Colour gamut enhancement with remote light conversion mechanism

NASA Astrophysics Data System (ADS)

Koseoglu, D.; Sezer, Y. S.; Karsli, K.

2018-01-01

The backlight unit spectrum of liquid crystal displays (LCD) directly affects the colour gamut. With the invention of GaN based blue light emitting diodes (LED), phosphors and quantum dots (QD) have gained considerable scientific interest due to their broad range of applications especially in lighting and display technologies. These phosphors and QDs are used to convert the blue light of the LEDs into white in general lighting. On the other hand, in display systems, they are used to generate red and green bands. There are different application methods such as on-chip and remote configurations. In this study, we concentrate on remote phosphor and QD backlight configurations where the light conversion is done away from the chips. In our display designs, we used GaN based blue LED lateral chips as an excitation source, on the other hand, light conversion layers were placed in backlight units as a thin film for the emission of green and red bands. The mixing ratios of these composite layers were arranged to match the emission spectrum of the blue LEDs and the light conversion layer to the colour filters of the LCD, so that the green, blue, and red bands efficiently widens the colour space. The results were also compared with the on-chip phosphor arrangements.

[Analysis of color gamut of LCD system based on LED backlight with area-controlling technique].

PubMed

Li, Fu-Wen; Jin, Wei-Qi; Shao, Xi-Bin; Zhang, Li-Lei; Wan, Li-Fang

2010-05-01

Color gamut as a significant performance index for display system describes the color reproduction ability IN real scenes. Liquid crystal display (LCD) is the most popular technology in flat panel display. However, conventional cold cathode fluorescent lamp (CCFL) backlight of LCD can not behave high color gamut compared with cathode ray tube (CRT). The common used method of color gamut measuring for LCD system is introduced at the beginning. According to the inner structure and display principle of LCD system, there are three major factors deciding LCD's color gamut: spectral properties of backlight, transmittance properties of color filters and performance of liquid crystal panel. Instead of conventional backlight CCFL, RGB-LED backlight is used for improving color reproduction of LCD display system. Due to the imperfect match between RGB-LED' s spectra and color filter's transmittance, the color filter would reduce the color gamut of LCD system more or less. Therefore, LCD system based on LED backlight with area-control technique is introduced which modifies backlight control signal according to the input signal After analyzing and calculating the spectra of LED backlight which passes through the color filters using method of colorimetry, the area sizes of color gamut triangles of RGB-LED backlight with area-control and RGB-LED backlight without area-control LCD systems are compared and the relationship between color gamut and varying contrast of liquid crystal panel is analyzed. It is indicated that LED backlight with area-control technique can avoid color saturation dropping and have little effects on the contrast variation of liquid crystal panel. In other words, LED backlight with area-control technique relaxes the requirements of both color filter performance and liquid crystal panel. Thus, it is of importance to improve the color gamut of the current LCD system with area-control LED backlight.

Technology of Wide Color Gamut Backlight with Light-Emitting Diode for Liquid Crystal Display Television

NASA Astrophysics Data System (ADS)

Kakinuma, Koichiro

2006-05-01

The development of light-emitting diode (LED) backlight a wide-color-gamut and mercury-free has become active in liquid crystal display (LCD) industry. Reports on the development of backlights, such as a direct illumination-type back-light and a guided light illumination-type LED backlight were published. The fabrication of an actual commercial product has been progressing under this active development. Sony Corporation launched an LED-backlit LCD television (TV) model, dubbed QUALIA 005, the world’s first home-use television featuring LED backlighting. This product offers a very wide color reproduction range, delivering a color gamut of 150% of that typically achieved by conventional televisions. In this paper, the background of the development of the LED backlight system “TriluminosTM” and the technologies used to realize the wide color gamut are discussed. The main issues to be solved for the commercialization were how to reduce the brightness/color non uniformity of the backlight and how to treat heat generation from the LED. The standardization of wide color space definition xvYCC and LED backlight LCD television combination is expected to result in a more vivid and correct color expression, and a forecast that extends to the market in the future.

Bit-mapped Holograms Using Phase Transition Mastering (PTM) and Blu-ray Disks

NASA Astrophysics Data System (ADS)

Barnhart, Donald

2013-02-01

Due to recent advances made in data storage, cloud computing, and Blu-ray mastering technology, it is now straight forward to calculate, store, transfer, and print bitmapped holograms that use terabytes of data and tera-pixels of information. This presentation reports on the potential of using the phase transition mastering (PTM) process to construct bitmapped, computer generated holograms with spatial resolutions of 5000 line-pairs/mm (70 nm pixel width). In particular, for Blu-ray disk production, Sony has developed a complete process that could be alternately deployed in holographic applications. The PTM process uses a 405 nm laser to write phase patterns onto a layer of imperfect transition metal oxides that is deposited onto an 8 inch silicon wafer. After the master hologram has been constructed, its imprint can then be cheaply mass produced with the same process as Blu-ray disks or embossed holograms. Unlike traditional binary holograms made with expensive e-beam lithography, the PTM process has the potential for multiple phase levels using inexpensive optics similar to consumer-grade desktop Blu-ray writers. This PTM process could revolutionise holography for entertainment, industrial, and scientific applications.

Masked-backlighter technique used to simultaneously image x-ray absorption and x-ray emission from an inertial confinement fusion plasma.

PubMed

Marshall, F J; Radha, P B

2014-11-01

A method to simultaneously image both the absorption and the self-emission of an imploding inertial confinement fusion plasma has been demonstrated on the OMEGA Laser System. The technique involves the use of a high-Z backlighter, half of which is covered with a low-Z material, and a high-speed x-ray framing camera aligned to capture images backlit by this masked backlighter. Two strips of the four-strip framing camera record images backlit by the high-Z portion of the backlighter, while the other two strips record images aligned with the low-Z portion of the backlighter. The emission from the low-Z material is effectively eliminated by a high-Z filter positioned in front of the framing camera, limiting the detected backlighter emission to that of the principal emission line of the high-Z material. As a result, half of the images are of self-emission from the plasma and the other half are of self-emission plus the backlighter. The advantage of this technique is that the self-emission simultaneous with backlighter absorption is independently measured from a nearby direction. The absorption occurs only in the high-Z backlit frames and is either spatially separated from the emission or the self-emission is suppressed by filtering, or by using a backlighter much brighter than the self-emission, or by subtraction. The masked-backlighter technique has been used on the OMEGA Laser System to simultaneously measure the emission profiles and the absorption profiles of polar-driven implosions.

Reduced-thickness backlighter for autostereoscopic display and display using the backlighter

NASA Technical Reports Server (NTRS)

Eichenlaub, Jesse B (Inventor); Gruhlke, Russell W (Inventor)

1999-01-01

A reduced-thickness backlighter for an autostereoscopic display is disclosed having a lightguide and at least one light source parallel to an edge of the lightguide so as to be substantially coplanar with the lightguide. The lightguide is provided with a first surface which has a plurality of reflective linear regions, such as elongated grooves or glossy lines, parallel to the illuminated edge of the lightguide. Preferably the lightguide further has a second surface which has a plurality of lenticular lenses for reimaging the reflected light from the linear regions into a series of thin vertical lines outside the guide. Because of the reduced thickness of the backlighter system, autostereoscopic viewing is enabled in applications requiring thin backlighter systems. In addition to taking up less space, the reduced-thickness backlighter uses less lamps and less power. For accommodating 2-D applications, a 2-D diffuser plate or a 2-D lightguide parallel to the 3-D backlighter is disclosed for switching back and forth between 3-D viewing and 2-D viewing.

Pediatric fatality from gun bluing solution: the need for a chemical equivalent of the one-pill-can-kill list.

PubMed

Chomchai, Chulathida; Sirisamut, Thanakorn; Silpasupagornwong, Uraiwan

2012-06-01

Gun bluing solution is commonly used to polish guns and prevent rusting. The authors report a case of a 2-year-old boy who inadvertently ingested approximately 15 ml of his father's Fox Gun Blue solution. The patient subsequently developed acidosis, hypotension, and coma. He died within four hours after ingestion. His plasma selenium level was 857 ng/ml. A brief review of other reported ingestion of gun bluing liquid in both adults and children is also included.

A Long-Term Counterinsurgency Strategy

DTIC Science & Technology

2010-01-01

The New York Times, October 13, 2001, quoted in Dunlap, “Making Revolutionary Change: Airpower in COIN Today,” 59. 44. Such as JDAM and GBU - 39 Small Diameter Bomb (SDB). 45. Such as the BLU-109 and BLU-116.

76 FR 56796 - In the Matter of Certain Devices for Improving Uniformity Used in a Backlight Module and...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-09-14

... Taiwan and ITRI International Inc. of San Jose, California. A letter supplementing the complaint was... (``the `932 patent''). The complaint further alleges that an industry in the United States exists as... patent, and whether an industry in the United States exists as required by subsection (a)(2) of section...

Improved LED backlight with unique color and intensity control and NVIS capability

NASA Astrophysics Data System (ADS)

Herman, Robert; Zagar, Pete; Ulijasz, Ted; Hansen, Hans C.; Ellner, Fred

2006-05-01

Currently deployed conventional flat panel AMLCD displays employ fluorescent lamp backlights to achieve the required lighting levels for cockpits in high performance aircraft. Advances have been made in backlighting technology by replacing fluorescent lamps with high performance LEDs. However, these new LED-based backlights are lacking in control of color and luminance intensity especially when related to NVIS requirements in a cockpit. This paper describes a unique integration of LED, electronic, and optical components to meet the requirements of high performance aircraft over their extreme range of operating environments. The LED-based backlight utilizes state-of-art components to enable daylight, night, and NVIS requirements to be implemented in a simple cost-effective package. The performance results presented highlight the advantages of this new design when compared to currently available backlighting designs. Techniques as described in section 2 of this paper are covered under patent application to the US and International Patent Offices.

Array-on-a-disk? How Blu-ray technology can be applied to molecular diagnostics.

PubMed

Morais, Sergi; Tortajada-Genaro, Luis; Maquieira, Angel

2014-09-01

This editorial comments on the balance and perspectives of compact disk technology applied to molecular diagnostics. The development of sensitive, rapid and multiplex assays using Blu-ray technology for the determination of biomarkers, drug allergens, pathogens and detection of infections would have a direct impact on diagnostics. Effective tests for use in clinical, environmental and food applications require versatile and low-cost platforms as well as cost-effective detectors. Blu-ray technology accomplishes those requirements and advances on the concept of high density arrays for massive screening to achieve the demands of point of care or in situ analysis.

E-Cigarette Market Trends in Traditional U.S. Retail Channels, 2012–2013

PubMed Central

Hammond, David; Corey, Catherine G.; Ambrose, Bridget K.; Delnevo, Cristine D.

2015-01-01

Introduction: E-cigarette sales continue to increase in the United States. To date, little surveillance research has documented the specific product attributes driving growth. This study uses national market scanner data to describe sales trends in traditional U.S. tobacco retail channels between 2012 and 2013 and identifies product features associated with sales increases. Methods: Data on e-cigarette sales in convenience stores, drug stores, grocery stores, and mass merchandisers in the United States were obtained from the Nielsen Company. Each product was coded for attributes such as brand, flavor, and unit size. Total sales volume, market share, and percent growth were calculated for various product attributes. Results: E-cigarette sales more than doubled between 2012 and 2013, from $273.6 million to $636.2 million, respectively. Growth was particularly strong in the convenience store channel. Blu eCigs quickly emerged as the best-selling brand and in 2013 constituted nearly half (44.1%) of overall sales. Although fruit-flavored and other flavored products experienced marked growth, unflavored and menthol e-cigarettes overwhelmingly dominated the market. Sales of single unit products (likely disposable e-cigarettes) increased by 216.4%, a much faster rate than multi-unit packs and cartridge refills. Conclusions: In traditional U.S. retail channels, particularly the convenience store channel, sales of e-cigarettes continue to grow, with brands like blu and disposable products as the likely drivers. Given the rapidly-changing market, expanded surveillance is needed to monitor sales not only in traditional retail locations, but sales online and in specialty “vape shops,” as well. PMID:25542918

78 FR 3916 - Certain Blu-Ray Disc Players, Components Thereof and Products Containing the Same; Termination of...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-01-17

... INTERNATIONAL TRADE COMMISSION [Investigation No. 337-TA-824] Certain Blu-Ray Disc Players.... International Trade Commission. ACTION: Notice. SUMMARY: Notice is hereby given that the U.S. International Trade Commission has determined not to review the presiding administrative law judge's (``ALJ'') initial...

Color dependence with horizontal-viewing angle and colorimetric characterization of two displays using different backlighting

NASA Astrophysics Data System (ADS)

Castro, José J.; Pozo, Antonio M.; Rubiño, Manuel

2013-11-01

In this work we studied the color dependence with a horizontal-viewing angle and colorimetric characterization of two liquid-crystal displays (LCD) using two different backlighting: Cold Cathode Fluorescent Lamps (CCFLs) and light-emitting diodes (LEDs). The LCDs studied had identical resolution, size, and technology (TFT - thin film transistor). The colorimetric measurements were made with the spectroradiometer SpectraScan PR-650 following the procedure recommended in the European guideline EN 61747-6. For each display, we measured at the centre of the screen the chromaticity coordinates at horizontal viewing angles of 0, 20, 40, 60 and 80 degrees for the achromatic (A), red (R), green (G) and blue (B) channels. Results showed a greater color-gamut area for the display with LED backlight, compared with the CCFL backlight, showing a greater range of colors perceptible by human vision. This color-gamut area diminished with viewing angle for both displays. Higher differences between trends for viewing angles were observed in the LED-backlight, especially for the R- and G-channels, demonstrating a higher variability of the chromaticity coordinates with viewing angle. The best additivity was reached by the LED-backlight display (a lower error percentage). LED-backlight display provided better color performance of visualization.

Evaluation of simulation alternatives for the brute-force ray-tracing approach used in backlight design

NASA Astrophysics Data System (ADS)

Desnijder, Karel; Hanselaer, Peter; Meuret, Youri

2016-04-01

A key requirement to obtain a uniform luminance for a side-lit LED backlight is the optimised spatial pattern of structures on the light guide that extract the light. The generation of such a scatter pattern is usually performed by applying an iterative approach. In each iteration, the luminance distribution of the backlight with a particular scatter pattern is analysed. This is typically performed with a brute-force ray-tracing algorithm, although this approach results in a time-consuming optimisation process. In this study, the Adding-Doubling method is explored as an alternative way for evaluating the luminance of a backlight. Due to the similarities between light propagating in a backlight with extraction structures and light scattering in a cloud of light scatterers, the Adding-Doubling method which is used to model the latter could also be used to model the light distribution in a backlight. The backlight problem is translated to a form upon which the Adding-Doubling method is directly applicable. The calculated luminance for a simple uniform extraction pattern with the Adding-Doubling method matches the luminance generated by a commercial raytracer very well. Although successful, no clear computational advantage over ray tracers is realised. However, the dynamics of light propagation in a light guide as used the Adding-Doubling method, also allow to enhance the efficiency of brute-force ray-tracing algorithms. The performance of this enhanced ray-tracing approach for the simulation of backlights is also evaluated against a typical brute-force ray-tracing approach.

Accountability: The Ethics of Devising a Practice-as-Research Performance with Learning-Disabled Practitioners

ERIC Educational Resources Information Center

Leighton, Fran

2009-01-01

This article discusses the dilemmas encountered by non-disabled performance researchers and practitioners working with learning-disabled people. I demonstrate how the "accounts" of empirical social scientists informed my PARIP [practice-as-research-in-performance] project, "BluYesBlu," and how Judith Butler's reformulation of the concept of…

78 FR 39691 - Closed Captioning of Internet Protocol-Delivered Video Programming: Implementation of the Twenty...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-07-02

... captioning synchronization requirements for covered apparatus, and on how DVD and Blu-ray players can fulfill... captioning capabilities of certain apparatus on which consumers view video programming. DATES: Comments are... synchronization requirements for covered apparatus, and on how DVD and Blu-ray players can fulfill the closed...

Study of optical design of Blu-ray pickup head system with a liquid crystal element.

PubMed

Fang, Yi-Chin; Yen, Chih-Ta; Hsu, Jui-Hsin

2014-10-10

This paper proposes a newly developed optical design and an active compensation method for a Blu-ray pickup head system with a liquid crystal (LC) element. Different from traditional pickup lens design, this new optical design delivers performance as good as the conventional one but has more room for tolerance control, which plays a role in antishaking devices, such as portable Blu-ray players. A hole-pattern electrode and LC optics with external voltage input were employed to generate a symmetric nonuniform electrical field in the LC layer that directs LC molecules into the appropriate gradient refractive index distribution, resulting in the convergence or divergence of specific light beams. LC optics deliver fast and, most importantly, active compensation through optical design when errors occur. Simulations and tolerance analysis were conducted using Code V software, including various tolerance analyses, such as defocus, tilt, and decenter, and their related compensations. Two distinct Blu-ray pickup head system designs were examined in this study. In traditional Blu-ray pickup head system designs, the aperture stop is always set on objective lenses. In the study, the aperture stop is on the LC lens as a newly developed lens. The results revealed that an optical design with aperture stop set on the LC lens as an active compensation device successfully eliminated up to 57% of coma aberration compared with traditional optical designs so that this pickup head lens design will have more space for tolerance control.

Fabrication and performance study of light guide plate for LCD backlight based on quantum-dot scattering microstructure array

NASA Astrophysics Data System (ADS)

Xie, Hongxing; Huang, Jiamin; Ye, Yun; Chen, Enguo; Xu, Sheng

2017-10-01

Light Guide Plate (LGP) plays an irreplaceable role in Liquid Crystal Display (LCD) backlight. LGP with quantum-dot (QD) shows promise in the development of next-generation displays because of QDs' beneficial characteristics. In this paper, we present a novel QD LGP for LCD backlight based on QD scattering microstructure array (SMA), in which the QD net dots are located discretely and arranged in arrays on the bottom surface of LGP. The paper first introduces the QD backlight briefly, then discusses the preparation and fabrication process of the proposed prototype, and finally presents a systematic photometric approach to reveal the remarkable advantages of QD backlight. The white-balance is achieved by adjusting the proportion of the QDs in the mixture and optimizing the R-QD / G-QD ratio. The apparent morphology of QD SMA is characterized by OLYMPUS laser microscope, while the optical properties of QD backlight are investigated by F-4600 fluorescence spectrophotometer and SRC-200M spectrum color luminance meter, respectively. Experimental results show that the white balance can be achieved when the QDs account for a certain proportion about 7% within the mixture, and the ratio of R-QD / G-QD is optimized to about 1:12. The proposed system offers an alternative and feasible method for fabricating QD backlight, which may have great application prospects in the future.

E-Cigarette Market Trends in Traditional U.S. Retail Channels, 2012-2013.

PubMed

Giovenco, Daniel P; Hammond, David; Corey, Catherine G; Ambrose, Bridget K; Delnevo, Cristine D

2015-10-01

E-cigarette sales continue to increase in the United States. To date, little surveillance research has documented the specific product attributes driving growth. This study uses national market scanner data to describe sales trends in traditional U.S. tobacco retail channels between 2012 and 2013 and identifies product features associated with sales increases. Data on e-cigarette sales in convenience stores, drug stores, grocery stores, and mass merchandisers in the United States were obtained from the Nielsen Company. Each product was coded for attributes such as brand, flavor, and unit size. Total sales volume, market share, and percent growth were calculated for various product attributes. E-cigarette sales more than doubled between 2012 and 2013, from $273.6 million to $636.2 million, respectively. Growth was particularly strong in the convenience store channel. Blu eCigs quickly emerged as the best-selling brand and in 2013 constituted nearly half (44.1%) of overall sales. Although fruit-flavored and other flavored products experienced marked growth, unflavored and menthol e-cigarettes overwhelmingly dominated the market. Sales of single unit products (likely disposable e-cigarettes) increased by 216.4%, a much faster rate than multi-unit packs and cartridge refills. In traditional U.S. retail channels, particularly the convenience store channel, sales of e-cigarettes continue to grow, with brands like blu and disposable products as the likely drivers. Given the rapidly-changing market, expanded surveillance is needed to monitor sales not only in traditional retail locations, but sales online and in specialty "vape shops," as well. © The Author 2014. Published by Oxford University Press on behalf of the Society for Research on Nicotine and Tobacco. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

77 FR 9899 - 36(b)(1) Arms Sales Notification

Federal Register 2010, 2011, 2012, 2013, 2014

2012-02-21

... Medium Range Air-to-Air Missiles, 42 GBU-49 Enhanced PAVEWAY II 500 lb Bombs, 200 GBU-54 (2000 lb) Laser Joint Direct Attack Munitions (JDAM) Bombs, 642 BLU-111 (500 lb) General Purpose Bombs, 127 MK-82 (500 lb) General Purpose Bombs, 80 BLU-117 (2000 lb) General Purpose Bombs, 4 MK-84 (2000 lb) Inert...

Spectral measurements of asymmetrically irradiated capsule backlighters

DOE PAGES

Keiter, P. A.; Drake, R. P.

2016-09-09

Capsule backlighters provide a quasi-continuum x-ray spectrum over a wide range of photon energies. Ideally one irradiates the capsule backlighter symmetrically, however, in complex experimental geometries, this is not always possible. In recent experiments we irradiated capsule backlighters asymmetrically and measured the x-ray spectrum from multiple directions. We will present time-integrated spectra over the photon energy range of ~2-13 keV and time-resolved spectra over the photon energy range of ~2-3 keV. Lastly, we will compare the spectra from different lines of sight to determine if the laser asymmetry results in an angular dependence in the x-ray emission.

Power management of direct-view LED backlight for liquid crystal display

NASA Astrophysics Data System (ADS)

Lee, Xuan-Hao; Lin, Che-Chu; Chang, Yu-Yu; Chen, He-Xiang; Sun, Ching-Cherng

2013-03-01

In this paper, we present a study of management of power in function of luminous efficacy of white LED as well as the efficiency enhancement of the direct-view backlight with photon recycling. A cavity efficiency as high as 90.7% is demonstrated for a direct-view backlight with photon recycling. In the future, with a 90% backlight cavity, luminous efficacy of 200 lm/W for white LEDs, and a transmission efficiency of 10% for the liquid crystal panel, the required power of LEDs could be only 16 W. Up to 85% energy saving could be achieved in comparison to the power of the current liquid crystal display.

Gold sputtered Blu-Ray disks as novel and cost effective sensors for surface enhanced Raman spectroscopy

NASA Astrophysics Data System (ADS)

Nieuwoudt, Michél. K.; Martin, Jacob W.; Oosterbeek, Reece N.; Novikova, Nina I.; Wang, Xindi; Malmström, Jenny; Williams, David E.; Simpson, M. C.

2015-03-01

Surface Enhanced Raman spectroscopy (SERS) offers sensitive and non-invasive detection of a variety of compounds as well as unparalleled information for establishing the molecular identity of both inorganic and organic compounds, not only in biological fluids but in all other aqueous and non-aqueous media. The localized hotspots produced through SERS at the solution/nanostructure interface of clustered gold or silver nano-particles enables detection levels of parts per trillion. Recent developments in advanced fabrication methods have enabled the manufacture of SERS substrates with repeatable surface nanostructures which provide reproducible quantitative analysis, historically a weakness of the SERS technique. In this paper we describe the novel use of gold sputtered Blu-Ray surfaces as SERS substrates. Blu-Ray disks provide ideal surfaces of SERS substrates with their repeatable and regular nano-gratings. We show that the unique surface features and composition of the recording surface enables the formation of gold nano-islands with nanogaps, simply through gold sputtering, and relate this to a 600 fold signal increase of the melamine Raman signal in aqueous solutions and detection to 68 ppb. Melamine is a triazine compound and appears not only as environmental contaminant in environmental groundwater but also as an adulterant in foods due to its high nitrogen content. We have shown significant SERS signal enhancements for spectra of melamine using gold-sputtered Blu-Ray disk surfaces, with reproducibility of 12%. Blu-Ray disks have a unique combination of design, surface features and composition of the recording surface which makes them ideal for preparation of SERS substrates by gold sputter-coating.

Development of multi-touch panel backlight system

NASA Astrophysics Data System (ADS)

Chomiczewski, J.; Długosz, M.; Godlewski, G.; Kochanowicz, M.

2013-10-01

The paper presents design, simulation analysis, and measurements of parameters of optical multi touch panel backlight system. Comparison of optical technology with commercially available solutions was also performed. The numerical simulation of laser based backlight system was made. The influence of the laser power, beam divergence, and placing reflective surfaces on the uniformity of illumination were examined. Optimal illumination system was used for further studies.

Analysis of a color-matching backlight system using a blazed grating and a lenticular lens array.

PubMed

Son, Chang-Gyun; Gwag, Jin Seok; Lee, Jong Hoon; Kwon, Jin Hyuk

2012-12-20

A high efficiency LCD employing a color-matching backlight system that consists of a collimation lenticular lens sheet, a blazed grating, and a focusing lenticular lens array is proposed and analyzed. The RGB lights that are collimated and dispersed from the collimation lenticular lens sheet and the blazed grating are incident on the RGB color filters by the focusing lenticular lens array. The color-matched transmittance was increased 183% and 121% for divergence angles of 2° and 11°, respectively, compared to a conventional backlight that does not use a blazed grating. The design, simulation, and experimental results for the prototype color-matching backlight system are presented.

Lightweight compact 2D/3D autostereoscopic LCD backlight for games, monitor, and notebook applications

NASA Astrophysics Data System (ADS)

Eichenlaub, Jesse B.

1998-04-01

At the 1997 conference DTI first reported on a low cost, thin, lightweight backlight for LCDs that generates a special illumination pattern to create autostereoscopic 3D images and can switch to conventional diffuse illumination for 2D images. The backlight is thin and efficient enough for use in portable computer and hand held games, as well as thin desktop displays. The system has been embodied in 5' (13 cm) diagonal backlights for gambling machines, and in the 12.1' (31 cm) diagonal DTI Virtual Window(TM) desktop product. During the past year, DTI has improved the technology considerably, reducing crosstalk, increasing efficiency, improving components for mass production, and developing prototypes that move the 3D viewing zones in response to the observer's head position. The paper will describe the 2D/3D backlights, improvements that have been made to their function, and their embodiments within the latest display products and prototypes.

X-ray backlighting of imploding aluminium liners on PTS facility

NASA Astrophysics Data System (ADS)

Yang, Qingguo; Liu, Dongbing; Mu, Jian; Huang, Xianbin; Dan, Jiakun; Xie, Xudong; Deng, Wu; Feng, Shuping; Wang, Meng; Ye, Yan; Peng, Qixian; Li, Zeren

2016-09-01

The x-ray backlighting systems, including a 1.865 keV (Si Heα line) spherically bent crystal imaging system and an ˜8.3 keV (Cu Heα line) point-projection imaging system, newly fielded on the Primary Test Stand facility are introduced and its preliminary experimental results in radiography of the aluminium (Al) liners with seeded sinusoidal perturbations are presented. The x-ray backlighter source is created using a 1 TW, 1 kJ Nd: glass high power laser, kilo-joule laser system, recently constructed at China Academy of Engineering Physics. The ablation melt and instability of the imploding Al liner outer edge under the driving current of ˜7.5 MA are successfully observed using these two backlighting systems, respectively.

Image-classification-based global dimming algorithm for LED backlights in LCDs

NASA Astrophysics Data System (ADS)

Qibin, Feng; Huijie, He; Dong, Han; Lei, Zhang; Guoqiang, Lv

2015-07-01

Backlight dimming can help LCDs reduce power consumption and improve CR. With fixed parameters, dimming algorithm cannot achieve satisfied effects for all kinds of images. The paper introduces an image-classification-based global dimming algorithm. The proposed classification method especially for backlight dimming is based on luminance and CR of input images. The parameters for backlight dimming level and pixel compensation are adaptive with image classifications. The simulation results show that the classification based dimming algorithm presents 86.13% power reduction improvement compared with dimming without classification, with almost same display quality. The prototype is developed. There are no perceived distortions when playing videos. The practical average power reduction of the prototype TV is 18.72%, compared with common TV without dimming.

The Apparent Bluing of Aerosols Near Clouds

NASA Technical Reports Server (NTRS)

Marshak, Alexander

2008-01-01

Numerous studies based on satellite observations have reported that aerosol optical depths increase with increasing cloud cover. Part of the increase comes from the humidification and consequent growth of aerosol particles in the moist cloud environment, but part comes from 3D cloud-radiative transfer effects on the retrieved aerosol properties. Often, discerning whether the observed increases in aerosol optical depths are artifacts or real proves difficult. I describe a simple model that quantifies the enhanced illumination of cloud-free columns in the vicinity of clouds that are used in the aerosol retrievals. This model is based on the assumption that the enhancement in the cloud-free column radiance comes from enhanced Rayleigh scattering that results from the presence of the nearby clouds. This assumption leads to a larger increase of AOT for shorter wavelengths, or to a "bluing" of aerosols near clouds. Examples from the MODIS observations that illustrate the apparent bluing of aerosols near clouds will be discussed.

Laser backlight unit based on a leaky optical fiber

NASA Astrophysics Data System (ADS)

Okuda, Yuuto; Onoda, Kousuke; Fujieda, Ichiro

2012-07-01

A backlight unit is constructed by laying out an optical fiber on a two-dimensional plane and letting the light leak out in a controlled manner. In experiment, we formed multiple grooves on the surface of a plastic optical fiber by pressing a heated knife edge. The depth of the groove determined the percentage of the optical power leaking out. The optical fiber with multiple grooves was embedded in an acrylic plate with a spiral trench, and a diffuser sheet was placed over it. When we injected laser light into the end of the optical fiber, this configuration successfully worked as an area illuminator. However, the coherent nature of the laser light caused severe speckle noise. We evaluated the speckle contrast under darkness, and it varied from 80% to 23%, depending on the lens aperture used to capture the images of the illuminator. We glued an ultrasound generator to the optical fiber to introduce phase modulation for the light propagating inside the optical fiber. In this way, the speckle contrast was reduced by a factor of seven to four. Under room lighting, the speckle noise was made barely noticeable by turning on the ultrasound generator.

Exploration of the fragmentation of laser shock-melted aluminum using x-ray backlighting

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

Zhang, Lin, E-mail: zhanglinbox@263.net, E-mail: zhanglinbox@caep.cn; Li, Ying-Hua; Li, Xue-Mei

The fragmentation of shock-melted metal material is an important scientific problem in shock physics and is suitable for experimentally investigating by the laser-driven x-ray backlighting technique. This letter reports on the exploration of laser shock-melted aluminum fragmentation by means of x-ray backlighting at the SGII high energy facility in China. High-quality and high-resolution radiographs with negligible motion blur were obtained and these images enabled analysis of the mass distribution of the fragmentation product.

A 7.2 keV spherical x-ray crystal backlighter for two-frame, two-color backlighting at Sandia's Z Pulsed Power Facility

NASA Astrophysics Data System (ADS)

Schollmeier, M. S.; Knapp, P. F.; Ampleford, D. J.; Harding, E. C.; Jennings, C. A.; Lamppa, D. C.; Loisel, G. P.; Martin, M. R.; Robertson, G. K.; Shores, J. E.; Smith, I. C.; Speas, C. S.; Weis, M. R.; Porter, J. L.; McBride, R. D.

2017-10-01

Many experiments on Sandia National Laboratories' Z Pulsed Power Facility—a 30 MA, 100 ns rise-time, pulsed-power driver—use a monochromatic quartz crystal backlighter system at 1.865 keV (Si He α ) or 6.151 keV (Mn He α ) x-ray energy to radiograph an imploding liner (cylindrical tube) or wire array z-pinch. The x-ray source is generated by the Z-Beamlet laser, which provides two 527-nm, 1 kJ, 1-ns laser pulses. Radiographs of imploding, thick-walled beryllium liners at convergence ratios CR above 15 [ C R = r i ( 0 ) / r i ( t ) ] using the 6.151-keV backlighter system were too opaque to identify the inner radius r i of the liner with high confidence, demonstrating the need for a higher-energy x-ray radiography system. Here, we present a 7.242 keV backlighter system using a Ge(335) spherical crystal with the Co He α resonance line. This system operates at a similar Bragg angle as the existing 1.865 keV and 6.151 keV backlighters, enhancing our capabilities for two-color, two-frame radiography without modifying the system integration at Z. The first data taken at Z include 6.2-keV and 7.2-keV two-color radiographs as well as radiographs of low-convergence (CR about 4-5), high-areal-density liner implosions.

A 7.2 keV spherical x-ray crystal backlighter for two-frame, two-color backlighting at Sandia’s Z Pulsed Power Facility

DOE PAGES

Schollmeier, M. S.; Knapp, P. F.; Ampleford, D. J.; ...

2017-10-10

Many experiments on Sandia National Laboratories’ Z Pulsed Power Facility—a 30 MA, 100 ns rise-time, pulsed-power driver—use a monochromatic quartz crystal backlighter system at 1.865 keV (Si He α) or 6.151 keV (Mn He α) x-ray energy to radiograph an imploding liner (cylindrical tube) or wire array z-pinch. The x-ray source is generated by the Z-Beamlet laser, which provides two 527-nm, 1 kJ, 1-ns laser pulses. Radiographs of imploding, thick-walled beryllium liners at convergence ratios C R above 15 [C R=r i(0)/r i(t)] using the 6.151-keV backlighter system were too opaque to identify the inner radius ri of the linermore » with high confidence, demonstrating the need for a higher-energy x-ray radiography system. Here, we present a 7.242 keV backlighter system using a Ge(335) spherical crystal with the Co He α resonance line. This system operates at a similar Bragg angle as the existing 1.865 keV and 6.151 keV backlighters, enhancing our capabilities for two-color, two-frame radiography without modifying the system integration at Z. The first data taken at Z include 6.2-keV and 7.2-keV two-color radiographs as well as radiographs of low-convergence (C R about 4-5), high-areal-density liner implosions.« less

A 7.2 keV spherical x-ray crystal backlighter for two-frame, two-color backlighting at Sandia’s Z Pulsed Power Facility

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

Schollmeier, M. S.; Knapp, P. F.; Ampleford, D. J.

Many experiments on Sandia National Laboratories’ Z Pulsed Power Facility—a 30 MA, 100 ns rise-time, pulsed-power driver—use a monochromatic quartz crystal backlighter system at 1.865 keV (Si He α) or 6.151 keV (Mn He α) x-ray energy to radiograph an imploding liner (cylindrical tube) or wire array z-pinch. The x-ray source is generated by the Z-Beamlet laser, which provides two 527-nm, 1 kJ, 1-ns laser pulses. Radiographs of imploding, thick-walled beryllium liners at convergence ratios C R above 15 [C R=r i(0)/r i(t)] using the 6.151-keV backlighter system were too opaque to identify the inner radius ri of the linermore » with high confidence, demonstrating the need for a higher-energy x-ray radiography system. Here, we present a 7.242 keV backlighter system using a Ge(335) spherical crystal with the Co He α resonance line. This system operates at a similar Bragg angle as the existing 1.865 keV and 6.151 keV backlighters, enhancing our capabilities for two-color, two-frame radiography without modifying the system integration at Z. The first data taken at Z include 6.2-keV and 7.2-keV two-color radiographs as well as radiographs of low-convergence (C R about 4-5), high-areal-density liner implosions.« less

Possibilities for retracing of copyright violations on current video game consoles by optical disk analysis

NASA Astrophysics Data System (ADS)

Irmler, Frank; Creutzburg, Reiner

2014-02-01

This paper deals with the possibilities of retracing copyright violations on current video game consoles (e.g. Microsoft Xbox, Sony PlayStation, ...) by studying the corresponding optical storage media DVD and Blu-ray. The possibilities of forensic investigation of DVD and Blu-ray Discs are presented. It is shown which information can be read by using freeware and commercial software for forensic examination. A detailed analysis is given on the visualization of hidden content and the possibility to find out information about the burning hardware used for writing on the optical discs. In connection with a forensic analysis of the Windows registry of a suspects PC a detailed overview of the crime scene for forged DVD and Blu-ray Discs can be obtained. Optical discs are examined under forensic aspects and the obtained results are implemented into automatic analysis scripts for the commercial forensics program EnCase Forensic. It is shown that for the optical storage media a possibility of identification of the drive used for writing can be obtained. In particular Blu-ray Discs contain the serial number of the burner. These and other findings were incorporated into the creation of various EnCase scripts for the professional forensic investigation with EnCase Forensic. Furthermore, a detailed flowchart for a forensic investigation of copyright infringement was developed.

LED-driven backlights for automotive displays

NASA Astrophysics Data System (ADS)

Strauch, Frank

2007-09-01

As a light source the LED has some advantage over the traditionally used fluorescence tube such as longer life or lower space consumption. Consequently customers are asking for the LED lighting design in their products. We introduced in a company owned backlight the white LED technology. This step opens the possibility to have access to the components in the display market. Instead of having a finalized display product which needs to be integrated in the head unit of a car we assemble the backlight, the glass, own electronics and the housing. A major advantage of this concept is the better control of the heat flow generated by the LEDs to the outer side because only a common housing is used for all the components. Also the requirement for slim products can be fulfilled. As always a new technology doesn't come with advantages only. An LED represents a point source compared to the well-known tube thus requiring a mixing zone for the multiple point sources when they enter a light guide. This zone can't be used in displays because of the lack of homogeneity. It's a design goal to minimize this zone which can be helped by the right choice of the LED in terms of slimness. A step ahead is the implementation of RGB LEDs because of their higher color rendering abilities. This allows for the control of the chromaticity point under temperature change but as a drawback needs a larger mixing zone.

Dynamics of backlight luminance for using smartphone in dark environment

NASA Astrophysics Data System (ADS)

Na, Nooree; Jang, Jiho; Suk, Hyeon-Jeong

2014-02-01

This study developed dynamic backlight luminance, which gradually changes as time passes for comfortable use of a smartphone display in a dark environment. The study was carried out in two stages. In the first stage, a user test was conducted to identify the optimal luminance by assessing the facial squint level, subjective glare evaluation, eye blink frequency and users' subjective preferences. Based on the results of the user test, the dynamics of backlight luminance was designed. It has two levels of luminance: the optimal level for initial viewing to avoid sudden glare or fatigue to users' eyes, and the optimal level for constant viewing, which is comfortable, but also bright enough for constant reading of the displayed material. The luminance for initial viewing starts from 10 cd/m2, and it gradually increases to 40 cd/m2 for users' visual comfort at constant viewing for 20 seconds; In the second stage, a validation test on dynamics of backlight luminance was conducted to verify the effectiveness of the developed dynamics. It involving users' subjective preferences, eye blink frequency, and brainwave analysis using the electroencephalogram (EEG) to confirm that the proposed dynamic backlighting enhances users' visual comfort and visual cognition, particularly for using smartphones in a dark environment.

Subjective quality of video sequences rendered on LCD with local backlight dimming at different lighting conditions

NASA Astrophysics Data System (ADS)

Mantel, Claire; Korhonen, Jari; Pedersen, Jesper M.; Bech, Søren; Andersen, Jakob Dahl; Forchhammer, Søren

2015-01-01

This paper focuses on the influence of ambient light on the perceived quality of videos displayed on Liquid Crystal Display (LCD) with local backlight dimming. A subjective test assessing the quality of videos with two backlight dimming methods and three lighting conditions, i.e. no light, low light level (5 lux) and higher light level (60 lux) was organized to collect subjective data. Results show that participants prefer the method exploiting local dimming possibilities to the conventional full backlight but that this preference varies depending on the ambient light level. The clear preference for one method at the low light conditions decreases at the high ambient light, confirming that the ambient light significantly attenuates the perception of the leakage defect (light leaking through dark pixels). Results are also highly dependent on the content of the sequence, which can modulate the effect of the ambient light from having an important influence on the quality grades to no influence at all.

Short pulse, high resolution, backlighters for point projection high-energy radiography at the National Ignition Facility

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

Tommasini, R.; Bailey, C.; Bradley, D. K.

High-resolution, high-energy X-ray backlighters are very active area of research for radiography experiments at the National Ignition Facility (NIF) [Miller et al., Nucl. Fusion 44, S228 (2004)], in particular those aiming at obtaining Compton-scattering produced radiographs from the cold, dense fuel surrounding the hot spot. We report on experiments to generate and characterize point-projection-geometry backlighters using short pulses from the advanced radiographic capability (ARC) [Crane et al., J. Phys. 244, 032003 (2010); Di Nicola et al., Proc. SPIE 2015, 93450I-12], at the NIF, focused on Au micro-wires. We show the first hard X-ray radiographs, at photon energies exceeding 60 keV,more » of static objects obtained with 30 ps-long ARC laser pulses, and the measurements of strength of the X-ray emission, the pulse duration and the source size of the Au micro-wire backlighters. For the latter, a novel technique has been developed and successfully applied.« less

Short pulse, high resolution, backlighters for point projection high-energy radiography at the National Ignition Facility

NASA Astrophysics Data System (ADS)

Tommasini, R.; Bailey, C.; Bradley, D. K.; Bowers, M.; Chen, H.; Di Nicola, J. M.; Di Nicola, P.; Gururangan, G.; Hall, G. N.; Hardy, C. M.; Hargrove, D.; Hermann, M.; Hohenberger, M.; Holder, J. P.; Hsing, W.; Izumi, N.; Kalantar, D.; Khan, S.; Kroll, J.; Landen, O. L.; Lawson, J.; Martinez, D.; Masters, N.; Nafziger, J. R.; Nagel, S. R.; Nikroo, A.; Okui, J.; Palmer, D.; Sigurdsson, R.; Vonhof, S.; Wallace, R. J.; Zobrist, T.

2017-05-01

High-resolution, high-energy X-ray backlighters are very active area of research for radiography experiments at the National Ignition Facility (NIF) [Miller et al., Nucl. Fusion 44, S228 (2004)], in particular those aiming at obtaining Compton-scattering produced radiographs from the cold, dense fuel surrounding the hot spot. We report on experiments to generate and characterize point-projection-geometry backlighters using short pulses from the advanced radiographic capability (ARC) [Crane et al., J. Phys. 244, 032003 (2010); Di Nicola et al., Proc. SPIE 2015, 93450I-12], at the NIF, focused on Au micro-wires. We show the first hard X-ray radiographs, at photon energies exceeding 60 keV, of static objects obtained with 30 ps-long ARC laser pulses, and the measurements of strength of the X-ray emission, the pulse duration and the source size of the Au micro-wire backlighters. For the latter, a novel technique has been developed and successfully applied.

Short pulse, high resolution, backlighters for point projection high-energy radiography at the National Ignition Facility

DOE PAGES

Tommasini, R.; Bailey, C.; Bradley, D. K.; ...

2017-05-09

High-resolution, high-energy X-ray backlighters are very active area of research for radiography experiments at the National Ignition Facility (NIF) [Miller et al., Nucl. Fusion 44, S228 (2004)], in particular those aiming at obtaining Compton-scattering produced radiographs from the cold, dense fuel surrounding the hot spot. We report on experiments to generate and characterize point-projection-geometry backlighters using short pulses from the advanced radiographic capability (ARC) [Crane et al., J. Phys. 244, 032003 (2010); Di Nicola et al., Proc. SPIE 2015, 93450I-12], at the NIF, focused on Au micro-wires. We show the first hard X-ray radiographs, at photon energies exceeding 60 keV,more » of static objects obtained with 30 ps-long ARC laser pulses, and the measurements of strength of the X-ray emission, the pulse duration and the source size of the Au micro-wire backlighters. For the latter, a novel technique has been developed and successfully applied.« less

Crystal and source characterization for the Crystal Backlighter Imager capability at the National Ignition Facility

NASA Astrophysics Data System (ADS)

Krauland, C. M.; Hall, G. N.; Buscho, J. G.; Hibbard, R.; McCarville, T. J.; Lowe-Webb, R.; Ayers, S. L.; Kalantar, D.; Kohut, T.; Kemp, G. E.; Bradley, D. K.; Bell, P.; Landen, O. L.; Brewster, T. N.; Piston, K.

2017-10-01

The Crystal Backlighter Imager (CBI) is a very narrow bandwidth ( 10 eV) x-ray radiography system that uses Bragg reflection from a spherically-curved crystal at near normal incidence. This diagnostic has the capability to image late in an ICF implosion because it only requires the brightness of the backlighter to be larger than the capsule self-emission in that narrow bandwidth. While the limited bandwidth is advantageous for this reason, it also requires that the effective energy of the backlighter atomic line is known to 1 eV accuracy for proper crystal alignment. Any Doppler shift in the line energy must be understood for the imaging system to work. The work presented details characterization experiments done at the Jupiter Laser Facility with a Si (8 6 2) crystal that will be used with a Selenium backlighter in the NIF CBI diagnostic. We used the spherically-bent crystals to image a small ( 200 µm) He α source generated by the Janus laser on a Se foil. Scanning Bragg angles over multiple shots allowed us to map out the spectral line intensity distribution for optimal alignment in NIF. A subsequent Doppler shift measurement using CBI on NIF will also be presented with complementary HYDRA modeling for both experiments. Prepared by LLNL under Contract DE-AC52-07NA27344 and by General Atomics under Contract DE-NA0001808.

Streaked x-ray backlighting with twin-slit imager for study of density profile and trajectory of low-density foam target filled with deuterium liquid

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

Shiraga, H.; Mahigashi, N.; Yamada, T.

2008-10-15

Low-density plastic foam filled with liquid deuterium is one of the candidates for inertial fusion target. Density profile and trajectory of 527 nm laser-irradiated planer foam-deuterium target in the acceleration phase were observed with streaked side-on x-ray backlighting. An x-ray imager employing twin slits coupled to an x-ray streak camera was used to simultaneously observe three images of the target: self-emission from the target, x-ray backlighter profile, and the backlit target. The experimentally obtained density profile and trajectory were in good agreement with predictions by one-dimensional hydrodynamic simulation code ILESTA-1D.

Small-Size High-Current Generators for X-Ray Backlighting

NASA Astrophysics Data System (ADS)

Chaikovsky, S. A.; Artyomov, A. P.; Zharova, N. V.; Zhigalin, A. S.; Lavrinovich, I. V.; Oreshkin, V. I.; Ratakhin, N. A.; Rousskikh, A. G.; Fedunin, A. V.; Fedushchak, V. F.; Erfort, A. A.

2017-12-01

The paper deals with the soft X-ray backlighting based on the X-pinch as a powerful tool for physical studies of fast processes. Proposed are the unique small-size pulsed power generators operating as a low-inductance capacitor bank. These pulse generators provide the X-pinch-based soft X-ray source (hν = 1-10 keV) of micron size at 2-3 ns pulse duration. The small size and weight of pulse generators allow them to be transported to any laboratory for conducting X-ray backlighting of test objects with micron space resolution and nanosecond exposure time. These generators also allow creating synchronized multi-frame radiographic complexes with frame delay variation in a broad range.

Guidelines for application of fluorescent lamps in high-performance avionic backlight systems

NASA Astrophysics Data System (ADS)

Syroid, Daniel D.

1997-07-01

Fluorescent lamps have proven to be well suited for use in high performance avionic backlight systems as demonstrated by numerous production applications for both commercial and military cockpit displays. Cockpit display applications include: Boeing 777, new 737s, F-15, F-16, F-18, F-22, C- 130, Navy P3, NASA Space Shuttle and many others. Fluorescent lamp based backlights provide high luminance, high lumen efficiency, precision chromaticity and long life for avionic active matrix liquid crystal display applications. Lamps have been produced in many sizes and shapes. Lamp diameters range from 2.6 mm to over 20 mm and lengths for the larger diameter lamps range to over one meter. Highly convoluted serpentine lamp configurations are common as are both hot and cold cathode electrode designs. This paper will review fluorescent lamp operating principles, discuss typical requirements for avionic grade lamps, compare avionic and laptop backlight designs and provide guidelines for the proper application of lamps and performance choices that must be made to attain optimum system performance considering high luminance output, system efficiency, dimming range and cost.

A 7.2 keV spherical crystal backlighter system for Sandia's Z Pulsed Power Facility

NASA Astrophysics Data System (ADS)

Schollmeier, M.; Knapp, P. F.; Ampleford, D. J.; Loisel, G. P.; Robertson, G.; Shores, J. E.; Smith, I. C.; Speas, C. S.; Porter, J. L.; McBride, R. D.

2016-10-01

Many experiments on Sandia's Z facility, a 30 MA, 100 ns rise-time, pulsed-power driver, use a monochromatic Quartz crystal imaging backlighter system at 1.865 keV (Si Heα) or 6.151 keV (Mn Heα) x-ray energy to radiograph an imploding liner (cylindrical tube) or wire array. The x-ray source is generated by the Z-Beamlet Laser (ZBL), which provides up to 4.5 kJ at 527 nm during a 6 ns window. Radiographs of an imploding thick-walled Beryllium liner at a convergence ratio of about 20 [CR =Rin . (0) /Rin . (t) ] were too opaque to identify the inner surface of the liner with high confidence, demonstrating the need for a higher-energy x-ray backlighter between 6 and 10 keV. We present the design, test and first application of a Ge (335) spherical crystal x-ray backlighter system using the 7.242 keV Co Heα resonance line. The system operates at an almost identical Bragg angle as the existing 1.865 and 6.151 keV backlighters, enhancing our capabilities such as two-color, two-frame radiography, without changing detector shielding hardware. SAND No: SAND2016-6724 A. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corp., a wholly owned subsidiary of Lockheed Martin Corp., for the U.S. DoE NNSA under contract DE-AC04-94AL85000.

Integrated light-guide plates that can control the illumination angle for liquid crystal display backlight system

NASA Astrophysics Data System (ADS)

Feng, Di; Yang, Xingpeng; Jin, Guofan; Yan, Yingbai; Fan, Shoushan

2006-01-01

Liquid crystal displays (LCDs) with edge-lit backlight systems offer several advantages, such as low energy consuming, low weight, and high uniformity of intensity, over traditional cathode-ray tube displays, and make them ideal for many applications including monitors in notebook personal computers, screens for TV, and many portable information terminals, such as mobile phones, personal digital assistants, etc. To satisfy market requirements for mobile and personal display panels, it is more and more necessary to modify the backlight system and make it thinner, lighter, and brighter all at once. In this paper, we have proposed a new integrated LGP based on periodic and aperiodic microprism structures by using polymethyl methacrylate material, which can be designed to control the illumination angle, and to get high uniformity of intensity. So the backlight system will be simplified to use only light sources and one LGP without using other optical sheets, such as reflection sheet, diffusion sheet and prism sheets. By using optimizing program and ray tracing method, the designed LGPs can achieve a uniformity of intensity better than 86%, and get a peak illumination angle from +400 to -200, without requiring other optical sheets. We have designed a backlight system with only one LED light source and one LGP, and other LGP design examples with different sizes (1.8 inches and 14.1 inches) and different light source (LED or CCFL), are performed also.

Recent laser upgrades at Sandia’s Z-backlighter facility in order to accommodate new requirements for magnetized liner inertial fusion on the Z-machine

DOE PAGES

Schwarz, Jens; Rambo, Patrick; Armstrong, Darrell; ...

2016-10-21

The Z-backlighter laser facility primarily consists of two high energy, high-power laser systems. Z-Beamlet laser (ZBL) (Rambo et al., Appl. Opt. 44, 2421 (2005)) is a multi-kJ-class, nanosecond laser operating at 1054 nm which is frequency doubled to 527 nm in order to provide x-ray backlighting of high energy density events on the Z-machine. Z-Petawatt (ZPW) (Schwarz et al., J. Phys.: Conf. Ser. 112, 032020 (2008)) is a petawatt-class system operating at 1054 nm delivering up to 500 J in 500 fs for backlighting and various short-pulse laser experiments (see also Figure 10 for a facility overview). With the developmentmore » of the magnetized liner inertial fusion (MagLIF) concept on the Z-machine, the primary backlighting missions of ZBL and ZPW have been adjusted accordingly. As a result, we have focused our recent efforts on increasing the output energy of ZBL from 2 to 4 kJ at 527 nm by modifying the fiber front end to now include extra bandwidth (for stimulated Brillouin scattering suppression). The MagLIF concept requires a well-defined/behaved beam for interaction with the pressurized fuel. Hence we have made great efforts to implement an adaptive optics system on ZBL and have explored the use of phase plates. We are also exploring concepts to use ZPW as a backlighter for ZBL driven MagLIF experiments. Alternatively, ZPW could be used as an additional fusion fuel pre-heater or as a temporally flexible high energy pre-pulse. All of these concepts require the ability to operate the ZPW in a nanosecond long-pulse mode, in which the beam can co-propagate with ZBL. Finally, some of the proposed modifications are complete and most of them are well on their way.« less

Recent laser upgrades at Sandia’s Z-backlighter facility in order to accommodate new requirements for magnetized liner inertial fusion on the Z-machine

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

Schwarz, Jens; Rambo, Patrick; Armstrong, Darrell

The Z-backlighter laser facility primarily consists of two high energy, high-power laser systems. Z-Beamlet laser (ZBL) (Rambo et al., Appl. Opt. 44, 2421 (2005)) is a multi-kJ-class, nanosecond laser operating at 1054 nm which is frequency doubled to 527 nm in order to provide x-ray backlighting of high energy density events on the Z-machine. Z-Petawatt (ZPW) (Schwarz et al., J. Phys.: Conf. Ser. 112, 032020 (2008)) is a petawatt-class system operating at 1054 nm delivering up to 500 J in 500 fs for backlighting and various short-pulse laser experiments (see also Figure 10 for a facility overview). With the developmentmore » of the magnetized liner inertial fusion (MagLIF) concept on the Z-machine, the primary backlighting missions of ZBL and ZPW have been adjusted accordingly. As a result, we have focused our recent efforts on increasing the output energy of ZBL from 2 to 4 kJ at 527 nm by modifying the fiber front end to now include extra bandwidth (for stimulated Brillouin scattering suppression). The MagLIF concept requires a well-defined/behaved beam for interaction with the pressurized fuel. Hence we have made great efforts to implement an adaptive optics system on ZBL and have explored the use of phase plates. We are also exploring concepts to use ZPW as a backlighter for ZBL driven MagLIF experiments. Alternatively, ZPW could be used as an additional fusion fuel pre-heater or as a temporally flexible high energy pre-pulse. All of these concepts require the ability to operate the ZPW in a nanosecond long-pulse mode, in which the beam can co-propagate with ZBL. Finally, some of the proposed modifications are complete and most of them are well on their way.« less

Loss of heterozygosity and methylation of multiple tumor suppressor genes on chromosome 3 in hepatocellular carcinoma.

PubMed

Zhang, Xiaoying; Li, Hiu Ming; Liu, Zhiyan; Zhou, Gengyin; Zhang, Qinghui; Zhang, Tingguo; Zhang, Jianping; Zhang, Cuijuan

2013-01-01

Genetic and epigenetic alterations are the two key mechanisms in the development of hepatocellular carcinoma (HCC). However, how they contribute to hepatocarcinogenesis and the correlation between them has not been fully elucidated. A total of 48 paired HCCs and noncancerous tissues were used to detect loss of heterozygosity (LOH) and the methylation profiles of five tumor suppressor genes (RASSF1A, BLU, FHIT, CRBP1, and HLTF) on chromosome 3 by using polymerase chain reaction (PCR) and methylation-specific PCR. Gene expression was analyzed by immunohistochemistry and reverse transcription (RT)-PCR. Sixteen of 48 (33.3 %) HCCs had LOH on at least one locus on chromosome 3, and two smallest common deleted regions (3p22.3-24.3 and 3p12.3-14.2) were identified. RASSF1A, BLU, and FHIT showed very high frequencies of methylation in HCCs (100, 81.3, and 64.6 %, respectively) and noncancerous tissues, but not in liver tissues from control patients. Well-differentiated HCCs showed high methylation frequencies of these genes but very low frequencies of LOH. Furthermore, BLU methylation was associated with an increased level of alpha-fetoprotein, and FHIT methylation was inversely correlated with HCC recurrence. In comparison, CRBP1 showed moderate frequencies of methylation, while HLTF showed low frequencies of methylation, and CRBP1 methylation occurred mainly in elderly patients. Treatment with 5-aza-2'-deoxycytidine demethylated at least one of these genes and restored their expression in a DNA methylation-dependent or -independent manner. Hypermethylation of RASSF1A, BLU, and FHIT is a common and very early event in hepatocarcinogenesis; CRBP1 methylation may also be involved in the later stage. Although LOH was not too frequent on chromosome 3, it may play a role as another mechanism in hepatocarcinogenesis.

A broadband proton backlighting platform to probe shock propagation in low-density systems

DOE PAGES

Sio, H.; Hua, R.; Ping, Y.; ...

2017-01-17

A proton backlighting platform has been developed for the study of strong shock propagation in low-density systems in planar geometry. Electric fields at the converging shock front in inertial confinement fusion implosions have been previously observed, demonstrating the presence of—and the need to understand—strong electric fields not modeled in standard radiation-hydrodynamic simulations. In this planar configuration, long-pulse ultraviolet lasers are used to drive a strong shock into a gas-cell target, while a short-pulse proton backlighter side-on radiographs the shock propagation. Finally, the capabilities of the platform are presented here. Future experiments will vary shock strength and gas fill, to probemore » shock conditions at different Z and T e.« less

A multi-directional backlight for a wide-angle, glasses-free three-dimensional display.

PubMed

Fattal, David; Peng, Zhen; Tran, Tho; Vo, Sonny; Fiorentino, Marco; Brug, Jim; Beausoleil, Raymond G

2013-03-21

Multiview three-dimensional (3D) displays can project the correct perspectives of a 3D image in many spatial directions simultaneously. They provide a 3D stereoscopic experience to many viewers at the same time with full motion parallax and do not require special glasses or eye tracking. None of the leading multiview 3D solutions is particularly well suited to mobile devices (watches, mobile phones or tablets), which require the combination of a thin, portable form factor, a high spatial resolution and a wide full-parallax view zone (for short viewing distance from potentially steep angles). Here we introduce a multi-directional diffractive backlight technology that permits the rendering of high-resolution, full-parallax 3D images in a very wide view zone (up to 180 degrees in principle) at an observation distance of up to a metre. The key to our design is a guided-wave illumination technique based on light-emitting diodes that produces wide-angle multiview images in colour from a thin planar transparent lightguide. Pixels associated with different views or colours are spatially multiplexed and can be independently addressed and modulated at video rate using an external shutter plane. To illustrate the capabilities of this technology, we use simple ink masks or a high-resolution commercial liquid-crystal display unit to demonstrate passive and active (30 frames per second) modulation of a 64-view backlight, producing 3D images with a spatial resolution of 88 pixels per inch and full-motion parallax in an unprecedented view zone of 90 degrees. We also present several transparent hand-held prototypes showing animated sequences of up to six different 200-view images at a resolution of 127 pixels per inch.

Design considerations for a backlight with switchable viewing angles

NASA Astrophysics Data System (ADS)

Fujieda, Ichiro; Takagi, Yoshihiko; Rahadian, Fanny

2006-08-01

Small-sized liquid crystal displays are widely used for mobile applications such as cell phones. Electronic control of a viewing angle range is desired in order to maintain privacy for viewing in public as well as to provide wide viewing angles for solitary viewing. Conventionally, a polymer-dispersed liquid crystal (PDLC) panel is inserted between a backlight and a liquid crystal panel. The PDLC layer either transmits or scatters the light from the backlight, thus providing an electronic control of viewing angles. However, such a display system is obviously thick and expensive. Here, we propose to place an electronically-controlled, light-deflecting device between an LED and a light-guide of a backlight. For example, a liquid crystal lens is investigated for other applications and its focal length is controlled electronically. A liquid crystal phase grating either transmits or diffracts an incoming light depending on whether or not a periodic phase distribution is formed inside its liquid crystal layer. A bias applied to such a device will control the angular distribution of the light propagating inside a light-guide. Output couplers built in the light-guide extract the propagating light to outside. They can be V-shaped grooves, pyramids, or any other structures that can refract, reflect or diffract light. When any of such interactions occur, the output couplers translate the changes in the propagation angles into the angular distribution of the output light. Hence the viewing-angle characteristic can be switched. The designs of the output couplers and the LC devices are important for such a backlight system.

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

Stoeckl, C., E-mail: csto@lle.rochester.edu; Bedzyk, M.; Brent, G.

A high-performance cryogenic DT inertial confinement fusion implosion experiment is an especially challenging backlighting configuration because of the high self-emission of the core at stagnation and the low opacity of the DT shell. High-energy petawatt lasers such as OMEGA EP promise significantly improved backlighting capabilities by generating high x-ray intensities and short emission times. A narrowband x-ray imager with an astigmatism-corrected bent quartz crystal for the Si He{sub α} line at ∼1.86 keV was developed to record backlit images of cryogenic direct-drive implosions. A time-gated recording system minimized the self-emission of the imploding target. A fast target-insertion system capable ofmore » moving the backlighter target ∼7 cm in ∼100 ms was developed to avoid interference with the cryogenic shroud system. With backlighter laser energies of ∼1.25 kJ at a 10-ps pulse duration, the radiographic images show a high signal-to-background ratio of >100:1 and a spatial resolution of the order of 10 μm. The backlit images can be used to assess the symmetry of the implosions close to stagnation and the mix of ablator material into the dense shell.« less

High surface plasmon resonance sensitivity enabled by optical disks.

PubMed

Dou, Xuan; Phillips, Blayne M; Chung, Pei-Yu; Jiang, Peng

2012-09-01

We report a systematic, experimental, and theoretical investigation on the surface plasmon resonance (SPR) sensing using optical disks with different track pitches, including Blu-ray disk (BD), digital versatile disk (DVD), and compact disk (CD). Optical reflection measurements indicate that CD and DVD exhibit much higher SPR sensitivity than BD. Both experiments and finite-difference time-domain simulations reveal that the SPR sensitivity is significantly affected by the diffraction order of the SPR peaks and higher diffraction order results in lower sensitivity. Numerical simulations also show that very high sensitivity (∼1600  nm per refractive index unit) is achievable by CDs.

X-ray imaging of fibers

NASA Astrophysics Data System (ADS)

Moosman, B.; Song, Y.; Weathers, L.; Wessel, F.

1996-11-01

A pulsed x-ray backlighter was developed to image exploding wires and cryogenic fibers. The x-ray pulse width is between 10-20 ns, with an output of 100-150 mJ, mostly in the Al k-shell (1.486 keV). The backlighter is located 50 cm from the 20-50 micron diameter target (typically, a copper wire). A 15 micron Al filter eliminates UV emission from the backlighter and target. It is placed 3 cm from the target with SB-5 film directly behind it. From the optical density of the film, target absorption and density can be calculated. The spatial resolution of this system is better than 40 microns. The wire is exploded using a 10 kA, 1 microsecond pulser. Analysis with simultaneous Moire imaging will also be presented. Supported by Los Alamos National Laboratories

Single line-of-sight dual energy backlighter for mix width experiments

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

Baker, K. L., E-mail: baker7@llnl.gov; Glendinning, S. G.; Martinez, D.

2014-11-15

We present a diagnostic technique used to spatially multiplex two x-ray radiographs of an object onto a detector along a single line-of-sight. This technique uses a thin, <2 μm, cosputtered backlighter target to simultaneously produce both Ni and Zn He{sub α} emission. A Ni picket fence filter, 500 μm wide bars and troughs, is then placed in front of the detector to pass only the Ni He{sub α} emission in the bar region and both energies in the trough region thereby spatially multiplexing the two radiographs on a single image. Initial experimental results testing the backlighter spectrum are presented alongmore » with simulated images showing the calculated radiographic images though the nickel picket fence filter which are used to measure the mix width in an accelerated nickel foam.« less

The Crystal Backlighter Imager: a spherically-bent crystal imager for radiography on the National Ignition Facility

NASA Astrophysics Data System (ADS)

Hall, Gareth; Krauland, Christine; Buscho, Justin; Hibbard, Robin; McCarville, Thomas; Lowe-Webb, Roger; Ayers, Shannon; Kalantar, Daniel; Kohut, Thomas; Kemp, G. Elijah; Bradley, David; Bell, Perry; Landen, Otto; Brewster, Nathaniel; Piston, Kenneth

2017-10-01

The Crystal Backlighter Imager (CBI) is a quasi-monochromatic, near-normal incidence, spherically-bent crystal imager being developed for the NIF, which will allow ICF capsule implosions to be radiographed close to stagnation for the first time. This has not been possible using the previous pinhole-based area-backlighter configuration, as the self-emission from the capsule hotspot overwhelms the backlighter in the final stages of the implosion. CBI mitigates the broadband self-emission from the capsule hot spot by using the extremely narrow bandwidth (a few eV) inherent to imagers based on near-normal-incidence Bragg x-ray optics. The development of a diagnostic with the capability to image the capsule during the final stages of the implosion (r less than 200um) is important, as it will allow the shape, integrity and density of the shell to be measured, and will allow the evolution of features, such as the fill tube and capsule support structure, to be imaged close to bang time. The concept and operation of the 11.6keV CBI diagnostic will be discussed, and the first results from experiments on the NIF will be presented. Prepared by LLNL under Contract DE-AC52-07NA27344.

New reversing freeform lens design method for LED uniform illumination with extended source and near field

NASA Astrophysics Data System (ADS)

Zhao, Zhili; Zhang, Honghai; Zheng, Huai; Liu, Sheng

2018-03-01

In light-emitting diode (LED) array illumination (e.g. LED backlighting), obtainment of high uniformity in the harsh condition of the large distance height ratio (DHR), extended source and near field is a key as well as challenging issue. In this study, we present a new reversing freeform lens design algorithm based on the illuminance distribution function (IDF) instead of the traditional light intensity distribution, which allows uniform LED illumination in the above mentioned harsh conditions. IDF of freeform lens can be obtained by the proposed mathematical method, considering the effects of large DHR, extended source and near field target at the same time. In order to prove the claims, a slim direct-lit LED backlighting with DHR equal to 4 is designed. In comparison with the traditional lenses, illuminance uniformity of LED backlighting with the new lens increases significantly from 0.45 to 0.84, and CV(RMSE) decreases dramatically from 0.24 to 0.03 in the harsh condition. Meanwhile, luminance uniformity of LED backlighting with the new lens is obtained as high as 0.92 at the condition of extended source and near field. This new method provides a practical and effective way to solve the problem of large DHR, extended source and near field for LED array illumination.

Puffing Topography and Nicotine Intake of Electronic Cigarette Users

PubMed Central

Behar, Rachel Z.; Hua, My; Talbot, Prue

2015-01-01

Background Prior electronic cigarette (EC) topography data are based on two video analyses with limited parameters. Alternate methods for measuring topography are needed to understand EC use and nicotine intake. Objectives This study evaluated EC topography with a CReSS Pocket device and quantified nicotine intake. Methods Validation tests on pressure drop, flow rate, and volume confirmed reliable performance of the CReSS Pocket device. Twenty participants used Blu Cigs and V2 Cigs for 10 minute intervals with a 10–15 minute break between brands. Brand order was reversed and repeated within 7 days Data were analyzed to determine puff duration, puff count, volume, flow rate, peak flow, and inter-puff interval. Nicotine intake was estimated from cartomizer fluid consumption and topography data. Results Nine patterns of EC use were identified. The average puff count and inter-puff interval were 32 puffs and 17.9 seconds. All participants, except one, took more than 20 puffs/10 minutes. The averages for puff duration (2.65 seconds/puff), volume/puff (51ml/puff), total puff volume (1,579 ml), EC fluid consumption (79.6 mg), flow rate (20 ml/s), and peak flow rate (27 ml/s) were determined for 10-minute sessions. All parameters except total puff count were significantly different for Blu versus V2 EC. Total volume for Blu versus V2 was four-times higher than for conventional cigarettes. Average nicotine intake for Blu and V2 across both sessions was 1.2 ± 0.5 mg and 1.4 ± 0.7 mg, respectively, which is similar to conventional smokers. Conclusions EC puffing topography was variable among participants in the study, but often similar within an individual between brands or days. Puff duration, inter-puff interval, and puff volume varied from conventional cigarette standards. Data on total puff volume and nicotine intake are consistent with compensatory usage of EC. These data can contribute to the development of a standard protocol for laboratory testing of EC products. PMID:25664463

Measurement of inflight shell areal density perturbations in NIF capsule implosions near peak velocity

NASA Astrophysics Data System (ADS)

Hammel, B. A.; Pickworth, L.; Smalyuk, V.; Macphee, A.; Scott, H. A.; Robey, H.; Barrios, M.; Regan, S. P.

2015-11-01

Quantitative measurements of shell-RhoR perturbations in capsules near peak implosion velocity (PV) are challenging. An external backlighter samples both sides of the shell, unless a re-entrant cone is used (potentially perturbing implosion). Emission from the hot core, after shock-stagnation and prior to PV, has been used as a self-backlighter, providing a means to sample one side of the capsule. Adding high-Z gas (~ 1% Ar) to the capsule fill in Symcaps (4He), has produced a continuum backlighter with significant increase in emission at photon energies ~ 8 keV over nominal fills. From images of the transmitted self-emission, above and below the K-edge of an internally doped Cu layer, we infer the growth at PV of imposed perturbations (100 nm amplitude, mode 40). Prepared by LLNL under Contract DE-AC52-07NA27344.

The Laser-Driven X-ray Big Area Backlighter (BABL): Design, Optimization, and Evolution

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

Flippo, Kirk Adler; DeVolder, Barbara Gloria; Doss, Forrest William

The Big Area BackLigher (BABL) has been developed for large area laser-driven x-ray backlighting on the National Ignition Facility (NIF), which can be used for general High Energy Density (HED) experiments. The BABL has been optimized via hydrodynamic simulations to produce laser-to-x-ray conversion efficiencies of up to nearly 5%. Lastly, four BABL foil materials, Zn, Fe, V, and Cu, have been used for He-α x ray production.

Visual ergonomic evaluations on four different designs of LED traffic signs

NASA Astrophysics Data System (ADS)

Chen, Yi-Chun; Huang, Ting-Yuan; Lee, Tsung-Xian; Sun, Ching-Cherng

2017-08-01

To investigate the legibility and visual comfort of LED traffic signs, an ergonomic experiment is performed on four custom-designed LED traffic signs, including three self-luminous ones as LED lightbox, LED backlight and regional LED backlight, and one non-self-luminous sign with external LED lighting. The four signs are hanged side-by-side and evaluated by observers through questionnaires. The signage dimension is one-sixth of the real freeway traffic signs, and the observation distance is 25 m. The luminance of three self-luminous signs is 216 cd/m2. The illuminance of external LED lighting is 400 lux on the traffic sign. The ambient illuminance is 2.8 and 6.0 lux in two rounds. The results show that self-luminous traffic signs provide superior legibility, visual comfort and user preference than the non-self-luminous one. Among the three self-luminous signs, regional LED backlight is most susceptible to the ambient illumination. LED lightbox has significantly better preference score than LED backlight under darker ambient lighting. Only LED lightbox has significantly better visual comfort than external LED lighting in the brighter environment. Based on the four LED traffic signs evaluated in this study, we suggest LED lightbox as the prior choice. Further investigations on the effect of ambient illumination and other designs of self-luminous traffic signs are in progress.

The Effects of Space Weathering at UV Wavelengths: S-Class Asteroids

NASA Technical Reports Server (NTRS)

Hendrix, Amanda R.; Vilas, Faith

2006-01-01

We present evidence that space weathering manifests itself at near-UV wavelengths as a bluing of the spectrum, in contrast with the spectral reddening that has been seen at visible-near-IR wavelengths. Furthermore, the effects of space weathering at UV wavelengths tend to appear with less weathering than do the longer wavelength effects, suggesting that the UV wavelength range is a more sensitive indicator of weathering, and thus age. We report results from analysis of existing near-UV (approx.220-350 nm) measurements of S-type asteroids from the International Ultraviolet Explorer and the Hubble Space Telescope and comparisons with laboratory measurements of meteorites to support this hypothesis. Composite spectra of S asteroids are produced by combining UV spacecraft data with ground-based longer wavelength data. At visible-near-IR wavelengths, S-type asteroids are generally spectrally redder (and darker) than ordinary chondrite meteorites, whereas the opposite is generally true at near-UV wavelengths. Similarly, laboratory measurements of lunar samples show that lunar soils (presumably more weathered) are spectrally redder at longer wavelengths, and spectrally bluer at near-UV wavelengths, than less weathered crushed lunar rocks. The UV spectral bluing may be a result of the addition of nanophase iron to the regolith through the weathering process. The UV bluing is most prominent in the 300-400 nm range, where the strong UV absorption edge is degraded with weathering.

Compressibility of two polyvinyl siloxane interocclusal record materials and its effect on mounted cast relationships.

PubMed

Campos, A A; Nathanson, D

1999-10-01

Addition silicones (polyvinyl siloxanes) are universally accepted as accurate and stable impression materials. They have also gained popularity as interocclusal record materials. However, it has not been defined if it is possible to work with polyvinyl siloxanes without changing the recorded maxillomandibular relations. This study examined the compressibility of 2 addition silicones as interocclusal record materials, analyzing the changes of maxillomandibular relations at the condyle region when different compressive forces are used to stabilize articulated casts. Sixteen interocclusal records, obtained from the same patient (8 of each polyvinyl siloxane, Blu-Mousse, Fast Set), were interposed between the patient casts in a new measuring system obtaining 48 curves of load versus maxillomandibular positional changes in 3 axes (x, y, z). These curves were compared with curves obtained with the casts in maximum intercuspation without interocclusal records (reference curves). Analysis of variance was used to compare maxillomandibular positional changes among the 3 groups (n = 48 each): Blu-Mousse, Fast Set, and control group or maximum intercuspation without interocclusal record. There was no significant change in maxillomandibular relations when forces up to 1 kgf were applied to stabilize the casts related by means of Blu-Mousse and Fast Set addition silicone interocclusal records. It is possible to use these polyvinyl siloxanes as interocclusal record materials without changing the recorded maxillomandibular relations.

Backlighting Direct-Drive Cryogenic DT Implosions on OMEGA

NASA Astrophysics Data System (ADS)

Stoeckl, C.

2016-10-01

X-ray backlighting has been frequently used to measure the in-flight characteristics of an imploding shell in both direct- and indirect-drive inertial confinement fusion implosions. These measurements provide unique insight into the early time and stagnation stages of an implosion and guide the modeling efforts to improve the target designs. Backlighting a layered DT implosion on OMEGA is a particular challenge because the opacity of the DT shell is low, the shell velocity is high, the size and wall thickness of the shell is small, and the self-emission from the hot core at the onset of burn is exceedingly bright. A framing-camera-based crystal imaging system with a Si Heα backlighter at 1.865keV driven by 10-ps short pulses from OMEGA EP was developed to meet these radiography challenges. A fast target inserter was developed to accurately place the Si backlighter foil at a distance of 5 mm to the implosion target following the removal of the cryogenic shroud and an ultra-stable triggering system was implemented to reliably trigger the framing camera coincident with the arrival of the OMEGA EP pulse. This talk will report on a series of implosions in which the DT shell is imaged for a range of convergence ratios and in-flight aspect ratios. The images acquired have been analyzed for low-mode shape variations, the DT shell thickness, the level of ablator mixing into the DT fuel (even 0.1% of carbon mix can be reliably inferred), the areal density of the DT shell, and the impact of the support stalk. The measured implosion performance will be compared with hydrodynamic simulations that include imprint (up to mode 200), cross-beam energy transfer, nonlocal thermal transport, and initial low-mode perturbations such as power imbalance and target misalignment. This material is based upon work supported by the Department of Energy National Nuclear Security Administration under Award Number DE-NA0001944.

Low-intensity calibration source for optical imaging systems

NASA Astrophysics Data System (ADS)

Holdsworth, David W.

2017-03-01

Laboratory optical imaging systems for fluorescence and bioluminescence imaging have become widely available for research applications. These systems use an ultra-sensitive CCD camera to produce quantitative measurements of very low light intensity, detecting signals from small-animal models labeled with optical fluorophores or luminescent emitters. Commercially available systems typically provide quantitative measurements of light output, in units of radiance (photons s-1 cm-2 SR-1) or intensity (photons s-1 cm-2). One limitation to current systems is that there is often no provision for routine quality assurance and performance evaluation. We describe such a quality assurance system, based on an LED-illuminated thin-film transistor (TFT) liquid-crystal display module. The light intensity is controlled by pulse-width modulation of the backlight, producing radiance values ranging from 1.8 x 106 photons s-1 cm-2 SR-1 to 4.2 x 1013 photons s-1 cm-2 SR-1. The lowest light intensity values are produced by very short backlight pulses (i.e. approximately 10 μs), repeated every 300 s. This very low duty cycle is appropriate for laboratory optical imaging systems, which typically operate with long-duration exposures (up to 5 minutes). The low-intensity light source provides a stable, traceable radiance standard that can be used for routine quality assurance of laboratory optical imaging systems.

RGB LED with smart control in the backlight and lighting

NASA Astrophysics Data System (ADS)

Ku, Johnson C. S.; Lee, C. J.

2008-02-01

To improve the LED (Light Emitting Diode) efficacy is the major consideration when the backlight and lighting system are implemented. An important source of poor efficacy come from the chip process or heat dissipation. White LED used blue chip with phosphor is the current solution and inadequate for the tunable color temperature system. The use of RGB (Red, Green and Blue) LED with smart control is presented in this study. The resulting coupled optical and thermal shows the better performance when it is synthesized in conjunction with a degree of color mixing technology.

Colorimetric TMPRSS2-ERG Gene Fusion Detection in Prostate Cancer Urinary Samples via Recombinase Polymerase Amplification.

PubMed

Koo, Kevin M; Wee, Eugene J H; Trau, Matt

2016-01-01

TMPRSS2 (Exon 1)-ERG (Exon 4) is the most frequent gene fusion event in prostate cancer (PC), and is highly PC-specific unlike the current serum prostate specific antigen (PSA) biomarker. However, TMPRSS2-ERG levels are currently measured with quantitative reverse-transcription PCR (RT-qPCR) which is time-consuming and requires costly equipment, thus limiting its use in clinical diagnostics. Herein, we report a novel rapid, cost-efficient and minimal-equipment assay named "FusBLU" for detecting TMPRSS2-ERG gene fusions from urine. TMPRSS2-ERG mRNA was amplified by isothermal reverse transcription-recombinase polymerase amplification (RT-RPA), magnetically-isolated, and detected through horseradish peroxidase (HRP)-catalyzed colorimetric reaction. FusBLU was specific for TMPRSS2-ERG mRNA with a low visual detection limit of 10(5) copies. We also demonstrated assay readout versatility on 3 potentially useful platforms. The colorimetric readout was detectable by naked eye for a quick yes/no evaluation of gene fusion presence. On the other hand, a more quantitative TMPRSS2-ERG detection was achievable by absorbance/electrochemical measurements. FusBLU was successfully applied to 12 urinary samples and results were validated by gold-standard RT-qPCR. We also showed that sediment RNA was likely the main source of TMPRSS2-ERG mRNA in urinary samples. We believe that our assay is a potential clinical screening tool for PC and could also have wide applications for other disease-related fusion genes.

LED backlight system with fiber-optic red, green, blue to white color combiner

NASA Astrophysics Data System (ADS)

Kim, Hye R.; Jeong, Yunsong; Lee, Jhang-Woo; Oh, Kyunghwan

2006-09-01

As an application in the backlight system of small LCD display, we realized a pure white light source by mixing red, green, blue (RGB) lights using a 3 X 3 Hard Plastic Cladding Fiber (HPCF) coupler. We also proposed the 0.44 inch LED backlight system with these fiber-optic pure white sources and characterized its illumination characteristics. Using optimized fusion-tapering technique, we fabricated HPCF coupler which combines three input lights over the circularly formed waist. HPCF has the core diameter of 200 μm and clad diameter of 230 μm. The fabricated 3 X 3 HPCF coupler has the perfect uniformity of about 0.3 dB, low insertion loss of 5.5 dB, and low excess loss of 0.8 dB, which shows excellent uniform power splitting ratio. In order to improve the transmission performance, The RGB chip LEDs were butt-coupled directly to the ferruled input ports of the coupler and packaged by TO46-can type. In the produced white color by HPCF coupler, the photometric brightness at the circular endface of outputs of HPCF coupler was in a rage of 10062 ~ 10094 cd/m2. The fiber optic white color combiner provides tunable white sources excluding heat source and having thickness of 200 μm. We also proposed a 0.44 inch LED backlight system with these fiber-optic pure white sources. With the proposed device, we obtain the improved uniformity in luminance distribution and wide color gamut by using the white light mixing red, green and blue lights.

High-efficiency directional backlight design for an automotive display.

PubMed

Chen, Bo-Tsuen; Pan, Jui-Wen

2018-06-01

We propose a high-efficiency directional backlight module (DBM) for automotive display applications. The DBM is composed of light sources, a light guide plate (LGP), and an optically patterned plate (OPP). The LGP has a collimator on the input surface that serves to control the angle of the light emitted to be in the horizontal direction. The OPP has an inverse prism to adjust the light emission angle in the vertical direction. The DBM has a simple structure and high optical efficiency. Compared with conventional backlight systems, the DBM has higher optical efficiency and a suitable viewing angle. This is an improvement in normalized on-axis luminous intensity of 2.6 times and a twofold improvement in optical efficiency. The viewing angles are 100° in the horizontal direction and 35° in the vertical direction. The angle of the half-luminous intensity is 72° in the horizontal direction and 20° in the vertical direction. The uniformity of the illuminance reaches 82%. The DBM is suitable for use in the center information displays of automobiles.

New optical architecture for holographic data storage system compatible with Blu-ray Disc™ system

NASA Astrophysics Data System (ADS)

Shimada, Ken-ichi; Ide, Tatsuro; Shimano, Takeshi; Anderson, Ken; Curtis, Kevin

2014-02-01

A new optical architecture for holographic data storage system which is compatible with a Blu-ray Disc™ (BD) system is proposed. In the architecture, both signal and reference beams pass through a single objective lens with numerical aperture (NA) 0.85 for realizing angularly multiplexed recording. The geometry of the architecture brings a high affinity with an optical architecture in the BD system because the objective lens can be placed parallel to a holographic medium. Through the comparison of experimental results with theory, the validity of the optical architecture was verified and demonstrated that the conventional objective lens motion technique in the BD system is available for angularly multiplexed recording. The test-bed composed of a blue laser system and an objective lens of the NA 0.85 was designed. The feasibility of its compatibility with BD is examined through the designed test-bed.

LLE review. Quarterly report, January 1994--March 1994, Volume 58

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

Simon, A.

1994-07-01

This volume of the LLE Review, covering the period Jan - Mar 1994, contains articles on backlighting diagnostics; the effect of electron collisions on ion-acoustic waves and heat flow; using PIC code simulations for analysis of ultrashort laser pulses interacting with solid targets; creating a new instrument for characterizing thick cryogenic layers; and a description of a large-aperture ring amplifier for laser-fusion drivers. Three of these articles - backlighting diagnostics; characterizing thick cryogenic layers; and large-aperture ring amplifier - are directly related to the OMEGA Upgrade, now under construction. Separate abstracts have been prepared for articles from this report.

Color enhancement for portable LCD displays in low-power mode

NASA Astrophysics Data System (ADS)

Shih, Kuang-Tsu; Huang, Tai-Hsiang; Chen, Homer H.

2011-09-01

Switching the backlight of handheld devices to low power mode saves energy but affects the color appearance of an image. In this paper, we consider the chroma degradation problem and propose an enhancement algorithm that incorporates the CIECAM02 appearance model to quantitatively characterize the problem. In the proposed algorithm, we enhance the color appearance of the image in low power mode by weighted linear superposition of the chroma of the image and that of the estimated dim-backlight image. Subjective tests are carried out to determine the perceptually optimal weighting and prove the effectiveness of our framework.

Accuracy of five intraoral scanners compared to indirect digitalization.

PubMed

Güth, Jan-Frederik; Runkel, Cornelius; Beuer, Florian; Stimmelmayr, Michael; Edelhoff, Daniel; Keul, Christine

2017-06-01

Direct and indirect digitalization offer two options for computer-aided design (CAD)/ computer-aided manufacturing (CAM)-generated restorations. The aim of this study was to evaluate the accuracy of different intraoral scanners and compare them to the process of indirect digitalization. A titanium testing model was directly digitized 12 times with each intraoral scanner: (1) CS 3500 (CS), (2) Zfx Intrascan (ZFX), (3) CEREC AC Bluecam (BLU), (4) CEREC AC Omnicam (OC) and (5) True Definition (TD). As control, 12 polyether impressions were taken and the referring plaster casts were digitized indirectly with the D-810 laboratory scanner (CON). The accuracy (trueness/precision) of the datasets was evaluated by an analysing software (Geomagic Qualify 12.1) using a "best fit alignment" of the datasets with a highly accurate reference dataset of the testing model, received from industrial computed tomography. Direct digitalization using the TD showed the significant highest overall "trueness", followed by CS. Both performed better than CON. BLU, ZFX and OC showed higher differences from the reference dataset than CON. Regarding the overall "precision", the CS 3500 intraoral scanner and the True Definition showed the best performance. CON, BLU and OC resulted in significantly higher precision than ZFX did. Within the limitations of this in vitro study, the accuracy of the ascertained datasets was dependent on the scanning system. The direct digitalization was not superior to indirect digitalization for all tested systems. Regarding the accuracy, all tested intraoral scanning technologies seem to be able to reproduce a single quadrant within clinical acceptable accuracy. However, differences were detected between the tested systems.

Color separation system with angularly positioned light source module for pixelized backlighting.

PubMed

Chen, Po-Chou; Lin, Hui-Hsiung; Chen, Cheng-Huan; Lee, Chi-Hung; Lu, Mao-Hong

2010-01-18

A color-separation system that angularly positions color LEDs to produce color separation and a lens array to focus this light onto the pixels is proposed. The LED rays from different incident angles are mapped into corresponding sub-pixel positions to efficiently display color image, which can be used to replace the absorbing color filter in the conventional liquid crystal layer. In this paper, the prototype backlight has been designed, fabricated and characterized. The measurement results of this module showed that a gain factor of transmission efficiency three times more than that of conventional color filters efficiency improvement and a larger color gamut are expected.

Microscopic video observation of capillary vessel systems using diffuse back lighting

NASA Astrophysics Data System (ADS)

Sakai, Minako; Arai, Hiroki; Iwai, Toshiaki

2017-04-01

We have been developing a simple and practical video microscopy system based on absorption spectra of biological substance to perform spectroscopic observation of living tissues. The diffuse backlighting effect is actively used in the developed system, which is generated by multiple light scattering in the tissue. It is demonstrated that the light specularly reflected from the skin surface can be completely suppressed in the microscopic observation and the biological activity of the capillary vessel systems distributed under the skin can be successfully observed. As a result, we can confirm the effectiveness of the video microscopy system using diffuse backlighting and the applicability of our developed system.

Novel photonics polymer and its application in IT

NASA Astrophysics Data System (ADS)

Koike, Yasuhiro

2003-07-01

In the field of LANs, transmission systems based on a multimode silica fiber network is heading towards capacities of Gb/s. We have proposed a low-loss, high-bandwidth and large-core graded-index plastic optical fiber (GI POF) in data-com. area. We sill show that GI POF enables to virtually eliminate the "modal noise" problem cased by the medium-core silica fibers. Therefore, stable high-speed data transmission is realized by GI POF rather than silica fibers. Furthermore, advent of perfluorinated (PF) polymer based GI POF network can support higher transmission than silica fibers network because of the small material dispersion of PF polymer compared with silica. In addition, we proposed a "highly scattering optical transmission (HSOT) polymer" and applied it to a light guide plate of a liquid crystal display (LCD) backlight. The advanced HSOT polymer backlight that was proposed using the HSOT designing simulation program demonstrated approximately three times higher luminance than the conventional flat-type HSOT backlight of 14.1-inch diagonal because of the microscopic prism structures at the bottom of the advanced HSOT light guide plate. The HSOT polymer containing the optimized heterogeneous structures produced homogeneous scattered light with forward directivity and sufficient color uniformity.

Once in a blue moon: detection of `bluing' during debris transits in the white dwarf WD 1145+017

NASA Astrophysics Data System (ADS)

Hallakoun, N.; Xu, S.; Maoz, D.; Marsh, T. R.; Ivanov, V. D.; Dhillon, V. S.; Bours, M. C. P.; Parsons, S. G.; Kerry, P.; Sharma, S.; Su, K.; Rengaswamy, S.; Pravec, P.; Kušnirák, P.; Kučáková, H.; Armstrong, J. D.; Arnold, C.; Gerard, N.; Vanzi, L.

2017-08-01

The first transiting planetesimal orbiting a white dwarf was recently detected in K2 data of WD 1145+017 and has been followed up intensively. The multiple, long and variable transits suggest the transiting objects are dust clouds, probably produced by a disintegrating asteroid. In addition, the system contains circumstellar gas, evident by broad absorption lines, mostly in the u΄ band, and a dust disc, indicated by an infrared excess. Here we present the first detection of a change in colour of WD 1145+017 during transits, using simultaneous multiband fast-photometry ULTRACAM measurements over the u΄g΄r΄I΄ bands. The observations reveal what appears to be 'bluing' during transits; transits are deeper in the redder bands, with a u΄ - r΄ colour difference of up to ˜-0.05 mag. We explore various possible explanations for the bluing, including limb darkening or peculiar dust properties. 'Spectral' photometry obtained by integrating over bandpasses in the spectroscopic data in and out of transit, compared to the photometric data, shows that the observed colour difference is most likely the result of reduced circumstellar absorption in the spectrum during transits. This indicates that the transiting objects and the gas share the same line of sight and that the gas covers the white dwarf only partially, as would be expected if the gas, the transiting debris and the dust emitting the infrared excess are part of the same general disc structure (although possibly at different radii). In addition, we present the results of a week-long monitoring campaign of the system using a global network of telescopes.

Genetic separation of phototropism and blue light inhibition of stem elongation

NASA Technical Reports Server (NTRS)

Liscum, E.; Young, J. C.; Poff, K. L.; Hangarter, R. P.

1992-01-01

Blue light-induced regulation of cell elongation is a component of the signal response pathway for both phototropic curvature and inhibition of stem elongation in higher plants. To determine if blue light regulates cell elongation in these responses through shared or discrete pathways, phototropism and hypocotyl elongation were investigated in several blue light response mutants in Arabidopsis thaliana. Specifically, the blu mutants that lack blue light-dependent inhibition of hypocotyl elongation were found to exhibit a normal phototropic response. In contrast, a phototropic null mutant (JK218) and a mutant that has a 20- to 30-fold shift in the fluence dependence for first positive phototropism (JK224) showed normal inhibition of hypocotyl elongation in blue light. F1 progeny of crosses between the blu mutants and JK218 showed normal phototropism and inhibition of hypocotyl elongation, and approximately 1 in 16 F2 progeny were double mutants lacking both responses. Thus, blue light-dependent inhibition of hypocotyl elongation and phototropism operate through at least some genetically distinct components.

Bluetooth as a Playful Public Art Interface

NASA Astrophysics Data System (ADS)

Stukoff, Maria N.

This chapter investigates how the application of emergent communication technologies assisted in the design of playful art experience in a public place. Every Passing Moment (EPM), was a mobile public artwork that tracked and recorded any discoverable Bluetooth device to automatically seed a flower in a virtual garden projected onto an urban screen. The EPM was the first public art work to run blu_box, a custom-designed Bluetooth system for mobile telephony. The aim of blu_box was to build a system that supported playful interactions between the public and an urban screen, openly accessible to anyone with a Bluetooth-enabled mobile phone. This participatory engagement was observed in EPM on three levels, namely; unconscious, conscious, and dynamic play. Furthermore, this chapter highlights how sound and face-to-face communication proved imperative in the play dynamics of EPM. In conclusion, this chapter proposes ways in which the use of emergent communication technologies in public places, especially when interfaced with urban screening platforms, can construct playful city spaces for the public at large.

The Corralitos Observatory program for the detection of lunar transient phenomena

NASA Technical Reports Server (NTRS)

Hynek, J. A.; Dunlap, J. R.; Hendry, E. M.

1976-01-01

This is a final report on the establishment, observing procedures, and observational results of a survey program for the detection of lunar transient phenomena (LTP's) by electro-optical image conversion means. For survey, a unique detection system with an image orthicon was used as the primary element in conjunction with a 24-in. f/20 Cassegrainian telescope. Observations in three spectral ranges, with 6,466 man-hours of observing, were actually performed during the period from October 27, 1965, to April 26, 1972. Within this entire period, no color or feature change within the detection capabilities of the instrumentation was observed, either independently or in follow up of amateur LTP reports, with the exception of one general bluing and several localized bluings (probably ascribable to the effects of the terrestrial atmosphere) that were observed solely by the Corralitos system. A table is presented indicating amateur and professional reports of LTP's and the results of efforts to confirm these reports through the Corralitos system.

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

Schollmeier, Marius S.; Geissel, Matthias; Shores, Jonathon E.

We present calculations for the field of view (FOV), image fluence, image monochromaticity, spectral acceptance, and image aberrations for spherical crystal microscopes, which are used as self-emission imaging or backlighter systems at large-scale high energy density physics facilities. Our analytic results are benchmarked with ray-tracing calculations as well as with experimental measurements from the 6.151 keV backlighter system at Sandia National Laboratories. Furthermore, the analytic expressions can be used for x-ray source positions anywhere between the Rowland circle and object plane. We discovered that this enables quick optimization of the performance of proposed but untested, bent-crystal microscope systems to findmore » the best compromise between FOV, image fluence, and spatial resolution for a particular application.« less

A direct-drive exploding-pusher implosion as the first step in development of a monoenergetic charged-particle backlighting platforn at the National Ignition Facility

DOE PAGES

Rosenberg, M. J.; Zylstra, A. B.; Seguin, F. H.; ...

2016-01-18

A thin-glass-shell, D 3He-filled exploding-pusher inertial confinement fusion implosion at the National Ignition Facility (NIF) has been demonstrated as a proton source that serves as a promising first step toward development of a monoenergetic proton, alpha, and triton backlighting platform at the NIF. Among the key measurements, the D3He-proton emission on this experiment (shot N121128) has been well-characterized spectrally, temporally, and in terms of emission isotropy, revealing a highly monoenergetic (ΔE/E~4%) and isotropic source (~3% proton fluence variation and ~0.5% proton energy variation). On a similar shot (N130129, with D 2 fill), the DD-proton spectrum has been obtained as well,more » illustrating that monoenergetic protons of multiple energies may be utilized in a single experiment. In conclusion, these results, and experiments on OMEGA, point toward future steps in the development of a precision, monoenergetic proton, alpha, and triton source that can readily be implemented at the NIF for backlighting a broad range of high energy density physics (HEDP) experiments in which fields and flows are manifest, and also utilized for studies of stopping power in warm dense matter and in classical plasmas.« less

A direct-drive exploding-pusher implosion as the first step in development of a monoenergetic charged-particle backlighting platforn at the National Ignition Facility

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

Rosenberg, M. J.; Zylstra, A. B.; Seguin, F. H.

A thin-glass-shell, D 3He-filled exploding-pusher inertial confinement fusion implosion at the National Ignition Facility (NIF) has been demonstrated as a proton source that serves as a promising first step toward development of a monoenergetic proton, alpha, and triton backlighting platform at the NIF. Among the key measurements, the D3He-proton emission on this experiment (shot N121128) has been well-characterized spectrally, temporally, and in terms of emission isotropy, revealing a highly monoenergetic (ΔE/E~4%) and isotropic source (~3% proton fluence variation and ~0.5% proton energy variation). On a similar shot (N130129, with D 2 fill), the DD-proton spectrum has been obtained as well,more » illustrating that monoenergetic protons of multiple energies may be utilized in a single experiment. In conclusion, these results, and experiments on OMEGA, point toward future steps in the development of a precision, monoenergetic proton, alpha, and triton source that can readily be implemented at the NIF for backlighting a broad range of high energy density physics (HEDP) experiments in which fields and flows are manifest, and also utilized for studies of stopping power in warm dense matter and in classical plasmas.« less

Antioxidant activity, phenolic and anthocyanin contents of various rhubarb (Rheum-spp.) varieties

USDA-ARS?s Scientific Manuscript database

Antioxidant activity (ABTS assay), total phenolics, and total anthocyanins were determined in the petioles of fifteen rhubarb (Rheum spp.) varieties. Antioxidant activity ranged from 491 ± 60 (Victoria 574/27) to 1820 'mol Trolox/g DW (Valentine). The phenolic content varied from 673 ± 41 (Loher Blu...

Janice VanCleave's World: Fluffy and White.

ERIC Educational Resources Information Center

VanCleave, Janice

2000-01-01

Uses charcoal briquettes, ammonia, water, table salt, and laundry bluing to create white fluffy crystals. Briquettes are placed in a bowl while the remaining ingredients are mixed together and poured over the briquettes. The result is white fluffy crystals forming on top of the charcoal. This experiment dramatizes chemical reactions to…

76 FR 12994 - In the Matter of Certain Digital Televisions and Components Thereof, and Certain Electronic...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-03-09

... INTERNATIONAL TRADE COMMISSION [Inv. No. 337-TA-764] In the Matter of Certain Digital Televisions and Components Thereof, and Certain Electronic Devices Having a Blu-Ray Disc Player and Components Thereof; Notice of Investigation AGENCY: U.S. International Trade Commission. ACTION: Institution of...

76 FR 58841 - Certain Digital Televisions and Components Thereof, and Certain Electronic Devices Having a Blu...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-09-22

... INTERNATIONAL TRADE COMMISSION [Investigation No. 337-TA-764] Certain Digital Televisions and... Based on a Settlement Agreement; Termination of Investigation AGENCY: U.S. International Trade Commission. ACTION: Notice. SUMMARY: Notice is hereby given that the U.S. International Trade Commission has...

78 FR 5441 - Ocean Transportation Intermediary License Applicants

Federal Register 2010, 2011, 2012, 2013, 2014

2013-01-25

... Trade Name Blu Logistics. Brutos International Corp. (NVO & OFF), 428 S. Atlantic Blvd., Suite 203, Monterey Park, CA 91754, Officers: Janet Li, Secretary (QI), Jesse Wu, CEO/CFO, Application Type: New NVO..., President (QI), Olen D. Woods, Director, Application Type: New NVO License. Global Logistics New Jersey, LLC...

Optical imaging module for astigmatic detection system

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

Wang, Wei-Min; Cheng, Chung-Hsiang; Department of Mechanical Engineering, National Taiwan University, Taipei 10617, Taiwan

2016-05-15

In this paper, an optical imaging module design for an astigmatic detection system (ADS) is presented. The module is based on a commercial optical pickup unit (OPU) and it contains a coaxial illuminant for illuminating a specimen. Furthermore, the imaging module facilitates viewing the specimen and the detection laser spot of the ADS with a lateral resolution of approximately 1 μm without requiring the removal of an element of the OPU. Two polarizers and one infrared filter are used to eliminate stray laser light in the OPU and stray light produced by the illuminant. Imaging modules designed for digital versatilemore » disks (DVDs) and Blu-ray DVDs were demonstrated. Furthermore, the module can be used for imaging a small cantilever with approximate dimensions of 2 μm (width) × 5 μm (length), and therefore, it has the potential to be used in high-speed atomic force microscopy.« less

Development of a short duration backlit pinhole for radiography on the National Ignition Facility

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

Huntington, C. M.; Krauland, C. M.; Kuranz, C. C.

2010-10-15

Experiments on the National Ignition Facility (NIF) will require bright, short duration, near-monochromatic x-ray backlighters for radiographic diagnosis of many high-energy density systems. This paper details a vanadium pinhole backlighter producing (1.8{+-}0.5)x10{sup 15} x-ray photons into 4{pi} sr near the vanadium He-like characteristic x-ray energy of 5.18 keV. The x-ray yield was quantified from a set of Ross filters imaged to a calibrated image plate, with the Dante diagnostic used to confirm the quasimonochromatic nature of the spectrum produced. Additionally, an x-ray film image shows a source-limited image resolution of 26 {mu}m from a 20 {mu}m diameter pinhole.

Automated platform for determination of LEDs spatial radiation pattern

NASA Astrophysics Data System (ADS)

Vladescu, Marian; Vuza, Dan Tudor

2015-02-01

Nowadays technologies lead to remarkable properties of the light-emitting diodes (LEDs), making them attractive for more and more applications, such as: interior and exterior lighting, outdoor LED panels, traffic signals, automotive (tail and brake lights, backlighting in dashboard and switches), backlighting of display panels, LCD displays, symbols on switches, keyboards, graphic boards and measuring scales. Usually, LEDs are small light sources consisting of a chip placed into a package, which may bring additional optics to this encapsulated ensemble, resulting in a less or more complex spatial distribution of the light intensity, with particular radiation patterns. This paper presents an automated platform designed to allow a quick and accurate determination of the spatial radiation patterns of LEDs encapsulated in various packages. Keywords: LED, luminous

Digital Devices Invade Campus, and Networks Feel the Strain

ERIC Educational Resources Information Center

New, Jake

2013-01-01

Inside campus libraries and dormitory rooms, thousands of students connect to the Internet not only to study with online systems like Blackboard but also to watch movies and TV shows on Netflix. Computers, smartphones, wireless printers, tablets, iPods, Xboxes, handheld gaming systems, e-readers, smart TVs, Blu-ray players--students now bring an…

Metals Emissions from the Open Detonation Treatment of Energetic Wastes

DTIC Science & Technology

2004-10-01

CPIA Publication 477, Vol. I, March 1988. p. 139. 12. Naval Air Warfare Center Weapons Division. "Fragment Breakup Testing of BLU-97 Bomblets with PBXN ...volume at the time the particulate sample was collected was approximately 106 m3. For unknown reasons, the Army did not convert the detonation plume

78 FR 56736 - Certain Digital Media Devices, Including Televisions, Blu-Ray Disc Players, Home Theater Systems...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-09-13

... Intervenor Status to Google, Inc. AGENCY: U.S. International Trade Commission. ACTION: Notice. SUMMARY: Notice is hereby given that the U.S. International Trade Commission has determined not to review an...: Robert Needham, Office of the General Counsel, U.S. International Trade Commission, 500 E Street SW...

76 FR 77014 - Certain Blu-Ray Disc Players; Receipt of Complaint; Solicitation of Comments Relating to the...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-12-09

...; Solicitation of Comments Relating to the Public Interest AGENCY: U.S. International Trade Commission. ACTION: Notice. SUMMARY: Notice is hereby given that the U.S. International Trade Commission has received a... public interest issues raised by the complaint. FOR FURTHER INFORMATION CONTACT: James R. Holbein...

Tempo-spatial dynamics of adult plum curculio (Coleoptera: Curculionidae) based on semiochemical-baited trap captures in blueberries

USDA-ARS?s Scientific Manuscript database

Plum curculio, Conotrachelus nenuphar (Herbst), has become an important pest of highbush blueberries in the northeastern USA. Here, we conducted experiments in 2010-2013 to compare the efficacy of semiochemical-baited traps for C. nenuphar versus conventional (beating cloth) sampling methods in blu...

Binning and filtering: the six-color solution

NASA Astrophysics Data System (ADS)

Ashdown, Ian; Robinson, Shane; Salsbury, Marc

2006-08-01

The use of LED backlighting for LCD displays requires careful binning of red, green, and blue LEDs by dominant wavelength to maintain the color gamuts as specified by NTSC, SMPTE, and EBU/ITU standards. This problem also occurs to a lesser extent with RGB and RGBA assemblies for solid-state lighting, where color gamut consistency is required for color-changing luminaires. In this paper, we propose a "six-color solution," based on Grassman's laws, that does not require color binning, but nevertheless guarantees a fixed color gamut that subsumes the color gamuts of carefully-binned RGB assemblies. A further advantage of this solution is that it solves the problem of peak wavelength shifts with varying junction temperatures. The color gamut can thus remain fixed over the full range of LED intensities and ambient temperatures. A related problem occurs with integrated circuit (IC) colorimeters used for optical feedback with LED backlighting and RGB(A) solid-state lighting, wherein it can be difficult to distinguish between peak wavelength shifts and changes in LED intensity. We apply our six-color solution to the design of a novel colorimeter for LEDs that independently measures changes in peak wavelength and intensity. The design is compatible with current manufacturing techniques for tristimulus colorimeter ICs. Together, the six-color solution for LEDs and colorimeters enables less expensive LED backlighting and solid-state lighting systems with improved color stability.

Endochondral Ossification Is Accelerated in Cholinesterase-Deficient Mice and in Avian Mesenchymal Micromass Cultures

PubMed Central

Spieker, Janine; Mudersbach, Thomas; Vogel-Höpker, Astrid; Layer, Paul G.

2017-01-01

Most components of the cholinergic system are detected in skeletogenic cell types in vitro, yet the function of this system in skeletogenesis remains unclear. Here, we analyzed endochondral ossification in mutant murine fetuses, in which genes of the rate-limiting cholinergic enzymes acetyl- (AChE), or butyrylcholinesterase (BChE), or both were deleted (called here A-B+, A+B-, A-B-, respectively). In all mutant embryos bone growth and cartilage remodeling into mineralizing bone were accelerated, as revealed by Alcian blue (A-blu) and Alizarin red (A-red) staining. In A+B- and A-B- onset of mineralization was observed before E13.5, about 2 days earlier than in wild type and A-B+ mice. In all mutants between E18.5 to birth A-blu staining disappeared from epiphyses prematurely. Instead, A-blu+ cells were dislocated into diaphyses, most pronounced so in A-B- mutants, indicating additive effects of both missing ChEs in A-B- mutant mice. The remodeling effects were supported by in situ hybridization (ISH) experiments performed on cryosections from A-B- mice, in which Ihh, Runx2, MMP-13, ALP, Col-II and Col-X were considerably decreased, or had disappeared between E18.5 and P0. With a second approach, we applied an improved in vitro micromass model from chicken limb buds that allowed histological distinction between areas of cartilage, apoptosis and mineralization. When treated with the AChE inhibitor BW284c51, or with nicotine, there was decrease in cartilage and accelerated mineralization, suggesting that these effects were mediated through nicotinic receptors (α7-nAChR). We conclude that due to absence of either one or both cholinesterases in KO mice, or inhibition of AChE in chicken micromass cultures, there is increase in cholinergic signalling, which leads to increased chondroblast production and premature mineralization, at the expense of incomplete chondrogenic differentiation. This emphasizes the importance of cholinergic signalling in cartilage and bone formation. PMID:28118357

'No power' (green) electrowetting display

NASA Astrophysics Data System (ADS)

Jentsch, Michael; Rawert, Juergen; Jerosch, Dieter; Blankenbach, Karlheinz

2011-05-01

Electrowetting displays were first reported in 1981, several approaches were examined. However, ADT's "Droplet- Driven-Displays" technology is the only bistable one which makes them very attractive for energy-saving systems. That means that the power supply can completely shut off after changing the content and it will keep its information for years. More features that make the ADT approach very unique are paper like white appearance (even in the powerless OFFstate) and the capability for backlighting (most of the other e-paper technologies like electrophoretics can not be backlighted). Further achievements are a white state reflectance of about 70% resulting in sunlight readability and a pixel size in the range from 0.3mm to 10mm. Summarizing, ADT's electrowetting technology is highly suitable for lowest power (means eco-friendly or "green") displays.

Comparisons of NIF convergent ablation simulations with radiograph data.

PubMed

Olson, R E; Hicks, D G; Meezan, N B; Koch, J A; Landen, O L

2012-10-01

A technique for comparing simulation results directly with radiograph data from backlit capsule implosion experiments will be discussed. Forward Abel transforms are applied to the kappa*rho profiles of the simulation. These provide the transmission ratio (optical depth) profiles of the simulation. Gaussian and top hat blurs are applied to the simulated transmission ratio profiles in order to account for the motion blurring and imaging slit resolution of the experimental measurement. Comparisons between the simulated transmission ratios and the radiograph data lineouts are iterated until a reasonable backlighter profile is obtained. This backlighter profile is combined with the blurred, simulated transmission ratios to obtain simulated intensity profiles that can be directly compared with the radiograph data. Examples will be shown from recent convergent ablation (backlit implosion) experiments at the NIF.

Omni-Directional Viewing-Angle Switching through Control of the Beam Divergence Angle in a Liquid Crystal Panel

NASA Astrophysics Data System (ADS)

Baek, Jong-In; Kim, Ki-Han; Kim, Jae Chang; Yoon, Tae-Hoon

2010-01-01

This paper proposes a method of omni-directional viewing-angle switching by controlling the beam diverging angle (BDA) in a liquid crystal (LC) panel. The LCs aligned randomly by in-cell polymer structures diffuse the collimated backlight for the bright state of the wide viewing-angle mode. We align the LCs homogeneously by applying an in-plane field for the narrow viewing-angle mode. By doing this the scattering is significantly reduced so that the small BDA is maintained as it passes through the LC layer. The dark state can be obtained by aligning the LCs homeotropically with a vertical electric field. We demonstrated experimentally the omni-directional switching of the viewing-angle, without an additional panel or backlighting system.

Performance of bent-crystal x-ray microscopes for high energy density physics research

DOE PAGES

Schollmeier, Marius S.; Geissel, Matthias; Shores, Jonathon E.; ...

2015-05-29

We present calculations for the field of view (FOV), image fluence, image monochromaticity, spectral acceptance, and image aberrations for spherical crystal microscopes, which are used as self-emission imaging or backlighter systems at large-scale high energy density physics facilities. Our analytic results are benchmarked with ray-tracing calculations as well as with experimental measurements from the 6.151 keV backlighter system at Sandia National Laboratories. Furthermore, the analytic expressions can be used for x-ray source positions anywhere between the Rowland circle and object plane. We discovered that this enables quick optimization of the performance of proposed but untested, bent-crystal microscope systems to findmore » the best compromise between FOV, image fluence, and spatial resolution for a particular application.« less

M60 Tank Personnel Heater Comparison Test, Fort Carson, Colorado

DTIC Science & Technology

1983-05-01

A study should be made considering the logisites and cost implications of developing a kit to upgrade the Model "C" heater to include self ...l f L Summary of Questionnaire Respose -for BLU (Model "A" with Engine Filter/Heat Tape) System Driver Loader Gunner TC’* " # % # % * % # 9 12. Heat

Effects of pulsed electric fields pretreatment and drying method on drying characteristics and nutritive quality of blueberries

USDA-ARS?s Scientific Manuscript database

Fresh blueberries were pretreated with pulsed electric fields (PEF) at 2 kV/cm and then dried at 45, 60 and 75 degrees C by conventional hot air or vacuum drying. Drying characteristics and changes in contents of moisture, anthocyanin, total phenolics, vitamin C, and antioxidant activity in the blu...

78 FR 36573 - Certain Digital Media Devices, Including Televisions, Blu-Ray Disc Players, Home Theater Systems...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-06-18

... Thereof and Associated Software AGENCY: U.S. International Trade Commission. ACTION: Notice, Institution... thereof and associated software, by reason of infringement of U.S. Patent No. 8,028,323 (``the `323 patent... mobile phones, components thereof and associated software by reason of infringement of one or more of...

Feedback and Assessment in the New Kindergarten Teacher Education in Norway

ERIC Educational Resources Information Center

Haukenes, Marie Brandvoll

2017-01-01

This paper investigates the feedback and assessment routines that are being established in the subject of pedagogy in the new model of Kindergarten Teacher Education (Barnehagelaererutdanning--BLU) in Norway. This scope is chosen due to the particular role of the subject of pedagogy in strengthening the understanding of the practice field, and in…

78 FR 29156 - Certain Digital Media Devices, Including Televisions, Blu-Ray Disc Players, Home Theater Systems...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-05-17

... AGENCY: U.S. International Trade Commission. ACTION: Notice. SUMMARY: Notice is hereby given that the U.S... the complaint or complainant's filing under section 210.8(b) of the Commission's Rules of Practice and Procedure (19 CFR 210.8(b)). FOR FURTHER INFORMATION CONTACT: Lisa R. Barton, Acting Secretary to the...

77 FR 1725 - Certain Blu-Ray Disc Players, Components Thereof and Products Containing Same; Notice of...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-01-11

..., Components Thereof and Products Containing Same; Notice of Institution of Investigation AGENCY: U.S... the U.S. International Trade Commission on December 5, 2011, under section 337 of the Tariff Act of 1930, as amended, 19 U.S.C. 1337, on behalf of Walker Digital, LLC, of Stamford, Connecticut. Letters...

Air Force Flight Evaluation (Systems) of the A-10A Prototype Aircraft

DTIC Science & Technology

1973-03-01

problem was traced to a defective electrical relay. The relay was replaced and no further trouble was experienced. REMARKS: Only MK-82, BLU-l, and BDU...IMPACT (AfIL-STD-88.,) CATEGORY * 711 LIV ~ ESIABE ~ DMAE SUB3SYSTE (-V DEGRADES [3MAINTENANCE R INJURY PERSONN EL M- RESTRICTS 73SYSTEM PERFORMANCE

Capsule implosions for continuum x-ray backlighting of opacity samples at the National Ignition Facility

NASA Astrophysics Data System (ADS)

Opachich, Y. P.; Heeter, R. F.; Barrios, M. A.; Garcia, E. M.; Craxton, R. S.; King, J. A.; Liedahl, D. A.; McKenty, P. W.; Schneider, M. B.; May, M. J.; Zhang, R.; Ross, P. W.; Kline, J. L.; Moore, A. S.; Weaver, J. L.; Flippo, K. A.; Perry, T. S.

2017-06-01

Direct drive implosions of plastic capsules have been performed at the National Ignition Facility to provide a broad-spectrum (500-2000 eV) X-ray continuum source for X-ray transmission spectroscopy. The source was developed for the high-temperature plasma opacity experimental platform. Initial experiments using 2.0 mm diameter polyalpha-methyl styrene capsules with ˜20 μm thickness have been performed. X-ray yields of up to ˜1 kJ/sr have been measured using the Dante multichannel diode array. The backlighter source size was measured to be ˜100 μm FWHM, with ˜350 ps pulse duration during the peak emission stage. Results are used to simulate transmission spectra for a hypothetical iron opacity sample at 150 eV, enabling the derivation of photometrics requirements for future opacity experiments.

Current progress and technical challenges of flexible liquid crystal displays

NASA Astrophysics Data System (ADS)

Fujikake, Hideo; Sato, Hiroto

2009-02-01

We focused on several technical approaches to flexible liquid crystal (LC) display in this report. We have been developing flexible displays using plastic film substrates based on polymer-dispersed LC technology with molecular alignment control. In our representative devices, molecular-aligned polymer walls keep plastic-substrate gap constant without LC alignment disorder, and aligned polymer networks create monostable switching of fast-response ferroelectric LC (FLC) for grayscale capability. In the fabrication process, a high-viscosity FLC/monomer solution was printed, sandwiched and pressed between plastic substrates. Then the polymer walls and networks were sequentially formed based on photo-polymerization-induced phase separation in the nematic phase by two exposure processes of patterned and uniform ultraviolet light. The two flexible backlight films of direct illumination and light-guide methods using small three-primary-color light-emitting diodes were fabricated to obtain high-visibility display images. The fabricated flexible FLC panels were driven by external transistor arrays, internal organic thin film transistor (TFT) arrays, and poly-Si TFT arrays. We achieved full-color moving-image displays using the flexible FLC panel and the flexible backlight film based on field-sequential-color driving technique. Otherwise, for backlight-free flexible LC displays, flexible reflective devices of twisted guest-host nematic LC and cholesteric LC were discussed with molecular-aligned polymer walls. Singlesubstrate device structure and fabrication method using self-standing polymer-stabilized nematic LC film and polymer ceiling layer were also proposed for obtaining LC devices with excellent flexibility.

Atypical gnawing and cage destructive behavior in one strain of laboratory rat.

PubMed

Jacobs, H K; Van Pelt, L F; Dunlap, B K

1984-06-01

Approximately 80% of a colony of 900 Long Evans rats, Blu:(LE), gnawed on polypropylene shoe box type cages around the automatic watering grommet. The gnawing led to cage destruction and escape of the animals. The addition of a large stainless steel shield between the original grommet backing and the cage prevented further gnawing on the cage.

Non-destructive forensic latent fingerprint acquisition with chromatic white light sensors

NASA Astrophysics Data System (ADS)

Leich, Marcus; Kiltz, Stefan; Dittmann, Jana; Vielhauer, Claus

2011-02-01

Non-destructive latent fingerprint acquisition is an emerging field of research, which, unlike traditional methods, makes latent fingerprints available for additional verification or further analysis like tests for substance abuse or age estimation. In this paper a series of tests is performed to investigate the overall suitability of a high resolution off-the-shelf chromatic white light sensor for the contact-less and non-destructive latent fingerprint acquisition. Our paper focuses on scanning previously determined regions with exemplary acquisition parameter settings. 3D height field and reflection data of five different latent fingerprints on six different types of surfaces (HDD platter, brushed metal, painted car body (metallic and non-metallic finish), blued metal, veneered plywood) are experimentally studied. Pre-processing is performed by removing low-frequency gradients. The quality of the results is assessed subjectively; no automated feature extraction is performed. Additionally, the degradation of the fingerprint during the acquisition period is observed. While the quality of the acquired data is highly dependent on surface structure, the sensor is capable of detecting the fingerprint on all sample surfaces. On blued metal the residual material is detected; however, the ridge line structure dissolves within minutes after fingerprint placement.

X-ray absorption spectroscopy of aluminum z-pinch plasma with tungsten backlighter planar wire array source.

PubMed

Osborne, G C; Kantsyrev, V L; Safronova, A S; Esaulov, A A; Weller, M E; Shrestha, I; Shlyaptseva, V V; Ouart, N D

2012-10-01

Absorption features from K-shell aluminum z-pinch plasmas have recently been studied on Zebra, the 1.7 MA pulse power generator at the Nevada Terawatt Facility. In particular, tungsten plasma has been used as a semi-backlighter source in the generation of aluminum K-shell absorption spectra by placing a single Al wire at or near the end of a single planar W array. All spectroscopic experimental results were recorded using a time-integrated, spatially resolved convex potassium hydrogen phthalate (KAP) crystal spectrometer. Other diagnostics used to study these plasmas included x-ray detectors, optical imaging, laser shadowgraphy, and time-gated and time-integrated x-ray pinhole imagers. Through comparisons with previous publications, Al K-shell absorption lines are shown to be from much lower electron temperature (∼10-40 eV) plasmas than emission spectra (∼350-500 eV).

Impact of different cleaning processes on the laser damage threshold of antireflection coatings for Z-Backlighter optics at Sandia National Laboratories

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

Field, Ella; Bellum, John; Kletecka, Damon

We have examined how different cleaning processes affect the laser-induced damage threshold of antireflection coatings for large dimension, Z-Backlighter laser optics at Sandia National Laboratories. Laser damage thresholds were measured after the coatings were created, and again 4 months later to determine which cleaning processes were most effective. There is a nearly twofold increase in laser-induced damage threshold between the antireflection coatings that were cleaned and those that were not cleaned. Aging of the coatings after 4 months resulted in even higher laser-induced damage thresholds. Also, the laser-induced damage threshold results revealed that every antireflection coating had a high defectmore » density, despite the cleaning process used, which indicates that improvements to either the cleaning or deposition processes should provide even higher laser-induced damage thresholds.« less

Error Budgeting

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

Vinyard, Natalia Sergeevna; Perry, Theodore Sonne; Usov, Igor Olegovich

2017-10-04

We calculate opacity from k (hn)=-ln[T(hv)]/pL, where T(hv) is the transmission for photon energy hv, p is sample density, and L is path length through the sample. The density and path length are measured together by Rutherford backscatter. Δk =more » $$\\partial k$$\\ $$\\partial T$$ ΔT + $$\\partial k$$\\ $$\\partial (pL)$$. We can re-write this in terms of fractional error as Δk/k = Δ1n(T)/T + Δ(pL)/(pL). Transmission itself is calculated from T=(U-E)/(V-E)=B/B0, where B is transmitted backlighter (BL) signal and B 0 is unattenuated backlighter signal. Then ΔT/T=Δln(T)=ΔB/B+ΔB 0/B 0, and consequently Δk/k = 1/T (ΔB/B + ΔB$$_0$$/B$$_0$$ + Δ(pL)/(pL). Transmission is measured in the range of 0.2« less

Iron Opacity Platform Performance Characterization at the National Ignition Facility

NASA Astrophysics Data System (ADS)

Opachich, Y. P.; Ross, P. W.; Heeter, R. F.; Barrios, M. A.; Liedahl, D. A.; May, M. J.; Schneider, M. B.; Craxton, R. S.; Garcia, E. M.; McKenty, P. W.; Zhang, R.; Weaver, J. L.; Flippo, K. A.; Kline, J. L.; Perry, T. S.; Los Alamos National Laboratory Collaboration; Naval Research Laboratory Collaboration; University of Rochester LaboratoryLaser Energetics Collaboration; Lawrence Livermore National Lab Collaboration; National Security Technologies, LLC Collaboration

2016-10-01

A high temperature opacity platform has been fielded at the National Ignition Facility (NIF). The platform will be used to study opacity in iron at a temperature of 160 eV. The platform uses a 6 mm diameter hohlraum driven by 128 laser beams with 530 kJ of energy in a 3 ns pulse to heat an iron sample. Absorption spectra of the heated sample are generated with a broadband pulsed X-ray backlighter produced by imploding a vacuum-filled CH shell. The shell is 2 mm in diameter and 20 microns thick, driven by 64 beams with 250 kJ in a 2.5 ns pulse. The hohlraum and backlighter performance have both been investigated recently and will be discussed in this presentation. This work was performed by National Security Technologies, LLC, under Contract No. DE-AC52-06NA25946 with the U.S. Department of Energy. DOE/NV/25946-2892.

Capsule implosions for continuum x-ray backlighting of opacity samples at the National Ignition Facility

DOE PAGES

Opachich, Y. P.; Heeter, R. F.; Barrios, M. A.; ...

2017-06-08

Direct drive implosions of plastic capsules have been performed at the National Ignition Facility to provide a broad-spectrum (500–2000 eV) X-ray continuum source for X-ray transmission spectroscopy. The source was developed for the high-temperature plasma opacity experimental platform. Initial experiments using 2.0 mm diameter polyalpha-methyl styrene capsules with ~20 μm thickness have been performed. X-ray yields of up to ~1 kJ/sr have been measured using the Dante multichannel diode array. The backlighter source size was measured to be ~100 μm FWHM, with ~350 ps pulse duration during the peak emission stage. Lastly, these results are used to simulate transmission spectramore » for a hypothetical iron opacity sample at 150 eV, enabling the derivation of photometrics requirements for future opacity experiments.« less

Fluorescent protein integrated white LEDs for displays

NASA Astrophysics Data System (ADS)

Press, Daniel Aaron; Melikov, Rustamzhon; Conkar, Deniz; Nur Firat-Karalar, Elif; Nizamoglu, Sedat

2016-11-01

The usage time of displays (e.g., TVs, mobile phones, etc) is in general shorter than their functional life time, which worsens the electronic waste (e-waste) problem around the world. The integration of biomaterials into electronics can help to reduce the e-waste problem. In this study, we demonstrate fluorescent protein integrated white LEDs to use as a backlight source for liquid crystal (LC) displays for the first time. We express and purify enhanced green fluorescent protein (eGFP) and monomeric Cherry protein (mCherry), and afterward we integrate these proteins as a wavelength-converter on a blue LED chip. The protein-integrated backlight exhibits a high luminous efficacy of 248 lm/Wopt and the area of the gamut covers 80% of the NTSC color gamut. The resultant colors and objects in the image on the display can be well observed and distinguished. Therefore, fluorescent proteins show promise for display applications.

Lighting, backlighting and watercolor illusions and the laws of figurality.

PubMed

Pinna, Baingio; Reeves, Adam

2006-01-01

We report some novel 'lighting' and 'backlighting' effects in plane figures similar to those which induce the 'watercolor illusion', that is, figures made with outlines composed of juxtaposed parallel lines varying in brightness and chromatic color. These new effects show 'illumination' as an emergent percept, and show how arrangements of 'dark and light' along the boundaries of various plane figures model the volume and strengthen the illusion of depth. To account for these various effects we propose several phenomenological 'laws of figurality' to add to the Gestalt laws of organization and figure-ground segregation. We offer a set of meta-laws which are speculative but which serve to integrate and organize the phenomenological laws. These laws indicate how luminance gradient profiles across boundary contours define both the 3D appearance of figures and the properties of the light reflected from their volumetric shapes.

Electrochromic projection and writing device

DOEpatents

Branz, Howard M.; Benson, David K.

2002-01-01

A display and projection apparatus includes an electrochromic material and a photoconductive material deposited in tandem used in conjunction with a light filtering means for filtering light transmitted through the electrochromic material. When an electric field is applied across the electrochromic material and the photoconductive material, light that is incident onto the photoconductive material through the surface of the projection apparatus causes the photoconductive material to conduct current locally in proportion to the amount of light incident on the photoconductive material. The flow of current causes the underlying portions of the electrochromic material to switch from an opaque state to a clear or transmissive state, thereby allowing back-light to propagate through the electrochromic material to create a visible image on the surface of the projection apparatus. Reversal of the electric field causes the electrochromic material to revert back to its opaque state, thereby blocking the transmission of back-light and effectively erasing the image from the surface of the projection apparatus.

Capsule implosions for continuum x-ray backlighting of opacity samples at the National Ignition Facility.

PubMed

Opachich, Y P; Heeter, R F; Barrios, M A; Garcia, E M; Craxton, R S; King, J A; Liedahl, D A; McKenty, P W; Schneider, M B; May, M J; Zhang, R; Ross, P W; Kline, J L; Moore, A S; Weaver, J L; Flippo, K A; Perry, T S

2017-06-01

Direct drive implosions of plastic capsules have been performed at the National Ignition Facility to provide a broad-spectrum (500-2000 eV) X-ray continuum source for X-ray transmission spectroscopy. The source was developed for the high-temperature plasma opacity experimental platform. Initial experiments using 2.0 mm diameter polyalpha-methyl styrene capsules with ∼20  μ m thickness have been performed. X-ray yields of up to ∼1 kJ/sr have been measured using the Dante multichannel diode array. The backlighter source size was measured to be ∼100  μ m FWHM, with ∼350 ps pulse duration during the peak emission stage. Results are used to simulate transmission spectra for a hypothetical iron opacity sample at 150 eV, enabling the derivation of photometrics requirements for future opacity experiments.

Impact of different cleaning processes on the laser damage threshold of antireflection coatings for Z-Backlighter optics at Sandia National Laboratories

DOE PAGES

Field, Ella; Bellum, John; Kletecka, Damon

2014-11-06

We have examined how different cleaning processes affect the laser-induced damage threshold of antireflection coatings for large dimension, Z-Backlighter laser optics at Sandia National Laboratories. Laser damage thresholds were measured after the coatings were created, and again 4 months later to determine which cleaning processes were most effective. There is a nearly twofold increase in laser-induced damage threshold between the antireflection coatings that were cleaned and those that were not cleaned. Aging of the coatings after 4 months resulted in even higher laser-induced damage thresholds. Also, the laser-induced damage threshold results revealed that every antireflection coating had a high defectmore » density, despite the cleaning process used, which indicates that improvements to either the cleaning or deposition processes should provide even higher laser-induced damage thresholds.« less

Directional backlight liquid crystal autostereoscopic display: technical challenges, research progress, and prospect (Conference Presentation)

NASA Astrophysics Data System (ADS)

Fan, Hang; Li, Kunyang; Zhou, Yangui; Liang, Haowen; Wang, Jiahui; Zhou, Jianying

2016-09-01

Recent upsurge on virtual and augmented realities (VR and AR) has re-ignited the interest to the immerse display technology. The VR/AR technology based on stereoscopic display is believed in its early stage as glasses-free, or autostereoscopic display, will be ultimately adopted for the viewing convenience, visual comfort and for the multi-viewer purposes. On the other hand, autostereoscopic display has not yet received positive market response for the past years neither with stereoscopic displays using shutter or polarized glasses. We shall present the analysis on the real-world applications, rigid user demand, the drawbacks to the existing barrier- and lenticular lens-based LCD autostereoscopy. We shall emphasize the emerging autostereoscopic display, and notably on directional backlight LCD technology using a hybrid spatial- and temporal-control scenario. We report the numerical simulation of a display system using Monte-Carlo ray-tracing method with the human retina as the real image receiver. The system performance is optimized using newly developed figure of merit for system design. The reduced crosstalk in an autostereoscopic system, the enhanced display quality, including the high resolution received by the retina, the display homogeneity without Moiré- and defect-pattern, will be highlighted. Recent research progress including a novel scheme for diffraction-free backlight illumination, the expanded viewing zone for autostereoscopic display, and the novel Fresnel lens array to achieve a near perfect display in 2D/3D mode will be introduced. The experimental demonstration will be presented to the autostereoscopic display with the highest resolution, low crosstalk, Moiré- and defect- pattern free.

Airsickness during Naval Flight Officer Training: Basic Squadron VT-10

DTIC Science & Technology

1979-04-08

coupled angular acceleration stimuli prodvoed by paced head 30 TIVDS motions on a rotating chair., TSVDT donote the time of day the 31 T1VDP teso was...Laboratory, 1977. 38 TWIA These mare pertn to th. notion siolasm symptom ating 39 IWItS element of" th se Vu - Vst ~bulor blu’stlo TesO (VV1T). 40 TWVIP TVYIR

CD, DVD, and Blu-Ray Disc Diffraction with a Laser Ray Box

ERIC Educational Resources Information Center

DeWeerd, Alan J.

2016-01-01

A compact disc (CD) can be used as a diffraction grating, even though its track consists of a series of pits, not a continuous groove. Previous authors described how to measure the track spacing on a CD using an incident laser beam normal to the surface or one at an oblique angle. In both cases, the diffraction pattern was projected on a screen…

Integration of Demilitarization Contractors and Recyclers - Collateral Benefits of On-Site Training of Recyclers

DTIC Science & Technology

2010-07-01

item Spherical? Wedge Shaped? Cylindrical? These items are potentially very dangerous 29 Spherical = Not Good If found in a recycling yard, don’t...touch! Call 9-1-1 BLU-63 30 Wedge Shape = Not Good If found in a recycling yard, don’t touch! Call 9-1-1 M72M43 31 Cylindrical = Not Good If found in a

77 FR 65579 - Certain Devices for Improving Uniformity Used in a Backlight Module and Components Thereof and...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-10-29

... Determination and Recommended Determination on Remedy and Bonding in the above-captioned investigation. The... Recommended Determination on Remedy and Bonding issued in this investigation on October 22, 2012. Comments...

77 FR 77043 - 36(b)(1) Arms Sales Notification

Federal Register 2010, 2011, 2012, 2013, 2014

2012-12-31

... MK-84 2000 lb General Purpose Bombs; 1,725 MK-82 500 lb General Purpose Bombs; 1,725 BLU-109 Bombs; 3,450 GBU-39 Small Diameter Bombs; 11,500 FMU-139 Fuses; 11,500 FMU-143 Fuses; and 11,500 FMU-152 Fuses... and 1,725 KMU-572 (GBU-38) for MK-82 warheads); 3,450 MK-84 2000 lb General Purpose Bombs; 1,725 MK-82...

49 CFR 40.209 - What procedural problems do not result in the cancellation of a test and do not require correction?

Code of Federal Regulations, 2012 CFR

2012-10-01

... significant adverse effect on the right of the employee to have a fair and accurate test. Matters that do not result in the cancellation of a test include, but are not limited to, the following: (1) A minor... that does not affect employee protections under this part (e.g., the collector's failure to add bluing...

49 CFR 40.209 - What procedural problems do not result in the cancellation of a test and do not require correction?

Code of Federal Regulations, 2014 CFR

2014-10-01

... significant adverse effect on the right of the employee to have a fair and accurate test. Matters that do not result in the cancellation of a test include, but are not limited to, the following: (1) A minor... that does not affect employee protections under this part (e.g., the collector's failure to add bluing...

Optimizing density patterns to achieve desired light extraction for displays

NASA Astrophysics Data System (ADS)

Davenport, T. L. R.; Cassarly, W. J.

2007-01-01

In displays such as backlights and signage, it is often desirable to produce a particular spatial luminance distribution of light. This work demonstrates an iterative optimization technique for determining the density of light extractors required to produce desired luminance distributions.

Optical damage testing at the Z-Backlighter facility at Sandia National Laboratories

NASA Astrophysics Data System (ADS)

Kimmel, Mark; Rambo, Patrick; Broyles, Robin; Geissel, Matthias; Schwarz, Jens; Bellum, John; Atherton, Briggs

2009-10-01

To enable laser-based radiography of high energy density physics events on the Z-Accelerator[4,5] at Sandia National Laboratories, a facility known as the Z-Backlighter has been developed. Two Nd:Phosphate glass lasers are used to create x-rays and/or proton beams capable of this radiographic diagnosis: Z-Beamlet (a multi-kilojoule laser operating at 527nm in a few nanoseconds) and Z-Petawatt (a several hundred joule laser operating at 1054nm in the subpicosecond regime) [1,2]. At the energy densities used in these systems, it is necessary to use high damage threshold optical materials, some of which are poorly characterized (especially for the sub-picosecond pulse). For example, Sandia has developed a meter-class dielectric coating capability for system optics. Damage testing can be performed by external facilities for nanosecond 532nm pulses, measuring high reflector coating damage thresholds >80J/cm2 and antireflection coating damage thresholds >20J/cm2 [3]. However, available external testing capabilities do not use femtosecond/picosecond scale laser pulses. To this end, we have constructed a sub-picoseond-laser-based optical damage test system. The damage tester system also allows for testing in a vacuum vessel, which is relevant since many optics in the Z-Backlighter system are used in vacuum. This paper will present the results of laser induced damage testing performed in both atmosphere and in vacuum, with 1054nm sub-picosecond laser pulses. Optical materials/coatings discussed are: bare fused silica and protected gold used for benchmarking; BK7; Zerodur; protected silver; and dielectric optical coatings (halfnia/silica layer pairs) produced by Sandia's in-house meter-class coating capability.

What can the occult do for you?

NASA Astrophysics Data System (ADS)

Holwerda, B. W.; Keel, W. C.

2017-03-01

Interstellar dust is still a dominant uncertainty in Astronomy, limiting precision in e.g., cosmological distance estimates and models of how light is re-processed within a galaxy. When a foreground galaxy serendipitously overlaps a more distant one, the latter backlights the dusty structures in the nearer foreground galaxy. Such an overlapping or occulting galaxy pair can be used to measure the distribution of dust in the closest galaxy with great accuracy. The STARSMOG program uses Hubble to map the distribution of dust in foreground galaxies in fine (<100 pc) detail. Integral Field Unit (IFU) observations will map the effective extinction curve, disentangling the role of fine-scale geometry and grain composition on the path of light through a galaxy. The overlapping galaxy technique promises to deliver a clear understanding of the dust in galaxies: geometry, a probability function of dimming as a function of galaxy mass and radius, and its dependence on wavelength.

Characterization of typical platelet injector flow configurations. [liquid propellant rocket engines

NASA Technical Reports Server (NTRS)

Hickox, C. E.

1975-01-01

A study to investigate the hydraulic atomization characteristics of several novel injector designs for use in liquid propellant rocket engines is presented. The injectors were manufactured from a series of thin stainless steel platelets through which orifices were very accurately formed by a photoetching process. These individual platelets were stacked together and the orifices aligned so as to produce flow passages of prescribed geometry. After alignment, the platelets were bonded into a single, 'platelet injector', unit by a diffusion bonding process. Because of the complex nature of the flow associated with platelet injectors, it was necessary to use experimental techniques, exclusively, throughout the study. Large scale models of the injectors were constructed from aluminum plates and the appropriate fluids were modeled using a glycerol-water solution. Stop-action photographs of test configurations, using spark-shadowgraph or stroboscopic back-lighting, are shown.

Green emitting phosphors and blends thereof

DOEpatents

Setlur, Anant Achyut; Siclovan, Oltea Puica; Nammalwar, Prasanth Kumar; Sathyanarayan, Ramesh Rao; Porob, Digamber G.; Chandran, Ramachandran Gopi; Heward, William Jordan; Radkov, Emil Vergilov; Briel, Linda Jane Valyou

2010-12-28

Phosphor compositions, blends thereof and light emitting devices including white light emitting LED based devices, and backlights, based on such phosphor compositions. The devices include a light source and a phosphor material as described. Also disclosed are phosphor blends including such a phosphor and devices made therefrom.

New reversing design method for LED uniform illumination.

PubMed

Wang, Kai; Wu, Dan; Qin, Zong; Chen, Fei; Luo, Xiaobing; Liu, Sheng

2011-07-04

In light-emitting diode (LED) applications, it is becoming a big issue that how to optimize light intensity distribution curve (LIDC) and design corresponding optical component to achieve uniform illumination when distance-height ratio (DHR) is given. A new reversing design method is proposed to solve this problem, including design and optimization of LIDC to achieve high uniform illumination and a new algorithm of freeform lens to generate the required LIDC by LED light source. According to this method, two new LED modules integrated with freeform lenses are successfully designed for slim direct-lit LED backlighting with thickness of 10mm, and uniformities of illuminance increase from 0.446 to 0.915 and from 0.155 to 0.887 when DHRs are 2 and 3 respectively. Moreover, the number of new LED modules dramatically decreases to 1/9 of the traditional LED modules while achieving similar uniform illumination in backlighting. Therefore, this new method provides a practical and simple way for optical design of LED uniform illumination when DHR is much larger than 1.

Cyclic Dinitroureas As Self-Remediating Munition Charges

DTIC Science & Technology

2009-02-26

Octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine NAWCWD Naval Air Warfare Center Weapons Division NMR Nuclear magnetic resonance PBXN Plastic Bonded...problems as UXO. A typical submunition fill, such as PBXN -107 in the BLU- 97/B, employs RDX as the main explosive charge. RDX is known to exhibit... 106 ; “maximum lambda” 1050; “lambda factor” 10. Results and Accomplishments As kinetic runs under the various conditions of humidity and soil

Transforming a Traditional Hands-On Activity into an Enquiry Activity to Foster More In-Depth Understanding of the Concept of Density

ERIC Educational Resources Information Center

Lee, Yeung Chung; Kwok, Ping Wai

2010-01-01

Traditional methods used to teach the concept of density that employ solid objects of different masses and volumes can be supplemented by enquiry activities in which students vary the mass-to-volume ratio of the same object to test ideas about density and flotation. A simple substance, Blu-Tack, is an ideal material to use in this case. The…

77 FR 6583 - Certain Devices for Improving Uniformity Used in a Backlight Module and Components Thereof and...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-02-08

... add as respondents LG Display Co., Ltd. of Seoul, South Korea and LG Display America, Inc. of San Jose..., South Korea; LG Electronics, Inc. of Seoul, South Korea; and LG Electronics, U.S.A., Inc. of Englewood...

Study of Interpolated Timing Recovery Phase-Locked Loop with Linearly Constrained Adaptive Prefilter for Higher-Density Optical Disc

NASA Astrophysics Data System (ADS)

Kajiwara, Yoshiyuki; Shiraishi, Junya; Kobayashi, Shoei; Yamagami, Tamotsu

2009-03-01

A digital phase-locked loop (PLL) with a linearly constrained adaptive filter (LCAF) has been studied for higher-linear-density optical discs. LCAF has been implemented before an interpolated timing recovery (ITR) PLL unit in order to improve the quality of phase error calculation by using an adaptively equalized partial response (PR) signal. Coefficient update of an asynchronous sampled adaptive FIR filter with a least-mean-square (LMS) algorithm has been constrained by a projection matrix in order to suppress the phase shift of the tap coefficients of the adaptive filter. We have developed projection matrices that are suitable for Blu-ray disc (BD) drive systems by numerical simulation. Results have shown the properties of the projection matrices. Then, we have designed the read channel system of the ITR PLL with an LCAF model on the FPGA board for experiments. Results have shown that the LCAF improves the tilt margins of 30 gigabytes (GB) recordable BD (BD-R) and 33 GB BD read-only memory (BD-ROM) with a sufficient LMS adaptation stability.

AI canis minoris, a pulsating low-mass supergiant at an early transition phase from the AGB to the post-AGB stage of evolution

NASA Astrophysics Data System (ADS)

Arkhipova, V. P.; Ikonnikova, N. P.; Esipov, V. F.; Komissarova, G. V.

2017-06-01

The U BV photometry and low-resolution spectroscopy for the semiregular variable AI CMi, a candidate for post-AGB objects, performed in 1996-2016 and 2000-2013, respectively, are presented. The star showed multiperiodic brightness variations with an amplitude up to 1\\underset{\\cdot}{m} 5 in the V band, a significant (up to 0\\underset{\\cdot}{m} 4) bluing of the B - V and U - B colors as the star faded, and a change of its spectrum from G5 I to K3-5 I, depending on its brightness. A possible long-term fading of AI CMi below 8\\underset{\\cdot}{m} 5 in the period from May 2013 to early 2015 is observed in the light curve. The colors in this episode did not change the pattern of their unusual behavior with brightness. The main feature of the spectrum for AI CMi is the appearance and strengthening of TiO absorption bands as its brightness declines, which are atypical in the spectra of ordinary G5-K3 supergiants. The bluing of the B - V and U - B colors is interpreted as the blanketing of stellar radiation predominantly in V (and to a lesser extent in B) by the TiO absorption bands whose intensity increases dramatically with decreasing brightness. Another cause of the bluing can be the scattering of stellar radiation by small dust particles in the gas-dust shell of AI CMi. The star's continuum-normalized spectra over the period from 2000 to 2013 in the wavelength range 4200 to 7700 or 9200 Å are presented. These were taken at different phases of the pulsation cycle and clearly demonstrate the behavior of the TiO absorption bands depending on the V magnitude and B - V color. The equivalent widths of individual TiO bands weremeasured, and their correlation with the photometric parameters of the star is shown. AI CMi belongs to the O-rich branch of AGB/post-AGB supergiants and has a luminosity of 4000 L ⊙ at a distance of 1500 ± 700 pc. The mass of AI CMi is most likely small and close to the lower mass limit for post-AGB stars. The connection of the star's pulsational activity and nonstationary wind with the formation of its molecular and dust shells is discussed briefly.

Radiographic Appearance of Interocclusal Record Materials for Cone Beam Computed Tomography-Guided Implant Surgeries.

PubMed

Mohunta, Vrinda V; McGlumphy, Edwin A; Kim, Do-Gyoon; Azer, Shereen S

To select an ideal interocclusal record material for cone beam computed tomography (CBCT)-guided implant surgery based on the material's radiodensity on the scan. Twelve commonly used interocclusal record materials were used for this investigation: two were waxes, one was polyether, and nine were polyvinyl-siloxane-type materials. A scan template was fabricated by duplicating existing dentures in Ortho-Jet acrylic resin mixed with 30% barium powder for the teeth and 10% barium powder for the denture base between the teeth and the tissue. An interocclusal record was fabricated with each material, and the same template was used to obtain a CBCT scan with an ICAT machine (Imaging Sciences International) at 0.3 voxel and 14-bit depth settings. Twelve CBCT scans were obtained and analyzed. The radiopacity of the barium teeth was used as a control and was compared with the opacity of the 12 materials using a paired t test. A post hoc analysis of variance (ANOVA) test was used to compare the densities of the various materials with each other. There was a statistically significant difference between the radiopacity of barium teeth (gray value: 1,959.475) and that of Modelling Wax (gray value: 750; P = .0026), Aluwax (gray value: 795.22; P = .0022), Blu-Bite CT (gray value: 1,105; P = .005), Ramitec (gray value: 1,105.3; P = .08), Memosil 2 (gray value: 1,202; P = .01) followed by Reprosil (gray value: 1,407.73; P = .01). Compared with the barium teeth, there was no statistically significant difference between the densities of Futar D (gray value: 1,866.5; P = .51), Jet Bite (gray value: 1,660.04; P = .08), Lab-Putty (gray value: 1,402.14; P = .19), and Memoreg 2 (gray value: 1,754.72; P = .1). The highest radiodensity was seen with Blu-Mousse (gray value: 2,949; P = .007) and Take 1 (gray value: 2,229.85; P = .025), which were also significantly different from the density of the barium teeth but in the opposite direction, making them more opaque. Within the limitations of this in vitro study, the most radiolucent appearance of Modelling Wax, Aluwax, Memosil 2, Blu-Bite CT, and Ramitec made them the suitable materials of choice of those tested, as the interocclusal registration record during CBCT scanning allowed clear visualization of barium teeth.

Comparison of 10 efficient protocols for photodynamic therapy of actinic keratosis: How relevant are effective light dose and local damage in predicting the complete response rate at 3 months?

PubMed

Vignion-Dewalle, Anne-Sophie; Baert, Gregory; Thecua, Elise; Lecomte, Fabienne; Vicentini, Claire; Abi-Rached, Henry; Mortier, Laurent; Mordon, Serge

2018-04-18

Topical photodynamic therapy is an established treatment modality for various dermatological conditions, including actinic keratosis. In Europe, the approved protocols for photodynamic therapy of actinic keratosis involve irradiation with either an Aktilite CL 128 lamp or daylight, whereas irradiation with the Blu-U illuminator is approved in the United States. Many other protocols using irradiation by a variety of light sources are also clinically efficient. This paper aims to compare 10 different protocols with clinically proven efficacy for photodynamic therapy of actinic keratosis and the available spectral irradiance of the light source. Effective irradiance, effective light dose, and local damage are compared. We also investigate whether there is an association between the complete response rate at 3 months and the effective light dose or local damage. The effective irradiance, also referred to as protoporphyrin IX-weighted irradiance, is obtained by integrating the spectral irradiance weighted by the normalized absorption spectrum of protoporphyrin IX over the wavelength. Integrating the effective irradiance over the irradiation time yields the effective light dose, which is also known as the protoporphyrin IX-weighted light dose. Local damage, defined as the total cumulative singlet oxygen molecules produced during treatment, is estimated using mathematical modeling of the photodynamic therapy process. This modeling is based on an iterative procedure taking into account the spatial and temporal variations in the protoporphyrin IX absorption spectrum during treatment. The protocol for daylight photodynamic therapy on a clear sunny day, the protocol for daylight photodynamic therapy on an overcast day, the photodynamic therapy protocol for a white LED lamp for operating rooms and the photodynamic therapy protocol for the Blu-U illuminator perform better than the six other protocols-all involving red light illumination-in terms of both effective light dose and local damage. However, no association between the complete response rate at 3 months and the effective light dose or local damage was found. Protocols that achieve high complete response rates at 3 months and low pain scores should be preferred regardless of the effective light dose and local damage. Lasers Surg. Med. © 2018 Wiley Periodicals, Inc. © 2018 Wiley Periodicals, Inc.

49 CFR Appendix B to Part 234 - Alternate Methods of Protection Under 49 CFR 234.105(c), 234.106, and 234.107(c)

Code of Federal Regulations, 2010 CFR

2010-10-01

... Protection Under 49 CFR 234.105(c), 234.106, and 234.107(c) [This is a summary—see body of text for complete... pair of lights designed to flash alternatively, one light does not work (and back-lights from other...

Prism Foil from an LCD Monitor as a Tool for Teaching Introductory Optics

ERIC Educational Resources Information Center

Planinsic, Gorazd; Gojkosek, Mihael

2011-01-01

Transparent prism foil is part of a backlight system in LCD monitors that are widely used today. This paper describes the optical properties of the prism foil and several pedagogical applications suitable for undergraduate introductory physics level. Examples include experiments that employ refraction, total internal reflection, diffraction and…

Issues and solutions: opportunities for European LED manufacturers

NASA Astrophysics Data System (ADS)

Pearsall, T. P.

2007-09-01

Marketing studies by EPIC show significant revenue opportunities by 2012 for UHB-LEDs in the automotive, LCD backlighting, and architectural lighting sectors. The goal of this workshop on manufacturing issues is to consider five key issues for UHB-LED manufacturing and to propose solutions that will pave the way to full exploitation of the opportunities.

Miniature Color Display Phase 4

DTIC Science & Technology

1993-05-01

is used to generate full color. By spectral tuning of the xenon arc-lamp backlight and the color polarizers, a color gamut comparable to that of a...5 1.2 Phase IV Accom plishments ................................... 5 1.2.1 Subtractive Color Gamut ...Technical Achievem ents .............................................. 8 2.1 Subtractive Color Gamut 2.1.1 Sub Color LC Technology

Intricate Valley Glaciers on Pluto

NASA Image and Video Library

2015-09-17

The backlighting highlights the intricate flow lines on the glaciers. The flow front of the ice is moving into the informally named Sputnik Planum. The origin of the ridges and pits on the right side of the image remains uncertain. This image is 390 miles (630 kilometers) across. http://photojournal.jpl.nasa.gov/catalog/PIA19943

Photometric study of single-shot energy-dispersive x-ray diffraction at a laser plasma facility

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

Hoidn, O. R.; Seidler, G. T., E-mail: seidler@uw.edu

The low repetition rates and possible shot-to-shot variations in laser-plasma studies place a high value on single-shot diagnostics. For example, white-beam scattering methods based on broadband backlighter x-ray sources are used to determine changes in the structure of laser-shocked crystalline materials by the evolution of coincidences of reciprocal lattice vectors and kinematically allowed momentum transfers. Here, we demonstrate that white-beam techniques can be extended to strongly disordered dense plasma and warm dense matter systems where reciprocal space is only weakly structured and spectroscopic detection is consequently needed to determine the static structure factor and thus, the ion-ion radial distribution function.more » Specifically, we report a photometric study of energy-dispersive x-ray diffraction (ED-XRD) for structural measurement of high energy density systems at large-scale laser facilities such as OMEGA and the National Ignition Facility. We find that structural information can be obtained in single-shot ED-XRD experiments using established backlighter and spectrometer technologies.« less

The effect of the thicknesses of the various layers on the colour emitted by an organic electroluminescent device

NASA Astrophysics Data System (ADS)

Jolinat, P.; Clergereaux, R.; Farenc, J.; Destruel, P.

1998-05-01

Organic electroluminescent diodes based on thin organic layers are one of the most promising next-generation systems for the backlighting of the liquid crystal screens. Among other methods to obtain white light, three-layer luminescent devices with each layer emitting one of the three fundamental colours have been studied here. Red, green and blue light were produced by 0022-3727/31/10/018/img1 doped with Nile red, 0022-3727/31/10/018/img1 and TPD layers respectively. A fourth thin film of TAZ has been inserted between TPD and 0022-3727/31/10/018/img1 to control injection of electrons into the TPD. The effect of the layers' thicknesses on the spectral emission of the device has been examined. Results show that the thicknesses of TAZ and doped 0022-3727/31/10/018/img1 layers have to be controlled to within a precision of better than 5 Å. The discussion turns on the possibility of applying this technology to screen backlighting.

Fully Solution-Processed Tandem White Quantum-Dot Light-Emitting Diode with an External Quantum Efficiency Exceeding 25.

PubMed

Jiang, Congbiao; Zou, Jianhua; Liu, Yu; Song, Chen; He, Zhiwei; Zhong, Zhenji; Wang, Jian; Yip, Hin-Lap; Peng, Junbiao; Cao, Yong

2018-06-15

Solution-processed electroluminescent tandem white quantum-dot light-emitting diodes (TWQLEDs) have the advantages of being low-cost and high-efficiency and having a wide color gamut combined with color filters, making this a promising backlight technology for high-resolution displays. However, TWQLEDs are rarely reported due to the challenge of designing device structures and the deterioration of film morphology with component layers that can be deposited from solutions. Here, we report an interconnecting layer with the optical, electrical, and mechanical properties required for fully solution-processed TWQLED. The optimized TWQLEDs exhibit a state-of-the-art current efficiency as high as 60.4 cd/A and an extremely high external quantum efficiency of 27.3% at a luminance of 100 000 cd/m 2 . A high color gamut of 124% NTSC 1931 standard can be achieved when combined with commercial color filters. These results represent the highest performance for solution-processed WQLEDs, unlocking the great application potential of TWQLEDs as backlights for new-generation displays.

Visualizing density perturbations in the capsule shell in NIF implosions near peak velocity

NASA Astrophysics Data System (ADS)

Pickworth, L. A.; Hammel, B. A.; Smalyuk, V. A.; Macphee, A.; Scott, H. A.; Robey, H. F.; Field, J.; Barrios, M.; Regan, S. P.

2016-10-01

Engineering features on the capsule (surface roughness, support structures, etc.) can introduce outer surface perturbations that are ultimately detrimental to the performance of the capsule. Recent experiments have assessed minimal support structures and alternate pulse shapes using a re-entrant cone and back lighter that is perturbing to the implosion below radii of 500 μ m. Emission from the hot core, after shock-stagnation and prior to peak velocity (PV), has been used as a self-backlighter, providing a means to sample one side of the capsule at smaller radii. Adding high-Z gas ( 1 % Ar) to the capsule fill in Symcaps (4He), has produced a continuum backlighter with significant increase in emission at hv 8 keV over nominal fills. High-resolution imaging diagnostics with photon energy selectivity form 2D images of the transmitted self-emission, above and below the K-edge of an internally doped Cu layer. We can infer from these images the growth at PV of outer surface perturbations. Prepared by LLNL under Contract DE-AC52-07NA27344. LLNL-ABS-697620.

Measuring the temperature history of isochorically heated warm dense metals

NASA Astrophysics Data System (ADS)

McGuffey, Chris; Kim, J.; Park, J.; Moody, J.; Emig, J.; Heeter, B.; Dozieres, M.; Beg, Fn; McLean, Hs

2017-10-01

A pump-probe platform has been designed for soft X-ray absorption spectroscopy near edge structure measurements in isochorically heated Al or Cu samples with temperature of 10s to 100s of eV. The method is compatible with dual picosecond-class laser systems and may be used to measure the temperature of the sample heated directly by the pump laser or by a laser-driven proton beam Knowledge of the temperature history of warm dense samples will aid equation of state measurements. First, various low- to mid-Z targets were evaluated for their suitability as continuum X-ray backlighters over the range 200-1800 eV using a 10 J picosecond-class laser with relativistic peak intensity Alloys were found to be more suitable than single-element backlighters. Second, the heated sample package was designed with consideration of target thickness and tamp layers using atomic physics codes. The results of the first demonstration attempts will be presented. This work was supported by the U.S. DOE under Contract No. DE-SC0014600.

Acoustic Response and Detection of Marine Mammals Using an Advanced Digital Acoustic Recording Tag(Rev 3)

DTIC Science & Technology

2007-03-13

Victor Gonzalez, University of La Laguna. Fieldwork was supported by University of La Laguna and Governments of El Hierro and the Canary Islands...team in El Hierro and the Field team in Liguria. Fieldwork support was provided by Universidad de La Laguna (ULL), BluWest, NATO Undersea Research...Center (NURC), and Governments of El Hierro and the Canary Islands. Some of Peter Madsen’s work was supported by a Steno Fellowship from the

Multimedia Archiving: Videotape, Compact Disc (CD), Digital Versatile Disc (DVD), and Blu-Ray Disc (BD) Media

DTIC Science & Technology

2010-02-01

color and memory SMPTE Society of Motion Picture and Television Engineers SP Superior Performance ( Betacam SP) S-VHS Super VHS TBC time base...modified Iron Oxide 1.5 mil 3/4 inch ENG, Independent production Betamax 1/2 inch Consumer Betacam Cobalt-modified Iron Oxide, Chromium Dioxide 0.8...mil 1/2 inch ENG, Independent production, Government Betacam SP Metal particle 0.55 mil 1/2 inch ENG, Independent production M-II Metal particle

Ultrashort x-ray backlighters and applications

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

Umstadter, D., University of Michigan

Previously, using ultrashort laser pulses focused onto solid targets, we have experimentally studied a controllable ultrafast broadband radiation source in the extreme ultraviolet for time-resolved dynamical studies in ultrafast science [J. Workman, A. Maksimchuk, X. Llu, U. Ellenberger, J. S. Coe, C.-Y. Chien, and D. Umstadter, ``Control of Bright Picosecond X-Ray Emission from Intense Sub- Picosecond Laser-Plasma Interactions,`` Phys. Rev. Lett. 75, 2324 (1995)]. Once armed with a bright ultrafast broadband continuum x-ray source and appropriate detectors, we used the source as a backlighter to study a remotely produced plasma. The application of the source to a problem relevant tomore » high-density matter completes the triad: creating and controlling, efficiently detecting, and applying the source. This work represented the first use of an ultrafast laser- produced x-ray source as a time-resolving probe in an application relevant to atomic, plasma and high-energy-density matter physics. Using the x-ray source as a backlighter, we adopted a pump-probe geometry to investigate the dynamic changes in electronic structure of a thin metallic film as it is perturbed by an ultrashort laser pulse. Because the laser deposits its energy in a skin depth of about 100 {Angstrom} before expansion occurs, up to gigabar pressure shock waves lasting picosecond in duration have been predicted to form in these novel plasmas. This raises the possibility of studying high- energy-density matter relevant to inertial confinement fusion (ICF) and astrophysics in small-scale laboratory experiments. In the past, time-resolved measurements of K-edge shifts in plasmas driven by nanosecond pulses have been used to infer conditions in highly compressed materials. In this study, we used 100-fs laser pulses to impulsively drive shocks into a sample (an untamped 1000 {Angstrom} aluminum film on 2000 {Angstrom} of parylene-n), measuring L-edge shifts.« less

An optical technique for detecting minute-amplitude standing waves on a liquid jet

NASA Astrophysics Data System (ADS)

Takahashi, I.; Mori, Y. H.

1995-10-01

A liquid jet emerging from a nozzle or an orifice whose outlet is slightly elliptic has a series of minute-amplitude waves on its surface. A quite simple technique is proposed which enables detecting such waves even if they are no longer recognizable with the aid of ordinary backlighting of the jet.

HST,survey views of Hubble after berthing in payload bay on Flight Day 3

NASA Image and Video Library

1997-02-13

S82-E-5140 (13 Feb. 1997) --- A back-lighted full view of the Hubble Space Telescope (HST) in the grasp of the Remote Manipulation System (RMS) following capture early today. The limb of Earth forms part of the background. This view was taken with an Electronic Still Camera (ESC).

JBluIce–EPICS control system for macromolecular crystallography

PubMed Central

Stepanov, Sergey; Makarov, Oleg; Hilgart, Mark; Pothineni, Sudhir Babu; Urakhchin, Alex; Devarapalli, Satish; Yoder, Derek; Becker, Michael; Ogata, Craig; Sanishvili, Ruslan; Venugopalan, Nagarajan; Smith, Janet L.; Fischetti, Robert F.

2011-01-01

The trio of macromolecular crystallography beamlines constructed by the General Medicine and Cancer Institutes Collaborative Access Team (GM/CA-CAT) in Sector 23 of the Advanced Photon Source (APS) have been in growing demand owing to their outstanding beam quality and capacity to measure data from crystals of only a few micrometres in size. To take full advantage of the state-of-the-art mechanical and optical design of these beamlines, a significant effort has been devoted to designing fast, convenient, intuitive and robust beamline controls that could easily accommodate new beamline developments. The GM/CA-CAT beamline controls are based on the power of EPICS for distributed hardware control, the rich Java graphical user interface of Eclipse RCP and the task-oriented philosophy as well as the look and feel of the successful SSRL BluIce graphical user interface for crystallography. These beamline controls feature a minimum number of software layers, the wide use of plug-ins that can be written in any language and unified motion controls that allow on-the-fly scanning and optimization of any beamline com­ponent. This paper describes the ways in which BluIce was combined with EPICS and converted into the Java-based JBluIce, discusses the solutions aimed at streamlining and speeding up operations and gives an overview of the tools that are provided by this new open-source control system for facilitating crystallo­graphic experiments, especially in the field of microcrystallo­graphy. PMID:21358048

A simple model for the cloud adjacency effect and the apparent bluing of aerosols near clouds

NASA Astrophysics Data System (ADS)

Marshak, Alexander; Wen, Guoyong; Coakley, James A.; Remer, Lorraine A.; Loeb, Norman G.; Cahalan, Robert F.

2008-07-01

In determining aerosol-cloud interactions, the properties of aerosols must be characterized in the vicinity of clouds. Numerous studies based on satellite observations have reported that aerosol optical depths increase with increasing cloud cover. Part of the increase comes from the humidification and consequent growth of aerosol particles in the moist cloud environment, but part comes from 3-D cloud-radiative transfer effects on the retrieved aerosol properties. Often, discerning whether the observed increases in aerosol optical depths are artifacts or real proves difficult. The paper only addresses the cloud-clear sky radiative transfer interaction part. It provides a simple model that quantifies the enhanced illumination of cloud-free columns in the vicinity of clouds that are used in the aerosol retrievals. This model is based on the assumption that the enhancement in the cloud-free column radiance comes from enhanced Rayleigh scattering that results from the presence of the nearby clouds. This assumption leads to a larger increase of AOT for shorter wavelengths, or to a "bluing" of aerosols near clouds. The assumption that contribution from molecular scattering dominates over aerosol scattering and surface reflection is justified for the case of shorter wavelengths, dark surfaces, and an aerosol layer below the cloud tops. The enhancement in Rayleigh scattering is estimated using a stochastic cloud model to obtain the radiative flux reflected by broken clouds and comparing this flux with that obtained with the molecules in the atmosphere causing extinction, but no scattering.

Diffusion of Messages from an Electronic Cigarette Brand to Potential Users through Twitter

PubMed Central

Chu, Kar-Hai; Unger, Jennifer B.; Allem, Jon-Patrick; Pattarroyo, Monica; Soto, Daniel; Cruz, Tess Boley; Yang, Haodong; Jiang, Ling; Yang, Christopher C.

2015-01-01

Objective This study explores the presence and actions of an electronic cigarette (e-cigarette) brand, Blu, on Twitter to observe how marketing messages are sent and diffused through the retweet (i.e., message forwarding) functionality. Retweet networks enable messages to reach additional Twitter users beyond the sender’s local network. We follow messages from their origin through multiple retweets to identify which messages have more reach, and the different users who are exposed. Methods We collected three months of publicly available data from Twitter. A combination of techniques in social network analysis and content analysis were applied to determine the various networks of users who are exposed to e-cigarette messages and how the retweet network can affect which messages spread. Results The Blu retweet network expanded during the study period. Analysis of user profiles combined with network cluster analysis showed that messages of certain topics were only circulated within a community of e-cigarette supporters, while other topics spread further, reaching more general Twitter users who may not support or use e-cigarettes. Conclusions Retweet networks can serve as proxy filters for marketing messages, as Twitter users decide which messages they will continue to diffuse among their followers. As certain e-cigarette messages extend beyond their point of origin, the audience being exposed expands beyond the e-cigarette community. Potential implications for health education campaigns include utilizing Twitter and targeting important gatekeepers or hubs that would maximize message diffusion. PMID:26684746

Review – Quantum Dots and Their Application in Lighting, Displays, and Biology

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

Frecker, Talitha; Bailey, Danielle; Arzeta-Ferrer, Xochitl

2015-08-18

In this review, we focus on the advancement of white light emitting nanocrystals, their usage as the emissive layer in LEDs and display backlights, and examine the increased efficiency and longevity of quantum dots based colored LEDs. In addition, we also explore recent discoveries on quantum dots as biological labels, dynamic trackers, and applications in drug delivery.

Electrophoresis Gel Quantification with a Flatbed Scanner and Versatile Lighting from a Screen Scavenged from a Liquid Crystal Display (LCD) Monitor

ERIC Educational Resources Information Center

Yeung, Brendan; Ng, Tuck Wah; Tan, Han Yen; Liew, Oi Wah

2012-01-01

The use of different types of stains in the quantification of proteins separated on gels using electrophoresis offers the capability of deriving good outcomes in terms of linear dynamic range, sensitivity, and compatibility with specific proteins. An inexpensive, simple, and versatile lighting system based on liquid crystal display backlighting is…

A stepwise under-prepared osteotomy technique improves primary stability in shallow-placed implants: a preliminary study for simultaneous vertical ridge augmentation.

PubMed

Ueno, Daisuke; Nakamura, Kei; Kojima, Kousuke; Toyoshima, Takeshi; Tanaka, Hideaki; Ueda, Kazuhiko; Koyano, Kiyoshi; Kodama, Toshiro

2018-04-01

Simultaneous vertical ridge augmentation (VRA) can reduce treatment procedures and surgery time, but the concomitant reduction in primary stability (PS) of a shallow-placed implant imparts risk to its prognosis. Although several studies have reported improvements in PS, there is little information from any simultaneous VRA model. This study aimed to evaluate whether tapered implants with stepwise under-prepared osteotomy could improve the PS of shallow-placed implants in an in vitro model of simultaneous VRA. Tapered implants (Straumann ® Bone Level Tapered implant; BLT) and hybrid implants (Straumann ® Bone Level implant; BL) were investigated in this study. A total of 80 osteotomies of different depths (4, 6, 8, 10 mm) were created in rigid polyurethane foam blocks, and each BLT and BL was inserted by either standard (BLT-S, BL-S) or a stepwise under-prepared (BLT-U, BL-U) osteotomy protocol. The PS was evaluated by measuring maximum insertion torque (IT), implant stability quotient (ISQ), and removal torque (RT). The significance level was set at P < 0.05. There were no significant differences in IT, ISQ or RT when comparing BLT-S and BL-S or BLT-U and BL-U at placement depths of 6 and 8 mm. When comparison was made between osteotomy protocols, IT was significantly greater in BLT-U than in BLT-S at all placement depths. A stepwise under-prepared osteotomy protocol improves initial stability of a tapered implant even in a shallow-placed implant model. BLT-U could be a useful protocol for simultaneous VRA.

Homogeneous free-form directional backlight for 3D display

NASA Astrophysics Data System (ADS)

Krebs, Peter; Liang, Haowen; Fan, Hang; Zhang, Aiqin; Zhou, Yangui; Chen, Jiayi; Li, Kunyang; Zhou, Jianying

2017-08-01

Realization of a near perfect homogeneous secondary emission source for 3D display is proposed and demonstrated. The light source takes advantage of an array of free-form emission surface with a specially tailored light guiding structure, a light diffuser and Fresnel lens. A seamless and homogeneous directional emission is experimentally obtained which is essential for a high quality naked-eye 3D display.

78 FR 26068 - Certain Devices for Improving Uniformity Used in a Backlight Module and Components Thereof and...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-05-03

... and bonding. In particular, the ALJ found that claims 6, 9 and 10 of the `932 patent are not infringed literally or under the Doctrine of Equivalents by the accused products under his construction of the claim... containing same by reason of infringement of certain claims of U.S. Patent No. 6,883,932 (``the `932 patent...

Electrowetting-Based Variable-Focus Lens for Miniature Systems

NASA Astrophysics Data System (ADS)

Hendriks, B. H. W.; Kuiper, S.; van As, M. A. J.; et al.

The meniscus between two immiscible liquids of different refractive indices can be used as a lens. A change in curvature of this meniscus by electrostatic control of the solid/liquid interfacial tension leads to a change in focal distance. It is demonstrated that two liquids in a tube form a self-centred variable-focus lens. The optical properties of this lens were investigated experimentally. We designed and constructed a miniature camera module based on this variable lens suitable for mobile applications. Furthermore, the liquid lens was applied in a Blu-ray Disc optical recording system to enable dual layer disc reading/writing.

Manufacturer’s Catalog Data of Automation and Surveillance Systems for Utility Plants at Fort Leonard Wood, Missouri, Volume 2

DTIC Science & Technology

1975-04-30

JH’iA «4.1 UP SINGLE SYSTEM LOG ISO BLU-ELtll-ELECTRIC BEMANO PBOFIU 01EN 110MHH C’S J538DOI JPK ". t s MW ObPW 4...55 Start-Stop Programs 55 1 .xpansion Capacity 27000 points with added channels and memory tNVIRONMHNTAL: +32 to I05F. 95’? RH maximum POWBR...JC/80 System remedies this deficiency since data transmitted over telephone lines is limited to exceptions" B^T "I V. J 13 iso * i it is

The Japanese hallucinogenic mushrooms Psilocybe and a new synonym of P. subcaerulipes with three asiatic species belong to section Zapotecorum (Higher Basidiomycetes).

PubMed

Guzman, Gaston; Cortes-Perez, Alonso; Ramirez-Guillen, Florencia

2013-01-01

The subtropical Japanese bluing mushroom Psilocybe subcaerulipes, described by Hongo, has several synonyms: P. argentipes by Yokoyama (also from Japan), P. taiwanensis by Guzman and Yang (from Taiwan), and P. thaizapoteca by Guzman, Ramirez-Guillen, and Karunaratna (from Thailand). The study of the holotypes and others specimens of these mushrooms shows that they have basidiospores, pleurocystidia, cheilocystidia, and several other important taxonomic features in common, as well as habitat. Recent discussions of all Japanese hallucinogenic species of Psilocybe and their neurotropic effects are also considered.

International Symposium on Genetic Control of Host Resistance to Infection and Malignancy (2nd) held in Montreal, Canada, on May 12-16, 1985

DTIC Science & Technology

1985-11-01

BR, BIO.SM, BIO.M, BIO.D2, Blu.S and BIO.PL animals and is typified by fibrous scars which consist of inflammatory cells within linear bands c fibrous...connective tissue rather than discrete foci of necrosis. These linear bands of connective tissue contain the same degree of mononuclear cell...per granulome were significantly higher in the liver aid in the lungs of the B1O.D2n mice. Both, mononuclear and neutrophil.s are present in the

Smartphone based Tomographic PIV using colored shadows

NASA Astrophysics Data System (ADS)

Aguirre-Pablo, Andres A.; Alarfaj, Meshal K.; Li, Er Qiang; Thoroddsen, Sigurdur T.

2016-11-01

We use low-cost smartphones and Tomo-PIV, to reconstruct the 3D-3C velocity field of a vortex ring. The experiment is carried out in an octagonal tank of water with a vortex ring generator consisting of a flexible membrane enclosed by a cylindrical chamber. This chamber is pre-seeded with black polyethylene microparticles. The membrane is driven by an adjustable impulsive air-pressure to produce the vortex ring. Four synchronized smartphone cameras, of 40 Mpx each, are used to capture the location of particles from different viewing angles. We use red, green and blue LED's as backlighting sources, to capture particle locations at different times. The exposure time on the smartphone cameras are set to 2 seconds, while exposing each LED color for about 80 μs with different time steps that can go below 300 μs. The timing of these light pulses is controlled with a digital delay generator. The backlight is blocked by the instantaneous location of the particles in motion, leaving a shadow of the corresponding color for each time step. The image then is preprocessed to separate the 3 different color fields, before using the MART reconstruction and cross-correlation of the time steps to obtain the 3D-3C velocity field. This proof of concept experiment represents a possible low-cost Tomo-PIV setup.

Development and Characterization of a 16.3 keV X-Ray Source at the National Ignition Facility

NASA Astrophysics Data System (ADS)

Fournier, K. B.; Barrios, M. A.; Schneider, M. B.; Khan, S.; Chen, H.; Coppari, F.; Rygg, R.; Hohenberger, M.; Albert, F.; Moody, J.; Ralph, J.; Kemp, G. E.; Regan, S. P.

2014-10-01

X-ray sources at the National Ignition Facility are needed for radiography of in-flight capsules in inertial confinement fusion experiments and for diffraction studies of materials at high pressures. In the former case, we want to optimize signal to noise and signal over background ratios for the radiograph, in the latter case, we want to minimize high-energy emission from the backlighter that creates background on the diffraction data. Four interleaved shots at NIF were taken in one day, with laser irradiances on a Zr backlighter target ranging from 5 to 14 × 1015 W/cm2. Two shots were for source optimization as a function of laser irradiance. X-ray fluxes were measured with the time-resolved NIF X-ray Spectrometer (NXS) and the DANTE array of calibrated, filtered diodes. Two shots were optimized to make backscatter measurements with the FABS and NBI optical power systems. The backscatter levels are investigated to look for correlation with hot electron populations inferred from high-energy x rays measured with the FFLEX broadband spectrometer. Results from all shots are presented and compared with models. Work performed under the auspices of the U.S. DOE by LLNL under Contract No. DE-AC52-07NA27344.

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

Baker, Kevin L.

The purpose of this LDRD project was to demonstrate high spatial and temporal resolution x-ray imaging using optical detectors, and in particular the VISAR and OHRV diagnostics on the OMEGA laser. The x-ray source being imaged was a backlighter capsule being imploded by 39 beams of the OMEGA laser. In particular this approach utilized a semiconductor with the side facing the backlighter capsule coated with a thin aluminum layer to allow x rays to pass through the metal layer and then get absorbed in the semiconductor. The other side of the semiconductor was AR coated to allow the VISAR ormore » OHRV probe beam to sample the phase change of the semiconductor as the x rays were absorbed in the semiconductor. This technique is capable of acquiring sub-picosecond 2-D or 1-D x-ray images, detector spatial resolution of better than 10 um and the ability to operate in a high neutron flux environment expected on ignition shots with burning plasmas. In addition to demonstrating this technique on the OMEGA laser, several designs were made to improve the phase sensitivity, temporal resolution and number of frames over the existing diagnostics currently implemented on the OMEGA laser. These designs included both 2-d imaging diagnostics as well as improved 1-D imaging diagnostics which were streaked in time.« less

Overview of FTV (free-viewpoint television)

NASA Astrophysics Data System (ADS)

Tanimoto, Masayuki

2010-07-01

We have developed a new type of television named FTV (Free-viewpoint TV). FTV is the ultimate 3DTV that enables us to view a 3D scene by freely changing our viewpoints. We proposed the concept of FTV and constructed the world's first real-time system including the complete chain of operation from image capture to display. FTV is based on the rayspace method that represents one ray in real space with one point in the ray-space. We have developed ray capture, processing and display technologies for FTV. FTV can be carried out today in real time on a single PC or on a mobile player. We also realized FTV with free listening-point audio. The international standardization of FTV has been conducted in MPEG. The first phase of FTV was MVC (Multi-view Video Coding) and the second phase is 3DV (3D Video). MVC was completed in May 2009. The Blu-ray 3D specification has adopted MVC for compression. 3DV is a standard that targets serving a variety of 3D displays. The view generation function of FTV is used to decouple capture and display in 3DV. FDU (FTV Data Unit) is proposed as a data format for 3DV. FTU can compensate errors of the synthesized views caused by depth error.

Effect of different heat treatments and disinfectants on the survival of Prototheca zopfii.

PubMed

Lassa, Henryka; Jagielski, Tomasz; Malinowski, Edward

2011-03-01

Bovine mastitis caused by the yeast-like alga Prototheca zopfii represents a serious veterinary problem and may result in heavy economic losses to particular dairy farms. The purpose of this study was to evaluate the survival of 50 isolates of P. zopfii in milk subjected to different heat treatments and the survival of further 106 P. zopfii isolates after exposure to three classes of teat disinfectants: iodine (Dipal), quaternary ammonium compounds (Teat), and dodecylbenzenesulphonic acid (Blu-gard). Of the 50 isolates tested for thermal tolerance, 29 (58%) survived heat treatment at 62 °C for 30 s and 13 (26% of all isolates) of those survived after heat treatment at 72 °C for 15 s. None of the 106 isolates were able to withstand the in-use concentrations of the three disinfectants tested. The highest disinfectant concentrations that permitted survival of at least one isolate were dilutions: 1:1,000 for Dipal (survival rate of 52.8-57.5%), 1:100 for Teat (88.7-90.6%), and 1:10 for Blu-gard (100%). No differences in the survival rates of P. zopfii were observed with respect to the duration of exposure to disinfectant. The results of this study support the previous findings that P. zopfii may resist high-temperature treatments, including that applied in the high-temperature, short-time (HTST) pasteurization process. The obtained data also demonstrate the efficacy of the three classes of teat disinfectants against P. zopfii, with the efficacy of iodine being most pronounced. The study emphasizes the necessity of using higher temperatures in the pasteurization of raw milk to kill the Prototheca algae, as well as the particular suitability of the iodine for the control procedures of protothecal mastitis.

Phenolic Compounds from Fermented Berry Beverages Modulated Gene and Protein Expression To Increase Insulin Secretion from Pancreatic β-Cells in Vitro.

PubMed

Johnson, Michelle H; de Mejia, Elvira Gonzalez

2016-03-30

Berries are a rich source of bioactive phenolic compounds that are able to bind and inhibit the enzyme dipeptidyl peptidase-IV (DPP-IV), a current target for type-2 diabetes therapy. The objectives were to determine the role of berry phenolic compounds to modulate incretin-cleaving DPP-IV and its substrate glucagon-like peptide-1 (GLP-1), insulin secretion from pancreatic β-cells, and genes and proteins involved in the insulin secretion pathway using cell culture. Anthocyanins (ANC) from 50% blueberry-50% blackberry (Blu-Bla) and 100% blackberry (Bla) fermented beverages at 50 μM cyanidin-3-glucoside equivalents increased (p < 0.05) glucose-stimulated insulin secretion from pancreatic β-cells (iNS-1E) both when applied directly and following simulated absorption through Caco-2 cells (by 233 and 100 μIU insulin/mL, respectively). ANC 50%Blu-Bla and ANC 100%Bla upregulated the gene for incretin hormone GLP-1 (fold-change 3.0 ± 1.4 and 2.0 ± 0.3, respectively) and genes in the insulin secretory pathway including insulin-like growth factor 1 receptor (iGF1R, 2.3 ± 0.6 and 1.6 ± 0.3, respectively), and increased (p < 0.05) the protein expression of insulin-like growth factor 2 (IGF-II), insulin-like growth factor binding proteins (IGFBP-2 and 3), and vascular endothelial growth factor (VEGF) in iNS-1E cells. Taken together, anthocyanins, predominantly delphinidin-3-arabinoside, from fermented berry beverages have the potential to modulate DPP-IV and its substrate GLP-1, to increase insulin secretion, and to upregulate expression of mRNA of insulin-receptor associated genes and proteins in pancreatic β-cells.

Brain oxygen utilization is unchanged by hypoglycemia in normal humans: lactate, alanine, and leucine uptake are not sufficient to offset energy deficit.

PubMed

Lubow, Jeffrey M; Piñón, Ivan G; Avogaro, Angelo; Cobelli, Claudio; Treeson, David M; Mandeville, Katherine A; Toffolo, Gianna; Boyle, Patrick J

2006-01-01

During hypoglycemia, substrates other than glucose have been suggested to serve as alternate neural fuels. We evaluated brain uptake of endogenously produced lactate, alanine, and leucine at euglycemia and during insulin-induced hypoglycemia in 17 normal subjects. Cross-brain arteriovenous differences for plasma glucose, lactate, alanine, leucine, and oxygen content were quantitated. Cerebral blood flow (CBF) was measured by Fick methodology using N(2)O as the dilution indicator gas. Substrate uptake was measured as the product of CBF and the arteriovenous concentration difference. As arterial glucose concentration fell, cerebral oxygen utilization and CBF remained unchanged. Brain glucose uptake (BGU) decreased from 36.3+/-2.6 to 26.6+/-2.1 micromol.100 g of brain(-1).min(-1) (P<0.001), equivalent to a drop in ATP of 291 micromol.100 g(-1).min(-1). Arterial lactate rose (P<0.001), whereas arterial alanine and leucine fell (P<0.009 and P<0.001, respectively). Brain lactate uptake (BLU) increased from a net release of -1.8+/- 0.6 to a net uptake of 2.5+/-1.2 micromol.100 g(-1).min(-1) (P<0.001), equivalent to an increase in ATP of 74 micromol.100 g(-1).min(-1). Brain leucine uptake decreased from 7.1+/-1.2 to 2.5 +/- 0.5 micromol.100 g(-1).min(-1) (P<0.001), and brain alanine uptake trended downward (P<0.08). We conclude that the ATP generated from the physiological increase in BLU during hypoglycemia accounts for no more than 25% of the brain glucose energy deficit.

Ride-along data LOS 130, 170 & LO330 shots z3139, 3140 and 3141

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

Loisel, Guillaume Pascal

Each instrument records the x-ray emission from the Z-pinch dynamic hohlraum (ZPDH); LOS 130 TIXTLs instruments record the absorption of the pinch backlighter through an expanding NaF/Mg foil; LOS 170 MLM instruments record monochromatic images at 276 and 528 eV energies near and before ZPDH stagnation time; LOS 330 TREX 6A & B: recoded time resolved absorption spectra from a radiatively heated Ne gas.

77 FR 77092 - Certain Devices for Improving Uniformity Used in a Backlight Module and Components Thereof and...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-12-31

...Notice is hereby given that the U.S. International Trade Commission has determined to review the presiding administrative law judge's (``ALJ'') final initial determination (``ID'') issued on October 22, 2012, finding no violation of section 337 of the Tariff Act of 1930, (as amended), 19 U.S.C. 1337 (``section 337''), in the above- captioned investigation. The Commission has also determined to remand- in-part the investigation to the ALJ.

Electrophoretic display technologies for e-book readers: system integration aspects

NASA Astrophysics Data System (ADS)

Gentric, Philippe

2011-03-01

Emerging screen technologies, such as Electrophoretic Displays (EPD) used in E-book Readers, are changing product power requirements due to their advantageous properties such as bi-stability (effective "zero power" static display) and reflective mode of operation (no backlight). We will first review the emerging screen technologies under the angle of system and IC design impact. We will explain power management consequences for IC design, with a focus on Application Engine SOCs for the wireless/portable markets.

Refraction-enhanced backlit imaging of axially symmetric inertial confinement fusion plasmas.

PubMed

Koch, Jeffrey A; Landen, Otto L; Suter, Laurence J; Masse, Laurent P; Clark, Daniel S; Ross, James S; Mackinnon, Andrew J; Meezan, Nathan B; Thomas, Cliff A; Ping, Yuan

2013-05-20

X-ray backlit radiographs of dense plasma shells can be significantly altered by refraction of x rays that would otherwise travel straight-ray paths, and this effect can be a powerful tool for diagnosing the spatial structure of the plasma being radiographed. We explore the conditions under which refraction effects may be observed, and we use analytical and numerical approaches to quantify these effects for one-dimensional radial opacity and density profiles characteristic of inertial-confinement fusion (ICF) implosions. We also show how analytical and numerical approaches allow approximate radial plasma opacity and density profiles to be inferred from point-projection refraction-enhanced radiography data. This imaging technique can provide unique data on electron density profiles in ICF plasmas that cannot be obtained using other techniques, and the uniform illumination provided by point-like x-ray backlighters eliminates a significant source of uncertainty in inferences of plasma opacity profiles from area-backlit pinhole imaging data when the backlight spatial profile cannot be independently characterized. The technique is particularly suited to in-flight radiography of imploding low-opacity shells surrounding hydrogen ice, because refraction is sensitive to the electron density of the hydrogen plasma even when it is invisible to absorption radiography. It may also provide an alternative approach to timing shockwaves created by the implosion drive, that are currently invisible to absorption radiography.

Dynamic granularity of imaging systems

DOE PAGES

Geissel, Matthias; Smith, Ian C.; Shores, Jonathon E.; ...

2015-11-04

Imaging systems that include a specific source, imaging concept, geometry, and detector have unique properties such as signal-to-noise ratio, dynamic range, spatial resolution, distortions, and contrast. Some of these properties are inherently connected, particularly dynamic range and spatial resolution. It must be emphasized that spatial resolution is not a single number but must be seen in the context of dynamic range and consequently is better described by a function or distribution. We introduce the “dynamic granularity” G dyn as a standardized, objective relation between a detector’s spatial resolution (granularity) and dynamic range for complex imaging systems in a given environmentmore » rather than the widely found characterization of detectors such as cameras or films by themselves. We found that this relation can partly be explained through consideration of the signal’s photon statistics, background noise, and detector sensitivity, but a comprehensive description including some unpredictable data such as dust, damages, or an unknown spectral distribution will ultimately have to be based on measurements. Measured dynamic granularities can be objectively used to assess the limits of an imaging system’s performance including all contributing noise sources and to qualify the influence of alternative components within an imaging system. Our article explains the construction criteria to formulate a dynamic granularity and compares measured dynamic granularities for different detectors used in the X-ray backlighting scheme employed at Sandia’s Z-Backlighter facility.« less

Multi-keV X-ray area source intensity at SGII laser facility

NASA Astrophysics Data System (ADS)

Wang, Rui-rong; An, Hong-hai; Xie, Zhi-yong; Wang, Wei

2018-05-01

Experiments for investigating the feasibility of multi-keV backlighters for several different metallic foil targets were performed at the Shenguang II (SGII) laser facility in China. Emission spectra in the energy range of 1.65-7.0 keV were measured with an elliptically bent crystal spectrometer, and the X-ray source size was measured with a pinhole camera. The X-ray intensity near 4.75 keV and the X-ray source size for titanium targets at different laser intensity irradiances were studied. By adjusting the total laser energy at a fixed focal spot size, laser intensity in the range of 1.5-5.0 × 1015 W/cm2, was achieved. The results show that the line emission intensity near 4.75 keV and the X-ray source size are dependent on the laser intensity and increase as the laser intensity increases. However, an observed "peak" in the X-ray intensity near 4.75 keV occurs at an irradiance of 4.0 × 1015 W/cm2. For the employed experimental conditions, it was confirmed that the laser intensity could play a significant role in the development of an efficient multi-keV X-ray source. The experimental results for titanium indicate that the production of a large (˜350 μm in diameter) intense backlighter source of multi-keV X-rays is feasible at the SGII facility.

Fast-response LCDs for virtual reality applications

NASA Astrophysics Data System (ADS)

Chen, Haiwei; Peng, Fenglin; Gou, Fangwang; Wand, Michael; Wu, Shin-Tson

2017-02-01

We demonstrate a fast-response liquid crystal display (LCD) with an ultra-low-viscosity nematic LC mixture. The measured average motion picture response time is only 6.88 ms, which is comparable to 6.66 ms for an OLED at a 120 Hz frame rate. If we slightly increase the TFT frame rate and/or reduce the backlight duty ratio, image blurs can be further suppressed to unnoticeable level. Potential applications of such an image-blur-free LCD for virtual reality, gaming monitors, and TVs are foreseeable.

Two stacked tandem white organic light-emitting diodes employing WO3 as a charge generation layer

NASA Astrophysics Data System (ADS)

Bin, Jong-Kwan; Lee, Na Yeon; Lee, SeungJae; Seo, Bomin; Yang, JoongHwan; Kim, Jinook; Yoon, Soo Young; Kang, InByeong

2016-09-01

Recently, many studies have been conducted to improve the electroluminescence (EL) performance of organic lightemitting diodes (OLEDs) by using appropriate organic or inorganic materials as charge generation layer (CGL) for their application such as full color displays, backlight units, and general lighting source. In a stacked tandem white organic light-emitting diodes (WOLEDs), a few emitting units are electrically interconnected by a CGL, which plays the role of generating charge carriers, and then facilitate the injection of it into adjacent emitting units. In the present study, twostacked WOLEDs were fabricated by using tungsten oxide (WO3) as inorganic charge generation layer and 1,4,5,8,9,11- hexaazatriphenylene hexacarbonitrile (HAT-CN) as organic charge generation layer (P-CGL). Organic P-CGL materials were used due to their ease of use in OLED fabrication as compared to their inorganic counterparts. To obtain high efficiency, we demonstrate two-stacked tandem WOLEDs as follows: ITO/HIL/HTL/HTL'/B-EML/ETL/N-CGL/P-CGL (WO3 or HAT-CN)/HTL″/YG-EML/ETL/LiF/Al. The tandem devices with blue- and yellow-green emitting layers were sensitive to the thickness of an adjacent layer, hole transporting layer for the YG emitting layer. The WOLEDs containing the WO3 as charge generation layer reach a higher power efficiency of 19.1 lm/W and the current efficiency of 51.2 cd/A with the white color coordinate of (0.316, 0.318) than the power efficiency of 13.9 lm/W, and the current efficiency of 43.7 cd/A for organic CGL, HAT-CN at 10 mA/cm2, respectively. This performance with inserting WO3 as CGL exhibited the highest performance with excellent CIE color coordinates in the two-stacked tandem OLEDs.

Practical aspects of modern interferometry for optical manufacturing quality control: Part 2

NASA Astrophysics Data System (ADS)

Smythe, Robert

2012-07-01

Modern phase shifting interferometers enable the manufacture of optical systems that drive the global economy. Semiconductor chips, solid-state cameras, cell phone cameras, infrared imaging systems, space based satellite imaging and DVD and Blu-Ray disks are all enabled by phase shifting interferometers. Theoretical treatments of data analysis and instrument design advance the technology but often are not helpful towards the practical use of interferometers. An understanding of the parameters that drive system performance is critical to produce useful results. Any interferometer will produce a data map and results; this paper, in three parts, reviews some of the key issues to minimize error sources in that data and provide a valid measurement.

Practical aspects of modern interferometry for optical manufacturing quality control, Part 3

NASA Astrophysics Data System (ADS)

Smythe, Robert A.

2012-09-01

Modern phase shifting interferometers enable the manufacture of optical systems that drive the global economy. Semiconductor chips, solid-state cameras, cell phone cameras, infrared imaging systems, space-based satellite imaging, and DVD and Blu-Ray disks are all enabled by phase-shifting interferometers. Theoretical treatments of data analysis and instrument design advance the technology but often are not helpful toward the practical use of interferometers. An understanding of the parameters that drive the system performance is critical to produce useful results. Any interferometer will produce a data map and results; this paper, in three parts, reviews some of the key issues to minimize error sources in that data and provide a valid measurement.

The spatial distribution of soil organic carbon in tidal wetland soils of the continental United States.

PubMed

Hinson, Audra L; Feagin, Rusty A; Eriksson, Marian; Najjar, Raymond G; Herrmann, Maria; Bianchi, Thomas S; Kemp, Michael; Hutchings, Jack A; Crooks, Steve; Boutton, Thomas

2017-12-01

Tidal wetlands contain large reservoirs of carbon in their soils and can sequester carbon dioxide (CO 2 ) at a greater rate per unit area than nearly any other ecosystem. The spatial distribution of this carbon influences climate and wetland policy. To assist with international accords such as the Paris Climate Agreement, national-level assessments such as the United States (U.S.) National Greenhouse Gas Inventory, and regional, state, local, and project-level evaluation of CO 2 sequestration credits, we developed a geodatabase (CoBluCarb) and high-resolution maps of soil organic carbon (SOC) distribution by linking National Wetlands Inventory data with the U.S. Soil Survey Geographic Database. For over 600,000 wetlands, the total carbon stock and organic carbon density was calculated at 5-cm vertical resolution from 0 to 300 cm of depth. Across the continental United States, there are 1,153-1,359 Tg of SOC in the upper 0-100 cm of soils across a total of 24 945.9 km 2 of tidal wetland area, twice as much carbon as the most recent national estimate. Approximately 75% of this carbon was found in estuarine emergent wetlands with freshwater tidal wetlands holding about 19%. The greatest pool of SOC was found within the Atchafalaya/Vermilion Bay complex in Louisiana, containing about 10% of the U.S. total. The average density across all tidal wetlands was 0.071 g cm -3 across 0-15 cm, 0.055 g cm -3 across 0-100 cm, and 0.040 g cm -3 at the 100 cm depth. There is inherent variability between and within individual wetlands; however, we conclude that it is possible to use standardized values at a range of 0-100 cm of the soil profile, to provide first-order quantification and to evaluate future changes in carbon stocks in response to environmental perturbations. This Tier 2-oriented carbon stock assessment provides a scientific method that can be copied by other nations in support of international requirements. © 2017 John Wiley & Sons Ltd.

Fluid Interfaces of Triangular Containers in Reduced Gravity Environments

NASA Technical Reports Server (NTRS)

Guttromson, Jayleen; Manning, Robert; Collicott, Steven H.

2002-01-01

Capillary dominated fluid dynamics will be examined in a reduced-gravity environment onboard the KC-135; in particular, the behavior of the lower portion of the meniscus in triangular tank geometries. Seven clear acrylic tanks were constructed to view seven angles of the four geometries. Silicon oil with two different viscosities, 2cs and 5cs silicon oil, were used on different days of the flight. Six tanks and one control tank are filled with a certain viscosity fluid for each flight day. During each parabola, three tanks are tested at time. The experimental tanks are exchanged between parabola sets on the KC-135. The 60deg -60deg -60deg control tank is viewed throughout the flight. To gather data, two digital video cameras and one digital still camera are placed perpendicular the viewing surface. To provide a greater contrast in the meniscus, an EL backlighting sheet was used to backlight the tanks. These images and video are then digitized, passed through NASA's mini-tracker software, and compared to a theory published my M. M. Weislogel, "Fluid Interface Phenomena in a Low-Gravity Environment: Recent Results from Drop Tower Experimentation." By focusing on a lower portion of the meniscus and using longer periods of reduced gravity, this experiment may confirm that a stationary point exists on the fluid surface. This information will enable better designing of propellant management devices, especially satellite propellant refilling and gas venting. Also, biological and material processing systems in reduced gravity environments will benefit from this data.

Inertial fusion program and national laser users facility program

NASA Astrophysics Data System (ADS)

1995-01-01

This is the 1994 annual report for the University of Rochester, Laboratory for Laser Energetics. The report is presented as a series of research type reports. The titles emphasize the breadth of work carried out. They are: stability analysis of unsteady ablation fronts; characterization of laser-produced plasma density profiles using grid image refractometry; transport and sound waves in plasmas with light and heavy ions; three-halves-harmonic radiation from long-scale-length plasmas revisited; OMEGA upgrade status report; target imaging and backlighting diagnosis; effect of electron collisions on ion-acoustic waves and heat flow; particle-in-cell code simulations of the interaction of gaussian ultrashort laser pulses with targets of varying initial scale lengths; characterization of thick cryogenic fuel layers: compensation for the lens effect using convergent beam interferometry; compact, multijoule-output, Nd:Glass, large-aperture ring amplifier; atomic force microscopy observation of water-induced morphological changes in Y2O3 monolayer coatings; observation of longitudinal acceleration of electrons born in a high-intensity laser focus; spatial intensity nonuniformities of an OMEGA beam due to nonlinear beam propagation; calculated X-ray backlighting images of mixed imploded targets; evaluation of cosmic rays for use in the monitoring of the MEDUSA scintillator-photomultiplier diagnostic array; highly efficient second-harmonic generation of ultra-intense Nd:Glass laser pulses multiple cutoff wave numbers of the ablative Rayleigh-Taylor instability; ultrafast, all-silicon light modulator; angular dependence of the stimulated Brillouin scattering in homogeneous plasma; and femtosecond excited-state dynamics of a conjugated ladder polymer.

Conceptual design of initial opacity experiments on the national ignition facility

NASA Astrophysics Data System (ADS)

Heeter, R. F.; Bailey, J. E.; Craxton, R. S.; Devolder, B. G.; Dodd, E. S.; Garcia, E. M.; Huffman, E. J.; Iglesias, C. A.; King, J. A.; Kline, J. L.; Liedahl, D. A.; McKenty, P. W.; Opachich, Y. P.; Rochau, G. A.; Ross, P. W.; Schneider, M. B.; Sherrill, M. E.; Wilson, B. G.; Zhang, R.; Perry, T. S.

2017-02-01

Accurate models of X-ray absorption and re-emission in partly stripped ions are necessary to calculate the structure of stars, the performance of hohlraums for inertial confinement fusion and many other systems in high-energy-density plasma physics. Despite theoretical progress, a persistent discrepancy exists with recent experiments at the Sandia Z facility studying iron in conditions characteristic of the solar radiative-convective transition region. The increased iron opacity measured at Z could help resolve a longstanding issue with the standard solar model, but requires a radical departure for opacity theory. To replicate the Z measurements, an opacity experiment has been designed for the National Facility (NIF). The design uses established techniques scaled to NIF. A laser-heated hohlraum will produce X-ray-heated uniform iron plasmas in local thermodynamic equilibrium (LTE) at temperatures eV and electron densities 21~\\text{cm}-3$ . The iron will be probed using continuum X-rays emitted in a ps, diameter source from a 2 mm diameter polystyrene (CH) capsule implosion. In this design, of the NIF beams deliver 500 kJ to the mm diameter hohlraum, and the remaining directly drive the CH capsule with 200 kJ. Calculations indicate this capsule backlighter should outshine the iron sample, delivering a point-projection transmission opacity measurement to a time-integrated X-ray spectrometer viewing down the hohlraum axis. Preliminary experiments to develop the backlighter and hohlraum are underway, informing simulated measurements to guide the final design.

Simulated space weathering of Fe- and Mg-rich aqueously altered minerals using pulsed laser irradiation

NASA Astrophysics Data System (ADS)

Kaluna, H. M.; Ishii, H. A.; Bradley, J. P.; Gillis-Davis, J. J.; Lucey, P. G.

2017-08-01

Simulated space weathering experiments on volatile-rich carbonaceous chondrites (CCs) have resulted in contrasting spectral behaviors (e.g. reddening vs bluing). The aim of this work is to investigate the origin of these contrasting trends by simulating space weathering on a subset of minerals found in these meteorites. We use pulsed laser irradiation to simulate micrometeorite impacts on aqueously altered minerals and observe their spectral and physical evolution as a function of irradiation time. Irradiation of the mineral lizardite, a Mg-phyllosilicate, produces a small degree of reddening and darkening, but a pronounced reduction in band depths with increasing irradiation. In comparison, irradiation of an Fe-rich aqueously altered mineral assemblage composed of cronstedtite, pyrite and siderite, produces significant darkening and band depth suppression. The spectral slopes of the Fe-rich assemblage initially redden then become bluer with increasing irradiation time. Post-irradiation analyses of the Fe-rich assemblage using scanning and transmission electron microscopy reveal the presence of micron sized carbon-rich particles that contain notable fractions of nitrogen and oxygen. Radiative transfer modeling of the Fe-rich assemblage suggests that nanometer sized metallic iron (npFe0) particles result in the initial spectral reddening of the samples, but the increasing production of micron sized carbon particles (μpC) results in the subsequent spectral bluing. The presence of npFe0 and the possible catalytic nature of cronstedtite, an Fe-rich phyllosilicate, likely promotes the synthesis of these carbon-rich, organic-like compounds. These experiments indicate that space weathering processes may enable organic synthesis reactions on the surfaces of volatile-rich asteroids. Furthermore, Mg-rich and Fe-rich aqueously altered minerals are dominant at different phases of the aqueous alteration process. Thus, the contrasting spectral slope evolution between the Fe- and Mg-rich samples in these experiments may indicate that space weathering trends of volatile-rich asteroids have a compositional dependency that could be used to determine the aqueous histories of asteroid parent bodies.

A label-free nanostructured plasmonic biosensor based on Blu-ray discs with integrated microfluidics for sensitive biodetection.

PubMed

López-Muñoz, Gerardo A; Estevez, M-Carmen; Peláez-Gutierrez, E Cristina; Homs-Corbera, Antoni; García-Hernandez, M Carmen; Imbaud, J Ignacio; Lechuga, Laura M

2017-10-15

Nanostructure-based plasmonic biosensors have quickly positioned themselves as interesting candidates for the design of portable optical biosensor platforms considering the potential benefits they can offer in integration, miniaturization, multiplexing, and real-time label-free detection. We have developed a simple integrated nanoplasmonic sensor taking advantage of the periodic nanostructured array of commercial Blu-ray discs. Sensors with two gold film thicknesses (50 and 100nm) were fabricated and optically characterized by varying the oblique-angle of the incident light in optical reflectance measurements. Contrary to the use normal light incidence previously reported with other optical discs, we observed an enhancement in sensitivity and a narrowing of the resonant linewidths as the light incidence angle was increased, which could be related to the generation of Fano resonant modes. The new sensors achieve a figure of merit (FOM) up to 35 RIU -1 and a competitive bulk limit of detection (LOD) of 6.3×10 -6 RIU. These values significantly improve previously reported results obtained with normal light incidence reflectance measurements using similar structures. The sensor has been combined with versatile, simple, ease to-fabricate microfluidics. The integrated chip is only 1cm 2 (including a PDMS flow cell with a 50µm height microfluidic channel fabricated with double-sided adhesive tape) and all the optical components are mounted on a 10cm×10cm portable prototype, illustrating its facile miniaturization, integration and potential portability. Finally, to assess the label-free biosensing capability of the new sensor, we have evaluated the presence of specific antibodies against the GTF2b protein, a tumor-associate antigen (TAA) related to colorectal cancer. We have achieved a LOD in the pM order and have assessed the feasibility of directly measuring biological samples such as human serum. Copyright © 2017 Elsevier B.V. All rights reserved.

Frequent epigenetic inactivation of chromosome 3p candidate tumor suppressor genes in gallbladder carcinoma.

PubMed

Riquelme, Erick; Tang, Moying; Baez, Sergio; Diaz, Alfonso; Pruyas, Martha; Wistuba, Ignacio I; Corvalan, Alejandro

2007-05-18

Gallbladder carcinoma (GBC) is a highly malignant neoplasm that represents the leading cause of death for cancer in Chilean females. There is limited information about the molecular abnormalities involved in its pathogenesis. We have identified a number of molecular changes in GBC, including frequent allelic losses at chromosome 3p regions. Four distinct 3p sites (3p12, 3p14.2, 3p21.3 and 3p22-24) with frequent and early allelic losses in the sequential pathogenesis of this neoplasm have been detected. We investigated epigenetic and genetic abnormalities in GBC affecting 6 candidate tumor suppressor genes (TSG) located in chromosome 3p, including DUTT1 (3p12), FHIT (3p14.2), BLU, RASSF1A, SEMA3B and hMLH1 (3p21.3). DNA extracted from frozen tissue obtained from 50 surgical resected GBCs was examined for gene promoter methylation using MSP (methylation-specific PCR) technique after bisulfite treatment in all 6 genes. In addition, we performed PCR-based mutation examination using SSCP in FHIT and RASSF1A genes and loss of heterozygosity (LOH) analysis using microdissected tissue in a subset of tumors for the 3p21.3 region with 8 microsatellite markers. A very high frequency of GBC methylation was detected in SEMA3B (46/50, 92%) and FHIT (33/50, 66%), intermediate incidences in BLU (13/50, 26%) and DUTT1 (11/50, 22%) and very low frequencies in RASSF1A (4/50, 8%) and hMLH1 (2/50, 4%). Allelic loss at 3p21.3 was found in nearly half of the GBCs examined. We conclude that epigenetic inactivation by abnormal promoter methylation is a frequent event in chromosome 3p candidate TSGs in GBC pathogenesis, especially affecting genes SEMA3B (3p21.3) and FHIT (3p14.2).

AT on Buried LPG Tanks Over 13 m3: An Innovative and Practical Solution

NASA Astrophysics Data System (ADS)

Di Fratta, Crescenzo; Ferraro, Antonio; Tscheliesnig, Peter; Lackner, Gerald; Correggia, Vincenzo; Altamura, Nicola

In Italy, since 2005, techniques based on Acoustic Emission have been introduced for testing of underground LPG tanks up to 13 m3, according to the European standard EN 12818:2004. The testing procedure for these tanks plans to install one or more pairs of sensors inside the "dome" suited for the access to the valves and fittings of the tank, directly on the accessible metal shell. This methodology is not applicable for the underground LPG buried tanks, where it is necessary to install a larger number of AE sensors, in order to cover at 100% the whole tank shell, even at very deep positions. Already in 2004, the European standard EN 12820 (Appendix C - Informative)give the possibility to use Acoustic Emission testing of LPG underground or buried tanks with a capacity exceeding 13 m3, but no technique was specified for the application. In 2008, TÜV AUSTRIA ITALIA - BLU SOLUTIONS srl - Italian company of TÜV AUSTRIA Group - has developed a technique to get access at tank shell, where tank capacity is greater than 13 m3 and its' diameter greater than 3,5 m. This methodology was fully in comply with the provisions of the European Standard EN 12819:2010, becoming an innovative solution widely appreciated and is used in Italy since this time. Currently, large companies and petrochemical plants, at the occurrence of the tank's requalification, have engaged TÜV AUSTRIA ITALIA - BLU SOLUTIONS to install such permanent predispositions, which allow access to the tank shell - test object - with diameters from 4 to 8 m. Through this access, you can install the AE sensors needed to cover at 100% the tank surface and then to perform AE test. In an economic crisis period, this technique is proving a valid and practically applicable answer, in order to reduce inspection costs and downtime by offering a technically advanced solution (AT), increasing the safety of the involved operators, protecting natural resources and the environment.

Experimental study of combustion processes involved in hypergolic propellant coaxial injector operation

NASA Astrophysics Data System (ADS)

Habiballah, M.; Dubois, I.; Gicquel, P.; Foucaud, R.

1992-07-01

The first results are presented of an experimental research program to understand the operation of a coaxial injector using hypergolic propellants. Mechanisms and processes involved in coaxial injector operation are identified for a two-plate injector and a coaxial injector. The usefulness of backlight cinematography and laser sheet visualization in the study of coaxial injector operation is examined. A review of the literature on injector elements using highly reactive hypergolic propellants is presented along with an analysis of fundamental mechanisms involved in these propellants.

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

Casey, D. T., E-mail: casey21@llnl.gov; Munro, D. H.; Grim, G. P.

The Neutron Imaging System at the National Ignition Facility is used to observe the primary ∼14 MeV neutrons from the hotspot and down-scattered neutrons (6-12 MeV) from the assembled shell. Due to the strong spatial dependence of the primary neutron fluence through the dense shell, the down-scattered image is convolved with the primary-neutron fluence much like a backlighter profile. Using a characteristic scattering angle assumption, we estimate the primary neutron fluence and compensate the down-scattered image, which reveals information about asymmetry that is otherwise difficult to extract without invoking complicated models.

Super-resolution imaging based on the temperature-dependent electron-phonon collision frequency effect of metal thin films

NASA Astrophysics Data System (ADS)

Ding, Chenliang; Wei, Jingsong; Xiao, Mufei

2018-05-01

We herein propose a far-field super-resolution imaging with metal thin films based on the temperature-dependent electron-phonon collision frequency effect. In the proposed method, neither fluorescence labeling nor any special properties are required for the samples. The 100 nm lands and 200 nm grooves on the Blu-ray disk substrates were clearly resolved and imaged through a laser scanning microscope of wavelength 405 nm. The spot size was approximately 0.80 μm , and the imaging resolution of 1/8 of the laser spot size was experimentally obtained. This work can be applied to the far-field super-resolution imaging of samples with neither fluorescence labeling nor any special properties.

Aerodynamic Loads and Separation Characteristics of the BLU-27B/B, MK- 82SE, and GBU-8 Weapons in the F-16 Aircraft Flow Field at Mach Numbers from 0.4 to 1.2

DTIC Science & Technology

1976-10-01

76-147 Cm 1.2 0.8 o.q 0 SIMBOL CONFIG = ~ STORE ® IS E 0.60 MK-SESE m 15 E 0.80 MK-SESE IS E 0.90 MK-82SE IS E 0.95 MK-B2SE PYLON RRCK 6 M...0 10 .0 1 2 6 A E D C - T R - 7 6 - 1 4 7 SIMBOL CONFIG = H. STORE PILON RICK ~tt 0 11 I0 0.80 MK-82SE 7 I - 3 0 B II 10 0.60 HR-B2SE 7 T

Observation of a Hydrodynamically Driven, Radiative Precursor Shock

NASA Astrophysics Data System (ADS)

Keiter, P. A.; Drake, R. P.; Perry, T. S.; Robey, H.; Remington, B. A.; Iglesias, C. A.; Turner, N.; Stone, J.; Knauer, J.

2001-10-01

Many astrophysical systems, such as supernova remnants and jets, produce radiative-precursor shock waves. In a radiative-precursor shock, radiation from the shock ionizes and heats the medium ahead of it. The simulation of such systems requires that one treat both the emission and the absorption of the radiation. An important goal of this effort is to produce an experiment that can be modeled by astrophysical codes without implementing laser absorption physics into an astrophysical code. We report here the first measurements of a radiative-precursor shock in such an experiment. The experimental design is based on a past experiment[1,2] that used the Nova laser facility to simulate young supernova remnants. The target consists of a 60 νm CH plastic plug followed by a 150 νm vacuum gap and 2 mm of SiO2 aerogel foam. For the experiment, the density of the components and the laser-irradiation conditions are chosen so that the driven shock will produce an observable radiative precursor. We observed the radiative-precursor by using absorption spectroscopy. By backlighting the silicate aerogel foam with a thulium backlighter, we were able to observe both the 1s-2p and 1s-3p lines. These observations will allow us to determine the temperature profile in the precursor. 1. R.P. Drake, et al, Phys. Rev. Lett. 81, 2068 (1998). 2. R.P. Drake, et al., Phys. Plasmas, 7, 2142 (2000) Work supported by the U.S. Department of Energy both directly and through the Lawrence Livermore National Laboratory

Image analysis algorithms for the advanced radiographic capability (ARC) grating tilt sensor at the National Ignition Facility

NASA Astrophysics Data System (ADS)

Roberts, Randy S.; Bliss, Erlan S.; Rushford, Michael C.; Halpin, John M.; Awwal, Abdul A. S.; Leach, Richard R.

2014-09-01

The Advance Radiographic Capability (ARC) at the National Ignition Facility (NIF) is a laser system designed to produce a sequence of short pulses used to backlight imploding fuel capsules. Laser pulses from a short-pulse oscillator are dispersed in wavelength into long, low-power pulses, injected in the NIF main laser for amplification, and then compressed into high-power pulses before being directed into the NIF target chamber. In the target chamber, the laser pulses hit targets which produce x-rays used to backlight imploding fuel capsules. Compression of the ARC laser pulses is accomplished with a set of precision-surveyed optical gratings mounted inside of vacuum vessels. The tilt of each grating is monitored by a measurement system consisting of a laser diode, camera and crosshair, all mounted in a pedestal outside of the vacuum vessel, and a mirror mounted on the back of a grating inside the vacuum vessel. The crosshair is mounted in front of the camera, and a diffraction pattern is formed when illuminated with the laser diode beam reflected from the mirror. This diffraction pattern contains information related to relative movements between the grating and the pedestal. Image analysis algorithms have been developed to determine the relative movements between the gratings and pedestal. In the paper we elaborate on features in the diffraction pattern, and describe the image analysis algorithms used to monitor grating tilt changes. Experimental results are provided which indicate the high degree of sensitivity provided by the tilt sensor and image analysis algorithms.

Recognition and Matching of Clustered Mature Litchi Fruits Using Binocular Charge-Coupled Device (CCD) Color Cameras

PubMed Central

Wang, Chenglin; Tang, Yunchao; Zou, Xiangjun; Luo, Lufeng; Chen, Xiong

2017-01-01

Recognition and matching of litchi fruits are critical steps for litchi harvesting robots to successfully grasp litchi. However, due to the randomness of litchi growth, such as clustered growth with uncertain number of fruits and random occlusion by leaves, branches and other fruits, the recognition and matching of the fruit become a challenge. Therefore, this study firstly defined mature litchi fruit as three clustered categories. Then an approach for recognition and matching of clustered mature litchi fruit was developed based on litchi color images acquired by binocular charge-coupled device (CCD) color cameras. The approach mainly included three steps: (1) calibration of binocular color cameras and litchi image acquisition; (2) segmentation of litchi fruits using four kinds of supervised classifiers, and recognition of the pre-defined categories of clustered litchi fruit using a pixel threshold method; and (3) matching the recognized clustered fruit using a geometric center-based matching method. The experimental results showed that the proposed recognition method could be robust against the influences of varying illumination and occlusion conditions, and precisely recognize clustered litchi fruit. In the tested 432 clustered litchi fruits, the highest and lowest average recognition rates were 94.17% and 92.00% under sunny back-lighting and partial occlusion, and sunny front-lighting and non-occlusion conditions, respectively. From 50 pairs of tested images, the highest and lowest matching success rates were 97.37% and 91.96% under sunny back-lighting and non-occlusion, and sunny front-lighting and partial occlusion conditions, respectively. PMID:29112177

LLE 1994 annual report, October 1993--September 1994

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

NONE

1995-01-01

This is the 1994 annual report for the University of Rochester, Laboratory for Laser Energetics. The report is presented as a series of research type reports. The titles emphasize the breadth of work carried out. They are: stability analysis of unsteady ablation fronts; characterization of laser-produced plasma density profiles using grid image refractometry; transport and sound waves in plasmas with light and heavy ions; three-halves-harmonic radiation from long-scale-length plasmas revisited; OMEGA upgrade status report; target imaging and backlighting diagnosis; effect of electron collisions on ion-acoustic waves and heat flow; particle-in-cell code simulations of the interaction of gaussian ultrashort laser pulsesmore » with targets of varying initial scale lengths; characterization of thick cryogenic fuel layers: compensation for the lens effect using convergent beam interferometry; compact, multijoule-output, Nd:Glass, large-aperture ring amplifier; atomic force microscopy observation of water-induced morphological changes in Y{sub 2}O{sub 3} monolayer coatings; observation of longitudinal acceleration of electrons born in a high-intensity laser focus; spatial intensity nonuniformities of an OMEGA beam due to nonlinear beam propagation; calculated X-ray backlighting images of mixed imploded targets; evaluation of cosmic rays for use in the monitoring of the MEDUSA scintillator-photomultiplier diagnostic array; highly efficient second-harmonic generation of ultra-intense Nd:Glass laser pulses multiple cutoff wave numbers of the ablative Rayleigh-Taylor instability; ultrafast, all-silicon light modulator; angular dependence of the stimulated Brillouin scattering in homogeneous plasma; femtosecond excited-state dynamics of a conjugated ladder polymer.« less

Spectral content of buried Ag foils at 10{sup 16} W/cm{sup 2} laser illumination

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

Huntington, C. M., E-mail: huntington4@llnl.gov; Maddox, B. R.; Park, H.-S.

2014-11-15

Sources of 5–12 keV thermal Heα x-rays are readily generated by laser irradiation of mid-Z foils at intensities >10{sup 14} W/cm{sup 2}, and are widely used as probes for inertial confinement fusion and high-energy-density experiments. Higher energy 17–50 keV x-ray sources are efficiently produced from “cold” Kα emission using short pulse, petawatt lasers at intensities >10{sup 18} W/cm{sup 2} [H.-S. Park, B. R. Maddox et al., “High-resolution 17–75 keV backlighters for high energy density experiments,” Phys. Plasmas 15(7), 072705 (2008); B. R. Maddox, H. S. Park, B. A. Remington et al., “Absolute measurements of x-ray backlighter sources at energies abovemore » 10 keV,” Phys. Plasmas 18(5), 056709 (2011)]. However, when long pulse (>1 ns) lasers are used with Z > 30 elements, the spectrum contains contributions from both K shell transitions and from ionized atomic states. Here we show that by sandwiching a silver foil between layers of high-density carbon, the ratio of Kα:Heα in the x-ray spectrum is significant increased over directly illuminated Ag foils, with narrower lines from K-shell transitions. Additionally, the emission volume is more localized for the sandwiched target, producing a more planar x-ray sheet. This technique may be useful for generating probes requiring spectral purity and a limited spatial extent, for example, in incoherent x-ray Thomson scattering experiments.« less

Measurement of inflight shell areal density near peak velocity using a self backlighting technique

NASA Astrophysics Data System (ADS)

Pickworth, L. A.; Hammel, B. A.; Smalyuk, V. A.; MacPhee, A. G.; Scott, H. A.; Robey, H. F.; Landen, O. L.; Barrios, M. A.; Regan, S. P.; Schneider, M. B.; Hoppe, M., Jr.; Kohut, T.; Holunga, D.; Walters, C.; Haid, B.; Dayton, M.

2016-05-01

The growth of perturbations in inertial confinement fusion (ICF) capsules can lead to significant variation of inflight shell areal density (ρR), ultimately resulting in poor compression and ablator material mixing into the hotspot. As the capsule is accelerated inward, the perturbation growth results from the initial shock-transit through the shell and then amplification by Rayleigh-Taylor as the shell accelerates inwards. Measurements of ρR perturbations near peak implosion velocity (PV) are essential to our understanding of ICF implosions because they reflect the integrity of the capsule, after the inward acceleration growth is complete, of the actual shell perturbations including native capsule surface roughness and “isolated defects”. Quantitative measurements of shell-ρR perturbations in capsules near PV are challenging, requiring a new method with which to radiograph the shell. An innovative method, utilized in this paper, is to use the self-emission from the hotspot to “self- backlight” the shell inflight. However, with nominal capsule fills there is insufficient self-emission for this method until the capsule nears peak compression (PC). We produce a sufficiently bright continuum self-emission backlighter through the addition of a high-Z gas (∼ 1% Ar) to the capsule fill. This provides a significant (∼10x) increase in emission at hυ∼8 keV over nominal fills. “Self backlit” radiographs are obtained for times when the shock is rebounding from the capsule center, expanding out to meet the incoming shell, providing a means to sample the capsule optical density though only one side, as it converges through PV.

Design of a backlighting structure for very large-area luminaries

NASA Astrophysics Data System (ADS)

Carraro, L.; Mäyrä, A.; Simonetta, M.; Benetti, G.; Tramonte, A.; Benedetti, M.; Randone, E. M.; Ylisaukko-Oja, A.; Keränen, K.; Facchinetti, T.; Giuliani, G.

2017-02-01

A novel approach for RGB semiconductor LED-based backlighting system is developed to satisfy the requirements of the Project LUMENTILE funded by the European Commission, whose scope is to develop a luminous electronic tile that is foreseen to be manufactured in millions of square meters each year. This unconventionally large-area surface of uniform, high-brightness illumination requires a specific optical design to keep a low production cost, while maintaining high optical extraction efficiency and a reduced thickness of the structure, as imposed by architectural design constraints. The proposed solution is based on a light-guiding layer to be illuminated by LEDs in edge configuration, or in a planar arrangement. The light guiding slab is finished with a reflective top interface and a diffusive or reflective bottom interface/layer. Patterning is used for both the top interface (punctual removal of reflection and generation of a light scattering centers) and for the bottom layer (using dark/bright printed pattern). Computer-based optimization algorithms based on ray-tracing are used to find optimal solutions in terms of uniformity of illumination of the top surface and overall light extraction efficiency. Through a closed-loop optimization process, that assesses the illumination uniformity of the top surface, the algorithm generates the desired optimized top and bottom patterns, depending on the number of LED sources used, their geometry, and the thickness of the guiding layer. Specific low-cost technologies to realize the patterning are discussed, with the goal of keeping the production cost of these very large-area luminaries below the value of 100$/sqm.

Magnesium-based photocathodes for triggering back-lighted thyratrons

NASA Astrophysics Data System (ADS)

Sozer, Esin B.

This dissertation presents experimental studies of application of magnesium-based photocathodes to optically triggered pseudospark switches, called back-lighted thyratrons (BLTs). Magnesium was chosen as a low work function metal photocathode for its potential to increase triggering performance of the switch with a higher photoemission performance than traditional BLT cathodes. Improvement in triggering performance of plasma switches is of interest for device development of compact pulsed power systems where the size of switching units can limit the overall size and the mobility of the system. Experiments were conducted on photoemission performance of photocathode candidates under BLT-relevant conditions; and delay and jitter performance of a BLT with photocathode candidates with changing helium pressure and switch voltages. A review of photocathode literature showed that Mg and Cu are the most promising candidates for increasing the photoemission during the triggering of BLTs. As a commonly used BLT cathode in the switch literature, Mo was chosen together with Mg and Cu to be tested under BLT-relevant pressure and field conditions. Quantum efficiency measurements of high-purity foils of Mg, Cu and Mo showed a superior performance of Mg and Cu over Mo. Mg had the highest quantum efficiency of 1.5 x 10-5 among all three materials. After photoemission measurements in a test bed were concluded, testing of these cathodes for their switching performance was done in two stages. First, an unfocused UV laser beam (8.5 x 106 W/cm 2) with a wavelength of 266 nm was used for delay measurements of a BLT with Mg, Cu and Mo-based cathodes. Mg-based cathodes showed at least a thirty-fold reduction in delay and jitter compared to Cu-based and at least an eighty-fold reduction in delay and jitter compared to Mo-based cathodes at any given helium pressure and switch voltage pair. Subsequently, a partial focusing of the same light source was utilized (7.4 x 107W/cm 2) for delay measurements of a BLT with copper electrodes at constant switch voltage and changing helium pressure before and after integration of a Mg foil. These measurements showed an order of magnitude shorter delay and jitter throughout the pressure range when the high-purity Mg-foil was present at the switch cathode. Theoretical estimations of electron emission from the cathode during the triggering suggested that the main mechanism responsible for the observed change in delay and jitter was the increased photoemission due to the lower work function of the Mg cathode and that the effect of temperature on triggering is negligible. SEM images of the high-purity Mg foil integrated at the BLT cathode for 106 shots showed signs of melting around the bore hole. No degradation of the switch performance was observed for the duration of 10 6 shots. In conclusion, magnesium-based cathodes for BLTs showed an important potential for small triggering units for optical triggering, especially when the intensity of the optical source is limited. A future work involving plasma simulations is suggested for assessing potential of different cathode/optical source pairs for triggering BLTs.

Mitigation of hard x-ray background in backlit pinhole imagers

DOE PAGES

Fein, J. R.; Keiter, P. A.; Holloway, J. P.; ...

2016-09-16

Experiments were performed to mitigate the hard x-ray background commonly observed in backlit pinhole imagers. The material of the scaffold holding the primary backlighter foil was varied to reduce the laser-plasma instabilities responsible for hot electrons and resulting hard x-ray background. Radiographic measurements with image plates showed a factor of >25 decrease in x-rays between 30 and 67 keV when going from a plastic to Al or V scaffold. Here, a potential design using V scaffold offers a signal-to-background ratio of 6:1, a factor of 2 greater than using the bare plastic scaffold.

Peak wavelength shifts and opponent color theory

NASA Astrophysics Data System (ADS)

Ashdown, Ian; Salsbury, Marc

2007-09-01

We adapt the tenets of Hering's opponent color theory to the processing of data obtained from a tristimulus colorimeter to independently determine the intensity and possible peak wavelength shift of a narrowband LED. This information may then be used for example in an optical feedback loop to maintain constant intensity and chromaticity for a light source consisting of two LEDs with different peak wavelengths. This approach is particularly useful for LED backlighting of LCD display panels using red, green, and blue LEDs, wherein a tristimulus colorimeter can be used to maintain primary chromaticities to within broadcast standard limits in real time.

On the prospects of application and development of solid-state photomultipliers for the task of analog detecting of pulsed optical signals

NASA Astrophysics Data System (ADS)

Bogdanov, S. V.; Kolobov, N. A.; Levin, E. V.; Pozdnyakov, Y. I.; Shubin, V. E.; Shushakov, D. A.; Sitarsky, K. Yu.; Torgovnikov, R. A.

2018-02-01

In this paper, we analyze the influence of the crosstalk level and the dynamic range on the basic characteristics of a silicon solid-state photomultiplier and demonstrate their importance for detecting of optical signals with backlight illumination, in particular, for LIDAR application. Experimental results obtained in the study of threshold and fluctuation parameters of detectors with different levels of crosstalk and dynamic range are presented. It is shown that the detector design combining a high dynamic range with a small crosstalk gives a noticeable advantage in such applications.

Data analysis and interpretation of lunar dust exosphere

NASA Technical Reports Server (NTRS)

Andrews, George A., Jr.

1992-01-01

The lunar horizon glow observed by Apollo astronauts and captured on film during the Surveyor mission is believed to result from the scattering of sunlight off lunar fines suspended in a dust layer over the lunar surface. For scale heights on the order of tens of kilometers, it is anticipated that the size of the dust particles will be small enough to admit Rayleigh scattering. Such events would result in scattered light which is polarized to a degree which is a function of observation angle and produce spectra containing large high frequency components ('bluing'). Believing these signatures to be observable from ground based telescopes, observational data has been collected from McDonald Observatory and the task of reduction and analysis of this data is the focus of the present report.

Efficiency analysis on platform over the top (OTT) to deploy content and applications (edutainment) in digital television on optical network link

NASA Astrophysics Data System (ADS)

Puche, William S.; Sierra, Javier E.; Moreno, Gustavo A.

2014-08-01

The convergence of new technologies in the digital world has made devices with internet connectivity such as televisions, smatphone, Tablet, Blu-ray, game consoles, among others, to increase more and more. Therefore the major research centers are in the task of improving the network performance to mitigate the bottle neck phenomenon regarding capacity and high transmission rates in information and data. The implementation of standard HbbTV (Hybrid Broadcast Broadband TV), and technological platforms OTT (Over the Top), capable of distributing video, audio, TV, and other Internet services via devices connected directly to the cloud. Therefore a model to improve the transmission capacity required by content distribution networks (CDN) for online TV, with high-capacity optical networks is proposed.

Experimental far-field imaging properties of a ~5-μm diameter spherical lens.

PubMed

Ye, Ran; Ye, Yong-Hong; Ma, Hui Feng; Ma, Jun; Wang, Bin; Yao, Jie; Liu, Shuai; Cao, Lingling; Xu, Huanhuan; Zhang, Jia-Yu

2013-06-01

Microscale lenses are mostly used as near-sighted lenses. The far-field imaging properties of a microscale spherical lens, where the lens is spatially separated from the object, are experimentally studied. Our experimental results show that, for a blu-ray disc (an object) whose spacing is 300 nm, the lens can magnify the stripe patterns of the disc when the lens is spatially separated from the object. In the experimentally tested range (0-14 μm), all the magnified images are virtual images. When the distance is increased from 0 to 14 μm the magnification decreases from 1.47× to 1.20× and the field of view increases from 3.8 to 12.2 μm. The image magnification cannot be described by standard geometrical optics.

Conceptual design of initial opacity experiments on the national ignition facility

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

Heeter, R.  F.; Bailey, J.  E.; Craxton, R.  S.

Accurate models of X-ray absorption and re-emission in partly stripped ions are necessary to calculate the structure of stars, the performance of hohlraums for inertial confinement fusion and many other systems in high-energy-density plasma physics. Despite theoretical progress, a persistent discrepancy exists with recent experiments at the Sandia Z facility studying iron in conditions characteristic of the solar radiative–convective transition region. The increased iron opacity measured at Z could help resolve a longstanding issue with the standard solar model, but requires a radical departure for opacity theory. To replicate the Z measurements, an opacity experiment has been designed for the National Facility (NIF). The design uses established techniques scaled to NIF. A laser-heated hohlraum will produce X-ray-heated uniform iron plasmas in local thermodynamic equilibrium (LTE) at temperaturesmore » $${\\geqslant}150$$ eV and electron densities$${\\geqslant}7\\times 10^{21}~\\text{cm}^{-3}$$. The iron will be probed using continuum X-rays emitted in a$${\\sim}200$$ ps,$${\\sim}200~\\unicode[STIX]{x03BC}\\text{m}$$diameter source from a 2 mm diameter polystyrene (CH) capsule implosion. In this design,$2/3$$of the NIF beams deliver 500 kJ to the$${\\sim}6$$ mm diameter hohlraum, and the remaining$$1/3$directly drive the CH capsule with 200 kJ. Calculations indicate this capsule backlighter should outshine the iron sample, delivering a point-projection transmission opacity measurement to a time-integrated X-ray spectrometer viewing down the hohlraum axis. Preliminary experiments to develop the backlighter and hohlraum are underway, informing simulated measurements to guide the final design.« less

Light sources and output couplers for a backlight with switchable emission angles

NASA Astrophysics Data System (ADS)

Fujieda, Ichiro; Imai, Keita; Takagi, Yoshihiko

2007-09-01

For switching viewing angles of a liquid crystal display, we proposed to place a liquid crystal device between an LED and a light-guide of a backlight. The first key component for this configuration is a light source with electronically-controlled emission angles. Here, we construct such a device by stacking an optical film and a polymer-network liquid crystal (PNLC) cell on top of a chip-type LED. The optical film contains opaque parallel plates that limit the LED output in a narrow angular range. The PNLC cell either transmits or scatters the light emerging from the optical film. Experiment using a 15μm-thick PNLC cell shows that the angular distribution becomes 2.3 times wider by turning off the PNLC cell. We place this light source at one end of a light-guide so that the angular distribution of the light propagating inside is controlled. The second key component is some types of micro-strucrures built on the light-guide to out-couple the propagating light. We first attached various optical films on a light-guide surface. Although the angular distribution of the extracted light was switched successfully, light was mostly emitted into an oblique direction, approximately 60° from the plane normal. Next, we used a half-cylinder in place of the optical films. The curved surface of the cylinder was attached to the light-guide with a small amount of matching oil, which constituted an optical window. We measured that the angular distribution of the extracted light decreased to 35° FWHM from 62° FWHM by turning on the PNLC cell.

Machine learning techniques for energy optimization in mobile embedded systems

NASA Astrophysics Data System (ADS)

Donohoo, Brad Kyoshi

Mobile smartphones and other portable battery operated embedded systems (PDAs, tablets) are pervasive computing devices that have emerged in recent years as essential instruments for communication, business, and social interactions. While performance, capabilities, and design are all important considerations when purchasing a mobile device, a long battery lifetime is one of the most desirable attributes. Battery technology and capacity has improved over the years, but it still cannot keep pace with the power consumption demands of today's mobile devices. This key limiter has led to a strong research emphasis on extending battery lifetime by minimizing energy consumption, primarily using software optimizations. This thesis presents two strategies that attempt to optimize mobile device energy consumption with negligible impact on user perception and quality of service (QoS). The first strategy proposes an application and user interaction aware middleware framework that takes advantage of user idle time between interaction events of the foreground application to optimize CPU and screen backlight energy consumption. The framework dynamically classifies mobile device applications based on their received interaction patterns, then invokes a number of different power management algorithms to adjust processor frequency and screen backlight levels accordingly. The second strategy proposes the usage of machine learning techniques to learn a user's mobile device usage pattern pertaining to spatiotemporal and device contexts, and then predict energy-optimal data and location interface configurations. By learning where and when a mobile device user uses certain power-hungry interfaces (3G, WiFi, and GPS), the techniques, which include variants of linear discriminant analysis, linear logistic regression, non-linear logistic regression, and k-nearest neighbor, are able to dynamically turn off unnecessary interfaces at runtime in order to save energy.

A note on the contribution of multi-photon processes to radiative opacity

NASA Astrophysics Data System (ADS)

Pain, Jean-Christophe

2018-03-01

Recently, Bailey et al. performed iron opacity measurements on the Z machine at Sandia National Laboratory in conditions close to the ones of the base of the convective zone of the Sun. Such experiments have raised questions about the physical models commonly used in opacity codes. To understand the discrepancy between experiment and theory, More et al. investigated the role of two-photon processes. In the present work we show, by simple estimate and using hydrogenic formulas, that due to the intensity of the backlight radiation seen by the sample, such processes are likely to play an important role only for highly excited states.

Ultraviolet excitation of remote phosphor with symmetrical illumination used in dual-sided liquid-crystal display.

PubMed

Huang, Hsin-Tao; Tsai, Chuang-Chuang; Huang, Yi-Pai

2010-08-01

The UV-excited flat lighting (UFL) technique differs from conventional fluorescent lamp or LED illumination. It involves using a remote phosphor film to convert the wavelength of UV light to visible light, achieving high brightness and planar and uniform illumination. In particular, UFL can accomplish compact size, low power consumption, and symmetrical dual-sided illumination. Additionally, UFL utilizes a thermal radiation mechanism to release the large amount of heat that is generated upon illumination without thermal accumulation. These characteristics of the UFL technique can motivate a wide range of lighting applications in thin-film transistor LCD backlighting or general lighting.

Hunting behavior of a marine mammal beneath the antarctic fast Ice

PubMed

Davis; Fuiman; Williams; Collier; Hagey; Kanatous; Kohin; Horning

1999-02-12

The hunting behavior of a marine mammal was studied beneath the Antarctic fast ice with an animal-borne video system and data recorder. Weddell seals stalked large Antarctic cod and the smaller subice fish Pagothenia borchgrevinki, often with the under-ice surface for backlighting, which implies that vision is important for hunting. They approached to within centimeters of cod without startling the fish. Seals flushed P. borchgrevinki by blowing air into subice crevices or pursued them into the platelet ice. These observations highlight the broad range of insights that are possible with simultaneous recordings of video, audio, three-dimensional dive paths, and locomotor effort.

Microgravity

NASA Image and Video Library

1991-04-03

The USML-1 Glovebox (GBX) is a multi-user facility supporting 16 experiments in fluid dynamics, combustion sciences, crystal growth, and technology demonstration. The GBX has an enclosed working space which minimizes the contamination risks to both Spacelab and experiment samples. The GBX supports four charge-coupled device (CCD) cameras (two of which may be operated simultaneously) with three black-and-white and three color camera CCD heads available. The GBX also has a backlight panel, a 35 mm camera, and a stereomicroscope that offers high-magnification viewing of experiment samples. Video data can also be downlinked in real-time. The GBX also provides electrical power for experiment hardware, a time-temperature display, and cleaning supplies.

Microgravity

NASA Image and Video Library

1995-08-29

The USML-1 Glovebox (GBX) is a multi-user facility supporting 16 experiments in fluid dynamics, combustion sciences, crystal growth, and technology demonstration. The GBX has an enclosed working space which minimizes the contamination risks to both Spacelab and experiment samples. The GBX supports four charge-coupled device (CCD) cameras (two of which may be operated simultaneously) with three black-and-white and three color camera CCD heads available. The GBX also has a backlight panel, a 35 mm camera, and a stereomicroscope that offers high-magnification viewing of experiment samples. Video data can also be downlinked in real-time. The GBX also provides electrical power for experiment hardware, a time-temperature display, and cleaning supplies.

Realizing Rec. 2020 color gamut with quantum dot displays.

PubMed

Zhu, Ruidong; Luo, Zhenyue; Chen, Haiwei; Dong, Yajie; Wu, Shin-Tson

2015-09-07

We analyze how to realize Rec. 2020 wide color gamut with quantum dots. For photoluminescence, our simulation indicates that we are able to achieve over 97% of the Rec. 2020 standard with quantum dots by optimizing the emission spectra and redesigning the color filters. For electroluminescence, by optimizing the emission spectra of quantum dots is adequate to render over 97% of the Rec. 2020 standard. We also analyze the efficiency and angular performance of these devices, and then compare results with LCDs using green and red phosphors-based LED backlight. Our results indicate that quantum dot display is an outstanding candidate for achieving wide color gamut and high optical efficiency.

Recent progress of carbon nanotube field emitters and their application.

PubMed

Seelaboyina, Raghunandan; Choi, Wonbong

2007-01-01

The potential of utilizing carbon nanotube field emission properties is an attractive feature for future vacuum electronic devices including: high power microwave, miniature x-ray, backlight for liquid crystal displays and flat panel displays. Their high emission current, nano scale geometry, chemical inertness and low threshold voltage for emission are attractive features for the field emission applications. In this paper we review the recent developments of carbon nanotube field emitters and their device applications. We also discuss the latest results on field emission current amplification achieved with an electron multiplier microchannel plate, and emission performance of multistage field emitter based on oxide nanowire operated in poor vacuum.

Fluence-compensated down-scattered neutron imaging using the neutron imaging system at the National Ignition Facility.

PubMed

Casey, D T; Volegov, P L; Merrill, F E; Munro, D H; Grim, G P; Landen, O L; Spears, B K; Fittinghoff, D N; Field, J E; Smalyuk, V A

2016-11-01

The Neutron Imaging System at the National Ignition Facility is used to observe the primary ∼14 MeV neutrons from the hotspot and down-scattered neutrons (6-12 MeV) from the assembled shell. Due to the strong spatial dependence of the primary neutron fluence through the dense shell, the down-scattered image is convolved with the primary-neutron fluence much like a backlighter profile. Using a characteristic scattering angle assumption, we estimate the primary neutron fluence and compensate the down-scattered image, which reveals information about asymmetry that is otherwise difficult to extract without invoking complicated models.

Indirect competitive assays on DVD for direct multiplex detection of drugs of abuse in oral fluids.

PubMed

Zhang, Lingling; Li, Xiaochun; Li, Yunchao; Shi, Xiaoli; Yu, Hua-Zhong

2015-02-03

On-site oral fluid testing for drugs of abuse has become prominent in order to take immediate administrative action in an enforcement process. Herein, we report a DVD technology-based indirect competitive immunoassay platform for the quantitative detection of drugs of abuse. A microfluidic approach was adapted to prepare multiplex immunoassays on a standard DVD-R, an unmodified multimode DVD/Blu-Ray drive to read signal, and a free disc-quality analysis software program to process the data. The DVD assay platform was successfully demonstrated for the simultaneous, quantitative detection of drug candidates (morphine and cocaine) in oral fluids with high selectivity. The detection limit achieved was as low as 1.0 ppb for morphine and 5.0 ppb for cocaine, comparable with that of standard mass spectrometry and ELISA methods.

High-power AlGaInN lasers for Blu-ray disc system

NASA Astrophysics Data System (ADS)

Takeya, Motonubu; Ikeda, Shinroh; Sasaki, Tomomi; Fujimoto, Tsuyoshi; Ohfuji, Yoshio; Mizuno, Takashi; Oikawa, Kenji; Yabuki, Yoshifumi; Uchida, Shiro; Ikeda, Masao

2003-07-01

This paper describes an improved laser structure for AlGaInN based blue-violet lasers (BV-LDs). The design realizes a small beam divergence angle perpendicular to the junction plane and high characteristic temperature wihtout significant increase in threshold current density (Jth) by optimizing the position of the Mg-doped layer and introducing an undoped AlGaN layer between the active layer and the Mg-doped electron-blocking layer. The mean time to failure (MTTF) of devices based on this design was found to be closely related to the dislocation density of ELO-GaN basal layer. Under 50 mW CW operation at 70°C, a MTTF of over 5000 h was realized whenthe dark spot density (indicative of dislocation density) is less than ~5×106 cm-2. Power consumption under 50mW CW operation at 70°C was approximately 0.33 W, independent of the dislocation density.

Monochromatic radiography of high energy density physics experiments on the MAGPIE generator.

PubMed

Hall, G N; Burdiak, G C; Suttle, L; Stuart, N H; Swadling, G F; Lebedev, S V; Smith, R A; Patankar, S; Suzuki-Vidal, F; de Grouchy, P; Harvey-Thompson, A J; Bennett, M; Bland, S N; Pickworth, L; Skidmore, J

2014-11-01

A monochromatic X-ray backlighter based on Bragg reflection from a spherically bent quartz crystal has been developed for the MAGPIE pulsed power generator at Imperial College (1.4 MA, 240 ns) [I. H. Mitchell et al., Rev. Sci. Instrum. 67, 1533 (2005)]. This instrument has been used to diagnose high energy density physics experiments with 1.865 keV radiation (Silicon He-α) from a laser plasma source driven by a ∼7 J, 1 ns pulse from the Cerberus laser. The design of the diagnostic, its characterisation and performance, and initial results in which the instrument was used to radiograph a shock physics experiment on MAGPIE are discussed.

Toward a US Army Pacific (USARPAC) rapid deployment medical component in support of Human Assistance/Disaster Relief (HA/DR) operations: challenges with "Going in Light".

PubMed

Johnson, Ralph J

2016-01-01

This article reports the exploratory development and study efforts regarding the viability of a novel "going-in light" or "Going Light" medical component in support of US Army Pacific (USARPAC) Humanitarian Assistance/Disaster Relief (HA/DR) missions, namely, a BLU-MED ® incremental modular equipment package along with a Rapid Deployment Medical Team (RDMT). The study was conducted to uncover a way for the U.S. Army to: (1) better medically support the greater U.S. military Pacific Command, (2) prepare the Army for Pacific HA/DR contingencies, and (3) imprint a swift presence and positive contribution to Pacific HA/DR operations. The findings were derived from an intensive quasi-Military Decision Making Planning (MDMP) process, specifically, the Oracle Delphi. This process was used to: (1) review a needs assessment on the profile of disasters in general and the Pacific in particular and (2) critically examine the viability and issues surrounding a Pacific HA/DR medical response of going in light and incrementally. The Pacific area of operations contains 9 of 15 countries most at risk for disasters in the most disaster-prone region of the world. So, it is not a matter of whether a major, potentially large-scale lethal disaster will occur but rather when. Solid empirical research has shown that by every outcome measured Joint Forces (Army, Navy, Air Force, and Marines) medical HA/DR operations have been inordinately successful and cost-effective when they employed U.S. Army medical assets inland near disasters' kinetic impact and combined sister services' logistical support and expertise. In this regard, USARPAC has the potential to go in light and successfully fill a vital HA/DR medical response gap with the RDMT and a BLU-MED ® . However, initially going in fast and light and expanding and contracting as the situation dictates comes with subsequent challenges as briefly described herein that must be addressed. The challenges to going in light are not insurmountable "show stoppers." They can be identified and addressed through planning and preparation. Hopefully, the acquisition rapid response light components will equip commanders with more effective options with which to conduct Pacific HA/DR operations and be a focal point for effective joint operations.

New cryogenic temperature monitor: PLT-HPT-32

NASA Astrophysics Data System (ADS)

Viera Curbelo, Teodora Aleida; Martín-Fernández, Sergio Gonzáles; Hoyland, R.; Vega-Moreno, A.; Cozar Castellano, Juan; Gómez Reñasco, M. F.; Aguiar-González, M.; Pérez de Taoro, Angeles; Sánchez-de la Rosa, V.; Rubiño-Martín, J. A.; Génova-Santos, R.

2016-07-01

The PLT-HPT-32, a new cryogenic temperature monitor, has been developed by the Institute of Astrophysics of the Canary Islands (IAC) and an external engineering company (Sergio González Martín-Fernandez). The PLT-HPT-32 temperature monitor offers precision measurement in a wide range of cryogenic and higher-temperature applications with the ability to easily monitor up to 32 sensor channels. It provides better measurement performance in applications where researchers need to ensure accuracy and precision in their low cryogenic temperature monitoring. The PLT-HPT-32 supports PTC RTDs such as platinum sensors, and diodes such as the Lake Shore DT-670 Series. Used with silicon diodes, it provides accurate measurements in cryo-cooler applications from 16 K to above room temperature. The resolution of the measurement is less than 0.1K. Measurements can be displayed in voltage units or Kelvin units. For it, two different tables can be used. One can be programmed by the user, and the other one corresponds to Lake Shore DT670 sensor that comes standard. There are two modes of measuring, the instantaneous mode and averaged mode. In this moment, all channels must work in the same mode but in the near future it expected to be used in blocks of eight channels. The instantaneous mode takes three seconds to read all channels. The averaged mode takes one minute to average twenty samples in all channels. Alarm thresholds can be configured independently for each input. The alarm events, come from the first eight channels, can activate the unit's relay outputs for hard-wired triggering of other systems or audible annunciators. Activate relays on high, low, or both alarms for any input. For local monitoring, "Stand-Alone Mode", the front panel of the PLT-HPT-32 features a bright liquid crystal display with an LED backlight that shows up to 32 readings simultaneously. Plus, monitoring can be done over a network "Remote Control Mode". Using the Ethernet port on the PLT-HPT-32, you can keep an eye on temperatures, log measurement and configured remotely via a Networked local PC or even remotely over a TCP/IP Internet connection from anywhere.

Tobacco industry tactics with advertisements at the point of sale in Mumbai.

PubMed

Patel, S; Rendell, H; Maudgal, S; Oswal, K

2013-01-01

The Cigarettes and Other Tobacco Products (Prohibition of Advertising and Regulations of Trade and Commerce, Production, Supply and Distribution) Act 2003 (COTPA) set out a number of stringent regulations to address tobacco promotion, some of which were revised in 2004. The aim of the study was to monitor the industry tactics at the point of sale with advertising and promotion of tobacco product in Mumbai. The study was carried out by Cancer Patients Aid Association in Mumbai with the help of volunteers. The surveys consisted of two parts, observational information and an interviewer administered questionnaire. Observations like size of board, display of advertisement, backlighting, and use of any promotion were noted. A questionnaire captured information about any incentives from tobacco companies for advertisement and promotion was administered to the vendors who agreed to participate. Study was approved by the Scientific and independent Ethics committee. Total 125 establishments (58 shops, 55 kiosks, 12 other sites) with display boards were surveyed across 5 wards in Mumbai. It was noted that the most common violation was the placements of boards, mainly placed above the shop. The display boards were oversized and few of the advertisements were highlighted with backlights. Out of 125 tobacco vendors surveyed, 107 (85.5%) vendors agreed to answer the questionnaire. We noted that a majority of 67% (84 vendors) stated that they had been approached by tobacco companies to place the signages during the past 5 years post COTPA came into effect. 79 vendors (65 %) admitted to being paid by the tobacco companies. Although the civil society and various non-governmental organizations has casted voice against the industry tactics but ineffective enforcement of the law is a major hurdle. It is likely that cigarette companies will be further able to overcome advertising restrictions by finding loopholes in tobacco legislation unless the decision makers ban it comprehensively as evident in other countries.

Constancy of built-in luminance meter measurements in diagnostic displays

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

Silosky, M., E-mail: michael.silosky@ucdenver.edu; Marsh, R. M.

2013-12-15

Purpose: Liquid crystal displays used to interpret medical images are often equipped with built-in luminance meters to evaluate luminance response and Grayscale Standard Display Function conformance. This work evaluates agreement between luminance reported by the built-in meters and external measurements. Methods: The white level luminance was measured using a built-in meter and an external meter for 93 primary review workstations (Models MFGD 3420 and MDCG 3120-CB) with between 117 and 49 336 backlight hours (BLH). Measured luminance values were compared viat-test for displays with less than 25 000 BLH and those with more than 25 000 BLH. Bias between meters was also evaluated.more » Changes in luminance uniformity with increasing backlight hours were explored by determining the maximum luminance deviation (MLD) for subsets of these displays with less than 800 BLH and greater than 35 000 BLH. Results: The mean difference between built-in and external luminance measurements was 5.84% and 38.92% for displays with less than 25 000 and greater than 25 000 BLH, respectively, with a statistically significant difference in the means (p < 0.001). For displays with low BLH, a statistically significant bias was observed (p < 0.001) between built-in and external measurements. A high degree of correlation was observed between measurements made with two separate external meters (r = 0.999). The mean MLD was 9.5% and 11.2% for MDCG 3120-CB displays with less than 800 and greater than 35 000 BLH, respectively. The difference in the mean values was not statistically significant (p < 0.001). Conclusions: Disagreement between the white level luminance measured using the built-in and external meter increased with BLH. Consequently, reliance on values reported by the built-in luminance meter may result in a reduction in image contrast with time. Recommendations have been proposed regarding luminance response testing and corrective action for failing displays.« less

Backlighting the Universe: Understanding the Large-Scale Structure Through Cosmic Microwave Background Observations

NASA Astrophysics Data System (ADS)

Schaan, Emmanuel Sebastien

The primary fluctuations in the cosmic microwave background (CMB), the leftover heat from the big bang, have revealed invaluable clues about our universe (age, history, geometry, composition), and are now measured almost to the cosmic variance limit. While important fundamental physics questions remain to be answered from the primary CMB alone (e.g., detection of gravitational waves from inflation, number of relativistic species), many others require looking beyond the primary anisotropies: what is dark energy, this mysterious component responsible for the accelerated expansion of the universe? What is the nature of the dark matter, five times more abundant than ordinary matter? What are the masses of the neutrinos? The clustering pattern in the spatial distribution of galaxies across the universe, the so-called large-scale structure (LSS), contains the key to these fundamental physics questions, as well as many tightly related astrophysical questions: what are the key processes in galaxy formation? How did the universe transition from neutral to ionized, one billion years after the big bang? However, several hurdles hinder extracting this information: non-linear evolution under gravity is complex to model and turns independent Gaussian initial conditions into coupled non-Gaussian modes; uncertain astrophysical effects obscure the connection between visible and dark matter, and alter the matter power spectrum on small-scales; LSS observables are often complex and systematics-limited. In this thesis, I tackle these issues and explore various ways of using the CMB as a backlight for the LSS, to illuminate aspects of its uncertain physics and systematics. In the coming years, ever more sensitive CMB experiments (AdvACT, SPT-3G, Simons Observatory, CMB Stage 4) will overlap with imaging surveys (DES, HSC, LSST, Euclid, WFIRST) and spectroscopic surveys (DESI, PFS), thus greatly magnifying the power of the methods I developed, and helping to answer some of the most pressing astrophysics and fundamental physics questions.

X-ray diffraction diagnostic design for the National Ignition Facility

NASA Astrophysics Data System (ADS)

Ahmed, Maryum F.; House, Allen; Smith, R. F.; Ayers, Jay; Lamb, Zachary S.; Swift, David W.

2013-09-01

This paper describes the design considerations for Target Diffraction In-Situ (TARDIS), an x-ray diffraction diagnostic at the National Ignition Facility. A crystal sample is ramp-compressed to peak pressures between 10 and 30 Mbar and, during a pressure hold period, is probed with quasi-monochromatic x-rays emanating from a backlighter source foil. The crystal spectrography diffraction lines are recorded onto image plates. The crystal sample, filter, and image plates are packaged into one assembly, allowing for accurate and repeatable target to image plate registration. Unconverted laser light impinges upon the device, generating debris, the effects of which have been mitigated. Dimpled blast shields, high strength steel alloy, and high-z tungsten are used to shield and protect the image plates. A tapered opening was designed to provide adequate thickness of shielding materials without blocking the drive beams or x-ray source from reaching the crystal target. The high strength steel unit serves as a mount for the crystal target and x-ray source foil. A tungsten body contains the imaging components. Inside this sub-assembly, there are three image plates: a 160 degree field of view curved plate directly opposite the target opening and two flat plates for the top and bottom. A polycarbonate frame, coated with the appropriate filter material and embedded with registration features for image plate location, is inserted into the diagnostic body. The target assembly is metrologized and then the diagnostic assembly is attached.

Inspiring our future citizens and scientists: follow the Blue Paths (Percorsi nel Blu)!

NASA Astrophysics Data System (ADS)

Mioni, Erika; Stroobant, Mascha; Merlino, Silvia; Traverso, Roberto

2016-04-01

Very often we hear about scientific communication and education as separate and disconnected domains: in fact while the first one is seen more as a moment of disclosure for disseminating results and latest achievements and consequences (a look to our direct future), the second is, instead, identified as a formative moment in the long term, that often is based on obsolete and dated programs that refer to the past. What would happen if these two domains were, instead, considered as inseparable? As stated by Andrea Schleicher (OECD): "Schools have to prepare students for jobs that have not yet been created, technologies that have not yet been invented and problems that we don't know will arise." How to manage this challenge? The European Commission has proposed seven recommendations to follow for improving Science education and to bring more and more young people closer to STEM (Science, Technology, Engineering and Mathematics) disciplines. Especially three of them (Reccomendation n. 1, 4 and 7) pin out the to-do list for improving communication an education in Science, indicating that "a primary goal of science education across the EU should be to educate students both about the major explanations of the material world that science offers and about the way science works. Moreover teachers of science of the highest quality should be provided for students in primary and lower secondary school; moreover the emphasis in science education before 14 should be on engaging students with science and scientific phenomena (extended investigative work and 'hands-on' experimentation and not through a stress on the acquisition of canonical concepts). Last but not least: good quality teachers, with up to date knowledge and skills, are the foundation of any system of formal science education. Systems to ensure the recruitment, retention and continuous professional training of such individuals must be a policy priority in Europe". Blue Paths (Percorsi nel Blu) is a transversal project of Biological Sciences, carried out in a pilot school of La Spezia (ISA 2 "2 Giugno"), and that since several years involves students aged 4 to 18 years (and their families) in a long-term training program for environmental awareness and marine scientific research. The project is aimed at monitoring marine biocenosis (flora and fauna) from the upper and middle shore, using and integrating the Reef-Check Protocol (C.E.M. Coastal Environment Monitoring Protocol) with a new approach that motivates students to science, continuously over the years and bringing them closer to the work of Marine Scientists, raising awareness on biodiversity loss and the pollution within a specific area such as that of the Pelagos Sanctuary in the North Tyrrhenian and Ligurian Seas. Blue Paths (Percorsi nel Blu) is, hence, an example of education with a wider communication spectrum (not focused only to form a single class of students, but a whole community) and made possible thanks to a network of partners (including technology clusters, Institutions, Museums, Research Centers, Marine Protected Areas etc.). The presence of the network has allowed the enhancement of the Project under different points of view, including: - transformation in a participatory research project (the scientific results obtained by students are real products of research) of citizen science; - increase of educational opportunities (peer education, intergenerational education, tutoring); - increased visibility thanks to the participation in European projects for the Science Communication (European Researchers' Night project funded by the European Commission under the Marie Sklodowska-Curie actions); - enrichment of students' curriculum thanks to an adequate and real acquisition of key skills for future careers that can also inspire their actions as future citizens.

Droplet combustion at reduced gravity

NASA Technical Reports Server (NTRS)

Dryer, F. L.; Williams, F. A.

1988-01-01

The current work involves theoretical analyses of the effects identified, experiments in the NASA Lewis drop towers performed in the middeck areas of the Space Shuttle. In addition, there is laboratory work associated with the design of the flight apparatus. Calculations have shown that some of the test-matrix data can be obtained in drop towers, and some are achievable only in the space experiments. The apparatus consists of a droplet dispensing device (syringes), a droplet positioning device (opposing, retractable, hollow needles), a droplet ignition device (two matched pairs of retractable spark electrodes), gas and liquid handling systems, a data acquisition system (mainly giving motion-picture records of the combustion in two orthogonal views, one with backlighting for droplet resolution), and associated electronics.

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

Hall, G. N., E-mail: hall98@llnl.gov; Izumi, N.; Landen, O. L.

Compton radiography provides a means to measure the integrity, ρR and symmetry of the DT fuel in an inertial confinement fusion implosion near peak compression. Upcoming experiments at the National Ignition Facility will use the ARC (Advanced Radiography Capability) laser to drive backlighter sources for Compton radiography experiments and will use the newly commissioned AXIS (ARC X-ray Imaging System) instrument as the detector. AXIS uses a dual-MCP (micro-channel plate) to provide gating and high DQE at the 40–200 keV x-ray range required for Compton radiography, but introduces many effects that contribute to the spatial resolution. Experiments were performed at energiesmore » relevant to Compton radiography to begin characterization of the spatial resolution of the AXIS diagnostic.« less

Polar tent for reduced perturbation of NIF ignition capsules

NASA Astrophysics Data System (ADS)

Hammel, B. A.; Pickworth, L.; Stadermann, M.; Field, J.; Robey, H.; Scott, H. A.; Smalyuk, V.

2016-10-01

In simulations, a tent that contacts the capsule near the poles and departs tangential to the capsule surface greatly reduces the capsule perturbation, and the resulting mass injected into the hot-spot, compared to current capsule support methods. Target fabrication appears feasible with a layered tent (43-nm polyimide + 8-nm C) for increased stiffness. We are planning quantitative measurements of the resulting shell- ρR perturbation near peak implosion velocity (PV) using enhanced self-emission backlighting, achieved by adding 1% Ar to the capsule fill in Symcaps (4He + H). Layered DT implosions are also planned for an integrated test of capsule performance. We will describe the design and simulation predictions. Prepared by LLNL under Contract DE-AC52-07NA27344.

Annular flow in rod-bundle: Effect of spacer on disturbance waves

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

Pham, Son H.; Kunugi, Tomoaki

2016-08-01

A high-speed camera technique is used to study the effect of spacers on the disturbance waves present in annular two-phase flow within a rod-bundle geometry. Images obtained using a backlight configuration to visualize the spacer-wave interactions at the micro-scale resolution (in time and space) are discussed. This paper also presents additional images obtained using a reflected light configuration which provides new observations of the disturbance waves. These images show the separation effect caused by the spacer on the liquid film in which the size of generated liquid droplets can be controlled by the gas superficial velocity. Furthermore, the data confirmmore » that the spacer breaks the circumferential coherent structures of the waves.« less

Talbot-Lau x-ray deflectometer electron density diagnostic for laser and pulsed power high energy density plasma experiments (invited).

PubMed

Valdivia, M P; Stutman, D; Stoeckl, C; Mileham, C; Begishev, I A; Theobald, W; Bromage, J; Regan, S P; Klein, S R; Muñoz-Cordovez, G; Vescovi, M; Valenzuela-Villaseca, V; Veloso, F

2016-11-01

Talbot-Lau X-ray deflectometry (TXD) has been developed as an electron density diagnostic for High Energy Density (HED) plasmas. The technique can deliver x-ray refraction, attenuation, elemental composition, and scatter information from a single Moiré image. An 8 keV Talbot-Lau interferometer was deployed using laser and x-pinch backlighters. Grating survival and electron density mapping were demonstrated for 25-29 J, 8-30 ps laser pulses using copper foil targets. Moiré pattern formation and grating survival were also observed using a copper x-pinch driven at 400 kA, ∼1 kA/ns. These results demonstrate the potential of TXD as an electron density diagnostic for HED plasmas.

Proven high-performance display solution

NASA Astrophysics Data System (ADS)

Johnson, Rick J.; Shaw, James E.; Mosier, Don; Liss, Raymond L.; Prouty, Todd D.; Davis, Josh; Marzen, Vincent P.; Deloy, Christian T.

2002-08-01

Rockwell Collins serves both the military and the commercial segments by exploiting the common elements of these applications. Rockwell Collins has created a liquid crystal display family capable of 100:1 contrast ratio, 40:1 high ambient contrast, 0.25% specular reflectance, 0.1% diffuse reflectance, enhanced color stability over +/- 55H, 0-30V field of view, 300 fL with 10K:1 dimming range, color NVIS B compliance while exceeding environmental performance requirements though ruggedization. In order to meet the full range of display requirements at a system level, all the components must be understood and managed to meet the end solution of the final system. This paper details Rockwell Collins' optical performance using an avionics grade panel, third generation custom compensation, and solid state backlight.

KSC-08pd2340

NASA Image and Video Library

2008-08-07

CAPE CANAVERAL, Fla. – The Fine Guidance Sensor, or FGS, is being prepared for backlight inspection and cleaning in the Payload Hazardous Servicing Facility at NASA's Kennedy Space Center. The FGS is part of the payload for the fifth and final Hubble servicing mission, STS-125, aboard space shuttle Atlantis. An FGS consists of a large structure housing a collection of mirrors, lenses, servos, prisms, beam splitters and photomultiplier tubes. There are three fine guidance sensors on Hubble located at 90-degree intervals around the circumference of the telescope. Along with the gyroscopes, the optical sensors are a key component of Hubble’s highly complex but extraordinarily effective “pointing control system.” Atlantis is targeted to launch Oct. 8. Photo credit: NASA/Jack Pfaller

Talbot-Lau X-ray Deflectometer electron density diagnostic for laser and pulsed power high energy density plasma experiments

DOE PAGES

Valdivia, M. P.; Stutman, D.; Stoeckl, C.; ...

2016-04-21

Talbot-Lau X-ray Deflectometry has been developed as an electron density diagnostic for High Energy Density plasmas. The technique can deliver x-ray refraction, attenuation, elemental composition, and scatter information from a single Moiré image. An 8 keV Talbot-Lau interferometer was deployed using laser and x-pinch backlighters. Grating survival and electron density mapping was demonstrated for 25-29 J, 8-30 ps laser pulses using copper foil targets. Moire pattern formation and grating survival was also observed using a copper x-pinch driven at 400 kA, ~1 kA/ns. Lastly, these results demonstrate the potential of TXD as an electron density diagnostic for HED plasmas.

Low-β magnetic reconnection driven by the intense lasers with a double-turn capacitor-coil

NASA Astrophysics Data System (ADS)

Yuan, Xiaoxia; Zhong, Jiayong; Zhang, Zhe; Zhou, Weimin; Teng, Jian; Li, Yutong; Han, Bo; Yuan, Dawei; Lin, Jun; Liu, Chang; Li, Yanfei; Zhu, Baojun; Wei, Huigang; Liang, Guiyun; Hong, Wei; He, Shukai; Yang, Siqian; Zhao, Yongqiang; Deng, Zhigang; Lu, Feng; Zhang, Zhimeng; Zhu, Bin; Zhou, Kainan; Su, Jingqin; Zhao, Zongqing; Gu, Yuqiu; Zhao, Gang; Zhang, Jie

2018-06-01

A double-turn capacitor-coil is used to produce a magnetic field (38.5 T) and construct a topology of magnetic reconnection in a low-β (β < 1) plasma environment. The device is constructed with two metallic U-turn coils connecting two parallel metallic disks. High energy lasers are employed to ablate one disk spontaneously driving two currents in the two coils, which produces an interactive magnetic field topology. We demonstrated through experiments and numerical simulations that the reconnection process takes place between two non-uniform magnetic fields created by the coils, and that the plasma state and the associated magnetic topology in the process can be seen via the technology of the optical probe beam and the proton backlight.

Spool piece aperture: warm to cold temperature position changes

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

McInturff, A.D.

1982-12-01

In an effort to determine the position of the correction coil system contained in the spool piece in operation, a series of experiments were done in Lab 2 during the cryogenic testing of the spools. A special turn-around box was constructed which had a window through which a sighting could be made of the aperture of the coil packages. A set of four survey monuments were constructed with three point suspension, which were back-lighted by placing a small bulb behind each target which could be turned on individually external to the spool string while under vacuum and at any temperature.more » The targets were located at the ends of each correction coil package in their beam tube.« less

Improvement of density resolution in short-pulse hard x-ray radiographic imaging using detector stacks

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

Borm, B.; Gärtner, F.; Khaghani, D.

2016-09-15

We demonstrate that stacking several imaging plates (IPs) constitutes an easy method to increase hard x-ray detection efficiency. Used to record x-ray radiographic images produced by an intense-laser driven hard x-ray backlighter source, the IP stacks resulted in a significant improvement of the radiograph density resolution. We attribute this to the higher quantum efficiency of the combined detectors, leading to a reduced photon noise. Electron-photon transport simulations of the interaction processes in the detector reproduce the observed contrast improvement. Increasing the detection efficiency to enhance radiographic imaging capabilities is equally effective as increasing the x-ray source yield, e.g., by amore » larger drive laser energy.« less

Role Of High Speed Photography In The Testing Capabilities Of The Arnold Engineering Development Center (AEDC) Range And Track Facilities

NASA Astrophysics Data System (ADS)

Hendrix, Roy E.; Dugger, Paul H.

1983-03-01

Since the onset of user testing in the AEDC aeroballistic ranges in 1961, concentrated efforts in such areas as model launching techniques, test environment simulation, and specialized instrumentation have been made to enhance the usefulness of these test facilities. A wide selection of specialized instrumentation has been developed over the years to provide, among other features, panoramic photographic coverage of test models during flight. Pulsed ruby lasers, xenon flash lamps, visible-light spark sources, and flash X-ray systems are employed as short-duration radiation sources in various front-light and back-light photographic systems. Visible-light and near infrared image intensifier diodes are used to achieve high-speed shuttering in photographic pyrometry systems that measure surface temperatures of test models in flight. Turbine-driven framing cameras are used to provide multiframe photography of such high-speed phenomena as impact debris formation and model encounter with erosive fields. As a result, the capabilities of these ballistic range test units have increased significantly in regard to the types of tests that can be accommodated and to the quality and quantity of data that can be provided. Presently, five major range and companion track facilities are active in conducting hypervelocity testing in AEDC's von K6rman Gas Dynamics Facility (VKF): Ranges G, K, and S-1 and Tracks G and K. The following types of tests are conducted in these test units: ablation/erosion, transpiration-cooled nosetip (TCNT), nosetip transition, heat transfer, aerodynamic, cannon projectile, rocket contrail, reentry physics, and hypervelocity impact. The parallel achievements in high-speed photography and testing capabilities are discussed, and the significant role of photographic systems in the development of the overall testing capabilities of the AEDC range and track facilities is illustrated in numerous examples of photographic results.

Implicit high-order discontinuous Galerkin method with HWENO type limiters for steady viscous flow simulations

NASA Astrophysics Data System (ADS)

Jiang, Zhen-Hua; Yan, Chao; Yu, Jian

2013-08-01

Two types of implicit algorithms have been improved for high order discontinuous Galerkin (DG) method to solve compressible Navier-Stokes (NS) equations on triangular grids. A block lower-upper symmetric Gauss-Seidel (BLU-SGS) approach is implemented as a nonlinear iterative scheme. And a modified LU-SGS (LLU-SGS) approach is suggested to reduce the memory requirements while retain the good convergence performance of the original LU-SGS approach. Both implicit schemes have the significant advantage that only the diagonal block matrix is stored. The resulting implicit high-order DG methods are applied, in combination with Hermite weighted essentially non-oscillatory (HWENO) limiters, to solve viscous flow problems. Numerical results demonstrate that the present implicit methods are able to achieve significant efficiency improvements over explicit counterparts and for viscous flows with shocks, and the HWENO limiters can be used to achieve the desired essentially non-oscillatory shock transition and the designed high-order accuracy simultaneously.

The applicability of ordinary least squares to consistently short distances between taxa in phylogenetic tree construction and the normal distribution test consequences.

PubMed

Roux, C Z

2009-05-01

Short phylogenetic distances between taxa occur, for example, in studies on ribosomal RNA-genes with slow substitution rates. For consistently short distances, it is proved that in the completely singular limit of the covariance matrix ordinary least squares (OLS) estimates are minimum variance or best linear unbiased (BLU) estimates of phylogenetic tree branch lengths. Although OLS estimates are in this situation equal to generalized least squares (GLS) estimates, the GLS chi-square likelihood ratio test will be inapplicable as it is associated with zero degrees of freedom. Consequently, an OLS normal distribution test or an analogous bootstrap approach will provide optimal branch length tests of significance for consistently short phylogenetic distances. As the asymptotic covariances between branch lengths will be equal to zero, it follows that the product rule can be used in tree evaluation to calculate an approximate simultaneous confidence probability that all interior branches are positive.

Spectroscopic and crystal-field analysis of new Yb-doped laser materials

NASA Astrophysics Data System (ADS)

Haumesser, Paul-Henri; Gaumé, Romain; Viana, Bruno; Antic-Fidancev, Elisabeth; Vivien, Daniel

2001-06-01

Crystal-field effects are very important as far as laser performances of Yb-doped materials are concerned. In order to simplify the interpretation of low-temperature spectra, two tools derived from a careful examination of crystal-field interaction are presented. Both approaches are successfully applied in the case of new Yb-doped materials, namely Ca3Y2(BO3)4 (CYB), Ca3Gd2(BO3)4 (CaGB), Sr3Y(BO3)3 (SrYBO), Ba3Lu(BO3)3 (BLuB), Y2SiO5 (YSO), Ca2Al2SiO7 (CAS) and SrY4(SiO4)3O (SYS). The 2F7/2 splitting is particularly large in these materials and favourable to a quasi-three-level laser operating scheme. Calculations performed using the point charge electrostatic model for these compounds and using a consistent set of effective atomic charges confirm the experimental results. This should permit to use this model in a predictive approach.

Optical multidimensional multiple access(O-MDMA): a new concept for free-space laser communication based on photonic mixer devices

NASA Astrophysics Data System (ADS)

Hess, Holger; Albrecht, Martin; Grothof, Markus; Hussmann, Stephan; Schwarte, Rudolf

2004-01-01

Working on optical distance measurement a new optical correlator was developed at the Institute for Data Processing of the University of Siegen in the last years. The so called Photonic Mixer Device (PMD), to be meant originally for laser ranging systems, offers a lot of advantages for wireless optical data communication like high speed spatial light demodulation up to the GHz range and inherent backlight suppression. This contribution describes the application of such PMDs in a free space interconnect based on the principle of Multi Dimensional Multiple Access (MDMA) and the advantages of this new approach, starting from the MDMA principle and followed by the fundamental functionality of PMDs. After that an Optical MDMA (O-MDMA) demonstrator and first measurement results will be presented.

Talbot-Lau x-ray deflectometer electron density diagnostic for laser and pulsed power high energy density plasma experiments (invited)

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

Valdivia, M. P., E-mail: mpvaldivia@pha.jhu.edu; Stutman, D.; Stoeckl, C.

2016-11-15

Talbot-Lau X-ray deflectometry (TXD) has been developed as an electron density diagnostic for High Energy Density (HED) plasmas. The technique can deliver x-ray refraction, attenuation, elemental composition, and scatter information from a single Moiré image. An 8 keV Talbot-Lau interferometer was deployed using laser and x-pinch backlighters. Grating survival and electron density mapping were demonstrated for 25–29 J, 8–30 ps laser pulses using copper foil targets. Moiré pattern formation and grating survival were also observed using a copper x-pinch driven at 400 kA, ∼1 kA/ns. These results demonstrate the potential of TXD as an electron density diagnostic for HED plasmas.

Counterpropagating Radiative Shock Experiments on the Orion Laser

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

Suzuki-Vidal, F.; Clayson, T.; Stehlé, C.

We present new experiments to study the formation of radiative shocks and the interaction between two counterpropagating radiative shocks. The experiments are performed at the Orion laser facility, which is used to drive shocks in xenon inside large aspect ratio gas cells. The collision between the two shocks and their respective radiative precursors, combined with the formation of inherently three-dimensional shocks, provides a novel platform particularly suited for the benchmarking of numerical codes. The dynamics of the shocks before and after the collision are investigated using point-projection x-ray backlighting while, simultaneously, the electron density in the radiative precursor was measuredmore » via optical laser interferometry. Modeling of the experiments using the 2D radiation hydrodynamic codes nym and petra shows very good agreement with the experimental results.« less

Design of Initial Opacity Platform at the National Ignition Facility

NASA Astrophysics Data System (ADS)

Heeter, R. F.; Ahmed, M. F.; Ayers, S. L.; Emig, J. A.; Iglesias, C. A.; Liedahl, D. A.; Schneider, M. B.; Wilson, B. G.; Huffman, E. J.; King, J. A.; Opachich, Y. P.; Ross, P. W.; Bailey, J. E.; Rochau, G. A.; Craxton, R. S.; Garcia, E. M.; McKenty, P. W.; Zhang, R.; Cardenas, T.; Devolder, B. G.; Dodd, E. S.; Kline, J. L.; Sherrill, M. E.; Perry, T. S.

2016-10-01

The absorption and re-emission of x-rays by partly stripped ions plays a critical role in stars and in many laboratory plasmas. A NIF Opacity Platform has been designed to resolve a persistent disagreement between theory and experiments on the Sandia Z facility, studying iron in conditions closely related to the solar radiation-convection transition boundary. A laser heated hohlraum ``oven'' will produce iron plasmas at temperatures >150 eV and electron densities >=7x1021/cm3, and be probed with continuum X-rays from a capsule implosion backlighter source. The resulting X-ray transmission spectra will be recorded on a specially designed Opacity Spectrometer. This work was performed under the auspices of the U.S. Department of Energy by LLNL under Contract DE-AC52-07NA27344.

Closer Look: Majestic Mountains and Frozen Plains

NASA Image and Video Library

2015-09-17

Just 15 minutes after its closest approach to Pluto on July 14, 2015, NASA's New Horizons spacecraft looked back toward the sun and captured a near-sunset view of the rugged, icy mountains and flat ice plains extending to Pluto's horizon. The smooth expanse of the informally named Sputnik Planum (right) is flanked to the west (left) by rugged mountains up to 11,000 feet (3,500 meters) high, including the informally named Norgay Montes in the foreground and Hillary Montes on the skyline. The backlighting highlights more than a dozen layers of haze in Pluto's tenuous but distended atmosphere. The image was taken from a distance of 11,000 miles (18,000 kilometers) to Pluto; the scene is 230 miles (380 kilometers) across. http://photojournal.jpl.nasa.gov/catalog/PIA19947

A comparison of hydro-instabilities in CH, HDC, and beryllium ablators on NIF

NASA Astrophysics Data System (ADS)

Smalyuk, V. A.; Robey, H. F.; Ali, S.; Berzak Hopkins, L. F.; Casey, D. T.; Celliers, P. M.; Clark, D. S.; Felker, S. J.; Field, J. E.; Haan, S. W.; Hammel, B. A.; Hsing, W. W.; Kroll, J. J.; Landen, O. L.; Lepape, S.; Macphee, A. G.; Martinez, D.; Milovich, J.; Nikroo, A.; Pickworth, L.; Stadermann, M.; Weber, C. R.; Kline, J.; Loomis, E.; Yi, A.

2017-10-01

A comparison of the hydrodynamic growth in plastic, high-density carbon, and beryllium ablators will be presented in indirect-drive implosions on National Ignition Facility. This comparison is based on experimentally measured instabilities in all phases of implosions for the three ablators. The 2-D and 3-D perturbations were measured at the ablation-surface with the Hydrodynamic Growth Radiography platform. In the deceleration phase of implosions, innovative self-emission and ``self-backlight'' techniques were used. Results of the 3-D perturbation growth including engineering features will also be presented for convergence up to 20 and compared for the three ablators. This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.

Switching of liquid crystal devices between reflective and transmissive modes

NASA Astrophysics Data System (ADS)

Lin, Hui-Chi; Wang, Chih-Hung

Transflective liquid crystal displays (LCD) are commonly known that each pixel is divided into reflective (R) and transmissive (T) subpixels. The R mode uses ambient light, while the T mode utilizes a backlight to display images. However, the division of the pixel decreases the light efficiency and the resolution. This study demonstrates a gelator-doped liquid crystal (LC) devices, that is switchable between R and T modes, without sub-pixel division. The R and T modes are designed to have bend configurations with phase retardation of π/2 and π, respectively. The phase retardation of a LC device can be varied and fixed by the thermoreversible association and dissociation of the gelator molecules. It is believed that the proposed device is a potential candidate for portable information systems.

Proton Radiography of Spontaneous Fields, Plasma Flows and Dynamics in X-Ray Driven Inertial-Confinement Fusion Implosions

NASA Astrophysics Data System (ADS)

Li, C. K.; Seguin, F. H.; Frenje, J. A.; Rosenberg, M.; Zylstra, A. B.; Rinderknecht, H. G.; Petrasso, R. D.; Amendt, P. A.; Landen, O. L.; Town, R. P. J.; Betti, R.; Knauer, J. P.; Meyerhofer, D. D.; Back, C. A.; Kilkenny, J. D.; Nikroo, A.

2010-11-01

Backlighting of x-ray-driven implosions in empty hohlraums with mono-energetic protons on the OMEGA laser facility has allowed a number of important phenomena to be observed. Several critical parameters were determined, including plasma flow, three types of spontaneous electric fields and megaGauss magnetic fields. These results provide insight into important issues in indirect-drive ICF. Even though the cavity is effectively a Faraday cage, the strong, local fields inside the hohlraum can affect laser-plasma instabilities, electron distributions and implosion symmetry. They are of fundamental scientific importance for a range of new experiments at the frontiers of high-energy-density physics. Future experiments designed to characterize the field formation and evolution in low-Z gas fill hohlraums will be discussed.

Numerical analysis of lateral illumination lightpipes using elliptical grooves

NASA Astrophysics Data System (ADS)

Sánchez-Guerrero, Guillermo E.; Viera-González, Perla M.; Martínez-Guerra, Edgar; Ceballos-Herrera, Daniel E.

2017-09-01

Lightpipes are used for illumination in applications such as back-lighting or solar cell concentrators due to the high irradiance uniformity, but its optimal design requires several parameters. This work presents a procedure to design a square lightpipe to control the light-extraction on its lateral face using commercial LEDs placed symmetrically in the lightpipe frontal face. We propose the use of grooves using total internal reflection placed successively in the same face of extraction to control the area of emission. The LED area of emission is small compared with the illuminated area, and, as expected, the lateral face total power is attenuated. These grooves reduce the optical elements in the system and can control areas of illumination. A mathematical and numerical analysis are presented to determine the dependencies on the light-extraction.

Counterpropagating Radiative Shock Experiments on the Orion Laser.

PubMed

Suzuki-Vidal, F; Clayson, T; Stehlé, C; Swadling, G F; Foster, J M; Skidmore, J; Graham, P; Burdiak, G C; Lebedev, S V; Chaulagain, U; Singh, R L; Gumbrell, E T; Patankar, S; Spindloe, C; Larour, J; Kozlova, M; Rodriguez, R; Gil, J M; Espinosa, G; Velarde, P; Danson, C

2017-08-04

We present new experiments to study the formation of radiative shocks and the interaction between two counterpropagating radiative shocks. The experiments are performed at the Orion laser facility, which is used to drive shocks in xenon inside large aspect ratio gas cells. The collision between the two shocks and their respective radiative precursors, combined with the formation of inherently three-dimensional shocks, provides a novel platform particularly suited for the benchmarking of numerical codes. The dynamics of the shocks before and after the collision are investigated using point-projection x-ray backlighting while, simultaneously, the electron density in the radiative precursor was measured via optical laser interferometry. Modeling of the experiments using the 2D radiation hydrodynamic codes nym and petra shows very good agreement with the experimental results.

Xenia Mission: Spacecraft Design Concept

NASA Technical Reports Server (NTRS)

Hopkins, R. C.; Johnson, C. L.; Kouveliotou, C.; Jones, D.; Baysinger, M.; Bedsole, T.; Maples, C. C.; Benfield, P. J.; Turner, M.; Capizzo, P.;

Counterpropagating Radiative Shock Experiments on the Orion Laser

DOE PAGES

Suzuki-Vidal, F.; Clayson, T.; Stehlé, C.; ...

2017-08-02

We present new experiments to study the formation of radiative shocks and the interaction between two counterpropagating radiative shocks. The experiments are performed at the Orion laser facility, which is used to drive shocks in xenon inside large aspect ratio gas cells. The collision between the two shocks and their respective radiative precursors, combined with the formation of inherently three-dimensional shocks, provides a novel platform particularly suited for the benchmarking of numerical codes. The dynamics of the shocks before and after the collision are investigated using point-projection x-ray backlighting while, simultaneously, the electron density in the radiative precursor was measuredmore » via optical laser interferometry. Modeling of the experiments using the 2D radiation hydrodynamic codes nym and petra shows very good agreement with the experimental results.« less

Field lens multiplexing in holographic 3D displays by using Bragg diffraction based volume gratings

NASA Astrophysics Data System (ADS)

Fütterer, G.

2016-11-01

Applications, which can profit from holographic 3D displays, are the visualization of 3D data, computer-integrated manufacturing, 3D teleconferencing and mobile infotainment. However, one problem of holographic 3D displays, which are e.g. based on space bandwidth limited reconstruction of wave segments, is to realize a small form factor. Another problem is to provide a reasonable large volume for the user placement, which means to provide an acceptable freedom of movement. Both problems should be solved without decreasing the image quality of virtual and real object points, which are generated within the 3D display volume. A diffractive optical design using thick hologram gratings, which can be referred to as Bragg diffraction based volume gratings, can provide a small form factor and high definition natural viewing experience of 3D objects. A large collimated wave can be provided by an anamorphic backlight unit. The complex valued spatial light modulator add local curvatures to the wave field he is illuminated with. The modulated wave field is focused onto to the user plane by using a volume grating based field lens. Active type liquid crystal gratings provide 1D fine tracking of approximately +/- 8° deg. Diffractive multiplex has to be implemented for each color and for a set of focus functions providing coarse tracking. Boundary conditions of the diffractive multiplexing are explained. This is done in regards to the display layout and by using the coupled wave theory (CWT). Aspects of diffractive cross talk and its suppression will be discussed including longitudinal apodized volume gratings.

Compact submicrosecond, high current generator for wire explosion experiments

NASA Astrophysics Data System (ADS)

Aranchuk, L. E.; Chuvatin, A. S.; Larour, J.

2004-01-01

The PIAF generator was designed for low total energy and high energy density experiments with liners, X-pinch or fiber Z-pinch loads. These studies are of interest for such applications as surface and material science, microscopy of biological specimens, lithography of x-ray sensitive resists, and x-ray backlighting of pulsed-power plasmas. The generator is based on an RLC circuit that includes six NWL 180 nF-50 kV capacitors that store up to 1.3 kJ. The capacitors are connected in parallel to a single multispark switch designed to operate at atmospheric pressure. The switch allows reaching a time delay between the trigger pulse and the current pulse of less than 80 ns and has jitter of 6 ns. The total inductance without a load compartment was optimized to be as low as 16 nH, which leads to extremely low impedance of ˜0.12 Ω. A 40 kV initial voltage provides 250 kA maximum current in a 6 nH inductive load with a 180 ns current rise time. PIAF has dimensions of 660×660×490 mm and weight of less than 100 kg, thus manifesting itself as robust, simple to operate, and cost effective. A description of the PIAF generator and the initial experimental results on PIAF with an X-pinch type load are reported. The generator was demonstrated to operate successfully with an X-pinch type load. The experiments first started with investigation of the previously unexplored X-pinch conduction time range, 100 ns-1 μs. A single short radiation pulse was obtained that came from a small, point-like plasma. The following x-ray source characteristics were achieved: typical hot spot size of 50-100 μm, radiation pulse duration of 1.5-2 ns, and radiation yield of about 250-500 mJ in the softer spectral range (hν⩾700 eV) and 50-100 mJ in the harder one (hν⩾1 keV). These results provide the potential for further application of this source, such as use as a backlight diagnostic tool.

Capillary-Driven Heat Transfer Experiment: Keeping It Cool in Space

NASA Technical Reports Server (NTRS)

Lekan, Jack F.; Allen, Jeffrey S.

1998-01-01

Capillary-pumped loops (CPL's) are devices that are used to transport heat from one location to another--specifically to transfer heat away from something. In low-gravity applications, such as satellites (and possibly the International Space Station), CPL's are used to transfer heat from electrical devices to space radiators. This is accomplished by evaporating one liquid surface on the hot side of the CPL and condensing the vapor produced onto another liquid surface on the cold side. Capillary action, the phenomenon that causes paper towels to absorb spilled liquids, is used to "pump" the liquid back to the evaporating liquid surface (hot side) to complete the "loop." CPL's require no power to operate and can transfer heat over distances as large as 30 ft or more. Their reliance upon evaporation and condensation to transfer heat makes them much more economical in terms of weight than conventional heat transfer systems. Unfortunately, they have proven to be unreliable in space operations, and the explanation for this unreliability has been elusive. The Capillary-Driven Heat Transfer (CHT) experiment is investigating the fundamental fluid physics phenomena thought to be responsible for the failure of CPL's in low-gravity operations. If the failure mechanism can be identified, then appropriate design modifications can be developed to make capillary phase-change heat-transport devices a more viable option in space applications. CHT was conducted onboard the Space Shuttle Columbia during the first Microgravity Science Laboratory (MSL-1) mission, STS-94, which flew from July 1 to 17, 1997. The CHT glovebox investigation, which was conceived by Dr. Kevin Hallinan and Jeffrey Allen of the University of Dayton, focused on studying the dynamics associated with the heating and cooling at the evaporating meniscus within a capillary phase-change device in a low-gravity environment. The CHT experimental hardware was designed by a small team of engineers from Aerospace Design & Fabrication (ADF), the NASA Lewis Research Center, and the University of Dayton. The hardware consisted of two experiment modules that each contained an instrumented test loop (idealized capillary-pumped loop), a base unit for power conversion and backlighting, a display unit with 15 LED's (light-emitting diodes) to display temperatures, pressure, heater power, and time, a control unit to select heaters and heater settings, a cooling fan, and associated cables.

Recent results of the Defect-Induced Mix Experiments (DIME) on NIF

NASA Astrophysics Data System (ADS)

Schmitt, M. J.; Bradley, P. A.; Cobble, J. A.; Hakel, P.; Hsu, S. C.; Krasheninnikova, N. S.; Kyrala, G. A.; Murphy, T. J.; Obrey, K. A.; Shah, R. C.; Tregillis, I. L.; Craxton, S. C.; McKenty, P. W.; Mancini, R. C.; Johns, H. M.; Joshi, Tirtha; Mayes, Daniel

2012-10-01

Investigations of directly driven implosions have been performed including experiments on Omega, and more recently NIF, to deduce the extent and uniformity of 4π and defect-induced mix near the shell/gas interface of plastic (CH) capsules filled with 5 atm D2 gas. Imaging diagnostics are used to measure the spatial variation of mix caused by the growth of non-uniformities in both capsule and laser drive characteristics. Thin (2μm) layers containing 1-2% (atomic) mid-Z dopants are imaged spectrally at late time in the implosion using multiple monochromatic imaging of H-like and He-like atomic line emission. Areal image backlighting of the capsules provides both r(t) and the symmetry of the implosion. Recent results will be shown including inferred 4π mix width, laser imprint induced mix, and mix from capsule variations.

X-Pinch And Its Applications In X-ray Radiograph

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

Zou Xiaobing; Wang Xinxin; Liu Rui

2009-07-07

An X-pinch device and the related diagnostics of x-ray emission from X-pinch were briefly described. The time-resolved x-ray measurements with photoconducting diodes show that the x-ray pulse usually consists of two subnanosecond peaks with a time interval of about 0.5 ns. Being consistent with these two peaks of the x-ray pulse, two point x-ray sources of size ranging from 100 mum to 5 mum and depending on cut-off x-ray photon energy were usually observed on the pinhole pictures. The x-pinch was used as x-ray source for backlighting of the electrical explosion of single wire and the evolution of X-pinch, andmore » for phase-contrast imaging of soft biological objects such as a small shrimp and a mosquito.« less

Review of the evolution of display technologies for next-generation aircraft

NASA Astrophysics Data System (ADS)

Tchon, Joseph L.; Barnidge, Tracy J.

2015-05-01

Advancements in electronic display technologies have provided many benefits for military avionics. The modernization of legacy tanker transport aircraft along with the development of next-generation platforms, such as the KC-46 aerial refueling tanker, offers a timeline of the evolution of avionics display approaches. The adaptation of advanced flight displays from the Boeing 787 for the KC-46 flight deck also provides examples of how avionics display solutions may be leveraged across commercial and military flight decks to realize greater situational awareness and improve overall mission effectiveness. This paper provides a review of the display technology advancements that have led to today's advanced avionics displays for the next-generation KC-46 tanker aircraft. In particular, progress in display operating modes, backlighting, packaging, and ruggedization will be discussed along with display certification considerations across military and civilian platforms.

Pattern optimization of compound optical film for uniformity improvement in liquid-crystal displays

NASA Astrophysics Data System (ADS)

Huang, Bing-Le; Lin, Jin-tang; Ye, Yun; Xu, Sheng; Chen, En-guo; Guo, Tai-Liang

2017-12-01

The density dynamic adjustment algorithm (DDAA) is designed to efficiently promote the uniformity of the integrated backlight module (IBLM) by adjusting the microstructures' distribution on the compound optical film (COF), in which the COF is constructed in the SolidWorks and simulated in the TracePro. In order to demonstrate the universality of the proposed algorithm, the initial distribution is allocated by the Bezier curve instead of an empirical value. Simulation results maintains that the uniformity of the IBLM reaches over 90% only after four rounds. Moreover, the vertical and horizontal full width at half maximum of angular intensity are collimated to 24 deg and 14 deg, respectively. Compared with the current industry requirement, the IBLM has an 85% higher luminance uniformity of the emerging light, which demonstrate the feasibility and universality of the proposed algorithm.

KSC-08pd2342

NASA Image and Video Library

2008-08-08

CAPE CANAVERAL, Fla. – Technicians in the Payload Hazardous Servicing Facility at NASA's Kennedy Space Center perform backlight inspection and cleaning on the Fine Guidance Sensor, or FGS. The FGS is part of the payload for the fifth and final Hubble servicing mission, STS-125, aboard space shuttle Atlantis. Black light inspection uses UVA fluorescence to detect possible particulate microcontamination, minute cracks or fluid leaks. An FGS consists of a large structure housing a collection of mirrors, lenses, servos, prisms, beam splitters and photomultiplier tubes. There are three fine guidance sensors on Hubble located at 90-degree intervals around the circumference of the telescope. Along with the gyroscopes, the optical sensors are a key component of Hubble’s highly complex but extraordinarily effective “pointing control system.” Atlantis is targeted to launch Oct. 8. Photo credit: NASA/Jack Pfaller

KSC-08pd2341

NASA Image and Video Library

2008-08-08

CAPE CANAVERAL, Fla. – Technicians in the Payload Hazardous Servicing Facility at NASA's Kennedy Space Center perform backlight inspection and cleaning on the Fine Guidance Sensor, or FGS. The FGS is part of the payload for the fifth and final Hubble servicing mission, STS-125, aboard space shuttle Atlantis. Black light inspection uses UVA fluorescence to detect possible particulate microcontamination, minute cracks or fluid leaks. An FGS consists of a large structure housing a collection of mirrors, lenses, servos, prisms, beam splitters and photomultiplier tubes. There are three fine guidance sensors on Hubble located at 90-degree intervals around the circumference of the telescope. Along with the gyroscopes, the optical sensors are a key component of Hubble’s highly complex but extraordinarily effective “pointing control system.” Atlantis is targeted to launch Oct. 8. Photo credit: NASA/Jack Pfaller

Flash Kα radiography of laser-driven solid sphere compression for fast ignition

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

Sawada, H.; Lee, S.; Shiroto, T.

2016-06-20

Time-resolved compression of a laser-driven solid deuterated plastic sphere with a cone was measured with flash Kα x-ray radiography. A spherically converging shockwave launched by nanosecond GEKKO XII beams was used for compression while a flash of 4.51 keV Ti Kα x-ray backlighter was produced by a high-intensity, picosecond laser LFEX (Laser for Fast ignition EXperiment) near peak compression for radiography. Areal densities of the compressed core were inferred from two-dimensional backlit x-ray images recorded with a narrow-band spherical crystal imager. The maximum areal density in the experiment was estimated to be 87 ± 26 mg/cm 2. Lastly, the temporalmore » evolution of the experimental and simulated areal densities with a 2-D radiation-hydrodynamics code is in good agreement.« less

Note: A monoenergetic proton backlighter for the National Ignition Facility

DOE PAGES

Rygg, J. R.; Zylstra, A. B.; Seguin, F. H.; ...

2015-11-12

Here, a monoenergetic, isotropic proton source suitable for proton radiography applications has been demonstrated at the National Ignition Facility (NIF). A deuterium and helium-3 gas-filled glass capsule was imploded with 39 kJ of laser energy from 24 of NIF’s 192 beams. Spectral, spatial, and temporal measurements of the 15-MeV proton product of the 3He(d,p) 4He nuclear reaction reveal a bright (10 10 protons/sphere), monoenergetic (ΔE/E = 4%) spectrum with a compact size (80 µm) and isotropic emission (~13% proton fluence variation and <0.4% mean energy variation). Simultaneous measurements of products produced by the D(d,p)T and D(d,n) 3He reactions also showmore » 2 × 10 10 isotropically distributed 3-MeV protons.« less

Spatial resolution measurements of the advanced radiographic capability x-ray imaging system at energies relevant to Compton radiography

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

Hall, G. N.; Izumi, N.; Landen, O. L.

2016-08-03

Compton radiography provides a means to measure the integrity, ρR and symmetry of the DT fuel in an inertial confinement fusion implosion near peak compression. Upcoming experiments at the National Ignition Facility will use the ARC (Advanced Radiography Capability) laser to drive backlighter sources for Compton radiography experiments, and will use the newly commissioned AXIS (ARC X-ray Imaging System) instrument as the detector. AXIS uses a dual-MCP (micro channel plate) to provide gating and high DQE at the 40–200keV x-ray range required for Compton radiography, but introduces many effects that contribute to the spatial resolution. Here, experiments were performed atmore » energies relevant to Compton radiography to begin characterization of the spatial resolution of the AXIS diagnostic.« less

Flash Kα radiography of laser-driven solid sphere compression for fast ignition

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

Sawada, H.; Lee, S.; Nagatomo, H.

2016-06-20

Time-resolved compression of a laser-driven solid deuterated plastic sphere with a cone was measured with flash Kα x-ray radiography. A spherically converging shockwave launched by nanosecond GEKKO XII beams was used for compression while a flash of 4.51 keV Ti Kα x-ray backlighter was produced by a high-intensity, picosecond laser LFEX (Laser for Fast ignition EXperiment) near peak compression for radiography. Areal densities of the compressed core were inferred from two-dimensional backlit x-ray images recorded with a narrow-band spherical crystal imager. The maximum areal density in the experiment was estimated to be 87 ± 26 mg/cm{sup 2}. The temporal evolution of the experimental andmore » simulated areal densities with a 2-D radiation-hydrodynamics code is in good agreement.« less

Observation of Burial and Migration of Instrumented Surrogate Munitions Deployed in the Swash Zone

NASA Astrophysics Data System (ADS)

Cristaudo, D.; Puleo, J. A.; Bruder, B. L.

2017-12-01

Munitions (also known as unexploded ordnance; UXO) in the nearshore environment due to past military activities, may be found on the beach, constituting a risk for beach users. Munitions may be transported from offshore to shallower water and/or migrate along the coast. In addition, munitions may bury in place or be exhumed due to hydrodynamic forcing. Observations on munitions mobility have generally been collected offshore, while observations in the swash zone are scarce. The swash zone is the region of the beach alternately covered by wave runup where hydrodynamic processes may be intense. Studies of munitions mobility require the use of realistic surrogates to quantify mobility/burial and hydrodynamic forcing conditions. Four surrogates (BLU-61 Cluster Bomb, 81 mm Mortar, M151-70 Hydra Rocket and M107 155 mm High Explosive Howitzer) were developed and tested during large-scale laboratory and field studies. Surrogates house sensors that measure different components of motion. Errors between real munitions and surrogate parameters (mass, center of gravity and axial moment of inertia) are all within an absolute error of 20%. Internal munitions sensors consist of inertial motion units (for acceleration and angular velocity in and around the three directions and orientation), pressure transducers (for water depth above surrogate), shock recorders (for high frequency acceleration to detect wave impact on the surrogate), and an in-house designed array of optical sensors (for burial/exposure and rolling). An in situ array of sensors to measure hydrodynamics, bed morphology and sediment concentrations, was deployed in the swash zone, aligned with the surrogate deployment. Data collected during the studies will be shown highlighting surrogate sensor capabilities. Sensors response will be compared with GPS measurements and imagery from cameras overlooking the study sites of surrogate position as a function of time. Examples of burial/exposure and migration of surrogates will be discussed. Relationships between burial/migration and incoming forcing conditions, bed slope and munitions characteristics (such as specific density, length/diameter) will all be shown.

Learning in the thick of it.

PubMed

Darling, Marilyn; Parry, Charles; Moore, Joseph

2005-01-01

The U.S. Army's Opposing Force (OPFOR) is a 2,500-member brigade whose job is to help prepare soldiers for combat. Created to be the meanest, toughest foe that soldiers will ever face, OPFOR engages units-in-training in a variety of mock campaigns under a wide range of conditions. Every month, a fresh brigade of more than 4,000 soldiers takes on this standing enemy. OPFOR, which is stationed in the California desert, always has the home-court advantage. But the force being trained--called BLU FOR--is numerically and technologically superior. It possesses more resources and better, more available data. It is made up of experienced soldiers. And it knows just what to expect, because OPFOR shares its methods from previous campaigns with BLUFOR's commanders. In short, each BLUFOR brigade is given practically every edge. Yet OPFOR almost always wins. Underlying OPFOR's consistent success is the way it uses the after-action review (AAR), a method for extracting lessons from one event or project and applying them to others. AAR meetings became a popular business tool after Shell Oil began experimenting with them in 1998. Most corporate AARs, however, are faint echoes of the rigorous reviews performed by OPFOR. Companies tend to treat the process as a pro-forma wrap-up, drawing lessons from an action but rarely learning them. OPFOR's AARs, by contrast, generate raw material that is fed back into the execution cycle. And while OPFOR's reviews extract numerous lessons, the brigade does not consider a lesson to be learned until it is successfully applied and validated. It might not make sense for companies to adopt OPFOR's AAR processes in their entirety, but four fundamentals are mandatory: Lessons must benefit the team that extracts them. The AAR process must start atthe beginning of the activity. Lessons must link explicitly to future actions. And leaders must hold everyone, especially themselves, accountable for learning.

Effects of hydroxycinnamic acids on blue color expression of cyanidin derivatives and their metal chelates.

PubMed

Sigurdson, G T; Robbins, R J; Collins, T M; Giusti, M M

2017-11-01

Mechanisms to recreate many anthocyanin blue hues in nature are not fully understood, but interactions with metal ions and phenolic compounds are thought to play important roles. Bluing effects of hydroxycinnamic acids on cyanidin and chelates were investigated by addition of the acids to triglycosylated cyanidin (0-50×[anthocyanin]) and by comparison to hydroxycinnamic acid monoacylated and diacylated Cy fractions by spectrophotometry (380-700nm) and colorimetry in pH 5-8. With no metal ions, λ max and absorbance was greatest for cyanidin with diacylation>monoacylation>increasing [acids]. Hydroxycinnamic acids added to cyanidin solutions weakly impacted color characteristics (ΔE<5); while acylation (covalent acid attachment) resulted in ΔE 5-15. Triglycosylated cyanidin expressed blue color (pH 7-8), suggesting glycosylation pattern also plays a role. Al 3+ chelation increased absorbance 2-42× and λ max ≳40nm (pH 5-6) compared to added hydroxycinnamic acids. Metal chelation and aromatic diacylation resulted in the most blue hues. Copyright © 2017 Elsevier Ltd. All rights reserved.

Air launch wireless sensor nodes (ALSN) for battle damage assessment (BDA)

NASA Astrophysics Data System (ADS)

Back, Jason M.; Beck, Steven D.; Frank, Mark A.; Hoenes, Eric

2006-05-01

This paper summarizes the Defense Threat Reduction Agency (DTRA) sponsored development and demonstration of an Air Launched Sensor Node (ALSN) system designed to fill DTRA's immediate need to support the Global Strike requirement of weapon-borne deliverable sensors for Battle Damage Assessment (BDA). Unattended ground sensors were integrated into a CBU-103 Tactical Munitions Dispenser (TMD), and flight test demonstrated with the 46 th Test Wing at Eglin AFB, FL. The objectives of the ALSN program were to repackage an existing multi-sensor node system to conform to the payload envelope and deployment configuration design; to integrate this payload into the CBU-103 TMD; and to conduct a combined payload flight test demonstration. The final sensor node included multiple sensors a microphone, a geophone, and multiple directional Passive Infrared (PIR) detectors with processing electronics, a low power wireless communications 802.15.4 mesh network, GPS (Global Positioning System), and power integrated into a form-fit BLU-97 munitions deployable package. This paper will present and discuss the flight test, results, and ALSN performance.

Key experimental information on intermediate-range atomic structures in amorphous Ge2Sb2Te5 phase change material

NASA Astrophysics Data System (ADS)

Hosokawa, Shinya; Pilgrim, Wolf-Christian; Höhle, Astrid; Szubrin, Daniel; Boudet, Nathalie; Bérar, Jean-François; Maruyama, Kenji

2012-04-01

Laser-induced crystalline-amorphous phase change of Ge-Sb-Te alloys is the key mechanism enabling the fast and stable writing/erasing processes in rewritable optical storage devices, such as digital versatile disk (DVD) or blu-ray disk. Although the structural information in the amorphous phase is essential for clarifying this fast process, as well as long lasting stabilities of both the phases, experimental works were mostly limited to the short-range order by x ray absorption fine structure. Here we show both the short and intermediate-range atomic structures of amorphous DVD material, Ge2Sb2Te5 (GST), investigated by a combination of anomalous x ray scattering and reverse Monte Carlo modeling. From the obtained atomic configurations of amorphous GST, we have found that the Sb atoms and half of the Ge atoms play roles in the fast phase change process of order-disorder transition, while the remaining Ge atoms act for the proper activation energy of barriers between the amorphous and crystalline phases.

A Simple Model for the Cloud Adjacency Effect and the Apparent Bluing of Aerosols Near Clouds

NASA Technical Reports Server (NTRS)

Marshak, Alexander; Wen, Guoyong; Coakley, James A., Jr.; Remer, Lorraine A.; Loeb,Norman G.; Cahalan, Robert F.

2008-01-01

In determining aerosol-cloud interactions, the properties of aerosols must be characterized in the vicinity of clouds. Numerous studies based on satellite observations have reported that aerosol optical depths increase with increasing cloud cover. Part of the increase comes from the humidification and consequent growth of aerosol particles in the moist cloud environment, but part comes from 3D cloud-radiative transfer effects on the retrieved aerosol properties. Often, discerning whether the observed increases in aerosol optical depths are artifacts or real proves difficult. The paper provides a simple model that quantifies the enhanced illumination of cloud-free columns in the vicinity of clouds that are used in the aerosol retrievals. This model is based on the assumption that the enhancement in the cloud-free column radiance comes from enhanced Rayleigh scattering that results from the presence of the nearby clouds. The enhancement in Rayleigh scattering is estimated using a stochastic cloud model to obtain the radiative flux reflected by broken clouds and comparing this flux with that obtained with the molecules in the atmosphere causing extinction, but no scattering.

NE-CAT Upgrade of the Bending Magnet Beamline 8BM at the ALS

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

Wang Jun; Ogata, Craig; Yang Xiaochun

2007-01-19

NE-CAT, North East Collaborative Access Team, bending magnet beamline (8BM) is a beamline for protein crystallography. Recently, the beamline has undergone upgrades of its x-ray optics, control system, and the addition of a robot automounter. The first crystal of the double crystal monochromator was replaced by a new design offered by Oxford Danfysik with a micro-finned, direct water-cooled crystal assembly that would provide better cooling and reduced thermal distortion, pressure induced bulge, and residual strain. Gear reduced motors were added to enhance the torque of the bender and obtain better control. For measuring displacement of the bender directly, two linearmore » variable differential transformers (LVDT) were installed to the second crystal assembly. Early optics characterization and analysis has been carried out. Besides the upgrade of the optical components, the Blu-Ice control system originally developed at SSRL has been implemented. The installation of an automated robotic sample mounting system, from the ALS, was carried out in collaboration with the engineering group at LBNL. Preliminary results are presented.« less

Critical assessment of the formation of hydrogen peroxide in dough by fermenting yeast cells.

PubMed

Rezaei, Mohammad N; Dornez, Emmie; Verstrepen, Kevin J; Courtin, Christophe M

2015-02-01

Fermentation of bread dough leads to strengthening of the dough matrix. This effect has previously been ascribed to the action of hydrogen peroxide (H2O2) produced by yeast in dough. In this study, we re-evaluate the production of H2O2 by yeast in dough and aqueous fermentation broth. Results show that the previously reported high levels of H2O2 in fermenting dough were most probably due to the lack of specificity of the potassium dichromate/acetic acid-based method used. Using the chemiluminescent HyPerBlu assay, no yeast H2O2 production could be detected in fermented dough or broth. Even though the formation of low levels of H2O2 cannot be ruled out due to the presence of catalase in flour and the fast reaction of H2O2 with gluten proteins, our results suggest that the changes in dough matrix rheological properties upon fermentation are not due to production of H2O2 by yeast. Copyright © 2014 Elsevier Ltd. All rights reserved.

Gold/silver/gold trilayer films on nanostructured polycarbonate substrates for direct and label-free nanoplasmonic biosensing.

PubMed

López-Muñoz, Gerardo A; Estévez, M-Carmen; Vázquez-García, Marc; Berenguel-Alonso, Miguel; Alonso-Chamarro, Julián; Homs-Corbera, Antoni; Lechuga, Laura M

2018-05-01

Ultrasmooth gold/silver/gold trilayer nanostructured plasmonic sensors were obtained using commercial Blu-ray optical discs as nanoslits-based flexible polymer substrates. A thin gold film was used as an adhesion and nucleation layer to improve the chemical stability and reduce the surface roughness of the overlying silver film, without increasing ohmic plasmon losses. The structures were physically and optically characterized and compared with nanostructures of single gold layer. Ultrasmooth and chemically stable trilayer nanostructures with a surface roughness <0.5 nm were obtained following a simple and reproducible fabrication process. They showed a figure of merit (FOM) value up to 69.2 RIU -1 which is significantly higher (more than 95%) than the gold monolayer counterpart. Their potential for biosensing was demonstrated by employing the trilayer sensor for the direct and refractometric (label-free) detection of C-reactive protein (CRP) biomarker in undiluted urine achieving a Limit of Detection (LOD) in the pM order. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Wide field of view 3D label-free super-resolution imaging

NASA Astrophysics Data System (ADS)

Nolvi, Anton; Laidmäe, Ivo; Maconi, Göran; Heinämäki, Jyrki; Hæggström, Edward; Kassamakov, Ivan

2018-02-01

Recently, 3D label-free super-resolution profilers based on microsphere-assisted scanning white light interferometry were introduced having vertical resolution of few angstroms (Å) and a lateral resolution approaching 100 nm. However, the use of a single microsphere to generate the photonic nanojet (PNJ) limits their field of view. We overcome this limitation by using polymer microfibers to generate the PNJ. This increases the field of view by order of magnitude in comparison to the previously developed solutions while still resolving sub 100 nm features laterally and keeping the vertical resolution in 1nm range. To validate the capabilities of our system we used a recordable Blu-ray disc as a sample. It features a grooved surface topology with heights in the range of 20 nm and with distinguishable sub 100 nm lateral features that are unresolvable by diffraction limited optics. We achieved agreement between all three measurement devices across lateral and vertical dimensions. The field of view of our instrument was 110 μm by 2 μm and the imaging time was a couple of seconds.

Absolute calibration of the Agfa Structurix series films at energies between 2.7 and 6.2 keV.

PubMed

Lanier, N E; Cowan, J S

2014-11-01

Although photo-emulsion technology is many decades old, x-ray film still remains a key asset for diagnosing hydrodynamic features in High-Energy Density (HED) experiments. For decades, the preferred option had been Kodak's direct exposure film. After its discontinuance in 2004, the push to find alternatives began. In many situations, the Agfa Structurix series offers the most favorable substitute, but being new to the HED community, its characterization was lacking. To remedy this, recent experiments, conducted at Brookhaven's National Synchrotron Light Source, provide absolute, monochromatic calibration data for the Agfa Structurix series films at K-shell backlighter energies between 2.7 and 6.2 keV. Absolute response curves are presented for Agfa D8, D7, D4, D4sc, D3, and D2. Moreover, the transmission of each film type is also measured.

Defect-induced mix experiment for NIF

NASA Astrophysics Data System (ADS)

Schmitt, M. J.; Bradley, P. A.; Cobble, J. A.; Hsu, S. C.; Krasheninnikova, N. S.; Kyrala, G. A.; Magelssen, G. R.; Murphy, T. J.; Obrey, K. A.; Tregillis, I. L.; Wysocki, F. J.; Finnegan, S. M.

2013-11-01

The Defect Induced Mix Experiment (DIME-II) will measure the implosion and mix characteristics of CH capsules filled with 5 atmospheres of DT by incorporating mid-Z dopant layers of Ge and Ga. This polar direct drive (PDD) experiment also will demonstrate the filling of a CH capsule at target chamber center using a fill tube. Diagnostics for these experiments include areal x-ray backlighting to obtain early time images of the implosion trajectory and a multiple-monochromatic imager (MMI) to collect spectrally-resolved images of the capsule dopant line emission near bangtime. The inclusion of two (or more) thin dopant layers at separate depths within the capsule shell facilitates spatial correlation of mix between the layers and the hot gas core on a single shot. The dopant layers are typically 2 μm thick and contain dopant concentrations of 1.5%. Three dimensional Hydra simulations have been performed to assess the effects of PDD asymmetry on capsule performance.

K-shell photoabsorption edge of strongly coupled aluminum driven by laser-converted radiation

NASA Astrophysics Data System (ADS)

Zhao, Yang; Zhang, Zhiyu; Qing, Bo; Yang, Jiamin; Zhang, Jiyan; Wei, Minxi; Yang, Guohong; Song, Tianming; Xiong, Gang; Lv, Min; Hu, Zhimin; Deng, Bo; Hu, Xin; Zhang, Wenhai; Shang, Wanli; Hou, Lifei; Du, Huabing; Zhan, Xiayu; Yu, Ruizhen

2017-03-01

The first observation of the K-shell photoabsorption edge of strongly coupled aluminum generated by intense x-ray radiation-driven shocks is reported. By using a “dog bone” gold hohlraum as an x-ray converter, colliding shocks compression and preheating shielding are achieved to generate an unexplored state with a density of 5.5 g/cm3 and temperature of 0.43 eV (the ion-ion coupling parameter Γii is around 240). The time-resolved K-shell photoabsorption edges are measured with a crystal spectrometer using a short x-ray backlighter. The broadenings and redshifts of the edges are studied by using the slope fitting of the edge and quantum molecular dynamics calculations. This work shows that the K-edge of aluminum driven by laser-converted radiation provides a novel capability to probe WDM at extended conditions.

Investigation into the electromagnetic impulses from long-pulse laser illuminating solid targets inside a laser facility

NASA Astrophysics Data System (ADS)

Yi, Tao; Yang, Jinwen; Yang, Ming; Wang, Chuanke; Yang, Weiming; Li, Tingshuai; Liu, Shenye; Jiang, Shaoen; Ding, Yongkun; Xiao, Shaoqiu

2016-09-01

Emission of the electromagnetic pulses (EMP) due to laser-target interaction in laser facility had been evaluated using a cone antenna in this work. The microwave in frequencies ranging from several hundreds of MHz to 2 GHz was recorded when long-pulse lasers with several thousands of joules illuminated the solid targets, meanwhile the voltage signals from 1 V to 4 V were captured as functions of laser energy and backlight laser, where the corresponding electric field strengths were obtained by simulating the cone antenna in combination with conducting a mathematical process (Tiknohov Regularization with L curve). All the typical coupled voltage oscillations displayed multiple peaks and had duration of up to 80 ns before decaying into noise and mechanisms of the EMP generation was schematically interpreted in basis of the practical measuring environments. The resultant data were expected to offer basic know-how to achieve inertial confinement fusion.

On-demand stereoscopic 3D displays for avionic and military applications

NASA Astrophysics Data System (ADS)

Sarma, Kalluri; Lu, Kanghua; Larson, Brent; Schmidt, John; Cupero, Frank

2010-04-01

High speed AM LCD flat panels are evaluated for use in Field Sequential Stereoscopic (FSS) 3D displays for military and avionic applications. A 120 Hz AM LCD is used in field-sequential mode for constructing eyewear-based as well as autostereoscopic 3D display demonstrators for test and evaluation. The COTS eyewear-based system uses shutter glasses to control left-eye/right-eye images. The autostereoscopic system uses a custom backlight to generate illuminating pupils for left and right eyes. It is driven in synchronization with the images on the LCD. Both displays provide 3D effect in full-color and full-resolution in the AM LCD flat panel. We have realized luminance greater than 200 fL in 3D mode with the autostereoscopic system for sunlight readability. The characterization results and performance attributes of both systems are described.

Light beam shaping for collimated emission from white organic light-emitting diodes using customized lenticular microlens arrays structure

NASA Astrophysics Data System (ADS)

Zhou, Lei; Bai, Gui-Lin; Guo, Xin; Shen, Su; Ou, Qing-Dong; Fan, Yuan-Yuan

2018-05-01

We present a design approach to realizing a desired collimated planar incoherent light source (CPILS) by incorporating lenticular microlens arrays (LMLAs) onto the substrates of discrete white organic light-emitting diode (WOLED) light sources and demonstrate the effectiveness of this method in collimated light beam shaping and luminance enhancement simultaneously. The obtained collimated WOLED light source shows enhanced luminance by a factor of 2.7 compared with that of the flat conventional device at the normal polar angle and, more importantly, exhibits a narrowed angular emission with a full-width at half-maximum (FWHM) of ˜33.6°. We anticipate that the presented strategy could provide an alternative way for achieving the desired large scale CPILS, thereby opening the door to many potential applications, including LCD backlights, three-dimensional displays, car headlights, and so forth.

Structurally integrated fiber optic damage assessment system for composite materials.

PubMed

Measures, R M; Glossop, N D; Lymer, J; Leblanc, M; West, J; Dubois, S; Tsaw, W; Tennyson, R C

1989-07-01

Progress toward the development of a fiber optic damage assessment system for composite materials is reported. This system, based on the fracture of embedded optical fibers, has been characterized with respect to the orientation and location of the optical fibers in the composite. Together with a special treatment, these parameters have been tailored to yield a system capable of detecting the threshold of damage for various impacted Kevlar/epoxy panels. The technique has been extended to measure the growth of a damage region which could arise from either impact, manufacturing flaws, or static overloading. The mechanism of optical fiber fracture has also been investigated. In addition, the influence of embedded optical fibers on the tensile and compressive strength of the composite material has been studied. Image enhanced backlighting has been shown to be a powerful and convenient method of assessing internal damage to translucent composite materials.

Pluto Majestic Mountains, Frozen Plains and Foggy Hazes

NASA Image and Video Library

2015-09-17

Just 15 minutes after its closest approach to Pluto on July 14, 2015, NASA's New Horizons spacecraft looked back toward the sun and captured this near-sunset view of the rugged, icy mountains and flat ice plains extending to Pluto's horizon. The smooth expanse of the informally named icy plain Sputnik Planum (right) is flanked to the west (left) by rugged mountains up to 11,000 feet (3,500 meters) high, including the informally named Norgay Montes in the foreground and Hillary Montes on the skyline. To the right, east of Sputnik, rougher terrain is cut by apparent glaciers. The backlighting highlights more than a dozen layers of haze in Pluto's tenuous but distended atmosphere. The image was taken from a distance of 11,000 miles (18,000 kilometers) to Pluto; the scene is 780 miles (1,250 kilometers) wide. http://photojournal.jpl.nasa.gov/catalog/PIA19948

Temperature in subsonic and supersonic radiation fronts measured at OMEGA

NASA Astrophysics Data System (ADS)

Johns, Heather; Kline, John; Lanier, Nick; Perry, Ted; Fontes, Chris; Fryer, Chris; Brown, Colin; Morton, John

2017-10-01

Propagation of heat fronts relevant to astrophysical plasmas is challenging in the supersonic regime. Plasma Te changes affect opacity and equation of state without hydrodynamic change. In the subsonic phase density perturbations form at material interfaces as the plasma responds to radiation pressure of the front. Recent experiments at OMEGA studied this transition in aerogel foams driven by a hohlraum. In COAX, two orthogonal backlighters drive x-ray radiography and K-shell absorption spectroscopy to diagnose the subsonic shape of the front and supersonic Te profiles. Past experiments used absorption spectroscopy in chlorinated foams to measure the heat front; however, Cl dopant is not suitable for higher material temperatures at NIF. COAX has developed use of Sc and Ti dopants to diagnose Te between 60-100eV and 100-180eV. Analysis with PrismSPECT using OPLIB tabular opacity data will evaluate the platform's ability to advance radiation transport in this regime.

Design and engineering of a target for x-ray Thomson scattering measurements on matter at extreme densities and gigabar pressures

DOE PAGES

Boehm, K. -J.; Hash, N.; Barker, D.; ...

2016-06-24

Reconciling the experimental and system requirements during the development of a new target system is one of the most challenging tasks in the design and engineering of targets used in the National Ignition Facility. Targets for the GigaBar 3 campaign were meant to allow the detection of extremely weak Thomson scattering from matter at extreme densities in the face of very bright backlighter and laser entry hole plasma emissions. The problem was to shield the detector sufficiently while maintaining beamline and view clearances, and observing target mass restrictions. A new construction process, based on a rapid prototype frame structure, wasmore » used to develop this target. As a result, details of the design process for these targets are described, and lessons from this development for production and target assembly teams are discussed.« less

Non-Toxic Gold Nanoclusters for Solution-Processed White Light-Emitting Diodes.

PubMed

Chao, Yu-Chiang; Cheng, Kai-Ping; Lin, Ching-Yi; Chang, Yu-Li; Ko, Yi-Yun; Hou, Tzu-Yin; Huang, Cheng-Yi; Chang, Walter H; Lin, Cheng-An J

2018-06-11

Solution-processed optoelectronic devices are attractive because of the potential low-cost fabrication and the compatibility with flexible substrate. However, the utilization of toxic elements such as lead and cadmium in current optoelectronic devices on the basis of colloidal quantum dots raises environmental concerns. Here we demonstrate that white-light-emitting diodes can be achieved by utilizing non-toxic and environment-friendly gold nanoclusters. Yellow-light-emitting gold nanoclusters were synthesized and capped with trioctylphosphine. These gold nanoclusters were then blended with the blue-light-emitting organic host materials to form the emissive layer. A current efficiency of 0.13 cd/A was achieved. The Commission Internationale de l'Eclairage chromaticity coordinates of (0.27, 0.33) were obtained from our experimental analysis, which is quite close to the ideal pure white emission coordinates (0.33, 0.33). Potential applications include innovative lighting devices and monitor backlight.

Absolute calibration of the Agfa Structurix series films at energies between 2.7 and 6.2 keVa)

NASA Astrophysics Data System (ADS)

Lanier, N. E.; Cowan, J. S.

2014-11-01

Although photo-emulsion technology is many decades old, x-ray film still remains a key asset for diagnosing hydrodynamic features in High-Energy Density (HED) experiments. For decades, the preferred option had been Kodak's direct exposure film. After its discontinuance in 2004, the push to find alternatives began. In many situations, the Agfa Structurix series offers the most favorable substitute, but being new to the HED community, its characterization was lacking. To remedy this, recent experiments, conducted at Brookhaven's National Synchrotron Light Source, provide absolute, monochromatic calibration data for the Agfa Structurix series films at K-shell backlighter energies between 2.7 and 6.2 keV. Absolute response curves are presented for Agfa D8, D7, D4, D4sc, D3, and D2. Moreover, the transmission of each film type is also measured.

3D integrated HYDRA simulations of hohlraums including fill tubes

NASA Astrophysics Data System (ADS)

Marinak, M. M.; Milovich, J.; Hammel, B. A.; Macphee, A. G.; Smalyuk, V. A.; Kerbel, G. D.; Sepke, S.; Patel, M. V.

2017-10-01

Measurements of fill tube perturbations from hydro growth radiography (HGR) experiments on the National Ignition Facility show spoke perturbations in the ablator radiating from the base of the tube. These correspond to the shadow of the 10 μm diameter glass fill tube cast by hot spots at early time. We present 3D integrated HYDRA simulations of these experiments which include the fill tube. Meshing techniques are described which were employed to resolve the fill tube structure and associated perturbations in the simulations. We examine the extent to which the specific illumination geometry necessary to accommodate a backlighter in the HGR experiment contributes to the spoke pattern. Simulations presented include high resolution calculations run on the Trinity machine operated by the Alliance for Computing at Extreme Scale (ACES) partnership. This work was performed under the auspices of the Lawrence Livermore National Security, LLC, (LLNS) under Contract No. DE-AC52-07NA27344.

Study of the hydrodynamics of the formation of flows caused by the interaction of a shock wave with two-dimensional density perturbations on the Iskra-5 laser facility

NASA Astrophysics Data System (ADS)

Babanov, A. V.; Barinov, M. A.; Barinov, S. P.; Garanin, R. V.; Zhidkov, N. V.; Kalmykov, N. A.; Kovalenko, V. P.; Kokorin, S. N.; Pinegin, A. V.; Solomatina, E. Yu.; Solomatin, I. I.; Suslov, N. A.

2017-03-01

The hydrodynamics of the flow formation due to the interaction of a shock wave with two-dimensional density perturbations is experimentally investigated on the Iskra-5 laser facility. Shadow images of a jet arising as a result of the impact of a shock wave (formed by a soft X-ray pulse from a target-illuminator) on a flat aluminium target with a blind cylindrical cavity are recorded in experiments with point-like X-ray backlighting having a photon energy of ~4.5 keV. The sizes and mass of the jet ejected from the aluminium cavity by this shock wave are estimated. The experimental data are compared with the results of numerical simulation of the jet formation and dynamics according to the two-dimensional MID-ND2D code.

Collapsing Radiative Shocks in Xenon Gas on the Omega Laser

NASA Astrophysics Data System (ADS)

Reighard, A. B.; Glendinning, S. G.; Knauer, J.; Bouquet, S.; Koenig, M.

2005-10-01

A number of astrophysical systems involve radiative shocks that collapse spatially in response to energy lost through radiation, producing thin shells believed to be Vishniac unstable. We report experiments intended to study such collapsing shocks. The Omega laser drives a thin slab of material at >100 km/s through Xe gas. Simulations predict a collapsed layer in which the density reaches 45 times initial density. X-ray backlighting techniques have yielded images of a collapsed shock compressed to <1/25 its initial thickness (45 μm) at a speed of ˜100 km/s when the shock has traveled 1.3 mm. Optical depth before and behind the shock is important for comparison to astrophysical systems. This research was sponsored by the National Nuclear Security Administration under the Stewardship Science Academic Alliances program through DOE Research Grants DE-FG52-03NA00064, DE-FG53-2005-NA26014, and other grants and contracts.

Monochromatic x-ray radiography for areal-density measurement of inertial fusion energy fuel in fast ignition experiment.

PubMed

Fujioka, Shinsuke; Fujiwara, Takashi; Tanabe, Minoru; Nishimura, Hiroaki; Nagatomo, Hideo; Ohira, Shinji; Inubushi, Yuichi; Shiraga, Hiroyuki; Azechi, Hiroshi

2010-10-01

Ultrafast, two-dimensional x-ray imaging is an important diagnostics for the inertial fusion energy research, especially in investigating implosion dynamics at the final stage of the fuel compression. Although x-ray radiography was applied to observing the implosion dynamics, intense x-rays emitted from the high temperature and dense fuel core itself are often superimposed on the radiograph. This problem can be solved by coupling the x-ray radiography with monochromatic x-ray imaging technique. In the experiment, 2.8 or 5.2 keV backlight x-rays emitted from laser-irradiated polyvinyl chloride or vanadium foils were selectively imaged by spherically bent quartz crystals with discriminating the out-of-band emission from the fuel core. This x-ray radiography system achieved 24 μm and 100 ps of spatial and temporal resolutions, respectively.

Effect of microbubble-induced cavitation on the dispersion of sprays

NASA Astrophysics Data System (ADS)

van der Voort, D. D.; Dam, N. J.; Kunnen, R. P. J.; van Heijst, G. J. F.; Clercx, H. J. H.

2017-03-01

The presence of bubbles and voids inside nozzles has a large effect on the morphology and atomization of sprays. In this investigation the voids formed by microbubbles entering the nozzle are investigated using transparent glass nozzles, pressure transducers, and high-speed diffuse backlight imaging. A correlation is found between the magnitude of pressure pulses inside the nozzle and the size of the bubbles causing these pulses. This relation allows the prediction of cavity formation also in nontransparent nozzles, which allow more realistic conditions of operation. Subsequently, the direct measurements of dispersion derived from the spread of glowing fluid showed no significant increase of the dispersion compared to cavitation-free conditions. This indicates that, while the spray angle may increase, the turbulence (in both liquid and gas phase) that governs the dispersion remains the same and the cavitation bubble events do not have a significant impact on this process.

Enhancing light emission in flexible AC electroluminescent devices by tetrapod-like zinc oxide whiskers.

PubMed

Wen, Li; Liu, Nishuang; Wang, Siliang; Zhang, Hui; Zhao, Wanqiu; Yang, Zhichun; Wang, Yumei; Su, Jun; Li, Luying; Long, Fei; Zou, Zhengguang; Gao, Yihua

2016-10-03

Flexible alternating current electroluminescent devices (ACEL) are more and more popular and widely used in liquid-crystal display back-lighting, large-scale architectural and decorative lighting due to their uniform light emission, low power consumption and high resolution. However, presently how to acquire high brightness under a certain voltage are confronted with challenges. Here, we demonstrate an electroluminescence (EL) enhancing strategy that tetrapod-like ZnO whiskers (T-ZnOw) are added into the bottom electrode of carbon nanotubes (CNTs) instead of phosphor layer in flexible ACEL devices emitting blue, green and orange lights, and the brightness is greatly enhanced due to the coupling between the T-ZnOw and ZnS phosphor dispersed in the flexible polydimethylsiloxane (PDMS) layer. This strategy provides a new routine for the development of high performance, flexible and large-area ACEL devices.

Observable Protein Crystal Growth Apparatus

NASA Technical Reports Server (NTRS)

2001-01-01

This diagram shows a cross sectrion of the fluid volume of an individual cell in the Observable Protein Crystal Growth Apparatus (OPCGA) to be operated aboard the International Space Station (ISS). The principal investigator is Dr. Alex McPherson of the University of California, Irvine. Each individual cell comprises two sample chambers with a rotating center section that isolates the two from each other until the start of the experiment and after it is completed. The cells are made from optical-quality quartz glass to allow photography and interferometric observations. Each cell has a small light-emitting diode and lens to back-light the solution. In protein crystal growth experiments, a precipitating agent such as a salt solution is used to absorb and hold water but repel the protein molecules. This increases the concentration of protein until the molecules nucleate to form crystals. This cell is one of 96 that make up the experiment module portion of the OPCGA.

High-energy (>70 keV) x-ray conversion efficiency measurement on the ARC laser at the National Ignition Facility

NASA Astrophysics Data System (ADS)

Chen, Hui; Hermann, M. R.; Kalantar, D. H.; Martinez, D. A.; Di Nicola, P.; Tommasini, R.; Landen, O. L.; Alessi, D.; Bowers, M.; Browning, D.; Brunton, G.; Budge, T.; Crane, J.; Di Nicola, J.-M.; Döppner, T.; Dixit, S.; Erbert, G.; Fishler, B.; Halpin, J.; Hamamoto, M.; Heebner, J.; Hernandez, V. J.; Hohenberger, M.; Homoelle, D.; Honig, J.; Hsing, W.; Izumi, N.; Khan, S.; LaFortune, K.; Lawson, J.; Nagel, S. R.; Negres, R. A.; Novikova, L.; Orth, C.; Pelz, L.; Prantil, M.; Rushford, M.; Shaw, M.; Sherlock, M.; Sigurdsson, R.; Wegner, P.; Widmayer, C.; Williams, G. J.; Williams, W.; Whitman, P.; Yang, S.

2017-03-01

The Advanced Radiographic Capability (ARC) laser system at the National Ignition Facility (NIF) is designed to ultimately provide eight beamlets with a pulse duration adjustable from 1 to 30 ps, and energies up to 1.5 kJ per beamlet. Currently, four beamlets have been commissioned. In the first set of 6 commissioning target experiments, the individual beamlets were fired onto gold foil targets with energy up to 1 kJ per beamlet at 20-30 ps pulse length. The x-ray energy distribution and pulse duration were measured, yielding energy conversion efficiencies of 4-9 × 10-4 for x-rays with energies greater than 70 keV. With greater than 3 J of such x-rays, ARC provides a high-precision x-ray backlighting capability for upcoming inertial confinement fusion and high-energy-density physics experiments on NIF.

Citrus fruit recognition using color image analysis

NASA Astrophysics Data System (ADS)

Xu, Huirong; Ying, Yibin

2004-10-01

An algorithm for the automatic recognition of citrus fruit on the tree was developed. Citrus fruits have different color with leaves and branches portions. Fifty-three color images with natural citrus-grove scenes were digitized and analyzed for red, green, and blue (RGB) color content. The color characteristics of target surfaces (fruits, leaves, or branches) were extracted using the range of interest (ROI) tool. Several types of contrast color indices were designed and tested. In this study, the fruit image was enhanced using the (R-B) contrast color index because results show that the fruit have the highest color difference among the objects in the image. A dynamic threshold function was derived from this color model and used to distinguish citrus fruit from background. The results show that the algorithm worked well under frontlighting or backlighting condition. However, there are misclassifications when the fruit or the background is under a brighter sunlight.

Grating-coupled surface plasmon enhanced short-circuit current in organic thin-film photovoltaic cells.

PubMed

Baba, Akira; Aoki, Nobutaka; Shinbo, Kazunari; Kato, Keizo; Kaneko, Futao

2011-06-01

In this study, we demonstrate the fabrication of grating-coupled surface plasmon resonance (SPR) enhanced organic thin-film photovoltaic cells and their improved photocurrent properties. The cell consists of a grating substrate/silver/P3HT:PCBM/PEDOT:PSS structure. Blu-ray disk recordable substrates are used as the diffraction grating substrates on which silver films are deposited by vacuum evaporation. P3HT:PCBM films are spin-coated on silver/grating substrates. Low conductivity PEDOT:PSS/PDADMAC layer-by-layer ultrathin films deposited on P3HT:PCBM films act as the hole transport layer, whereas high conductivity PEDOT:PSS films deposited by spin-coating act as the anode. SPR excitations are observed in the fabricated cells upon irradiation with white light. Up to a 2-fold increase in the short-circuit photocurrent is observed when the surface plasmon (SP) is excited on the silver gratings as compared to that without SP excitation. The finite-difference time-domain simulation indicates that the electric field in the P3HT:PCBM layer can be increased using the grating-coupled SP technique. © 2011 American Chemical Society

Relative contributions of occlusion, maximum bite force, and chewing cycle kinematics to masticatory performance.

PubMed

Lepley, Casey R; Throckmorton, Gaylord S; Ceen, Richard F; Buschang, Peter H

2011-05-01

The purpose of this study was to explore the contributions of occlusion, maximum bite force, and chewing cycle kinematics to masticatory performance. A prospective cross-sectional study was performed on 30 subjects with Class I occlusion. Masticatory performance was measured with the test food Cuttersil (Heraeus Kulzer, South Bend, Ind) and the fractional-sieve technique. Blu-Mousse (Parkell Biomaterials, Farmingdale, NY) bite registrations were used to measure occlusal contact areas. The American Board of Orthodontics occlusal discrepancies were measured on the subjects' dental models. Maximum bite forces were recorded with a custom transducer, and 3-dimensional chewing cycle kinematics were tracked with an opto-electric computer system and Optotrak software (Northern Digital, Waterloo, Ontario, Canada). Masticatory performance was most closely correlated with occlusal contact area, indicating larger contact areas in subjects with better performance. Occlusal contact area and occlusal discrepancies were also related to bite force and chewing cycle kinematics. Maximum bite force was positively related with masticatory performance. Although masticatory performance is related, both directly and indirectly, to a number of morphologic and functional factors, it is most closely related to occlusal factors. Copyright © 2011 American Association of Orthodontists. Published by Mosby, Inc. All rights reserved.

From the surface to volume: concepts for the next generation of optical-holographic data-storage materials.

PubMed

Bruder, Friedrich-Karl; Hagen, Rainer; Rölle, Thomas; Weiser, Marc-Stephan; Fäcke, Thomas

2011-05-09

Optical data storage has had a major impact on daily life since its introduction to the market in 1982. Compact discs (CDs), digital versatile discs (DVDs), and Blu-ray discs (BDs) are universal data-storage formats with the advantage that the reading and writing of the digital data does not require contact and is therefore wear-free. These formats allow convenient and fast data access, high transfer rates, and electricity-free data storage with low overall archiving costs. The driving force for development in this area is the constant need for increased data-storage capacity and transfer rate. The use of holographic principles for optical data storage is an elegant way to increase the storage capacity and the transfer rate, because by this technique the data can be stored in the volume of the storage material and, moreover, it can be optically processed in parallel. This Review describes the fundamental requirements for holographic data-storage materials and compares the general concepts for the materials used. An overview of the performance of current read-write devices shows how far holographic data storage has already been developed. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Automation of Vapor-Diffusion Growth of Protein Crystals

NASA Technical Reports Server (NTRS)

Hamrick, David T.; Bray, Terry L.

2005-01-01

Some improvements have been made in a system of laboratory equipment developed previously for studying the crystallization of proteins from solution by use of dynamically controlled flows of dry gas. The improvements involve mainly (1) automation of dispensing of liquids for starting experiments, (2) automatic control of drying of protein solutions during the experiments, and (3) provision for automated acquisition of video images for monitoring experiments in progress and for post-experiment analysis. The automation of dispensing of liquids was effected by adding an automated liquid-handling robot that can aspirate source solutions and dispense them in either a hanging-drop or a sitting-drop configuration, whichever is specified, in each of 48 experiment chambers. A video camera of approximately the size and shape of a lipstick dispenser was added to a mobile stage that is part of the robot, in order to enable automated acquisition of images in each experiment chamber. The experiment chambers were redesigned to enable the use of sitting drops, enable backlighting of each specimen, and facilitate automation.

Defect Induced Mix Experiments (DIME) for NIF

NASA Astrophysics Data System (ADS)

Schmitt, Mark; Bradley, Paul; Cobble, James; Hsu, Scott; Krasheninnikova, Natalia; Magelssen, Glenn; Murphy, Thomas; Obrey, Kimberly; Tregillis, Ian; Wysocki, Frederick

2011-10-01

Los Alamos National Laboratory will be performing FY12 NIF experiments using polar direct drive to measure the effects of high mode number defects on ICF implosion hydrodynamics and yield. The effect of equatorial groove features will be assessed using both x-ray backlighting and spectrally resolved imaging of higher-Z dopant layers in 2.2 mm diameter (30 microns thick) CH capsules using a multiple monochromatic imager (MMI). By placing thin, 2 micron thick, layers containing ~1.5% of either Ge or Se at different depths in the capsule, we will be able to characterize the mixing and heating of these layers in both perturbed and unperturbed regions of the capsule. Precursor experiments have been performed on Omega to validate these measurement methods using Ti and V layers. An overview of our current results from Omega and design efforts for NIF will be presented. Work performed by Los Alamos National Laboratory under contract DE-AC52-06NA25396 for the National Nuclear Security Administration of the U.S. Department of Energy.

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

Smalyuk, V. A.; Robey, H. F.; Casey, D. T.

Several new platforms have been developed to experimentally measure hydrodynamic instabilities in all phases of indirect-drive, inertial confinement fusion implosions on National Ignition Facility. At the ablation front, instability growth of pre-imposed modulations was measured with a face-on, x-ray radiography platform in the linear regime using the Hydrodynamic Growth Radiography (HGR) platform. Modulation growth of "native roughness" modulations and engineering features (fill tubes and capsule support membranes) were measured in conditions relevant to layered DT implosions. A new experimental platform was developed to measure instability growth at the ablator-ice interface. Here in the deceleration phase of implosions, several experimental platformsmore » were developed to measure both low-mode asymmetries and high-mode perturbations near peak compression with x-ray and nuclear techniques. In one innovative technique, the self-emission from the hot spot was enhanced with argon dopant to "self-backlight" the shell in-flight. To stabilize instability growth, new "adiabat-shaping" techniques were developed using the HGR platform and applied in layered DT implosions.« less

Mix and hydrodynamic instabilities on NIF

NASA Astrophysics Data System (ADS)

Smalyuk, V. A.; Robey, H. F.; Casey, D. T.; Clark, D. S.; Döppner, T.; Haan, S. W.; Hammel, B. A.; MacPhee, A. G.; Martinez, D.; Milovich, J. L.; Peterson, J. L.; Pickworth, L.; Pino, J. E.; Raman, K.; Tipton, R.; Weber, C. R.; Baker, K. L.; Bachmann, B.; Berzak Hopkins, L. F.; Bond, E.; Caggiano, J. A.; Callahan, D. A.; Celliers, P. M.; Cerjan, C.; Dixit, S. N.; Edwards, M. J.; Felker, S.; Field, J. E.; Fittinghoff, D. N.; Gharibyan, N.; Grim, G. P.; Hamza, A. V.; Hatarik, R.; Hohenberger, M.; Hsing, W. W.; Hurricane, O. A.; Jancaitis, K. S.; Jones, O. S.; Khan, S.; Kroll, J. J.; Lafortune, K. N.; Landen, O. L.; Ma, T.; MacGowan, B. J.; Masse, L.; Moore, A. S.; Nagel, S. R.; Nikroo, A.; Pak, A.; Patel, P. K.; Remington, B. A.; Sayre, D. B.; Spears, B. K.; Stadermann, M.; Tommasini, R.; Widmayer, C. C.; Yeamans, C. B.; Crippen, J.; Farrell, M.; Giraldez, E.; Rice, N.; Wilde, C. H.; Volegov, P. L.; Gatu Johnson, M.

2017-06-01

Several new platforms have been developed to experimentally measure hydrodynamic instabilities in all phases of indirect-drive, inertial confinement fusion implosions on National Ignition Facility. At the ablation front, instability growth of pre-imposed modulations was measured with a face-on, x-ray radiography platform in the linear regime using the Hydrodynamic Growth Radiography (HGR) platform. Modulation growth of "native roughness" modulations and engineering features (fill tubes and capsule support membranes) were measured in conditions relevant to layered DT implosions. A new experimental platform was developed to measure instability growth at the ablator-ice interface. In the deceleration phase of implosions, several experimental platforms were developed to measure both low-mode asymmetries and high-mode perturbations near peak compression with x-ray and nuclear techniques. In one innovative technique, the self-emission from the hot spot was enhanced with argon dopant to "self-backlight" the shell in-flight. To stabilize instability growth, new "adiabat-shaping" techniques were developed using the HGR platform and applied in layered DT implosions.

X-ray grating spectrometer for opacity measurements in the 50 eV to 250 eV spectral range at the LULI 2000 laser facility

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

Reverdin, Charles; Caillaud, T.; Gilleron, F.

2012-10-15

An x-ray grating spectrometer was built in order to measure opacities in the 50 eV to 250 eV spectral range with an average spectral resolution {approx} 50. It has been used at the LULI-2000 laser facility at Ecole Polytechnique (France) to measure the {Delta}n = 0, n = 3 transitions of several elements with neighboring atomic number: Cr, Fe, Ni, and Cu in the same experimental conditions. Hence a spectrometer with a wide spectral range is required. This spectrometer features one line of sight looking through a heated sample at backlighter emission. It is outfitted with one toroidal condensing mirrormore » and several flat mirrors cutting off higher energy photons. The spectral dispersion is obtained with a flatfield grating. Detection consists of a streak camera sensitive to soft x-ray radiation. Some experimental results showing the performance of this spectrometer are presented.« less

KSC-2009-2155

NASA Image and Video Library

2009-03-17

CAPE CANAVERAL, Fla. – At the Astrotech facility in Titusville, Fla., technicians perform backlight inspection and cleaning on NASA's Lunar Reconnaissance Orbiter, or LRO. Black light inspection uses UVA fluorescence to detect possible particulate microcontamination, minute cracks or fluid leaks. The orbiter will carry seven instruments to provide scientists with detailed maps of the lunar surface and enhance our understanding of the moon's topography, lighting conditions, mineralogical composition and natural resources. Information gleaned from LRO will be used to select safe landing sites, determine locations for future lunar outposts and help mitigate radiation dangers to astronauts. The polar regions of the moon are the main focus of the mission because continuous access to sunlight may be possible and water ice may exist in permanently shadowed areas of the poles. Accompanying LRO on its journey to the moon will be the Lunar CRater Observation and Sensing Satellite, or LCROSS, a mission that will impact the lunar surface in its search for water ice. Launch of LRO is targeted for May 20. Photo credit: NASA/Kim Shiflett

Direct Observations of Graphene Dispersed in Solution by Twilight Fluorescence Microscopy.

PubMed

Matsuno, Yutaka; Sato, Yu-Uya; Sato, Hikaru; Sano, Masahito

2017-06-01

Graphene and graphene oxide (GO) in solution were directly observed by a newly developed twilight fluorescence (TwiF) microscopy. A nanocarbon dispersion was mixed with a highly concentrated fluorescent dye solution and placed in a cell with a viewing glass at the bottom. TwiF microscopy images the nanocarbon material floating within a few hundred μm of the glass surface by utilizing two optical processes to provide a faintly illuminating backlight and visualizes GO as either a dark image by absorption and energy transfer processes or a bright image by alternation of fluorophore chemistry and autofluorescence. Individual graphene and GO sheets ranging from submicron to submillimeter widths were clearly imaged at different wavelengths, which were selectable based on the dye used. Graphene could be differentiated from GO coexisting in the same solution. Partial transparency revealed layering and network structures. Motions in tumbling flow were recognized in real time. An effect of changing the solvent and the process of adhesion on the glass surface were followed in situ.

An x-ray backlit Talbot-Lau deflectometer for high-energy-density electron density diagnostics.

PubMed

Valdivia, M P; Stutman, D; Stoeckl, C; Theobald, W; Mileham, C; Begishev, I A; Bromage, J; Regan, S P

2016-02-01

X-ray phase-contrast techniques can measure electron density gradients in high-energy-density plasmas through refraction induced phase shifts. An 8 keV Talbot-Lau interferometer consisting of free standing ultrathin gratings was deployed at an ultra-short, high-intensity laser system using K-shell emission from a 1-30 J, 8 ps laser pulse focused on thin Cu foil targets. Grating survival was demonstrated for 30 J, 8 ps laser pulses. The first x-ray deflectometry images obtained under laser backlighting showed up to 25% image contrast and thus enabled detection of electron areal density gradients with a maximum value of 8.1 ± 0.5 × 10(23) cm(-3) in a low-Z millimeter sized sample. An electron density profile was obtained from refraction measurements with an error of <8%. The 50 ± 15 μm spatial resolution achieved across the full field of view was found to be limited by the x-ray source-size, similar to conventional radiography.

FSC LCD technology for military and avionics applications

NASA Astrophysics Data System (ADS)

Sarma, Kalluri R.; Schmidt, John; Roush, Jerry

2009-05-01

Field sequential color (FSC) liquid crystal displays (LCD) using a high speed LCD mode and an R, G, B LED backlight, offers a significant potential for lower power consumption, higher resolution, higher brightness and lower cost compared to the conventional R, G, B color filter based LCD, and thus is of interest to various military and avionic display applications. While the DLP projection TVs, and Camcorder LCD view finder type displays using the FSC technology have been introduced in the consumer market, large area direct view LCD displays based on the FSC technology have not reached the commercial market yet. Further, large area FSC LCDs can present unique operational issues in avionic and military environments particularly for operation in a broad temperature range and with respect to its susceptibility for the color breakup image artifact. In this paper we will review the current status of the FSC LCD technology and then discuss the results of our efforts on the FSC LCD technology evaluation for the avionic applications.

A new data processing technique for Rayleigh-Taylor instability growth experiments

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

Yuan, Yongteng; Tu, Shaoyong; Miao, Wenyong

Typical face-on experiments for Rayleigh-Taylor instability study involve the time-resolved radiography of an accelerated foil with line-of-sight of the radiography along the direction of motion. The usual method which derives perturbation amplitudes from the face-on images reverses the actual image transmission procedure, so the obtained results will have a large error in the case of large optical depth. In order to improve the accuracy of data processing, a new data processing technique has been developed to process the face-on images. This technique based on convolution theorem, refined solutions of optical depth can be achieved by solving equations. Furthermore, we discussmore » both techniques for image processing, including the influence of modulation transfer function of imaging system and the backlighter spatial profile. Besides, we use the two methods to the process the experimental results in Shenguang-II laser facility and the comparison shows that the new method effectively improve the accuracy of data processing.« less

X-ray grating spectrometer for opacity measurements in the 50 eV to 250 eV spectral range at the LULI 2000 laser facility.

PubMed

Reverdin, Charles; Thais, Frédéric; Loisel, Guillaume; Busquet, M; Bastiani-Ceccotti, S; Blenski, T; Caillaud, T; Ducret, J E; Foelsner, W; Gilles, D; Gilleron, F; Pain, J C; Poirier, M; Serres, F; Silvert, V; Soullie, G; Turck-Chieze, S; Villette, B

2012-10-01

An x-ray grating spectrometer was built in order to measure opacities in the 50 eV to 250 eV spectral range with an average spectral resolution ∼ 50. It has been used at the LULI-2000 laser facility at École Polytechnique (France) to measure the Δn = 0, n = 3 transitions of several elements with neighboring atomic number: Cr, Fe, Ni, and Cu in the same experimental conditions. Hence a spectrometer with a wide spectral range is required. This spectrometer features one line of sight looking through a heated sample at backlighter emission. It is outfitted with one toroidal condensing mirror and several flat mirrors cutting off higher energy photons. The spectral dispersion is obtained with a flatfield grating. Detection consists of a streak camera sensitive to soft x-ray radiation. Some experimental results showing the performance of this spectrometer are presented.

Laser-Stimulated Fluorescence in Paleontology

PubMed Central

Kaye, Thomas G.; Falk, Amanda R.; Pittman, Michael; Sereno, Paul C.; Burnham, David A.; Gong, Enpu; Xu, Xing; Wang, Yinan

2015-01-01

Fluorescence using ultraviolet (UV) light has seen increased use as a tool in paleontology over the last decade. Laser-stimulated fluorescence (LSF) is a next generation technique that is emerging as a way to fluoresce paleontological specimens that remain dark under typical UV. A laser’s ability to concentrate very high flux rates both at the macroscopic and microscopic levels results in specimens fluorescing in ways a standard UV bulb cannot induce. Presented here are five paleontological case histories that illustrate the technique across a broad range of specimens and scales. Novel uses such as back-lighting opaque specimens to reveal detail and detection of specimens completely obscured by matrix are highlighted in these examples. The recent cost reductions in medium-power short wavelength lasers and use of standard photographic filters has now made this technique widely accessible to researchers. This technology has the potential to automate multiple aspects of paleontology, including preparation and sorting of microfossils. This represents a highly cost-effective way to address paleontology's preparatory bottleneck. PMID:26016843

3-D Modeling of Planar Target-Mount Perturbation Experiments on OMEGA

NASA Astrophysics Data System (ADS)

Collins, T. J. B.; Marshall, F. J.; Marozas, J. A.; Bonino, M. J.; Forties, R.; Goncharov, V. N.; Igumenshchev, I. V.; McKenty, P. W.; Smalyuk, V. A.

2008-11-01

OMEGA cryogenic targets are suspended in the target chamber using four spider silks attached to a C-shaped mount. The spider silks are typically composed of two entwined protein strands comparable to 1 μm in diameter. The silks and mount refract the incident laser light and cast shadows on the target surface. Experiments to measure the effects of the silks on target illumination have been performed in planar geometry using silks suspended parallel to a 20-μm-thick laser-driven target. The evolution of the surface perturbations introduced by the silks was measured using x-ray backlighting. The results of these experiments will be compared to simulations performed with DRACO, employing three-dimensional (3-D) planar hydrodynamics and a new 3-D refractive ray-trace package written specifically for this geometry. This work was supported by the U.S. Department of Energy Office of Inertial Confinement Fusion under Cooperative Agreement No. DE-FC52-08NA28302.

Heat resistive dielectric multi-layer micro-mirror array in epitaxial lateral overgrowth gallium nitride.

PubMed

Huang, Chen-Yang; Ku, Hao-Min; Liao, Wei-Tsai; Chao, Chu-Li; Tsay, Jenq-Dar; Chao, Shiuh

2009-03-30

Ta2O5 / SiO2 dielectric multi-layer micro-mirror array (MMA) with 3mm mirror size and 6mm array period was fabricated on c-plane sapphire substrate. The MMA was subjected to 1200 degrees C high temperature annealing and remained intact with high reflectance in contrast to the continuous multi-layer for which the layers have undergone severe damage by 1200 degrees C annealing. Epitaxial lateral overgrowth (ELO) of gallium nitride (GaN) was applied to the MMA that was deposited on both sapphire and sapphire with 2:56 mm GaN template. The MMA was fully embedded in the ELO GaN and remained intact. The result implies that our MMA is compatible to the high temperature growth environment of GaN and the MMA could be incorporated into the structure of the micro-LED array as a one to one micro backlight reflector, or as the patterned structure on the large area LED for controlling the output light.

KSC-2009-2153

NASA Image and Video Library

2009-03-17

CAPE CANAVERAL, Fla. – At the Astrotech facility in Titusville, Fla., technicians perform backlight inspection and cleaning on NASA's Lunar Reconnaissance Orbiter, or LRO. Black light inspection uses UVA fluorescence to detect possible particulate microcontamination, minute cracks or fluid leaks. The orbiter will carry seven instruments to provide scientists with detailed maps of the lunar surface and enhance our understanding of the moon's topography, lighting conditions, mineralogical composition and natural resources. Information gleaned from LRO will be used to select safe landing sites, determine locations for future lunar outposts and help mitigate radiation dangers to astronauts. The polar regions of the moon are the main focus of the mission because continuous access to sunlight may be possible and water ice may exist in permanently shadowed areas of the poles. Accompanying LRO on its journey to the moon will be the Lunar CRater Observation and Sensing Satellite, or LCROSS, a mission that will impact the lunar surface in its search for water ice. Launch of LRO is targeted for May 20. Photo credit: NASA/Kim Shiflett

KSC-2009-2154

NASA Image and Video Library

2009-03-17

CAPE CANAVERAL, Fla. – At the Astrotech facility in Titusville, Fla., technicians perform backlight inspection and cleaning on NASA's Lunar Reconnaissance Orbiter, or LRO. Black light inspection uses UVA fluorescence to detect possible particulate microcontamination, minute cracks or fluid leaks. The orbiter will carry seven instruments to provide scientists with detailed maps of the lunar surface and enhance our understanding of the moon's topography, lighting conditions, mineralogical composition and natural resources. Information gleaned from LRO will be used to select safe landing sites, determine locations for future lunar outposts and help mitigate radiation dangers to astronauts. The polar regions of the moon are the main focus of the mission because continuous access to sunlight may be possible and water ice may exist in permanently shadowed areas of the poles. Accompanying LRO on its journey to the moon will be the Lunar CRater Observation and Sensing Satellite, or LCROSS, a mission that will impact the lunar surface in its search for water ice. Launch of LRO is targeted for May 20. Photo credit: NASA/Kim Shiflett

Solar spectral conversion for improving the photosynthetic activity in algae reactors.

PubMed

Wondraczek, Lothar; Batentschuk, Miroslaw; Schmidt, Markus A; Borchardt, Rudolf; Scheiner, Simon; Seemann, Benjamin; Schweizer, Peter; Brabec, Christoph J

2013-01-01

Sustainable biomass production is expected to be one of the major supporting pillars for future energy supply, as well as for renewable material provision. Algal beds represent an exciting resource for biomass/biofuel, fine chemicals and CO2 storage. Similar to other solar energy harvesting techniques, the efficiency of algal photosynthesis depends on the spectral overlap between solar irradiation and chloroplast absorption. Here we demonstrate that spectral conversion can be employed to significantly improve biomass growth and oxygen production rate in closed-cycle algae reactors. For this purpose, we adapt a photoluminescent phosphor of the type Ca0.59Sr0.40Eu0.01S, which enables efficient conversion of the green part of the incoming spectrum into red light to better match the Qy peak of chlorophyll b. Integration of a Ca0.59Sr0.40Eu0.01S backlight converter into a flat panel algae reactor filled with Haematococcus pluvialis as a model species results in significantly increased photosynthetic activity and algae reproduction rate.

Mix and hydrodynamic instabilities on NIF

DOE PAGES

Smalyuk, V. A.; Robey, H. F.; Casey, D. T.; ...

2017-06-01

Several new platforms have been developed to experimentally measure hydrodynamic instabilities in all phases of indirect-drive, inertial confinement fusion implosions on National Ignition Facility. At the ablation front, instability growth of pre-imposed modulations was measured with a face-on, x-ray radiography platform in the linear regime using the Hydrodynamic Growth Radiography (HGR) platform. Modulation growth of "native roughness" modulations and engineering features (fill tubes and capsule support membranes) were measured in conditions relevant to layered DT implosions. A new experimental platform was developed to measure instability growth at the ablator-ice interface. Here in the deceleration phase of implosions, several experimental platformsmore » were developed to measure both low-mode asymmetries and high-mode perturbations near peak compression with x-ray and nuclear techniques. In one innovative technique, the self-emission from the hot spot was enhanced with argon dopant to "self-backlight" the shell in-flight. To stabilize instability growth, new "adiabat-shaping" techniques were developed using the HGR platform and applied in layered DT implosions.« less

Study of ablation and implosion stages in wire arrays using coupled ultraviolet and X-ray probing diagnostics

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

Anderson, A. A.; Ivanov, V. V.; Astanovitskiy, A. L.

2015-11-15

Star and cylindrical wire arrays were studied using laser probing and X-ray radiography at the 1-MA Zebra pulse power generator at the University of Nevada, Reno. The Leopard laser provided backlighting, producing a laser plasma from a Si target which emitted an X-ray probing pulse at the wavelength of 6.65 Å. A spherically bent quartz crystal imaged the backlit wires onto X-ray film. Laser probing diagnostics at the wavelength of 266 nm included a 3-channel polarimeter for Faraday rotation diagnostic and two-frame laser interferometry with two shearing interferometers to study the evolution of the plasma electron density at the ablation and implosionmore » stages. Dynamics of the plasma density profile in Al wire arrays at the ablation stage were directly studied with interferometry, and expansion of wire cores was measured with X-ray radiography. The magnetic field in the imploding plasma was measured with the Faraday rotation diagnostic, and current was reconstructed.« less

Modeling of Multi-Kilovolt X-ray Driven Ablation and Closure of Pinholes during Point-Projection Backlit Imaging

NASA Astrophysics Data System (ADS)

Bullock, A. B.; Landen, O. L.; Bradley, D. K.

2000-10-01

Pinhole-assisted point-projection backlighting of large samples with few µm pinholes can result in pinhole closure due to x-ray driven ablation of the high Z pinhole substrate, thereby potentially limiting the usefulness of this imaging method. The results of a previous study[1] using streaked 1-D backlit imaging of 25 mm W wires at the OMEGA laser are compared to simulations produced by HYADES, a 1-D Lagrangian hydrodynamics code. Interestingly, the observed image resolution stays fixed while the pinhole transmission drops within 1-2 ns, suggesting rapid filling by a long scale-length of low density substrate material. These results will be compared to time-dependent HYADES predictions of pinhole closure timescales and resolution. 1 A.B. bullock, D.K. Bradley, and O.L. Landen, to be published in RSI (2001). *This work was performed under the auspices of the U.S. Department of Energy by University of California/Lawrence Livermore National Laboratory under Contract No. W-7405-Eng-48.

High-energy (> 70 KeV) x-ray conversion efficiency measurement on the ARC laser at the National Ignition Facility

DOE PAGES

Chen, Hui; Hermann, M. R.; Kalantar, D. H.; ...

2017-03-16

Here, the Advanced Radiographic Capability (ARC) laser system at the National Ignition Facility (NIF) is designed to ultimately provide eight beamlets with a pulse duration adjustable from 1 to 30 ps, and energies up to 1.5 kJ per beamlet. Currently, four beamlets have been commissioned. In the first set of 6 commissioning target experiments, the individual beamlets were fired onto gold foil targets with energy up to 1 kJ per beamlet at 20–30 ps pulse length. The x-ray energy distribution and pulse duration were measured, yielding energy conversion efficiencies of 4–9 × 10 –4 for x-rays with energies greater thanmore » 70 keV. With greater than 3 J of such x-rays, ARC provides a high-precision x-ray backlighting capability for upcoming inertial confinement fusion and high-energy-density physics experiments on NIF.« less

An Experimental Investigation of the Flow Over the Rear End of a Notchback Automobile Configuration

NASA Technical Reports Server (NTRS)

Jenkins, Luther N.

2000-01-01

An experimental investigation of the flow over the rear end of a 0.16 scale notchback automobile configuration has been conducted in the NASA Langley Basic Aerodynamics Research Tunnel (BART). The objective of this work was to investigate the flow separation that occurs behind the backlight and obtain experimental data that can be used to understand the physics and time-averaged structure of the flow field. A three-component laser velocimeter was used to make non-intrusive, velocity measurements in the center plane and in a single cross-flow plane over the decklid. In addition to off-body measurements, flow conditions on the car surface were documented via surface flow visualization, boundary layer measurements, and surface pressures. The experimental data show several features previously identified by other researchers, but also reveal differences between the flow field associated with this particular configuration and the generally accepted models for the flow over a notchback rear end.

Emerging trends in X-ray spectroscopic studies of plasma produced by intense laser beams

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

Arora, V., E-mail: arora@rrcat.gov.in; Chakera, J. A.; Naik, P. A.

2015-07-31

X-ray line emission from hot dense plasmas, produced by ultra-short high intensity laser systems, has been studied experimentally in recent years for applications in materials science as well as for back-lighter applications. By virtue of the CPA technology, several laser facilities delivering pulses with peak powers in excess of one petawatt (focused intensities > 10{sup 20} W-cm{sup −2}) have either been commissioned across the globe during the last few years or are presently under construction. On the other hand, hard x-ray sources on table top, generating ultra-short duration x-rays at a repetition rate up to 10 kHz, are routinely available formore » time resolved x-ray diffraction studies. In this paper, the recent experiments on x-ray spectroscopic studies of plasma produced by 45 fs, Ti:sapphire laser pulses (focused iintensity > 10{sup 18} W-cm{sup −2}) at RRCAT Indore will be presented.« less

Microgravity

NASA Image and Video Library

2001-01-24

This photo shows the Handheld Diffusion Test Cell (HH-DTC) apparatus flown on the Space Shuttle. Similar cells (inside the plastic box) will be used in the Observable Protein Crystal Growth Apparatus (OPCGA) to be operated aboard the International Space Station (ISS). The principal investigator is Dr. Alex McPherson of the University of California, Irvine. Each individual cell comprises two sample chambers with a rotating center section that isolates the two from each other until the start of the experiment and after it is completed. The cells are made from optical-quality quartz glass to allow photography and interferometric observations. Each cell has a small light-emitting diode and lens to back-light the solution. In protein crystal growth experiments, a precipitating agent such as a salt solution is used to absorb and hold water but repel the protein molecules. This increases the concentration of protein until the molecules nucleate to form crystals. This cell is one of 96 that make up the experiment module portion of the OPCGA.

Microgravity

NASA Image and Video Library

2001-01-24

This photo shows an individual cell from the Handheld Diffusion Test Cell (HH-DTC) apparatus flown on the Space Shuttle. Similar cells will be used in the Observable Protein Crystal Growth Apparatus (OPCGA) to be operated aboard the International Space Station (ISS). The principal investigator is Dr. Alex McPherson of the University of California, Irvine. Each individual cell comprises two sample chambers with a rotating center section that isolates the two from each other until the start of the experiment and after it is completed. The cells are made from optical-quality quartz glass to allow photography and interferometric observations. Each cell has a small light-emitting diode and lens to back-light the solution. In protein crystal growth experiments, a precipitating agent such as a salt solution is used to absorb and hold water but repel the protein molecules. This increases the concentration of protein until the molecules nucleate to form crystals. This cell is one of 96 that make up the experiment module portion of the OPCGA.

Development and evaluation of amusement machine using autostereoscopic 3D display

NASA Astrophysics Data System (ADS)

Kawai, Takashi; Shibata, Takashi; Shimizu, Yoichi; Kawata, Mitsuhiro; Suto, Masahiro

2004-05-01

Pachinko is a pinball-like game peculiar to Japan, and is one of the most common pastimes around the country. Recently, with the videogame market contracting, various multimedia technologies have been introduced into Pachinko machines. The authors have developed a Pachinko machine incorporating an autostereoscopic 3D display, and evaluated its effect on the visual function. As of April 2003, the new Pachinko machine has been on sale in Japan. The stereoscopic 3D image is displayed using an LCD. Backlighting for the right and left images is separate, and passes through a polarizing filter before reaching the LCD, which is sandwiched with a micro polarizer. The content selected for display was ukiyoe pictures (Japanese traditional woodblocks). The authors intended to reduce visual fatigue by presenting 3D images with depth "behind" the display and switching between 3D and 2D images. For evaluation of the Pachinko machine, a 2D version with identical content was also prepared, and the effects were examined and compared by testing psycho-physiological responses.

Replicating the Z iron opacity experiments on the NIF

NASA Astrophysics Data System (ADS)

Perry, T. S.; Heeter, R. F.; Opachich, Y. P.; Ross, P. W.; Kline, J. L.; Flippo, K. A.; Sherrill, M. E.; Dodd, E. S.; DeVolder, B. G.; Cardenas, T.; Archuleta, T. N.; Craxton, R. S.; Zhang, R.; McKenty, P. W.; Garcia, E. M.; Huffman, E. J.; King, J. A.; Ahmed, M. F.; Emig, J. A.; Ayers, S. L.; Barrios, M. A.; May, M. J.; Schneider, M. B.; Liedahl, D. A.; Wilson, B. G.; Urbatsch, T. J.; Iglesias, C. A.; Bailey, J. E.; Rochau, G. A.

2017-06-01

X-ray opacity is a crucial factor of all radiation-hydrodynamics calculations, yet it is one of the least validated of the material properties in the simulation codes. Recent opacity experiments at the Sandia Z-machine have shown up to factors of two discrepancies between theory and experiment, casting doubt on the validity of the opacity models. Therefore, a new experimental opacity platform is being developed on the National Ignition Facility (NIF) not only to verify the Z-machine experimental results but also to extend the experiments to other temperatures and densities. The first experiments will be directed towards measuring the opacity of iron at a temperature of ∼160 eV and an electron density of ∼7 × 1021 cm-3. Preliminary experiments on NIF have demonstrated the ability to create a sufficiently bright point backlighter using an imploding plastic capsule and also a hohlraum that can heat the opacity sample to the desired conditions. The first of these iron opacity experiments is expected to be performed in 2017.

A Photometric Technique for Determining Fluid Concentration using Consumer-Grade Hardware

NASA Technical Reports Server (NTRS)

Leslie, F.; Ramachandran, N.

1999-01-01

In support of a separate study to produce an exponential concentration gradient in a magnetic fluid, a noninvasive technique for determining, species concentration from off-the-shelf hardware has been developed. The approach uses a backlighted fluid test cell photographed with a commercial digital camcorder. Because the light extinction coefficient is wavelength dependent, tests were conducted to determine the best filter color to use, although some guidance was also provided using an absorption spectrophotometer. With the appropriate filter in place, the provide attenuation of the light passing, through the test cell was captured by the camcorder. The digital image was analyzed for intensity using, software from Scion Image Corp. downloaded from the Internet. The analysis provides a two-dimensional array of concentration with an average error of 0.0095 ml/ml. This technique is superior to invasive techniques, which require extraction of a sample that disturbs the concentration distribution in the test cell. Refinements of this technique using a true monochromatic laser light Source are also discussed.

Simulations of the interaction of intense petawatt laser pulses with dense Z-pinch plasmas : final report LDRD 39670.

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

Welch, Dale Robert; MacFarlane, Joseph John; Mehlhorn, Thomas Alan

We have studied the feasibility of using the 3D fully electromagnetic implicit hybrid particle code LSP (Large Scale Plasma) to study laser plasma interactions with dense, compressed plasmas like those created with Z, and which might be created with the planned ZR. We have determined that with the proper additional physics and numerical algorithms developed during the LDRD period, LSP was transformed into a unique platform for studying such interactions. Its uniqueness stems from its ability to consider realistic compressed densities and low initial target temperatures (if required), an ability that conventional PIC codes do not possess. Through several testmore » cases, validations, and applications to next generation machines described in this report, we have established the suitability of the code to look at fast ignition issues for ZR, as well as other high-density laser plasma interaction problems relevant to the HEDP program at Sandia (e.g. backlighting).« less

Organic light emitters gain longevity

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

Service, R.E.

1996-08-16

Organic thin-film displays were for many years a research curiosity with no staying power. Now their stamina is beginning to match their unbeatable toughness and lightness. For much of the past decade, researchers have been promising to put thin films of light-emitting plastics and other organic materials on display: large, flexible, inexpensive and efficient screens to be used for everything from lightweight backlights for computer displays to TVs that you can hang flat on the wall or roll up and put in your pocket. Yet, many of these promises have fallen flat as well. Organic lights have tended to burnmore » out after just days or weeks of operation. But now long-lived organic thin film displays are beginning to shine. By crafting films without as many burnout causing defects and building devices with additional film layers to enhance light emission, researchers around the work have recently improved the brightness, lifetime, and future prosects of their devices. This article describes recent developments and improvements in the field.« less

Evaluation of Wavelength Detuning to Mitigate Cross-Beam Energy Transfer Using the Nike Laser

NASA Astrophysics Data System (ADS)

McKenty, P. W.; Delettrez, J. A.; Marozas, J. A.; Weaver, J.; Obenschain, S.; Schmitt, A.

2014-10-01

Cross-beam energy transfer (CBET) has become a serious threat to the overall success of polar-drive-ignition experiments. CBET redirects incident laser light before it can be absorbed into the target, thereby degrading overall target performance. CBET is particularly effective over the equator of the target, which is hydrodynamically very sensitive to such losses. A promising solution uses laser wavelength detuning between beams to break the resonance between them and reduce energy transfer. Testing this process for direct drive has been limited because of the lack of sufficient detuning capabilities. However, the Naval Research Laboratory's Nike laser has the capability of providing a wide range of detuning between its main drive and backlighter beams. This paper explores the design of an experimental platform on Nike to directly evaluate the benefit of frequency detuning in mitigating CBET. This material is based upon work supported by the Department of Energy National Nuclear Security Administration under Award Number DE-NA0001944.

Dynamics of Laser-Driven Shock Waves in Solid Targets

NASA Astrophysics Data System (ADS)

Aglitskiy, Y.; Karasik, M.; Velikovich, A. L.; Serlin, V.; Weaver, J.; Schmitt, A. J.; Obenschain, S. P.; Grun, J.; Metzler, N.; Zalesak, S. T.; Gardner, J. H.; Oh, J.; Harding, E. C.

2009-11-01

Accurate shock timing is a key issue of both indirect- and direct-drive laser fusions. The experiments on the Nike laser at NRL presented here were made possible by improvements in the imaging capability of our monochromatic x-ray diagnostics based on Bragg reflection from spherically curved crystals. Side-on imaging implemented on Nike makes it possible to observe dynamics of the shock wave and ablation front in laser-driven solid targets. We can choose to observe a sequence of 2D images or a continuous time evolution of an image resolved in one spatial dimension. A sequence of 300 ps snapshots taken using vanadium backlighter at 5.2 keV reveals propagation of a shock wave in a solid plastic target. The shape of the shock wave reflects the intensity distribution in the Nike beam. The streak records with continuous time resolution show the x-t trajectory of a laser-driven shock wave in a 10% solid density DVB foam.

Emissive flat panel displays: A challenge to the AMLCD

NASA Astrophysics Data System (ADS)

Walko, R. J.

According to some sources, flat panel displays (FPD's) for computers will represent a 20-40 billion dollar industry by the end of the decade and could leverage up to 100-200 billion dollars in computer sales. Control of the flat panel display industry could be a significant factor in the global economy if FPD's manage to tap into the enormous audio/visual consumer market. Japan presently leads the world in active matrix liquid crystal display (AMLCD) manufacturing, the current leading FPD technology. The AMLCD is basically a light shutter which does not emit light on its own, but modulates the intensity of a separate backlight. However, other technologies, based on light emitting phosphors, could eventually challenge the AMLCD's lead position. These light-emissive technologies do not have the size, temperature and viewing angle limitations of AMLCD's. In addition, they could also be less expensive to manufacture, and require a smaller capital outlay for a manufacturing plant. An overview of these alternative technologies is presented.

On the properties of synchrotron-like X-ray emission from laser wakefield accelerated electron beams

NASA Astrophysics Data System (ADS)

McGuffey, C.; Schumaker, W.; Matsuoka, T.; Chvykov, V.; Dollar, F.; Kalintchenko, G.; Kneip, S.; Najmudin, Z.; Mangles, S. P. D.; Vargas, M.; Yanovsky, V.; Maksimchuk, A.; Thomas, A. G. R.; Krushelnick, K.

2018-04-01

The electric and magnetic fields responsible for electron acceleration in a Laser Wakefield Accelerator (LWFA) also cause electrons to radiate x-ray photons. Such x-ray pulses have several desirable properties including short duration and being well collimated with tunable high energy. We measure the scaling of this x-ray source experimentally up to laser powers greater than 100 TW. An increase in laser power allows electron trapping at a lower density as well as with an increased trapped charge. These effects resulted in an x-ray fluence that was measured to increase non-linearly with laser power. The fluence of x-rays was also compared with that produced from K-α emission resulting from a solid target interaction for the same energy laser pulse. The flux was shown to be comparable, but the LWFA x-rays had a significantly smaller source size. This indicates that such a source may be useful as a backlighter for probing high energy density plasmas with ultrafast temporal resolution.

Forensic practice in the field of protection of cultural heritage

NASA Astrophysics Data System (ADS)

Kotrlý, Marek; Turková, Ivana

2012-06-01

Microscopic methods play a key role in issues covering analyses of objects of art that are used on the one hand as screening ones, on the other hand they can lead to obtaining data relevant for completion of expertise. Analyses of artworks, gemmological objects and other highly valuable commodities usually do not rank among routine ones, but every analysis is specific, be it e.g. material investigation of artworks, historical textile materials and other antiques (coins, etc.), identification of fragments (from transporters, storage places, etc.), period statues, sculptures compared to originals, analyses of gems and jewellery, etc. A number of analytical techniques may be employed: optical microscopy in transmitted and reflected light, polarization and fluorescence in visible, UV and IR radiation; image analysis, quantitative microspectrophotometry; SEM/EDS/WDS; FTIR and Raman spectroscopy; XRF and microXRF, including mobile one; XRD and microXRD; x-ray backlight or LA-ICP-MS, SIMS, PIXE; further methods of organic analysis are also utilised - GS-MS, MALDI-TOF, etc.

Handheld Diffusion Test Cells

NASA Technical Reports Server (NTRS)

2001-01-01

This photo shows the Handheld Diffusion Test Cell (HH-DTC) apparatus flown on the Space Shuttle. Similar cells (inside the plastic box) will be used in the Observable Protein Crystal Growth Apparatus (OPCGA) to be operated aboard the International Space Station (ISS). The principal investigator is Dr. Alex McPherson of the University of California, Irvine. Each individual cell comprises two sample chambers with a rotating center section that isolates the two from each other until the start of the experiment and after it is completed. The cells are made from optical-quality quartz glass to allow photography and interferometric observations. Each cell has a small light-emitting diode and lens to back-light the solution. In protein crystal growth experiments, a precipitating agent such as a salt solution is used to absorb and hold water but repel the protein molecules. This increases the concentration of protein until the molecules nucleate to form crystals. This cell is one of 96 that make up the experiment module portion of the OPCGA.

Handheld Diffusion Test Cells

NASA Technical Reports Server (NTRS)

2001-01-01

This photo shows an individual cell from the Handheld Diffusion Test Cell (HH-DTC) apparatus flown on the Space Shuttle. Similar cells will be used in the Observable Protein Crystal Growth Apparatus (OPCGA) to be operated aboard the International Space Station (ISS). The principal investigator is Dr. Alex McPherson of the University of California, Irvine. Each individual cell comprises two sample chambers with a rotating center section that isolates the two from each other until the start of the experiment and after it is completed. The cells are made from optical-quality quartz glass to allow photography and interferometric observations. Each cell has a small light-emitting diode and lens to back-light the solution. In protein crystal growth experiments, a precipitating agent such as a salt solution is used to absorb and hold water but repel the protein molecules. This increases the concentration of protein until the molecules nucleate to form crystals. This cell is one of 96 that make up the experiment module portion of the OPCGA.

Lightweight Target Generates Bright, Energetic X-Rays

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

Hazi, A

Radiography with x rays is a long-established method to see inside objects, from human limbs to weapon parts. Livermore scientists have a continuing need for powerful x rays for such applications as backlighting, or illuminating, inertial confinement fusion (ICF) experiments and imaging still or exploding materials for the nation's Stockpile Stewardship Program. X-radiography is one of the prime diagnostics for ICF experiments because it captures the fine detail needed to determine what happens to nearly microscopic targets when they are compressed by laser light. For example, Livermore scientists participating in the National Ignition Facility's (NIF's) 18-month-long Early Light experimental campaign,more » which ended in 2004, used x rays to examine hydrodynamic instabilities in jets of plasma. In these experiments, one laser beam irradiated a solid target of titanium, causing it to form a high-temperature plasma that generated x rays of about 4.65 kiloelectronvolts (keV). These x rays backlit a jet of plasma formed when two other laser beams hit a plastic ablator and sent a shock to an aluminum washer. Livermore physicist Kevin Fournier of the Physics and Advanced Technologies Directorate leads a team that is working to increase the efficiency of converting laser energy into x rays so the resulting images provide more information about the object being illuminated. The main characteristics of x-ray sources are energy and brightness. ''As experimental targets get larger and as compression of the targets increases, the backlighter sources must be brighter and more energetic'', says Fournier. The more energetic the x rays, the further they penetrate an object. The brighter the source--that is, the more photons it has--the clearer the image. historically, researchers have used solid targets such as thin metal foils to generate x rays. however, when photon energies are greater than a few kiloelectronvolts, the conversion efficiency of solid targets is only a fraction of 1 percent. Solid targets have low efficiencies because much of the laser energy is deposited far from the target's x-ray emitting region, and the energy is carried by the relatively slow process of thermal conduction. ''The laser beam ablates material from the massive target, and that material moves away from the target's surface'', says Fournier. With a nanosecond pulse or longer, the laser interacts with the blow-off plasma rather than the remaining bulk sample. As a result, much of the laser's energy goes into the kinetic energy of the blow-off material, not into heating the bulk of the foil.« less

Characterization and Prediction of Cracks in Coated Materials: Direction and Length of Crack Propagation in Bimaterials

PubMed Central

Azari, Z.; Pappalettere, C.

2015-01-01

The behaviour of materials is governed by the surrounding environment. The contact area between the material and the surrounding environment is the likely spot where different forms of degradation, particularly rust, may be generated. A rust prevention treatment, like bluing, inhibitors, humidity control, coatings, and galvanization, will be necessary. The galvanization process aims to protect the surface of the material by depositing a layer of metallic zinc by either hot-dip galvanizing or electroplating. In the hot-dip galvanizing process, a metallic bond between steel and metallic zinc is obtained by immersing the steel in a zinc bath at a temperature of around 460°C. Although the hot-dip galvanizing procedure is recognized to be one of the most effective techniques to combat corrosion, cracks can arise in the intermetallic δ layer. These cracks can affect the life of the coated material and decrease the lifetime service of the entire structure. In the present paper the mechanical response of hot-dip galvanized steel submitted to mechanical loading condition is investigated. Experimental tests were performed and corroborative numerical and analytical methods were then applied in order to describe both the mechanical behaviour and the processes of crack/cracks propagation in a bimaterial as zinc-coated material. PMID:27347531

Characterization and Prediction of Cracks in Coated Materials: Direction and Length of Crack Propagation in Bimaterials.

PubMed

Pruncu, C I; Azari, Z; Casavola, C; Pappalettere, C

2015-01-01

The behaviour of materials is governed by the surrounding environment. The contact area between the material and the surrounding environment is the likely spot where different forms of degradation, particularly rust, may be generated. A rust prevention treatment, like bluing, inhibitors, humidity control, coatings, and galvanization, will be necessary. The galvanization process aims to protect the surface of the material by depositing a layer of metallic zinc by either hot-dip galvanizing or electroplating. In the hot-dip galvanizing process, a metallic bond between steel and metallic zinc is obtained by immersing the steel in a zinc bath at a temperature of around 460°C. Although the hot-dip galvanizing procedure is recognized to be one of the most effective techniques to combat corrosion, cracks can arise in the intermetallic δ layer. These cracks can affect the life of the coated material and decrease the lifetime service of the entire structure. In the present paper the mechanical response of hot-dip galvanized steel submitted to mechanical loading condition is investigated. Experimental tests were performed and corroborative numerical and analytical methods were then applied in order to describe both the mechanical behaviour and the processes of crack/cracks propagation in a bimaterial as zinc-coated material.

The Trend of Voluntary Warnings in Electronic Nicotine Delivery System Magazine Advertisements.

PubMed

Shang, Ce; Chaloupka, Frank J

2017-01-10

Some manufacturers of electronic nicotine delivery systems (ENDS) voluntarily carried health warnings in their advertisements. This study examined these voluntary warnings in magazine ads and plotted their trends between 2012 and early 2015. ENDS magazine ads were obtained through Kantar media and warnings were collected from the Chicago Public Library or the Trinkets and Trash surveillance system. The prevalence of voluntary warnings, warnings with the specific capitalized word "WARNING", and MarkTen warnings were examined after being weighted using factors related to exposure between January 2012 and March 2015. Five brands (MarkTen, NJOY, MISTIC, and some Blu) carried warnings during the study period. The prevalence of warnings post 2012 that contained a description of nicotine did not significantly increase until the launch of MarkTen, which also happened several months before April 2014 when the U.S. food and drug administration (FDA) published its proposed deeming rule. In addition, none of these warnings met the criteria required by the FDA in the final rules. Voluntary warnings, particularly MarkTen warnings, significantly increased in ENDS magazine ads between 2014 and 2015. It is important to monitor how ENDS manufacturers will comply with the FDA regulation related to warnings and how this regulation will ultimately impact ENDS risk perceptions and use.

Automatic detection of artifacts in converted S3D video

NASA Astrophysics Data System (ADS)

Bokov, Alexander; Vatolin, Dmitriy; Zachesov, Anton; Belous, Alexander; Erofeev, Mikhail

2014-03-01

In this paper we present algorithms for automatically detecting issues specific to converted S3D content. When a depth-image-based rendering approach produces a stereoscopic image, the quality of the result depends on both the depth maps and the warping algorithms. The most common problem with converted S3D video is edge-sharpness mismatch. This artifact may appear owing to depth-map blurriness at semitransparent edges: after warping, the object boundary becomes sharper in one view and blurrier in the other, yielding binocular rivalry. To detect this problem we estimate the disparity map, extract boundaries with noticeable differences, and analyze edge-sharpness correspondence between views. We pay additional attention to cases involving a complex background and large occlusions. Another problem is detection of scenes that lack depth volume: we present algorithms for detecting at scenes and scenes with at foreground objects. To identify these problems we analyze the features of the RGB image as well as uniform areas in the depth map. Testing of our algorithms involved examining 10 Blu-ray 3D releases with converted S3D content, including Clash of the Titans, The Avengers, and The Chronicles of Narnia: The Voyage of the Dawn Treader. The algorithms we present enable improved automatic quality assessment during the production stage.

The Trend of Voluntary Warnings in Electronic Nicotine Delivery System Magazine Advertisements

PubMed Central

Shang, Ce; Chaloupka, Frank J.

2017-01-01

Some manufacturers of electronic nicotine delivery systems (ENDS) voluntarily carried health warnings in their advertisements. This study examined these voluntary warnings in magazine ads and plotted their trends between 2012 and early 2015. ENDS magazine ads were obtained through Kantar media and warnings were collected from the Chicago Public Library or the Trinkets and Trash surveillance system. The prevalence of voluntary warnings, warnings with the specific capitalized word “WARNING”, and MarkTen warnings were examined after being weighted using factors related to exposure between January 2012 and March 2015. Five brands (MarkTen, NJOY, MISTIC, and some Blu) carried warnings during the study period. The prevalence of warnings post 2012 that contained a description of nicotine did not significantly increase until the launch of MarkTen, which also happened several months before April 2014 when the U.S. food and drug administration (FDA) published its proposed deeming rule. In addition, none of these warnings met the criteria required by the FDA in the final rules. Voluntary warnings, particularly MarkTen warnings, significantly increased in ENDS magazine ads between 2014 and 2015. It is important to monitor how ENDS manufacturers will comply with the FDA regulation related to warnings and how this regulation will ultimately impact ENDS risk perceptions and use. PMID:28075420

Effects of blue light and caffeine on mood.

PubMed

Ekström, Johan G; Beaven, C Martyn

2014-09-01

Both short wavelength (blue) light and caffeine have been studied for their mood enhancing effects on humans. The ability of blue light to increase alertness, mood and cognitive function via non-image forming neuropathways has been suggested as a non-pharmacological countermeasure for depression across a range of occupational settings. This experimental study compared blue light and caffeine and aimed to test the effects of blue light/placebo (BLU), white light/240-mg caffeine (CAF), blue light/240-mg caffeine (BCAF) and white light/placebo (PLA), on mood. A randomised, controlled, crossover design study was used, in a convenience population of 20 healthy volunteers. The participants rated their mood on the Swedish Core Affect Scales (SCAS) prior to and after each experimental condition to assess the dimensions of valence and activation. There was a significant main effect of light (p = 0.009), and the combination of blue light and caffeine had clear positive effects on core effects (ES, ranging from 0.41 to 1.20) and global mood (ES, 0.61 ± 0.53). The benefits of the combination of blue light and caffeine should be further investigated across a range of applications due to the observed effects on the dimensions of arousal, valence and pleasant activation.

Analyzing the Chemical and Spectral Effects of Pulsed Laser Irradiation to Simulate Space Weathering of a Carbonaceous Chondrite

NASA Technical Reports Server (NTRS)

Thompson, M. S.; Keller, L. P.; Christoffersen, R.; Loeffler, M. J.; Morris, R. V.; Graff, T. G.; Rahman, Z.

2017-01-01

Space weathering processes alter the chemical composition, microstructure, and spectral characteristics of material on the surfaces of airless bodies. The mechanisms driving space weathering include solar wind irradiation and the melting, vaporization and recondensation effects associated with micrometeorite impacts e.g., [1]. While much work has been done to understand space weathering of lunar and ordinary chondritic materials, the effects of these processes on hydrated carbonaceous chondrites is poorly understood. Analysis of space weathering of carbonaceous materials will be critical for understanding the nature of samples returned by upcoming missions targeting primitive, organic-rich bodies (e.g., OSIRIS-REx and Hayabusa 2). Recent experiments have shown the spectral properties of carbonaceous materials and associated minerals are altered by simulated weathering events e.g., [2-5]. However, the resulting type of alteration i.e., reddening vs. bluing of the reflectance spectrum, is not consistent across all experiments [2-5]. In addition, the microstructural and crystal chemical effects of many of these experiments have not been well characterized, making it difficult to attribute spectral changes to specific mineralogical or chemical changes in the samples. Here we report results of a pulsed laser irradiation experiment on a chip of the Murchison CM2 carbonaceous chondrite to simulate micrometeorite impact processing.

K-Shell Photoabsorption Edge of Strongly Coupled Matter Driven by Laser-Converted Radiation

NASA Astrophysics Data System (ADS)

Zhao, Yang; Yang, Jiamin; Zhang, Jiyan; Yang, Guohong; Wei, Minxi; Xiong, Gang; Song, Tianming; Zhang, Zhiyu; Bao, Lihua; Deng, Bo; Li, Yukun; He, Xiaoan; Li, Chaoguang; Mei, Yu; Yu, Ruizhen; Jiang, Shaoen; Liu, Shenye; Ding, Yongkun; Zhang, Baohan

2013-10-01

The first observation of the K-shell photoabsorption edge of strongly coupled matter with an ion-ion coupling parameter of about 65 generated by intense x-ray radiation-driven shocks is reported. The soft x-ray radiation generated by laser interaction with a “dog bone” high-Z hohlraum is used to ablate two thick CH layers, which cover a KCl sample, to create symmetrical inward shocks. While the two shocks impact at the central KCl sample, a highly compressed KCl is obtained with a density of 3-5 times solid density and a temperature of about 2-4 eV. The photoabsorption spectra of chlorine near the K-shell edge are measured with a crystal spectrometer using a short x-ray backlighter. The redshift of the K edge up to 11.7 eV and broadening of 15.2 eV are obtained for the maximum compression. A comparison of the measured redshifts and broadenings with dense plasma calculations are made, and it indicates potential improvements in the theoretical description.

Recent advances in the science and technology for solid state lighting

NASA Astrophysics Data System (ADS)

Munkholm, Anneli

2003-03-01

Recent development of high power light emitting diodes (LEDs) has enabled fabrication of solid state devices with efficiencies that surpass that of incandescent light, as well as providing a total light output significantly exceeding that of conventional indicator LEDs. This breakthrough in high flux is opening up new applications for use of high power LEDs, such as liquid crystal display backlighting and automotive headlights. Some of the key elements to this technological breakthrough are the flip-chip device design, power packaging and phosphor coating technology, which will be discussed. In addition to device design improvements, our fundamental knowledge of the III-nitride material system is improving and has resulted in higher internal quantum efficiencies. Strain plays a significant role in complex AlInGaN heterostructures used in current devices. Using a multi-beam optical strain sensor (MOSS) system to measure the wafer curvature in situ, we have characterized the strain during metal-organic chemical vapor deposition of III-nitrides. Strain measurements of InGaN, AlGaN and Si-doped GaN films on GaN will be presented.

Simulations of Converging Shock Collisions for Shock Ignition

NASA Astrophysics Data System (ADS)

Sauppe, Joshua; Dodd, Evan; Loomis, Eric

2016-10-01

Shock ignition (SI) has been proposed as an alternative to achieving high gain in inertial confinement fusion (ICF) targets. A central hot spot below the ignition threshold is created by an initial compression pulse, and a second laser pulse drives a strong converging shock into the fuel. The collision between the rebounding shock from the compression pulse and the converging shock results in amplification of the converging shock and increases the hot spot pressure above the ignition threshold. We investigate shock collision in SI drive schemes for cylindrical targets with a polystyrene foam interior using radiation-hydrodynamics simulations with the RAGE code. The configuration is similar to previous targets fielded on the Omega laser. The CH interior results in a lower convergence ratio and the cylindrical geometry facilitates visualization of the shock transit using an axial X-ray backlighter, both of which are important for comparison to potential experimental measurements. One-dimensional simulations are used to determine shock timing, and the effects of low mode asymmetries in 2D computations are also quantified. LA-UR-16-24773.

Detection of significant differences between absorption spectra of neutral helium and low temperature photoionized helium plasmas

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

Bartnik, A.; Wachulak, P.; Fiedorowicz, H.

2013-11-15

In this work, spectral investigations of photoionized He plasmas were performed. The photoionized plasmas were created by irradiation of helium stream, with intense pulses from laser-plasma extreme ultraviolet (EUV) source. The EUV source was based on a double-stream Xe/Ne gas-puff target irradiated with 10 ns/10 J Nd:YAG laser pulses. The most intense emission from the source spanned a relatively narrow spectral region below 20 nm, however, spectrally integrated intensity at longer wavelengths was also significant. The EUV radiation was focused onto a gas stream, injected into a vacuum chamber synchronously with the EUV pulse. The long-wavelength part of the EUVmore » radiation was used for backlighting of the photoionized plasmas to obtain absorption spectra. Both emission and absorption spectra in the EUV range were investigated. Significant differences between absorption spectra acquired for neutral helium and low temperature photoionized plasmas were demonstrated for the first time. Strong increase of intensities and spectral widths of absorption lines, together with a red shift of the K-edge, was shown.« less

Large Arrays of Microcavity Plasma Devices for Active Displays and Backlighting

NASA Astrophysics Data System (ADS)

Eden, J. Gary; Park, Sung-Jin; Ostrom, Nels P.; Chen, Kuo-Feng; Kim, Kwang Soo

2005-09-01

Developments of the past several years in the technology of microcavity plasma devices having characteristic dimensions of 10-100 µm suggests their applicability to the next generation of active and passive displays. Two examples of device structures that are well suited for economically manufactured arrays of large active area are presented. Arrays as large as 500 x 500 (2.5 ṡ 105) pixels of Si inverted pyramid microplasma devices, with emitting apertures of 50 x 50 µm2 and designed for AC or bipolar excitation, have been designed and operated successfully in the rare gases at pressures up to and beyond one atmosphere. Multilayer Al/nanostructured Al2O3 microplasma devices having 100-300 µm diam. cylindrical microcavities are robust and operate in the abnormal glow mode for rare gas or Ar/2-5% N2 mixture pressures of 500-700 torr. Grown by a wet chemical process, the nanoporous Al2O3 dielectric yields a lightweight, flexible structure that produces intense visible or ultraviolet emission when driven by sinusoidal AC or bipolar voltage waveforms.

Realization of 95% of the Rec. 2020 color gamut in a highly efficient LCD using a patterned quantum dot film.

PubMed

Kim, Hyo-Jun; Shin, Min-Ho; Lee, Jae-Yong; Kim, Ji-Hoon; Kim, Young-Joo

2017-05-15

An optically efficient liquid-crystal display (LCD) structure using a patterned quantum dot (QD) film and a short-pass filter (SPF) was proposed and fabricated. The patterned QD film contributed to the generation of 95% in the area ratio (or 90% in the coverage ratio) of the Rec. 2020 color gamut. This was achieved by avoiding the problem of interaction between white backlight and broad transmittance spectra of color filters (CFs) as seen in a conventional LCD with a mixed QD film as a reference. The patterned QD film can maintain the narrow bandwidth of the green and the red QD colors before passing through the CFs. Additionally, the optical intensities of the red, green, and blue spectra were enhanced to 1.63, 1.72, and 2.16 times the reference LCD values, respectively. This was a result of separated emission of the red and green patterned QD film and reflection of the red and green light to the forward direction by the SPF.

Color matrix display simulation based upon luminance and chromatic contrast sensitivity of early vision

NASA Technical Reports Server (NTRS)

Martin, Russel A.; Ahumada, Albert J., Jr.; Larimer, James O.

1992-01-01

This paper describes the design and operation of a new simulation model for color matrix display development. It models the physical structure, the signal processing, and the visual perception of static displays, to allow optimization of display design parameters through image quality measures. The model is simple, implemented in the Mathematica computer language, and highly modular. Signal processing modules operate on the original image. The hardware modules describe backlights and filters, the pixel shape, and the tiling of the pixels over the display. Small regions of the displayed image can be visualized on a CRT. Visual perception modules assume static foveal images. The image is converted into cone catches and then into luminance, red-green, and blue-yellow images. A Haar transform pyramid separates the three images into spatial frequency and direction-specific channels. The channels are scaled by weights taken from human contrast sensitivity measurements of chromatic and luminance mechanisms at similar frequencies and orientations. Each channel provides a detectability measure. These measures allow the comparison of images displayed on prospective devices and, by that, the optimization of display designs.

An embedded fibre optic sensor for impact damage detection in composite materials

NASA Astrophysics Data System (ADS)

Glossop, Neil David William

1989-09-01

A structurally embedded fiber optic damage detection sensor for composite materials is described. The system is designed specifically for the detection of barely visible damage resulting from low velocity impacts in Kevlar-epoxy laminates. By monitoring the light transmission properties of optical fiber embedded in the composite, it was shown that the integrity of the material can be accurately determined. The effect of several parameters on the sensitivity of the system was investigated, including the effect of the optical fiber orientation and depth of embedding within the composite. A novel surface was also developed for the optical fibers to ensure they will fracture at the requisite damage level. The influence of the optical fiber sensors on the tensile and compressive material properties and on the impact resistance of the laminate was also studied. Extensive experimental results from impact tests are reported and a numerical model of the impact event is presented which is able to predict and model the damage mechanism and sensor system. A new and powerful method of nondestructive evaluation for translucent composite materials based on image enhanced backlighting is also described.

A white organic light emitting diode based on anthracene-triphenylamine derivatives

NASA Astrophysics Data System (ADS)

Jiang, Quan; Qu, Jianjun; Yu, Junsheng; Tao, Silu; Gan, Yuanyuan; Jiang, Yadong

2010-10-01

White organic lighting-diode (WOLED) can be used as flat light sources, backlights for liquid crystal displays and full color displays. Recently, a research mainstream of white OLED is to develop the novel materials and optimize the structure of devices. In this work a WOLED with a structure of ITO/NPB/PAA/Alq3: x% rubrene/Alq3/Mg: Ag, was fabricated. The device has two light-emitting layers. NPB is used as a hole transport layer, PAA as a blue emitting layer, Alq3: rubrene host-guest system as a yellow emitting layer, and Alq3 close to the cathode as an electron transport layer. In the experiment, the doping concentration of rubrene was optimized. WOLED 1 with 4% rubrene achieved a maximum luminous efficiency of 1.80 lm/W, a maximum luminance of 3926 cd/m2 and CIE coordinates of (0.374, 0.341) .WOLED 2 with 2% rubrene achieved a maximum luminous efficiency of 0.65 lm/W, a maximum luminance of 7495cd/m2 and CIE coordinates of (0.365,0.365).

Evolution of elastic x-ray scattering in laser-shocked warm dense lithium.

PubMed

Kugland, N L; Gregori, G; Bandyopadhyay, S; Brenner, C M; Brown, C R D; Constantin, C; Glenzer, S H; Khattak, F Y; Kritcher, A L; Niemann, C; Otten, A; Pasley, J; Pelka, A; Roth, M; Spindloe, C; Riley, D

2009-12-01

We have studied the dynamics of warm dense Li with near-elastic x-ray scattering. Li foils were heated and compressed using shock waves driven by 4-ns-long laser pulses. Separate 1-ns-long laser pulses were used to generate a bright source of 2.96 keV Cl Ly- alpha photons for x-ray scattering, and the spectrum of scattered photons was recorded at a scattering angle of 120 degrees using a highly oriented pyrolytic graphite crystal operated in the von Hamos geometry. A variable delay between the heater and backlighter laser beams measured the scattering time evolution. Comparison with radiation-hydrodynamics simulations shows that the plasma is highly coupled during the first several nanoseconds, then relaxes to a moderate coupling state at later times. Near-elastic scattering amplitudes have been successfully simulated using the screened one-component plasma model. Our main finding is that the near-elastic scattering amplitudes are quite sensitive to the mean ionization state Z[over ] and by extension to the choice of ionization model in the radiation-hydrodynamics simulations used to predict plasma properties within the shocked Li.

Talbot-Lau x-ray interferometry for high energy density plasma diagnostic.

PubMed

Stutman, D; Finkenthal, M

2011-11-01

High resolution density diagnostics are difficult in high energy density laboratory plasmas (HEDLP) experiments due to the scarcity of probes that can penetrate above solid density plasmas. Hard x-rays are one possible probe for such dense plasmas. We study the possibility of applying an x-ray method recently developed for medical imaging, differential phase-contrast with Talbot-Lau interferometers, for the diagnostic of electron density and small-scale hydrodynamic instabilities in HEDLP experiments. The Talbot method uses micro-periodic gratings to measure the refraction and ultra-small angle scatter of x-rays through an object and is attractive for HEDLP diagnostic due to its capability to work with incoherent and polychromatic x-ray sources such as the laser driven backlighters used for HEDLP radiography. Our paper studies the potential of the Talbot method for HEDLP diagnostic, its adaptation to the HEDLP environment, and its extension of high x-ray energy using micro-periodic mirrors. The analysis is illustrated with experimental results obtained using a laboratory Talbot interferometer. © 2011 American Institute of Physics

Replicating the Z iron opacity experiments on the NIF

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

Perry, T. S.; Heeter, R. F.; Opachich, Y. P.

Here, X-ray opacity is a crucial factor of all radiation-hydrodynamics calculations, yet it is one of the least validated of the material properties in the simulation codes. Recent opacity experiments at the Sandia Z-machine have shown up to factors of two discrepancies between theory and experiment, casting doubt on the validity of the opacity models. Therefore, a new experimental opacity platform is being developed on the National Ignition Facility (NIF) not only to verify the Z-machine experimental results but also to extend the experiments to other temperatures and densities. The first experiments will be directed towards measuring the opacity ofmore » iron at a temperature of ~160 eV and an electron density of ~7 x 10 21 cm -3. Preliminary experiments on NIF have demonstrated the ability to create a sufficiently bright point backlighter using an imploding plastic capsule and also a hohlraum that can heat the opacity sample to the desired conditions. The first of these iron opacity experiments is expected to be performed in 2017.« less

Convergent Geometry Foam Buffered Direct Drive Experiments*

NASA Astrophysics Data System (ADS)

Watt, R. G.; Wilson, D. C.; Hollis, R. V.; Gobby, P. L.; Chrien, R. E.; Mason, R. J.; Kopp, R. A.; Willi, O.; Iwase, A.; Barringer, L. H.; Gaillard, R.; Kalantar, D. H.; Lerche, R. A.; MacGowan, B.; Nelson, M.; Phillips, T.; Knauer, J. P.; McKenty, P. W.

1996-11-01

A serious concern for directly driven ICF implosions is the asymmetry imparted to the capsule by laser drive non-uniformities, particularly the ``early time imprint'' remaining despite the use of random phase plates and smoothing with spectral dispersion. The use of a foam buffer has been proposed as a means to reduce this imprint. Two types of convergent geometry tests of the technique to correct static nonuniformities have been studied to date; cylindrical implosions at the Trident and Vulcan lasers, and spherical implosions at the NOVA laser, all using 527 nm laser drive. Cylindrical implosions used end on x-ray backlighter imaging of inner surface disruption due an intentional hole in the drive footprint, using 50 mg/cc acyrlate foam with a thin Au preheat layer. Spherical implosions used 50 mg/cc polystyrene foam plus Au to study yield and imploded core symmetry of capsules with and without a foam buffer, in comparison to ``clean 1D'' calculations. For thick enough layers, all cases showed improvement. Details of the experiments and theoretical unpinnings will be shown. *Work performed under US DOE Contract No. W-7405-Eng-36.

LED-based high-speed visible light communications

NASA Astrophysics Data System (ADS)

Chi, Nan; Shi, Meng; Zhao, Yiheng; Wang, Fumin; Shi, Jianyang; Zhou, Yingjun; Lu, Xingyu; Qiao, Liang

2018-01-01

We are seeing a growing use of light emitting diodes (LEDs) in a range of applications including lighting, TV and backlight board screen, display etc. In comparison with the traditional incandescent and fluorescent light bulbs, LEDs offer long life-space, much higher energy efficiency, high performance cost ratio and above all very fast switching capability. LED based Visible Light Communications (VLC) is an emerging field of optical communications that focuses on the part of the electromagnetic spectrum that humans can see. Depending on the transmission distance, we can divide the whole optical network into two categories, long haul and short haul. Visible light communication can be a promising candidate for short haul applications. In this paper, we outline the configuration of VLC, its unique benefits, and describe the state of the art research contributions consisting of advanced modulation formats including adaptive bit loading OFDM, carrierless amplitude and phase (CAP), pulse amplitude modulation (PAM) and single carrier Nyquist, linear equalization and nonlinear distortion mitigation based on machine learning, quasi-balanced coding and phase-shifted Manchester coding. These enabling technologies can support VLC up to 10Gb/s class free space transmission.

Colloidal Synthesis of CH3 NH3 PbBr3 Nanoplatelets with Polarized Emission through Self-Organization.

PubMed

Liu, Lige; Huang, Sheng; Pan, Longfei; Shi, Li-Jie; Zou, Bingsuo; Deng, Luogen; Zhong, Haizheng

2017-02-06

We report a combined experimental and theoretical study of the synthesis of CH 3 NH 3 PbBr 3 nanoplatelets through self-organization. Shape transformation from spherical nanodots to square or rectangular nanoplatelets can be achieved by keeping the preformed colloidal nanocrystals at a high concentration (3.5 mg mL -1 ) for 3 days, or combining the synthesis of nanodots with self-organization. The average thickness of the resulting CH 3 NH 3 PbBr 3 nanoplatelets is similar to the size of the original nanoparticles, and we also noticed several nanoplatelets with circular or square holes, suggesting that the shape transformation experienced a self-organization process through dipole-dipole interactions along with a realignment of dipolar vectors. Additionally, the CH 3 NH 3 PbBr 3 nanoplatelets exhibit excellent polarized emissions for stretched CH 3 NH 3 PbBr 3 nanoplatelets embedded in a polymer composite film, showing advantageous photoluminescence properties for display backlights. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Energy transport in short-pulse-laser-heated targets measured using extreme ultraviolet laser backlighting.

PubMed

Wilson, L A; Tallents, G J; Pasley, J; Whittaker, D S; Rose, S J; Guilbaud, O; Cassou, K; Kazamias, S; Daboussi, S; Pittman, M; Delmas, O; Demailly, J; Neveu, O; Ros, D

2012-08-01

The accurate characterization of thermal electron transport and the determination of heating by suprathermal electrons in laser driven solid targets are both issues of great importance to the current experiments being performed at the National Ignition Facility, which aims to achieve thermonuclear fusion ignition using lasers. Ionization, induced by electronic heat conduction, can cause the opacity of a material to drop significantly once bound-free photoionization is no longer energetically possible. We show that this drop in opacity enables measurements of the transmission of extreme ultraviolet (EUV) laser pulses at 13.9 nm to act as a signature of the heating of thin (50 nm) iron layers with a 50-nm thick parylene-N (CH) overlay irradiated by 35-fs pulses at irradiance 3×10(16) Wcm(-2). Comparing EUV transmission measurements at different times after irradiation to fluid code simulations shows that the target is instantaneously heated by hot electrons (with approximately 10% of the laser energy), followed by thermal conduction with a flux limiter of ≈0.05.

Replicating the Z iron opacity experiments on the NIF

DOE PAGES

Perry, T. S.; Heeter, R. F.; Opachich, Y. P.; ...

2017-05-12

Here, X-ray opacity is a crucial factor of all radiation-hydrodynamics calculations, yet it is one of the least validated of the material properties in the simulation codes. Recent opacity experiments at the Sandia Z-machine have shown up to factors of two discrepancies between theory and experiment, casting doubt on the validity of the opacity models. Therefore, a new experimental opacity platform is being developed on the National Ignition Facility (NIF) not only to verify the Z-machine experimental results but also to extend the experiments to other temperatures and densities. The first experiments will be directed towards measuring the opacity ofmore » iron at a temperature of ~160 eV and an electron density of ~7 x 10 21 cm -3. Preliminary experiments on NIF have demonstrated the ability to create a sufficiently bright point backlighter using an imploding plastic capsule and also a hohlraum that can heat the opacity sample to the desired conditions. The first of these iron opacity experiments is expected to be performed in 2017.« less

Demonstration of imaging X-ray Thomson scattering on OMEGA EP.

PubMed

Belancourt, Patrick X; Theobald, Wolfgang; Keiter, Paul A; Collins, Tim J B; Bonino, Mark J; Kozlowski, Pawel M; Regan, Sean P; Drake, R Paul

2016-11-01

Foams are a common material for high-energy-density physics experiments because of low, tunable densities, and being machinable. Simulating these experiments can be difficult because the equation of state is largely unknown for shocked foams. The focus of this experiment was to develop an x-ray scattering platform for measuring the equation of state of shocked foams on OMEGA EP. The foam used in this experiment is resorcinol formaldehyde with an initial density of 0.34 g/cm 3 . One long-pulse (10 ns) beam drives a shock into the foam, while the remaining three UV beams with a 2 ns square pulse irradiate a nickel foil to create the x-ray backlighter. The primary diagnostic for this platform, the imaging x-ray Thomson spectrometer, spectrally resolves the scattered x-ray beam while imaging in one spatial dimension. Ray tracing analysis of the density profile gives a compression of 3 ± 1 with a shock speed of 39 ± 6 km/s. Analysis of the scattered x-ray spectra gives an upper bound temperature of 20 eV.

Fabrication of a simultaneous red-green-blue reflector using single-pitched cholesteric liquid crystals.

PubMed

Ha, Na Young; Ohtsuka, Youko; Jeong, Soon Moon; Nishimura, Suzushi; Suzaki, Goroh; Takanishi, Yoichi; Ishikawa, Ken; Takezoe, Hideo

2008-01-01

A cholesteric liquid crystal (CLC) is a self-assembled photonic crystal formed by rodlike molecules, including chiral molecules, that arrange themselves in a helical fashion. The CLC has a single photonic bandgap and an associated one-colour reflection band for circularly polarized light with the same handedness as the CLC helix (selective reflection). These optical characteristics, particularly the circular polarization of the reflected light, are attractive for applications in reflective colour displays without using a backlight, for use as polarizers or colour filters and for mirrorless lasing. Recently, we showed by numerical simulation that simultaneous multicolour reflection is possible by introducing fibonaccian phase defects. Here, we design and fabricate a CLC system consisting of thin isotropic films and of polymeric CLC films, and demonstrate experimentally simultaneous red, green and blue reflections (multiple photonic bandgaps) using the single-pitched polymeric CLC films. The experimental reflection spectra are well simulated by calculations. The presented system can extend applications of CLCs to a wide-band region and could give rise to new photonic devices, in which white or multicolour light is manipulated.

Blue laser diode (LD) and light emitting diode (LED) applications

NASA Astrophysics Data System (ADS)

Bergh, Arpad A.

2004-09-01

The family of blue LEDs, edge emitting and surface emitting lasers, enable a number of applications. Blue lasers are used in digital applications such as optical storage in high density DVDs. The resolution of the spot size and hence the storage density is diffraction limited and is inversely proportional to the square of the wavelength of the laser. Other applications include printing, optical scanners, and high-resolution photo-lithography.As light emitters, blue LEDs are used for signaling and in direct view large area emissive displays. They are also making inroads into signage and LCD back-lighting, mobile platforms, and decorative accent lighting in curtains, furniture, etc.Blue LEDs produce white light either with phosphor wavelength converters or in combination with red and green LEDs. The full potential of LED light sources will require three devices to enable complete control over color and intensity.Sensing and medical/bio applications have a major impact on home security, on monitoring the environment, and on health care. New emerging diagnostic and therapeutic applications will improve the quality and reduce the cost of health care.

An x-ray backlit Talbot-Lau deflectometer for high-energy-density electron density diagnostics

DOE PAGES

Valdivia, M. P.; Stutman, D.; Stoeckl, C.; ...

2016-02-10

X-ray phase-contrast techniques can measure electron density gradients in high-energy-density plasmas through refraction induced phase shifts. An 8 keV Talbot-Lau interferometer consisting of free standing ultrathin gratings was deployed at an ultra-short, high-intensity laser system using K-shell emission from a 1-30 J, 8 ps laser pulse focused on thin Cu foil targets. Grating survival was demonstrated for 30 J, 8 ps laser pulses. The first x-ray deflectometry images obtained under laser backlighting showed up to 25% image contrast and thus enabled detection of electron areal density gradients with a maximum value of 8.1 ± 0.5 × 10 23 cm ₋3more » in a low-Z millimeter sized sample. An electron density profile was obtained from refraction measurements with an error of <8%. We found the 50 ± 15 μm spatial resolution achieved across the full field of view was limited by the x-ray source-size, similar to conventional radiography.« less

Velocity and void distribution in a counter-current two-phase flow

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

Gabriel, S.; Schulenberg, T.; Laurien, E.

2012-07-01

Different flow regimes were investigated in a horizontal channel. Simulating a hot leg injection in case of a loss of coolant accident or flow conditions in reflux condenser mode, the hydraulic jump and partially reversed flow were identified as major constraints for a high amount of entrained water. Trying to simulate the reflux condenser mode, the test section now includes an inclined section connected to a horizontal channel. The channel is 90 mm high and 110 mm wide. Tests were carried out for water and air at ambient pressure and temperature. High speed video-metry was applied to obtain velocities frommore » flow pattern maps of the rising and falling fluid. In the horizontal part of the channel with partially reversed flow the fluid velocities were measured by planar particle image velocimetry. To obtain reliable results for the gaseous phase, this analysis was extended by endoscope measurements. Additionally, a new method based on the optical refraction at the interface between air and water in a back-light was used to obtain time-averaged void fraction. (authors)« less

Modulation of visualized electrical field

NASA Astrophysics Data System (ADS)

Chuang, Chin-Jung; Wu, Chi-Chung; Wang, Yi-Ting; Huang, Shiuan-Hau

2015-10-01

Polarization is an important concept of electromagnetism, and polarizers were traditionally applied to demonstrate this concept in a laboratory. We set up a optical system with the optical component "axis finder" to visualize the polarization direction immediately. The light phenomena, such as birefringence, circular polarization, and Brewster's angle, can be examined polarization visually. In addition, the principle of different waveplate and optical axis can be presented in a straightforward approach. By means of image analysis, the great precision of polarizing direction can be measured up to 0.01 degree. Modulated polarized light is applied to a few optical devices, like Liquid-crystal display. It is marvelous to trace the light polarization between the backlight module, polarizer, and panel. As seeing is believing, the visualized electrical field allows educators to teach polarization in a smooth and strikingly manifest manner. Without any polarizer and analyzer, we examine the rotary power of different concentration syrup, presenting the relationship with polarization change. We also demonstrate the wide application of polarization light in modern life, and examine the principle through this visualized electrical field system.

Asymmetrically cut crystal pair as x-ray magnifier for imaging at high intensity laser facilitiesa)

NASA Astrophysics Data System (ADS)

Szabo, C. I.; Feldman, U.; Seely, J. F.; Curry, J. J.; Hudson, L. T.; Henins, A.

2010-10-01

The potential of an x-ray magnifier prepared from a pair of asymmetrically cut crystals is studied to explore high energy x-ray imaging capabilities at high intensity laser facilities. OMEGA-EP and NIF when irradiating mid and high Z targets can be a source of high-energy x-rays whose production mechanisms and use as backlighters are a subject of active research. This paper studies the properties and potential of existing asymmetric cut crystal pairs from the National Institute of Standards and Technology (NIST) built in a new enclosure for imaging x-ray sources. The technique of the x-ray magnifier has been described previously. This new approach is aimed to find a design that could be used at laser facilities by magnifying the x-ray source into a screen far away from the target chamber center, with fixed magnification defined by the crystals' lattice spacing and the asymmetry angles. The magnified image is monochromatic and the imaging wavelength is set by crystal asymmetry and incidence angles. First laboratory results are presented and discussed.

Mixing Characteristics of Coaxial Injectors at High Gas to Liquid Momentum Ratios

NASA Technical Reports Server (NTRS)

Strakey, P. A.; Talley, D. G.; Hutt, J. J.

1999-01-01

A study of the spray of a swirl coaxial gas-liquid injector operating at high gas to liquid momentum ratios is reported. Mixing and droplet size characteristics of the swirl injector are also compared to a shear coaxial injector, currently being used in the Space Shuttle Main Engine fuel preburner. The injectors were tested at elevated chamber pressures using water as a LOX simulant and nitrogen and helium as gaseous hydrogen simulants. The elevated chamber pressure allowed for matching of several of the preburner injector conditions including; gas to liquid momentum ratio, density ratio and Mach number. Diagnostic techniques used to characterize the spray included; strobe back-light imaging, laser sheet spray imaging, mechanical patternation, and a phase Doppler interferometry. Results thus far indicate that the radial spreading of the swirl coaxial spray is much less than was reported in previous studies of swirl injectors operating at atmospheric back-pressure. The swirl coaxial spray does, however, exhibit a smaller overall droplet size which may be interpreted as an increase in local mixing.

In situ determination of flocculated suspended material settling velocities and characteristics using a floc camera

USGS Publications Warehouse

Schoellhamer, David H.; Haught, Dan; Manning, Andrew

2012-01-01

Estimates of suspended sediment settling are necessary for numerical sediment models, water quality studies, and rehabilitation of coastal ecosystems. Settling of cohesive sediment, which is common in estuaries, is more difficult to quantify than noncohesive sediment because of flocculation. Flocs are composed of an aggregation of finer silts, clays, and organic material. Floc characteristics, such as the diameter, density, porosity, and water content determine floc settling velocities. A floc camera provides the ability to capture the settling velocities and other desired characteristics of individual flocs in situ. Water samples taken using a Van Dorn sampler are immediately subsampled using a pipette and transferred to the floc camera. The Perspex settling column is outfitted with a LED backlighting to distinguish flocs. The floc camera’s high pixel and temporal resolution allows image analysis software to detect individual flocs and process floc statistics per image. Observed changes in floc location with respect to time presents a way of calculating settling velocities. This work presents results of validation tests with known sediment size distributions and of deployment of the camera during a field study.

Luminescence in Sulfides: A Rich History and a Bright Future

PubMed Central

Smet, Philippe F.; Moreels, Iwan; Hens, Zeger; Poelman, Dirk

2010-01-01

Sulfide-based luminescent materials have attracted a lot of attention for a wide range of photo-, cathodo- and electroluminescent applications. Upon doping with Ce3+ and Eu2+, the luminescence can be varied over the entire visible region by appropriately choosing the composition of the sulfide host. Main application areas are flat panel displays based on thin film electroluminescence, field emission displays and ZnS-based powder electroluminescence for backlights. For these applications, special attention is given to BaAl2S4:Eu, ZnS:Mn and ZnS:Cu. Recently, sulfide materials have regained interest due to their ability (in contrast to oxide materials) to provide a broad band, Eu2+-based red emission for use as a color conversion material in white-light emitting diodes (LEDs). The potential application of rare-earth doped binary alkaline-earth sulfides, like CaS and SrS, thiogallates, thioaluminates and thiosilicates as conversion phosphors is discussed. Finally, this review concludes with the size-dependent luminescence in intrinsic colloidal quantum dots like PbS and CdS, and with the luminescence in doped nanoparticles.

Disparity profiles in 3DV applications: overcoming the issue of heterogeneous viewing conditions in stereoscopic delivery

NASA Astrophysics Data System (ADS)

Boisson, Guillaume; Chamaret, Christel

2012-03-01

More and more numerous 3D movies are released each year. Thanks to the current spread of 3D-TV displays, these 3D Video (3DV) contents are about to enter massively the homes. Yet viewing conditions determine the stereoscopic features achievable for 3DV material. Because the conditions at home - screen size and distance to screen - differ significantly from a theater, 3D Cinema movies need to be repurposed before broadcast and replication on 3D Blu-ray Discs for being fully enjoyed at home. In that paper we tackle that particular issue of how to handle the variety of viewing conditions in stereoscopic contents delivery. To that extend we first investigate what is basically at stake for granting stereoscopic viewers' comfort, through the well-known - and sometimes dispraised - vergence-accommodation conflict. Thereby we define a set of basic rules that can serve as guidelines for 3DV creation. We propose disparity profiles as new requirements for 3DV production and repurposing. Meeting proposed background and foreground constraints prevents from visual fatigue, and occupying the whole depth budget available grants optimal 3D effects. We present an efficient algorithm for automatic disparity-based 3DV retargeting depending on the viewing conditions. Variants are proposed depending on the input format (stereoscopic binocular content or depth-based format) and the level of complexity achievable.

Altered lung biology of healthy never smokers following acute inhalation of E-cigarettes.

PubMed

Staudt, Michelle R; Salit, Jacqueline; Kaner, Robert J; Hollmann, Charleen; Crystal, Ronald G

2018-05-14

Little is known about health risks associated with electronic cigarette (EC) use although EC are rising in popularity and have been advocated as a means to quit smoking cigarettes. Ten never-smokers, without exposure history to tobacco products or EC, were assessed at baseline with questionnaire, chest X-ray, lung function, plasma levels of endothelial microparticles (EMP), and bronchoscopy to obtain small airway epithelium (SAE) and alveolar macrophages (AM). One week later, subjects inhaled 10 puffs of "Blu" brand EC, waited 30 min, then another 10 puff; n = 7 were randomized to EC with nicotine and n = 3 to EC without nicotine to assess biological responses in healthy, naive individuals. Two hr. post-EC exposure, subjects were again assessed as at baseline. No significant changes in clinical parameters were observed. Biological changes were observed compared to baseline, including altered transcriptomes of SAE and AM for all subjects and elevated plasma EMP levels following inhalation of EC with nicotine. This study provides in vivo human data demonstrating that acute inhalation of EC aerosols dysregulates normal human lung homeostasis in a limited cohort of healthy naïve individuals. These observations have implications to new EC users, nonsmokers exposed to secondhand EC aerosols and cigarette smokers using EC to quit smoking. ClinicalTrials.gov NCT01776398 (registered 10/12/12), NCT02188511 (registered 7/2/14).

Design and implementation of a channel decoder with LDPC code

NASA Astrophysics Data System (ADS)

Hu, Diqing; Wang, Peng; Wang, Jianzong; Li, Tianquan

2008-12-01

Because Toshiba quit the competition, there is only one standard of blue-ray disc: BLU-RAY DISC, which satisfies the demands of high-density video programs. But almost all the patents are gotten by big companies such as Sony, Philips. As a result we must pay much for these patents when our productions use BD. As our own high-density optical disk storage system, Next-Generation Versatile Disc(NVD) which proposes a new data format and error correction code with independent intellectual property rights and high cost performance owns higher coding efficiency than DVD and 12GB which could meet the demands of playing the high-density video programs. In this paper, we develop Low-Density Parity-Check Codes (LDPC): a new channel encoding process and application scheme using Q-matrix based on LDPC encoding has application in NVD's channel decoder. And combined with the embedded system portable feature of SOPC system, we have completed all the decoding modules by FPGA. In the NVD experiment environment, tests are done. Though there are collisions between LDPC and Run-Length-Limited modulation codes (RLL) which are used in optical storage system frequently, the system is provided as a suitable solution. At the same time, it overcomes the defects of the instability and inextensibility, which occurred in the former decoding system of NVD--it was implemented by hardware.

Xenobiotic Compounds Degradation by Heterologous Expression of a Trametes sanguineus Laccase in Trichoderma atroviride

PubMed Central

Balcázar-López, Edgar; Méndez-Lorenzo, Luz Helena; Batista-García, Ramón Alberto; Esquivel-Naranjo, Ulises; Ayala, Marcela; Kumar, Vaidyanathan Vinoth; Savary, Olivier; Cabana, Hubert; Herrera-Estrella, Alfredo; Folch-Mallol, Jorge Luis

2016-01-01

Fungal laccases are enzymes that have been studied because of their ability to decolorize and detoxify effluents; they are also used in paper bleaching, synthesis of polymers, bioremediation, etc. In this work we were able to express a laccase from Trametes (Pycnoporus) sanguineus in the filamentous fungus Trichoderma atroviride. For this purpose, a transformation vector was designed to integrate the gene of interest in an intergenic locus near the blu17 terminator region. Although monosporic selection was still necessary, stable integration at the desired locus was achieved. The native signal peptide from T. sanguineus laccase was successful to secrete the recombinant protein into the culture medium. The purified, heterologously expressed laccase maintained similar properties to those observed in the native enzyme (Km and kcat and kcat/km values for ABTS, thermostability, substrate range, pH optimum, etc). To determine the bioremediation potential of this modified strain, the laccase-overexpressing Trichoderma strain was used to remove xenobiotic compounds. Phenolic compounds present in industrial wastewater and bisphenol A (an endocrine disruptor) from the culture medium were more efficiently removed by this modified strain than with the wild type. In addition, the heterologously expressed laccase was able to decolorize different dyes as well as remove benzo[α]pyrene and phenanthrene in vitro, showing its potential for xenobiotic compound degradation. PMID:26849129

Automatic view synthesis by image-domain-warping.

PubMed

Stefanoski, Nikolce; Wang, Oliver; Lang, Manuel; Greisen, Pierre; Heinzle, Simon; Smolic, Aljosa

2013-09-01

Today, stereoscopic 3D (S3D) cinema is already mainstream, and almost all new display devices for the home support S3D content. S3D distribution infrastructure to the home is already established partly in the form of 3D Blu-ray discs, video on demand services, or television channels. The necessity to wear glasses is, however, often considered as an obstacle, which hinders broader acceptance of this technology in the home. Multiviewautostereoscopic displays enable a glasses free perception of S3D content for several observers simultaneously, and support head motion parallax in a limited range. To support multiviewautostereoscopic displays in an already established S3D distribution infrastructure, a synthesis of new views from S3D video is needed. In this paper, a view synthesis method based on image-domain-warping (IDW) is presented that automatically synthesizes new views directly from S3D video and functions completely. IDW relies on an automatic and robust estimation of sparse disparities and image saliency information, and enforces target disparities in synthesized images using an image warping framework. Two configurations of the view synthesizer in the scope of a transmission and view synthesis framework are analyzed and evaluated. A transmission and view synthesis system that uses IDW is recently submitted to MPEG's call for proposals on 3D video technology, where it is ranked among the four best performing proposals.

Shaken Snow Globes: Kinematic Tracers of the Multiphase Condensation Cascade in Massive Galaxies, Groups, and Clusters

NASA Astrophysics Data System (ADS)

Gaspari, M.; McDonald, M.; Hamer, S. L.; Brighenti, F.; Temi, P.; Gendron-Marsolais, M.; Hlavacek-Larrondo, J.; Edge, A. C.; Werner, N.; Tozzi, P.; Sun, M.; Stone, J. M.; Tremblay, G. R.; Hogan, M. T.; Eckert, D.; Ettori, S.; Yu, H.; Biffi, V.; Planelles, S.

2018-02-01

We propose a novel method to constrain turbulence and bulk motions in massive galaxies, galaxy groups, and clusters, exploring both simulations and observations. As emerged in the recent picture of top-down multiphase condensation, hot gaseous halos are tightly linked to all other phases in terms of cospatiality and thermodynamics. While hot halos (∼107 K) are perturbed by subsonic turbulence, warm (∼104 K) ionized and neutral filaments condense out of the turbulent eddies. The peaks condense into cold molecular clouds (<100 K) raining in the core via chaotic cold accretion (CCA). We show that all phases are tightly linked in terms of the ensemble (wide-aperture) velocity dispersion along the line of sight. The correlation arises in complementary long-term AGN feedback simulations and high-resolution CCA runs, and is corroborated by the combined Hitomi and new Integral Field Unit measurements in the Perseus cluster. The ensemble multiphase gas distributions (from the UV to the radio band) are characterized by substantial spectral line broadening (σ v,los ≈ 100–200 {km} {{{s}}}-1) with a mild line shift. On the other hand, pencil-beam detections (as H I absorption against the AGN backlight) sample the small-scale clouds displaying smaller broadening and significant line shifts of up to several 100 {km} {{{s}}}-1 (for those falling toward the AGN), with increased scatter due to the turbulence intermittency. We present new ensemble σ v,los of the warm Hα+[N II] gas in 72 observed cluster/group cores: the constraints are consistent with the simulations and can be used as robust proxies for the turbulent velocities, in particular for the challenging hot plasma (otherwise requiring extremely long X-ray exposures). Finally, we show that the physically motivated criterion C ≡ t cool/t eddy ≈ 1 best traces the condensation extent region and the presence of multiphase gas in observed clusters and groups. The ensemble method can be applied to many available spectroscopic data sets and can substantially advance our understanding of multiphase halos in light of the next-generation multiwavelength missions.

Efficient Production of 4-KeV X Rays from Laser-Heated Xe Gas = Confined Within a Hohlraum

NASA Astrophysics Data System (ADS)

Grun, Jacob; Suter, Larry J.; Back, Christina A.; Decker, Chris; Kauffman, Robert L.; Davis, John F.

1996-11-01

Clean (debris-free) and efficient multi-kilovolt x-ray sources are needed for irradiating large military test objects and for use as backlighters in future Inertial Confinement Fusion experiments. Laser-plasma x-ray sources are particularly attractive for these uses since their spectrum can be controlled by proper choice of plasma material and laser intensity; and because many laser-plasma sources can be designed to produce little or no particulate debris. We report on an experiment in which we measured the production-efficiency, spectrum, and time history of 1-4 KeV x-rays from beryllium hohlraums which were filled with 1 and 2 atm of Xe gas and then irradiated by a 2-nsec pulse from the NOVA laser. It is predicted that 17be converted into > 4KeV x rays and 30history of >4KeV part of the spectrum is predicted to exhibit a dip in intensity whose depth and location vary with fill pressure and hohlraum size.. We also measured the debris produced by these sources. Work supported by the Defense Special Weapons Agency and the U.S. Department of Energy at LLNL under W-7405-ENG-48.

Characterizing fluid dynamics in a bubble column aimed for the determination of reactive mass transfer

NASA Astrophysics Data System (ADS)

Kováts, Péter; Thévenin, Dominique; Zähringer, Katharina

2018-02-01

Bubble column reactors are multiphase reactors that are used in many process engineering applications. In these reactors a gas phase comes into contact with a fluid phase to initiate or support reactions. The transport process from the gas to the liquid phase is often the limiting factor. Characterizing this process is therefore essential for the optimization of multiphase reactors. For a better understanding of the transfer mechanisms and subsequent chemical reactions, a laboratory-scale bubble column reactor was investigated. First, to characterize the flow field in the reactor, two different methods have been applied. The shadowgraphy technique is used for the characterisation of the bubbles (bubble diameter, velocity, shape or position) for various process conditions. This technique is based on particle recognition with backlight illumination, combined with particle tracking velocimetry (PTV). The bubble trajectories in the column can also be obtained in this manner. Secondly, the liquid phase flow has been analysed by particle image velocimetry (PIV). The combination of both methods, delivering relevant information concerning disperse (bubbles) and continuous (liquid) phases, leads to a complete fluid dynamical characterization of the reactor, which is the pre-condition for the analysis of mass transfer between both phases.

Characterization of laser-cut copper foil X-pinches

NASA Astrophysics Data System (ADS)

Collins, G. W.; Valenzuela, J. C.; Hansen, S. B.; Wei, M. S.; Reed, C. T.; Forsman, A. C.; Beg, F. N.

2016-10-01

Quantitative data analyses of laser-cut Cu foil X-pinch experiments on the 150 ns quarter-period, ˜250 kA GenASIS driver are presented. Three different foil designs are tested to determine the effects of initial structure on pinch outcome. Foil X-pinch data are also presented alongside the results from wire X-pinches with comparable mass. The X-ray flux and temporal profile of the emission from foil X-pinches differed significantly from that of wire X-pinches, with all emission from the foil X-pinches confined to a ˜3 ns period as opposed to the delayed, long-lasting electron beam emission common in wire X-pinches. Spectroscopic data show K-shell as well as significant L-shell emission from both foil and wire X-pinches. Fits to synthetic spectra using the SCRAM code suggest that pinching foil X's produced a ˜1 keV, ne ≥ 1023 cm-3 plasma. The spectral data combined with the improved reliability of the source timing, flux, and location indicate that foil X-pinches generate a reproducible, K-shell point-projection radiography source that can be easily modified and tailored to suit backlighting needs across a variety of applications.

Late-Time Evolution of Broad-Bandwidth, Laser-Imposed Nonuniformities in Accelerated Foils

NASA Astrophysics Data System (ADS)

Smalyuk, V. A.; Boehly, T. R.; Bradley, D. K.; Knauer, J. P.; Meyerhofer, D. D.; Oron, D.; Srebro, Y.; Shvarts, D.

1998-11-01

The late-time evolution of broad-bandwidth nonuniformities is studied in planar-foil experiments on the OMEGA laser system. Five beams with ~600-μm-diam uniform region accelerate 20-μm-thick CH foils at an average intensity of 2×10^14\\:W/cm^2 in a 3-ns square pulse. Growth of perturbations seeded by irradiation nonuniformities was observed using time-gated, pinhole photographs of ~1.2-keV x rays from a backlighter. At late times collective saturation is observed at levels similar to Haan's prediction.(S. W. Haan, Phys. Rev. A 39), 5812 (1989). The maximum of the nonuniformity spectrum moves toward longer wavelength in time as expected. Target images taken at different times show the formation of bubbles and spikes from initial elongated ``wormy'' structures. This work was supported by the U.S. Department of Energy Office of Inertial Confinement Fusion under Cooperative Agreement No. DE-FC03-92SF19460, the University of Rochester, and the New York State Energy Research and Development Authority. The support of DOE does not constitute an endorsement by DOE of the views expressed in this article.

Bright x-ray stainless steel K-shell source development at the National Ignition Facility

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

May, M. J.; Fournier, K. B.; Colvin, J. D.

2015-06-15

High x-ray conversion efficiency (XRCE) K-shell sources are being developed for high energy density experiments for use as backlighters and for the testing of materials exposed to high x-ray fluxes and fluences. Recently, sources with high XRCE in the K-shell x-ray energy range of iron and nickel were investigated at the National Ignition Facility (NIF). The x-ray conversion efficiency in the 5–9 keV spectral range was determined to be 6.8% ± 0.3%. These targets were 4.1 mm diameter, 4 mm tall hollow epoxy tubes having a 50 μm thick wall supporting a tube of 3 to 3.5 μm thick stainless steel. The NIF laser deposited ∼460 kJ ofmore » 3ω light into the target in a 140 TW, 3.3 ns square pulse. The absolute x-ray emission of the source was measured by two calibrated Dante x-ray spectrometers. Time resolved images filtered for the Fe K-shell were recorded to follow the heating of the target. Time integrated high-resolution spectra were recorded in the K-shell range.« less

Moiré deflectometry using the Talbot-Lau interferometer as refraction diagnostic for High Energy Density plasmas at energies below 10 keV

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

Valdivia, M. P.; Stutman, D.; Finkenthal, M.

2014-07-15

The highly localized density gradients expected in High Energy Density (HED) plasma experiments can be characterized by x-ray phase-contrast imaging in addition to conventional attenuation radiography. Moiré deflectometry using the Talbot-Lau grating interferometer setup is an attractive HED diagnostic due to its high sensitivity to refraction induced phase shifts. We report on the adaptation of such a system for operation in the sub-10 keV range by using a combination of free standing and ultrathin Talbot gratings. This new x-ray energy explored matches well the current x-ray backlighters used for HED experiments, while also enhancing phase effects at lower electron densities.more » We studied the performance of the high magnification, low energy Talbot-Lau interferometer, for single image phase retrieval using Moiré fringe deflectometry. Our laboratory and simulation studies indicate that such a device is able to retrieve object electron densities from phase shift measurements. Using laboratory x-ray sources from 7 to 15 μm size we obtained accurate simultaneous measurements of refraction and attenuation for both sharp and mild electron density gradients.« less

Moiré deflectometry using the Talbot-Lau interferometer as refraction diagnostic for high energy density plasmas at energies below 10 keV.

PubMed

Valdivia, M P; Stutman, D; Finkenthal, M

2014-07-01

The highly localized density gradients expected in High Energy Density (HED) plasma experiments can be characterized by x-ray phase-contrast imaging in addition to conventional attenuation radiography. Moiré deflectometry using the Talbot-Lau grating interferometer setup is an attractive HED diagnostic due to its high sensitivity to refraction induced phase shifts. We report on the adaptation of such a system for operation in the sub-10 keV range by using a combination of free standing and ultrathin Talbot gratings. This new x-ray energy explored matches well the current x-ray backlighters used for HED experiments, while also enhancing phase effects at lower electron densities. We studied the performance of the high magnification, low energy Talbot-Lau interferometer, for single image phase retrieval using Moiré fringe deflectometry. Our laboratory and simulation studies indicate that such a device is able to retrieve object electron densities from phase shift measurements. Using laboratory x-ray sources from 7 to 15 μm size we obtained accurate simultaneous measurements of refraction and attenuation for both sharp and mild electron density gradients.

Dynamic swelling of tunable full-color block copolymer photonic gels via counterion exchange.

PubMed

Lim, Ho Sun; Lee, Jae-Hwang; Walish, Joseph J; Thomas, Edwin L

2012-10-23

One-dimensionally periodic block copolymer photonic lamellar gels with full-color tunability as a result of a direct exchange of counteranions were fabricated via a two-step procedure comprising the self-assembly of a hydrophobic block-hydrophilic polyelectrolyte block copolymer, polystyrene-b-poly(2-vinyl pyridine) (PS-b-P2VP), followed by sequential quaternization of the P2VP layers in 1-bromoethane solution. Depending on the hydration characteristics of each counteranion, the selective swelling of the block copolymer lamellar structures leads to large tunability of the photonic stop band from blue to red wavelengths. More extensive quaternization of the P2VP block allows the photonic lamellar gels to swell more and red shift to longer wavelength. Here, we investigate the dynamic swelling behavior in the photonic gel films through time-resolved in situ measurement of UV-vis transmission. We model the swelling behavior using the transfer matrix method based on the experimentally observed reflectivity data with substitution of appropriate counterions. These tunable structural color materials may be attractive for numerous applications such as high-contrast displays without using a backlight, color filters, and optical mirrors for flexible lasing.

Chain of evidence generation for contrast enhancement in digital image forensics

NASA Astrophysics Data System (ADS)

Battiato, Sebastiano; Messina, Giuseppe; Strano, Daniela

2010-01-01

The quality of the images obtained by digital cameras has improved a lot since digital cameras early days. Unfortunately, it is not unusual in image forensics to find wrongly exposed pictures. This is mainly due to obsolete techniques or old technologies, but also due to backlight conditions. To extrapolate some invisible details a stretching of the image contrast is obviously required. The forensics rules to produce evidences require a complete documentation of the processing steps, enabling the replication of the entire process. The automation of enhancement techniques is thus quite difficult and needs to be carefully documented. This work presents an automatic procedure to find contrast enhancement settings, allowing both image correction and automatic scripting generation. The technique is based on a preprocessing step which extracts the features of the image and selects correction parameters. The parameters are thus saved through a JavaScript code that is used in the second step of the approach to correct the image. The generated script is Adobe Photoshop compliant (which is largely used in image forensics analysis) thus permitting the replication of the enhancement steps. Experiments on a dataset of images are also reported showing the effectiveness of the proposed methodology.

Radial density distribution of a warm dense plasma formed by underwater electrical explosion of a copper wire

NASA Astrophysics Data System (ADS)

Nitishinskiy, M.; Yanuka, D.; Virozub, A.; Krasik, Ya. E.

2017-12-01

Time- and space-resolved evolution of the density (down to 0.07 of solid state density) of a copper wire during its microsecond timescale electrical explosion in water was obtained by X-ray backlighting. In the present research, a flash X-ray source of 20 ns pulse-width and >60 keV photon energy was used. The conductivity of copper was evaluated for a temperature of 10 kK and found to be in good agreement with the data obtained in earlier experiments [DeSilva and Katsouros, Phys. Rev. E 57, 5945 (1998) and Sheftman and Krasik, Phys. Plasmas 18, 092704 (2011)] where only electrical and optical diagnostics were applied. Magneto-hydrodynamic simulation shows a good agreement between the simulated and experimental waveforms of the current and voltage and measured the radial expansion of the exploding wire. Also, the radial density distribution obtained by an inverse Abel transform analysis agrees with the results of these simulations. Thus, the validity of the equations of state for copper and the conductivity model used in the simulations was confirmed for the parameters of the exploding wire realized in the present research.

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

Hansen, Stephanie B.; Harding, Eric C.; Knapp, Patrick F.

The burning core of an inertial confinement fusion (ICF) plasma produces bright x-rays at stagnation that can directly diagnose core conditions essential for comparison to simulations and understanding fusion yields. These x-rays also backlight the surrounding shell of warm, dense matter, whose properties are critical to understanding the efficacy of the inertial confinement and global morphology. In this work, we show that the absorption and fluorescence spectra of mid-Z impurities or dopants in the warm dense shell can reveal the optical depth, temperature, and density of the shell and help constrain models of warm, dense matter. This is illustrated bymore » the example of a high-resolution spectrum collected from an ICF plasma with a beryllium shell containing native iron impurities. Lastly, analysis of the iron K-edge provides model-independent diagnostics of the shell density (2.3 × 10 24 e/cm 3) and temperature (10 eV), while a 12-eV red shift in Kβ and 5-eV blue shift in the K-edge discriminate among models of warm dense matter: Both shifts are well described by a self-consistent field model based on density functional theory but are not fully consistent with isolated-atom models using ad-hoc density effects.« less

Bright x-ray stainless steel K-shell source development at the National Ignition Facility

DOE PAGES

May, M. J.; Fournier, K. B.; Colvin, J. D.; ...

2015-06-01

High x-ray conversion efficiency (XRCE) K-shell sources are being developed for high energy density experiments for use as backlighters and for the testing of materials exposed to high x-ray fluxes and fluences. Recently, sources with high XRCE in the K-shell x-ray energy range of iron and nickel were investigated at the National Ignition Facility (NIF). The x-ray conversion efficiency in the 5–9 keV spectral range was determined to be 6.8% ± 0.3%. These targets were 4.1 mm diameter, 4 mm tall hollow epoxy tubes having a 50 μm thick wall supporting a tube of 3 to 3.5 μm thick stainlessmore » steel. The NIF laser deposited ~460 kJ of 3ω light into the target in a 140 TW, 3.3 ns square pulse. The absolute x-ray emission of the source was measured by two calibrated Dante x-ray spectrometers. In conclusion, time resolved images filtered for the Fe K-shell were recorded to follow the heating of the target. Time integrated high-resolution spectra were recorded in the K-shell range« less

Hybrid X-pinch Experiments on a MA Linear Transformer Driver

NASA Astrophysics Data System (ADS)

Patel, S. G.; Yager-Elorriaga, D. A.; Steiner, A. M.; Gilgenbach, R. M.; Jordan, N. M.; Chalenski, D. A.; Lau, Y. Y.

2013-10-01

X-pinch experiments have been conducted on the Linear Transformer Driver (LTD) at the University of Michigan. The x-pinch consists of a single wire separated by conical electrodes between two current return plates. The LTD was charged to +/-70 kV resulting in approximately 0.5 MA passing through a 35 μm Al wire. Multiple, short x-ray bursts were detected over the 400 ns current pulse. Ultimately the x-pinch will be located in parallel with a planar foil in order to backlight the Magneto-Rayleigh-Taylor instability. A smaller 100 kA driver is also in development and may be used to independently energize the x-pinch. The x-pinch chamber has been constructed and the results of these experiments will be presented. This work was supported by DoE award number DE-SC0002590, NSF grant number PHY 0903340, and US DoE through Sandia National Labs award numbers 240985 and 76822 to the U of Michigan. S.G Patel and A.M Steiner are supported by NPSC funded by Sandia National Labs. D.A. Yager-Elorriaga is supported by an NSF fellowship under grant number DGE 1256260.

Effect of equation of state on laser imprinting by comparing diamond and polystyrene foils

NASA Astrophysics Data System (ADS)

Kato, H.; Shigemori, K.; Nagatomo, H.; Nakai, M.; Sakaiya, T.; Ueda, T.; Terasaki, H.; Hironaka, Y.; Shimizu, K.; Azechi, H.

2018-03-01

We present herein a comprehensive study of how the equation of state affects laser imprinting by nonuniform laser irradiation of an inertial fusion target. It has been suggested that a stiffer and denser material would reduce laser imprinting based on the equation of motion with pressure perturbation. We examine the detailed temporal evolution of the imprint amplitude by using the two-dimensional radiation hydrodynamic simulation PINOCO-2D for diamond, which is a candidate stiff-ablator material for inertial fusion targets. The simulated laser imprinting amplitude is compared with experimental measurements of areal-density perturbations obtained by using face-on x-ray backlighting for diamond and polystyrene (PS) (the latter as a reference). The experimental results are well reproduced by the results of the PINOCO-2D simulation, which indicates that the imprinting amplitude due to nonuniform irradiation (average intensity, 4.0 × 1012 to 5.0 × 1013) differs by a factor of two to three between diamond and PS. The difference in laser imprinting is mainly related to the material density and compressibility. These parameters are key factors that determine the laser imprinting amplitude.

Side-emitting illuminators using LED sources

NASA Astrophysics Data System (ADS)

Zhao, Feng; Van Derlofske, John F.

2003-11-01

This study investigates illuminators composed of light emitting diode (LED) array sources and side-emitting light guides to provide efficient general illumination. Specifically, new geometries are explored to increase the efficiency of current systems while maintaining desired light distribution. LED technology is already successfully applied in many illumination applications, such as traffic signals and liquid crystal display (LCD) backlighting. It provides energy-efficient, small-package, long-life, and color-adjustable illumination. However, the use of LEDs in general illumination is still in its early stages. Current side-emitting systems typically use a light guide with light sources at one end, an end-cap surface at the other end, and light releasing sidewalls. This geometry introduces efficiency loss that can be as high as 40%. The illuminators analyzed in this study use LED array sources along the longitude of a light guide to increase the system efficiency. These new geometries also provide the freedom of elongating the system without sacrificing system efficiency. In addition, alternative geometries can be used to create white light with monochromatic LED sources. As concluded by this study, the side-emitting illuminators using LED sources gives the possibility of an efficient, distribution-controllable linear lighting system.

The potential influence of LED lighting on mental illness.

PubMed

Bauer, Michael; Glenn, Tasha; Monteith, Scott; Gottlieb, John F; Ritter, Philipp S; Geddes, John; Whybrow, Peter C

2018-02-01

Two recent scientific breakthroughs may alter the treatment of mental illness, as discussed in this narrative review. The first was the invention of white light-emitting diodes (LEDs), which enabled an ongoing, rapid transition to energy-efficient LEDs for lighting, and the use of LEDs to backlight digital devices. The second was the discovery of melanopsin-expressing photosensitive retinal ganglion cells, which detect environmental irradiance and mediate non-image forming (NIF) functions including circadian entrainment, melatonin secretion, alertness, sleep regulation and the pupillary light reflex. These two breakthroughs are interrelated because unlike conventional lighting, white LEDs have a dominant spectral wavelength in the blue light range, near the peak sensitivity for the melanopsin system. Pertinent articles were identified. Blue light exposure may suppress melatonin, increase alertness, and interfere with sleep in young, healthy volunteers and in animals. Areas of concern in mental illness include the influence of blue light on sleep, other circadian-mediated symptoms, prescribed treatments that target the circadian system, measurement using digital apps and devices, and adolescent sensitivity to blue light. While knowledge in both fields is expanding rapidly, future developments must address the potential impact of blue light on NIF functions for healthy individuals and those with mental illness.

Investigation of High Pressure, Multi-Hole Diesel Fuel Injection Using High Speed Imaging

NASA Astrophysics Data System (ADS)

Morris, Steven; Eagle, Ethan; Wooldridge, Margaret

2012-10-01

Research to experimentally capture and understand transient fuel spray behavior of modern fuel injection systems remains underdeveloped. To this end, a high-pressure diesel common-rail fuel injector was instrumented in a spherical, constant volume combustion chamber to image the early time history of injection of diesel fuel. The research-geometry fuel injector has four holes aligned on a radial plane of the nozzle with hole sizes of 90, 110, 130 and 150 μm in diameter. Fuel was injected into a non-reacting environment with ambient densities of 17.4, 24.0, and 31.8 kg/m3 at fuel rail pressures of 1000, 1500, and 2000 bar. High speed images of fuel injection were taken using backlighting at 100,000 frames per second (100 kfps) and an image processing algorithm. The experimental results are compared with a one-dimensional fuel-spray model that was historically developed and applied to fuel sprays from single-hole fuel injectors. Fuel spray penetration distance was evaluated as a function of time for the different injector hole diameters, fuel injection pressures and ambient densities. The results show the differences in model predictions and experimental data at early times in the spray development.

Highly luminescent and photostable quantum dot-silica monolith and its application to light-emitting diodes.

PubMed

Jun, Shinae; Lee, Junho; Jang, Eunjoo

2013-02-26

A highly luminescent and photostable quantum dot-silica monolith (QD-SM) substance was prepared by preliminary surface exchange of the QDs and base-catalyzed sol-gel condensation of silica. The SM was heavily doped with 6-mercaptohexanol exchanged QDs up to 12 vol % (26 wt %) without particle aggregation. Propylamine catalyst was important in maintaining the original luminescence of the QDs in the SM during sol-gel condensation. The silica layer was a good barrier against oxygen and moisture, so that the QD-SM maintained its initial luminescence after high-power UV radiation (∼1 W) for 200 h and through the 150 °C LED encapsulant curing process. Green and red light-emitting QD-SMs were applied as color-converting layers on blue LEDs, and the external quantum efficiency reached up to 89% for the green QD-SM and 63% for the red one. A white LED made with a mixture of green and red QDs in the SM, in which the color coordinate was adjusted at (0.23, 0.21) in CIE1931 color space for a backlight application, showed an efficacy of 47 lm/W, the highest value yet reported.

Striation Formation in Cylindrical Liners Made of Various Materials Driven by a 1 MA Pulsed Power Generator

NASA Astrophysics Data System (ADS)

Atoyan, Levon; Byvank, Tom; Engelbrecht, Joseph; Greenly, John; Pikuz, Sergei; Potter, William; Shelkovenko, Tania; Kusse, Bruce; Hammer, David

2016-10-01

Peterson et al. found on the 20 MA Z machine that, without any applied external axial magnetic field, horizontal striations appear in radiographic images of a metal liner [Phys. Plasmas 19, 092701, 2012], a result that has been reproduced on other pulsed power machines since. In this work we present experimental results of horizontal striations on the 1 MA, 100-200 ns COBRA pulsed power generator [T. A. Shelkovenko et al., Rev. Sci. Instrum. 77, 10F521, 2006]. The pattern is observed in our experiments using extreme ultraviolet imaging, laser imaging, and X-ray backlighting. Using this combination of diagnostics, we were able to view simultaneously the pattern near the liner surface as well as in the higher density portion of the liner, displaying features with different wavelengths. Furthermore, materials such as Al, Cu, and Ti will be used for the liner to determine if the striation formation is affected by the nature of the material. This research is supported by the NNSA Stewardship Sciences Academic Programs under Department of Energy Cooperative Agreement DE-NA0001836 and DOE account DE-NA0002952.

Bifocal computational near eye light field displays and Structure parameters determination scheme for bifocal computational display.

PubMed

Liu, Mali; Lu, Chihao; Li, Haifeng; Liu, Xu

2018-02-19

We propose a bifocal computational near eye light field display (bifocal computational display) and structure parameters determination scheme (SPDS) for bifocal computational display that achieves greater depth of field (DOF), high resolution, accommodation and compact form factor. Using a liquid varifocal lens, two single-focal computational light fields are superimposed to reconstruct a virtual object's light field by time multiplex and avoid the limitation on high refresh rate. By minimizing the deviation between reconstructed light field and original light field, we propose a determination framework to determine the structure parameters of bifocal computational light field display. When applied to different objective to SPDS, it can achieve high average resolution or uniform resolution display over scene depth range. To analyze the advantages and limitation of our proposed method, we have conducted simulations and constructed a simple prototype which comprises a liquid varifocal lens, dual-layer LCDs and a uniform backlight. The results of simulation and experiments with our method show that the proposed system can achieve expected performance well. Owing to the excellent performance of our system, we motivate bifocal computational display and SPDS to contribute to a daily-use and commercial virtual reality display.

Bright x-ray stainless steel K-shell source development at the National Ignition Facility

NASA Astrophysics Data System (ADS)

May, M. J.; Fournier, K. B.; Colvin, J. D.; Barrios, M. A.; Dewald, E. L.; Hohenberger, M.; Moody, J.; Patterson, J. R.; Schneider, M.; Widmann, K.; Regan, S. P.

2015-06-01

High x-ray conversion efficiency (XRCE) K-shell sources are being developed for high energy density experiments for use as backlighters and for the testing of materials exposed to high x-ray fluxes and fluences. Recently, sources with high XRCE in the K-shell x-ray energy range of iron and nickel were investigated at the National Ignition Facility (NIF). The x-ray conversion efficiency in the 5-9 keV spectral range was determined to be 6.8% ± 0.3%. These targets were 4.1 mm diameter, 4 mm tall hollow epoxy tubes having a 50 μm thick wall supporting a tube of 3 to 3.5 μm thick stainless steel. The NIF laser deposited ˜460 kJ of 3ω light into the target in a 140 TW, 3.3 ns square pulse. The absolute x-ray emission of the source was measured by two calibrated Dante x-ray spectrometers. Time resolved images filtered for the Fe K-shell were recorded to follow the heating of the target. Time integrated high-resolution spectra were recorded in the K-shell range.

Fluorescence and absorption spectroscopy for warm dense matter studies and ICF plasma diagnostics

NASA Astrophysics Data System (ADS)

Hansen, S. B.; Harding, E. C.; Knapp, P. F.; Gomez, M. R.; Nagayama, T.; Bailey, J. E.

2018-05-01

The burning core of an inertial confinement fusion (ICF) plasma produces bright x-rays at stagnation that can directly diagnose core conditions essential for comparison to simulations and understanding fusion yields. These x-rays also backlight the surrounding shell of warm, dense matter, whose properties are critical to understanding the efficacy of the inertial confinement and global morphology. We show that the absorption and fluorescence spectra of mid-Z impurities or dopants in the warm dense shell can reveal the optical depth, temperature, and density of the shell and help constrain models of warm, dense matter. This is illustrated by the example of a high-resolution spectrum collected from an ICF plasma with a beryllium shell containing native iron impurities. Analysis of the iron K-edge provides model-independent diagnostics of the shell density (2.3 × 1024 e/cm3) and temperature (10 eV), while a 12-eV red shift in Kβ and 5-eV blue shift in the K-edge discriminate among models of warm dense matter: Both shifts are well described by a self-consistent field model based on density functional theory but are not fully consistent with isolated-atom models using ad-hoc density effects.

Analysis of circadian properties and healthy levels of blue light from smartphones at night.

PubMed

Oh, Ji Hye; Yoo, Heeyeon; Park, Hoo Keun; Do, Young Rag

2015-06-18

This study proposes representative figures of merit for circadian and vision performance for healthy and efficient use of smartphone displays. The recently developed figures of merit for circadian luminous efficacy of radiation (CER) and circadian illuminance (CIL) related to human health and circadian rhythm were measured to compare three kinds of commercial smartphone displays. The CIL values for social network service (SNS) messenger screens from all three displays were higher than 41.3 biolux (blx) in a dark room at night, and the highest CIL value reached 50.9 blx. These CIL values corresponded to melatonin suppression values (MSVs) of 7.3% and 11.4%, respectively. Moreover, smartphone use in a bright room at night had much higher CIL and MSV values (58.7 ~ 105.2 blx and 15.4 ~ 36.1%, respectively). This study also analyzed the nonvisual and visual optical properties of the three smartphone displays while varying the distance between the screen and eye and controlling the brightness setting. Finally, a method to possibly attenuate the unhealthy effects of smartphone displays was proposed and investigated by decreasing the emitting wavelength of blue LEDs in a smartphone LCD backlight and subsequently reducing the circadian effect of the display.

Employing the conventional edge-lighting technology into ultraviolet-range: a preliminary study by optical simulation

NASA Astrophysics Data System (ADS)

Ye, Linchao; Belloni, Paola; Möller, Knut

2011-10-01

Within the framework of a project conducted together with an industrial partner, a self-disinfecting operation interface with a glass panel is being developed. The concept of self-disinfection is based on the exploitation of the photocatalytical effect induced by a TiO2-coating on the glass surface under UV(A) light, which would make the touch screen antimicrobial. High-power UV-LEDs instead of conventional UV-lamps have been employed as light source. The main goal and challenge of the optical design is to generate an efficient and preferably homogeneous UV field on the TiO2-coated side while keeping the UV-LEDs concealed, i.e. invisible to the user. Therefore common backlighting systems have been used as reference and modified to meet the concrete requirements. Primary analysis and optical simulations have been performed with the software LightTools®. Several patterns for light redirection (i.e. 3D-spherical texture, 3D-rectangular texture and 2D-circular serigraph) have been investigated, compared and evaluated. Finally the pattern design which both fulfills all the predefined boundary conditions and simultaneously reduces the costs has been chosen.

Micromachined edge illuminated optically transparent automotive light guide panels

NASA Astrophysics Data System (ADS)

Ronny, Rahima Afrose; Knopf, George K.; Bordatchev, Evgueni; Tauhiduzzaman, Mohammed; Nikumb, Suwas

2012-03-01

Edge-lit backlighting has been used extensively for a variety of small and medium-sized liquid crystal displays (LCDs). The shape, density and spatial distribution pattern of the micro-optical elements imprinted on the surface of the flat light-guide panel (LGP) are often "optimized" to improve the overall brightness and luminance uniformity. A similar concept can be used to develop interior convenience lighting panels and exterior tail lamps for automotive applications. However, costly diffusive sheeting and brightness enhancement films are not be considered for these applications because absolute luminance uniformity and the minimization of Moiré fringe effects are not significant factors in assessing quality of automotive lighting. A new design concept that involves micromilling cylindrical micro-optical elements on optically transparent plastic substrates is described in this paper. The variable parameter that controls illumination over the active regions of the panel is the depth of the individual cylindrical micro-optical elements. LightTools™ is the optical simulation tool used to explore how changing the micro-optical element depth can alter the local and global luminance. Numerical simulation and microfabrication experiments are performed on several (100mmx100mmx6mm) polymethylmethacrylate (PMMA) test samples in order to verify the illumination behavior.

Liquid-crystal displays for medical imaging: a discussion of monochrome versus color

NASA Astrophysics Data System (ADS)

Wright, Steven L.; Samei, Ehsan

2004-05-01

A common view is that color displays cannot match the performance of monochrome displays, normally used for diagnostic x-ray imaging. This view is based largely on historical experience with cathode-ray tube (CRT) displays, and does not apply in the same way to liquid-crystal displays (LCDs). Recent advances in color LCD technology have considerably narrowed performance differences with monochrome LCDs for medical applications. The most significant performance advantage of monochrome LCDs is higher luminance, a concern for use under bright ambient conditions. LCD luminance is limited primarily by backlight design, yet to be optimized for color LCDs for medical applications. Monochrome LCDs have inherently higher contrast than color LCDs, but this is not a major advantage under most conditions. There is no practical difference in luminance precision between color and monochrome LCDs, with a slight theoretical advantage for color. Color LCDs can provide visualization and productivity enhancement for medical applications, using digital drive from standard commercial graphics cards. The desktop computer market for color LCDs far exceeds the medical monitor market, with an economy of scale. The performance-to-price ratio for color LCDs is much higher than monochrome, and warrants re-evaluation for medical applications.

Saturn's depths in a new light: Novel views of meteorology, circulation and dynamics by Cassini/VIMS

NASA Astrophysics Data System (ADS)

Baines, Kevin; Momary, Thomas; Roos-Serote, Maarten; Showman, Adam; Atreya, Sushil K.; Brown, Robert H.; Buratti, Bonnie; Clark, Roger; Nicholson, Phillip

The depths of Saturn below the ubiquitous covering of ammonia hazes have been revealed in detail by the Visual Infrared Mapping Spectrometer (VIMS) onboard the Cassini orbiter. Using Saturn's own indigenous glow produced by warm air at depth to back-light deep clouds, a diverse array of cloud features have been discovered near the 3-bar level, some 75 km underneath the ammonia clouds. Likely comprised of ammonia hydrosulfide, perhaps with a complement of water, the menagerie of deep cloud structures - including dozens of surprisingly narrow axisymmetric "zones", "smoke rings", a long-lived "string of pearls" spanning 1/4 of the planet, large plume-like and cyclonic features, and a deep-seated hexagonal feature circumscribing the north pole - reveal Saturn at depth to be a dynamic, meteorologically active planet much more like frenetic Jupiter than the classically serene face Saturn shows in sunlight. Additional information on Saturn's dynamically active nature is provided by daytime imagery of discrete clouds observed at the southpole - revealing two compositional types of clouds, suggesting a variety of upwelling phenomena - and the latitudinal variability of the trace disequilibrium gases arsine and phosphine observed in VIMS spectra.

Engineering of Semiconductor Nanocrystals for Light Emitting Applications

PubMed Central

Todescato, Francesco; Fortunati, Ilaria; Minotto, Alessandro; Signorini, Raffaella; Jasieniak, Jacek J.; Bozio, Renato

2016-01-01

Semiconductor nanocrystals are rapidly spreading into the display and lighting markets. Compared with liquid crystal and organic LED displays, nanocrystalline quantum dots (QDs) provide highly saturated colors, wide color gamut, resolution, rapid response time, optical efficiency, durability and low cost. This remarkable progress has been made possible by the rapid advances in the synthesis of colloidal QDs and by the progress in understanding the intriguing new physics exhibited by these nanoparticles. In this review, we provide support to the idea that suitably engineered core/graded-shell QDs exhibit exceptionally favorable optical properties, photoluminescence and optical gain, while keeping the synthesis facile and producing QDs well suited for light emitting applications. Solid-state laser emitters can greatly profit from QDs as efficient gain materials. Progress towards fabricating low threshold, solution processed DFB lasers that are optically pumped using one- and two-photon absorption is reviewed. In the field of display technologies, the exploitation of the exceptional photoluminescence properties of QDs for LCD backlighting has already advanced to commercial levels. The next big challenge is to develop the electroluminescence properties of QD to a similar state. We present an overview of QLED devices and of the great perspectives for next generation display and lighting technologies. PMID:28773794

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

Colbert, C.; Moles, D.R.

This paper reports that the authors developed for the Air Force the Mark VI Personal Identity Verifier (PIV) for controlling access to a fixed or mobile ICBM site, a computer terminal, or mainframe. The Mark VI records the digitized silhouettes of four fingers of each hand on an AT and T smart card. Like fingerprints, finger shapes, lengths, and widths constitute an unguessable biometric password. A Security Officer enrolls an authorized person who places each hand, in turn, on a backlighted panel. An overhead scanning camera records the right and left hand reference templates on the smart card. The Securitymore » Officer adds to the card: name, personal identification number (PIN), and access restrictions such as permitted days of the week, times of day, and doors. To gain access, cardowner inserts card into a reader slot and places either hand on the panel. Resulting access template is matched to the reference template by three sameness algorithms. The final match score is an average of 12 scores (each of the four fingers, matched for shape, length, and width), expressing the degree of sameness. (A perfect match would score 100.00.) The final match score is compared to a predetermined score (threshold), generating an accept or reject decision.« less

Characterization of cylindrically imploded magnetized plasma by spectroscopy and proton probing

NASA Astrophysics Data System (ADS)

Dozieres, M.; Forestier-Colleoni, P.; Wei, M. S.; Gourdain, P.-A.; Davies, J. R.; Fujioka, S.; Peebles, J.; Campbell, M.; Santos, J. J.; Batani, D.; McGuffey, C.; Beg, F. N.

2017-10-01

Understanding the role of magnetic field in relativistic electron beam transport and energy deposition is important for several applications including fast ignition inertial confinement fusion. We report the development of a cylindrically compressed target platform with externally applied magnetic fields on OMEGA. As a first step, we performed an experiment to characterize the imploded plasma and compressed field condition. The implosion of the target was performed using 36 UV beams (400 J per beam, 1.5 ns square pulse), and the magnetic field was measured by proton deflection using mono-energetic protons produced from D3He capsule implosion. The target was a CH foam cylinder doped with 1% chlorine in order to detect the time-resolved 1s-2p Cl absorption structures, using a gold foil as a broad band backlighter source. A Cu foil at the beginning of the foam cylinder and a Zn foil at the end, allowed us to measure the K α and the 1s-2p transitions of He-like and Li-like ions for both elements. The emission and absorption spectroscopic data are compared to atomic physics codes to determine the plasma temperature and density under the influence of the magnetic field. FOA-0001568.

X-ray opacity measurements in mid-Z dense plasmas with a new target design of indirect heating

NASA Astrophysics Data System (ADS)

Dozières, M.; Thais, F.; Bastiani-Ceccotti, S.; Blenski, T.; Fariaut, J.; Fölsner, W.; Gilleron, F.; Khaghani, D.; Pain, J.-C.; Reverdin, C.; Rosmej, F.; Silvert, V.; Soullié, G.; Villette, B.

2015-12-01

X-ray transmission spectra of copper, nickel and aluminum laser produced plasmas were measured at the LULI2000 laser facility with an improved target design of indirect heating. Measurements were performed in plasmas close to local thermodynamic equilibrium at temperatures around 25 eV and densities between 10-3g/cm3 and 10-2 g/cm3. This improved design provides several advantages, which are discussed in this paper. The sample is a thin foil of mid-Z material inserted between two gold cavities heated by two 300J, 2ω, nanosecond laser beams. A third laser beam irradiates a gold foil to create a spectrally continuous X-ray source (backlight) used to probe the sample. We investigate 2p-3d absorption structures in Ni and Cu plasmas as well as 1s-2p transitions in an additional Al plasma layer to infer the in-situ plasma temperature. Geometric and hydrodynamic calculations indicate that the improved geometry reduces spatial gradients during the transmission measurements. Experimental absorption spectra are in good agreement with calculations from the hybrid atomic physics code SCO-RCG.

Multiexcitation Fluorogenic Labeling of Surface, Intracellular, and Total Protein Pools in Living Cells

PubMed Central

2016-01-01

Malachite green (MG) is a fluorogenic dye that shows fluorescence enhancement upon binding to its engineered cognate protein, a fluorogen activating protein (FAP). Energy transfer donors such as cyanine and rhodamine dyes have been conjugated with MG to modify the spectral properties of the fluorescent complexes, where the donor dyes transfer energy through Förster resonance energy transfer to the MG complex resulting in binding-conditional fluorescence emission in the far-red region. In this article, we use a violet-excitable dye as a donor to sensitize the far-red emission of the MG-FAP complex. Two blue emitting fluorescent coumarin dyes were coupled to MG and evaluated for energy transfer to the MG-FAP complex via its secondary excitation band. 6,8-Difluoro-7-hydroxycoumarin-3-carboxylic acid (Pacific blue, PB) showed the most efficient energy transfer and maximum brightness in the far-red region upon violet (405 nm) excitation. These blue-red (BluR) tandem dyes are spectrally varied from other tandem dyes and are able to produce fluorescence images of the MG-FAP complex with a large Stokes shift (>250 nm). These dyes are cell-permeable and are used to label intracellular proteins. Used together with a cell-impermeable hexa-Cy3-MG (HCM) dye that labels extracellular proteins, we are able to visualize extracellular, intracellular, and total pools of cellular protein using one fluorogenic tag that combines with distinct dyes to effect different spectral characteristics. PMID:27159569

The UV reflectance of Patroclus: Exploring the surface composition and origins of Jupiter Trojans

NASA Astrophysics Data System (ADS)

Molyneux, Pippa

2017-08-01

(617) Patroclus is a binary system comprising two almost equally sized Trojan asteroids, Patroclus and Menoetius. (617) Patroclus has never been observed in the UV spectral region, which contains important diagnostic features of major Trojan surface constituents inferred from fits to visible-near IR spectra. Previous spectral observations have not been spatially resolved, precluding a direct spectral comparison of the two bodies. We propose to obtain full surface UV reflectance maps of both Patroclus and Menoetius using the STIS G230L mode, to search for characteristic absorption features of silicates, carbons/graphites and NH3, which together make up the major inferred Jupiter Trojan surface constituents, and for signs of ''spectral bluing'' that occurs for space-weathered objects. The Jupiter Trojans are believed to represent the most readily accessible Kuiper Belt material in the solar system, having been scattered from that region to their current orbits following a dynamical instability. A direct spectral comparison of Patroclus and Menoetius, indicating whether the objects share a common origin and evolution, will explore the hypothesis that the system is a rare binary survivor of this scattering. (617) Patroclus is also a target of the upcoming Lucy mission, and constraints on surface composition would represent a valuable input to instrument configuration and observation planning work for the mission. As Lucy will not carry a UV instrument, the proposed observations would remain unique and complementary to the results of the mission.

Electron microscopic visualization of sites of nascent DNA synthesis by streptavidin-gold binding to biotinylated nucleotides incorporated in vivo

PubMed Central

1988-01-01

Biotinylated nucleotides (bio-11-dCTP, bio-11-dUTP, and bio-7-dATP) were microinjected into unfertilized and fertilized Xenopus laevis eggs. The amounts introduced were comparable to in vivo deoxy- nucleoside triphosphate pools. At various times after microinjection, DNA was extracted from eggs or embryos and subjected to electrophoresis on agarose gels. Newly synthesized biotinylated DNA was analyzed by Southern transfer and visualized using either the BluGENE or Detek-hrp streptavidin-based nucleic acid detection systems. Quantitation of the amount of biotinylated DNA observed at various times showed that the microinjected biotinylated nucleotides were efficiently incorporated in vivo, both into replicating endogenous chromosomal DNA and into replicating microinjected exogenous plasmid DNA. At least one biotinylated nucleotide could be incorporated in vivo for every eight nucleotides of DNA synthesized. Control experiments also showed that heavily biotinylated DNA was not subjected to detectable DNA repair during early embryogenesis (for at least 5 h after activation of the eggs). The incorporated biotinylated nucleotides were visualized by electron microscopy by using streptavidin-colloidal gold or streptavidin-ferritin conjugates to bind specifically to the biotin groups projecting from the newly replicated DNA. The incorporated biotinylated nucleotides were thus made visible as electron-dense spots on the underlying DNA molecules. Biotinylated nucleotides separated by 20-50 bases could be resolved. We conclude that nascent DNA synthesized in vivo in Xenopus laevis eggs can be visualized efficiently and specifically using the techniques described. PMID:3392102

Multi-wavelength photometry of the T Tauri binary V582 Mon (KH 15D): A new epoch of occultations

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

Windemuth, Diana; Herbst, William, E-mail: dwindemuth@wesleyan.edu

2014-01-01

We present multi-wavelength (VRIJHK) observations of KH 15D obtained in 2012/2013, as well as a master table of standard photometry spanning the years 1967 to 2013. The system is a close, eccentric T Tauri binary embedded in an inclined precessing circumbinary (CB) ring. The most recent data show the continued rise of star B with respect to the trailing edge of the occulting horizon as the system's maximum brightness steadily increases. The wealth of data in time and wavelength domains allows us to track the long-term CCD color evolution of KH 15D. We find that the V – I behaviormore » is consistent with direct and scattered light from the composite color of two stars with slightly different temperatures. There is no evidence for any reddening or bluing associated with extinction or scattering by interstellar-medium-size dust grains. Furthermore, we probe the system's faint phase behavior at near-infrared wavelengths in order to investigate extinction properties of the ring and signatures of a possible shepherding planet sometimes invoked to confine the CB ring at ∼5 AU. The wavelength independence of eclipse depth at second contact is consistent with the ring material being fully opaque to 2.2 μm. The color-magnitude diagrams demonstrate excess flux in J and H at low light levels, which may be due to the presence of a hot, young Jupiter-mass planet.« less

Precision molding of advanced glass optics: innovative production technology for lens arrays and free form optics

NASA Astrophysics Data System (ADS)

Pongs, Guido; Bresseler, Bernd; Bergs, Thomas; Menke, Gert

2012-10-01

Today isothermal precision molding of imaging glass optics has become a widely applied and integrated production technology in the optical industry. Especially in consumer electronics (e.g. digital cameras, mobile phones, Blu-ray) a lot of optical systems contain rotationally symmetrical aspherical lenses produced by precision glass molding. But due to higher demands on complexity and miniaturization of optical elements the established process chain for precision glass molding is not sufficient enough. Wafer based molding processes for glass optics manufacturing become more and more interesting for mobile phone applications. Also cylindrical lens arrays can be used in high power laser systems. The usage of unsymmetrical free-form optics allows an increase of efficiency in optical laser systems. Aixtooling is working on different aspects in the fields of mold manufacturing technologies and molding processes for extremely high complex optical components. In terms of array molding technologies, Aixtooling has developed a manufacturing technology for the ultra-precision machining of carbide molds together with European partners. The development covers the machining of multi lens arrays as well as cylindrical lens arrays. The biggest challenge is the molding of complex free-form optics having no symmetrical axis. A comprehensive CAD/CAM data management along the entire process chain is essential to reach high accuracies on the molded lenses. Within a national funded project Aixtooling is working on a consistent data handling procedure in the process chain for precision molding of free-form optics.

Ethnomycology, biochemistry, and cultivation of Psilocybe samuiensis Guzmán, Bandala and Allen, a new psychoactive fungus from Koh Samui, Thailand.

PubMed

Gartz, J; Allen, J W; Merlin, M D

1994-07-08

Several specimens of Psilocybe and Copelandia species in Koh Samui, Thailand were recently collected for herbarium deposit and scientific study. This paper presents an ethnomycological and biochemical study of one of the species; P. samuiensis Guzmán, Bandala and Allen, a new psychoactive gill fungus reported from Thailand. Mycelium for the cultivation of P. samuiensis was obtained on 6% malt agar from the spores of a dried specimen. The growth of P. samuiensis was similar to that of P. tampanensis Guzmán and Pollock, but more rapid than the mycelium of P. semilanceata (Fr.:Sacc.) Kumm. Laboratory analyses indicates that the alkaloid content in cultured fruit bodies of P. samuiensis is of the same order of magnitude as that found in naturally occurring mushrooms of this species. HPLC analyses of both naturally occurring and in vitro cultivated fruit bodies of P. samuiensis revealed high concentrations of psilocybin and psilocin. Small amounts of baeocystin were also detected. Psilocybin levels varied from 0.23% up to 0.90%. The psilocybin content was highest in the caps. Psilocybin was also found in the cultured non-bluing mycelia of P. samuiensis and varied from 0.24% to 0.32% dry weight. The relative alkaloidal content of psilocybin, psilocin, and baeocystin found in P. samuiensis was similar to that measured in many other psychoactive fungi species, but completely different from that found in P. semilanceata.

Multi-wavelength Photometry of the T Tauri Binary V582 Mon (KH 15D): a New Epoch of Occultations

NASA Astrophysics Data System (ADS)

Windemuth, Diana; Herbst, William

2014-01-01

We present multi-wavelength (VRIJHK) observations of KH 15D obtained in 2012/2013, as well as a master table of standard photometry spanning the years 1967 to 2013. The system is a close, eccentric T Tauri binary embedded in an inclined precessing circumbinary (CB) ring. The most recent data show the continued rise of star B with respect to the trailing edge of the occulting horizon as the system's maximum brightness steadily increases. The wealth of data in time and wavelength domains allows us to track the long-term CCD color evolution of KH 15D. We find that the V - I behavior is consistent with direct and scattered light from the composite color of two stars with slightly different temperatures. There is no evidence for any reddening or bluing associated with extinction or scattering by interstellar-medium-size dust grains. Furthermore, we probe the system's faint phase behavior at near-infrared wavelengths in order to investigate extinction properties of the ring and signatures of a possible shepherding planet sometimes invoked to confine the CB ring at ~5 AU. The wavelength independence of eclipse depth at second contact is consistent with the ring material being fully opaque to 2.2 μm. The color-magnitude diagrams demonstrate excess flux in J and H at low light levels, which may be due to the presence of a hot, young Jupiter-mass planet.

The Effects of Varying Electronic Cigarette Warning Label Design Features On Attention, Recall, and Product Perceptions Among Young Adults.

PubMed

Mays, Darren; Villanti, Andrea; Niaura, Raymond S; Lindblom, Eric N; Strasser, Andrew A

2017-12-13

This study was a 3 (Brand: Blu, MarkTen, Vuse) by 3 (Warning Size: 20%, 30%, or 50% of advertisement surface) by 2 (Warning Background: White, Red) experimental investigation of the effects of electronic cigarette (e-cigarette) warning label design features. Young adults aged 18-30 years (n = 544) were recruited online, completed demographic and tobacco use history measures, and randomized to view e-cigarette advertisements with warning labels that varied by the experimental conditions. Participants completed a task assessing self-reported visual attention to advertisements with a-priori regions of interest defined around warning labels. Warning message recall and perceived addictiveness of e-cigarettes were assessed post-exposure. Approximately half of participants reported attending to warning labels and reported attention was greater for warnings on red versus white backgrounds. Recall of the warning message content was also greater among those reporting attention to the warning label. Overall, those who viewed warnings on red backgrounds reported lower perceived addictiveness than those who viewed warnings on white backgrounds, and e-cigarette users reported lower perceived addictiveness than non-users. Among e-cigarette users, viewing warnings on white backgrounds produced perceptions more similar to non-users. Greater recall was significantly correlated with greater perceived addictiveness. This study provides some of the first evidence that e-cigarette warning label design features including size and coloring affect self-reported attention and content recall.

Investigation of air-assisted sprays submitted to high frequency transverse acoustic fields: Droplet clustering

NASA Astrophysics Data System (ADS)

Ficuciello, A.; Blaisot, J. B.; Richard, C.; Baillot, F.

2017-06-01

An experimental investigation of the effects of a high amplitude transverse acoustic field on coaxial jets is presented in this paper. Water and air are used as working fluids at ambient pressure. The coaxial injectors are placed on the top of a semi-open resonant cavity where the acoustic pressure fluctuations of the standing wave can reach a maximum peak-to-peak amplitude of 12 kPa at the forcing frequency of 1 kHz. Several test conditions are considered in order to quantify the influence of injection conditions, acoustic field amplitude, and injector position with respect to the standing wave acoustic field. A high speed back-light visualization technique is used to characterize the jet response. Image processing is used to obtain valuable information about the jet behavior. It is shown that the acoustic field drastically affects the atomization process for all atomization regimes. The position of the injector in the acoustic field determines the jet response, and a droplet-clustering phenomenon is highlighted in multi-point injection conditions and quantified by determining discrete droplet location distributions. A theoretical model based on nonlinear acoustics related to the spatial distribution of the radiation pressure exerted on an object explains the behavior observed.

Time-Resolved K-shell Photoabsorption Edge Measurement in a Strongly Coupled Matter Driven by Laser-converted Radiation

NASA Astrophysics Data System (ADS)

Zhao, Yang; Yang, Jia-Min; Zhang, Ji-Yan; Yang, Guo-Hong; Xiong, Gang; Wei, Min-Xi; Song, Tian-Ming; Zhang, Zhi-Yu

2013-06-01

A time-resolved K edge absorption measurement of warm dense KCl was performed on Shenguang II laser facility. The x-ray radiation driven shocks were adopted to take colliding shocks compression. By using Dog bone hohlraum the CH/KCl/CH sample was shielded from the laser hitting point to suppress the M band preheating and enhance the compressibility. Thus, an unexplored and extreme region of the plasma state with the maximum 5 times solid density and temperature lower than 3 eV (with coupling constant Γii around 100) was first obtained. The photoabsorption spectra of chlorine near the K-shell edge have been measured with a crystal spectrometer using a short x-ray backlighter. The K edge red shift up to 11.7 eV and broadening of 15.2 eV were obtained for the maximum compression. The electron temperature, inferred by Fermi-Dirac fit of the measured K-edge broadening, was consistent with the hydrodynamic predictions. The comparison of the K edge shift with a plasma model, in which the ionization effect, continuum lowering and partial degeneracy are considered, shows that more improvements are desired to describe in details the variation of K edge shift. This work might extend future study of WDM in extreme conditions of high compression.

Direct Growth of III-Nitride Nanowire-Based Yellow Light-Emitting Diode on Amorphous Quartz Using Thin Ti Interlayer

NASA Astrophysics Data System (ADS)

Prabaswara, Aditya; Min, Jung-Wook; Zhao, Chao; Janjua, Bilal; Zhang, Daliang; Albadri, Abdulrahman M.; Alyamani, Ahmed Y.; Ng, Tien Khee; Ooi, Boon S.

2018-02-01

Consumer electronics have increasingly relied on ultra-thin glass screen due to its transparency, scalability, and cost. In particular, display technology relies on integrating light-emitting diodes with display panel as a source for backlighting. In this study, we undertook the challenge of integrating light emitters onto amorphous quartz by demonstrating the direct growth and fabrication of a III-nitride nanowire-based light-emitting diode. The proof-of-concept device exhibits a low turn-on voltage of 2.6 V, on an amorphous quartz substrate. We achieved 40% transparency across the visible wavelength while maintaining electrical conductivity by employing a TiN/Ti interlayer on quartz as a translucent conducting layer. The nanowire-on-quartz LED emits a broad linewidth spectrum of light centered at true yellow color ( 590 nm), an important wavelength bridging the green-gap in solid-state lighting technology, with significantly less strain and dislocations compared to conventional planar quantum well nitride structures. Our endeavor highlighted the feasibility of fabricating III-nitride optoelectronic device on a scalable amorphous substrate through facile growth and fabrication steps. For practical demonstration, we demonstrated tunable correlated color temperature white light, leveraging on the broadly tunable nanowire spectral characteristics across red-amber-yellow color regime.

Prospects of III-nitride optoelectronics grown on Si.

PubMed

Zhu, D; Wallis, D J; Humphreys, C J

2013-10-01

The use of III-nitride-based light-emitting diodes (LEDs) is now widespread in applications such as indicator lamps, display panels, backlighting for liquid-crystal display TVs and computer screens, traffic lights, etc. To meet the huge market demand and lower the manufacturing cost, the LED industry is moving fast from 2 inch to 4 inch and recently to 6 inch wafer sizes. Although Al2O3 (sapphire) and SiC remain the dominant substrate materials for the epitaxy of nitride LEDs, the use of large Si substrates attracts great interest because Si wafers are readily available in large diameters at low cost. In addition, such wafers are compatible with existing processing lines for 6 inch and larger wafers commonly used in the electronics industry. During the last decade, much exciting progress has been achieved in improving the performance of GaN-on-Si devices. In this contribution, the status and prospects of III-nitride optoelectronics grown on Si substrates are reviewed. The issues involved in the growth of GaN-based LED structures on Si and possible solutions are outlined, together with a brief introduction to some novel in situ and ex situ monitoring/characterization tools, which are especially useful for the growth of GaN-on-Si structures.

Imaging diagnostics of pulsed plasma discharges in saline generated with various sharp pin powered electrodes

NASA Astrophysics Data System (ADS)

Asimakoulas, L.; Karim, M. L.; Dostal, L.; Krcma, F.; Graham, W. G.; Field, T. A.

2016-09-01

Plasmas formed by 1 ms pulses of between 180 and 300 V applied to sharp pin-like electrodes immersed in saline solution have been imaged with a Photron SA-X2 fast framing camera and an Andor iStar 510 ICCD camera. Stainless steel, Tungsten and Gold electrodes were investigated with tip diameters of 30 μm, 1 μm and < 1 μ m respectively. As previously observed, a vapour layer forms around the electrode prior to plasma ignition. For gold and stainless steel lower voltages were required to minimize electrode damage. Preliminary anlaysis indicates at lower voltages for all tips the fast framing results show that light emission is normally centred on a single small volume, which appears to move about, but remains close to the tip. In the case of Tungsten with higher voltages or longer pulses the tip of the needle can heat up to incandescent temperatures. At higher voltages shock wave fronts appear to be observed as the vapour layer collapses at the end of the voltage pulse. Backlighting and no lighting to observe bubble/vapour layer formation and emission due to plasma formation were employed. Sometimes at higher voltages a thicker vapour layer engulfs the tip and no plasma emission/current is observed.

Anisotropic structural and optical properties of semi-polar (11-22) GaN grown on m-plane sapphire using double AlN buffer layers.

PubMed

Zhao, Guijuan; Wang, Lianshan; Yang, Shaoyan; Li, Huijie; Wei, Hongyuan; Han, Dongyue; Wang, Zhanguo

2016-02-10

We report the anisotropic structural and optical properties of semi-polar (11-22) GaN grown on m-plane sapphire using a three-step growth method which consisted of a low temperature AlN buffer layer, followed by a high temperature AlN buffer layer and GaN growth. By introducing double AlN buffer layers, we substantially improve the crystal and optical qualities of semi-polar (11-22) GaN, and significantly reduce the density of stacking faults and dislocations. The high resolution x-ray diffraction measurement revealed that the in-plane anisotropic structural characteristics of GaN layer are azimuthal dependent. Transmission electron microscopy analysis showed that the majority of dislocations in the GaN epitaxial layer grown on m-sapphire are the mixed-type and the orientation of GaN layer was rotated 58.4° against the substrate. The room temperature photoluminescence (PL) spectra showed the PL intensity and wavelength have polarization dependence along parallel and perpendicular to the [1-100] axis (polarization degrees ~ 0.63). The realization of a high polarization semi-polar GaN would be useful to achieve III-nitride based lighting emission device for displays and backlighting.

Optimization of a high-yield, low-areal-density fusion product source at the National Ignition Facility with applications in nucleosynthesis experiments

NASA Astrophysics Data System (ADS)

Gatu Johnson, M.; Casey, D. T.; Hohenberger, M.; Zylstra, A. B.; Bacher, A.; Brune, C. R.; Bionta, R. M.; Craxton, R. S.; Ellison, C. L.; Farrell, M.; Frenje, J. A.; Garbett, W.; Garcia, E. M.; Grim, G. P.; Hartouni, E.; Hatarik, R.; Herrmann, H. W.; Hohensee, M.; Holunga, D. M.; Hoppe, M.; Jackson, M.; Kabadi, N.; Khan, S. F.; Kilkenny, J. D.; Kohut, T. R.; Lahmann, B.; Le, H. P.; Li, C. K.; Masse, L.; McKenty, P. W.; McNabb, D. P.; Nikroo, A.; Parham, T. G.; Parker, C. E.; Petrasso, R. D.; Pino, J.; Remington, B.; Rice, N. G.; Rinderknecht, H. G.; Rosenberg, M. J.; Sanchez, J.; Sayre, D. B.; Schoff, M. E.; Shuldberg, C. M.; Séguin, F. H.; Sio, H.; Walters, Z. B.; Whitley, H. D.

2018-05-01

Polar-direct-drive exploding pushers are used as a high-yield, low-areal-density fusion product source at the National Ignition Facility with applications including diagnostic calibration, nuclear security, backlighting, electron-ion equilibration, and nucleosynthesis-relevant experiments. In this paper, two different paths to improving the performance of this platform are explored: (i) optimizing the laser drive, and (ii) optimizing the target. While the present study is specifically geared towards nucleosynthesis experiments, the results are generally applicable. Example data from T2/3He-gas-filled implosions with trace deuterium are used to show that yield and ion temperature (Tion) from 1.6 mm-outer-diameter thin-glass-shell capsule implosions are improved at a set laser energy by switching from a ramped to a square laser pulse shape, and that increased laser energy further improves yield and Tion, although by factors lower than predicted by 1 D simulations. Using data from D2/3He-gas-filled implosions, yield at a set Tion is experimentally verified to increase with capsule size. Uniform D3He-proton spectra from 3 mm-outer-diameter CH shell implosions demonstrate the utility of this platform for studying charged-particle-producing reactions relevant to stellar nucleosynthesis.

Application of time-resolved shadowgraph imaging and computer analysis to study micrometer-scale response of superfluid helium

NASA Astrophysics Data System (ADS)

Sajjadi, Seyed; Buelna, Xavier; Eloranta, Jussi

2018-01-01

Application of inexpensive light emitting diodes as backlight sources for time-resolved shadowgraph imaging is demonstrated. The two light sources tested are able to produce light pulse sequences in the nanosecond and microsecond time regimes. After determining their time response characteristics, the diodes were applied to study the gas bubble formation around laser-heated copper nanoparticles in superfluid helium at 1.7 K and to determine the local cavitation bubble dynamics around fast moving metal micro-particles in the liquid. A convolutional neural network algorithm for analyzing the shadowgraph images by a computer is presented and the method is validated against the results from manual image analysis. The second application employed the red-green-blue light emitting diode source that produces light pulse sequences of the individual colors such that three separate shadowgraph frames can be recorded onto the color pixels of a charge-coupled device camera. Such an image sequence can be used to determine the moving object geometry, local velocity, and acceleration/deceleration. These data can be used to calculate, for example, the instantaneous Reynolds number for the liquid flow around the particle. Although specifically demonstrated for superfluid helium, the technique can be used to study the dynamic response of any medium that exhibits spatial variations in the index of refraction.

Development of a Dual Windowed Test Vehicle for Live Streaming of Cook-Off in Energetic Materials

NASA Astrophysics Data System (ADS)

Cheese, Phil; Reeves, Tom; White, Nathan; Stennett, Christopher; Wood, Andrew; Cook, Malcolm; Syanco Ltd Team; Cranfield University Team; DE&S, MoD Abbey Wood Team

2017-06-01

A modular, axially connected test vehicle for researching the influence of various heating rates (cook-off) on energetic materials and how they fundamentally decompose, leading to a violent reaction has been developed and tested. The vehicle can accommodate samples measuring up to 50 mm in diameter, with thicknesses variable from 0.5 mm up to 50 mm long. A unique feature of this vehicle is the ability to have a live high speed camera view, without compromising confinement during the cook-off process. This is achieved via two special windows that allow artificial backlighting to be provided at one end for clear observation of the test sample; this has allowed unprecedented views of how explosives decompose and runaway to violent reactions, and has given insight into the reaction mechanisms operating, and challenges current theories. Using glass windows, a burst pressure of 20 MPa has been measured. The heating rate is fully adjustable from slow to fast rates, and its design allows for confinement to be varied to study the influence on the violence of reaction during cook-off. In addition to being able to view the test sample during cook-off, embedded thermocouples provide detailed temperature records and the ability to use PDV instrumentation is also incorporated.

High Precision Edge Detection Algorithm for Mechanical Parts

NASA Astrophysics Data System (ADS)

Duan, Zhenyun; Wang, Ning; Fu, Jingshun; Zhao, Wenhui; Duan, Boqiang; Zhao, Jungui

2018-04-01

High precision and high efficiency measurement is becoming an imperative requirement for a lot of mechanical parts. So in this study, a subpixel-level edge detection algorithm based on the Gaussian integral model is proposed. For this purpose, the step edge normal section line Gaussian integral model of the backlight image is constructed, combined with the point spread function and the single step model. Then gray value of discrete points on the normal section line of pixel edge is calculated by surface interpolation, and the coordinate as well as gray information affected by noise is fitted in accordance with the Gaussian integral model. Therefore, a precise location of a subpixel edge was determined by searching the mean point. Finally, a gear tooth was measured by M&M3525 gear measurement center to verify the proposed algorithm. The theoretical analysis and experimental results show that the local edge fluctuation is reduced effectively by the proposed method in comparison with the existing subpixel edge detection algorithms. The subpixel edge location accuracy and computation speed are improved. And the maximum error of gear tooth profile total deviation is 1.9 μm compared with measurement result with gear measurement center. It indicates that the method has high reliability to meet the requirement of high precision measurement.

Atomic kinetics of a neon photoionized plasma experiment at Z

NASA Astrophysics Data System (ADS)

Mayes, Daniel C.; Mancini, Roberto; Bailey, James E.; Loisel, Guillaume; Rochau, Gregory; ZAPP Collaboration

2018-06-01

We discuss an experimental effort to study the atomic kinetics in astrophysically relevant photoionized plasmas via K-shell line absorption spectroscopy. The experiment employs the intense x-ray flux emitted at the collapse of a Z-pinch to heat and backlight a photoionized plasma contained within a cm-scale gas cell placed at a variable distance from the Z-pinch and filled with neon gas pressures in the range from 3.5 to 30 Torr. The experimental platform affords an order of magnitude range in the ionization parameter characterizing the photoionized plasma at the peak of the x-ray drive from about 5 to 80 erg*cm/s. Thus, the experiment allows for the study of trends in ionization distribution as a function of the ionization parameter. An x-ray crystal spectrometer capable of time-integrated and/or time-gated configurations is used to collect absorption spectra. The spectra show line absorption by several ionization stages of neon, including Be-, Li-, He-, and H-like ions. Analysis of these spectra yields ion areal densities and charge state distributions, which can be compared with simulation results from atomic kinetics codes. In addition, the electron temperature is extracted from level population ratios of nearby energy levels in Li- and Be-like ions, which can be used to test heating models of photoionized plasmas.

Direct Growth of III-Nitride Nanowire-Based Yellow Light-Emitting Diode on Amorphous Quartz Using Thin Ti Interlayer.

PubMed

Prabaswara, Aditya; Min, Jung-Wook; Zhao, Chao; Janjua, Bilal; Zhang, Daliang; Albadri, Abdulrahman M; Alyamani, Ahmed Y; Ng, Tien Khee; Ooi, Boon S

2018-02-06

Consumer electronics have increasingly relied on ultra-thin glass screen due to its transparency, scalability, and cost. In particular, display technology relies on integrating light-emitting diodes with display panel as a source for backlighting. In this study, we undertook the challenge of integrating light emitters onto amorphous quartz by demonstrating the direct growth and fabrication of a III-nitride nanowire-based light-emitting diode. The proof-of-concept device exhibits a low turn-on voltage of 2.6 V, on an amorphous quartz substrate. We achieved ~ 40% transparency across the visible wavelength while maintaining electrical conductivity by employing a TiN/Ti interlayer on quartz as a translucent conducting layer. The nanowire-on-quartz LED emits a broad linewidth spectrum of light centered at true yellow color (~ 590 nm), an important wavelength bridging the green-gap in solid-state lighting technology, with significantly less strain and dislocations compared to conventional planar quantum well nitride structures. Our endeavor highlighted the feasibility of fabricating III-nitride optoelectronic device on a scalable amorphous substrate through facile growth and fabrication steps. For practical demonstration, we demonstrated tunable correlated color temperature white light, leveraging on the broadly tunable nanowire spectral characteristics across red-amber-yellow color regime.

A young solar twin in the Rosette cluster NGC 2244 line of sight

NASA Astrophysics Data System (ADS)

Huber, Jeremy M.; Kielkopf, John F.; Mengel, Matthew; Carter, Bradley D.; Ferland, Gary J.; Clark, Frank O.

2018-05-01

Based on prior precision photometry and cluster age analysis, the bright star GSC 00154-01819 is a possible young pre-main sequence member of the Rosette cluster, NGC 2244. As part of a comprehensive study of the large-scale structure of the Rosette and its excitation by the cluster stars, we noted this star as a potential backlight for a probe of the interstellar medium and extinction along the sight line towards a distinctive nebular feature projected on to the cluster centre. New high-resolution spectra of the star were taken with the University College London Echelle Spectrograph of the AAT. They reveal that rather than being a reddened spectral type B or A star within the Mon OB2 association, it is a nearby, largely unreddened, solar twin of spectral type G2V less than 180 Myr old. It is about 219 pc from the Sun with a barycentric radial velocity of +14.35 ± 1.99 km s-1. The spectrum of the Rosette behind it and along this line of sight shows a barycentric radial velocity of +26.0 ± 2.4 km s-1 in H α, and a full width at half-maximum velocity dispersion of 61.94 ± 1.38 km s-1.

Analysis of circadian properties and healthy levels of blue light from smartphones at night

PubMed Central

Oh, Ji Hye; Yoo, Heeyeon; Park, Hoo Keun; Do, Young Rag

2015-01-01

This study proposes representative figures of merit for circadian and vision performance for healthy and efficient use of smartphone displays. The recently developed figures of merit for circadian luminous efficacy of radiation (CER) and circadian illuminance (CIL) related to human health and circadian rhythm were measured to compare three kinds of commercial smartphone displays. The CIL values for social network service (SNS) messenger screens from all three displays were higher than 41.3 biolux (blx) in a dark room at night, and the highest CIL value reached 50.9 blx. These CIL values corresponded to melatonin suppression values (MSVs) of 7.3% and 11.4%, respectively. Moreover, smartphone use in a bright room at night had much higher CIL and MSV values (58.7 ~ 105.2 blx and 15.4 ~ 36.1%, respectively). This study also analyzed the nonvisual and visual optical properties of the three smartphone displays while varying the distance between the screen and eye and controlling the brightness setting. Finally, a method to possibly attenuate the unhealthy effects of smartphone displays was proposed and investigated by decreasing the emitting wavelength of blue LEDs in a smartphone LCD backlight and subsequently reducing the circadian effect of the display. PMID:26085126

Optimization of a high-yield, low-areal-density fusion product source at the National Ignition Facility with applications in nucleosynthesis experiments

DOE PAGES

Gatu Johnson, M.; Casey, D. T.; Hohenberger, M.; ...

2018-05-09

Polar-direct-drive exploding pushers are used as a high-yield, low-areal-density fusion product source at the National Ignition Facility with applications including diagnostic calibration, nuclear security, backlighting, electron-ion equilibration, and nucleosynthesis-relevant experiments. In this paper, two different paths to improving the performance of this platform are explored: (i) optimizing the laser drive, and (ii) optimizing the target. While the present study is specifically geared towards nucleosynthesis experiments, the results are generally applicable. Example data from T 2/ 3He-gas-filled implosions with trace deuterium are used to show that yield and ion temperature (Tion) from 1.6 mm-outer-diameter thin-glass-shell capsule implosions are improved at amore » set laser energy by switching from a ramped to a square laser pulse shape, and that increased laser energy further improves yield and Tion, although by factors lower than predicted by 1 D simulations. Using data from D2-3He-gas-filled implosions, yield at a set Tion is experimentally verified to increase with capsule size. Uniform D-3He-proton spectra from 3 mm-outer-diameter CH shell implosions demonstrate the utility of this platform for studying charged-particle-producing reactions relevant to stellar nucleosynthesis.« less

AXIS: an instrument for imaging Compton radiographs using the Advanced Radiography Capability on the NIF.

PubMed

Hall, G N; Izumi, N; Tommasini, R; Carpenter, A C; Palmer, N E; Zacharias, R; Felker, B; Holder, J P; Allen, F V; Bell, P M; Bradley, D; Montesanti, R; Landen, O L

2014-11-01

Compton radiography is an important diagnostic for Inertial Confinement Fusion (ICF), as it provides a means to measure the density and asymmetries of the DT fuel in an ICF capsule near the time of peak compression. The AXIS instrument (ARC (Advanced Radiography Capability) X-ray Imaging System) is a gated detector in development for the National Ignition Facility (NIF), and will initially be capable of recording two Compton radiographs during a single NIF shot. The principal reason for the development of AXIS is the requirement for significantly improved detection quantum efficiency (DQE) at high x-ray energies. AXIS will be the detector for Compton radiography driven by the ARC laser, which will be used to produce Bremsstrahlung X-ray backlighter sources over the range of 50 keV-200 keV for this purpose. It is expected that AXIS will be capable of recording these high-energy x-rays with a DQE several times greater than other X-ray cameras at NIF, as well as providing a much larger field of view of the imploded capsule. AXIS will therefore provide an image with larger signal-to-noise that will allow the density and distribution of the compressed DT fuel to be measured with significantly greater accuracy as ICF experiments are tuned for ignition.

Ice Particle Impacts on a Moving Wedge

NASA Technical Reports Server (NTRS)

Vargas, Mario; Struk, Peter M.; Kreeger, Richard E.; Palacios, Jose; Iyer, Kaushik A.; Gold, Robert E.

2014-01-01

This work presents the results of an experimental study of ice particle impacts on a moving wedge. The experiment was conducted in the Adverse Environment Rotor Test Stand (AERTS) facility located at Penn State University. The wedge was placed at the tip of a rotating blade. Ice particles shot from a pressure gun intercepted the moving wedge and impacted it at a location along its circular path. The upward velocity of the ice particles varied from 7 to 12 meters per second. Wedge velocities were varied from 0 to 120 meters per second. Wedge angles tested were 0 deg, 30 deg, 45 deg, and 60 deg. High speed imaging combined with backlighting captured the impact allowing observation of the effect of velocity and wedge angle on the impact and the post-impact fragment behavior. It was found that the pressure gun and the rotating wedge could be synchronized to consistently obtain ice particle impacts on the target wedge. It was observed that the number of fragments increase with the normal component of the impact velocity. Particle fragments ejected immediately after impact showed velocities higher than the impact velocity. The results followed the major qualitative features observed by other researchers for hailstone impacts, even though the reduced scale size of the particles used in the present experiment as compared to hailstones was 4:1.

Spray Droplet Characterization from a Single Nozzle by High Speed Image Analysis Using an In-Focus Droplet Criterion

PubMed Central

Vulgarakis Minov, Sofija; Cointault, Frédéric; Vangeyte, Jürgen; Pieters, Jan G; Nuyttens, David

2016-01-01

Accurate spray characterization helps to better understand the pesticide spray application process. The goal of this research was to present the proof of principle of a droplet size and velocity measuring technique for different types of hydraulic spray nozzles using a high speed backlight image acquisition and analysis system. As only part of the drops of an agricultural spray can be in focus at any given moment, an in-focus criterion based on the gray level gradient was proposed to decide whether a given droplet is in focus or not. In a first experiment, differently sized droplets were generated with a piezoelectric generator and studied to establish the relationship between size and in-focus characteristics. In a second experiment, it was demonstrated that droplet sizes and velocities from a real sprayer could be measured reliably in a non-intrusive way using the newly developed image acquisition set-up and image processing. Measured droplet sizes ranged from 24 μm to 543 μm, depending on the nozzle type and size. Droplet velocities ranged from around 0.5 m/s to 12 m/s. The droplet size and velocity results were compared and related well with the results obtained with a Phase Doppler Particle Analyzer (PDPA). PMID:26861338

Spray Droplet Characterization from a Single Nozzle by High Speed Image Analysis Using an In-Focus Droplet Criterion.

PubMed

Minov, Sofija Vulgarakis; Cointault, Frédéric; Vangeyte, Jürgen; Pieters, Jan G; Nuyttens, David

2016-02-06

Accurate spray characterization helps to better understand the pesticide spray application process. The goal of this research was to present the proof of principle of a droplet size and velocity measuring technique for different types of hydraulic spray nozzles using a high speed backlight image acquisition and analysis system. As only part of the drops of an agricultural spray can be in focus at any given moment, an in-focus criterion based on the gray level gradient was proposed to decide whether a given droplet is in focus or not. In a first experiment, differently sized droplets were generated with a piezoelectric generator and studied to establish the relationship between size and in-focus characteristics. In a second experiment, it was demonstrated that droplet sizes and velocities from a real sprayer could be measured reliably in a non-intrusive way using the newly developed image acquisition set-up and image processing. Measured droplet sizes ranged from 24 μm to 543 μm, depending on the nozzle type and size. Droplet velocities ranged from around 0.5 m/s to 12 m/s. The droplet size and velocity results were compared and related well with the results obtained with a Phase Doppler Particle Analyzer (PDPA).

Measuring the Ablative Richtmyer-Meshkov Growth of Isolated Defects on Plastic Capsules

NASA Astrophysics Data System (ADS)

Loomis, Eric; Braun, Dave; Batha, Steve; Sedillo, Tom; Evans, Scott; Sorce, Chuck; Landen, Otto

2010-11-01

To achieve thermonuclear ignition at Megajoule class laser systems such as the NIF using inertially confined plasmas, targets must be designed with high in-flight aspect ratios (IFAR) resulting in low shell stability. Recent simulations and experiments have shown that isolated features on the outer surface of an ignition capsule can profoundly impact capsule performance by leading to material jetting or mix into the hotspot. Unfortunately, our ability to accurately predict these effects is uncertain due to disagreement between equation of state (EOS) models. In light of this, we have begun a campaign to measure the growth of isolated defects due to ablative Richtmyer-Meshkov in CH capsules to validate these models. Face- on transmission radiography has been used to measure the evolution of Gaussian bump arrays in plastic targets. Targets were indirectly-driven using Au halfraums to radiation temperatures near 65-75 eV at the Omega laser (Laboratory for Laser Energetics, University of Rochester, NY) simultaneous with x-ray backlighting from a saran (Cl) foil. Shock speed measurements were also made to determine drive conditions in the target. The results from these experiments will aid in the design of ignition drive pulses that minimize bump amplitude at the time of shell acceleration.

Proactive detection of bones in poultry processing

NASA Astrophysics Data System (ADS)

Daley, W. D. R.; Stewart, John

2009-05-01

Bones continue to be a problem of concern for the poultry industry. Most further processed products begin with the requirement for raw material with minimal bones. The current process for generating deboned product requires systems for monitoring and inspecting the output product. The current detection systems are either people palpitating the product or X-ray systems. The current performance of these inspection techniques are below the desired levels of accuracies and are costly. We propose a technique for monitoring bones that conduct the inspection operation in the deboning the process so as to have enough time to take action to reduce the probability that bones will end up in the final product. This is accomplished by developing active cones with built in illumination to backlight the cage (skeleton) on the deboning line. If the bones of interest are still on the cage then the bones are not in the associated meat. This approach also allows for the ability to practice process control on the deboning operation to keep the process under control as opposed to the current system where the detection is done post production and does not easily present the opportunity to adjust the process. The proposed approach shows overall accuracies of about 94% for the detection of the clavicle bones.

Optimization of a high-yield, low-areal-density fusion product source at the National Ignition Facility with applications in nucleosynthesis experiments

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

Gatu Johnson, M.; Casey, D. T.; Hohenberger, M.

Polar-direct-drive exploding pushers are used as a high-yield, low-areal-density fusion product source at the National Ignition Facility with applications including diagnostic calibration, nuclear security, backlighting, electron-ion equilibration, and nucleosynthesis-relevant experiments. In this paper, two different paths to improving the performance of this platform are explored: (i) optimizing the laser drive, and (ii) optimizing the target. While the present study is specifically geared towards nucleosynthesis experiments, the results are generally applicable. Example data from T 2/ 3He-gas-filled implosions with trace deuterium are used to show that yield and ion temperature (Tion) from 1.6 mm-outer-diameter thin-glass-shell capsule implosions are improved at amore » set laser energy by switching from a ramped to a square laser pulse shape, and that increased laser energy further improves yield and Tion, although by factors lower than predicted by 1 D simulations. Using data from D2-3He-gas-filled implosions, yield at a set Tion is experimentally verified to increase with capsule size. Uniform D-3He-proton spectra from 3 mm-outer-diameter CH shell implosions demonstrate the utility of this platform for studying charged-particle-producing reactions relevant to stellar nucleosynthesis.« less

Betatron x-ray radiation from laser-plasma accelerators driven by femtosecond and picosecond laser systems

NASA Astrophysics Data System (ADS)

Albert, F.; Lemos, N.; Shaw, J. L.; King, P. M.; Pollock, B. B.; Goyon, C.; Schumaker, W.; Saunders, A. M.; Marsh, K. A.; Pak, A.; Ralph, J. E.; Martins, J. L.; Amorim, L. D.; Falcone, R. W.; Glenzer, S. H.; Moody, J. D.; Joshi, C.

2018-05-01

A comparative experimental study of betatron x-ray radiation from laser wakefield acceleration in the blowout and self-modulated regimes is presented. Our experiments use picosecond duration laser pulses up to 150 J (self-modulated regime) and 60 fs duration laser pulses up to 10 J (blowout regime), for plasmas with electronic densities on the order of 1019 cm-3. In the self-modulated regime, where betatron radiation has been very little studied compared to the blowout regime, electrons accelerated in the wake of the laser pulse are subject to both the longitudinal plasma and transverse laser electrical fields. As a result, their motion within the wake is relatively complex; consequently, the experimental and theoretical properties of the x-ray source based on self-modulation differ from the blowout regime of laser wakefield acceleration. In our experimental configuration, electrons accelerated up to about 250 MeV and betatron x-ray spectra with critical energies of about 10-20 keV and photon fluxes between 108 and 1010 photons/eV Sr are reported. Our experiments open the prospect of using betatron x-ray radiation for applications, and the source is competitive with current x-ray backlighting methods on multi-kilojoule laser systems.

Fluorescence and absorption spectroscopy for warm dense matter studies and ICF plasma diagnostics

DOE PAGES

Hansen, Stephanie B.; Harding, Eric C.; Knapp, Patrick F.; ...

2018-03-07

The burning core of an inertial confinement fusion (ICF) plasma produces bright x-rays at stagnation that can directly diagnose core conditions essential for comparison to simulations and understanding fusion yields. These x-rays also backlight the surrounding shell of warm, dense matter, whose properties are critical to understanding the efficacy of the inertial confinement and global morphology. In this work, we show that the absorption and fluorescence spectra of mid-Z impurities or dopants in the warm dense shell can reveal the optical depth, temperature, and density of the shell and help constrain models of warm, dense matter. This is illustrated bymore » the example of a high-resolution spectrum collected from an ICF plasma with a beryllium shell containing native iron impurities. Lastly, analysis of the iron K-edge provides model-independent diagnostics of the shell density (2.3 × 10 24 e/cm 3) and temperature (10 eV), while a 12-eV red shift in Kβ and 5-eV blue shift in the K-edge discriminate among models of warm dense matter: Both shifts are well described by a self-consistent field model based on density functional theory but are not fully consistent with isolated-atom models using ad-hoc density effects.« less

Luminance requirements for lighted signage

NASA Astrophysics Data System (ADS)

Freyssinier, Jean Paul; Narendran, Nadarajah; Bullough, John D.

2006-08-01

Light-emitting diode (LED) technology is presently targeted to displace traditional light sources in backlighted signage. The literature shows that brightness and contrast are perhaps the two most important elements of a sign that determine its attention-getting capabilities and its legibility. Presently, there are no luminance standards for signage, and the practice of developing brighter signs to compete with signs in adjacent businesses is becoming more commonplace. Sign luminances in such cases may far exceed what people usually need for identifying and reading a sign. Furthermore, the practice of higher sign luminance than needed has many negative consequences, including higher energy use and light pollution. To move toward development of a recommendation for lighted signage, several laboratory human factors evaluations were conducted. A scale model of a storefront was used to present human subjects with a typical red channel-letter sign at luminances ranging from 8 cd/m2 to 1512 cd/m2 under four background luminances typical of nighttime outdoor and daytime inside-mall conditions (1, 100, 300, 1000 cd/m2), from three scaled viewing distances (30, 60, 340 ft), and either in isolation or adjacent to two similar signs. Subjects rated the brightness, acceptability, and ease of reading of the test sign for each combination of sign and background luminances and scaled viewing distances.

Analysis of circadian properties and healthy levels of blue light from smartphones at night

NASA Astrophysics Data System (ADS)

Oh, Ji Hye; Yoo, Heeyeon; Park, Hoo Keun; Do, Young Rag

2015-06-01

This study proposes representative figures of merit for circadian and vision performance for healthy and efficient use of smartphone displays. The recently developed figures of merit for circadian luminous efficacy of radiation (CER) and circadian illuminance (CIL) related to human health and circadian rhythm were measured to compare three kinds of commercial smartphone displays. The CIL values for social network service (SNS) messenger screens from all three displays were higher than 41.3 biolux (blx) in a dark room at night, and the highest CIL value reached 50.9 blx. These CIL values corresponded to melatonin suppression values (MSVs) of 7.3% and 11.4%, respectively. Moreover, smartphone use in a bright room at night had much higher CIL and MSV values (58.7 ~ 105.2 blx and 15.4 ~ 36.1%, respectively). This study also analyzed the nonvisual and visual optical properties of the three smartphone displays while varying the distance between the screen and eye and controlling the brightness setting. Finally, a method to possibly attenuate the unhealthy effects of smartphone displays was proposed and investigated by decreasing the emitting wavelength of blue LEDs in a smartphone LCD backlight and subsequently reducing the circadian effect of the display.

Magnetically-Driven Convergent Instability Growth platform on Z.

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

Knapp, Patrick; Mattsson, Thomas; Martin, Matthew

Hydrodynamic instability growth is a fundamentally limiting process in many applications. In High Energy Density Physics (HEDP) systems such as inertial confinement fusion implosions and stellar explosions, hydro instabilities can dominate the evolution of the object and largely determine the final state achievable. Of particular interest is the process by which instabilities cause perturbations at a density or material interface to grow nonlinearly, introducing vorticity and eventually causing the two species to mix across the interface. Although quantifying instabilities has been the subject of many investigations in planar geometry, few have been done in converging geometry. During FY17, the teammore » executed six convergent geometry instability experiments. Based on earlier results, the platform was redesigned and improved with respect to load centering at installation making the installation reproducible and development of a new 7.2 keV, Co He-a backlighter system to better penetrate the liner. Together, the improvements yielded significantly improved experimental results. The results in FY17 demonstrate the viability of using experiments on Z to quantify instability growth in cylindrically convergent geometry. Going forward, we will continue the partnership with staff and management at LANL to analyze the past experiments, compare to hydrodynamics growth models, and design future experiments.« less

Gallium

USGS Publications Warehouse

Foley, Nora K.; Jaskula, Brian W.; Kimball, Bryn E.; Schulte, Ruth F.; Schulz, Klaus J.; DeYoung,, John H.; Seal, Robert R.; Bradley, Dwight C.

2017-12-19

Gallium is a soft, silvery metallic element with an atomic number of 31 and the chemical symbol Ga. Gallium is used in a wide variety of products that have microelectronic components containing either gallium arsenide (GaAs) or gallium nitride (GaN). GaAs is able to change electricity directly into laser light and is used in the manufacture of optoelectronic devices (laser diodes, light-emitting diodes [LEDs], photo detectors, and solar cells), which are important for aerospace and telecommunications applications and industrial and medical equipment. GaAs is also used in the production of highly specialized integrated circuits, semiconductors, and transistors; these are necessary for defense applications and high-performance computers. For example, cell phones with advanced personal computer-like functionality (smartphones) use GaAs-rich semiconductor components. GaN is used principally in the manufacture of LEDs and laser diodes, power electronics, and radio-frequency electronics. Because GaN power transistors operate at higher voltages and with a higher power density than GaAs devices, the uses for advanced GaN-based products are expected to increase in the future. Gallium technologies also have large power-handling capabilities and are used for cable television transmission, commercial wireless infrastructure, power electronics, and satellites. Gallium is also used for such familiar applications as screen backlighting for computer notebooks, flat-screen televisions, and desktop computer monitors.Gallium is dispersed in small amounts in many minerals and rocks where it substitutes for elements of similar size and charge, such as aluminum and zinc. For example, gallium is found in small amounts (about 50 parts per million) in such aluminum-bearing minerals as diaspore-boehmite and gibbsite, which form bauxite deposits, and in the zinc-sulfide mineral sphalerite, which is found in many mineral deposits. At the present time, gallium metal is derived mainly as a byproduct of the processing of bauxite ore for aluminum; lesser amounts of gallium metal are produced from the processing of sphalerite ore from three types of deposits (sediment-hosted, Mississippi Valley-type, and volcanogenic massive sulfide) for zinc. The United States is expected to meet its current and expected future needs for gallium through imports of primary, recycled, and refined gallium, as well as through domestic production of recycled and refined gallium. The U.S. Geological Survey estimates that world resources of gallium in bauxite exceed 1 billion kilograms, and a considerable quantity of gallium could be present in world zinc reserves.

Mutations in ZMYND10, a Gene Essential for Proper Axonemal Assembly of Inner and Outer Dynein Arms in Humans and Flies, Cause Primary Ciliary Dyskinesia

PubMed Central

Moore, Daniel J.; Onoufriadis, Alexandros; Shoemark, Amelia; Simpson, Michael A.; zur Lage, Petra I.; de Castro, Sandra C.; Bartoloni, Lucia; Gallone, Giuseppe; Petridi, Stavroula; Woollard, Wesley J.; Antony, Dinu; Schmidts, Miriam; Didonna, Teresa; Makrythanasis, Periklis; Bevillard, Jeremy; Mongan, Nigel P.; Djakow, Jana; Pals, Gerard; Lucas, Jane S.; Marthin, June K.; Nielsen, Kim G.; Santoni, Federico; Guipponi, Michel; Hogg, Claire; Antonarakis, Stylianos E.; Emes, Richard D.; Chung, Eddie M.K.; Greene, Nicholas D.E.; Blouin, Jean-Louis; Jarman, Andrew P.; Mitchison, Hannah M.

2013-01-01

Primary ciliary dyskinesia (PCD) is a ciliopathy characterized by airway disease, infertility, and laterality defects, often caused by dual loss of the inner dynein arms (IDAs) and outer dynein arms (ODAs), which power cilia and flagella beating. Using whole-exome and candidate-gene Sanger resequencing in PCD-affected families afflicted with combined IDA and ODA defects, we found that 6/38 (16%) carried biallelic mutations in the conserved zinc-finger gene BLU (ZMYND10). ZMYND10 mutations conferred dynein-arm loss seen at the ultrastructural and immunofluorescence level and complete cilia immotility, except in hypomorphic p.Val16Gly (c.47T>G) homozygote individuals, whose cilia retained a stiff and slowed beat. In mice, Zmynd10 mRNA is restricted to regions containing motile cilia. In a Drosophila model of PCD, Zmynd10 is exclusively expressed in cells with motile cilia: chordotonal sensory neurons and sperm. In these cells, P-element-mediated gene silencing caused IDA and ODA defects, proprioception deficits, and sterility due to immotile sperm. Drosophila Zmynd10 with an equivalent c.47T>G (p.Val16Gly) missense change rescued mutant male sterility less than the wild-type did. Tagged Drosophila ZMYND10 is localized primarily to the cytoplasm, and human ZMYND10 interacts with LRRC6, another cytoplasmically localized protein altered in PCD. Using a fly model of PCD, we conclude that ZMYND10 is a cytoplasmic protein required for IDA and ODA assembly and that its variants cause ciliary dysmotility and PCD with laterality defects. PMID:23891471

High-density grids for efficient data collection from multiple crystals

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

Baxter, Elizabeth L.; Aguila, Laura; Alonso-Mori, Roberto

Higher throughput methods to mount and collect data from multiple small and radiation-sensitive crystals are important to support challenging structural investigations using microfocus synchrotron beamlines. Furthermore, efficient sample-delivery methods are essential to carry out productive femtosecond crystallography experiments at X-ray free-electron laser (XFEL) sources such as the Linac Coherent Light Source (LCLS). To address these needs, a high-density sample grid useful as a scaffold for both crystal growth and diffraction data collection has been developed and utilized for efficient goniometer-based sample delivery at synchrotron and XFEL sources. A single grid contains 75 mounting ports and fits inside an SSRL cassettemore » or uni-puck storage container. The use of grids with an SSRL cassette expands the cassette capacity up to 7200 samples. Grids may also be covered with a polymer film or sleeve for efficient room-temperature data collection from multiple samples. New automated routines have been incorporated into theBlu-Ice/DCSSexperimental control system to support grids, including semi-automated grid alignment, fully automated positioning of grid ports, rastering and automated data collection. Specialized tools have been developed to support crystallization experiments on grids, including a universal adaptor, which allows grids to be filled by commercial liquid-handling robots, as well as incubation chambers, which support vapor-diffusion and lipidic cubic phase crystallization experiments. Experiments in which crystals were loaded into grids or grown on grids using liquid-handling robots and incubation chambers are described. As a result, crystals were screened at LCLS-XPP and SSRL BL12-2 at room temperature and cryogenic temperatures.« less

Identifying the Optimal Water-Occluding Earplugs: A Scientific Simulation Study.

PubMed

Kovoor, Joshua; Al Hussaini, Ali; Backhouse, Steven

2016-12-01

Numerous types of water-occluding earplugs are available as a means of preventing infection in patients with external and middle ear disease. However, little is known about the comparative efficacies of these earplugs with prolonged water exposure. In this study, we assessed the water impermeability of various earplug materials to prolonged water exposure. Nine earplugs were tested: cotton wool mixed with petroleum jelly, cotton wool externally coated with petroleum jelly, Blu-Tack, foam earplugs, silicone putty, silicone earplugs, flanged earplugs, and hard and soft silicone custom-moulds. Precision-engineered cups were filled with 30 mL water and sealed with lids that contained a 10 mm diameter hole to simulate the ear canal. The aperture was occluded with different earplugs, and the cup was inverted. Computer software was used to record the water loss to the nearest 10 milligrams 720 times over a three-hour period. The test was repeated five times for each material. The water permeability onset, rate, and total amount of water loss varied markedly between the materials; cotton wool mixed with petroleum jelly demonstrated the fastest onset of leak and the highest rate of water loss (p < 0.00001), as well as the largest amount of cumulative water loss (p = 0.00213). The soft silicone custom-mould plugs, hard silicone custom-mould plugs, foam plugs, and silicone putty demonstrated no leaks. This study demonstrates a wide range of water permeabilities of commonly used ear-occluding materials during prolonged water exposure. We found that the generally suggested regimen of cotton wool mixed with petroleum jelly may be inefficacious for substantial periods of water exposure.

High-density grids for efficient data collection from multiple crystals

PubMed Central

Baxter, Elizabeth L.; Aguila, Laura; Alonso-Mori, Roberto; Barnes, Christopher O.; Bonagura, Christopher A.; Brehmer, Winnie; Brunger, Axel T.; Calero, Guillermo; Caradoc-Davies, Tom T.; Chatterjee, Ruchira; Degrado, William F.; Fraser, James S.; Ibrahim, Mohamed; Kern, Jan; Kobilka, Brian K.; Kruse, Andrew C.; Larsson, Karl M.; Lemke, Heinrik T.; Lyubimov, Artem Y.; Manglik, Aashish; McPhillips, Scott E.; Norgren, Erik; Pang, Siew S.; Soltis, S. M.; Song, Jinhu; Thomaston, Jessica; Tsai, Yingssu; Weis, William I.; Woldeyes, Rahel A.; Yachandra, Vittal; Yano, Junko; Zouni, Athina; Cohen, Aina E.

2016-01-01

Higher throughput methods to mount and collect data from multiple small and radiation-sensitive crystals are important to support challenging structural investigations using microfocus synchrotron beamlines. Furthermore, efficient sample-delivery methods are essential to carry out productive femtosecond crystallography experiments at X-ray free-electron laser (XFEL) sources such as the Linac Coherent Light Source (LCLS). To address these needs, a high-density sample grid useful as a scaffold for both crystal growth and diffraction data collection has been developed and utilized for efficient goniometer-based sample delivery at synchrotron and XFEL sources. A single grid contains 75 mounting ports and fits inside an SSRL cassette or uni-puck storage container. The use of grids with an SSRL cassette expands the cassette capacity up to 7200 samples. Grids may also be covered with a polymer film or sleeve for efficient room-temperature data collection from multiple samples. New automated routines have been incorporated into the Blu-Ice/DCSS experimental control system to support grids, including semi-automated grid alignment, fully automated positioning of grid ports, rastering and automated data collection. Specialized tools have been developed to support crystallization experiments on grids, including a universal adaptor, which allows grids to be filled by commercial liquid-handling robots, as well as incubation chambers, which support vapor-diffusion and lipidic cubic phase crystallization experiments. Experiments in which crystals were loaded into grids or grown on grids using liquid-handling robots and incubation chambers are described. Crystals were screened at LCLS-XPP and SSRL BL12-2 at room temperature and cryogenic temperatures. PMID:26894529

Synthesis, Processing, and Thermoelectric Properties of Germanium-Antimony-Tellurium Based Compounds and Alloys

NASA Astrophysics Data System (ADS)

Williams, Jared Brett

Society has become increasingly more aware of the negative impacts which nonrenewable energy sources have on the environment, and therefore the search for new and more efficient means of energy production has become an important research endeavor. Thermoelectric modules possess the unique ability to convert wasted heat into useful electrical energy via solid state processes, which could vastly improve the efficiency of a number of applications. The materials which accomplish this are typically comprised of semiconductors which exhibit high electrical conductivity, Seebeck coefficient, and thermal resistivity. Together these properties give us a gauge for the overall efficiency of the thermal to electrical energy conversion. Phase change materials are a class of materials primarily used for optical data storage in CDs, DVDs, and Blu-Ray discs. Today's state of the art phase change materials are based on alloys of GeTe and Sb2Te3. These materials have also been found to exhibit high thermoelectric efficiencies. These high efficiencies stem from their complex crystal structure and degenerate semiconducting nature. The purpose of this work was to study and engineer the thermoelectric properties of various alloys and compounds which belong to this family of materials. Specifically studied were the compounds Ge4SbTe5 and Ge17Sb2Te20. In each case various synthesis and processing strategies were implemented to increase the thermoelectric performance and better understand the fundamental electrical and thermal properties. Finally various proposals for future work on these materials are presented, all of which are based on the findings described herein.

E-cigarette advertising expenditures in the U.S., 2011-2012.

PubMed

Kim, Annice E; Arnold, Kristin Y; Makarenko, Olga

2014-04-01

Electronic cigarettes (e-cigarettes) are growing in popularity, but little is known about the extent to which these products are advertised to consumers. To estimate expenditures for e-cigarette advertising in magazines, TV, the Internet, newspapers, and radio in the U.S. from 2011 to 2012. E-cigarette advertising data were obtained from leading media intelligence companies, Kantar Media and Nielsen. Estimated e-cigarette advertising expenditures were summarized across media channels for 2011 and 2012. Additional information on brands advertised and market-level buys (i.e., local versus national) also was examined. Overall, e-cigarette advertising expenditures across media channels tripled from $6.4 million in 2011 to $18.3 million in 2012. Expenditures were highest in magazines and TV and lowest in newspapers and on the Internet. More than 80 unique brands were advertised, but blu eCigs dominated ad spending, comprising 76.7% of all e-cigarette advertising expenditures in 2012. National markets were increasingly targeted from 54.9% of ad buys in 2011 to 87.0% of ad buys in 2012. E-cigarette advertising expenditures are increasing, with a greater focus on national markets and TV ads, which will likely increase consumer awareness and use of e-cigarettes in the future. Federal-level efforts are needed to mandate that e-cigarette companies report their advertising expenditures. Future studies should examine how e-cigarette advertising expenditures and message content influence consumer awareness of, interest in, and use of e-cigarettes. © 2013 American Journal of Preventive Medicine Published by American Journal of Preventive Medicine All rights reserved.

LOCATING THE TRAILING EDGE OF THE CIRCUMBINARY RING IN THE KH 15D SYSTEM

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

Capelo, Holly L.; Herbst, William; Leggett, S. K.

2012-09-20

Following two years of complete occultation of both stars in the binary T Tauri star KH 15D by its opaque circumbinary ring, KH 15D has abruptly brightened again during apastron phases, reaching I = 15 mag. Here, we show that the brightening is accompanied by a change in spectral class from K6/K7 (the spectral class of star A) to {approx}K1, and a bluing of the system in V - I by about 0.3 mag. A radial velocity measurement confirms that, at apastron, we are now seeing direct light from star B, which is more luminous and of earlier spectral classmore » than star A. Evidently, the trailing edge of the occulting screen has just become tangent to one anse of star B's projected orbit. This confirms a prediction of the precession models, supports the view that the tilted ring is self-gravitating, and ushers in a new era of the system's evolution that should be accompanied by the same kind of dramatic phenomena observed from 1995 to 2009. It also promotes KH 15D from a single-lined to a double-lined eclipsing binary, greatly enhancing its value for testing pre-main-sequence models. The results of our study strengthen the case for truncation of the outer ring at around 4 AU by a sub-stellar object such as an extremely young giant planet. The system is currently at an optimal configuration for detecting the putative planet and we urge expedient follow-up observations.« less

THE UV/BLUE EFFECTS OF SPACE WEATHERING MANIFESTED IN S-COMPLEX ASTEROIDS. I. QUANTIFYING CHANGE WITH ASTEROID AGE

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

Vilas, Faith; Hendrix, Amanda R., E-mail: fvilas@psi.edu

Evidence for the manifestation of space weathering in S-complex asteroids as a bluing of the UV/blue reflectance spectrum is extended using high resolution CCD reflectance spectra of 21 main-belt, 1 Mars-crossing, and 3 near-Earth asteroids covering a wavelength range of 320–620 nm. Demonstration of the transition of iron-bearing materials from volume scattering to surface (Fresnel) scattering is apparent as an abrupt downturn at wavelengths just short of 400 nm in reflectance spectra of fresh asteroid surfaces. The weathering away of this downturn is demonstrated by its absence in reflectance spectra of mature S-complex asteroids, consistent with an increase in npFe{supmore » 0} on the material's surface. Modeling of the effects of the addition of small amounts of npFe{sup 0} to particles from both a hypothetical mineral and a terrestrial basalt shows that evidence of the addition of 0.0001% npFe{sup 0} affects the reflectance at UV/blue wavelengths, while the addition of 0.01% is required to see the visible/near-infrared reddening and diminution of absorption features. Thus, the UV/blue reflectance characteristics allow earlier detection of the onset of space weathering effects. Combining UV/blue spectral characteristics of asteroids and ordinary chondrite meteorites with estimated ages of the young Datura family, we establish a method of dating asteroid surface ages during the early stages of space weathering. We demonstrate by dating the surface of NEA 163249 2002 GT to be 109 (±18) to 128 (±10) Kyr.« less

High-density grids for efficient data collection from multiple crystals

DOE PAGES

Baxter, Elizabeth L.; Aguila, Laura; Alonso-Mori, Roberto; ...

2015-11-03

Higher throughput methods to mount and collect data from multiple small and radiation-sensitive crystals are important to support challenging structural investigations using microfocus synchrotron beamlines. Furthermore, efficient sample-delivery methods are essential to carry out productive femtosecond crystallography experiments at X-ray free-electron laser (XFEL) sources such as the Linac Coherent Light Source (LCLS). To address these needs, a high-density sample grid useful as a scaffold for both crystal growth and diffraction data collection has been developed and utilized for efficient goniometer-based sample delivery at synchrotron and XFEL sources. A single grid contains 75 mounting ports and fits inside an SSRL cassettemore » or uni-puck storage container. The use of grids with an SSRL cassette expands the cassette capacity up to 7200 samples. Grids may also be covered with a polymer film or sleeve for efficient room-temperature data collection from multiple samples. New automated routines have been incorporated into theBlu-Ice/DCSSexperimental control system to support grids, including semi-automated grid alignment, fully automated positioning of grid ports, rastering and automated data collection. Specialized tools have been developed to support crystallization experiments on grids, including a universal adaptor, which allows grids to be filled by commercial liquid-handling robots, as well as incubation chambers, which support vapor-diffusion and lipidic cubic phase crystallization experiments. Experiments in which crystals were loaded into grids or grown on grids using liquid-handling robots and incubation chambers are described. As a result, crystals were screened at LCLS-XPP and SSRL BL12-2 at room temperature and cryogenic temperatures.« less

Rayleigh-Taylor instability experiments in cryogenic deuterium

NASA Astrophysics Data System (ADS)

Hansen, J. F.; Smalyuk, V. A.

2005-10-01

We report on experiments under way at the Omega laser, using cryogenic deuterium to study Rayleigh-Taylor instabilities in laser targets. These instabilities are important in astrophysical situations (e.g., mixing of the different shells during a supernova explosion) and in inertial fusion (during the compression stage of a fusion target). They can be studied in small (˜1 mm) shock tubes filled with one heavy and one light material, with an interface between the two materials that is machined to seed the instability. A high-energy laser (˜5 kJ) drives a shock from the heavy to the light material. The evolution of the interface is studied using gated x-ray cameras, where x-ray illumination is obtained from additional laser beams focused on metal backlighter foils. Traditionally the heavy material is CH (1 g/cm^3) doped with I or Br for improved contrast, while the light material is a low-density (˜0.1 g/cm^3) C foam. The goal of the current experiments is to determine if contrast can be improved even further by replacing the foam with cryogenic deuterium, which has a density similar to the foam, but a lower x-ray opacity allowing clearer images, including images taken at late times in the evolution. Work performed under the auspices of the Department of Energy by the Lawrence Livermore National Laboratory under contract number W-7405-ENG-48.

Tamper asymmetry and its effect on transmission for x-ray driven opacity simulations

DOE PAGES

Morris, H. E.; Tregillis, I. L.; Hoffman, N. M.; ...

2017-08-01

This paper reports on synthetic transmission results from Lasnex [1] radiation-hydrodynamics simulations of opacity experiments carried out at Sandia National Laboratories' recently upgraded ZR facility. The focus is on experiments utilizing disk targets composed of a half-moon Fe/Mg mixture tamped on either end with 10- m CH and an additional 35- m beryllium tamper accessory on the end facing the spectrometer. Five x-ray sources with peak power ranging from 10 to 24 TW were used in the simulations to heat and backlight the opacity target. The dominant effect is that the beryllium behind the Fe/Mg mixture is denser and moremore » opaque than the beryllium unshielded by metal during the times of greatest importance for the transmission measurement for all drives. This causes the simulated transmission to be lower than expected, and this is most pronounced for the case using the lowest drive power. While beryllium has a low opacity, its areal density is sufficiently high such that the expected reduction of the measured transmission is significant. This situation leads to an overestimate of iron opacity by 10-215% for a photon energy range of 975- 1775 eV for the 10-TW case. It is shown that if the tamper conditions are known, the transmission through each component of the target can be calculated and the resulting opacity can be corrected.« less

Antares Reference Telescopes System

NASA Astrophysics Data System (ADS)

Viswanathan, V. K.; Kaprelian, E.; Swann, T.; Parker, J.; Wolfe, P.; Woodfin, G.; Knight, D.

1983-11-01

Antares is a 24-beam, 40-TW carbon-dioxide laser fusion system currently nearing completion at the Los Alamos National Laboratory. The 24 beams will be focused onto a tiny target (typically 300-1000 pm in diameter) located approximately at the center of a 7.3-m diameter by 9.3-m long vacuum (10-6 torr) chamber. The design goal is to position the targets to within 10 μm of a selected nominal position, which may be anywhere within a fixed spherical region 1 cm in diameter. The Antares Reference Telescope System is intended to help achieve this goal for alignment and viewing of the various targets used in the laser system. The Antares Reference Telescope System consists of two similar electro-optical systems positioned in a near orthogonal manner in the target chamber area of the laser. Each of these consists of four subsystems: 1) a fixed 9X optical imaging subsystem which produces an image of the target at the vidicon; 2) a reticle projection subsystem which superimposes an image of the reticle pattern at the vidicon; 3) an adjustable front-lighting subsystem which illuminates tne target; and 4) an adjustable back-lighting subsystem which also can be used to illuminate the target. The various optical, mechanical, and vidicon design considerations and trade-offs are discussed. The final system chosen (which is being built) and its current status are described in detail.

Development of an imaging system for single droplet characterization using a droplet generator.

PubMed

Minov, S Vulgarakis; Cointault, F; Vangeyte, J; Pieters, J G; Hijazi, B; Nuyttens, D

2012-01-01

The spray droplets generated by agricultural nozzles play an important role in the application accuracy and efficiency of plant protection products. The limitations of the non-imaging techniques and the recent improvements in digital image acquisition and processing increased the interest in using high speed imaging techniques in pesticide spray characterisation. The goal of this study was to develop an imaging technique to evaluate the characteristics of a single spray droplet using a piezoelectric single droplet generator and a high speed imaging technique. Tests were done with different camera settings, lenses, diffusers and light sources. The experiments have shown the necessity for having a good image acquisition and processing system. Image analysis results contributed in selecting the optimal set-up for measuring droplet size and velocity which consisted of a high speed camera with a 6 micros exposure time, a microscope lens at a working distance of 43 cm resulting in a field of view of 1.0 cm x 0.8 cm and a Xenon light source without diffuser used as a backlight. For measuring macro-spray characteristics as the droplet trajectory, the spray angle and the spray shape, a Macro Video Zoom lens at a working distance of 14.3 cm with a bigger field of view of 7.5 cm x 9.5 cm in combination with a halogen spotlight with a diffuser and the high speed camera can be used.

Monochromatic x-ray radiography of laser-driven spherical targets using high-energy, picoseconds LFEX laser

NASA Astrophysics Data System (ADS)

Sawada, Hiroshi; Fujioka, S.; Lee, S.; Arikawa, Y.; Shigemori, K.; Nagatomo, H.; Nishimura, H.; Sunahara, A.; Theobald, W.; Perez, F.; Patel, P. K.; Beg, F. N.

2015-11-01

Formation of a high density fusion fuel is essential in both conventional and advanced Inertial Confinement Fusion (ICF) schemes for the self-sustaining fusion process. In cone-guided Fast Ignition (FI), a metal cone is attached to a spherical target to maintain the path for the injection of an intense short-pulse ignition laser from blow-off plasma created when nanoseconds compression lasers drive the target. We have measured a temporal evolution of a compressed deuterated carbon (CD) sphere using 4.5 keV K-alpha radiography with the Kilo-Joule, picosecond LFEX laser at the Institute of Laser Engineering. A 200 μm CD sphere attached to the tip of a Au cone was directly driven by 9 Gekko XII beams with 300 J/beam in a 1.3 ns Gaussian pulse. The LFEX laser irradiated on a Ti foil to generate 4.51 Ti K-alpha x-ray. By varying the delay between the compression and backlighter lasers, the measured radiograph images show an increase of the areal density of the imploded target. The detail of the quantitative analyses to infer the areal density and comparisons to hydrodynamics simulations will be presented. This work was performed with the support and under the auspices of the NIFS Collaboration Research program (NIFS13KUGK072). H.S. was supported by the UNR's International Activities Grant program.

AXIS: An instrument for imaging Compton radiographs using the Advanced Radiography Capability on the NIF

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

Hall, G. N., E-mail: hall98@llnl.gov; Izumi, N.; Tommasini, R.

2014-11-15

Compton radiography is an important diagnostic for Inertial Confinement Fusion (ICF), as it provides a means to measure the density and asymmetries of the DT fuel in an ICF capsule near the time of peak compression. The AXIS instrument (ARC (Advanced Radiography Capability) X-ray Imaging System) is a gated detector in development for the National Ignition Facility (NIF), and will initially be capable of recording two Compton radiographs during a single NIF shot. The principal reason for the development of AXIS is the requirement for significantly improved detection quantum efficiency (DQE) at high x-ray energies. AXIS will be the detectormore » for Compton radiography driven by the ARC laser, which will be used to produce Bremsstrahlung X-ray backlighter sources over the range of 50 keV–200 keV for this purpose. It is expected that AXIS will be capable of recording these high-energy x-rays with a DQE several times greater than other X-ray cameras at NIF, as well as providing a much larger field of view of the imploded capsule. AXIS will therefore provide an image with larger signal-to-noise that will allow the density and distribution of the compressed DT fuel to be measured with significantly greater accuracy as ICF experiments are tuned for ignition.« less

Development of new platforms for hydrodynamic instability and asymmetry measurements in deceleration phase of indirectly-driven implosions on NIF

NASA Astrophysics Data System (ADS)

Pickworth, Louisa

2017-10-01

Hydrodynamic instabilities and asymmetries are a major obstacle in the quest to achieve ignition as they cause pre-existing capsule perturbations to grow and ultimately quench the fusion burn in experiments at the National Ignition Facility (NIF). This talk will review recent developments of the experimental platforms and techniques to measure high-mode instabilities and low-mode asymmetries in the deceleration phase of implosions. These new platforms provide a natural link between the acceleration-phase experiments and neutron performance of layered deuterium-tritium implosions. In one innovative technique, self-emission from the hot spot was enhanced with argon dopant to ``self-backlight'' the shell in-flight around peak compression. Experiments with pre-imposed 2-D perturbations measured instability growth factors, while experiments with 3-D, ``native-roughness'' perturbations measured shell integrity in the deceleration phase of implosions. In a complimentary technique, the inner surface of the shell, along with its low-mode asymmetries and high-mode perturbations were visualized in implosions using x-ray emission of a high-Z dopant added to the inner surface of the capsule. These new measurements were instrumental in revealing unexpected surprises and providing improved understanding of the role of instabilities and asymmetries on implosion performance. This work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.

The Experimental Study of Rayleigh-Taylor Instability using a Linear Induction Motor Accelerator

NASA Astrophysics Data System (ADS)

Yamashita, Nicholas; Jacobs, Jeffrey

2009-11-01

The experiments to be presented utilize an incompressible system of two stratified miscible liquids of different densities that are accelerated in order to produce the Rayleigh-Taylor instability. Three liquid combinations are used: isopropyl alcohol with water, a calcium nitrate solution or a lithium polytungstate solution, giving Atwood numbers of 0.11, 0.22 and 0.57, respectively. The acceleration required to drive the instability is produced by two high-speed linear induction motors mounted to an 8 m tall drop tower. The motors are mounted in parallel and have an effective acceleration length of 1.7 m and are each capable of producing 15 kN of thrust. The liquid system is contained within a square acrylic tank with inside dimensions 76 x76x184 mm. The tank is mounted to an aluminum plate, which is driven by the motors to create constant accelerations in the range of 1-20 g's, though the potential exists for higher accelerations. Also attached to the plate are a high-speed camera and an LED backlight to provide continuous video of the instability. In addition, an accelerometer is used to provide acceleration measurements during each experiment. Experimental image sequences will be presented which show the development of a random three-dimensional instability from an unforced initial perturbation. Measurements of the mixing zone width will be compared with traditional growth models.

Ultrafast high-repetition imaging of fuel sprays using picosecond fiber laser.

PubMed

Purwar, Harsh; Wang, Hongjie; Tang, Mincheng; Idlahcen, Saïd; Rozé, Claude; Blaisot, Jean-Bernard; Godin, Thomas; Hideur, Ammar

2015-12-28

Modern diesel injectors operate at very high injection pressures of about 2000 bar resulting in injection velocities as high as 700 m/s near the nozzle outlet. In order to better predict the behavior of the atomization process at such high pressures, high-resolution spray images at high repetition rates must be recorded. However, due to extremely high velocity in the near-nozzle region, high-speed cameras fail to avoid blurring of the structures in the spray images due to their exposure time. Ultrafast imaging featuring ultra-short laser pulses to freeze the motion of the spray appears as an well suited solution to overcome this limitation. However, most commercial high-energy ultrafast sources are limited to a few kHz repetition rates. In the present work, we report the development of a custom-designed picosecond fiber laser generating ∼ 20 ps pulses with an average power of 2.5 W at a repetition rate of 8.2 MHz, suitable for high-speed imaging of high-pressure fuel jets. This fiber source has been proof tested by obtaining backlight images of diesel sprays issued from a single-orifice injector at an injection pressure of 300 bar. We observed a consequent improvement in terms of image resolution compared to standard white-light illumination. In addition, the compactness and stability against perturbations of our fiber laser system makes it particularly suitable for harsh experimental conditions.

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

Perry, Theodore Sonne; Dodd, Evan S.; DeVolder, Barbara Gloria

X-ray opacity is a crucial factor in all radiation-hydrodynamics calculations, yet it is one of the least validated of the material properties in simulation codes for high-energy-density plasmas. Recent opacity experiments at the Sandia Z-machine have shown up to factors of two discrepancies between theory and experiment for various mid-Z elements (Fe, Cr, Ni). These discrepancies raise doubts regarding the accuracy of the opacity models which are used in ICF and stewardship as well as in astrophysics. Therefore, a new experimental opacity platform has been developed on the National Ignition Facility (NIF), not only to verify the Z-machine experimental results,more » but also to extend the experiments to other temperatures and densities. Within the context of the national opacity strategy, the first NIF experiments were directed towards measuring the opacity of iron at a temperature of ~160 eV and an electron density of ~7xl021 cm-3(Anchor 1). The Z data agree with theory at these conditions, providing a reference point for validation of the NIF platform. Development shots on NIF have demonstrated the ability to create a sufficiently bright point backlighter using an imploding plastic capsule, and also a combined hohlraum, sample and laser drive able to produce iron plasmas at the desired conditions. Spectrometer qualification has been completed, albeit with additional improvements planned, and the first iron absorption spectra have now been obtained.« less

High-efficiency high-energy Ka source for the critically-required maximum illumination of x-ray optics on Z using Z-petawatt-driven laser-breakout-afterburner accelerated ultrarelativistic electrons LDRD .

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

Sefkow, Adam B.; Bennett, Guy R.

2010-09-01

Under the auspices of the Science of Extreme Environments LDRD program, a <2 year theoretical- and computational-physics study was performed (LDRD Project 130805) by Guy R Bennett (formally in Center-01600) and Adam B. Sefkow (Center-01600): To investigate novel target designs by which a short-pulse, PW-class beam could create a brighter K{alpha} x-ray source than by simple, direct-laser-irradiation of a flat foil; Direct-Foil-Irradiation (DFI). The computational studies - which are still ongoing at this writing - were performed primarily on the RedStorm supercomputer at Sandia National Laboratories Albuquerque site. The motivation for a higher efficiency K{alpha} emitter was very clear: asmore » the backlighter flux for any x-ray imaging technique on the Z accelerator increases, the signal-to-noise and signal-to-background ratios improve. This ultimately allows the imaging system to reach its full quantitative potential as a diagnostic. Depending on the particular application/experiment this would imply, for example, that the system would have reached its full design spatial resolution and thus the capability to see features that might otherwise be indiscernible with a traditional DFI-like x-ray source. This LDRD began FY09 and ended FY10.« less

Illumination design for semiconductor backlight inspection and application extensions

NASA Astrophysics Data System (ADS)

Zhou, Wei; Rutherford, Todd; Hart, Darcy

2013-09-01

High speed strobe based illumination scheme is one of the most critical factors for high throughput semiconductor defect inspection applications. HB LEDs are always the first and best options for such applications due to numerous unique advantages such as excellent spatial and temporal stability, fast responding time, large and linear intensity dynamic range and no heat issue for the extremely low duty cycle applications. For some applications where a large area is required to be illuminated simultaneously, it remains a great challenge to efficiently package a large amount of HB-LEDs in a highly confined 3D space, to generate a seamless illuminated area with high luminance efficiency and spatial uniformity. A novel 3D structured collimation lens is presented in this paper. The non-circular edge shape reduces the intensity drop at the channel boundaries, while the secondary curvatures on the top of the collimator lens efficiently guides the light into desired angular space. The number of the edges and the radius of the top surface curvature are control parameters for the system level performance and the manufacture cost trade-off. The proposed 3D structured LED collimation lens also maintains the benefits of traditional LED collimation lens such as coupling efficiency and mold manufacture capability. The applications can be extended into other non-illumination area like parallelism measurement and solar panel concentrator etc.

Preliminary display comparison for dental diagnostic applications

NASA Astrophysics Data System (ADS)

Odlum, Nicholas; Spalla, Guillaume; van Assche, Nele; Vandenberghe, Bart; Jacobs, Reinhilde; Quirynen, Marc; Marchessoux, Cédric

2012-02-01

The aim of this study is to predict the clinical performance and image quality of a display system for viewing dental images. At present, the use of dedicated medical displays is not uniform among dentists - many still view images on ordinary consumer displays. This work investigated whether the use of a medical display improved the perception of dental images by a clinician, compared to a consumer display. Display systems were simulated using the MEdical Virtual Imaging Chain (MEVIC). Images derived from two carefully performed studies on periodontal bone lesion detection and endodontic file length determination, were used. Three displays were selected: a medical grade one and two consumer displays (Barco MDRC-2120, Dell 1907FP and Dell 2007FPb). Some typical characteristics of the displays are evaluated by measurements and simulations like the Modulation Function (MTF), the Noise Power Spectrum (NPS), backlight stability or calibration. For the MTF, the display with the largest pixel pitch has logically the worst MTF. Moreover, the medical grade display has a slightly better MTF and the displays have similar NPS. The study shows the instability effect for the emitted intensity of the consumer displays compared to the medical grade one. Finally the study on the calibration methodology of the display shows that the signal in the dental images will be always more perceivable on the DICOM GSDF display than a gamma 2,2 display.

A distributed system of wireless signs using Gyricon electronic paper displays

NASA Astrophysics Data System (ADS)

Sprague, Robert A.

2006-04-01

The proliferation of digital information is leading to a wide range of applications which make it desirable to display data easily in many locations, all changeable and updateable. The difficulty in achieving such ubiquitous displays is the cost of signage, the cost of installation, and the software and systems to control the information being sent to each of these signs. In this paper we will talk about a networked system of such signs which are made from gyricon electronic paper. Gyricon electronic paper is a reflective, bistable display which can be made in large web sheets at a reasonable price. Since it does not require a backlight nor does it require power to refresh the display image, such technology is ideal for making signs which can be run on batteries with extremely long battery life, often not needing replacement for years. The display also has a very broad illumination scattering profile which makes it readily viewable from any angle. The basic operating mechanism of the display, its manufacturing technique, and achieved performance will be described, along with the description of a networked solution using many such signs controlled with system software to identify speakers and meetings in conference rooms, hospitality suites, or classrooms in universities. Systems will also be shown which are adapted to retail pricing signage and others which can be used for large format outdoor billboards.