMed

Lee, Tae Ho; Kim, Kyeong Heon; Lee, Byeong Ryong; Park, Ju Hyun; Schubert, E Fred; Kim, Tae Geun

2016-12-28

Nitride-based ultraviolet light-emitting diodes (UV LEDs) are promising replacements for conventional UV lamps. However, the external quantum efficiency of UV LEDs is much lower than for visible LEDs due to light absorption in the p-GaN contact and electrode layers, along with p-AlGaN growth and doping issues. To minimize such absorption, we should obtain direct ohmic contact to p-AlGaN using UV-transparent ohmic electrodes and not use p-GaN as a contact layer. Here, we propose a glass-based transparent conductive electrode (TCE) produced using electrical breakdown (EBD) of an AlN thin film, and we apply the thin film to four (Al)GaN-based visible and UV LEDs with thin buffer layers for current spreading and damage protection. Compared to LEDs with optimal ITO contacts, our LEDs with AlN TCEs exhibit a lower forward voltage, higher light output power, and brighter light emission for all samples. The ohmic transport mechanism for current injection and spreading from the metal electrode to p-(Al)GaN layer via AlN TCE is also investigated by analyzing the p-(Al)GaN surface before and after EBD.

A longitudinal study of externally visible cigarette advertising on retail storefronts in Massachusetts before and after the Master Settlement Agreement

PubMed Central

Celebucki, C; Diskin, K

2002-01-01

Methods: Observations were conducted on the number of cigarette advertisements visible from outside tobacco retail establishments in a paired convenience sample (n = 556) in Massachusetts before and after the MSA. Archival databases containing information on merchant compliance with age related sales laws during the time period were used to assess the relation of total cigarette advertising with sales to underage youth. Paired sample t tests assessed planned comparisons pre- to post-MSA; Spearman's ρ tested associations for dichotomous variables. Results: Significant post-ban increases were observed in the prevalence of exterior cigarette advertising on gas (petrol) stations and gas mini/marts (gasoline retailers) buildings, windows, and doors. Significant declines were observed on windows of liquor stores. Winston advertising declined overall, while advertisements of the "all other" brand category increased. Correlations between advertising and illegal sales, while modest, were significant. Conclusions: These pre- to post-MSA increases suggest the tobacco industry may be shifting expenditures selectively from billboard advertising to retailer exteriors more favoured by youth. Greater amount of cigarette advertising visible from outside over-the-counter tobacco retailers is associated with greater cigarette sales to minors. PMID:12034982

STS-27 Atlantis, Orbiter Vehicle (OV) 104, at KSC Launch Complex (LC) pad 39B

NASA Technical Reports Server (NTRS)

1988-01-01

STS-27 Atlantis, Orbiter Vehicle (OV) 104, sits atop the mobile launcher platform at Kennedy Space Center (KSC) Launch Complex (LC) pad 39B. Profile of OV-104 mounted on external tank and flanked by solid rocket boosters (SRBs) is obscured by a flock of seagulls in the foreground. The fixed service structure (FSS) with rotating service structure (RSS) retracted appears in the background. Water resevoir is visible at the base of the launch pad concrete structure.

KSC-07pd0599

NASA Image and Video Library

2007-03-09

KENNEDY SPACE CENTER, FLA. -- In Highbay 1 inside the Vehicle Assembly Building, technicians carefully apply red dye to the external tank as part of repair operations. A severe thunderstorm with golf ball-sized hail caused visible divots in the giant tank's foam insulation and minor surface damage to about 26 heat shield tiles on the shuttle's left wing. A new target launch date has not been determined, but teams will focus on preparing Atlantis for liftoff in late April on mission STS-117. Photo credit: NASA/Jim Grossmann

KSC-07pd0595

NASA Image and Video Library

2007-03-09

KENNEDY SPACE CENTER, FLA. -- In Highbay 1 inside the Vehicle Assembly Building, a technician carefully applies red dye to the external tank as part of repair operations. A severe thunderstorm with golf ball-sized hail caused visible divots in the giant tank's foam insulation and minor surface damage to about 26 heat shield tiles on the shuttle's left wing. A new target launch date has not been determined, but teams will focus on preparing Atlantis for liftoff in late April on mission STS-117. Photo credit: NASA/Jim Grossmann

KSC-07pd0601

NASA Image and Video Library

2007-03-09

KENNEDY SPACE CENTER, FLA. -- In Highbay 1 inside the Vehicle Assembly Building, workers secure scaffolding around the external tank to prepare it for repairs. A severe thunderstorm with golf ball-sized hail caused visible divots in the giant tank's foam insulation and minor surface damage to about 26 heat shield tiles on the shuttle's left wing. A new target launch date has not been determined, but teams will focus on preparing Atlantis for liftoff in late April on mission STS-117. Photo credit: NASA/Jim Grossmann

KSC-07pd0597

NASA Image and Video Library

2007-03-09

KENNEDY SPACE CENTER, FLA. -- In Highbay 1 inside the Vehicle Assembly Building, a technician carefully applies red dye to the external tank as part of repair operations. A severe thunderstorm with golf ball-sized hail caused visible divots in the giant tank's foam insulation and minor surface damage to about 26 heat shield tiles on the shuttle's left wing. A new target launch date has not been determined, but teams will focus on preparing Atlantis for liftoff in late April on mission STS-117. Photo credit: NASA/Jim Grossmann

Examination of Aircraft Interior Emergency Lighting in a Postcrash Fire Environment.

DTIC Science & Technology

1982-06-01

levels under realistic external fuel-fire conditions; (3) to compare black fuel-fire smoke with an enert white screen fog (references I and 2); (4... black smoke condition" at 52 seconds after the fuel fire was ignited and zero visibility a the 60-inch level at 120 seconds. Because it was closer to the...suitable stand was fabricated for each sign and the holes designed for aircraft mounting were utilized for securing the light to the stand. Two 28 AVG

Why do naked singularities form in gravitational collapse? II

DOE Office of Scientific and Technical Information (OSTI.GOV)

Joshi, Pankaj S.; Goswami, Rituparno; Dadhich, Naresh

We examine physical features that could lead to formation of a naked singularity rather than black hole, as end state of spherical collapse. Generalizing earlier results on dust collapse to general type I matter fields, it is shown that collapse always creates black hole if shear vanishes or density is homogeneous. It follows that nonzero shear is a necessary condition for singularity to be visible to external observers, when trapped surface formation is delayed by shearing forces or inhomogeneity within the collapsing cloud.

Combustion and Mixing Studies in Compressible Flows.

DTIC Science & Technology

1996-09-01

which extracts a gas sample from the supersonic mixing region and analyzes it externally using hot-wire anemometry in conjunction with pressure and...shown in 3020 cmŕ ethylene Raman line. The images were Figure 1. A Nd:YAG laser operating at its taken with an exposure time of 0.2 sec. The...pressure levels. This effect is sec. Figure 7 shows Raman images of ethylene for not visible in the 633 nm spectra due to its pressure readings of 0.15

Effect of External Pressure and Catheter Gauge on Flow Rate, Kinetic Energy, and Endothelial Injury During Intravenous Fluid Administration in a Rabbit Model.

PubMed

Hu, Mei-Hua; Chan, Wei-Hung; Chen, Yao-Chang; Cherng, Chen-Hwan; Lin, Chih-Kung; Tsai, Chien-Sung; Chou, Yu-Ching; Huang, Go-Shine

2016-01-01

The effects of intravenous (IV) catheter gauge and pressurization of IV fluid (IVF) bags on fluid flow rate have been studied. However, the pressure needed to achieve a flow rate equivalent to that of a 16 gauge (G) catheter through smaller G catheters and the potential for endothelial damage from the increased kinetic energy produced by higher pressurization are unclear. Constant pressure on an IVF bag was maintained by an automatic adjustable pneumatic pressure regulator of our own design. Fluids running through 16 G, 18 G, 20 G, and 22 G catheters were assessed while using IV bag pressurization to achieve the flow rate equivalent to that of a 16 G catheter. We assessed flow rates, kinetic energy, and flow injury to rabbit inferior vena cava endothelium. By applying sufficient external constant pressure to an IVF bag, all fluids could be run through smaller (G) catheters at the flow rate in a 16 G catheter. However, the kinetic energy increased significantly as the catheter G increased. Damage to the venous endothelium was negligible or minimal/patchy cell loss. We designed a new rapid infusion system, which provides a constant pressure that compresses the fluid volume until it is free from visible residual fluid. When large-bore venous access cannot be obtained, multiple smaller catheters, external pressure, or both should be considered. However, caution should be exercised when fluid pressurized to reach a flow rate equivalent to that in a 16 G catheter is run through a smaller G catheter because of the profound increase in kinetic energy that can lead to venous endothelium injury.

Internal and external spatial attention examined with lateralized EEG power spectra.

PubMed

Van der Lubbe, Rob H J; Bundt, Carsten; Abrahamse, Elger L

2014-10-02

Several authors argued that retrieval of an item from visual short term memory (internal spatial attention) and focusing attention on an externally presented item (external spatial attention) are similar. Part of the neuroimaging support for this view may be due to the employed experimental procedures. Furthermore, as internal spatial attention may have a more induced than evoked nature some effects may not have been visible in event related analyses of the electroencephalogram (EEG), which limits the possibility to demonstrate differences. In the current study, a colored frame cued which stimulus, one out of four presented in separate quadrants, required a response, which depended on the form of the cued stimulus (circle or square). Importantly, the frame occurred either before (precue), simultaneously with (simultaneous cue), or after the stimuli (postcue). The precue and simultaneous cue condition both concern external attention, while the postcue condition implies the involvement of internal spatial attention. Event-related lateralizations (ERLs), reflecting evoked effects, and lateralized power spectra (LPS), reflecting both evoked and induced effects, were determined. ERLs revealed a posterior contralateral negativity (PCN) only in the precue condition. LPS analyses on the raw EEG showed early increased contralateral theta power at posterior sites and later increased ipsilateral alpha power at occipito-temporal sites in all cue conditions. Responses were faster when the internally or externally attended location corresponded with the required response side than when not. These findings provide further support for the view that internal and external spatial attention share their underlying mechanism. Copyright © 2014 Elsevier B.V. All rights reserved.

Into the blue: AO science with MagAO in the visible

NASA Astrophysics Data System (ADS)

Close, Laird M.; Males, Jared R.; Follette, Katherine B.; Hinz, Phil; Morzinski, Katie; Wu, Ya-Lin; Kopon, Derek; Riccardi, Armando; Esposito, Simone; Puglisi, Alfio; Pinna, Enrico; Xompero, Marco; Briguglio, Runa; Quiros-Pacheco, Fernando

2014-08-01

We review astronomical results in the visible (λ<1μm) with adaptive optics. Other than a brief period in the early 1990s, there has been little astronomical science done in the visible with AO until recently. The most productive visible AO system to date is our 6.5m Magellan telescope AO system (MagAO). MagAO is an advanced Adaptive Secondary system at the Magellan 6.5m in Chile. This secondary has 585 actuators with < 1 msec response times (0.7 ms typically). We use a pyramid wavefront sensor. The relatively small actuator pitch (~23 cm/subap) allows moderate Strehls to be obtained in the visible (0.63-1.05 microns). We use a CCD AO science camera called "VisAO". On-sky long exposures (60s) achieve <30mas resolutions, 30% Strehls at 0.62 microns (r') with the VisAO camera in 0.5" seeing with bright R < 8 mag stars. These relatively high visible wavelength Strehls are made possible by our powerful combination of a next generation ASM and a Pyramid WFS with 378 controlled modes and 1000 Hz loop frequency. We'll review the key steps to having good performance in the visible and review the exciting new AO visible science opportunities and refereed publications in both broad-band (r,i,z,Y) and at Halpha for exoplanets, protoplanetary disks, young stars, and emission line jets. These examples highlight the power of visible AO to probe circumstellar regions/spatial resolutions that would otherwise require much larger diameter telescopes with classical infrared AO cameras.

Impacts of PM concentrations on visibility impairment

NASA Astrophysics Data System (ADS)

Jie, Guo; Wang, Mei-mei; Han, Ye-Xing; Yu, Zhi-Wei; Tang, Huai-Wu

2016-11-01

In the paper, an accurate and sensitive cavity attenuated phase shift spectroscopy (CAPS) sensor was used to monitor the atmospheric visibility. The CAPS system mainly includes a LED light source, a band-pass filter, an optical resonant cavity (composed of two high mirror, reflectivity is greater than 99.99%), a photoelectric detector and a lock-in amplifier. The 2L/min flow rate, the optical sensor rise and fall response time is about 15 s, so as to realize the fast measurement of visibility. An Allan variance analysis was carried out evaluating the optical system stability (and hence the maximum averaging time for the minimum detection limit) of the CAPS system. The minima ( 0.1 Mm-1) in the Allan plots show the optimum average time ( 100s) for optimum detection performance of the CAPS system. During this period, the extinction coefficient was correlated with PM2.5 mass (0.88), the extinction coefficient was correlated with PM10 mass (0.85). The atmospheric visibility was correlated with PM2.5 mass (0.74). The atmospheric visibility was correlated with PM10 mass (0.66).

Risk factors for whole carcass condemnations in the Swiss slaughter cattle population.

PubMed

Vial, Flavie; Schärrer, Sara; Reist, Martin

2015-01-01

We used meat-inspection data collected over a period of three years in Switzerland to evaluate slaughterhouse-level, farm-level and animal-level factors that may be associated with whole carcass condemnation (WCC) in cattle after slaughter. The objective of this study was to identify WCC risk factors so they can be communicated to, and managed by, the slaughter industry and veterinary services. During meat inspection, there were three main important predictors of the risk of WCC; the slaughtered animal's sex, age, and the size of the slaughterhouse it was processed in. WCC for injuries and significant weight loss (visible welfare indicators) were almost exclusive to smaller slaughterhouses. Cattle exhibiting clinical syndromes that were not externally visible (e.g. pneumonia lesions) and that are associated with fattening of cattle, end up in larger slaughterhouses. For this reason, it is important for animal health surveillance to collect data from both types of slaughterhouses. Other important risk factors for WCC were on-farm mortality rate and the number of cattle on the farm of origin. This study highlights the fact that the many risk factors for WCC are as complex as the production system itself, with risk factors interacting with one another in ways which are sometimes difficult to interpret biologically. Risk-based surveillance aimed at farms with reoccurring health problems (e.g. a history of above average condemnation rates) may be more appropriate than the selection, of higher-risk animals arriving at slaughter. In Switzerland, the introduction of a benchmarking system that would provide feedback to the farmer with information on condemnation reasons, and his/her performance compared to the national/regional average could be a first step towards improving herd-management and financial returns for producers.

Risk Factors for Whole Carcass Condemnations in the Swiss Slaughter Cattle Population

PubMed Central

Vial, Flavie; Schärrer, Sara; Reist, Martin

2015-01-01

We used meat-inspection data collected over a period of three years in Switzerland to evaluate slaughterhouse-level, farm-level and animal-level factors that may be associated with whole carcass condemnation (WCC) in cattle after slaughter. The objective of this study was to identify WCC risk factors so they can be communicated to, and managed by, the slaughter industry and veterinary services. During meat inspection, there were three main important predictors of the risk of WCC; the slaughtered animal's sex, age, and the size of the slaughterhouse it was processed in. WCC for injuries and significant weight loss (visible welfare indicators) were almost exclusive to smaller slaughterhouses. Cattle exhibiting clinical syndromes that were not externally visible (e.g. pneumonia lesions) and that are associated with fattening of cattle, end up in larger slaughterhouses. For this reason, it is important for animal health surveillance to collect data from both types of slaughterhouses. Other important risk factors for WCC were on-farm mortality rate and the number of cattle on the farm of origin. This study highlights the fact that the many risk factors for WCC are as complex as the production system itself, with risk factors interacting with one another in ways which are sometimes difficult to interpret biologically. Risk-based surveillance aimed at farms with reoccurring health problems (e.g. a history of above average condemnation rates) may be more appropriate than the selection, of higher-risk animals arriving at slaughter. In Switzerland, the introduction of a benchmarking system that would provide feedback to the farmer with information on condemnation reasons, and his/her performance compared to the national/regional average could be a first step towards improving herd-management and financial returns for producers. PMID:25901751

Circulating Magnetic Microbubbles for Localized Real-Time Control of Drug Delivery by Ultrasonography-Guided Magnetic Targeting and Ultrasound

PubMed Central

Chertok, Beata; Langer, Robert

2018-01-01

Image-guided and target-selective modulation of drug delivery by external physical triggers at the site of pathology has the potential to enable tailored control of drug targeting. Magnetic microbubbles that are responsive to magnetic and acoustic modulation and visible to ultrasonography have been proposed as a means to realize this drug targeting strategy. To comply with this strategy in vivo, magnetic microbubbles must circulate systemically and evade deposition in pulmonary capillaries, while also preserving magnetic and acoustic activities in circulation over time. Unfortunately, challenges in fabricating magnetic microbubbles with such characteristics have limited progress in this field. In this report, we develop magnetic microbubbles (MagMB) that display strong magnetic and acoustic activities, while also preserving the ability to circulate systemically and evade pulmonary entrapment. Methods: We systematically evaluated the characteristics of MagMB including their pharmacokinetics, biodistribution, visibility to ultrasonography and amenability to magneto-acoustic modulation in tumor-bearing mice. We further assessed the applicability of MagMB for ultrasonography-guided control of drug targeting. Results: Following intravenous injection, MagMB exhibited a 17- to 90-fold lower pulmonary entrapment compared to previously reported magnetic microbubbles and mimicked circulation persistence of the clinically utilized Definity microbubbles (>10 min). In addition, MagMB could be accumulated in tumor vasculature by magnetic targeting, monitored by ultrasonography and collapsed by focused ultrasound on demand to activate drug deposition at the target. Furthermore, drug delivery to target tumors could be enhanced by adjusting the magneto-acoustic modulation based on ultrasonographic monitoring of MagMB in real-time. Conclusions: Circulating MagMB in conjunction with ultrasonography-guided magneto-acoustic modulation may provide a strategy for tailored minimally-invasive control over drug delivery to target tissues. PMID:29290812

Aspects of Synthetic Vision Display Systems and the Best Practices of the NASA's SVS Project

NASA Technical Reports Server (NTRS)

Bailey, Randall E.; Kramer, Lynda J.; Jones, Denise R.; Young, Steven D.; Arthur, Jarvis J.; Prinzel, Lawrence J.; Glaab, Louis J.; Harrah, Steven D.; Parrish, Russell V.

2008-01-01

NASA s Synthetic Vision Systems (SVS) Project conducted research aimed at eliminating visibility-induced errors and low visibility conditions as causal factors in civil aircraft accidents while enabling the operational benefits of clear day flight operations regardless of actual outside visibility. SVS takes advantage of many enabling technologies to achieve this capability including, for example, the Global Positioning System (GPS), data links, radar, imaging sensors, geospatial databases, advanced display media and three dimensional video graphics processors. Integration of these technologies to achieve the SVS concept provides pilots with high-integrity information that improves situational awareness with respect to terrain, obstacles, traffic, and flight path. This paper attempts to emphasize the system aspects of SVS - true systems, rather than just terrain on a flight display - and to document from an historical viewpoint many of the best practices that evolved during the SVS Project from the perspective of some of the NASA researchers most heavily involved in its execution. The Integrated SVS Concepts are envisagements of what production-grade Synthetic Vision systems might, or perhaps should, be in order to provide the desired functional capabilities that eliminate low visibility as a causal factor to accidents and enable clear-day operational benefits regardless of visibility conditions.

An Automated Self-Learning Quantification System to Identify Visible Areas in Capsule Endoscopy Images.

PubMed

Hashimoto, Shinichi; Ogihara, Hiroyuki; Suenaga, Masato; Fujita, Yusuke; Terai, Shuji; Hamamoto, Yoshihiko; Sakaida, Isao

2017-08-01

Visibility in capsule endoscopic images is presently evaluated through intermittent analysis of frames selected by a physician. It is thus subjective and not quantitative. A method to automatically quantify the visibility on capsule endoscopic images has not been reported. Generally, when designing automated image recognition programs, physicians must provide a training image; this process is called supervised learning. We aimed to develop a novel automated self-learning quantification system to identify visible areas on capsule endoscopic images. The technique was developed using 200 capsule endoscopic images retrospectively selected from each of three patients. The rate of detection of visible areas on capsule endoscopic images between a supervised learning program, using training images labeled by a physician, and our novel automated self-learning program, using unlabeled training images without intervention by a physician, was compared. The rate of detection of visible areas was equivalent for the supervised learning program and for our automatic self-learning program. The visible areas automatically identified by self-learning program correlated to the areas identified by an experienced physician. We developed a novel self-learning automated program to identify visible areas in capsule endoscopic images.

Probing quantum correlation functions through energy-absorption interferometry

NASA Astrophysics Data System (ADS)

Withington, S.; Thomas, C. N.; Goldie, D. J.

2017-08-01

An interferometric technique is described for determining the spatial forms of the individual degrees of freedom through which a many-body system can absorb energy from its environment. The method separates out the spatial forms of the coherent excitations present at any single frequency; it is not necessary to sweep the frequency and then infer the spatial forms of possible excitations from resonant absorption features. The system under test is excited with two external sources, which create generalized forces, and the fringe in the total power dissipated is measured as the relative phase between the sources is varied. If the complex fringe visibility is measured for different pairs of source locations, the anti-Hermitian part of the complex-valued nonlocal correlation tensor can be determined, which can then be decomposed to give the natural dynamical modes of the system and their relative responsivities. If each source in the interferometer creates a different kind of force, the spatial forms of the individual excitations that are responsible for cross-correlated response can be found. The technique is related to holography, but measures the state of coherence to which the system is maximally sensitive. It can be applied across a wide range of wavelengths, in a variety of ways, to homogeneous media, thin films, patterned structures, and components such as sensors, detectors, and energy-harvesting absorbers.

Analysis of the Variability of Poor Visibility Events in North and Central United Arab Emirates

NASA Astrophysics Data System (ADS)

Aldababseh, Amal; Temimi, Marouane

2016-12-01

Good visibility is essential for the safety of ground transportation and aviation sectors. Degradation in visibility can occur during wet or dry conditions and can therefore be a proxy for air pollution and atmospheric conditions. Moreover, visibility indicates the long-term impact on human health and climate and the relationship with local atmospheric pollution. The major factors triggering the degradation of visibility can be inferred by analyzing visibility long-term trends. In the UAE, we expect that the unprecedented growth in urban development and the aviation sector has impacted visibility records. This study is the first attempt to thoroughly investigate temporal and spatial variations in poor visibility measurements in the UAE and at four different visibility observation levels; less than 5000m, 2500m, 1000m and 100m, as well as to analyze the correlation between poor visibility measurements and different meteorological parameters (relative humidity, air temperature, wind direction and speed) under two weather conditions; wet and dry. Results show that eliminating all meteorological conditions (fog, mist, haze, and precipitation and dust) does not change the overall decreasing trend in visibility, this suggests that the changes in the air quality might be responsible for the long-term visibility degradation. The decreasing trends in visibility vary from the different major cities in the UAE. All the meteorological parameters studied are significantly related to visibility, indicating the existence of complex mechanisms (physical and chemical) that affect the visibility in the atmosphere. Visibility is positively correlated to relative humidity and wind direction, however, it is negatively correlated with temperature, wind speed and dew point. This is possibly related to the weather systems in summer and winter. In summer the presence of synoptic systems along with the very high temperature, low pressure, very high humidity, and very high wind speed due to the Shamal often lead to low visibility, whereas in winter the relatively high wind speed suggests more efficient diffusion conditions and dilutes pollutions and dust particulates to low concentration, with lower temperature and limited precipitation favors high visibility.

Systems and Methods for Automated Water Detection Using Visible Sensors

NASA Technical Reports Server (NTRS)

Rankin, Arturo L. (Inventor); Matthies, Larry H. (Inventor); Bellutta, Paolo (Inventor)

2016-01-01

Systems and methods are disclosed that include automated machine vision that can utilize images of scenes captured by a 3D imaging system configured to image light within the visible light spectrum to detect water. One embodiment includes autonomously detecting water bodies within a scene including capturing at least one 3D image of a scene using a sensor system configured to detect visible light and to measure distance from points within the scene to the sensor system, and detecting water within the scene using a processor configured to detect regions within each of the at least one 3D images that possess at least one characteristic indicative of the presence of water.

Taxiway Navigation and Situation Awareness (T-NASA) System : problem, design philosophy, and description of an integrated display suite for low-visibility airport surface operations

DOT National Transportation Integrated Search

1996-01-01

An integrated cockpit display suite, the T-NASA (Taxiway Navigation and : Situation Awareness) system, is under development for NASA's Terminal Area : Productivity (TAP) Low-Visibility Landing and Surface Operations (LVLASO) : program. This system ha...

Battlefield training in impaired visibility

NASA Astrophysics Data System (ADS)

Gammarino, Rudolph R.; Surhigh, James W.

1991-04-01

A laser training system entitled Shoot Through Obscuration MILES (STOM) is being developed to operate with Forward Looking InfraRed (FLIR) systems during battlefield exercises where visibility is impaired. The STOM system is capable of ranges in excess of 6 km and can penetrate battlefield obscurants such as fog-oil, smoke, dust, and rain.

Visible and near-infrared photothermal catalyzed hydrogenation of gaseous CO 2 over nanostructured Pd@Nb 2O 5

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jia, Jia; O'Brien, Paul G.; He, Le

2016-07-05

The reverse water gas shift (RWGS) reaction driven by Nb 2O 5 nanorod-supported Pd nanocrystals without external heating using visible and near infrared (NIR) light is demonstrated. By measuring the dependence of the RWGS reaction rates on the intensity and spectral power distribution of filtered light incident onto the nanostructured Pd@Nb 2O 5 catalyst, it is determined that the RWGS reaction is activated photothermally. That is the RWGS reaction is initiated by heat generated from thermalization of charge carriers in the Pd nanocrystals that are excited by interband and intraband absorption of visible and NIR light. Taking advantage of thismore » photothermal effect, a visible and NIR responsive Pd@Nb 2O 5 hybrid catalyst that efficiently hydrogenates CO 2 to CO at an impressive rate as high as 1.8 mmol gcat –1 h –1 is developed. The mechanism of this photothermal reaction involves H 2 dissociation on Pd nanocrystals and subsequent spillover of H to the Nb 2O 5 nanorods whereupon adsorbed CO 2 is hydrogenated to CO. Here, this work represents a significant enhancement in our understanding of the underlying mechanism of photothermally driven CO 2 reduction and will help guide the way toward the development of highly efficient catalysts that exploit the full solar spectrum to convert gas-phase CO 2 to valuable chemicals and fuels.« less

A feasibility study of an integrated NIR/gamma/visible imaging system for endoscopic sentinel lymph node mapping.

PubMed

Kang, Han Gyu; Lee, Ho-Young; Kim, Kyeong Min; Song, Seong-Hyun; Hong, Gun Chul; Hong, Seong Jong

2017-01-01

The aim of this study is to integrate NIR, gamma, and visible imaging tools into a single endoscopic system to overcome the limitation of NIR using gamma imaging and to demonstrate the feasibility of endoscopic NIR/gamma/visible fusion imaging for sentinel lymph node (SLN) mapping with a small animal. The endoscopic NIR/gamma/visible imaging system consists of a tungsten pinhole collimator, a plastic focusing lens, a BGO crystal (11 × 11 × 2 mm 3 ), a fiber-optic taper (front = 11 × 11 mm 2 , end = 4 × 4 mm 2 ), a 122-cm long endoscopic fiber bundle, an NIR emission filter, a relay lens, and a CCD camera. A custom-made Derenzo-like phantom filled with a mixture of 99m Tc and indocyanine green (ICG) was used to assess the spatial resolution of the NIR and gamma images. The ICG fluorophore was excited using a light-emitting diode (LED) with an excitation filter (723-758 nm), and the emitted fluorescence photons were detected with an emission filter (780-820 nm) for a duration of 100 ms. Subsequently, the 99m Tc distribution in the phantom was imaged for 3 min. The feasibility of in vivo SLN mapping with a mouse was investigated by injecting a mixture of 99m Tc-antimony sulfur colloid (12 MBq) and ICG (0.1 mL) into the right paw of the mouse (C57/B6) subcutaneously. After one hour, NIR, gamma, and visible images were acquired sequentially. Subsequently, the dissected SLN was imaged in the same way as the in vivo SLN mapping. The NIR, gamma, and visible images of the Derenzo-like phantom can be obtained with the proposed endoscopic imaging system. The NIR/gamma/visible fusion image of the SLN showed a good correlation among the NIR, gamma, and visible images both for the in vivo and ex vivo imaging. We demonstrated the feasibility of the integrated NIR/gamma/visible imaging system using a single endoscopic fiber bundle. In future, we plan to investigate miniaturization of the endoscope head and simultaneous NIR/gamma/visible imaging with dichroic mirrors and three CCD cameras. © 2016 American Association of Physicists in Medicine.

Virtual Laparoscopic Training System Based on VCH Model.

PubMed

Tang, Jiangzhou; Xu, Lang; He, Longjun; Guan, Songluan; Ming, Xing; Liu, Qian

2017-04-01

Laparoscopy has been widely used to perform abdominal surgeries, as it is advantageous in that the patients experience lower post-surgical trauma, shorter convalescence, and less pain as compared to traditional surgery. Laparoscopic surgeries require precision; therefore, it is imperative to train surgeons to reduce the risk of operation. Laparoscopic simulators offer a highly realistic surgical environment by using virtual reality technology, and it can improve the training efficiency of laparoscopic surgery. This paper presents a virtual Laparoscopic surgery system. The proposed system utilizes the Visible Chinese Human (VCH) to construct the virtual models and simulates real-time deformation with both improved special mass-spring model and morph target animation. Meanwhile, an external device that integrates two five-degrees-of-freedom (5-DOF) manipulators was designed and made to interact with the virtual system. In addition, the proposed system provides a modular tool based on Unity3D to define the functions and features of instruments and organs, which could help users to build surgical training scenarios quickly. The proposed virtual laparoscopic training system offers two kinds of training mode, skills training and surgery training. In the skills training mode, the surgeons are mainly trained for basic operations, such as laparoscopic camera, needle, grasp, electric coagulation, and suturing. In the surgery-training mode, the surgeons can practice cholecystectomy and removal of hepatic cysts by guided or non-guided teaching.

Clinical comparative study with a large-area amorphous silicon flat-panel detector: image quality and visibility of anatomic structures on chest radiography.

PubMed

Fink, Christian; Hallscheidt, Peter J; Noeldge, Gerd; Kampschulte, Annette; Radeleff, Boris; Hosch, Waldemar P; Kauffmann, Günter W; Hansmann, Jochen

2002-02-01

The objective of this study was to compare clinical chest radiographs of a large-area, flat-panel digital radiography system and a conventional film-screen radiography system. The comparison was based on an observer preference study of image quality and visibility of anatomic structures. Routine follow-up chest radiographs were obtained from 100 consecutive oncology patients using a large-area, amorphous silicon flat-panel detector digital radiography system (dose equivalent to a 400-speed film system). Hard-copy images were compared with previous examinations of the same individuals taken on a conventional film-screen system (200-speed). Patients were excluded if changes in the chest anatomy were detected or if the time interval between the examinations exceeded 1 year. Observer preference was evaluated for the image quality and the visibility of 15 anatomic structures using a five-point scale. Dose measurements with a chest phantom showed a dose reduction of approximately 50% with the digital radiography system compared with the film-screen radiography system. The image quality and the visibility of all but one anatomic structure of the images obtained with the digital flat-panel detector system were rated significantly superior (p < or = 0.0003) to those obtained with the conventional film-screen radiography system. The image quality and visibility of anatomic structures on the images obtained by the flat-panel detector system were perceived as equal or superior to the images from conventional film-screen chest radiography. This was true even though the radiation dose was reduced approximately 50% with the digital flat-panel detector system.

Design of large zoom for visible and infrared optical system in hemisphere space

NASA Astrophysics Data System (ADS)

Xing, Yang-guang; Li, Lin; Zhang, Juan

2018-01-01

In the field of space optical, the application of advanced optical instruments for related target detection and identification has become an advanced technology in modern optics. In order to complete the task of search in wide field of view and detailed investigation in small field of view, it is inevitable to use the structure of the zoom system to achieve a better observation for important targets. The innovation of this paper lies in using the zoom optical system in space detection, which achieve firstly military needs of searched target in the large field of view and recognized target in the small field of view. At the same time, this paper also completes firstly the design of variable focus optical detection system in the range of hemisphere space, the zoom optical system is working in the range of visible and infrared wavelengths, the perspective angle reaches 360 ° and the zoom ratio of the visible system is up to 15. The visible system has a zoom range of 60-900 mm, a detection band of 0.48-0.70μm, and a F-number of 2.0 to 5.0. The infrared system has a zoom range of 150 900mm, a detection band of 8-12μm, and a F-number of 1.2 to 3.0. The MTF of the visible zoom system is above 0.4 at spatial frequency of 45 lp / mm, and the infrared zoom system is above 0.4 at spatial frequency of 11 lp / mm. The design results show that the system has a good image quality.

Differential phenolic production in leaves of Vitis vinifera cv. Alvarinho affected with esca disease.

PubMed

Lima, Marta R M; Felgueiras, Mafalda L; Cunha, Ana; Chicau, Gisela; Ferreres, Federico; Dias, Alberto C P

2017-03-01

Esca is a destructive disease of complex etiology affecting grapevines worldwide. A major constraint to the study and control of esca is that the disease is not diagnosed until external leaf and/or fruit symptoms are visible; however external symptoms usually appear several years after infection onset. We studied the phenolic content of V. vinifera cv. Alvarinho leaves using high performance liquid chromatography-diode array detection-mass spectrometry (HPLC-DAD-MS)/LC-MS. Leaves from affected cordons with and without visible symptoms (diseased and apparently healthy leaves, respectively) and leaves from asymptomatic cordons (healthy leaves) were analyzed. Application of principal components analysis (PCA) to HPLC data showed a clear separation between diseased, apparently healthy, and healthy leaves, with the apparently healthy leaves clustered in a medial position. Several compounds were highly correlated with diseased leaves indicating a differential phenolic production due to esca disease in V. vinifera cv. Alvarinho leaves. Total phenolic production was shown to significantly increase in diseased leaves, compared to healthy leaves, with apparently healthy leaves containing a medial amount. Trans-caffeoyltartaric acid, trans-coumaroyl-tartaric acid, quercetin-3-O-glucoside, quercetin-3-O-galactoside, kaempferol-3-glucoside and myricetin were identified among the compounds associated with disease and their content shown to change similarly to total phenolic production. This study shows that it is possible to discriminate between diseased, healthy and apparently healthy leaves by applying PCA to HPLC data. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Hybrid density functional study on the mechanism for the enhanced photocatalytic properties of the ultrathin hybrid layered nanocomposite g-C3N4/BiOCl

NASA Astrophysics Data System (ADS)

Yao, Wenzhi; Zhang, Jihua; Wang, Yuanxu; Ren, Fengzhu

2018-03-01

To investigate the origin of the high photocatalytic performance of experimentally synthesized g-C3N4/ BiOCl, we studied its geometry structure, electronic structure, and photocatalytic properties by means of hybrid density-functional theory (DFT). The calculated band alignment of g-C3N4 and few-layer BiOCl sheets clearly shows that g-C3N4/ BiOCl is a standard type-II nanocomposite. The density of states, Bader charge, partial charge density, charge density difference, and the effective masses show that electron-hole pair can be effectively separated in the g-C3N4/BiOCl interface. The calculated absorption coefficients indicate an obvious redshift of the absorption edge. The band gap of g-C3N4/BiOCl can be modulated by external electric field, and a semiconductor-semimetal transition is observed. The type-II vdW heterostructure is still maintained during the changes of external electric field. Especially, when the electric field reaches to +0.7 V/Å, the impurity states have been eliminated with the band gap of 2.3 eV. An analysis of optical properties shows that the absorption coefficient in the visible-light region is enhanced considerably as the electric-field strength increases. Our calculation results suggest that the ultrathin hybrid layered g-C3N4/BiOCl nanocomposite may have significant advantages for visible-light photocatalysis.

Head-up transition behavior of pilots with and without head-up display in simulated low-visibility approaches

NASA Technical Reports Server (NTRS)

Haines, R. F.; Fischer, E.; Price, T. A.

1980-01-01

To quantify head-up transition behavior with and without a flightpath type head-up display, eight rated B-727 pilots each flew 31 manual and coupled approaches in a simulator with B-727 dynamics and collimated model board external scene. Data were also obtained on the roll played by the head-up display in the coupled-to-manual transition. Various wind shears, low visibilities, and ceilings were tested along with unexpected misalignment between the runway and head-up display symbology. The symbolic format used was a conformal scene. Every pilot except one stayed head-up, flying with the display after descending below the ceiling. Without the display and as altitude decreased, the number of lookups from the instrument panel decreased and the duration of each one increased. No large differences in mean number or duration of transitions up or down were found during the head-up display runs comparing the no-misalignment with the lateral instrument landing system offset misalignment runs. The head-up display led to fewer transitions after the pilot made a decision to land or execute a missed approach. Without the display, pilots generally waited until they had descended below the ceiling to look outside the first time, but with it several pilots looked down at their panel at relatively high altitudes (if they looked down at all). Manual takeover of control was rapid and smooth both with and without the display which permitted smoother engine power changes.

Device for wavelength-selective imaging

DOEpatents

Frangioni, John V.

2010-09-14

An imaging device captures both a visible light image and a diagnostic image, the diagnostic image corresponding to emissions from an imaging medium within the object. The visible light image (which may be color or grayscale) and the diagnostic image may be superimposed to display regions of diagnostic significance within a visible light image. A number of imaging media may be used according to an intended application for the imaging device, and an imaging medium may have wavelengths above, below, or within the visible light spectrum. The devices described herein may be advantageously packaged within a single integrated device or other solid state device, and/or employed in an integrated, single-camera medical imaging system, as well as many non-medical imaging systems that would benefit from simultaneous capture of visible-light wavelength images along with images at other wavelengths.

Lidar systems for measuring visibility : a technical assessment

DOT National Transportation Integrated Search

1974-09-01

A study has been made of the feasibility of using a laser backscatter system (lidar) to measure slant visibility at airports. This report summarizes the present status of lidar from a technical standpoint. Based largely on the results of experimental...

A Protective Mechanism of Visible Red Light in Normal Human Dermal Fibroblasts: Enhancement of GADD45A-Mediated DNA Repair Activity.

PubMed

Kim, Yeo Jin; Kim, Hyoung-June; Kim, Hye Lim; Kim, Hyo Jeong; Kim, Hyun Soo; Lee, Tae Ryong; Shin, Dong Wook; Seo, Young Rok

2017-02-01

The phototherapeutic effects of visible red light on skin have been extensively investigated, but the underlying biological mechanisms remain poorly understood. We aimed to elucidate the protective mechanism of visible red light in terms of DNA repair of UV-induced oxidative damage in normal human dermal fibroblasts. The protective effect of visible red light on UV-induced DNA damage was identified by several assays in both two-dimensional and three-dimensional cell culture systems. With regard to the protective mechanism of visible red light, our data showed alterations in base excision repair mediated by growth arrest and DNA damage inducible, alpha (GADD45A). We also observed an enhancement of the physical activity of GADD45A and apurinic/apyrimidinic endonuclease 1 (APE1) by visible red light. Moreover, UV-induced DNA damages were diminished by visible red light in an APE1-dependent manner. On the basis of the decrease in GADD45A-APE1 interaction in the activating transcription factor-2 (ATF2)-knockdown system, we suggest a role for ATF2 modulation in GADD45A-mediated DNA repair upon visible red light exposure. Thus, the enhancement of GADD45A-mediated base excision repair modulated by ATF2 might be a potential protective mechanism of visible red light. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

Penta-P2X (X=C, Si) monolayers as wide-bandgap semiconductors: A first principles prediction

NASA Astrophysics Data System (ADS)

Naseri, Mosayeb; Lin, Shiru; Jalilian, Jaafar; Gu, Jinxing; Chen, Zhongfang

2018-06-01

By means of density functional theory computations, we predicted two novel two-dimensional (2D) nanomaterials, namely P2X (X=C, Si) monolayers with pentagonal configurations. Their structures, stabilities, intrinsic electronic, and optical properties as well as the effect of external strain to the electronic properties have been systematically examined. Our computations showed that these P2C and P2Si monolayers have rather high thermodynamic, kinetic, and thermal stabilities, and are indirect semiconductors with wide bandgaps (2.76 eV and 2.69 eV, respectively) which can be tuned by an external strain. These monolayers exhibit high absorptions in the UV region, but behave as almost transparent layers for visible light in the electromagnetic spectrum. Their high stabilities and exceptional electronic and optical properties suggest them as promising candidates for future applications in UV-light shielding and antireflection layers in solar cells.

CARCINOMA IN SITU OF THE UTERINE CERVIX—DIAGNOSIS BY BIOPSY

PubMed Central

Fluhmann, C. Frederic; Lyons, Harold M.

1960-01-01

In 50 cases of carcinoma in situ of the cervix uteri, the lesion was present in the cervical canal in 36 instances, but the squamous epithelium of the portio was involved in only 14 cases. Since single biopsy from the portio or external os may show no malignant change even in cases in which vaginal smears are positive for cancer, single biopsy is indicated only in the presence of gross suspicious lesions. When positive smears have been obtained, cold-knife cone biopsy is indicated (a) whenever gross lesions are not visible on the ectocervix, (b) if carcinoma in situ is found in a biopsy of the external os, in order to determine the presence or absence of invasion, and (c) when there are repeated positive smears and biopsy of the portio has not shown the presence of malignancy. The technique of cone biopsy is given in detail. PMID:13823610

Algorithm of resonance orders for the objects

NASA Astrophysics Data System (ADS)

Zhang, YongGang; Zhang, JianXue

2018-03-01

In mechanical engineering, the object resonance phenomena often occur when the external incident wave frequency is close to object of the natural frequency. Object resonance phenomena get the maximum value when the external incident frequency is equal to object the natural frequency. Experiments found that resonance intension of the object is changed, different objects resonance phenomena present different characteristics of ladders. Based on object orders resonance characteristics, the calculation method of object orders resonance is put forward in the paper, and the application for the light and sound waves on the seven order resonance characteristics by people feel, the result error is less than 1%.Visible in this paper, the method has high accuracy and usability. The calculation method reveals that some object resonance occur present order characteristic only four types, namely the first-orders resonance characteristics, third-orders characteristics, five orders characteristic, and seven orders characteristic.

Muslim and Hindu Women's public and private behaviors: gender, family, and communalized politics in India.

PubMed

Desai, Sonalde; Temsah, Gheda

2014-12-01

Prior research on fundamentalist religious movements has focused attention on the complicated relationship among gender, family, and religion. Using data from a nationally representative survey of 30,000 Hindu and Muslim women, this study compares the daily public and private behaviors of women in India to examine how gender and family norms are shaped in the context of communalized identity politics. Building on the theoretical framework of "doing gender," we argue that because communal identities are expressed through externally visible behaviors, greater religious differences are expected in external markers of gendered behaviors and family norms. Results indicate that Muslim women are more likely to engage in veiling and less likely to venture outside the home for recreation and employment. However, religious differences are absent when attention is directed at private behaviors, such as household decision-making power, gender segregation within households, and discrimination against daughters. Results underscore the multidimensionality of gender.

Spin effects in transport through single-molecule magnets in the sequential and cotunneling regimes

NASA Astrophysics Data System (ADS)

Misiorny, Maciej; Weymann, Ireneusz; Barnaś, Józef

2009-06-01

We analyze the stationary spin-dependent transport through a single-molecule magnet weakly coupled to external ferromagnetic leads. Using the real-time diagrammatic technique, we calculate the sequential and cotunneling contributions to current, tunnel magnetoresistance, and Fano factor in both linear and nonlinear response regimes. We show that the effects of cotunneling are predominantly visible in the blockade regime and lead to enhancement of tunnel magnetoresistance (TMR) above the Julliere value, which is accompanied with super-Poissonian shot noise due to bunching of inelastic cotunneling processes through different virtual spin states of the molecule. The effects of external magnetic field and the role of type and strength of exchange interaction between the LUMO level and the molecule’s spin are also considered. When the exchange coupling is ferromagnetic, we find an enhanced TMR, while in the case of antiferromagnetic coupling we predict a large negative TMR effect.

Embryonic development of Python sebae - I: Staging criteria and macroscopic skeletal morphogenesis of the head and limbs.

PubMed

Boughner, Julia C; Buchtová, Marcela; Fu, Katherine; Diewert, Virginia; Hallgrímsson, Benedikt; Richman, Joy M

2007-01-01

This study explores the post-ovipositional craniofacial development of the African Rock Python (Python sebae). We first describe a staging system based on external characteristics and next use whole-mount skeletal staining supplemented with Computed tomography (CT) scanning to examine skeletal development. Our results show that python embryos are in early stages of organogenesis at the time of laying, with separate facial prominences and pharyngeal clefts still visible. Limb buds are also visible. By 11 days (stage 3), the chondrocranium is nearly fully formed; however, few intramembranous bones can be detected. One week later (stage 4), many of the intramembranous upper and lower jaw bones are visible but the calvaria are not present. Skeletal elements in the limbs also begin to form. Between stages 4 (day 18) and 7 (day 44), the complete set of intramembranous bones in the jaws and calvaria develops. Hindlimb development does not progress beyond stage 6 (33 days) and remains rudimentary throughout adult life. In contrast to other reptiles, there are two rows of teeth in the upper jaw. The outer tooth row is attached to the maxillary and premaxillary bones, whereas the inner row is attached to the pterygoid and palatine bones. Erupted teeth can be seen in whole-mount stage 10 specimens and are present in an unerupted, mineralized state at stage 7. Micro-CT analysis reveals that all the young membranous bones can be recognized even out of the context of the skull. These data demonstrate intrinsic patterning of the intramembranous bones, even though they form without a cartilaginous template. In addition, intramembranous bone morphology is established prior to muscle function, which can influence bone shape through differential force application. After careful staging, we conclude that python skeletal development occurs slowly enough to observe in good detail the early stages of craniofacial skeletogenesis. Thus, reptilian animal models will offer unique opportunities for understanding the early influences that contribute to perinatal bone shape.

GOES Imager Instrument - NOAA Satellite Information System (NOAASIS);

Science.gov Websites

Instrument Characteristics (GOES I-M) Channel number: 1 (Visible) 2 (Shortwave) 3 (Moisture) 4 (IR 1) 5 (IR 2 ) Infrared: 30 minutes typical System absolute accuracy IR channels: less than or equal to 1 K Visible

Low Visibility Operations/Surface Movement Guidance and Control System (LVO/SMGCS) Chart Symbology

DOT National Transportation Integrated Search

2016-02-01

This study examined which symbol shapes are considered to be representative of information shown on Low Visibility Operations/Surface Movement Guidance and Control System (LVO/SMGCS) charts, and how useful pilots perceive that information to be. The ...

A monolithic and flexible fluoropolymer film microreactor for organic synthesis applications.

PubMed

Kim, Jin-Oh; Kim, Heejin; Ko, Dong-Hyeon; Min, Kyoung-Ik; Im, Do Jin; Park, Soo-Young; Kim, Dong-Pyo

2014-11-07

A photocurable and viscous fluoropolymer with chemical stability is a highly desirable material for fabrication of microchemical devices. Lack of a reliable fabrication method, however, limits actual applications for organic reactions. Herein, we report fabrication of a monolithic and flexible fluoropolymer film microreactor and its use as a new microfluidic platform. The fabrication involves facile soft lithography techniques that enable partial curing of thin laminates, which can be readily bonded by conformal contact without any external forces. We demonstrate fabrication of various functional channels (~300 μm thick) such as those embedded with either a herringbone micromixer pattern or a droplet generator. Organic reactions under strongly acidic and basic conditions can be carried out in this film microreactor even at elevated temperature with excellent reproducibility. In particular, the transparent film microreactor with good deformability could be wrapped around a light-emitting lamp for close contact with the light source for efficient photochemical reactions with visible light, which demonstrates easy integration with optical components for functional miniaturized systems.

Mobile phone based mini-spectrometer for rapid screening of skin cancer

NASA Astrophysics Data System (ADS)

Das, Anshuman; Swedish, Tristan; Wahi, Akshat; Moufarrej, Mira; Noland, Marie; Gurry, Thomas; Aranda-Michel, Edgar; Aksel, Deniz; Wagh, Sneha; Sadashivaiah, Vijay; Zhang, Xu; Raskar, Ramesh

2015-06-01

We demonstrate a highly sensitive mobile phone based spectrometer that has potential to detect cancerous skin lesions in a rapid, non-invasive manner. Earlier reports of low cost spectrometers utilize the camera of the mobile phone to image the field after moving through a diffraction grating. These approaches are inherently limited by the closed nature of mobile phone image sensors and built in optical elements. The system presented uses a novel integrated grating and sensor that is compact, accurate and calibrated. Resolutions of about 10 nm can be achieved. Additionally, UV and visible LED excitation sources are built into the device. Data collection and analysis is simplified using the wireless interfaces and logical control on the smart phone. Furthermore, by utilizing an external sensor, the mobile phone camera can be used in conjunction with spectral measurements. We are exploring ways to use this device to measure endogenous fluorescence of skin in order to distinguish cancerous from non-cancerous lesions with a mobile phone based dermatoscope.

Exploring diabetes management amongst immigrant Sikhs in the Greater Toronto Area: a qualitative study.

PubMed

Uppal, Gina; Sibbald, Shannon L; Melling, James

2016-12-01

This study describes the ethnocultural influences associated with managing diabetes (Type 2) in a small sample of older Sikh immigrants in Toronto, Canada. The South Asian community, which includes Sikhs, is the fastest growing immigrant population, the second largest visible minority in Canada, and is five times more likely to have diabetes than their Canadian counterparts. The relationship between culture, immigration, and management of diabetes has been recognized, but research of how these areas intersect in the Sikh community is sparse. Data were collected using qualitative semi-structured interviews, and participants were recruited via purposive and snowball sampling techniques. Data were analysed using constant comparative methods. The complexities of diabetes management are organized in this study as the (1) external (2) internal and (3) actualized experiences participants faced navigating cultural dynamics, understanding their diagnosis, and interacting with health resources. An individual's diabetes diagnosis and treatment plan interacts with layers beyond the health system which must be understood in order to provide health care that is truly an empowering resource.

Optically Tunable Resistive-Switching Memory in Multiferroic Heterostructures

NASA Astrophysics Data System (ADS)

Zheng, Ming; Ni, Hao; Xu, Xiaoke; Qi, Yaping; Li, Xiaomin; Gao, Ju

2018-04-01

Electronic phase separation has been used to realize exotic functionalities in complex oxides with external stimuli, such as magnetic field, electric field, current, light, strain, etc. Using the Nd0.7Sr0.3MnO3/0.7 Pb (Mg1 /3Nb2 /3)O3-0 .3 PbTiO3 multiferroic heterostructure as a model system, we investigate the electric field and light cocontrol of phase separation in resistive switching. The electric-field-induced nonvolatile electroresistance response is achieved at room temperature using reversible ferroelastic domain switching, which can be robustly modified on illumination of light. Moreover, the electrically controlled ferroelastic strain can effectively enhance the visible-light-induced photoresistance effect. These findings demonstrate that the electric-field- and light-induced effects strongly correlate with each other and are essentially driven by electronic phase separation. Our work opens a gate to design electrically tunable multifunctional storage devices based on multiferroic heterostructures by adding light as an extra control parameter.

A method for depth-dose distribution measurements in tissue irradiated by a proton beam

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gambarini, G.; Birattari, C.; Bartolo, D. de

1994-12-31

The use of protons and heavy ions for the treatment of malignant and non-malignant disease has aroused a growing interest in the last decade. The notable advantage of heavy charged particles over photons in external beam radiotherapy lies in the possibility of irradiating a small localized region within the body, keeping a low value for the entrance dose. Owing to this high disuniformity of energy deposition, an essential requirement for treatment planning is a precise evaluation of the spatial distribution of absorbed dose. The proposed method for depth-dose distribution measurements utilizes a chemical dosimeter (ferrous sulphate solution plus sulfuric acidmore » and eventually xylenol orange) incorporated in a gelatine, whose role is the maintenance of spatial information. Ionizing radiation causes a variation in some parameters of the system such as the proton relaxation rates in the solution (measurable by NMR analysis) or the optical absorption of the gel in the visible spectrum (measurable by spectrophotometry).« less

Photonic and Phononic Entanglement with Hybrid Species Ion Chains

NASA Astrophysics Data System (ADS)

Crocker, Clayton; Lichtman, Martin; Sosnova, Ksenia; Nguyen, Tuan; Carter, Allison; Inlek, Volkan; Ruth, Hanna; Monroe, Christopher

2017-04-01

Trapped atomic ions represent a leading platform for quantum information networks due to their long coherence times and diverse set of entangling operations. External fields can drive strong local entangling interactions via phonons, and remote qubits can be entangled via emitted photons. Unfortunately, resonant light from the photonic entanglement process can disrupt nearby memory qubits. We resolve this crosstalk by introducing a separate atomic species to the trap for use as a photonic entanglement qubit. We report successful demonstration of both entangling gates between the mixed species qubit pair through their collective motion, and entanglement between our remote entanglement qubit and emitted visible photons. We additionally report our progress on a new trapping apparatus that was implemented to improve these operations to a level required for scaling up the system size. This work is supported by the ARO with funding from the IARPA LogiQ program, the AFOSR, the ARO MURI on Modular Quantum Circuits, the AFOSR MURI on Quantum Transduction, and the ARL Center for Distributed Quantum Information.

40 CFR 62.14412 - What stack opacity and visible emissions requirements apply?

Code of Federal Regulations, 2014 CFR

2014-07-01

... requirements apply? (a) Your HMIWI (regardless of size category) must not discharge into the atmosphere from... atmosphere visible emissions of combustion ash from an ash conveying system (including conveyor transfer... emissions limit does cover visible emissions discharged to the atmosphere from buildings or enclosures of...

40 CFR 62.14412 - What stack opacity and visible emissions requirements apply?

Code of Federal Regulations, 2013 CFR

2013-07-01

... requirements apply? (a) Your HMIWI (regardless of size category) must not discharge into the atmosphere from... atmosphere visible emissions of combustion ash from an ash conveying system (including conveyor transfer... emissions limit does cover visible emissions discharged to the atmosphere from buildings or enclosures of...

Comprehensive Investigation of Visibility Problems on Highways: Developing Real Time Monitoring and Prediction System for Reduced Visibility and Understanding Traffic and Human Factors Implications

DOT National Transportation Integrated Search

2017-07-01

Instances of fog or fog enhanced with smoke (non-photochemical smog) routinely reduce driver visibility on roadways throughout Georgia. Georgia has the fifth highest reduced-visibilityassociated crash frequency of any state. This report provides a...

Accurate visible speech synthesis based on concatenating variable length motion capture data.

PubMed

Ma, Jiyong; Cole, Ron; Pellom, Bryan; Ward, Wayne; Wise, Barbara

2006-01-01

We present a novel approach to synthesizing accurate visible speech based on searching and concatenating optimal variable-length units in a large corpus of motion capture data. Based on a set of visual prototypes selected on a source face and a corresponding set designated for a target face, we propose a machine learning technique to automatically map the facial motions observed on the source face to the target face. In order to model the long distance coarticulation effects in visible speech, a large-scale corpus that covers the most common syllables in English was collected, annotated and analyzed. For any input text, a search algorithm to locate the optimal sequences of concatenated units for synthesis is desrcribed. A new algorithm to adapt lip motions from a generic 3D face model to a specific 3D face model is also proposed. A complete, end-to-end visible speech animation system is implemented based on the approach. This system is currently used in more than 60 kindergarten through third grade classrooms to teach students to read using a lifelike conversational animated agent. To evaluate the quality of the visible speech produced by the animation system, both subjective evaluation and objective evaluation are conducted. The evaluation results show that the proposed approach is accurate and powerful for visible speech synthesis.

Wide-Band Spatially Tunable Photonic Bandgap in Visible Spectral Range and Laser based on a Polymer Stabilized Blue Phase

PubMed Central

Lin, Jia-De; Wang, Tsai-Yen; Mo, Ting-Shan; Huang, Shuan-Yu; Lee, Chia-Rong

2016-01-01

This work successfully develops a largely-gradient-pitched polymer-stabilized blue phase (PSBP) photonic bandgap (PBG) device with a wide-band spatial tunability in nearly entire visible region within a wide blue phase (BP) temperature range including room temperature. The device is fabricated based on the reverse diffusion of two injected BP-monomer mixtures with a low and a high chiral concentrations and afterwards through UV-curing. This gradient-pitched PSBP can show a rainbow-like reflection appearance in which the peak wavelength of the PBG can be spatially tuned from the blue to the red regions at room temperature. The total tuning spectral range for the cell is as broad as 165 nm and covers almost the entire visible region. Based on the gradient-pitched PSBP, a spatially tunable laser is also demonstrated in this work. The temperature sensitivity of the lasing wavelength for the laser is negatively linear and approximately −0.26 nm/°C. The two devices have a great potential for use in applications of photonic devices and displays because of their multiple advantages, such as wide-band tunability, wide operated temperature range, high stability and reliability, no issue of hysteresis, no need of external controlling sources, and not slow tuning speed (mechanically). PMID:27456475

Identifying representative symbology for low visibility operations/surface movement guidance and control system (LVO/SMGCS) paper charts

DOT National Transportation Integrated Search

2015-05-04

The Volpe Center developed a questionnaire to examine the representativeness of symbol shapes and the usefulness of information depicted on Low Visibility Operations/Surface Movement Guidance and Control System (LVO/SMGCS) paper charts. One-hundred f...

Development of a real-time internal and external marker tracking system for particle therapy: a phantom study using patient tumor trajectory data

PubMed Central

Cho, Junsang; Cheon, Wonjoong; Ahn, Sanghee; Jung, Hyunuk; Sheen, Heesoon; Park, Hee Chul

2017-01-01

Abstract Target motion–induced uncertainty in particle therapy is more complicated than that in X-ray therapy, requiring more accurate motion management. Therefore, a hybrid motion-tracking system that can track internal tumor motion and as well as an external surrogate of tumor motion was developed. Recently, many correlation tests between internal and external markers in X-ray therapy have been developed; however, the accuracy of such internal/external marker tracking systems, especially in particle therapy, has not yet been sufficiently tested. In this article, the process of installing an in-house hybrid internal/external motion-tracking system is described and the accuracy level of tracking system was acquired. Our results demonstrated that the developed in-house external/internal combined tracking system has submillimeter accuracy, and can be clinically used as a particle therapy system as well as a simulation system for moving tumor treatment. PMID:28201522

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shedlock, Daniel; Dugan, Edward T.; Jacobs, Alan M.

X-ray backscatter radiography by selective detection (RSD) is a field tested and innovative approach to non-destructive evaluation (NDE). RSD is an enhanced single-side x-ray Compton backscatter imaging (CBI) technique which selectively detects scatter components to improve image contrast and quality. Scatter component selection is accomplished through a set of specially designed detectors with fixed and movable collimators. Experimental results have shown that this NDE technique can be used to detect boric acid deposition on a metallic plate through steel foil reflective insulation commonly covering reactor pressure vessels. The current system is capable of detecting boric acid deposits with sub-millimeter resolution,more » through such insulating materials. Industrial systems have been built for Lockheed Martin Space Co. and NASA. Currently the x-ray backscatter RSD scanning systems developed by the University of Florida are being used to inspect the spray-on foam insulation (SOFI) used on the external tank of the space shuttle. RSD inspection techniques have found subsurface cracking in the SOFI thought to be responsible for the foam debris which separated from the external tank during the last shuttle launch. These industrial scanning systems can be customized for many applications, and a smaller, lighter, more compact unit design is being developed. The smaller design is approximately four inches wide, three inches high, and about 12 inches in length. This smaller RSD system can be used for NDE of areas that cannot be reached with larger equipment. X-ray backscatter RSD is a proven technology that has been tested on a wide variety of materials and applications. Currently the system has been used to inspect materials such as aluminum, plastics, honeycomb laminates, reinforced carbon composites, steel, and titanium. The focus of RSD is for one-sided detection for applications where conventional non-destructive examination methods either will not work or give poor results. Acquired images have clearly shown, for a variety of conditions, that proper selection of x-ray field scatter components leads to a significant improvement in image quality and contrast. Improvements are significant enough in some cases that objects not visible to conventional CBI or transmission radiography become readily discernable with RSD. (authors)« less

Transnational Terrorism’s Affect on the U.S. Economy

DTIC Science & Technology

2004-03-19

economic stability is still visible; however the research in this paper indicates the U.S. economy is very resilient and that it would take a great deal of domestic and external pressure to generate a long-term and lasting economic affect. This paper analyzes the impact terrorism has had on the U.S. economy and seeks to determine how well the U.S. economy will stand to future terrorist attacks on U.S. soil that match magnitude of economic affect caused by the attacks of September 11 2001. To the

Hyla gratiosa (barking treefrog) intestinal hernia

USGS Publications Warehouse

Mitchell, J.C.; Green, D.E.

2003-01-01

Deformities and malformations in anurans occur in a variety of manifestations (Meteyer 2000. Field Guide to Malformations of Frogs and Toads with Radiographic Interpretations. Biol. Sci. Rep., USGS/BRD/BSR-2000-0005, 18 pp.). Most of those described in the literature are visible externally (e.g., ectromelia, brachydactyly, polydactyly, brachygnathia, kyphosis) (Ouellet et al. 1997. J. Wildlife Dis. 33:95-104). Internal malformations are less well known and seldom reported (Reeder et al. 1998. Environ. Health Persp. 106:261-266). Here we describe an unusual condition heretofore unreported for a hylid frog.

KSC-03pd0075

NASA Image and Video Library

2003-01-15

KENNEDY SPACE CENTER, FLA. -- After rollback of the Rotating Service Structure on Launch Pad 39A, the top of Space Shuttle Columbia's external tank and solid rocket booster are bathed in sunlight. Shadows from the Fixed Service Structure stretch across the Shuttle and landscape. Visible are the orbiter access arm with the White Room extended to Columbia's cockpit, and at the top, the gaseous oxygen vent arm and cap, called the "beanie cap." Columbia is scheduled for launch Jan. 16 at 10:39 a.m. EST on mission STS-107, a research mission.

KSC-07pd0605

NASA Image and Video Library

2007-03-09

KENNEDY SPACE CENTER, FLA. -- In Highbay 1 inside the Vehicle Assembly Building, a technician carefully begins to sand away the red dye that has been applied to the external tank to help expose cracks or compression dents. A severe thunderstorm with golf ball-sized hail caused visible divots in the giant tank's foam insulation and minor surface damage to about 26 heat shield tiles on the shuttle's left wing. A new target launch date has not been determined, but teams will focus on preparing Atlantis for liftoff in late April on mission STS-117. Photo credit: NASA/Jim Grossmann

KSC-07pd0596

NASA Image and Video Library

2007-03-09

KENNEDY SPACE CENTER, FLA. -- In Highbay 1 inside the Vehicle Assembly Building, technicians perform repair techniques to the external tank inside a tented area that protects the top of the tank. A severe thunderstorm with golf ball-sized hail caused visible divots in the giant tank's foam insulation and minor surface damage to about 26 heat shield tiles on the shuttle's left wing. A new target launch date has not been determined, but teams will focus on preparing Atlantis for liftoff in late April on mission STS-117. Photo credit: NASA/Jim Grossmann

KSC-07pd0604

NASA Image and Video Library

2007-03-09

KENNEDY SPACE CENTER, FLA. -- In Highbay 1 inside the Vehicle Assembly Building, an area near the top of the external tank has been covered in a red dye to help expose cracks or compression dents. A severe thunderstorm with golf ball-sized hail caused visible divots in the giant tank's foam insulation and minor surface damage to about 26 heat shield tiles on the shuttle's left wing. A new target launch date has not been determined, but teams will focus on preparing Atlantis for liftoff in late April on mission STS-117. Photo credit: NASA/Jim Grossmann

KSC-07pd0609

NASA Image and Video Library

2007-03-09

KENNEDY SPACE CENTER, FLA. -- In Highbay 1 inside the Vehicle Assembly Building, technicians carefully sand away the red dye that has been applied to the external tank to help expose cracks or compression dents. A severe thunderstorm with golf ball-sized hail caused visible divots in the giant tank's foam insulation and minor surface damage to about 26 heat shield tiles on the shuttle's left wing. A new target launch date has not been determined, but teams will focus on preparing Atlantis for liftoff in late April on mission STS-117. Photo credit: NASA/Jim Grossmann

KSC-07pd1080

NASA Image and Video Library

2007-05-09

KENNEDY SPACE CENTER, FLA. -- In NASA Kennedy Space Center's Vehicle Assembly Building, technicians observe the sander used to repair hail damage on Atlantis' nose cone. In late February, Atlantis' external tank received hail damage during a severe thunderstorm that passed through the Kennedy Space Center Launch Complex 39 area. The hail caused visible divots in the giant tank's foam insulation as well as minor surface damage to about 26 heat shield tiles on the shuttle's left wing. The launch of Space Shuttle Atlantis on mission STS-117 now is targeted for June 8. Photo credit: NASA/Jack Pfaller

KSC-07pd0607

NASA Image and Video Library

2007-03-09

KENNEDY SPACE CENTER, FLA. -- In Highbay 1 inside the Vehicle Assembly Building, technicians begin to carefully sand away the red dye that has been applied to the external tank to help expose cracks or compression dents. A severe thunderstorm with golf ball-sized hail caused visible divots in the giant tank's foam insulation and minor surface damage to about 26 heat shield tiles on the shuttle's left wing. A new target launch date has not been determined, but teams will focus on preparing Atlantis for liftoff in late April on mission STS-117. Photo credit: NASA/Jim Grossmann

KSC-07pd1081

NASA Image and Video Library

2007-05-09

KENNEDY SPACE CENTER, FLA. -- In NASA Kennedy Space Center's Vehicle Assembly Building, technicians adjust the sander used to repair hail damage on Atlantis' nose cone. In late February, Atlantis' external tank received hail damage during a severe thunderstorm that passed through the Kennedy Space Center Launch Complex 39 area. The hail caused visible divots in the giant tank's foam insulation as well as minor surface damage to about 26 heat shield tiles on the shuttle's left wing. The launch of Space Shuttle Atlantis on mission STS-117 now is targeted for June 8. Photo credit: NASA/Jack Pfaller

KSC-07pd0602

NASA Image and Video Library

2007-03-09

KENNEDY SPACE CENTER, FLA. -- In Highbay 1 inside the Vehicle Assembly Building, technicians work on repair techniques to the external tank. They are inside a tented area that protects the tank. A severe thunderstorm with golf ball-sized hail caused visible divots in the giant tank's foam insulation and minor surface damage to about 26 heat shield tiles on the shuttle's left wing. A new target launch date has not been determined, but teams will focus on preparing Atlantis for liftoff in late April on mission STS-117. Photo credit: NASA/Jim Grossmann

KSC-07pd0603

NASA Image and Video Library

2007-03-09

KENNEDY SPACE CENTER, FLA. -- In Highbay 1 inside the Vehicle Assembly Building, technicians carefully inspect a portion of the external tank foam that has been covered in red dye to help expose cracks or compression dents. A severe thunderstorm with golf ball-sized hail caused visible divots in the giant tank's foam insulation and minor surface damage to about 26 heat shield tiles on the shuttle's left wing. A new target launch date has not been determined, but teams will focus on preparing Atlantis for liftoff in late April on mission STS-117. Photo credit: NASA/Jim Grossmann

In-vessel visible inspection system on KSTAR

NASA Astrophysics Data System (ADS)

Chung, Jinil; Seo, D. C.

2008-08-01

To monitor the global formation of the initial plasma and damage to the internal structures of the vacuum vessel, an in-vessel visible inspection system has been installed and operated on the Korean superconducting tokamak advanced research (KSTAR) device. It consists of four inspection illuminators and two visible/H-alpha TV cameras. Each illuminator uses four 150W metal-halide lamps with separate lamp controllers, and programmable progressive scan charge-coupled device cameras with 1004×1004 resolution at 48frames/s and a resolution of 640×480 at 210frames/s are used to capture images. In order to provide vessel inspection capability under any operation condition, the lamps and cameras are fully controlled from the main control room and protected by shutters from deposits during plasma operation. In this paper, we describe the design and operation results of the visible inspection system with the images of the KSTAR Ohmic discharges during the first plasma campaign.

Body-Based Gender Recognition Using Images from Visible and Thermal Cameras

PubMed Central

Nguyen, Dat Tien; Park, Kang Ryoung

2016-01-01

Gender information has many useful applications in computer vision systems, such as surveillance systems, counting the number of males and females in a shopping mall, accessing control systems in restricted areas, or any human-computer interaction system. In most previous studies, researchers attempted to recognize gender by using visible light images of the human face or body. However, shadow, illumination, and time of day greatly affect the performance of these methods. To overcome this problem, we propose a new gender recognition method based on the combination of visible light and thermal camera images of the human body. Experimental results, through various kinds of feature extraction and fusion methods, show that our approach is efficient for gender recognition through a comparison of recognition rates with conventional systems. PMID:26828487

Body-Based Gender Recognition Using Images from Visible and Thermal Cameras.

PubMed

Nguyen, Dat Tien; Park, Kang Ryoung

2016-01-27

Gender information has many useful applications in computer vision systems, such as surveillance systems, counting the number of males and females in a shopping mall, accessing control systems in restricted areas, or any human-computer interaction system. In most previous studies, researchers attempted to recognize gender by using visible light images of the human face or body. However, shadow, illumination, and time of day greatly affect the performance of these methods. To overcome this problem, we propose a new gender recognition method based on the combination of visible light and thermal camera images of the human body. Experimental results, through various kinds of feature extraction and fusion methods, show that our approach is efficient for gender recognition through a comparison of recognition rates with conventional systems.

External Surface Changes Observed on the International Space Station (ISS) Through 2012

NASA Technical Reports Server (NTRS)

Golden, Johnny L.

2012-01-01

As the International Space Station (ISS) surpasses 13 years of on-orbit operation, 11 of those years continuously inhabited, external surfaces of the vehicle have shown a wide variety of visible environmental effects. Throughout, the ISS program has maintained a significant effort to routinely document the vehicle external surface condition and to monitor those changes with time. The impacts of micrometeoroids and orbital debris, surface changes from molecular contamination of various sources, and the effects of ultraviolet radiation and atomic oxygen have all been noted. The tremendous size and complexity of the ISS vehicle has yielded a wide variety of observations of interest to the spacecraft materials engineer concerning long-term, low earth orbit (LEO) space environmental effects (SEE). In addition, inadvertent materials substitutions have been identified because of these environmental effects, as well as inadequate contamination control practices likely occurring during hardware manufacture and assembly. Some of the observations from our photography are purely artifacts of the unusual lighting conditions and environments that exist in space. A compilation of ISS on-orbit photography representing all of these aspects is presented, demonstrating the various SEE and their impacts as a function of time in LEO, including interpretations of those effects.

High-visibility photonic crystal fiber interferometer for ultrasensitive refractometric sensing

NASA Astrophysics Data System (ADS)

Cárdenas-Sevilla, Guillermo A.; Fávero, Fernando C.; Finazzi, Vittoria; Villatoro, Joel; Pruneri, Valerio

2011-09-01

A simple and compact photonic crystal fiber (PCF) interferometer that operates in reflection mode is proposed for refractive index (RI) sensing. The device consists of a ~12mm-long stub of commercially available PCF (LMA-10) fusion spliced to standard optical fiber (SMF-28). The device reflection spectrum exhibits interference patterns with fringe contrast up to 40 dB. One of the excited modes in the PCF is sensitive to external RI therefore the device can be useful for refractrometry. The shift of the interference pattern can be monitored as a function of the external index. In the operating range, from 1.33 to 1.43, the maximum shift is less than the interferometer period, so there is no-ambiguity in the measurements. The maximum sensitivity and resolution achieved were 735 nm per RI units and 7×10-5, respectively. Another approach to measure the external RI consists of monitoring the reflection power located at the quadrature point of the inference pattern in a properly selected wavelength. Consequently the measuring range is narrower but the resolution is higher, up ~7×10-6, thanks to the high fringe contrast.

COBEL model as part of a terminal-area ceiling and visibility (C and V) nowcast system : a progress report

DOT National Transportation Integrated Search

1996-07-18

The Federal Aviation Administration (FAA) Integrated Terminal Weather System (ITWS) is supporting the development of products aimed at providing automated guidance to the air traffic managers for the anticipation of changes in ceiling and visibility ...

STS-113 Astronauts Work on Port One (P1) Truss on International Space Station

NASA Technical Reports Server (NTRS)

2002-01-01

The 16th American assembly flight and 112th overall American flight to the International Space Station (ISS) launched on November 23, 2002 from Kennedy's launch pad 39A aboard the Space Shuttle Orbiter Endeavor STS-113. Mission objectives included the delivery of the Expedition Six Crew to the ISS, the return of Expedition Five crew back to Earth, and the installation and activation of the Port 1 Integrated Truss Assembly (P1). The first major component installed on the left side of the Station, the P1 truss provides an additional three External Thermal Control System radiators. Weighing in at 27,506 pounds, the P1 truss is 45 feet (13.7 meters) long, 15 feet (4.6 meters) wide, and 13 feet (4 meters) high. Three space walks, aided by the use of the Robotic Manipulator Systems of both the Shuttle and the Station, were performed in the installation of P1. In this photograph, astronauts Michael E. Lopez-Alegria (above) and John B. Herrington (below) work on the newly installed P1 truss during the mission's second scheduled session of extravehicular activity. The space walk lasted 6 hours, 10 minutes. The end effector of the Canadarm2 or Space Station Remote Manipulator System (SSRMS) and Earth's horizon are visible in the bottom of frame.

Solar receiver with integrated optics

NASA Astrophysics Data System (ADS)

Jiang, Lun; Winston, Roland

2012-10-01

The current challenge for PV/Thermal (PV/T) systems is the reduction of radiation heat loss. Compared to solar thermal selective coating, the solar cells cannot be used as an efficient thermal absorber due to their large emissivity of the encapsulation material. Many commercial PV/T products therefore require a high concentration (more than 10x) to reach an acceptable thermal efficiency for their receivers. Such a concentration system inevitably has to track or semi-track, which induces additional cost and collects only the direct radiation from the sun. We propose a new PV/T design using a vacuum encapsulated thin film cell to solve this problem. The proposed design also collects the diffuse sun light efficiently by using an external compound parabolic concentrator (XCPC). Since the transparent electrode (TCO) of thin film cell is inherently transparent in visible light and reflective beyond infrared, this design uses this layer instead of the conventional solar cell encapsulation as the outmost heat loss surface. By integrating such a vacuum design with a tube shaped absorber, we reduce the complexity of conducting the heat energy and electricity out of the device. A low concentration standalone non-tracking solar collector is proposed in this paper. We also analyzed the thermosyphon system configuration using heat transfer and ray tracing models. The economics of such a receiver are presented.

Advanced Computational Methods in Bio-Mechanics.

PubMed

Al Qahtani, Waleed M S; El-Anwar, Mohamed I

2018-04-15

A novel partnership between surgeons and machines, made possible by advances in computing and engineering technology, could overcome many of the limitations of traditional surgery. By extending surgeons' ability to plan and carry out surgical interventions more accurately and with fewer traumas, computer-integrated surgery (CIS) systems could help to improve clinical outcomes and the efficiency of healthcare delivery. CIS systems could have a similar impact on surgery to that long since realised in computer-integrated manufacturing. Mathematical modelling and computer simulation have proved tremendously successful in engineering. Computational mechanics has enabled technological developments in virtually every area of our lives. One of the greatest challenges for mechanists is to extend the success of computational mechanics to fields outside traditional engineering, in particular to biology, the biomedical sciences, and medicine. Biomechanics has significant potential for applications in orthopaedic industry, and the performance arts since skills needed for these activities are visibly related to the human musculoskeletal and nervous systems. Although biomechanics is widely used nowadays in the orthopaedic industry to design orthopaedic implants for human joints, dental parts, external fixations and other medical purposes, numerous researches funded by billions of dollars are still running to build a new future for sports and human healthcare in what is called biomechanics era.

Dual-Modality PET/Ultrasound imaging of the Prostate

DOE Office of Scientific and Technical Information (OSTI.GOV)

Huber, Jennifer S.; Moses, William W.; Pouliot, Jean

2005-11-11

Functional imaging with positron emission tomography (PET)will detect malignant tumors in the prostate and/or prostate bed, as well as possibly help determine tumor ''aggressiveness''. However, the relative uptake in a prostate tumor can be so great that few other anatomical landmarks are visible in a PET image. Ultrasound imaging with a transrectal probe provides anatomical detail in the prostate region that can be co-registered with the sensitive functional information from the PET imaging. Imaging the prostate with both PET and transrectal ultrasound (TRUS) will help determine the location of any cancer within the prostate region. This dual-modality imaging should helpmore » provide better detection and treatment of prostate cancer. LBNL has built a high performance positron emission tomograph optimized to image the prostate.Compared to a standard whole-body PET camera, our prostate-optimized PET camera has the same sensitivity and resolution, less backgrounds and lower cost. We plan to develop the hardware and software tools needed for a validated dual PET/TRUS prostate imaging system. We also plan to develop dual prostate imaging with PET and external transabdominal ultrasound, in case the TRUS system is too uncomfortable for some patients. We present the design and intended clinical uses for these dual imaging systems.« less

Attempt to run urinary protein electrophoresis using capillary technique.

PubMed

Falcone, Michele

2014-10-01

The study of urinary protein has a predominant place in the diagnosis of kidney disease. The most common technique is agarose gel electrophoresis (AGE). For several years, the technique of choice applied to the analysis of serum proteins has been CE, a system that uses capillary fused silica, subjected to high voltage to separate and measure serum proteins. The purpose of this paper was to perform capillary electrophoresis on urinary proteins which, at present, are not interpretable due to the many nonspecific peaks visible when using gel electrophoresis. In order to carry out our research, we used a capillary V8 analyzer together with an agarose gel system from the same company. AGE was taken as the reference method, for which urine was used without any pretreatment. For the V8 system, urine was subjected to purification on granular-activated carbon and then inserted into the V8 analyzer, selecting a program suitable for liquids with low protein content. We examined 19 urine samples collected over 24 hrs from both hospitalized and external patients with different types of proteinuria plus a serum diluted 1/61 considered as a control to recognize the bands. Both methods showed the same protein fractions and classified the proteinuria in a similar way. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Effective organizational control: implications for academic medicine.

PubMed

Wilkes, Michael S; Srinivasan, Malathi; Flamholtz, Eric

2005-11-01

This article provides a framework for understanding the nature, role, functioning, design, and effects of organizational oversight systems. Using a case study with elements recognizable to an academic audience, the authors explore how a dean of a fictitious School of Medicine might use organizational control structures to develop effective solutions to global disarray within the academic medical center. Organizational control systems are intended to help influence the behavior of people as members of a formal organization. They are necessary to motivate people toward organizational goals, to coordinate diverse efforts, and to provide feedback about problems. The authors present a model of control to make this process more visible within organizations. They explore the overlap among academic medical centers and large businesses-for instance, each is a billion-dollar enterprise with complex internal and external demands and multiple audiences. The authors identify and describe how to use the key components of an organization's control system: environment, culture, structure, and core control system. Elements of the core control system are identified, described, and explored. These closely articulating elements include planning, operations, measurement, evaluation, and feedback systems. Use of control portfolios is explored to achieve goal-outcome congruence. Additionally, the authors describe how the components of the control system can be used synergistically by academic leadership to create organizational change, congruent with larger organizational goals. The enterprise of medicine is quickly learning from the enterprise of business. Achieving goal-action congruence will better position academic medicine to meet its multiple missions.

The x-ray light valve: a potentially low-cost, digital radiographic imaging system-concept and implementation considerations.

PubMed

Webster, Christie Ann; Koprinarov, Ivaylo; Germann, Stephen; Rowlands, J A

2008-03-01

New x-ray radiographic systems based on large-area flat-panel technology have revolutionized our capability to produce digital x-ray images. However, these imagers are extraordinarily expensive compared to the systems they are replacing. Hence, there is a need for a low-cost digital imaging system for general applications in radiology. A novel potentially low-cost radiographic imaging system based on established technologies is proposed-the X-Ray Light Valve (XLV). This is a potentially high-quality digital x-ray detector made of a photoconducting layer and a liquid-crystal cell, physically coupled in a sandwich structure. Upon exposure to x rays, charge is collected on the surface of the photoconductor. This causes a change in the optical properties of the liquid-crystal cell and a visible image is generated. Subsequently, it is digitized by a scanned optical imager. The image formation is based on controlled modulation of light from an external source. The operation and practical implementation of the XLV system are described. The potential performance of the complete system and issues related to sensitivity, spatial resolution, noise, and speed are discussed. The feasibility of clinical use of an XLV device based on amorphous selenium (a-Se) as the photoconductor and a reflective electrically controlled birefringence cell is analyzed. The results of our analysis indicate that the XLV can potentially be adapted to a wide variety of radiographic tasks.

Indoor anti-occlusion visible light positioning systems based on particle filtering

NASA Astrophysics Data System (ADS)

Jiang, Meng; Huang, Zhitong; Li, Jianfeng; Zhang, Ruqi; Ji, Yuefeng

2015-04-01

As one of the most popular categories of mobile services, a rapid growth of indoor location-based services has been witnessed over the past decades. Indoor positioning methods based on Wi-Fi, radio-frequency identification or Bluetooth are widely commercialized; however, they have disadvantages such as low accuracy or high cost. An emerging method using visible light is under research recently. The existed visible light positioning (VLP) schemes using carrier allocation, time allocation and multiple receivers all have limitations. This paper presents a novel mechanism using particle filtering in VLP system. By this method no additional devices are needed and the occlusion problem in visible light would be alleviated which will effectively enhance the flexibility for indoor positioning.

Walking straight into circles.

PubMed

Souman, Jan L; Frissen, Ilja; Sreenivasa, Manish N; Ernst, Marc O

2009-09-29

Common belief has it that people who get lost in unfamiliar terrain often end up walking in circles. Although uncorroborated by empirical data, this belief has widely permeated popular culture. Here, we tested the ability of humans to walk on a straight course through unfamiliar terrain in two different environments: a large forest area and the Sahara desert. Walking trajectories of several hours were captured via global positioning system, showing that participants repeatedly walked in circles when they could not see the sun. Conversely, when the sun was visible, participants sometimes veered from a straight course but did not walk in circles. We tested various explanations for this walking behavior by assessing the ability of people to maintain a fixed course while blindfolded. Under these conditions, participants walked in often surprisingly small circles (diameter < 20 m), though rarely in a systematic direction. These results rule out a general explanation in terms of biomechanical asymmetries or other general biases [1-6]. Instead, they suggest that veering from a straight course is the result of accumulating noise in the sensorimotor system, which, without an external directional reference to recalibrate the subjective straight ahead, may cause people to walk in circles.

STS-113 Astronaut Herrington Performs Third Scheduled Space Walk

NASA Technical Reports Server (NTRS)

2002-01-01

STS-113, the 16th American assembly flight and 112th overall American flight to the International Space Station (ISS), launched on November 23, 2002 from Kennedy's launch pad 39A aboard the Space Shuttle Orbiter Endeavour. The main mission objective was the the installation and activation of the Port 1 Integrated Truss Assembly (P1). The first major component installed on the left side of the Station, the P1 truss provides an additional three External Thermal Control System radiators. Weighing in at 27,506 pounds, the P1 truss is 45 feet (13.7 meters) long, 15 feet (4.6 meters) wide, and 13 feet (4 meters) high. Three space walks, aided by the use of the Robotic Manipulator Systems of both the Shuttle and the Station, were performed in the installation of P1. In this photograph astronaut and mission specialist John B. Herrington, (center left frame), participates in the mission's third space walk. The forward section of the Space Shuttle Endeavour, docked to the Pressurized Mating Adapter (PMA-2) on the ISS, is visible center frame. The station's Canadarm2 appears to stand in between the shuttle and Herrington.

Runaway electron generation and control

NASA Astrophysics Data System (ADS)

Esposito, B.; Boncagni, L.; Buratti, P.; Carnevale, D.; Causa, F.; Gospodarczyk Martin-Solis, M., Jr.; Popovic, Z.; Agostini, M.; Apruzzese, G.; Bin, W.; Cianfarani, C.; De Angelis, R.; Granucci, G.; Grosso, A.; Maddaluno, G.; Marocco, D.; Piergotti, V.; Pensa, A.; Podda, S.; Pucella, G.; Ramogida, G.; Rocchi, G.; Riva, M.; Sibio, A.; Sozzi, C.; Tilia, B.; Tudisco, O.; Valisa, M.; FTU Team

2017-01-01

We present an overview of FTU experiments on runaway electron (RE) generation and control carried out through a comprehensive set of real-time (RT) diagnostics/control systems and newly installed RE diagnostics. An RE imaging spectrometer system detects visible and infrared synchrotron radiation. A Cherenkov probe measures RE escaping the plasma. A gamma camera provides hard x-ray radial profiles from RE bremsstrahlung interactions in the plasma. Experiments on the onset and suppression of RE show that the threshold electric field for RE generation is larger than that expected according to a purely collisional theory, but consistent with an increase due to synchrotron radiation losses. This might imply a lower density to be targeted with massive gas injection for RE suppression in ITER. Experiments on active control of disruption-generated RE have been performed through feedback on poloidal coils by implementing an RT boundary-reconstruction algorithm evaluated on magnetic moments. The results indicate that the slow plasma current ramp-down and the simultaneous reduction of the reference plasma external radius are beneficial in dissipating the RE beam energy and population, leading to reduced RE interactions with plasma facing components. RE active control is therefore suggested as a possible alternative or complementary technique to massive gas injection.

Fast photoresponse and high detectivity in copper indium selenide (CuIn7Se11) phototransistors

NASA Astrophysics Data System (ADS)

Ghosh, Sujoy; Patil, Prasanna D.; Wasala, Milinda; Lei, Sidong; Nolander, Andrew; Sivakumar, Pooplasingam; Vajtai, Robert; Ajayan, Pulickel; Talapatra, Saikat

2018-03-01

The fast and sensitive detection of light can lead to a variety of optoelectronics and/or photonic-based applications in fields ranging from fast optical switching devices to health and environmental monitoring systems. Although several systems based on organic and inorganic materials show high sensitivity to visible light, in general they suffer from slow response times. Here we show that phototransistors fabricated using multilayers of CuIn7Se11 exhibit response times of ~ tens of µs with responsivity (R) values  >  10 AW-1 and with external quantum efficiencies reaching beyond 103 % when excited with a 658 nm wavelength laser. These devices also show high specific detectivity (D *) values of ~1012 Jones. The responsivity and detectivity exhibited by these phototransistors are at least an order of magnitude better than commercially available conventional Si-based photodetectors, coupled with response times that are orders of magnitude better than several other families of layered materials investigated so far. The properties of the CuIn7Se11 phototransistor can be further tuned and enhanced by applying a back-gate voltage. Our investigations indicate that such layered ternary compounds can potentially be used as components in opto-electronics-related applications.

Photonic Crystal Structures with Tunable Structure Color as Colorimetric Sensors

PubMed Central

Wang, Hui; Zhang, Ke-Qin

2013-01-01

Colorimetric sensing, which transduces environmental changes into visible color changes, provides a simple yet powerful detection mechanism that is well-suited to the development of low-cost and low-power sensors. A new approach in colorimetric sensing exploits the structural color of photonic crystals (PCs) to create environmentally-influenced color-changeable materials. PCs are composed of periodic dielectrics or metallo-dielectric nanostructures that affect the propagation of electromagnetic waves (EM) by defining the allowed and forbidden photonic bands. Simultaneously, an amazing variety of naturally occurring biological systems exhibit iridescent color due to the presence of PC structures throughout multi-dimensional space. In particular, some kinds of the structural colors in living organisms can be reversibly changed in reaction to external stimuli. Based on the lessons learned from natural photonic structures, some specific examples of PCs-based colorimetric sensors are presented in detail to demonstrate their unprecedented potential in practical applications, such as the detections of temperature, pH, ionic species, solvents, vapor, humidity, pressure and biomolecules. The combination of the nanofabrication technique, useful design methodologies inspired by biological systems and colorimetric sensing will lead to substantial developments in low-cost, miniaturized and widely deployable optical sensors. PMID:23539027

[Development of a monitor for quantifying personal eye exposure to visible and ultraviolet radiation and its application in epidemiology].

PubMed

Eto, Norihito; Tsubota, Kazuo; Tanaka, Taichiro; Nishiwaki, Yuji

2013-01-01

Eye diseases including cataract, keratitis and pterygium have been reported to be sun-exposure-related. The association between macular degeneration and blue light has also been discussed. Moreover, it is hypothesized that retinal exposure to blue light may influence the human circadian rhythm. However, no monitoring devices exist that can measure eye exposure to visible and ultraviolet (UV) radiation over time. To measure the exact dose at specific times, we have developed a novel sensing system (ray-sensing glass system: RaySeG). RaySeG can continuously measure and record the composition and intensity of light with a time-stamped system. Subjects wearing RaySeG were instructed to walk under various light conditions such as indoor and outdoor. RaySeG consists of two sensors embedded in the eyeglasses. These sensors are for UV (260-400 nm), visible lights (red, 615 nm; green, 540 nm; and blue, 465 nm: peak wavelength for each). The total weight of the system is about 100 g, and the size is comparable to that of a digital audio player. The system continuously recorded changes in visible and UV light exposure under various conditions. After accuracy validation, further experiments with a larger number of subjects are required. Our final goal is to apply the system to evaluating personal eye exposure to UV and visible light in epidemiological studies of eye diseases and circadian rhythm abnormality.

Identification of penetration path and deposition distribution of radionuclides in houses by experiments and numerical model

NASA Astrophysics Data System (ADS)

Hirouchi, Jun; Takahara, Shogo; Iijima, Masashi; Watanabe, Masatoshi; Munakata, Masahiro

2017-11-01

In order to lift of an evacuation order in evacuation areas and return residents to their homes, human dose assessments are required. However, it is difficult to exactly assess indoor external dose rate because the indoor distribution and infiltration pathways of radionuclides are unclear. This paper describes indoor and outdoor dose rates measured in eight houses in the difficult-to-return area in Fukushima Prefecture and identifies the distribution and main infiltration pathway of radionuclides in houses. In addition, it describes dose rates calculated with a Monte Carlo photon transport code to aid a thorough understanding of the measurements. The measurements and calculations indicate that radionuclides mainly infiltrate through visible openings such as vents, windows, and doors, and then deposit near these visible openings; however, they hardly infiltrate through sockets and air conditioning outlets. The measurements on rough surfaces such as bookshelves implies that radionuclides discharged from the Fukushima-Daiichi nuclear power plant did not deposit locally on rough surfaces.

Non-destructive evaluation of impact damage on carbon fiber laminates: Comparison between ESPI and Shearography

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pagliarulo, V., E-mail: v.pagliarulo@isasi.cnr.it; Ferraro, P.; Lopresto, V.

2016-06-28

The aim of this paper is to investigate the ability of two different interferometric NDT techniques to detect and evaluate barely visible impact damage on composite laminates. The interferometric techniques allow to investigate large and complex structures. Electronic Speckle Pattern Interferometry (ESPI) works through real-time surface illumination by visible laser (i.e. 532 nm) and the range and the accuracy are related to the wavelength. While the ESPI works with the “classic” holographic configuration, that is reference beam and object beam, the Shearography uses the object image itself as reference: two object images are overlapped creating a shear image. This makes themore » method much less sensitive to external vibrations and noise but with one difference, it measures the first derivative of the displacement. In this work, different specimens at different impact energies have been investigated by means of both methods. The delaminated areas have been estimated and compared.« less

Enhancement of lateral flow assay performance by electromagnetic relocation of reporter particles

PubMed Central

Jacinto, Maria João; Trabuco, João R. C.; Vu, Binh V.; Garvey, Gavin; Khodadady, Mohammad; Azevedo, Ana M.; Aires-Barros, Maria Raquel; Chang, Long; Kourentzi, Katerina; Litvinov, Dmitri

2018-01-01

Lateral flow assays (LFAs) are a widely-used point-of care diagnostic format, but suffer from limited analytical sensitivity, especially when read by eye. It has recently been reported that LFA performance can be improved by using magnetic reporter particles and an external magnetic field applied at the test line. The mechanism of sensitivity/performance enhancement was suggested to be concentration/retardation of reporter particles at the test line. Here we demonstrate an additional mechanism of particle relocation where reporter particles from the lower depths of the translucent LFA strip relocate to more-visible locations nearer to the top surface, producing a more visible signal. With a magnetic field we observed an improvement in sensitivity of human chorionic gonadotropin (hCG) detection from 1.25 ng/mL to 0.31 ng/mL. We also observed an increase of the color intensity per particle in test lines when the magnetic field was present. PMID:29309424

Solar Extreme UV radiation and quark nugget dark matter model

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhitnitsky, Ariel, E-mail: arz@phas.ubc.ca

2017-10-01

We advocate the idea that the surprising emission of extreme ultra violet (EUV) radiation and soft x-rays from the Sun are powered externally by incident dark matter (DM) particles. The energy and the spectral shape of this otherwise unexpected solar irradiation is estimated within the quark nugget dark matter model. This model was originally invented as a natural explanation of the observed ratio Ω{sub dark} ∼ Ω{sub visible} when the DM and visible matter densities assume the same order of magnitude values. This generic consequence of the model is a result of the common origin of both types of mattermore » which are formed during the same QCD transition and both proportional to the same fundamental dimensional parameter Λ{sub QCD}. We also present arguments suggesting that the transient brightening-like 'nanoflares' in the Sun may be related to the annihilation events which inevitably occur in the solar atmosphere within this dark matter scenario.« less

Efficient Gate-tunable light-emitting device made of defective boron nitride nanotubes: from ultraviolet to the visible

PubMed Central

Attaccalite, Claudio; Wirtz, Ludger; Marini, Andrea; Rubio, Angel

2013-01-01

Boron nitride is a promising material for nanotechnology applications due to its two-dimensional graphene-like, insulating, and highly-resistant structure. Recently it has received a lot of attention as a substrate to grow and isolate graphene as well as for its intrinsic UV lasing response. Similar to carbon, one-dimensional boron nitride nanotubes (BNNTs) have been theoretically predicted and later synthesised. Here we use first principles simulations to unambiguously demonstrate that i) BN nanotubes inherit the highly efficient UV luminescence of hexagonal BN; ii) the application of an external perpendicular field closes the electronic gap keeping the UV lasing with lower yield; iii) defects in BNNTS are responsible for tunable light emission from the UV to the visible controlled by a transverse electric field (TEF). Our present findings pave the road towards optoelectronic applications of BN-nanotube-based devices that are simple to implement because they do not require any special doping or complex growth. PMID:24060843

All solution-processed lead halide perovskite-BiVO4 tandem assembly for photolytic solar fuels production.

PubMed

Chen, Yong-Siou; Manser, Joseph S; Kamat, Prashant V

2015-01-21

The quest for economic, large-scale hydrogen production has motivated the search for new materials and device designs capable of splitting water using only energy from the sun. Here we introduce an all solution-processed tandem water splitting assembly composed of a BiVO4 photoanode and a single-junction CH3NH3PbI3 hybrid perovskite solar cell. This unique configuration allows efficient solar photon management, with the metal oxide photoanode selectively harvesting high energy visible photons, and the underlying perovskite solar cell capturing lower energy visible-near IR wavelengths in a single-pass excitation. Operating without external bias under standard AM 1.5G illumination, the photoanode-photovoltaic architecture, in conjunction with an earth-abundant cobalt phosphate catalyst, exhibits a solar-to-hydrogen conversion efficiency of 2.5% at neutral pH. The design of low-cost tandem water splitting assemblies employing single-junction hybrid perovskite materials establishes a potentially promising new frontier for solar water splitting research.

A fibre-coupled UHV-compatible variable angle reflection-absorption UV/visible spectrometer

NASA Astrophysics Data System (ADS)

Stubbing, J. W.; Salter, T. L.; Brown, W. A.; Taj, S.; McCoustra, M. R. S.

2018-05-01

We present a novel UV/visible reflection-absorption spectrometer for determining the refractive index, n, and thicknesses, d, of ice films. Knowledge of the refractive index of these films is of particular relevance to the astrochemical community, where they can be used to model radiative transfer and spectra of various regions of space. In order to make these models more accurate, values of n need to be recorded under astronomically relevant conditions, that is, under ultra-high vacuum (UHV) and cryogenic cooling. Several design considerations were taken into account to allow UHV compatibility combined with ease of use. The key design feature is a stainless steel rhombus coupled to an external linear drive (z-shift) allowing a variable reflection geometry to be achieved, which is necessary for our analysis. Test data for amorphous benzene ice are presented as a proof of concept, the film thickness, d, was found to vary linearly with surface exposure, and a value for n of 1.43 ± 0.07 was determined.

Trap-assisted large gain in Cu{sub 2}O/C{sub 60} hybrid ultraviolet/visible photodetectors

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liu, Lan; Xi, Qiaoyue; Gao, Ge

2016-04-18

Photomultiplication-type ultraviolet (UV)/visible photodetectors (PDs) are demonstrated in an electrodeposited Cu{sub 2}O/C{sub 60} hybrid structure. These simple organic/inorganic hybrid PDs exhibit external quantum efficiencies (EQEs) of 1.1 × 10{sup 4}% under illumination of 365 nm UV light at −3 V, indicating a large gain of photocurrent for these devices. Such an EQE is one of the highest values among the reported organic/inorganic hybrid PDs at the same voltage. Cu{sub 2}O and C{sub 60} are found to play different roles in realizing the photomultiplication. Copper vacancies are proposed as the defects in the electrodeposited Cu{sub 2}O layers, which can trap photogenerated holes. Such trapped holesmore » will trigger the injection of multiple electrons and hence result in the photocurrent gain of the devices while C{sub 60} primarily acts as a light absorption media to provide free holes.« less

Projecting sensations to external objects: evidence from skin conductance response.

PubMed

Armel, K Carrie; Ramachandran, V S

2003-07-22

Subjects perceived touch sensations as arising from a table (or a rubber hand) when both the table (or the rubber hand) and their own real hand were repeatedly tapped and stroked in synchrony with the real hand hidden from view. If the table or rubber hand was then 'injured', subjects displayed a strong skin conductance response (SCR) even though nothing was done to the real hand. Sensations could even be projected to anatomically impossible locations. The illusion was much less vivid, as indicated by subjective reports and SCR, if the real hand was simultaneously visible during stroking, or if the real hand was hidden but touched asynchronously. The fact that the illusion could be significantly diminished when the real hand was simultaneously visible suggests that the illusion and associated SCRs were due to perceptual assimilation of the table (or rubber hand) into one's body image rather than associative conditioning. These experiments demonstrate the malleability of body image and the brain's remarkable capacity for detecting statistical correlations in the sensory input.

Projecting sensations to external objects: evidence from skin conductance response.

PubMed Central

Armel, K Carrie; Ramachandran, V S

2003-01-01

Subjects perceived touch sensations as arising from a table (or a rubber hand) when both the table (or the rubber hand) and their own real hand were repeatedly tapped and stroked in synchrony with the real hand hidden from view. If the table or rubber hand was then 'injured', subjects displayed a strong skin conductance response (SCR) even though nothing was done to the real hand. Sensations could even be projected to anatomically impossible locations. The illusion was much less vivid, as indicated by subjective reports and SCR, if the real hand was simultaneously visible during stroking, or if the real hand was hidden but touched asynchronously. The fact that the illusion could be significantly diminished when the real hand was simultaneously visible suggests that the illusion and associated SCRs were due to perceptual assimilation of the table (or rubber hand) into one's body image rather than associative conditioning. These experiments demonstrate the malleability of body image and the brain's remarkable capacity for detecting statistical correlations in the sensory input. PMID:12965016

Mirror-symmetric magneto-optical Kerr rotation using visible light in [(GeTe)2(Sb2Te3)1]n topological superlattices.

PubMed

Bang, Do; Awano, Hiroyuki; Tominaga, Junji; Kolobov, Alexander V; Fons, Paul; Saito, Yuta; Makino, Kotaro; Nakano, Takashi; Hase, Muneaki; Takagaki, Yukihiko; Giussani, Alessandro; Calarco, Raffaella; Murakami, Shuichi

2014-07-17

Interfacial phase change memory (iPCM), that has a structure of a superlattice made of alternating atomically thin GeTe and Sb2Te3 layers, has recently attracted attention not only due to its superior performance compared to the alloy of the same average composition in terms of energy consumption but also due to its strong response to an external magnetic field (giant magnetoresistance) that has been speculated to arise from switching between topological insulator (RESET) and normal insulator (SET) phases. Here we report magneto-optical Kerr rotation loops in the visible range, that have mirror symmetric resonances with respect to the magnetic field polarity at temperatures above 380 K when the material is in the SET phase that has Kramers-pairs in spin-split bands. We further found that this threshold temperature may be controlled if the sample was cooled in a magnetic field. The observed results open new possibilities for use of iPCM beyond phase-change memory applications.

Effects of face feature and contour crowding in facial expression adaptation.

PubMed

Liu, Pan; Montaser-Kouhsari, Leila; Xu, Hong

2014-12-01

Prolonged exposure to a visual stimulus, such as a happy face, biases the perception of subsequently presented neutral face toward sad perception, the known face adaptation. Face adaptation is affected by visibility or awareness of the adapting face. However, whether it is affected by discriminability of the adapting face is largely unknown. In the current study, we used crowding to manipulate discriminability of the adapting face and test its effect on face adaptation. Instead of presenting flanking faces near the target face, we shortened the distance between facial features (internal feature crowding), and reduced the size of face contour (external contour crowding), to introduce crowding. We are interested in whether internal feature crowding or external contour crowding is more effective in inducing crowding effect in our first experiment. We found that combining internal feature and external contour crowding, but not either of them alone, induced significant crowding effect. In Experiment 2, we went on further to investigate its effect on adaptation. We found that both internal feature crowding and external contour crowding reduced its facial expression aftereffect (FEA) significantly. However, we did not find a significant correlation between discriminability of the adapting face and its FEA. Interestingly, we found a significant correlation between discriminabilities of the adapting and test faces. Experiment 3 found that the reduced adaptation aftereffect in combined crowding by the external face contour and the internal facial features cannot be decomposed into the effects from the face contour and facial features linearly. It thus suggested a nonlinear integration between facial features and face contour in face adaptation.

An approach to improve management visibility within the procurement and financial group at Goldstone

NASA Technical Reports Server (NTRS)

Maiocco, F. R.; Rozek, J. B.

1976-01-01

Improvements in the operational efficiency of the data management systems at the Goldstone Deep Space Communications Complex (GDSCC) are discussed. This addresses the existing procurement and financial management data system at GDSCC, identifies management requirements for better visibility, describes a proposed computerized data management system, summarizes results to data, and identifies plans for future development.

Functional anatomy of the prostate: implications for treatment planning.

PubMed

McLaughlin, Patrick W; Troyer, Sara; Berri, Sally; Narayana, Vrinda; Meirowitz, Amichay; Roberson, Peter L; Montie, James

2005-10-01

To summarize the functional anatomy relevant to prostate cancer treatment planning. Coronal, axial, and sagittal T2 magnetic resonance imaging (MRI) and MRI angiography were fused by mutual information and registered with computed tomography (CT) scan data sets to improve definition of zonal anatomy of the prostate and critical adjacent structures. The three major prostate zones (inner, outer, and anterior fibromuscular) are visible by T2 MRI imaging. The bladder, bladder neck, and internal (preprostatic) sphincter are a continuous muscular structure and clear definition of the preprostatic sphincter is difficult by MRI. Transition zone hypertrophy may efface the bladder neck and internal sphincter. The external "lower" sphincter is clearly visible by T2 MRI with wide variations in length. The critical erectile structures are the internal pudendal artery (defined by MRI angiogram or T2 MRI), corpus cavernosum, and neurovascular bundle. The neurovascular bundle is visible along the posterior lateral surface of the prostate on CT and MRI, but its terminal branches (cavernosal nerves) are not visible and must be defined by their relationship to the urethra within the genitourinary diaphragm. Visualization of the ejaculatory ducts within the prostate is possible on sagittal MRI. The anatomy of the prostate-rectum interface is clarified by MRI, as is the potentially important distinction of rectal muscle and rectal mucosa. Improved understanding of functional anatomy and imaging of the prostate and critical adjacent structures will improve prostate radiation therapy by improvement of dose and toxicity correlation, limitation of dose to critical structures, and potential improvement in post therapy quality of life.

A longitudinal study of externally visible cigarette advertising on retail storefronts in Massachusetts before and after the Master Settlement Agreement.

PubMed

Celebucki, Carolyn C; Diskin, K

2002-06-01

To assess the effect of the Master Settlement Agreement (MSA) on the amount of cigarette advertisements visible from outside of over-the-counter tobacco retailers, for five specific premium brands and an "all other" category, for five types of establishments, and in three areas (windows/doors, building/other detached areas, and sidewalks); to assess the relation of total exterior retail cigarette advertising to illegal sales to youth. Observations were conducted on the number of cigarette advertisements visible from outside tobacco retail establishments in a paired convenience sample (n = 556) in Massachusetts before and after the MSA. Archival databases containing information on merchant compliance with age related sales laws during the time period were used to assess the relation of total cigarette advertising with sales to underage youth. Paired sample t tests assessed planned comparisons pre- to post-MSA; Spearman's rho tested associations for dichotomous variables. Significant post-ban increases were observed in the prevalence of exterior cigarette advertising on gas (petrol) stations and gas mini/marts (gasoline retailers) buildings, windows, and doors. Significant declines were observed on windows of liquor stores. Winston advertising declined overall, while advertisements of the "all other" brand category increased. Correlations between advertising and illegal sales, while modest, were significant. These pre- to post-MSA increases suggest the tobacco industry may be shifting expenditures selectively from billboard advertising to retailer exteriors more favoured by youth. Greater amount of cigarette advertising visible from outside over-the-counter tobacco retailers is associated with greater cigarette sales to minors.

40 CFR 52.1183 - Visibility protection.

Code of Federal Regulations, 2014 CFR

2014-07-01

...) Regulation for visibility monitoring and new source review. The provisions of §§ 52.26 and 52.28 are hereby... Cement facility located in Charlevoix, Michigan, shall operate continuous emission monitoring systems to... section shall be use of a continuous emission monitoring system operated in conformance with 40 CFR part...

Transformation of somatic embryos of Prunus incisa ‘February Pink’ with a visible reporter gene

USDA-ARS?s Scientific Manuscript database

An Agrobacterium-mediated transformation system was developed for the ornamental cherry species Prunus incisa. This system uses both an antibiotic resistance gene (NPTII) and a visible selectable marker, the green fluorescent protein (GFP), to select plants. Cells from leaf and root explants were tr...

Chronic anal fissure: morphometric analysis of the anal canal at 3.0 Tesla MR imaging.

PubMed

Erden, Ayşe; Peker, Elif; Gençtürk, Zeynep Bıyıklı

2017-02-01

OBJECTıVE: To compare the morphometric data relating to the muscular structures of the anal canal, in patients with chronic anal fissure and in control group, examined at a 3.0 Tesla MR system. Forty-seven consecutive patients with chronic anal fissure and randomly selected 40 patients who had no claims for perianal disease during their life time were included in the study. T2-weighted sagittal, high-resolution (HR) T2-weighted, and contrast-enhanced fat-suppressed T1-weighted oblique axial and oblique coronal images were retrospectively analyzed by two observers in consensus. Thickness of sphincteric muscles, anal canal length, anorectal angle, thickness of anococcygeal ligament, depth of Minor triangle, width between subcutaneous sphincters, vascularity of posterior commissure, visibility of posterosuperior projection of external sphincter, and angle between the distal anal canal and posterosuperior projection of external sphincter (H angle) in patients and in controls were compared and analyzed using t test, Mann-Whitney U test, and Spearman correlation. The patients with chronic anal fissure had longer anal canal (51.50 mm ± 0.91 vs. 44.11 mm ± 0.71; p = 0.000), thicker internal anal sphincter muscle at mid-anal level (4.18 ± 0.15 vs. 3.39 ± 0.07; p = 0.007), and wider space between subcutaneous external sphincters (11.39 ± 0.50 vs. 6.89 ± 0.22; p = 0.000). In patients, there was a positive correlation between H angle and external sphincter thickness at proximal (r = 0.347; p = 0.021), middle (r = 0427; p = 0.000), and distal (r = 0.518; p = 0.000)) levels of the anal canal. CONCLUSıON: 3.0 Tesla MR imaging provides detailed information about the morphometric changes in the anal sphincter muscles in patients with chronic anal fissure.

A novel variable baseline visibility detection system and its measurement method

NASA Astrophysics Data System (ADS)

Li, Meng; Jiang, Li-hui; Xiong, Xing-long; Zhang, Guizhong; Yao, JianQuan

2017-10-01

As an important meteorological observation instrument, the visibility meter can ensure the safety of traffic operation. However, due to the optical system contamination as well as sample error, the accuracy and stability of the equipment are difficult to meet the requirement in the low-visibility environment. To settle this matter, a novel measurement equipment was designed based upon multiple baseline, which essentially acts as an atmospheric transmission meter with movable optical receiver, applying weighted least square method to process signal. Theoretical analysis and experiments in real atmosphere environment support this technique.

CMOS-compatible plenoptic detector for LED lighting applications.

PubMed

Neumann, Alexander; Ghasemi, Javad; Nezhadbadeh, Shima; Nie, Xiangyu; Zarkesh-Ha, Payman; Brueck, S R J

2015-09-07

LED lighting systems with large color gamuts, with multiple LEDs spanning the visible spectrum, offer the potential of increased lighting efficiency, improved human health and productivity, and visible light communications addressing the explosive growth in wireless communications. The control of this "smart lighting system" requires a silicon-integrated-circuit-compatible, visible, plenoptic (angle and wavelength) detector. A detector element, based on an offset-grating-coupled dielectric waveguide structure and a silicon photodetector, is demonstrated with an angular resolution of less than 1° and a wavelength resolution of less than 5 nm.

Pedestrian Detection Based on Adaptive Selection of Visible Light or Far-Infrared Light Camera Image by Fuzzy Inference System and Convolutional Neural Network-Based Verification.

PubMed

Kang, Jin Kyu; Hong, Hyung Gil; Park, Kang Ryoung

2017-07-08

A number of studies have been conducted to enhance the pedestrian detection accuracy of intelligent surveillance systems. However, detecting pedestrians under outdoor conditions is a challenging problem due to the varying lighting, shadows, and occlusions. In recent times, a growing number of studies have been performed on visible light camera-based pedestrian detection systems using a convolutional neural network (CNN) in order to make the pedestrian detection process more resilient to such conditions. However, visible light cameras still cannot detect pedestrians during nighttime, and are easily affected by shadows and lighting. There are many studies on CNN-based pedestrian detection through the use of far-infrared (FIR) light cameras (i.e., thermal cameras) to address such difficulties. However, when the solar radiation increases and the background temperature reaches the same level as the body temperature, it remains difficult for the FIR light camera to detect pedestrians due to the insignificant difference between the pedestrian and non-pedestrian features within the images. Researchers have been trying to solve this issue by inputting both the visible light and the FIR camera images into the CNN as the input. This, however, takes a longer time to process, and makes the system structure more complex as the CNN needs to process both camera images. This research adaptively selects a more appropriate candidate between two pedestrian images from visible light and FIR cameras based on a fuzzy inference system (FIS), and the selected candidate is verified with a CNN. Three types of databases were tested, taking into account various environmental factors using visible light and FIR cameras. The results showed that the proposed method performs better than the previously reported methods.

Patterning in systems driven by nonlocal external forces.

PubMed

Luneville, L; Mallick, K; Pontikis, V; Simeone, D

2016-11-01

This work focuses on systems displaying domain patterns resulting from competing external and internal dynamics. To this end, we introduce a Lyapunov functional capable of describing the steady states of systems subject to external forces, by adding nonlocal terms to the Landau Ginzburg free energy of the system. Thereby, we extend the existing methodology treating long-range order interactions, to the case of external nonlocal forces. By studying the quadratic term of this Lyapunov functional, we compute the phase diagram in the temperature versus external field and we determine all possible modulated phases (domain patterns) as a function of the external forces and the temperature. Finally, we investigate patterning in chemical reactive mixtures and binary mixtures under irradiation, and we show that the last case opens the path toward micro-structural engineering of materials.

Patterning in systems driven by nonlocal external forces

NASA Astrophysics Data System (ADS)

Luneville, L.; Mallick, K.; Pontikis, V.; Simeone, D.

2016-11-01

This work focuses on systems displaying domain patterns resulting from competing external and internal dynamics. To this end, we introduce a Lyapunov functional capable of describing the steady states of systems subject to external forces, by adding nonlocal terms to the Landau Ginzburg free energy of the system. Thereby, we extend the existing methodology treating long-range order interactions, to the case of external nonlocal forces. By studying the quadratic term of this Lyapunov functional, we compute the phase diagram in the temperature versus external field and we determine all possible modulated phases (domain patterns) as a function of the external forces and the temperature. Finally, we investigate patterning in chemical reactive mixtures and binary mixtures under irradiation, and we show that the last case opens the path toward micro-structural engineering of materials.

Development of a real-time internal and external marker tracking system for particle therapy: a phantom study using patient tumor trajectory data.

PubMed

Cho, Junsang; Cheon, Wonjoong; Ahn, Sanghee; Jung, Hyunuk; Sheen, Heesoon; Park, Hee Chul; Han, Youngyih

2017-09-01

Target motion-induced uncertainty in particle therapy is more complicated than that in X-ray therapy, requiring more accurate motion management. Therefore, a hybrid motion-tracking system that can track internal tumor motion and as well as an external surrogate of tumor motion was developed. Recently, many correlation tests between internal and external markers in X-ray therapy have been developed; however, the accuracy of such internal/external marker tracking systems, especially in particle therapy, has not yet been sufficiently tested. In this article, the process of installing an in-house hybrid internal/external motion-tracking system is described and the accuracy level of tracking system was acquired. Our results demonstrated that the developed in-house external/internal combined tracking system has submillimeter accuracy, and can be clinically used as a particle therapy system as well as a simulation system for moving tumor treatment. © The Author 2017. Published by Oxford University Press on behalf of The Japan Radiation Research Society and Japanese Society for Radiation Oncology.

External heart deformities in passerine birds exposed to environmental mixtures of polychlorinated biphenyls during development.

PubMed

DeWitt, Jamie C; Millsap, Deborah S; Yeager, Ronnie L; Heise, Steve S; Sparks, Daniel W; Henshel, Diane S

2006-02-01

Necropsy-observable cardiac deformities were evaluated from 283 nestling passerines collected from one reference site and five polychlorinated biphenyl (PCB)-contaminated sites around Bloomington and Bedford, Indiana, USA. Hearts were weighed and assessed on relative scales in three dimensions (height, length, and width) and for externally visible deformities. Heart weights normalized to body weight (heart somatic index) were decreased significantly at the more contaminated sites in both house wren (Troglodytes aedon) and tree swallow (Tachycineta bicolor). Heart somatic indices significantly correlated with log PCB concentrations in Carolina chickadee (Parus carolinesis) and tree swallow and with log 2,3,7,8-tetrachlorodibenzo-p-dioxin toxic equivalent values in tree swallow alone. Ventricular length was increased significantly in eastern bluebirds (Sialia sialis) and decreased significantly in Carolina chickadee and tree swallow from contaminated sites versus the reference site. Heart length regressed significantly against the log PCB concentrations (Carolina chickadee and tree swallow) or the square of the PCB concentrations (red-winged blackbird [Agelaius phoeniceus]) in a sibling bird. The deformities that were observed most at the contaminated sites included abnormal tips (pointed, rounded, or flattened), center rolls, macro- and microsurface roughness, ventricular indentations on the ventral or dorsal surface, lateral ventricular notches, visibly thin ventricular walls, and changes in overall heart shape. A pooled heart deformity index regressed significantly against the logged contaminant concentrations for all species except red-winged blackbird. These results indicate that developmental changes in heart morphometrics and shape abnormalities are quantifiable and may be sensitive and useful indicators of PCB-related developmental impacts across many avian species.

Innervation of the human cricopharyngeal muscle by the recurrent laryngeal nerve and external branch of the superior laryngeal nerve.

PubMed

Uludag, Mehmet; Aygun, Nurcihan; Isgor, Adnan

2017-06-01

The major component of the upper esophageal sphincter is the cricopharyngeal muscle (CPM). We assessed the contribution of the laryngeal nerves to motor innervation of the CPM. We performed an intraoperative electromyographic study of 27 patients. The recurrent laryngeal nerve (RLN), vagus nerve, external branch of the superior laryngeal nerve (EBSLN), and pharyngeal plexus (PP) were stimulated. Responses were evaluated by visual observation of CPM contractions and electromyographic examination via insertion of needle electrodes into the CPM. In total, 46 CPMs (24 right, 22 left) were evaluated. PP stimulation produced both positive visual contractions and electromyographic (EMG) responses in 42 CPMs (2080 ± 1583 μV). EBSLN stimulation produced visual contractions of 28 CPMs and positive EMG responses in 35 CPMs (686 ± 630 μV). Stimulation of 45 RLNs produced visible contractions of 37 CPMs and positive EMG activity in 41 CPMs (337 ± 280 μV). Stimulation of 42 vagal nerves resulted in visible contractions of 36 CPMs and positive EMG responses in 37 CPMs (292 ± 229 μV). Motor activity was noted in 32 CPMs by both RLN and EBSLN stimulation, 9 CPMs by RLN stimulation, and 3 CPMs by EBSLN stimulation; 2 CPMs exhibited no response. This is the first study to show that the EBSLN contributes to motor innervation of the human CPM. The RLN, EBSLN, or both of the nerves innervate the 90, 75, and 70 % of the CPMs ipsilaterally, respectively.

Visibility graph analysis on heartbeat dynamics of meditation training

NASA Astrophysics Data System (ADS)

Jiang, Sen; Bian, Chunhua; Ning, Xinbao; Ma, Qianli D. Y.

2013-06-01

We apply the visibility graph analysis to human heartbeat dynamics by constructing the complex networks of heartbeat interval time series and investigating the statistical properties of the network before and during chi and yoga meditation. The experiment results show that visibility graph analysis can reveal the dynamical changes caused by meditation training manifested as regular heartbeat, which is closely related to the adjustment of autonomous neural system, and visibility graph analysis is effective to evaluate the effect of meditation.

Using Vision System Technologies for Offset Approaches in Low Visibility Operations

NASA Technical Reports Server (NTRS)

Kramer, Lynda J.; Bailey, Randall E.; Ellis, Kyle K.

2015-01-01

Flight deck-based vision systems, such as Synthetic Vision Systems (SVS) and Enhanced Flight Vision Systems (EFVS), have the potential to provide additional margins of safety for aircrew performance and enable the implementation of operational improvements for low visibility surface, arrival, and departure operations in the terminal environment with equivalent efficiency to visual operations. Twelve air transport-rated crews participated in a motion-base simulation experiment to evaluate the use of SVS/EFVS in Next Generation Air Transportation System low visibility approach and landing operations at Chicago O'Hare airport. Three monochromatic, collimated head-up display (HUD) concepts (conventional HUD, SVS HUD, and EFVS HUD) and three instrument approach types (straight-in, 3-degree offset, 15-degree offset) were experimentally varied to test the efficacy of the SVS/EFVS HUD concepts for offset approach operations. The findings suggest making offset approaches in low visibility conditions with an EFVS HUD or SVS HUD appear feasible. Regardless of offset approach angle or HUD concept being flown, all approaches had comparable ILS tracking during the instrument segment and were within the lateral confines of the runway with acceptable sink rates during the visual segment of the approach. Keywords: Enhanced Flight Vision Systems; Synthetic Vision Systems; Head-up Display; NextGen

Implications of Using Computer-Based Training with the AN/SQQ-89(v) Sonar System: Operating and Support Costs

DTIC Science & Technology

2012-06-01

Visibility and Management of Operating and Support Costs (VAMOSC...VAMOSC Visibility and Management of Operating and Support Costs VMA Variant Manning Average WAP Weapons Alternate Processor WCS Work Center...Visibility and Management of Operating and Support Costs (VAMOSC), under Unit Level Consumption and Manhours—Organizational Corrective Maintenance. C

78 FR 25118 - Self-Regulatory Organizations; New York Stock Exchange LLC; Notice of Filing of Proposed Rule...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-04-29

... not marked dark is already visible to DMMs. Similarly, aggregated information for interest not marked dark is visible to any market participant beyond the Floor via OpenBook.\\20\\ \\19\\ Exchange systems make... ``dark'' orders that are not visible to the DMM, which would prevent any communication about such...

Satellite data driven modeling system for predicting air quality and visibility during wildfire and prescribed burn events

NASA Astrophysics Data System (ADS)

Nair, U. S.; Keiser, K.; Wu, Y.; Maskey, M.; Berendes, D.; Glass, P.; Dhakal, A.; Christopher, S. A.

2012-12-01

The Alabama Forestry Commission (AFC) is responsible for wildfire control and also prescribed burn management in the state of Alabama. Visibility and air quality degradation resulting from smoke are two pieces of information that are crucial for this activity. Currently the tools available to AFC are the dispersion index available from the National Weather Service and also surface smoke concentrations. The former provides broad guidance for prescribed burning activities but does not provide specific information regarding smoke transport, areas affected and quantification of air quality and visibility degradation. While the NOAA operational air quality guidance includes surface smoke concentrations from existing fire events, it does not account for contributions from background aerosols, which are important for the southeastern region including Alabama. Also lacking is the quantification of visibility. The University of Alabama in Huntsville has developed a state-of-the-art integrated modeling system to address these concerns. This system based on the Community Air Quality Modeling System (CMAQ) that ingests satellite derived smoke emissions and also assimilates NASA MODIS derived aerosol optical thickness. In addition, this operational modeling system also simulates the impact of potential prescribed burn events based on location information derived from the AFC prescribed burn permit database. A lagrangian model is used to simulate smoke plumes for the prescribed burns requests. The combined air quality and visibility degradation resulting from these smoke plumes and background aerosols is computed and the information is made available through a web based decision support system utilizing open source GIS components. This system provides information regarding intersections between highways and other critical facilities such as old age homes, hospitals and schools. The system also includes satellite detected fire locations and other satellite derived datasets relevant for fire and smoke management.

Design and fabrication of a real-time measurement system for the capsaicinoid content of Korean red pepper (Capsicum annuum L.) powder by visible and near-infrared spectroscopy

USDA-ARS?s Scientific Manuscript database

This research aims to design and fabricate a system to measure the capsaicinoid content of red pepper powder in a non-destructive and rapid method through visible and near infrared spectroscopy (VNIR). The developed system scans a well-leveled powder surface continuously to minimize the influence of...

9. Water Purification System and Instrument Air Receiver Tank, view ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

9. Water Purification System and Instrument Air Receiver Tank, view to the south. The water purification system is visible in the right foreground of the photograph and the instrument air receiver tank is visible in the right background of the photograph. - Washington Water Power Clark Fork River Cabinet Gorge Hydroelectric Development, Powerhouse, North Bank of Clark Fork River at Cabinet Gorge, Cabinet, Bonner County, ID

Active modulation of laser coded systems using near infrared video projection system based on digital micromirror device (DMD)

NASA Astrophysics Data System (ADS)

Khalifa, Aly A.; Aly, Hussein A.; El-Sherif, Ashraf F.

2016-02-01

Near infrared (NIR) dynamic scene projection systems are used to perform hardware in-the-loop (HWIL) testing of a unit under test operating in the NIR band. The common and complex requirement of a class of these units is a dynamic scene that is spatio-temporal variant. In this paper we apply and investigate active external modulation of NIR laser in different ranges of temporal frequencies. We use digital micromirror devices (DMDs) integrated as the core of a NIR projection system to generate these dynamic scenes. We deploy the spatial pattern to the DMD controller to simultaneously yield the required amplitude by pulse width modulation (PWM) of the mirror elements as well as the spatio-temporal pattern. Desired modulation and coding of high stable, high power visible (Red laser at 640 nm) and NIR (Diode laser at 976 nm) using the combination of different optical masks based on DMD were achieved. These spatial versatile active coding strategies for both low and high frequencies in the range of kHz for irradiance of different targets were generated by our system and recorded using VIS-NIR fast cameras. The temporally-modulated laser pulse traces were measured using array of fast response photodetectors. Finally using a high resolution spectrometer, we evaluated the NIR dynamic scene projection system response in terms of preserving the wavelength and band spread of the NIR source after projection.

Space Shuttle with rail system and aft thrust structure securing solid rocket boosters to external tank

NASA Technical Reports Server (NTRS)

Vonpragenau, G. L. (Inventor)

1984-01-01

The configuration and relationship of the external propellant tank and solid rocket boosters of space transportation systems such as the space shuttle are described. The space shuttle system with the improved propellant tank is shown. The external tank has a forward pressure vessel for liquid hydrogen and an aft pressure vessel for liquid oxygen. The solid rocket boosters are joined together by a thrust frame which extends across and behind the external tank. The thrust of the orbiter's main rocket engines are transmitted to the aft portion of the external tank and the thrust of the solid rocket boosters are transmitted to the aft end of the external tank.

Testing Method for External Cladding Systems - Incerc Romania

NASA Astrophysics Data System (ADS)

Simion, A.; Dragne, H.

2017-06-01

This research presents a new testing method in a natural scale for external cladding systems tested on buildings with minimum than 3 floors [1]. The testing method is unique in Romania and it is similar about many fire testing current methods from European Union states. Also, presents the fire propagation and the effect of fire smoke on the building façade composed of thermal insulation. Laboratory of testing and research for building fire safety from National Institute INCERC Bucharest, provides a test method for determining the fire performance characteristics of non-loadbearing external cladding systems and external wall insulation systems when applied to the face of a building and exposed to an external fire under controlled conditions [2]. The fire exposure is representative of an external fire source or a fully-developed (post-flashover) fire in a room, venting through an opening such as a window aperture that exposes the cladding to the effects of external flames, or an external fire source. On the future, fire tests will be experimented for answer demande a number of high-profile fires where the external facade of tall buildings provided a route for vertical fire spread.

Growth Modeling of Aspergillus niger Strains Isolated from Citrus Fruit as a Function of Temperature on a Synthetic Medium from Lime (Citrus latifolia T.) Pericarp.

PubMed

Sandoval-Contreras, T; Marín, S; Villarruel-López, A; Gschaedler, A; Garrido-Sánchez, L; Ascencio, F

2017-07-01

Molds are responsible for postharvest spoilage of citrus fruits. The objective of this study was to evaluate the effect of temperature on growth rate and the time to visible growth of Aspergillus niger strains isolated from citrus fruits. The growth of these strains was studied on agar lime medium (AL) at different temperatures, and growth rate was estimated using the Baranyi and Roberts model (Int. J. Food Microbiol. 23:277-294, 1994). The Rosso et al. cardinal model with inflexion (L. Rosso, J. R. Lobry, S. Bajard, and J. P. Flandrois, J. Theor. Biol. 162:447-463, 1993) was used as a secondary model to describe the effect of temperature on growth rate and the lag phase. We hypothesized that the same model could be used to calculate the time for the mycelium to become visible (t v ) by substituting the lag phase (1/λ and 1/λ opt ) with the time to visible colony (1/t v -opt and 1/t v ), respectively, in the Rosso et al. High variability was observed at suboptimal conditions. Extremes of temperature of growth for A. niger seem to have a normal variability. For the growth rate and time t v , the model was satisfactorily compared with results of previous studies. An external validation was performed in lime fruits; the bias and accuracy factors were 1.3 and 1.5, respectively, for growth rate and 0.24 and 3.72, respectively, for the appearance time. The discrepancy may be due to the influence of external factors. A. niger grows significantly more slowly on lime fruit than in culture medium, probably because the nutrients are more easily available in medium than in fruits, where the peel consistency may be a physical barrier. These findings will help researchers understand the postharvest behavior of mold on lime fruits, host-pathogen interactions, and environmental conditions infecting fruit and also help them develop guidelines for future work in the field of predictive mycology to improve models for control of postharvest fungi.

Changing Systems of External Examination

ERIC Educational Resources Information Center

Stensaker, Bjorn; Brandt, Ellen; Solum, Nils Henrik

2008-01-01

Purpose: The purpose of this paper is to review and identify changes in systems of external examinations in Denmark, the UK and Norway. Design/methodology/approach: Comparative analysis of studies, reviews and documents concerning the purpose and functioning of systems of external examination in three selected countries. Findings: The paper…

Advancement of China’s Visible Light Remote Sensing Technology In Aerospace,

DTIC Science & Technology

1996-03-19

Aerospace visible light film systems were among the earliest space remote sensing systems to be developed in China. They have been applied very well...makes China the third nation in the world to master space remote sensing technology, it also puts recoverable remote sensing satellites among the first

Hybrid sunlight/LED illumination and renewable solar energy saving concepts for indoor lighting.

PubMed

Tsuei, Chih-Hsuan; Sun, Wen-Shing; Kuo, Chien-Cheng

2010-11-08

A hybrid method for using sunlight and light-emitting diode (LED) illumination powered by renewable solar energy for indoor lighting is simulated and presented in this study. We can illuminate an indoor space and collect the solar energy using an optical switching system. When the system is turned off, the full spectrum of the sunlight is concentrated by a concentrator, to be absorbed by solar photovoltaic devices that provide the electricity to power the LEDs. When the system is turned on, the sunlight collected by the concentrator is split into visible and non-visible rays by a beam splitter. The visible rays pass through the light guide into a light box where it is mixed with LED light to ultimately provide uniform illumination by a diffuser. The non-visible rays are absorbed by the solar photovoltaic devices to provide electrical power for the LEDs. Simulation results show that the efficiency of the hybrid sunlight/LED illumination with the renewable solar energy saving design is better than that of LED and traditional lighting systems.

`Googling' Terrorists: Are Northern Irish Terrorists Visible on Internet Search Engines?

NASA Astrophysics Data System (ADS)

Reilly, P.

In this chapter, the analysis suggests that Northern Irish terrorists are not visible on Web search engines when net users employ conventional Internet search techniques. Editors of mass media organisations traditionally have had the ability to decide whether a terrorist atrocity is `newsworthy,' controlling the `oxygen' supply that sustains all forms of terrorism. This process, also known as `gatekeeping,' is often influenced by the norms of social responsibility, or alternatively, with regard to the interests of the advertisers and corporate sponsors that sustain mass media organisations. The analysis presented in this chapter suggests that Internet search engines can also be characterised as `gatekeepers,' albeit without the ability to shape the content of Websites before it reaches net users. Instead, Internet search engines give priority retrieval to certain Websites within their directory, pointing net users towards these Websites rather than others on the Internet. Net users are more likely to click on links to the more `visible' Websites on Internet search engine directories, these sites invariably being the highest `ranked' in response to a particular search query. A number of factors including the design of the Website and the number of links to external sites determine the `visibility' of a Website on Internet search engines. The study suggests that Northern Irish terrorists and their sympathisers are unlikely to achieve a greater degree of `visibility' online than they enjoy in the conventional mass media through the perpetration of atrocities. Although these groups may have a greater degree of freedom on the Internet to publicise their ideologies, they are still likely to be speaking to the converted or members of the press. Although it is easier to locate Northern Irish terrorist organisations on Internet search engines by linking in via ideology, ideological description searches, such as `Irish Republican' and `Ulster Loyalist,' are more likely to generate links pointing towards the sites of research institutes and independent media organisations than sites sympathetic to Northern Irish terrorist organisations. The chapter argues that Northern Irish terrorists are only visible on search engines if net users select the correct search terms.

ViLLaGEs: opto-mechanical design of an on-sky visible-light MEMS-based AO system

NASA Astrophysics Data System (ADS)

Grigsby, Bryant; Lockwood, Chris; Baumann, Brian; Gavel, Don; Johnson, Jess; Ammons, S. Mark; Dillon, Daren; Morzinski, Katie; Reinig, Marc; Palmer, Dave; Severson, Scott; Gates, Elinor

2008-07-01

Visible Light Laser Guidestar Experiments (ViLLaGEs) is a new Micro-Electro Mechanical Systems (MEMS) based visible-wavelength adaptive optics (AO) testbed on the Nickel 1-meter telescope at Lick Observatory. Closed loop Natural Guide Star (NGS) experiments were successfully carried out during engineering during the fall of 2007. This is a major evolutionary step, signaling the movement of AO technologies into visible light with a MEMS mirror. With on-sky Strehls in I-band of greater than 20% during second light tests, the science possibilities have become evident. Described here is the advanced engineering used in the design and construction of the ViLLaGEs system, comparing it to the LickAO infrared system, and a discussion of Nickel dome infrastructural improvements necessary for this system. A significant portion of the engineering discussion revolves around the sizable effort that went towards eliminating flexure. Then, we detail upgrades to ViLLaGEs to make it a facility class instrument. These upgrades will focus on Nyquist sampling the diffraction limited point spread function during open loop operations, motorization and automation for technician level alignments, adding dithering capabilities and changes for near infrared science.

MaROS: Information Management Service

NASA Technical Reports Server (NTRS)

Allard, Daniel A.; Gladden, Roy E.; Wright, Jesse J.; Hy, Franklin H.; Rabideau, Gregg R.; Wallick, Michael N.

2011-01-01

This software is provided by the Mars Relay Operations Service (MaROS) task to a variety of Mars projects for the purpose of coordinating communications sessions between landed spacecraft assets and orbiting spacecraft assets at Mars. The Information Management Service centralizes a set of functions previously distributed across multiple spacecraft operations teams, and as such, greatly improves visibility into the end-to-end strategic coordination process. Most of the process revolves around the scheduling of communications sessions between the spacecraft during periods of time when a landed asset on Mars is geometrically visible by an orbiting spacecraft. These relay sessions are used to transfer data both to and from the landed asset via the orbiting asset on behalf of Earth-based spacecraft operators. This software component is an application process running as a Java virtual machine. The component provides all service interfaces via a Representational State Transfer (REST) protocol over https to external clients. There are two general interaction modes with the service: upload and download of data. For data upload, the service must execute logic specific to the upload data type and trigger any applicable calculations including pass delivery latencies and overflight conflicts. For data download, the software must retrieve and correlate requested information and deliver to the requesting client. The provision of this service enables several key advancements over legacy processes and systems. For one, this service represents the first time that end-to-end relay information is correlated into a single shared repository. The software also provides the first multimission latency calculator; previous latency calculations had been performed on a mission-by-mission basis.

Visual Advantage of Enhanced Flight Vision System During NextGen Flight Test Evaluation

NASA Technical Reports Server (NTRS)

Kramer, Lynda J.; Harrison, Stephanie J.; Bailey, Randall E.; Shelton, Kevin J.; Ellis, Kyle K.

2014-01-01

Synthetic Vision Systems and Enhanced Flight Vision System (SVS/EFVS) technologies have the potential to provide additional margins of safety for aircrew performance and enable operational improvements for low visibility operations in the terminal area environment. Simulation and flight tests were jointly sponsored by NASA's Aviation Safety Program, Vehicle Systems Safety Technology project and the Federal Aviation Administration (FAA) to evaluate potential safety and operational benefits of SVS/EFVS technologies in low visibility Next Generation Air Transportation System (NextGen) operations. The flight tests were conducted by a team of Honeywell, Gulfstream Aerospace Corporation and NASA personnel with the goal of obtaining pilot-in-the-loop test data for flight validation, verification, and demonstration of selected SVS/EFVS operational and system-level performance capabilities. Nine test flights were flown in Gulfstream's G450 flight test aircraft outfitted with the SVS/EFVS technologies under low visibility instrument meteorological conditions. Evaluation pilots flew 108 approaches in low visibility weather conditions (600 feet to 3600 feet reported visibility) under different obscurants (mist, fog, drizzle fog, frozen fog) and sky cover (broken, overcast). Flight test videos were evaluated at three different altitudes (decision altitude, 100 feet radar altitude, and touchdown) to determine the visual advantage afforded to the pilot using the EFVS/Forward-Looking InfraRed (FLIR) imagery compared to natural vision. Results indicate the EFVS provided a visual advantage of two to three times over that of the out-the-window (OTW) view. The EFVS allowed pilots to view the runway environment, specifically runway lights, before they would be able to OTW with natural vision.

Unintended adverse consequences of a clinical decision support system: two cases.

PubMed

Stone, Erin G

2018-05-01

Many institutions have implemented clinical decision support systems (CDSSs). While CDSS research papers have focused on benefits of these systems, there is a smaller body of literature showing that CDSSs may also produce unintended adverse consequences (UACs). Detailed here are 2 cases of UACs resulting from a CDSS. Both of these cases were related to external systems that fed data into the CDSS. In the first case, lack of knowledge of data categorization in an external pharmacy system produced a UAC; in the second case, the change of a clinical laboratory instrument produced the UAC. CDSSs rely on data from many external systems. These systems are dynamic and may have changes in hardware, software, vendors, or processes. Such changes can affect the accuracy of CDSSs. These cases point to the need for the CDSS team to be familiar with these external systems. This team (manager and alert builders) should include members in specific clinical specialties with deep knowledge of these external systems.

External Dependencies-Driven Architecture Discovery and Analysis of Implemented Systems

NASA Technical Reports Server (NTRS)

Ganesan, Dharmalingam; Lindvall, Mikael; Ron, Monica

2014-01-01

A method for architecture discovery and analysis of implemented systems (AIS) is disclosed. The premise of the method is that architecture decisions are inspired and influenced by the external entities that the software system makes use of. Examples of such external entities are COTS components, frameworks, and ultimately even the programming language itself and its libraries. Traces of these architecture decisions can thus be found in the implemented software and is manifested in the way software systems use such external entities. While this fact is often ignored in contemporary reverse engineering methods, the AIS method actively leverages and makes use of the dependencies to external entities as a starting point for the architecture discovery. The AIS method is demonstrated using the NASA's Space Network Access System (SNAS). The results show that, with abundant evidence, the method offers reusable and repeatable guidelines for discovering the architecture and locating potential risks (e.g. low testability, decreased performance) that are hidden deep in the implementation. The analysis is conducted by using external dependencies to identify, classify and review a minimal set of key source code files. Given the benefits of analyzing external dependencies as a way to discover architectures, it is argued that external dependencies deserve to be treated as first-class citizens during reverse engineering. The current structure of a knowledge base of external entities and analysis questions with strategies for getting answers is also discussed.

Phase Curves of Nix and Hydra from the New Horizons Imaging Cameras

NASA Astrophysics Data System (ADS)

Verbiscer, Anne J.; Porter, Simon B.; Buratti, Bonnie J.; Weaver, Harold A.; Spencer, John R.; Showalter, Mark R.; Buie, Marc W.; Hofgartner, Jason D.; Hicks, Michael D.; Ennico-Smith, Kimberly; Olkin, Catherine B.; Stern, S. Alan; Young, Leslie A.; Cheng, Andrew; (The New Horizons Team

2018-01-01

NASA’s New Horizons spacecraft’s voyage through the Pluto system centered on 2015 July 14 provided images of Pluto’s small satellites Nix and Hydra at viewing angles unattainable from Earth. Here, we present solar phase curves of the two largest of Pluto’s small moons, Nix and Hydra, observed by the New Horizons LOng Range Reconnaissance Imager and Multi-spectral Visible Imaging Camera, which reveal the scattering properties of their icy surfaces in visible light. Construction of these solar phase curves enables comparisons between the photometric properties of Pluto’s small moons and those of other icy satellites in the outer solar system. Nix and Hydra have higher visible albedos than those of other resonant Kuiper Belt objects and irregular satellites of the giant planets, but not as high as small satellites of Saturn interior to Titan. Both Nix and Hydra appear to scatter visible light preferentially in the forward direction, unlike most icy satellites in the outer solar system, which are typically backscattering.

Ultrahigh resolution retinal imaging by visible light OCT with longitudinal achromatization

PubMed Central

Chong, Shau Poh; Zhang, Tingwei; Kho, Aaron; Bernucci, Marcel T.; Dubra, Alfredo; Srinivasan, Vivek J.

2018-01-01

Chromatic aberrations are an important design consideration in high resolution, high bandwidth, refractive imaging systems that use visible light. Here, we present a fiber-based spectral/Fourier domain, visible light OCT ophthalmoscope corrected for the average longitudinal chromatic aberration (LCA) of the human eye. Analysis of complex speckles from in vivo retinal images showed that achromatization resulted in a speckle autocorrelation function that was ~20% narrower in the axial direction, but unchanged in the transverse direction. In images from the improved, achromatized system, the separation between Bruch’s membrane (BM), the retinal pigment epithelium (RPE), and the outer segment tips clearly emerged across the entire 6.5 mm field-of-view, enabling segmentation and morphometry of BM and the RPE in a human subject. Finally, cross-sectional images depicted distinct inner retinal layers with high resolution. Thus, with chromatic aberration compensation, visible light OCT can achieve volume resolutions and retinal image quality that matches or exceeds ultrahigh resolution near-infrared OCT systems with no monochromatic aberration compensation. PMID:29675296

Luminescence- and nanoparticle-mediated increase of light absorption by photoreceptor cells: Converting UV light to visible light.

PubMed

Li, Lei; Sahi, Sunil K; Peng, Mingying; Lee, Eric B; Ma, Lun; Wojtowicz, Jennifer L; Malin, John H; Chen, Wei

2016-02-10

We developed new optic devices - singly-doped luminescence glasses and nanoparticle-coated lenses that convert UV light to visible light - for improvement of visual system functions. Tb(3+) or Eu(3+) singly-doped borate glasses or CdS-quantum dot (CdS-QD) coated lenses efficiently convert UV light to 542 nm or 613 nm wavelength narrow-band green or red light, or wide-spectrum white light, and thereby provide extra visible light to the eye. In zebrafish (wild-type larvae and adult control animals, retinal degeneration mutants, and light-induced photoreceptor cell degeneration models), the use of Tb(3+) or Eu(3+) doped luminescence glass or CdS-QD coated glass lenses provide additional visible light to the rod and cone photoreceptor cells, and thereby improve the visual system functions. The data provide proof-of-concept for the future development of optic devices for improvement of visual system functions in patients who suffer from photoreceptor cell degeneration or related retinal diseases.

In vivo high-resolution cortical imaging with extended-focus optical coherence microscopy in the visible-NIR wavelength range

NASA Astrophysics Data System (ADS)

Marchand, Paul J.; Szlag, Daniel; Bouwens, Arno; Lasser, Theo

2018-03-01

Visible light optical coherence tomography has shown great interest in recent years for spectroscopic and high-resolution retinal and cerebral imaging. Here, we present an extended-focus optical coherence microscopy system operating from the visible to the near-infrared wavelength range for high axial and lateral resolution imaging of cortical structures in vivo. The system exploits an ultrabroad illumination spectrum centered in the visible wavelength range (λc = 650 nm, Δλ ˜ 250 nm) offering a submicron axial resolution (˜0.85 μm in water) and an extended-focus configuration providing a high lateral resolution of ˜1.4 μm maintained over ˜150 μm in depth in water. The system's axial and lateral resolution are first characterized using phantoms, and its imaging performance is then demonstrated by imaging the vasculature, myelinated axons, and neuronal cells in the first layers of the somatosensory cortex of mice in vivo.

Optical mapping of surface roughness by implementation of a spatial light modulator

NASA Astrophysics Data System (ADS)

Aulbach, Laura; Pöller, Franziska; Lu, Min; Wang, Shengjia; Koch, Alexander W.

2017-08-01

It is well-known that the surface roughness of materials plays an important role in the operation and performance of technological systems. The roughness influences key parameters, such as friction and wear, and is directly connected to the functionality and durability of the respective system. Tactile methods are widely used for the measurement of surface roughness, but a destructive measurement procedure and the lack of feasibility of online monitoring are crucial drawbacks. In the last decades, several non-contact, usually optical systems for surface roughness measurements have been developed, e.g., white light interferometry, light scatter analysis, or speckle correlation. These techniques are in turn often unable to assign the roughness to a certain surface area or involve inappropriate adjustment procedures. One promising and straightforward optical measurement method is the surface roughness measurement by analyzing the fringe visibility of an interferometric fringe pattern. In our work, we employed a spatial light modulator in the interferometric setup to vary the fringe visibility and provide a stable and reliable measurement system. In previous research, either the averaged fringe visibility or the fringe visibility along a defined observation profile were analyzed. In this article, the analysis of the fringe visibility is extended to generate a complete roughness map of the measurement target. Thus, surface defects or areas of different roughness can be easily located.

[Design and analysis of a novel light visible spectrum imaging spectrograph optical system].

PubMed

Shen, Man-de; Li, Fei; Zhou, Li-bing; Li, Cheng; Ren, Huan-huan; Jiang, Qing-xiu

2015-02-01

A novel visible spectrum imaging spectrograph optical system was proposed based on the negative dispersion, the arbitrary phase modulation characteristics of diffractive optical element and the aberration correction characteristics of freeform optical element. The double agglutination lens was substituted by a hybrid refractive/diffractive lens based on the negative dispersion of diffractive optical element. Two freeform optical elements were used in order to correct some aberration based on the aberration correction characteristics of freeform optical element. An example and frondose design process were presented. When the design parameters were uniform, compared with the traditional system, the novel visible spectrum imaging spectrograph optical system's weight was reduced by 22.9%, the total length was reduced by 26.6%, the maximal diameter was reduced by 30.6%, and the modulation transfer function (MTF) in 1.0 field-of-view was improved by 0.35 with field-of-view improved maximally. The maximal distortion was reduced by 1.6%, the maximal longitudinal aberration was reduced by 56.4%, and the lateral color aberration was reduced by 59. 3%. From these data, we know that the performance of the novel system was advanced quickly and it could be used to put forward a new idea for modern visible spectrum imaging spectrograph optical system design.

Visible-to-visible four-photon ultrahigh resolution microscopic imaging with 730-nm diode laser excited nanocrystals.

PubMed

Wang, Baoju; Zhan, Qiuqiang; Zhao, Yuxiang; Wu, Ruitao; Liu, Jing; He, Sailing

2016-01-25

Further development of multiphoton microscopic imaging is confronted with a number of limitations, including high-cost, high complexity and relatively low spatial resolution due to the long excitation wavelength. To overcome these problems, for the first time, we propose visible-to-visible four-photon ultrahigh resolution microscopic imaging by using a common cost-effective 730-nm laser diode to excite the prepared Nd(3+)-sensitized upconversion nanoparticles (Nd(3+)-UCNPs). An ordinary multiphoton scanning microscope system was built using a visible CW diode laser and the lateral imaging resolution as high as 161-nm was achieved via the four-photon upconversion process. The demonstrated large saturation excitation power for Nd(3+)-UCNPs would be more practical and facilitate the four-photon imaging in the application. A sample with fine structure was imaged to demonstrate the advantages of visible-to-visible four-photon ultrahigh resolution microscopic imaging with 730-nm diode laser excited nanocrystals. Combining the uniqueness of UCNPs, the proposed visible-to-visible four-photon imaging would be highly promising and attractive in the field of multiphoton imaging.

Technical Challenges in the Development of a NASA Synthetic Vision System Concept

NASA Technical Reports Server (NTRS)

Bailey, Randall E.; Parrish, Russell V.; Kramer, Lynda J.; Harrah, Steve; Arthur, J. J., III

2002-01-01

Within NASA's Aviation Safety Program, the Synthetic Vision Systems Project is developing display system concepts to improve pilot terrain/situation awareness by providing a perspective synthetic view of the outside world through an on-board database driven by precise aircraft positioning information updating via Global Positioning System-based data. This work is aimed at eliminating visibility-induced errors and low visibility conditions as a causal factor to civil aircraft accidents, as well as replicating the operational benefits of clear day flight operations regardless of the actual outside visibility condition. Synthetic vision research and development activities at NASA Langley Research Center are focused around a series of ground simulation and flight test experiments designed to evaluate, investigate, and assess the technology which can lead to operational and certified synthetic vision systems. The technical challenges that have been encountered and that are anticipated in this research and development activity are summarized.

STS-45 Atlantis, OV-104, lifts off from KSC Launch Complex (LC) Pad

NASA Image and Video Library

1992-03-24

STS-45 Atlantis, Orbiter Vehicle (OV) 104, lifts off from a Kennedy Space Center (KSC) Launch Complex (LC) Pad at 8:13:40:048 am (Eastern Standard Time (EST)). Exhaust billows out the solid rocket boosters (SRBs) as OV-104 atop its external tank (ET) soars above the mobile launcher platform and is nearly clear of the fixed service structure (FSS) tower. The diamond shock effect produced by the space shuttle main engines (SSMEs) is visible. The glow of the SRB/SSME firings is reflected in a nearby waterway. An exhaust cloud covers the launch pad area.

KSC-07pd0598

NASA Image and Video Library

2007-03-09

KENNEDY SPACE CENTER, FLA. -- In Highbay 1 inside the Vehicle Assembly Building, technicians work on repair techniques to the hail-damaged external tank. They are inside a tented area that protects the tank. Scaffolding around the tank can be seen below. A severe thunderstorm with golf ball-sized hail caused visible divots in the giant tank's foam insulation and minor surface damage to about 26 heat shield tiles on the shuttle's left wing. A new target launch date has not been determined, but teams will focus on preparing Atlantis for liftoff in late April on mission STS-117. Photo credit: NASA/Jim Grossmann

KSC-07pd1082

NASA Image and Video Library

2007-05-09

KENNEDY SPACE CENTER, FLA. -- In NASA Kennedy Space Center's Vehicle Assembly Building, technicians place a piece of foam on the side of Atlantis' nose cone to rest the sander while they make adjustments. In late February, Atlantis' external tank received hail damage during a severe thunderstorm that passed through the Kennedy Space Center Launch Complex 39 area. The hail caused visible divots in the giant tank's foam insulation as well as minor surface damage to about 26 heat shield tiles on the shuttle's left wing. The launch of Space Shuttle Atlantis on mission STS-117 now is targeted for June 8. Photo credit: NASA/Jack Pfaller

KSC-07pd0606

NASA Image and Video Library

2007-03-09

KENNEDY SPACE CENTER, FLA. -- In Highbay 1 inside the Vehicle Assembly Building, a technician carefully begins to carefully sand away the red dye that has been applied to the external tank to help expose cracks or compression dents. A severe thunderstorm with golf ball-sized hail caused visible divots in the giant tank's foam insulation and minor surface damage to about 26 heat shield tiles on the shuttle's left wing. A new target launch date has not been determined, but teams will focus on preparing Atlantis for liftoff in late April on mission STS-117. Photo credit: NASA/Jim Grossmann

KSC-07pd1083

NASA Image and Video Library

2007-05-09

KENNEDY SPACE CENTER, FLA. -- In NASA Kennedy Space Center's Vehicle Assembly Building, one technician adjusts the sander while another observes as they work on repairing the hail damage to Atlantis' nose cone. In late February, Atlantis' external tank received hail damage during a severe thunderstorm that passed through the Kennedy Space Center Launch Complex 39 area. The hail caused visible divots in the giant tank's foam insulation as well as minor surface damage to about 26 heat shield tiles on the shuttle's left wing. The launch of Space Shuttle Atlantis on mission STS-117 now is targeted for June 8. Photo credit: NASA/Jack Pfaller

A Customizable Multimodality Imaging Compound That Relates External Landmarks to Internal Structures.

PubMed

Semework, Mulugeta

2015-12-01

Numerous research and clinical interventions, such as targeting drug deliveries or surgeries and finding blood clots, abscesses, or lesions, require accurate localization of various body parts. Individual differences in anatomy make it hard to use typical stereotactic procedures that rely on external landmarks and standardized atlases. For instance, it is not unusual to incorrectly place a craniotomy in brain surgery. This project was thus performed to find a new and easy method to correctly establish the relationship between external landmarks and medical scans of internal organs, such as specific regions of the brain. This paper introduces an MRI, CT, and radiographically visible compound that can be applied to any surface and therefore provide an external reference point to an internal (eye-invisible) structure. Tested on nonhuman primates and isolated brain scans, this compound showed up with the same color in different scan types, making practical work possible. Conventional, and mostly of specific utility, products such as contrast agents were differentially colored or completely failed to show up and were not flexible. This compound can be customized to have different viscosities, colors, odors, and other characteristics. It can also be mixed with hardening materials such as acrylic for industrial or engineering uses, for example. Laparoscopy wands, electroencephalogram leads, and other equipment could also be embedded with or surrounded by the compound for ease in 3-dimensional visualizations. A pending U.S. patent endorses this invention. © 2015 by the Society of Nuclear Medicine and Molecular Imaging, Inc.

Visible-light-enhanced Cr(VI) reduction at Pd-decorated silicon nanowire photocathode in photoelectrocatalytic microbial fuel cell.

PubMed

Han, He-Xing; Shi, Chen; Zhang, Nan; Yuan, Li; Sheng, Guo-Ping

2018-10-15

Hexavalent chromium (Cr(VI)) is a prominent toxic metal with significant adverse human health effects. Photocatalytic reduction of Cr(VI) to less-toxic trivalent chromium (Cr(III)) is a promising method for removing Cr(VI) from aquatic environments. However, this technique often suffers from electron-hole recombination of semiconductors and poor reduction efficiency. The photoelectrocatalytic microbial fuel cell (Photo-MFC), which can use wastewater and light to recover electricity, has recently been proven to improve the separation of photocarriers of semiconductors and enhance cathodic reduction of pollutants. Here, the reduction of Cr(VI) was investigated in a Photo-MFC with a Pd-decorated p-type silicon nanowire (Pd/SiNW) photocathode and a bioanode under visible light. The Cr(VI) reduction efficiency reached 98.7% in 8 h under visible light, which was much higher than that under dark condition (56.2%) and open-circuit condition (19.4%). The enhanced Cr(VI) removal was mainly attributed to the synergistic effect of Pd/SiNW photocathode and bioanode. Cr(VI) reduction in the Photo-MFC fitted well with pseudo-first-order kinetics. The kinetics constants and reduction efficiencies of Cr(VI) decreased with the increase of pH, initial Cr(VI) concentration and external resistance. This work provides a promising alternative to mitigate Cr(VI) pollution in aquatic environments. Copyright © 2018 Elsevier B.V. All rights reserved.

Down-conversion emission of Ce3+-Tb3+ co-doped CaF2 hollow spheres and application for solar cells

NASA Astrophysics Data System (ADS)

Cheng, Yufei; Wang, Yongbo; Teng, Feng; Dong, Hua; Chen, Lida; Mu, Jianglong; Sun, Qian; Fan, Jun; Hu, Xiaoyun; Miao, Hui

2018-03-01

Luminescent downconversion is a promising way to harvest ultraviolet sunlight and transform it into visible light that can be absorbed by solar cells, and has potential to improve their photoelectric conversion efficiency. In this work, the uniform hollow spheres and well dispersed CaF2 phosphors doped with rare-earth Ce3+ and Tb3+ ions are prepared by a one-step hydrothermal synthesis method. Benefiting from the stronger ability of absorption and emission and excellent transparency property, we demonstrate that the application of the doped nanocrystals can efficiently improve visible light transmittance. The chosen phosphors are added in the SiO2 sols so as to get the anti-reflection coatings with wavelength conversion bi-functional films, promoting the optical transmittance in the visible and near-infrared range which matches with the range of the band gap energy of silicon semiconductor. Optimized photoelectric conversion efficiency of 14.35% and the external quantum efficiency over 70% from 450 to 950 nm are obtained through the silicon solar cells with 0.10 g phosphors coating. Compared with the pure glass devices, the photoelectric conversion efficiency is enhanced by 0.69%. This work indicates that fluorescent downconversion not only can serve as proof of principles for improving photoelectric conversion efficiency of solar cells but also may be helpful to practical application in the future.

Analysis of Gibbs monolayer adsorbed at the toluene/water interface by UV-visible partial internal reflection spectrometry.

PubMed

Moriya, Yoshio; Hasegawa, Takeshi; Okada, Tetsuo; Ogawa, Nobuaki; Kawai, Erika; Abe, Kosuke; Ogasawara, Masataka; Kato, Sumio; Nakata, Shinichi

2006-11-15

Gibbs monolayers of lipophilic tetraphenylporphyrinatomanganese(III) and hydrophilic diacid of meso-tetrakis(4-sulfonatopheny)porphyrin adsorbed at the liquid-liquid interface have been analyzed by UV-visible external reflection (ER) and partial internal reflection (PIR) spectra measured at different angles of incidence. The angle-dependent ER and PIR spectra over the Brewster angles (thetaERB and thetaIRB) have readily been measured at the toluene/water interface. As preliminarily expected in our previous study, the present study has first proved that the reflection-absorbance of UV-visible PIR spectra quantitatively agrees with the theoretical calculations for the Gibbs monolayer over thetaIRB. In addition, it has also been proved that the absorbance of the PIR spectra is greatly enhanced in comparison to that of the ATR spectra. The enhancement is caused by an optical effect in the monolayer sandwiched between two phases of toluene and water that have different but refractive indices close to each other. This optical enhancement requires an optically perfect contact between the phases, which is difficult to prepare for a solid-solid contact. At the liquid/liquid interface, however, an ideal optical contact is easily realized, which makes the enhancement as much as the theoretical expectation. The PIR spectrometry will be recognized to be a new high-sensitive analytical tool to study Gibbs monolayer at the liquid/liquid interface.

Enhancement in visible light photocatalytic activity by embedding Cu nanoparticles over CuS/MCM-41 nanocomposite

NASA Astrophysics Data System (ADS)

Sohrabnezhad, Sh.; Karamzadeh, M.

2017-07-01

This article indicate the biogenic synthesis of copper nanoparticles (Cu NPs) using the borage flowers extract of Borago officinalis over CuS/MCM-41 nanocomposite (NC). No external reducing was utilized in the developed method. The CuS-MCM-41 NC was used as stabilizing agent. The synthesis of CuS nanostructure in MCM-41 material has been realized by hydrothermal method. Their physiochemical properties have been characterized by X-ray diffraction, transmission electron microscopy (TEM), UV-Visible diffuse reflectance spectroscopy, and Fourier transform infrared spectroscopy. On the basis of TEM images, a layer of Cu NPs has been located over CuS/MCM-41 NC with average diameter of 60-80 nm. The results revealed the spherical nature of the prepared Cu NPs with diameter less than 10 nm. The DR spectra of Cu NPs in MCM-41 and CuS-MCM-41 NCs showed surface plasmon resonance bands at 570 and 500-600 nm, respectively. The photocatalytic activity was evaluated under visible light irradiation using the photocatalytic degradation of methylene blue (MB) as a model reaction. The prepared Cu/CuS/MCM-41 nanocomposite microspheres showed higher photodegradation ability for MB than CuS/MCM-41. The degradation of MB achieved up to 80% after 60 min and the nanocomposite could be recycled and reused.

Enhanced and Synthetic Vision for Terminal Maneuvering Area NextGen Operations

NASA Technical Reports Server (NTRS)

Kramer, Lynda J.; Bailey, Randall E.; Ellis, Kyle K. E.; Norman, R. Michael; Williams, Steven P.; Arthur, Jarvis J., III; Shelton, Kevin J.; Prinzel, Lawrence J., III

2011-01-01

Synthetic Vision Systems and Enhanced Flight Vision System (SVS/EFVS) technologies have the potential to provide additional margins of safety for aircrew performance and enable operational improvements for low visibility operations in the terminal area environment with equivalent efficiency as visual operations. To meet this potential, research is needed for effective technology development and implementation of regulatory and design guidance to support introduction and use of SVS/EFVS advanced cockpit vision technologies in Next Generation Air Transportation System (NextGen) operations. A fixed-base pilot-in-the-loop simulation test was conducted at NASA Langley Research Center that evaluated the use of SVS/EFVS in NextGen low visibility ground (taxi) operations and approach/landing operations. Twelve crews flew approach and landing operations in a simulated NextGen Chicago O Hare environment. Various scenarios tested the potential for EFVS for operations in visibility as low as 1000 ft runway visibility range (RVR) and SVS to enable lower decision heights (DH) than can currently be flown today. Expanding the EFVS visual segment from DH to the runway in visibilities as low as 1000 RVR appears to be viable as touchdown performance was excellent without any workload penalties noted for the EFVS concept tested. A lower DH to 150 ft and/or possibly reduced visibility minima by virtue of SVS equipage appears to be viable when implemented on a Head-Up Display, but the landing data suggests further study for head-down implementations.

Note: Optics design of a periscope for the KSTAR visible inspection system with mitigated neutron damages on the camera

NASA Astrophysics Data System (ADS)

Lee, Kyuhang; Ko, Jinseok; Wi, Hanmin; Chung, Jinil; Seo, Hyeonjin; Jo, Jae Heung

2018-06-01

The visible TV system used in the Korea Superconducting Tokamak Advanced Research device has been equipped with a periscope to minimize the damage on its CCD pixels from neutron radiation. The periscope with more than 2.3 m in overall length has been designed for the visible camera system with its semi-diagonal field of view as wide as 30° and its effective focal length as short as 5.57 mm. The design performance of the periscope includes the modulation transfer function greater than 0.25 at 68 cycles/mm with low distortion. The installed periscope system has confirmed the image qualities as designed and also as comparable as those from its predecessor but with far less probabilities of neutral damages on the camera.

Improvement of fog predictability in a coupled system of PAFOG and WRF

NASA Astrophysics Data System (ADS)

Kim, Wonheung; Yum, Seong Soo; Kim, Chang Ki

2017-04-01

Fog is difficult to predict because of the multi-scale nature of its formation mechanism: not only the synoptic conditions but also the local meteorological conditions crucially influence fog formation. Coarse vertical resolution and parameterization errors in fog prediction models are also critical reasons for low predictability. In this study, we use a coupled model system of a 3D mesoscale model (WRF) and a single column model with a fine vertical resolution (PAFOG, PArameterized FOG) to simulate fogs formed over the southern coastal region of the Korean Peninsula, where National Center for Intensive Observation of Severe Weather (NCIO) is located. NCIO is unique in that it has a 300 m meteorological tower built at the location to measure basic meteorological variables (temperature, dew point temperature and winds) at eleven different altitudes, and comprehensive atmospheric physics measurements are made with the various remote sensing instruments such as visibility meter, cloud radar, wind profiler, microwave radiometer, and ceilometer. These measurement data are used as input data to the model system and for evaluating the results. Particularly the data for initial and external forcings, which are tightly connected to the predictability of coupled model system, are derived from the tower measurement. This study aims at finding out the most important factors that influence fog predictability of the coupled system for NCIO. Nudging of meteorological tower data and soil moisture variability are found to be critically influencing fog predictability. Detailed results will be discussed at the conference.

Muslim and Hindu Women’s Public and Private Behaviors: Gender, Family and Communalized Politics in India

PubMed Central

Desai, Sonalde; Temsah, Gheda

2015-01-01

Prior research on fundamentalist religious movements has focused attention on the complicated relationship between gender, family and religion. Using data from a nationally representative survey of 30,000 Hindu and Muslim women, this study compares the daily public and private behaviors of women in India to examine how gender and family norms are shaped in the context of communalized identity politics. Building on the theoretical framework of “doing gender”, it argues that because communal identities are expressed through externally visible behaviors, greater religious differences are expected in external markers of gendered behaviors and family norms. Results indicate that Muslim women are more likely to engage in veiling and less likely to venture outside the home for recreation and employment. However, religious differences are absent when attention is directed at private behaviors such as household decision making power, gender segregation within households, and discrimination against daughters. Results underscore the multidimensionality of gender. PMID:25143018

An infrared flash contemporaneous with the gamma-rays of GRB 041219a.

PubMed

Blake, C H; Bloom, J S; Starr, D L; Falco, E E; Skrutskie, M; Fenimore, E E; Duchêne, G; Szentgyorgyi, A; Hornstein, S; Prochaska, J X; McCabe, C; Ghez, A; Konopacky, Q; Stapelfeldt, K; Hurley, K; Campbell, R; Kassis, M; Chaffee, F; Gehrels, N; Barthelmy, S; Cummings, J R; Hullinger, D; Krimm, H A; Markwardt, C B; Palmer, D; Parsons, A; McLean, K; Tueller, J

2005-05-12

The explosion that results in a cosmic gamma-ray burst (GRB) is thought to produce emission from two physical processes: the central engine gives rise to the high-energy emission of the burst through internal shocking, and the subsequent interaction of the flow with the external environment produces long-wavelength afterglows. Although observations of afterglows continue to refine our understanding of GRB progenitors and relativistic shocks, gamma-ray observations alone have not yielded a clear picture of the origin of the prompt emission nor details of the central engine. Only one concurrent visible-light transient has been found and it was associated with emission from an external shock. Here we report the discovery of infrared emission contemporaneous with a GRB, beginning 7.2 minutes after the onset of GRB 041219a (ref. 8). We acquired 21 images during the active phase of the burst, yielding early multi-colour observations. Our analysis of the initial infrared pulse suggests an origin consistent with internal shocks.

Innervation of the cricothyroid muscle by the recurrent laryngeal nerve.

PubMed

Masuoka, Hiroo; Miyauchi, Akira; Yabuta, Tomonori; Fukushima, Mitsuhiro; Miya, Akihiro

2016-04-01

The recurrent laryngeal nerve (RLN) and the external branch of the superior laryngeal nerve (SLN) are generally thought to innervate the endolaryngeal muscles and the cricothyroid muscle (CTM), respectively. Meticulous anatomic studies found communication between these nerves (ie, the human communicating nerve). In this study, we report the innervation of the CTM by the RLN. We performed electromyographic studies of 50 patients during thyroidectomy (20 total and 30 hemithyroidectomies). During surgery, the external branch of the SLN, RLN, and vagus nerve were stimulated. Responses were evaluated by visual observation of the CTM and by electromyographies through needle electrodes inserted into the CTM. Seventy CTMs were evaluated. The RLN stimulation yielded both visible contractions and clear electromyographic responses (>300 µV) in 27 (39%), either response in 24 (34%), and neither response in 19 (27%) of the CTMs. The vagus stimulation gave similar results. The RLN innervated the CTM at least in 39% cases. © 2015 Wiley Periodicals, Inc. Head Neck 38: E441-E445, 2016. © 2015 Wiley Periodicals, Inc.

KSC-07pd0885

NASA Image and Video Library

2007-04-13

KENNEDY SPACE CENTER, FLA. -- In the Vehicle Assembly Building, markers show the hail damage being repaired on the external tank of Space Shuttle Atlantis. The white hole with a red circle around it is a hole prepared for molding and material application. The red material is sealant tape so the mold doesn't leak when the foam rises against the mold. The white/translucent square mold is an area where the foam has been applied and the foam has risen and cured against the mold surface. The area will be de-molded and sanded flush with the adjacent area. In late February, Atlantis' external tank received hail damage during a severe thunderstorm that passed through the Kennedy Space Center Launch Complex 39 area. The hail caused visible divots in the giant tank's foam insulation as well as minor surface damage to about 26 heat shield tiles on the shuttle's left wing. The launch now is targeted for June 8. Photo credit: NASA/George Shelton

KSC-07pd0848

NASA Image and Video Library

2007-04-09

KENNEDY SPACE CENTER, FLA. -- In the Vehicle Assembly Building, markers show the hail damage being repaired on the external tank of Space Shuttle Atlantis. The white hole with a red circle around it is a hole prepared for molding and material application. The red material is sealant tape so the mold doesn't leak when the foam rises against the mold. The white/translucent square mold is an area where the foam has been applied and the foam has risen and cured against the mold surface. The area will be de-molded and sanded flush the with adjacent area. In late February, Atlantis' external tank received hail damage during a severe thunderstorm that passed through the Kennedy Space Center Launch Complex 39 area. The hail caused visible divots in the giant tank's foam insulation as well as minor surface damage to about 26 heat shield tiles on the shuttle's left wing. The March launch was postponed and has not yet been rescheduled due to the repair process. Photo credit: NASA/George Shelton

KSC-07pd0849

NASA Image and Video Library

2007-04-09

KENNEDY SPACE CENTER, FLA. -- In the Vehicle Assembly Building, United Space Alliance technicians Brenda Morris and Brian Williams are applying foam and molds on Space Shuttle Atlantis' external tank to areas damaged by hail. The white hole with a red circle around it (upper right) is a hole prepared for molding and material application. The red material is sealant tape so the mold doesn't leak when the foam rises against the mold. The white/translucent square mold is an area where the foam has been applied and the foam has risen and cured against the mold surface. In late February, Atlantis' external tank received hail damage during a severe thunderstorm that passed through the Kennedy Space Center Launch Complex 39 area. The hail caused visible divots in the giant tank's foam insulation as well as minor surface damage to about 26 heat shield tiles on the shuttle's left wing. The March launch was postponed and has not yet been rescheduled due to the repair process. Photo credit: NASA/George Shelton

The Large Angle Spectroscopic Coronagraph (LASCO): Visible light coronal imaging and spectroscopy

NASA Technical Reports Server (NTRS)

Brueckner, Guenter E.; Howard, Russell A.; Koomen, Martin J.; Korendyke, C.; Michels, D. J.; Socker, D. G.; Lamy, Philippe; Llebaria, Antoine; Maucherat, J.; Schwenn, Rainer

1992-01-01

The Large Angle Spectroscopic Coronagraph (LASCO) is a triple coronagraph being jointly developed for the Solar and Heliospheric Observatory (SOHO) mission. LASCO comprises three nested coronagraphs (C1, C2, and C3) that image the solar corona for 1.1 to 30 solar radii (C1: 1.1 to 3 solar radii, C2: 1.5 to 6 solar radii, and C3: 3 to 30.0 solar radii). The inner coronagraph (C1) is a newly developed mirror version of the classic Lyot coronagraph without an external occultor, while the middle coronagraph (C2) and the outer coronagraph (C3) are externally occulted instruments. High resolution coronal spectroscopy from 1.1 to 3 R solar radii can be performed by using a Fabry-Perot interferometer, which is part of C1. High volume memories and a high speed microprocessor enable extensive onboard image processing. Image compression by factors of 10 to 20 will result in the transmission of 10 to 20 full images per hour.

Optical Fiber Connection Navigation System Using Visible Light Communication in Central Office with Economic Evaluation

NASA Astrophysics Data System (ADS)

Waki, Masaki; Uruno, Shigenori; Ohashi, Hiroyuki; Manabe, Tetsuya; Azuma, Yuji

We propose an optical fiber connection navigation system that uses visible light communication for an integrated distribution module in a central office. The system realizes an accurate database, requires less skilled work to operate and eliminates human error. This system can achieve a working time reduction of up to 88.0% compared with the conventional work without human error for the connection/removal of optical fiber cords, and is economical as regards installation and operation.

An Auto-flag Method of Radio Visibility Data Based on Support Vector Machine

NASA Astrophysics Data System (ADS)

Dai, Hui-mei; Mei, Ying; Wang, Wei; Deng, Hui; Wang, Feng

2017-01-01

The Mingantu Ultrawide Spectral Radioheliograph (MUSER) has entered a test observation stage. After the construction of the data acquisition and storage system, it is urgent to automatically flag and eliminate the abnormal visibility data so as to improve the imaging quality. In this paper, according to the observational records, we create a credible visibility set, and further obtain the corresponding flag model of visibility data by using the support vector machine (SVM) technique. The results show that the SVM is a robust approach to flag the MUSER visibility data, and can attain an accuracy of about 86%. Meanwhile, this method will not be affected by solar activities, such as flare eruptions.

Advanced sensor-simulation capability

NASA Astrophysics Data System (ADS)

Cota, Stephen A.; Kalman, Linda S.; Keller, Robert A.

1990-09-01

This paper provides an overview of an advanced simulation capability currently in use for analyzing visible and infrared sensor systems. The software system, called VISTAS (VISIBLE/INFRARED SENSOR TRADES, ANALYSES, AND SIMULATIONS) combines classical image processing techniques with detailed sensor models to produce static and time dependent simulations of a variety of sensor systems including imaging, tracking, and point target detection systems. Systems modelled to date include space-based scanning line-array sensors as well as staring 2-dimensional array sensors which can be used for either imaging or point source detection.

Head-Mounted and Head-Up Display Glossary

NASA Technical Reports Server (NTRS)

Newman, Richard L.; Allen, J. Edwin W. (Technical Monitor)

1997-01-01

One of the problems in head-up and helmet-mounted display (HMD) literature has been a lack of standardization of words and abbreviations. Several different words have been used for the same concept; for example, flight path angle, flight path marker, velocity vector, and total velocity vector all refer to the same thing. In other cases, the same term has been used with two different meanings, such as binocular field-of-view which means the field-of-view visible to both left and right eyes according to some or the field-of-view visible to either the left or right eye or both according to others. Many of the terms used in HMD studies have not been well-defined. We need to have a common language to ensure that system descriptions are communicated. As an example, the term 'stabilized' has been widely used with two meanings. 'Roll-stabilized' has been used to mean a symbol which rotates to indicate the roll or bank of the aircraft. 'World-stabilized' and 'head-stabilized' have both been used to indicate symbols which move to remain fixed with respect to external objects. HMDs present unique symbology problems not found in HUDs. Foremost among these is the issue of maintaining spatial orientation of the symbols. All previous flight displays, round dial instruments, HDDs, and HUDs have been fixed in the cockpit. With the HMD, the flight display can move through a large angle. The coordinates use in transforming from the real-world to the aircraft to the HMD have not been consistently defined. This glossary contains terms relating to optics and vision, displays, and flight information, weapons and aircraft systems. Some definitions, such as Navigation Display, have been added to clarify the definitions for Primary Flight Display and Primary Flight Reference. A list of HUD/HMD related abbreviations is also included.

INTERIOR DETAIL, NORTH GARRET DOOR. THE WIRES VISIBLE ABOVE THE ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

INTERIOR DETAIL, NORTH GARRET DOOR. THE WIRES VISIBLE ABOVE THE DOOR ARE REMNANTS OF AN EARLY ELECTRICAL SYSTEM INSTALLED BY THE CEMETERY COMPANY - The Woodlands, 4000 Woodlands Avenue, Philadelphia, Philadelphia County, PA

External female genitalia of six species of the genus Meccus (Hemiptera: Reduviidae: Triatominae).

PubMed

Rivas, Nancy; Sánchez-Cordero, Victor; Camacho, Alejandro D; Alejandre-Aguilar, Ricardo

2017-12-01

Triatomine classification is based on morphological characteristics. Studies have been conducted to improve their identification by observing many characteristics. However, there are problems of differentiating among highly interrelated species and new criteria are required. The purpose of this study was to determine the morphological differences in the external female genitalia of M. pallidipennis, M. longipennis, M. picturatus, M. bassolsae, M. mazzottii, and M. phyllosomus in order to distinguish among species using scanning electron microscopy. Observations were made of the dorsal, posterior, lateral, and ventral views of the female external genitalia for each species. In the six species we studied, relevant differences were observed in the dorsal view of the X segment, as well as the IX, VIII, and VII tergites. In the posterior and lateral view, the most visible differences were registered in the gonocoxite size of the segments VIII, IX, and X. Finally, in the ventral view of the VII sternite, differences among species were observed in the size of the inflection in the top and upper corner. Our results show that it was possible to differentiate among the triatominae species for each of the four views by using a scanning electron microscope to analyze morphological characteristics of the VII, VIII, IX, and X abdomen segments. © 2017 The Society for Vector Ecology.

[Structure of the retina of Pacific salmon fry in twilight illumination during the geomagnetic field changes].

PubMed

Maksimovich, A A; Gniubkina, V P

2010-01-01

The retinomotor response of the masu salmon Oncorhynchus masou fry retina was studied under the conditions of mesopic (twilight) illumination after experimental geomagnetic field (GMF) compensation which was reached using the Helmholtz coils. In the control group, the retinomotor response of masu salmon fry to twilight illumination was usual: the nuclei of the neurosensory rod cells were located immediately above the external limiting layer, while the nuclei of the neurosensory cone cells were displaced closer to the pigment epithelium. After experimental GMF compensation, the masu salmon fry retina reaction was unusual: the neurosensory cone cell nuclei adhered to the external limiting membrane, while the nuclei of the neurosensory rod cells were displaced closer to the pigment epithelium layer. Double and central neurosensory cone cells occupied the position that was inadequate to normal reaction to twilight: the bodies of these cells were considerably elongated, and the external segments reached the pigment epithelium layer. Thus, in the experiment with GMF compensation, we have found the unusual structure of the retina, which only vaguely corresponded to a reaction to mesopic adaptation. The results suggest, that the visible light is not a unique variety of the electromagnetic field, that could be perceived by the fish retina.

Home Page: NYS Government Information Locator Service: New York State

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Constitution external link - from the New York State Department of State NYS Judicial System (NYS Unified Courts System) Unified Court System external link - the main resource for information about New York's decisions of the New York courts in the Official Reports. The searchable Legal Research Portal external link

External tank project new technology plan. [development of space shuttle external tank system

NASA Technical Reports Server (NTRS)

1973-01-01

A production plan for the space shuttle external tank configuration is presented. The subjects discussed are: (1) the thermal protection system, (2) thermal coating application techniques, (3) manufacturing and tooling, (4) propulsion system configurations and components, (5) low temperature rotating and sliding joint seals, (6) lightning protection, and (7) nondestructive testing technology.

SU-E-T-247: Determinations of the Optimal Phase for Respiratory Gated Radiotherapy From Statistical Analysis Using a Visible Guidance System

DOE Office of Scientific and Technical Information (OSTI.GOV)

Oh, S; Yea, J; Kang, M

Purpose: Respiratory gated radiation therapy (RGRT) is used to minimize the radiation dose to normal tissue in lung cancer patients. Determination of the optimal point in the respiratory phase of a patient is important in RGRT but it is not easy. The goal of the present study was to see if a visible guidance system is helpful in determining the optimal phase in respiratory gated therapy. Methods: The breathing signals of 23 lung cancer patients were recorded with a Real-time Position Management (RPM) respiratory gating system (Varian, USA). The patients underwent breathing training with our visible guidance system, after whichmore » their breathing signals were recorded during 5 min of free breathing and 5 min of guided breathing. The breathing signals recorded between 3 and 5 min before and after training were compared. We performed statistical analysis of the breathing signals to find the optimal duty cycle in guided breathing for RGRT. Results: The breathing signals aided by the visible guidance system had more regular cycles over time and smaller variations in the positions of the marker block than the free breathing signals. Of the 23 lung cancer patients, 19 showed statistically significant differences by time when the values obtained before and after breathing were compared (p < 0.05); 30% and 40% of the duty cycle, respectively, was determined to be the most effective, and the corresponding phases were 30 60% (duty cycle, 30%; p < 0.05) and 30 70% (duty cycle, 40%; p < 0.05). Conclusion: Respiratory regularity was significantly improved with the use of the RPM with our visible guiding system; therefore, it would help improve the accuracy and efficiency of RGRT.« less

Enhanced/synthetic vision and head-worn display technologies for terminal maneuvering area NextGen operations

NASA Astrophysics Data System (ADS)

Arthur, Jarvis J., III; Prinzel, Lawrence J., III; Williams, Steven P.; Bailey, Randall E.; Shelton, Kevin J.; Norman, R. Mike

2011-06-01

NASA is researching innovative technologies for the Next Generation Air Transportation System (NextGen) to provide a "Better-Than-Visual" (BTV) capability as adjunct to "Equivalent Visual Operations" (EVO); that is, airport throughputs equivalent to that normally achieved during Visual Flight Rules (VFR) operations rates with equivalent and better safety in all weather and visibility conditions including Instrument Meteorological Conditions (IMC). These new technologies build on proven flight deck systems and leverage synthetic and enhanced vision systems. Two piloted simulation studies were conducted to access the use of a Head-Worn Display (HWD) with head tracking for synthetic and enhanced vision systems concepts. The first experiment evaluated the use a HWD for equivalent visual operations to San Francisco International Airport (airport identifier: KSFO) compared to a visual concept and a head-down display concept. A second experiment evaluated symbology variations under different visibility conditions using a HWD during taxi operations at Chicago O'Hare airport (airport identifier: KORD). Two experiments were conducted, one in a simulated San Francisco airport (KSFO) approach operation and the other, in simulated Chicago O'Hare surface operations, evaluating enhanced/synthetic vision and head-worn display technologies for NextGen operations. While flying a closely-spaced parallel approach to KSFO, pilots rated the HWD, under low-visibility conditions, equivalent to the out-the-window condition, under unlimited visibility, in terms of situational awareness (SA) and mental workload compared to a head-down enhanced vision system. There were no differences between the 3 display concepts in terms of traffic spacing and distance and the pilot decision-making to land or go-around. For the KORD experiment, the visibility condition was not a factor in pilot's rating of clutter effects from symbology. Several concepts for enhanced implementations of an unlimited field-of-regard BTV concept for low-visibility surface operations were determined to be equivalent in pilot ratings of efficacy and usability.

Enhanced/Synthetic Vision and Head-Worn Display Technologies for Terminal Maneuvering Area NextGen Operations

NASA Technical Reports Server (NTRS)

Arthur, Jarvis J., III; Prinzell, Lawrence J.; Williams, Steven P.; Bailey, Randall E.; Shelton, Kevin J.; Norman, R. Mike

2011-01-01

NASA is researching innovative technologies for the Next Generation Air Transportation System (NextGen) to provide a "Better-Than-Visual" (BTV) capability as adjunct to "Equivalent Visual Operations" (EVO); that is, airport throughputs equivalent to that normally achieved during Visual Flight Rules (VFR) operations rates with equivalent and better safety in all weather and visibility conditions including Instrument Meteorological Conditions (IMC). These new technologies build on proven flight deck systems and leverage synthetic and enhanced vision systems. Two piloted simulation studies were conducted to access the use of a Head-Worn Display (HWD) with head tracking for synthetic and enhanced vision systems concepts. The first experiment evaluated the use a HWD for equivalent visual operations to San Francisco International Airport (airport identifier: KSFO) compared to a visual concept and a head-down display concept. A second experiment evaluated symbology variations under different visibility conditions using a HWD during taxi operations at Chicago O'Hare airport (airport identifier: KORD). Two experiments were conducted, one in a simulated San Francisco airport (KSFO) approach operation and the other, in simulated Chicago O'Hare surface operations, evaluating enhanced/synthetic vision and head-worn display technologies for NextGen operations. While flying a closely-spaced parallel approach to KSFO, pilots rated the HWD, under low-visibility conditions, equivalent to the out-the-window condition, under unlimited visibility, in terms of situational awareness (SA) and mental workload compared to a head-down enhanced vision system. There were no differences between the 3 display concepts in terms of traffic spacing and distance and the pilot decision-making to land or go-around. For the KORD experiment, the visibility condition was not a factor in pilot's rating of clutter effects from symbology. Several concepts for enhanced implementations of an unlimited field-of-regard BTV concept for low-visibility surface operations were determined to be equivalent in pilot ratings of efficacy and usability.

Spectroscopic imaging of limiter heat and particle fluxes and the resulting impurity sources during Wendelstein 7-X startup plasmas.

PubMed

Stephey, L; Wurden, G A; Schmitz, O; Frerichs, H; Effenberg, F; Biedermann, C; Harris, J; König, R; Kornejew, P; Krychowiak, M; Unterberg, E A

2016-11-01

A combined IR and visible camera system [G. A. Wurden et al., "A high resolution IR/visible imaging system for the W7-X limiter," Rev. Sci. Instrum. (these proceedings)] and a filterscope system [R. J. Colchin et al., Rev. Sci. Instrum. 74, 2068 (2003)] were implemented together to obtain spectroscopic data of limiter and first wall recycling and impurity sources during Wendelstein 7-X startup plasmas. Both systems together provided excellent temporal and spatial spectroscopic resolution of limiter 3. Narrowband interference filters in front of the camera yielded C-III and H α photon flux, and the filterscope system provided H α , H β , He-I, He-II, C-II, and visible bremsstrahlung data. The filterscopes made additional measurements of several points on the W7-X vacuum vessel to yield wall recycling fluxes. The resulting photon flux from both the visible camera and filterscopes can then be compared to an EMC3-EIRENE synthetic diagnostic [H. Frerichs et al., "Synthetic plasma edge diagnostics for EMC3-EIRENE, highlighted for Wendelstein 7-X," Rev. Sci. Instrum. (these proceedings)] to infer both a limiter particle flux and wall particle flux, both of which will ultimately be used to infer the complete particle balance and particle confinement time τ P .

Design of visible and IR infrared dual-band common-path telescope system

NASA Astrophysics Data System (ADS)

Guo, YuLin; Yu, Xun; Tao, Yu; Jiang, Xu

2018-01-01

The use of visible and IR infrared dual-band combination can effectively improve the performance of photoelectric detection system,TV and IR system were designed with the common path by the common reflection optical system.A TV/IR infrared common-caliber and common-path system is designed,which can realize the Remote and all-day information.For the 640×512 cooled focal plane array,an infrared middle wave system was presented with a focal length of 600mm F number of 4 field of view(FOV) of 0.38°×0.43°, the system uses optical passive thermal design, has o compact structure and can meet 100% cold shield efficiency,meanwhile it meets the design requirements of lightweight and athermalization. For the 1920×1080 pixels CCD,a visible (TV) system ,which had 500mm focal length, 4F number,was completed.The final optical design along with their modulation transfer function is presented,showing excellent imaging performance in dual-band at the temperature range between -40° and 60°.

Optical Fiber Illumination System for visual flight simulation

NASA Technical Reports Server (NTRS)

Hollow, R. H.

1981-01-01

An electronically controlled lighting system simulating runway, aircraft carrier, and landing aid lights for flight simulations is described. The various colored lights that would be visible to a pilot by day, at dusk, or at night are duplicated at the distances the lights would normally become visible. Plastic optical fiber illuminators using tungsten halogen lights are distributed behind the model. The tips of the fibers of illuminators simulating runway lights are bevelled in order that they may be seen from long distances and at low angles. Fibers representing taxiway lights are pointed and polished for omni-directional visibility. The electronic intensity controls, which can be operated either manually or remotely, regulate the intensity of the lights to simulate changes in distance. A dichronic mirror, infrared filter system is used to maintain color integrity.

Evaluation of guardrail embedded lighting system in Trinidad, Colorado.

DOT National Transportation Integrated Search

2014-02-01

This report provides information on the design considerations of the embedded highway lighting : design on Interstate-25 in Trinidad, Colorado, in terms of visibility. The information is based on : visibility characterizations of small targets using ...

Archeological treasures protection based on early forest wildfire multi-band imaging detection system

NASA Astrophysics Data System (ADS)

Gouverneur, B.; Verstockt, S.; Pauwels, E.; Han, J.; de Zeeuw, P. M.; Vermeiren, J.

2012-10-01

Various visible and infrared cameras have been tested for the early detection of wildfires to protect archeological treasures. This analysis was possible thanks to the EU Firesense project (FP7-244088). Although visible cameras are low cost and give good results during daytime for smoke detection, they fall short under bad visibility conditions. In order to improve the fire detection probability and reduce the false alarms, several infrared bands are tested ranging from the NIR to the LWIR. The SWIR and the LWIR band are helpful to locate the fire through smoke if there is a direct Line Of Sight. The Emphasis is also put on the physical and the electro-optical system modeling for forest fire detection at short and longer ranges. The fusion in three bands (Visible, SWIR, LWIR) is discussed at the pixel level for image enhancement and for fire detection.

1 × 4 MMI visible light wavelength demultiplexer based on a GaN slot-waveguide structure

NASA Astrophysics Data System (ADS)

Shoresh, Tamir; Katanov, Nadav; Malka, Dror

2018-07-01

High transmission losses are the key problem that limits the performance of visible light communication systems, which work on wavelength division multiplexing (WDM) technology. To overcome this problem, we propose a novel design for a 1 × 4 optical demultiplexer based on the multimode interference in a slot-waveguide structure that operates at 547 nm, 559 nm, 566 nm, and 584 nm. Gallium nitride and silicon oxide were found to be excellent materials for the slot-waveguide structure. Simulation results showed that the proposed device can transmit four channels that work in the visible light range with a low transmission loss of 0.983-1.423 dB, crosstalk of 13.8-18.3 dB, and bandwidth of 1.8-3.2 nm. Thus, this device can be very useful in visible light networking systems, which work on the WDM technology.

A simple and high-resolution stereolithography-based 3D bioprinting system using visible light crosslinkable bioinks.

PubMed

Wang, Zongjie; Abdulla, Raafa; Parker, Benjamin; Samanipour, Roya; Ghosh, Sanjoy; Kim, Keekyoung

2015-12-22

Bioprinting is a rapidly developing technique for biofabrication. Because of its high resolution and the ability to print living cells, bioprinting has been widely used in artificial tissue and organ generation as well as microscale living cell deposition. In this paper, we present a low-cost stereolithography-based bioprinting system that uses visible light crosslinkable bioinks. This low-cost stereolithography system was built around a commercial projector with a simple water filter to prevent harmful infrared radiation from the projector. The visible light crosslinking was achieved by using a mixture of polyethylene glycol diacrylate (PEGDA) and gelatin methacrylate (GelMA) hydrogel with eosin Y based photoinitiator. Three different concentrations of hydrogel mixtures (10% PEG, 5% PEG + 5% GelMA, and 2.5% PEG + 7.5% GelMA, all w/v) were studied with the presented systems. The mechanical properties and microstructure of the developed bioink were measured and discussed in detail. Several cell-free hydrogel patterns were generated to demonstrate the resolution of the solution. Experimental results with NIH 3T3 fibroblast cells show that this system can produce a highly vertical 3D structure with 50 μm resolution and 85% cell viability for at least five days. The developed system provides a low-cost visible light stereolithography solution and has the potential to be widely used in tissue engineering and bioengineering for microscale cell patterning.

Reliable motion detection of small targets in video with low signal-to-clutter ratios

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nichols, S.A.; Naylor, R.B.

1995-07-01

Studies show that vigilance decreases rapidly after several minutes when human operators are required to search live video for infrequent intrusion detections. Therefore, there is a need for systems which can automatically detect targets in live video and reserve the operator`s attention for assessment only. Thus far, automated systems have not simultaneously provided adequate detection sensitivity, false alarm suppression, and ease of setup when used in external, unconstrained environments. This unsatisfactory performance can be exacerbated by poor video imagery with low contrast, high noise, dynamic clutter, image misregistration, and/or the presence of small, slow, or erratically moving targets. This papermore » describes a highly adaptive video motion detection and tracking algorithm which has been developed as part of Sandia`s Advanced Exterior Sensor (AES) program. The AES is a wide-area detection and assessment system for use in unconstrained exterior security applications. The AES detection and tracking algorithm provides good performance under stressing data and environmental conditions. Features of the algorithm include: reliable detection with negligible false alarm rate of variable velocity targets having low signal-to-clutter ratios; reliable tracking of targets that exhibit motion that is non-inertial, i.e., varies in direction and velocity; automatic adaptation to both infrared and visible imagery with variable quality; and suppression of false alarms caused by sensor flaws and/or cutouts.« less

Mandibular kinematics represented by a non-orthogonal floating axis joint coordinate system.

PubMed

Leader, Joseph K; Boston, J Robert; Debski, Richard E; Rudy, Thomas E

2003-02-01

There are many methods used to represent joint kinematics (e.g., roll, pitch, and yaw angles; instantaneous center of rotation; kinematic center; helical axis). Often in biomechanics internal landmarks are inferred from external landmarks. This study represents mandibular kinematics using a non-orthogonal floating axis joint coordinate system based on 3-D geometric models with parameters that are "clinician friendly" and mathematically rigorous. Kinematics data for two controls were acquired from passive fiducial markers attached to a custom dental clutch. The geometric models were constructed from MRI data. The superior point along the arc of the long axis of the condyle was used to define the coordinate axes. The kinematic data and geometric models were registered through fiducial markers visible during both protocols. The mean absolute maxima across the subjects for sagittal rotation, coronal rotation, axial rotation, medial-lateral translation, anterior-posterior translation, and inferior-superior translation were 34.10 degrees, 1.82 degrees, 1.14 degrees, 2.31, 21.07, and 6.95 mm, respectively. All the parameters, except for one subject's axial rotation, were reproducible across two motion recording sessions. There was a linear correlation between sagittal rotation and translation, the dominant motion plane, with approximately 1.5 degrees of rotation per millimeter of translation. The novel approach of combining the floating axis system with geometric models succinctly described mandibular kinematics with reproducible and clinician friendly parameters.

Nervous systems in 3D: a comparison of Caridean, anomuran, and brachyuran zoea-I (Decapoda).

PubMed

Geiselbrecht, Hannes; Melzer, Roland R

2013-12-01

Using serial semi-thin sections and digital 3D-reconstructions we studied the nervous systems of zoea-I larvae in three decapod species, Hippolyte inermis (Leach, 1815), Porcellana platycheles (Pennant, 1777), and Pachygrapsus marmoratus (Fabricius, 1787). These taxa represent three decapod lineages, that is, Caridea, Anomura, and Brachyura, each characterized by specific zoea-I morphology. Special attention was paid to development of ganglia, neuropil composition, and segmental nerves. In all zoeae studied, the overall elements, for example, the segmental ganglia, their neuropils and most of the nerves of the adult decapod nervous system are present. Ongoing differentiation processes are observable as well, most obvious in segments with well-developed limbs the ganglia are in a more advanced stage of differentiation and more voluminous compared to segments with only limb buds or without externally visible limb anlagen. Intra- and interspecific comparisons indicate that neuromere differentiation thus deviates from a simple anterior-posterior gradient as, for example, posterior thoracic neuromeres are less developed than those of the pleon. In addition, the differences in the progress of the development of ganglia between the studied taxa can best be attributed to heterochronic mechanisms. Taxon and stage-specific morphologies indicate that neuronal architecture reflects both, morphogenesis to the adult stage and specific larval adaptions, and provides sets of characters relevant to understanding the corresponding phylogeny. © 2013 Wiley Periodicals, Inc.

High-power LED light sources for optical measurement systems operated in continuous and overdriven pulsed modes

NASA Astrophysics Data System (ADS)

Stasicki, Bolesław; Schröder, Andreas; Boden, Fritz; Ludwikowski, Krzysztof

2017-06-01

The rapid progress of light emitting diode (LED) technology has recently resulted in the availability of high power devices with unprecedented light emission intensities comparable to those of visible laser light sources. On this basis two versatile devices have been developed, constructed and tested. The first one is a high-power, single-LED illuminator equipped with exchangeable projection lenses providing a homogenous light spot of defined diameter. The second device is a multi-LED illuminator array consisting of a number of high-power LEDs, each integrated with a separate collimating lens. These devices can emit R, G, CG, B, UV or white light and can be operated in pulsed or continuous wave (CW) mode. Using an external trigger signal they can be easily synchronized with cameras or other devices. The mode of operation and all parameters can be controlled by software. Various experiments have shown that these devices have become a versatile and competitive alternative to laser and xenon lamp based light sources. The principle, design, achieved performances and application examples are given in this paper.

A single extraction and HPLC procedure for simultaneous analysis of phytosterols, tocopherols and lutein in soybeans.

PubMed

Slavin, Margaret; Yu, Liangli Lucy

2012-12-15

A saponification/extraction procedure and high performance liquid chromatography (HPLC) analysis method were developed and validated for simultaneous analysis of phytosterols, tocopherols and lutein (a carotenoid) in soybeans. Separation was achieved on a phenyl column with a ternary, isocratic solvent system of acetonitrile, methanol and water (48:22.5:29.5, v/v/v). Evaporative light scattering detection (ELSD) was used to quantify β-sitosterol, stigmasterol, campesterol, and α-, δ- and γ-tocopherols, while lutein was quantified with visible light absorption at 450 nm. Peak identification was verified by retention times and spikes with external standards. Standard curves were constructed (R(2)>0.99) to allow for sample quantification. Recovery of the saponification and extraction was demonstrated via analysis of spiked samples. Also, the accuracy of results of four soybeans using the described saponification and HPLC analytical method was validated against existing methods. This method offers a more efficient alternative to individual methods for quantifying lutein, tocopherols and sterols in soybeans. Copyright © 2012 Elsevier Ltd. All rights reserved.

Enhanced chemiluminescent detection scheme for trace vapor sensing in pneumatically-tuned hollow core photonic bandgap fibers.

PubMed

Stolyarov, Alexander M; Gumennik, Alexander; McDaniel, William; Shapira, Ofer; Schell, Brent; Sorin, Fabien; Kuriki, Ken; Benoit, Gilles; Rose, Aimee; Joannopoulos, John D; Fink, Yoel

2012-05-21

We demonstrate an in-fiber gas phase chemical detection architecture in which a chemiluminescent (CL) reaction is spatially and spectrally matched to the core modes of hollow photonic bandgap (PBG) fibers in order to enhance detection efficiency. A peroxide-sensitive CL material is annularly shaped and centered within the fiber's hollow core, thereby increasing the overlap between the emission intensity and the intensity distribution of the low-loss fiber modes. This configuration improves the sensitivity by 0.9 dB/cm compared to coating the material directly on the inner fiber surface, where coupling to both higher loss core modes and cladding modes is enhanced. By integrating the former configuration with a custom-built optofluidic system designed for concomitant controlled vapor delivery and emission measurement, we achieve a limit-of-detection of 100 parts per billion (ppb) for hydrogen peroxide vapor. The PBG fibers are produced by a new fabrication method whereby external gas pressure is used as a control knob to actively tune the transmission bandgaps through the entire visible range during the thermal drawing process.

Measured Polarized Spectral Responsivity of JPSS J1 VIIRS Using the NIST T-SIRCUS

NASA Technical Reports Server (NTRS)

McIntire, Jeff; Young, James B.; Moyer, David; Waluschka, Eugene; Xiong, Xiaoxiong

2015-01-01

Recent pre-launch measurements performed on the Joint Polar Satellite System (JPSS) J1 Visible Infrared Imaging Radiometer Suite (VIIRS) using the National Institute of Standards and Technology (NIST) Traveling Spectral Irradiance and Radiance Responsivity Calibrations Using Uniform Sources (T-SIRCUS) monochromatic source have provided wavelength dependent polarization sensitivity for select spectral bands and viewing conditions. Measurements were made at a number of input linear polarization states (twelve in total) and initially at thirteen wavelengths across the bandpass (later expanded to seventeen for some cases). Using the source radiance information collected by an external monitor, a spectral responsivity function was constructed for each input linear polarization state. Additionally, an unpolarized spectral responsivity function was derived from these polarized measurements. An investigation of how the centroid, bandwidth, and detector responsivity vary with polarization state was weighted by two model input spectra to simulate both ground measurements as well as expected on-orbit conditions. These measurements will enhance our understanding of VIIRS polarization sensitivity, improve the design for future flight models, and provide valuable data to enhance product quality in the post-launch phase.

Evaluation of Equivalent Vision Technologies for Supersonic Aircraft Operations

NASA Technical Reports Server (NTRS)

Kramer, Lynda J.; Williams, Steven P.; Wilz, Susan P.; Arthur, Jarvis J., III; Bailey, Randall E.

2009-01-01

Twenty-four air transport-rated pilots participated as subjects in a fixed-based simulation experiment to evaluate the use of Synthetic/Enhanced Vision (S/EV) and eXternal Vision System (XVS) technologies as enabling technologies for future all-weather operations. Three head-up flight display concepts were evaluated a monochromatic, collimated Head-up Display (HUD) and a color, non-collimated XVS display with a field-of-view (FOV) equal to and also, one significantly larger than the collimated HUD. Approach, landing, departure, and surface operations were conducted. Additionally, the apparent angle-of-attack (AOA) was varied (high/low) to investigate the vertical field-of-view display requirements and peripheral, side window visibility was experimentally varied. The data showed that lateral approach tracking performance and lateral landing position were excellent regardless of the display type and AOA condition being evaluated or whether or not there were peripheral cues in the side windows. Longitudinal touchdown and glideslope tracking were affected by the display concepts. Larger FOV display concepts showed improved longitudinal touchdown control, superior glideslope tracking, significant situation awareness improvements and workload reductions compared to smaller FOV display concepts.

The STS-97 crew meets with the media at Launch Pad 39B

NASA Technical Reports Server (NTRS)

2000-01-01

The STS-97 crew poses for another photo after meeting with the media at the slidewire landing zone. They are, left to right, Commander Brent Jett, Pilot Mike Bloomfield and Mission Specialists Joe Tanner, Marc Garneau and Carlos Noriega. Garneau is with the Canadian Space Agency. The nets suspended behind them are a braking system catch net for the slidewire baskets that provide emergency exit from the orbiter and Fixed Service Structure. The crew is at KSC to take part in Terminal Countdown Demonstration Test activities that include emergency egress training, familiarization with the payload, and a simulated launch countdown. Visible in the background are the solid rocket booster and external tank on Space Shuttle Endeavour. Mission STS-97is the sixth construction flight to the International Space Station. Its payload includes the P6 Integrated Truss Structure and a photovoltaic (PV) module, with giant solar arrays that will provide power to the Station. The mission includes two spacewalks to complete the solar array connections. STS-97 is scheduled to launch Nov. 30 at 10:05 p.m. EST.