Optics of twisted nematic and supertwisted nematic liquid-crystal displays

Science.gov (United States)

Leenhouts, F.; Schadt, M.

1986-11-01

For the first time calculations of the off-state transmission of twisted nematic liquid-crystal displays (LCD's) are presented which exhibit twist angles greater than the conventional 90 °. The transmission has been calculated using a treatment introduced by Priestley. In addition, the CIE (Commission Internationale d'Eclairage) color coordinates were evaluated which, together with the brightness, determine the optical appearance of an LCD. The finite efficiency of the polarizers was taken into account. The results are compared with those obtained for conventional 90 ° twisted nematic LCD's. From the calculations follow the conditions required to obtain optimal contrast and steep electro-optical characteristics in 180 ° supertwisted LCD's designed for high information content applications.

Supramolecular Liquid Crystal Displays Construction and Applications

OpenAIRE

Hoogboom, J.T.V.

2004-01-01

This thesis describes chemical methodologies, which can be ued to construct alignment layers for liquid crystal display purposes in a non-clean room environment, by making use of supramolecular chemistry. These techniques are subsequently used to attain control over LCD-properties, both pre- and post-LCD construction. In addition, the thesis describes the application of LCD technology in biosensors.

A liquid-crystal-on-silicon color sequential display using frame buffer pixel circuits

Science.gov (United States)

Lee, Sangrok

Next generation liquid-crystal-on-silicon (LCOS) high definition (HD) televisions and image projection displays will need to be low-cost and high quality to compete with existing systems based on digital micromirror devices (DMDs), plasma displays, and direct view liquid crystal displays. In this thesis, a novel frame buffer pixel architecture that buffers data for the next image frame while displaying the current frame, offers such a competitive solution is presented. The primary goal of the thesis is to demonstrate the LCOS microdisplay architecture for high quality image projection displays and at potentially low cost. The thesis covers four main research areas: new frame buffer pixel circuits to improve the LCOS performance, backplane architecture design and testing, liquid crystal modes for the LCOS microdisplay, and system integration and demonstration. The design requirements for the LCOS backplane with a 64 x 32 pixel array are addressed and measured electrical characteristics matches to computer simulation results. Various liquid crystal (LC) modes applicable for LCOS microdisplays and their physical properties are discussed. One- and two-dimensional director simulations are performed for the selected LC modes. Test liquid crystal cells with the selected LC modes are made and their electro-optic effects are characterized. The 64 x 32 LCOS microdisplays fabricated with the best LC mode are optically tested with interface circuitry. The characteristics of the LCOS microdisplays are summarized with the successful demonstration.

Flexoelectric effect in an in-plane switching (IPS) liquid crystal cell for low-power consumption display devices.

Science.gov (United States)

Kim, Min Su; Bos, Philip J; Kim, Dong-Woo; Yang, Deng-Ke; Lee, Joong Hee; Lee, Seung Hee

2016-10-12

Technology of displaying static images in portable displays, advertising panels and price tags pursues significant reduction in power consumption and in product cost. Driving at a low-frequency electric field in fringe-field switching (FFS) mode can be one of the efficient ways to save powers of the recent portable devices, but a serious drop of image-quality, so-called image-flickering, has been found in terms of the coupling of elastic deformation to not only quadratic dielectric effect but linear flexoelectric effect. Despite of the urgent requirement of solving the issue, understanding of such a phenomenon is yet vague. Here, we thoroughly analyze and firstly report the flexoelectric effect in in-plane switching (IPS) liquid crystal cell. The effect takes place on the area above electrodes due to splay and bend deformations of nematic liquid crystal along oblique electric fields, so that the obvious spatial shift of the optical transmittance is experimentally observed and is clearly demonstrated based on the relation between direction of flexoelectric polarization and electric field polarity. In addition, we report that the IPS mode has inherent characteristics to solve the image-flickering issue in the low-power consumption display in terms of the physical property of liquid crystal material and the electrode structure.

Viewing angle switching of patterned vertical alignment liquid crystal display

International Nuclear Information System (INIS)

Lim, Young Jin; Jeong, Eun; Chin, Mi Hyung; Lee, Seung Hee; Ji, Seunghoon; Lee, Gi-Dong

2008-01-01

Viewing angle control of a patterned vertical alignment (PVA) liquid crystal display using only one panel is investigated. In conventional PVA modes, a vertically aligned liquid crystal (LC) director tilts down in four directions making 45 deg. with respect to crossed polarizers to exhibit a wide viewing angle. In the viewing angle control device, one pixel was divided into two sub-pixels such that the LC director in the main pixel is controlled to be tilted down in multiple directions making an angle with the polarizer, playing the role of main display with the wide viewing angle, while the LC director in the sub-pixel is controlled to be tilted down to the polarizer axis, playing the role of sub-pixel to the viewing angle control for the narrow viewing angle. Using sub-pixel control, light leakage or any type of information such as characters and image can be generated in oblique viewing directions without distorting the image quality in the normal direction, which will prevent others from peeping at the displayed image by overlapping the displayed image with the made image

Active learning in optics and photonics: Liquid Crystal Display in the do-it-yourself

Science.gov (United States)

Vauderwange, Oliver; Haiss, Ulrich; Wozniak, Peter; Israel, Kai; Curticapean, Dan

2015-10-01

Monitors are in the center of media productions and hold an important function as the main visual interface. Tablets and smartphones are becoming more and more important work tools in the media industry. As an extension to our lecture contents an intensive discussion of different display technologies and its applications is taking place now. The established LCD (Liquid Crystal Display) technology and the promising OLED (Organic Light Emitting Diode) technology are in the focus. The classic LCD is currently the most important display technology. The paper will present how the students should develop sense for display technologies besides the theoretical scientific basics. The workshop focuses increasingly on the technical aspects of the display technology and has the goal of deepening the students understanding of the functionality by building simple Liquid Crystal Displays by themselves. The authors will present their experience in the field of display technologies. A mixture of theoretical and practical lectures has the goal of a deeper understanding in the field of digital color representation and display technologies. The design and development of a suitable learning environment with the required infrastructure is crucial. The main focus of this paper is on the hands-on optics workshop "Liquid Crystal Display in the do-it-yourself".

Formulation of electroclinic, ferroelectric and antiferroelectric liquid crystal mixtures suitable for display devices

Science.gov (United States)

Debnath, Asim; Goswami, Debarghya; Mandal, Pradip Kumar

2018-04-01

Most of the liquid crystal display (LCD) devices starting from simplest wrist watches or calculators to complex laptops or flat TV sets are based on nematics. Although a tremendous improvement in the quality of display as well as reduction of manufacturing cost has taken place over the years, there are many issues which the LC industry is trying hard to address. Ferroelectric liquid crystals (FLC) are of current interest in the LCD industry since among various other advantages FLC based displays have micro-second order switching compared to milli-second order switching in nematic based displays. To meet the market demand much effort has been made to optimize the physical parameters of FLCs, such as temperature range, spontaneous polarization (PS), helical pitch (p), switching time (τ), tilt angle (θ) and rotational viscosity (γ). Multicomponent mixtures are, therefore, formulated to optimize all the required properties for practical applications since no single FLC compound can satisfy the above requirements. To the best of our knowledge electroclinic, ferroelectric and antiferroelectric liquid crystal mixtures have been formulated first time by any Indian group which have properties suitable for FLC based display devices and at par with mixtures used in the industry.

Technical and radiological image quality comparison of different liquid crystal displays for radiology

Directory of Open Access Journals (Sweden)

Dams FE

2014-10-01

Full Text Available Francina EM Dams,2 KY Esther Leung,1 Pieter HM van der Valk,2 Marc CJM Kock,2 Jeroen Bosman,1 Sjoerd P Niehof1 1Medical Physics and Technology, 2Department of Radiology, Albert Schweitzer Hospital, Dordrecht, The Netherlands Background: To inform cost-effective decisions in purchasing new medical liquid crystal displays, we compared the image quality in displays made by three manufacturers. Methods: We recruited 19 radiologists and residents to compare the image quality of four liquid crystal displays, including 3-megapixel Barco®, Eizo®, and NEC® displays and a 6-megapixel Barco display. The evaluators were blinded to the manufacturers' names. Technical assessments were based on acceptance criteria and test patterns proposed by the American Association of Physicists in Medicine. Radiological assessments were performed on images from the American Association of Physicists in Medicine Task Group 18. They included X-ray images of the thorax, knee, and breast, a computed tomographic image of the thorax, and a magnetic resonance image of the brain. Image quality was scored on an analog scale (range 0–10. Statistical analysis was performed with repeated-measures analysis of variance. Results: The Barco 3-megapixel display passed all acceptance criteria. The Eizo and NEC displays passed the acceptance criteria, except for the darkest pixel value in the grayscale display function. The Barco 6-megapixel display failed criteria for the maximum luminance response and the veiling glare. Mean radiological assessment scores were 7.8±1.1 (Barco 3-megapixel, 7.8±1.2 (Eizo, 8.1±1.0 (NEC, and 8.1±1.0 (Barco 6-megapixel. No significant differences were found between displays. Conclusion: According to the tested criteria, all the displays had comparable image quality; however, there was a three-fold difference in price between the most and least expensive displays. Keywords: data display, humans, radiographic image enhancement, user-computer interface

Recycling acetic acid from polarizing film of waste liquid crystal display panels by sub/supercritical water treatments.

Science.gov (United States)

Wang, Ruixue; Chen, Ya; Xu, Zhenming

2015-05-19

Waste liquid crystal display (LCD) panels mainly contain inorganic materials (glass substrate) and organic materials (polarizing film and liquid crystal). The organic materials should be removed first since containing polarizing film and liquid crystal is to the disadvantage of the indium recycling process. In the present study, an efficient and environmentally friendly process to obtain acetic acid from waste LCD panels by sub/supercritical water treatments is investigated. Furthermore, a well-founded reaction mechanism is proposed. Several highlights of this study are summarized as follows: (i) 99.77% of organic matters are removed, which means the present technology is quite efficient to recycle the organic matters; (ii) a yield of 78.23% acetic acid, a quite important fossil energy based chemical product is obtained, which can reduce the consumption of fossil energy for producing acetic acid; (iii) supercritical water acts as an ideal solvent, a requisite reactant as well as an efficient acid-base catalyst, and this is quite significant in accordance with the "Principles of Green Chemistry". In a word, the organic matters of waste LCD panels are recycled without environmental pollution. Meanwhile, this study provides new opportunities for alternating fossil-based chemical products for sustainable development, converting "waste" into "fossil-based chemicals".

Liquid crystal true 3D displays for augmented reality applications

Science.gov (United States)

Li, Yan; Liu, Shuxin; Zhou, Pengcheng; Chen, Quanming; Su, Yikai

2018-02-01

Augmented reality (AR) technology, which integrates virtual computer-generated information into the real world scene, is believed to be the next-generation human-machine interface. However, most AR products adopt stereoscopic 3D display technique, which causes the accommodation-vergence conflict. To solve this problem, we have proposed two approaches. The first is a multi-planar volumetric display using fast switching polymer-stabilized liquid crystal (PSLC) films. By rapidly switching the films between scattering and transparent states while synchronizing with a high-speed projector, the 2D slices of a 3D volume could be displayed in time sequence. We delved into the research on developing high-performance PSLC films in both normal mode and reverse mode; moreover, we also realized the demonstration of four-depth AR images with correct accommodation cues. For the second approach, we realized a holographic AR display using digital blazed gratings and a 4f system to eliminate zero-order and higher-order noise. With a 4k liquid crystal on silicon device, we achieved a field of view (FOV) of 32 deg. Moreover, we designed a compact waveguidebased holographic 3D display. In the design, there are two holographic optical elements (HOEs), each of which functions as a diffractive grating and a Fresnel lens. Because of the grating effect, holographic 3D image light is coupled into and decoupled out of the waveguide by modifying incident angles. Because of the lens effect, the collimated zero order light is focused at a point, and got filtered out. The optical power of the second HOE also helps enlarge FOV.

Performance of NCAP projection displays

Science.gov (United States)

Jones, Philip J.; Tomita, Akira; Wartenberg, Mark

1991-08-01

Prototypes of projection displays based on dispersions of liquid crystal in polymer matrices are beginning to appear. The principle of operation depends on electrically switchable light scattering. They are potentially much brighter than current cathode ray tube (CRT) or twisted nematic liquid crystal (TN LC) cell based displays. Comparisons of efficacy and efficiency show this. The contrast and brightness of such displays depend on a combination of the f- number of the projection system and the scattering characteristics of the light valve. Simplified equations can be derived to show these effects. The degree of scattering of current NCAP formulations is sufficient to produce good contrast projection displays, at convenient voltages, that are around three times brighter than TN LC projectors because of the lack of polarizers in the former.

Value Recovery from Waste Liquid Crystal Display Glass Cullet through Leaching: Understanding the Correlation between Indium Leaching Behavior and Cullet Piece Size

OpenAIRE

Basudev Swain; Chan Gi Lee; Hyun Seon Hong

2018-01-01

For hydrometallurgical recovery of indium from glass cullet after dismantling a waste liquid crystal display (LCD), leaching is the rudimentary stage. Though size reduction of the cullet pieces adds convenience for recycling, from an efficiency and cost-effectiveness perspective regarding leaching process development, determining the proper cullet piece size is essential. Hence, in this study, leaching efficiency of indium as a function of cullet piece size was investigated, wherein the prope...

Color Gamut of a Nematic Liquid Crystal Display

Science.gov (United States)

Shimomura, Teruo; Mada, Hitoshi; Kobayashi, Shunsuke

1980-05-01

The theoretical color gamut of a nematic liquid crystal display is described. The color gamut of a tunable birefringence mode and a guest host mode are revealed with the CIE chromaticity diagram and color solid. In order to account for the quantitative color gamut, color matching between the given chromaticity coordinates and those calculated is investigated. Color matching is performed by a combination of three liquid crystal subcells (A, B, C), where each subcell receives the voltage VA, VB, VC or contains the dye amount a, b, c. Calculation of the value of voltage or dye amount was executed by the matrix representation method. The calculated data are in good agreement with the given data within 0.50 CIE-UNIT color difference in the 1964 CIE (U*, V*, W*) color scale.

Electro-Optical Characterization of Bistable Smectic A Liquid Crystal Displays

Science.gov (United States)

Buyuktanir, Ebru Aylin

My dissertation focuses the characterization and optimization of the electro-optical properties of smectic A (SmA) based liquid crystal (LC) displays. I present the development of robust and flexible bistable SmA LC displays utilizing polymer dispersed liquid crystal (PDLC) technology. The SmA PDLC displays produced on plastic substrates present electrically reversible memory, high contrast ratio, paper-like sunlight readability, and wide viewing angle characteristics. In order to optimize the SmA PDLC display, I investigated polymerization conditions, such as polymer concentration effect, polymerization temperature, and UV-light intensity variations. I characterized the electro-optical responses-such as static-response, time-response, threshold characteristics, and contrast ratio values' of the optimized SmA PDLC display and compared them to those of the pure SmA LC. The best electro-optical performance of SmA PDLC formulation was obtained using the combination of low mW/cm 2 and high mW/cm2 UV-light curing intensity. The contrast ratio of the optimum SmA PDLC at a 5o collection angle was 83% of that of the pure SmA material on plastic substrates. I fabricated 2.5 x 2.5 in., 4 x 4 in., and 6 x 6 in. sized monochrome flexible SmA PDLC displays, as well as red, yellow, and fluorescent dyes colored SmA PDLC displays on plastic substrates. The electro-optic performance of the bistable SmA LC display consisting of a patterned field-induced polymer wall infrastructure was also studied and compared to those of pure SmA material. I found that the contrast ratio of the SmA LC encapsulated between polymer walls was much greater than that of the SmA PDLC system, approaching the contrast ratio value of the pure SmA material. I also improved the electro-optical characteristics of bistable SmA LC displays by adding ferroparticles into the system. Finally, I illustrated the unique capabilities of polarized confocal Raman microscopy (CRM) to resolve the orientational order of Sm

[Application of the grayscale standard display function to general purpose liquid-crystal display monitors for clinical use].

Science.gov (United States)

Tanaka, Nobukazu; Naka, Kentaro; Sueoka, Masaki; Higashida, Yoshiharu; Morishita, Junji

2010-01-20

Interpretations of medical images have been shifting to soft-copy readings with liquid-crystal display (LCD) monitors. The display function of the medical-grade LCD monitor for soft-copy readings is recommended to calibrate the grayscale standard display function (GSDF) in accordance with the guidelines of Japan and other countries. In this study, the luminance and display function of five models of eight general purpose LCD monitors were measured to gain an understanding of their characteristics. Moreover, the display function (gamma 2.2 or gamma 1.8) of general purpose LCD monitors was converted to GSDF through the use of a look-up table, and the detectability of a simulated lung nodule in the chest x-ray image was examined. As a result, the maximum luminance, contrast ratio, and luminance uniformity of general purpose LCD monitors, except for one model of two LCD monitors, met the management grade 1 standard in the guideline JESRA X-0093-2005. In addition, the detectability of simulated lung nodule in the mediastinal space was obviously improved by converting the display function of a general purpose LCD monitor into GSDF.

A single-gap transflective fringe field switching display using a liquid crystal with positive dielectric anisotropy

International Nuclear Information System (INIS)

Lim, Young Jin; Lee, Myong-Hoon; Lee, Gi-Dong; Jang, Won-Gun; Lee, Seung Hee

2007-01-01

There is considerable difficulty in fabricating a reflector with embossing in an array substrate using a conventional single gap transflective fringe-field switching nematic liquid-crystal display. In order to solve this problem, we propose a new structure, which consists of a reflector on a colour filter substrate. The newly proposed structure with a complex field direction has problems such that the voltage-dependent transmittance and reflectance curves do not match each other, which necessitate a dual driving circuit. This paper reports the optimized electrode structure and calculated electro-optical results realizing a single gamma curve and high light efficiency

A novel composite alignment layer for transflective liquid crystal display

Energy Technology Data Exchange (ETDEWEB)

Li Shuangyao; Li Xuan [State Key Laboratory of Applied Optics, Changchun Institute of Optics, Fine mechanics and Physics, Chinese Academy of Sciences, Changchun 130033 (China); Tao Du; Chigrinov, Vladimir; Kwok, Hoi Sing, E-mail: eechigr@ust.h [Center for Display Research, Department of Electronic and Computer Engineering, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon (Hong Kong)

2010-10-20

A novel composite photoalignment layer for transflective liquid crystal displays is explored. The key technique is to introduce a functional photo-crosslinkage into a rewritable azodye material with proper mixing. Bearing good alignment quality derived from the azodye material, the composite layer provides strong azimuthal and polar anchoring energy comparable to that of rubbed polyimide layers. The capability of dual modes fabrication in one cell exhibited by azodyes could be well retained and the new alignment film exhibits a display resolution of up to 2 {mu}m. Furthermore, after exposure to strong LED unpolarized light the composite layer shows much better stability than that with a pure azodye material.

A novel composite alignment layer for transflective liquid crystal display

International Nuclear Information System (INIS)

Li Shuangyao; Li Xuan; Tao Du; Chigrinov, Vladimir; Kwok, Hoi Sing

2010-01-01

A novel composite photoalignment layer for transflective liquid crystal displays is explored. The key technique is to introduce a functional photo-crosslinkage into a rewritable azodye material with proper mixing. Bearing good alignment quality derived from the azodye material, the composite layer provides strong azimuthal and polar anchoring energy comparable to that of rubbed polyimide layers. The capability of dual modes fabrication in one cell exhibited by azodyes could be well retained and the new alignment film exhibits a display resolution of up to 2 μm. Furthermore, after exposure to strong LED unpolarized light the composite layer shows much better stability than that with a pure azodye material.

Efficient, deep-blue TADF-emitters for OLED display applications (Conference Presentation)

Science.gov (United States)

Volz, Daniel; Baumann, Thomas

2016-09-01

Currently, the mobile display market is strongly shifting towards AMOLED technology, in order to enable curved and flexible displays. This leads to a growing demand for highly efficient OLED emitters to reduce the power consumption and increase display resolution at the same time. While highly efficient green and red OLEDs already found their place in commercial OLED-displays, the lack of efficient blue emitters is still an issue. Consequently, the active area for blue is considerably larger than for green and red pixels, to make up for the lower efficiency. We intend to close this efficiency-gap with novel emitters based on thermally activated delayed fluorescence (TADF) technology. Compared to state-of-the-art fluorescent dopants, the efficiency of TADF-emitters is up to four times higher. At the same time, it is possible to design them in a way to maintain deep blue emission, i.e. CIE y < 0.2. These aspects are relevant to produce efficient high resolution AMOLED displays. Apart from these direct customer benefits, our TADF technology does not contain any rare elements, which allows for the fabrication of sustainable OLED technology. In this work, we highlight one of our recently developed blue TADF materials. Basic material properties as well as first device results are discussed. In a bottom-emitting device, a CIEx/CIEy coordinate of (0.16/0.17) was achieved with efficiency values close to 20% EQE.

Loop-mirror laser neural network using a fast liquid-crystal display

NARCIS (Netherlands)

Mos, E.C.; Schleipen, J.J.H.B.; Waardt, de H.; Khoe, G.D.

1999-01-01

In our laser neural network (LNN) all-optical threshold action is obtained by application of controlled optical feedback to a laser diode. Here an extended experimental LNN is presented with as many as 32 neurons and 12 inputs. In the setup we use a fast liquid-crystal display to implement an

Psychophysical analysis of monitor display functions affecting observer diagnostic performance of CT image on liquid crystal display monitors

International Nuclear Information System (INIS)

Yamaguchi, M.; Fujita, H.; Asai, Y.; Uemura, M.; Ookura, Y.; Matsumoto, M.; Johkoh, T.

2005-01-01

The aim of the present study was to propose suitable display functions for CT image representation on liquid crystal display (LCD) monitors by analyzing the characteristics of the monitor's typical display functions using psychophysical analysis. The luminance of the LCD monitor was adjusted to a maximum of 275 cd/m 2 and 480 cd/m 2 . Three types of postcalibrated display functions (i.e., GSDF, CIELAB, and Exponential γ 2.2) were evaluated. Luminance calculation of a new grayscale test pattern (NGTP) was done for the conversion of the digital driving level (DDL) into the CT value. The psychophysical gradient δ of display functions for the CT value was evaluated and compared via statistical analysis. The δ value of GSDF and CIE decreased exponentially; however, the δ value of Exponential γ 2.2 showed a convex curve with a peak at a specific point. There was a statistically significant difference among the δ values of the three types of display functions on the 480 cd/m 2 maximum via Kruskal Wallis test (P<0.001). The GSDF was suitable for observation of abdominal and lung CT images; however, the display function combined the Exponential γ 2.2 and the GSDF functions and was ideal for observation of brain CT images by psychophysical analysis. (orig.)

Prize for Industrial Applications of Physics: Reflective Cholesteric Liquid Crystals - Innovations in Materials, Display Technology, and Commercialization

Science.gov (United States)

Khan, Asad

Reflective Cholesteric Liquid Crystals have been the subject of much research, development, and commercialization - in display technology as well as other embodiments, such as sensors, privacy films, etc. The liquid Crystal Institute (LCI) at Kent State University (KSU) served as a hot bed of much of the research and development in this field in the early 1990's. From here, the reflective technology was licensed to Kent Displays (KDI) to further develop and commercialize. The 90's saw some development in flexible technologies, drive scheme, display design, as well as materials. The early part of the century took a turn with a strong effort in encapsulation based flexible display development. In 2006, KDI engineers and technologists started firming up ambitious plans for the world's first roll-to-roll manufacturing line for bistable cholesteric displays. In 2009, this became a reality! In early 2010, the first eWriter product was launched into the consumer market under the brand Boogie Board®. Within months, this became a success forcing the rapid development of the manufacturing process for the flexible displays. Today, the company has two manufacturing lines, 24 hour roll-to-roll production of flexible displays, millions of Boogie Board products in the global market place, and a growing OEM business in the Boogie Board technology. KDI continues to do basic research, development, and exploration in the bistable display field. It also has had to become an expert in the supply chain management of the unique raw materials needed for flexible display manufacturing, while still managing global operations with sales offices in several continents and a growing and diversified group of individuals. In this presentation, we will present the story, research, development, technology, and latest trends in bistable cholesteric liquid crystal materials with a particular emphasis on the eWriter technology and market.

Efficient green lasers for high-resolution scanning micro-projector displays

Science.gov (United States)

Bhatia, Vikram; Bauco, Anthony S.; Oubei, Hassan M.; Loeber, David A. S.

2010-02-01

Laser-based projectors are gaining increased acceptance in mobile device market due to their low power consumption, superior image quality and small size. The basic configuration of such micro-projectors is a miniature mirror that creates an image by raster scanning the collinear red, blue and green laser beams that are individually modulated on a pixel-bypixel basis. The image resolution of these displays can be limited by the modulation bandwidth of the laser sources, and the modulation speed of the green laser has been one of the key limitations in the development of these displays. We will discuss how this limitation is fundamental to the architecture of many laser designs and then present a green laser configuration which overcomes these difficulties. In this green laser architecture infra-red light from a distributed Bragg-reflector (DBR) laser diode undergoes conversion to green light in a waveguided second harmonic generator (SHG) crystal. The direct doubling in a single pass through the SHG crystal allows the device to operate at the large modulation bandwidth of the DBR laser. We demonstrate that the resultant product has a small footprint (9% electrical-to-optical conversion) and large modulation bandwidth (>100 MHz).

Polymer Dispersed Liquid Crystal Displays

Science.gov (United States)

Doane, J. William

The following sections are included: * INTRODUCTION AND HISTORICAL DEVELOPMENT * PDLC MATERIALS PREPARATION * Polymerization induced phase separation (PIPS) * Thermally induced phase separation (TIPS) * Solvent induced phase separation (SIPS) * Encapsulation (NCAP) * RESPONSE VOLTAGE * Dielectric and resistive effects * Radial configuration * Bipolar configuration * Other director configurations * RESPONSE TIME * DISPLAY CONTRAST * Light scattering and index matching * Incorporation of dyes * Contrast measurements * PDLC DISPLAY DEVICES AND INNOVATIONS * Reflective direct view displays * Large-scale, flexible displays * Switchable windows * Projection displays * High definition spatial light modulator * Haze-free PDLC shutters: wide angle view displays * ENVIRONMENTAL STABILITY * ACKNOWLEDGEMENTS * REFERENCES

Efficient identification of phosphatidylserine-binding proteins by ORF phage display

International Nuclear Information System (INIS)

Caberoy, Nora B.; Zhou, Yixiong; Alvarado, Gabriela; Fan, Xianqun; Li, Wei

2009-01-01

To efficiently elucidate the biological roles of phosphatidylserine (PS), we developed open-reading-frame (ORF) phage display to identify PS-binding proteins. The procedure of phage panning was optimized with a phage clone expressing MFG-E8, a well-known PS-binding protein. Three rounds of phage panning with ORF phage display cDNA library resulted in ∼300-fold enrichment in PS-binding activity. A total of 17 PS-binding phage clones were identified. Unlike phage display with conventional cDNA libraries, all 17 PS-binding clones were ORFs encoding 13 real proteins. Sequence analysis revealed that all identified PS-specific phage clones had dimeric basic amino acid residues. GST fusion proteins were expressed for 3 PS-binding proteins and verified for their binding activity to PS liposomes, but not phosphatidylcholine liposomes. These results elucidated previously unknown PS-binding proteins and demonstrated that ORF phage display is a versatile technology capable of efficiently identifying binding proteins for non-protein molecules like PS.

Current progress and technical challenges of flexible liquid crystal displays

Science.gov (United States)

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.

Investigation of Energy-Efficient Supermarket Display Cases

Energy Technology Data Exchange (ETDEWEB)

Walker, D.H.

2005-01-21

contributing about 3/4 of that fraction. Consequently, the focus of this investigation has tilted toward the open, vertical, multi-deck medium temperature case type. Various technologies and control methods are energy efficiency measures (EEMs) that could be applied to display cases and result in the reduction of the refrigeration load and of the energy consumption of the supermarket refrigeration system. An extensive evaluation of the EEMs was conducted in order to select those that met the following criteria: (1) Near-term implementation--All EEMs considered could be implemented with existing refrigeration hardware and technology. (2) Potential for energy-efficiency improvements--Energy savings and/or refrigeration load reduction must be obtained by the implementation of the EEM. (3) Enhancement of the ability to maintain target product temperature--Proper operation of the display case and maintenance of the stored product temperature could not be compromised by the use of the EEM. The energy impact of a number of viable display case EEMs was quantified by performing whole building hourly simulations. A special version of the U.S. Department of Energy's (DOE-2.3) program was used to develop a model of a supermarket. The model was then calibrated using available end-use monitored data to increase confidence in simulation results.

An efficient spectral crystal plasticity solver for GPU architectures

Science.gov (United States)

Malahe, Michael

2018-03-01

We present a spectral crystal plasticity (CP) solver for graphics processing unit (GPU) architectures that achieves a tenfold increase in efficiency over prior GPU solvers. The approach makes use of a database containing a spectral decomposition of CP simulations performed using a conventional iterative solver over a parameter space of crystal orientations and applied velocity gradients. The key improvements in efficiency come from reducing global memory transactions, exposing more instruction-level parallelism, reducing integer instructions and performing fast range reductions on trigonometric arguments. The scheme also makes more efficient use of memory than prior work, allowing for larger problems to be solved on a single GPU. We illustrate these improvements with a simulation of 390 million crystal grains on a consumer-grade GPU, which executes at a rate of 2.72 s per strain step.

JTEC panel on display technologies in Japan

Science.gov (United States)

Tannas, Lawrence E., Jr.; Glenn, William E.; Credelle, Thomas; Doane, J. William; Firester, Arthur H.; Thompson, Malcolm

1992-01-01

This report is one in a series of reports that describes research and development efforts in Japan in the area of display technologies. The following are included in this report: flat panel displays (technical findings, liquid crystal display development and production, large flat panel displays (FPD's), electroluminescent displays and plasma panels, infrastructure in Japan's FPD industry, market and projected sales, and new a-Si active matrix liquid crystal display (AMLCD) factory); materials for flat panel displays (liquid crystal materials, and light-emissive display materials); manufacturing and infrastructure of active matrix liquid crystal displays (manufacturing logistics and equipment); passive matrix liquid crystal displays (LCD basics, twisted nematics LCD's, supertwisted nematic LCD's, ferroelectric LCD's, and a comparison of passive matrix LCD technology); active matrix technology (basic active matrix technology, investment environment, amorphous silicon, polysilicon, and commercial products and prototypes); and projection displays (comparison of Japanese and U.S. display research, and technical evaluation of work).

Anti-Solvent Crystallization Strategies for Highly Efficient Perovskite Solar Cells

Directory of Open Access Journals (Sweden)

Maria Konstantakou

2017-09-01

Full Text Available Solution-processed organic-inorganic halide perovskites are currently established as the hottest area of interest in the world of photovoltaics, ensuring low manufacturing cost and high conversion efficiencies. Even though various fabrication/deposition approaches and device architectures have been tested, researchers quickly realized that the key for the excellent solar cell operation was the quality of the crystallization of the perovskite film, employed to assure efficient photogeneration of carriers, charge separation and transport of the separated carriers at the contacts. One of the most typical methods in chemistry to crystallize a material is anti-solvent precipitation. Indeed, this classical precipitation method worked really well for the growth of single crystals of perovskite. Fortunately, the method was also effective for the preparation of perovskite films by adopting an anti-solvent dripping technique during spin-coating the perovskite precursor solution on the substrate. With this, polycrystalline perovskite films with pure and stable crystal phases accompanied with excellent surface coverage were prepared, leading to highly reproducible efficiencies close to 22%. In this review, we discuss recent results on highly efficient solar cells, obtained by the anti-solvent dripping method, always in the presence of Lewis base adducts of lead(II iodide. We present all the anti-solvents that can be used and what is the impact of them on device efficiencies. Finally, we analyze the critical challenges that currently limit the efficacy/reproducibility of this crystallization method and propose prospects for future directions.

Plastic substrates for active matrix liquid crystal display incapable of withstanding processing temperature of over 200 C and method of fabrication

Energy Technology Data Exchange (ETDEWEB)

Carey, P.G.; Smith, P.M.; Havens, J.H.; Jones, P.

1999-01-05

Bright-polarizer-free, active-matrix liquid crystal displays (AMLCDs) are formed on plastic substrates. The primary components of the display are a pixel circuit fabricated on one plastic substrate, an intervening liquid-crystal material, and a counter electrode on a second plastic substrate. The-pixel circuit contains one or more thin-film transistors (TFTs) and either a transparent or reflective pixel electrode manufactured at sufficiently low temperatures to avoid damage to the plastic substrate. Fabrication of the TFTs can be carried out at temperatures less than 100 C. The liquid crystal material is a commercially made nematic curvilinear aligned phase (NCAP) film. The counter electrode is comprised of a plastic substrate coated with a transparent conductor, such as indium-doped tin oxide (ITO). By coupling the active matrix with NCAP, a high-information content can be provided in a bright, fully plastic package. Applications include any low cost portable electronics containing flat displays where ruggedization of the display is desired. 12 figs.

Towards an optimal model for a bistable nematic liquid crystal display device

KAUST Repository

Cummings, L. J.

2013-03-13

Bistable liquid crystal displays offer the potential for considerable power savings compared with conventional (monostable) LCDs. The existence of two stable field-free states that are optically distinct means that contrast can be maintained in a display without an externally applied electric field. An applied field is required only to switch the device from one state to the other, as needed. In this paper we examine a theoretical model of a possible bistable device, originally proposed by Cummings and Richardson (Euro J Appl Math 17:435-463 2006), and explore means by which it may be optimized, in terms of optical contrast, manufacturing considerations, switching field strength, and switching times. The compromises inherent in these conflicting design criteria are discussed. © 2013 Springer Science+Business Media Dordrecht.

NCAP projection displays

Science.gov (United States)

Havens, John R.; Ishioka, J.; Jones, Philip J.; Lau, Aldrich; Tomita, Akira; Asano, A.; Konuma, Nobuhiro; Sato, Kazuhiko; Takemoto, Iwao

1997-05-01

Projectors based on polymer-eNCAPsulated liquid crystals can provide bright displays suitable for use in conference rooms with normal lighting. Contrast is generated by light scattering among the droplets, rather than by light absorption with crossed polarizers. We have demonstrated a full-color, compact projector showing 1200 ANSI lumens with 200 watts of lamp power - a light efficiency of 6 lumens/watt. This projector is based on low-voltage NCAP material, highly reflective CMOS die, and matched illumination and projection optics. We will review each of these areas and discuss the integrated system performance.

Modeling the Color Image and Video Quality on Liquid Crystal Displays with Backlight Dimming

DEFF Research Database (Denmark)

Korhonen, Jari; Mantel, Claire; Burini, Nino

2013-01-01

Objective image and video quality metrics focus mostly on the digital representation of the signal. However, the display characteristics are also essential for the overall Quality of Experience (QoE). In this paper, we use a model of a backlight dimming system for Liquid Crystal Display (LCD......) and show how the modeled image can be used as an input to quality assessment algorithms. For quality assessment, we propose an image quality metric, based on Peak Signal-to-Noise Ratio (PSNR) computation in the CIE L*a*b* color space. The metric takes luminance reduction, color distortion and loss...

Plastic substrates for active matrix liquid crystal display incapable of withstanding processing temperature of over 200.degree. C and method of fabrication

Energy Technology Data Exchange (ETDEWEB)

Carey, Paul G. (Mountain View, CA); Smith, Patrick M. (San Ramon, CA); Havens, John (San Diego, CA); Jones, Phil (Marlborough, GB)

1999-01-01

Bright-polarizer-free, active-matrix liquid crystal displays (AMLCDs) are formed on plastic substrates. The primary components of the display are a pixel circuit fabricated on one plastic substrate, an intervening liquid-crystal material, and a counter electrode on a second plastic substrate. The-pixel circuit contains one or more thin-film transistors (TFTs) and either a transparent or reflective pixel electrode manufactured at sufficiently low temperatures to avoid damage to the plastic substrate. Fabrication of the TFTs can be carried out at temperatures less than 100.degree. C. The liquid crystal material is a commercially made nematic curvilinear aligned phase (NCAP) film. The counter electrode is comprised of a plastic substrate coated with a transparent conductor, such as indium-doped tin oxide (ITO). By coupling the active matrix with NCAP, a high-information content can be provided in a bright, fully plastic package. Applications include any low cost portable electronics containing flat displays where ruggedization of the display is desired.

Highly efficient single-pass sum frequency generation by cascaded nonlinear crystals

DEFF Research Database (Denmark)

Hansen, Anders Kragh; Andersen, Peter E.; Jensen, Ole Bjarlin

2015-01-01

, despite differences in the phase relations of the involved fields. An unprecedented 5.5 W of continuous-wave diffraction-limited green light is generated from the single-pass sum frequency mixing of two diode lasers in two periodically poled nonlinear crystals (conversion efficiency 50%). The technique......The cascading of nonlinear crystals has been established as a simple method to greatly increase the conversion efficiency of single-pass second-harmonic generation compared to a single-crystal scheme. Here, we show for the first time that the technique can be extended to sum frequency generation...... is generally applicable and can be applied to any combination of fundamental wavelengths and nonlinear crystals....

Corelli: Efficient single crystal diffraction with elastic discrimination

Indian Academy of Sciences (India)

Here, we discuss the potential of the cross-correlation technique for efficient measurement of single crystal diffuse scattering with energy discrimination, as will be implemented in a novel instrument, Corelli. Utilizing full experiment simulations, we show that this technique readily leads up to a fifty-fold gain in efficiency, ...

Improved power conversion efficiency of dye-sensitized solar cells using side chain liquid crystal polymer embedded in polymer electrolytes

Energy Technology Data Exchange (ETDEWEB)

Cho, Woosum [Department of Chemistry Education, and Department of Frontier Materials Chemistry, and Institute for Plastic Information and Energy Materials, Pusan National University, Busan 609-735 (Korea, Republic of); Lee, Jae Wook, E-mail: jlee@donga.ac.kr [Department of Chemistry, Dong-A University, Busan 604-714 (Korea, Republic of); Gal, Yeong-Soon [Polymer Chemistry Lab, College of General Education, Kyungil University, Hayang 712-701 (Korea, Republic of); Kim, Mi-Ra, E-mail: mrkim2@pusan.ac.kr [Department of Polymer Science and Engineering, Pusan National University, Busan 609-735 (Korea, Republic of); Jin, Sung Ho, E-mail: shjin@pusan.ac.kr [Department of Chemistry Education, and Department of Frontier Materials Chemistry, and Institute for Plastic Information and Energy Materials, Pusan National University, Busan 609-735 (Korea, Republic of)

2014-02-14

Side chain liquid crystal polymer (SCLCP) embedded in poly(vinylidenefluoride-co-hexafluoropropylene) (PVdF-co-HFP)-based polymer electrolytes (PVdF-co-HFP:side chain liquid crystal polymer (SCLCP)) was prepared for dye-sensitized solar cell (DSSC) application. The polymer electrolytes contained tetrabutylammonium iodide (TBAI), iodine (I{sub 2}), and 8 wt% PVdF-co-HFP in acetonitrile. DSSCs comprised of PVdF-co-HFP:SCLCP-based polymer electrolytes displayed enhanced redox couple reduction and reduced charge recombination in comparison to those of the conventional PVdF-co-HFP-based polymer electrolyte. The significantly increased short-circuit current density (J{sub sc}, 10.75 mA cm{sup −2}) of the DSSCs with PVdF-co-HFP:SCLCP-based polymer electrolytes afforded a high power conversion efficiency (PCE) of 5.32% and a fill factor (FF) of 0.64 under standard light intensity of 100 mW cm{sup −2} irradiation of AM 1.5 sunlight. - Highlights: • We developed the liquid crystal polymer embedded on polymer electrolyte for DSSCs. • We fabricated the highly efficient DSSCs using polymer electrolyte. • The best PCE achieved for P1 is 5.32% using polymer electrolyte.

Improved power conversion efficiency of dye-sensitized solar cells using side chain liquid crystal polymer embedded in polymer electrolytes

International Nuclear Information System (INIS)

Cho, Woosum; Lee, Jae Wook; Gal, Yeong-Soon; Kim, Mi-Ra; Jin, Sung Ho

2014-01-01

Side chain liquid crystal polymer (SCLCP) embedded in poly(vinylidenefluoride-co-hexafluoropropylene) (PVdF-co-HFP)-based polymer electrolytes (PVdF-co-HFP:side chain liquid crystal polymer (SCLCP)) was prepared for dye-sensitized solar cell (DSSC) application. The polymer electrolytes contained tetrabutylammonium iodide (TBAI), iodine (I 2 ), and 8 wt% PVdF-co-HFP in acetonitrile. DSSCs comprised of PVdF-co-HFP:SCLCP-based polymer electrolytes displayed enhanced redox couple reduction and reduced charge recombination in comparison to those of the conventional PVdF-co-HFP-based polymer electrolyte. The significantly increased short-circuit current density (J sc , 10.75 mA cm −2 ) of the DSSCs with PVdF-co-HFP:SCLCP-based polymer electrolytes afforded a high power conversion efficiency (PCE) of 5.32% and a fill factor (FF) of 0.64 under standard light intensity of 100 mW cm −2 irradiation of AM 1.5 sunlight. - Highlights: • We developed the liquid crystal polymer embedded on polymer electrolyte for DSSCs. • We fabricated the highly efficient DSSCs using polymer electrolyte. • The best PCE achieved for P1 is 5.32% using polymer electrolyte

Uniform LED illuminator for miniature displays

Science.gov (United States)

Medvedev, Vladimir; Pelka, David G.; Parkyn, William A.

1998-10-01

The Total Internally Reflecting (TIR) lens is a faceted structure composed of prismatic elements that collect a source's light over a much larger angular range than a conventional Fresnel lens. It has been successfully applied to the efficient collimation of light from incandescent and fluorescent lamps, and from light-emitting diodes (LEDs). A novel LED-powered collimating backlight is presented here, for uniformly illuminating 0.25'-diagonal miniature liquid- crystal displays, which are a burgeoning market for pagers, cellular phones, digital cameras, camcorders, and virtual- reality displays. The backlight lens consists of a central dual-asphere refracting section and an outer TIR section, properly curved with a curved exit face.

Liquid crystal displays with plastic substrates

Science.gov (United States)

Lueder, Ernst H.

1998-04-01

Plastic substrates for the cells of displays exhibit only 1/6 of the weight of glass substrates; they are virtually unbreakable; their flexibility allows the designer to give them a shape suppressing reflections, to realize a display board on a curved surface or meeting the requirements for an appealing styling; displays with plastics are thinner which provides a wider viewing angle. These features render them attractive for displays in portable systems such as mobile phones, pagers, smart cards, personal digital assistants (PDAs) and portable computers. Reflective displays are especially attractive as they don't need a back light. The most important requirements are the protection of plastics against gas permeation and chemical agents, the prevention of layers on plastics to crack or peel off when the plastic is bent and the development of low temperature thin film processes because the plastics, as a rule, only tolerate temperatures below 150 degrees Celsius. Bistable reflective FLC- and PSCT-displays with plastic substrates will be introduced. Special sputtered SiO2-orientation layers preserve the displayed information even if pressure or torsion is applied. MIM-addressed PDLC-displays require additional Al- or Ti-layers which provide the necessary ductility. Sputtered or PECVD-generated TFTs can be fabricated on plastics at temperatures below 150 degrees Celsius.

Flat panel display - Impurity doping technology for flat panel displays

Energy Technology Data Exchange (ETDEWEB)

Suzuki, Toshiharu [Advanced Technology Planning, Sumitomo Eaton Nova Corporation, SBS Tower 9F, 10-1, Yoga 4-chome, Setagaya-ku, 158-0097 Tokyo (Japan)]. E-mail: suzuki_tsh@senova.co.jp

2005-08-01

Features of the flat panel displays (FPDs) such as liquid crystal display (LCD) and organic light emitting diode (OLED) display, etc. using low temperature poly-Si (LTPS) thin film transistors (TFTs) are briefly reviewed comparing with other FPDs. The requirements for fabricating TFTs used for high performance FPDs and system on glass (SoG) are addressed. This paper focuses on the impurity doping technology, which is one of the key technologies together with crystallization by laser annealing, formation of high quality gate insulator and gate-insulator/poly-Si interface. The issues to be solved in impurity doping technology for state of the art and future TFTs are clarified.

Flat panel display - Impurity doping technology for flat panel displays

International Nuclear Information System (INIS)

Suzuki, Toshiharu

2005-01-01

Features of the flat panel displays (FPDs) such as liquid crystal display (LCD) and organic light emitting diode (OLED) display, etc. using low temperature poly-Si (LTPS) thin film transistors (TFTs) are briefly reviewed comparing with other FPDs. The requirements for fabricating TFTs used for high performance FPDs and system on glass (SoG) are addressed. This paper focuses on the impurity doping technology, which is one of the key technologies together with crystallization by laser annealing, formation of high quality gate insulator and gate-insulator/poly-Si interface. The issues to be solved in impurity doping technology for state of the art and future TFTs are clarified

Efficient terahertz wave generation from GaP crystals pumped by chirp-controlled pulses from femtosecond photonic crystal fiber amplifier

International Nuclear Information System (INIS)

Li, Jiang; Shi, Junkai; Xu, Baozhong; Xing, Qirong; Wang, Chingyue; Chai, Lu; Liu, Bowen; Hu, Minglie; Li, Yanfeng; Fedotov, Andrey B.; Zheltikov, Aleksei M.

2014-01-01

A chirp-tunable femtosecond 10 W, 42 MHz photonic-crystal-fiber oscillator-amplifier system that is capable of delivering sub-60 fs light pulses at 1040 nm is used to demonstrate high-efficiency terahertz radiation generation via optical rectification in GaP crystals only a few millimeters in length. The optimization of the chirp of the fiber-laser pulses is shown to radically enhance the terahertz output, indicating one possible way to more efficiently use these extended nonlinear crystals in compact fiber-pumped terahertz radiation sources

Error diffusion applied to the manipulation of liquid-crystal display subpixels

Science.gov (United States)

Dallas, William J.; Fan, Jiahua; Roehrig, Hans; Krupinski, Elizabeth A.

2004-05-01

Flat-panel displays based on liquid crystal technology are becoming widely used in the medical imaging arena. Despite the impressive capabilities of presently-existing panels, some medical images push their boundaries. We are working with mammograms that contain up to 4800 x 6400 14-bit pixels. Stated differently, these images contain 30 mega-pixels each. In the standard environment, for film viewing, the mammograms are hung four-up, i.e. four images are located side by side. Because many of the LCD panels used for monochrome display of medical images are based on color models, the pixels of the panels are divided into sub-pixels. These sub-pixels vary in their numbers and in the degrees of independence. Manufacturers have used both spatial and temporal modulation of these sub-pixels to improve the quality of images presented by the monitors. In this presentation we show how the sub-pixel structure of some present and future displays can be used to attain higher spatial resolution than the full-pixel resolution specification would suggest while also providing increased contrast resolution. The error diffusion methods we discuss provide a natural way of controlling sub-pixels and implementing trade-offs. In smooth regions of the image contrast resolution can maximized. In rapidly-varying regions of the image spatial resolution can be favored.

Volume reflection efficiency for negative particles in bent crystals

Energy Technology Data Exchange (ETDEWEB)

Biryukov, V.M., E-mail: valery.biryukov@ihep.ru

2017-02-10

We suggest a formula for the efficiency of a single volume reflection of negatively charged particles in bent crystal planes and compare it to recent experiments at SLAC, MAMI and CERN with electrons and negative pions in the energy range from 0.855 to 150 GeV in Si crystals. We show that Lindhard reversibility rule provides sufficient basis for quantitative understanding of these experiments.

Microencapsulated Electrophoretic Films for Electronic Paper Displays

Science.gov (United States)

Amundson, Karl

2003-03-01

Despite the dominance of liquid crystal displays, they do not perform some functions very well. While backlit liquid crystal displays can offer excellent color performance, they wash out in bright lighting and suffer from high power consumption. Reflective liquid crystal displays have limited brightness, making these devices challenging to read for long periods of time. Flexible liquid crystal displays are difficult to manufacture and keep stable. All of these attributes (long battery lifetime, bright reflective appearance, compatibility with flexible substrates) are traits that would be found in an ideal electronic paper display - an updateable substitute for paper that could be employed in electronic books, newspapers, and other applications. I will discuss technologies that are being developed for electronic-paper-like displays, and especially on particle-based technologies. A microencapsulated electrophoretic display technology is being developed at the E Ink corporation. This display film offers offer high brightness and an ink-on-paper appearance, compatibility with flexible substrates, and image stability that can lead to very low power consumption. I will present some of the physical and chemical challenges associated with making display films with high performance.

Microprocessor based beam intensity and efficiency display system for the Fermilab accelerator

International Nuclear Information System (INIS)

Biwer, R.

1979-01-01

The Main Accelerator display system for the Fermilab accelerator gathers charge data and displays it including processed transfer efficiencies of each of the accelerators. To accomplish this, strategically located charge converters monitor the circulating internal beam of each of the Fermilab accelerators. Their outputs are processed via an asynchronously triggered, multiplexed analog-to-digital converter. The data is converted into a digital byte containing address code and data, then stores it into two 16-bit memories. One memory outputs the interleaved data as a data pulse train while the other interfaces directly to a local host computer for further analysis. The microprocessor based display unit synchronizes displayed data during normal operation as well as special storage modes. The display unit outputs data to the fron panel in the form of a numeric value and also makes digital-to-analog conversions of displayed data for external peripheral devices. 5 refs

Secondary indium production from end-of-life liquid crystal displays

Energy Technology Data Exchange (ETDEWEB)

Amato, Alessia; Rocchetti, Laura; Fonti, Viviana; Ruello, Maria Letizia; Beolchini, Francesca [Universita Politecnica of Marche, DISVA, Via Brecce Bianche, 60131 Ancona (Italy)

2016-12-15

In 2014, the European Union identified 20 raw materials critical for economic importance and high supply risk. Indium, used in several innovative technologies, is among such critical raw materials. Generally, it is mined as a by-product of zinc from a mineral named sphalerite, with a concentration between 1 and 100 ppm. Currently, the largest producer of indium is China and about 84% of the worldwide indium consumption is used for liquid crystal display (LCD) production, in particular to form an indium-tin-oxide (ITO) film with transparent conductor properties. The fast evolution of LCD technologies caused a double effect: the growth of indium demand and an increase of waste electrical and electronic equipment (WEEE). Considering these two factors, the aim of this study is to make the end-of-life LCDs a secondary indium resource. With this purpose, an indium recovery process was developed carrying out an acidic leaching, followed by a zinc cementation. The first step allowed a complete indium extraction using 2M sulfuric acid at 80 C for 10 min. The problem of low indium concentration in the scraps (around 150 ppm) was overcome using a cross-current configuration in the leaching phase that allowed an increase of metal concentration and a decrease of reagents consumption. An indium recovery higher than 90% was obtained in the final cementation step, using 5 g/L of zinc powder at pH 3 and 55 C for 10 min. Considering its high efficiency, this process is promising in a context of circular economy, where a waste becomes a resource. (copyright 2016 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Novel cell parameter determination of a twisted-nematic liquid crystal display

International Nuclear Information System (INIS)

Huang Xia; Jing Hai; Fu Guozhu

2008-01-01

In this paper a novel method is proposed to determine the cell parameters including the twist angle, optic retardation and rubbing direction of twisted-nematic liquid crystal displays (TNLCD) by rotating the TNLCD. It is a single-wavelength method. Because using subtraction equation of transmittance as curve fitting equation, the influence of the light from environment and the absorption by polarizer, the sample of TNLCD and analyser on the transmittance is eliminated. Accurate results can also be obtained in imperfect darkness. By large numbers of experiments, we found that not only the experimental setup is quite simple and can be easily adopted to be carried out, but also the results are accurate

Improvement of diffraction efficiency of three-dimensional magneto-optic spatial light modulator with magnetophotonic crystal

Energy Technology Data Exchange (ETDEWEB)

Nakamura, K.; Takagi, H., E-mail: takagi@ee.tut.ac.jp; Lim, P. B.; Inoue, M., E-mail: inoue@tut.ac.jp [Department of Electrical and Electronic Information Engineering, Toyohashi University of Technology, Toyohashi, Aichi 441 8580 (Japan); Goto, Taichi [Department of Electrical and Electronic Information Engineering, Toyohashi University of Technology, Toyohashi, Aichi 441 8580 (Japan); JST, PRESTO, 4-1-8 Honcho, Kawaguchi, Saitama 332-0012 (Japan); Horimai, H. [HolyMine Corporation, Atsugi, Kanagawa 243 0813 (Japan); Yoshikawa, H. [Department of Computer Engineering, College of Science and Technology, Nihon University, Funabashi, Chiba 274 8501 (Japan); Bove, V. M. [MIT Media Lab, Cambridge, Massachusetts 02139 (United States)

2016-01-11

We have developed three-dimensional magneto-optic spatial light modulators (3D-MOSLMs) that use magnetic domains as submicron scale pixels to represent holograms. Our display system uses a submicron-scale magnetic pixel array on an amorphous TbFe film to create a wide viewing angle hologram. However, in previous work the reconstructed images had a low intensity and a low optical contrast; brightness of the reconstructed image was 4.4 × 10{sup −2 }cd/m{sup 2} with 532 nm illumination light at 10.8 mW/cm{sup 2}, while display standard ISO13406 recommends 100 cd/m{sup 2} or more. In this paper, we describe our development of a 3D-MOSLM composed of an artificial magnetic lattice structure of magnetophotonic crystals (MPCs). The MPCs enhance the diffraction efficiency of reconstructed 3D images and reduce the power consumption for controlling the magnetic pixels by a light localization effect. We demonstrate reconstructed 3D images using the MPC and show significant brightness improvement.

Crystal Collimation efficiency measured with the Medipix detector in SPS UA9 experiment.

CERN Document Server

Laface, E; Tlustos, L; Ippolito, V

2010-01-01

The UA9 experiment was performed in 6 MDs from May to November 2009 with the goal of studying the collimation properties of a crystal in the framework of a future exploitation in the LHC collimation system. An important parameter evaluated for the characterization of the crystal collimation is the efficiency of halo extraction when the crystal is in channeling mode. In this paper it is explained how this efficiency can be measured using a pixel detector, the Medipix, installed in the Roman Pot of UA9. The number of extracted particles counted by the Medipix is compared with the total number of circulating particles measured by the Beam Current Transformers (BCTs): from this comparison the efficiency of the system composed by the crystal, used in channeling mode, and a tungsten absorber is proved to be greater than 85%.

European display scene

Science.gov (United States)

Bartlett, Christopher T.

2000-08-01

The manufacture of Flat Panel Displays (FPDs) is dominated by Far Eastern sources, particularly in Active Matrix Liquid Crystal Displays (AMLCD) and Plasma. The United States has a very powerful capability in micro-displays. It is not well known that Europe has a very active research capability which has lead to many innovations in display technology. In addition there is a capability in display manufacturing of organic technologies as well as the licensed build of Japanese or Korean designs. Finally, Europe has a display systems capability in military products which is world class.

UV durable colour pigment doped SmA liquid crystal composites for outdoor trans-reflective bi-stable displays

Science.gov (United States)

Xu, H.; Davey, A. B.; Crossland, W. A.; Chu, D. P.

2012-10-01

High brightness trans-reflective bi-stable displays based on smectic A (SmA) liquid crystals (LCs) can have nearly perfect transparency in the clear state and very high reflection in the scattered state. Because the LC material in use is stable under UV radiation, this kind of displays can stand for strong day-light and therefore be ideal for outdoor applications from e-books to public signage and advertisement. However, the colour application has been limited because the traditional colourants in use are conventional dyes which are lack of UV stability and that their colours are easily photo bleached. Here we present a colour SmA display demonstrator using pigments as colourant. Mixing pigments with SmA LCs and maintain the desirable optical switching performance is not straightforward. We show here how it can be done, including how to obtain fine sized pigment nano-particles, the effects of particle size and size distribution on the display performance. Our optimized pigments/SmA compositions can be driven by a low frequency waveform (~101Hz) to a scattered state to exhibit colour while by a high frequency waveform (~103Hz) to a cleared state showing no colour. Finally, we will present its excellent UV life-time (at least <7.2 years) in comparison with that of dye composition (~2.4 years). The complex interaction of pigment nano-particles with LC molecules and the resulting effects on the LC electro-optical performances are still to be fully understood. We hope this work will not only demonstrate a new and practical approach for outdoor reflective colour displays but also provide a new material system for fundamental liquid crystal colloid research work.

Fabrication of topology optimized photonic crystal waveguide Z-bend displaying large bandwidth with very low bend loss

DEFF Research Database (Denmark)

Harpøth, Anders; Frandsen, Lars Hagedorn; Kristensen, Martin

2004-01-01

We have designed, simulated and fabricated a photonic crystal waveguide Z-bend, which displays a total bend loss of ~1dB per bend in a wavelength range of more than 200nm. The fabricated component performs in excellent agreement with 3D finite-difference time-domain calculations....

Single-crystal charge transfer interfaces for efficient photonic devices (Conference Presentation)

Science.gov (United States)

Alves, Helena; Pinto, Rui M.; Maçôas, Ermelinda M. S.; Baleizão, Carlos; Santos, Isabel C.

2016-09-01

Organic semiconductors have unique optical, mechanical and electronic properties that can be combined with customized chemical functionality. In the crystalline form, determinant features for electronic applications such as molecular purity, the charge mobility or the exciton diffusion length, reveal a superior performance when compared with materials in a more disordered form. Combining crystals of two different conjugated materials as even enable a new 2D electronic system. However, the use of organic single crystals in devices is still limited to a few applications, such as field-effect transistors. In 2013, we presented the first system composed of single-crystal charge transfer interfaces presenting photoconductivity behaviour. The system composed of rubrene and TCNQ has a responsivity reaching 1 A/W, corresponding to an external quantum efficiency of nearly 100%. A similar approach, with a hybrid structure of a PCBM film and rubrene single crystal also presents high responsivity and the possibility to extract excitons generated in acceptor materials. This strategy led to an extended action towards the near IR. By adequate material design and structural organisation of perylediimides, we demonstrate that is possible to improve exciton diffusion efficiency. More recently, we have successfully used the concept of charge transfer interfaces in phototransistors. These results open the possibility of using organic single-crystal interfaces in photonic applications.

Handbook of display technology

CERN Document Server

Castellano, Joseph A

1992-01-01

This book presents a comprehensive review of technical and commercial aspects of display technology. It provides design engineers with the information needed to select proper technology for new products. The book focuses on flat, thin displays such as light-emitting diodes, plasma display panels, and liquid crystal displays, but it also includes material on cathode ray tubes. Displays include a large number of products from televisions, auto dashboards, radios, and household appliances, to gasoline pumps, heart monitors, microwave ovens, and more.For more information on display tech

[Comparison of detectability of liquid crystal displays (LCDs) and film using phantoms of small adenocarcinomas as abnormalities].

Science.gov (United States)

Mochizuki, Yasuo; Abe, Shinji; Monma, Masahiko; Yamaguchi, Kojirou; Adachi, Toshiki

2011-01-01

Following the trend of the digitalization of the modalities used for diagnostic imaging, the devices for such imaging have increasingly included monitors. The present study was undertaken to evaluate the usefulness of soft-copy (liquid crystal display; LCD) images of phantoms of small adenocarcinomas using receiver operating characteristic (ROC) analysis of two different display systems: LCD and hard copy (film). A two-tailed paired t-test and the jackknife method (parametric methods) were performed, and no significant differences were found in the area under the ROC curve (AUC) for the pulmonary fields, lungs, ribs, or mediastinum between the film and LCD display systems, and the detectability did not differ between the film and LCD monitors. A Mann-Whitney U test, which is a non-parametric method that applies to the analysis of a small sample, also showed no significant differences in the AUC. The results of this study suggest that LCDs can replace hard-copy film as a display system if the signals.

Ultra-High-Efficiency Apodized Grating Coupler Using a Fully Etched Photonic Crystal

DEFF Research Database (Denmark)

Ding, Yunhong; Peucheret, Christophe; Ou, Haiyan

2013-01-01

We demonstrate an apodized fiber-to-chip grating coupler using fully etched photonic crystal holes on the silicon-on-insulator platform. An ultra-high coupling efficiency of 1.65 dB (68%) with 3 dB bandwidth of 60 nm is experimentally demonstrated.......We demonstrate an apodized fiber-to-chip grating coupler using fully etched photonic crystal holes on the silicon-on-insulator platform. An ultra-high coupling efficiency of 1.65 dB (68%) with 3 dB bandwidth of 60 nm is experimentally demonstrated....

Crosstalk evaluation in stereoscopic displays

NARCIS (Netherlands)

Wang, L.; Teunissen, C.; Tu, Yan; Chen, Li; Zhang, P.; Zhang, T.; Heynderickx, I.E.J.

2011-01-01

Substantial progress in liquid-crystal display and polarization film technology has enabled several types of stereoscopic displays. Despite all progress, some image distortions still exist in these 3-D displays, of which interocular crosstalk - light leakage of the image for one eye to the other eye

Searching for the preferred backlight intensity in liquid crystal displays with local backlight dimming

DEFF Research Database (Denmark)

Korhonen, Jari; Mantel, Claire; Burini, Nino

2013-01-01

Local backlight dimming is one of the most promising techniques for reducing power consumption and improving contrast characteristics of liquid crystal displays (LCD). In practice, due to light diffusion and a smaller number of backlight sources than pixels, local backlight dimming must often trade......-off between leakage of light in dark pixels and clipping of luminance in bright pixels. Only few studies have analyzed the subjective preferences between different luminance and contrast levels. In this paper, we present a method for defining the perceptually optimal backlight level via subjective...

On Integrity of Flexible Displays

Science.gov (United States)

Bouten, Piet C. P.

Nowadays two display types are dominant in the display market: the bulky cathode ray tube (CRT) and liquid crystal displays (LCD). Both types use glass as substrate material. The LCD display is the dominant player for mobile applications, in for instance mobile phones and portable computers. In the development of displays and their applications a clear interest exists to replace the rigid rectangular display cells by free-shaped, curved or even roll-up cells. These types of applications require flexible displays.

Design and characterization of Ga-doped indium tin oxide films for pixel electrode in liquid crystal display

International Nuclear Information System (INIS)

Choi, J.H.; Kang, S.H.; Oh, H.S.; Yu, T.H.; Sohn, I.S.

2013-01-01

Indium tin oxide (ITO) thin films doped with various metal atoms were investigated in terms of phase transition behavior and electro-optical properties for the purpose of upgrading ITO and indium zinc oxide (IZO) films, commonly used for pixel electrodes in flat panel displays. We explored Ce, Mg, Zn, and Ga atoms as dopants to ITO by the co-sputtering technique, and Ga-doped ITO films (In:Sn:Ga = 87.4:6.7:5.9 at.%) showed the phase transition behavior at 210 °C within 20 min with high visible transmittance of 91% and low resistivity of 0.22 mΩ cm. The film also showed etching rate similar to amorphous ITO, and no etching residue on glass surfaces. These results were confirmed with the film formed from a single Ga-doped ITO target with slightly different compositions (In:Sn:Ga = 87:9:4 at.%). Compared to the ITO target, Ga-doped ITO target left 1/4 less nodules on the target surface after sputtering. These results suggest that Ga-doped ITO films could be an excellent alternative to ITO and IZO for pixel electrodes in thin film transistor liquid crystal display (TFT-LCD). - Highlights: ► We report Ga-doped In–Sn–O films for a pixel electrode in liquid crystal display. ► Ga-doped In–Sn–O films show phase transition behavior at 210 °C. ► Ga-doped In–Sn–O films show high wet etchability and low resistivity

Beam steering for virtual/augmented reality displays with a cycloidal diffractive waveplate.

Science.gov (United States)

Chen, Haiwei; Weng, Yishi; Xu, Daming; Tabiryan, Nelson V; Wu, Shin-Tson

2016-04-04

We proposed a switchable beam steering device with cycloidal diffractive waveplate (CDW) for eye tracking in a virtual reality (VR) or augmented reality (AR) display system. Such a CDW diffracts the incident circularly polarized light to the first order with over 95% efficiency. To convert the input linearly polarized light to right-handed or left-handed circular polarization, we developed a broadband polarization switch consisting of a twisted nematic liquid crystal cell and an achromatic quarter-wave retardation film. By cascading 2-3 CDWs together, multiple diffraction angles can be achieved. To suppress the color dispersion, we proposed two approaches to obtain the same diffraction angle for red, green, and blue LEDs-based full color displays. Our device exhibits several advantages, such as high diffraction efficiency, fast response time, low power consumption, and low cost. It holds promise for the emerging VR/AR displays.

Ultrahigh-efficiency apodized grating coupler using fully etched photonic crystals

DEFF Research Database (Denmark)

Ding, Yunhong; Ou, Haiyan; Peucheret, Christophe

2013-01-01

We present an efficient method to design apodized grating couplers with Gaussian output profiles for efficient coupling between standard single mode fibers and silicon chips. An apodized grating coupler using fully etched photonic crystal holes on the silicon-on-insulator platform is designed......, and fabricated in a single step of lithography and etching. An ultralow coupling loss of x2212;1.74x2009;x2009;dB (67% coupling efficiency) with a 3xA0;dB bandwidth of 60xA0;nm is experimentally measured....

EVALUATION OF CHROMATICITY COORDINATES SHIFT FOR IMAGE DISPLAYED ON LIQUID CRYSTAL PANELS WITH VARIOUS PROPERTIES ON COLOR REPRODUCTION

Directory of Open Access Journals (Sweden)

I. O. Zharinov

2016-03-01

Full Text Available Subject of Research.We consider the problem of evaluation of chromaticity coordinates shift for image displayed on liquid crystal panels with various properties on color reproduction. A mathematical model represents the color reproduction characteristics. The spread of the color characteristics of the screens has a statistical nature. Differences of color reproduction for screens are perceived by the observer in the form of different colors and shades that are displayed on the same type of commercially available screens. Color differences are characterized by numerical measure of the difference of colors and can be mathematically compensated. The solution of accounting problem of the statistical nature of the color characteristics spread for the screens has a particular relevance to aviation instrumentation. Method. Evaluation of chromaticity coordinates shift of the image is based on the application of the Grassmann laws of color mixing.Basic data for quantitative calculation of shift are the profiles of two different liquid crystal panels defined by matrixes of scales for components of primary colors (red, green, blue. The calculation is based on solving the system of equations and calculating the color difference in the XY-plane. In general, the calculation can be performed in other color spaces: UV, Lab. The statistical nature of the spread of the color characteristics for the screens is accounted for in the proposed mathematical model based on the interval setting of coordinate values of the color gamut triangle vertices on the set of commercially available samples. Main Results. Carried outresearches result in the mathematical expressions allowing to recalculate values of chromaticity coordinates of the image displayed on various samples of liquid crystal screens. It is shown that the spread of the color characteristics of the screens follows bivariate normal distribution law with the accuracy sufficient for practice. The results of

Assessment of Anisotropic Semiconductor Nanorod and Nanoplatelet Heterostructures with Polarized Emission for Liquid Crystal Display Technology.

Science.gov (United States)

Cunningham, Patrick D; Souza, João B; Fedin, Igor; She, Chunxing; Lee, Byeongdu; Talapin, Dmitri V

2016-06-28

Semiconductor nanorods can emit linear-polarized light at efficiencies over 80%. Polarization of light in these systems, confirmed through single-rod spectroscopy, can be explained on the basis of the anisotropy of the transition dipole moment and dielectric confinement effects. Here we report emission polarization in macroscopic semiconductor-polymer composite films containing CdSe/CdS nanorods and colloidal CdSe nanoplatelets. Anisotropic nanocrystals dispersed in polymer films of poly butyl-co-isobutyl methacrylate (PBiBMA) can be stretched mechanically in order to obtain unidirectionally aligned arrays. A high degree of alignment, corresponding to an orientation factor of 0.87, was achieved and large areas demonstrated polarized emission, with the contrast ratio I∥/I⊥ = 5.6, making these films viable candidates for use in liquid crystal display (LCD) devices. To some surprise, we observed significant optical anisotropy and emission polarization for 2D CdSe nanoplatelets with the electronic structure of quantum wells. The aligned nanorod arrays serve as optical funnels, absorbing unpolarized light and re-emitting light from deep-green to red with quantum efficiencies over 90% and high degree of linear polarization. Our results conclusively demonstrate the benefits of anisotropic nanostructures for LCD backlighting. The polymer films with aligned CdSe/CdS dot-in-rod and rod-in-rod nanostructures show more than 2-fold enhancement of brightness compared to the emitter layers with randomly oriented nanostructures. This effect can be explained as the combination of linearly polarized luminescence and directional emission from individual nanostructures.

Surface-treated self-standing curved crystals as high-efficiency elements for X- and γ-ray optics: theory and experiment.

Science.gov (United States)

Bonnini, Elisa; Buffagni, Elisa; Zappettini, Andrea; Doyle, Stephen; Ferrari, Claudio

2015-06-01

The efficiency of a Laue lens for X- and γ-ray focusing in the energy range 60-600 keV is closely linked to the diffraction efficiency of the single crystals composing the lens. A powerful focusing system is crucial for applications like medical imaging and X-ray astronomy where wide beams must be focused. Mosaic crystals with a high density, such as Cu or Au, and bent crystals with curved diffracting planes (CDPs) are considered for the realization of a focusing system for γ-rays, owing to their high diffraction efficiency in a predetermined angular range. In this work, a comparison of the efficiency of CDP crystals and Cu and Au mosaic crystals was performed on the basis of the theory of X-ray diffraction. Si, GaAs and Ge CDP crystals with optimized thicknesses and moderate radii of curvature of several tens of metres demonstrate comparable or superior performance with respect to the higher atomic number mosaic crystals generally used. In order to increase the efficiency of the lens further, a stack of several CDP crystals is proposed as an optical element. CDP crystals were obtained by a surface-damage method, and a stack of two surface-damaged bent Si crystals was prepared and tested. Rocking curves of the stack were performed with synchrotron radiation at 19 keV to check the lattice alignment: they exhibited only one diffraction peak.

Elimination of image flicker in a fringe-field switching liquid crystal display by applying a bipolar voltage wave.

Science.gov (United States)

Oh, Seung-Won; Park, Jun-Hee; Lee, Ji-Hoon; Yoon, Tae-Hoon

2015-09-07

Recently, low-frequency driving of liquid crystal display (LCD) panels to minimize power consumption has drawn much attention. In the case in which an LCD panel is driven by a fringe-field at a low frequency, the image flickering phenomenon occurs when the sign of the applied electric field is reversed. We investigated image flickering induced by the flexoelectric effect in a fringe-field switching (FFS) liquid crystal cell in terms of the transmittance difference between frames and the ripple phenomenon. Experimental results show that image flicker due to transmittance difference can be eliminated completely and that the ripple phenomena can be reduced significantly by applying a bipolar voltage wave to the FFS cell.

OLED displays and lighting

CERN Document Server

Koden, Mitsuhiro

2017-01-01

Organic light-emitting diodes (OLEDs) have emerged as the leading technology for the new display and lighting market. OLEDs are solid-state devices composed of thin films of organic molecules that create light with the application of electricity. OLEDs can provide brighter, crisper displays on electronic devices and use less power than conventional light-emitting diodes (LEDs) or liquid crystal displays (LCDs) used today. This book covers both the fundamentals and practical applications of flat and flexible OLEDs.

An efficient method for isolating antibody fragments against small peptides by antibody phage display

DEFF Research Database (Denmark)

Duan, Zhi; Siegumfeldt, Henrik

2010-01-01

We generated monoclonal scFv (single chain variable fragment) antibodies from an antibody phage display library towards three small synthetic peptides derived from the sequence of s1-casein. Key difficulties for selection of scFv-phages against small peptides were addressed. Small peptides do....... The scFvs were sequenced and characterized, and specificity was characterized by ELISA. The methods developed in this study are universally applicable for antibody phage display to efficiently produce antibody fragments against small peptides....

Latest development of display technologies

International Nuclear Information System (INIS)

Gao Hong-Yue; Yao Qiu-Xiang; Liu Pan; Zheng Zhi-Qiang; Liu Ji-Cheng; Zheng Hua-Dong; Zeng Chao; Yu Ying-Jie; Sun Tao; Zeng Zhen-Xiang

2016-01-01

In this review we will focus on recent progress in the field of two-dimensional (2D) and three-dimensional (3D) display technologies. We present the current display materials and their applications, including organic light-emitting diodes (OLEDs), flexible OLEDs quantum dot light emitting diodes (QLEDs), active-matrix organic light emitting diodes (AMOLEDs), electronic paper (E-paper), curved displays, stereoscopic 3D displays, volumetric 3D displays, light field 3D displays, and holographic 3D displays. Conventional 2D display devices, such as liquid crystal devices (LCDs) often result in ambiguity in high-dimensional data images because of lacking true depth information. This review thus provides a detailed description of 3D display technologies. (topical review)

Yeast cell surface display: An efficient strategy for improvement of bioethanol fermentation performance.

Science.gov (United States)

Chen, Xianzhong

2017-03-04

The cell surface serves as a functional interface between the inside and the outside of the cell. Within the past 20 y the ability of yeast (Saccharomyces cerevisiae) to display heterologous proteins on the cell surface has been demonstrated. Furthermore, S. cerevisiae has been both developed and applied in expression of various proteins on the cell surface. Using this novel and useful strategy, proteins and peptides of various kinds can be displayed on the yeast cell surface by fusing the protein of interest with the glycosylphosphatidylinositol (GPI)-anchoring system. Consolidated bioprocessing (CBP) using S. cerevisiae represents a promising technology for bioethanol production. However, further work is needed to improve the fermentation performance. There is some excellent previous research regarding construction of yeast biocatalyst using the surface display system to decrease cost, increase efficiency of ethanol production and directly utilize starch or biomass for fuel production. In this commentary, we reviewed the yeast surface display system and highlighted recent work. Additionally, the strategy for decrease of phytate phosphate content in dried distillers grains with solubles (DDGS) by display of phytase on the yeast cell surface is discussed.

MyCrystals - a simple visual data management program for laboratory-scale crystallization experiments

DEFF Research Database (Denmark)

Løvgreen, Monika Nøhr; Løvgreen, Mikkel; Christensen, Hans Erik Mølager

2009-01-01

MyCrystals is designed as a user-friendly program to display crystal images and list crystallization conditions. The crystallization conditions entry fields can be customized to suit the experiments. MyCrystals is also able to sort the images by the entered crystallization conditions, which...

Efficient femtosecond mid-infrared pulse generation by dispersivewave radiation in bulk lithium niobate crystal

DEFF Research Database (Denmark)

Zhou, Binbin; Guo, Hairun; Bache, Morten

2014-01-01

We experimentally demonstrate efficient mid-infrared pulse generation by dispersive wave radiation in bulk lithium niobate crystal. Femtosecond mid-IR pulses centering from 2.8–2.92 µm are generated using the single pump wavelengths from 1.25–1.45 µm.......We experimentally demonstrate efficient mid-infrared pulse generation by dispersive wave radiation in bulk lithium niobate crystal. Femtosecond mid-IR pulses centering from 2.8–2.92 µm are generated using the single pump wavelengths from 1.25–1.45 µm....

High efficient OLED displays prepared with the air-gapped bridges on quantum dot patterns for optical recycling

Science.gov (United States)

Kim, Hyo-Jun; Shin, Min-Ho; Kim, Joo-Suc; Kim, Se-Eun; Kim, Young-Joo

2017-02-01

An optically efficient structure was proposed and fabricated to realize high brightness organic light emitting diode (OLED) displays based on a white OLED prepared with the air-gapped bridges on the quantum dot (QD) patterns. Compared with a conventional white OLED display, in our experiments, the optical intensity of the proposed OLED display shows the enhancement of 58.2% in the red color and 16.8% in the green color after applying the air-gapped bridge structure on QD patterns of 20 wt% concentration. This enhancement comes from the two facts that the QD patterns downconvert unnecessary blue or blue/green light to the required green or red light and the air-gapped bridges increase the color conversion efficiency of QDs by optical recycling using total internal reflection (TIR) at the interface. In addition, the color gamut of the proposed OLED display increases from 65.5 to 75.9% (NTSC x, y ratio) due to the narrow emission spectra of QDs.

The ergonomics approach for thin film transistor-liquid crystal display manufacturing process.

Science.gov (United States)

Lu, Chih-Wei; Yao, Chia-Chun; Kuo, Chein-Wen

2012-01-01

The thin film transistor-liquid crystal display (TFT-LCD) has been used all over the world. Although the manufacture process of TFT-LCD was highly automated, employees are hired to do manual job in module assembly process. The operators may have high risk of musculoskeletal disorders because of the long work hours and the repetitive activities in an unfitted work station. The tools of this study were questionnaire, checklist and to evaluate the work place design. The result shows that the participants reported high musculoskeletal disorder symptoms in shoulder (59.8%), neck (49.5%), wrist (39.5%), and upper back (30.6%). And, to reduce the ergonomic risk factors, revising the height of the work benches, chairs and redesigning the truck to decrease the chance of unsuitable positions were recommended and to reduce other ergonomics hazards and seta good human machine interface and appropriate job design.

Possibility of high efficient beam extraction from the CERN SPS with a bent crystal. Simulation results

Energy Technology Data Exchange (ETDEWEB)

Scandale, W. [CERN, European Organization for Nuclear Research, CH-1211 Geneva 23 (Switzerland); Laboratoire de l' AccelerateurLineaire (LAL), Universite Paris SudOrsay, Orsay (France); INFN Sezione di Roma, Piazzale Aldo Moro 2, 00185 Rome (Italy); Kovalenko, A.D.; Taratin, A.M. [Joint Institute for Nuclear Research, 141980 Dubna, Moscow Region (Russian Federation)

2017-03-11

The extraction of the SPS beam of 270 GeV/c protons assisted by a bent crystal was studied by simulation. Two methods for delivering the SPS beam onto a crystal were considered: transverse diffusion and orbit bump of the beam. It was shown that the main condition for high efficient beam extraction with a bent crystal, which is a small divergence of the incident beam, can be fulfilled. Extraction efficiency up to 99% can be reached for both methods of the beam delivering. The irradiation of the electrostatic septum wires during the beam extraction can be considerably reduced.

Nano crystals for Electronic and Optoelectronic Applications

International Nuclear Information System (INIS)

Zhu, T.; Cloutier, S.G.; Ivanov, I; Knappenberger Jr, K.L.; Robel, I.; Zhang, F

2012-01-01

Electronic and optoelectronic devices, from computers and smart cell phones to solar cells, have become a part of our life. Currently, devices with featured circuits of 45 nm in size can be fabricated for commercial use. However, further development based on traditional semiconductor is hindered by the increasing thermal issues and the manufacturing cost. During the last decade, nano crystals have been widely adopted in various electronic and optoelectronic applications. They provide alternative options in terms of ease of processing, low cost, better flexibility, and superior electronic/optoelectronic properties. By taking advantage of solution-processing, self-assembly, and surface engineering, nano crystals could serve as new building blocks for low-cost manufacturing of flexible and large area devices. Tunable electronic structures combined with small exciton binding energy, high luminescence efficiency, and low thermal conductivity make nano crystals extremely attractive for FET, memory device, solar cell, solid-state lighting/display, photodetector, and lasing applications. Efforts to harness the nano crystal quantum tunability have led to the successful demonstration of many prototype devices, raising the public awareness to the wide range of solutions that nano technology can provide for an efficient energy economy. This special issue aims to provide the readers with the latest achievements of nano crystals in electronic and optoelectronic applications, including the synthesis and engineering of nano crystals towards the applications and the corresponding device fabrication, characterization and computer modeling.

Self-assembled hierarchical nanostructures for high-efficiency porous photonic crystals.

Science.gov (United States)

Passoni, Luca; Criante, Luigino; Fumagalli, Francesco; Scotognella, Francesco; Lanzani, Guglielmo; Di Fonzo, Fabio

2014-12-23

The nanoscale modulation of material properties such as porosity and morphology is used in the natural world to mold the flow of light and to obtain structural colors. The ability to mimic these strategies while adding technological functionality has the potential to open up a broad array of applications. Porous photonic crystals are one such technological candidate, but have typically underachieved in terms of available materials, structural and optical quality, compatibility with different substrates (e.g., silicon, flexible organics), and scalability. We report here an alternative fabrication method based on the bottom-up self-assembly of elementary building blocks from the gas phase into high surface area photonic hierarchical nanostructures at room temperature. Periodic refractive index modulation is achieved by stacking layers with different nanoarchitectures. High-efficiency porous Bragg reflectors are successfully fabricated with sub-micrometer thick films on glass, silicon, and flexible substrates. High diffraction efficiency broadband mirrors (R≈1), opto-fluidic switches, and arrays of photonic crystal pixels with size<10 μm are demonstrated. Possible applications in filtering, sensing, electro-optical modulation, solar cells, and photocatalysis are envisioned.

A portable contamination monitor with a numerical display

International Nuclear Information System (INIS)

Jones, A.R.

1980-10-01

A portable contamination monitor, its performance and application are described. The monitor is equipped with two 15.5 cm 2 'pancake' type Geiger-Mueller counters with thin windows ( 2 ). The summed counting rate is displayed in the range 0.2000 counts/s on a liquid crystal digital voltmeter. Every tenth pulse is signaled by flashing an LED and emitting a short (0.1 s) pulse of sound. The efficiencies for detecting a variety of α-, β- and γ- emitters have been measured and are reported. Data on the effects of varying battery voltage and temperature are also reported. (auth)

Measurement of neutron detection efficiencies in NaI using the Crystal Ball detector

Energy Technology Data Exchange (ETDEWEB)

Stanislaus, T.D.S.; Koetke, D.D. E-mail: donald.koetke@valpo.edu; Allgower, C.; Bekrenev, V.; Benslama, K.; Berger, E.; Briscoe, W.J.; Clajus, M.; Comfort, J.R.; Craig, K.; Gibson, A.; Grosnick, D.; Huber, G.M.; Isenhower, D.; Kasprzyk, T.; Knecht, N.; Koulbardis, A.; Kozlenko, N.; Kruglov, S.; Kycia, T.; Lolos, G.J.; Lopatin, I.; Manley, D.M.; Manweiler, R.; Marusic, A.; McDonald, S.; Nefkens, B.M.K.; Olmsted, J.; Papandreou, Z.; Peaslee, D.; Peterson, R.J.; Phaisangittisakul, N.; Pulver, M.; Ramirez, A.F.; Sadler, M.; Shafi, A.; Slaus, I.; Spinka, H.; Starostin, A.; Staudenmaier, H.M.; Supek, I.; Thoms, J.; Tippens, W.B

2001-04-21

We report on a measurement of the neutron detection efficiency in NaI crystals in the Crystal Ball (CB) detector obtained from a study of {pi}{sup -}p{yields}{pi} degree sign n reactions at the Brookhaven National Laboratory AGS. A companion GEANT-based Monte Carlo study has been done to simulate these reactions in the CB, and a comparison with the data is provided.

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

Science.gov (United States)

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…

Flexible Bistable Cholesteric Reflective Displays

Science.gov (United States)

Yang, Deng-Ke

2006-03-01

Cholesteric liquid crystals (ChLCs) exhibit two stable states at zero field condition-the reflecting planar state and the nonreflecting focal conic state. ChLCs are an excellent candidate for inexpensive and rugged electronic books and papers. This paper will review the display cell structure,materials and drive schemes for flexible bistable cholesteric (Ch) reflective displays.

Effect of Li and NH4 doping on the crystal perfection, second harmonic generation efficiency and laser damage threshold of potassium pentaborate crystals

Science.gov (United States)

Vigneshwaran, A. N.; Kalainathan, S.; Raja, C. Ramachandra

2018-03-01

Potassium pentaborate (KB5) is an excellent nonlinear optical material especially in the UV region. In this work, Li and NH4 doped KB5 crystals were grown using slow evaporation solution growth method. The incorporation of dopant has been confirmed and analysed by Energy dispersive X-ray analysis (EDAX), Inductively coupled plasma (ICP) analysis and Raman spectroscopy. The crystalline perfection of pure and doped KB5 crystals was studied by High resolution X-ray diffraction (HRXRD) analysis. Structural grain boundaries were observed in doped crystals. Second harmonic generation was confirmed for pure and doped crystals and output values revealed the enhancement of SHG efficiency in doped crystals. Resistance against laser damage was carried out using 1064 nm Nd-YAG laser of pulse width 10 ns. The laser damage threshold value is increased in Li doped crystal and decreased in NH4 doped crystal when compared to pure KB5 crystal.

Fundamentals of liquid crystal devices

CERN Document Server

Yang, Deng-Ke

2014-01-01

Revised throughout to cover the latest developments in the fast moving area of display technology, this 2nd edition of Fundamentals of Liquid Crystal Devices, will continue to be a valuable resource for those wishing to understand the operation of liquid crystal displays. Significant updates include new material on display components, 3D LCDs and blue-phase displays which is one of the most promising new technologies within the field of displays and it is expected that this new LC-technology will reduce the response time and the number of optical components of LC-modules. Prof. Yang is a pion

Fab is the most efficient format to express functional antibodies by yeast surface display.

Science.gov (United States)

Sivelle, Coline; Sierocki, Raphaël; Ferreira-Pinto, Kelly; Simon, Stéphanie; Maillere, Bernard; Nozach, Hervé

2018-04-30

Multiple formats are available for engineering of monoclonal antibodies (mAbs) by yeast surface display, but they do not all lead to efficient expression of functional molecules. We therefore expressed four anti-tumor necrosis factor and two anti-IpaD mAbs as single-chain variable fragment (scFv), antigen-binding fragment (Fab) or single-chain Fabs and compared their expression levels and antigen-binding efficiency. Although the scFv and scFab formats are widely used in the literature, 2 of 6 antibodies were either not or weakly expressed. In contrast, all 6 antibodies expressed as Fab revealed strong binding and high affinity, comparable to that of the soluble form. We also demonstrated that the variations in expression did not affect Fab functionality and were due to variations in light chain display and not to misfolded dimers. Our results suggest that Fab is the most versatile format for the engineering of mAbs.

High efficient OLED displays prepared with the air-gapped bridges on quantum dot patterns for optical recycling

OpenAIRE

Hyo-Jun Kim; Min-Ho Shin; Joo-Suc Kim; Se-Eun Kim; Young-Joo Kim

2017-01-01

An optically efficient structure was proposed and fabricated to realize high brightness organic light emitting diode (OLED) displays based on a white OLED prepared with the air-gapped bridges on the quantum dot (QD) patterns. Compared with a conventional white OLED display, in our experiments, the optical intensity of the proposed OLED display shows the enhancement of 58.2% in the red color and 16.8% in the green color after applying the air-gapped bridge structure on QD patterns of 20?wt% co...

Flexoelectric effect in an in-plane switching (IPS) liquid crystal cell for low-power consumption display devices

OpenAIRE

Kim, Min Su; Bos, Philip J.; Kim, Dong-Woo; Yang, Deng-Ke; Lee, Joong Hee; Lee, Seung Hee

2016-01-01

Technology of displaying static images in portable displays, advertising panels and price tags pursues significant reduction in power consumption and in product cost. Driving at a low-frequency electric field in fringe-field switching (FFS) mode can be one of the efficient ways to save powers of the recent portable devices, but a serious drop of image-quality, so-called image-flickering, has been found in terms of the coupling of elastic deformation to not only quadratic dielectric effect but...

Calculated Absolute Detection Efficiencies of Cylindrical Nal (Tl) Scintillation Crystals for Aqueous Spherical Sources

Energy Technology Data Exchange (ETDEWEB)

Strindehag, O; Tollander, B

1968-08-15

Calculated values of the absolute total detection efficiencies of cylindrical scintillation crystals viewing spherical sources of various sizes are presented. The calculation is carried out for 2 x 2 inch and 3 x 3 inch Nal(Tl) crystals and for sources which have the radii 1/4, 1/2, 3/4 and 1 times the crystal radius. Source-detector distances of 5-20 cm and gamma energies in the range 0.1 - 5 MeV are considered. The correction factor for absorption in the sample container wall and in the detector housing is derived and calculated for a practical case.

Nanophosphor CaSO4:Eu2+ for photoluminescence liquid crystal display (PLLCD)

Science.gov (United States)

Patle, Anita; Patil, R. R.; Moharil, S. V.

2018-05-01

In this work PL enhancement of CaSO4:Eu2+ nanophosphor which was synthesized with 0.01M molarity by co-precipitation method is presented. Synthesized phosphor was characterized by XRD, SEM, TEM and PL measurements. Average particle size is found to be in the range 80-100nm with Hexagonal morphology and PL studies showed emission peaks at 380nm, when samples were excited by 254nm. The observed PL emission is characteristic emission of Eu2+ similar to that observed in bulk CaSO4:Eu2. However under identical condition it is observed that intensity of emission get enhanced for 0.01M size which is doubled to that of 0.1M with similar emission at 380nm. A phosphor with narrow emission band around 390 nm is desirable, since at this wavelength the transmission of standard glass, polarizing plastic, other coating and LCD material is at acceptable level. Strong Eu2+ emission is observed in CaSO4:Eu nanophosphor which finds applications for PLLCD (photoluminescent liquid crystal display).

Technological process and optimum design of organic materials vacuum pyrolysis and indium chlorinated separation from waste liquid crystal display panels

Energy Technology Data Exchange (ETDEWEB)

Ma, En; Xu, Zhenming, E-mail: zmxu@sjtu.edu.cn

2013-12-15

Highlights: • The vacuum pyrolysis–vacuum chlorinated separation system was proposed to recover the waste LCD panel. • The system can recycle the whole waste LCD panels efficiently without negative effects to environment. • The 82.03% of the organic materials was reclaimed. All pyrolysis products can be utilized by a reasonable way. • The separation of indium was optimized by the central composite design (CCD) under response surface methodology (RSM). • The recovery ratio of indium was further increased to 99.97%. -- Abstract: In this study, a technology process including vacuum pyrolysis and vacuum chlorinated separation was proposed to convert waste liquid crystal display (LCD) panels into useful resources using self-design apparatuses. The suitable pyrolysis temperature and pressure are determined as 300 °C and 50 Pa at first. The organic parts of the panels were converted to oil (79.10 wt%) and gas (2.93 wt%). Then the technology of separating indium was optimized by central composite design (CCD) under response surface methodology (RSM). The results indicated the indium recovery ratio was 99.97% when the particle size is less than 0.16 mm, the weight percentage of NH{sub 4}Cl to glass powder is 50 wt% and temperature is 450 °C. The research results show that the organic materials, indium and glass of LCD panel can be recovered during the recovery process efficiently and eco-friendly.

Robustness of average Stokes polarimetry characterization of digitally addressed parallel-aligned LCoS displays

OpenAIRE

Martínez Guardiola, Francisco Javier; Márquez Ruiz, Andrés; Gallego Rico, Sergi; Ortuño Sánchez, Manuel; Francés Monllor, Jorge; Beléndez Vázquez, Augusto; Pascual Villalobos, Inmaculada

2014-01-01

Parallel-aligned liquid crystal on silicon (PA-LCoS) displays have become the most attractive spatial light modulator device for a wide range of applications, due to their superior resolution and light efficiency, added to their phase-only capability. Recently we proposed a novel polarimetric method, based on Stokes polarimetry, enabling the characterization of their linear retardance and the magnitude of their associated phase fluctuations, if existent, as it happens in most of digital backp...

Quantitative assessment of slit Mura defect in a thin film transistor-liquid crystal display based on chromaticity and optical density

International Nuclear Information System (INIS)

Tzu, Fu-Ming; Chou, Jung-Hua

2010-01-01

An innovative non-contact optical inspection method is developed to quantify slit Mura defects for thin film transistor–liquid crystal displays (TFT-LCDs). From the measurements of both chromaticity and optical densities across the slit Mura, the results indicate that the optical density profile is a concave shape and the chromaticity distribution is a convex shape. A linear relation with a negative slope exists between the chromaticity and optical density. A larger colour difference has a steeper slope, and vice versa. All of the measurements with uncertainties of a 99.7% confidence interval satisfy the requirements of the flat panel display industry. The proposed method can accurately quantify the pattern of blue slit Mura of TFT-LCDs; even the perceptibility is below the just noticeable difference

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

Science.gov (United States)

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.

Highly nonlinear organic crystal OHQ-T for efficient ultra-broadband terahertz wave generation beyond 10 THz.

Science.gov (United States)

Kang, Bong Joo; Baek, In Hyung; Lee, Seung-Heon; Kim, Won Tae; Lee, Seung-Jun; Jeong, Young Uk; Kwon, O-Pil; Rotermund, Fabian

2016-05-16

We report on efficient generation of ultra-broadband terahertz (THz) waves via optical rectification in a novel nonlinear organic crystal with acentric core structure, i.e. 2-(4-hydroxystyryl)-1-methylquinolinium 4-methylbenzenesulfonate (OHQ-T), which possesses an ideal molecular structure leading to a maximized nonlinear optical response for near-infrared-pumped THz wave generation. By systematic studies on wavelength-dependent phase-matching conditions in OHQ-T crystals of different thicknesses we are able to generate coherent THz waves with a high peak-to-peak electric field amplitude of up to 650 kV/cm and an upper cut-off frequency beyond 10 THz. High optical-to-THz conversion efficiency of 0.31% is achieved by efficient index matching with a selective pumping at 1300 nm.

JAVA Stereo Display Toolkit

Science.gov (United States)

Edmonds, Karina

2008-01-01

This toolkit provides a common interface for displaying graphical user interface (GUI) components in stereo using either specialized stereo display hardware (e.g., liquid crystal shutter or polarized glasses) or anaglyph display (red/blue glasses) on standard workstation displays. An application using this toolkit will work without modification in either environment, allowing stereo software to reach a wider audience without sacrificing high-quality display on dedicated hardware. The toolkit is written in Java for use with the Swing GUI Toolkit and has cross-platform compatibility. It hooks into the graphics system, allowing any standard Swing component to be displayed in stereo. It uses the OpenGL graphics library to control the stereo hardware and to perform the rendering. It also supports anaglyph and special stereo hardware using the same API (application-program interface), and has the ability to simulate color stereo in anaglyph mode by combining the red band of the left image with the green/blue bands of the right image. This is a low-level toolkit that accomplishes simply the display of components (including the JadeDisplay image display component). It does not include higher-level functions such as disparity adjustment, 3D cursor, or overlays all of which can be built using this toolkit.

Monocular display unit for 3D display with correct depth perception

Science.gov (United States)

Sakamoto, Kunio; Hosomi, Takashi

2009-11-01

A study of virtual-reality system has been popular and its technology has been applied to medical engineering, educational engineering, a CAD/CAM system and so on. The 3D imaging display system has two types in the presentation method; one is a 3-D display system using a special glasses and the other is the monitor system requiring no special glasses. A liquid crystal display (LCD) recently comes into common use. It is possible for this display unit to provide the same size of displaying area as the image screen on the panel. A display system requiring no special glasses is useful for a 3D TV monitor, but this system has demerit such that the size of a monitor restricts the visual field for displaying images. Thus the conventional display can show only one screen, but it is impossible to enlarge the size of a screen, for example twice. To enlarge the display area, the authors have developed an enlarging method of display area using a mirror. Our extension method enables the observers to show the virtual image plane and to enlarge a screen area twice. In the developed display unit, we made use of an image separating technique using polarized glasses, a parallax barrier or a lenticular lens screen for 3D imaging. The mirror can generate the virtual image plane and it enlarges a screen area twice. Meanwhile the 3D display system using special glasses can also display virtual images over a wide area. In this paper, we present a monocular 3D vision system with accommodation mechanism, which is useful function for perceiving depth.

A comparison of leaf crystal macropatterns in the two sister genera Piper and Peperomia (Piperaceae).

Science.gov (United States)

Horner, Harry T; Wanke, Stefan; Samain, Marie-Stéphanie

2012-06-01

This is the first large-scale study comparing leaf crystal macropatterns of the species-rich sister genera Piper and Peperomia. It focuses on identifying types of calcium oxalate crystals and their macropatterns in leaves of both genera. The Piper results are placed in a phylogenetic context to show evolutionary patterns. This information will expand knowledge about crystals and provide specific examples to help study their form and function. One example is the first-time observation of Piper crystal sand tumbling in chlorenchyma vacuoles. Herbarium and fresh leaves were cleared of cytoplasmic content and examined with polarizing microscopy to identify types of crystals and their macropatterns. Selected hydrated herbarium and fresh leaf punches were processed for scanning electron microscopy and x-ray elemental analysis. Vibratome sections of living Piper and Peperomia leaves were observed for anatomical features and crystal movement. Both genera have different leaf anatomies. Piper displays four crystal types in chlorenchyma-crystal sand, raphides, styloids, and druses, whereas Peperomia displays three types-druses, raphides, and prisms. Because of different leaf anatomies and crystal types between the genera, macropatterns are completely different. Crystal macropattern evolution in both is characterized by increasing complexity, and both may use their crystals for light gathering and reflection for efficient photosynthesis under low-intensity light environments. Both genera have different leaf anatomies, types of crystals and crystal macropatterns. Based on Piper crystals associated with photosynthetic tissues and low-intensity light, further study of their function and association with surrounding chloroplasts is warranted, especially active crystal movement.

High-efficiency transmision neutron polarizer for high-resolution double crystal diffractometer

International Nuclear Information System (INIS)

Ioffe, A.; Krist, T.; Mezei, F.; Gordeev, G.; Ibrayev, B.

1997-01-01

An efficient transmission geometry neutron polarizer for the high-resolution double crystal diffractometer at HMI (λ=4.8 A) is described. A polarization of about 94% was achieved and the polarized neutron beam intensity amounts to 40% of the nonpolarized beam intensity. This opens up wide possibilities for the study of magnetic small-angle scattering for extremely small momentum transfer (Q∝10 -5 A -1 ). (orig.)

Comparison of liquid crystal display monitors calibrated with gray-scale standard display function and with γ 2.2 and iPad: observer performance in detection of cerebral infarction on brain CT.

Science.gov (United States)

Yoshimura, Kumiko; Nihashi, Takashi; Ikeda, Mitsuru; Ando, Yoshio; Kawai, Hisashi; Kawakami, Kenichi; Kimura, Reiko; Okada, Yumiko; Okochi, Yoshiyuki; Ota, Naotoshi; Tsuchiya, Kenichi; Naganawa, Shinji

2013-06-01

The purpose of the study was to compare observer performance in the detection of cerebral infarction on a brain CT using medical-grade liquid crystal display (LCD) monitors calibrated with the gray-scale standard display function and with γ 2.2 and using an iPad with a simulated screen setting. We amassed 97 sample sets, from 47 patients with proven cerebral infarction and 50 healthy control subjects. Nine radiologists independently assessed brain CT on a gray-scale standard display function LCD, a γ 2.2 LCD, and an iPad in random order over 4-week intervals. Receiver operating characteristic (ROC) analysis was performed by using the continuous scale, and the area under the ROC curve (A(z)) was calculated for each monitor. The A(z) values for gray-scale standard display function LCD, γ 2.2 LCD, and iPad were 0.875, 0.884, and 0.839, respectively. The difference among the three monitors was very small. There was no significant difference between gray-scale standard display function LCD and γ 2.2 LCD. However, the A(z) value was statistically significantly smaller for the iPad than the γ 2.2 LCD (p iPad was poorer than that using the other LCDs, the difference was small. Therefore, the iPad could not substitute for other LCD monitors. However, owing to the promising potential advantages of tablet PCs, such as portability, further examination is needed into the clinical use of tablet PCs.

Optimal enhancement in conversion efficiency of crystalline Si solar cells using inverse opal photonic crystals as back reflectors

International Nuclear Information System (INIS)

Chaouachi, A; M’nif, A; Hamzaoui, A H; Chtourou, R

2015-01-01

The effect of using inverse opal photonic crystals as back reflectors on the power conversion efficiency of c-Si solar cells is investigated. The reflection spectra of inverse opal photonic crystals with different diameters of air spheres are simulated using the finite difference time domain (FDTD) method. The reflection peaks are correlated with photonic band gaps present in the photonic band gap diagram. Significant improvement in the optical absorption of the crystalline silicon layer is recorded when inverse opal photonic crystals are considered. Physical mechanisms which may contribute to the enhancement of the light absorption are underlined. With higher short-circuit current enhancement possible, and with no corresponding degradation in open-circuit voltage V oc or the fill factor, the power conversion efficiency is increased significantly when inverse opal photonic crystals are used as back reflectors with optimized diameter of air spheres. (paper)

Highly-reliable operation of 638-nm broad stripe laser diode with high wall-plug efficiency for display applications

Science.gov (United States)

Yagi, Tetsuya; Shimada, Naoyuki; Nishida, Takehiro; Mitsuyama, Hiroshi; Miyashita, Motoharu

2013-03-01

Laser based displays, as pico to cinema laser projectors have gathered much attention because of wide gamut, low power consumption, and so on. Laser light sources for the displays are operated mainly in CW, and heat management is one of the big issues. Therefore, highly efficient operation is necessitated. Also the light sources for the displays are requested to be highly reliable. 638 nm broad stripe laser diode (LD) was newly developed for high efficiency and highly reliable operation. An AlGaInP/GaAs red LD suffers from low wall plug efficiency (WPE) due to electron overflow from an active layer to a p-cladding layer. Large optical confinement factor (Γ) design with AlInP cladding layers is adopted to improve the WPE. The design has a disadvantage for reliable operation because the large Γ causes high optical density and brings a catastrophic optical degradation (COD) at a front facet. To overcome the disadvantage, a window-mirror structure is also adopted in the LD. The LD shows WPE of 35% at 25°C, highest record in the world, and highly stable operation at 35°C, 550 mW up to 8,000 hours without any catastrophic optical degradation.

Polarized quantum dot emission in electrohydrodynamic jet printed photonic crystals

International Nuclear Information System (INIS)

See, Gloria G.; Xu, Lu; Nuzzo, Ralph G.; Sutanto, Erick; Alleyne, Andrew G.; Cunningham, Brian T.

2015-01-01

Tailored optical output, such as color purity and efficient optical intensity, are critical considerations for displays, particularly in mobile applications. To this end, we demonstrate a replica molded photonic crystal structure with embedded quantum dots. Electrohydrodynamic jet printing is used to control the position of the quantum dots within the device structure. This results in significantly less waste of the quantum dot material than application through drop-casting or spin coating. In addition, the targeted placement of the quantum dots minimizes any emission outside of the resonant enhancement field, which enables an 8× output enhancement and highly polarized emission from the photonic crystal structure

Double-layered liquid crystal light shutter for control of absorption and scattering of the light incident to a transparent display device

Science.gov (United States)

Huh, Jae-Won; Yu, Byeong-Hun; Shin, Dong-Myung; Yoon, Tae-Hoon

2015-03-01

Recently, a transparent display has got much attention as one of the next generation display devices. Especially, active studies on a transparent display using organic light-emitting diodes (OLEDs) are in progress. However, since it is not possible to obtain black color using a transparent OLED, it suffers from poor visibility. This inevitable problem can be solved by using a light shutter. Light shutter technology can be divided into two types; light absorption and scattering. However, a light shutter based on light absorption cannot block the background image perfectly and a light shutter based on light scattering cannot provide black color. In this work we demonstrate a light shutter using two liquid crystal (LC) layers, a light absorption layer and a light scattering layer. To realize a light absorption layer and a light scattering layer, we use the planar state of a dye-doped chiral nematic LC (CNLC) cell and the focal-conic state of a long-pitch CNLC cell, respectively. The proposed light shutter device can block the background image perfectly and show black color. We expect that the proposed light shutter can increase the visibility of a transparent display.

High-Efficiency Volume Reflection of an Ultrarelativistic Proton Beam with a Bent Silicon Crystal

CERN Document Server

Scandale, Walter; Carnera, Alberto; Della Mea, Gianantonio; De Salvador, Davide; Milan, Riccardo; Vomiero, Alberto; Baricordi, Stefano; Dalpiaz, Pietro; Fiorini, Massimiliano; Guidi, Vincenzo; Martinelli,Giuliano; Mazzolari, Andrea; Milan, Emiliano; Ambrosi, Giovanni; Azzarello, Philipp; Battiston, Roberto; Bertucci, Bruna; Burger, William J; Ionica, Maria; Zuccon, Paolo; Cavoto, Gianluca; Santacesaria, Roberta; Valente, Paolo; Vallazza, Erik; Afonin, Alexander G; Baranov, Vladimir T; Chesnokov, Yury A; Kotov, Vladilen I; Maisheev, Vladimir A; Yaznin, Igor A; Afansiev, Sergey V; Kovalenko, Alexander D; Taratin, Alexander M; Denisov, Alexander S; Gavrikov, Yury A; Ivanov, Yuri M; Ivochkin, Vladimir G; Kosyanenko, Sergey V; Petrunin, Anatoli A; Skorobogatov, Vyacheslav V; Suvorov, Vsevolod M; Bolognini, Davide; Foggetta,Luca; Hasan, Said; Prest, Michela

2007-01-01

The volume reflection phenomenon was detected while investigating 400 GeV proton interactions with bent silicon crystals in the external beam H8 of the CERN Super Proton Synchrotron. Such a process was observed for a wide interval of crystal orientations relative to the beam axis, and its efficiency exceeds 95%, thereby surpassing any previously observed value. These observations suggest new perspectives for the manipulation of high-energy beams, e.g., for collimation and extraction in new-generation hadron colliders, such as the CERN Large Hadron Collider.

Spectral distribution of the efficiency of terahertz difference frequency generation upon collinear propagation of interacting waves in semiconductor crystals

International Nuclear Information System (INIS)

Orlov, Sergei N; Polivanov, Yurii N

2007-01-01

Dispersion phase matching curves and spectral distributions of the efficiency of difference frequency generation in the terahertz range are calculated for collinear propagation of interacting waves in zinc blende semiconductor crystals (ZnTe, CdTe, GaP, GaAs). The effect of the pump wavelength, the nonlinear crystal length and absorption in the terahertz range on the spectral distribution of the efficiency of difference frequency generation is analysed. (nonlinear optical phenomena)

Display technologies for augmented reality

Science.gov (United States)

Lee, Byoungho; Lee, Seungjae; Jang, Changwon; Hong, Jong-Young; Li, Gang

2018-02-01

With the virtue of rapid progress in optics, sensors, and computer science, we are witnessing that commercial products or prototypes for augmented reality (AR) are penetrating into the consumer markets. AR is spotlighted as expected to provide much more immersive and realistic experience than ordinary displays. However, there are several barriers to be overcome for successful commercialization of AR. Here, we explore challenging and important topics for AR such as image combiners, enhancement of display performance, and focus cue reproduction. Image combiners are essential to integrate virtual images with real-world. Display performance (e.g. field of view and resolution) is important for more immersive experience and focus cue reproduction may mitigate visual fatigue caused by vergence-accommodation conflict. We also demonstrate emerging technologies to overcome these issues: index-matched anisotropic crystal lens (IMACL), retinal projection displays, and 3D display with focus cues. For image combiners, a novel optical element called IMACL provides relatively wide field of view. Retinal projection displays may enhance field of view and resolution of AR displays. Focus cues could be reconstructed via multi-layer displays and holographic displays. Experimental results of our prototypes are explained.

Crystal growth for high-efficiency silicon solar cells workshop: Summary

Science.gov (United States)

Dumas, K. A.

1985-01-01

The state of the art in the growth of silicon crystals for high-efficiency solar cells are reviewed, sheet requirements are defined, and furture areas of research are identified. Silicon sheet material characteristics that limit cell efficiencies and yields were described as well as the criteria for the ideal sheet-growth method. The device engineers wish list to the material engineer included: silicon sheet with long minority carrier lifetime that is uniform throughout the sheet, and which doesn't change during processing; and sheet material that stays flat throughout device processing, has uniform good mechanical strength, and is low cost. Impurities in silicon solar cells depreciate cell performance by reducing diffusion length and degrading junctions. The impurity behavior, degradation mechanisms, and variations in degradation threshold with diffusion length for silicon solar cells were described.

Increasing the lasing efficiency in cholesteric liquid-crystal photonic structures

Energy Technology Data Exchange (ETDEWEB)

Palto, S. P., E-mail: palto@online.ru; Shtykov, N M; Barnik, M I; Umanskii, B A [Russian Academy of Sciences, Shubnikov Institute of Crystallography (Russian Federation)

2010-03-15

Two types of lasing in cholesteric liquid crystals (LCs) in the range of luminescence of laser dye molecules have been investigated. The first type belongs to the Bragg modes at the photonic band edge, which propagate along the normal to the LC layer. The second type of lasing is related to the modes leaking into the substrate and propagating at small angles to the LC layer. It is shown that the Bragg lasing efficiency can be significantly increased under wide-aperture optical pumping. The method proposed for increasing the lasing efficiency is based on suppressing the excitation of leaky laser modes using partially absorbing thin films as the coatings for LC-orienting substrates. Both experimental results and the theoretical model of the effect using the numerical simulation data are discussed.

The sweet world of liquid crystals : The synthesis of non-amphiphilic carbohydrate-derived liquid crystals

NARCIS (Netherlands)

Smits, E

1998-01-01

The research in carbohydrate-derived liquid crystals was initiated by a review article by Jeffrey in 1986. This is rather late if one considers that the research on liquid crystals underwent a revival already in the 1960s after the discovery of the liquid crystal display (LCD). Carbohydrates were

Structuring β-Ga2O3 photonic crystal photocatalyst for efficient degradation of organic pollutants.

Science.gov (United States)

Li, Xiaofang; Zhen, Xiuzheng; Meng, Sugang; Xian, Jiangjun; Shao, Yu; Fu, Xianzhi; Li, Danzhen

2013-09-03

Coupling photocatalysts with photonic crystals structure is based on the unique property of photonic crystals in confining, controlling, and manipulating the incident photons. This combination enhances the light absorption in photocatalysts and thus greatly improves their photocatalytic performance. In this study, Ga2O3 photonic crystals with well-arranged skeleton structures were prepared via a dip-coating infiltration method. The positions of the electronic band absorption for Ga2O3 photonic crystals could be made to locate on the red edge, on the blue edge, and away from the edge of their photonic band gaps by changing the pore sizes of the samples, respectively. Particularly, the electronic band absorption of the Ga2O3 photonic crystal with a pore size of 135 nm was enhanced more than other samples by making it locate on the red edge of its photonic band gap, which was confirmed by the higher instantaneous photocurrent and photocatalytic activity for the degradation of various organic pollutants under ultraviolet light irradiation. Furthermore, the degradation mechanism over Ga2O3 photonic crystals was discussed. The design of Ga2O3 photonic crystals presents a prospective application of photonic crystals in photocatalysis to address light harvesting and quantum efficiency problems through manipulating photons or constructing photonic crystal structure as groundwork.

Selection of mRNA 5'-untranslated region sequence with high translation efficiency through ribosome display

International Nuclear Information System (INIS)

Mie, Masayasu; Shimizu, Shun; Takahashi, Fumio; Kobatake, Eiry

2008-01-01

The 5'-untranslated region (5'-UTR) of mRNAs functions as a translation enhancer, promoting translation efficiency. Many in vitro translation systems exhibit a reduced efficiency in protein translation due to decreased translation initiation. The use of a 5'-UTR sequence with high translation efficiency greatly enhances protein production in these systems. In this study, we have developed an in vitro selection system that favors 5'-UTRs with high translation efficiency using a ribosome display technique. A 5'-UTR random library, comprised of 5'-UTRs tagged with a His-tag and Renilla luciferase (R-luc) fusion, were in vitro translated in rabbit reticulocytes. By limiting the translation period, only mRNAs with high translation efficiency were translated. During translation, mRNA, ribosome and translated R-luc with His-tag formed ternary complexes. They were collected with translated His-tag using Ni-particles. Extracted mRNA from ternary complex was amplified using RT-PCR and sequenced. Finally, 5'-UTR with high translation efficiency was obtained from random 5'-UTR library

New methods of highly efficient controlled generation of radiation by liquid crystal nanostructures in a wide spectral range

International Nuclear Information System (INIS)

Bagayev, S N; Klementyev, V M; Nyushkov, B N; Pivtsov, V S; Trashkeev, S I

2012-01-01

We report the recent results of research focused on a new kind of soft matter-the liquid-crystal nanocomposites with controllable mechanical and nonlinear optical properties. These are promising media for implementation of ultra-compact photonic devices and efficient sources of coherent radiation in a wide spectral range. We overview the technology of preparation of nematic-liquid-crystal media saturated with disclination defects. The defects were formed in different ways: by embedding nanoparticles and molecular objects, by exposure to alpha-particle flux. The defect locations were controlled by applying an electric field. We also present and discuss the recently discovered features of nematic-liquid-crystal media: a thermal orientation effect leading to the fifth-order optical nonlinearity, enormous second-order susceptibility revealed by measurements, and structural changes upon exposure to laser radiation. We report on efficient generation of harmonics, sum and difference optical frequencies in nematic-liquid-crystal media. In addition, transformation of laser radiation spectra to spectral supercontinua, and filamentation of laser beams were also observed in nematic-liquid-crystal media. We conclude that most nonlinear optical effects result from changes of the orientational order in the examined nematic liquid crystals. These changes lead to the symmetry breaking and disclination appearances.

Combat vehicle crew helmet-mounted display: next generation high-resolution head-mounted display

Science.gov (United States)

Nelson, Scott A.

1994-06-01

The Combat Vehicle Crew Head-Mounted Display (CVC HMD) program is an ARPA-funded, US Army Natick Research, Development, and Engineering Center monitored effort to develop a high resolution, flat panel HMD for the M1 A2 Abrams main battle tank. CVC HMD is part of the ARPA High Definition Systems (HDS) thrust to develop and integrate small (24 micrometers square pels), high resolution (1280 X 1024 X 6-bit grey scale at 60 frame/sec) active matrix electroluminescent (AMEL) and active matrix liquid crystal displays (AMLCD) for head mounted and projection applications. The Honeywell designed CVC HMD is a next generation head-mounted display system that includes advanced flat panel image sources, advanced digital display driver electronics, high speed (> 1 Gbps) digital interconnect electronics, and light weight, high performance optical and mechanical designs. The resulting dramatic improvements in size, weight, power, and cost have already led to program spin offs for both military and commercial applications.

Phage display selection of efficient glutamine-donor substrate peptides for transglutaminase 2.

Science.gov (United States)

Keresztessy, Zsolt; Csosz, Eva; Hársfalvi, Jolán; Csomós, Krisztián; Gray, Joe; Lightowlers, Robert N; Lakey, Jeremy H; Balajthy, Zoltán; Fésüs, László

2006-11-01

Understanding substrate specificity and identification of natural targets of transglutaminase 2 (TG2), the ubiquitous multifunctional cross-linking enzyme, which forms isopeptide bonds between protein-linked glutamine and lysine residues, is crucial in the elucidation of its physiological role. As a novel means of specificity analysis, we adapted the phage display technique to select glutamine-donor substrates from a random heptapeptide library via binding to recombinant TG2 and elution with a synthetic amine-donor substrate. Twenty-six Gln-containing sequences from the second and third biopanning rounds were susceptible for TG2-mediated incorporation of 5-(biotinamido)penthylamine, and the peptides GQQQTPY, GLQQASV, and WQTPMNS were modified most efficiently. A consensus around glutamines was established as pQX(P,T,S)l, which is consistent with identified substrates listed in the TRANSDAB database. Database searches showed that several proteins contain peptides similar to the phage-selected sequences, and the N-terminal glutamine-rich domain of SWI1/SNF1-related chromatin remodeling proteins was chosen for detailed analysis. MALDI/TOF and tandem mass spectrometry-based studies of a representative part of the domain, SGYGQQGQTPYYNQQSPHPQQQQPPYS (SnQ1), revealed that Q(6), Q(8), and Q(22) are modified by TG2. Kinetic parameters of SnQ1 transamidation (K(M)(app) = 250 microM, k(cat) = 18.3 sec(-1), and k(cat)/K(M)(app) = 73,200) classify it as an efficient TG2 substrate. Circular dichroism spectra indicated that SnQ1 has a random coil conformation, supporting its accessibility in the full-length parental protein. Added together, here we report a novel use of the phage display technology with great potential in transglutaminase research.

Plasmonic enhancement in BiVO4 photonic crystals for efficient water splitting.

Science.gov (United States)

Zhang, Liwu; Lin, Chia-Yu; Valev, Ventsislav K; Reisner, Erwin; Steiner, Ullrich; Baumberg, Jeremy J

2014-10-15

Photo-electrochemical water splitting is a very promising and environmentally friendly route for the conversion of solar energy into hydrogen. However, the solar-to-H2 conversion efficiency is still very low due to rapid bulk recombination of charge carriers. Here, a photonic nano-architecture is developed to improve charge carrier generation and separation by manipulating and confining light absorption in a visible-light-active photoanode constructed from BiVO4 photonic crystal and plasmonic nanostructures. Synergistic effects of photonic crystal stop bands and plasmonic absorption are observed to operate in this photonic nanostructure. Within the scaffold of an inverse opal photonic crystal, the surface plasmon resonance is significantly enhanced by the photonic Bragg resonance. Nanophotonic photoanodes show AM 1.5 photocurrent densities of 3.1 ± 0.1 mA cm(-2) at 1.23 V versus RHE, which is among the highest for oxide-based photoanodes and over 4 times higher than the unstructured planar photoanode. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Efficiency Improvement Opportunities for Personal Computer Monitors. Implications for Market Transformation Programs

Energy Technology Data Exchange (ETDEWEB)

Park, Won Young [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Phadke, Amol [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Shah, Nihar [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

2012-06-29

Displays account for a significant portion of electricity consumed in personal computer (PC) use, and global PC monitor shipments are expected to continue to increase. We assess the market trends in the energy efficiency of PC monitors that are likely to occur without any additional policy intervention and estimate that display efficiency will likely improve by over 40% by 2015 compared to today’s technology. We evaluate the cost effectiveness of a key technology which further improves efficiency beyond this level by at least 20% and find that its adoption is cost effective. We assess the potential for further improving efficiency taking into account the recent development of universal serial bus (USB) powered liquid crystal display (LCD) monitors and find that the current technology available and deployed in USB powered monitors has the potential to deeply reduce energy consumption by as much as 50%. We provide insights for policies and programs that can be used to accelerate the adoption of efficient technologies to capture global energy saving potential from PC monitors which we estimate to be 9.2 terawatt-hours [TWh] per year in 2015.

A cadmium-zinc-telluride crystal array spectrometer

International Nuclear Information System (INIS)

McHugh, H. R.; Quam, W.; DeVore, T.; Vogle, R.; Weslowski, J.

2003-01-01

This paper describes a gamma detector employing an array of eight cadmium-zinc-telluride (CZT) crystals configured as a high resolution gamma ray spectrometer. This detector is part of a more complex instrument that identifies the isotope,displays this information, and records the gamma spectrum. Various alarms and other operator features are incorporated in this battery operated rugged instrument. The CZT detector is the key component of this instrument and will be described in detail in this paper. We have made extensive spectral measurements of the usual laboratory gamma sources, common medical isotopes, and various Special Nuclear Materials (SNM) with this detector. Some of these data will be presented as spectra. We will also present energy resolution and detection efficiency for the basic 8-crystal array. Additional data will also be presented for a 32-crystal array. The basic 8-crystal array development was completed two years ago, and the system electronic design has been imp roved recently. This has resulted in significantly improved noise performance. We expect to have a much smaller detector package, using 8 crystals, in a few months. This package will use flip-chip packaging to reduce the electronics physical size by a factor of 5

A new computationally-efficient two-dimensional model for boron implantation into single-crystal silicon

International Nuclear Information System (INIS)

Klein, K.M.; Park, C.; Yang, S.; Morris, S.; Do, V.; Tasch, F.

1992-01-01

We have developed a new computationally-efficient two-dimensional model for boron implantation into single-crystal silicon. This paper reports that this new model is based on the dual Pearson semi-empirical implant depth profile model and the UT-MARLOWE Monte Carlo boron ion implantation model. This new model can predict with very high computational efficiency two-dimensional as-implanted boron profiles as a function of energy, dose, tilt angle, rotation angle, masking edge orientation, and masking edge thickness

The development of a colour liquid crystal display spatial light modulator and applications in polychromatic optical data processing

Science.gov (United States)

Aiken, John Charles

The development of a colour Spatial Light Modulator (SLM) and its application to optical information processing is described. Whilst monochrome technology has been established for many years, this is not the case for colour where commercial systems are unavailable. A main aspect of this study is therefore, how the use of colour can add an additional dimension to optical information processing. A well established route to monochrome system development has been the use of (black and white) liquid crystal televisions (LCTV) as SLM, providing useful performance at a low-cost. This study is based on the unique use of a colour display removed from a LCTV and operated as a colour SLM. A significant development has been the replacement of the original TV electronics operating the display with enhanced drive electronics specially developed for this application. Through a computer interface colour images from a drawing package or video camera can now be readily displayed on the LCD as input to an optical system. A detailed evaluation of the colour LCD optical properties, indicates that the new drive electronics have considerably improved the operation of the display for use as a colour SLM. Applications are described employing the use of colour in Fourier plane filtering, image correlation and speckle metrology. The SLM (and optical system) developed demonstrates, how the addition of colour has greatly enhanced its capabilities to implement principles of optical data processing, conventionally performed monochromatically. The hybrid combination employed, combining colour optical data processing with electronic techniques has resulted in a capable development system. Further development of the system using current colour LCDs and the move towards a portable system, is considered in the study conclusion.

An inkjet printed stripe-type color filter of liquid crystal display

International Nuclear Information System (INIS)

Chen, Chin-Tai; Wu, Kuo-Hua; Shieh, Fanny; Lu, Chun-Fu

2010-01-01

In this paper, we propose a comprehensive concept and new design of a drop-on-demand (DOD) inkjet printing process for fabricating color filter (CF) layers of liquid crystal displays (LCDs) onto the structured surfaces of flat substrates, composed of 'physical sidewalls' for aligning and controlling the liquid morphology. Several fundamental guidelines of the design have been addressed in current inkjet-printing techniques. Using a droplet generator (printhead) of the deposition system, the color-ink drops can be jetted and placed over the specific domains, where the sidewalls align the flow merged from a stream of droplets and fulfill the coverage of the defined areas, in which the geometrical relations correlating the droplets and sidewalls are explicitly expressed in the study. According to the results of the simulation and analysis, the proposed sidewalls, acting as the physical barriers, can control the liquid morphology through the simple geometric factors such as sidewall widths, heights and contact angles. The experimental results showed that the solid RGB color layers were self-assembled from the liquid droplets and formed with the uniform thickness, except for the neighborhood of the sidewalls. It indicated that the sidewalls serving as 'physical barriers' had a remarkable effect in confining and self-aligning the droplet flow within the desirable regions. This inkjet-printing method would alternatively offer one cost-effective and high-flexibility method for the production of the versatile LCD CF, thus being particularly beneficial for large-area printing and flexible substrates.

Speckle noise reduction on a laser projection display via a broadband green light source.

Science.gov (United States)

Yu, Nan Ei; Choi, Ju Won; Kang, Heejong; Ko, Do-Kyeong; Fu, Shih-Hao; Liou, Jiun-Wei; Kung, Andy H; Choi, Hee Joo; Kim, Byoung Joo; Cha, Myoungsik; Peng, Lung-Han

2014-02-10

A broadband green light source was demonstrated using a tandem-poled lithium niobate (TPLN) crystal. The measured wavelength and temperature bandwidth were 6.5 nm and 100 °C, respectively, spectral bandwidth was 36 times broader than the periodically poled case. Although the conversion efficiency was smaller than in the periodic case, the TPLN device had a good figure of merit owing to the extremely large bandwidth for wavelength and temperature. The developed broadband green light source exhibited speckle noise approximately one-seventh of that in the conventional approach for a laser projection display.

New ultraportable display technology and applications

Science.gov (United States)

Alvelda, Phillip; Lewis, Nancy D.

1998-08-01

MicroDisplay devices are based on a combination of technologies rooted in the extreme integration capability of conventionally fabricated CMOS active-matrix liquid crystal display substrates. Customized diffraction grating and optical distortion correction technology for lens-system compensation allow the elimination of many lenses and systems-level components. The MicroDisplay Corporation's miniature integrated information display technology is rapidly leading to many new defense and commercial applications. There are no moving parts in MicroDisplay substrates, and the fabrication of the color generating gratings, already part of the CMOS circuit fabrication process, is effectively cost and manufacturing process-free. The entire suite of the MicroDisplay Corporation's technologies was devised to create a line of application- specific integrated circuit single-chip display systems with integrated computing, memory, and communication circuitry. Next-generation portable communication, computer, and consumer electronic devices such as truly portable monitor and TV projectors, eyeglass and head mounted displays, pagers and Personal Communication Services hand-sets, and wristwatch-mounted video phones are among the may target commercial markets for MicroDisplay technology. Defense applications range from Maintenance and Repair support, to night-vision systems, to portable projectors for mobile command and control centers.

Synthesis of SAPO-56 with controlled crystal size

Energy Technology Data Exchange (ETDEWEB)

Wu, Ting; Feng, Xuhui [Colorado School of Mines, Chemical and Biological Engineering Department (United States); Carreon, Maria L. [University of Tulsa, Rusell School of Chemical Engineering (United States); Carreon, Moises A., E-mail: mcarreon@mines.edu [Colorado School of Mines, Chemical and Biological Engineering Department (United States)

2017-03-15

Herein, we present the hydrothermal synthesis of SAPO-56 crystals with relatively controlled crystal/particle size. The effects of water content, aluminum source, gel composition, stirring, crystallization temperature and time, as well as the incorporation of crystal growth inhibitors during synthesis were systematically investigated. The synthesized SAPO-56 crystals displayed BET surface areas as high as ∼630 m{sup 2} g{sup −1} with relative narrow size distribution in the ∼5–60 μm range. Nitrogen BET surface areas in the 451 to 631 m{sup 2} g{sup −1} range were observed. Decreasing the crystallization temperature from 220 to 210 °C helped to decrease the average SAPO-56 crystal size. Diluted gel compositions promoted the formation of smaller crystals. Crystal growth inhibitors were found to be helpful in reducing crystal size and narrow the size distribution. Specifically, ∼5 μm SAPO-56 crystals displaying narrow size distribution were synthesized employing aluminum-tri-sec-butoxide as Al source, high water content, and high stirring rates.

Synthesis of SAPO-56 with controlled crystal size

International Nuclear Information System (INIS)

Wu, Ting; Feng, Xuhui; Carreon, Maria L.; Carreon, Moises A.

2017-01-01

Herein, we present the hydrothermal synthesis of SAPO-56 crystals with relatively controlled crystal/particle size. The effects of water content, aluminum source, gel composition, stirring, crystallization temperature and time, as well as the incorporation of crystal growth inhibitors during synthesis were systematically investigated. The synthesized SAPO-56 crystals displayed BET surface areas as high as ∼630 m"2 g"−"1 with relative narrow size distribution in the ∼5–60 μm range. Nitrogen BET surface areas in the 451 to 631 m"2 g"−"1 range were observed. Decreasing the crystallization temperature from 220 to 210 °C helped to decrease the average SAPO-56 crystal size. Diluted gel compositions promoted the formation of smaller crystals. Crystal growth inhibitors were found to be helpful in reducing crystal size and narrow the size distribution. Specifically, ∼5 μm SAPO-56 crystals displaying narrow size distribution were synthesized employing aluminum-tri-sec-butoxide as Al source, high water content, and high stirring rates.

Crystallization in metglass: growth mechanism of crystals and radiation effects in Fe Ni P B

International Nuclear Information System (INIS)

Limoge, Y.; Barbu, A.

1981-08-01

Studying crystallization mechanisms and transport properties in amorphous metallic alloys we propose a model for systems wich are displaying eutectoid decomposition. Bringing together self diffusion, electron microscopy and electron irradiation experiments on a Fe Ni P B alloys we have shown that crystallization controlled by interfacial diffusion at the crystal surface can explain all the observed features of the experimental behaviour

Efficient parametric interactions in a low loss GaInP photonic crystal waveguide

DEFF Research Database (Denmark)

Cestier, I.; Willinger, A.; Colman, Pierre

2011-01-01

We describe time domain characterizations of dynamic four-wave mixing in a low loss modified W1 GaInP photonic crystal waveguide. Using 32 ps wide pump pulses with peak powers of up to 1:1W we achieved a very large conversion efficiency of ?6:8 dB as well as a 1:3 dB parametric gain experienced...

Subjective comparison of brightness preservation methods for local backlight dimming displays

DEFF Research Database (Denmark)

Korhonen, Jari; Mantel, Claire; Forchhammer, Søren

2015-01-01

Local backlight dimming is a popular technology in high quality Liquid Crystal Displays (LCDs). In those displays, the backlight is composed of contributions from several individually adjustable backlight segments, set at different backlight luminance levels in different parts of the screen, acco...

Pyrolysis characteristics and pyrolysis products separation for recycling organic materials from waste liquid crystal display panels

Energy Technology Data Exchange (ETDEWEB)

Wang, Ruixue; Xu, Zhenming, E-mail: zmxu@sjtu.edu.cn

2016-01-25

Highlights: • Pyrolysis characteristics are conducted for a better understanding of LCDs pyrolysis. • Optimum design is developed which is significant to guide the further industrial process. • Acetic acid and TPP are recycled and separated. - Abstract: Waste liquid crystal display (LCD) panels mainly contain inorganic materials (glass substrate with indium-tin oxide film), and organic materials (polarizing film and liquid crystal). The organic materials should be removed beforehand since the organic matters would hinder the indium recycling process. In the present study, pyrolysis process is used to remove the organic materials and recycle acetic as well as and triphenyl phosphate (TPP) from waste LCD panels in an environmental friendly way. Several highlights of this study are summarized as follows: (i) Pyrolysis characteristics and pyrolysis kinetics analysis are conducted which is significant to get a better understanding of the pyrolysis process. (ii) Optimum design is developed by applying Box–Behnken Design (BBD) under response surface methodology (RSM) for engineering application which is significant to guide the further industrial recycling process. The oil yield could reach 70.53 wt% and the residue rate could reach 14.05 wt% when the pyrolysis temperature is 570 °C, nitrogen flow rate is 6 L min{sup −1} and the particle size is 0.5 mm. (iii) Furthermore, acetic acid and TPP are recycled, and then separated by rotary evaporation, which could reduce the consumption of fossil energy for producing acetic acid, and be reused in electronics manufacturing industry.

Pyrolysis characteristics and pyrolysis products separation for recycling organic materials from waste liquid crystal display panels

International Nuclear Information System (INIS)

Wang, Ruixue; Xu, Zhenming

2016-01-01

Highlights: • Pyrolysis characteristics are conducted for a better understanding of LCDs pyrolysis. • Optimum design is developed which is significant to guide the further industrial process. • Acetic acid and TPP are recycled and separated. - Abstract: Waste liquid crystal display (LCD) panels mainly contain inorganic materials (glass substrate with indium-tin oxide film), and organic materials (polarizing film and liquid crystal). The organic materials should be removed beforehand since the organic matters would hinder the indium recycling process. In the present study, pyrolysis process is used to remove the organic materials and recycle acetic as well as and triphenyl phosphate (TPP) from waste LCD panels in an environmental friendly way. Several highlights of this study are summarized as follows: (i) Pyrolysis characteristics and pyrolysis kinetics analysis are conducted which is significant to get a better understanding of the pyrolysis process. (ii) Optimum design is developed by applying Box–Behnken Design (BBD) under response surface methodology (RSM) for engineering application which is significant to guide the further industrial recycling process. The oil yield could reach 70.53 wt% and the residue rate could reach 14.05 wt% when the pyrolysis temperature is 570 °C, nitrogen flow rate is 6 L min"−"1 and the particle size is 0.5 mm. (iii) Furthermore, acetic acid and TPP are recycled, and then separated by rotary evaporation, which could reduce the consumption of fossil energy for producing acetic acid, and be reused in electronics manufacturing industry.

Chiral crystal of a C2v-symmetric 1,3-diazaaulene derivative showing efficient optical second harmonic generation

KAUST Repository

Ma, Xiaohua

2011-03-01

Achiral nonlinear optical (NLO) chromophores 1,3-diazaazulene derivatives, 2-(4â€-aminophenyl)-6-nitro-1,3-diazaazulene (APNA) and 2-(4â€-N,N-diphenylaminophenyl)-6-nitro-1,3-diazaazulene (DPAPNA), were synthesized with high yield. Despite the moderate static first hyperpolarizabilities (β0) for both APNA [(136 ± 5) à - 10-30 esu] and DPAPNA [(263 ± 20) à - 10-30 esu], only APNA crystal shows a powder efficiency of second harmonic generation (SHG) of 23 times that of urea. It is shown that the APNA crystallization driven cooperatively by the strong H-bonding network and the dipolar electrostatic interactions falls into the noncentrosymmetric P2 12121 space group, and that the helical supramolecular assembly is solely responsible for the efficient SHG response. To the contrary, the DPAPNA crystal with centrosymmetric P-1 space group is packed with antiparalleling dimmers, and is therefore completely SHG-inactive. 1,3-Diazaazulene derivatives are suggested to be potent building blocks for SHG-active chiral crystals, which are advantageous in high thermal stability, excellent near-infrared transparency and high degree of designing flexibility. © 2011 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys, 2011 Optical crystals based on 1,3-diazaazulene derivatives are reported as the first example of organic nonlinear optical crystal whose second harmonic generation activity is found to originate solely from the chirality of their helical supramolecular orientation. The strong H-bond network forming between adjacent choromophores is found to act cooperatively with dipolar electrostatic interactions in driving the chiral crystallization of this material. Copyright © 2011 Wiley Periodicals, Inc.

Simple down conversion nano-crystal coatings for enhancing Silicon-solar cells efficiency

Directory of Open Access Journals (Sweden)

Gur Mittelman

2016-09-01

Full Text Available Utilizing self-assembled nano-structured coatings on top of existing solar cells has thepotential to increase the total quantum efficiency of the cell using a simple and cheap process. In ourwork we have exploited the controlled absorption of nano-crystal with different band gaps to realizedown conversion artificial antennas that self-assembled on the device surface. The UV sun light isconverted to the visible light enhancing the solar cell performance in two complementary routes; a.protecting the solar cell and coatings from the UV illumination and therefore reducing the UVradiation damage. b. enhancing the total external quantum efficiency of the cell by one percent. Thisis achieved using a simple cheap process that can be adjusted to many different solar cells.

A crystal barrel

CERN Multimedia

2007-01-01

The production of crystals for the barrel of the CMS electromagnetic calorimeter has been completed. This is an important milestone for the experiment, which received the last of its 62,960 crystals on 9 March. The members of the team responsible for the crystal acceptance testing at CERN display the last crystal for the CMS electromagnetic calorimeter barrel. From left to right: Igor Tarasov, Etiennette Auffray and Hervé Cornet.One of the six machines specially developed to measure 67 different parameters on each crystal. Igor Tarasov is seen inserting the last batch of crystals into the machine. The last of the 62,960 CMS barrel crystals arrived at CERN on 9 March. Once removed from its polystyrene protection, this delicate crystal, like thousands of its predecessors, will be inserted into the last of the 36 supermodules of the barrel electromagnetic calorimeter in a few days' time. This marks the end of an important chapter in an almost 15-year-long journey by the CMS crystals team, some of whose member...

Thermotropic Ionic Liquid Crystals

Science.gov (United States)

Axenov, Kirill V.; Laschat, Sabine

2011-01-01

The last five years’ achievements in the synthesis and investigation of thermotropic ionic liquid crystals are reviewed. The present review describes the mesomorphic properties displayed by organic, as well as metal-containing ionic mesogens. In addition, a short overview on the ionic polymer and self-assembled liquid crystals is given. Potential and actual applications of ionic mesogens are also discussed. PMID:28879986

Thermotropic Ionic Liquid Crystals

Directory of Open Access Journals (Sweden)

Sabine Laschat

2011-01-01

Full Text Available The last five years’ achievements in the synthesis and investigation of thermotropic ionic liquid crystals are reviewed. The present review describes the mesomorphic properties displayed by organic, as well as metal-containing ionic mesogens. In addition, a short overview on the ionic polymer and self-assembled liquid crystals is given. Potential and actual applications of ionic mesogens are also discussed.

Thermotropic Ionic Liquid Crystals.

Science.gov (United States)

Axenov, Kirill V; Laschat, Sabine

2011-01-14

The last five years' achievements in the synthesis and investigation of thermotropic ionic liquid crystals are reviewed. The present review describes the mesomorphic properties displayed by organic, as well as metal-containing ionic mesogens. In addition, a short overview on the ionic polymer and self-assembled liquid crystals is given. Potential and actual applications of ionic mesogens are also discussed.

Thermotropic Ionic Liquid Crystals

OpenAIRE

Axenov, Kirill V.; Laschat, Sabine

2011-01-01

The last five years’ achievements in the synthesis and investigation of thermotropic ionic liquid crystals are reviewed. The present review describes the mesomorphic properties displayed by organic, as well as metal-containing ionic mesogens. In addition, a short overview on the ionic polymer and self-assembled liquid crystals is given. Potential and actual applications of ionic mesogens are also discussed.

Slow-light-enhanced energy efficiency for graphene microheaters on silicon photonic crystal waveguides

Science.gov (United States)

Yan, Siqi; Zhu, Xiaolong; Frandsen, Lars Hagedorn; Xiao, Sanshui; Mortensen, N. Asger; Dong, Jianji; Ding, Yunhong

2017-01-01

Slow light has been widely utilized to obtain enhanced nonlinearities, enhanced spontaneous emissions and increased phase shifts owing to its ability to promote light–matter interactions. By incorporating a graphene on a slow-light silicon photonic crystal waveguide, here we experimentally demonstrate an energy-efficient graphene microheater with a tuning efficiency of 1.07 nmmW−1 and power consumption per free spectral range of 3.99 mW. The rise and decay times (10–90%) are only 750 and 525 ns, which, to the best of our knowledge, are the fastest reported response times for microheaters in silicon photonics. The corresponding figure of merit of the device is 2.543 nW s, one order of magnitude better than results reported in previous studies. The influence of the length and shape of the graphene heater to the tuning efficiency is further investigated, providing valuable guidelines for enhancing the tuning efficiency of the graphene microheater. PMID:28181531

Efficient Inorganic Perovskite Light-Emitting Diodes with Polyethylene Glycol Passivated Ultrathin CsPbBr3 Films.

Science.gov (United States)

Song, Li; Guo, Xiaoyang; Hu, Yongsheng; Lv, Ying; Lin, Jie; Liu, Zheqin; Fan, Yi; Liu, Xingyuan

2017-09-07

Efficient inorganic perovskite light-emitting diodes (PeLEDs) with an ultrathin perovskite emission layer (∼30 nm) were realized by doping Lewis base polyethylene glycol (PEG) into CsPbBr 3 films. PEG in the perovskite films not only physically fills the crystal boundaries but also interacts with the perovskite crystals to passivate the crystal grains, reduce nonradiative recombination, and ensure efficient luminance and high efficiency. As a result, promoted brightness, current efficiency (CE), and external quantum efficiency (EQE) were achieved. The nonradiative decay rate of the PEG:CsPbBr 3 composite film is 1 order of magnitude less than that of the neat CsPbBr 3 film. After further optimization of the molar ratio between CsBr and PbBr 2 , a peak CE of 19 cd/A, a maximum EQE of 5.34%, and a maximum brightness of 36600 cd/m 2 were achieved, demonstrating the interaction between PEG and the precursors. The results are expected to offer some helpful implications in optimizing the polymer-assisted PeLEDs with ultrathin emission layers, which might have potential application in see-through displays.

Third-Generation Display Technology: Nominally Transparent Material

Directory of Open Access Journals (Sweden)

Charles Willow

2010-12-01

Full Text Available Display technology is reshaping the consumer, business, government, and even not-for-profit markets in the midst of the digital convergence, coupled with recent smart phones led by Apple, Inc. First-Generation (1G display technology was dominated by the Cathode Ray Tubes, followed by Liquid Crystal Display and Plasma in 2G. A radically innovative shift as a disruptive technology is expected to follow in 3G to utilize virtually any transparent material, which wirelessly connects to portable access points. This paper studies the feasibility of the 3G Display Technology (DT with Technology S-Curves, and presents possible business models and technology strategies which may be generated from it. Additional subsets of business models may be derived for a wide range of industry applications.

Photonic crystal light source

Science.gov (United States)

Fleming, James G [Albuquerque, NM; Lin, Shawn-Yu [Albuquerque, NM; Bur, James A [Corrales, NM

2004-07-27

A light source is provided by a photonic crystal having an enhanced photonic density-of-states over a band of frequencies and wherein at least one of the dielectric materials of the photonic crystal has a complex dielectric constant, thereby producing enhanced light emission at the band of frequencies when the photonic crystal is heated. The dielectric material can be a metal, such as tungsten. The spectral properties of the light source can be easily tuned by modification of the photonic crystal structure and materials. The photonic crystal light source can be heated electrically or other heating means. The light source can further include additional photonic crystals that exhibit enhanced light emission at a different band of frequencies to provide for color mixing. The photonic crystal light source may have applications in optical telecommunications, information displays, energy conversion, sensors, and other optical applications.

Frequency Doubling Broadband Light in Multiple Crystals

International Nuclear Information System (INIS)

Alford, William J.; Smith, Arlee V.

2000-01-01

The authors compare frequency doubling of broadband light in a single nonlinear crystal with doubling in five crystals with intercrystal temporal walk off compensation, and with doubling in five crystals adjusted for offset phase matching frequencies. Using a plane-wave, dispersive numerical model of frequency doubling they study the bandwidth of the second harmonic and the conversion efficiency as functions of crystal length and fundamental irradiance. For low irradiance the offset phase matching arrangement has lower efficiency than a single crystal of the same total length but gives a broader second harmonic bandwidth. The walk off compensated arrangement gives both higher conversion efficiency and broader bandwidth than a single crystal. At high irradiance, both multicrystal arrangements improve on the single crystal efficiency while maintaining broad bandwidth

A multistep single-crystal-to-single-crystal bromodiacetylene dimerization

Science.gov (United States)

Hoheisel, Tobias N.; Schrettl, Stephen; Marty, Roman; Todorova, Tanya K.; Corminboeuf, Clémence; Sienkiewicz, Andrzej; Scopelliti, Rosario; Schweizer, W. Bernd; Frauenrath, Holger

2013-04-01

Packing constraints and precise placement of functional groups are the reason that organic molecules in the crystalline state often display unusual physical or chemical properties not observed in solution. Here we report a single-crystal-to-single-crystal dimerization of a bromodiacetylene that involves unusually large atom displacements as well as the cleavage and formation of several bonds. Density functional theory computations support a mechanism in which the dimerization is initiated by a [2 + 1] photocycloaddition favoured by the nature of carbon-carbon short contacts in the crystal structure. The reaction proceeded up to the theoretical degree of conversion without loss of crystallinity, and it was also performed on a preparative scale with good yield. Moreover, it represents the first synthetic pathway to (E)-1,2-dibromo-1,2-diethynylethenes, which could serve as synthetic intermediates for the preparation of molecular carbon scaffolds. Our findings both extend the scope of single-crystal-to-single-crystal reactions and highlight their potential as a synthetic tool for complex transformations.

Lyotropic Liquid Crystal Phases from Anisotropic Nanomaterials

Directory of Open Access Journals (Sweden)

Ingo Dierking

2017-10-01

Full Text Available Liquid crystals are an integral part of a mature display technology, also establishing themselves in other applications, such as spatial light modulators, telecommunication technology, photonics, or sensors, just to name a few of the non-display applications. In recent years, there has been an increasing trend to add various nanomaterials to liquid crystals, which is motivated by several aspects of materials development. (i addition of nanomaterials can change and thus tune the properties of the liquid crystal; (ii novel functionalities can be added to the liquid crystal; and (iii the self-organization of the liquid crystalline state can be exploited to template ordered structures or to transfer order onto dispersed nanomaterials. Much of the research effort has been concentrated on thermotropic systems, which change order as a function of temperature. Here we review the other side of the medal, the formation and properties of ordered, anisotropic fluid phases, liquid crystals, by addition of shape-anisotropic nanomaterials to isotropic liquids. Several classes of materials will be discussed, inorganic and mineral liquid crystals, viruses, nanotubes and nanorods, as well as graphene oxide.

Fluorinated tolane and dioxane liquid crystals for ferroelectric display applications

International Nuclear Information System (INIS)

Chu Chuan Dong

1994-05-01

The aim of this thesis was to make low viscosity, low birefringence, large negative dielectric anisotropy liquid-crystalline materials for use in ferroelectric liquid crystal mixtures to be used in high speed display devices. Saturated heterocyclic rings, dioxane and dioxaborinane, were chosen separately to be linked with a difluorophenyl system as the main component of the mesogenic core. In order to optimise the physical properties and to reduce the cost of the chiral materials, the strategy of making dopant-host mixtures was used. In addition to the difluorobiphenyl dioxaborinanes, three types of compounds were prepared possessing difluorophenyl rings and a dioxane ring: (i) difluorophenyl dioxanes and difluorobiphenyl dioxanes with the fluorinated ring in the middle of or at the end of the core; (ii) a number of compounds with linking groups, dimethylene (CH 2 CH 2 ), ester (COO), ethenylene (CH=CH) and ethynylene (C≡C) between adjacent benzene rings or between a dioxane ring and a benzene ring; (iii) difluorobiphenyl dioxanes possessing a chiral aliphatic chain were chosen as chiral dopants whose structure matched those of the host materials. Other compounds which have been synthesised are the difluorotolanes and difluorophenyl-ethynyl compounds, which were targeted because of the low viscosity of the tolane compounds and the negative dielectric anisotropy of the difluorophenyl ring. Fifty-six 2-(2,3-difluorobiphenyl-4'-yl)-1,3-dioxanes (n = 5-9, m = 5-10 or O5-O9; or n = 9, R' = OCH 2 CH(CH 3 )C 4 H 9 ) were prepared. Smectic C and nematic phases were observed for most of the alkyl-alkoxy homologues. Conversely, most of the dialkyl compounds exhibited smectic C, smectic A and nematic phases. The birefringences (Δn) and the dielectric anisotropies (Δε) of a number of materials have been determined. Three 2-(2,3-difluorobiphenyl-4-yl)-5-alkyl-1,3-dioxanes (n = 7, m = O7-O9) were prepared and only exhibit nematic phases. Two difluorophenyl dioxanes were

Holographic storage of three-dimensional image and data using photopolymer and polymer dispersed liquid crystal films

International Nuclear Information System (INIS)

Gao Hong-Yue; Liu Pan; Zeng Chao; Yao Qiu-Xiang; Zheng Zhiqiang; Liu Jicheng; Zheng Huadong; Yu Ying-Jie; Zeng Zhen-Xiang; Sun Tao

2016-01-01

We present holographic storage of three-dimensional (3D) images and data in a photopolymer film without any applied electric field. Its absorption and diffraction efficiency are measured, and reflective analog hologram of real object and image of digital information are recorded in the films. The photopolymer is compared with polymer dispersed liquid crystals as holographic materials. Besides holographic diffraction efficiency of the former is little lower than that of the latter, this work demonstrates that the photopolymer is more suitable for analog hologram and big data permanent storage because of its high definition and no need of high voltage electric field. Therefore, our study proposes a potential holographic storage material to apply in large size static 3D holographic displays, including analog hologram displays, digital hologram prints, and holographic disks. (special topic)

A versatile, highly-efficient, high-resolution von Hamos Bragg crystal x-ray spectrometer

International Nuclear Information System (INIS)

Vane, C.R.; Smith, M.S.; Raman, S.

1988-01-01

An efficient, high-resolution, vertical-focusing, Bragg crystal x-ray spectrometer has been specifically designed and constructed for use in measurements of x rays produced in collisions of energetic heavy ions. In this report the design and resulting operational characteristics of the final instrument are fully described. A wide variety of sample data is also included to illustrate the utility of this device in several areas of research. 14 refs., 38 figs

Liquid crystal interfaces: Experiments, simulations and biosensors

Science.gov (United States)

Popov, Piotr

Interfacial phenomena are ubiquitous and extremely important in various aspects of biological and industrial processes. For example, many liquid crystal applications start by alignment with a surface. The underlying mechanisms of the molecular organization of liquid crystals at an interface are still under intensive study and continue to be important to the display industry in order to develop better and/or new display technology. My dissertation research has been devoted to studying how complex liquid crystals can be guided to organize at an interface, and to using my findings to develop practical applications. Specifically, I have been working on developing biosensors using liquid-crystal/surfactant/lipid/protein interactions as well as the alignment of low-symmetry liquid crystals for potential new display and optomechanical applications. The biotechnology industry needs better ways of sensing biomaterials and identifying various nanoscale events at biological interfaces and in aqueous solutions. Sensors in which the recognition material is a liquid crystal naturally connects the existing knowledge and experience of the display and biotechnology industries together with surface and soft matter sciences. This dissertation thus mainly focuses on the delicate phenomena that happen at liquid interfaces. In the introduction, I start by defining the interface and discuss its structure and the relevant interfacial forces. I then introduce the general characteristics of biosensors and, in particular, describe the design of biosensors that employ liquid crystal/aqueous solution interfaces. I further describe the basic properties of liquid crystal materials that are relevant for liquid crystal-based biosensing applications. In CHAPTER 2, I describe the simulation methods and experimental techniques used in this dissertation. In CHAPTER 3 and CHAPTER 4, I present my computer simulation work. CHAPTER 3 presents insight of how liquid crystal molecules are aligned by

Designing High-Efficiency Thin Silicon Solar Cells Using Parabolic-Pore Photonic Crystals

Science.gov (United States)

Bhattacharya, Sayak; John, Sajeev

2018-04-01

We demonstrate the efficacy of wave-interference-based light trapping and carrier transport in parabolic-pore photonic-crystal, thin-crystalline silicon (c -Si) solar cells to achieve above 29% power conversion efficiencies. Using a rigorous solution of Maxwell's equations through a standard finite-difference time domain scheme, we optimize the design of the vertical-parabolic-pore photonic crystal (PhC) on a 10 -μ m -thick c -Si solar cell to obtain a maximum achievable photocurrent density (MAPD) of 40.6 mA /cm2 beyond the ray-optical, Lambertian light-trapping limit. For a slanted-parabolic-pore PhC that breaks x -y symmetry, improved light trapping occurs due to better coupling into parallel-to-interface refraction modes. We achieve the optimum MAPD of 41.6 mA /cm2 for a tilt angle of 10° with respect to the vertical axis of the pores. This MAPD is further improved to 41.72 mA /cm2 by introducing a 75-nm SiO2 antireflective coating on top of the solar cell. We use this MAPD and the associated charge-carrier generation profile as input for a numerical solution of Poisson's equation coupled with semiconductor drift-diffusion equations using a Shockley-Read-Hall and Auger recombination model. Using experimentally achieved surface recombination velocities of 10 cm /s , we identify semiconductor doping profiles that yield power conversion efficiencies over 29%. Practical considerations of additional upper-contact losses suggest efficiencies close to 28%. This improvement beyond the current world record is largely due to an open-circuit voltage approaching 0.8 V enabled by reduced bulk recombination in our thin silicon architecture while maintaining a high short-circuit current through wave-interference-based light trapping.

Ultrastable, high efficiency picosecond green light generation using K3B6O10Br series nonlinear optical crystals

Science.gov (United States)

Hou, Z. Y.; Xia, M. J.; Wang, L. R.; Xu, B.; Yan, D. X.; Meng, L. P.; Liu, L. J.; Xu, D. G.; Zhang, L.; Wang, X. Y.; Li, R. K.; Chen, C. T.

2017-09-01

Two perovskite-structure K3B6O10Br1-x Cl x (x  =  0 and 0.5) series nonlinear optical crystals were thoroughly investigated for their picosecond 532 nm laser pulses abilities and high power outputs were achieved via second harmonic generation (SHG) technique for the first time. SHG conversion efficiency of 57.3% with a 13.2 mm length K3B6O10Br (KBB) crystal was achieved using a laser source of pulse repetition rate of 10 Hz and pulse width of 25 ps, which is the highest conversion efficiency of ps visible laser based on KBB crystal. And by employing an 80 MHz, 10 ps fundamental laser beam, maximum power outputs of 12 W with K3B6O10Br0.5Cl0.5 (KBBC) and 11.86 W with KBB crystals were successfully demonstrated. Furthermore, the standard deviation jitters of the average power outputs are less than 0.6% and 1.17% by KBB and KBBC, respectively, showing ultrastable power stabilities favorable for practical applications. In addition, the other optical parameters including acceptance angle and temperature bandwidth were also investigated.

Periodically poled self-frequency-doubling green laser fabricated from Nd:Mg:LiNbO₃ single crystal.

Science.gov (United States)

Wang, Dong Zhou; Sun, De Hui; Kang, Xue Liang; Sang, Yuan Hua; Yan, Bo Xia; Liu, Hong; Bi, Yong

2015-07-13

Although a breakthrough in the fabrication of green laser diodes has occurred, the high costs associated with the difficulty of manufacture still present a great obstacle for its practical application. Another approach for producing a green laser, by combining a laser device and a nonlinear crystal, entails the fabrication of complex structures and exhibits unstable performance due to interface contact defects, thus limiting its application. In this work, we report the fabrication by domain engineering of high quality periodically poled LiNbO₃, co-doped with Nd³⁺ and Mg²⁺, which combines a laser medium and a high efficiency second harmonic conversion crystal into a single system that is designed to overcome the above problems. An 80 mW self-frequency doubling green laser was constructed for the first time from a periodically poled Nd:Mg:LiNbO₃ crystal of 16 mm in length. This crystal can be used for developing compact, stable, highly efficient mini-solid-state-lasers, which promise to have many applications in portable laser-based spectroscopy, photo-communications, terahertz wave generation, and laser displays.

A nanobody:GFP bacterial platform that enables functional enzyme display and easy quantification of display capacity.

Science.gov (United States)

Wendel, Sofie; Fischer, Emil C; Martínez, Virginia; Seppälä, Susanna; Nørholm, Morten H H

2016-05-03

Bacterial surface display is an attractive technique for the production of cell-anchored, functional proteins and engineering of whole-cell catalysts. Although various outer membrane proteins have been used for surface display, an easy and versatile high-throughput-compatible assay for evaluating and developing surface display systems is missing. Using a single domain antibody (also called nanobody) with high affinity for green fluorescent protein (GFP), we constructed a system that allows for fast, fluorescence-based detection of displayed proteins. The outer membrane hybrid protein LppOmpA and the autotransporter C-IgAP exposed the nanobody on the surface of Escherichia coli with very different efficiency. Both anchors were capable of functionally displaying the enzyme Chitinase A as a fusion with the nanobody, and this considerably increased expression levels compared to displaying the nanobody alone. We used flow cytometry to analyse display capability on single-cell versus population level and found that the signal peptide of the anchor has great effect on display efficiency. We have developed an inexpensive and easy read-out assay for surface display using nanobody:GFP interactions. The assay is compatible with the most common fluorescence detection methods, including multi-well plate whole-cell fluorescence detection, SDS-PAGE in-gel fluorescence, microscopy and flow cytometry. We anticipate that the platform will facilitate future in-depth studies on the mechanism of protein transport to the surface of living cells, as well as the optimisation of applications in industrial biotech.

Mesoscopic surface roughness of ice crystals pervasive across a wide range of ice crystal conditions

Science.gov (United States)

Magee, N. B.; Miller, A.; Amaral, M.; Cumiskey, A.

2014-11-01

Here we show high-magnification images of hexagonal ice crystals acquired by environmental scanning electron microscopy (ESEM). Most ice crystals were grown and sublimated in the water vapor environment of an FEI-Quanta-200 ESEM, but crystals grown in a laboratory diffusion chamber were also transferred intact and imaged via ESEM. All of these images display prominent mesoscopic topography including linear striations, ridges, islands, steps, peaks, pits, and crevasses; the roughness is not observed to be confined to prism facets. The observations represent the most highly magnified images of ice surfaces yet reported and expand the range of conditions in which rough surface features are known to be conspicuous. Microscale surface topography is seen to be ubiquitously present at temperatures ranging from -10 °C to -40 °C, in supersaturated and subsaturated conditions, on all crystal facets, and irrespective of substrate. Despite the constant presence of surface roughness, the patterns of roughness are observed to be dramatically different between growing and sublimating crystals, and transferred crystals also display qualitatively different patterns of roughness. Crystals are also demonstrated to sometimes exhibit inhibited growth in moderately supersaturated conditions following exposure to near-equilibrium conditions, a phenomenon interpreted as evidence of 2-D nucleation. New knowledge about the characteristics of these features could affect the fundamental understanding of ice surfaces and their physical parameterization in the context of satellite retrievals and cloud modeling. Links to supplemental videos of ice growth and sublimation are provided.

Power Efficient Design of DisplayPort (7.0) Using Low-voltage differential signaling IO Standard Via UltraScale Field Programming Gate Arrays

DEFF Research Database (Denmark)

Das, Bhagwan; Abdullah, M.F.L.; Hussain, Dil muhammed Akbar

2017-01-01

Port (7.0) need be reduced. In this paper, a power efficient design for DisplayPort (7.0) is proposed using LVDS IO Standard. The proposed design is tested for different frequencies; 500 MHz, 700 MHz, 1.0 GHz, and 1.6 GHz. The design is implemented using vhdl in UltraScale FPGA. It is determined...... the designed vhdl based design of DisplayPort (7.0) can reduced 92% using LVDS IO Standard for all frequencies; 500 MHz, 700 MHz, 1.0 GHz, and 1.6 GHz, compared to vhdl based design of DisplayPort (7.0) without using IO Standard. The proposed design of vhdl based design of DisplayPort (7.0) using LVDS IO...... Standard offers no power consumption for DisplayPort (7.0) in standby mode. The vhdl based design of DisplayPort (7.0) using LVDS IO Standard will be helpful to process the high resolution video at low power consumption....

Highly-efficient mid-infrared CW laser operation in a lightly-doped 3 at.% Er:SrF2 single crystal.

Science.gov (United States)

Su, Liangbi; Guo, Xinsheng; Jiang, Dapeng; Wu, Qinghui; Qin, Zhipeng; Xie, Guoqiang

2018-03-05

3 at.% Er:SrF 2 laser crystals with high optical quality were successfully grown using the temperature gradient technique (TGT). The intense mid-infrared emission was observed around 2.7 μm with excitation by a 970 nm LD. Based on the Judd-Ofelt theory, the emission cross-sections of the 4 I 13/2 - 4 I 11/2 transition were calculated by using the Fuchtbauer-Ladenburg (FL) method. Efficient continuous-wave laser operation at 2.8 µm was achieved with the lightly-doped 3 at.% Er:SrF 2 crystal pumped by a 970 nm laser diode. The laser output power reached up to 1.06 W with a maximum slope efficiency of 26%.

crystal

Science.gov (United States)

Yu, Yi; Huang, Yisheng; Zhang, Lizhen; Lin, Zhoubin; Sun, Shijia; Wang, Guofu

2014-07-01

A Nd3+:Na2La4(WO4)7 crystal with dimensions of ϕ 17 × 30 mm3 was grown by the Czochralski method. The thermal expansion coefficients of Nd3+:Na2La4(WO4)7 crystal are 1.32 × 10-5 K-1 along c-axis and 1.23 × 10-5 K-1 along a-axis, respectively. The spectroscopic characteristics of Nd3+:Na2La4(WO4)7 crystal were investigated. The Judd-Ofelt theory was applied to calculate the spectral parameters. The absorption cross sections at 805 nm are 2.17 × 10-20 cm2 with a full width at half maximum (FWHM) of 15 nm for π-polarization, and 2.29 × 10-20 cm2 with a FWHM of 14 nm for σ-polarization. The emission cross sections are 3.19 × 10-20 cm2 for σ-polarization and 2.67 × 10-20 cm2 for π-polarization at 1,064 nm. The fluorescence quantum efficiency is 67 %. The quasi-cw laser of Nd3+:Na2La4(WO4)7 crystal was performed. The maximum output power is 80 mW. The slope efficiency is 7.12 %. The results suggest Nd3+:Na2La4(WO4)7 crystal as a promising laser crystal fit for laser diode pumping.

Demonstrations with a Liquid Crystal Shutter

Science.gov (United States)

Kraftmakher, Yaakov

2012-01-01

The experiments presented show the response of a liquid crystal shutter to applied electric voltages and the delay of the operations. Both properties are important for liquid crystal displays of computers and television sets. Two characteristics of the shutter are determined: (i) the optical transmittance versus applied voltage of various…

Crystal growth, spectral and laser properties of Nd:LuAG single crystal

International Nuclear Information System (INIS)

Xu, X D; Meng, J Q; Cheng, Y; Li, D Z; Cheng, S S; Wu, F; Zhao, Z W; Wang, X D; Xu, J

2009-01-01

Nd:LuAG (Nd:Lu 3 Al 5 O 12 ) crystal was grown by the Czochralski method. X-ray powder diffraction experiments show that the Nd:LuAG crystal crystallizes in the cubic with space group Ia3d and has the cell parameter: a = 1.1907 nm, V = 1.6882 nm 3 . The absorption and fluorescence spectra of Nd:LuAG crystal at room temperature were investigated. With a fiber-coupled diode laser as pump source, the continuous-wave (CW) laser action of Nd:LuAG crystal was demonstrated. The maximum output power at 1064 nm was obtained to be 3.8 W under the incident pump power of 17.3 W, with the optical conversion efficiency 22.0% and the slope efficiency 25.7%

Crystal growth, spectral and laser properties of Nd:LuAG single crystal

Science.gov (United States)

Xu, X. D.; Wang, X. D.; Meng, J. Q.; Cheng, Y.; Li, D. Z.; Cheng, S. S.; Wu, F.; Zhao, Z. W.; Xu, J.

2009-09-01

Nd:LuAG (Nd:Lu3Al5O12) crystal was grown by the Czochralski method. X-ray powder diffraction experiments show that the Nd:LuAG crystal crystallizes in the cubic with space group Ia3d and has the cell parameter: a = 1.1907 nm, V = 1.6882 nm3. The absorption and fluorescence spectra of Nd:LuAG crystal at room temperature were investigated. With a fiber-coupled diode laser as pump source, the continuous-wave (CW) laser action of Nd:LuAG crystal was demonstrated. The maximum output power at 1064 nm was obtained to be 3.8 W under the incident pump power of 17.3 W, with the optical conversion efficiency 22.0% and the slope efficiency 25.7%.

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

Science.gov (United States)

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.

Comparison of total experimental and theoretical absolute γ-ray detection efficiencies of a cylindrical NaI(Tl) crystal

International Nuclear Information System (INIS)

Uosif, M.A.; El-Taher, A.

2005-01-01

A new fit function has been developed to calculate theoretically the absolute gamma ray detection efficiencies (ηTh) of a cylindrical NaI(Tl) crystal, for calculating the absolute efficiency at any interesting gamma energy in the energy range between 10 and 1300 keV and distance between 0 and 8 cm. The total absolute gamma ray detection efficiencies have been calculated for five detectors, four are 2x2 and one is 3x 3 inches NaI(Tl) crystal at different distances. The absolute efficiency of the different detectors was calculated at the specific energy of the standard sources for each measuring distances. In this calculation, experimental (ηExp) and theoretical (ηTh) have been calculated. The uncertainties of efficiency calibration have been calculated also for quality control. Measurements were performed with calibrated point source. Gamma-ray energies under consideration were 0.356, 0.662, 1.17 and 1.33 MeV. The differences between (ηExp) and (ηTh) at these energies are 1.30E-06, 7.99E-05, 2.29E-04 and 2.42E-04 respectively. The results obtained on the basis of (ηExp) and (ηTh) seem to be in very good agreement

Wide color gamut display with white and emerald backlighting.

Science.gov (United States)

Duan, Lvyin; Lei, Zhichun

2018-02-20

This paper proposes a wide color gamut approach that uses white and emerald lighting units as the backlight of the liquid crystal display. The white and emerald backlights are controlled by the image to be displayed. The mixing ratio of the white and the emerald lighting is analyzed so that the maximal color gamut coverage ratio can be achieved. Experimental results prove the effectiveness of the wide color gamut approach using white and emerald backlights.

Nuclear Medicine Image Display. Chapter 14

Energy Technology Data Exchange (ETDEWEB)

Bergmann, H. [Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna (Austria)

2014-12-15

The final step in a medical imaging procedure is to display the image(s) on a suitable display system where it is presented to the medical specialist for diagnostic interpretation. The display of hard copy images on X ray film or photographic film has largely been replaced today by soft copy image display systems with cathode ray tube (CRT) or liquid crystal display (LCD) monitors as the image rendering device. Soft copy display requires a high quality display monitor and a certain amount of image processing to optimize the image both with respect to the properties of the display device and to some psychophysiological properties of the human visual system. A soft copy display system, therefore, consists of a display workstation providing some basic image processing functions and the display monitor as the intrinsic display device. Display devices of lower quality may be used during intermediate steps of the acquisition and analysis of a patient study. Display monitors with a quality suitable for diagnostic reading by the specialist medical doctor are called primary devices, also known as diagnostic devices. Monitors with lower quality but good enough to be used for positioning, processing of studies, presentation of images in the wards, etc. are referred to as secondary devices or clinical devices. Nuclear medicine images can be adequately displayed even for diagnostic purposes on secondary devices. However, the increasing use of X ray images on which to report jointly with images from nuclear medicine studies, such as those generated by dual modality imaging, notably by positron emission tomography (PET)/computed tomography (CT) and single photon emission computed tomography (SPECT)/CT, requires display devices capable of visualizing high resolution grey scale images at diagnostic quality, i.e. primary display devices. Both grey scale and colour display devices are used, the latter playing an important role in the display of processed nuclear medicine images and

Nuclear Medicine Image Display. Chapter 14

International Nuclear Information System (INIS)

Bergmann, H.

2014-01-01

The final step in a medical imaging procedure is to display the image(s) on a suitable display system where it is presented to the medical specialist for diagnostic interpretation. The display of hard copy images on X ray film or photographic film has largely been replaced today by soft copy image display systems with cathode ray tube (CRT) or liquid crystal display (LCD) monitors as the image rendering device. Soft copy display requires a high quality display monitor and a certain amount of image processing to optimize the image both with respect to the properties of the display device and to some psychophysiological properties of the human visual system. A soft copy display system, therefore, consists of a display workstation providing some basic image processing functions and the display monitor as the intrinsic display device. Display devices of lower quality may be used during intermediate steps of the acquisition and analysis of a patient study. Display monitors with a quality suitable for diagnostic reading by the specialist medical doctor are called primary devices, also known as diagnostic devices. Monitors with lower quality but good enough to be used for positioning, processing of studies, presentation of images in the wards, etc. are referred to as secondary devices or clinical devices. Nuclear medicine images can be adequately displayed even for diagnostic purposes on secondary devices. However, the increasing use of X ray images on which to report jointly with images from nuclear medicine studies, such as those generated by dual modality imaging, notably by positron emission tomography (PET)/computed tomography (CT) and single photon emission computed tomography (SPECT)/CT, requires display devices capable of visualizing high resolution grey scale images at diagnostic quality, i.e. primary display devices. Both grey scale and colour display devices are used, the latter playing an important role in the display of processed nuclear medicine images and

Liquid crystals: high technology materials for potential applications

International Nuclear Information System (INIS)

Saeed, M.A.; Badaruddin; Rizvi, T.Z.

1993-01-01

Liquid crystals have very rapidly emerged as a basis of many high technology fields within the last few decades. These materials because of their intriguing physical properties are regarded as the fourth state of matter. At present the applications of liquid crystals are established in digital display devices, electro-optical switches, optical computing, acousto-optics, thermo-indicators, laser thermo-recording, photo-chemical image recording and optical communication networks. More recently due to the concept of molecularly based electronics (MBE): the logical extreme for miniaturization of electronic device, liquid crystals are foreseen to play a vital role in the future optics based technologies. This paper gives a brief introduction to liquid crystals, the types of meso phases found in these materials together with their applications in research and industry. Some technical details of the construction liquid crystal cells for some typical applications in digital displays and other electro optical devices have also been discussed with special emphasis on relevant physical processes occurring at molecular level. (author)

An integrated port camera and display system for laparoscopy.

Science.gov (United States)

Terry, Benjamin S; Ruppert, Austin D; Steinhaus, Kristen R; Schoen, Jonathan A; Rentschler, Mark E

2010-05-01

In this paper, we built and tested the port camera, a novel, inexpensive, portable, and battery-powered laparoscopic tool that integrates the components of a vision system with a cannula port. This new device 1) minimizes the invasiveness of laparoscopic surgery by combining a camera port and tool port; 2) reduces the cost of laparoscopic vision systems by integrating an inexpensive CMOS sensor and LED light source; and 3) enhances laparoscopic surgical procedures by mechanically coupling the camera, tool port, and liquid crystal display (LCD) screen to provide an on-patient visual display. The port camera video system was compared to two laparoscopic video systems: a standard resolution unit from Karl Storz (model 22220130) and a high definition unit from Stryker (model 1188HD). Brightness, contrast, hue, colorfulness, and sharpness were compared. The port camera video is superior to the Storz scope and approximately equivalent to the Stryker scope. An ex vivo study was conducted to measure the operative performance of the port camera. The results suggest that simulated tissue identification and biopsy acquisition with the port camera is as efficient as with a traditional laparoscopic system. The port camera was successfully used by a laparoscopic surgeon for exploratory surgery and liver biopsy during a porcine surgery, demonstrating initial surgical feasibility.

Performance analysis of multi-primary color display based on OLEDs/PLEDs

Science.gov (United States)

Xiong, Yan; Deng, Fei; Xu, Shan; Gao, Shufang

2017-09-01

A multi-primary color display, such as the six-primary color format, is a solution in expanding the color gamut of a full-color flat panel display. The performance of a multi-primary color display based on organic/polymer light-emitting diodes was analyzed in this study using the fitting curves of the characteristics of devices (i.e., current density, voltage, luminance). A white emitter was introduced into a six-primary color format to form a seven-primary color format that contributes to energy saving, and the ratio of power efficiency of a seven-primary color display to that of a six-primary color display would increase from 1.027 to 1.061 by using emitting diodes with different electroluminescent efficiencies. Different color matching schemes of the seven-primary color format display were compared in a uniform color space, and the scheme of the color reproduction did not significantly affect the display performance. Although seven- and six-primary color format displays benefit a full-color display with higher quality, they are less efficient than three-primary (i.e., red (R), green (G), and blue (B), RGB) and four-primary (i.e., RGB+white, RGBW) color format displays. For the seven-primary color formats considered in this study, the advantages of white-primary-added display with efficiently developed light-emitting devices were more evident than the format without a white primary.

Fully-etched apodized fiber-to-chip grating coupler on the SOI platform with -0.78 dB coupling efficiency using photonic crystals and bonded Al mirror

DEFF Research Database (Denmark)

Ding, Yunhong; Ou, Haiyan; Peucheret, Christophe

2014-01-01

We design and fabricate an ultra-high coupling efficiency fully-etched apodized grating coupler on the SOI platform using photonic crystals and bonded aluminum mirror. Ultra-high coupling efficiency of -0.78 dB with a 3 dB bandwidth of 74 nm are demonstrated.......We design and fabricate an ultra-high coupling efficiency fully-etched apodized grating coupler on the SOI platform using photonic crystals and bonded aluminum mirror. Ultra-high coupling efficiency of -0.78 dB with a 3 dB bandwidth of 74 nm are demonstrated....

Actively addressed single pixel full-colour plasmonic display

Science.gov (United States)

Franklin, Daniel; Frank, Russell; Wu, Shin-Tson; Chanda, Debashis

2017-05-01

Dynamic, colour-changing surfaces have many applications including displays, wearables and active camouflage. Plasmonic nanostructures can fill this role by having the advantages of ultra-small pixels, high reflectivity and post-fabrication tuning through control of the surrounding media. However, previous reports of post-fabrication tuning have yet to cover a full red-green-blue (RGB) colour basis set with a single nanostructure of singular dimensions. Here, we report a method which greatly advances this tuning and demonstrates a liquid crystal-plasmonic system that covers the full RGB colour basis set, only as a function of voltage. This is accomplished through a surface morphology-induced, polarization-dependent plasmonic resonance and a combination of bulk and surface liquid crystal effects that manifest at different voltages. We further demonstrate the system's compatibility with existing LCD technology by integrating it with a commercially available thin-film-transistor array. The imprinted surface interfaces readily with computers to display images as well as video.

View interpolation for medical images on autostereoscopic displays

NARCIS (Netherlands)

Zinger, S.; Ruijters, D.; Do, Q.L.; With, de P.H.N.

2012-01-01

We present an approach for efficient rendering and transmitting views to a high-resolution autostereoscopic display for medical purposes. Displaying biomedical images on an autostereoscopic display poses different requirements than in a consumer case. For medical usage, it is essential that the

Proceedings of the Flat-Plate Solar Array Project Workshop on Crystal Gowth for High-Efficiency Silicon Solar Cells

Science.gov (United States)

Dumas, K. A. (Editor)

1985-01-01

A Workshop on Crystal Growth for High-Efficiency Silicon Solar Cells was held December 3 and 4, 1984, in San Diego, California. The Workshop offered a day and a half of technical presentations and discussions and an afternoon session that involved a panel discussion and general discussion of areas of research that are necessary to the development of materials for high-efficiency solar cells. Topics included the theoretical and experimental aspects of growing high-quality silicon crystals, the effects of growth-process-related defects on photovoltaic devices, and the suitability of various growth technologies as cost-effective processes. Fifteen invited papers were presented, with a discussion period following each presentation. The meeting was organized by the Flat-Plate Solar Array Project of the Jet Propulsion Laboratory. These Proceedings are a record of the presentations and discussions, edited for clarity and continuity.

Efficiency improvement opportunities for personal computer monitors. Implications for market transformation programs

Energy Technology Data Exchange (ETDEWEB)

Park, Won Young; Phadke, Amol; Shah, Nihar [Environmental Energy Technologies Division, Lawrence Berkeley National Laboratory, Berkeley, CA (United States)

2013-08-15

Displays account for a significant portion of electricity consumed in personal computer (PC) use, and global PC monitor shipments are expected to continue to increase. We assess the market trends in the energy efficiency of PC monitors that are likely to occur without any additional policy intervention and estimate that PC monitor efficiency will likely improve by over 40 % by 2015 with saving potential of 4.5 TWh per year in 2015, compared to today's technology. We discuss various energy-efficiency improvement options and evaluate the cost-effectiveness of three of them, at least one of which improves efficiency by at least 20 % cost effectively beyond the ongoing market trends. We assess the potential for further improving efficiency taking into account the recent development of universal serial bus-powered liquid crystal display monitors and find that the current technology available and deployed in them has the potential to deeply and cost effectively reduce energy consumption by as much as 50 %. We provide insights for policies and programs that can be used to accelerate the adoption of efficient technologies to further capture global energy saving potential from PC monitors which we estimate to be 9.2 TWh per year in 2015.

Enhancement of Solar Cell Efficiency for Space Applications Using Two-Dimensional Photonic Crystals

Directory of Open Access Journals (Sweden)

Postigo P.A.

2017-01-01

Full Text Available The effects of having a nanopatterned photonic crystal (PC structure in the surface of a solar cell can be usefully employed to increase the energy conversion efficiency, which may be critical for space applications. In this work, we have measured the reflectance (R and transmittance (T of thin InP layers (270 nm thick bonded to a glass substrate and nanopatterned with holes down to the glass in a triangular symmetry lattice separated by a lattice parameter a=450nm and maintaining a value of r/a=0.32. The optical spectra were measured with angular resolution in the range from 0.55 to 2.0 eV. There are noticeable changes in the spectra of the PC sample, with minima and maxima of the R and T clearly shifted with respect to the unpatterned sample, and new features that alter significantly the overall lineshape of each spectrum. Those features correspond in a first approximation to the well-known Fano-like resonances of the discrete photonic modes of the PC lattice and they have been used before to determine experimentally the position of the PC bands. The observed features can be translated to the optical absorption (A defined as A=1-R-T provided there are low or negligible scattering effects. The generated absorption spectra show enhancements above and below the electronic band edge of the InP that can be correlated with the photonic band structure. Even using a thicker semiconductor layer, the abovementioned effects can justify to use a photonic crystal front surface with sub-wavelength motifs. In this way, we have fabricated and characterized a complete Ge/InGaP solar cell with a 2D-PC on its front surface. An increase in the photocurrent up to a 8% was achieved on a solar cell with a 40% of its surface covered with a PC pattern. Enhancements of the external quantum efficiency (EQE of 22% for a wide range of wavelengths and up to a 46% for specific wavelengths have been measured, without use of any anti-reflection coating (ARC. A correlation

Key Developments in Ionic Liquid Crystals

OpenAIRE

Fernandez, A.A.; Kouwer, P.H.J.

2016-01-01

Ionic liquid crystals are materials that combine the classes of liquid crystals and ionic liquids. The first one is based on the multi-billion-dollar flat panel display industry, whilst the latter quickly developed in the past decades into a family of highly-tunable non-volatile solvents. The combination yields materials with a unique set of properties, but also with many challenges ahead. In this review, we provide an overview of the key concepts in ionic liquid crystals, particularly from a...

Effect of irradiation temperature and initial crystal doping level on defect creation efficiency in silicon

International Nuclear Information System (INIS)

Korshunov, F.P.; Markevich, V.P.; Medvedeva, I.F.; Murin, L.I.

1990-01-01

The defect creation processes in n-type silicon irradiated by 60 Co gamma-rays or fast electrons (E = 4 MeV) have been investigated. Using electrical measurements the dependences of introduction efficiencies of the main radiation defects (A-, E-centres, carbon-related complexes) on the irradiation temperature (T irr = 77-470 K) and material doping level (N h = 2 x 10 12 - 2 x 10 15 cm -3 ) are obtained. It is shown that the efficiency of these defects formation is conditioned by the probability of the Frenkel pairs separation and depends strongly on the Fermi level position in crystals being irradiated. 9 refs.; 3 figs.; 1 tab

Modeling Power-Constrained Optimal Backlight Dimming for Color Displays

DEFF Research Database (Denmark)

Burini, Nino; Nadernejad, Ehsan; Korhonen, Jari

2013-01-01

In this paper, we present a framework for modeling color liquid crystal displays (LCDs) having local light-emitting diode (LED) backlight with dimming capability. The proposed framework includes critical aspects like leakage, clipping, light diffusion and human perception of luminance and allows...

Slow-light-enhanced energy efficiency for graphene microheaters on silicon photonic crystal waveguides

DEFF Research Database (Denmark)

Yan, Siqi; Zhu, Xiaolong; Frandsen, Lars Hagedorn

2017-01-01

Slow light has been widely utilized to obtain enhanced nonlinearities, enhanced spontaneous emissions and increased phase shifts owing to its ability to promote light-matter interactions. By incorporating a graphene on a slow-light silicon photonic crystal waveguide, here we experimentally...... in silicon photonics. The corresponding figure of merit of the device is 2.543 nW s, one order of magnitude better than results reported in previous studies. The influence of the length and shape of the graphene heater to the tuning efficiency is further investigated, providing valuable guidelines...

High-efficiency deflection of high energy protons due to channeling along the 〈110〉 axis of a bent silicon crystal

Directory of Open Access Journals (Sweden)

W. Scandale

2016-09-01

Full Text Available A deflection efficiency of about 61% was observed for 400 GeV/c protons due to channeling, most strongly along the 〈110〉 axis of a bent silicon crystal. It is comparable with the deflection efficiency in planar channeling and considerably larger than in the case of the 〈111〉 axis. The measured probability of inelastic nuclear interactions of protons in channeling along the 〈110〉 axis is only about 10% of its amorphous level whereas in channeling along the (110 planes it is about 25%. High efficiency deflection and small beam losses make this axial orientation of a silicon crystal a useful tool for the beam steering of high energy charged particles.

Optical see-through head-mounted display with occlusion capability

Science.gov (United States)

Gao, Chunyu; Lin, Yuxiang; Hua, Hong

2013-05-01

Lack of mutual occlusion capability between computer-rendered and real objects is one of fundamental problems for most existing optical see-through head-mounted displays (OST-HMD). Without the proper occlusion management, the virtual view through an OST-HMD appears "ghost-like", floating in the real world. To address this challenge, we have developed an innovative optical scheme that uniquely combines the eyepiece and see-through relay optics to achieve an occlusion-capable OST-HMD system with a very compelling form factor and high optical performances. The proposed display system was based on emerging freeform optical design technologies and was designed for highly efficient liquid crystal on silicon (LCoS) type spatial light modulator (SLM) and bright Organic LED (OLED) microdisplay. The proposed display technology was capable of working in both indoor and outdoor environments. Our current design offered a 1280x1024 color resolution based on 0.8" microdisplay and SLM. The MTF values for the majority of the fields at the cutoff frequency of 40lps/mm, which is determined by the pixel size of the microdisplay, are better than 15%. The design achieved a diagonal FOV of 40 degrees, 31.7 degrees horizontally and 25.6 degrees vertically, an exit pupil diameter of 8mm (non-vignetted), and an eye clearance of 18mm. The optics weights about 20 grams per eye. Our proposed occlusion capable OST-HMD system can easily find myriads of applications in various military and commercial sectors such as military training, gaming and entertainment.

Research on Mechanical Behaviors of Micro-crystal Muscovite/UHMWPE Composites to Impact Loading

Directory of Open Access Journals (Sweden)

Hu Huarong

2016-01-01

Full Text Available UHMWPE composites were prepared by hot pressing process with micro-crystal muscovite as reinforced particulates. The mechanical behaviors of composites to impact loading was evaluated by split Hopkinson bar. The results demonstrated that dynamic yield stress and failure stress of UHMWPE composites were gradually increased when the filling amount was less than 20%; when the filling content of muscovite was around 15%, the energy absorption efficiency of the composite reaches maximum value. It was also found that when strain rate within 3200/s, the dynamic yield stress, failure stress and energy absorption efficiency of UHMWPE composites increased with the increase of strain rate and display strain rate enhancement effect.

A nanobody:GFP bacterial platform that enables functional enzyme display and easy quantification of display capacity

DEFF Research Database (Denmark)

Wendel, Sofie; Christian Fischer, Emil; Martinez, Virginia

2016-01-01

Background: Bacterial surface display is an attractive technique for the production of cell-anchored, functional proteins and engineering of whole-cell catalysts. Although various outer membrane proteins have been used for surface display, an easy and versatile high-throughput-compatible assay...... to displaying the nanobody alone. We used flow cytometry to analyse display capability on single-cell versus population level and found that the signal peptide of the anchor has great effect on display efficiency.Conclusions: We have developed an inexpensive and easy read-out assay for surface display using...... nanobody: GFP interactions. The assay is compatible with the most common fluorescence detection methods, including multi-well plate whole-cell fluorescence detection, SDS-PAGE in-gel fluorescence, microscopy and flow cytometry. We anticipate that the platform will facilitate future in-depth studies...

Alignment structures in ferroelectric liquid crystals

Energy Technology Data Exchange (ETDEWEB)

Islam, N.U

1998-07-01

Although for many years liquid crystals were of purely scientific interest, they have now become ubiquitous in everyday life. The use of the nematic liquid crystal phase in flat panel display applications has been the main factor in this popularity. However, with the advent of the SuperTwist Nematic (STN) device, the limits to which this phase could be exploited for display applications was perhaps reached. With the discovery by Clark et al. of the Surface Stabilised Ferroelectric Liquid Crystal (SSFLC) configuration, the possibility arose of using chiral smectic liquid crystals to create large area, passively addressed, fast switching, flat panel displays. Unfortunately, the structures that form within smectic liquid crystals, and the dynamics of the switching within these, are still not fully understood. In this thesis we address the former of these, making a detailed the study of the structures that form within tilted smectic liquid crystal devices. We present here the first complete theoretical and experimental study of various different ferroelectric liquid crystal materials, where we employed theoretical models based on a simple set of assumptions to understand the behaviour of a set of increasingly complex experimental systems. We started with the simplest of these, Freely Suspended Smectic Films (FSSFs) and then worked with progressively more realistic systems in the form of homeotropically, and later, homogeneously aligned liquid crystal cells. The equilibrium structures that form get particularly complex in the last case, taking the form of tilted and chevron layering structures. In each of these cases, the predictions of the modelling are compared with our experimental results. Further, we present here the first model of the chevron cusp that seeks to include the effects of biaxiality in the S{sub C} phase. We also present a model that seeks to analyse the stability of the chevron layering structure and its relationship with tilted layers. This includes

Alignment structures in ferroelectric liquid crystals

International Nuclear Information System (INIS)

Islam, N.U.

1998-01-01

Although for many years liquid crystals were of purely scientific interest, they have now become ubiquitous in everyday life. The use of the nematic liquid crystal phase in flat panel display applications has been the main factor in this popularity. However, with the advent of the SuperTwist Nematic (STN) device, the limits to which this phase could be exploited for display applications was perhaps reached. With the discovery by Clark et al. of the Surface Stabilised Ferroelectric Liquid Crystal (SSFLC) configuration, the possibility arose of using chiral smectic liquid crystals to create large area, passively addressed, fast switching, flat panel displays. Unfortunately, the structures that form within smectic liquid crystals, and the dynamics of the switching within these, are still not fully understood. In this thesis we address the former of these, making a detailed the study of the structures that form within tilted smectic liquid crystal devices. We present here the first complete theoretical and experimental study of various different ferroelectric liquid crystal materials, where we employed theoretical models based on a simple set of assumptions to understand the behaviour of a set of increasingly complex experimental systems. We started with the simplest of these, Freely Suspended Smectic Films (FSSFs) and then worked with progressively more realistic systems in the form of homeotropically, and later, homogeneously aligned liquid crystal cells. The equilibrium structures that form get particularly complex in the last case, taking the form of tilted and chevron layering structures. In each of these cases, the predictions of the modelling are compared with our experimental results. Further, we present here the first model of the chevron cusp that seeks to include the effects of biaxiality in the S C phase. We also present a model that seeks to analyse the stability of the chevron layering structure and its relationship with tilted layers. This includes an

Soap, science, and flat-screen TVs a history of liquid crystals

CERN Document Server

Dunmur, David

2011-01-01

The terms 'liquid crystal' or 'liquid crystal display' (LCD) are well-known in the context of flat-screen televisions, but the properties and history of liquid crystals are little understood. This book tells the story of liquid crystals, from their controversial discovery at the end of the nineteenth century, to their eventual acceptance as another state of matter to rank alongside gases, liquids and solids. As their story unfolds, the scientists involved and their works are put into illuminating broader socio-political contexts. In recent years, liquid crystals have had a major impact on the display industry, culminating in the now widely available flat-screen televisions; this development is described in detail over three chapters, and the basic science behind it is explained in simple terms accessible to a general reader. New applications of liquid crystals in materials, bio-systems, medicine and technology are also explained.

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

Science.gov (United States)

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.

A green-color portable waveguide eyewear display system

Science.gov (United States)

Xia, Lingbo; Xu, Ke; Wu, Zhengming; Hu, Yingtian; Li, Zhenzhen; Wang, Yongtian; Liu, Juan

2013-08-01

Waveguide display systems are widely used in various display fields, especially in head mounted display. Comparing with the traditional head mounted display system, this device dramatically reduce the size and mass. However, there are still several fatal problems such as high scatting, the cumbersome design and chromatic aberration that should be solved. We designed and fabricated a monochromatic portable eyewear display system consist of a comfortable eyewear device and waveguide system with two holographic gratings located on the substrate symmetrically. We record the gratings on the photopolymer medium with high efficiency and wavelength sensitivity. The light emitting from the micro-display is diffracted by the grating and trapped in the glass substrate by total internal reflection. The relationship between the diffraction efficiency and exposure value is studied and analyzed, and we fabricated the gratings with appropriate diffraction efficiency in a optimization condition. To avoid the disturbance of the stray light, we optimize the waveguide system numerically and perform the optical experiments. With this system, people can both see through the waveguide to obtain the information outside and catch the information from the micro display. After considering the human body engineering and industrial production, we design the structure in a compact and portable way. It has the advantage of small-type configuration and economic acceptable. It is believe that this kind of planar waveguide system is a potentially replaceable choice for the portable devices in future mobile communications.

Depth-enhanced three-dimensional-two-dimensional convertible display based on modified integral imaging.

Science.gov (United States)

Park, Jae-Hyeung; Kim, Hak-Rin; Kim, Yunhee; Kim, Joohwan; Hong, Jisoo; Lee, Sin-Doo; Lee, Byoungho

2004-12-01

A depth-enhanced three-dimensional-two-dimensional convertible display that uses a polymer-dispersed liquid crystal based on the principle of integral imaging is proposed. In the proposed method, a lens array is located behind a transmission-type display panel to form an array of point-light sources, and a polymer-dispersed liquid crystal is electrically controlled to pass or to scatter light coming from these point-light sources. Therefore, three-dimensional-two-dimensional conversion is accomplished electrically without any mechanical movement. Moreover, the nonimaging structure of the proposed method increases the expressible depth range considerably. We explain the method of operation and present experimental results.

Diode-laser-pumped high efficiency continuous-wave operation at 912 nm laser in Nd:GdVO4 crystal

International Nuclear Information System (INIS)

Yu, X; Chen, F; Gao, J; Li, X D; Yan, R P; Zhang, K; Yu, J H; Zhang, Z H

2009-01-01

High efficiency operation on continuous-wave (cw) 912 nm laser at room temperature in Nd:GdVO 4 crystal pumped by 808 nm diode-laser is reported in this letter. The maximum output power of 8.0 W was obtained at the incident un-polarized pump power of 47.0 W, giving the corresponding optical-to-optical conversion efficiency of 17.0% and the average slope efficiency of 22.9%. Further tests show that the lasing threshold is reduced and the efficiency is increased evidently when using the π-polarized 808 nm pump source. 4.8 W 912 nm laser was achieved at the polarized pump power of 21.8 W, optical-to-optical conversion efficiency is increased to 22.0% and average slope efficiency is up to 33.6%

Variations in performance of LCDs are still evident after DICOM gray-scale standard display calibration.

LENUS (Irish Health Repository)

Lowe, Joanna M

2010-07-01

Quality assurance in medical imaging is directly beneficial to image quality. Diagnostic images are frequently displayed on secondary-class displays that have minimal or no regular quality assurance programs, and treatment decisions are being made from these display types. The purpose of this study is to identify the impact of calibration on physical and psychophysical performance of liquid crystal displays (LCDs) and the extent of potential variance across various types of LCDs.

Liquid Crystal Colloids

Science.gov (United States)

Smalyukh, Ivan I.

2018-03-01

Colloids are abundant in nature, science, and technology, with examples ranging from milk to quantum dots and the colloidal atom paradigm. Similarly, liquid crystal ordering is important in contexts ranging from biological membranes to laboratory models of cosmic strings and liquid crystal displays in consumer devices. Some of the most exciting recent developments in both of these soft matter fields emerge at their interface, in the fast-growing research arena of liquid crystal colloids. Mesoscale self-assembly in such systems may lead to artificial materials and to structures with emergent physical behavior arising from patterning of molecular order and nano- or microparticles into precisely controlled configurations. Liquid crystal colloids show exceptional promise for new discovery that may impinge on composite material fabrication, low-dimensional topology, photonics, and so on. Starting from physical underpinnings, I review the state of the art in this fast-growing field, with a focus on its scientific and technological potential.

Phosphorus zoning as a recorder of crystal growth kinetics

DEFF Research Database (Denmark)

Baziotis, I.; Asimow, P.D.; Ntaflos, T.

2017-01-01

spectrometry. The petrogenetic history of each vein involves melt intrusion, cooling accompanied by both wall-rock reaction and crystallization, quench of melt to a glass, and possibly later modifications. Exotic secondary olivine crystals in the veins display concentric phosphorus (P)-rich zoning, P...

ACCURACY EVALUATION OF THE OBJECT LOCATION VISUALIZATION FOR GEO-INFORMATION AND DISPLAY SYSTEMS OF MANNED AIRCRAFTS NAVIGATION COMPLEXES

Directory of Open Access Journals (Sweden)

M. O. Kostishin

2014-01-01

Full Text Available The paper deals with the issue of accuracy estimating for the object location display in the geographic information systems and display systems of manned aircrafts navigation complexes. Application features of liquid crystal screens with a different number of vertical and horizontal pixels are considered at displaying of geographic information data on different scales. Estimation display of navigation parameters values on board the aircraft is done in two ways: a numeric value is directly displayed on the screen of multi-color indicator, and a silhouette of the object is formed on the screen on a substrate background, which is a graphical representation of area map in the flight zone. Various scales of area digital map display currently used in the aviation industry have been considered. Calculation results of one pixel scale interval, depending on the specifications of liquid crystal screen and zoom of the map display area on the multifunction digital display, are given. The paper contains experimental results of the accuracy evaluation for area position display of the aircraft based on the data from the satellite navigation system and inertial navigation system, obtained during the flight program run of the real object. On the basis of these calculations a family of graphs was created for precision error display of the object reference point position using the onboard indicators with liquid crystal screen with different screen resolutions (6 "×8", 7.2 "×9.6", 9"×12" for two map display scales (1:0 , 25 km, 1-2 km. These dependency graphs can be used both to assess the error value of object area position display in existing navigation systems and to calculate the error value in upgrading facilities.

Evaluation of an organic light-emitting diode display for precise visual stimulation.

Science.gov (United States)

Ito, Hiroyuki; Ogawa, Masaki; Sunaga, Shoji

2013-06-11

A new type of visual display for presentation of a visual stimulus with high quality was assessed. The characteristics of an organic light-emitting diode (OLED) display (Sony PVM-2541, 24.5 in.; Sony Corporation, Tokyo, Japan) were measured in detail from the viewpoint of its applicability to visual psychophysics. We found the new display to be superior to other display types in terms of spatial uniformity, color gamut, and contrast ratio. Changes in the intensity of luminance were sharper on the OLED display than those on a liquid crystal display. Therefore, such OLED displays could replace conventional cathode ray tube displays in vision research for high quality stimulus presentation. Benefits of using OLED displays in vision research were especially apparent in the fields of low-level vision, where precise control and description of the stimulus are needed, e.g., in mesopic or scotopic vision, color vision, and motion perception.

Modeling liquid crystal polymeric devices

Science.gov (United States)

Gimenez Pinto, Vianney Karina

The main focus of this work is the theoretical and numerical study of materials that combine liquid crystal and polymer. Liquid crystal elastomers are polymeric materials that exhibit both the ordered properties of the liquid crystals and the elastic properties of rubbers. Changing the order of the liquid crystal molecules within the polymer network can induce shape change. These materials are very valuable for applications such as actuators, sensors, artificial muscles, haptic displays, etc. In this work we apply finite element elastodynamics simulations to study the temperature induced shape deformation in nematic elastomers with complex director microstructure. In another topic, we propose a novel numerical method to model the director dynamics and microstructural evolution of three dimensional nematic and cholesteric liquid crystals. Numerical studies presented in this work are in agreement with experimental observations and provide insight into the design of application devices.

Crystal growth, spectral and laser properties of Nd:LSAT single crystal

Science.gov (United States)

Hu, P. C.; Yin, J. G.; Zhao, C. C.; Gong, J.; He, X. M.; Zhang, L. H.; Liang, X. Y.; Hang, Y.

2011-10-01

Nd:(La, Sr)(Al, Ta)O3 (Nd:LSAT) crystal was grown by the Czochralski method. The absorption and fluorescence spectra of Nd:LSAT crystal at room temperature were investigated. With a fiber-coupled diode laser as pump source, the continuous-wave (CW) laser action of Nd:LSAT crystal was demonstrated. The result of diode-pumped laser operation of Nd:LSAT crystal single crystal is reported for what is to our knowledge the first time. The maximum output power at 1064 nm was obtained to be 165 mW under the incident pump power of 3 W, with the slope efficiency 10.9%.

Highly efficient dual-wavelength mid-infrared CW Laser in diode end-pumped Er:SrF2 single crystals

Science.gov (United States)

Ma, Weiwei; Qian, Xiaobo; Wang, Jingya; Liu, Jingjing; Fan, Xiuwei; Liu, Jie; Su, Liangbi; Xu, Jun

2016-11-01

The spectral properties and laser performance of Er:SrF2 single crystals were investigated and compared with Er:CaF2. Er:SrF2 crystals have larger absorption cross-sections at the pumping wavelength, larger mid-infrared stimulated emission cross-sections and much longer fluorescence lifetimes of the upper laser level (Er3+:4I11/2 level) than those of Er:CaF2 crystals. Dual-wavelength continuous-wave (CW) lasers around 2.8 μm were demonstrated in both 4at.% and 10at.% Er:SrF2 single crystals under 972 nm laser diode (LD) end pumping. The laser wavelengths are 2789.3 nm and 2791.8 nm in the former, and 2786.4 nm and 2790.7 nm in the latter, respectively. The best laser performance has been demonstrated in lightly doped 4at.% Er:SrF2 with a low threshold of 0.100 W, a high slope efficiency of 22.0%, an maximum output power of 0.483 W.

Discharge efficiency in high-Xe-content plasma display panels

NARCIS (Netherlands)

Hayashi, D.; Kroesen, G.M.W.; Hagelaar, G.J.M.; Heusler, G.

2004-01-01

We study theoretically the overall output performance and the dominating reaction processes of the vacuum ultraviolet (UV) radiation production in high-Xe partial pressures in plasma display panels (PDPs) with Ne-Xe gas mixtures. A two-dimensional self-consistent fluid model is applied for the

Chiral crystal of a C2v-symmetric 1,3-diazaaulene derivative showing efficient optical second harmonic generation

KAUST Repository

Ma, Xiaohua; Fu, Limin; Zhao, Yunfeng; Ai, Xicheng; Zhang, Jianping; Han, Yu; Guo, Zhixin

2011-01-01

the moderate static first hyperpolarizabilities (β0) for both APNA [(136 ± 5) à - 10-30 esu] and DPAPNA [(263 ± 20) à - 10-30 esu], only APNA crystal shows a powder efficiency of second harmonic generation (SHG) of 23 times that of urea. It is shown

Optical efficiency enhancement in white organic light-emitting diode display with high color gamut using patterned quantum dot film and long pass filter

Science.gov (United States)

Kim, Hyo-Jun; Shin, Min-Ho; Kim, Young-Joo

2016-08-01

A new structure for white organic light-emitting diode (OLED) displays with a patterned quantum dot (QD) film and a long pass filter (LPF) was proposed and evaluated to realize both a high color gamut and high optical efficiency. Since optical efficiency is a critical parameter in white OLED displays with a high color gamut, a red or green QD film as a color-converting component and an LPF as a light-recycling component are introduced to be adjusted via the characteristics of a color filter (CF). Compared with a conventional white OLED without both a QD film and the LPF, it was confirmed experimentally that the optical powers of red and green light in a new white OLED display were increased by 54.1 and 24.7% using a 30 wt % red QD film and a 20 wt % green QD film with the LPF, respectively. In addition, the white OLED with both a QD film and the LPF resulted in an increase in the color gamut from 98 to 107% (NTSC x,y ratio) due to the narrow emission linewidth of the QDs.

Optimization of methanol crystallization for highly efficient separation of palmitic acid from palm fatty acid mixture using response surface methodology

Directory of Open Access Journals (Sweden)

A. A.W. Japir

2018-01-01

Full Text Available The objective of the current study was to develop parameters for the separation of palmitic acid (PA from a crude palm oil saturated fatty acid (SFAs mixture by using the methanol crystallization method. The conditions of methanol crystallization were optimized by the response surface methodology (RSM with the D-optimal design. The procedure of developing the solvent crystallization method was based on various different parameters. The fatty acid composition was carried out using a gas chromatography flame ionization detector (GC-FID as fatty acid methyl esters. The highest percentage of SFAs was more than 96% with the percentage yield of 87.5% under the optimal conditions of fatty acids-to-methanol ratio of 1: 20 (w/v, the crystallization temperature of -15 °C, and the crystallization time of 24 hours, respectively. The composition of separated SFAs in the solid fraction contains 96.7% of palmitic acid (C16:0 as a dominant component and 3.3% of stearic acid (C18:0. The results showed that utilizing methanol as a crystallization solvent is recommended because of its high efficiency, low cost, stability, availability, comparative ease of recovery and its ability to form needle-like crystals which have good filtering and washing characteristics.

Optimization of methanol crystallization for highly efficient separation of palmitic acid from palm fatty acid mixture using response surface methodology

International Nuclear Information System (INIS)

Japir, A.A.W.; Salimon, J.; Derawi, D.; Yahaya, B.H.; Jamil, M.S.M.; Yusop, M.R.

2017-01-01

The objective of the current study was to develop parameters for the separation of palmitic acid (PA) from a crude palm oil saturated fatty acid (SFAs) mixture by using the methanol crystallization method. The conditions of methanol crystallization were optimized by the response surface methodology (RSM) with the D-optimal design. The procedure of developing the solvent crystallization method was based on various different parameters. The fatty acid composition was carried out using a gas chromatography flame ionization detector (GC-FID) as fatty acid methyl esters. The highest percentage of SFAs was more than 96% with the percentage yield of 87.5% under the optimal conditions of fatty acids-to-methanol ratio of 1: 20 (w/v), the crystallization temperature of -15 °C, and the crystallization time of 24 hours, respectively. The composition of separated SFAs in the solid fraction contains 96.7% of palmitic acid (C16:0) as a dominant component and 3.3% of stearic acid (C18:0). The results showed that utilizing methanol as a crystallization solvent is recommended because of its high efficiency, low cost, stability, availability, comparative ease of recovery and its ability to form needle-like crystals which have good filtering and washing characteristics. [es

Reverse-mode PSLC multi-plane optical see-through display for AR applications.

Science.gov (United States)

Liu, Shuxin; Li, Yan; Zhou, Pengcheng; Chen, Quanming; Su, Yikai

2018-02-05

In this paper we propose an optical see-through multi-plane display with reverse-mode polymer-stabilized liquid crystal (PSLC). Our design solves the problem of accommodation-vergence conflict with correct focus cues. In the reverse mode PSLC system, power consumption could be reduced to ~1/(N-1) of that in a normal mode system if N planes are displayed. The PSLC films fabricated in our experiment exhibit a low saturation voltage ~20 V rms , a high transparent-state transmittance (92%), and a fast switching time within 2 ms and polarization insensitivity. A proof-of-concept two-plane color display prototype and a four-plane monocolor display prototype were implemented.

Effect of irradiation temperature on the efficiency of introduction of multivacancy defects into n-Si crystals

International Nuclear Information System (INIS)

Pagava, T. A.

2006-01-01

The n-Si single crystals are studied in order to gain insight into the effect of the temperature of irradiation T irr on the defect-production process. The samples under study were irradiated with 2-MeV electrons in the range T irr = 20-400 deg. C. Irradiated crystals were annealed isochronously in the temperature range from 80 to 600 deg. C. Measurements were carried out by the Hall method in the temperature range from 77 to 300 K. It is shown that the efficiency of introduction of radiation defects with a high thermal stability (T ann ≥ 350 deg. C) attains a maximum at T irr = 150 deg. C. The observed effect is accounted for by formation of multivacancy defects PV 2 on the basis of ionized E centers and nonequilibrium vacancies

A Multi-Mode Video Driver for a High Resolution LCoS Display

OpenAIRE

Farrell, Ronan; Jacob, Mark; Maher, Roger

2000-01-01

This paper describes the design of a display driver for Liquid Crystal on Silicon (LCoS) microdisplays. These are high resolution reflective display devices which allow up to 1280x1024 pixels on an area of 3.75cm2, and are typically refreshed at 120Hz. The required driver consists of a digital section capable of taking the common display formats such as SVGA and new formats, SXGA, and processing these to a common 120HzRGB signal, requiring an output rate of 160 mega-pixels/second. This signal...

Solution growth of single crystal methylammonium lead halide perovskite nanostructures for optoelectronic and photovoltaic applications.

Science.gov (United States)

Fu, Yongping; Meng, Fei; Rowley, Matthew B; Thompson, Blaise J; Shearer, Melinda J; Ma, Dewei; Hamers, Robert J; Wright, John C; Jin, Song

2015-05-06

Understanding crystal growth and improving material quality is important for improving semiconductors for electronic, optoelectronic, and photovoltaic applications. Amidst the surging interest in solar cells based on hybrid organic-inorganic lead halide perovskites and the exciting progress in device performance, improved understanding and better control of the crystal growth of these perovskites could further boost their optoelectronic and photovoltaic performance. Here, we report new insights on the crystal growth of the perovskite materials, especially crystalline nanostructures. Specifically, single crystal nanowires, nanorods, and nanoplates of methylammonium lead halide perovskites (CH3NH3PbI3 and CH3NH3PbBr3) are successfully grown via a dissolution-recrystallization pathway in a solution synthesis from lead iodide (or lead acetate) films coated on substrates. These single crystal nanostructures display strong room-temperature photoluminescence and long carrier lifetime. We also report that a solid-liquid interfacial conversion reaction can create a highly crystalline, nanostructured MAPbI3 film with micrometer grain size and high surface coverage that enables photovoltaic devices with a power conversion efficiency of 10.6%. These results suggest that single-crystal perovskite nanostructures provide improved photophysical properties that are important for fundamental studies and future applications in nanoscale optoelectronic and photonic devices.

The effect of crystal orientation on the aluminum anodes of the aluminum-air batteries in alkaline electrolytes

Science.gov (United States)

Fan, Liang; Lu, Huimin; Leng, Jing; Sun, Zegao; Chen, Chunbo

2015-12-01

Recently, aluminum-air (Al-air) batteries have received attention from researchers as an exciting option for safe and efficient batteries. The electrochemical performance of Aluminum anode remains an active area of investigation. In this paper, the electrochemical properties of polycrystalline Al, Al (001), (110) and (111) single crystals are investigated using potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) in 4 M NaOH and KOH. Hydrogen corrosion rates of the Al anodes are determined by hydrogen collection. Battery performance using the anodes is tested by constant current discharge at 10 mA cm-2. This is the first report showing that the electrochemical properties of Al are closely related to the crystallographic orientation in alkaline electrolytes. The (001) crystallographic plane has good corrosion resistance but (110) is more sensitive. Al (001) single crystals display higher anode efficiency and capacity density. Controlling the crystallographic orientation of the Al anode is another way to improve the performance of Al-air batteries in alkaline electrolytes.

Domain-Reversed Lithium Niobate Single-Crystal Fibers are Potentially for Efficient Terahertz Wave Generation

Directory of Open Access Journals (Sweden)

Yalin Lu

2008-01-01

Full Text Available Nonlinear frequency conversion remains one of the dominant approaches to efficiently generate THz waves. Significant material absorption in the THz range is the main factor impeding the progress towards this direction. In this research, a new multicladding nonlinear fiber design was proposed to solve this problem, and as the major experimental effort, periodic domain structure was introduced into lithium niobate single-crystal fibers by electrical poling. The introduced periodic domain structures were nondestructively revealed using a crossly polarized optical microscope and a confocal scanning optical microscope for quality assurance.

The study of thermal tunable coupling between a Superconducting photonic crystal waveguide and semi-circular photonic crystal

Energy Technology Data Exchange (ETDEWEB)

Oskooi, Somayeh; Barvestani, Jamal, E-mail: barvestani@tabrizu.ac.ir

2016-08-15

Highlights: • The light coupling between superconducting photonic crystal waveguide and a semi-circular photonic crystal has been studied. • We utilized the finite difference time domain and plane wave expansion methods in the calculations. • The effect of the size of the nearest neighbor rods of waveguide on the coupling efficiency has been investigated. • The coupling efficiencies are reported versus the temperature of the superconducting waveguide. - Abstract: Through the present study, we investigated the light coupling between superconducting photonic crystal waveguide and a semi-circular photonic crystal. By using the finite difference time domain method, we evaluated the coupling efficiency between the mentioned structures at the various temperatures for different waveguide sizes. Calculation demonstrated that the coupling efficiency strongly depended on the temperature of the superconductor. The peak value of the coupling efficiency was influenced by the size of the nearest neighbor rods of waveguide. The results have shown that it is possible to obtain high efficiency at the desired temperature with proper selection of physical parameters in far-infrared frequency region. This structure has great potential in the optical integration and other areas.

Non-binary Colour Modulation for Display Device Based on Phase Change Materials

Science.gov (United States)

Ji, Hong-Kai; Tong, Hao; Qian, Hang; Hui, Ya-Juan; Liu, Nian; Yan, Peng; Miao, Xiang-Shui

2016-12-01

A reflective-type display device based on phase change materials is attractive because of its ultrafast response time and high resolution compared with a conventional display device. This paper proposes and demonstrates a unique display device in which multicolour changing can be achieved on a single device by the selective crystallization of double layer phase change materials. The optical contrast is optimized by the availability of a variety of film thicknesses of two phase change layers. The device exhibits a low sensitivity to the angle of incidence, which is important for display and colour consistency. The non-binary colour rendering on a single device is demonstrated for the first time using optical excitation. The device shows the potential for ultrafast display applications.

Non-binary Colour Modulation for Display Device Based on Phase Change Materials.

Science.gov (United States)

Ji, Hong-Kai; Tong, Hao; Qian, Hang; Hui, Ya-Juan; Liu, Nian; Yan, Peng; Miao, Xiang-Shui

2016-12-19

A reflective-type display device based on phase change materials is attractive because of its ultrafast response time and high resolution compared with a conventional display device. This paper proposes and demonstrates a unique display device in which multicolour changing can be achieved on a single device by the selective crystallization of double layer phase change materials. The optical contrast is optimized by the availability of a variety of film thicknesses of two phase change layers. The device exhibits a low sensitivity to the angle of incidence, which is important for display and colour consistency. The non-binary colour rendering on a single device is demonstrated for the first time using optical excitation. The device shows the potential for ultrafast display applications.

Scanning laser beam displays based on a 2D MEMS

Science.gov (United States)

Niesten, Maarten; Masood, Taha; Miller, Josh; Tauscher, Jason

2010-05-01

The combination of laser light sources and MEMS technology enables a range of display systems such as ultra small projectors for mobile devices, head-up displays for vehicles, wearable near-eye displays and projection systems for 3D imaging. Images are created by scanning red, green and blue lasers horizontally and vertically with a single two-dimensional MEMS. Due to the excellent beam quality of laser beams, the optical designs are efficient and compact. In addition, the laser illumination enables saturated display colors that are desirable for augmented reality applications where a virtual image is used. With this technology, the smallest projector engine for high volume manufacturing to date has been developed. This projector module has a height of 7 mm and a volume of 5 cc. The resolution of this projector is WVGA. No additional projection optics is required, resulting in an infinite focus depth. Unlike with micro-display projection displays, an increase in resolution will not lead to an increase in size or a decrease in efficiency. Therefore future projectors can be developed that combine a higher resolution in an even smaller and thinner form factor with increased efficiencies that will lead to lower power consumption.

Crystal growth, spectral properties, and laser demonstration of laser crystal Nd:LYSO

Science.gov (United States)

Li, D. Z.; Xu, X. D.; Zhou, D. H.; Zhuang, S. D.; Wang, Z. P.; Xia, C. T.; Wu, F.; Xu, J.

2010-11-01

A Nd:LYSO crystal has been grown by the Czochralski technique. The cell parameters were analyzed with X-ray diffraction (XRD). The Judd-Ofelt intense parameters Ω2,4,6 were obtained to be 2.65, 5.75, and 7.37×10-20 cm2, respectively. The absorption and emission cross sections and the branching ratios were calculated. The large absorption cross section (6.14×10-20 cm2) and broad absorption band (5 nm) around 811 nm indicate that this crystal can be pumped efficiently by laser diodes. The broad emission band from the 4F3/2 multiplet shows that the crystal is a promising medium for ultrashort pulse lasers. Pumped by a laser diode, the maximum 814 mW continuous-wave laser output has been obtained with a slope efficiency of 28.9%. All the results show that this crystal is a promising laser material.

Crystal growth, spectral properties, and laser demonstration of laser crystal Nd:LYSO

International Nuclear Information System (INIS)

Li, D Z; Xu, X D; Zhou, D H; Xia, C T; Wu, F; Zhuang, S D; Wang, Z P; Xu, J

2010-01-01

A Nd:LYSO crystal has been grown by the Czochralski technique. The cell parameters were analyzed with X-ray diffraction (XRD). The Judd-Ofelt intense parameters Ω 2,4,6 were obtained to be 2.65, 5.75, and 7.37×10 -20 cm 2 , respectively. The absorption and emission cross sections and the branching ratios were calculated. The large absorption cross section (6.14×10 -20 cm 2 ) and broad absorption band (5 nm) around 811 nm indicate that this crystal can be pumped efficiently by laser diodes. The broad emission band from the 4 F 3/2 multiplet shows that the crystal is a promising medium for ultrashort pulse lasers. Pumped by a laser diode, the maximum 814 mW continuous-wave laser output has been obtained with a slope efficiency of 28.9%. All the results show that this crystal is a promising laser material

Controlling Power Consumption for Displays With Backlight Dimming

DEFF Research Database (Denmark)

Mantel, Claire; Burini, Nino; Nadernejad, Ehsan

2013-01-01

Backlight dimming of Liquid Crystal Displays (LCD) is a technology which aims at saving power and improving visual quality. The evolution of energy standards and the increasing public expectations regarding power consumption have made it necessary for backlight systems to manage their power....... Such a control is challenging to implement, because for LCD displays quality and power are closely interlinked, and one cannot be modified without affecting the other. To address this issue, we present a framework for power controlled backlight dimming defining some key concepts. Two methods to obtain backlights...... with a predefined power level for images are presented: one method has low complexity and the other achieves high performance in terms of quality/power trade-off. Those methods are evaluated on a modeled Light-Emitting Diode edge-lit backlight display. The high-performance method performs significantly better than...

Structural coloration of chitosan-cationized cotton fabric using photonic crystals

Science.gov (United States)

Yavuz, G.; Zille, A.; Seventekin, N.; Souto, A. P.

2017-10-01

In this work, poly (styrene-methyl methacrylate-acrylic acid) P(St-MMA-AA) composite nanospheres were deposited onto chitosan-cationized woven cotton fabrics followed by a second layer of chitosan. The deposited photonic crystals (PCs) on the fabrics were evaluated for coating efficiency and resistance, chemical analysis and color variation by optical and SEM microscopy, ATR-FTIR, diffuse reflectance spectroscopy and washing fastness. Chitosan deposition on cotton fabric provided cationic groups on the fiber surface promoting electrostatic interaction with photonic crystals. SEM images of the washed samples indicate that the PCs are firmly coated on the cotton surface only in the chitosan treated sample. The photonic nanospheres show an average diameter of 280 nm and display a face-centered cubic closepacking structure with an average thickness of 10 μm. A further chitosan post-treatment enhances color yield of the samples due to the chitosan transparent covering layer that induce bright reflections where the angles of incidence and reflection are the same. After washing, no photonic crystal can be detected on control fabric surface. However, the sample that received a chitosan post-treatment showed a good washing fastness maintaining a reasonable degree of iridescence. Chitosan fills the spaces between the polymer spheres in the matrix stabilizing the photonic structure. Sizeable variations in lattice spacing will allow color variations using more flexible non-close-packed photonic crystal arrays in chitosan hydrogels matrices.

Large-screen display industry: market and technology trends for direct view and projection displays

Science.gov (United States)

Castellano, Joseph A.; Mentley, David E.

1996-03-01

Large screen information displays are defined as dynamic electronic displays that can be viewed by more than one person and are at least 2-feet wide. These large area displays for public viewing provide convenience, entertainment, security, and efficiency to the viewers. There are numerous uses for large screen information displays including those in advertising, transportation, traffic control, conference room presentations, computer aided design, banking, and military command/control. A noticeable characteristic of the large screen display market is the interchangeability of display types. For any given application, the user can usually choose from at least three alternative technologies, and sometimes from many more. Some display types have features that make them suitable for specific applications due to temperature, brightness, power consumption, or other such characteristic. The overall worldwide unit consumption of large screen information displays of all types and for all applications (excluding consumer TV) will increase from 401,109 units in 1995 to 655,797 units in 2002. On a unit consumption basis, applications in business and education represent the largest share of unit consumption over this time period; in 1995, this application represented 69.7% of the total. The market (value of shipments) will grow from DOL3.1 billion in 1995 to DOL3.9 billion in 2002. The market will be dominated by front LCD projectors and LCD overhead projector plates.

Crystal collimator systems for high energy frontier

Science.gov (United States)

Sytov, A. I.; Tikhomirov, V. V.; Lobko, A. S.

2017-07-01

Crystalline collimators can potentially considerably improve the cleaning performance of the presently used collimator systems using amorphous collimators. A crystal-based collimation scheme which relies on the channeling particle deflection in bent crystals has been proposed and extensively studied both theoretically and experimentally. However, since the efficiency of particle capture into the channeling regime does not exceed ninety percent, this collimation scheme partly suffers from the same leakage problems as the schemes using amorphous collimators. To improve further the cleaning efficiency of the crystal-based collimation system to meet the requirements of the FCC, we suggest here a double crystal-based collimation scheme, to which the second crystal is introduced to enhance the deflection of the particles escaping the capture to the channeling regime in its first crystal. The application of the effect of multiple volume reflection in one bent crystal and of the same in a sequence of crystals is simulated and compared for different crystal numbers and materials at the energy of 50 TeV. To enhance also the efficiency of use of the first crystal of the suggested double crystal-based scheme, we propose: the method of increase of the probability of particle capture into the channeling regime at the first crystal passage by means of fabrication of a crystal cut and the method of the amplification of nonchanneled particle deflection through the multiple volume reflection in one bent crystal, accompanying the particle channeling by a skew plane. We simulate both of these methods for the 50 TeV FCC energy.

An Exopolysaccharide-Deficient Mutant of Lactobacillus rhamnosus GG Efficiently Displays a Protective Llama Antibody Fragment against Rotavirus on Its Surface.

Science.gov (United States)

Álvarez, Beatriz; Krogh-Andersen, Kasper; Tellgren-Roth, Christian; Martínez, Noelia; Günaydın, Gökçe; Lin, Yin; Martín, M Cruz; Álvarez, Miguel A; Hammarström, Lennart; Marcotte, Harold

2015-09-01

Rotavirus is the leading cause of infantile diarrhea in developing countries, where it causes a high number of deaths among infants. Two vaccines are available, being highly effective in developed countries although markedly less efficient in developing countries. As a complementary treatment to the vaccines, a Lactobacillus strain producing an anti-rotavirus antibody fragment in the gastrointestinal tract could potentially be used. In order to develop such an alternative therapy, the effectiveness of Lactobacillus rhamnosus GG to produce and display a VHH antibody fragment (referred to as anti-rotavirus protein 1 [ARP1]) on the surface was investigated. L. rhamnosus GG is one of the best-characterized probiotic bacteria and has intrinsic antirotavirus activity. Among four L. rhamnosus GG strains [GG (CMC), GG (ATCC 53103), GG (NCC 3003), and GG (UT)] originating from different sources, only GG (UT) was able to display ARP1 on the bacterial surface. The genomic analysis of strain GG (UT) showed that the genes welE and welF of the EPS cluster are inactivated, which causes a defect in exopolysaccharide (EPS) production, allowing efficient display of ARP1 on its surface. Finally, GG (UT) seemed to confer a level of protection against rotavirus-induced diarrhea similar to that of wild-type GG (NCC 3003) in a mouse pup model, indicating that the EPS may not be involved in the intrinsic antirotavirus activity. Most important, GG (EM233), a derivative of GG (UT) producing ARP1, was significantly more protective than the control strain L. casei BL23. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

Magnetic switching of optical reflectivity in nanomagnet/micromirror suspensions: colloid displays as a potential alternative to liquid crystal displays.

Science.gov (United States)

Bubenhofer, S B; Athanassiou, E K; Grass, R N; Koehler, F M; Rossier, M; Stark, W J

2009-12-02

Two-particle colloids containing nanomagnets and microscale mirrors can be prepared from iron oxide nanoparticles, microscale metal flakes and high-density liquids stabilizing the mirror suspension against sedimentation by matching the constituent's density. The free Brownian rotation of the micromirrors can be magnetically controlled through an anisotropic change in impulse transport arising from impacts of the magnetic nanoparticles onto the anisotropic flakes. The resulting rapid mirror orientation allows large changes in light transmission and switchable optical reflectivity. The preparation of a passive display was conceptually demonstrated through colloid confinement in a planar cavity over an array of individually addressable solenoids and resulted in 4 x 4 digit displays with a reaction time of less than 100 ms.

Crystal ball data acquisition system

International Nuclear Information System (INIS)

Chestnut, R.; Kiesling, C.; Bloom, E.; Bulos, F.; Gaiser, J.; Godfrey, G.; Oreglia, M.; Partridge, R.; Peck, C.; Porter, F.; Aschman, D.; Cavali-Sforza, M.; Coyne, D.; Sadrozinski, H.; Kollmann, W.; Richardson, M.

1979-01-01

The data acquisition system for the Crystal Ball project at SLAC is described. A PDP-11/t55 using RSX-11M connected to the SLAC Triplex is the basis of the system. A ''physics pipeline'' allows physicists to write their own equipment-monitoring or physics tasks which require event sampling. As well, an interactive analysis package (MULTI) is in the pipeline. Histogram collection and display on the PDP are implemented using the Triplex histogramming package. Various interactive event displays are also implemented

Nanomechanical resonant structures in single-crystal diamond

OpenAIRE

Burek, Michael J.; Ramos, Daniel; Patel, Parth; Frank, Ian W.; Lončar, Marko

2013-01-01

With its host of outstanding material properties, single-crystal diamond is an attractive material for nanomechanical systems. Here, the mechanical resonance characteristics of freestanding, single-crystal diamond nanobeams fabricated by an angled-etching methodology are reported. Resonance frequencies displayed evidence of significant compressive stress in doubly clamped diamond nanobeams, while cantilever resonance modes followed the expected inverse-length-squared trend. Q-factors on the o...

Adaptive controller for volumetric display of neuroimaging studies

Science.gov (United States)

Bleiberg, Ben; Senseney, Justin; Caban, Jesus

2014-03-01

Volumetric display of medical images is an increasingly relevant method for examining an imaging acquisition as the prevalence of thin-slice imaging increases in clinical studies. Current mouse and keyboard implementations for volumetric control provide neither the sensitivity nor specificity required to manipulate a volumetric display for efficient reading in a clinical setting. Solutions to efficient volumetric manipulation provide more sensitivity by removing the binary nature of actions controlled by keyboard clicks, but specificity is lost because a single action may change display in several directions. When specificity is then further addressed by re-implementing hardware binary functions through the introduction of mode control, the result is a cumbersome interface that fails to achieve the revolutionary benefit required for adoption of a new technology. We address the specificity versus sensitivity problem of volumetric interfaces by providing adaptive positional awareness to the volumetric control device by manipulating communication between hardware driver and existing software methods for volumetric display of medical images. This creates a tethered effect for volumetric display, providing a smooth interface that improves on existing hardware approaches to volumetric scene manipulation.

IR Sensor Synchronizing Active Shutter Glasses for 3D HDTV with Flexible Liquid Crystal Lenses

Directory of Open Access Journals (Sweden)

Jeong In Han

2013-12-01

Full Text Available IR sensor synchronizing active shutter glasses for three-dimensional high definition television (3D HDTV were developed using a flexible liquid crystal (FLC lens. The FLC lens was made on a polycarbonate (PC substrate using conventional liquid crystal display (LCD processes. The flexible liquid crystal lens displayed a maximum transmission of 32% and total response time of 2.56 ms. The transmittance, the contrast ratio and the response time of the flexible liquid crystal lens were superior to those of glass liquid crystal lenses. Microcontroller unit and drivers were developed as part of a reception module with power supply for the IR sensor synchronizing active shutter glasses with the flexible liquid crystal lens prototypes. IR sensor synchronizing active shutter glasses for 3D HDTV with flexible liquid crystal lenses produced excellent 3D images viewing characteristics.

Market trends in the projection display industry

Science.gov (United States)

Dash, Sweta

2000-04-01

The projection display industry represents a multibillion- dollar market that includes four distinct technologies. High-volume consumer products and high-value business products drive the market, with different technologies being used in different application markets. The consumer market is dominated by rear CRT technology, especially in the projection television segment. But rear LCD (liquid crystal display) and rear reflective (DLP, or Digital Light ProcessingTM) televisions are slowly emerging as future competitors to rear CRT projectors. Front CRT projectors are still popular in the high-end home theater market. Front LCD technology and front DLP technology dominate the business market. Traditional light valve technology was the only solution for applications requiring high light outputs, but new three-chip DLP projectors meet the higher light output requirements at a lower price. In the last few years the strongest growth has been in the business market for multimedia presentation applications. This growth was due to the continued increase in display pixel formats, the continued reduction in projector weight, and the improved price/performance ratio. The projection display market will grow at a significant rate during the next five years, driven by the growth in ultraportable (market to digital and HDTV products.

Generating Efficient Femtosecond Mid-infrared Pulse by Single Near-infrared Pump Wavelength in Bulk Nonlinear Crystal Without Phase-matching

DEFF Research Database (Denmark)

Zhou, Binbin; Guo, Hairun; Bache, Morten

2014-01-01

We experimentally demonstrate efficient mid-infrared pulse generation by dispersive wave radiation in bulk lithium niobate crystal. Femtosecond mid-IR pulses centering from 2.8-2.92 μm are generated using the single pump wavelengths from 1.25-1.45 μm. © 2014 Optical Society of America...

Crystallization of glycine with ultrasound

DEFF Research Database (Denmark)

Louhi-Kultanen, Marjatta; Karjalainen, Milja; Rantanen, Jukka

2006-01-01

Sonocrystallization has proved to be an efficient tool to influence the external appearance and structure of a crystalline product obtained by various crystallization methods. The present work focuses on high intensity sonocrystallization of glycine by varying amplitude of ultrasound with an ultr...... ultrasound power. This study also showed, the higher the ultrasound amplitude the smaller the crystals obtained.......Sonocrystallization has proved to be an efficient tool to influence the external appearance and structure of a crystalline product obtained by various crystallization methods. The present work focuses on high intensity sonocrystallization of glycine by varying amplitude of ultrasound...... with an ultrasound frequency of 20kHz at two temperature ranges 40-50 and 20-30 degrees C in a jacketed 250-ml cooling crystallizer equipped with a stirrer. The polymorph composition of the obtained crystals was analyzed with a temperature variable X-ray powder diffractometer (XRPD). XRPD results showed that...

Crystal Clear - New crystals for LHC experiments help to improve PET scanners Exhibition LEPFest 2000

CERN Multimedia

2000-01-01

Better resolution through smaller crystals Better images through higher light yieldHigh efficiency, stability and gain by using avalanche photodiodes and low noise electronics Reduced cost of crystals (1/10) through mass production

New generation of one-dimensional photonic crystal cavities as robust high-efficient frequency converter

Science.gov (United States)

Parvini, T. S.; Tehranchi, M. M.; Hamidi, S. M.

2017-07-01

An effective method is proposed to design finite one-dimensional photonic crystal cavities (PhCCs) as robust high-efficient frequency converter. For this purpose, we consider two groups of PhCCs which are constructed by stacking m nonlinear (LiNbO3) and n linear (air) layers with variable thicknesses. In the first group, the number of linear layers is less than the nonlinear layers by one and in the second group by two. The conversion efficiency is calculated as a function of the arrangement and thicknesses of the linear and nonlinear layers by benefiting from nonlinear transfer matrix method. Our numerical simulations show that for each group of PhCCs, there is a structural formula by which the configurations with the highest efficiency can be constructed for any values of m and n (i.e. any number of layers). The efficient configurations are equivalent to Fabry-Pérot cavities that depend on the relationship between m and n and the mirrors in two sides of these cavities can be periodic or nonperiodic. The conversion efficiencies of these designed PhCCs are more than 5 orders of magnitude higher than the perfect ones which satisfy photonic bandgap edge and quasi-phase matching. Moreover, the results reveal that conversion efficiencies of Fabry-Pérot cavities with non-periodic mirrors are one order of magnitude higher than those with periodic mirrors. The major physical mechanisms of the enhancement are quasi-phase matching effect, cavity effect induced by dispersive mirrors, and double resonance for the pump and the harmonic fields in defect state. We believe that this method is very beneficial to the design of high-efficient compact optical frequency converters.

Crystal collimator systems for high energy frontier

CERN Document Server

AUTHOR|(CDS)2100516; Tikhomirov, Viktor; Lobko, Alexander

2017-01-01

Crystalline collimators can potentially considerably improve the cleaning performance of the presently used collimator systems using amorphous collimators. A crystal-based collimation scheme which relies on the channeling particle deflection in bent crystals has been proposed and extensively studied both theoretically and experimentally. However, since the efficiency of particle capture into the channeling regime does not exceed ninety percent, this collimation scheme partly suffers from the same leakage problems as the schemes using amorphous collimators. To improve further the cleaning efficiency of the crystal-based collimation system to meet the requirements of the FCC, we suggest here a double crystal-based collimation scheme, to which the second crystal is introduced to enhance the deflection of the particles escaping the capture to the channeling regime in its first crystal. The application of the effect of multiple volume reflection in one bent crystal and of the same in a sequence of crystals is simu...

Photonic crystals cause active colour change in chameleons

Science.gov (United States)

Teyssier, Jérémie; Saenko, Suzanne V.; van der Marel, Dirk; Milinkovitch, Michel C.

2015-03-01

Many chameleons, and panther chameleons in particular, have the remarkable ability to exhibit complex and rapid colour changes during social interactions such as male contests or courtship. It is generally interpreted that these changes are due to dispersion/aggregation of pigment-containing organelles within dermal chromatophores. Here, combining microscopy, photometric videography and photonic band-gap modelling, we show that chameleons shift colour through active tuning of a lattice of guanine nanocrystals within a superficial thick layer of dermal iridophores. In addition, we show that a deeper population of iridophores with larger crystals reflects a substantial proportion of sunlight especially in the near-infrared range. The organization of iridophores into two superposed layers constitutes an evolutionary novelty for chameleons, which allows some species to combine efficient camouflage with spectacular display, while potentially providing passive thermal protection.

Efficient continuous-wave nonlinear frequency conversion in high-Q gallium nitride photonic crystal cavities on silicon

Directory of Open Access Journals (Sweden)

Mohamed Sabry Mohamed

2017-03-01

Full Text Available We report on nonlinear frequency conversion from the telecom range via second harmonic generation (SHG and third harmonic generation (THG in suspended gallium nitride slab photonic crystal (PhC cavities on silicon, under continuous-wave resonant excitation. Optimized two-dimensional PhC cavities with augmented far-field coupling have been characterized with quality factors as high as 4.4 × 104, approaching the computed theoretical values. The strong enhancement in light confinement has enabled efficient SHG, achieving a normalized conversion efficiency of 2.4 × 10−3 W−1, as well as simultaneous THG. SHG emission power of up to 0.74 nW has been detected without saturation. The results herein validate the suitability of gallium nitride for integrated nonlinear optical processing.

Protein Crystal Growth

Science.gov (United States)

2003-01-01

In order to rapidly and efficiently grow crystals, tools were needed to automatically identify and analyze the growing process of protein crystals. To meet this need, Diversified Scientific, Inc. (DSI), with the support of a Small Business Innovation Research (SBIR) contract from NASA s Marshall Space Flight Center, developed CrystalScore(trademark), the first automated image acquisition, analysis, and archiving system designed specifically for the macromolecular crystal growing community. It offers automated hardware control, image and data archiving, image processing, a searchable database, and surface plotting of experimental data. CrystalScore is currently being used by numerous pharmaceutical companies and academic and nonprofit research centers. DSI, located in Birmingham, Alabama, was awarded the patent Method for acquiring, storing, and analyzing crystal images on March 4, 2003. Another DSI product made possible by Marshall SBIR funding is VaporPro(trademark), a unique, comprehensive system that allows for the automated control of vapor diffusion for crystallization experiments.

Growth, spectral, linear and nonlinear optical characteristics of an efficient semiorganic acentric crystal: L-valinium L-valine chloride

Energy Technology Data Exchange (ETDEWEB)

Nageshwari, M.; Jayaprakash, P.; Kumari, C. Rathika Thaya [PG & Research Department of Physics, Arignar Anna Govt. Arts College, Cheyyar 604407, Tamil Nadu (India); Vinitha, G. [Department of Physics, School of Advanced Sciences, VIT Chennai, 600127 Tamil Nadu (India); Caroline, M. Lydia, E-mail: lydiacaroline2006@yahoo.co.in [PG & Research Department of Physics, Arignar Anna Govt. Arts College, Cheyyar 604407, Tamil Nadu (India)

2017-04-15

An efficient nonlinear optical semiorganic material L-valinium L-valine chloride (LVVCl) was synthesized and grown-up by means of slow evaporation process. Single crystal XRD evince that LVVCl corresponds to monoclinic system having acentric space group P2{sub 1}. The diverse functional groups existing in LVVCl were discovered with FTIR spectral investigation. The UV-Visible and photoluminescence spectrum discloses the optical and electronic properties respectively for the grown crystal. Several optical properties specifically extinction coefficient, reflectance, linear refractive index, electrical and optical conductivity were also determined. The SEM analysis was also carried out and it portrayed the surface morphology of LVVCl. The calculated value of laser damage threshold was 2.59 GW/cm{sup 2}. The mechanical and dielectric property of LVVCl was investigated employing microhardness and dielectric studies. The second and third order nonlinear optical characteristics of LVVCl was characterized utilizing Kurtz Perry and Z scan technique respectively clearly suggest its suitability in the domain of optics and photonics. - Graphical abstract: Good quality transparent single crystals of L-valinium L-valine chloride single crystal was grown by slow evaporation technique. The grown crystals were analyzed using different instrumentation methods to check its usefulness for the device fabrication. The determination of nonlinear refractive index (n{sub 2}), absorption coefficient (β) and third order nonlinear susceptibility was determined by Z scan technique, highlighted that LVVCl can serve as a promising candidate for opto electronic and nonlinear optical applications.

Biotin-tagged proteins: Reagents for efficient ELISA-based serodiagnosis and phage display-based affinity selection.

Science.gov (United States)

Verma, Vaishali; Kaur, Charanpreet; Grover, Payal; Gupta, Amita; Chaudhary, Vijay K

2018-01-01

The high-affinity interaction between biotin and streptavidin has opened avenues for using recombinant proteins with site-specific biotinylation to achieve efficient and directional immobilization. The site-specific biotinylation of proteins carrying a 15 amino acid long Biotin Acceptor Peptide tag (BAP; also known as AviTag) is effected on a specific lysine either by co-expressing the E. coli BirA enzyme in vivo or by using purified recombinant E. coli BirA enzyme in the presence of ATP and biotin in vitro. In this paper, we have designed a T7 promoter-lac operator-based expression vector for rapid and efficient cloning, and high-level cytosolic expression of proteins carrying a C-terminal BAP tag in E. coli with TEV protease cleavable N-terminal deca-histidine tag, useful for initial purification. Furthermore, a robust three-step purification pipeline integrated with well-optimized protocols for TEV protease-based H10 tag removal, and recombinant BirA enzyme-based site-specific in vitro biotinylation is described to obtain highly pure biotinylated proteins. Most importantly, the paper demonstrates superior sensitivities in indirect ELISA with directional and efficient immobilization of biotin-tagged proteins on streptavidin-coated surfaces in comparison to passive immobilization. The use of biotin-tagged proteins through specific immobilization also allows more efficient selection of binders from a phage-displayed naïve antibody library. In addition, for both these applications, specific immobilization requires much less amount of protein as compared to passive immobilization and can be easily multiplexed. The simplified strategy described here for the production of highly pure biotin-tagged proteins will find use in numerous applications, including those, which may require immobilization of multiple proteins simultaneously on a solid surface.

Spectroscopic analysis and efficient diode-pumped 1.9 μm Tm3+-doped β'-Gd2(MoO4)3 crystal laser.

Science.gov (United States)

Tang, Jianfeng; Chen, Yujin; Lin, Yanfu; Gong, Xinghong; Huang, Jianhua; Luo, Zundu; Huang, Yidong

2011-07-04

Tm3+-doped β'-Gd2(MoO4)3 single crystal was grown by the Czochralski method. Spectroscopic analysis was carried out along different polarizations. End-pumped by a quasi-cw diode laser at 795 nm in a plano-concave cavity, an average laser output power of 58 mW around 1.9 μm was achieved in a 0.93-mm-thick crystal when the output coupler transmission was 7.1%. The absorbed pump threshold was 8 mW and the slope efficiency of the laser was 57%. This crystal has smooth and broad gain curve around 1.9 μm, which shows that it is also a potential gain medium for tunable and short pulse lasers.

Augmenting digital displays with computation

Science.gov (United States)

Liu, Jing

As we inevitably step deeper and deeper into a world connected via the Internet, more and more information will be exchanged digitally. Displays are the interface between digital information and each individual. Naturally, one fundamental goal of displays is to reproduce information as realistically as possible since humans still care a lot about what happens in the real world. Human eyes are the receiving end of such information exchange; therefore it is impossible to study displays without studying the human visual system. In fact, the design of displays is rather closely coupled with what human eyes are capable of perceiving. For example, we are less interested in building displays that emit light in the invisible spectrum. This dissertation explores how we can augment displays with computation, which takes both display hardware and the human visual system into consideration. Four novel projects on display technologies are included in this dissertation: First, we propose a software-based approach to driving multiview autostereoscopic displays. Our display algorithm can dynamically assign views to hardware display zones based on multiple observers' current head positions, substantially reducing crosstalk and stereo inversion. Second, we present a dense projector array that creates a seamless 3D viewing experience for multiple viewers. We smoothly interpolate the set of viewer heights and distances on a per-vertex basis across the arrays field of view, reducing image distortion, crosstalk, and artifacts from tracking errors. Third, we propose a method for high dynamic range display calibration that takes into account the variation of the chrominance error over luminance. We propose a data structure for enabling efficient representation and querying of the calibration function, which also allows user-guided balancing between memory consumption and the amount of computation. Fourth, we present user studies that demonstrate that the ˜ 60 Hz critical flicker fusion

Three-Dimensional Inverse Opal Photonic Crystal Substrates toward Efficient Capture of Circulating Tumor Cells.

Science.gov (United States)

Xu, Hongwei; Dong, Biao; Xiao, Qiaoqin; Sun, Xueke; Zhang, Xinran; Lyu, Jiekai; Yang, Yudan; Xu, Lin; Bai, Xue; Zhang, Shuang; Song, Hongwei

2017-09-13

Artificial fractal structures have attracted considerable scientific interest in circulating tumor cells (CTCs) detection and capture, which plays a pivotal role in the diagnosis and prognosis of cancer. Herein, we designed a bionic TiO 2 inverse opal photonic crystal (IOPC) structure for highly efficient immunocapture of CTCs by combination of a magnetic Fe 3 O 4 @C6@silane nanoparticles with anti-EpCAM (antiepithelial cell adhesion molecule) and microchannel structure. Porous structure and dimension of IOPC TiO 2 can be precisely controlled for mimicking cellular components, and anti-EpCAM antibody was further modified on IOPC interface by conjugating with polydopamine (PDA). The improvement of CTCs capture efficiency reaches a surprising factor of 20 for the IOPC interface compared to that on flat glass, suggesting that the IOPCs are responsible for the dramatic enhancement of the capture efficiency of MCF-7 cells. IOPC substrate with pore size of 415 nm leads to the optimal CTCs capture efficiency of 92% with 1 mL/h. Besides the cell affinity, IOPCs also have the advantage of light scattering property which can enhance the excitation and emission light of fluorescence labels, facilitating the real-time monitoring of CTCs capture. The IOPC-based platform demonstrates excellent performance in CTCs capture, which will take an important step toward specific recognition of disease-related rare cells.

Remote Sensing of Crystal Shapes in Ice Clouds

Science.gov (United States)

van Diedenhoven, Bastiaan

2017-01-01

Ice crystals in clouds exist in a virtually limitless variation of geometries. The most basic shapes of ice crystals are columnar or plate-like hexagonal prisms with aspect ratios determined by relative humidity and temperature. However, crystals in ice clouds generally display more complex structures owing to aggregation, riming and growth histories through varying temperature and humidity regimes. Crystal shape is relevant for cloud evolution as it affects microphysical properties such as fall speeds and aggregation efficiency. Furthermore, the scattering properties of ice crystals are affected by their general shape, as well as by microscopic features such as surface roughness, impurities and internal structure. To improve the representation of ice clouds in climate models, increased understanding of the global variation of crystal shape and how it relates to, e.g., location, cloud temperature and atmospheric state is crucial. Here, the remote sensing of ice crystal macroscale and microscale structure from airborne and space-based lidar depolarization observations and multi-directional measurements of total and polarized reflectances is reviewed. In addition, a brief overview is given of in situ and laboratory observations of ice crystal shape as well as the optical properties of ice crystals that serve as foundations for the remote sensing approaches. Lidar depolarization is generally found to increase with increasing cloud height and to vary with latitude. Although this variation is generally linked to the variation of ice crystal shape, the interpretation of the depolarization remains largely qualitative and more research is needed before quantitative conclusions about ice shape can be deduced. The angular variation of total and polarized reflectances of ice clouds has been analyzed by numerous studies in order to infer information about ice crystal shapes from them. From these studies it is apparent that pristine crystals with smooth surfaces are generally

Dermal quercetin smartCrystals®: Formulation development, antioxidant activity and cellular safety.

Science.gov (United States)

Hatahet, T; Morille, M; Hommoss, A; Dorandeu, C; Müller, R H; Bégu, S

2016-05-01

Flavonoids are natural plant pigments, which possess high antioxidative and antiradical activities. However, their poor water solubility led to a limited bioavailability. To overcome this major hurdle, quercetin nanocrystals were produced implementing smartCrystals® technology. This process combines bead milling and subsequent high-pressure homogenization at relatively low pressure (300bar). To test the possibility to develop a dermal formulation from quercetin smartCrystals®, quercetin nanosuspensions were admixed to Lutrol® F127 and hydroxythylcellulose nonionic gels. The physicochemical properties (morphology, size and charge), saturation solubility, dissolution velocity and the antioxidant properties (DPPH assay) as well as the cellular interaction of the produced quercetin smartCrystals® were studied and compared to crude quercetin powder. Quercetin smartCrystals® showed a strong increase in the saturation solubility and the dissolution velocity (7.6 fold). SmartCrystals® loaded or not into gels proved to be physically stable over a period of three months at 25°C. Interestingly, in vitro DPPH assay confirmed the preservation of quercetin antioxidative properties after nanonization. In parallel, the nanocrystalline form did not display cellular toxicity, even at high concentration (50μg/ml), as assayed on an epithelial cell line (VERO cells). In addition, the nanocrystalline form confirmed a protective activity for VERO cells against hydrogen peroxide induced toxicity in vitro. This new formulation presents a promising approach to deliver quercetin efficiently to skin in well-tolerated formulations. Copyright © 2016 Elsevier B.V. All rights reserved.

Impact of one-dimensional photonic crystal back reflector in thin-film c-Si solar cells on efficiency

Science.gov (United States)

Jalali, Tahmineh

2018-05-01

In this work, the effect of one-dimensional photonic crystal on optical absorption, which is implemented at the back side of thin-film crystalline silicon (c-Si) solar cells, is extensively discussed. The proposed structure acts as a Bragg reflector which reflects back light to the active layer as well as nanograting which couples the incident light to enhance optical absorption. To understand the optical mechanisms responsible for the enhancement of optical absorption, quantum efficiency and current density for all structures are calculated and the effect of influential parameters, such as grating period is investigated. The results confirm that our proposed structure have a great deal for substantial efficiency enhancement in a broad range from 400 to 1100 nm.

Is targeted reconstruction necessary for evaluating contrast-enhanced chest computed tomography using a liquid crystal display monitor?

International Nuclear Information System (INIS)

Ozawa, Yoshiyuki; Oshima, Hidekazu; Kitase, Masanori; Shibamoto, Yuta; Hara, Masaki; Ohashi, Kazuya

2008-01-01

The aim of this study was to examine whether 20-cm field-of-view (FOV) targeted reconstruction (TR) on contrast-enhanced (CE) chest computed tomography (CT) might improve the diagnostic value compared with simple zooming (SZ) from whole-thorax FOV images using a 2 million (2M)-pixel liquid crystal display (LCD) monitor. We prospectively evaluated 44 patients. SZ images were magnified from a FOV of 26-34 cm (mean 29.7 cm). Parameters were 512 x 512 matrix and 3 mm thickness and interval. Images were reconstructed using a soft-tissue kernel. Three radiologists evaluated contour, spiculation, notch, pleural tag, invasion, and internal characteristics of the lesions using 5-scale scores. We also performed a phantom study to evaluate the spatial resolution of images. The diagnostic value of the TR images was similar to that of the SZ images, with the findings identified in 88%-100% of the cases. Artifacts from highdensity structures deteriorated the image quality in six (14%), and the SZ images were judged to be preferable in five of them. In the phantom study, there was little difference in spatial resolution between the two images. The SZ images from whole-thorax FOV on CE chest CT were similar in quality to TR images using a 2M-pixel LCD monitor. (author)

Photoaligning and Photopatterning — A New Challenge in Liquid Crystal Photonics

Directory of Open Access Journals (Sweden)

Vladimir G. Chigrinov

2013-03-01

Full Text Available Photoalignment possesses obvious advantages in comparison with the usually “rubbing” treatment of the substrates of liquid crystal display (LCD cells. The application of the photoalignment and photopatterning nanotechnology for the new generation of photonic and display devices will be reviewed.

Structural Color Patterns by Electrohydrodynamic Jet Printed Photonic Crystals.

Science.gov (United States)

Ding, Haibo; Zhu, Cun; Tian, Lei; Liu, Cihui; Fu, Guangbin; Shang, Luoran; Gu, Zhongze

2017-04-05

In this work, we demonstrate the fabrication of photonic crystal patterns with controllable morphologies and structural colors utilizing electrohydrodynamic jet (E-jet) printing with colloidal crystal inks. The final shape of photonic crystal units is controlled by the applied voltage signal and wettability of the substrate. Optical properties of the structural color patterns are tuned by the self-assembly of the silica nanoparticle building blocks. Using this direct printing technique, it is feasible to print customized functional patterns composed of photonic crystal dots or photonic crystal lines according to relevant printing mode and predesigned tracks. This is the first report for E-jet printing with colloidal crystal inks. Our results exhibit promising applications in displays, biosensors, and other functional devices.

30.2 Digital PWM-driven AMOLED display on flex reducing static power consumption

NARCIS (Netherlands)

Genoe, J.; Obata, K.; Ameys, M.; Myny, K.; Ke, T.H.; Nag, M.; Steudel, S.; Schols, S.; Maas, J.; Tripathi, A.; Van Der Steen, J.-L.; Ellis, T.; Gelinck, G.H.; Heremans, P.

2014-01-01

The efficiency of small-molecule OLED devices increased substantially in recent years, creating opportunities for power-efficient displays, as only light is generated proportional to the subpixel intensity. However, current active matrix OLED (AMOLED) displays on foil do not validate this

Key Developments in Ionic Liquid Crystals.

Science.gov (United States)

Alvarez Fernandez, Alexandra; Kouwer, Paul H J

2016-05-16

Ionic liquid crystals are materials that combine the classes of liquid crystals and ionic liquids. The first one is based on the multi-billion-dollar flat panel display industry, whilst the latter quickly developed in the past decades into a family of highly-tunable non-volatile solvents. The combination yields materials with a unique set of properties, but also with many challenges ahead. In this review, we provide an overview of the key concepts in ionic liquid crystals, particularly from a molecular perspective. What are the important molecular parameters that determine the phase behavior? How should they be introduced into the molecules? Finally, which other tools does one have to realize specific properties in the material?

Key Developments in Ionic Liquid Crystals

Directory of Open Access Journals (Sweden)

Alexandra Alvarez Fernandez

2016-05-01

Full Text Available Ionic liquid crystals are materials that combine the classes of liquid crystals and ionic liquids. The first one is based on the multi-billion-dollar flat panel display industry, whilst the latter quickly developed in the past decades into a family of highly-tunable non-volatile solvents. The combination yields materials with a unique set of properties, but also with many challenges ahead. In this review, we provide an overview of the key concepts in ionic liquid crystals, particularly from a molecular perspective. What are the important molecular parameters that determine the phase behavior? How should they be introduced into the molecules? Finally, which other tools does one have to realize specific properties in the material?

Highly Efficient LiYF4:Yb(3+), Er(3+) Upconversion Single Crystal under Solar Cell Spectrum Excitation and Photovoltaic Application.

Science.gov (United States)

Chen, Xu; Xu, Wen; Song, Hongwei; Chen, Cong; Xia, Haiping; Zhu, Yongsheng; Zhou, Donglei; Cui, Shaobo; Dai, Qilin; Zhang, Jiazhong

2016-04-13

Luminescent upconversion is a promising way to harvest near-infrared (NIR) sunlight and transforms it into visible light that can be directly absorbed by active materials of solar cells and improve their power conversion efficiency (PCE). However, it is still a great challenge to effectively improve the PCE of solar cells with the assistance of upconversion. In this work, we demonstrate the application of the transparent LiYF4:Yb(3+), Er(3+) single crystal as an independent luminescent upconverter to improve the PCE of perovskite solar cells. The LiYF4:Yb(3+), Er(3+) single crystal is prepared by an improved Bridgman method, and its internal quantum efficiency approached to 5.72% under 6.2 W cm(-2) 980 nm excitation. The power-dependent upconversion luminescence indicated that under the excitation of simulated sunlight the (4)F(9/2)-(4)I(15/2) red emission originally results from the cooperation of a 1540 nm photon and a 980 nm photon. Furthermore, when the single crystal is placed in front of the perovskite solar cells, the PCE is enhanced by 7.9% under the irradiation of simulated sunlight by 7-8 solar constants. This work implies the upconverter not only can serve as proof of principle for improving PCE of solar cells but also is helpful to practical application.

Dramatic improvement of crystal quality for low-temperature-grown rabbit muscle aldolase

International Nuclear Information System (INIS)

Park, HaJeung; Rangarajan, Erumbi S.; Sygusch, Jurgen; Izard, Tina

2010-01-01

Rabbit muscle aldolase (RMA) was crystallized in complex with the low-complexity domain (LC4) of sorting nexin 9. Monoclinic crystals were obtained at room temperature that displayed large mosaicity and poor X-ray diffraction. However, orthorhombic RMA–LC4 crystals grown at 277 K under similar conditions exhibited low mosaicity, allowing data collection to 2.2 Å Bragg spacing and structure determination. Rabbit muscle aldolase (RMA) was crystallized in complex with the low-complexity domain (LC4) of sorting nexin 9. Monoclinic crystals were obtained at room temperature that displayed large mosaicity and poor X-ray diffraction. However, orthorhombic RMA–LC4 crystals grown at 277 K under similar conditions exhibited low mosaicity, allowing data collection to 2.2 Å Bragg spacing and structure determination. It was concluded that the improvement of crystal quality as indicated by the higher resolution of the new RMA–LC4 complex crystals was a consequence of the introduction of new lattice contacts at lower temperature. The lattice contacts corresponded to an increased number of interactions between high-entropy side chains that mitigate the lattice strain incurred upon cryocooling and accompanying mosaic spread increases. The thermodynamically unfavorable immobilization of high-entropy side chains used in lattice formation was compensated by an entropic increase in the bulk-solvent content owing to the greater solvent content of the crystal lattice

Crystal growth and optical properties of Sm:CaNb2O6 single crystal

International Nuclear Information System (INIS)

Di Juqing; Xu Xiaodong; Xia Changtai; Zeng Huidan; Cheng Yan; Li Dongzhen; Zhou Dahua; Wu Feng; Cheng Jimeng; Xu Jun

2012-01-01

Highlights: ► Sm:CaNb 2 O 6 single crystal was grown by the Czochralski method. ► Thermal expansion coefficients and J–O parameters were calculated. ► We found that this crystal had high quantum efficiency of 97%. - Abstract: Sm:CaNb 2 O 6 single crystal has been grown by the Czochralski method. Its high-temperature X-ray powder diffraction, optical absorption, emission spectroscopic as well as lifetime have been studied. Thermal expansion coefficients (α), J–O parameters (Ω i ), radiative lifetime (τ rad ), branching ratios (β) and stimulated emission cross-sections (σ e ) were calculated. The quantum efficiency (η) was calculated to be 97%. The intense peak emission cross section at 610, 658 nm were calculated to be 2.40 × 10 −21 , 2.42 × 10 −21 cm 2 . These results indicate that Sm:CaNb 2 O 6 crystal has potential use in visible laser and photonic devices area.

DKDP crystal growth controlled by cooling rate

Science.gov (United States)

Xie, Xiaoyi; Qi, Hongji; Shao, Jianda

2017-08-01

The performance of deuterated potassium dihydrogen phosphate (DKDP) crystal directly affects beam quality, energy and conversion efficiency in the Inertial Confinement Fusion（ICF）facility, which is related with the initial saturation temperature of solution and the real-time supersaturation during the crystal growth. However, traditional method to measure the saturation temperature is neither efficient nor accurate enough. Besides, the supersaturation is often controlled by experience, which yields the higher error and leads to the instability during the crystal growth. In this paper, DKDP solution with 78% deuteration concentration is crystallized in different temperatures. We study the relation between solubility and temperature of DKDP and fit a theoretical curve with a parabola model. With the model, the measurement of saturation temperature is simplified and the control precision of the cooling rate is improved during the crystal growth, which is beneficial for optimizing the crystal growth process.

Instrument for 3D characterization of autostereoscopic displays

Science.gov (United States)

Prévoteau, J.; Chalençon-Piotin, S.; Debons, D.; Lucas, L.; Remion, Y.

2011-03-01

We now have numerous autostereoscopic displays, and it is mandatory to characterize them because it will allow to optimize their performances and to make efficient comparison between them. Therefore we need standards so we have to be able to quantify the quality of the viewer's perception. The purpose of the present paper is twofold; we first present a new instrument of characterization of the 3D perception on a given autostereoscopic display; then we propose a new way to realize an experimental protocol allowing to get a full characterization. This instrument will allow us to compare efficiently the different autostereoscopic displays but it will also validate practically the adequacy between the shooting and rendering geometries. In this aim, we are going to match a perceived scene with the virtual scene. It is hardly possible to determine the scene perceived by a viewer placed in front of an autostereoscopic display. Indeed if it may be executable on the pop-out, it is impossible on the depth effect because the depth of the virtual scene is set behind the screen. Therefore, we will have to use an optical illusion based on the deflection of light by a mirror to know the position which the viewer perceives some points of the virtual scene on an autostereoscopic display.

Efficient second harmonic generation by para-nitroaniline embedded in electro-spun polymeric nanofibres

Science.gov (United States)

Gonçalves, Hugo; Saavedra, Inês; Ferreira, Rute AS; Lopes, PE; de Matos Gomes, Etelvina; Belsley, Michael

2018-03-01

Intense well polarized second harmonic light was generated by poly(methyl methacrylate) nanofibres with embedded para-nitroaniline nanocrystals. Subwavelength diameter fibres were electro-spun using a 1:2 weight ratio of chromophore to polymer. Analysis of the generated second harmonic light indicates that the para-nitroaniline molecules, which nominally crystalize in the centrosymmetric space group, were organized into noncentrosymmetric structures leading to a second order susceptibility dominated by a single tensor element. Under the best deposition conditions, the nanofibrers display an effective nonlinear optical susceptibility approximately two orders of magnitude greater than that of potassium dihydrogen phosphate. Generalizing this approach to a broad range of organic molecules with strong individual molecular second order nonlinear responses, but which nominally form centrosymmetric organic crystals, could open a new pathway for the fabrication of efficient sub-micron sized second harmonic light generators.

Highly efficient single-pass frequency doubling of a continuous-wave distributed feedback laser diode using a PPLN waveguide crystal at 488 nm.

Science.gov (United States)

Jechow, Andreas; Schedel, Marco; Stry, Sandra; Sacher, Joachim; Menzel, Ralf

2007-10-15

A continuous-wave distributed feedback diode laser emitting at 976 nm was frequency doubled by the use of a periodically poled lithium niobate waveguide crystal with a channel size of 3 microm x 5 microm and an interaction length of 10 mm. A laser to waveguide coupling efficiency of 75% could be achieved resulting in 304 mW of incident infrared light inside the waveguide. Blue laser light emission of 159 mW at 488 nm has been generated, which equals to a conversion efficiency of 52%. The resulting wall plug efficiency was 7.4%.

Identifying Bacterial Immune Evasion Proteins Using Phage Display.

Science.gov (United States)

Fevre, Cindy; Scheepmaker, Lisette; Haas, Pieter-Jan

2017-01-01

Methods aimed at identification of immune evasion proteins are mainly rely on in silico prediction of sequence, structural homology to known evasion proteins or use a proteomics driven approach. Although proven successful these methods are limited by a low efficiency and or lack of functional identification. Here we describe a high-throughput genomic strategy to functionally identify bacterial immune evasion proteins using phage display technology. Genomic bacterial DNA is randomly fragmented and ligated into a phage display vector that is used to create a phage display library expressing bacterial secreted and membrane bound proteins. This library is used to select displayed bacterial secretome proteins that interact with host immune components.

A study of RHIC crystal collimation

International Nuclear Information System (INIS)

Trbojevic, D.; Harrison, M.; Parker, B.; Thompson, P.; Stevens, A.; Biryukov, V.; Mokhov, N.; Drozhdin, A.

1998-01-01

The Relativistic Heavy Ion Collider (RHIC) will experience increasing longitudinal and transverse heavy ion emittances, mostly due to intra-beam scattering (IBS). The experiments in RHIC are expected to not only have reduced luminosities due to IBS but also background caused by beam halo. Primary betatron collimators will be used to remove the large amplitude particles. The efficiency of the primary collimator in RHIC strongly depends on the alignment of the jaws which needs to be within about ten micro-radians for the optimum conditions. As proposed by V. biryukov bent crystals could be used to improve the efficiency of an existing collimation system by installing them upstream of the collimator jaws. Bent crystals have been successfully used in SPS, Protvino and Fermilab for extraction of the beam particles channeled through them. This study examines possible improvements of the primary collimator system for heavy ions at RHIC by use of bent crystals. Bent crystals will reduce the collimator jaws alignment requirement and will increase collimator efficiency thereby reducing detector background

Liquid crystals in micron-scale droplets, shells and fibers

Science.gov (United States)

Urbanski, Martin; Reyes, Catherine G.; Noh, JungHyun; Sharma, Anshul; Geng, Yong; Subba Rao Jampani, Venkata; Lagerwall, Jan P. F.

2017-04-01

The extraordinary responsiveness and large diversity of self-assembled structures of liquid crystals are well documented and they have been extensively used in devices like displays. For long, this application route strongly influenced academic research, which frequently focused on the performance of liquid crystals in display-like geometries, typically between flat, rigid substrates of glass or similar solids. Today a new trend is clearly visible, where liquid crystals confined within curved, often soft and flexible, interfaces are in focus. Innovation in microfluidic technology has opened for high-throughput production of liquid crystal droplets or shells with exquisite monodispersity, and modern characterization methods allow detailed analysis of complex director arrangements. The introduction of electrospinning in liquid crystal research has enabled encapsulation in optically transparent polymeric cylinders with very small radius, allowing studies of confinement effects that were not easily accessible before. It also opened the prospect of functionalizing textile fibers with liquid crystals in the core, triggering activities that target wearable devices with true textile form factor for seamless integration in clothing. Together, these developments have brought issues center stage that might previously have been considered esoteric, like the interaction of topological defects on spherical surfaces, saddle-splay curvature-induced spontaneous chiral symmetry breaking, or the non-trivial shape changes of curved liquid crystal elastomers with non-uniform director fields that undergo a phase transition to an isotropic state. The new research thrusts are motivated equally by the intriguing soft matter physics showcased by liquid crystals in these unconventional geometries, and by the many novel application opportunities that arise when we can reproducibly manufacture these systems on a commercial scale. This review attempts to summarize the current understanding of

Liquid crystals in micron-scale droplets, shells and fibers

International Nuclear Information System (INIS)

Urbanski, Martin; Reyes, Catherine G; Noh, JungHyun; Sharma, Anshul; Geng, Yong; Subba Rao Jampani, Venkata; Lagerwall, Jan P F

2017-01-01

The extraordinary responsiveness and large diversity of self-assembled structures of liquid crystals are well documented and they have been extensively used in devices like displays. For long, this application route strongly influenced academic research, which frequently focused on the performance of liquid crystals in display-like geometries, typically between flat, rigid substrates of glass or similar solids. Today a new trend is clearly visible, where liquid crystals confined within curved, often soft and flexible, interfaces are in focus. Innovation in microfluidic technology has opened for high-throughput production of liquid crystal droplets or shells with exquisite monodispersity, and modern characterization methods allow detailed analysis of complex director arrangements. The introduction of electrospinning in liquid crystal research has enabled encapsulation in optically transparent polymeric cylinders with very small radius, allowing studies of confinement effects that were not easily accessible before. It also opened the prospect of functionalizing textile fibers with liquid crystals in the core, triggering activities that target wearable devices with true textile form factor for seamless integration in clothing. Together, these developments have brought issues center stage that might previously have been considered esoteric, like the interaction of topological defects on spherical surfaces, saddle-splay curvature-induced spontaneous chiral symmetry breaking, or the non-trivial shape changes of curved liquid crystal elastomers with non-uniform director fields that undergo a phase transition to an isotropic state. The new research thrusts are motivated equally by the intriguing soft matter physics showcased by liquid crystals in these unconventional geometries, and by the many novel application opportunities that arise when we can reproducibly manufacture these systems on a commercial scale. This review attempts to summarize the current understanding of

Crystal growth, spectroscopic and laser properties of Tm:LuAG crystal

Science.gov (United States)

Xu, X. D.; Wang, X. D.; Lin, Z. F.; Cheng, Y.; Li, D. Z.; Cheng, S. S.; Wu, F.; Zhao, Z. W.; Gao, C. Q.; Gao, M. W.; Xu, J.

2009-11-01

Tm:Lu3Al5O12 (Tm:LuAG) crystal was grown by the Czochralski method. The segregation coefficient was measured by Inductively Coupled Plasma Atomic Emission Spectrometer. The cell parameters were analyzed with X-ray powder diffraction experiments. The absorption and fluorescence spectra of Tm:LuAG crystal at room temperature were investigated. With a 20 W fiber-coupled diode laser as pump source, the continuous-wave (CW) laser action of Tm:LuAG crystal was demonstrated. The maximum output power at 2020 nm was obtained to be 3.04 W, and the slope efficiency was 25.3%.

Nucleation and growth of the Naica giant gypsum crystals.

Science.gov (United States)

Otálora, Fermín; García-Ruiz, JuanMa

2014-04-07

The Cave of Giant Crystals in the Naica mine (Mexico) is one of the most amazing displays of mineral beauty ever created in nature. In addition to the colossal crystals of gypsum, which in some cases exceed eleven meters in length and one meter in thickness, the scenery fashioned by the crystalline beams that thrust through the darkness of the cave from floor to ceiling with a luster like moonlight is a unique example of harmony based on crystal symmetry. We review the crystallogenesis of this remarkable and challenging phenomenon of mineralization near equilibrium that can be used to teach the basics of nucleation and crystal growth.

Highly efficient fluorescence sensing with hollow core photonic crystal fibers

DEFF Research Database (Denmark)

Smolka, Stephan; Barth, Michael; Benson, Oliver

2008-01-01

We investigate hollow core photonic crystal fibers for ultra-sensitive fluorescence detection by selectively infiltrating the central hole with fluorophores. Dye concentrations down to 10(-9) M can be detected using only nanoliter sample volumes.......We investigate hollow core photonic crystal fibers for ultra-sensitive fluorescence detection by selectively infiltrating the central hole with fluorophores. Dye concentrations down to 10(-9) M can be detected using only nanoliter sample volumes....

Recovery of indium from In2O3 and liquid crystal display powder via a chloride volatilization process using polyvinyl chloride

International Nuclear Information System (INIS)

Park, Kye-Sung; Sato, Wakao; Grause, Guido; Kameda, Tomohito; Yoshioka, Toshiaki

2009-01-01

Indium (In) was recovered from indium oxide (In 2 O 3 ) and liquid crystal display (LCD) powder via a chloride volatilization process using polyvinyl chloride (PVC) as the chlorination agent. The recovery of In from In 2 O 3 increased with an increasing molar Cl/In ratio in N 2 and air atmospheres. The degree of In recovery at a Cl/In molar ratio of 11 and a temperature of 350 o C was 98.7% and 96.6%, for N 2 and air, respectively. The In recovery also increased notably with increasing temperature in N 2 atmosphere. In both atmospheres, the In recovery increased with an increasing degradation temperature of PVC. However, the In recovery from LCD powder was lower than that from In 2 O 3 . For LCD powder, the degree of In recovery at a Cl/In molar ratio of 11 and a temperature of 350 o C was 66.7% and 54.1%, for N 2 and air, respectively.

Low-temperature (75 °C) solid-state reaction enhanced by less-crystallized nanoporous PbI2 films for efficient CH3NH3PbI3 perovskite solar cells

International Nuclear Information System (INIS)

Zheng, Huifeng; Liu, Yangqiao; Sun, Jing

2017-01-01

Highlights: • Efficient perovskite solar cells were prepared with solid-state reaction at 75 °C. • Ln-PbI 2 is superior to c-PbI 2 when applied in low-temperature solid-state reaction. • A higher champion PCE was obtained at 75 °C (13.8%) than that of 140 °C (11.8%). • Non-radiative defects increase significantly when annealed at high temperature. - Abstract: Organohalide perovskite films are usually prepared with the solid-state reaction at a high temperature ≥100 °C, which causes the increase of non-radiative defects and decomposition of perovskite films. Here, we demonstrate it’s feasible to prepare high-quality perovskite films with the solid-state reaction method even at a temperature of 75 °C, when enhanced by less-crystallized nanoporous PbI 2 (ln-PbI 2 ) films. The replacement of compact PbI 2 (c-PbI 2 ) by ln-PbI 2 , results in a significant improvement of crystallinity of perovskite films, besides the elimination of remnant PbI 2 . As a result, ln-PbI 2 based perovskite solar cells display much higher power conversion efficiency (PCE) and better stability. Moreover, annealing duration was found to be critical for high PCE and was optimized as 60 min. Finally, with the optimal process, the champion device displayed a PCE of 13.8% and the average PCE reached 10.1% with a satisfactory deviation. Furthermore, we found annealing at high temperature (140 °C) led to a lower PCE compared with that annealed at 75 °C, because non-radiative defects increased significantly during high-temperature annealing. This work may open up a promising avenue for preparing high-quality perovskite films with the low-temperature solid-state reaction method, which is desirable for real application.

Real-time monitoring of indium tin oxide laser ablation in liquid crystal display patterning

International Nuclear Information System (INIS)

Hong, M.H.; Lu, Y.F.; Meng, M.; Low, T.S.

1998-01-01

Audible acoustic wave detection is applied to investigate KrF excimer laser ablation of Indium Tin Oxide (ITO) thin film layer for Liquid Crystal Display (LCD) patterning. It is found that there is no acoustic wave generation if laser fluence is lower than ITO ablation threshold. For laser fluence higher than the threshold, audible acoustic wave will be detected due to shock wave generation during ITO laser ablation. The amplitude of the acoustic wave is closely related to the laser ablation rate. With more laser pulse applied, the amplitude is dropped to zero because the ITO layer is completely removed. However, if laser fluence is increased higher than ablation threshold for glass substrate, the amplitude is also dropped with pulse number but not to zero. It is due to laser ablation of ITO layer and glass substrate at the same time. Since the thickness of ITO layer is in a scale of 100 nm, laser interaction with glass substrate will happen even at the first pulse of higher laser fluence irradiation. Laser ablation induced ITO plasma emission spectrum in visible light region is analyzed by an Optical Multi-channel Analyzer (OMA). Specific spectral lines are In I (325.8, 410.2 and 451.1 nm) and In II 591.1 nm. Spectral intensities of 410.2 and 451.1 nm lines are selected to characterize the evolution of ITO plasma intensity with laser fluence and pulse number. It is found that the spectral intensities are reduced to zero with laser pulse number. It is also found that spectral lines other than ITO plasma will appear for laser fluence higher than ablation threshold for glass substrate. Threshold fluences for glass and ITO ablation are estimated for setting up a parameter window to control LCD patterning in real-time

Phenylacetic acid co-crystals with acridine, caffeine, isonicotinamide and nicotinamide: Crystal structures, thermal analysis, FTIR spectroscopy and Hirshfeld surface analysis

Science.gov (United States)

Amombo Noa, Francoise M.; Jacobs, Ayesha

2017-07-01

Co-crystals of phenylacetic acid (PAA) with acridine (ACR), caffeine (CAF), isonicotinamide (INM) and nicotinamide (NAM) have been successfully prepared and characterised by single crystal X-ray diffraction, FTIR spectroscopy, thermal analysis and Hirshfeld surface analysis. The ACR, INM and NAM co-crystals with PAA exhibit the carboxylic acid-pyridine heterosynthon. Furthermore the amide-amide supramolecular homosynthon is observed in the PAA co-crystals with INM and NAM as well as Nsbnd H⋯O interactions between the acid and the respective base. The CAF co-crystal exhibits hydrogen bonding between the imidazole nitrogen and the COOH group of the PAA. The compounds demonstrate different stoichiometries; for PAA·ACR and PAA·INM a 1:1 ratio is displayed, a 2:1 in 2PAA·CAF and a 2:2 in the case of 2PAA·2NAM.

X-ray characterization of curved crystals for hard x-ray astronomy

Science.gov (United States)

Buffagni, Elisa; Bonnini, Elisa; Ferrari, Claudio; Virgilli, Enrico; Frontera, Filippo

2015-05-01

Among the methods to focus photons the diffraction in crystals results as one of the most effective for high energy photons. An assembling of properly oriented crystals can form a lens able to focus x-rays at high energy via Laue diffraction in transmission geometry; this is a Laue lens. The x-ray diffraction theory provides that the maximum diffraction efficiency is achieved in ideal mosaic crystals, but real mosaic crystals show diffraction efficiencies several times lower than the ideal case due to technological problems. An alternative and convenient approach is the use of curved crystals. We have recently optimized an efficient method based on the surface damage of crystals to produce self-standing uniformly curved Si, GaAs and Ge tiles of thickness up to 2-3 mm and curvature radii R down to a few meters. We show that, for curved diffracting planes, such crystals have a diffraction efficiency nearly forty times higher than the diffraction efficiency of perfect similar flat crystals, thus very close to that of ideal mosaic crystals. Moreover, in an alternative configuration where the diffracting planes are perpendicular to the curved ones, a focusing effect occurs and will be shown. These results were obtained for several energies between 17 and 120 keV with lab sources or at high energy facilities such as LARIX at Ferrara (Italy), ESRF at Grenoble (France), and ANKA at Karlsruhe (Germany).

Bulk crystal growth and nonlinear optical characterization of semiorganic single crystal: Cadmium (II) dibromide L - Proline monohydrate

Energy Technology Data Exchange (ETDEWEB)

Balakrishnan, T., E-mail: balacrystalgrowth@gmail.com [Crystal Growth Laboratory, PG & Research Department of Physics, Periyar EVR College (Autonomous), Tiruchirappalli, 620 023, Tamil Nadu (India); Sathiskumar, S. [Crystal Growth Laboratory, PG & Research Department of Physics, Periyar EVR College (Autonomous), Tiruchirappalli, 620 023, Tamil Nadu (India); Ramamurthi, K. [Crystal Growth and Thin Film Laboratory, Department of Physics and Nanotechnology, SRM University, Kattankulathur, 603 203, Kancheepuram, Tamil Nadu (India); Thamotharan, S. [Department of Bioinformatics, School of Chemical and Biotechnology, SASTRA University, Thanjavur, 613 401 (India)

2017-01-15

Single crystal of a novel metal organic nonlinear optical (NLO) cadmium (II) dibromide L - proline monohydrate (CBLPM) of size 7 × 7 × 5 mm{sup 3} was grown from slow evaporation technique. Single crystal X – ray diffraction analysis reveals that the crystal belongs to orthorhombic system with lattice parameters a = 10.1891 (8) Å, b = 13.4961 (11) Å, c = 7.4491 (5) Å and space group P2{sub 1}2{sub 1}2{sub 1}. The powder X – ray diffraction pattern of CBLPM was recorded and the X – ray diffraction peaks were indexed. The various functional groups of CBLPM were identified by the FT – IR and FT – Raman spectral analyses. The optical transmittance window and lower cut off wavelength of CBLPM were identified from UV – Vis – NIR studies. The mechanical strength of the grown crystal was estimated using Vickers microhardness test. Dielectric constant and dielectric loss measurements were carried out at different temperatures in the frequency range of 50 Hz - 2 MHz. The photoluminescence spectrum was recorded in the wavelength range 200–400 nm and the estimated optical band gap was ∼4.1 eV. Etching studies were carried out for different etching time. Thermal stability of CBLPM was determined using thermogravimetric analysis. Laser induced damage threshold study was carried out for the grown crystal using Nd:YAG laser. Size dependent second harmonic generation efficiency of the grown crystal was determined by Kurtz and Perry powder technique with different particle size using Nd:YAG laser with wavelength 1064 nm. Second harmonic generation efficiency of the powdered CBLPM crystal was ∼2.3 times that of potassium dihydrogen orthophosphate. - Highlights: • CBLPM crystal belongs to orthorhombic crystal system with space group P2{sub 1}2{sub 1}2{sub 1.} • Transmittance of CBLPM is ∼80% in the 650–1100 nm range. • Powder SHG efficiency of CBLPM increases with increase in particle size. • SHG efficiency of 0.57 μm size powdered CBLPM is ∼2

A full description of a simple and scalable fabrication process for electrowetting displays

International Nuclear Information System (INIS)

Zhou, K; Heikenfeld, J; Dean, K A; Howard, E M; Johnson, M R

2009-01-01

Electrowetting displays provide a high white state reflectance of >50% and have attracted substantial world-wide interest, yet are primarily an industrially led effort with few details on preferred materials and fabrication processes. Reported herein is the first complete description of the electrowetting display fabrication process. The description includes materials selection, purification and all fabrication steps from substrate selection to sealing. Challenging materials and fabrication processes include dielectric optimization, fluoropolymer selection, hydrophilic grid patterning, liquid dosing, dye purification and liquid ionic content. The process described herein has produced pixel arrays that were switched at 2 . The majority of fabrication processes can conform to liquid-crystal style manufacturing equipment, and therefore can be readily adopted by many display practitioners. Also presented are additional tips and techniques, such as controlling the onset of oil film break-up in an electrowetting display. This paper should enable anyone skilled in displays or microfabrication to quickly and successfully set up research and fabrication of electrowetting displays

Measurement techniques of LC display systems

Science.gov (United States)

Kosmowski, Bogdan B.; Becker, Michael E.; Neumeier, Juergen

1993-10-01

The strong increase of applications of liquid crystal displays in various areas (measuring, medical equipment, automotive, telecommunication, office, etc.) has forced the demand for the adequate specification of the LCDs performances. The optical, electro-optical and spectral properties of LCDs are strongly dependent on viewing direction, electrical driving conditions, illumination and temperature. All these quantities have to be precisely controlled, when one of them is varied, the resulting optical response of the object is recorded. In this paper we present measuring methods proposed for LCD panels and the computer controlled measuring system (DMS) for their evaluation.

Crystal growth and properties of novel organic nonlinear optical crystals of 4-Nitrophenol urea

Energy Technology Data Exchange (ETDEWEB)

Mohan, M. Krishna, E-mail: krishnamohan.m@ktr.srmuniv.ac.in; Ponnusamy, S.; Muthamizhchelvan, C.

2017-07-01

Single crystals of 4-Nitrophenol urea have been grown from water using slow evaporation technique at constant temperature, with the vision to improve the properties of the crystals. The unit cell parameters of the grown crystals were determined by single crystal and powder X-Ray diffraction. FTIR studies reveals the presence of different vibrational bands. The Optical studies confirmed that the crystal is transparent up to 360 nm .TGA and DSC studies were carried out to understand the thermal behavior of crystals. The SHG studies show the suitability of the crystals for NLO applications. The etching studies were carried out to study the behavior of the crystals under different conditions.These studies reveal that the crystals of 4-Nitrophenol urea are suitable for device applications. - Highlights: • 4-Nitrophenol urea crystals of dimensions 14 mm × 1 mm were grown. • UV–Visible studies indicate the crystal is transparent in the region of 370–800 nm. • Thermal studies show the crystal starts decomposing at 170 °C. • SHG studies indicate that the crystals have NLO efficiency 3.5 times that of KDP.

Concept for power scaling second harmonic generation using a cascade of nonlinear crystals

DEFF Research Database (Denmark)

Hansen, Anders Kragh; Tawfieq, Mahmoud; Jensen, Ole Bjarlin

2015-01-01

for efficient power scaling of single-pass SHG beyond such limits using a cascade of nonlinear crystals, in which the first crystal is chosen for high nonlinear efficiency and the subsequent crystal(s) are chosen for power handling ability. Using this highly efficient singlepass concept, we generate 3.7 W...... successfully combines the high efficiency of the first stage with the good power handling properties of the subsequent stages. The concept is generally applicable and can be expanded with more stages to obtain even higher efficiency, and extends also to other combinations of nonlinear media suitable for other......Within the field of high-power second harmonic generation (SHG), power scaling is often hindered by adverse crystal effects such as thermal dephasing arising from the second harmonic (SH) light, which imposes limits on the power that can be generated in many crystals. Here we demonstrate a concept...

Biosorption of divalent Pb, Cd and Zn on aragonite and calcite mollusk shells

Energy Technology Data Exchange (ETDEWEB)

Du Yang; Lian Fei [Key Laboratory of Pollution Process and Environmental Criteria, Ministry of Education, Tianjin Key Laboratory of Urban Ecology Environmental Remediation and Pollution Control, College of Environmental Science and Engineering, Nankai University, Tianjin 300071 (China); Zhu Lingyan, E-mail: zhuly@nankai.edu.cn [Key Laboratory of Pollution Process and Environmental Criteria, Ministry of Education, Tianjin Key Laboratory of Urban Ecology Environmental Remediation and Pollution Control, College of Environmental Science and Engineering, Nankai University, Tianjin 300071 (China)

2011-07-15

The potential of using mollusk shell powder in aragonite (razor clam shells, RCS) and calcite phase (oyster shells, OS) to remove Pb{sup 2+}, Cd{sup 2+} and Zn{sup 2+} from contaminated water was investigated. Both biogenic sorbents displayed very high sorption capacities for the three metals except for Cd on OS. XRD, SEM and XPS results demonstrated that surface precipitation leading to crystal growth took place during sorption. Calcite OS displayed a remarkably higher sorption capacity to Pb than aragonite RCS, while the opposite was observed for Cd. However, both sorbents displayed similar sorption capacities to Zn. These could be due to the different extent of matching in crystal lattice between the metal bearing precipitate and the substrates. The initial pH of the solution, sorbent's dosage and grain size affected the removal efficiency of the heavy meals significantly, while the organic matter in mollusk shells affected the removal efficiency to a lesser extent. - Highlights: > Mollusk shells display high removal efficiency to heavy metals in contaminated water. > Surface precipitation leading to crystal growth takes place during the sorption. > Crystal structure similarity between precipitates and substrates affects the sorption. > pH, sorbent dosage and grain size of adsorbent affects the removal efficiency. > Organic matter in mollusk shells affects the removal efficiency to a less extent. - Mollusk shells display high sorption ability to heavy metals and crystal structure similarity between precipitates and substrates affects the sorption.

Hg+ ion density in low-pressure Ar-Hg discharge plasma used for liquid crystal display back-lighting

International Nuclear Information System (INIS)

Goto, Miki; Arai, Toshihiko

1995-01-01

The positive column of a low-pressure Ar-Hg discharge has been applied as a fluorescent light source for illumination. Many studies on the diagnostics and fundamental mechanisms have been carried out on both the classical fluorescent lamp (d=36 mm) and the compact fluorescent lamp (d=12 mm). On the other hand, a lamp of extremely narrow diameter (usually below 6 mm) has been recently developed for liquid crystal display (LCD) back-lighting and its importance is undoubtedly increasing. Some characteristics or mechanisms of the narrow-diameter lamp may be similar to those of the 36 mm one; however the similarity rule does not hold between them due to the contributions from a stepwise ionization process. Therefore, in order to clarify the excitation mechanism in the narrow-diameter lamp quantitatively, various parameters must be measured directly and some analysis must be done. The Hg + ion density and electron density are important parameters for the purpose of clarifying the excitation mechanism quantitatively. In this work, we have measured the Hg + ion density using the modified absorption method, and the electron density using the probe method in the Ar-Hg discharge of the 4 mm bore tube on bath temperature. Moreover, with combining the modified absorption method and the probe method, the Hg 2 + molecular ion density has been determined

Influence of Al{sub 2}O{sub 3} reflective layer under phosphor layer on luminance and luminous efficiency characteristics in alternating-current plasma display panel

Energy Technology Data Exchange (ETDEWEB)

Park, Choon-Sang [School of Electronics Engineering, College of IT Engineering, Kyungpook National University, Daegu (Korea, Republic of); Tae, Heung-Sik, E-mail: hstae@ee.knu.ac.kr [School of Electronics Engineering, College of IT Engineering, Kyungpook National University, Daegu (Korea, Republic of); Jung, Eun Young [Core Technology Lab., Corporate R and D Center, Samsung SDI Company Ltd., Cheonan (Korea, Republic of)

2013-11-29

This paper examines the optical and discharge characteristics of alternating-current plasma display panel when adopting the Al{sub 2}O{sub 3} reflective layer. The Al{sub 2}O{sub 3} reflective layer is deposited under the phosphor layer by using the screen-printing method. The resulting changes in the optical and discharge characteristics, including the power consumption, color temperature, luminance, luminous efficiency, scanning electron microscopy image, and reflectance, are then compared for both cases with and without Al{sub 2}O{sub 3} reflective layer. As a result of optimizing the thicknesses between the Al{sub 2}O{sub 3} and phosphor layers, the luminance and luminous efficiency are improved by about 17% and 7%, respectively. - Highlights: • We examine characteristics of plasma display panel when adopting reflective layer. • Al{sub 2}O{sub 3} reflective layer was deposited under the phosphor layer. • Al{sub 2}O{sub 3} reflective layer with flaky shape is very effective in enhancing luminance.

Crystal growth, optical properties, and laser operation of Yb3+-doped NYW single crystal

Science.gov (United States)

Cheng, Y.; Xu, X. D.; Yang, X. B.; Xin, Z.; Cao, D. H.; Xu, J.

2009-11-01

Laser crystal Yb3+-doped NaY(WO4)2 (Yb:NYW) with excellent quality has been grown by Czochralski technique. The rocking curves from (400) plane of as-grown Yb:NYW crystal was measured and the full-width value at half-maximum was 19.92″. The effective segregation coefficients were measured by the X-ray fluorescence method. The polarized absorption spectra and the fluorescence spectra of Yb:NYW crystal were measured at room temperature. The fluorescence decay lifetime of Yb3+ ion in NYW crystal has been investigated. The spectroscopic parameters of Yb:NYW crystal are calculated and compared with those of Yb:YAG crystal. A continuous wave output power of 3.06 W at 1031 nm was obtained with a slope efficiency of 42% by use of diode pumping.

[A new method for evaluating the degree of eyestrain: a comparison between color and monochrome liquid crystal display monitors].

Science.gov (United States)

Okumura, Akiyoshi; Koike, Rumi; Onoda, Yui; Matsui, Takurou; Arai, Kazuo; Shimooka, Ryouji; Tsurutani, Hiroshi

2011-01-01

Color and monochromatic liquid crystal displays (LCDs) were compared in terms of eyestrain by using a new method that uses Landolt rings for a visual perceptional test. In this method, the difference of the nearest distances to distinguish Landolt rings between before and after the usage of LCD monitors was used as the index of eyestrain. When the nearest distance for distinguishing Landolt rings increased, the eyestrain was considered to be severe. A total of 11 observers (2 physicians and 9 radiological technologists) participated to this observer study. In the observer study, the TG18-QC pattern, a standard clinical image of 400 images, and JESRA X-0093 were observed using color and monochromatic LCD monitors for approximately 30 minutes. In addition to the observer study, the noise power spectrum (NPS) of the color and the monochromatic monitors were measured using the NS2002 method. The ratio of the nearest distance after 30 minutes of reading and that of before reading was larger when the color LCD monitor was used than when the monochromatic LCD monitor was used (pLandolt rings measured before and after readings can be used to evaluate eyestrain in diagnostic radiology.

In-plane confinement and waveguiding of surface acoustic waves through line defects in pillars-based phononic crystal

Directory of Open Access Journals (Sweden)

Abdelkrim Khelif

2011-12-01

Full Text Available We present a theoretical analysis of an in-plane confinement and a waveguiding of surface acoustic waves in pillars-based phononic crystal. The artificial crystal is made up of cylindrical pillars placed on a semi-infinite medium and arranged in a square array. With a well-chosen of the geometrical parameters, this pillars-based system can display two kinds of complete band gaps for guided waves propagating near the surface, a low frequency gap based on locally resonant mode of pillars as well as a higher frequency gap appearing at Bragg scattering regime. In addition, we demonstrate a waveguiding of surface acoustic wave inside an extended linear defect created by removing rows of pillars in the perfect crystal. We discuss the transmission and the polarization of such confined mode appearing in the higher frequency band gap. We highlight the strong similarity of such defect mode and the Rayleigh wave of free surface medium. An efficient finite element analysis is used to simulate the propagation of guided waves through silicon pillars on a silicon substrate.

Time-Sequential Working Wavelength-Selective Filter for Flat Autostereoscopic Displays

Directory of Open Access Journals (Sweden)

René de la Barré

2017-02-01

Full Text Available A time-sequential working, spatially-multiplexed autostereoscopic 3D display design consisting of a fast switchable RGB-color filter array and a fast color display is presented. The newly-introduced 3D display design is usable as a multi-user display, as well as a single-user system. The wavelength-selective filter barrier emits the light from a larger aperture than common autostereoscopic barrier displays with similar barrier pitch and ascent. Measurements on a demonstrator with commercial display components, simulations and computational evaluations have been carried out to describe the proposed wavelength-selective display design in static states and to show the weak spots of display filters in commercial displays. An optical modelling of wavelength-selective barriers has been used for instance to calculate the light ray distribution properties of that arrangement. In the time-sequential implementation, it is important to avoid that quick eye or eyelid movement leads to visible color artifacts. Therefore, color filter cells, switching faster than conventional LC display cells, must distribute directed light from different primaries at the same time, to create a 3D presentation. For that, electric tunable liquid crystal Fabry–Pérot color filters are presented. They switch on-off the colors red, green and blue in the millisecond regime. Their active areas consist of a sub-micrometer-thick nematic layer sandwiched between dielectric mirrors and indium tin oxide (ITO-electrodes. These cells shall switch narrowband light of red, green or blue. A barrier filter array for a high resolution, glasses-free 3D display has to be equipped with several thousand switchable filter elements having different color apertures.

Wavy channel thin film transistor architecture for area efficient, high performance and low power displays

KAUST Repository

Hanna, Amir

2013-12-23

We demonstrate a new thin film transistor (TFT) architecture that allows expansion of the device width using continuous fin features - termed as wavy channel (WC) architecture. This architecture allows expansion of transistor width in a direction perpendicular to the substrate, thus not consuming extra chip area, achieving area efficiency. The devices have shown for a 13% increase in the device width resulting in a maximum 2.5× increase in \\'ON\\' current value of the WCTFT, when compared to planar devices consuming the same chip area, while using atomic layer deposition based zinc oxide (ZnO) as the channel material. The WCTFT devices also maintain similar \\'OFF\\' current value, ~100 pA, when compared to planar devices, thus not compromising on power consumption for performance which usually happens with larger width devices. This work offers an interesting opportunity to use WCTFTs as backplane circuitry for large-area high-resolution display applications. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Spectrometric performances of high quantum efficiency multi and single anode PMTs coupled to LaBr3(Ce) crystal

Energy Technology Data Exchange (ETDEWEB)

Cinti, Maria Nerina, E-mail: marianerina.cinti@uniroma1.it [Department of Molecular Medicine, Sapienza University of Rome, Rome 00161 (Italy); INFN Rome 1 Section, Rome (Italy); Pani, Roberto; Pellegrini, Rosanna [Department of Molecular Medicine, Sapienza University of Rome, Rome 00161 (Italy); INFN Rome 1 Section, Rome (Italy); Bennati, Paolo [Department of Molecular Medicine, Sapienza University of Rome, Rome 00161 (Italy); Orlandi, Chiara [Medical Physics Post Graduate School, Sapienza University of Rome, Rome 00161 (Italy); Fabbri, Andrea [Department of Physics, Roma Tre University, Rome (Italy); INFN Rome 3 Section, Rome (Italy); Ridolfi, Stefano; Scafè, Raffaele [Department of Molecular Medicine, Sapienza University of Rome, Rome 00161 (Italy)

2013-10-01

High quantum efficiency semiconductor photodetectors have recently drawn the attention of the scientific community for their potential in the realization of a new class of scintillation imagers with very high energy and spatial resolution performance. However, this goal does not seem within easy reach, due to various technological issues such as, for example, the difficulty to scale the characteristics of a single detector to an imager with suitable dimensions. Lately a definite technical improvement in increasing quantum efficiency up to 42% for position sensitive photomultipliers was achieved. The aim of this work is thus to test this new technological progress and to study the possible implications in imaging applications. Four Hamamatsu PMTs were tested: two multi anode photomultipliers, one with a bialkali (27% quantum efficiency) and the other one with a super-bialkali photocathode (38% quantum efficiency), and two 1×1 in. PMTs, both equipped with an ultra bialkali photocathode (42% quantum efficiency). In particular one of the ultra bialkali PMT has also an increased efficiency of first dynode charge collection. The results were compared with the ones obtained with a reference PMT (Hamamatsu R6231), mainly used in spectroscopy. The PMTs were coupled to LaBr3(Ce), NaI(Tl) and LSO(Ce) continuous scintillation crystals. The tests were done using two independent electronic chains: one dedicated for spectroscopic application and a second one, using a multi wire 64 channel readout, for imaging applications. The super-bialkali MA-PMTs have shown high energy resolution, both with spectroscopic and imaging setup, highlighting the appropriateness of these devices for the development of imaging devices with high spectroscopic performance. -- Highlights: • A study of energy resolution results coming from position sensitive photomultipliers are proposed. • The study is also extended on mono- anode photomultiplier. • The selected scintillation crystal is LeBr3(Ce

Technical trends of large-size photomasks for flat panel displays

Science.gov (United States)

Yoshida, Koichiro

2017-06-01

Currently, flat panel displays (FPDs) are one of the main parts for information technology devices and sets. From 1990's to 2000's, liquid crystal displays (LCDs) and plasma displays had been mainstream FPDs. In the middle of 2000's, demand of plasma displays declined and organic light emitting diodes (OLEDs) newly came into FPD market. And today, major technology of FPDs are LCDs and OLEDs. Especially for mobile devices, the penetration of OLEDs is remarkable. In FPDs panel production, photolithography is the key technology as same as LSI. Photomasks for FPDs are used not only as original master of circuit pattern, but also as a tool to form other functional structures of FPDs. Photomasks for FPDs are called as "Large Size Photomasks(LSPMs)", since the remarkable feature is " Size" which reaches over 1- meter square and over 100kg. In this report, we discuss three LSPMs technical topics with FPDs technical transition and trend. The first topics is upsizing of LSPMs, the second is the challenge for higher resolution patterning, and the last is "Multi-Tone Mask" for "Half -Tone Exposure".

Energy labelling of refrigerated display cases

NARCIS (Netherlands)

Sluis, S.M. van der

1996-01-01

Energy labelling of refrigerated display cabinets is a method to quickly assess the energy efficiency of a certain cabinet compared to the market average consumptions for similar cabinets. Labelling is also a method to obtain comparable data on cabinets from different manufacturers, which has time

Dramatic improvement of crystal quality for low-­temperature-grown rabbit muscle aldolase

OpenAIRE

Park, HaJeung; Rangarajan, Erumbi S.; Sygusch, Jurgen; Izard, Tina

2010-01-01

Rabbit muscle aldolase (RMA) was crystallized in complex with the low-complexity domain (LC4) of sorting nexin 9. Monoclinic crystals were obtained at room temperature that displayed large mosaicity and poor X-ray diffraction. However, orthorhombic RMA–LC4 crystals grown at 277 K under similar conditions exhibited low mosaicity, allowing data collection to 2.2 Å Bragg spacing and structure determination.

Methods and apparatus for transparent display using scattering nanoparticles

Science.gov (United States)

Hsu, Chia Wei; Qiu, Wenjun; Zhen, Bo; Shapira, Ofer; Soljacic, Marin

2016-05-10

Transparent displays enable many useful applications, including heads-up displays for cars and aircraft as well as displays on eyeglasses and glass windows. Unfortunately, transparent displays made of organic light-emitting diodes are typically expensive and opaque. Heads-up displays often require fixed light sources and have limited viewing angles. And transparent displays that use frequency conversion are typically energy inefficient. Conversely, the present transparent displays operate by scattering visible light from resonant nanoparticles with narrowband scattering cross sections and small absorption cross sections. More specifically, projecting an image onto a transparent screen doped with nanoparticles that selectively scatter light at the image wavelength(s) yields an image on the screen visible to an observer. Because the nanoparticles scatter light at only certain wavelengths, the screen is practically transparent under ambient light. Exemplary transparent scattering displays can be simple, inexpensive, scalable to large sizes, viewable over wide angular ranges, energy efficient, and transparent simultaneously.

Hewlett-Packard's Approaches to Full Color Reflective Displays

Science.gov (United States)

Gibson, Gary

2012-02-01

Reflective displays are desirable in applications requiring low power or daylight readability. However, commercial reflective displays are currently either monochrome or capable of only dim color gamuts. Low cost, high-quality color technology would be rapidly adopted in existing reflective display markets and would enable new solutions in areas such as retail pricing and outdoor digital signage. Technical breakthroughs are required to enable bright color gamuts at reasonable cost. Pixel architectures that rely on pure reflection from a single layer of side-by-side primary-color sub-pixels use only a fraction of the display area to reflect incident light of a given color and are, therefore, unacceptably dark. Reflective devices employing stacked color primaries offer the possibility of a somewhat brighter color gamut but can be more complex to manufacture. In this talk, we describe HP's successes in addressing these fundamental challenges and creating both high performance stacked-primary reflective color displays as well as inexpensive single layer prototypes that provide good color. Our stacked displays utilize a combination of careful light management techniques, proprietary high-contrast electro-optic shutters, and highly transparent active-matrix TFT arrays based on transparent metal oxides. They also offer the possibility of relatively low cost manufacturing through roll-to-roll processing on plastic webs. To create even lower cost color displays with acceptable brightness, we have developed means for utilizing photoluminescence to make more efficient use of ambient light in a single layer device. Existing reflective displays create a desired color by reflecting a portion of the incident spectrum while absorbing undesired wavelengths. We have developed methods for converting the otherwise-wasted absorbed light to desired wavelengths via tailored photoluminescent composites. Here we describe a single active layer prototype display that utilizes these materials

Superhigh-resolution 200ppi series TFT-LCDs; Chokoseisai 200ppi ekisho display series

Energy Technology Data Exchange (ETDEWEB)

Kawamata, K.; Hirai, H. [Toshiba Corp., Tokyo (Japan)

2000-02-01

We have developed a 202 pixels per inch (ppi) thin-film transistor liquid crystal display (TFT-LCD) using low-temperature polycrystalline silicon (LTPS) technology. The superhigh resolution of 202 ppi offers the same image quality as printed matter such as magazines. The 200 ppi series TFT-LCDs are expected to support further developments in such areas as electronic books (e-books) and personal digital-picture viewers. Our lineup of 200 ppi TFT-LCDs includes a 4-inch display with VGA resolution, which is suitable for palmtop-size applications, and a 6.3-inch display with XGA resolution, which is suitable for typical photograph or paperback book-size applications. Larger size LCDs with 200 ppi resolution will be developed. (author)

Liquid crystal dimers

CERN Document Server

Kumar Pal, Santanu

2017-01-01

This book covers in-depth discussion of design principles, synthesis and thermal behavior of all types of liquid crystal (LC) dimers. The text presents recent advances in the field of LC dimers consisting of different mesogenic units such as calamitic, discotic and bent-core molecules. It starts with a chapter on the introduction of liquid crystal dimers, including their odd-even behavior, basic classification of dimers and common mesophases in dimers. The text shows how the molecular architectures are being used to develop new materials to study a range of interesting phenomena such as the biaxial nematic phase containing rod-like and disc-like mesogenic units. Finally, the text presents perspectives related to technological relevance of these dimers such as dopants in LC display mixtures exhibiting faster relaxation time, strong flexoelectric coupling and others to effect control over the properties of these materials.

Controlling the volatility of the written optical state in electrochromic DNA liquid crystals

Science.gov (United States)

Liu, Kai; Varghese, Justin; Gerasimov, Jennifer Y.; Polyakov, Alexey O.; Shuai, Min; Su, Juanjuan; Chen, Dong; Zajaczkowski, Wojciech; Marcozzi, Alessio; Pisula, Wojciech; Noheda, Beatriz; Palstra, Thomas T. M.; Clark, Noel A.; Herrmann, Andreas

2016-05-01

Liquid crystals are widely used in displays for portable electronic information display. To broaden their scope for other applications like smart windows and tags, new material properties such as polarizer-free operation and tunable memory of a written state become important. Here, we describe an anhydrous nanoDNA-surfactant thermotropic liquid crystal system, which exhibits distinctive electrically controlled optical absorption, and temperature-dependent memory. In the liquid crystal isotropic phase, electric field-induced colouration and bleaching have a switching time of seconds. Upon transition to the smectic liquid crystal phase, optical memory of the written state is observed for many hours without applied voltage. The reorientation of the DNA-surfactant lamellar layers plays an important role in preventing colour decay. Thereby, the volatility of optoelectronic state can be controlled simply by changing the phase of the material. This research may pave the way for developing a new generation of DNA-based, phase-modulated, photoelectronic devices.

Experimental and density functional theory (DFT): A dual approach to probe the key properties of creatininium L-tartrate monohydrate single crystal for nonlinear optical applications

Science.gov (United States)

Thirumurugan, R.; Babu, B.; Anitha, K.; Chandrasekaran, J.

2017-12-01

A novel organic nonlinear optical (NLO) material, creatininium L-tartrate monohydrate (CTM) was synthesized and it was grown as single crystals with optical quality. 1H and 13C NMR spectral studies were performed and molecular structure of synthesized CTM compound was confirmed. Single crystal X-ray diffraction (SXRD) analysis confirmed that CTM was crystallized in orthorhombic system with non-centrosymmetric (NCS), P212121, space group. The grown crystal exhibited admirable properties such as second harmonic generation efficiency (SHG) (1.9 times KDP), and high laser damage threshold (LDT) value of 3.7 GW cm-2. CTM crystal displayed high transparency (∼60%) in the visible and near-IR region with low cut-off wavelength at 249 nm. Photoluminescence study confirmed blue wavelength emission (∼463 nm) of grown crystal. Thermal and mechanical behaviours have been successfully analysed for grown crystals. The dielectric studies were carried out for grown crystal as a function of frequencies at different temperatures. Hirshfeld surface and fingerprint plots provided the percentage of individual interactions contributed by each atom. Moreover, density functional theory (DFT) calculations have been employed to probe the frontier molecular orbitals (FMOs) and first hyperpolarizability (β) analysis of the optimized CTM structure. These results validated CTM as a suitable NLO candidate and were discussed in this work.

Autostereoscopic display technology for mobile 3DTV applications

Science.gov (United States)

Harrold, Jonathan; Woodgate, Graham J.

2007-02-01

Mobile TV is now a commercial reality, and an opportunity exists for the first mass market 3DTV products based on cell phone platforms with switchable 2D/3D autostereoscopic displays. Compared to conventional cell phones, TV phones need to operate for extended periods of time with the display running at full brightness, so the efficiency of the 3D optical system is key. The desire for increased viewing freedom to provide greater viewing comfort can be met by increasing the number of views presented. A four view lenticular display will have a brightness five times greater than the equivalent parallax barrier display. Therefore, lenticular displays are very strong candidates for cell phone 3DTV. Selection of Polarisation Activated Microlens TM architectures for LCD, OLED and reflective display applications is described. The technology delivers significant advantages especially for high pixel density panels and optimises device ruggedness while maintaining display brightness. A significant manufacturing breakthrough is described, enabling switchable microlenses to be fabricated using a simple coating process, which is also readily scalable to large TV panels. The 3D image performance of candidate 3DTV panels will also be compared using autostereoscopic display optical output simulations.

Avian leukosis virus is a versatile eukaryotic platform for polypeptide display

International Nuclear Information System (INIS)

Khare, Pranay D.; Russell, Stephen J.; Federspiel, Mark J.

2003-01-01

Display technology refers to methods of generating libraries of modularly coded biomolecules and screening them for particular properties. Retroviruses are good candidates to be a eukaryotic viral platform for the display of polypeptides synthesized in eukaryotic cells. Here we demonstrate that avian leukosis virus (ALV) provides an ideal platform for display of nonviral polyaeptides expressed in a eukaryotic cell substrate. Different sizes of polypeptides were genetically fused to the extreme N-terminus of the ALV envelope glycoprotein in an ALV infectious clone containing an alkaline phosphatase reporter gene. The chimeric envelope glycoproteins were efficiently incorporated into virions and were stably displayed on the surface of the virions through multiple virus replication cycles. The foreign polypeptides did not interfere with the attachment and entry functions of the underlying ALV envelope glycoproteins. The displayed polypeptides were fully functional and could efficiently mediate attachment of the recombinant viruses to their respective cognate receptors. This study demonstrates that ALV is an ideal display platform for the generation and selection of libraries of polypeptides where there is a need for expression, folding, and posttranslational modification in the endoplasmic reticulum of eukaryotic cells

Photon harvesting, coloring and polarizing in photovoltaic cell integrated color filters: efficient energy routing strategies for power-saving displays.

Science.gov (United States)

Wen, Long; Chen, Qin; Song, Shichao; Yu, Yan; Jin, Lin; Hu, Xin

2015-07-03

We describe the integral electro-optical strategies that combine the functionalities of photovoltaic (PV) electricity generation and color filtering as well as polarizing to realize more efficient energy routing in display technology. Unlike the conventional pigment-based filters and polarizers, which absorb substantial amounts of unwanted spectral components and dissipate them in the form of heat, we propose converting the energy of those photons into electricity by constructing PV cell-integrated color filters based on a selectively transmitting aluminum (Al) rear electrode perforated with nanoholes (NHs). Combining with a dielectric-metal-dielectric (DMD) front electrode, the devices were optimized to enable efficient cavity-enhanced photon recycling in the PV functional layers. We perform a comprehensive theoretical and numerical analysis to explore the extraordinary optical transmission (EOT) through the Al NHs and identify basic design rules for achieving structural coloring or polarizing in our PV color filters. We show that the addition of thin photoactive polymer layers on the symmetrically configured Al NH electrode narrows the bandwidth of the EOT-assisted high-pass light filtering due to the strongly damped anti-symmetric coupling of the surface modes excited on the front and rear surface of the Al NHs, which facilitates the whole visible coloring with relatively high purity for the devices. By engineering the cut-off characteristics of the plasmonic waveguide mode supported by the circular or ellipsoidal Al NHs, beyond the photon recycling capacity, PV color filters and PV polarizing color filters that allow polarization-insensitive and strong polarization-anisotropic color filtering were demonstrated. The findings presented here may shed some light on expanding the utilization of PV electricity generation across new-generation energy-saving electrical display devices.

Improved Light Extraction Efficiency by Photonic Crystal Arrays on Transparent Contact Layer Using Focused Ion Beams

International Nuclear Information System (INIS)

Wu, G.M.; Tsai, B.H.; Kung, S.F.; Wu, C.F.

2011-01-01

Nitride-based thin-film materials have become increasingly important for the high brightness light-emitting diode applications. The improvements in light extraction and lower power consumption are highly desired. Although the internal quantum efficiency of GaN-based LED has been relatively high, only a small fraction of light can be extracted. In this study, a new design of two-dimensional photonic crystal array has been prepared on the top transparent contact layer of indium-tin oxide film to improve the light extraction efficiency using focused ion beam. The acceleration voltage of the Ga dual-beam nanotechnology system SMI 3050 was 30 kV and the ion beam current was 100 pA. The cylindrical air holes had the diameter of 150 nm and depth of 100 nm. The micro photoluminescence analysis results showed that the light output intensity could be 1.5 times of that of the non-patterned control sample. In addition, the structural damage from the focused ion beam drilling of GaN step could be eliminated. The excellent I-V characteristics have been maintained, and the external light extraction efficiency would be still improved for the LED devices. (author)

Liquid crystals with novel terminal chains as ferroelectric liquid crystal hosts

International Nuclear Information System (INIS)

Cosquer, G.Y.

2000-02-01

Changes to the molecular structure of liquid crystals can have a significant effect upon their mesomorphism and ferroelectric properties. Most of the research in liquid crystal for display applications concentrates on the design and synthesis of novel mesogenic cores to which straight terminal alkyl or alkoxy chains are attached. However, little is known about the effects upon the mesomorphism and ferroelectric properties of varying the terminal chains. The compounds prepared in this work have a common core - a 2,3-difluoroterphenyl unit with a nine-atom alkyl (nonyl) or alkoxy (octyloxy) chain at the 4-position, but with an unusual chain at the 4''-position. In some cases the terminal chain contains hetero atoms such as silicon, oxygen, chlorine and bromine or has a bulky end group. In total 46 final materials were synthesised in an attempt to understand the effect of an unusual terminal chains on mesomorphism and for some of these compounds the effect upon the switching times when added to a standard ferroelectric mixture were investigated. It was found that most compounds containing a bulky end group only displayed a smectic C phase, compounds with a halogen substituent as an end unit displayed a smectic A phase and that increasing the chain flexibility by introducing an oxygen atom in the chain reduces the melting and clearing points. The electro-optical measurements carried out on ferroelectric mixtures containing a bulky end group compound showed that shorter switching times were produced than for the ferroelectric mixture containing a straight chain compound. It is suggested that a bulky end group diminishes te extent of interlayer mixing in the chiral smectic C phase and therefore the molecules move more easily with ferroelectric switching. (author)

Glow discharge processing in the liquid crystal display industry

International Nuclear Information System (INIS)

Schmitt, Jacques; Elyaakoubi, Mustapha; Sansonnens, Laurent

2002-01-01

The active matrix display industry is rapidly presented. The most challenging aspect for plasma source design lies in the substrate size which is now entering the 1-2 m range. This paper focuses on the conventional planar RF capacitor at 13.56 MHz. A detailed analysis of the local perturbation due to a hole in the metal susceptor illustrates the process effects of various plasma microscopic parameters. It appears that not only the process rate must be kept uniform, but also the ion bombardment. It is also shown that very wide capacitive reactors no longer follow some classical rules: (1) plasma RF conductivity is limited, its propagation is shown to be described by a telegraph equation, in agreement with numerical modelling and electrostatic measurements, (2) the RF wavelength is no longer infinite compared to the dimensions, this leads to standing waves. The presence of the plasma is shown to worsen the effect by shortening the RF propagation wavelength

[Current situations and problems of quality control for medical imaging display systems].

Science.gov (United States)

Shibutani, Takayuki; Setojima, Tsuyoshi; Ueda, Katsumi; Takada, Katsumi; Okuno, Teiichi; Onoguchi, Masahisa; Nakajima, Tadashi; Fujisawa, Ichiro

2015-04-01

Diagnostic imaging has been shifted rapidly from film to monitor diagnostic. Consequently, Japan medical imaging and radiological systems industries association (JIRA) have recommended methods of quality control (QC) for medical imaging display systems. However, in spite of its need by majority of people, executing rate is low. The purpose of this study was to validate the problem including check items about QC for medical imaging display systems. We performed acceptance test of medical imaging display monitors based on Japanese engineering standards of radiological apparatus (JESRA) X-0093*A-2005 to 2009, and performed constancy test based on JESRA X-0093*A-2010 from 2010 to 2012. Furthermore, we investigated the cause of trouble and repaired number. Medical imaging display monitors had 23 inappropriate monitors about visual estimation, and all these monitors were not criteria of JESRA about luminance uniformity. Max luminance was significantly lower year-by-year about measurement estimation, and the 29 monitors did not meet the criteria of JESRA about luminance deviation. Repaired number of medical imaging display monitors had 25, and the cause was failure liquid crystal panel. We suggested the problems about medical imaging display systems.

Crystal growth, spectroscopic characterization and laser performance of Tm/Mg:LiNbO3 crystal

Science.gov (United States)

Zhang, P. X.; Yin, J. G.; Zhang, R.; Li, H. Q.; Xu, J. Q.; Hang, Y.

2014-03-01

A Tm, Mg co-doped LiNbO3 crystal was grown by the traditional Czochralski method. The room-temperature absorption, photo-luminescence spectra and fluorescence lifetime of Tm3+ ions in the crystal have been investigated. The experimental results show that the co-doped of MgO can lead to the lengthening of the measured fluorescence lifetime of the upper Tm3+:3F4 level. Based on the Judd-Ofelt approach, the intensity parameters Ω2,4,6 of Tm3+ were calculated to be Ω2 (6.29 × 10-20 cm2), Ω4 (0.54 × 10-20 cm2) and Ω6 (0.79 × 10-20 cm2). Other spectroscopic parameters that relate to laser performance were also obtained. Non-photorefractive continuous wave laser operation with a Tm, Mg:LiNbO3 single crystal is demonstrated at room temperature for the first time. We obtained 1.026 W output power at 1.885 μm with a slope efficiency of near 14%, which, to the best of our knowledge, is the largest output power and the highest slope efficiency obtained for this crystal thus far. The output power was observed to be stable, and the crystal showed no sign of photorefractive damage.

Tuning the dielectric properties of thiourea analog crystals for efficient nonlinear optical applications

International Nuclear Information System (INIS)

Sabari Girisun, T.C.; Dhanuskodi, S.

2010-01-01

Materials with low dielectric constant have attracted a great deal of interest in the field of nonlinear applications and microelectronic industry. Metal complexes of thiourea with group II transition metals (Zn, Cd) as central atom and period III elements (S, Cl) were synthesized by chemical reaction method and single crystals were grown from aqueous solution by slow evaporation method. By parallel plate capacitor technique, the dielectric response, dissipation factor, ac conductivity and impedance of virgin and metal complexes have been studied in the frequency (100 Hz to 5 MHz) and temperature (303-423 K) ranges. Metal complexes of thiourea with cadmium substitute have a low dielectric constant less than 10. Also the presence of chlorine in the metal complex induces noncentro symmetric structure. Hence the role of group II transition metals and period III elements in tuning the dielectric properties for efficient nonlinear applications has been studied.

Structural coloration of chitosan coated cellulose fabrics by electrostatic self-assembled poly (styrene-methyl methacrylate-acrylic acid) photonic crystals.

Science.gov (United States)

Yavuz, Gönül; Zille, Andrea; Seventekin, Necdet; Souto, Antonio P

2018-08-01

The structural coloration of a chitosan-coated woven cotton fabric obtained by glutaraldehyde-stabilized deposition of electrostatic self-assembled monodisperse and spherically uniform (250 nm) poly (styrene-methyl methacrylate-acrylic acid) photonic crystal nanospheres (P(St-MMA-AA)) was investigated. Bright iridescent coatings displaying different colors in function of the viewing angle were obtained. The SEM, diffuse reflectance spectroscopy, TGA, DSC and FTIR analyses confirm the presence of structural color and the glutaraldehyde and chitosan ability to provide durable chemical bonding between cotton fabric and photonic crystal (PCs) coating with the highest degradation temperature and the lowest enthalpy. The coatings are characterized by a mixture of face-centered cubic and hexagonal close-packed arrays alternating random packing regions. For the first time a cost-efficient structural coloration with high washing and light fastness using self-assembled P(St-MMA-AA) photonic crystals was successfully developed onto woven cotton fabric using chitosan and/or glutaraldehyde as stabilizing agent opening new strategies for the development of dye-free coloration of textiles. Copyright © 2018 Elsevier Ltd. All rights reserved.

Fabricating colloidal crystals and construction of ordered nanostructures

Directory of Open Access Journals (Sweden)

Sun Zhiqiang

2006-01-01

Full Text Available AbstractColloidal crystals of polymeric or inorganic microspheres are of extensive interest due to their potential applications in such as sensing, optics, photonic bandgap and surface patterning. The article highlights a set of approaches developed in our group, which are efficient to prepare colloidal crystals with ordered voids, patterned colloidal crystals on non-planar surfaces, heterogeneous colloidal crystals of different building blocks, colloidal crystals composed of non-spherical polyhedrons, and colloidal crystals of non-close-packed colloidal microspheres in particular. The use of these colloidal crystals as templates for different microstructures range from nanoscale to micron-scale is also summarized.

Quantum Dot/Liquid Crystal Nanocomposites in Photonic Devices

Directory of Open Access Journals (Sweden)

Andrea L. Rodarte

2015-07-01

Full Text Available Quantum dot/liquid crystal nano-composites are promising new materials for a variety of applications in energy harvesting, displays and photonics including the liquid crystal laser. To realize many applications, however, we need to control and stabilize nano-particle dispersion in different liquid crystal host phases and understand how the particles behave in an anisotropic fluid. An ideal system will allow for the controlled assembly of either well-defined nano-particle clusters or a uniform particle distribution. In this paper, we investigate mesogen-functionalized quantum dots for dispersion in cholesteric liquid crystal. These nanoparticles are known to assemble into dense stable packings in the nematic phase, and such structures, when localized in the liquid crystal defects, can potentially enhance the coupling between particles and a cholesteric cavity. Controlling the dispersion and assembly of quantum dots using mesogenic surface ligands, we demonstrate how resonant fluid photonic cavities can result from the co-assembly of luminescent nanoparticles in the presence of cholesteric liquid crystalline ordering.

Insertion of liquid crystal molecules into hydrocarbon monolayers

Energy Technology Data Exchange (ETDEWEB)

Popov, Piotr, E-mail: ppopov@kent.edu; Mann, Elizabeth K. [Department of Physics, Kent State University, Kent, Ohio 44242 (United States); Lacks, Daniel J. [Department of Chemical Engineering, Case Western Reserve University, Cleveland, Ohio 44106 (United States); Jákli, Antal [Liquid Crystal Institute, Kent State University, Kent, Ohio 44242-0001 (United States)

2014-08-07

Atomistic molecular dynamics simulations were carried out to investigate the molecular mechanisms of vertical surface alignment of liquid crystals. We study the insertion of nCB (4-Cyano-4{sup ′}-n-biphenyl) molecules with n = 0,…,6 into a bent-core liquid crystal monolayer that was recently found to provide good vertical alignment for liquid crystals. The results suggest a complex-free energy landscape for the liquid crystal within the layer. The preferred insertion direction of the nCB molecules (core or tail first) varies with n, which can be explained by entropic considerations. The role of the dipole moments was found to be negligible. As vertical alignment is the leading form of present day liquid crystal displays (LCD), these results will help guide improvement of the LCD technology, as well as lend insight into the more general problem of insertion of biological and other molecules into lipid and surfactant layers.

A pocket warning γ-dosimeter with numerical display

International Nuclear Information System (INIS)

Jones, A.R.

1980-09-01

A pocket warning dosimeter is described. It provides alarms (continuous tone and a flashing red light) when a presettable dose has been accumulated in the range .064 - 16.4 rads (0.64 - 164 μGy). This warning level can be selected in nine steps of 2 with a switch inside the dosimeter. The dose rate is indicated by a series of sound pulses whose repetition rate is proportional to the dose rate. At 1 rad/h (10 mGy/h) about 17 pluses/minute are emitted. The accumulated dose up to 20 rads (0.2 Gy) is displayed in steps of 1 mrad (10 μGy) with a liquid crystal display. A red LED lights before battery failure occurs. The effects of changes in temperature, battery voltage, dose rate and photon energy upon dosimeter sensitivity are presented. Finally, the applications of the dosimeter are discussed. (auth)

Chitosan-Assisted Crystallization and Film Forming of Perovskite Crystals through Biomineralization.

Science.gov (United States)

Yang, Yang; Sun, Chen; Yip, Hin-Lap; Sun, Runcang; Wang, Xiaohui

2016-03-18

Biomimetic mineralization is a powerful approach for the synthesis of advanced composite materials with hierarchical organization and controlled structure. Herein, chitosan was introduced into a perovskite precursor solution as a biopolymer additive to control the crystallization and to improve the morphology and film-forming properties of a perovskite film by way of biomineralization. The biopolymer additive was able to control the size and morphology of the perovskite crystals and helped to form smooth films. The mechanism of chitosan-mediated nucleation and growth of the perovskite crystals was explored. As a possible application, the chitosan-perovskite composite film was introduced into a planar heterojunction solar cell and increased power conversion efficiency relative to that observed for the pristine perovskite film was achieved. The biomimetic mineralization method proposed in this study provides an alternative way of preparing perovskite crystals with well-controlled morphology and properties and extends the applications of perovskite crystals in photoelectronic fields, including planar-heterojunction solar cells. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Simple and Efficient One-Pot Synthesis, Spectroscopic Characterization and Crystal Structure of Methyl 5-(4-Chlorobenzoyloxy-1-phenyl-1H-pyrazole-3-carboxylate

Directory of Open Access Journals (Sweden)

Imtiaz Khan

2012-07-01

Full Text Available A facile one-pot synthesis of methyl 5-(4-chlorobenzoyloxy-1-phenyl-1H-pyrazole-3-carboxylate (4 is described. The title compound was efficiently synthesized by the reaction of phenyl hydrazine, dimethyl acetylenedicarboxylate and 4-chlorobenzoyl chloride in dichloromethane under reflux in good yield. The structure of the target compound was deduced by modern spectroscopic and analytical techniques and unequivocally confirmed by a single crystal X-ray diffraction analysis. The crystal of the title compound belongs to orthorhombic system, space group P 21 21 21 with cell parameters a = 6.6491(3 Å, b = 7.9627(6 Å, c = 30.621(5 Å, α = β = γ = 90° and Z = 4. The crystal packing of the compound (4 is stabilized by an offset π-stacking between the planar benzoyl-substituted diazole moieties.

A high-resolution and intelligent dead pixel detection scheme for an electrowetting display screen

Science.gov (United States)

Luo, ZhiJie; Luo, JianKun; Zhao, WenWen; Cao, Yang; Lin, WeiJie; Zhou, GuoFu

2018-02-01

Electrowetting display technology is realized by tuning the surface energy of a hydrophobic surface by applying a voltage based on electrowetting mechanism. With the rapid development of the electrowetting industry, how to analyze efficiently the quality of an electrowetting display screen has a very important significance. There are two kinds of dead pixels on the electrowetting display screen. One is that the oil of pixel cannot completely cover the display area. The other is that indium tin oxide semiconductor wire connecting pixel and foil was burned. In this paper, we propose a high-resolution and intelligent dead pixel detection scheme for an electrowetting display screen. First, we built an aperture ratio-capacitance model based on the electrical characteristics of electrowetting display. A field-programmable gate array is used as the integrated logic hub of the system for a highly reliable and efficient control of the circuit. Dead pixels can be detected and displayed on a PC-based 2D graphical interface in real time. The proposed dead pixel detection scheme reported in this work has promise in automating electrowetting display experiments.

75 FR 10311 - In the Matter of Certain Liquid Crystal Display Devices and Products Containing the Same; Notice...

Science.gov (United States)

2010-03-05

... the Commission may also be obtained by accessing its Internet server ( http://www.usitc.gov ). The... modules, and LCD televisions or professional displays containing the same that infringe claims 7 or 8 of..., LCD devices, including display panels and modules, and LCD televisions or professional displays...

Mechanical Stability of Flexible Graphene-Based Displays.

Science.gov (United States)

Anagnostopoulos, George; Pappas, Panagiotis-Nektarios; Li, Zheling; Kinloch, Ian A; Young, Robert J; Novoselov, Kostya S; Lu, Ching Yu; Pugno, Nicola; Parthenios, John; Galiotis, Costas; Papagelis, Konstantinos

2016-08-31

The mechanical behavior of a prototype touch panel display, which consists of two layers of CVD graphene embedded into PET films, is investigated in tension and under contact-stress dynamic loading. In both cases, laser Raman spectroscopy was employed to assess the stress transfer efficiency of the embedded graphene layers. The tensile behavior was found to be governed by the "island-like" microstructure of the CVD graphene, and the stress transfer efficiency was dependent on the size of graphene "islands" but also on the yielding behavior of PET at relatively high strains. Finally, the fatigue tests, which simulate real operation conditions, showed that the maximum temperature gradient developed at the point of "finger" contact after 80 000 cycles does not exceed the glass transition temperature of the PET matrix. The effect of these results on future product development and the design of new graphene-based displays are discussed.

Cell-surface display of enzymes by the yeast Saccharomyces cerevisiae for synthetic biology.

Science.gov (United States)

Tanaka, Tsutomu; Kondo, Akihiko

2015-02-01

In yeast cell-surface displays, functional proteins, such as cellulases, are genetically fused to an anchor protein and expressed on the cell surface. Saccharomyces cerevisiae, which is often utilized as a cell factory for the production of fuels, chemicals, and proteins, is the most commonly used yeast for cell-surface display. To construct yeast cells with a desired function, such as the ability to utilize cellulose as a substrate for bioethanol production, cell-surface display techniques for the efficient expression of enzymes on the cell membrane need to be combined with metabolic engineering approaches for manipulating target pathways within cells. In this Minireview, we summarize the recent progress of biorefinery fields in the development and application of yeast cell-surface displays from a synthetic biology perspective and discuss approaches for further enhancing cell-surface display efficiency. © FEMS 2015. All rights reserved. For permissions, please e-mail: journals.permission@oup.com.

Progress on photonic crystals

CERN Document Server

Lecoq, P; Gundacker, S; Hillemanns, H; Jarron, P; Knapitsch, A; Leclercq, J L; Letartre, X; Meyer, T; Pauwels, K; Powolny, F; Seassal, C

2010-01-01

The renewal of interest for Time of Flight Positron Emission Tomography (TOF PET) has highlighted the need for increasing the light output of scintillating crystals and in particular for improving the light extraction from materials with a high index of refraction. One possible solution to overcome the problem of total internal reflection and light losses resulting from multiple bouncing within the crystal is to improve the light extraction efficiency at the crystal/photodetector interface by means of photonic crystals, i.e. media with a periodic modulation of the dielectric constant at the wavelength scale. After a short reminder of the underlying principles this contribution proposes to present the very encouraging results we have recently obtained on LYSO pixels and the perspectives on other crystals such as BGO, LuYAP and LuAG. These results confirm the impressive predictions from our previously published Monte Carlo simulations. A detailed description of the sample preparation procedure is given as well ...

Increasing reconstruction quality of diffractive optical elements displayed with LC SLM

Science.gov (United States)

Cheremkhin, Pavel A.; Evtikhiev, Nikolay N.; Krasnov, Vitaly V.; Rodin, Vladislav G.; Starikov, Sergey N.

2015-03-01

Phase liquid crystal (LC) spatial light modulators (SLM) are actively used in various applications. However, majority of scientific applications require stable phase modulation which might be hard to achieve with commercially available SLM due to its consumer origin. The use of digital voltage addressing scheme leads to phase temporal fluctuations, which results in lower diffraction efficiency and reconstruction quality of displayed diffractive optical elements (DOE). Due to high periodicity of fluctuations it should be possible to use knowledge of these fluctuations during DOE synthesis to minimize negative effect. We synthesized DOE using accurately measured phase fluctuations of phase LC SLM "HoloEye PLUTO VIS" to minimize its negative impact on displayed DOE reconstruction. Synthesis was conducted with versatile direct search with random trajectory (DSRT) method in the following way. Before DOE synthesis begun, two-dimensional dependency of SLM phase shift on addressed signal level and time from frame start was obtained. Then synthesis begins. First, initial phase distribution is created. Second, random trajectory of consecutive processing of all DOE elements is generated. Then iterative process begins. Each DOE element sequentially has its value changed to one that provides better value of objective criterion, e.g. lower deviation of reconstructed image from original one. If current element value provides best objective criterion value then it left unchanged. After all elements are processed, iteration repeats until stagnation is reached. It is demonstrated that application of SLM phase fluctuations knowledge in DOE synthesis with DSRT method leads to noticeable increase of DOE reconstruction quality.

Evaluating stereoscopic displays : both efficiency measures and perceived workload sensitive to manipulations in binocular disparity

NARCIS (Netherlands)

Beurden, van M.H.P.H.; IJsselsteijn, W.A.; Kort, de Y.A.W.; Woods, A.J.; Holliman, N.S.; Dodgson, N.A.

2011-01-01

Stereoscopic displays are known to offer a number of key advantages in visualizing complex 3D structures or datasets. The large majority of studies that focus on evaluating stereoscopic displays for professional applications use completion time and/or the percentage of correct answers to measure

Real-time Image Generation for Compressive Light Field Displays

International Nuclear Information System (INIS)

Wetzstein, G; Lanman, D; Hirsch, M; Raskar, R

2013-01-01

With the invention of integral imaging and parallax barriers in the beginning of the 20th century, glasses-free 3D displays have become feasible. Only today—more than a century later—glasses-free 3D displays are finally emerging in the consumer market. The technologies being employed in current-generation devices, however, are fundamentally the same as what was invented 100 years ago. With rapid advances in optical fabrication, digital processing power, and computational perception, a new generation of display technology is emerging: compressive displays exploring the co-design of optical elements and computational processing while taking particular characteristics of the human visual system into account. In this paper, we discuss real-time implementation strategies for emerging compressive light field displays. We consider displays composed of multiple stacked layers of light-attenuating or polarization-rotating layers, such as LCDs. The involved image generation requires iterative tomographic image synthesis. We demonstrate that, for the case of light field display, computed tomographic light field synthesis maps well to operations included in the standard graphics pipeline, facilitating efficient GPU-based implementations with real-time framerates.

Exploring Virtual Worlds With Head-Mounted Displays

Science.gov (United States)

Chung, James C.; Harris, Mark R.; Brooks, Frederick P.; Fuchs, Henry; Kelley, Michael T.; Hughes, John W.; Ouh-Young, Ming; Cheung, Clement; Holloway, Richard L.; Pique, Michael

1989-09-01

For nearly a decade the University of North Carolina at Chapel Hill has been conducting research in the use of simple head-mounted displays in "real-world" applications. Such units provide the user with non-holographic true three-dimensional information, since the kinetic depth effect, stereoscopy, and other visual cues combine to immerse the user in a "virtual world" which behaves like the real world in some respects. UNC's head-mounted display was built inexpensively from commercially available off-the-shelf components. Tracking of the the user's head position and orientation is performed by a Polhemus Navigation Sciences' 3SPACE* tracker. The host computer uses the tracking information to generate updated images corresponding to the user's new left eye and right eye views. The images are broadcast to two liquid crystal television screens (220x320 pixels) mounted on a horizontal shelf at the user's forehead. The user views these color screens through half-silvered mirrors, enabling the computer-generated image to be superimposed upon the user's real physical environment. The head-mounted display has been incorporated into existing molecular modeling and architectural applications being developed at UNC. In molecular structure studies, chemists are presented with a room-sized molecule with which they can interact in a manner more intuitive than that provided by conventional two-dimensional displays and dial boxes. Walking around and through the large molecule may provide quicker understanding of its structure, and such problems as drug-enzyme docking may be approached with greater insight. In architecture, the head-mounted display enables clients to better appreciate three-dimensional designs, which may be misinterpreted in their conventional two-dimensional form by untrained eyes. The addition of a treadmill to the system provides additional kinesthetic input into the understanding of building size and scale.

Third harmonic frequency generation by type-I critically phase-matched LiB3O5 crystal by means of optically active quartz crystal.

Science.gov (United States)

Gapontsev, Valentin P; Tyrtyshnyy, Valentin A; Vershinin, Oleg I; Davydov, Boris L; Oulianov, Dmitri A

2013-02-11

We present a method of third harmonic generation at 355 nm by frequency mixing of fundamental and second harmonic radiation of an ytterbium nanosecond pulsed all-fiber laser in a type-I phase-matched LiB(3)O(5) (LBO) crystal where originally orthogonal polarization planes of the fundamental and second harmonic beams are aligned by an optically active quartz crystal. 8 W of ultraviolet light at 355 nm were achieved with 40% conversion efficiency from 1064 nm radiation. The conversion efficiency obtained in a type-I phase-matched LBO THG crystal was 1.6 times higher than the one achieved in a type-II LBO crystal at similar experimental conditions. In comparison to half-wave plates traditionally used for polarization alignment the optically active quartz crystal has much lower temperature dependence and requires simpler optical alignment.

UV response on dielectric properties of nano nematic liquid crystal

Directory of Open Access Journals (Sweden)

Kamal Kumar Pandey

2018-03-01

Full Text Available In this work, we investigate the effect of UV light irradiation on the dielectric parameters of nematic liquid crystal (5CB and ZnO nanoparticles dispersed liquid crystal. With addition of nanoparticles in nematic LC are promising new materials for a variety of application in energy harvesting, displays and photonics including the liquid crystal laser. To realize many applications, however we optimize the properties of liquid crystal and understand how the UV light irradiation interact the nanoparticles and LC molecules in dispersed/doped LC. The dielectric permittivity and loss factor have discussed the pure nematic LC and dispersed/doped system after, during and before UV light exposure. The dielectric relaxation spectroscopy was carried out in the frequency range 100 Hz–10 MHz in the nematic mesophase range. Keywords: Dielectric permittivity, Relaxation frequency, Nematic liquid crystal, UV light irradiation

Low-temperature (75 °C) solid-state reaction enhanced by less-crystallized nanoporous PbI{sub 2} films for efficient CH{sub 3}NH{sub 3}PbI{sub 3} perovskite solar cells

Energy Technology Data Exchange (ETDEWEB)

Zheng, Huifeng [State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Sciences, 1295 Dingxi Road, Shanghai 200050 (China); University of Chinese Academy of Sciences, 19 Yuquan Road, Beijing 100049 (China); Liu, Yangqiao, E-mail: yqliu@mail.sic.ac.cn [State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Sciences, 1295 Dingxi Road, Shanghai 200050 (China); Suzhou Institute of SICCAS (Shanghai Institute of Ceramics, Chinese Academy of Sciences), 238 North Changchun Road, Taicang 215499, Jiangsu Province (China); Sun, Jing, E-mail: jingsun@mail.sic.ac.cn [State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Sciences, 1295 Dingxi Road, Shanghai 200050 (China)

2017-05-31

Highlights: • Efficient perovskite solar cells were prepared with solid-state reaction at 75 °C. • Ln-PbI{sub 2} is superior to c-PbI{sub 2} when applied in low-temperature solid-state reaction. • A higher champion PCE was obtained at 75 °C (13.8%) than that of 140 °C (11.8%). • Non-radiative defects increase significantly when annealed at high temperature. - Abstract: Organohalide perovskite films are usually prepared with the solid-state reaction at a high temperature ≥100 °C, which causes the increase of non-radiative defects and decomposition of perovskite films. Here, we demonstrate it’s feasible to prepare high-quality perovskite films with the solid-state reaction method even at a temperature of 75 °C, when enhanced by less-crystallized nanoporous PbI{sub 2} (ln-PbI{sub 2}) films. The replacement of compact PbI{sub 2} (c-PbI{sub 2}) by ln-PbI{sub 2}, results in a significant improvement of crystallinity of perovskite films, besides the elimination of remnant PbI{sub 2}. As a result, ln-PbI{sub 2} based perovskite solar cells display much higher power conversion efficiency (PCE) and better stability. Moreover, annealing duration was found to be critical for high PCE and was optimized as 60 min. Finally, with the optimal process, the champion device displayed a PCE of 13.8% and the average PCE reached 10.1% with a satisfactory deviation. Furthermore, we found annealing at high temperature (140 °C) led to a lower PCE compared with that annealed at 75 °C, because non-radiative defects increased significantly during high-temperature annealing. This work may open up a promising avenue for preparing high-quality perovskite films with the low-temperature solid-state reaction method, which is desirable for real application.

Energy resolution measurements of LaBr3:Ce scintillating crystals with an ultra-high quantum efficiency photomultiplier tube

International Nuclear Information System (INIS)

Pani, R.; Cinti, M.N.; Scafe, R.; Pellegrini, R.; Vittorini, F.; Bennati, P.; Ridolfi, S.; Lo Meo, S.; Mattioli, M.; Baldazzi, G.; Pisacane, F.; Navarria, F.; Moschini, G.; Boccaccio, P.; Orsolini Cencelli, V.; Sacco, D.

2009-01-01

The performance of the new prototype of high quantum efficiency PMT (43% at 380 nm), Hamamatsu R7600U-200, was studied coupled to a LaBr 3 :Ce crystal with the size of o12.5 mmx12.5 mm. The energy resolution results were compared with ones from two PMTs, Hamamatsu R7600U and R6231MOD, with 22% and 30% quantum efficiency (QE), respectively. Moreover, the photodetectors were equipped with tapered and un-tapered voltage dividers to study the non-linearity effects on pulse height distribution, due to very high peak currents induced in the PMT by the fast and intense light pulse of LaBr 3 :Ce. The results show an energy resolution improvement with UBA PMT of about 20%, in the energy range of 80-662 keV, with respect to the BA one.

Modifications of micro-pulling-down method for the growth of selected Li-containing crystals for neutron scintillator and VUV scintillation crystals

Science.gov (United States)

Pejchal, J.; Fujimoto, Y.; Chani, V.; Yanagida, T.; Yokota, Y.; Yoshikawa, A.; Nikl, M.; Beitlerova, A.

2012-12-01

To develop new and efficient neutron scintillator, Ti-doped LiAlO2 single crystal was grown by micro-pulling-down method. The X-ray excited radioluminescence spectra and neutron light yield were measured. Positive effect of Mg codoping on the overall scintillation efficiency was found. The BaLu2F8 single crystal was grown by micro-pulling-down method using low temperature gradient at growth interface and applying quenching immediately after growth process.

Effects of the Maximum Luminance in a Medical-grade Liquid-crystal Display on the Recognition Time of a Test Pattern: Observer Performance Using Landolt Rings.

Science.gov (United States)

Doi, Yasuhiro; Matsuyama, Michinobu; Ikeda, Ryuji; Hashida, Masahiro

2016-07-01

This study was conducted to measure the recognition time of the test pattern and to investigate the effects of the maximum luminance in a medical-grade liquid-crystal display (LCD) on the recognition time. Landolt rings as signals of the test pattern were used with four random orientations, one on each of the eight gray-scale steps. Ten observers input the orientation of the gap on the Landolt rings using cursor keys on the keyboard. The recognition times were automatically measured from the display of the test pattern on the medical-grade LCD to the input of the orientation of the gap in the Landolt rings. The maximum luminance in this study was set to one of four values (100, 170, 250, and 400 cd/m(2)), for which the corresponding recognition times were measured. As a result, the average recognition times for each observer with maximum luminances of 100, 170, 250, and 400 cd/m(2) were found to be 3.96 to 7.12 s, 3.72 to 6.35 s, 3.53 to 5.97 s, and 3.37 to 5.98 s, respectively. The results indicate that the observer's recognition time is directly proportional to the luminance of the medical-grade LCD. Therefore, it is evident that the maximum luminance of the medical-grade LCD affects the test pattern recognition time.

Mechanical Stability of Flexible Graphene-Based Displays

Science.gov (United States)

2016-01-01

The mechanical behavior of a prototype touch panel display, which consists of two layers of CVD graphene embedded into PET films, is investigated in tension and under contact-stress dynamic loading. In both cases, laser Raman spectroscopy was employed to assess the stress transfer efficiency of the embedded graphene layers. The tensile behavior was found to be governed by the “island-like” microstructure of the CVD graphene, and the stress transfer efficiency was dependent on the size of graphene “islands” but also on the yielding behavior of PET at relatively high strains. Finally, the fatigue tests, which simulate real operation conditions, showed that the maximum temperature gradient developed at the point of “finger” contact after 80 000 cycles does not exceed the glass transition temperature of the PET matrix. The effect of these results on future product development and the design of new graphene-based displays are discussed. PMID:27494211

Unique Reversible Crystal-to-Crystal Phase Transition – Structural and Functional Properties of Fused Ladder Thienoarenes

KAUST Repository

Abe, Yuichiro

2017-08-15

Donor-acceptor type molecules based on fused ladder thienoarenes, indacenodithiophene (IDT) and dithienocyclopenta-thienothiophene (DTCTT), coupled with benzothiadiazole, are prepared and their solid-state structures are investigated. They display a rich variety of solid phases ranging from amorphous glass states to crystalline states, upon changes in the central aromatic core and side group structures. Most notably, the DTCTT-based derivatives showed reversible crystal-to-crystal phase transitions in heating and cooling cycles. Unlike what has been seen in π−conjugated molecules variable temperature XRD revealed that structural change occurs continuously during the transition. A columnar self-assembled structure with slip-stacked π−π interaction is proposed to be involved in the solid-state. This research provides the evidence of unique structural behavior of the DTCTT-based molecules through the detailed structural analysis. This unique structural transition paves the way for these materials to have self-healing of crystal defects, leading to improved optoelectronic properties.

Unique Reversible Crystal-to-Crystal Phase Transition – Structural and Functional Properties of Fused Ladder Thienoarenes

KAUST Repository

Abe, Yuichiro; Savikhin, Victoria; Yin, Jun; Grimsdale, Andrew C.; Soci, Cesare; Toney, Michael F.; Lam, Yeng Ming

2017-01-01

Donor-acceptor type molecules based on fused ladder thienoarenes, indacenodithiophene (IDT) and dithienocyclopenta-thienothiophene (DTCTT), coupled with benzothiadiazole, are prepared and their solid-state structures are investigated. They display a rich variety of solid phases ranging from amorphous glass states to crystalline states, upon changes in the central aromatic core and side group structures. Most notably, the DTCTT-based derivatives showed reversible crystal-to-crystal phase transitions in heating and cooling cycles. Unlike what has been seen in π−conjugated molecules variable temperature XRD revealed that structural change occurs continuously during the transition. A columnar self-assembled structure with slip-stacked π−π interaction is proposed to be involved in the solid-state. This research provides the evidence of unique structural behavior of the DTCTT-based molecules through the detailed structural analysis. This unique structural transition paves the way for these materials to have self-healing of crystal defects, leading to improved optoelectronic properties.

Study of channeling phenomena in bent crystals the new frontiers

CERN Document Server

Bolognini, Davide; Scandale, Walter; Vallazza, Erik

2008-01-01

More or less 30 years ago, it was experimentally demonstrated how a bent crystal can become a magnet: an object 1 mm thick, a couple of mm wide and a few cm high is, in fact, capable of steering particles as a dipole of several tens of Tesla. Exploiting this feature, from September 2006 the H8RD22 collaboration is testing several bent crystals in order to develop a crystal based collimation system for LHC: in very high energy accelerators, in fact, the typical multi-stage collimation system (that must be very efficient and must tolerate very high radiation) is expected not to allow to reach the nominal luminosity, limiting it to 40% of the desired value. A bent crystal could play a key role being a clever collimator: it is able to steer particles in a given direction with a high efficiency, thus increasing the cleaning efficiency, reducing the constraints on the alignment of the secondary collimator and finally increasing luminosity. But bent crystals are not only collimation: the radiation emitted by light p...

3D display system using monocular multiview displays

Science.gov (United States)

Sakamoto, Kunio; Saruta, Kazuki; Takeda, Kazutoki

2002-05-01

A 3D head mounted display (HMD) system is useful for constructing a virtual space. The authors have researched the virtual-reality systems connected with computer networks for real-time remote control and developed a low-priced real-time 3D display for building these systems. We developed a 3D HMD system using monocular multi-view displays. The 3D displaying technique of this monocular multi-view display is based on the concept of the super multi-view proposed by Kajiki at TAO (Telecommunications Advancement Organization of Japan) in 1996. Our 3D HMD has two monocular multi-view displays (used as a visual display unit) in order to display a picture to the left eye and the right eye. The left and right images are a pair of stereoscopic images for the left and right eyes, then stereoscopic 3D images are observed.

Characterization of physicochemical and thermal properties and crystallization behavior of krabok (Irvingia Malayana ) and rambutan seed fats.

Science.gov (United States)

Sonwai, Sopark; Ponprachanuvut, Punnee

2012-01-01

Fatty acid composition, physicochemical and thermal properties and crystallization behavior of fats extracted from the seeds of krabok (Irvingia Malayana) and rambutan (Nephelium lappaceum L.) trees grown in Thailand were studied and compared with cocoa butter (CB). The krabok seed fat, KSF, consisted of 46.9% lauric and 40.3% myristic acids. It exhibited the highest saponification value and slip melting point but the lowest iodine values. The three fats displayed different crystallization behavior at 25°C. KSF crystallized into a mixture of β' and pseudo-β' structures with a one-step crystallization curve and high solid fat content (SFC). The fat showed simple DSC crystallization and melting thermograms with one distinct peak. The rambutan seed fat, RSF, consisted of 42.5% arachidic and 33.1% oleic acids. Its crystallization behavior was more similar to CB than KSF, displaying a two-step crystallization curve with SFC lower than that of KSF. RSF solidified into a mixture of β' and pseudo-β' before transforming to β after 24 h. The large spherulitic microstructures were observed in both KSF and RSF. According to these results, the Thai KSF and RSF exhibited physicochemical, thermal characteristics and crystallization behavior that could be suitable for specific applications in several areas of the food, cosmetic and pharmaceutical industries.

Circular displays: control/display arrangements and stereotype strength with eight different display locations.

Science.gov (United States)

Chan, Alan H S; Hoffmann, Errol R

2015-01-01

Two experiments are reported that were designed to investigate control/display arrangements having high stereotype strengths when using circular displays. Eight display locations relative to the operator and control were tested with rotational and translational controls situated on different planes according to the Frame of Reference Transformation Tool (FORT) model of Wickens et al. (2010). (Left. No, Right! Development of the Frame of Reference Transformation Tool (FORT), Proceedings of the Human Factors and Ergonomics Society 54th Annual Meeting, 54: 1022-1026). In many cases, there was little effect of display locations, indicating the importance of the Worringham and Beringer (1998. Directional stimulus-response compatibility: a test of three alternative principles. Ergonomics, 41(6), 864-880) Visual Field principle and an extension of this principle for rotary controls (Hoffmann and Chan (2013). The Worringham and Beringer 'visual field' principle for rotary controls. Ergonomics, 56(10), 1620-1624). The initial indicator position (12, 3, 6 and 9 o'clock) had a major effect on control/display stereotype strength for many of the six controls tested. Best display/control arrangements are listed for each of the different control types (rotational and translational) and for the planes on which they are mounted. Data have application where a circular display is used due to limited display panel space and applies to space-craft, robotics operators, hospital equipment and home appliances. Practitioner Summary: Circular displays are often used when there is limited space available on a control panel. Display/control arrangements having high stereotype strength are listed for four initial indicator positions. These arrangements are best for design purposes.

Large Stroke High Fidelity PZN-PT Single-Crystal "Stake" Actuator.

Science.gov (United States)

Huang, Yu; Xia, Yuexue; Lin, Dian Hua; Yao, Kui; Lim, Leong Chew

2017-10-01

A new piezoelectric actuator design, called "Stake" actuator, is proposed and demonstrated in this paper. As an example, the stake actuator is made of four d 32 -mode PZN-5.5%PT single crystals (SCs), each of 25 mm ( L ) ×8 mm ( W ) ×0.4 mm (T) in dimensions, bonded with the aid of polycarbonate edge guide-cum-stiffeners into a square-pipe configuration for improved bending and twisting strengths and capped with top and bottom pedestals made of 1.5-mm-thick anodized aluminum. The resultant stake actuator measured 9 mm ×9 mm ×28 mm. The hollow structure is a key design feature, which optimizes SC usage efficiency and lowers the overall cost of the actuator. The displacement-voltage responses, blocking forces, resonance characteristics of the fabricated stake actuator, as well as the load and temperature effects, are measured and discussed. Since d 32 is negative for [011]-poled SC, the "Stake" actuator contracts in the axial direction when a positive-polarity field is applied to the crystals. Biased drive is thus recommended when extensional displacement is desired. The SC stake actuator has negligible (0.13% when driven up to +300 V (i.e., 0.75 kV/mm), which is close to the rhombohedral-to-orthorhombic transformation field ( E RO ) of 0.85 kV/mm of the SC used. The stake actuator displays a stroke of [Formula: see text] (at +300 V) despite its small overall dimensions, and has a blocking force of 114 N. The SC d 32 stake actuator fabricated displays more than 30% larger axial strain than the state-of-the-art PZT stack actuators of comparable length as well as moderate blocking forces. Said actuators are thus ideal for applications when large displacements with simple open-loop control are preferred.

Emerging Applications of Liquid Crystals Based on Nanotechnology

Directory of Open Access Journals (Sweden)

Jung Inn Sohn

2014-03-01

Full Text Available Diverse functionalities of liquid crystals (LCs offer enormous opportunities for their potential use in advanced mobile and smart displays, as well as novel non-display applications. Here, we present snapshots of the research carried out on emerging applications of LCs ranging from electronics to holography and self-powered systems. In addition, we will show our recent results focused on the development of new LC applications, such as programmable transistors, a transparent and active-type two-dimensional optical array and self-powered display systems based on LCs, and will briefly discuss their novel concepts and basic operating principles. Our research will give insights not only into comprehensively understanding technical and scientific applications of LCs, but also developing new discoveries of other LC-based devices.

Visual search asymmetries within color-coded and intensity-coded displays.

Science.gov (United States)

Yamani, Yusuke; McCarley, Jason S

2010-06-01

Color and intensity coding provide perceptual cues to segregate categories of objects within a visual display, allowing operators to search more efficiently for needed information. Even within a perceptually distinct subset of display elements, however, it may often be useful to prioritize items representing urgent or task-critical information. The design of symbology to produce search asymmetries (Treisman & Souther, 1985) offers a potential technique for doing this, but it is not obvious from existing models of search that an asymmetry observed in the absence of extraneous visual stimuli will persist within a complex color- or intensity-coded display. To address this issue, in the current study we measured the strength of a visual search asymmetry within displays containing color- or intensity-coded extraneous items. The asymmetry persisted strongly in the presence of extraneous items that were drawn in a different color (Experiment 1) or a lower contrast (Experiment 2) than the search-relevant items, with the targets favored by the search asymmetry producing highly efficient search. The asymmetry was attenuated but not eliminated when extraneous items were drawn in a higher contrast than search-relevant items (Experiment 3). Results imply that the coding of symbology to exploit visual search asymmetries can facilitate visual search for high-priority items even within color- or intensity-coded displays. PsycINFO Database Record (c) 2010 APA, all rights reserved.

Evaluating stereoscopic displays: both efficiency measures and perceived workload sensitive to manipulations in binocular disparity

Science.gov (United States)

van Beurden, Maurice H. P. H.; Ijsselsteijn, Wijnand A.; de Kort, Yvonne A. W.

2011-03-01

Stereoscopic displays are known to offer a number of key advantages in visualizing complex 3D structures or datasets. The large majority of studies that focus on evaluating stereoscopic displays for professional applications use completion time and/or the percentage of correct answers to measure potential performance advantages. However, completion time and accuracy may not fully reflect all the benefits of stereoscopic displays. In this paper, we argue that perceived workload is an additional valuable indicator reflecting the extent to which users can benefit from using stereoscopic displays. We performed an experiment in which participants were asked to perform a visual path-tracing task within a convoluted 3D wireframe structure, varying in level of complexity of the visualised structure and level of disparity of the visualisation. The results showed that an optimal performance (completion time, accuracy and workload), depend both on task difficulty and disparity level. Stereoscopic disparity revealed a faster and more accurate task performance, whereas we observed a trend that performance on difficult tasks stands to benefit more from higher levels of disparity than performance on easy tasks. Perceived workload (as measured using the NASA-TLX) showed a similar response pattern, providing evidence that perceived workload is sensitive to variations in disparity as well as task difficulty. This suggests that perceived workload could be a useful concept, in addition to standard performance indicators, in characterising and measuring human performance advantages when using stereoscopic displays.

The MORPHEUS II protein crystallization screen

Energy Technology Data Exchange (ETDEWEB)

Gorrec, Fabrice, E-mail: fgorrec@mrc-lmb.cam.ac.uk [MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge Biomedical Campus, Cambridge CB2 0QH (United Kingdom)

2015-06-27

MORPHEUS II is a 96-condition initial crystallization screen formulated de novo. The screen incorporates reagents selected from the Protein Data Bank to yield crystals that are not observed in traditional conditions. In addition, the formulation facilitates the optimization and cryoprotection of crystals. High-quality macromolecular crystals are a prerequisite for the process of protein structure determination by X-ray diffraction. Unfortunately, the relative yield of diffraction-quality crystals from crystallization experiments is often very low. In this context, innovative crystallization screen formulations are continuously being developed. In the past, MORPHEUS, a screen in which each condition integrates a mix of additives selected from the Protein Data Bank, a cryoprotectant and a buffer system, was developed. Here, MORPHEUS II, a follow-up to the original 96-condition initial screen, is described. Reagents were selected to yield crystals when none might be observed in traditional initial screens. Besides, the screen includes heavy atoms for experimental phasing and small polyols to ensure the cryoprotection of crystals. The suitability of the resulting novel conditions is shown by the crystallization of a broad variety of protein samples and their efficiency is compared with commercially available conditions.

The MORPHEUS II protein crystallization screen

International Nuclear Information System (INIS)

Gorrec, Fabrice

2015-01-01

MORPHEUS II is a 96-condition initial crystallization screen formulated de novo. The screen incorporates reagents selected from the Protein Data Bank to yield crystals that are not observed in traditional conditions. In addition, the formulation facilitates the optimization and cryoprotection of crystals. High-quality macromolecular crystals are a prerequisite for the process of protein structure determination by X-ray diffraction. Unfortunately, the relative yield of diffraction-quality crystals from crystallization experiments is often very low. In this context, innovative crystallization screen formulations are continuously being developed. In the past, MORPHEUS, a screen in which each condition integrates a mix of additives selected from the Protein Data Bank, a cryoprotectant and a buffer system, was developed. Here, MORPHEUS II, a follow-up to the original 96-condition initial screen, is described. Reagents were selected to yield crystals when none might be observed in traditional initial screens. Besides, the screen includes heavy atoms for experimental phasing and small polyols to ensure the cryoprotection of crystals. The suitability of the resulting novel conditions is shown by the crystallization of a broad variety of protein samples and their efficiency is compared with commercially available conditions

IR sensitive photorefractive polymers, the first updateable holographic three-dimensional display

Science.gov (United States)

Tay, Savas

This work presents recent advances in the development of infra-red sensitive photorefractive polymers, and updateable near real-time holographic 3D displays based on photorefractive polymers. Theoretical and experimental techniques used for design, fabrication and characterization of photorefractive polymers are outlined. Materials development and technical advances that made possible the use of photorefractive polymers for infra-red free-space optical communications, and 3D holographic displays are presented. Photorefractive polymers are dynamic holographic materials that allow recording of highly efficient reversible holograms. The longest operation wavelength for a photorefractive polymer before this study has been 950nm, far shorter than 1550nm, the wavelength of choice for optical communications and medical imaging. The polymers shown here were sensitized using two-photon absorption, a third order nonlinear effect, beyond the linear absorption spectrum of organic dyes, and reach 40% diffraction efficiency with a 35ms response time at this wavelength. As a consequence of two-photon absorption sensitization they exhibit non-destructive readout, which is an important advantage for applications that require high signal-to-noise ratios. Holographic 3D displays provide highly realistic images without the need for special eyewear, making them valuable tools for applications that require "situational awareness" such as medical, industrial and military imaging. Current commercially available holographic 3D displays employ photopolymers that lack image updating capability, resulting in their restricted use and high cost per 3D image. The holographic 3D display shown here employs photorefractive polymers with nearly 100% diffraction efficiency and fast writing time, hours of image persistence, rapid erasure and large area, a combination of properties that has not been shown before. The 3D display is based on stereography and utilizes world's largest photorefractive

Application of Matrix Projection Exposure Using a Liquid Crystal Display Panel to Fabricate Thick Resist Molds

Science.gov (United States)

Fukasawa, Hirotoshi; Horiuchi, Toshiyuki

2009-08-01

The patterning characteristics of matrix projection exposure using an analog liquid crystal display (LCD) panel in place of a reticle were investigated, in particular for oblique patterns. In addition, a new method for fabricating practical thick resist molds was developed. At first, an exposure system fabricated in past research was reconstructed. Changes in the illumination optics and the projection lens were the main improvements. Using fly's eye lenses, the illumination light intensity distribution was homogenized. The projection lens was changed from a common camera lens to a higher-grade telecentric lens. In addition, although the same metal halide lamp was used as an exposure light source, the central exposure wavelength was slightly shortened from 480 to 450 nm to obtain higher resist sensitivity while maintaining almost equivalent contrast between black and white. Circular and radial patterns with linewidths of approximately 6 µm were uniformly printed in all directions throughout the exposure field owing to these improvements. The patterns were smoothly printed without accompanying stepwise roughness caused by the cell matrix array. On the bases of these results, a new method of fabricating thick resist molds for electroplating was investigated. It is known that thick resist molds fabricated using the negative resist SU-8 (Micro Chem) are useful because very high aspect patterns are printable and the side walls are perpendicular to the substrate surfaces. However, the most suitable exposure wavelength of SU-8 is 365 nm, and SU-8 is insensitive to light of 450 nm wavelength, which is most appropriate for LCD matrix exposure. For this reason, a novel multilayer resist process was proposed, and micromolds of SU-8 of 50 µm thickness were successfully obtained. As a result, feasibility for fabricating complex resist molds including oblique patterns was demonstrated.

Conversion of broadband thermal radiation in lithium niobate crystals of various compositions

Science.gov (United States)

Syuy, A. V.; Litvinova, M. N.; Goncharova, P. S.; Sidorov, N. V.; Palatnikov, M. N.; Krishtop, V. V.; Likhtin, V. V.

2013-05-01

The conversion of the broadband thermal radiation in stoichiometric ( R = 1) lithium niobate single crystals that are grown from melt with 58.6 mol % of LiO2, congruent ( R = Li/Nb = 0.946) melt with the K2O flux admixture (4.5 and 6.0 wt %), and congruent melt and in congruent single crystals doped with the Zn2+, Gd3+, and Er3+ cations is studied. It is demonstrated that the conversion efficiency of the stoichiometric crystal that is grown from the melt with 58.6 mol % of LiO2 is less than the conversion efficiency of congruent crystal. In addition, the stoichiometric and almost stoichiometric crystals and the doped congruent crystals exhibit the blue shift of the peak conversion intensity in comparison with a nominally pure congruent crystal. For the congruent crystals, the conversion intensities peak at 520 and 495 nm, respectively.

Synthesis, crystal structure and luminescence properties of lanthanide coordination polymers with a new semirigid bridging thenylsalicylamide ligand

International Nuclear Information System (INIS)

Song, Xue-Qin; Wang, Li; Zhao, Meng-Meng; Wang, Xiao-Run; Peng, Yun-Qiao; Cheng, Guo-Quan

2013-01-01

Two new lanthanide coordination polymers based on a semirigid bridging thenylsalicylamide ligand ([Ln 2 L 3 (NO 3 ) 6 ]·(C 4 H 8 O 2 ) 2 ) ∞ were obtained and characterized by elemental analysis, X-ray diffraction, IR and TGA measurements. The two compounds are isostructure and possess one dimensional trapezoid ladder-like chain built up from the connection of isolated LnO 3 (NO 3 ) 3 polyhedra (distorted monocapped antisquare prism) through the ligand. The photoluminescence analysis suggest that there is an efficient ligand-to-Ln(III) energy transfer in Tb(III) complex and the ligand is an efficient “antenna” for Tb(III). From a more general perspective, the results demonstrated herein provide the possibility of controlling the formation of the desired lanthanide coordination structure to enrich the crystal engineering strategy and enlarge the arsenal for developing excellent luminescent lanthanide coordination polymers. - Graphical abstract: We present herein one dimensional lanthanide coordination polymers of a new semirigid exo-bidentate ligand which not only display interesting structures but also possess strong luminescence properties. Display Omitted - Highlights: • We present lanthanide coordination polymers of a new semirigid exo-bidentate ligand. • The lanthanide coordination polymers exhibit interesting structures. • The luminescent properties of Tb(III) complexes are discussed in detail

Yeast surface display platform for rapid discovery of conformationally selective nanobodies

DEFF Research Database (Denmark)

McMahon, Conor; Baier, Alexander S.; Pascolutti, Roberta

2018-01-01

this problem, we report a fully in vitro platform for nanobody discovery based on yeast surface display. We provide a blueprint for identifying nanobodies, demonstrate the utility of the library by crystallizing a nanobody with its antigen, and most importantly, we utilize the platform to discover...... conformationally selective nanobodies to two distinct human GPCRs. To facilitate broad deployment of this platform, the library and associated protocols are freely available for nonprofit research....

Investigation of self-frequency doubling crystals, yttrium calcium oxyborate (YCOB), doped with neodymium or ytterbium

Science.gov (United States)

Ye, Qing

1999-09-01

There is a need for low cost red, green, and blue (RGB) lasers for a number of commercial applications such as high-resolution laser printing, full color laser display. While semiconductor lasers still have both availability (green and blue) and beam quality (red) problems, nonlinear frequency conversion of diode-pumped solid state lasers are good alternatives. Among them, self- frequency doubling is an attractive approach because of its simpler design and lower cost. Unfortunately, few known crystals possess self-frequency doubling property. A newly discovered yttrium calcium oxyborate (YCOB) can fill in the role because it has adequate lasing and nonlinear frequency conversion efficiency. More importantly, YCOB crystal melts congruently so that high quality, large size single crystals can be grown using conventional Czochralski melt pulling technique. The thermal mechanical properties, linear and nonlinear optical properties of YCOB, laser properties of Nd:YCOB and Yb:YCOB crystals were investigated. Based on the calculated second harmonic phase matching angles, Nd:YCOB laser rods were fabricated. Self-frequency doubled green emission with 62 mW output power and red emission with 16 mW output power were successfully demonstrated using diode-pumping. It is the first time to achieve the continuous wave (cw) red lasing in Nd doped rare-earth calcium oxyborates. Rare-earth ions doping in YCOB crystal can not only achieve lasing, but also affect the physical and chemical properties of the crystal. The stability field of YCOB is reduced in proportion to both the ionic size differences from yttrium and doping concentrations of the rare-earth ions. The doping also changes the linear and nonlinear optical properties of the material. For example, the second harmonic conversion efficiency of 20% Yb doped YCOB was enhanced by more than 15% compared to undoped YCOB. The absorption cutoff edge of 20% Yb:YCOB was red- shift by more than 60 nm. Similar effects were observed in

Effects of ionizing radiation on struvite crystallization of livestock wastewater

International Nuclear Information System (INIS)

Kim, Tak- Hyun; Nam, Yun-Ku; Joo Lim, Seung

2014-01-01

Livestock wastewater is generally very difficult to be treated by conventional wastewater treatment techniques because it contains high-strength organics (COD), ammonium (NH 4 + ), phosphate (PO 4 3− ) and suspended solids. Struvite crystallization has been recently studied for the simultaneous removal of NH 4 + and PO 4 3− . In this study, gamma ray irradiation was carried out prior to struvite crystallization of the anaerobically digested livestock wastewater. The effects of gamma ray irradiation on the struvite crystallization of livestock wastewater were investigated. As a result, gamma ray irradiation can decrease the concentration of COD, NH 4 + and PO 4 3− contained in the livestock wastewater. This results in not only an enhancement of the struvite crystallization efficiency but also a decrease in the chemical demands for the struvite crystallization of livestock wastewater. - Highlights: • Gamma ray was applied prior to struvite crystallization of livestock wastewater. • Gamma ray resulted in an enhancement of struvite crystallization efficiency. • This is due to the decrease of COD concentration by gamma ray irradiation

[Influence of different lighting levels at workstations with video display terminals on operators' work efficiency].

Science.gov (United States)

Janosik, Elzbieta; Grzesik, Jan

2003-01-01

The aim of this work was to evaluate the influence of different lighting levels at workstations with video display terminals (VDTs) on the course of the operators' visual work, and to determine the optimal levels of lighting at VDT workstations. For two kinds of job (entry of figures from a typescript and edition of the text displayed on the screen), the work capacity, the degree of the visual strain and the operators' subjective symptoms were determined for four lighting levels (200, 300, 500 and 750 lx). It was found that the work at VDT workstations may overload the visual system and cause eyes complaints as well as the reduction of accommodation or convergence strength. It was also noted that the edition of the text displayed on the screen is more burdening for operators than the entry of figures from a typescript. Moreover, the examination results showed that the lighting at VDT workstations should be higher than 200 lx and that 300 lx makes the work conditions most comfortable during the entry of figures from a typescript, and 500 lx during the edition of the text displayed on the screen.

The effect of display movement angle, indicator type and display location on control/display stereotype strength.

Science.gov (United States)

Hoffmann, Errol R; Chan, Alan H S

2017-08-01

Much research on stereotype strength relating display and control movements for displays moving in the vertical or horizontal directions has been reported. Here we report effects of display movement angle, where the display moves at angles (relative to the vertical) of between 0° and 180°. The experiment used six different controls, four display locations relative to the operator and three types of indicator. Indicator types were included because of the strong effects of the 'scale-side principle' that are variable with display angle. A directional indicator had higher stereotype strength than a neutral indicator, and showed an apparent reversal in control/display stereotype direction beyond an angle of 90°. However, with a neutral indicator this control reversal was not present. Practitioner Summary: The effects of display moving at angles other than the four cardinal directions, types of control, location of display and types of indicator are investigated. Indicator types (directional and neutral) have an effect on stereotype strength and may cause an apparent control reversal with change of display movement angle.

CH3NH3PbCl3 Single Crystals: Inverse Temperature Crystallization and Visible-Blind UV-Photodetector

KAUST Repository

Maculan, Giacomo

2015-09-02

Single crystals of hybrid perovskites have shown remarkably improved physical properties compared to their polycrystalline film counterparts, underscoring their importance in the further development of advanced semiconductor devices. Here we present a new method of sizeable CH3NH3PbCl3 single crystal growth based on retrograde solubility behavior of hybrid perovskites. We show, for the first time, the energy band structure, charge-carrier recombination and transport properties of single crystal CH3NH3PbCl3. The chloride-based perovskite crystals exhibit trap-state density, charge carriers concentration, mobility and diffusion length comparable with the best quality crystals of methylammonium lead iodide or bromide perovskites reported so far. The high quality of the crystal along with its suitable optical bandgap enabled us to design and build an efficient visible-blind UV-photodetector, demonstrating the potential of this material to be employed in optoelectronic applications.

Advances in infrastructure support for flat panel display manufacturing

Science.gov (United States)

Bardsley, James N.; Ciesinski, Michael F.; Pinnel, M. Robert

1997-07-01

The success of the US display industry, both in providing high-performance displays for the US Department of Defense at reasonable cost and in capturing a significant share of the global civilian market, depends on maintaining technological leadership and on building efficient manufacturing capabilities. The US Display Consortium (USDC) was set up in 1993 by the US Government and private industry to guide the development of the infrastructure needed to support the manufacturing of flat panel displays. This mainly involves the supply of equipment and materials, but also includes the formation of partnerships and the training of a skilled labor force. Examples are given of successful development projects, some involving USDC participation, others through independent efforts of its member companies. These examples show that US-based companies can achieve leadership positions in this young and rapidly growing global market.

Design and prototype of an augmented reality display with per-pixel mutual occlusion capability.

Science.gov (United States)

Wilson, Austin; Hua, Hong

2017-11-27

State-of-the-art optical see-through head-mounted displays for augmented reality (AR) applications lack mutual occlusion capability, which refers to the ability to render correct light blocking relationship when merging digital and physical objects, such that the virtual views appear to be ghost-like and lack realistic appearance. In this paper, using off-the-shelf optical components, we present the design and prototype of an AR display which is capable of rendering per-pixel mutual occlusion. Our prototype utilizes a miniature organic light emitting display coupled with a liquid crystal on silicon type spatial light modulator to achieve an occlusion capable AR display offering a 30° diagonal field of view and an angular resolution of 1.24 arcminutes, with an optical performance of > 0.4 contrast over the full field at the Nquist frequency of 24.2 cycles/degree. We experimentally demonstrate a monocular prototype achieving >100:1 dynamic range in well-lighted environments.

The Mobility Enhancement of Indium Gallium Zinc Oxide Transistors via Low-temperature Crystallization using a Tantalum Catalytic Layer

OpenAIRE

Shin, Yeonwoo; Kim, Sang Tae; Kim, Kuntae; Kim, Mi Young; Oh, Saeroonter; Jeong, Jae Kyeong

2017-01-01

High-mobility indium gallium zinc oxide (IGZO) thin-film transistors (TFTs) are achieved through low-temperature crystallization enabled via a reaction with a transition metal catalytic layer. For conventional amorphous IGZO TFTs, the active layer crystallizes at thermal annealing temperatures of 600??C or higher, which is not suitable for displays using a glass substrate. The crystallization temperature is reduced when in contact with a Ta layer, where partial crystallization at the IGZO bac...

Yb3+:Sr3Y2(BO3)4: A potential ultrashort pulse laser crystal

International Nuclear Information System (INIS)

Sun, Shijia; Xu, Jinlong; Wei, Qi; Lou, Fei; Huang, Yisheng; Yuan, Feifei; Zhang, Lizhen; Lin, Zhoubin; He, Jingliang; Wang, Guofu

2015-01-01

Highlights: • A Yb 3+ :Sr 3 Y 2 (BO 3 ) 4 crystal was grown successfully by Czochralski method. • The crystal has wide absorption and emission bandwidth. • 3.47 W continuous wave laser output with a slope efficiency of 29% was obtained. • The results show that the crystal is a promising ultrashort pulse laser material. - Abstract: A Yb 3+ :Sr 3 Y 2 (BO 3 ) 4 crystal was grown successfully by the Czochralski method. The polarized spectral properties and continuous wave laser output of this crystal were investigated in detail. The crystal has larger absorption and emission cross sections compared with many mature Yb 3+ -doped borate crystals. The full width at half maximum of the emission bands around 1023 nm are 69 nm (E//a), 61 nm (E//b) and 65 nm (E//c). 3.47 W continuous wave laser output with a slope efficiency of 29% and an optical conversion efficiency of 24% was obtained. The results reveal that Yb 3+ :Sr 3 Y 2 (BO 3 ) 4 crystal is an excellent candidate for ultrashort pulse laser crystal

Growth of emerald single crystals

International Nuclear Information System (INIS)

Bukin, G.V.; Godovikov, A.A.; Klyakin, V.A.; Sobolev, V.S.

1986-01-01

In addition to its use for jewelry, emerald can also be used in low-noise microwave amplifiers. The authors discuss flux crystallization of emerald and note that when emerald is grown by this method, it is desirable to use solvents which dissolve emerald with minimum deviations from congruence but at the same time with sufficient high efficiency. Emerald synthesis and crystal growth from slowly cooled solutions is discussed as another possibility. The techniques are examined. Vapor synthesis and growht of beryl crystals re reviewed and the authors experimentally study the seeded CVD crystallization of beryl from BeO, Al 2 O 3 and SiO 2 oxides, by using complex compounds as carrier agents. The color of crystals of emerald and other varieties of beryl is detemined by slelective light absorption in teh visible part of the spectrum and depends on the density and structural positions of chromphore ions: chromium, iron, vanadium, nickel, manganese and cobalt

The Effect of Thermal Cycling on Crystal-Liquid Separation During Lunar Magma Ocean Differentiation

Science.gov (United States)

Mills, Ryan D.

2013-01-01

Differentiation of magma oceans likely involves a mixture of fractional and equilibrium crystallization [1]. The existence of: 1) large volumes of anorthosite in the lunar highlands and 2) the incompatible- rich (KREEP) reservoir suggests that fractional crystallization may have dominated during differentiation of the Moon. For this to have occurred, crystal fractionation must have been remarkably efficient. Several authors [e.g. 2, 3] have hypothesized that equilibrium crystallization would have dominated early in differentiation of magma oceans because of crystal entrainment during turbulent convection. However, recent numerical modeling [4] suggests that crystal settling could have occurred throughout the entire solidification history of the lunar magma ocean if crystals were large and crystal fraction was low. These results indicate that the crystal size distribution could have played an important role in differentiation of the lunar magma ocean. Here, I suggest that thermal cycling from tidal heating during lunar magma ocean crystallization caused crystals to coarsen, leading to efficient crystal-liquid separation.

Application of holographic elements in displays and planar illuminators

Science.gov (United States)

Putilin, Andrew; Gustomiasov, Igor

2007-05-01

Holographic Optical Elements (HOE's) on planar waveguides can be used to design the planar optics for backlit units, color selectors or filters, lenses for virtual reality displays. The several schemes for HOE recording are proposed to obtain planar stereo backlit unit and private eye displays light source. It is shown in the paper that the specific light transformation grating permits to construct efficient backlit units for display holograms and LCD. Several schemes of reflection/transmission backlit units and scattering films based on holographic optical elements are also proposed. The performance of the waveguide HOE can be optimized using the parameters of recording scheme and etching parameters. The schemes of HOE application are discussed and some experimental results are shown.

Automating the application of smart materials for protein crystallization.

Science.gov (United States)

Khurshid, Sahir; Govada, Lata; El-Sharif, Hazim F; Reddy, Subrayal M; Chayen, Naomi E

2015-03-01

The fabrication and validation of the first semi-liquid nonprotein nucleating agent to be administered automatically to crystallization trials is reported. This research builds upon prior demonstration of the suitability of molecularly imprinted polymers (MIPs; known as `smart materials') for inducing protein crystal growth. Modified MIPs of altered texture suitable for high-throughput trials are demonstrated to improve crystal quality and to increase the probability of success when screening for suitable crystallization conditions. The application of these materials is simple, time-efficient and will provide a potent tool for structural biologists embarking on crystallization trials.

Epitope selection from an uncensored peptide library displayed on avian leukosis virus

International Nuclear Information System (INIS)

Khare, Pranay D.; Rosales, Ana G.; Bailey, Kent R.; Russell, Stephen J.; Federspiel, Mark J.

2003-01-01

Phage display libraries have provided an extraordinarily versatile technology to facilitate the isolation of peptides, growth factors, single chain antibodies, and enzymes with desired binding specificities or enzymatic activities. The overall diversity of peptides in phage display libraries can be significantly limited by Escherichia coli protein folding and processing machinery, which result in sequence censorship. To achieve an optimal diversity of displayed eukaryotic peptides, the library should be produced in the endoplasmic reticulum of eukaryotic cells using a eukaryotic display platform. In the accompanying article, we presented experiments that demonstrate that polypeptides of various sizes could be efficiently displayed on the envelope glycoproteins of a eukaryotic virus, avian leukosis virus (ALV), and the displayed polypeptides could efficiently attach to cognate receptors without interfering with viral attachment and entry into susceptible cells. In this study, methods were developed to construct a model library of randomized eight amino acid peptides using the ALV eukaryotic display platform and screen the library for specific epitopes using immobilized antibodies. A virus library with approximately 2 x 10 6 different members was generated from a plasmid library of approximately 5 x 10 6 diversity. The sequences of the randomized 24 nucleotide/eight amino acid regions of representatives of the plasmid and virus libraries were analyzed. No significant sequence censorship was observed in producing the virus display library from the plasmid library. Different populations of peptide epitopes were selected from the virus library when different monoclonal antibodies were used as the target. The results of these two studies clearly demonstrate the potential of ALV as a eukaryotic platform for the display and selection of eukaryotic polypeptides libraries

Efficient production of D-tagatose using a food-grade surface display system.

Science.gov (United States)

Liu, Yi; Li, Sha; Xu, Hong; Wu, Lingtian; Xu, Zheng; Liu, Jing; Feng, Xiaohai

2014-07-16

D-tagatose, a functional sweetener, is commonly transformed from D-galactose by L-arabinose isomerase (L-AI). In this study, a novel type of biocatalyst, L-AI from Lactobacillus fermentum CGMCC2921 displayed on the spore surface of Bacillus subtilis 168, was developed for producing D-tagatose. The anchored L-AI, exhibiting the relatively high bioactivity, suggested that the surface display system using CotX as the anchoring protein was successfully constructed. The stability of the anchored L-AI was significantly improved. Specifically, the consolidation of thermal stability representing 87% of relative activity was retained even at 80 °C for 30 min, which remarkably favored the production of D-tagatose. Under the optimal conditions, the robust spores can convert 75% D-galactose (100 g/L) into D-tagatose after 24 h, and the conversion rate remained at 56% at the third cycle. Therefore, this biocatalysis system, which could express the target enzyme on the food-grade vector, was an alternative method for the value-added production of D-tagatose.

Extremely efficient crystallization of HKUST-1 and Keggin-loaded related phases through the epoxide route.

Science.gov (United States)

Oestreicher, Víctor; Jobbágy, Matías

2017-03-25

Highly crystalline HKUST-1 and COK-16-like phases were obtained based on a mild in situ alkalinization one-pot epoxide driven method. A slurry composed of finely ground trimesic acid, H 3 BTC, dispersed in a CuCl 2 aqueous solution quantitatively developed well crystallized HKUST-1 after the addition of propylene oxide. The use of solid H 3 BTC ensures a low concentration of free linker, favoring crystalline growth over the precipitation of amorphous or metastable impurities. An extreme space-time yield of 2.1 × 10 5 kg m -3 day -1 was reached, with no linker excess and minimum use of solvent. The method was equally efficient in the achievement of pure NENU/COK-16 phases, containing [PW 12 O 40 ] 3- , [PMo 12 O 40 ] 3- and [SiMo 12 O 40 ] 4- polyoxometalates.

Adoption of energy-efficient televisions for expanded off-grid electricity service

Directory of Open Access Journals (Sweden)

Won Young Park

Full Text Available Even though they dominate the global television (TV market, light-emitting diode backlit liquid crystal display (LED-LCD TVs have received little attention for use with off-grid household-scale renewable energy systems, primarily because of high up-front costs. However, technological advances and price declines mean that these TVs can now provide the same level of electricity service as standard LED-LCD TVs offer but at lower total energy cost. Moreover, LED-LCD TVs are inherently direct-current (DC-powered devices and therefore well suited for use with off-grid solar home systems. We estimate that DC-powered energy-efficient LED-LCD TVs can decrease the retail purchase price of solar home systems by about 25% by allowing use of 50% smaller photovoltaics and battery capacities than would be needed for the same energy system to power a standard LED-LCD TV. We recommend that policies such as awards, bulk procurement, incentives, and energy labels be considered to facilitate the adoption of these energy-efficient TVs in off-grid settings. Keywords: DC television, TV energy efficiency, Electricity access, Off-grid electricity service, Cost-benefit analysis

Design of retinal-projection-based near-eye display with contact lens.

Science.gov (United States)

Wu, Yuhang; Chen, Chao Ping; Mi, Lantian; Zhang, Wenbo; Zhao, Jingxin; Lu, Yifan; Guo, Weiqian; Yu, Bing; Li, Yang; Maitlo, Nizamuddin

2018-04-30

We propose a design of a retinal-projection-based near-eye display for achieving ultra-large field of view, vision correction, and occlusion. Our solution is highlighted by a contact lens combo, a transparent organic light-emitting diode panel, and a twisted nematic liquid crystal panel. Its design rules are set forth in detail, followed by the results and discussion regarding the field of view, angular resolution, modulation transfer function, contrast ratio, distortion, and simulated imaging.

Computer-generated holographic near-eye display system based on LCoS phase only modulator

Science.gov (United States)

Sun, Peng; Chang, Shengqian; Zhang, Siman; Xie, Ting; Li, Huaye; Liu, Siqi; Wang, Chang; Tao, Xiao; Zheng, Zhenrong

2017-09-01

Augmented reality (AR) technology has been applied in various areas, such as large-scale manufacturing, national defense, healthcare, movie and mass media and so on. An important way to realize AR display is using computer-generated hologram (CGH), which is accompanied by low image quality and heavy computing defects. Meanwhile, the diffraction of Liquid Crystal on Silicon (LCoS) has a negative effect on image quality. In this paper, a modified algorithm based on traditional Gerchberg-Saxton (GS) algorithm was proposed to improve the image quality, and new method to establish experimental system was used to broaden field of view (FOV). In the experiment, undesired zero-order diffracted light was eliminated and high definition 2D image was acquired with FOV broadened to 36.1 degree. We have also done some pilot research in 3D reconstruction with tomography algorithm based on Fresnel diffraction. With the same experimental system, experimental results demonstrate the feasibility of 3D reconstruction. These modifications are effective and efficient, and may provide a better solution in AR realization.

Research on tactical information display technology for interactive virtual cockpit

Science.gov (United States)

Sun, Zhongyun; Tian, Tao; Su, Feng

2018-04-01

Based on a fact that traditional tactical information display technology suffers from disadvantages of a large number of data to be transferred and low plotting efficiency in an interactive virtual cockpit, a GID protocol-based simulation has been designed. This method dissolves complex tactical information screens into basic plotting units. The indication of plotting units is controlled via the plotting commands, which solves the incompatibility between the tactical information display in traditional simulation and the desktop-based virtual simulation training system. Having been used in desktop systems for helicopters, fighters, and transporters, this method proves to be scientific and reasonable in design and simple and efficient in usage, which exerts a significant value in establishing aviation equipment technology support training products.

Atom interaction propensities of oxygenated chemical functions in crystal packings

Directory of Open Access Journals (Sweden)

Christian Jelsch

2017-03-01

Full Text Available The crystal contacts of several families of hydrocarbon compounds substituted with one or several types of oxygenated chemical groups were analyzed statistically using the Hirshfeld surface methodology. The propensity of contacts to occur between two chemical types is described with the contact enrichment descriptor. The systematic large enrichment ratios of some interactions like the O—H...O hydrogen bonds suggests that these contacts are a driving force in the crystal packing formation. The same statement holds for the weaker C—H...O hydrogen bonds in ethers, esters and ketones, in the absence of polar H atoms. The over-represented contacts in crystals of oxygenated hydrocarbons are generally of two types: electrostatic attractions (hydrogen bonds and hydrophobic interactions. While Cl...O interactions are generally avoided, in a minority of chloro-oxygenated hydrocarbons, significant halogen bonding does occur. General tendencies can often be derived for many contact types, but outlier compounds are instructive as they display peculiar or rare features. The methodology also allows the detection of outliers which can be structures with errors. For instance, a significant number of hydroxylated molecules displaying over-represented non-favorable oxygen–oxygen contacts turned out to have wrongly oriented hydroxyl groups. Beyond crystal packings with a single molecule in the asymmetric unit, the behavior of water in monohydrate compounds and of crystals with Z′ = 2 (dimers are also investigated. It was found in several cases that, in the presence of several oxygenated chemical groups, cross-interactions between different chemical groups (e.g. water/alcohols; alcohols/phenols are often favored in the crystal packings. While some trends in accordance with common chemical principles are retrieved, some unexpected results can however appear. For example, in crystals of alcohol–phenol compounds, the strong O—H...O hydrogen bonds between

High Thermal Rectifications Using Liquid Crystals Confined into a Conical Frustum

Science.gov (United States)

Silva, José Guilherme; Fumeron, Sébastien; Moraes, Fernando; Pereira, Erms

2018-05-01

In recent years, phononics, that studies thermal analogs of electronic devices, has become an important subject due to the need for better use of energy resources influenced by growing demand. On developing of these analogs, for example, thermal diodes, a successful route is the design of nanostructured materials (e.g., carbon nanotubes). However, these materials entail increased costs due to the use of complex techniques/equipments, while alternative cheaper materials present nearly comparable efficiency. In this work, we investigate how a thermal diode made by an alternative material (nematic liquid crystal), confined in a conical frustum capillary, can be optimized to achieve high rectifications. In such capillary tube, the thermotropic nematic liquid crystal 5CB produces an axially anisotropic defect called escaped radial disclination. With the molecular director field of such structure, we obtain the thermal conductivity tensor of the diode and solve the steady-state regime of Laplace and Fourier equations using the finite element method. We observed the anisotropy of the system with the non-linear temperature dependences of the molecular thermal conductivities that rectify the heat flux at rates up to 1266% at room temperature. Studying the sensitivity of the system with respect to shape and molecular and thermal aspects, we found that the improved thermal diode is suitable to be miniaturized and applied on well-determined areas, and it is robust against variations of the inward pumped heat flux. This work contributes to the usage of liquid crystals in non-display devices, having potential applications on controlling the heat flux through surfaces.

University of Nevada Las Vegas LED Display Engineering

Energy Technology Data Exchange (ETDEWEB)

None

2010-08-31

The primary objective of this part of the project is to develop and implement a method that compensates for the inefficiency of the green LED. The proposed engineering solution which will be the backbone of this project will be to use RGBW combination in every pixel to save energy. Two different RGBW geometrical pixel configurations will be implemented and compared against traditional LED configurations. These configurations will be analyzed for energy efficiency while keeping the quality of the display the same. Cost of the addition of white LEDs to displays along with energy cost savings will be presented and analyzed.

Improving the efficiency and directivity of THz photoconductive antennas by using a defective photonic crystal substrate

Science.gov (United States)

Rahmati, Ehsan; Ahmadi-Boroujeni, Mehdi

2018-04-01

One of the shortcomings of photoconductive (PC) antennas in terahertz (THz) generation is low effective radiated power in the desirable direction. In this paper, we propose a defective photonic crystal (DPC) substrate consisting of a customized 2D array of air holes drilled into a solid substrate in order to improve the radiation characteristics of THz PC antennas. The effect of the proposed structure on the performance of a conventional THz PC antenna has been examined from several aspects including radiation efficiency, directivity, and field distribution. By comparing the radiation performance of the THz antenna on the proposed DPC substrate to that of the conventional solid substrate, it is shown that the proposed technique can significantly improve the efficiency and directivity of the THz PC antenna over a wide frequency range. It is achieved by reducing the amount of power coupled to the substrate surface waves and limiting the radiation in undesirable directions. In addition, it is found that the sensitivity of directivity to the substrate thickness is considerably decreased and the adverse Fabry-Perot effects of the thick substrate are reduced by the application of the proposed DPC substrate.

An experimental and theoretical study of new phosphors for full color field emission displays

Science.gov (United States)

Zhang, Fu-Li

An in depth study is reported of the cathodoluminescent (CL) properties of three new highly efficiency blue phosphors for field emission display (FED) applications doped with fast activators. The superior performance of a new Eu-doped green SrGa2S4 will also be reported. This work addresses four main topics: (1) a detailed study of the dependence of the luminescent intensity on activator concentration, as a function of electron beam voltage and current density; (2) the optical properties of thew phosphors and the development of a CL efficiency characterization technique using a critical screen weight method, which can obtain maximum light output and improve measurement accuracy; (3) understanding the low voltage CL mechanism associated with nanocrystal size by developing a thin film and disk model based on transportation theory and experimental results; (4) Development of a comprehensive evaluation method of red, green, and blue (RGB) phosphors for full color displays by calculation of luminance ratios, required luminance, and measurements of spectra, efficiency and saturation behavior. For FEDs which combine the best properties of CRT and flat panel displays, the development of efficient phosphors at low voltages and high current densities is shown to be critical to meet the luminance and power requirement demands for portable displays. Of particular importance is the need for a good blue phosphor, and to understand the dependence of the CL efficiency on nanocrystal size, penetration depth, diffusion length and surface recombination rate. This has been obtained from the thin film and disk models and fits to experiment. Comparisons between full color phosphor sets show that the performance of a display can vary by over a factor of three depending on the choice of the RGB set. Other factors that are important for optimizing the performance of FED phosphors are reviewed.

Nonlinear and quantum optics with liquid crystals

International Nuclear Information System (INIS)

Lukishova, Svetlana G

2014-01-01

Thermotropic liquid crystals' usual application is display technology. This paper describes experiments on light interaction with pure and doped liquid crystals under for these materials unconventional incident light powers: (1) under high-power laser irradiation, and (2) at the single-photon level. In (1), I will outline several nonlinear optical effects under high-power, nanosecond laser irradiation which should be taken into account in the design of lasers with liquid crystal components and in fabrication of optical power limiters based on liquid crystals: (1.1) athermal helical pitch dilation and unwinding of cholesteric mirrors (both in free space and inside laser resonators); (1.2) some pitfalls in measurements of refractive nonlinearity using z-scan technique under two-photon or linear absorption of liquids; (1.3) the first observation of thermal lens effects in liquid crystals under several-nanosecond, low-pulse-repetition rate (2-10 Hz) laser irradiation in the presence of two-photon absorption; (1.4) feedback-free kaleidoscope of patterns (hexagons, stripes, etc.) in dye-doped liquid crystals. In (2), at the single-photon level, it will be shown that with a proper selection of liquid crystals and a single-emitter dopant spectral range, liquid crystal structures can be used to control emitted single photons (both polarization and count rate). The application of the latter research is absolutely secure quantum communication with polarization coding of information. In particular, in (2.1), definite handedness, circular polarized cholesteric microcavity resonance in quantum dot fluorescence is reported. In (2.2), definite linear polarization of single (antibunched) photons from single-dye-molecules in planar-aligned nematic host is discussed. In (2.3), some results on photon antibunching from NV-color center in nanodiamond in liquid crystal host and circularly polarized fluorescence of definite handedness from nanocrystals doped with trivalent ions of

Steering of sub-GeV electrons by ultrashort Si and Ge bent crystals

Energy Technology Data Exchange (ETDEWEB)

Sytov, A.I. [Ferrara Univ. (Italy). Dipt. di Fisica e Scienze della Terra; Belarusian State Univ., Minsk (Belarus). Inst. for Nuclear Problems; INFN Sezione di Ferrara (Italy); Bandiera, L.; Mazzolari, A.; Bagli, E.; Germogli, G.; Guidi, V.; Romagnoni, M. [Ferrara Univ. (Italy). Dipt. di Fisica e Scienze della Terra; INFN Sezione di Ferrara (Italy); De Salvador, D.; Carturan, S.; Maggioni, G. [INFN, Laboratori Nazionali di Legnaro (Italy); Padova Univ. (Italy). Dipt. di Fisica; Berra, A.; Prest, M. [Univ. dell' Insubria, Como (Italy); INFN, Sezione di Milano Bicocca, Milan (Italy); Durighello, C. [Ferrara Univ. (Italy). Dipt. di Fisica e Scienze della Terra; INFN, Laboratori Nazionali di Legnaro (Italy); Padova Univ. (Italy). Dipt. di Fisica; INFN Sezione di Ferrara (Italy); Klag, P.; Lauth, W. [Mainz Univ. (Germany). Inst. fuer Kernphysik; Tikhomirov, V.V. [Belarusian State Univ., Minsk (Belarus). Inst. for Nuclear Problems; Vallazza, E. [INFN, Sezione di Trieste (Italy)

2017-12-15

We report the observation of the steering of 855 MeV electrons by bent silicon and germanium crystals at the MAinzer MIkrotron. Crystals with 15 μm of length, bent along (111) planes, were exploited to investigate orientational coherent effects. By using a piezo-actuated mechanical holder, which allowed to remotely change the crystal curvature, it was possible to study the steering capability of planar channeling and volume reflection vs. the curvature radius and the atomic number, Z. For silicon, the channeling efficiency exceeds 35%, a record for negatively charged particles. This was possible due to the realization of a crystal with a thickness of the order of the dechanneling length. On the other hand, for germanium the efficiency is slightly below 10% due to the stronger contribution of multiple scattering for a higher-Z material. Nevertheless this is the first evidence of negative beam steering by planar channeling in a Ge crystal. Having determined for the first time the dechanneling length, one may design a Ge crystal based on such knowledge providing nearly the same channeling efficiency of silicon. The presented results are relevant for crystal-based beam manipulation as well as for the generation of e.m. radiation in bent and periodically bent crystals. (orig.)

Steering of Sub-GeV electrons by ultrashort Si and Ge bent crystals

Science.gov (United States)

Sytov, A. I.; Bandiera, L.; De Salvador, D.; Mazzolari, A.; Bagli, E.; Berra, A.; Carturan, S.; Durighello, C.; Germogli, G.; Guidi, V.; Klag, P.; Lauth, W.; Maggioni, G.; Prest, M.; Romagnoni, M.; Tikhomirov, V. V.; Vallazza, E.

2017-12-01

We report the observation of the steering of 855 MeV electrons by bent silicon and germanium crystals at the MAinzer MIkrotron. Crystals with 15 μ m of length, bent along (111) planes, were exploited to investigate orientational coherent effects. By using a piezo-actuated mechanical holder, which allowed to remotely change the crystal curvature, it was possible to study the steering capability of planar channeling and volume reflection vs. the curvature radius and the atomic number, Z. For silicon, the channeling efficiency exceeds 35%, a record for negatively charged particles. This was possible due to the realization of a crystal with a thickness of the order of the dechanneling length. On the other hand, for germanium the efficiency is slightly below 10% due to the stronger contribution of multiple scattering for a higher-Z material. Nevertheless this is the first evidence of negative beam steering by planar channeling in a Ge crystal. Having determined for the first time the dechanneling length, one may design a Ge crystal based on such knowledge providing nearly the same channeling efficiency of silicon. The presented results are relevant for crystal-based beam manipulation as well as for the generation of e.m. radiation in bent and periodically bent crystals.

Web data display system based on data segment technology of MDSplus

International Nuclear Information System (INIS)

Liu Rui; Zhang Ming; Wen Chuqiao; Zheng Wei; Zhuang Ge; Yu Kexun

2014-01-01

Long pulse operation is the main character of advanced Tokamak, so the technology of data storage and human-data interaction are vital for dealing with the large data generated in long pulse experiment. The Web data display system was designed. The system is based on the ASP. NET architecture, and it reads segmented-record data from MDSplus database by segmented-record technology and displays the data on Web page by using NI Measurement Studio control library. With the segmented-record technology, long pulse data could be divided into many small units, data segments. Users can read the certain data segments from the long pulse data according to their special needs. Also, the system develops an efficient strategy for reading segmented record data, showing the waveforms required by users accurately and quickly. The data display Web system was tested on J-TEXT Tokamak, and was proved to be reliable and efficient to achieve the initial design goal. (authors)

Transparent Solar Concentrator for Flat Panel Display

Science.gov (United States)

Yeh, Chia-Hung; Chang, Fuh-Yu; Young, Hong-Tsu; Hsieh, Tsung-Yen; Chang, Chia-Hsiung

2012-06-01

A new concept of the transparent solar concentrator for flat panel display is experimentally demonstrated without adversely affecting the visual effects. The solar concentrator is based on a solar light-guide plate with micro prisms, not only increasing the absorption area of solar energy but also enhancing the conversion efficiency. The incident light is guided by the designed solar light-guide plate according to the total internal reflection (TIR), and converted into electrical power by photovoltaic solar cells. The designed transparent solar concentrator was made and measured with high transparency, namely 94.8%. The developed solar energy system for display can store energy and supply the bias voltage to light on two light-emitting diodes (LEDs) successfully.

Efficient continuous-wave and passively Q-switched pulse laser operations in a diffusion-bonded sapphire/Er:Yb:YAl3(BO3)4/sapphire composite crystal around 1.55 μm.

Science.gov (United States)

Chen, Yujin; Lin, Yanfu; Huang, Jianhua; Gong, Xinghong; Luo, Zundu; Huang, Yidong

2018-01-08

A composite crystal consisting of a 1.5-mm-thick Er:Yb:YAl 3 (BO 3 ) 4 crystal between two 1.2-mm-thick sapphire crystals was fabricated by the thermal diffusion bonding technique. Compared with a lone Er:Yb:YAl 3 (BO 3 ) 4 crystal measured under the identical experimental conditions, higher laser performances were demonstrated in the sapphire/Er:Yb:YAl 3 (BO 3 ) 4 /sapphire composite crystal due to the reduction of the thermal effects. End-pumped by a 976 nm laser diode in a hemispherical cavity, a 1.55 μm continuous-wave laser with a maximum output power of 1.75 W and a slope efficiency of 36% was obtained in the composite crystal when the incident pump power was 6.54 W. Passively Q-switched by a Co 2+ :MgAl 2 O 4 crystal, a 1.52 μm pulse laser with energy of 10 μJ and repetition frequency of 105 kHz was also realized in the composite crystal. Pulse width was 315 ns. The results show that the sapphire/Er:Yb:YAl 3 (BO 3 ) 4 /sapphire composite crystal is an excellent active element for 1.55 μm laser.

Feasibility study on the use of liquid crystal/dye cells for digital signage

Science.gov (United States)

Itaya, Shunsuke; Azumi, Nada Dianah B. M.; Ohta, Masamichi; Ozawa, Shintaro; Fujieda, Ichiro

2016-03-01

Elongated dye molecules orient themselves with surrounding liquid crystal molecules. We propose to incorporate such a guest-host cell in a screen of a projection display. This configuration might be applied for digital signage to be installed on building walls. Dual-mode operation is realized by the bias applied to the cell. In display-mode, the dye molecules are oriented in parallel to the substrate of the cell. When excited by ultra-violet light, photoluminescence (PL) is generated. Because it is mostly perpendicular to the long axis of the molecule, it exits the cell efficiently. In powerharvesting mode, they are oriented vertically. The PL generated by ambient light is directed to edge surfaces where solar cells are mounted. In experiment, we fabricated a cell with commonly-available materials (coumarin 6 and a nematic liquid crystal). Anti-parallel alignment condition was adopted. We recorded PL spectra from the cell for the two excitation conditions. First, the center of the cell was irradiated by a 1.69mW blue laser beam. Second, the whole cell was uniformly exposed to the light from a fluorescent lamp at illuminance of 800lx. From the measured spectra for these cases, the contrast of luminance is calculated to be 3.2 ×105 . This factor is improved to 5 7.5×105 by attaching a polarizer sheet on the cell surface. The optical power reaching its edge surfaces is measured and it roughly agrees with the prediction by a simple model neglecting self-absorption. Development of phosphor materials with a large Stokes shift is desired to boost performance of the proposed system.

Digital Display Integration Project Project Online 2.0

International Nuclear Information System (INIS)

Bardsley, J. N.

1999-01-01

transfer; and optimizing techniques to reduce communications bandwidth. Additional topics that will be addressed include: obtaining greater color control; minimization of seam widths in tiled displays; and the human factors that impact the efficient use of high resolution displays. The scope of the project will include both direct-view displays, for use by individuals and small groups, and projection systems for conference rooms and auditoriums

Status of UA9, the Crystal Collimation Experiment in the SPS

CERN Document Server

Scandale, W

2011-01-01

UA9 was operated at the CERN-SPS for more than two years to investigate the feasibility of halo collimation with bent crystals. Silicon crystals 2 mm long with bending angles of about 170 μrad were used as primary collimators. The crystal collimation process was steadily achieved through channeling, with high efficiency. The crystal orientation was easily set and optimized with an installed goniometer that has an angular accuracy of about ± 10 μrad. In channeling orientation, the loss rate of the halo particles interacting with the crystal is reduced by half an order of magnitude, whilst the residual off momentum halo escaping from the crystal-collimator area is reduced by a factor two to five. The crystal channeling efficiency of about 75% is reasonably consistent with simulations and with single pass data collected in the extracted proton beam of the SPS North Experimental Area. The accumulated observations, shown in this paper, support our expectation that the coherent deflection of the beam halo by a b...

Digested livestock wastewater treatment using gamma-ray irradiation and struvite crystallization

International Nuclear Information System (INIS)

Kim, Tak Hyun; Lee, Sang Ryul; Nam, Youn Ku; Lee, Myun Joo

2009-01-01

Livestock wastewater generally contains high strength of organics (COD), ammonia nitrogen (NH 4 + -N), phosphate phosphorus (PO 4 3- -P) and suspended solids. It is very difficult to treat by conventional wastewater treatment techniques. In this study, struvite crystallization was carried out to treat the digested livestock wastewater. 1.0 :1.2 :1.2 was determined as an optimal NH 4 + :Mg 2+ : PO 4 3- mol ratio of struvite crystallization. For the digested livestock wastewater, COD, NH 4 + -N and PO 4 3- -P removal efficiencies by struvite crystallization were 72.4%, 98.9%, and 74.8%, respectively. Gamma-ray irradiation was carried out prior to struvite crystallization of livestock wastewater. The enhancement of struvite crystallization efficiency could be obtained by the pretreatment of gamma-ray irradiation due to the decrease of COD, NH 4 + -N and PO 4 3- -P concentration

Common display performance requirements for military and commercial aircraft product lines

Science.gov (United States)

Hoener, Steven J.; Behrens, Arthur J.; Flint, John R.; Jacobsen, Alan R.

2001-09-01

Obtaining high quality Active Matrix Liquid Crystal (AMLCD) glass to meet the needs of the commercial and military aerospace business is a major challenge, at best. With the demise of all domestic sources of AMLCD substrate glass, the industry is now focused on overseas sources, which are primarily producing glass for consumer electronics. Previous experience with ruggedizing commercial glass leads to the expectation that the aerospace industry can leverage off the commercial market. The problem remains, while the commercial industry is continually changing and improving its products, the commercial and military aerospace industries require stable and affordable supplies of AMLCD glass for upwards of 20 years to support production and maintenance operations. The Boeing Engineering and Supplier Management Process Councils have chartered a group of displays experts from multiple aircraft product divisions within the Boeing Company, the Displays Process Action Team (DPAT), to address this situation from an overall corporate perspective. The DPAT has formulated a set of Common Displays Performance Requirements for use across the corporate line of commercial and military aircraft products. Though focused on the AMLCD problem, the proposed common requirements are largely independent of display technology. This paper describes the strategy being pursued within the Boeing Company to address the AMLCD supply problem and details the proposed implementation process, centered on common requirements for both commercial and military aircraft displays. Highlighted in this paper are proposed common, or standard, display sizes and the other major requirements established by the DPAT, along with the rationale for these requirements.

Improving Light Extraction of Organic Light-Emitting Devices by Attaching Nanostructures with Self-Assembled Photonic Crystal Patterns

Directory of Open Access Journals (Sweden)

Kai-Yu Peng

2014-01-01

Full Text Available A single-monolayered hexagonal self-assembled photonic crystal (PC pattern fabricated onto polyethylene terephthalate (PET films by using simple nanosphere lithography (NSL method has been demonstrated in this research work. The patterned nanostructures acted as a scattering medium to extract the trapped photons from substrate mode of optical-electronic device for improving the overall external quantum efficiency of the organic light-emitting diodes (OLEDs. With an optimum latex concentration, the distribution of self-assembled polystyrene (PS nanosphere patterns on PET films can be easily controlled by adjusting the rotation speed of spin-coater. After attaching the PS nanosphere array brightness enhancement film (BEF sheet as a photonic crystal pattern onto the device, the luminous intensity of OLEDs in the normal viewing direction is 161% higher than the one without any BEF attachment. The electroluminescent (EL spectrum of OLEDs with PS patterned BEF attachment also showed minor color offset and superior color stabilization characteristics, and thus it possessed the potential applications in all kinds of display technology and solid-state optical-electronic devices.

Clinical evaluation of a medical high dynamic range display

International Nuclear Information System (INIS)

Marchessoux, Cedric; Paepe, Lode de; Vanovermeire, Olivier; Albani, Luigi

2016-01-01

Purpose: Recent new medical displays do have higher contrast and higher luminance but do not have a High Dynamic Range (HDR). HDR implies a minimum luminance value close to zero. A medical HDR display prototype based on two Liquid Crystal layers has been developed. The goal of this study is to evaluate the potential clinical benefit of such display in comparison with a low dynamic range (LDR) display. Methods: The study evaluated the clinical performance of the displays in a search and detection task. Eight radiologists read chest x-ray images some of which contained simulated lung nodules. The study used a JAFROC (Jacknife Free Receiver Operating Characteristic) approach for analyzing FROC data. The calculated figure of merit (FoM) is the probability that a lesion is rated higher than all rated nonlesions on all images. Time per case and accuracy for locating the center of the nodules were also compared. The nodules were simulated using Samei’s model. 214 CR and DR images [half were “healthy images” (chest nodule-free) and half “diseased images”] were used resulting in a total number of nodules equal to 199 with 25 images with 1 nodule, 51 images with 2 nodules, and 24 images with 3 nodules. A dedicated software interface was designed for visualizing the images for each session. For the JAFROC1 statistical analysis, the study is done per nodule category: all nodules, difficult nodules, and very difficult nodules. Results: For all nodules, the averaged FoM HDR is slightly higher than FoM LDR with 0.09% of difference. For the difficult nodules, the averaged FoM HDR is slightly higher than FoM LDR with 1.38% of difference. The averaged FoM HDR is slightly higher than FoM LDR with 0.71% of difference. For the true positive fraction (TPF), both displays (the HDR and the LDR ones) have similar TPF for all nodules, but looking at difficult and very difficult nodules, there are more TP for the HDR display. The true positive fraction has been also computed in

Anomalous transparency in photonic crystals and its application to point-by-point grating inscription in photonic crystal fibers.

Science.gov (United States)

Baghdasaryan, Tigran; Geernaert, Thomas; Chah, Karima; Caucheteur, Christophe; Schuster, Kay; Kobelke, Jens; Thienpont, Hugo; Berghmans, Francis

2018-04-03

It is common belief that photonic crystals behave similarly to isotropic and transparent media only when their feature sizes are much smaller than the wavelength of light. Here, we counter that belief and we report on photonic crystals that are transparent for anomalously high normalized frequencies up to 0.9, where the crystal's feature sizes are comparable with the free space wavelength. Using traditional photonic band theory, we demonstrate that the isofrequency curves can be circular in the region above the first stop band for triangular lattice photonic crystals. In addition, by simulating how efficiently a tightly focused Gaussian beam propagates through the photonic crystal slab, we judge on the photonic crystal's transparency rather than on isotropy only. Using this approach, we identified a wide range of photonic crystal parameters that provide anomalous transparency. Our findings indicate the possibility to scale up the features of photonic crystals and to extend their operational wavelength range for applications including optical cloaking and graded index guiding. We applied our result in the domain of femtosecond laser micromachining, by demonstrating what we believe to be the first point-by-point grating inscribed in a multi-ring photonic crystal fiber.

Downstream Processability of Crystal Habit-Modified Active Pharmaceutical Ingredient

DEFF Research Database (Denmark)

Pudasaini, Nawin; Upadhyay, Pratik Pankaj; Parker, Christian Richard

2017-01-01

Efficient downstream processing of active pharmaceutical ingredients (APIs) can depend strongly on their particulate properties, such as size and shape distributions. Especially in drug products with high API content, needle-like crystal habit of an API may show compromised flowability and tablet......Efficient downstream processing of active pharmaceutical ingredients (APIs) can depend strongly on their particulate properties, such as size and shape distributions. Especially in drug products with high API content, needle-like crystal habit of an API may show compromised flowability...

Self-standing quasi-mosaic crystals for focusing hard X-rays

International Nuclear Information System (INIS)

Camattari, Riccardo; Guidi, Vincenzo; Bellucci, Valerio; Neri, Ilaria; Frontera, Filippo; Jentschel, Michael

2013-01-01

A quasi mosaic bent crystal for high-resolution diffraction of X and γ rays has been realized. A net curvature was imprinted to the crystal thanks to a series of superficial grooves to keep the curvature without external devices. The crystal highlights very high diffraction efficiency due to quasi mosaic curvature. Quasi mosaic crystals of this kind are proposed for the realization of a high-resolution focusing Laue lens for hard X-rays.

Hydrothermal Growth of Polyscale Crystals

Science.gov (United States)

Byrappa, Kullaiah

In this chapter, the importance of the hydrothermal technique for growth of polyscale crystals is discussed with reference to its efficiency in synthesizing high-quality crystals of various sizes for modern technological applications. The historical development of the hydrothermal technique is briefly discussed, to show its evolution over time. Also some of the important types of apparatus used in routine hydrothermal research, including the continuous production of nanosize crystals, are discussed. The latest trends in the hydrothermal growth of crystals, such as thermodynamic modeling and understanding of the solution chemistry, are elucidated with appropriate examples. The growth of some selected bulk, fine, and nanosized crystals of current technological significance, such as quartz, aluminum and gallium berlinites, calcite, gemstones, rare-earth vanadates, electroceramic titanates, and carbon polymorphs, is discussed in detail. Future trends in the hydrothermal technique, required to meet the challenges of fast-growing demand for materials in various technological fields, are described. At the end of this chapter, an Appendix 18.A containing a more or less complete list of the characteristic families of crystals synthesized by the hydrothermal technique is given with the solvent and pressure-temperature (PT) conditions used in their synthesis.

Photonic quasi-crystal terahertz lasers

Science.gov (United States)

Vitiello, Miriam Serena; Nobile, Michele; Ronzani, Alberto; Tredicucci, Alessandro; Castellano, Fabrizio; Talora, Valerio; Li, Lianhe; Linfield, Edmund H.; Davies, A. Giles

2014-12-01

Quasi-crystal structures do not present a full spatial periodicity but are nevertheless constructed starting from deterministic generation rules. When made of different dielectric materials, they often possess fascinating optical properties, which lie between those of periodic photonic crystals and those of a random arrangement of scatterers. Indeed, they can support extended band-like states with pseudogaps in the energy spectrum, but lacking translational invariance, they also intrinsically feature a pattern of ‘defects’, which can give rise to critically localized modes confined in space, similar to Anderson modes in random structures. If used as laser resonators, photonic quasi-crystals open up design possibilities that are simply not possible in a conventional periodic photonic crystal. In this letter, we exploit the concept of a 2D photonic quasi crystal in an electrically injected laser; specifically, we pattern the top surface of a terahertz quantum-cascade laser with a Penrose tiling of pentagonal rotational symmetry, reaching 0.1-0.2% wall-plug efficiencies and 65 mW peak output powers with characteristic surface-emitting conical beam profiles, result of the rich quasi-crystal Fourier spectrum.

Optimized dipole antennas on photonic band gap crystals

International Nuclear Information System (INIS)

Cheng, S.D.; Biswas, R.; Ozbay, E.; McCalmont, S.; Tuttle, G.; Ho, K.

1995-01-01

Photonic band gap crystals have been used as a perfectly reflecting substrate for planar dipole antennas in the 12--15 GHz regime. The position, orientation, and driving frequency of the dipole antenna on the photonic band gap crystal surface, have been optimized for antenna performance and directionality. Virtually no radiated power is lost to the photonic crystal resulting in gains and radiation efficiencies larger than antennas on other conventional dielectric substrates. copyright 1995 American Institute of Physics

Control of PbI2 nucleation and crystallization: towards efficient perovskite solar cells based on vapor-assisted solution process

Science.gov (United States)

Yang, Chongqiu; Peng, Yanke; Simon, Terrence; Cui, Tianhong

2018-04-01

Perovskite solar cells (PSC) have outstanding potential to be low-cost, high-efficiency photovoltaic devices. The PSC can be fabricated by numerous techniques; however, the power conversion efficiency (PCE) for the two-step-processed PSC falls behind that of the one-step method. In this work, we investigate the effects of relative humidity (RH) and dry air flow on the lead iodide (PbI2) solution deposition process. We conclude that the quality of the PbI2 film is critical to the development of the perovskite film and the performance of the PSC device. Low RH and dry air flow used during the PbI2 spin coating procedure can increase supersaturation concentration to form denser PbI2 nuclei and a more suitable PbI2 film. Moreover, airflow-assisted PbI2 drying and thermal annealing steps can smooth transformation from the nucleation stage to the crystallization stage.

Expression and display of UreA of Helicobacter acinonychis on the surface of Bacillus subtilis spores

Directory of Open Access Journals (Sweden)

De Felice Maurilio

2010-01-01

Full Text Available Abstract Background The bacterial endospore (spore has recently been proposed as a new surface display system. Antigens and enzymes have been successfully exposed on the surface layers of the Bacillus subtilis spore, but only in a few cases the efficiency of expression and the effective surface display and have been determined. We used this heterologous expression system to produce the A subunit of the urease of the animal pathogen Helicobater acinonychis. Ureases are multi-subunit enzymes with a central role in the virulence of various bacterial pathogens and necessary for colonization of the gastric mucosa by the human pathogen H. pylori. The urease subunit UreA has been recognized as a major antigen, able to induce high levels of protection against challenge infections. Results We expressed UreA from H. acinonychis on the B. subtilis spore coat by using three different spore coat proteins as carriers and compared the efficiency of surface expression and surface display obtained with the three carriers. A combination of western-, dot-blot and immunofluorescence microscopy allowed us to conclude that, when fused to CotB, UreA is displayed on the spore surface (ca. 1 × 103 recombinant molecules per spore, whereas when fused to CotC, although most efficiently expressed (7-15 × 103 recombinant molecules per spore and located in the coat layer, it is not displayed on the surface. Experiments with CotG gave results similar to those with CotC, but the CotG-UreA recombinant protein appeared to be partially processed. Conclusion UreA was efficiently expressed on the spore coat of B. subtilis when fused to CotB, CotC or CotG. Of these three coat proteins CotC allows the highest efficiency of expression, whereas CotB is the most appropriate for the display of heterologous proteins on the spore surface.

Expression and display of UreA of Helicobacter acinonychis on the surface of Bacillus subtilis spores.

Science.gov (United States)

Hinc, Krzysztof; Isticato, Rachele; Dembek, Marcin; Karczewska, Joanna; Iwanicki, Adam; Peszyńska-Sularz, Grazyna; De Felice, Maurilio; Obuchowski, Michał; Ricca, Ezio

2010-01-18

The bacterial endospore (spore) has recently been proposed as a new surface display system. Antigens and enzymes have been successfully exposed on the surface layers of the Bacillus subtilis spore, but only in a few cases the efficiency of expression and the effective surface display and have been determined. We used this heterologous expression system to produce the A subunit of the urease of the animal pathogen Helicobater acinonychis. Ureases are multi-subunit enzymes with a central role in the virulence of various bacterial pathogens and necessary for colonization of the gastric mucosa by the human pathogen H. pylori. The urease subunit UreA has been recognized as a major antigen, able to induce high levels of protection against challenge infections. We expressed UreA from H. acinonychis on the B. subtilis spore coat by using three different spore coat proteins as carriers and compared the efficiency of surface expression and surface display obtained with the three carriers. A combination of western-, dot-blot and immunofluorescence microscopy allowed us to conclude that, when fused to CotB, UreA is displayed on the spore surface (ca. 1 x 10(3) recombinant molecules per spore), whereas when fused to CotC, although most efficiently expressed (7-15 x 10(3) recombinant molecules per spore) and located in the coat layer, it is not displayed on the surface. Experiments with CotG gave results similar to those with CotC, but the CotG-UreA recombinant protein appeared to be partially processed. UreA was efficiently expressed on the spore coat of B. subtilis when fused to CotB, CotC or CotG. Of these three coat proteins CotC allows the highest efficiency of expression, whereas CotB is the most appropriate for the display of heterologous proteins on the spore surface.

Nonlinear mapping of the luminance in dual-layer high dynamic range displays

Science.gov (United States)

Guarnieri, Gabriele; Ramponi, Giovanni; Bonfiglio, Silvio; Albani, Luigi

2009-02-01

It has long been known that the human visual system (HVS) has a nonlinear response to luminance. This nonlinearity can be quantified using the concept of just noticeable difference (JND), which represents the minimum amplitude of a specified test pattern an average observer can discern from a uniform background. The JND depends on the background luminance following a threshold versus intensity (TVI) function. It is possible to define a curve which maps physical luminances into a perceptually linearized domain. This mapping can be used to optimize a digital encoding, by minimizing the visibility of quantization noise. It is also commonly used in medical applications to display images adapting to the characteristics of the display device. High dynamic range (HDR) displays, which are beginning to appear on the market, can display luminance levels outside the range in which most standard mapping curves are defined. In particular, dual-layer LCD displays are able to extend the gamut of luminance offered by conventional liquid crystals towards the black region; in such areas suitable and HVS-compliant luminance transformations need to be determined. In this paper we propose a method, which is primarily targeted to the extension of the DICOM curve used in medical imaging, but also has a more general application. The method can be modified in order to compensate for the ambient light, which can be significantly greater than the black level of an HDR display and consequently reduce the visibility of the details in dark areas.

Synthesis, crystal growth, optical, thermal, and mechanical properties of a nonlinear optical single crystal: ammonium sulfate hydrogen sulphamate (ASHS)

Science.gov (United States)

Sudhakar, K.; Nandhini, S.; Muniyappan, S.; Arumanayagam, T.; Vivek, P.; Murugakoothan, P.

2018-04-01

Ammonium sulfate hydrogen sulphamate (ASHS), an inorganic nonlinear optical crystal, was grown from the aqueous solution by slow evaporation solution growth technique. The single-crystal XRD confirms that the grown single crystal belongs to the orthorhombic system with the space group of Pna21. Powder XRD confirms the crystalline nature and the diffraction planes were indexed. Crystalline perfection of grown crystal was analysed by high-resolution X-ray diffraction rocking curve technique. UV-Vis-NIR studies revealed that ASHS crystal has optical transparency 65% and lower cut-off wavelength at 218 nm. The violet light emission of the crystal was identified by photoluminescence studies. The particle size-dependent second-harmonic generation efficiency for ASHS crystal was evaluated by Kurtz-Perry powder technique using Nd:YAG laser which established the existence of phase matching. Surface laser damage threshold value was evaluated using Nd:YAG laser. Optical homogeneity of the crystal was evaluated using modified channel spectrum method through birefringence study. Thermal analysis reveals that ASHS crystal is stable up to 213 °C. The mechanical behaviour of the ASHS crystal was analysed using Vickers microhardness study.

Recent progress in Bacillus subtilis spore-surface display: concept, progress, and future.

Science.gov (United States)

Wang, He; Wang, Yunxiang; Yang, Ruijin

2017-02-01

With the increased knowledge on spore structure and advances in biotechnology engineering, the newly developed spore-surface display system confers several inherent advantages over other microbial cell-surface display systems including enhanced stability and high safety. Bacillus subtilis is the most commonly used Bacillus species for spore-surface display. The expression of heterologous antigen or protein on the surface of B. subtilis spores has now been practiced for over a decade with noteworthy success. As an update and supplement to other previous reviews, we comprehensively summarize recent studies in the B. subtilis spore-surface display technique. We focus on its benefits as well as the critical factors affecting its display efficiency and offer suggestions for the future success of this field.

Amended Final Report - Antibodies to Radionuclides. Engineering by Surface Display for Immunosensors

Energy Technology Data Exchange (ETDEWEB)

Blake, Diane A. [Tulane Univ., New Orleans, LA (United States)

2013-06-14

The relatively new techniques of antibody display, which permit molecular engineering of antibody structure and function, have the potential to revolutionize the way scientists generate binding proteins for specific applications. However, the skills required to efficiently use antibody display techniques have proven difficult for other laboratories to acquire without hands-on training and exchange of laboratory personnel. This research project is designed bring important expertise in antibody display to the State of Louisiana while pursuing a project with direct relevance to the DOE’s EM program.

Dramatic Improvement of Crystal Quality for Low-temperature-grown Rabbit Muscle Aldolase

Energy Technology Data Exchange (ETDEWEB)

Park, H.; Rangarajan, E; Sygusch, J; Izard, T

2010-01-01

Rabbit muscle aldolase (RMA) was crystallized in complex with the low-complexity domain (LC4) of sorting nexin 9. Monoclinic crystals were obtained at room temperature that displayed large mosaicity and poor X-ray diffraction. However, orthorhombic RMA-LC4 crystals grown at 277 K under similar conditions exhibited low mosaicity, allowing data collection to 2.2 {angstrom} Bragg spacing and structure determination. It was concluded that the improvement of crystal quality as indicated by the higher resolution of the new RMA-LC4 complex crystals was a consequence of the introduction of new lattice contacts at lower temperature. The lattice contacts corresponded to an increased number of interactions between high-entropy side chains that mitigate the lattice strain incurred upon cryocooling and accompanying mosaic spread increases. The thermodynamically unfavorable immobilization of high-entropy side chains used in lattice formation was compensated by an entropic increase in the bulk-solvent content owing to the greater solvent content of the crystal lattice.

Dramatic improvement of crystal quality for low-temperature-grown rabbit muscle aldolase.

Science.gov (United States)

Park, Hajeung; Rangarajan, Erumbi S; Sygusch, Jurgen; Izard, Tina

2010-05-01

Rabbit muscle aldolase (RMA) was crystallized in complex with the low-complexity domain (LC4) of sorting nexin 9. Monoclinic crystals were obtained at room temperature that displayed large mosaicity and poor X-ray diffraction. However, orthorhombic RMA-LC4 crystals grown at 277 K under similar conditions exhibited low mosaicity, allowing data collection to 2.2 A Bragg spacing and structure determination. It was concluded that the improvement of crystal quality as indicated by the higher resolution of the new RMA-LC4 complex crystals was a consequence of the introduction of new lattice contacts at lower temperature. The lattice contacts corresponded to an increased number of interactions between high-entropy side chains that mitigate the lattice strain incurred upon cryocooling and accompanying mosaic spread increases. The thermodynamically unfavorable immobilization of high-entropy side chains used in lattice formation was compensated by an entropic increase in the bulk-solvent content owing to the greater solvent content of the crystal lattice.

Ion Density Analysis of Single-Stranded DNA in Liquid Crystal

Science.gov (United States)

Iwabata, Kazuki; Seki, Yasutaka; Toizumi, Ryota; Shimada, Yuki; Furue, Hirokazu; Sakaguchi, Kengo

2013-09-01

With the widespread use of liquid crystals (LCs) in liquid crystal displays, we have looked into the application of liquid crystals in biotechnology. The purpose of the study described here is to investigate the physical properties of DNA using LCs. Synthetic oligonucleotide molecules were dispersed in MLC6884, the sample injected into antiparallel cells, and the amount of mobile ions was measured. The LC cell doped with oligonucleotide molecules showed a sequence-dependent, specific correlation between oligonucleotide concentration and the amount of mobile ions in the LC cells. In the framework of the Stokes model and polyacrylamide gel electrophoresis (PAGE) analysis, we speculate that this result arises from the difference in ion mobility, which is caused by the shape of the oligonucleotide molecule in the LC.

A potentiometric titration method for the crystallization of drug-like organic molecules.

Science.gov (United States)

Du-Cuny, Lei; Huwyler, Jörg; Fischer, Holger; Kansy, Manfred

2007-09-05

It is generally accepted, that crystalline solids representing a low energy polymorph should be selected for development of oral dosage forms. As a consequence, efficient and robust procedures are needed at an early stage during drug discovery to prepare crystals from drug-like organic molecules. In contrast to the use of supersaturated solutions, we present a potentiometric crystallization procedure where saturated solutions are prepared in a controlled manner by pH-titration. Crystallization is carried out under defined conditions using the sample concentration and experimental pK(a) values as input parameters. Crystals of high quality were obtained for 11 drugs selected to demonstrate the efficiency and applicability of the new method. Technical improvements are suggested to overcome practical limitations and to enhance the possibility of obtaining crystals from molecules in their uncharged form.

Experimental investigation and crystal-field modeling of Er{sup 3+} energy levels in GSGG crystal

Energy Technology Data Exchange (ETDEWEB)

Gao, J.Y., E-mail: jygao1985@sina.com [Anhui Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Hefei 230031 (China); Sun, D.L.; Zhang, Q.L. [Anhui Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Hefei 230031 (China); Wang, X.F. [Anhui Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Hefei 230031 (China); Graduate School of the Chinese Academy of Sciences, Beijing 100049 (China); Liu, W.P.; Luo, J.Q.; Sun, G.H.; Yin, S.T. [Anhui Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Hefei 230031 (China)

2016-06-25

The Er{sup 3+}-doped Gd{sub 3}Sc{sub 2}Ga{sub 3}O{sub 12} (Er{sup 3+}:GSGG) single crystal, a excellent medium of the mid-infrared and anti-radiation solid state laser pumped by laser diode, was grown by Czochralski method successfully. The absorption spectra were measured and analyzed in a wider spectral wavelength range of 350–1700 nm at different temperatures of 7.6, 77, 200 and 300 K. The free-ions and crystal-field parameters were fitted to the experimental energy levels with the root mean square deviation of 9.86 cm{sup −1}. According to the crystal-field calculations, 124 degenerate energy levels of Er{sup 3+} in GSGG host crystals were assigned. The fitting results of free-ions and crystal-field parameters were compared with those already reported of Er{sup 3+}:YSGG. The results indicated that the free-ions parameters for Er{sup 3+} in GSGG host are similar to those in YSGG host crystals, and the crystal-field interaction of GSGG is weaker than that of YSGG, which may result in the better laser characterization of Er{sup 3+}:GSGG crystal. - Highlights: • The efficient diode-end-pumped laser crystal Er:GSGG has been grown successfully. • The absorption spectra of Er:GSGG have been measured in range of 350–1700 nm. • The fitting result is very well for the root mean square deviation is 9.86 cm{sup −1}. • The 124 levels of Er:GSGG have been assigned from the crystal-field calculations.

Impact of the phase-mismatch in the SHG crystal and consequential self-action of the fundamental wave by cascaded second-order effects on the THG efficiency of a Q-switched 1342 nm Nd:YVO₄ laser.

Science.gov (United States)

Koch, Peter; Bartschke, Juergen; L'huillier, Johannes A

2015-05-18

We report on the influence of self-focusing and self-defocusing in the phase-mismatched frequency doubling crystal on the third harmonic generation (THG) efficiency in a two crystal frequency tripling scheme. By detuning the temperature of the doubling crystal, the impact of a phase-mismatch in second harmonic generation (SHG) on the subsequent sum frequency mixing process was investigated. It was found that adjusting the temperature not only affected the power ratio of the second harmonic to the fundamental but also the beam diameter of the fundamental beam in the THG crystal, which was caused by self-focusing and self-defocusing of the fundamental beam, respectively. This self-action was induced by a cascaded χ(2) : χ(2) process in the phase-mismatched SHG crystal. Self-defocusing was observable for positive detuning and self-focusing for negative detuning of the phase-matching temperature. Hence, the THG efficiency was not symmetric with respect to the point of optimum phase-matching. Optimum THG was obtained for positive detuning and the resulting self-defocusing in combination with the focusing lens in front of the THG stage was also beneficial for the beam quality of the third harmonic.

Growth and characterization of nonlinear optical single crystal: Nicotinic L-tartaric

Energy Technology Data Exchange (ETDEWEB)

Sheelarani, V.; Shanthi, J., E-mail: shanthinelson@gmail.com [Department of Physics, Avinashilingam Institute for Home Science and Higher Education for Women, Coimbatore-641043 (India)

2015-06-24

Nonlinear optical single crystals were grown from Nicotinic and L-Tartaric acid by slow evaporation technique at room temperature. Structure of the grown crystal was confirmed by single crystal X-ray diffraction studies, The crystallinity of the Nicotinic L-Tartaric (NLT) crystals was confirmed from the powder XRD pattern. The transparent range and cut off wavelength of the grown crystal was studied by the UV–Vis spectroscopic analysis.The thermal stability of the crystal was studied by TG-DTA. The second harmonic generation (SHG) efficiency of NLT was confirmed by Kurtz Perry technique.

High-Efficiency Intracavity Continuous-Wave Green-Light Generation by Quasiphase Matching in a Bulk Periodically Poled MgO:LiNbO3 Crystal

Directory of Open Access Journals (Sweden)

Shaowei Chu

2008-01-01

Full Text Available 908 mW of green light at 532 nm were generated by intracavity quasiphase matching in a bulk periodically poled MgO:LiNbO3 (PPMgLN crystal. A maximum optical-to-optical conversion efficiency of 33.5% was obtained from a 0.5 mm thick, 10 mm long, and 5 mol% MgO:LiNbO3 crystal with an end-pump power of 2.7 W at 808 nm. The temperature bandwidth between the intracavity and single-pass frequency doubling was found to be different for the PPMgLN. Reliability and stability of the green laser were evaluated. It was found that for continuous operation of 100 hours, the output stability was better than 97.5% and no optical damage was observed.

Conversion of xylan by recyclable spores of Bacillus subtilis displaying thermophilic enzymes.

Science.gov (United States)

Mattossovich, Rosanna; Iacono, Roberta; Cangiano, Giuseppina; Cobucci-Ponzano, Beatrice; Isticato, Rachele; Moracci, Marco; Ricca, Ezio

2017-11-28

The Bacillus subtilis spore has long been used to display antigens and enzymes. Spore display can be accomplished by a recombinant and a non-recombinant approach, with the latter proved more efficient than the recombinant one. We used the non-recombinant approach to independently adsorb two thermophilic enzymes, GH10-XA, an endo-1,4-β-xylanase (EC 3.2.1.8) from Alicyclobacillus acidocaldarius, and GH3-XT, a β-xylosidase (EC 3.2.1.37) from Thermotoga thermarum. These enzymes catalyze, respectively, the endohydrolysis of (1-4)-β-D-xylosidic linkages of xylans and the hydrolysis of (1-4)-β-D-xylans to remove successive D-xylose residues from the non-reducing termini. We report that both purified enzymes were independently adsorbed on purified spores of B. subtilis. The adsorption was tight and both enzymes retained part of their specific activity. When spores displaying either GH10-XA or GH3-XT were mixed together, xylan was hydrolysed more efficiently than by a mixture of the two free, not spore-adsorbed, enzymes. The high total activity of the spore-bound enzymes is most likely due to a stabilization of the enzymes that, upon adsorption on the spore, remained active at the reaction conditions for longer than the free enzymes. Spore-adsorbed enzymes, collected after the two-step reaction and incubated with fresh substrate, were still active and able to continue xylan degradation. The recycling of the mixed spore-bound enzymes allowed a strong increase of xylan degradation. Our results indicate that the two-step degradation of xylans can be accomplished by mixing spores displaying either one of two required enzymes. The two-step process occurs more efficiently than with the two un-adsorbed, free enzymes and adsorbed spores can be reused for at least one other reaction round. The efficiency of the process, the reusability of the adsorbed enzymes, and the well documented robustness of spores of B. subtilis indicate the spore as a suitable platform to display enzymes

Crystal structure of actinide metals at high compression

International Nuclear Information System (INIS)

Fast, L.; Soederlind, P.

1995-08-01

The crystal structures of some light actinide metals are studied theoretically as a function of applied pressure. The first principles electronic structure theory is formulated in the framework of density functional theory, with the gradient corrected local density approximation of the exchange-correlation functional. The light actinide metals are shown to be well described as itinerant (metallic) f-electron metals and generally, they display a crystal structure which have, in agreement with previous theoretical suggestions, increasing degree of symmetry and closed-packing upon compression. The theoretical calculations agree well with available experimental data. At very high compression, the theory predicts closed-packed structures such as the fcc or the hcp structures or the nearly closed-packed bcc structure for the light actinide metals. A simple canonical band picture is presented to explain in which particular closed-packed form these metals will crystallize at ultra-high pressure

Heteroplasmon hybridization in stacked complementary plasmo-photonic crystals.

Science.gov (United States)

Iwanaga, Masanobu; Choi, Bongseok

2015-03-11

We constructed plasmo-photonic crystals in which efficient light-trapping, plasmonic resonances couple with photonic guided resonances of large density of states and high-quality factor. We have numerically and experimentally shown that heteroplasmon hybrid modes emerge in stacked complementary (SC) plasmo-photonic crystals. The resonant electromagnetic-field distributions evidence that the two hybrid modes originate from two different heteroplasmons, exhibiting a large energy splitting of 300 meV. We further revealed a series of plasmo-photonic modes in the SC crystals.

Flat-panel electronic displays: a triumph of physics, chemistry and engineering.

Science.gov (United States)

Hilsum, Cyril

2010-03-13

This paper describes the history and science behind the development of modern flat-panel displays, and assesses future trends. Electronic displays are an important feature of modern life. For many years the cathode ray tube, an engineering marvel, was universal, but its shape was cumbersome and its operating voltage too high. The need for a flat-panel display, working at a low voltage, became imperative, and much research has been applied to this need. Any versatile flat-panel display will exploit an electro-optical effect, a transparent conductor and an addressing system to deliver data locally. The first need is to convert an electrical signal into a visible change. Two methods are available, the first giving emission of light, the second modulating ambient illumination. The most useful light-emitting media are semiconductors, historically exploiting III-V or II-VI compounds, but more recently organic or polymer semiconductors. Another possible effect uses gas plasma discharges. The modulating, or subtractive, effects that have been studied include liquid crystals, electrophoresis, electrowetting and electrochromism. A transparent conductor makes it possible to apply a voltage to an extended area while observing the results. The design is a compromise, since the free electrons that carry current also absorb light. The first materials used were metals, but some semiconductors, when heavily doped, give a better balance, with high transmission for a low resistance. Delivering data unambiguously to a million or so picture elements across the display area is no easy task. The preferred solution is an amorphous silicon thin-film transistor deposited at each cross-point in an X-Y matrix. Success in these endeavours has led to many applications for flat-panel displays, including television, flexible displays, electronic paper, electronic books and advertising signs.

Automating the application of smart materials for protein crystallization

International Nuclear Information System (INIS)

Khurshid, Sahir; Govada, Lata; EL-Sharif, Hazim F.; Reddy, Subrayal M.; Chayen, Naomi E.

2015-01-01

The first semi-liquid, non-protein nucleating agent for automated protein crystallization trials is described. This ‘smart material’ is demonstrated to induce crystal growth and will provide a simple, cost-effective tool for scientists in academia and industry. The fabrication and validation of the first semi-liquid nonprotein nucleating agent to be administered automatically to crystallization trials is reported. This research builds upon prior demonstration of the suitability of molecularly imprinted polymers (MIPs; known as ‘smart materials’) for inducing protein crystal growth. Modified MIPs of altered texture suitable for high-throughput trials are demonstrated to improve crystal quality and to increase the probability of success when screening for suitable crystallization conditions. The application of these materials is simple, time-efficient and will provide a potent tool for structural biologists embarking on crystallization trials

Characterization of Crystals for Steering of Protons through Channelling in Hadronic Accelerators

CERN Document Server

Guidi, V; Boscolo-Marchi, E; Carnera, A; Chesnokov, Yu A; Della Mea, G; De Salvador, D; Fiorini, M; Ivanov, Y M; Martinelli, G; Mazzolari, A; Milan, E; Milan, R; Sambo, A; Scandale, Walter; Todros, S; Vomiero, A

2006-01-01

Channeling of relativistic particles through a crystal may be useful for many applications in accelerators, and particularly for collimation in hadronic colliders. Efficiency proved to be dependent on the state of the crystal surface and hence on the method used for preparation. We investigated the morphology and structure of the surface of the samples that have been used in accelerators with high efficiency. We found that crystal fabrication by only mechanical methods (dicing, lapping, and others) leads to a superficial damaged layer, which is correlated to performance limitation in accelerators. A planar chemical etching was studied and applied in order to remove the superficial damaged layer. RBS channeling analysis with low-energy protons and 4He+ highlighted better crystal perfection at surface, as a result of the etching. A protocol for preparation and characterization of crystal for channelling has been developed, which may be of interest for reliable operation with crystals in accelerators.

Channeling and Volume Reflection Based Crystal Collimation of Tevatron Circulating Beam Halo

CERN Document Server

Shiltsev, V.; Drozhdin, A.; Johnson, T.; Legan, A.; Mokhov, N.; Reilly, R.; Still, D.; Tesarek, R.; Zagel, J.; Peggs, S.; Assmann, R.; Previtali, V.; Scandale, W.; Chesnokov, Y.; Yazynin, I.; Guidi, V.; Ivanov, Y.

2010-01-01

The T980 crystal collimation experiment is underway at the Tevatron to determine if this technique could increase 980 GeV beam-halo collimation efficiency at high-energy hadron colliders such as the Tevatron and the LHC. T980 also studies various crystal types and parameters. The setup has been substantially enhanced during the Summer 2009 shutdown by installing a new O-shaped crystal in the horizontal goniometer, as well as adding a vertical goniometer with two alternating crystals (O-shaped and multi-strip) and additional beam diagnostics. First measurements with the new system are quite encouraging, with channeled and volume-reflected beams observed on the secondary collimators as predicted. Investigation of crystal collimation efficiencies with crystals in volume reflection and channeling modes are described in comparison with an amorphous primary collimator. Results on the system performance are presented for the end-of-store studies and for entire collider stores. The first investigation of colliding be...

One-pot preparation of mRNA/cDNA display by a novel and versatile puromycin-linker DNA.

Science.gov (United States)

Mochizuki, Yuki; Biyani, Manish; Tsuji-Ueno, Sachika; Suzuki, Miho; Nishigaki, Koichi; Husimi, Yuzuru; Nemoto, Naoto

2011-09-12

A rapid, easy, and robust preparation method for mRNA/cDNA display using a newly designed puromycin-linker DNA is presented. The new linker is structurally simple, easy to synthesize, and cost-effective for use in "in vitro peptide and protein selection". An introduction of RNase T1 nuclease site to the new linker facilitates the easy recovery of mRNA/cDNA displayed protein by an improvement of the efficiency of ligating the linker to mRNAs and efficient release of mRNA/cDNA displayed protein from the solid-phase (magnetic bead). For application demonstration, affinity selections were successfully performed. Furthermore, we introduced a "one-pot" preparation protocol to perform mRNA display easy. Unlike conventional approaches that require tedious and downstream multistep process including purification, this protocol will make the mRNA/cDNA display methods more practical and convenient and also facilitate the development of next-generation, high-throughput mRNA/cDNA display systems amenable to automation.

Development of longer Nd:LGGG crystal for high power laser application

Science.gov (United States)

Yin, Yanru; Tian, Hanlin; Zhang, Jian; Mu, Wenxiang; Zhang, Baitao; Jia, Zhitai; He, Jingliang; Tao, Xutang

2017-11-01

In order to further improve the Nd3+:(LuxGd1-x)3Ga5O12 (Nd:LGGG) crystal performance in high power laser field, a long Nd:LGGG crystal with dimensions of Φ 23 × 112 mm3 has been grown successfully by the Czochralski (Cz) method for laser rod fabrication. Compared with the normal size LGGG crystals (like 30-50 mm in length), we overcame several difficulties in the growth of longer ones, including crystal cracking by a large longitudinal temperature gradient, spiral growth by a small radial temperature gradient, and growth instability and even constitutional super cooling by Ga2O3 volatilizing continuously. The doping concentrations of Nd3+ and Lu3+ in the as-grown crystal and the crystal optical quality have been measured. The performance of diode-side-pumped Nd:LGGG rod laser has been preliminarily tested for the first time, simply by replacing the Nd:YAG crystal rod inside a commercial laser module. Under an incident pump power of 160 W, the maximum continuous wave output power of 38 W has been obtained, corresponding to an optical-optical conversion efficiency of 23.8% and a slope efficiency of 40.8%, respectively.

Fiscal 2000 research achievement report on the pioneering research and development involving next-generation liquid crystal process base technologies; 2000 nendo jisedai ekisho process kiban gijutsu ni kakawaru sendo kenkyu kaihatsu seika hokokusho

Energy Technology Data Exchange (ETDEWEB)

NONE

2001-03-01

For the enhancement of energy conservation in the liquid crystal display manufacturing process, activities are conducted in the three fields of (1) low temperature thin film fabrication technology, (2) zone-selective thin film growth technology, and (3) next-generation liquid crystal process base technology and comprehensive surveys. Conducted in field (1) are pioneering studies of low temperature high quality Si film fabrication by electromagnetic annealing, low temperature high quality thin film fabrication by EPA (electron plasma annealing), and low temperature normal pressure film fabrication. Conducted in field (2) are pioneering studies of zone-selective fabrication of high quality Si crystal film, high precision control of reforming (doping), and free pattern low resistance wiring fabrication. Conducted in field (3) are tentative fabrication, evaluation, and analysis of ultimate performance TFTs (thin film transistors) produced by the state-of-the-art purification enhancement technology; next-generation liquid crystal process; and surveys of functional thin film to be a novel material for substrates. In the pioneering study of low temperature high quality Si film fabrication by means of electromagnetic annealing, microwave annealing is studied as an energy efficient process to replace the currently favored ELA (excimer laser annealing) method, and then it is proved that the microwave annealing method is much higher in energy efficiency than the ELA method. (NEDO)

Thermal neutron detectors based on complex oxide crystals

CERN Document Server

Ryzhikov, V; Volkov, V; Chernikov, V; Zelenskaya, O

2002-01-01

The ways of improvement of spectrometric quality of CWO and GSO crystals have been investigated with the aim of their application in thermal neutron detectors based on radiation capture reactions. The efficiency of the neutron detection by these crystals was measured, and the obtained data were compared with the results for sup 6 LiI(Tl) crystals. It is shown that the use of complex oxide crystals and neutron-absorption filters for spectrometry of thermal and resonance neutrons could be a promising method in combination with computer data processing. Numerical calculations are reported for spectra of gamma-quanta due to radiation capture of the neutrons. To compensate for the gamma-background lines, we used a crystal pair of heavy complex oxides with different sensitivity to neutrons.

High-Efficiency and High-Color-Rendering-Index Semitransparent Polymer Solar Cells Induced by Photonic Crystals and Surface Plasmon Resonance.

Science.gov (United States)

Shen, Ping; Wang, Guoxin; Kang, Bonan; Guo, Wenbin; Shen, Liang

2018-02-21

Semitransparent polymer solar cells (ST-PSCs) show attractive potential in power-generating windows or building-integrated photovoltaics. However, the development of ST-PSCs is lagging behind opaque PSCs because of the contradiction between device efficiency and transmission. Herein, Ag/Au alloy nanoparticles and photonic crystals (PCs) were simultaneously introduced into ST-PSCs, acting compatibly as localized surface plasmon resonances and distributed Bragg reflectors to enhance light absorption and transmission. As a result, ST-PSCs based on a hybrid PTB7-Th:PC 71 BM active layer contribute an efficiency as high as 7.13 ± 0.15% and an average visible transmission beyond 20%, which are superior to most of the reported results. Furthermore, PCs can partly compensate valley range of transmission by balancing reflection and transmission regions, yielding a high color rendering index of 95. We believe that the idea of two light management methods compatibly enhancing the performance of ST-PSCs can offer a promising path to develop photovoltaic applications.

Thin aligned organic polymer films for liquid crystal devices