WorldWideScience

Sample records for plate light image

  1. Pixelated neutron image plates

    Science.gov (United States)

    Schlapp, M.; Conrad, H.; von Seggern, H.

    2004-09-01

    Neutron image plates (NIPs) have found widespread application as neutron detectors for single-crystal and powder diffraction, small-angle scattering and tomography. After neutron exposure, the image plate can be read out by scanning with a laser. Commercially available NIPs consist of a powder mixture of BaFBr : Eu2+ and Gd2O3 dispersed in a polymer matrix and supported by a flexible polymer sheet. Since BaFBr : Eu2+ is an excellent x-ray storage phosphor, these NIPs are particularly sensitive to ggr-radiation, which is always present as a background radiation in neutron experiments. In this work we present results on NIPs consisting of KCl : Eu2+ and LiF that were fabricated into ceramic image plates in which the alkali halides act as a self-supporting matrix without the necessity for using a polymeric binder. An advantage of this type of NIP is the significantly reduced ggr-sensitivity. However, the much lower neutron absorption cross section of LiF compared with Gd2O3 demands a thicker image plate for obtaining comparable neutron absorption. The greater thickness of the NIP inevitably leads to a loss in spatial resolution of the image plate. However, this reduction in resolution can be restricted by a novel image plate concept in which a ceramic structure with square cells (referred to as a 'honeycomb') is embedded in the NIP, resulting in a pixelated image plate. In such a NIP the read-out light is confined to the particular illuminated pixel, decoupling the spatial resolution from the optical properties of the image plate material and morphology. In this work, a comparison of experimentally determined and simulated spatial resolutions of pixelated and unstructured image plates for a fixed read-out laser intensity is presented, as well as simulations of the properties of these NIPs at higher laser powers.

  2. Partially light-controlled imager based on liquid crystal plate and image intensifier for aurora and airglow measurement.

    Science.gov (United States)

    Tang, Yuanhe; Cao, Xiangang; Liu, Hanchen; Shepherd, G G; Liu, Shulin; Gao, Haiyang; Yang, Xusan; Wu, Yong; Wang, Shuiwei

    2012-04-20

    In order to obtain information both of aurora and airglow in one image by the same detector, a PLCI based on liquid crystal plate LCP and super second-generation image intensifier SSGII is proposed in this research. The detection thresholds of the CCD for aurora and airglow are calculated. For the detectable illumination range of 10(4)-10(-2) lx, the corresponding electron count is 1.57×10(5) - 0.2 for every pixel of CCD. The structure and work principle of the PLCI are described. An LC is introduced in the front of CCD to decrease the intensities of aurora in overexposure areas by means of controlling transmittances pixel by pixel, while an image intensifier is set between the LC and CCD to increase the intensity of the weak airglow. The modulation transfer function MTF of this system is calculated as 0.391 at a Nyquist frequency of 15 lp/mm. The curve of transmittance with regard to gray level for the LC is obtained by calibration experiment. Based on the design principle, the prototype is made and used to take photos of objects under strong light greater than 2×10(5) lx. The clear details of [symbols: see text] presented in the image indicate that the PLCI can greatly improve the imaging quality. The theoretical calculations and experiment results prove that this device can extend the dynamic range and it provides a more effective method for upper atmospheric wind measurement.

  3. High-space resolution imaging plate analysis of extreme ultraviolet (EUV) light from tin laser-produced plasmas.

    Science.gov (United States)

    Musgrave, Christopher S A; Murakami, Takehiro; Ugomori, Teruyuki; Yoshida, Kensuke; Fujioka, Shinsuke; Nishimura, Hiroaki; Atarashi, Hironori; Iyoda, Tomokazu; Nagai, Keiji

    2017-03-01

    With the advent of high volume manufacturing capabilities by extreme ultraviolet lithography, constant improvements in light source design and cost-efficiency are required. Currently, light intensity and conversion efficiency (CE) measurments are obtained by charged couple devices, faraday cups etc, but also phoshpor imaging plates (IPs) (BaFBr:Eu). IPs are sensitive to light and high-energy species, which is ideal for studying extreme ultraviolet (EUV) light from laser produced plasmas (LPPs). In this work, we used IPs to observe a large angular distribution (10°-90°). We ablated a tin target by high-energy lasers (1064 nm Nd:YAG, 10(10) and 10(11) W/cm(2)) to generate the EUV light. The europium ions in the IP were trapped in a higher energy state from exposure to EUV light and high-energy species. The light intensity was angular dependent; therefore excitation of the IP depends on the angle, and so highly informative about the LPP. We obtained high-space resolution (345 μm, 0.2°) angular distribution and grazing spectrometer (5-20 nm grate) data simultaneously at different target to IP distances (103 mm and 200 mm). Two laser systems and IP types (BAS-TR and BAS-SR) were also compared. The cosine fitting values from the IP data were used to calculate the CE to be 1.6% (SD ± 0.2) at 13.5 nm 2% bandwidth. Finally, a practical assessment of IPs and a damage issue are disclosed.

  4. High-space resolution imaging plate analysis of extreme ultraviolet (EUV) light from tin laser-produced plasmas

    Science.gov (United States)

    Musgrave, Christopher S. A.; Murakami, Takehiro; Ugomori, Teruyuki; Yoshida, Kensuke; Fujioka, Shinsuke; Nishimura, Hiroaki; Atarashi, Hironori; Iyoda, Tomokazu; Nagai, Keiji

    2017-03-01

    With the advent of high volume manufacturing capabilities by extreme ultraviolet lithography, constant improvements in light source design and cost-efficiency are required. Currently, light intensity and conversion efficiency (CE) measurments are obtained by charged couple devices, faraday cups etc, but also phoshpor imaging plates (IPs) (BaFBr:Eu). IPs are sensitive to light and high-energy species, which is ideal for studying extreme ultraviolet (EUV) light from laser produced plasmas (LPPs). In this work, we used IPs to observe a large angular distribution (10°-90°). We ablated a tin target by high-energy lasers (1064 nm Nd:YAG, 1010 and 1011 W/cm2) to generate the EUV light. The europium ions in the IP were trapped in a higher energy state from exposure to EUV light and high-energy species. The light intensity was angular dependent; therefore excitation of the IP depends on the angle, and so highly informative about the LPP. We obtained high-space resolution (345 μm, 0.2°) angular distribution and grazing spectrometer (5-20 nm grate) data simultaneously at different target to IP distances (103 mm and 200 mm). Two laser systems and IP types (BAS-TR and BAS-SR) were also compared. The cosine fitting values from the IP data were used to calculate the CE to be 1.6% (SD ± 0.2) at 13.5 nm 2% bandwidth. Finally, a practical assessment of IPs and a damage issue are disclosed.

  5. Light splitting with imperfect wave plates.

    Science.gov (United States)

    Jackson, Jarom S; Archibald, James L; Durfee, Dallin S

    2017-02-01

    We discuss the use of wave plates with arbitrary retardances, in conjunction with a linear polarizer, to split linearly polarized light into two linearly polarized beams with an arbitrary splitting fraction. We show that for non-ideal wave plates, a much broader range of splitting ratios is typically possible when a pair of wave plates, rather than a single wave plate, is used. We discuss the maximum range of splitting fractions possible with one or two wave plates as a function of the wave plate retardances, and how to align the wave plates to achieve the maximum splitting range possible when simply rotating one of the wave plates while keeping the other one fixed. We also briefly discuss an alignment-free polarization rotator constructed from a pair of half-wave plates.

  6. White Light Photorefractive Phase Zone Plates

    Institute of Scientific and Technical Information of China (English)

    GAO Yuan-Mei; LIU Si-Min

    2008-01-01

    Incoherent white light from an incandescent source is employed to Fabricate volume phase zone plates in LiNbO3:Fe,for the first time to our knowledge,which can guide and modulate the input white light or laser light.The diffractive efficiency of the white light volume phase zone plates fabricated can reach as high as 12%.In addition,we test the volume phase zone plates by a probe beam and find that the volume phase zone plate is present in the direction perpendicular to the c-axis and absent in the direction parallel to the c-axis.This directly proves the existence of photovoltalc photorefractive anisotropy of white light.

  7. Evaluating Picture Quality of Image Plates in Digital CR Systems

    Energy Technology Data Exchange (ETDEWEB)

    Kwak, Byung Joon [Dept. of Radiological Tecnology, Choonhae College of Health Science, Ulsan (Korea, Republic of); Ji Tae Jeong [Dept. of Radiological Science, Kaya University, Kimhae (Korea, Republic of)

    2011-12-15

    Lab effectively supplemented the effects of outside radiation on image plates in the process of image acquisition of CR (computed radiography) systems and conducted for effective utilization in the case of clinical application. For this, Lab classified the storage places and time periods of image plates and compared and analyzed the differences between small dark spots. Lab also assessed the concentration distribution within the boundaries of images. Lab compared and measured the number of dark spots in a light room and a dark room depending on the storage places of image plates and found that dark spots slightly increased in an image plate when stored in a light room on the first and second days. Dark spots increased in proportion to the length of time stored. In the case of the image plate stored in a dark room, the number of dark spots remarkably decreased. With regard to picture quality as related to the location of image plates, the damage to picture quality could be reduced by locating regions of interest in the center. With regard to differences in sharpness following changes in the thickness of subjects, fewer scatter rays occurred and sharpness improved by reducing the thickness of subjects as much as possible. To get medical images of excellent quality, image plates should be managed effectively and it is desirable to keep images plates in dark iron plate boxes and not to expose them to outside radiation for a long time.

  8. Light Imaging Section

    Data.gov (United States)

    Federal Laboratory Consortium — The mission of the Light Imaging Section is to give NIAMS scientists access to state-of-the-art light imaging equipment and to offer training and assistance at all...

  9. An Automatic Number Plate Recognition System under Image Processing

    Directory of Open Access Journals (Sweden)

    Sarbjit Kaur

    2016-03-01

    Full Text Available Automatic Number Plate Recognition system is an application of computer vision and image processing technology that takes photograph of vehicles as input image and by extracting their number plate from whole vehicle image , it display the number plate information into text. Mainly the ANPR system consists of 4 phases: - Acquisition of Vehicle Image and Pre-Processing, Extraction of Number Plate Area, Character Segmentation and Character Recognition. The overall accuracy and efficiency of whole ANPR system depends on number plate extraction phase as character segmentation and character recognition phases are also depend on the output of this phase. Further the accuracy of Number Plate Extraction phase depends on the quality of captured vehicle image. Higher be the quality of captured input vehicle image more will be the chances of proper extraction of vehicle number plate area. The existing methods of ANPR works well for dark and bright/light categories image but it does not work well for Low Contrast, Blurred and Noisy images and the detection of exact number plate area by using the existing ANPR approach is not successful even after applying existing filtering and enhancement technique for these types of images. Due to wrong extraction of number plate area, the character segmentation and character recognition are also not successful in this case by using the existing method. To overcome these drawbacks I proposed an efficient approach for ANPR in which the input vehicle image is pre-processed firstly by iterative bilateral filtering , adaptive histogram equalization and number plate is extracted from pre-processed vehicle image using morphological operations, image subtraction, image binarization/thresholding, sobel vertical edge detection and by boundary box analysis. Sometimes the extracted plate area also contains noise, bolts, frames etc. So the extracted plate area is enhanced by using morphological operations to improve the quality of

  10. Microchannel Plate Imaging Detectors for the Ultraviolet

    Science.gov (United States)

    Siegmund, O. H. W.; Gummin, M. A.; Stock, J.; Marsh, D.

    1992-01-01

    There has been significant progress over the last few years in the development of technologies for microchannel plate imaging detectors in the Ultraviolet (UV). Areas where significant developments have occurred include enhancements of quantum detection efficiency through improved photocathodes, advances in microchannel plate performance characteristics, and development of high performance image readout techniques. The current developments in these areas are summarized, with their applications in astrophysical instrumentation.

  11. Image simulation for automatic license plate recognition

    Science.gov (United States)

    Bala, Raja; Zhao, Yonghui; Burry, Aaron; Kozitsky, Vladimir; Fillion, Claude; Saunders, Craig; Rodríguez-Serrano, José

    2012-01-01

    Automatic license plate recognition (ALPR) is an important capability for traffic surveillance applications, including toll monitoring and detection of different types of traffic violations. ALPR is a multi-stage process comprising plate localization, character segmentation, optical character recognition (OCR), and identification of originating jurisdiction (i.e. state or province). Training of an ALPR system for a new jurisdiction typically involves gathering vast amounts of license plate images and associated ground truth data, followed by iterative tuning and optimization of the ALPR algorithms. The substantial time and effort required to train and optimize the ALPR system can result in excessive operational cost and overhead. In this paper we propose a framework to create an artificial set of license plate images for accelerated training and optimization of ALPR algorithms. The framework comprises two steps: the synthesis of license plate images according to the design and layout for a jurisdiction of interest; and the modeling of imaging transformations and distortions typically encountered in the image capture process. Distortion parameters are estimated by measurements of real plate images. The simulation methodology is successfully demonstrated for training of OCR.

  12. Imaging plates calibration to X-rays

    Science.gov (United States)

    Curcio, A.; Andreoli, P.; Cipriani, M.; Claps, G.; Consoli, F.; Cristofari, G.; De Angelis, R.; Giulietti, D.; Ingenito, F.; Pacella, D.

    2016-05-01

    The growing interest for the Imaging Plates, due to their high sensitivity range and versatility, has induced, in the last years, to detailed characterizations of their response function in different energy ranges and kind of radiation/particles. A calibration of the Imaging Plates BAS-MS, BAS-SR, BAS-TR has been performed at the ENEA-Frascati labs by exploiting the X-ray fluorescence of different targets (Ca, Cu, Pb, Mo, I, Ta) and the radioactivity of a BaCs source, in order to cover the X-ray range between few keV to 80 keV.

  13. Thermal neutron imaging using microchannel plates

    Science.gov (United States)

    Fraser, George W.; Pearson, James F.; Al-Horayess, O. S.; Feller, W. Bruce; Cook, Lee M.

    1993-02-01

    Microchannel plates (MCPs) are compact electron multipliers of high gain, widely used for the high resolution imaging of charged particles and photons. In this paper, we consider the use of lead glass MCPs for the imaging of thermal neutrons. Two contrasting techniques are described. The first method involves direct neutron detection within a special channel plate structure containing lithium and/or boron. We review the constraints of glass chemistry on the attainable lithium oxide and boron oxide fractions and, hence, on the maximum neutron detection efficiency. The second method involves the detection, using MCPs of standard glass composition, of the internal conversion electrons from a thin gadolinium foil. We present the first measurements of the detection efficiency, pulse height resolution and imaging properties of a pulse-counting MCP/Gd detector system.

  14. An Automatic Number Plate Recognition System under Image Processing

    OpenAIRE

    Sarbjit Kaur

    2016-01-01

    Automatic Number Plate Recognition system is an application of computer vision and image processing technology that takes photograph of vehicles as input image and by extracting their number plate from whole vehicle image , it display the number plate information into text. Mainly the ANPR system consists of 4 phases: - Acquisition of Vehicle Image and Pre-Processing, Extraction of Number Plate Area, Character Segmentation and Character Recognition. The overall accuracy and efficiency of whol...

  15. Light-Field Imaging Toolkit

    Science.gov (United States)

    Bolan, Jeffrey; Hall, Elise; Clifford, Chris; Thurow, Brian

    The Light-Field Imaging Toolkit (LFIT) is a collection of MATLAB functions designed to facilitate the rapid processing of raw light field images captured by a plenoptic camera. An included graphical user interface streamlines the necessary post-processing steps associated with plenoptic images. The generation of perspective shifted views and computationally refocused images is supported, in both single image and animated formats. LFIT performs necessary calibration, interpolation, and structuring steps to enable future applications of this technology.

  16. Light field display and 3D image reconstruction

    Science.gov (United States)

    Iwane, Toru

    2016-06-01

    Light field optics and its applications become rather popular in these days. With light field optics or light field thesis, real 3D space can be described in 2D plane as 4D data, which we call as light field data. This process can be divided in two procedures. First, real3D scene is optically reduced with imaging lens. Second, this optically reduced 3D image is encoded into light field data. In later procedure we can say that 3D information is encoded onto a plane as 2D data by lens array plate. This transformation is reversible and acquired light field data can be decoded again into 3D image with the arrayed lens plate. "Refocusing" (focusing image on your favorite point after taking a picture), light-field camera's most popular function, is some kind of sectioning process from encoded 3D data (light field data) to 2D image. In this paper at first I show our actual light field camera and our 3D display using acquired and computer-simulated light field data, on which real 3D image is reconstructed. In second I explain our data processing method whose arithmetic operation is performed not in Fourier domain but in real domain. Then our 3D display system is characterized by a few features; reconstructed image is of finer resolutions than density of arrayed lenses and it is not necessary to adjust lens array plate to flat display on which light field data is displayed.

  17. Guided wave topological imaging of isotropic plates.

    Science.gov (United States)

    Rodriguez, S; Deschamps, M; Castaings, M; Ducasse, E

    2014-09-01

    Topological imaging is a recent method. So far, it has been applied to bulk waves, and high resolution has been demonstrated for imaging scatterers even with a single ultrasonic insonification of the inspected medium. This method consists of (i) emitting waves and measuring the response of the medium; (ii) solving two propagation problems: the direct problem, where the experimental source is simulated, and the adjoint problem, where the source is the time-reversed difference between the measured wave field and that obtained from the direct problem; (iii) computing the image by simply multiplying both wave fields together in the frequency domain, and integrating over the frequency. The speed of the method depends only on the cost of the field computations that are performed in the defect-free medium. The present work deals with the application of topological imaging to plate guided waves. Combining modal theory and Fourier analysis, the computations are performed in a very short time. In the investigated cases, two-dimensional in-plane imaging is based on propagation of the single S0 Lamb mode. Despite very high dispersion of that mode, scatterers are accurately located and the spatial resolution is equal to about one wavelength.

  18. Calibration and equivalency analysis of image plate scanners

    Energy Technology Data Exchange (ETDEWEB)

    Williams, G. Jackson, E-mail: williams270@llnl.gov; Maddox, Brian R.; Chen, Hui [Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550 (United States); Kojima, Sadaoki [Institute of Laser Engineering, Osaka University, Yamada-oka, 2-6, Suita, Osaka 565-0871 (Japan); Millecchia, Matthew [Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623 (United States)

    2014-11-15

    A universal procedure was developed to calibrate image plate scanners using radioisotope sources. Techniques to calibrate scanners and sources, as well as cross-calibrate scanner models, are described to convert image plate dosage into physical units. This allows for the direct comparison of quantitative data between any facility and scanner. An empirical relation was also derived to establish sensitivity response settings for arbitrary gain settings. In practice, these methods may be extended to any image plate scanning system.

  19. Tomographic imaging with polarized light.

    Science.gov (United States)

    Soloviev, Vadim Y; Zacharakis, Giannis; Spiliopoulos, George; Favicchio, Rosy; Correia, Teresa; Arridge, Simon R; Ripoll, Jorge

    2012-06-01

    We report three-dimensional tomographic reconstruction of optical parameters for the mesoscopic light scattering regime from experimentally obtained datasets by using polarized light. We present a numerically inexpensive approximation to the radiative transfer equation governing the polarized light transport. This approximation is employed in the reconstruction algorithm, which computes two optical parameters by using parallel and perpendicular polarizations of transmitted light. Datasets were obtained by imaging a scattering phantom embedding highly absorbing inclusions. Reconstruction results are presented and discussed.

  20. Slow light in flight imaging

    CERN Document Server

    Wilson, Kali; Gariepy, Genevieve; Henderson, Robert; Howell, John; Faccio, Daniele

    2016-01-01

    Slow-light media are of interest in the context of quantum computing and enhanced measurement of quantum effects, with particular emphasis on using slow-light with single photons. We use light-in-flight imaging with a single photon avalanche diode camera-array to image in situ pulse propagation through a slow light medium consisting of heated rubidium vapour. Light-in-flight imaging of slow light propagation enables direct visualisation of a series of physical effects including simultaneous observation of spatial pulse compression and temporal pulse dispersion. Additionally, the single-photon nature of the camera allows for observation of the group velocity of single photons with measured single-photon fractional delays greater than 1 over 1 cm of propagation.

  1. Robust sky light polarization detection with an S-wave plate in a light field camera.

    Science.gov (United States)

    Zhang, Wenjing; Zhang, Xuanzhe; Cao, Yu; Liu, Haibo; Liu, Zejin

    2016-05-01

    The sky light polarization navigator has many advantages, such as low cost, no decrease in accuracy with continuous operation, etc. However, current celestial polarization measurement methods often suffer from low performance when the sky is covered by clouds, which reduce the accuracy of navigation. In this paper we introduce a new method and structure based on a handheld light field camera and a radial polarizer, composed of an S-wave plate and a linear polarizer, to detect the sky light polarization pattern across a wide field of view in a single snapshot. Each micro-subimage has a special intensity distribution. After extracting the texture feature of these subimages, stable distribution information of the angle of polarization under a cloudy sky can be obtained. Our experimental results match well with the predicted properties of the theory. Because the polarization pattern is obtained through image processing, rather than traditional methods based on mathematical computation, this method is less sensitive to errors of pixel gray value and thus has better anti-interference performance.

  2. Singular Value Decomposition of Images from Scanned Photographic Plates

    CERN Document Server

    Kolev, Vasil; Tsvetkov, Milcho

    2013-01-01

    We want to approximate the mxn image A from scanned astronomical photographic plates (from the Sofia Sky Archive Data Center) by using far fewer entries than in the original matrix. By using rank of a matrix, k we remove the redundant information or noise and use as Wiener filter, when rank kimage of astronomical plate without that image details, is obtained. The SVD of images from scanned photographic plates (SPP) is considered and its possible image compression.

  3. The Light Velocity Casimir Effect Does the Velocity of Light Increase when Propagating Between the Casimir Plates?

    CERN Document Server

    Ostoma, T; Ostoma, Tom; Trushyk, Mike

    1999-01-01

    We propose experiments that might be set up to detect the increase in the velocity of light in a vacuum in the laboratory frame for photons travelling between (and perpendicular to) the Casimir plates in a vacuum. The Casimir plates are two closely spaced, conductive plates, where an attractive force is observed to exist between the plates called the 'Casimir Force'. We propose that the velocity of light in a vacuum increases when propagating between two transparent Casimir Plates. We call this effect the 'Light Velocity Casimir Effect' or LVC effect. The LVC effect happens because the vacuum energy density in between the plates is lower than that outside the Casimir plates. The conductive plates disallow certain frequencies of electrically charged virtual particles to exist inside the plates, thus lowering the inside vacuum particle density, compared to the density outside the plates. The reduced (electrically charged) virtual particle density results in fewer photon scattering events inside the plates, whic...

  4. Application of Cosine Zone Plates to Image Encryption

    Institute of Scientific and Technical Information of China (English)

    GE Fan; CHEN Lin-Fei; ZHAO Dao-Mu

    2008-01-01

    @@ We analyse the diffraction result of optical field after Cosine zone plate, and theoretically deduce its transform matrix. Under some conditions, its diffraction distribution is a mixture of fractional Fourier spectra. Then we use Cosine zone plate and its diffraction result to image encryption. Possible optical image encryption and decryption implementations are proposed, and some numerical simulation results are also provided.

  5. Quantitative Assessment of Birefringent Skin Structures in Scattered Light Confocal Imaging Using Radially Polarized Light

    Directory of Open Access Journals (Sweden)

    Natallia Eduarda Uzunbajakava

    2013-09-01

    Full Text Available The polarization characteristics of birefringent tissues could be only partially obtained using linearly polarized light in polarization sensitive optical imaging. Here we analyze the change in polarization of backscattered light from birefringent structures versus the orientations of the incident polarizations using linearly, circularly and radially polarized light in a cross-polarized confocal microscope. A spatially variable retardation plate composed of eight sectors of λ/2 wave plates was used to transform linearly polarized light into a radially polarized light. Based on the experimental data obtained from ex-vivo measurements on human scalp hairs and in-vivo measurements on hair and skin, we exemplify that the underestimation of the birefringence content resulting from the orientation related effects associated with the use of linearly polarized light for imaging tissues containing wavy birefringent structures could be minimized by using radially polarized light.

  6. Quantitative assessment of birefringent skin structures in scattered light confocal imaging using radially polarized light.

    Science.gov (United States)

    Varghese, Babu; Verhagen, Rieko; Hussain, Altaf; Boudot, Clemence; Tai, Qiangqiang; Ding, Siqi; Holz, Jasmin Alexandra; Uzunbajakava, Natallia Eduarda

    2013-09-17

    The polarization characteristics of birefringent tissues could be only partially obtained using linearly polarized light in polarization sensitive optical imaging. Here we analyze the change in polarization of backscattered light from birefringent structures versus the orientations of the incident polarizations using linearly, circularly and radially polarized light in a cross-polarized confocal microscope. A spatially variable retardation plate composed of eight sectors of λ/2 wave plates was used to transform linearly polarized light into a radially polarized light. Based on the experimental data obtained from ex-vivo measurements on human scalp hairs and in-vivo measurements on hair and skin, we exemplify that the underestimation of the birefringence content resulting from the orientation related effects associated with the use of linearly polarized light for imaging tissues containing wavy birefringent structures could be minimized by using radially polarized light.

  7. Imaging with straight-edge phase plates in the TEM.

    Science.gov (United States)

    Edgcombe, C J

    2017-06-22

    The image of a simple phase object produced by a round lens with a Foucault or Hilbert phase plate can be determined with Abbe imaging theory and a 2D transform expressed in cylindrical coordinates. The contributions to the image amplitude from a uniform disc object and an azimuthally varying plate can then be distinguished and their phases relative to the incident wave can be compared. It appears that the usual choice of added phase for a Hilbert plate causes the image of a weak disc object to vanish as the plate edge approaches the axis, but a different choice of plate thickness can enable a weak phase object to provide a linear contribution to image intensity. Copyright © 2017 Elsevier B.V. All rights reserved.

  8. Improved Zone Plate Coded Imaging Technique by Using Four Special Designed Gabor Zone Plates

    Institute of Scientific and Technical Information of China (English)

    CAO Lei-Feng; SHEN Yu-Ji; ZHENG Zhi-Jian; DING Yong-Kun

    2005-01-01

    @@ Direct-current component, high-order artifacts, and side lobe distortion provide serious drawbacks in the application of Fresnel zone plate coded imaging (ZPCI).The presentation provided here proposes a novel way to resolve all the above-mentioned problems.Four different Gabor zone plates are suggested to substitute the one Fresnel zone plate used in the conventional ZPCI.Perfect reconstruction will be obtained when integrally analysing the four coded images.Primary numerical simulation provided here shows good result.

  9. A study of LED light-linear device for light guide plate applications

    Science.gov (United States)

    Chien, Chao-Heng; Chen, Zhi-Peng

    2007-09-01

    A conventional backlight unit (BLU) is utilized to as the light module to present uniform light of liquid crystal display (LCD). In general, cold cathode fluorescent lamp (CCFL) is used to be the light source of BLU. The light emitting diode (LED) is well known as a promising device for solid state lighting. It has the advantages of long life, no mercury containing and good endurance of heavy impact. To satisfy the market demands of the thin-film liquid crystal display (LCD) and the green product, the LED is applied to as the light source to make display thinner, lighter, no Hg containing. In this research, the LED light-linear device with microprism structure is demonstrated that it can make the point-like light to distribute propagating-light line pattern successfully. By optimizing the distributions and sizes of microprisms, the designed LED-linear device can achieve an illuminative efficiency more than 80%~90%, and its light output area is two times the input light source. Thus, the LED light-linear device with microprsims not only can decrease the LED to save the space, but also increase the optical efficiency. In future, a novel LED light module could make displays thinner and lighter for light guide plate (LGP) applications.

  10. AstroImageJ: Image Processing and Photometric Extraction for Ultra-Precise Astronomical Light Curves

    CERN Document Server

    Collins, Karen A; Stassun, Keivan G

    2016-01-01

    ImageJ is a graphical user interface (GUI) driven, public domain, Java-based, software package for general image processing traditionally used mainly in life sciences fields. The image processing capabilities of ImageJ are useful and extendable to other scientific fields. Here we present AstroImageJ (AIJ), which provides an astronomy specific image display environment and tools for astronomy specific image calibration and data reduction. Although AIJ maintains the general purpose image processing capabilities of ImageJ, AIJ is streamlined for time-series differential photometry, light curve detrending and fitting, and light curve plotting, especially for applications requiring ultra-precise light curves (e.g., exoplanet transits). AIJ reads and writes standard FITS files, as well as other common image formats, provides FITS header viewing and editing, and is World Coordinate System (WCS) aware, including an automated interface to the astrometry.net web portal for plate solving images. Although AIJ provides re...

  11. Nanosecond gating properties of proximity focused microchannel plate image intensifiers

    Science.gov (United States)

    King, N. S. P.; King, N. S. P.; Yates, G. J.; Jaramillo, S. A.; Noel, B. W.; Detch, J. L., Jr.; Ogle, J. W.

    The optical gating properties of Multichannel plate image intensifiers were characterized. Emphasis was placed on parameters relevant to gating speed and correlations between the applied electrical and resultant optical gates.

  12. Surface Patterning of Ceramic Phosphor Plate for Light Extraction

    Science.gov (United States)

    Mao, An

    Light-Emitting Diodes (LEDs) are expected to replace traditional lighting sources in the near future due to their energy-efficiency, optical design flexibility and good reliability over traditional lighting sources. III-V nitride blue LEDs with powdered phosphors have been used commercially to get white emission. However, due to scattering losses, thermal issues as well as the surface reactivity with common encapsulants, LEDs fabricated with powdered phosphors have limitations in achieving high luminous efficacy, high chromatic stability and good color-rendering properties. Solid, non-scattering phosphors could avoid many of these limitations, but issues of light extraction and coupling of excitation radiation to the phosphor require development to insure efficient operation. Photonic crystal structures fabricated into or on non-scattering phosphors can be used to address these challenges. In this thesis, a lift-off process with bilayer resist system is developed to create nanopatterns. A photonic crystal structure is fabricated by low cost molecular transfer lithography (MxL) with bi-layer resist system on non-scattering phosphor plate used for white emission to increase the extraction efficiency. In Chapter 1, some basic background concepts which appear frequently in this thesis are introduced. These concepts include the Stokes shift and backscattering phenomenon for powder phosphors as well as non-scattering phosphors. In Chapter 2, a non-scattering single crystal phosphor with a patterned surface is proposed to replace the powdered phosphors used for color converted LEDs. A non-scattering phosphor YAG:Ce ceramic phosphor plate (CPP) patterned with TiO2 photonic crystal structure is selected for convenience to demonstrate the concept. The physical origin of light extraction of the proposed structure is discussed. The simulation principles and results are discussed in this chapter to find the optimized photonic crystal structure for light extraction. In Chapter 3

  13. Application of atomic layer deposited microchannel plates to imaging photodetectors with high time resolution

    Energy Technology Data Exchange (ETDEWEB)

    Siegmund, O; McPhate, J; Tremsin, Anton S; Vallerga, J V; Ertley, C D; Richner, N J; Gerard, T M; Frisch, H.; Elam, Jeffrey W.; Mane, Anil U.; Wagner, Robert G.; Minot, Michael J.; O' Mahony, Aileen O; Craven, C A

    2015-07-01

    Novel microchannel plates have been constructed using borosilicate glass micro-capillary array substrates with 20 mu m and 10 mu m pores and coated with resistive, and secondary electron emissive, layers by atomic layer deposition. Microchannel plates in 33 mm, 50 mm and 20 cm square formats have been made and tested. Although their amplification, imaging, and timing properties are comparable to standard glass microchannel plates, the background rates and lifetime characteristics are considerably improved. Sealed tube detectors based on the Planacon tube, and a 25 mm cross delay line readout tube with a GaN(Mg) opaque photocathode deposited on borosilicate microchannel plates have been fabricated. Considerable progress has also been made with 20 cm microchannel plates for a 20 cm format sealed tube sensor with strip-line readout that is being developed for Cherenkov light detection.

  14. Application of atomic layer deposited microchannel plates to imaging photodetectors with high time resolution

    Energy Technology Data Exchange (ETDEWEB)

    Siegmund, O.H.W., E-mail: ossy@ssl.berkeley.edu [Experimental Astrophysics Group, Space Sciences Laboratory, 7 Gauss Way, University of California, Berkeley, CA 94720 (United States); McPhate, J.B.; Tremsin, A.S.; Vallerga, J.V.; Ertley, C.D.; Richner, N.J.; Gerard, T.M. [Experimental Astrophysics Group, Space Sciences Laboratory, 7 Gauss Way, University of California, Berkeley, CA 94720 (United States); Frisch, H.J. [University of Chicago, 5640 S. Ellis Ave., Chicago, Il 60637 (United States); Elam, J.W.; Mane, A.U.; Wagner, R.G. [Argonne National Laboratory, 9700 S. Cass Ave. Lemont, Il 60439 (United States); Minot, M.J.; O' Mahony, A.; Craven, C.A. [Incom Inc., 294 Southbridge Road, Charlton, MA, 01507 (United States)

    2015-07-01

    Novel microchannel plates have been constructed using borosilicate glass micro-capillary array substrates with 20 µm and 10 µm pores and coated with resistive, and secondary electron emissive, layers by atomic layer deposition. Microchannel plates in 33 mm, 50 mm and 20 cm square formats have been made and tested. Although their amplification, imaging, and timing properties are comparable to standard glass microchannel plates, the background rates and lifetime characteristics are considerably improved. Sealed tube detectors based on the Planacon tube, and a 25 mm cross delay line readout tube with a GaN(Mg) opaque photocathode deposited on borosilicate microchannel plates have been fabricated. Considerable progress has also been made with 20 cm microchannel plates for a 20 cm format sealed tube sensor with strip-line readout that is being developed for Cherenkov light detection.

  15. Confocal Image 3D Surface Measurement with Optical Fiber Plate

    Institute of Scientific and Technical Information of China (English)

    WANG Zhao; ZHU Sheng-cheng; LI Bing; TAN Yu-shan

    2004-01-01

    A whole-field 3D surface measurement system for semiconductor wafer inspection is described.The system consists of an optical fiber plate,which can split the light beam into N2 subbeams to realize the whole-field inspection.A special prism is used to separate the illumination light and signal light.This setup is characterized by high precision,high speed and simple structure.

  16. Si microchannel plates for image intensification

    Science.gov (United States)

    Smith, Arlynn W.; Beetz, Charles P., Jr.; Boerstler, Robert W.; Winn, D. R.; Steinbeck, John W.

    2000-11-01

    Glass microchannel plates (MCPs) have been in use by numerous manufactuers in a variety of electron multiplication applications. Conventional fabrication of MCPs follow the lines of glass drawing and etching technology. Core and clad glass are drawn together, stacked, drawn again, and finally stacked in the desired pattern. The soluble core is removed with wet chemical processing. These techniques are beginning to run into their feasible limits in terms of channel size, open area ratio, uniformity, and material issues. A strong desire exists to fabricate MCPs with accepted lithographic techniques using Si as the base material to improve uniformity and throughput. Open area ratios of as high as 95% have been achieved using lithography. However, attempts to meet other channel plate characteristics met with little success due to thermal runaway or arcing during operation, high voltage is required for electron gain. Processing improvements have lead to the complete oxidation of the Si matrix eliminating the conducting Si in the channel walls of the Si MCPs allowing high voltages to be supported. Complete oxidation of the Si to silica allows processing temperatures high than conventional glass matrices can withstand. This fact allows for high temperature growth of conductive and secondary emissive materials on the channel walls of the structure. Si MCPs with gain have now been fabricated and tested with voltages comparable to conventional glass MCPs. Channel plate characteristics such as operating voltage, strip current, and gain for Si MCPs will be presented and compared to glass MCPs.

  17. Magnetic Imaging with a Novel Hole-Free Phase Plate

    DEFF Research Database (Denmark)

    Pollard, Shawn; Malac, Marek; Beleggia, Marco

    2014-01-01

    One of the main interests in phase plate imaging is motivated by a decrease in irradiation dose needed to obtain desired signal to noise ratio, a result of improved contrast transfer [1]. The decrease in irradiation improves the imaging of biological materials [2]. Here we demonstrate that phase ...

  18. Simulation of computed radiography with imaging plate detectors

    Energy Technology Data Exchange (ETDEWEB)

    Tisseur, D.; Costin, M. [CEA LIST, CEA Saclay 91191 Gif sur Yvette Cedex (France); Mathy, F. [CEA-LETI, Campus Minatec, F-38054, Grenoble (France); Schumm, A. [EDF R and D, 1 avenue du général de gaulle 92141 Clamart (France)

    2014-02-18

    Computed radiography (CR) using phosphor imaging plate detectors is taking an increasing place in Radiography Testing. CR uses similar equipment as conventional radiography except that the classical X-ray film is replaced by a numerical detector, called image plate (IP), which is made of a photostimulable layer and which is read by a scanning device through photostimulated luminescence. Such digital radiography has already demonstrated important benefits in terms of exposure time, decrease of source energies and thus reduction of radioprotection area besides being a solution without effluents. This paper presents a model for the simulation of radiography with image plate detectors in CIVA together with examples of validation of the model. The study consists in a cross comparison between experimental and simulation results obtained on a step wedge with a classical X-ray tube. Results are proposed in particular with wire Image quality Indicator (IQI) and duplex IQI.

  19. Imaging by Zernike phase plates in the TEM.

    Science.gov (United States)

    Edgcombe, C J

    2016-08-01

    The images produced from simple phase objects, lenses and Zernike phase plates when all have rotational symmetry can be calculated by 1D Fourier-Bessel transforms. For a simple disc object producing a uniform phase shift over its diameter, the resulting image can be defined for any size of object phase change. The monotonic range of intensity variation with object phase is found to depend strongly on the phase change introduced by the phase plate; this property of the system is not well predicted by the weak phase approximation. The effect of spreading the phase transition at the plate over a range of radius is beneficial if the plate phase change is sufficiently small. Weak-phase calculations for a phase distribution more typical of a spherical object are also shown.

  20. Imaging features of ductal plate malformations in adults

    Energy Technology Data Exchange (ETDEWEB)

    Venkatanarasimha, N., E-mail: nandashettykv@yahoo.com [Department of Radiology, Derriford Hospital, Plymouth (United Kingdom); Thomas, R.; Armstrong, E.M.; Shirley, J.F.; Fox, B.M.; Jackson, S.A. [Department of Radiology, Derriford Hospital, Plymouth (United Kingdom)

    2011-11-15

    Ductal plate malformations, also known as fibrocystic liver diseases, are a group of congenital disorders resulting from abnormal embryogenesis of the biliary ductal system. The abnormalities include choledochal cyst, Caroli's disease and Caroli's syndrome, adult autosomal dominant polycystic liver disease, and biliary hamartoma. The hepatic lesions can be associated with renal anomalies such as autosomal recessive polycystic kidney disease (ARPKD), medullary sponge kidney, and nephronophthisis. A clear knowledge of the embryology and pathogenesis of the ductal plate is central to the understanding of the characteristic imaging appearances of these complex disorders. Accurate diagnosis of ductal plate malformations is important to direct appropriate clinical management and prevent misdiagnosis.

  1. Digital image quantification of siderophores on agar plates

    Directory of Open Access Journals (Sweden)

    Megan Y. Andrews

    2016-03-01

    Full Text Available This article presents visual image data and detailed methodology for the use of a new method for quantifying the exudation of siderophores during fungal growth. The data include images showing time series for calibration, fungal exudation, and negative controls, as well as replication accuracy information. In addition, we provide detailed protocols for making CAS assay layer plates, the digital analysis protocol for determining area of color change, and discuss growth media that do and do not work with the layer plate method. The results of these data, their interpretation, and further discussion can be found in Andrews et al., 2016 [1].

  2. Measurement of imaging properties of scintillating fiber optic plate

    Science.gov (United States)

    Zentai, George; Ganguly, Arundhuti; Star-Lack, Josh; Virshup, Gary; Hirsh, Hayley; Shedlock, Daniel; Humber, David

    2014-03-01

    Scintillating Fiber Optic Plates (SFOP) or Fiber Optic Scintillator (FOS) made with scintillating fiber-glass, were investigated for x-ray imaging. Two different samples (T x W x L = 2cm x 5cm x 5cm) were used; Sample A: 10μm fibers, Sample B: 50μm fibers both with statistically randomized light absorbing fibers placed in the matrix. A customized holder was used to place the samples in close contact with photodiodes in an amorphous silicon flat panel detector (AS1000, Varian), typically used for portal imaging. The detector has a 392μm pixel pitch and in the standard configuration uses a gadolinium oxy-sulphide (GOS) screen behind a copper plate. X-ray measurements were performed at 120kV (RQA 9 spectrum), 1MeV (5mm Al filtration) and 6MeV (Flattening Filter Free) for Sample A and the latter 2 spectra for Sample B. A machined edge was used for MTF measurements. The measurements showed the MTF degraded with increased X-ray energies because of the increase in Compton scattering. However, at the Nyquist frequency of 1.3lp/mm, the MTF is still high (FOS value vs. Cu+GOS): (a) 37% and 21% at 120kVp for the 10μm FOS and the Cu+GOS arrays, (b) 31%, 20% and 20% at 1MeV and (c) 17%, 11% and 14% at 6MeV for the 10μm FOS, 50μm FOS and the Cu+GOS arrays. The DQE(0) value comparison were (a) at 120kV ~24% and ~13 % for the 10μm FOS and the Cu+GOS arrays (b) at 1MV 10%, 10% and 7% and (c) at 6MV 12%, ~19% and 1.6% for the 10μm FOS , 50μm FOS and Cu+GOS arrays.

  3. Non-invasive terahertz field imaging inside parallel plate waveguides

    DEFF Research Database (Denmark)

    Iwaszczuk, Krzysztof; Andryieuski, Andrei; Lavrinenko, Andrei

    2011-01-01

    We present a non-invasive broadband air photonic method of imaging of the electric field of THz pulses propagating inside a tapered parallel plate waveguide. The method is based on field-enhanced second harmonic generation of the fundamental laser beam in an external electric field. We apply...

  4. Terahertz field imaging inside tapered parallel plate waveguides

    DEFF Research Database (Denmark)

    Iwaszczuk, Krzysztof; Andryieuski, Andrei; Lavrinenko, Andrei

    We present a non-invasive broadband air photonic method of terahertz field imaging inside a tapered parallel plate waveguide. The method is based on the terahertz-enhanced second harmonic generation of the fundamental laser beam in an external electric field. We also demonstrate the direct...

  5. Neutron detection with imaging plates Part II. Detector characteristics

    CERN Document Server

    Thoms, M

    1999-01-01

    On the basis of the physical processes described in Neutron detection with imaging plates - part I: image storage and readout [Nucl. Instr. and Meth. A 424 (1999) 26-33] detector characteristics, such as quantum efficiency, detective quantum efficiency, sensitivity to neutron- and gamma-radiation, readout time and dynamic range are predicted. It is estimated that quantum efficiencies and detective quantum efficiencies close to 100% can be reached making these kind of detectors interesting for a wide range of applications.

  6. Image scanning microscopy with radially polarized light

    Science.gov (United States)

    Xiao, Yun; Zhang, Yunhai; Wei, Tongda; Huang, Wei; Shi, Yaqin

    2017-03-01

    In order to improve the resolution of image scanning microscopy, we present a method based on image scanning microscopy and radially polarized light. According to the theory of image scanning microscopy, we get the effective point spread function of image scanning microscopy with the longitudinal component of radially polarized light and a 1 AU detection area, and obtain imaging results of the analyzed samples using this method. Results show that the resolution can be enhanced by 7% compared with that in image scanning microscopy with circularly polarized light, and is 1.54-fold higher than that in confocal microscopy with a pinhole of 1 AU. Additionally, the peak intensity of ISM is 1.54-fold higher than that of a confocal microscopy with a pinhole of 1 AU. In conclusion, the combination of the image scanning microscopy and the radially polarized light could improve the resolution, and it could realize high-resolution and high SNR imaging at the same time.

  7. Development and characterisation of a visible light photon counting imaging detector system

    CERN Document Server

    Barnstedt, J

    2002-01-01

    We report on the development of a visible light photon counting imaging detector system. The detector concept is based on standard 25 mm diameter microchannel plate image intensifiers made by Proxitronic in Bensheim (Germany). Modifications applied to these image intensifiers are the use of three microchannel plates instead of two and a high resistance ceramics plate used instead of the standard phosphor output screen. A wedge and strip anode mounted directly behind the high resistance ceramics plate was used as a read out device. This wedge and strip anode picks up the image charge of electron clouds emerging from the microchannel plates. The charge pulses are fed into four charge amplifiers and subsequently into a digital position decoding electronics, achieving a position resolution of up to 1024x1024 pixels. Mounting the anode outside the detector tube is a new approach and has the great advantage of avoiding electrical feedthroughs from the anode so that the standard image intensifier fabrication process...

  8. Novel large format sealed tube microchannel plate detectors for Cherenkov timing and imaging

    Energy Technology Data Exchange (ETDEWEB)

    Siegmund, O.H.W., E-mail: ossy@ssl.berkeley.ed [Experimental Astrophysics Group, Space Sciences Laboratory, 7 Gauss Way, University of California, Berkeley, CA 94720 (United States); McPhate, J.B.; Vallerga, J.V.; Tremsin, A.S.; Jelinsky, S.R. [Experimental Astrophysics Group, Space Sciences Laboratory, 7 Gauss Way, University of California, Berkeley, CA 94720 (United States); Frisch, H.J. [Enrico Fermi Institute, 5640 S. Ellis Avenue, University of Chicago, Chicago, IL 60637 (United States)

    2011-05-21

    Large area (20x20 cm{sup 2}) sealed tube detectors using novel borosilicate glass microchannel plates, with bialkali photocathodes and strip-line readouts are being developed for Cherenkov light detection. Designs based on conventional sealed tubes with alumina brazed body construction and hot indium seals have been developed. Borosilicate glass substrates with 20 and 40 {mu}m holes have been processed using atomic layer deposition to produce functional microchannel plates. Initial results for these in a 33 mm format show gain, imaging performance, pulse shape and lifetime characteristics that are similar to standard glass microchannel plates. Large area (20x20 cm{sup 2}) borosilicate glass substrates with 20 {mu}m pores have also been made.

  9. AstroImageJ: Image Processing and Photometric Extraction for Ultra-precise Astronomical Light Curves

    Science.gov (United States)

    Collins, Karen A.; Kielkopf, John F.; Stassun, Keivan G.; Hessman, Frederic V.

    2017-02-01

    ImageJ is a graphical user interface (GUI) driven, public domain, Java-based, software package for general image processing traditionally used mainly in life sciences fields. The image processing capabilities of ImageJ are useful and extendable to other scientific fields. Here we present AstroImageJ (AIJ), which provides an astronomy specific image display environment and tools for astronomy specific image calibration and data reduction. Although AIJ maintains the general purpose image processing capabilities of ImageJ, AIJ is streamlined for time-series differential photometry, light curve detrending and fitting, and light curve plotting, especially for applications requiring ultra-precise light curves (e.g., exoplanet transits). AIJ reads and writes standard Flexible Image Transport System (FITS) files, as well as other common image formats, provides FITS header viewing and editing, and is World Coordinate System aware, including an automated interface to the astrometry.net web portal for plate solving images. AIJ provides research grade image calibration and analysis tools with a GUI driven approach, and easily installed cross-platform compatibility. It enables new users, even at the level of undergraduate student, high school student, or amateur astronomer, to quickly start processing, modeling, and plotting astronomical image data with one tightly integrated software package.

  10. Application of imaging plate neutron detector to neutron radiography

    CERN Document Server

    Fujine, S; Kamata, M; Etoh, M

    1999-01-01

    As an imaging plate neutron detector (IP-ND) has been available for thermal neutron radiography (TNR) which has high resolution, high sensitivity and wide range, some basic characteristics of the IP-ND system were measured at the E-2 facility of the KUR. After basic performances of the IP were studied, images with high quality were obtained at a neutron fluence of 2 to 7x10 sup 8 n cm sup - sup 2. It was found that the IP-ND system with Gd sub 2 O sub 3 as a neutron converter material has a higher sensitivity to gamma-ray than that of a conventional film method. As a successful example, clear radiographs of the flat view for the fuel side plates with boron burnable poison were obtained. An application of the IP-ND system to neutron radiography (NR) is presented in this paper.

  11. DAFS measurements using the image-plate Weissenberg method

    Energy Technology Data Exchange (ETDEWEB)

    Sugioka, N.; Matsumoto, K.; Sasaki, S. [Tokyo Inst. of Technology, Materials and Structures Lab., Yokohama (Japan); Tanaka, M.; Mori, T. [National Lab. for High Energy Physics, Photon Factory, Tsukuba (Japan)

    1998-05-01

    An instrumental technique for DAFS measurements which can provide site-specific information is proposed. The approach uses (i) focusing optics with parabolic mirrors and a double-crystal monochromator, (ii) the Laue and Bragg settings and (iii) data collection by the image-plate Weissenberg method. Six image exposures are recorded per plate at five intrinsic energies and one reference energy. The single-crystal measurements were performed at the Co K-absorption edge, and the 200, 220 and 311 reflections of CoO and 511 and 911 reflections of Co{sub 3}O{sub 4} were used for analysis. The regression analysis of {chi}(k), Fourier transforms of k{sup 3}{chi}(k) and back-Fourier filtering have been performed. 20 refs.

  12. DAFS measurements using the image-plate Weissenberg method.

    Science.gov (United States)

    Sugioka, N; Matsumoto, K; Tanaka, M; Mori, T; Sasaki, S

    1998-05-01

    An instrumental technique for DAFS measurements which can provide site-specific information is proposed. The approach uses (i) focusing optics with parabolic mirrors and a double-crystal monochromator, (ii) the Laue and Bragg settings and (iii) data collection by the image-plate Weissenberg method. Six image exposures are recorded per plate at five intrinsic energies and one reference energy. The single-crystal measurements were performed at the Co K-absorption edge, and the 200, 220 and 311 reflections of CoO and 511 and 911 reflections of Co(3)O(4) were used for analysis. The regression analysis of chi(k), Fourier transforms of k(3)chi(k) and back-Fourier filtering have been performed.

  13. The character and application of a neutron imaging plate (NIP)

    Science.gov (United States)

    Karasawa, Y.; Kumazawa, S.; Miimura, N.

    We have developed a neutron imaging plate (NIP) as a new neutron detector and already reported the fundamental features of the NIP. The optimization of the NIP was carried out by changing a molar ratio of converter materials to PSL (Photostimulated luminescence) materials and thickness of the NIP. Some problems such as γ-ray sensitivity and irradiation effect for the practical use of the NIP were discussed. Several examples of application of the NIP were introduced.

  14. Light-Weight, Low-Cost, Single-Phase, Liquid-Cooled Cold Plate (Presentation)

    Energy Technology Data Exchange (ETDEWEB)

    Narumanchi, S.

    2013-07-01

    This presentation, 'Light-Weight, Low-Cost, Single-Phase Liquid-Cooled Cold Plate,' directly addresses program goals of increased power density, specific power, and lower cost of power electronics components through improved thermal management.

  15. Hex-square moire patterns in imagers using microchannel plates

    Science.gov (United States)

    Lawrence, George M.

    1989-01-01

    In electronic imaging detectors using microchannel plates, the mismatch between the pixels on a square mesh and the microchannels on a hexagonal mesh produces moire image defects. Theoretical statistical estimates of the sizes of the microposition offsets and the flat field intensity errors are calculated, showing the trade-off between resolution and position accuracy. A distinction is made between moments of spot images and moments of the single-pixel-response functions. As the resolution between the hex and square meshes is improved, the detector resolution is improved, but at the expense of an about 10 percent moire pattern. These moire patterns will not be properly corrected by dividing by the flat field image.

  16. Improving poor fill factors for solar cells via light-induced plating

    Institute of Scientific and Technical Information of China (English)

    Xing Zhao; Jia Rui; Ding Wuchang; Meng Yanlong; Jin Zhi; Liu Xinyu

    2012-01-01

    Silicon solar cells are prepared following the conventional fabrication processes,except for the metallization firing process.The cells are divided into two groups with higher and lower fill factors,respectively.After light-induced plating (LIP),the fill factors of the solar cells in both groups with different initial values reach the same level.Scanning electron microscope (SEM) images are taken under the bulk silver electrodes,which prove that the improvement for cells with a poor factor after LIP should benefit from sufficient exploitation of the high density silver crystals formed during the firing process.Moreover,the application of LIP to cells with poor electrode contact performance,such as nanowire cells and radial junction solar cells,is proposed.

  17. Guided wave phased array beamforming and imaging in composite plates.

    Science.gov (United States)

    Yu, Lingyu; Tian, Zhenhua

    2016-05-01

    This paper describes phased array beamforming using guided waves in anisotropic composite plates. A generic phased array algorithm is presented, in which direction dependent guided wave parameters and the energy skew effect are considered. This beamforming at an angular direction is achieved based on the classic delay-and-sum principle by applying phase delays to signals received at array elements and adding up the delayed signals. The phase delays are determined with the goal to maximize the array output at the desired direction and minimize it otherwise. For array characterization, the beam pattern of rectangular grid arrays in composite plates is derived. In addition to the beam pattern, the beamforming factor in terms of wavenumber distribution is defined to provide intrinsic explanations for phased array beamforming. The beamforming and damage detection in a composite plate are demonstrated using rectangular grid arrays made by a non-contact scanning laser Doppler vibrometer. Detection images of the composite plate with multiple surface defects at various directions are obtained. The results show that the guided wave phased array method is a potential effective method for rapid inspection of large composite structures.

  18. Structured light field 3D imaging.

    Science.gov (United States)

    Cai, Zewei; Liu, Xiaoli; Peng, Xiang; Yin, Yongkai; Li, Ameng; Wu, Jiachen; Gao, Bruce Z

    2016-09-05

    In this paper, we propose a method by means of light field imaging under structured illumination to deal with high dynamic range 3D imaging. Fringe patterns are projected onto a scene and modulated by the scene depth then a structured light field is detected using light field recording devices. The structured light field contains information about ray direction and phase-encoded depth, via which the scene depth can be estimated from different directions. The multidirectional depth estimation can achieve high dynamic 3D imaging effectively. We analyzed and derived the phase-depth mapping in the structured light field and then proposed a flexible ray-based calibration approach to determine the independent mapping coefficients for each ray. Experimental results demonstrated the validity of the proposed method to perform high-quality 3D imaging for highly and lowly reflective surfaces.

  19. Relationship between image plates physical structure and quality of digital radiographic images in weld inspections

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Davi F.; Silva, Aline S.S.; Machado, Alessandra S.; Gomes, Celio S.; Nascimento, Joseilson; Lopes, Ricardo T., E-mail: davi@lin.ufrj.br.br, E-mail: aline@lin.ufrj.br, E-mail: celio@lin.ufrj.br, E-mail: alemachado@lin.ufrj.br, E-mail: joseilson@lin.ufrj.br, E-mail: ricardo@lin.ufrj.br [Coordenacao dos Programas de Pos-Graduacao em Engenharia (COPPE/UFRJ), Rio de Janeiro, RJ (Brazil). Lab. de Instrumentacao Nuclear

    2015-07-01

    In the last decades a new type of detector which is based on photostimulable luminescence was developed. There are currently many kinds of image plates (IPs) available on the market, originating from different manufacturers. Each kind of plate distinguishes itself from the others by its peculiar physical structure and composition, two factors which have a direct influence upon the quality of the digital radiographic images obtained through them. For this study, several kinds of IPs were tested in order to determine in which way such influence takes place. For this purpose, each kind of IP has been characterized and correlated to its response in the final image. The aim of this work was to evaluate procedures for employing Computed Radiography (CR) to welding inspections in laboratory conditions using the Simple Wall Simple Image Technique (SWSI). Tests were performed in steel welded joins of thickness 5.33, 12.70 and 25.40 mm, using CR scanner and IPs available on the market. It was used an X-Ray equipment as radiation source. The image quality parameters Basic Spatial Resolution (BSR), Normalized Signal-to-Noise Ratio (SNR{sub N}), contrast and detectability were evaluated. In order to determine in which way the IPs' properties are correlated to its response in the final image, the thickness of the sensitive layer was determined and the grain size and the elemental composition of this layer were evaluated. Based on the results drawn from this study, it is possible to conclude that the physical characteristics of image plates are essential for determining the quality of the digital radiography images acquired with them. Regarding the chemical composition of the plates, it was possible to determine that, apart from the chemical elements that were expected to be found (Ba, I and Br), only two plates, with high resolution, do not have fluorine in their composition; the presence of Strontium was also detected in the chemical composition of the plates supplied by a

  20. Performance of the low light level CCD camera for speckle imaging

    CERN Document Server

    Saha, S K

    2002-01-01

    A new generation CCD detector called low light level CCD (L3CCD) that performs like an intensified CCD without incorporating a micro channel plate (MCP) for light amplification was procured and tested. A series of short exposure images with millisecond integration time has been obtained. The L3CCD is cooled to about $-80^\\circ$ C by Peltier cooling.

  1. Image quality evaluation of light field photography

    Science.gov (United States)

    Fu, Qiang; Zhou, Zhiliang; Yuan, Yan; Xiangli, Bin

    2011-01-01

    Light field photography captures 4D radiance information of a scene. Digital refocusing and digital correction of aberrations could be done after the photograph is taken. However, capturing 4D light field is costly and tradeoffs between different image quality metrics should be made and evaluated. This paper explores the effects of light field photography on image quality by quantitatively evaluating some basic criteria for an imaging system. A simulation approach was first developed by ray-tracing a designed light field camera. A standard testing chart followed by ISO 12233 was provided as the input scene. A sequence of light field raw images were acquired and processed by light field rendering methods afterwards. Through-focus visual resolution and MTF were calculated and analyzed. As a comparison, the same tests were taken for the same main lens system as the results of conventional photography. An experimental light field system was built up and its performance was tested. This work helps better understanding the pros and cons of light field photography in contrast with conventional imaging methods and perceiving the way to optimize the joint digital-optical design of the system.

  2. Resistive Plate Chambers for Imaging Calorimetry - the DHCAL

    CERN Document Server

    Repond, Jose

    2014-01-01

    The DHCAL, the Digital Hadron Calorimeter, is a prototype calorimeter based on Resistive Plate Chambers (RPCs). The design emphasizes the imaging capabilities of the detector in an effort to optimize the calorimeter for the application of Particle Flow Algorithms (PFAs) to the reconstruction of hadronic jet energies in a colliding beam environment. The readout of the chambers is segmented into 1 x 1 cm2 pads, each read out with a 1-bit (single threshold) resolution. The prototype with approximately 500,000 readout channels underwent extensive testing in both the Fermilab and CERN test beams. This talk presents preliminary findings from the analysis of data collected at the test beams.

  3. Complex light modulation for lensless image projection

    Institute of Scientific and Technical Information of China (English)

    M. Makowski; A. Kolodziejczyk; A. Siemion; I. Ducin; K. Kakarenko; M. Sypek; A. M. Siemion; J. Suszek; D. Wojnowski; Z. Jaroszewicz

    2011-01-01

    We present a lensless projection of color images based on computer-generated Fourier holograms. Amplitude and phase modulation of three primary-colored laser beams is performed by a matched pair of spatial light modulators. The main advantage of the complex light modulation is the lack of iterative phase retrieval techniques. The advantage is the lack of speckles in the projected images. Experimental results are given and compared with the outcome of classical phase-only modulation.%We present a lensless projection of color images based on computer-generated Fourier holograms.Amplitude and phase modulation of three primary-colored laser beams is performed by a matched pair of spatial light modulators.The main advantage of the complex light modulation is the lack of iterative phase retrieval techniques.The advantage is the lack of speckles in the projected images.Experimental results are given and compared with the outcome of classical phase-only modulation.

  4. Imaging characteristics of the Extreme Ultraviolet Explorer microchannel plate detectors

    Science.gov (United States)

    Vallerga, J. V.; Kaplan, G. C.; Siegmund, O. H. W.; Lampton, M.; Malina, R. F.

    1989-01-01

    The Extreme Ultraviolet Explorer (EUVE) satellite will conduct an all-sky survey over the wavelength range from 70 A to 760 A using four grazing-incidence telescopes and seven microchannel-plate (MCP) detectors. The imaging photon-counting MCP detectors have active areas of 19.6 cm2. Photon arrival position is determined using a wedge-and-strip anode and associated pulse-encoding electronics. The imaging characteristics of the EUVE flight detectors are presented including image distortion, flat-field response, and spatial differential nonlinearity. Also included is a detailed discussion of image distortions due to the detector mechanical assembly, the wedge-and-strip anode, and the electronics. Model predictions of these distortions are compared to preflight calibration images which show distortions less than 1.3 percent rms of the detector diameter of 50 mm before correction. The plans for correcting these residual detector image distortions to less than 0.1 percent rms are also presented.

  5. Alveolar bone measurement precision for phosphor-plate images

    Science.gov (United States)

    HILDEBOLT, CHARLES F.; COUTURE, REX; GARCIA, NATHALIA M.; DIXON, DEBRA; SHANNON, WILLIAM DOUGLAS; LANGENWALTER, ERIC; CIVITELLI, ROBERTO

    2009-01-01

    Objectives To demonstrate methods for determining measurement precision and to determine the precision of alveolar-bone measurements made with a vacuum-coupled, positioning device and phosphor-plate images. Study design Subjects were rigidly attached to the x-ray tube by means of a vacuum coupling device and custom, cross-arch, bite plates. Original and repeat radiographs (taken within minutes of each other) were obtained of the mandibular posterior teeth of 51 subjects, and cementoenamel-junction-alveolar-crest (CEJ-AC) distances were measured on both sets of images. In addition, x-ray-transmission (radiodensity) and alveolar-crest-height differences were determined by subtracting one image from the other. Image subtractions and measurements were performed twice. Based on duplicate measurements, the root-mean-square standard deviation (precision) and least-significant change (LSC) were calculated. LSC is the magnitude of change in a measurement needed to indicate that a true biological change has occurred. Results The LSCs were 4% for x-ray transmission, 0.49 mm for CEJ-AC distance, and 0.06 mm for crest-height 0.06 mm. Conclusion The LSCs for our CEJ-AC and x-ray transmission measurements are similar to what has been reported. The LSC for alveolar-crest height (determined with image subtraction) was less than 0.1 mm. Compared with findings from previous studies, this represents a highly precise measurement of alveolar crest height. The methods demonstrated for calculating LSC can be used by investigators to determine how large changes in radiographic measurements need to be before the changes can be considered (with 95% confidence) true biological changes and not noise (that is, equipment/observer error). PMID:19716499

  6. Thermal light ghost imaging based on morphology

    Science.gov (United States)

    Chen, Zhipeng; Shi, Jianhong; Zeng, Guihua

    2016-12-01

    The quality of thermal light ghost imaging could be degraded by undersampling noise. This kind of noise is generated because of finite sampling, which could reduce the signal-to-noise ratio (SNR) of ghost imaging and submerge object information. In order to reduce the undersampling noise, we propose a thermal light ghost imaging scheme based on the morphology (GIM). In this scheme, the average size of the undersampling noise can be obtained by computing the second-order correlation function of the ghost imaging system. According to the average size of the undersampling noise, the corresponding structure element can be designed and used in the morphological filter; then, the GIM reconstructed image can be obtained. The experiment results show that the peak signal-to-noise ratio of the GIM reconstructed image can increased by 80% than that of conventional ghost imaging for the same number of measurements.

  7. White-light Quantitative Phase Imaging Unit

    CERN Document Server

    Baek, YoonSeok; Yoon, Jonghee; Kim, Kyoohyun; Park, YongKeun

    2016-01-01

    We introduce the white light quantitative phase imaging unit (WQPIU) as a practical realization of quantitative phase imaging (QPI) on standard microscope platforms. The WQPIU is a compact stand-alone unit which measures sample induced phase delay under white-light illumination. It does not require any modification of the microscope or additional accessories for its use. The principle of the WQPIU based on lateral shearing interferometry and phase shifting interferometry provides a cost-effective and user-friendly use of QPI. The validity and capacity of the presented method are demonstrated by measuring quantitative phase images of polystyrene beads, human red blood cells, HeLa cells and mouse white blood cells. With speckle-free imaging capability due to the use of white-light illumination, the WQPIU is expected to expand the scope of QPI in biological sciences as a powerful but simple imaging tool.

  8. Very high position resolution gamma imaging with resistive plate chambers

    Energy Technology Data Exchange (ETDEWEB)

    Blanco, A. [LIP, Laboratorio de Instrumentacao e Fisica Experimental de Particulas, Coimbra 3004-516 (Portugal)]. E-mail: alberto@coimbra.lip.pt; Carolino, N. [LIP, Laboratorio de Instrumentacao e Fisica Experimental de Particulas, Coimbra 3004-516 (Portugal); Correia, C.M.B.A. [CEI, Centro de Electronica e Instrumentacao, Universidade de Coimbra, Coimbra 3004-516 (Portugal); Fazendeiro, L. [LIP, Laboratorio de Instrumentacao e Fisica Experimental de Particulas, Coimbra 3004-516 (Portugal); Ferreira, Nuno C. [IBILI, Instituto Biomedico de Investigacao de Luz e Imagem, Faculty of Medicine, Coimbra 3000 (Portugal); Marques, M.F. Ferreira [ICEMS, Departamento de Fisica, Universidade de Coimbra, Coimbra 3004-516 (Portugal); ISEC, Instituto Superior de Engenharia de Coimbra, Coimbra 3031-199 (Portugal); Marques, R. Ferreira [LIP, Laboratorio de Instrumentacao e Fisica Experimental de Particulas, Coimbra 3004-516 (Portugal); Departamento de Fisica, Universidade de Coimbra, Coimbra 3004-516 (Portugal); Fonte, P. [LIP, Laboratorio de Instrumentacao e Fisica Experimental de Particulas, Coimbra 3004-516 (Portugal); ISEC, Instituto Superior de Engenharia de Coimbra, Coimbra 3031-199 (Portugal); Gil, C. [ICEMS, Departamento de Fisica, Universidade de Coimbra, Coimbra 3004-516 (Portugal); Macedo, M.P. [CEI, Centro de Electronica e Instrumentacao, Universidade de Coimbra, Coimbra 3004-516 (Portugal); ISEC, Instituto Superior de Engenharia de Coimbra, Coimbra 3031-199 (Portugal)

    2006-11-01

    In this study we present experimental results from a first prototype of a positron emission tomography system based on the resistive plate chamber (RPC) technology. The system is composed of two counting heads, each one containing 16 single-gap RPC detectors capable of detecting the photon interaction point in the transaxial plane. Uniformity studies were performed for image resolution and sensitivity, yielding a rather uniform image resolution close to 0.3 mm FWHM across the field of view. The contribution of the photons noncolinearity effect to the intrinsic spatial resolution was also studied, causing a variation from 0.52 to 0.63 mm when the system diameter ranges from 60 to 120 mm, in agreement with calculations.

  9. Resonance Light Scattering Imaging Determination of Heparin

    Institute of Scientific and Technical Information of China (English)

    Hong Ping GUO; Cheng Zhi HUANG; Jian LING

    2006-01-01

    A laser-induced resonance light scattering (RLS) imaging method to determine heparin is described based on the high light scattering emission power of the aggregation species of heparin with α, β, γ, δtetra(4-trimethylaminoniumphenyl)prophyrin (TAPP) in solution. By imaging the light scattering signals of the aggregation species, we proposed the method to determine the heparin with a detection range of 0.02 - 0.6 μg/mL and the detection limit (3 σ) of 1.3 ng/mL.

  10. Imaging with the invisible light

    CERN Document Server

    Bellazzini, R; Brez, A; Minuti, M; Baldini, L; Latronico, L; Massai, M M; Omodei, N; Pesce-Rollins, M; Sgrò, C; Razzano, M; Pinchera, M; Bregeon, J; Kuss, M; Braem, André

    2008-01-01

    We describe a UV photo-detector with single photon(electron) counting and imaging capability. It is based on a CsI photocathode, a GEM charge multiplier and a self triggering CMOS analog pixel chip with 105k pixels at 50 micron pitch. The single photoelectron produced by the absorption of a UV photon is drifted to and multiplied inside a single GEM hole. The coordinates of the GEM avalanche are reconstructed with high accuracy (4 micron rms) by the pixel chip. As a result the map of the GEM holes, arranged on a triangular pattern at 50micron pitch, is finely imaged.

  11. Low Voltage Low Light Imager and Photodetector

    Science.gov (United States)

    Nikzad, Shouleh (Inventor); Martin, Chris (Inventor); Hoenk, Michael E. (Inventor)

    2013-01-01

    Highly efficient, low energy, low light level imagers and photodetectors are provided. In particular, a novel class of Della-Doped Electron Bombarded Array (DDEBA) photodetectors that will reduce the size, mass, power, complexity, and cost of conventional imaging systems while improving performance by using a thinned imager that is capable of detecting low-energy electrons, has high gain, and is of low noise.

  12. Hybrid noise control in a duct using a light micro-perforated plate.

    Science.gov (United States)

    Wang, X N; Choy, Y S; Cheng, L

    2012-12-01

    A plate silencer consists of an expansion chamber with two side-branch cavities covered by light but extremely stiff plates. It works effectively with a wide stopband from low-to-medium frequencies only if the plate is extremely stiff, to ensure a strong reflection of acoustic wave to the upstream in the duct. However, a plate with a slightly weak bending stiffness will result in non-uniform transmission loss (TL) spectra with narrowed stopband. In this study, a hybrid silencer is proposed by introducing micro-perforations into the plate to elicit the sound absorption in order to compensate for the deficiency in the passband caused by the insufficient sound reflection in a certain frequency range due to weaker plate stiffness. A theoretical model, capable of dealing with the strong coupling between the vibrating micro-perforated plate and sound fields inside the cavity and the duct, is developed. Through proper balancing between the sound absorption and reflection, the proposed hybrid silencer provides a more flattened and uniform TL and a widened stopband by more than 20% while relaxing the harsh requirement on the bending stiffness of the plate. Theoretical predictions are validated by experimental data, with phenomenon explained through numerical analyses.

  13. Hyperspectral imaging using ultraviolet light

    OpenAIRE

    Porter, Michael A.

    2005-01-01

    The LINEATE IMAGING NEAR ULTRAVIOLET SPECTROMETER (LINUS) instrument has been used to remotely detect and measure sulfur dioxide (SO2). The sensor was calibrated in the lab, with curves of growth created for the 0.29 0.31 æ - spectral range of the LINUS sensor. Field observations were made of a coal burning plant in St. Johnâ s, Arizona at a range of 537 m. The Salt River Coronado plant stacks were emitting on average about 100 ppm and 200 ppm from the left and right stacks respectively. An...

  14. Calibration of a laboratory spectrophotometer for specular light by means of stacked glass plates.

    Science.gov (United States)

    Allen, W. A.; Richardson, A. J.

    1971-01-01

    Stacked glass plates have been used to calibrate a laboratory spectrophotometer, over the spectral range 0.5-2.5 microns, for specular light. The uncalibrated instrument was characterized by systematic errors when used to measure the reflectance and transmittance of stacked glass plates. Calibration included first, a determination of the reflectance of a standard composed of barium sulfate paint deposited on an aluminum plate; second, the approximation of the reflectance and transmittance residuals between observed and computed values by means of cubic equations; and, finally, the removal of the systematic errors by a computer. The instrument, after calibration, was accurate to 1% when used to measure the reflectance and transmittance of stacked glass plates.

  15. Nanosecond-gating properties of proximity-focused microchannel-plate image intensifiers

    Science.gov (United States)

    King, N. S. P.; Yates, G. J.; Jaramillo, S. A.; Ogle, J. W.

    Some fundamental properties of 18 mm-diam gated proximity focussed microchannel plate (MCP) image intensifiers used as fast image shutters in the 1 to 10 ns range were identified and studied. Light pulses from a modelocked dye laser optically sample the gated MCP. Shuttering is achieved by applying a forward biasing electrical gate pulse to the quiescently reverse-biased photocathode MCP interface. Variable delay between the gate pulse and the laser pulse permits tracing the MCP's optical response. Gating speeds, turn-on and turn-off patterns, the asymmetric spatial depedence of the MCP optical response, and resolution effects as functions of gate pulse width and photocathode-MCP bias were characterized. Variations in the intensity profiles of the phosphor's spatial response for uniform photocathode illumination are measured with a calibrated silicon intensified target focus projection, scan television camera and a high speed video digitizer while photomultipliers monitor the laser pulse and the phosphor's spatially integrated output intensities.

  16. Separation method of heavy-ion particle image from gamma-ray mixed images using an imaging plate

    CERN Document Server

    Yamadera, A; Ohuchi, H; Nakamura, T; Fukumura, A

    1999-01-01

    We have developed a separation method of alpha-ray and gamma-ray images using the imaging plate (IP). The IP from which the first image was read out by an image reader was annealed at 50 deg. C for 2 h in a drying oven and the second image was read out by the image reader. It was found out that an annealing ratio, k, which is defined as a ratio of the photo-stimulated luminescence (PSL) density at the first measurement to that at the second measurement, was different for alpha rays and gamma rays. By subtracting the second image multiplied by a factor of k from the first image, the alpha-ray image was separated from the alpha and gamma-ray mixed images. This method was applied to identify the images of helium, carbon and neon particles of high energies using the heavy-ion medical accelerator, HIMAC. (author)

  17. Neutron detection with imaging plates Part I. Image storage and readout

    CERN Document Server

    Thoms, M; Wilkinson, C

    1999-01-01

    The detection of neutrons with imaging plates is based on a sequence of physical processes, which are happening during the neutron exposure and the readout of the image information. These processes are investigated in detail starting with the neutron absorption and conversion to secondary radiation by various neutron converter materials and ending with the detection of the photostimulated luminescence, which is emitted during the readout. It is shown that these processes can be quantified by several key parameters, such as i.e. the neutron absorption cross section, the emitted secondary energy and the conversion efficiency of released secondary energy to storage centers in the storage phosphor. The resulting detector characteristics are described in the second part, namely, Neutron detection with imaging plates - part II: detector characteristics [Nucl. Instr. and Meth. A 424 (1999) 34-39].

  18. Neutron detection with imaging plates Part I. Image storage and readout

    Science.gov (United States)

    Thoms, M.; Myles, D.; Wilkinson, C.

    1999-11-01

    The detection of neutrons with imaging plates is based on a sequence of physical processes, which are happening during the neutron exposure and the readout of the image information. These processes are investigated in detail starting with the neutron absorption and conversion to secondary radiation by various neutron converter materials and ending with the detection of the photostimulated luminescence, which is emitted during the readout. It is shown that these processes can be quantified by several key parameters, such as i.e. the neutron absorption cross section, the emitted secondary energy and the conversion efficiency of released secondary energy to storage centers in the storage phosphor. The resulting detector characteristics are described in the second part, namely, Neutron detection with imaging plates - part II: detector characteristics [Nucl. Instr. and Meth. A 424 (1999) 34-39].

  19. Reconstructing light curves from HXMT imaging observations

    CERN Document Server

    Huo, Zhuo-Xi; Li, Yi-Ming; Zhou, Jian-Feng

    2014-01-01

    The Hard X-ray Modulation Telescope (HXMT) is a Chinese space telescope mission. It is scheduled for launch in 2015. The telescope will perform an all-sky survey in hard X-ray band (1 - 250 keV), a series of deep imaging observations of small sky regions as well as pointed observations. In this work we present a conceptual method to reconstruct light curves from HXMT imaging observation directly, in order to monitor time-varying objects such as GRB, AXP and SGR in hard X-ray band with HXMT imaging observations.

  20. A modified commercial scanner as an image plate for table-top optical applications

    Energy Technology Data Exchange (ETDEWEB)

    Casado-Rojo, S; Lorenzana, H E; Baonza, V G

    2008-12-09

    A reliable, accurate, and inexpensive optical detector for table-top applications is described here. Based on a commercial high resolution office scanner coupled to a projection on plate, it enables a large image plate surface, allowing recording of large images without systematic errors associated to coupling optics' aberrations. Several tests on distance-dependent and steady interference patterns will be presented and discussed. The extension to other types of optical measurement by substituting the projection on plate is proposed.

  1. Transurethral light delivery for prostate photoacoustic imaging

    Science.gov (United States)

    Lediju Bell, Muyinatu A.; Guo, Xiaoyu; Song, Danny Y.; Boctor, Emad M.

    2015-03-01

    Photoacoustic imaging has broad clinical potential to enhance prostate cancer detection and treatment, yet it is challenged by the lack of minimally invasive, deeply penetrating light delivery methods that provide sufficient visualization of targets (e.g., tumors, contrast agents, brachytherapy seeds). We constructed a side-firing fiber prototype for transurethral photoacoustic imaging of prostates with a dual-array (linear and curvilinear) transrectal ultrasound probe. A method to calculate the surface area and, thereby, estimate the laser fluence at this fiber tip was derived, validated, applied to various design parameters, and used as an input to three-dimensional Monte Carlo simulations. Brachytherapy seeds implanted in phantom, ex vivo, and in vivo canine prostates at radial distances of 5 to 30 mm from the urethra were imaged with the fiber prototype transmitting 1064 nm wavelength light with 2 to 8 mJ pulse energy. Prebeamformed images were displayed in real time at a rate of 3 to 5 frames per second to guide fiber placement and beamformed offline. A conventional delay-and-sum beamformer provided decreasing seed contrast (23 to 9 dB) with increasing urethra-to-target distance, while the short-lag spatial coherence beamformer provided improved and relatively constant seed contrast (28 to 32 dB) regardless of distance, thus improving multitarget visualization in single and combined curvilinear images acquired with the fiber rotating and the probe fixed. The proposed light delivery and beamforming methods promise to improve key prostate cancer detection and treatment strategies.

  2. Reliability and Lifetime Prediction of Remote Phosphor Plates in Solid-State Lighting Applications Using Accelerated Degradation Testing

    NARCIS (Netherlands)

    Yazdan Mehr, M.; Van Driel, W.D.; Zhang, G.Q.

    2015-01-01

    A methodology, based on accelerated degradation testing, is developed to predict the lifetime of remote phosphor plates used in solid-state lighting (SSL) applications. Both thermal stress and light intensity are used to accelerate degradation reaction in remote phosphor plates. A reliability model,

  3. Ultra-compact imaging plate scanner module using a MEMS mirror and specially designed MPPC

    Science.gov (United States)

    Miyamoto, Yuichi; Sasaki, Kensuke; Takasaka, Masaomi; Fujimoto, Masatoshi; Yamamoto, Koei

    2017-02-01

    Computed radiography (CR), which is one of the most useful methods for dental imaging and nondestructive testing, uses a phosphor imaging plate (IP) because it is flexible, reusable, and inexpensive. Conventional IP scanners utilize a galvanometer or a polygon mirror as a scanning device and a photomultiplier as an optical sensor. Microelectromechanical systems (MEMS) technology currently provides silicon-based devices and has the potential to replace such discrete devices and sensors. Using these devices, we constructed an ultra-compact IP scanner. Our extremely compact plate scanner utilizes a module that is composed of a one-dimensional MEMS mirror and a long multi-pixel photon counter (MPPC) that is combined with a specially designed wavelength filter and a rod lens. The MEMS mirror, which is a non-resonant electromagnetic type, is 2.6 mm in diameter with a recommended optical scanning angle up to +/-15°. The CR's wide dynamic range is maintained using a newly developed MPPC. The MPPC is a sort of silicon photomultiplier and is a high-sensitivity photon-counting device. To achieve such a wide dynamic range, we developed a long MPPC that has over 10,000 pixels. For size reduction and high optical efficiency, we set the MPPC close to an IP across the rod lens. To prevent the MPPC from detecting excitation light, which is much more intense than photo-stimulated light, we produced a sharp-cut wavelength filter that has a wide angle (+/-60°) of tolerance. We evaluated our constructed scanner module through gray chart and resolution chart images.

  4. Calibrating image plate sensitivity in the 700 to 5000 eV spectral energy range

    Science.gov (United States)

    Haugh, Michael J.; Lee, Joshua; Romano, Edward; Schneider, Marilyn

    2013-09-01

    This paper describes a method to calibrate image plate sensitivity for use in the low energy spectral range. Image plates, also known as photostimulable luminescence (PSL) detectors, have often proved to be a valuable tool as a detector for plasma physics studies. Their advantages of large dynamic range, high stopping power, and resistance to neutron damage sometimes outweigh the problems of limited resolution and the remote processing required. The neutron damage resistance is required when the X-ray source is producing a high neutron flux. The Static X-ray Imager (SXI) is a key diagnostic on the National Ignition Facility (NIF) target chamber at LLNL for use in determining the symmetry of the laser beams. The SXI is essential to proper interpretation of the data from the Dante diagnostic to determine the X-ray radiation temperature. It is comprised of two diagnostics located at the top and the bottom of the target chamber. The usual detector is a large array CCD camera. For shots giving high yields of neutrons, the camera would not only be blinded by the neutrons, it would be damaged. To get around this problem, an image plate (IP) is used as the detector. The NIF application covers the energy range from 700 to 5000 eV. The type of image plates typically used for plasma physics are the Fuji BAS-MS, BAS-SR, and BAS-TR models. All models consist of an X-ray sensitive material made of BaF(Br,I):Eu2+ embedded in a plastic binder. X-rays incident on the phosphor ionize the Eu 2+ producing Eu3+ and free electrons that are trapped in lattice defects (F-centers) produced by the absence of halogen ions in the BaF2 crystal. An image plate readout scanner irradiates the IP with a red laser causing reduction of the Eu3+ and emission of a blue photon. The photon is collected using a photomultiplier and digitized to make an electronic image. Image plates are cleared of all F-centers by putting them under a bright light for about 10 minutes. They are then ready for producing a

  5. Imaging electronic quantum motion with light

    CERN Document Server

    Dixit, Gopal; Santra, Robin; 10.1073/pnas.1202226109

    2012-01-01

    Imaging the quantum motion of electrons not only in real-time, but also in real-space is essential to understand for example bond breaking and formation in molecules, and charge migration in peptides and biological systems. Time-resolved imaging interrogates the unfolding electronic motion in such systems. We find that scattering patterns, obtained by X-ray time-resolved imaging from an electronic wavepacket, encode spatial and temporal correlations that deviate substantially from the common notion of the instantaneous electronic density as the key quantity being probed. Surprisingly, the patterns provide an unusually visual manifestation of the quantum nature of light. This quantum nature becomes central only for non-stationary electronic states and has profound consequences for time-resolved imaging.

  6. Coded source imaging simulation with visible light

    Science.gov (United States)

    Wang, Sheng; Zou, Yubin; Zhang, Xueshuang; Lu, Yuanrong; Guo, Zhiyu

    2011-09-01

    A coded source could increase the neutron flux with high L/ D ratio. It may benefit a neutron imaging system with low yield neutron source. Visible light CSI experiments were carried out to test the physical design and reconstruction algorithm. We used a non-mosaic Modified Uniformly Redundant Array (MURA) mask to project the shadow of black/white samples on a screen. A cooled-CCD camera was used to record the image on the screen. Different mask sizes and amplification factors were tested. The correlation, Wiener filter deconvolution and Richardson-Lucy maximum likelihood iteration algorithm were employed to reconstruct the object imaging from the original projection. The results show that CSI can benefit the low flux neutron imaging with high background noise.

  7. Installation of the light tight cover for the SSD modules (the modules are behind the aluminium plate). The silicon sensors are sensitive to light tight, so ambient light will increase the noise and may even damage them.

    CERN Multimedia

    Nooren, G.

    2004-01-01

    Installation of the light tight cover for the SSD modules (the modules are behind the aluminium plate). The silicon sensors are sensitive to light tight , so ambient light will increase the noise and may even damage them.

  8. Deeply trapped electrons in imaging plates and their utilization for extending the dynamic range

    Science.gov (United States)

    Ohuchi, Hiroko; Kondo, Yasuhiro

    2010-09-01

    The absorption spectra of deep centers in an imaging plate (IP) made of BaFBr 0:85I 0:15:Eu 2+ have been studied in the ultraviolet region. Electrons trapped in deep centers are considered to be the cause of unerasable and reappearing latent images in IPs over-irradiated with X-rays. Deep centers showed a dominant peak at around 320 nm, followed by two small peaks at around 345 and 380 nm. By utilizing deeply trapped electrons, we have attempted to extend the dynamic range of an IP. The IP was irradiated by 150-kV X-rays with doses from 8.07 mGy to 80.7 Gy. Reading out the latent image by the stimulation of Eu 2+ luminescence with a 633-nm He-Ne laser light from a conventional Fuji reader showed a linear relationship with irradiated dose up to 0.8 Gy, but then becoming non-linear. After fully erasing with visible light, unerasable latent images were read out using 635-nm semi-conductor laser light combined with a photon-counting detection system. The dose-response curve so obtained gave a further two orders of magnitude extending the dynamic range up to 80.7 Gy. Comprehensive results indicate that electrons supplied from deep centers to the F centers provided the extended dynamic range after the F centers became saturated. Based on these facts, a model of the excitation of deeply trapped electrons and PSL processes is proposed.

  9. Deeply trapped electrons in imaging plates and their utilization for extending the dynamic range

    Energy Technology Data Exchange (ETDEWEB)

    Ohuchi, Hiroko, E-mail: hiroko@mail.pharm.tohoku.ac.j [Graduate School of Pharmaceutical Sciences, Tohoku University, 6-3 Aoba, Aramaki, Aoba-ku, Sendai, Miyagi 980-8578 (Japan); Kondo, Yasuhiro [Ishinomaki Senshu University, 1 Shinmito Minamisakai Ishinomaki-shi, Miyagi 986-8580 (Japan)

    2010-09-21

    The absorption spectra of deep centers in an imaging plate (IP) made of BaFBr{sub 0:85}I{sub 0:15}:Eu{sup 2+} have been studied in the ultraviolet region. Electrons trapped in deep centers are considered to be the cause of unerasable and reappearing latent images in IPs over-irradiated with X-rays. Deep centers showed a dominant peak at around 320 nm, followed by two small peaks at around 345 and 380 nm. By utilizing deeply trapped electrons, we have attempted to extend the dynamic range of an IP. The IP was irradiated by 150-kV X-rays with doses from 8.07 mGy to 80.7 Gy. Reading out the latent image by the stimulation of Eu{sup 2+} luminescence with a 633-nm He-Ne laser light from a conventional Fuji reader showed a linear relationship with irradiated dose up to 0.8 Gy, but then becoming non-linear. After fully erasing with visible light, unerasable latent images were read out using 635-nm semi-conductor laser light combined with a photon-counting detection system. The dose-response curve so obtained gave a further two orders of magnitude extending the dynamic range up to 80.7 Gy. Comprehensive results indicate that electrons supplied from deep centers to the F centers provided the extended dynamic range after the F centers became saturated. Based on these facts, a model of the excitation of deeply trapped electrons and PSL processes is proposed.

  10. A Novel Continuous Extrusion Process to Fabricate Wedge-Shaped Light Guide Plates

    Directory of Open Access Journals (Sweden)

    Wen-Tse Hsiao

    2013-01-01

    Full Text Available Backlight modules are key components in thin-film transistor liquid crystal displays (TFT-LCD. Among the components of a backlight module, the light guide plate (LGP plays the most important role controlling the light projected to the eyes of users. A wedge-shaped LGP, with its asymmetrical structure, is usually fabricated by an injection proces, but the fabrication time of this process is long. This study proposes a continuous extrusion process to fabricate wedge-shaped LGPs. This continuous process has advantages for mass production. Besides a T-die and rollers, this system also has an in situ monitor of the melt-bank that forms during the extrusion process, helping control the plate thickness. Results show that the melt bank has a close relationship with the plate thickness. The temperature of the bottom heater and roller was adjusted to reduce the surface deformation of the wedge-shaped plate. This continuous extrusion system can successfully manufacture wedge-shaped LGPs for mass production.

  11. Monochromatization of femtosecond XUV light pulses with the use of reflection zone plates.

    Science.gov (United States)

    Metje, Jan; Borgwardt, Mario; Moguilevski, Alexandre; Kothe, Alexander; Engel, Nicholas; Wilke, Martin; Al-Obaidi, Ruba; Tolksdorf, Daniel; Firsov, Alexander; Brzhezinskaya, Maria; Erko, Alexei; Kiyan, Igor Yu; Aziz, Emad F

    2014-05-05

    We report on a newly built laser-based tabletop setup which enables generation of femtosecond light pulses in the XUV range employing the process of high-order harmonic generation (HHG) in a gas medium. The spatial, spectral, and temporal characteristics of the XUV beam are presented. Monochromatization of XUV light with minimum temporal pulse distortion is the central issue of this work. Off-center reflection zone plates are shown to be advantageous when selection of a desired harmonic is carried out with the use of a single optical element. A cross correlation technique was applied to characterize the performance of the zone plates in the time domain. By using laser pulses of 25 fs length to pump the HHG process, a pulse duration of 45 fs for monochromatized harmonics was achieved in the present setup.

  12. Applications and characteristics of imaging plates as detector in neutron radiography at SINQ

    CERN Document Server

    Kolbe, H; Gunia, W; Körner, S

    1999-01-01

    Imaging plate technique is a commonly accepted method in many fields as in medicine, biology and physics for detection of the distribution of beta- and gamma-radiation or X-rays on large areas. Recently a new type of imaging plate sensitive to neutrons has been developed. The storage layer is doped with gadolinium, which, after absorption of neutrons, produces radiation detectable by the same sensitive crystals used in conventional imaging plates. At the spallation neutron source, SINQ, at the Paul Scherrer Institut (CH) some of the characteristics of the neutron radiography station in combination with the imaging plate technique were investigated. The intensity distribution of the source was measured to check the accuracy for quantification of the image data. Also, the reproducibility of results obtained by this detection system was stated. For a test object, the high selectivity for different neutron absorption is demonstrated at details with low contrast. The obtainable spatial resolution was determined re...

  13. Calibration of the linear response range of x-ray imaging plates and their reader based on image grayscale values

    Science.gov (United States)

    Ren, Kuan; Xu, Tao; Zheng, Jianhua; Dong, Jianjun; Wei, Minxi; Li, Chaoguang; Cao, Zhurong; Du, Huabing; Yan, Ji; Yang, Guohong; Yi, Rongqing; Zhang, Jiyan; Huang, Tianxuan; Liu, Shenye; Wang, Feng; Yang, Zhiwen; Li, Jin; Chen, Yaohua; Lan, Ke; Ren, Guoli; Liu, Jie; Ding, Yongkun; Jiang, Shaoen

    2017-08-01

    X-ray imaging plates are one of the most important X-ray imaging detectors and are widely used in inertial-confinement fusion experiments. However, their linear response range, which is the foundation of their quantitative data analysis, has not been sufficiently deeply investigated. In this work, we develop an X-ray fluorescer calibration system and carefully explore the linear response range of X-ray imaging plates. For the first time, nearly the entire grayscale range of the X-ray imaging plate linear response—7819-64 879 in the range of 0-65 535—has been observed. Further, we discuss the uncertainties involved in the calibration process. This work demonstrates the excellent linear response qualities of X-ray imaging plates and provides a significant foundation for expanding their quantitative applied range.

  14. PLATE

    DEFF Research Database (Denmark)

    Kling, Joyce; Hjulmand, Lise-Lotte

    2008-01-01

    ’s level of English is sufficient for the increasing number of courses offered in English each semester. This paper addresses these concerns and describes a pilot project initiated in 2003 at CBS to gauge the overall English language proficiency of those teaching content courses in English. Through......Copenhagen Business School (CBS) finds itself needing to address the issue of English-medium instruction for its increasing number of foreign exchange and full degree students. With internationalisation as a main pillar of the institution’s agenda, there are concerns whether the teaching faculty...... the Project in Language Assessment for Teaching in English (PLATE) language professionals from CBS’s Language Center observe teachers and provide feedback using evaluation criteria from the Common European Framework for Reference (CEFR) supplemented by some additional criteria which take the LSP nature...

  15. PLATE

    DEFF Research Database (Denmark)

    Kling, Joyce; Hjulmand, Lise-Lotte

    2008-01-01

    Copenhagen Business School (CBS) finds itself needing to address the issue of English-medium instruction for its increasing number of foreign exchange and full degree students. With internationalisation as a main pillar of the institution’s agenda, there are concerns whether the teaching faculty......’s level of English is sufficient for the increasing number of courses offered in English each semester. This paper addresses these concerns and describes a pilot project initiated in 2003 at CBS to gauge the overall English language proficiency of those teaching content courses in English. Through...... the Project in Language Assessment for Teaching in English (PLATE) language professionals from CBS’s Language Center observe teachers and provide feedback using evaluation criteria from the Common European Framework for Reference (CEFR) supplemented by some additional criteria which take the LSP nature...

  16. Cross-calibration of Fuji TR image plate and RAR 2492 x-ray film to determine the response of a DITABIS Super Micron image plate scanner

    Science.gov (United States)

    Dunham, G.; Harding, E. C.; Loisel, G. P.; Lake, P. W.; Nielsen-Weber, L. B.

    2016-11-01

    Fuji TR image plate is frequently used as a replacement detector medium for x-ray imaging and spectroscopy diagnostics at NIF, Omega, and Z facilities. However, the familiar Fuji BAS line of image plate scanners is no longer supported by the industry, and so a replacement scanning system is needed. While the General Electric Typhoon line of scanners could replace the Fuji systems, the shift away from photo stimulated luminescence units to 16-bit grayscale Tag Image File Format (TIFF) leaves a discontinuity when comparing data collected from both systems. For the purposes of quantitative spectroscopy, a known unit of intensity applied to the grayscale values of the TIFF is needed. The DITABIS Super Micron image plate scanning system was tested and shown to potentially rival the resolution and dynamic range of Kodak RAR 2492 x-ray film. However, the absolute sensitivity of the scanner is unknown. In this work, a methodology to cross calibrate Fuji TR image plate and the absolutely calibrated Kodak RAR 2492 x-ray film is presented. Details of the experimental configurations used are included. An energy dependent scale factor to convert Fuji TR IP scanned on a DITABIS Super Micron scanner from 16-bit grayscale TIFF to intensity units (i.e., photons per square micron) is discussed.

  17. Cross-calibration of Fuji TR image plate and RAR 2492 x-ray film to determine the response of a DITABIS Super Micron image plate scanner

    Energy Technology Data Exchange (ETDEWEB)

    Dunham, G., E-mail: gsdunha@sandia.gov; Harding, E. C.; Loisel, G. P.; Lake, P. W.; Nielsen-Weber, L. B. [Sandia National Laboratories, Albuquerque, New Mexico 87185 (United States)

    2016-11-15

    Fuji TR image plate is frequently used as a replacement detector medium for x-ray imaging and spectroscopy diagnostics at NIF, Omega, and Z facilities. However, the familiar Fuji BAS line of image plate scanners is no longer supported by the industry, and so a replacement scanning system is needed. While the General Electric Typhoon line of scanners could replace the Fuji systems, the shift away from photo stimulated luminescence units to 16-bit grayscale Tag Image File Format (TIFF) leaves a discontinuity when comparing data collected from both systems. For the purposes of quantitative spectroscopy, a known unit of intensity applied to the grayscale values of the TIFF is needed. The DITABIS Super Micron image plate scanning system was tested and shown to potentially rival the resolution and dynamic range of Kodak RAR 2492 x-ray film. However, the absolute sensitivity of the scanner is unknown. In this work, a methodology to cross calibrate Fuji TR image plate and the absolutely calibrated Kodak RAR 2492 x-ray film is presented. Details of the experimental configurations used are included. An energy dependent scale factor to convert Fuji TR IP scanned on a DITABIS Super Micron scanner from 16-bit grayscale TIFF to intensity units (i.e., photons per square micron) is discussed.

  18. Cross-calibration of Fuji TR image plate and RAR 2492 x-ray film to determine the response of a DITABIS Super Micron image plate scanner.

    Science.gov (United States)

    Dunham, G; Harding, E C; Loisel, G P; Lake, P W; Nielsen-Weber, L B

    2016-11-01

    Fuji TR image plate is frequently used as a replacement detector medium for x-ray imaging and spectroscopy diagnostics at NIF, Omega, and Z facilities. However, the familiar Fuji BAS line of image plate scanners is no longer supported by the industry, and so a replacement scanning system is needed. While the General Electric Typhoon line of scanners could replace the Fuji systems, the shift away from photo stimulated luminescence units to 16-bit grayscale Tag Image File Format (TIFF) leaves a discontinuity when comparing data collected from both systems. For the purposes of quantitative spectroscopy, a known unit of intensity applied to the grayscale values of the TIFF is needed. The DITABIS Super Micron image plate scanning system was tested and shown to potentially rival the resolution and dynamic range of Kodak RAR 2492 x-ray film. However, the absolute sensitivity of the scanner is unknown. In this work, a methodology to cross calibrate Fuji TR image plate and the absolutely calibrated Kodak RAR 2492 x-ray film is presented. Details of the experimental configurations used are included. An energy dependent scale factor to convert Fuji TR IP scanned on a DITABIS Super Micron scanner from 16-bit grayscale TIFF to intensity units (i.e., photons per square micron) is discussed.

  19. Enhancement of microalgae production by embedding hollow light guides to a flat-plate photobioreactor.

    Science.gov (United States)

    Sun, Yahui; Huang, Yun; Liao, Qiang; Fu, Qian; Zhu, Xun

    2016-05-01

    To offset the adverse effects of light attenuation on microalgae growth, hollow polymethyl methacrylate (PMMA) tubes were embedded into a flat-plate photobioreactor (PBR) as light guides. In this way, a fraction of incident light could be transmitted and emitted to the interior of the PBR, providing a secondary light source for cells in light-deficient regions. The average light intensity of interior regions 3-6cm from surfaces with 70μmolm(-2)s(-1) incident light was enhanced 2-6.5 times after 3.5days cultivation, resulting in a 23.42% increase in biomass production to that cultivated in PBR without PMMA tubes. The photosynthetic efficiency of microalgae in the proposed PBR was increased to 12.52%. Moreover, the installation of hollow PMMA tubes induced turbulent flow in the microalgae suspension, promoting microalgae suspension mixing. However, the enhanced biomass production was mainly attributed to the optimized light distribution in the PBR. Copyright © 2016 Elsevier Ltd. All rights reserved.

  20. THE EFFECTS OF MANUFACTURING INACCURACIES ON THE IMAGING PROPERTIES OF ZONE PLATES

    OpenAIRE

    Simpson, M.; Browne, M.; Burge, R.; Charalambous, P; Duke, P.; Michette, A.

    1984-01-01

    Any process for making soft X-ray zone plates will have associated manufacturing errors which will affect the imaging properties. The errors possible in a lithographic manufacturing technique using a scanning transmission electron microscope are discussed, and it is concluded that sufficiently accurate zone plates may readily be made.

  1. Single Transducer Ultrasonic Imaging Method that Eliminates the Effect of Plate Thickness Variation in the Image

    Science.gov (United States)

    Roth, Don J.

    1996-01-01

    This article describes a single transducer ultrasonic imaging method that eliminates the effect of plate thickness variation in the image. The method thus isolates ultrasonic variations due to material microstructure. The use of this method can result in significant cost savings because the ultrasonic image can be interpreted correctly without the need for machining to achieve precise thickness uniformity during nondestructive evaluations of material development. The method is based on measurement of ultrasonic velocity. Images obtained using the thickness-independent methodology are compared with conventional velocity and c-scan echo peak amplitude images for monolithic ceramic (silicon nitride), metal matrix composite and polymer matrix composite materials. It was found that the thickness-independent ultrasonic images reveal and quantify correctly areas of global microstructural (pore and fiber volume fraction) variation due to the elimination of thickness effects. The thickness-independent ultrasonic imaging method described in this article is currently being commercialized under a cooperative agreement between NASA Lewis Research Center and Sonix, Inc.

  2. Effects of low-spatial-frequency response of phase plates on TEM imaging

    Science.gov (United States)

    Edgcombe, C. J.

    2015-10-01

    Images of simple objects produced by a perfect lens and a phase plate have been calculated by use of Abbe theory for Foucault, Hilbert and Zernike phase plates. The results show that with a Zernike plate, white outlines and ringing like those observed previously can be caused by the beam hole, which limits the low-spatial-frequency response of the system even when the lens behaves perfectly. When the change of phase added by the phase plate is distributed over a range of radius rather than a simple step, the unwanted effects are substantially reduced.

  3. Simulation study of x-ray backscatter imaging of pressure-plate improvised explosive devices

    Science.gov (United States)

    van den Heuvel, Johan; Fiore, Franco

    2012-06-01

    Improvised Explosive Devices (IEDs) triggered by pressure-plates are a serious threat in current theatres of operation. X-ray backscatter imaging (XBI) is a potential method for detecting buried pressure-plates. Monte-Carlo simulation code was developed in-house and has been used to study the potential of XBI for pressure-plate detection. It is shown that pressure-plates can be detected at depths up to 7 cm with high photon energies of 350 keV with reasonable speeds of 1 to 10 km/h. However, spatial resolution is relatively low due to multiple scattering.

  4. Design and fabrication of light-guiding plate for a photobioreactor that utilizes sunlight

    Science.gov (United States)

    Lim, Hyon-Chol; Kim, Hun; Jang, Kyungmin; Kim, Jae-Young; Baek, Joon-Hyuck; Yang, Seung-Jin; Jeong, Sang-Hwa; Park, Jong-Rak

    2015-10-01

    We present the results of the optical design and fabrication of a light-guiding plate (LGP) that utilizes sunlight to be adopted as an illumination system for photobioreactors. A solar daylighting system was employed as the light source for the LGP. We modeled the light sources (optical fiber exit ports of the solar daylighting system), a reflection film, and LGP patterns. An LGP (1000 mm × 500 mm × 10 mm) was designed and fabricated using a computerized numerical control machine. It was optimized for the average deviation of the illuminance distribution by varying the maximum pattern spacing, minimum pattern spacing, and spacing constant of the pattern spacing function expressed in the form of an exponential function. Average illuminance and uniformity of the illuminance distribution of the fabricated LGP were measured to be 8174 lx (photon flux density: 122.0 μΕ m-2 s-1) and 90.0 %, respectively.

  5. Versatile Micropatterning of Plasmonic Nanostructures by Visible Light Induced Electroless Silver Plating on Gold Nanoseeds.

    Science.gov (United States)

    Yoshikawa, Hiroyuki; Hironou, Asami; Shen, ZhengJun; Tamiya, Eiichi

    2016-09-14

    A versatile fabrication technique for plasmonic silver (Ag) nanostructures that uses visible light exposure for micropatterning and plasmon resonance tuning is presented. The surface of a glass substrate modified with gold (Au) nanoseeds by a thermal dewetting process was used as a Ag plating platform. When a solution containing silver nitrate and sodium citrate was dropped on the Au nanoseeds under visible light exposure, the plasmon-mediated reduction of Ag ions was induced on the Au nanoseeds to form Ag nanostructures. The plasmon resonance spectra of Ag nanostructures were examined by an absorption spectral measurement and a finite-difference time-domain (FDTD) simulation. Some examples of Ag nanostructure patterning were demonstrated by means of light exposure through a photomask, direct writing with a focused laser beam, and the interference between two laser beams. Surface enhanced Raman spectroscopy (SERS) of 4-aminothiophenol (4-ATP) was conducted with fabricated Ag nanostructures.

  6. A seismic reflection image for the base of a tectonic plate.

    Science.gov (United States)

    Stern, T A; Henrys, S A; Okaya, D; Louie, J N; Savage, M K; Lamb, S; Sato, H; Sutherland, R; Iwasaki, T

    2015-02-05

    Plate tectonics successfully describes the surface of Earth as a mosaic of moving lithospheric plates. But it is not clear what happens at the base of the plates, the lithosphere-asthenosphere boundary (LAB). The LAB has been well imaged with converted teleseismic waves, whose 10-40-kilometre wavelength controls the structural resolution. Here we use explosion-generated seismic waves (of about 0.5-kilometre wavelength) to form a high-resolution image for the base of an oceanic plate that is subducting beneath North Island, New Zealand. Our 80-kilometre-wide image is based on P-wave reflections and shows an approximately 15° dipping, abrupt, seismic wave-speed transition (less than 1 kilometre thick) at a depth of about 100 kilometres. The boundary is parallel to the top of the plate and seismic attributes indicate a P-wave speed decrease of at least 8 ± 3 per cent across it. A parallel reflection event approximately 10 kilometres deeper shows that the decrease in P-wave speed is confined to a channel at the base of the plate, which we interpret as a sheared zone of ponded partial melts or volatiles. This is independent, high-resolution evidence for a low-viscosity channel at the LAB that decouples plates from mantle flow beneath, and allows plate tectonics to work.

  7. Hyperspectral image reconstruction using RGB color for foodborne pathogen detection on agar plates

    Science.gov (United States)

    Yoon, Seung-Chul; Shin, Tae-Sung; Park, Bosoon; Lawrence, Kurt C.; Heitschmidt, Gerald W.

    2014-03-01

    This paper reports the latest development of a color vision technique for detecting colonies of foodborne pathogens grown on agar plates with a hyperspectral image classification model that was developed using full hyperspectral data. The hyperspectral classification model depended on reflectance spectra measured in the visible and near-infrared spectral range from 400 and 1,000 nm (473 narrow spectral bands). Multivariate regression methods were used to estimate and predict hyperspectral data from RGB color values. The six representative non-O157 Shiga-toxin producing Eschetichia coli (STEC) serogroups (O26, O45, O103, O111, O121, and O145) were grown on Rainbow agar plates. A line-scan pushbroom hyperspectral image sensor was used to scan 36 agar plates grown with pure STEC colonies at each plate. The 36 hyperspectral images of the agar plates were divided in half to create training and test sets. The mean Rsquared value for hyperspectral image estimation was about 0.98 in the spectral range between 400 and 700 nm for linear, quadratic and cubic polynomial regression models and the detection accuracy of the hyperspectral image classification model with the principal component analysis and k-nearest neighbors for the test set was up to 92% (99% with the original hyperspectral images). Thus, the results of the study suggested that color-based detection may be viable as a multispectral imaging solution without much loss of prediction accuracy compared to hyperspectral imaging.

  8. A fast microchannel plate-scintillator detector for velocity map imaging and imaging mass spectrometry.

    Science.gov (United States)

    Winter, B; King, S J; Brouard, M; Vallance, C

    2014-02-01

    The time resolution achievable using standard position-sensitive ion detectors, consisting of a chevron pair of microchannel plates coupled to a phosphor screen, is primarily limited by the emission lifetime of the phosphor, around 70 ns for the most commonly used P47 phosphor. We demonstrate that poly-para-phenylene laser dyes may be employed extremely effectively as scintillators, exhibiting higher brightness and much shorter decay lifetimes than P47. We provide an extensive characterisation of the properties of such scintillators, with a particular emphasis on applications in velocity-map imaging and microscope-mode imaging mass spectrometry. The most promising of the new scintillators exhibits an electron-to-photon conversion efficiency double that of P47, with an emission lifetime an order of magnitude shorter. The new scintillator screens are vacuum stable and show no signs of signal degradation even over longer periods of operation.

  9. (99m)Tc thyroid imaging system using multiple imaging plates.

    Science.gov (United States)

    Ito, Shigeki; Saze, Takuya; Ariga, Eiji; Deji, Shizuhiko; Hirota, Masahiro; Nishizawa, Kunihide

    2009-06-01

    A system for taking static thyroid (99m)Tc images was devised by using multiple imaging plates (IPs) and a low-energy high resolution collimator. System spatial resolution of the IP systems and the gamma camera was determined by referring to standards set by the National Electrical Manufacturers Association. Sensitivity was represented by using lower detection limits (LDLs). The sensitivity and resolution of IP systems using 16 IP probes connecting two collimators and 9 IPs were determined by using a 20 ml thyroid phantom, and compared with the sensitivity of gamma cameras. The sensitivity of the IP systems increased in proportion to the number of IPs. The sensitivity and resolution of a probe using 6 IPs and a high resolution collimator were equivalent to or superior to the gamma camera for taking static thyroid (99m)Tc images. IP systems can be applied clinically as mobile static nuclear imaging devices. The performance of IP systems should be thoroughly investigated for combinations of various collimators and the number of IPs in order to verify their efficacy for imaging all organs.

  10. Edge detection of steel plates at high temperature using image measurement

    Institute of Scientific and Technical Information of China (English)

    Qiong ZHOU; Qi AN

    2009-01-01

    An edge detection method for the measure-ment of steel plate's thermal expansion is proposed in this paper, where the shrinkage of a steel plate is measured when temperature drops. First, images are picked up by an imaging system; a method of regional edge detection based on grayscales' sudden change is then applied to detect the edges of the steel plate; finally, pixel coordinates of the edge position are transformed to physical coordinates through calibration parameters. The experiment shows that the real-time, high precision, and non-contact measure-ment of the steel plate's edge position under high temperature can be realized using the imaging measure-ment method established in this paper.

  11. Determining adaptive thresholds for image segmentation for a license plate recognition system

    Directory of Open Access Journals (Sweden)

    Siti Norul Huda Sheikh Abdullah

    2016-06-01

    Full Text Available A vehicle license plate recognition (LPR system is useful to many applications, such as entrance admission, security, parking control, airport and cargo, traffic and speed control. This paper describe an adaptive threshold for image segmentation applied to a system for Malaysian intelligent license plate recognition (MyiLPR. Due to the different types of license plates used, the requirements of an automatic LPR system are rather different for each country. Upon receiving the input car image, this system (MyiLPR detects and segments the license plate based on proposed adaptive threshold via image and blob histogram, and blob agglomeration, and finally, it extracts geometric character features and classifies them using neural network. The use of the proposed adaptive threshold increased the detection, segmentation and recognition rate to 99%, 94.98% and 90% correspondingly, from 95%, 78.27% and 71.08% obtained with the fixed threshold used in the originally proposed system.

  12. First light of the Gemini Planet imager.

    Science.gov (United States)

    Macintosh, Bruce; Graham, James R; Ingraham, Patrick; Konopacky, Quinn; Marois, Christian; Perrin, Marshall; Poyneer, Lisa; Bauman, Brian; Barman, Travis; Burrows, Adam S; Cardwell, Andrew; Chilcote, Jeffrey; De Rosa, Robert J; Dillon, Daren; Doyon, Rene; Dunn, Jennifer; Erikson, Darren; Fitzgerald, Michael P; Gavel, Donald; Goodsell, Stephen; Hartung, Markus; Hibon, Pascale; Kalas, Paul; Larkin, James; Maire, Jerome; Marchis, Franck; Marley, Mark S; McBride, James; Millar-Blanchaer, Max; Morzinski, Katie; Norton, Andrew; Oppenheimer, B R; Palmer, David; Patience, Jennifer; Pueyo, Laurent; Rantakyro, Fredrik; Sadakuni, Naru; Saddlemyer, Leslie; Savransky, Dmitry; Serio, Andrew; Soummer, Remi; Sivaramakrishnan, Anand; Song, Inseok; Thomas, Sandrine; Wallace, J Kent; Wiktorowicz, Sloane; Wolff, Schuyler

    2014-09-02

    The Gemini Planet Imager is a dedicated facility for directly imaging and spectroscopically characterizing extrasolar planets. It combines a very high-order adaptive optics system, a diffraction-suppressing coronagraph, and an integral field spectrograph with low spectral resolution but high spatial resolution. Every aspect of the Gemini Planet Imager has been tuned for maximum sensitivity to faint planets near bright stars. During first-light observations, we achieved an estimated H band Strehl ratio of 0.89 and a 5-σ contrast of 10(6) at 0.75 arcseconds and 10(5) at 0.35 arcseconds. Observations of Beta Pictoris clearly detect the planet, Beta Pictoris b, in a single 60-s exposure with minimal postprocessing. Beta Pictoris b is observed at a separation of 434 ± 6 milliarcseconds (mas) and position angle 211.8 ± 0.5°. Fitting the Keplerian orbit of Beta Pic b using the new position together with previous astrometry gives a factor of 3 improvement in most parameters over previous solutions. The planet orbits at a semimajor axis of [Formula: see text] near the 3:2 resonance with the previously known 6-AU asteroidal belt and is aligned with the inner warped disk. The observations give a 4% probability of a transit of the planet in late 2017.

  13. Restoration of uneven illumination in light sheet microscopy images.

    Science.gov (United States)

    Uddin, Mohammad Shorif; Lee, Hwee Kuan; Preibisch, Stephan; Tomancak, Pavel

    2011-08-01

    Light microscopy images suffer from poor contrast due to light absorption and scattering by the media. The resulting decay in contrast varies exponentially across the image along the incident light path. Classical space invariant deconvolution approaches, while very effective in deblurring, are not designed for the restoration of uneven illumination in microscopy images. In this article, we present a modified radiative transfer theory approach to solve the contrast degradation problem of light sheet microscopy (LSM) images. We confirmed the effectiveness of our approach through simulation as well as real LSM images.

  14. Nanosecond Gating Properties Of Proximity-Focused Microchannel-Plate Image Intensifiers

    Science.gov (United States)

    King, N. S.; Yates, G. J.; Jaramillo, S. A.; Ogle, J. W.; Detch, J. L.

    1981-12-01

    Some fundamental properties of 18-mm-diam gated proximity-focussed microchannel-plate (MCP) image intensifiers used as fast image shutters in the 1 to 10 ns range have been identified and studied. Light pulses (≍ 5-ps-wide) from a modelocked dye laser optically sample the gated MCP. Shuttering is achieved by applying a forward-biasing electrical gate pulse to the quiescently reverse-biased photocathode-MCP interface. Variable delay (≍ 30-ps jitter) between the gate pulse and the laser pulse permit tracing the MCP's optical response. Gating speeds, turn-on and turn-off patterns, the asymmetric spatial dependence of the MCP optical response, and resolution effects as functions of gate pulse width and photocathode-MCP bias have been characterized. Shutter times of >= 750 ps and <= 5 1p/mm resolution with the MCP fully on were observed. Variations in the intensity profiles of the phosphorl.s spatial response for uniform photocathode illumination are measured with a calibrated silicon-intensified-target (SIT) focus projection, scan (FPS) television camera and a high-speed video digitizer while photomultipliers (PMTs) monitor the laser pulse and the phosphor's spatially integrated output intensities. The characterization system, gating and biasing circuits, and experimental results will be presented.

  15. High power laser-driven ceramic phosphor plate for outstanding efficient white light conversion in application of automotive lighting.

    Science.gov (United States)

    Song, Young Hyun; Ji, Eun Kyung; Jeong, Byung Woo; Jung, Mong Kwon; Kim, Eun Young; Yoon, Dae Ho

    2016-08-09

    We report on Y3Al5O12: Ce(3+) ceramic phosphor plate (CPP) using nano phosphor for high power laser diode (LD) application for white light in automotive lighting. The prepared CPP shows improved luminous properties as a function of Ce(3+) concentration. The luminous properties of the Y3Al5O12: Ce(3+) CPP nano phosphor are improved when compared to the Y3Al5O12: Ce(3+) CPP with bulk phosphor, and hence, the luminous emittance, luminous flux, and conversion efficiency are improved. The Y3Al5O12: Ce(3+) CPP with an optimal Ce(3+) content of 0.5 mol % shows 2733 lm/mm(2) value under high power blue radiant flux density of 19.1 W/mm(2). The results indicate that Y3Al5O12: Ce(3+) CPP using nano phosphor can serve as a potential material for solid-state laser lighting in automotive applications.

  16. Adaptive Optics and Lucky Imager (AOLI): presentation and first light

    CERN Document Server

    Velasco, S; Mackay, C; Oscoz, A; King, D L; Crass, J; Díaz-Sánchez, A; Femenía, B; González-Escalera, V; Labadie, L; López, R L; Garrido, A Pérez; Puga, M; Rodríguez-Ramos, L F; Zuther, J

    2015-01-01

    In this paper we present the Adaptive Optics Lucky Imager (AOLI), a state-of-the-art instrument which makes use of two well proved techniques for extremely high spatial resolution with ground-based telescopes: Lucky Imaging (LI) and Adaptive Optics (AO). AOLI comprises an AO system, including a low order non-linear curvature wavefront sensor together with a 241 actuators deformable mirror, a science array of four 1024x1024 EMCCDs, allowing a 120x120 down to 36x36 arcseconds field of view, a calibration subsystem and a powerful LI software. Thanks to the revolutionary WFS, AOLI shall have the capability of using faint reference stars ({\\it I\\/} $\\sim$ 16.5-17.5), enabling it to be used over a much wider part of the sky than with common Shack-Hartmann AO systems. This instrument saw first light in September 2013 at William Herschel Telescope. Although the instrument was not complete, these commissioning demonstrated its feasibility, obtaining a FWHM for the best PSF of 0.151$\\pm$0.005 arcsec and a plate scale o...

  17. Structured light imaging of epicardial mechanics.

    Science.gov (United States)

    Laughner, Jacob I; Gong, Yuanzheng; Filas, Benjamen A; Zhang, Song; Efimov, Igor R

    2010-01-01

    There is a need for accurate measurements of mechanical strain and motion of the heart both in vitro and in vivo. We have developed a new structured-light imaging system capable of epicardial shape measurement at 333 fps at a resolution of 768 × 768 pixels. Here we present proof-of-concept data from our system applied to a beating rabbit heart in vitro to measure epicardial mechanics. This method will allow high resolution mapping of epicardial strain and virtual immobilization of the heart for removal of motion artifacts from epicardial recordings with fluorescence dyes. This will allow mapping of transmembrane potential and calcium transients in a beating heart, including in vivo.

  18. Structured-light Image Compression Based on Fractal Theory

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The method of fractal image compression is introduced which is applied to compress the line structured-light image. Based on the self-similarity of the structured-light image, we attain satisfactory compression ratio and higher peak signal-to-noise ratio (PSNR). The experimental results indicate that this method can achieve high performance.

  19. Magnetic imaging with a Zernike-type phase plate in a transmission electron microscope

    DEFF Research Database (Denmark)

    Pollard, Shawn; Malac, Marek; Beleggia, Marco

    2013-01-01

    We demonstrate the use of a hole-free phase plate (HFPP) for magnetic imaging in transmission electron microscopy by mapping the domain structure in PrDyFeB samples. The HFPP, a Zernike-like imaging method, allows for detecting magnetic signals in-focus to correlate the sample crystal structure a...

  20. HL-2A Tokamak Plasma Visible Light Imaging System

    Institute of Scientific and Technical Information of China (English)

    ZHENGYinjia; FENGZhen; LUOCuiwen; CHENGLiaoyuan

    2003-01-01

    Visible imagery is extremely useful to overview the edge and divertor structure. The plasma configuration and the position of the strike lines on the target plates can be also observed by imaging technique. By imaging the edge or core plasma with visible emission in the desired wavelength band, usually with a “tangential” view, the plasma position can be determined in principle.

  1. Electric modelling and image analysis of channel flow in bipolar plates

    Energy Technology Data Exchange (ETDEWEB)

    Martin, D.; Gonzalez, L.; Garcia-Alegre, M.C.; Guinea, D. [Instituto de Automatica Industrial, Consejo Superior de Investigaciones Cientificas, 28500 Arganda, Madrid (Spain); Guinea, D.M.; Moreno, B. [Instituto de Ceramica y Vidrio, Consejo Superior de Investigaciones Cientificas, Kelsen 5, 28049 Madrid (Spain)

    2007-07-15

    Bipolar plates are an essential part of Polymer Electrolyte Membrane Fuel Cells (PEMFC) and are related to fluid conduction. The topology of a bipolar plate is critical to the homogeneous distribution of the feeding gases over the accessible zone of the electrode. An electric model that simulates flow in bipolar plates and permits the optimisation of gas feeding in PEMFCs is proposed. As a first approach, an analogy is made between the gas pressure P and an electric voltage U in a circuit and a gas flow F and an electric current I. The fluidic resistance in a bipolar plate channel is thus R=P/F and is equivalent to the electric resistance R=U/I in a branch of a circuit. Computer image processing techniques allow the validation of the present flow estimation approach based on electrical variables. Separate plates were developed to experimentally implement a complete parallel bipolar topology. (author)

  2. The Gemini Planet Imager: First Light

    CERN Document Server

    Macintosh, Bruce; Ingraham, Patrick; Konopacky, Quinn; Marois, Christian; Perrin, Marshall; Poyneer, Lisa; Bauman, Brian; Barman, Travis; Burrows, Adam; Cardwell, Andrew; Chilcote, Jeffrey; De Rosa, Robert J; Dillon, Daren; Doyon, Rene; Dunn, Jennifer; Erikson, Darren; Fitzgerald, Michael; Gavel, Donald; Goodsell, Stephen; Hartung, Markus; Hibon, Pascale; Kalas, Paul G; Larkin, James; Maire, Jerome; Marchis, Franck; Marley, Mark; McBride, James; Millar-Blanchaer, Max; Morzinski, Katie; Norton, Andew; Oppenheimer, B R; Palmer, Dave; Patience, Jennifer; Pueyo, Laurent; Rantakyro, Fredrik; Sadakuni, Naru; Saddlemyer, Leslie; Savransky, Dmitry; Serio, Andrew; Soummer, Remi; Sivaramakrishnan, Anand; Song, Inseok; Thomas, Sandrine; Wallace, J Kent; Wiktorowicz, Sloane; Wolff, Schuyler

    2014-01-01

    The Gemini Planet Imager (GPI) is a dedicated facility for directly imaging and spectroscopically characterizing extrasolar planets. It combines a very high-order adaptive optics system, a diffraction-suppressing coronagraph, and an integral field spectrograph with low spectral resolution but high spatial resolution. Every aspect of GPI has been tuned for maximum sensitivity to faint planets near bright stars. During first light observations, we achieved an estimated H band Strehl ratio of 0.89 and a 5-sigma contrast of $10^6$ at 0.75 arcseconds and $10^5$ at 0.35 arcseconds. Observations of Beta Pictoris clearly detect the planet, Beta Pictoris b, in a single 60-second exposure with minimal post-processing. Beta Pictoris b is observed at a separation of $434 \\pm 6$ milli-arcseconds and position angle $211.8 \\pm 0.5$ deg. Fitting the Keplerian orbit of Beta Pic b using the new position together with previous astrometry gives a factor of three improvement in most parameters over previous solutions. The planet ...

  3. Interaction between hollow needles - electric field, light emission and ozone generation study in multineedle to plate electrical discharge

    Science.gov (United States)

    Kriha, Vitezslav

    2004-09-01

    Multi hollow needle to plate electrical discharges in air are studied as ozone sources. Dependence of ozone concentration as an function of applied voltage, discharge current, mutual hollow needles position and electrical connection, working gas flow rate, distances between needles tips and plate electrode, visible light emission was measured experimentally in these systems. Electric field was numerically modeled. Light emission and electrical field distributions were compared. Coming from light emission and electric field a model of energy density spatial distribution was built. This model was finally compared with ozone generation.

  4. Development of a PET/Cerenkov-light hybrid imaging system

    Energy Technology Data Exchange (ETDEWEB)

    Yamamoto, Seiichi, E-mail: s-yama@met.nagoya-u.ac.jp; Hamamura, Fuka; Kato, Katsuhiko; Ogata, Yoshimune [Radiological and Medical Laboratory Sciences, Nagoya University Graduate School of Medicine, Aichi 461-8673 (Japan); Watabe, Tadashi; Ikeda, Hayato; Kanai, Yasukazu; Hatazawa, Jun [Department of Molecular Imaging in Medicine, Osaka University Graduate School of Medicine, Osaka 565-0871 (Japan); Watabe, Hiroshi [CYRIC, Tohoku University, Miyagi 980-8578 (Japan)

    2014-09-15

    Purpose: Cerenkov-light imaging is a new molecular imaging technology that detects visible photons from high-speed electrons using a high sensitivity optical camera. However, the merit of Cerenkov-light imaging remains unclear. If a PET/Cerenkov-light hybrid imaging system were developed, the merit of Cerenkov-light imaging would be clarified by directly comparing these two imaging modalities. Methods: The authors developed and tested a PET/Cerenkov-light hybrid imaging system that consists of a dual-head PET system, a reflection mirror located above the subject, and a high sensitivity charge coupled device (CCD) camera. The authors installed these systems inside a black box for imaging the Cerenkov-light. The dual-head PET system employed a 1.2 × 1.2 × 10 mm{sup 3} GSO arranged in a 33 × 33 matrix that was optically coupled to a position sensitive photomultiplier tube to form a GSO block detector. The authors arranged two GSO block detectors 10 cm apart and positioned the subject between them. The Cerenkov-light above the subject is reflected by the mirror and changes its direction to the side of the PET system and is imaged by the high sensitivity CCD camera. Results: The dual-head PET system had a spatial resolution of ∼1.2 mm FWHM and sensitivity of ∼0.31% at the center of the FOV. The Cerenkov-light imaging system's spatial resolution was ∼275μm for a {sup 22}Na point source. Using the combined PET/Cerenkov-light hybrid imaging system, the authors successfully obtained fused images from simultaneously acquired images. The image distributions are sometimes different due to the light transmission and absorption in the body of the subject in the Cerenkov-light images. In simultaneous imaging of rat, the authors found that {sup 18}F-FDG accumulation was observed mainly in the Harderian gland on the PET image, while the distribution of Cerenkov-light was observed in the eyes. Conclusions: The authors conclude that their developed PET/Cerenkov-light

  5. X-ray modulation transfer functions of photostimulable phosphor image plates and scanners.

    Science.gov (United States)

    Seely, John F; Holland, Glenn E; Hudson, Lawrence T; Henins, Albert

    2008-11-01

    The modulation transfer functions of two types of photostimulable phosphor image plates were determined in the 10 keV to 50 keV x-ray energy range using a resolution test pattern with up to 10 line pairs per mm (LP/mm) and a wavelength dispersive x-ray spectrometer. Techniques were developed for correcting for the partial transmittance of the high energy x rays through the lead bars of the resolution test pattern, and the modulation transfer function (MTF) was determined from the measured change in contrast with LP/mm values. The MTF was convolved with the slit function of the image plate scanner, and the resulting point spread functions (PSFs) were in good agreement with the observed shapes and widths of x-ray spectral lines and with the PSF derived from edge spread functions. The shapes and the full width at half-maximum (FWHM) values of the PSF curves of the Fuji Superior Resolution (SR) and Fuji Maximum Sensitivity (MS) image plate detectors, consisting of the image plate and the scanner, determined by the three methods gave consistent results: The SR PSF is Gaussian with 0.13 mm FWHM, and the MS PSF is Lorentzian with 0.19 mm FWHM. These techniques result in the accurate determination of the spatial resolution achievable using image plate and scanner combinations and enable the optimization of spatial resolution for x-ray spectroscopy and radiography.

  6. Nondestructive imaging of hidden figures on license plates by X-ray radiograph.

    Science.gov (United States)

    Jeon, Oc-Yeub; Kim, Sang-Hyeon; Lee, Joong; Park, Jong-Taek; Kim, Tae-Hoon; Park, Hak-Soo; Huh, Il-Kwon; Kang, Hyung-Tae

    2009-07-01

    In this case, we investigated the modified license plates. The evidences had new embossing pressed serial numbers after erasing the original numbers on the license plates by hammering. The X-ray radiograph could visualize the hidden figures; those were virtually unseen by naked eyes or undetectable by ordinary photography. To reveal the erased figures, we performed image processing with computer software after X-ray radiographs. It proved to be an efficient nondestructive way to visualize the hidden original figures on metals.

  7. Dead-time effects in microchannel-plate imaging detectors

    Science.gov (United States)

    Zombeck, Martin V.; Fraser, George W.

    1991-01-01

    The observed counting rates of microchannel plate (MCP) based detectors for high resolution observations of celestial EUV and X-ray sources vary over many orders of magnitude; the counting capability of an individual channel, however, is not high, and is associated with dead-times ranging from 0.1 msec to 1 sec. The dead-time increases with the area illuminated; attention is presently given to laboratory determinations of the count rate characteristics of a MCP detector as a function of illuminated area, and a model is developed for these results' use in the interpretation of space observations.

  8. Middle infrared hyperspectral imaging of adhesives, varnishes and inks on Al plate and papers by using a bolometer camera and an imaging type interferometer

    Science.gov (United States)

    Sugawara, Shigeru; Yoshida, Mitsuhiro; Saito, Tsubasa; Nakayama, Yoshihiko; Tsutsui, Yasuyuki; Taniguchi, Hideya; Ishimaru, Ichiro

    2016-10-01

    We built a hyperspectral imaging apparatus using middle-infrared light of 8-14 μm, which has a strong ability to identify organic materials, and attempted visualization of the distribution of organic materials that could not be identified by a naked eye. For this purpose, we utilized a low-cost bolometer camera (Nippon Avionics co., ltd. C100V, Japan) for its easy availability rather than an expensive mercury cadmium telluride (MCT) array sensor. To compensate for the low sensitivity of this bolometer, we adopted a Fourier-type spectroscopic system (Aoi Electronics co. ltd., Japan) using an imaging interferometer devised by the Kagawa University, Japan; this interferometer has higher light-utilization efficiency than Michelson interferometers, which are used in popular interferometry techniques. In this study, 4 types of adhesives, 9 types of varnishes and more than 50 types of inks were put on Al plates of size 10 cm × 10 cm and were used as samples. Glossy paper for printing photos with an inkjet printer was also used as a sample. A 300 °C black body of size 15 cm × 15 cm was used as a light source. Spectra of 320 × 240 points were measured at a wavelength resolution of approximately 9 cm-1. The mirror was scanned only once. The measurement time was approximately 30 s. Hyperspectral images of adhesives, varnishes and inks on Al plate and paper were successfully measured. Spectra over a 5 × 5-pixel neighborhoods were averaged, and the averaged spectra were compared with those measured by a commercially available Fourier transform infrared (FTIR) spectroscopy. The averaged and measured spectra had absorption peaks at the same wavelengths. Furthermore, by analyzing the measured spectra, the distribution of substances invisible to the naked eye was visualized. Our results show that if low-absorbance organic materials are put on a high-reflectance surface such as an Al plate, the middle-infrared hyperspectral imaging could be measured using a bolometer

  9. Diffusion tensor imaging of the cortical plate and subplate in very-low-birth-weight infants

    Energy Technology Data Exchange (ETDEWEB)

    Dudink, Jeroen; Govaert, Paul; Zwol, Arjen L. van; Conneman, Nikk; Goudoever, Johannes B. van [Erasmus MC-Sophia Children' s Hospital, Division of Neonatology, Department of Paediatrics, Rotterdam (Netherlands); Buijs, Jan [Maxima Medical Center, Division of Neonatology, Department of Paediatrics, Veldhoven (Netherlands); Lequin, Maarten [Erasmus MC-Sophia Children' s Hospital, Division of Paediatrics, Department of Radiology, Rotterdam, Zuid-holland (Netherlands)

    2010-08-15

    Many intervention studies in preterm infants aim to improve neurodevelopmental outcome, but short-term proxy outcome measurements are lacking. Cortical plate and subplate development could be such a marker. Our aim was to provide normal DTI reference values for the cortical plate and subplate of preterm infants. As part of an ongoing study we analysed diffusion tensor imaging (DTI) images of 19 preterm infants without evidence of injury on conventional MRI, with normal outcome (Bayley-II assessed at age 2), and scanned in the first 4 days of life. Fractional anisotropy (FA) and apparent diffusion coefficient (ADC) values in the frontal and temporal subplate and cortical plate were measured in single and multiple voxel regions of interest (ROI) placed on predefined regions. Using single-voxel ROIs, statistically significant inverse correlation was found between gestational age (GA) and FA of the frontal (r = -0.5938, P = 0.0058) and temporal (r = -0.4912, P = 0.0327) cortical plate. ADC values had a significant positive correlation with GA in the frontal (r = 0.5427, P = 0.0164) and temporal (r = 0.5540, P = 0.0138) subplate. Diffusion tensor imaging allows in vivo exploration of the evolving cortical plate and subplate. We provide FA and ADC values of the subplate and cortical plate in very-low-birth-weight (VLBW) infants with normal developmental outcome that can be used as reference values. (orig.)

  10. X-ray imaging using the thermoluminescent properties of commercial Al2O3 ceramic plates.

    Science.gov (United States)

    Shinsho, Kiyomitsu; Kawaji, Yasuyuki; Yanagisawa, Shin; Otsubo, Keisuke; Koba, Yusuke; Wakabayashi, Genichiro; Matsumoto, Kazuki; Ushiba, Hiroaki

    2016-05-01

    This research demonstrated that commercially available alumina is well-suited for use in large area X-ray detectors. We discovered a new radiation imaging device that has a high spatial resolution, high sensitivity, wide dynamic range, large imaging area, repeatable results, and low operating costs. The high thermoluminescent (TL) properties of Al2O3 ceramic plates make them useful for X-ray imaging devices.

  11. Time-lapse 3-D measurements of a glucose biosensor in multicellular spheroids by light sheet fluorescence microscopy in commercial 96-well plates

    Science.gov (United States)

    Maioli, Vincent; Chennell, George; Sparks, Hugh; Lana, Tobia; Kumar, Sunil; Carling, David; Sardini, Alessandro; Dunsby, Chris

    2016-11-01

    Light sheet fluorescence microscopy has previously been demonstrated on a commercially available inverted fluorescence microscope frame using the method of oblique plane microscopy (OPM). In this paper, OPM is adapted to allow time-lapse 3-D imaging of 3-D biological cultures in commercially available glass-bottomed 96-well plates using a stage-scanning OPM approach (ssOPM). Time-lapse 3-D imaging of multicellular spheroids expressing a glucose Förster resonance energy transfer (FRET) biosensor is demonstrated in 16 fields of view with image acquisition at 10 minute intervals. As a proof-of-principle, the ssOPM system is also used to acquire a dose response curve with the concentration of glucose in the culture medium being varied across 42 wells of a 96-well plate with the whole acquisition taking 9 min. The 3-D image data enable the FRET ratio to be measured as a function of distance from the surface of the spheroid. Overall, the results demonstrate the capability of the OPM system to measure spatio-temporal changes in FRET ratio in 3-D in multicellular spheroids over time in a multi-well plate format.

  12. Development of a soft x-ray plasma camera with a Fresnel zone plate to image laser produced plasmas

    Science.gov (United States)

    Kado, M.; Mori, M.; Nishiuchi, M.; Ishino, M.; Kawachi, T.

    2009-09-01

    A soft x-ray plasma camera operated at 3.35nm in the water window x-ray region is developed and demonstrated imaging gas jet plasmas of several spices produced with a 10TW Ti: sapphire laser. The plasma camera consists of a 300nm thick Ag/Ti/Si3N4 x-ray band pass filter with bandwidth of 1.43nm to cut visible light and also to reduce colour aberration of the Fresnel zone plate, a Fresnel zone plate with diameter of 1mm and outermost zone width of 300nm, and a soft x-ray CCD camera. The magnification of the plasma camera is 10. The soft x-ray plasma camera powered by a Fresnel zone plate is a very powerful tool to observe laser produced plasmas since it is 1000 times brighter and has 5 times higher spatial resolution comparing ordinary x-ray pinhole camera. The soft x-ray images of helium, nitrogen, argon, krypton, and xenon gas jet plasmas are obtained changing gas pressure from 0.01MPa to 1MPa.

  13. Modelling of classical ghost images obtained using scattered light

    Science.gov (United States)

    Crosby, S.; Castelletto, S.; Aruldoss, C.; Scholten, R. E.; Roberts, A.

    2007-08-01

    The images obtained in ghost imaging with pseudo-thermal light sources are highly dependent on the spatial coherence properties of the incident light. Pseudo-thermal light is often created by reducing the coherence length of a coherent source by passing it through a turbid mixture of scattering spheres. We describe a model for simulating ghost images obtained with such partially coherent light, using a wave-transport model to calculate the influence of the scattering on initially coherent light. The model is able to predict important properties of the pseudo-thermal source, such as the coherence length and the amplitude of the residual unscattered component of the light which influence the resolution and visibility of the final ghost image. We show that the residual ballistic component introduces an additional background in the reconstructed image, and the spatial resolution obtainable depends on the size of the scattering spheres.

  14. A guided ultrasonic imaging approach in isotropic plate structures using edge reflections

    Science.gov (United States)

    Ebrahimkhanlou, Arvin; Dubuc, Brennan; Salamone, Salvatore

    2016-04-01

    This paper presents an imaging technique to locate damage in plate-like structures by permanently attached piezoelectric transducers (PZT) capable to generate and receive guided ultrasonic waves. The technique is based on a model capable of predicting envelope of scattered waves. Correlations between the estimated scattered waves and experimental data are used for image reconstruction. The approach is validated on an aluminum plate and results are compared with two common imaging algorithms, that is, Delay and Sum (DS) and Minimum Variance (MV). Damage is simulated by placing two magnets on sides of the plate. It is shown that the inclusion of Lamb wave reflections improves the localization accuracy while making use of fewer number of sensors possible.

  15. A neutron image plate quasi-Laue diffractometer for protein crystallography

    Energy Technology Data Exchange (ETDEWEB)

    Cipriani, F.; Castagna, J.C.; Wilkinson, C. [European Molecular Biology Laboratory, Grenoble (France)] [and others

    1994-12-31

    An instrument which is based on image plate technology has been constructed to perform cold neutron Laue crystallography on protein structures. The crystal is mounted at the center of a cylindrical detector which is 400mm long and has a circumference of 1000mm, with gadolinium oxide-containing image plates mounted on its exterior surface. Laue images registered on the plate are read out by rotating the drum and translating a laser read head parallel to the cylinder axis, giving a pixel size of 200{mu}m x 200{mu}m and a total read time of 5 minutes. Preliminary results indicate that it should be possible to obtain a complete data set from a protein crystal to atomic resolution in about two weeks.

  16. Tonpilz piezoelectric transducers with acoustic matching plates for underwater color image transmission.

    Science.gov (United States)

    Inoue, T; Nada, T; Tsuchiya, T; Nakanishi, T; Miyama, T; Konno, M

    1993-01-01

    Tonpilz piezoelectric transducers with multiple acoustic matching plates are suitable for color image acoustic transmission, to achieve wideband low-ripple characteristics as well as high-efficiency high-power transmitting capability. The design method for the transducers was investigated on the basis of multiple-mode filter synthesis theory. For transducers with single, double, and triple matching plates, optimum specific acoustic impedances and lengths were calculated. Moreover, based on this design method, a 24 kHz array comprising nine identical transducers with single matching plates was built and evaluated. As a result, this array showed high-efficiency, low-ripple, and wideband characteristics. Excellent agreement between theoretical values and experimental results was obtained. A field test was carried out on color image transmission from a 3500 m sea depth, using the fabricated array, during which good color images were received.

  17. Development of Noncontact Imaging Technology for the Detection of Internal Defects of a Nuclear Fuel Plate

    Energy Technology Data Exchange (ETDEWEB)

    Park, S. K.; Baik, S. H.; Lee, Y. S.; Cheong, Y. M.

    2012-01-15

    The object of the research is to develop a new imaging inspection technology for the quality testing of plate-type nuclear fuel whose demanding is currently increasing in nuclear research reactors. A new noncontact imaging inspection technique is developed for the detection of internal defects in plate-type nuclear fuel. To develop the imaging inspection technique, a hardware system based on active optical interference is configured. An operating software for the developed nondestructive inspection system is developed after designing an advanced signal processing algorithm to improve the detection capability of the system. The developed system is optimized through experiments and optimal heating condition is studied. The performance of a lock-in thermography is also evaluated to see the possibility of the plate-type nuclear fuel application.

  18. Spatially Varying Image Based Lighting by Light Probe Sequences, Capture, Processing and Rendering

    OpenAIRE

    Unger, Jonas; Gustavson, Stefan; Ynnerman, Anders

    2007-01-01

    We present a novel technique for capturing spatially or temporally resolved light probe sequences, and using them for image based lighting. For this purpose we have designed and built a real-time light probe, a catadioptric imaging system that can capture the full dynamic range of the lighting incident at each point in space at video frame rates, while being moved through a scene. The real-time light probe uses a digital imaging system which we have programmed to capture high quality, photome...

  19. Neutron diffractometer for bio-crystallography (BIX) with an imaging plate neutron detector

    Energy Technology Data Exchange (ETDEWEB)

    Niimura, Nobuo [Japan Atomic Energy Research Inst., Ibaraki-ken (Japan)

    1994-12-31

    We have constructed a dedicated diffractometer for neutron crystallography in biology (BIX) on the JRR-3M reactor at JAERI (Japan Atomic Energy Research Institute). The diffraction intensity from a protein crystal is weaker than that from most inorganic materials. In order to overcome the intensity problem, an elastically bent silicon monochromator and a large area detector system were specially designed. A preliminary result of diffraction experiment using BIX has been reported. An imaging plate neutron detector has been developed and a feasibility experiment was carried out on BIX. Results are reported. An imaging plate neutron detector has been developed and a feasibility test was carried out using BIX.

  20. Crack Imaging and Quantification in Aluminum Plates with Guided Wave Wavenumber Analysis Methods

    Science.gov (United States)

    Yu, Lingyu; Tian, Zhenhua; Leckey, Cara A. C.

    2015-01-01

    Guided wavefield analysis methods for detection and quantification of crack damage in an aluminum plate are presented in this paper. New wavenumber components created by abrupt wave changes at the structural discontinuity are identified in the frequency-wavenumber spectra. It is shown that the new wavenumbers can be used to detect and characterize the crack dimensions. Two imaging based approaches, filter reconstructed imaging and spatial wavenumber imaging, are used to demonstrate how the cracks can be evaluated with wavenumber analysis. The filter reconstructed imaging is shown to be a rapid method to map the plate and any existing damage, but with less precision in estimating crack dimensions; while the spatial wavenumber imaging provides an intensity image of spatial wavenumber values with enhanced resolution of crack dimensions. These techniques are applied to simulated wavefield data, and the simulation based studies show that spatial wavenumber imaging method is able to distinguish cracks of different severities. Laboratory experimental validation is performed for a single crack case to confirm the methods' capabilities for imaging cracks in plates.

  1. Phase contrast without phase plates and phase rings--optical solutions for improved imaging of phase structures.

    Science.gov (United States)

    Piper, Timm; Piper, Jörg

    2013-10-01

    Using the optical methods described, phase specimens can be observed with a modified light microscope in enhanced clarity, purified from typical artifacts which are apparent in standard phase contrast illumination. In particular, haloing and shade-off are absent, lateral and vertical resolution are maximized and the image quality remains constant even in problematic preparations which cannot be well examined in normal phase contrast, such as specimens beyond a critical thickness or covered by obliquely situated cover slips. The background brightness and thus the range of contrast can be continuously modulated and specimens can be illuminated in concentric-peripheral, axial or paraxial light. Additional contrast effects can be achieved by spectral color separation. Normal glass or mirror lenses can be used; they do not need to be fitted with a phase plate or a phase ring. The methods described should be of general interest for all disciplines using phase microscopy.

  2. External motion tracking for brain imaging: structured light tracking with invisible light

    DEFF Research Database (Denmark)

    Olesen, Oline Vinter; Paulsen, Rasmus Reinhold; Højgaard, Liselotte;

    2010-01-01

    The importance of motion correction in 3D medical imaging increases with increasing scanner resolution. It is necessary for scanners with long image acquisition and low contrast images to correct for patient motion in order to optimize image quality. We present a near infrared structured light st...

  3. High-resolution imaging X-ray detector. [using microchannel plates and electronic readout for spaceborne telescope

    Science.gov (United States)

    Kellogg, E.; Henry, P.; Murray, S.; Van Speybroeck, L.; Bjorkholm, P.

    1976-01-01

    The paper describes an X-ray detector using microchannel plates as a photocathode surface and imaging photoelectron multiplier, and a crossed wire grid as a two-dimensional position-sensitive detector. The position resolution is 10 microns. The crossed wire grid consists of 100-micron-diam wires on 200-micron centers. Position sensing is accomplished by electronic interpolation to 1/20 of the wire spacing. The quantum efficiency of the microchannel plates varies from 29% at 0.28 keV to 5% at 3 keV. This detector will provide second-of-arc X-ray imaging in the focal plane of the 342.9-cm focal length grazing-incidence telescope being prepared for the HEAO-B observatory. By addition of suitable photocathodes, it can be used for single-photon imaging light detection in the UV, visible, and near-IR-ranges. In all cases, it gives a very low dark counting rate, allows timing of individual events to 1 microsec or less, and can handle counting rates up to 10,000 per sec.

  4. X-ray imaging microscopy at 25 keV with Fresnel zone plate optics

    CERN Document Server

    Awaji, M; Takeuchi, A; Takano, H; Kamijo, N; Tamura, S; Yasumoto, M

    2001-01-01

    X-ray imaging microscopy with a sputtered-sliced Fresnel zone plate (SS-FZP) has been developed at an X-ray energy of 25 keV. Objects were imaged in transmission with the SS-FZP as an objective with a magnification of 10.2 times, and detected with a X-ray image sensor. The performance of the imaging microscope has been tested with a gold mesh and a resolution test pattern at an undulator beamline 47XU of SPring-8. The resolution test patterns up to 0.5 mu m line-and-space structures have been resolved.

  5. Non-invasive method of field imaging in parallel plate waveguides

    DEFF Research Database (Denmark)

    Iwaszczuk, Krzysztof; Andryieuski, Andrei; Lavrinenko, Andrei

    2011-01-01

    We present a new non-invasive air-photonic-based method of terahertz (THz) field imaging inside a parallel plate waveguide. The method is based on THz field-enhanced second harmonic generation of the fundamental laser beam in an external electric field. We also demonstrate the direct measurements...

  6. Calibration of photon counting imaging microchannel plate detectors for EUV astronomy

    Science.gov (United States)

    Siegmund, O. H. W.; Vallerga, J.; Jelinsky, P.

    1986-01-01

    The calibration of photon counting imaging detectors for satellite based EUV astronomy is a complex process designed to ensure the validity of the data received 'in orbit'. The methods developed to accomplish calibration of microchannel plate detectors for the Extreme Ultraviolet Explorer are described and illustrated. The characterization of these detectors can be subdivided into three categories: stabilization, performance tests, and environmental tests.

  7. A multiple-plate, multiple-pinhole camera for X-ray gamma-ray imaging

    Science.gov (United States)

    Hoover, R. B.

    1971-01-01

    Plates with identical patterns of precisely aligned pinholes constitute lens system which, when rotated about optical axis, produces continuous high resolution image of small energy X-ray or gamma ray source. Camera has applications in radiation treatment and nuclear medicine.

  8. Numerical analysis on the shoot resistance of heat treated light weight B-grade bulletproof steel plates

    Institute of Scientific and Technical Information of China (English)

    Ma Mingtu; Zhang Jingwen; Zhang Junping

    2014-01-01

    Bulletproof steel plates are widely used for the safety of special vehicles. This paper mainly resear-ches on the shoot resistance of heat treated light weight B-grade bulletproof steel plates through numerical analy-sis. Based on the flow behavior of bulletproof steel plates and bullet at various high strain rates,finite element (FE) model has been set up using ANSYS/LS-DYNA software. The simulation results are compared with the shooting results,which show a good consistency and a high reliability. Therefore,the simulation results are ef-ficient approaches and strategies to decide and select the mechanical property and thickness of bulletproof steel plates,saving a lot of work and the cost of experiments.

  9. Color, Scale, and Rotation Independent Multiple License Plates Detection in Videos and Still Images

    Directory of Open Access Journals (Sweden)

    Narasimha Reddy Soora

    2016-01-01

    Full Text Available Most of the existing license plate (LP detection systems have shown significant development in the processing of the images, with restrictions related to environmental conditions and plate variations. With increased mobility and internationalization, there is a need to develop a universal LP detection system, which can handle multiple LPs of many countries and any vehicle, in an open environment and all weather conditions, having different plate variations. This paper presents a novel LP detection method using different clustering techniques based on geometrical properties of the LP characters and proposed a new character extraction method, for noisy/missed character components of the LP due to the presence of noise between LP characters and LP border. The proposed method detects multiple LPs from an input image or video, having different plate variations, under different environmental and weather conditions because of the geometrical properties of the set of characters in the LP. The proposed method is tested using standard media-lab and Application Oriented License Plate (AOLP benchmark LP recognition databases and achieved the success rates of 97.3% and 93.7%, respectively. Results clearly indicate that the proposed approach is comparable to the previously published papers, which evaluated their performance on publicly available benchmark LP databases.

  10. Evaluation of tissue optical properties from light distribution images

    Science.gov (United States)

    Tsai, Cheng-Lun; Chang, Ming; Hsieh, Jui-Hsiang; Yang, Yi-Fong; Chou, Yi-Sheong

    2000-06-01

    Images of light distribution in biological soft tissue we used to study the optical characteristics of tissue. The light distribution image was taken under a microscope with light injected through a pinhole close to the edge of the top surface. Images taken on skin, fat, and muscle tissues were compared to study the effect of cellular structure and temperature on the light intensity distribution. Monte Carlo simulation with the same conditions was also performed to simulate the light intensity distribution in tissue for comparison. The anisotropy scattering of light in tissue is affected by the tissue microscopic structure, such as the direction of muscle tissue fibers. The change in optical properties of fat and muscle tissue with temperature was observed. The two-dimensional light distribution images offer more information than general reflectance and transmission measurements. By matching the simulated light intensity distribution with the light distribution image, the optical properties of biological tissue could be estimated. This method might be applied in tissue engineering as an economic way for evaluating the microscopic structure of tissue.

  11. Bifractal focusing and imaging properties of Thue-Morse Zone Plates.

    Science.gov (United States)

    Ferrando, Vicente; Giménez, Fernando; Furlan, Walter D; Monsoriu, Juan A

    2015-07-27

    We present a new family of Zone Plates (ZPs) designed using the Thue-Morse sequence. The focusing and imaging properties of these aperiodic diffractive lenses coined Thue-Morse Zone Plates (TMZPs) are examined. It is demonstrated that TMZPs produce a pair of self-similar and equally intense foci along the optical axis. As a consequence of this property, under broadband illumination, a TMZP produces two foci with an extended depth of focus and a strong reduction of the chromatic aberration compared with conventional periodic ZPs. This distinctive optical characteristic is experimentally confirmed.

  12. A quantitative damage imaging technique based on enhanced CCRTM for composite plates using 2D scan

    Science.gov (United States)

    He, Jiaze; Yuan, Fuh-Gwo

    2016-10-01

    A two-dimensional (2D) non-contact areal scan system was developed to image and quantify impact damage in a composite plate using an enhanced zero-lag cross-correlation reverse-time migration (E-CCRTM) technique. The system comprises a single piezoelectric wafer mounted on the composite plate and a laser Doppler vibrometer (LDV) for scanning a region in the vicinity of the PZT to capture the scattered wavefield. The proposed damage imaging technique takes into account the amplitude, phase, geometric spreading, and all of the frequency content of the Lamb waves propagating in the plate; thus, a reflectivity coefficients of the delamination is calculated and potentially related to damage severity. Comparisons are made in terms of damage imaging quality between 2D areal scans and 1D line scans as well as between the proposed and existing imaging conditions. The experimental results show that the 2D E-CCRTM performs robustly when imaging and quantifying impact damage in large-scale composites using a single PZT actuator with a nearby areal scan using LDV.

  13. Resolution and noise in ghost imaging with classical thermal light

    Institute of Scientific and Technical Information of China (English)

    Cheng Jing; Han Shen-Sheng; Yan Yi-Jing

    2006-01-01

    The resolution and classical noise in ghost imaging with a classical thermal light are investigated theoretically. For ghost imaging with a Gaussian Schell model source, the dependences of the resolution and noise on the spatial coherence of the source and the aperture in the imaging system are discussed and demonstrated by using numerical simulations.The results show that an incoherent source and a large aperture will lead to a good image quality and small noise.

  14. Imaging flaws in thin metal plates using a magneto-optic device

    Science.gov (United States)

    Wincheski, B.; Prabhu, D. R.; Namkung, M.; Birt, E. A.

    1992-01-01

    An account is given of the capabilities of the magnetooptic/eddy-current imager (MEI) apparatus in the case of aging aircraft structure-type flaws in 2024-T3 Al alloy plates. Attention is given to images of cyclically grown fatigue cracks from rivetted joints in fabricated lap-joint structures, electrical discharge machining notches, and corrosion spots. Although conventional eddy-current methods could have been used, the speed and ease of MEI's use in these tests is unmatched by such means. Results are displayed in real time as a test piece is scanned, furnishing easily interpreted flaw images.

  15. Elimination of the Background Noise of the Decoded Image in Fresnel Zone Plate Scanning Holography

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    A method of digitally high pass filtering in frequency domain is proposed to eliminate the background noise of the decoded image in Fresnel zone plate scanning holography. The high pass filter is designed as a circular stop, which should be suitable to suppressing the background noise significantly and remain much low frequency information of the object. The principle of high pass filtering is that the Fourier transform of the decoded image is multiplied with the high pass filter. Thus the frequency spectrum of the decoded image without the background noise is achieved. By inverse Fourier transform of the spectrum of the decoded image after multiplying operation, the decoded image without the background noise is obtained. Both of the computer simulations and the experimental results show that the contrast and the signal-to-noise ratio of the decoded image are significantly improved with digital filtering.

  16. Subdiffraction scattered light imaging of gold nanoparticles using structured illumination.

    Science.gov (United States)

    Chang, Bo-Jui; Lin, Shiuan Huei; Chou, Li-Jun; Chiang, Su-Yu

    2011-12-15

    A reflective light-scattering (RLS) microscope with structured illumination (SI) provides subdiffraction resolution and improves the image quality of gold nanoparticles in biological systems. The three-dimensional (3D)-structured pattern is rapidly and precisely controlled with a spatial light modulator and scrambled at the conjugate image plane to increase spatial incoherence. The reconstructed SI-RLS image of 100 nm gold nanoparticles reveals lateral and axial resolutions of approximately 117 and 428 nm. We present a high-resolution image of gold nanoparticles inside a HeLa cell, with improved contrast.

  17. Trinary flip-flops using Savart plate and spatial light modu-lator for optical computation in multivalued logic

    Institute of Scientific and Technical Information of China (English)

    Areal K Ghosh; Amitabha Basuray

    2008-01-01

    The memory devices in multi-valued logic are of most significance in modern research. This paper deals with the imple-mentation of basic memory devices in multi-valued logic using Savart plate and spatial light modulator (SLM) basedoptoelectronic circuits. Photons are used here as the carrier to speed up the operations. Optical tree architecture (OTA) hasbeen also utilized in the optical interconnection network. We have exploited the advantages of Savart plates, SLMs andOTA and proposed the SLM based high speed JK, D-type and T-type flip-flops in a trinary system.

  18. Compressive microscopic imaging with "positive-negative" light modulation

    Science.gov (United States)

    Yu, Wen-Kai; Yao, Xu-Ri; Liu, Xue-Feng; Lan, Ruo-Ming; Wu, Ling-An; Zhai, Guang-Jie; Zhao, Qing

    2016-07-01

    An experiment on compressive microscopic imaging with single-pixel detector and single-arm has been performed on the basis of "positive-negative" (differential) light modulation of a digital micromirror device (DMD). A magnified image of micron-sized objects illuminated by the microscope's own incandescent lamp has been successfully acquired. The image quality is improved by one more orders of magnitude compared with that obtained by conventional single-pixel imaging scheme with normal modulation using the same sampling rate, and moreover, the system is robust against the instability of light source and may be applied to very weak light condition. Its nature and the analysis of noise sources is discussed deeply. The realization of this technique represents a big step to the practical applications of compressive microscopic imaging in the fields of biology and materials science.

  19. High resolution, two-dimensional imaging, microchannel plate detector for use on a sounding rocket experiment

    Science.gov (United States)

    Bush, Brett C.; Cotton, Daniel M.; Siegmund, Oswald H.; Chakrabarti, Supriya; Harris, Walter; Clarke, John

    1991-01-01

    We discuss a high resolution microchannel plate (MCP) imaging detector to be used in measurements of Doppler-shifted hydrogen Lyman-alpha line emission from Jupiter and the interplanetary medium. The detector is housed in a vacuum-tight stainless steel cylinder (to provide shielding from magnetic fields) with a MgF2 window. Operating at nominal voltage, the four plate configuration provides a gain of 1.2 x 10 exp 7 electrons per incident photon. The wedge-and-strip anode has two-dimensional imaging capabilities, with a resolution of 40 microns FWHM over a one centimeter diameter area. The detector has a high quantum efficiency while retaining a low background rate. A KBr photocathode is used to enhance the quantum efficiency of the bare MCPs to a value of 35 percent at Lyman-alpha.

  20. Image edge-enhancement in optical microscopy with a phase mismatched spiral phase plate

    Institute of Scientific and Technical Information of China (English)

    Shibiao Wei; Jing Bu; Siwei Zhu; Xiaocong Yuan

    2011-01-01

    @@ We present a spiral phase filtering system with a large tolerance for edge enhancement of both phase and amplitude objects in optical microscopy.The method is based on a Fourier 4-f spatial filtering system.A phase mismatched spiral phase plate (SPP) fabricated by electron beam lithography is employed as the radial Hilbert transform for image edge enhancement.Compared with holography, SPP is simple,economical, reliable, and easy to integrate.%We present a spiral phase filtering system with a large tolerance for edge enhancement of both phase and amplitude objects in optical microscopy. The method is based on a Fourier 4-f spatial filtering system.A phase mismatched spiral phase plate (SPP) fabricated by electron beam lithography is employed as the radial Hilbert transform for image edge enhancement. Compared with holography, SPP is simple,economical, reliable, and easy to integrate.

  1. Large-format imaging plate and weissenberg camera for accurate protein crystallographic data collection using synchrotron radiation.

    Science.gov (United States)

    Sakabe, K; Sasaki, K; Watanabe, N; Suzuki, M; Wang, Z G; Miyahara, J; Sakabe, N

    1997-05-01

    Off-line and on-line protein data-collection systems using an imaging plate as a detector are described and their components reported. The off-line scanner IPR4080 was developed for a large-format imaging plate ;BASIII' of dimensions 400 x 400 mm and 400 x 800 mm. The characteristics of this scanner are a dynamic range of 10(5) photons pixel(-1), low background noise and high sensitivity. A means of reducing electronic noise and a method for finding the origin of the noise are discussed in detail. A dedicated screenless Weissenberg camera matching IPR4080 with synchrotron radiation was developed and installed on beamline BL6B at the Photon Factory. This camera can attach one or two sheets of 400 x 800 mm large-format imaging plate inside the film cassette by evacuation. The positional reproducibility of the imaging plate on the cassette is so good that the data can be processed by batch job. Data of 93% completeness up to 1.6 A resolution were collected on a single axis rotation and the value of R(merge) becomes 4% from a tetragonal lysozyme crystal using a set of two imaging-plate sheets. Comparing two types of imaging plates, the signal-to-noise ratio of the ST-VIP-type imaging plate is 25% better than that of the BASIII-type imaging plate for protein data collection using 1.0 and 0.7 A X-rays. A new on-line protein data-collection system with imaging plates is specially designed to use synchrotron radiation X-rays at maximum efficiency.

  2. Low-Light Image Enhancement Using Adaptive Digital Pixel Binning

    Directory of Open Access Journals (Sweden)

    Yoonjong Yoo

    2015-06-01

    Full Text Available This paper presents an image enhancement algorithm for low-light scenes in an environment with insufficient illumination. Simple amplification of intensity exhibits various undesired artifacts: noise amplification, intensity saturation, and loss of resolution. In order to enhance low-light images without undesired artifacts, a novel digital binning algorithm is proposed that considers brightness, context, noise level, and anti-saturation of a local region in the image. The proposed algorithm does not require any modification of the image sensor or additional frame-memory; it needs only two line-memories in the image signal processor (ISP. Since the proposed algorithm does not use an iterative computation, it can be easily embedded in an existing digital camera ISP pipeline containing a high-resolution image sensor.

  3. Image Analysis of Fabric Pilling Based on Light Projection

    Institute of Scientific and Technical Information of China (English)

    陈霞; 黄秀宝

    2003-01-01

    The objective assessment of fabric pilling based on light projection and image analysis has been exploited recently.The device for capturing the cross-sectional images of the pilled fabrics with light projection is elaborated.The detection of the profile line and integration of the sequential cross-sectional pilled image are discussed.The threshold based on Gaussian model is recommended for pill segmentation.The results show that the installed system is capable of eliminating the interference with pill information from the fabric color and pattern.

  4. Spatio-temporal mapping of plate boundary faults in California using geodetic imaging

    Science.gov (United States)

    Donnellan, Andrea; Arrowsmith, Ramon; DeLong, Stephen B.

    2017-01-01

    The Pacific–North American plate boundary in California is composed of a 400-km-wide network of faults and zones of distributed deformation. Earthquakes, even large ones, can occur along individual or combinations of faults within the larger plate boundary system. While research often focuses on the primary and secondary faults, holistic study of the plate boundary is required to answer several fundamental questions. How do plate boundary motions partition across California faults? How do faults within the plate boundary interact during earthquakes? What fraction of strain accumulation is relieved aseismically and does this provide limits on fault rupture propagation? Geodetic imaging, broadly defined as measurement of crustal deformation and topography of the Earth’s surface, enables assessment of topographic characteristics and the spatio-temporal behavior of the Earth’s crust. We focus here on crustal deformation observed with continuous Global Positioning System (GPS) data and Interferometric Synthetic Aperture Radar (InSAR) from NASA’s airborne UAVSAR platform, and on high-resolution topography acquired from lidar and Structure from Motion (SfM) methods. Combined, these measurements are used to identify active structures, past ruptures, transient motions, and distribution of deformation. The observations inform estimates of the mechanical and geometric properties of faults. We discuss five areas in California as examples of different fault behavior, fault maturity and times within the earthquake cycle: the M6.0 2014 South Napa earthquake rupture, the San Jacinto fault, the creeping and locked Carrizo sections of the San Andreas fault, the Landers rupture in the Eastern California Shear Zone, and the convergence of the Eastern California Shear Zone and San Andreas fault in southern California. These examples indicate that distribution of crustal deformation can be measured using interferometric synthetic aperture radar (InSAR), Global Navigation

  5. On the Origin of the Dragon Image on the Plate from Shilovka Burial Mound

    OpenAIRE

    Liphanov Nicolay А.

    2017-01-01

    The author of the article analyzes an unique image of two opposed dragons engraved on a bone plate discovered in 1992 at barrow No.1 of Shilovka burial mound located on the right bank of the Volga river in Ulyanovsk Oblast (the excavations were conducted by R.S. Bagautdinov). The burial mound is related to the cattle breeding population of late 7th century. The article considers different hypotheses concerning the origin of these dragon images in the artistic traditions of various regions: Ch...

  6. Note: spatial resolution of Fuji BAS-TR and BAS-SR imaging plates.

    Science.gov (United States)

    Fiksel, G; Marshall, F J; Mileham, C; Stoeckl, C

    2012-08-01

    The spatial resolution of two types of imaging plates, Fuji BAS-TR and Fuji BAS-SR, has been measured using a knife-edge x-ray source of 8-keV Cu K(α) radiation. The values for the spatial resolution, defined as the distance between 10% and 90% levels of the edge spread function, are 94 μm and 109 μm, respectively. The resolution values are important for quantitative analysis of x-ray and particle imaging and spectroscopic diagnostics.

  7. Needle image plates compared to conventional CR in chest radiography: Is dose reduction possible?

    Energy Technology Data Exchange (ETDEWEB)

    Berger-Kulemann, Vanessa, E-mail: vanessa.berger-kulemann@meduniwien.ac.at [Department of Radiology, Medical University of Vienna, Waehringer Guertel 18-20, 1090 Vienna (Austria); Pötter-Lang, Sarah; Gruber, Michael [Department of Radiology, Medical University of Vienna, Waehringer Guertel 18-20, 1090 Vienna (Austria); Berger, Rudolf [Department of Internal Medicine II, Division of Cardiology, Medical University of Vienna, Waehringer Guertel 18-20, 1090 Vienna (Austria); Vonbank, Karin [Department of Internal Medicine II, Division of Pneumology, Medical University of Vienna Waehringer Guertel 18-20, 1090 Vienna (Austria); Weber, Michael [Department of Radiology, Medical University of Vienna, Waehringer Guertel 18-20, 1090 Vienna (Austria); Rabitsch, Werner [Department of Internal Medicine I, Bone Marrow Transplantation, Medical University of Vienna, Waehringer Guertel 18-20, 1090 Vienna (Austria); Uffmann, Martin [Department of Radiology, Medical University of Vienna, Waehringer Guertel 18-20, 1090 Vienna (Austria); Department of Radiology, KH Neunkirchen, Peischinger Straße 19, 2620 Neunkirchen (Austria)

    2012-12-15

    Purpose: To compare image quality of standard-dose computed radiography and dose reduced needle-technology CR for supine CXR in a clinical setting. Materials and methods: We prospectively evaluated 128 radiographs of 32 immunocompromised patients. For each patient four clinical CXR were performed within one week, two with powder image plates (PIP; Fuji ST-V) and two with needle image plates (NIP; Agfa DXS) at standard and half dose, respectively. One experienced radiologist and two residents blinded to dose level and kind of imaging system rated different anatomical structures, image noise, tubes/lines and abnormalities on a image quality scale from 1 to 10 (1 = poor, 10 = excellent). The rating scores were tested for statistical differences using analysis of variance with repeated measures. Results: A statistical difference (p < 0.05) was found for the two systems as well as for the two dose levels. Overall rating scores were 6.5 for PIP with full dose, 6.2 for PIP with half dose, 7.6 for NIP with full dose and 7.4 for NIP with half dose. There was a significant difference in favour of the NIP system at the same dose level. Also the NIP images obtained at half dose were ranked significantly better compared to the PIP images at standard dose. The differences in ranking of anatomical structures and abnormalities were more pronounced in low absorption areas (pulmonary vessels, parenchyma) than in high absorption areas (mediastinum, spine). Conclusion: For supine chest radiograms the NIP technology allows for a dose reduction of 50% while providing higher image quality.

  8. Freestanding GaN-based light-emitting diode membranes on Y3Al5O12:Ce3+ crystal phosphor plate for efficient white light emission

    Science.gov (United States)

    Feng, Lungang; Li, Yufeng; Xiong, Han; Wang, Shuai; Wang, Jiangteng; Ding, Wen; Zhang, Ye; Yun, Feng

    2016-08-01

    GaN-based light-emitting diode (LED) membranes were peeled from the substrate using electrochemical etching of the bottom sacrificial layer. The freestanding membranes were transferred onto a Y3Al5O12:Ce3+ (YAG:Ce3+) crystal phosphor plate to realize a compact white light source. Verified by the Raman test, the initial strain within the original GaN layers was greatly released after the exfoliation process, which induced alleviation of the quantum confined stark effect. The electroluminescence measurement of a blue LED membranes-on-YAG:Ce3+ plate-structured device was conducted exhibiting color coordinates and a correlated color temperature of (0.3367,0.4525) and 5450 K at 10 mA, respectively.

  9. Optical and UV Sensing Sealed Tube Microchannel Plate Imaging Detectors with High Time Resolution

    Science.gov (United States)

    Siegmund, O.; Vallerga, J.; Tremsin, A.; Hull, J.; Elam, J.; Mane, A.

    2014-09-01

    Microchannel plate (MCP) based imaging, photon time tagging detector sealed tube schemes have a unique set of operational features that enable high time resolution astronomical and remote sensing applications to be addressed. New detectors using the cross strip (XS), cross delay line (XDL), or stripline anode readouts, a wide range of photocathode types, and advanced MCP technologies have been implemented to improve many performance characteristics. A variety of sealed tubes have been developed including 18mm XS readout devices with GaAs and SuperGenII photocathodes, 25mm XDL readout devices with SuperGenII and GaN photocathodes, and 20 x 20 cm sealed tubes with bialkali photocathodes and strip line readout. One key technology that has just become viable is the ability to make MCPs using atomic layer deposition (ALD) techniques. This employs nanofabrication of the active layers of an MCP on a microcapillary array. This technique opens new performance opportunities, including, very large MCP areas (>20cm), very low intrinsic background, lower radiation induced background, much longer overall lifetime and gain stability, and markedly lower outgassing which can improve the sealed tube lifetime and ease of fabrication. The XS readout has been implemented in formats of 22mm, 50mm and 100mm, and uses MCP charge signals detected on two orthogonal layers of conductive fingers to encode event X-Y positions. We have achieved spatial resolution XS detectors better than 25 microns FWHM, with good image linearity while at low gain (5 MHz with ~12% dead time and event timing accuracy of ~100ps. XDL sealed tubes in 25mm format demonstrate ~40 micron spatial resolution at up to ~2 MHz event rates, and have been developed with SupergenII visible regime photocathodes. The XDL tubes also achieve ~100 ps time resolution. Most recently ALD MCPs with an opaque GaN photocathode (100-350nm range) on the MCP surface has been demonstrated in a sealed tube configuration. These ALD MCPs show

  10. Using high-power light emitting diodes for photoacoustic imaging

    DEFF Research Database (Denmark)

    Hansen, René Skov

    The preliminary result of using a high-power light emitting diode, LED, for photoacoustic imaging is presented. The pulsed light source is created by a 1Watt red Luxeon LED. The LED delivers light pulses with 25W peak power when supplied by 40A peak, 60ns wide current pulses. The phantom used...... for the experiment consists of a 3mm high x 5mm wide slice of green colored gelatine overlaid by a 3cm layer of colorless gelatine. The light pulses from the LED is focused on the green gelatine. The photoacoustic response from the green gelatine is detected by a single transducer on the opposite (top) surface...

  11. An experimental study of yellow shift in injection-molded light guide plate

    Science.gov (United States)

    Min, Inki; Lee, Sungjun; Lee, Sunghee; Kim, Jongsun; Yoon, Kyunghwan

    2016-08-01

    Recently, the size of light guide plate (LGP) in LCD-BLU (Backlight Unit) module is getting thinner and larger than ever. The part reached critical thickness to mold it by conventional injection molding methods due to the low flowability, melt solidification, machine limitation, and so on. Therefore, severe conditions have been applied to the part to increase the flowability such as high injection speeds and higher melt temperature. However, these approaches lead to the degradation of material and loss of optical properties. These defects are connected to the invisible part failure, so called, yellowing and color shift. In the present study a series of injection molding experiments were conducted to understand the distribution of yellowness in injection-molded LGP, and how the optical properties change under various injection molding conditions. Optical properties of yellow index (YI), CIE xy, and spectral transmittances of LGP sample were analyzed by the UV-visible spectrophotometer. Also, correlations between optical properties and process conditions were investigated from the Design of experiment (DOE). Interestingly, the value of YI, i.e., yellow shift in CIE diagram showed the maximum near the gate and decreased as the distance from the gate increased. Furthermore, as far as yellow shift concerned the data of direct transmittance are much more useful than total transmittance for evaluating color behavior. Meanwhile, analysis of variance (ANOVA) was conducted to see the effectiveness of chosen processing parameters. Mold temperature was found to be the most influential factor on the color shift and injection speed, melt temperature, packing pressure were followed.

  12. TECHNICAL DESIGN NOTE: The method for controlling dew droplets deposited on a copper plate by scattered laser light

    Science.gov (United States)

    Matsumoto, Shigeaki

    2008-01-01

    Tiny dew droplets deposited on a copper plate were controlled constantly by a developed control technique using scattered laser light for studying initial dropwise condensation. The technique employs proportional control combined with shifting movement by an integrator. The droplets were controlled for 60 min at almost constant diameters in a range from only a few micrometers to tens of micrometers and were almost hemispherical in the initial condensation at room temperature.

  13. Image quality in double- and triple-intensity ghost imaging with classical partially polarized light

    CERN Document Server

    Kellock, Henri; Shirai, Tomohiro; Friberg, Ari T

    2012-01-01

    Classical ghost imaging is a correlation-imaging technique in which the image of the object is found through intensity correlations of light. We analyze three different quality parameters, namely the visibility, the signal-to-noise ratio (SNR), and the contrast-to-noise ratio (CNR), to assess the performance of double- and triple-intensity correlation-imaging setups. The source is a random partially polarized beam of light obeying Gaussian statistics and the image quality is evaluated as a function of the degree of polarization (DoP). We show that the visibility improves when the DoP and the order of imaging increase, while the SNR behaves oppositely. The CNR is for the most part independent of DoP and the imaging order. The results are important for the development of new imaging devices using partially polarized light.

  14. Super-weak asthenosphere models in light of plate motions and azimuthal anisotropy

    Science.gov (United States)

    Becker, T. W.

    2016-12-01

    Plate motions and azimuthal seismic anisotropy from surface waves are consistent with a strong, oceanic lithosphere that is predominantly dragged by slabs, and weakened upon subduction. Plates are underlain and sustained by a moderately weak asthenosphere, as expected from the temperature and pressure dependence of olivine viscosity for the upper mantle. However, recent observations from active source seismology, magneto-tellurics, body wave anisotropy, and postseismic surface deformation can be interpreted to imply the existence of a very weak channel of low viscosity material, potentially decoupling plates, not unlike a plume-fed asthenosphere scenario in several ways. Here, I explore the implications of such a decoupling channel for plate driving forces as well as observations of seismic anisotropy. The thickness and viscosity reduction of the channel are expected to trade off with each other, and plate motions are sensitive to the lateral extent of this super-weak asthenosphere. While there is some ambiguity of plate motion metrics with the strength of slabs, seismic anisotropy is expected to be sensitive to how shear is localized with depth. The overall good fit of azimuthal anisotropy patterns to flow model predictions brakes down for a number of the more extreme lateral and depth-dependent viscosity scenarios. This may imply that weakening mechanisms may not apply globally under plates, but are rather limited to isolated regions, perhaps associated with melt rich pockets that have limited connectivity.

  15. Halo performance on low light level image intensifiers

    Science.gov (United States)

    Cui, Dongxu; Ren, Ling; Chang, Benkang; Shi, Feng; Shi, Jifang; Qian, Yunsheng; Wang, Honggang; Zhang, Junju

    To analyze the formation mechanism of the halo on low light level image intensifiers and the influencing factors on the halo size, a halo tester has been designed. Under the illumination between 10-2 lx and 10-4 lx, we use the tester to collect a 0.1922 mm hole image directly with CoolSNAPK4 charge-coupled device (CCD) in a darkroom. The practical measurement result shows that the amplification ratio is 343.4. Then we put the super second and third generation image intensifiers after the hole, and the halo sizes of the hole images on the screens are determined as 0.2388 and 0.5533 mm respectively. The results are helpful to improve the quality of the low light level image intensifiers.

  16. Effect of specific light supply rate on photosynthetic efficiency of Nannochloropsis salina in a continuous flat plate photobioreactor.

    Science.gov (United States)

    Sforza, Eleonora; Calvaruso, Claudio; Meneghesso, Andrea; Morosinotto, Tomas; Bertucco, Alberto

    2015-10-01

    In this work, Nannochloropsis salina was cultivated in a continuous-flow flat-plate photobioreactor, working at different residence times and irradiations to study the effect of the specific light supply rate on biomass productivity and photosynthetic efficiency. Changes in residence times lead to different steady-state cell concentrations and specific growth rates. We observed that cultures at steady concentration were exposed to different values of light intensity per cell. This specific light supply rate was shown to affect the photosynthetic status of the cells, monitored by fluorescence measurements. High specific light supply rate can lead to saturation and photoinhibition phenomena if the biomass concentration is not optimized for the selected operating conditions. Energy balances were applied to quantify the biomass growth yield and maintenance requirements in N. salina cells.

  17. Reflective ghost imaging with classical Gaussian-state light

    Institute of Scientific and Technical Information of China (English)

    Deyang Duan; Yunjie Xia

    2012-01-01

    In this letter, we use quantum description and the Gaussian state to study reflective ghost imaging with two classical sources, and to provide their expressions. We find that the reflective ghost imaging of a rough-surfaced object, using Gaussian-state phase-insensitive or classically correlated phase-sensitive light, can be expressed in terms of the phase-insensitive or phase-sensitive cross-correlations between the two detected fields, including a background term. Moreover, reflective ghost imaging with two classical Gaussian-state lights is shown to have similar features as spatial resolution and field of view.%In this letter,we use quantum description and the Gaussian state to study reflective ghost imaging with two classical sources,and to provide their expressions.We find that the reflective ghost imaging of a rough-surfaced object,using Gaussian-state phase-insensitive or classically correlated phase-sensitive light,can be expressed in terms of the phase-insensitive or phase-sensitive cross-correlations between the two detected fields,including a background term.Moreover,reflective ghost imaging with two classical Gaussian-state lights is shown to have similar features as spatial resolution and field of view.

  18. Imaging the megathrust zone and Yakutat/Pacific plate interface in the Alaska subduction zone

    Science.gov (United States)

    Kim, Y.; Abers, G. A.; Li, J.; Christensen, D. H.; Rondenay, S.

    2013-12-01

    We image the subducted slab underneath a 450 km long transect of the Alaska subduction zone. Dense stations in southern Alaska are set up to investigate (1) the geometry and velocity structure of the downgoing plate and their relationship to slab seismicity, and (2) the interplate coupled zone where the great 1964 earthquake (magnitude 9.3) exhibited the largest amount of rupture. The joint teleseismic migration of two array datasets based on teleseismic receiver functions (RFs) reveals a prominent, shallow-dipping low-velocity layer at ~25-30 km depth in southern Alaska. Modeling of RF amplitudes suggests the existence of a thin (3-5 km) low-velocity layer (shear wave velocity of ~2.0-2.5 km/s) that is ~20-40% slower than underlying oceanic crustal velocities, and is sandwiched between the subducted slab and the overriding North America plate. The observed low-velocity megathrust layer (with P-to-S velocity ratio of 1.9-2.3) may be due to a thick sediment input from the trench in combination with elevated pore fluid pressure in the channel. The subducted crust below the low-velocity channel has gabbroic velocities with a thickness of ~15 km. Both velocities and thickness of the low-velocity channel abruptly increase downdip in central Alaska, which agrees with previously published results. Our image also includes an unusually thick low-velocity crust subducting with a ~20 degree dip down to 130 km depth at approximately 200 km inland beneath central Alaska. The unusual nature of this subducted segment has been suggested to be due to the subduction of the Yakutat terrane. We also show a clear image of the Yakutat and Pacific plate subduction beneath the Kenai Peninsula, and the along-strike boundary between them at megathrust depths. Our imaged western edge of the Yakutat terrane, at 25-30 km depth in the central Kenai along the megathrust, aligns with the western end of a geodetically locked patch with high slip deficit, and coincides with the boundary of

  19. Imaging megathrust zone and Yakutat/Pacific plate interface in Alaska subduction zone

    Science.gov (United States)

    Kim, Y.; Abers, G. A.; Li, J.; Christensen, D. H.; Calkins, J. A.

    2013-05-01

    We image the subducted slab underneath a 450 km long transect of the Alaska subduction zone. Dense stations in southern Alaska are set up to investigate (1) the geometry and velocity structure of the downgoing plate and their relation to slab seismicity, and (2) the interplate coupled zone where the great 1964 (magnitude 9.3) had greatest rupture. The joint teleseismic migration of two array datasets (MOOS, Multidisciplinary Observations of Onshore Subduction, and BEAAR, Broadband Experiment Across the Alaska Range) based on teleseismic receiver functions (RFs) using the MOOS data reveal a shallow-dipping prominent low-velocity layer at ~25-30 km depth in southern Alaska. Modeling of these RF amplitudes shows a thin (plate. The observed low-velocity megathrust layer (with P-to-S velocity ratio (Vp/Vs) exceeding 2.0) may be due to a thick sediment input from the trench in combination of elevated pore fluid pressure in the channel. The subducted crust below the low-velocity channel has gabbroic velocities with a thickness of 11-12 km. Both velocities and thickness of the low-velocity channel abruptly increase as the slab bends in central Alaska, which agrees with previously published RF results. Our image also includes an unusually thick low-velocity crust subducting with a ~20 degree dip down to 130 km depth at approximately 200 km inland beneath central Alaska. The unusual nature of this subducted segment has been suggested to be due to the subduction of the Yakutat terrane. We also show a clear image of the Yakutat and Pacific plate subduction beneath the Kenai Peninsula, and the along-strike boundary between them at megathrust depths. Our imaged western edge of the Yakutat terrane, at 25-30 km depth in the central Kenai along the megathrust, aligns with the western end of the geodetically locked patch with high slip deficit, and coincides with the boundary of aftershock events from the 1964 earthquake. It seems plausible that this sharp change in the nature of

  20. Study on detecting spatial distribution of neutrons and gamma rays using a multi-imaging plate system.

    Science.gov (United States)

    Tanaka, Kenichi; Sakurai, Yoshinori; Endo, Satoru; Takada, Jun

    2014-06-01

    In order to measure the spatial distributions of neutrons and gamma rays separately using the imaging plate, the requirement for the converter to enhance specific component was investigated with the PHITS code. Consequently, enhancing fast neutrons using recoil protons from epoxy resin was not effective due to high sensitivity of the imaging plate to gamma rays. However, the converter of epoxy resin doped with (10)B was found to have potential for thermal and epithermal neutrons, and graphite for gamma rays.

  1. Guided-wave tomography imaging plate defects by laser-based ultrasonic techniques

    Energy Technology Data Exchange (ETDEWEB)

    Park, Jun Pil; Lim, Ju Young; Cho, Youn Ho [School of Mechanical Engineering, Pusan National University, Pusan (Korea, Republic of)

    2014-12-15

    Contact-guided-wave tests are impractical for investigating specimens with limited accessibility and rough surfaces or complex geometric features. A non-contact setup with a laser-ultrasonic transmitter and receiver is quite attractive for guided-wave inspection. In the present work, we developed a non-contact guided-wave tomography technique using the laser-ultrasonic technique in a plate. A method for Lamb-wave generation and detection in an aluminum plate with a pulsed laser-ultrasonic transmitter and Michelson-interferometer receiver was developed. The defect shape and area in the images obtained using laser scanning, showed good agreement with the actual defect. The proposed approach can be used as a non-contact online inspection and monitoring technique.

  2. Coherent imaging with incoherent light in digital holographic microscopy

    Science.gov (United States)

    Chmelik, Radim

    2012-01-01

    Digital holographic microscope (DHM) allows for imaging with a quantitative phase contrast. In this way it becomes an important instrument, a completely non-invasive tool for a contrast intravital observation of living cells and a cell drymass density distribution measurement. A serious drawback of current DHMs is highly coherent illumination which makes the lateral resolution worse and impairs the image quality by a coherence noise and a parasitic interference. An uncompromising solution to this problem can be found in the Leith concept of incoherent holography. An off-axis hologram can be formed with arbitrary degree of light coherence in systems equipped with an achromatic interferometer and thus the resolution and the image quality typical for an incoherent-light wide-field microscopy can be achieved. In addition, advanced imaging modes based on limited coherence can be utilized. The typical example is a coherence-gating effect which provides a finite axial resolution and makes DHM image similar to that of a confocal microscope. These possibilities were described theoretically using the formalism of three-dimensional coherent transfer functions and proved experimentally by the coherence-controlled holographic microscope which is DHM based on the Leith achromatic interferometer. Quantitative-phase-contrast imaging is demonstrated with incoherent light by the living cancer cells observation and their motility evaluation. The coherence-gating effect was proved by imaging of model samples through a scattering layer and living cells inside an opalescent medium.

  3. An experimental investigation of a 100-W high-power light-emitting diode array using vapor chamber–based plate

    Directory of Open Access Journals (Sweden)

    Ping Zhang

    2015-11-01

    Full Text Available In this study, a compact 100-W input power light-emitting diode array vapor chamber–based plate has been fabricated to investigate the thermal performance. To make a comparison, a typical commercial chip on board–type light-emitting diode array using a copper-based plate which has the same chip layout and the same power input was also investigated. The surface temperature distribution and total thermal resistance corresponding to these two high-power light-emitting diode modules were measured using a thermal infrared camera and a MicReD T3Ster. The experimental results show that the thermal performance of the compact light-emitting diode array using vapor chamber–based plate is much better than that using copper-based plate. The average temperatures of light-emitting diode copper- and vapor chamber–based plates are 100.5°C and 41.5°C at 100 W power input, respectively. In addition, the maximal temperature difference of the 100-W light-emitting diode array vapor chamber–based plate is 2.2°C far less than 31.7°C of copper-based plate. Furthermore, the measurement results show that the vapor chamber can prominently lower the spreading resistance, diminish the hot-spot effect, and increase durability.

  4. Fast imaging of live organisms with sculpted light sheets

    Science.gov (United States)

    Chmielewski, Aleksander K.; Kyrsting, Anders; Mahou, Pierre; Wayland, Matthew T.; Muresan, Leila; Evers, Jan Felix; Kaminski, Clemens F.

    2015-04-01

    Light-sheet microscopy is an increasingly popular technique in the life sciences due to its fast 3D imaging capability of fluorescent samples with low photo toxicity compared to confocal methods. In this work we present a new, fast, flexible and simple to implement method to optimize the illumination light-sheet to the requirement at hand. A telescope composed of two electrically tuneable lenses enables us to define thickness and position of the light-sheet independently but accurately within milliseconds, and therefore optimize image quality of the features of interest interactively. We demonstrated the practical benefit of this technique by 1) assembling large field of views from tiled single exposure each with individually optimized illumination settings; 2) sculpting the light-sheet to trace complex sample shapes within single exposures. This technique proved compatible with confocal line scanning detection, further improving image contrast and resolution. Finally, we determined the effect of light-sheet optimization in the context of scattering tissue, devising procedures for balancing image quality, field of view and acquisition speed.

  5. Polarization changes in temporal imaging with pulses of random light.

    Science.gov (United States)

    Voipio, Timo; Setälä, Tero; Friberg, Ari T

    2013-04-08

    We consider polarization changes of randomly fluctuating electromagnetic pulsed light in temporal imaging. The polarization properties of pulses formed by the time lens are formulated in terms of the Stokes parameters. For Gaussian Schell-model pulses we show that the degree and state of polarization of the time-imaged pulse can be tailored in versatile ways, depending on the temporal polarization and coherence of the input pulse and the system parameters. In particular, weakly polarized central region of the pulse may become fully polarized without energy absorption. The results have potential applications in optical communication, micromachining, and light-matter interactions.

  6. Coherent x-ray diffraction imaging of paint pigmentparticles by scanning a phase plate modulator

    Energy Technology Data Exchange (ETDEWEB)

    Chu Y. S.; Chen B.; Zhang F.; Berenguer F.; Bean R.; Kewish C.; Vila-Comamala J.; Rodenburg J.; Robinson I.

    2011-10-19

    We have implemented a coherent x-ray diffraction imaging technique that scans a phase plate to modulate wave-fronts of the x-ray beam transmitted by samples. The method was applied to measure a decorative alkyd paint containing iron oxide red pigment particles. By employing an iterative algorithm for wave-front modulation phase retrieval, we obtained an image of the paint sample that shows the distribution of the pigment particles and is consistent with the result obtained from a transmission x-ray microscope. The technique has been experimentally proven to be a feasible coherent x-ray imaging method with about 120 nm spatial resolution and was shown to work well with industrially relevant specimens.

  7. On the Origin of the Dragon Image on the Plate from Shilovka Burial Mound

    Directory of Open Access Journals (Sweden)

    Liphanov Nicolay А.

    2017-07-01

    Full Text Available The author of the article analyzes an unique image of two opposed dragons engraved on a bone plate discovered in 1992 at barrow No.1 of Shilovka burial mound located on the right bank of the Volga river in Ulyanovsk Oblast (the excavations were conducted by R.S. Bagautdinov. The burial mound is related to the cattle breeding population of late 7th century. The article considers different hypotheses concerning the origin of these dragon images in the artistic traditions of various regions: China (A.V. Komar, D.G. Savinov, B. Totev, Pelevina, Central Asia (V.G. Kotov, V.E. Flyorova, India (N.A. Fonyakova. According to the author, this image has no apparent iconographic parallels in the traditions of these regions. Such analogues are found in the art of the Mediterranean where the ancient images of various mythological creatures exist alongside the image of the sea dragon “ketos” which later became part of the Christian tradition. The appearance of this monster in the images of the first half – middle of the 1st millennium A.D. is practically identical to the dragons from Shilovka burial mound. According to the author, certain impact on the formation of the considered dragon image was made by Iranian art.

  8. Conversion from film to image plates for transfer method neutron radiography of nuclear fuel

    Energy Technology Data Exchange (ETDEWEB)

    Craft, Aaron E.; Papaioannou, Glen C.; Chichester, David L.; Williams, Walter J.

    2017-02-01

    This paper summarizes efforts to characterize and qualify a computed radiography (CR) system for neutron radiography of irradiated nuclear fuel at Idaho National Laboratory (INL). INL has multiple programs that are actively developing, testing, and evaluating new nuclear fuels. Irradiated fuel experiments are subjected to a number of sequential post-irradiation examination techniques that provide insight into the overall behavior and performance of the fuel. One of the first and most important of these exams is neutron radiography, which provides more comprehensive information about the internal condition of irradiated nuclear fuel than any other non-destructive technique to date. Results from neutron radiography are often the driver for subsequent examinations of the PIE program. Features of interest that can be evaluated using neutron radiography include irradiation-induced swelling, isotopic and fuel-fragment redistribution, plate deformations, and fuel fracturing. The NRAD currently uses the foil-film transfer technique with film for imaging fuel. INL is pursuing multiple efforts to advance its neutron imaging capabilities for evaluating irradiated fuel and other applications, including conversion from film to CR image plates. Neutron CR is the current state-of-the-art for neutron imaging of highly-radioactive objects. Initial neutron radiographs of various types of nuclear fuel indicate that radiographs can be obtained of comparable image quality currently obtained using film. This paper provides neutron radiographs of representative irradiated fuel pins along with neutron radiographs of standards that informed the qualification of the neutron CR system for routine use. Additionally, this paper includes evaluations of some of the CR scanner parameters and their effects on image quality.

  9. Anatomy of the western Java plate interface from depth-migrated seismic images

    Science.gov (United States)

    Kopp, H.; Hindle, D.; Klaeschen, D.; Oncken, O.; Reichert, C.; Scholl, D.

    2009-01-01

    Newly pre-stack depth-migrated seismic images resolve the structural details of the western Java forearc and plate interface. The structural segmentation of the forearc into discrete mechanical domains correlates with distinct deformation styles. Approximately 2/3 of the trench sediment fill is detached and incorporated into frontal prism imbricates, while the floor sequence is underthrust beneath the d??collement. Western Java, however, differs markedly from margins such as Nankai or Barbados, where a uniform, continuous d??collement reflector has been imaged. In our study area, the plate interface reveals a spatially irregular, nonlinear pattern characterized by the morphological relief of subducted seamounts and thicker than average patches of underthrust sediment. The underthrust sediment is associated with a low velocity zone as determined from wide-angle data. Active underplating is not resolved, but likely contributes to the uplift of the large bivergent wedge that constitutes the forearc high. Our profile is located 100 km west of the 2006 Java tsunami earthquake. The heterogeneous d??collement zone regulates the friction behavior of the shallow subduction environment where the earthquake occurred. The alternating pattern of enhanced frictional contact zones associated with oceanic basement relief and weak material patches of underthrust sediment influences seismic coupling and possibly contributed to the heterogeneous slip distribution. Our seismic images resolve a steeply dipping splay fault, which originates at the d??collement and terminates at the sea floor and which potentially contributes to tsunami generation during co-seismic activity. ?? 2009 Elsevier B.V.

  10. Imaging the Juan de Fuca plate beneath southern Oregon using teleseismic P wave residuals

    Science.gov (United States)

    Harris, R.A.; Iyer, H.M.; Dawson, P.B.

    1991-01-01

    Images the Juan de Fuca plate in southern Oregon using seismic tomography. P wave travel time residuals from a 366-km-long seismic array operated in southern Oregon in 1982 are inverted. The southeast striking array extended from the Coast ranges to the Modoc Plateau and crossed the High Cascades at Crater Lake, Oregon. Three features under the array were imaged: one high-velocity zone and two low-velocity zones. The high-velocity zone is 3-4% faster than the surrounding upper mantle. It dips steeply at 65?? to the east beneath the Cascade Range and extends down to at least 200 km. It is proposed that this high-velocity feature is subducted Juan de Fuca plate. Two low-velocity zones were also imaged, both of which are 3-4% slower than the surrounding earth structure. The southeastern low-velocity zone may be caused by partially molten crust underlying the Crater Lake volcano region. -from Authors

  11. A Baseline-Free Defect Imaging Technique in Plates Using Time Reversal of Lamb Waves

    Institute of Scientific and Technical Information of China (English)

    Hyunjo Jeong; Sungjong Cho; Wei Wei

    2011-01-01

    @@ We present an analytical investigation for a baseline-free imaging of a defect in plate-like structures using the time-reversal of Lamb waves.We first consider the flexural wave (A mode) propagation in a plate containing a defect, and reception and time reversal process of the output signal at the receiver.The received output signal is then composed of two parts: a directly propagated wave and a scattered wave from the defect.The time reversal of these waves recovers the original input signal, and produces two additional sidebands that contain the time-of- flight information on the defect location.One of the side-band signals is then extracted as a pure defect signal.A defect localization image is then constructed from a beamforming technique based on the time-frequency analysis of the side band signal for each transducer pair in a network of sensors.The simulation results show that the proposed scheme enables the accurate, baseline-free imaging of a defect.

  12. X-ray imaging plate performance investigation based on a Monte Carlo simulation tool

    Energy Technology Data Exchange (ETDEWEB)

    Yao, M., E-mail: philippe.duvauchelle@insa-lyon.fr [Laboratoire Vibration Acoustique (LVA), INSA de Lyon, 25 Avenue Jean Capelle, 69621 Villeurbanne Cedex (France); Duvauchelle, Ph.; Kaftandjian, V. [Laboratoire Vibration Acoustique (LVA), INSA de Lyon, 25 Avenue Jean Capelle, 69621 Villeurbanne Cedex (France); Peterzol-Parmentier, A. [AREVA NDE-Solutions, 4 Rue Thomas Dumorey, 71100 Chalon-sur-Saône (France); Schumm, A. [EDF R& D SINETICS, 1 Avenue du Général de Gaulle, 92141 Clamart Cedex (France)

    2015-01-01

    Computed radiography (CR) based on imaging plate (IP) technology represents a potential replacement technique for traditional film-based industrial radiography. For investigating the IP performance especially at high energies, a Monte Carlo simulation tool based on PENELOPE has been developed. This tool tracks separately direct and secondary radiations, and monitors the behavior of different particles. The simulation output provides 3D distribution of deposited energy in IP and evaluation of radiation spectrum propagation allowing us to visualize the behavior of different particles and the influence of different elements. A detailed analysis, on the spectral and spatial responses of IP at different energies up to MeV, has been performed. - Highlights: • A Monte Carlo tool for imaging plate (IP) performance investigation is presented. • The tool outputs 3D maps of energy deposition in IP due to different signals. • The tool also provides the transmitted spectra along the radiation propagation. • An industrial imaging case is simulated with the presented tool. • A detailed analysis, on the spectral and spatial responses of IP, is presented.

  13. Note: Improving low-light-level image detection sensitivity with higher speed using auxiliary sinusoidal light signal

    Science.gov (United States)

    Tang, Hongying; Yu, Zhengtao

    2015-06-01

    An improved active imaging method, which upgraded the detection sensitivity by applying an auxiliary sawtooth wave light signal, was reported. Nevertheless, such method sacrificed the imaging speed. To speed up imaging, a sinusoidal light signal is used instead and superposed with the undetectable low-light-level signal on the image sensor. After acquiring a superimposed image set in one sine wave cycle, an unbiased low-light-level image estimation is obtained by using least-square optimization. Through probabilistic analysis and experimental study, we demonstrate that the sinusoidal signal could improve the detection sensitivity 1/3 faster than the sawtooth wave signal.

  14. Study of hot electrons generated from intense laser-plasma interaction employing Image Plate

    Institute of Scientific and Technical Information of China (English)

    LIANG WenXi; JIN Zhan; WEI ZhiYi; ZHAO Wei; LI YingJun; ZHANG Jie; LI YuTong; XU MiaoHua; YUAN XiaoHui; ZHENG ZhiYuan; ZHANG Yi; LIU Feng; WANG ZhaoHua; LI HanMing

    2008-01-01

    Image Plate (IP) is convenient to be used and very suitable for radiation detection because of its advantages such as wide dynamic range, high detective quantum efficiency, ultrahigh sensitivity and superior linearity. The function mechanism and characteristics of IP are introduced in this paper. IP was employed in the study of hot electrons generated from intense laser-plasma interaction. The angular distri-bution and energy spectrum of hot electrons were measured with IP in the experi-ments. The results demonstrate that IP is an effective radiation detector for the study of laser-plasma interaction.

  15. Study of hot electrons generated from intense laser-plasma interaction employing Image Plate

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Image Plate (IP) is convenient to be used and very suitable for radiation detection because of its advantages such as wide dynamic range, high detective quantum efficiency, ultrahigh sensitivity and superior linearity. The function mechanism and characteristics of IP are introduced in this paper. IP was employed in the study of hot electrons generated from intense laser-plasma interaction. The angular distri- bution and energy spectrum of hot electrons were measured with IP in the experi- ments. The results demonstrate that IP is an effective radiation detector for the study of laser-plasma interaction.

  16. Towards multi-order hard X-ray imaging with multilayer zone plates.

    Science.gov (United States)

    Osterhoff, Markus; Eberl, Christian; Döring, Florian; Wilke, Robin N; Wallentin, Jesper; Krebs, Hans-Ulrich; Sprung, Michael; Salditt, Tim

    2015-02-01

    This article describes holographic imaging experiments using a hard X-ray multilayer zone plate (MZP) with an outermost zone width of 10 nm at a photon energy of 18 keV. An order-sorting aperture (OSA) is omitted and emulated during data analysis by a 'software OSA'. Scanning transmission X-ray microscopy usually carried out in the focal plane is generalized to the holographic regime. The MZP focus is characterized by a three-plane phase-retrieval algorithm to an FWHM of 10 nm.

  17. Measurement of activity distribution using photostimulable phosphor imaging plates in decommissioned 10 MV medical linear accelerator.

    Science.gov (United States)

    Fujibuchi, Toshioh; Yonai, Shunsuke; Yoshida, Masahiro; Sakae, Takeji; Watanabe, Hiroshi; Abe, Yoshihisa; Itami, Jun

    2014-08-01

    Photonuclear reactions generate neutrons in the head of the linear accelerator. Therefore, some parts of the linear accelerator can become activated. Such activated materials must be handled as radioactive waste. The authors attempted to investigate the distribution of induced radioactivity using photostimulable phosphor imaging plates. Autoradiographs were produced from some parts of the linear accelerator (the target, upper jaw, multileaf collimator and shielding). The levels of induced radioactivity were confirmed to be non-uniform within each part from the autoradiographs. The method was a simple and highly sensitive approach to evaluating the relative degree of activation of the linear accelerators, so that appropriate materials management procedures can be carried out.

  18. Photostimulated phosphor based image plate detection system for HRVUV beamline at Indus-1 synchrotron radiation source

    OpenAIRE

    2014-01-01

    A high resolution vacuum ultraviolet (HRVUV) beamline based on a 6.65 meter off-plane Eagle spectrometer is in operation at the Indus-1 synchrotron radiation source, RRCAT, Indore, India. To facilitate position sensitive detection and fast spectral recording, a new BaFBr:Eu2+ phosphor based image plate (IP) detection system interchangeable with the existing photomultiplier (PMT) scanning system has been installed on this beamline. VUV photoabsorption studies on Xe, O2, N2O and SO2 are carried...

  19. Cranial fixation plates in cerebral magnetic resonance imaging: a 3 and 7 Tesla in vivo image quality study.

    Science.gov (United States)

    Chen, Bixia; Schoemberg, Tobias; Kraff, Oliver; Dammann, Philipp; Bitz, Andreas K; Schlamann, Marc; Quick, Harald H; Ladd, Mark E; Sure, Ulrich; Wrede, Karsten H

    2016-06-01

    This study assesses and quantifies impairment of postoperative magnetic resonance imaging (MRI) at 7 Tesla (T) after implantation of titanium cranial fixation plates (CFPs) for neurosurgical bone flap fixation. The study group comprised five patients who were intra-individually examined with 3 and 7 T MRI preoperatively and postoperatively (within 72 h/3 months) after implantation of CFPs. Acquired sequences included T1-weighted magnetization-prepared rapid-acquisition gradient-echo (MPRAGE), T2-weighted turbo-spin-echo (TSE) imaging, and susceptibility-weighted imaging (SWI). Two experienced neurosurgeons and a neuroradiologist rated image quality and the presence of artifacts in consensus reading. Minor artifacts occurred around the CFPs in MPRAGE and T2 TSE at both field strengths, with no significant differences between 3 and 7 T. In SWI, artifacts were accentuated in the early postoperative scans at both field strengths due to intracranial air and hemorrhagic remnants. After resorption, the brain tissue directly adjacent to skull bone could still be assessed. Image quality after 3 months was equal to the preoperative examinations at 3 and 7 T. Image quality after CFP implantation was not significantly impaired in 7 T MRI, and artifacts were comparable to those in 3 T MRI.

  20. Fluid Flow and Infrared Image Analyses on Endwall Fitted with Short Rectangular Plate Fin

    Institute of Scientific and Technical Information of China (English)

    Kenyu OYAKAWA; Islam Md. DIDARUL; Minoru YAGA

    2006-01-01

    An experimental investigation is carried out to study fluid flow and heat transfer characteristics on the endwall fitted with arrays ( 7 × 7 ) of short rectangular plate fins of different pattern (co-angular and zigzag) for different pitch ratio. Experiments were conducted in a rectangular duct of 50 mm height for an air flow of Reynolds number ranged from 18750 to 62500 based on the equivalent diameter and air velocity of the duct. Infrared image analysis technique was employed to make clear the characteristics of local heat transfer coefficients on fin base, endwall and overall surface. Flow pattern around the short rectangular plates were visualized by inducing fluorescent dye in a water channel and longitudinal vortices were observed. Increasing the distance between plates in flow direction causes heat transfer enhancement for co-angular pattern, while decreasing the distance causes heat transfer enhancement for zigzag pattern. Zigzag pattern with pitch ratio 2 is found to be more effective in heat transfer enhancement than any other cases investigated.

  1. Flaw Imaging Technique for Plate-Like Structures Using Scanning Laser Source Actuation

    Directory of Open Access Journals (Sweden)

    Changgil Lee

    2014-01-01

    Full Text Available Recently, the longitudinal, shear, and surface waves have been very widely used as ultrasonic wave-based exploration methods to identify internal defects of host structures. In this context, a noncontact nondestructive testing (NDT method is proposed to detect the damage of plate-like structures and to identify the location of the damage. To achieve this goal, a scanning laser source actuation technique is utilized to generate a guided wave and scans a specific area to find damage location more precisely. The ND:YAG pulsed laser is used to generate Lamb wave and a piezoelectric sensor is installed to measure the structural responses. The measured responses are analyzed using 3-dimensional Fourier transformation (3D FT. The damage-sensitive features are extracted by wavenumber filtering based on the 3D FT. Then, flaw imaging techniques of a plate-like structure are conducted using the damage-sensitive features. Finally, the plates with notches are investigated to verify the effectiveness and the robustness of the proposed NDT approach.

  2. A N2 Plasma Light Source Generated in Hollow Cathode Discharge and Its Application in Lithographic Plate Making

    Institute of Scientific and Technical Information of China (English)

    LI Chao-yang; CHEN Qiang; ZHANG Guang-qiu

    2007-01-01

    Computer to conventional plate (CTCP) technology is getting more and more attention in printing industries.In this paper we report a nitrogen plasma light source generated in hollow cathode discharge (HCD),which is used for pre-sensitivity (PS) plate exposure.The N2 molecule emits abundant spectrum ranging from 350 nm to 460 nm.With the voltage of 580 V,current of 1.8 A and pressure of 70 Pa in the discharge an optical power density of 0.46 mW/cm2 is obtained.The optical power density could be further increased with optimizing the lens system.The phototonus efficiency of this source is discussed in detail based upon the chemical principle and the FTIR analysis on the coating material.

  3. Optical Characterization of Optofluidic Waveguides Using Scattered Light Imaging.

    Science.gov (United States)

    Jenkins, Micah H; Phillips, Brian S; Zhao, Yue; Holmes, Matthew R; Schmidt, Holger; Hawkins, Aaron R

    2011-08-01

    The use of scattered light images is shown to be an attractive method for the characterization of optofluidic waveguides. The method is shown to be capable of measuring waveguide propagation losses and transmissions between solid and liquid-core structures. Measurement uncertainties are considered and characterized and were typically less than 15%.

  4. Hexabundles: imaging fiber arrays for low-light astronomical applications

    DEFF Research Database (Denmark)

    Bland-Hawthorn, Joss; Bryant, Julia; Robertson, Gordon;

    2011-01-01

    We demonstrate for the first time an imaging fibre bundle (“hexabundle”) that is suitable for low-light applications in astronomy. The most successful survey instruments at optical-infrared wavelengths today have obtained data on up to a million celestial sources using hundreds of multimode fibre...

  5. Functional Imaging of Tissue Morphology with Polarized Light Scattering Spectroscopy

    Science.gov (United States)

    Backman, Vadim

    2001-03-01

    We report a new imaging technique to study the morphology of living epithelial cells in vivo. The method is based on light scattering spectroscopy with polarized light (PLSS) and makes it possible to distinguish between single backscattering from epithelial cell nuclei and multiply scattered light. The spectrum of the single backscattering component is further analyzed to provide quantitative histological information about the epithelial cells such as the size distribution, refractive index, and chromatin content of the cell nuclei. The measurement of cell nuclear morphology is crucial for detection and diagnosis of cancerous and precancerous conditions in many human tissues. The method was successfully applied to image precancerous regions of several tissues. Clinical studies in five organs (esophagus, colon, bladder, oral cavity, and uterine cervix) showed the generality and efficacy of the technique.

  6. Novel flat-plate photobioreactors for microalgae cultivation with special mixers to promote mixing along the light gradient.

    Science.gov (United States)

    Huang, Jianke; Li, Yuanguang; Wan, Minxi; Yan, Yi; Feng, Fei; Qu, Xiaoxing; Wang, Jun; Shen, Guomin; Li, Wei; Fan, Jianhua; Wang, Weiliang

    2014-05-01

    Novel flat-plate photobioreactors (PBRs) with special mixers (type-a, type-b, and type-c) were designed based on increased mixing degree along the light gradient. The hydrodynamic and light regime characteristic of the novel PBRs were investigated through computational fluid dynamics. Compared with the control reactor without mixer, the novel reactors can effectively increase liquid velocity along the light gradient, the frequency of light/dark (L/D) cycles, and the algal growth rates of Chlorella pyrenoidosa. The maximum biomass concentrations in type-a, type-b, and type-c reactors were 42.9% (1.3 g L(-1)), 31.9% (1.2 g L(-1)), and 20.9% (1.1 g L(-1)) higher than that in the control reactor (0.91 g L(-1)), respectively, at an aeration rate of 1.0 vvm. Correlation analysis of algal growth rate with the characteristics of mixing and light regime shows the key factors affecting algal photoautotrophic growth are liquid velocity along the light gradient and L/D cycles rather than the macro-mixing degree.

  7. Cherenkov light imaging in astro-particle physics

    Energy Technology Data Exchange (ETDEWEB)

    Mirzoyan, Razmik, E-mail: Razmik.Mirzoyan@mpp.mpg.de

    2014-12-01

    Cherenkov light emission plays a key role in contemporary science; it is widely used in high energy, nuclear, and numerous astro-particle physics experiments. Most astro-particle physics experiments are based on the detection of light, and a vast majority of them on the measurement of Cherenkov light. Cherenkov light emission is measured in gases (used in air-Cherenkov technique), in water (for example, neutrino experiments BAIKAL, Super-Kamiokande, NESTOR, ANTARES, future KM3NeT; cosmic and γ-ray experiments Milagro, HAWC, AUGER) and in ice (IceCube). In this report our goal is not limited to simply listing the multitude of experiments that are based on using Cherenkov emission, but we will clarify the reasons making this emission so important and so frequently used. For completeness we will first give a short historical overview on the discovery and evolution of Cherenkov emission and then we will dwell on its main features and numerous applications in astro-particle physics experiments. - Highlights: • We explain why Cherenkov emission is so important and why it is so widely used. • A brief historical excursion is made to the very beginning of Cherenkov emission. • Imaging of the Cherenkov light emission is discussed in a great detail. • The principle of Cherenkov light imaging in diverse experiments is the same.

  8. Imaging the Juan de Fuca subduction plate using 3D Kirchoff Prestack Depth Migration

    Science.gov (United States)

    Cheng, C.; Bodin, T.; Allen, R. M.; Tauzin, B.

    2014-12-01

    We propose a new Receiver Function migration method to image the subducting plate in the western US that utilizes the US array and regional network data. While the well-developed CCP (common conversion point) poststack migration is commonly used for such imaging; our method applies a 3D prestack depth migration approach. The traditional CCP and post-stack depth mapping approaches implement the ray tracing and moveout correction for the incoming teleseismic plane wave based on a 1D earth reference model and the assumption of horizontal discontinuities. Although this works well in mapping the reflection position of relatively flat discontinuities (such as the Moho or the LAB), CCP is known to give poor results in the presence of lateral volumetric velocity variations and dipping layers. Instead of making the flat layer assumption and 1D moveout correction, seismic rays are traced in a 3D tomographic model with the Fast Marching Method. With travel time information stored, our Kirchoff migration is done where the amplitude of the receiver function at a given time is distributed over all possible conversion points (i.e. along a semi-elipse) on the output migrated depth section. The migrated reflectors will appear where the semicircles constructively interfere, whereas destructive interference will cancel out noise. Synthetic tests show that in the case of a horizontal discontinuity, the prestack Kirchoff migration gives similar results to CCP, but without spurious multiples as this energy is stacked destructively and cancels out. For 45 degree and 60 degree dipping discontinuities, it also performs better in terms of imaging at the right boundary and dip angle. This is especially useful in the Western US case, beneath which the Juan de Fuca plate subducted to ~450km with a dipping angle that may exceed 50 degree. While the traditional CCP method will underestimate the dipping angle, our proposed imaging method will provide an accurate 3D subducting plate image without

  9. Nondestructive Image Detection of Cracks for a Nuclear Fuel Plate by Using Active Thermal Phase

    Energy Technology Data Exchange (ETDEWEB)

    Park, Nak Kyu; Park, Seung Kyu; Baik, Sung Hoon; Lee, Yoon Sang; Cha, Byung Heon [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Kang, Young June [Chonbuk National University, Jeonju (Korea, Republic of)

    2012-05-15

    Nondestructive crack detection is a key process for the safety insurance of the nuclear fuel plates which are widely used in a nuclear research reactor. Among nondestructive detection techniques, X-ray inspection technique and ultrasonic inspection technique using high frequency are widely used to detect internal cracks of a nuclear fuel plate at present. Though X-ray inspection is fast and efficient technique by providing a crack image for whole specimen area, this technique hardly provides the delaminated crack information which should be detected. Ultrasonic inspection is also an efficient tool to detect internal cracks of materials. High frequency ultrasound based on the piezoelectric transducers is usually used to detect cracks of a nuclear fuel plate. Though it is useful technique, the inspection should be carried out by an immersion test in a water-tank and its signal is complex and it is time consuming technique because the inspection is scanned point by point in sequence for whole inspection area. A commercial scanning ultrasonic system using high frequency is usually adopted to detect cracks. An alternative inspection technique to overcome the disadvantages of the high frequency ultrasonic inspection technique is needed. Especially, nondestructive imaging techniques of the internal cracks will be useful because it can be easily used in the field. One of efficient nondestructive testing techniques is infrared thermo-graphic technique. Infrared thermographic is a contactless optical imaging technique by detecting the invisible infrared radiation. Pulsed and lock-in thermography are commonly used in thermo-graphic nondestructive evaluation techniques. The two techniques are distinctly different but are deployed in the inspection of similar components. In general, these techniques are suitable for the detection of shallow planer defects, e.g. delamination in composites or adhesion defect in surface coatings. The surface of a specimen is instantaneously heated

  10. A New Omni-Directional EMAT for Ultrasonic Lamb Wave Tomography Imaging of Metallic Plate Defects

    Directory of Open Access Journals (Sweden)

    Songling Huang

    2014-02-01

    Full Text Available This paper proposes a new omni-directional electromagnetic acoustic transducer (EMAT for the ultrasonic Lamb wave (ULW tomography imaging (TI of defects in metallic plates. The proposed EMAT is composed of a permanent magnet and a coil with a contra-flexure structure. This new EMAT coil structure is used for omni-directional ULW transmission and reception and ULW TI for the first time. The theoretical background and the working principles of this EMAT are presented and analyzed. The experimental results of its use on a 3 mm thick aluminum plate indicate that the EMAT with a contra-flexure coil (CFC can transmit and receive a pure single A0 mode ULW with a high signal-to-noise ratio (SNR. Thus, the extraction of the projection data used for ULW TI may be performed accurately. The circumferential consistency of the projection data is only slightly influenced by the distortion of the eddy current field that is induced by the new CFC with an irregular shape. When the new EMAT array is used for ULW TI using the cross-hole method and SIRT arithmetic, a desirable imaging quality can be achieved, and the estimated size of an artificial corrosion defect agreed well with its actual value. The relation between the reconstruction resolution and the number of the new EMATs used is analyzed. More TI experiments are carried out when the aluminum plate defect is in two different locations relative to the EMAT array, for the further investigation of the performances of the new EMATs.

  11. A new omni-directional EMAT for ultrasonic Lamb wave tomography imaging of metallic plate defects.

    Science.gov (United States)

    Huang, Songling; Wei, Zheng; Zhao, Wei; Wang, Shen

    2014-02-20

    This paper proposes a new omni-directional electromagnetic acoustic transducer (EMAT) for the ultrasonic Lamb wave (ULW) tomography imaging (TI) of defects in metallic plates. The proposed EMAT is composed of a permanent magnet and a coil with a contra-flexure structure. This new EMAT coil structure is used for omni-directional ULW transmission and reception and ULW TI for the first time. The theoretical background and the working principles of this EMAT are presented and analyzed. The experimental results of its use on a 3 mm thick aluminum plate indicate that the EMAT with a contra-flexure coil (CFC) can transmit and receive a pure single A0 mode ULW with a high signal-to-noise ratio (SNR). Thus, the extraction of the projection data used for ULW TI may be performed accurately. The circumferential consistency of the projection data is only slightly influenced by the distortion of the eddy current field that is induced by the new CFC with an irregular shape. When the new EMAT array is used for ULW TI using the cross-hole method and SIRT arithmetic, a desirable imaging quality can be achieved, and the estimated size of an artificial corrosion defect agreed well with its actual value. The relation between the reconstruction resolution and the number of the new EMATs used is analyzed. More TI experiments are carried out when the aluminum plate defect is in two different locations relative to the EMAT array, for the further investigation of the performances of the new EMATs.

  12. Millimeter wave imaging at up to 40 frames per second using an optoelectronic photo-injected Fresnel zone plate lens antenna

    Science.gov (United States)

    Robertson, Duncan A.; Gallacher, Thomas F.; Søndenâ, Rune; Macfarlane, David G.

    2016-05-01

    Optoelectronic methods are promising for rapid and highly reconfigurable beam steering across the microwave to the terahertz range. In particular, the photo-injected Fresnel zone plate antenna (piFZPA) offers high speed, wide angle, precise beam steering with good beam quality, to enable video rate millimeter wave imagery with no moving parts. We present a piFZPA demonstrator based on a commercial digital light projector (DLP) and high power laser which achieves steering rates up to 17,500 beams per second at 94 and 188 GHz. We also demonstrate radar imaging at 94 GHz at frame rates of 40 Hz (2D PPI) and 7 Hz (3D volumetric).

  13. Size measurement of radioactive aerosol particles in intense radiation fields using wire screens and imaging plates

    Energy Technology Data Exchange (ETDEWEB)

    Oki, Yuichi; Tanaka, Toru; Takamiya, Koichi; Ishi, Yoshihiro; UesugI, Tomonori; Kuriyama, Yasutoshi; Sakamoto, Masaaki; Ohtsuki, Tsutomu [Kyoto University Research Reactor Institute, Osaka (Japan); Nitta, Shinnosuke [Graduate School of Engineering, Kyoto University, Kyoto (Japan); Osada, Naoyuki [Advanced Science Research Center, Okayama University, Okayama (Japan)

    2016-09-15

    Very fine radiation-induced aerosol particles are produced in intense radiation fields, such as high-intensity accelerator rooms and containment vessels such as those in the Fukushima Daiichi nuclear power plant (FDNPP). Size measurement of the aerosol particles is very important for understanding the behavior of radioactive aerosols released in the FDNPP accident and radiation safety in high-energy accelerators. A combined technique using wire screens and imaging plates was developed for size measurement of fine radioactive aerosol particles smaller than 100 nm in diameter. This technique was applied to the radiation field of a proton accelerator room, in which radioactive atoms produced in air during machine operation are incorporated into radiation-induced aerosol particles. The size of 11C-bearing aerosol particles was analyzed using the wire screen technique in distinction from other positron emitters in combination with a radioactive decay analysis. The size distribution for 11C-bearing aerosol particles was found to be ca. 70 μm in geometric mean diameter. The size was similar to that for 7Be-bearing particles obtained by a Ge detector measurement, and was slightly larger than the number-based size distribution measured with a scanning mobility particle sizer. The particle size measuring method using wire screens and imaging plates was successfully applied to the fine aerosol particles produced in an intense radiation field of a proton accelerator. This technique is applicable to size measurement of radioactive aerosol particles produced in the intense radiation fields of radiation facilities.

  14. PHOTOACOUSTIC IMAGING: AN ORCHESTRA OF LIGHT AND SOUND

    Directory of Open Access Journals (Sweden)

    Namitha

    2013-11-01

    Full Text Available ABSTRACT: Photoacoustic imaging, also called optoacoustic imaging, is a new biomedical i maging modality based on the use of laser - generated ultrasound. It is a hybrid modality, combining the high - contrast and spectroscopy based specificity of optical imaging with the high spatial resolution of ultrasound imaging. In essence, a Photoacoustic i mage can be regarded as an ultrasound image in which the contrast depends not on the mechanical and elastic properties of the tissue, but its optical properties, specifically optical absorption. As a result, it offers greater specificity than conventional sonographic imaging with the ability to detect haemoglobin, lipids, water and other light - absorbing chromophores, but with greater penetration depth than purely optical imaging modalities that rely on ballistic photons. In addition to visualizing anatomica l structures such as the microvasculature, it can also provide functional information such as blood oxygenation, blood flow and temperature. These attributes make photoacoustic imaging applicable in clinical medicine, preclinical research and early detecti on of cancer, cardiovascular disease and abnormalities of microcirculation. Photoacoustic microscopy is a promising tool for imaging both dental decay and dental pulp. Using photoacoustics, near - infrared optical contrast between sound and carious dental ti ssues can be detected relatively easily and accurately at ultrasound resolution and may ultimately allow for continuous monitoring of caries before and during treatment. Photoacousting imaging compares favorably to other imaging modalities with its precise depth information, submillimeter resolution, and nanomolar sensitivity. With further improvement in background reduction, as well as the use of lasers with high - repetition rates, it is likely that Photoacoustic imaging will find wide use in the future in both basic research and clinical care. It is a highly vibrant research field in the

  15. Wavelength agile nonmechanical laser beam steering from Fresnel zone plates imprinted on a liquid crystal spatial light modulator

    Science.gov (United States)

    Lindle, James R.; Watnik, Abbie T.; Cassella, Vincent A.

    2016-09-01

    Multibeam, multicolor, large-angle beam-steering is demonstrated in the visible spectral region by imprinting Fresnel zone plates (FZP) on a liquid crystal spatial light modulator. Spectral dispersion, both diffractive and refractive, is observed but does not prevent the use of this technology for beam steering applications. The experimental results show that while diffractive dispersion dominates over refractive dispersion, wavelength-specific FZPs can be rendered to direct those beams on target, either simultaneously or consecutively. Only a slight correction in the FZP positon is necessary to compensate for refractive dispersion. The position, intensity, and wavelength of each beam can be controlled independently.

  16. Digital image fusion systems: color imaging and low-light targets

    Science.gov (United States)

    Estrera, Joseph P.

    2009-05-01

    This paper presents digital image fusion (enhanced A+B) systems in color imaging and low light target applications. This paper will discuss first the digital sensors that are utilized in the noted image fusion applications which is a 1900x1086 (high definition format) CMOS imager coupled to a Generation III image intensifier for the visible/near infrared (NIR) digital sensor and 320x240 or 640x480 uncooled microbolometer thermal imager for the long wavelength infrared (LWIR) digital sensor. Performance metrics for these digital imaging sensors will be presented. The digital image fusion (enhanced A+B) process will be presented in context of early fused night vision systems such as the digital image fused system (DIFS) and the digital enhanced night vision goggle and later, the long range digitally fused night vision sighting system. Next, this paper will discuss the effects of user display color in a dual color digital image fusion system. Dual color image fusion schemes such as Green/Red, Cyan/Yellow, and White/Blue for image intensifier and thermal infrared sensor color representation, respectively, are discussed. Finally, this paper will present digitally fused imagery and image analysis of long distance targets in low light from these digital fused systems. The result of this image analysis with enhanced A+B digital image fusion systems is that maximum contrast and spatial resolution is achieved in a digital fusion mode as compared to individual sensor modalities in low light, long distance imaging applications. Paper has been cleared by DoD/OSR for Public Release under Ref: 08-S-2183 on August 8, 2008.

  17. Real-time Image Generation for Compressive Light Field Displays

    Science.gov (United States)

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

    2013-02-01

    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.

  18. 基于条件随机场的低图像质量车牌字符分割%SEGMENTING CHARACTERS ON LICENSE PLATE WITH LOW IMAGE QUALITY BASED ON CONDITIONAL RANDOM FIELDS

    Institute of Scientific and Technical Information of China (English)

    傅建强; 冯瑞

    2014-01-01

    提出一种基于条件随机场的车牌字符分割算法,能够对光照不均、相机拍摄角度造成的低图像质量的车牌图像,特别是日益增多的车牌边框与字符相连接车牌图像进行有效的字符分割。算法首先进行车牌图像校正,然后利用标注车牌数据进行模型学习,对车牌图像像素列进行分类识别,最后组合成车牌字符分割结果。理论分析与实验结果验证了算法的有效性。%This paper proposes a conditional random fields-based character segmentation method,it can make effective characters segmentation for the license plate image with low image quality caused by uneven light and shooting angle of camera,etc.,in particular,for those increasingly growing license plates images whose plate characters are connected with plate borders.First,the correction of license plate image is conducted,and then the labelled plate data are used to train the model for the classification and identification of the pixel columns in license plate image,finally the segmentation results of the license plate characters are combined.Theoretical analysis and experimental results all verify the effectiveness of the algorithm.

  19. Light field moment imaging with the ptychographic iterative engine

    Energy Technology Data Exchange (ETDEWEB)

    Jiang, Zhilong; Pan, Xinchen; Liu, Cheng, E-mail: cheng.liu@hotmail.co.uk, E-mail: ling.wang@biw.kuleuven.be; Zhu, Jianqiang [Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800 (China); Wang, Ling, E-mail: cheng.liu@hotmail.co.uk, E-mail: ling.wang@biw.kuleuven.be [Department of Physics and Astronomy, KU Leuven, 3001, Heverlee (Belgium); NERF, 3001, Heverlee (Belgium)

    2014-10-15

    The recently developed Light Field Moment Imaging (LMI) is adopted to show the stereoscopic structure of the sample studied in Coherent Diffractive Imaging (CDI), where 3D image were always generated with complicated experimental procedure such as the rotation of the sample and time-consuming computation. The animation of large view angle can be generated with LMI very quickly, and the 3D structure of sample can be shown vividly. This method can find many applications for the coherent diffraction imaging with x-ray and electron beams, where a glimpse of the hierarchical structure required and the quick and simple 3D view of object is sufficient. The feasibility of this method is demonstrated theoretically and experimentally with a recently developed CDI method called Ptychographic Iterative Engine.

  20. Estimation of plate material properties by means of a complex wavenumber fit using Hankel's functions and the image source method

    Science.gov (United States)

    Roozen, N. B.; Leclère, Q.; Ege, K.; Gerges, Y.

    2017-03-01

    This paper presents a new wave fitting approach to estimate the frequency dependent material properties of thin isotropic plate structures from an experimentally obtained vibrational field, exciting the plate at a single point. The method projects the measurement data on to an analytical image source model, in which Hankel's functions are used for a description of the wave fields emanating from the point of excitation, including the reflected wave fields from the edges of the finite plate. By minimizing the error between the projected field and the measured field, varying the complex wave number and the source strengths of the image sources, an optimum fit is searched for. Thus the source strengths of the image sources do not need to be determined theoretically, but are estimated from the fit on to the experimental data instead (thus avoiding difficulties in theoretically assessing the reflection coefficient of the edges of the plate). The approach uses a complex wavenumber fit, enabling the determination of the dynamic stiffness of the plate structure and its damping properties as function of frequency. The method is especially suited for plates with a sufficient amount of damping, excited at high frequencies.

  1. Local orbital angular momentum revealed by spiral phase plate imaging in transmission electron microscopy

    CERN Document Server

    Juchtmans, Roeland

    2015-01-01

    The orbital angular momentum (OAM) of light and matter waves is a parameter that is getting increasingly more attention over the past couple of years. Beams with a well defined OAM, the so-called vortex beams, are applied already in e.g. telecommunication, astrophysics, nanomanipulation and chiral measurements in optics and electron microscopy. Also the OAM of a wave induced by the interaction with a sample, shows great potential of interest. In all these experiments it is crucial to measure the exact (local) OAM content of the wave, whether it is an incoming vortex beam or an exit wave after interacting with a sample. In this work we investigate the use of spiral phase plates as an alternative to the programmable phase plates used in optics to measure OAM. We derive analytically how these can be used to study the local OAM components of any wave function. By means of numerical simulations we illustrate how the OAM of a pure vortex beam can be measured. We also look at a sum of misaligned vortex beams and sho...

  2. Biophotonic imaging: lighting the way for chem/bio detection

    Science.gov (United States)

    Ripp, Steven; Jegier, Patricia; Lopes, Nicholas

    2009-05-01

    Biophotonic imaging is a versatile and powerful tool, that when combined with living microbial bioreporters, can be applied in diagnostic technologies for sensitive, nondestructive, real-time monitoring of chemical and biological targets. Bioreporters, consisting of bacteria as well as the viruses (bacteriophage) that infect them, can be genetically engineered to emit visible light upon interaction with a specific chemical or biological entity. By interfacing these bioreporters with imaging cameras or miniaturized integrated circuit microluminometers, fully standalone detection units are formed that can be deployed for intelligent distributed multi-target chem/bio monitoring.

  3. Temporal ghost imaging with pseudo-thermal speckle light

    Science.gov (United States)

    Devaux, Fabrice; Phan Huy, Kien; Denis, Séverine; Lantz, Eric; Moreau, Paul-Antoine

    2017-02-01

    We report ghost imaging of a single non-reproducible temporal signal with kHz resolution by using pseudo-thermal speckle light patterns and a single detector array with a million of pixels working without any temporal resolution. A set of speckle patterns is generated deterministically at a sampling rate of tens kHz, multiplied by the temporal signal and time integrated in a single shot by the camera. The temporal information is retrieved by computing the spatial intensity correlations between this time integrated image and each speckle pattern of the set.

  4. Temporal ghost imaging with pseudo-thermal speckle light

    CERN Document Server

    Devaux, Fabrice; Moreau, Paul-Antoine; Denis, Severine; Lantz, Eric

    2016-01-01

    We report ghost imaging of a single non-reproducible temporal signal in the range of tens kHz by using pseudo-thermal speckle light patterns and a single detector array with a million of pixels working without any temporal resolution. A set of speckle patterns is generated deterministically at radio-frequency rate, multiplied by the temporal signal and time integrated in a single shot by the camera. The temporal information is retrieved by computing the spatial intensity correlations between this time integrated image and each speckle pattern of the set.

  5. Scale-Up of flat plate photobioreactors considering diffuse and direct light characteristics.

    Science.gov (United States)

    Quinn, Jason C; Turner, Chris W; Bradley, Thomas H

    2012-02-01

    This study investigates the scaling of photobioreactor productivity based on the growth of Nannochloropsis salina incorporating the effects of direct and diffuse light. The scaling and optimization of photobioreactor geometry was analyzed by determining the growth response of a small-scale system designed to represent a core sample of a large-scale photobioreactor. The small-scale test apparatus was operated at a variety of light intensities on a batch time scale to generate a photosynthetic irradiance (PI) growth dataset, ultimately used to inform a PI growth model. The validation of the scalability of the PI growth model to predict productivity in large-scale systems was done by comparison with experimental growth data collected from two geometrically different large-scale photobioreactors operated at a variety of light intensities. For direct comparison, the small-scale and large-scale experimental systems presented were operated similarly and in such a way to incorporate cultivation relevant time scales, light intensities, mixing, and nutrient loads. Validation of the scalability of the PI growth model enables the critical evaluation of different photobioreactor geometries and design optimization incorporating growth effects from diffuse and direct light. Discussion focuses on the application of the PI growth model to assess the effect of diffuse light growth compared to direct light growth for the evaluation of photobioreactors followed by the use of the model for photobioreactor geometry optimization on the metric of areal productivity.

  6. Single-atom detection of light elements: Imaging or spectroscopy?

    Science.gov (United States)

    Senga, Ryosuke; Suenaga, Kazu

    2017-09-01

    Single-atom imaging and spectroscopy at a lower accelerating voltage (~60kV) has been largely facilitated by the development of aberration correctors for transmission electron microscopy (TEM)/ scanning TEM (STEM). Such an STEM condition will reduce beam damage and has therefore been demonstrated capable of detecting individual atoms of light elements including B, C, and N in mono-layered materials. However, other light elements such as Li, O, or F are still difficult to visualise as individual atoms by using conventional STEM/TEM imaging because their extremely weak contrast can be often smeared out by the other atoms nearby. In this paper, we demonstrate the successful detection of these 'hardly visible' atoms in the spectroscopy mode. Copyright © 2016 Elsevier B.V. All rights reserved.

  7. Absolute Calibration of Image Plate for electrons at energy between 100 keV and 4 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Chen, H; Back, N L; Eder, D C; Ping, Y; Song, P M; Throop, A

    2007-12-10

    The authors measured the absolute response of image plate (Fuji BAS SR2040) for electrons at energies between 100 keV to 4 MeV using an electron spectrometer. The electron source was produced from a short pulse laser irradiated on the solid density targets. This paper presents the calibration results of image plate Photon Stimulated Luminescence PSL per electrons at this energy range. The Monte Carlo radiation transport code MCNPX results are also presented for three representative incident angles onto the image plates and corresponding electron energies depositions at these angles. These provide a complete set of tools that allows extraction of the absolute calibration to other spectrometer setting at this electron energy range.

  8. An experimental investigation of a 100-W high-power light-emitting diode array using vapor chamber–based plate

    OpenAIRE

    Ping Zhang; Jianhua Zeng; Xianping Chen; Miao Cai; Jing Xiao; Daoguo Yang

    2015-01-01

    In this study, a compact 100-W input power light-emitting diode array vapor chamber–based plate has been fabricated to investigate the thermal performance. To make a comparison, a typical commercial chip on board–type light-emitting diode array using a copper-based plate which has the same chip layout and the same power input was also investigated. The surface temperature distribution and total thermal resistance corresponding to these two high-power light-emitting diode modules were measured...

  9. Vascular contrast in narrow-band and white light imaging.

    Science.gov (United States)

    Du Le, V N; Wang, Quanzeng; Gould, Taylor; Ramella-Roman, Jessica C; Pfefer, T Joshua

    2014-06-20

    Narrow-band imaging (NBI) is a spectrally selective reflectance imaging technique that is used clinically for enhancing visualization of superficial vasculature and has shown promise for applications such as early endoscopic detection of gastrointestinal neoplasia. We have studied the effect of vessel geometry and illumination wavelength on vascular contrast using idealized geometries in order to more quantitatively understand NBI and broadband or white light imaging of mucosal tissue. Simulations were performed using a three-dimensional, voxel-based Monte Carlo model incorporating discrete vessels. In all cases, either 415 or 540 nm illumination produced higher contrast than white light, yet white light did not always produce the lowest contrast. White light produced the lowest contrast for small vessels and intermediate contrast for large vessels (diameter≥100  μm) at deep regions (vessel depth≥200  μm). The results show that 415 nm illuminations provided superior contrast for smaller vessels at shallow depths while 540 nm provided superior contrast for larger vessels in deep regions. Besides 540 nm, our studies also indicate the potential of other wavelengths to achieve high contrast of large vessels at deep regions. Simulation results indicate the importance of three key mechanisms in determining spectral variations in contrast: intravascular hemoglobin (Hb) absorption in the vessel of interest, diffuse Hb absorption from collateral vasculature, and bulk tissue scattering. Measurements of NBI contrast in turbid phantoms incorporating 0.1-mm-diameter hemoglobin-filled capillary tubes indicated good agreement with modeling results. These results provide quantitative insights into light-tissue interactions and the effect of device and tissue properties on NBI performance.

  10. Reducing dose in urography while maintaining image quality - a comparison of storage phosphor plates and a flat-panel detector

    Energy Technology Data Exchange (ETDEWEB)

    Jansson, Margareta; Geijer, Haakan; Andersson, Torbjoern [Oerebro University Hospital, Department of Radiology, Oerebro (Sweden); Persliden, Jan [Oerebro University Hospital, Department of Medical Physics, Oerebro (Sweden); Linkoeping University, Department of Medicine and Care, Faculty of Health Sciences, Linkoeping (Sweden)

    2006-01-01

    The introduction of new flat-panel detector technology often forces us to accept too high dose levels as proposed by the manufacturers. We need a tool to compare the image quality of a new system with the accepted standard. The aim of this study was to obtain a comparable image quality for two systems - storage phosphor plates and a flat-panel system using intravenous urography (IVU) as a clinical model. The image quality figure was calculated using a contrast-detail phantom (CDRAD) for the two evaluated systems. This allowed us to set a dose for the flat-panel system that gave equivalent image quality to the storage phosphor plates. This reduced detector dose was used in an evaluation of clinical images to find out if the dose reduction from the phantom study indeed resulted in images of equal clinical image quality. The image quality was assessed using image criteria of the European guidelines for IVU with visual grading analysis. Equivalent image quality in image pairs was achieved at 30% of the dose. The CDRAD contrast-detail phantom makes it possible to find dose levels that give equal image quality using different imaging systems. (orig.)

  11. Multi-mode conversion imaging of the subducted Gorda and Juan de Fuca plates below the North American continent

    Science.gov (United States)

    Tauzin, Benoit; Bodin, Thomas; Debayle, Eric; Perrillat, Jean-Philippe; Reynard, Bruno

    2016-04-01

    Receiver function analysis and seismic tomography show tectonic structures dipping eastward in the mantle below the Cascadia volcanic arc (western US) that have been related to the subduction of the Gorda and Juan de Fuca oceanic micro-plates. Inconsistencies in the dip angle and depth extent of the slab between the two methods undermine the interpretation of the structure and processes at work. Receiver function imaging is biased by multiple reflection phases that interfere with converted phases, and produce spurious discontinuities in images. Here, we correct the interference using a multiple mode conversion imaging technique that efficiently removes artifacts under dipping structures. The method has the advantage of being applicable to large aperture arrays, and can image large-scale structures down to the transition zone. With this approach, the interfaces between the subducting and overriding plates and the oceanic Moho are imaged at shallow depths (<120 km) with a dip angle of ∼20°, consistently with former studies. In addition, several important features are imaged with the present method. Faint converters located between 100 and 400 km depth in the mantle wedge, and strong sub-horizontal seismic scatterers near 160 km depth, may highlight dehydration and metasomatism processes in the Cascadia subduction zone. A discontinuity located at ∼15 km depth in the lithospheric mantle of the subducted plates and associated with a negative impedance contrast is interpreted as the fossil fabric of the plates acquired at the spreading ridges.

  12. Surface enhanced Raman scattering imaging of developed thin-layer chromatography plates.

    Science.gov (United States)

    Freye, Chris E; Crane, Nichole A; Kirchner, Teresa B; Sepaniak, Michael J

    2013-04-16

    A method for hyphenating surface enhanced Raman scattering (SERS) and thin-layer chromatography (TLC) is presented that employs silver-polymer nanocomposites as an interface. Through the process of conformal blotting, analytes are transferred from TLC plates to nanocomposite films before being imaged via SERS. A procedure leading to maximum blotting efficiency was established by investigating various parameters such as time, pressure, and type and amount of blotting solvent. Additionally, limits of detection were established for test analytes malachite green isothiocyanate, 4-aminothiophenol, and Rhodamine 6G (Rh6G) ranging from 10(-7) to 10(-6) M. Band broadening due to blotting was minimal (∼10%) as examined by comparing the spatial extent of TLC-spotted Rh6G via fluorescence and then the SERS-based spot size on the nanocomposite after the blotting process. Finally, a separation of the test analytes was carried out on a TLC plate followed by blotting and the acquisition of distance × wavenumber × intensity three-dimensional TLC-SERS plots.

  13. Imaging of Cocos Plate Beneath Southern Costa Rica From Receiver Function Analysis

    Science.gov (United States)

    Dzierma, Y.; Thorwart, M.; Rabbel, W.

    2007-12-01

    A transect of 19 seismological broadband stations crossing the Talamanca Mountain Range in Southern Costa Rica was operated from March 2005 to April 2007 as a part of the Collaborative Research Center SFB 574 "Volatiles and Fluids in Subduction Zones". The aim of the seismological subproject A2 was to gain insight into the structure of the Central American subduction zone and possible pathways for fluid migration. Previous studies of active seismics and local seismicity suggested to explain the gap of volcanism in the Talamanca range with the lack of a subducting slab. They assumed that the Cocos Ridge underlies the overriding plate at a shallow dip. In contrast, our receiver function analysis of 322 teleseimic earthquakes is able to image the subducting Cocos Plate down to depths of at least 100 km. The dip angle of the slab closer to the trench is outside the network but appears to be shallow, consistent with former studies. Below 40 km, the dip increases to more than 45 deg. This is supported by accurately located seismicity from a tomography study also performed by our group. Crustal structure could also be resolved by the receiver function analysis in agreement with tomography and active seismic investigations. The existence of the subducting slab poses the question why volcanism stopped 4 Ma ago; several possible scenarios are discussed.

  14. Adaptive beamforming for array imaging of plate structures using lamb waves.

    Science.gov (United States)

    Engholm, Marcus; Stepinski, Tadeusz

    2010-12-01

    Lamb waves are considered a promising tool for the monitoring of plate structures. Large areas of plate structures can be monitored using active arrays employing beamforming techniques. Dispersion and multiple propagating modes are issues that need to be addressed when working with Lamb waves. Previous work has mainly focused on standard delay-and-sum (DAS) beamforming while reducing the effects of multiple modes through frequency selectivity and transducer design. This paper presents a minimum variance distortionless response (MVDR) approach for Lamb waves using a uniform rectangular array (URA) and a single transmitter. Theoretically calculated dispersion curves are used to compensate for dispersion. The combination of the MVDR approach and the two-dimensional array improves the suppression of interfering Lamb modes. The proposed approach is evaluated on simulated and experimental data and compared with the standard DAS beamformer. It is shown that the MVDR algorithm performs better in terms of higher resolution and better side lobe and mode suppression capabilities. Known issues of the MVDR approach, such as signal cancellation in highly correlated environments and poor robustness, are addressed using methods that have proven effective for the purpose in other fields of active imaging.

  15. Overall design of imaging spectrometer on-board light aircraft

    Energy Technology Data Exchange (ETDEWEB)

    Zhongqi, H.; Zhengkui, C.; Changhua, C.

    1996-11-01

    Aerial remote sensing is the earliest remote sensing technical system and has gotten rapid development in recent years. The development of aerial remote sensing was dominated by high to medium altitude platform in the past, and now it is characterized by the diversity platform including planes of high-medium-low flying altitude, helicopter, airship, remotely controlled airplane, glider, and balloon. The widely used and rapidly developed platform recently is light aircraft. Early in the close of 1970s, Beijing Research Institute of Uranium Geology began aerial photography and geophysical survey using light aircraft, and put forward the overall design scheme of light aircraft imaging spectral application system (LAISAS) in 19905. LAISAS is comprised of four subsystem. They are called measuring platform, data acquiring subsystem, ground testing and data processing subsystem respectively. The principal instruments of LAISAS include measuring platform controlled by inertia gyroscope, aerial spectrometer with high spectral resolution, imaging spectrometer, 3-channel scanner, 128-channel imaging spectrometer, GPS, illuminance-meter, and devices for atmospheric parameters measuring, ground testing, data correction and processing. LAISAS has the features of integrity from data acquisition to data processing and to application; of stability which guarantees the image quality and is comprised of measuring, ground testing device, and in-door data correction system; of exemplariness of integrated the technology of GIS, GPS, and Image Processing System; of practicality which embodied LAISAS with flexibility and high ratio of performance to cost. So, it can be used in the fields of fundamental research of Remote Sensing and large-scale mapping for resource exploration, environmental monitoring, calamity prediction, and military purpose.

  16. Ultrafast image-based dynamic light scattering for nanoparticle sizing

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Wu; Zhang, Jie; Liu, Lili; Cai, Xiaoshu, E-mail: usst-caixs@163.com [Institute of Particle and Two-Phase Flow Measurement, Shanghai Key Laboratory of Multiphase Flow and Heat Transfer in Power Engineering, University of Shanghai for Science and Technology, 516 Jungong Road, Shanghai 200093 (China)

    2015-11-15

    An ultrafast sizing method for nanoparticles is proposed, called as UIDLS (Ultrafast Image-based Dynamic Light Scattering). This method makes use of the intensity fluctuation of scattered light from nanoparticles in Brownian motion, which is similar to the conventional DLS method. The difference in the experimental system is that the scattered light by nanoparticles is received by an image sensor instead of a photomultiplier tube. A novel data processing algorithm is proposed to directly get correlation coefficient between two images at a certain time interval (from microseconds to milliseconds) by employing a two-dimensional image correlation algorithm. This coefficient has been proved to be a monotonic function of the particle diameter. Samples of standard latex particles (79/100/352/482/948 nm) were measured for validation of the proposed method. The measurement accuracy of higher than 90% was found with standard deviations less than 3%. A sample of nanosilver particle with nominal size of 20 ± 2 nm and a sample of polymethyl methacrylate emulsion with unknown size were also tested using UIDLS method. The measured results were 23.2 ± 3.0 nm and 246.1 ± 6.3 nm, respectively, which is substantially consistent with the transmission electron microscope results. Since the time for acquisition of two successive images has been reduced to less than 1 ms and the data processing time in about 10 ms, the total measuring time can be dramatically reduced from hundreds seconds to tens of milliseconds, which provides the potential for real-time and in situ nanoparticle sizing.

  17. Application of image plate for structural studies of carbon nanotubes by high-energy X-ray diffraction

    Energy Technology Data Exchange (ETDEWEB)

    Hawelek, L. [A. Chelkowski Institute of Physics, University of Silesia, ul. Uniwersytecka 4, 40-007 Katowice (Poland); Koloczek, J. [A. Chelkowski Institute of Physics, University of Silesia, ul. Uniwersytecka 4, 40-007 Katowice (Poland); Burian, A. [A. Chelkowski Institute of Physics, University of Silesia, ul. Uniwersytecka 4, 40-007 Katowice (Poland)]. E-mail: burian@us.edu.pl; Dore, J.C. [School of Physical Sciences, University of Kent, Canterbury CT2 7NR (United Kingdom); Honkimaeki, V. [European Synchrotron Radiation Facility, BP 220, F-38043 Grenoble (France); Kyotani, T. [Institute of Multidisciplinary Research and Advanced Materials, Tohoku University, Katahira, Sendai 980-8577 (Japan)

    2005-09-29

    An image plate detector coupled with high-energy synchrotron radiation was used to determine the structure factor and the radial distribution function of carbon nanotubes obtained by a template CVD process. The image plate detector has proved to be a very efficient tool for structural studies of nanotubes providing diffraction data of good quality in relatively short time. The diffraction data were converted to real space yielding the radial distribution function which can be used for quantitative analysis of the atomic arrangement of the carbon nanotubes. The obtained results are compared to those of traditional experiments using a conventional point Ge detector.

  18. Therapy imaging: a signal-to-noise analysis of metal plate/film detectors.

    Science.gov (United States)

    Munro, P; Rawlinson, J A; Fenster, A

    1987-01-01

    We have measured the modulation transfer functions [MTF (f)'s] and the noise power spectra [NPS (f)] of therapy x-ray detectors irradiated by 60Co, 6- and 18-MV radiotherapy beams. Using these quantities, we have calculated the noise-equivalent quanta [NEQ (f)] and the detective quantum efficiency [DQE (f)] to quantitate the limitations of therapy detectors. The detectors consisted of film or fluorescent screen-film combinations in contact with copper, lead, or tungsten metal plates. The resolution of the detectors was found to be comparable to fluorescent screen-film combinations used in diagnostic radiology, however, the signal-to-noise ratio [SNR (f)] of the detectors was limited due to film granularity. We conclude that improved images can be obtained by using alternative detector systems which have less noise or film granularity.

  19. Lamb-Wave-Based Tomographic Imaging Techniques for Hole-Edge Corrosion Monitoring in Plate Structures

    Directory of Open Access Journals (Sweden)

    Dengjiang Wang

    2016-11-01

    Full Text Available This study presents a novel monitoring method for hole-edge corrosion damage in plate structures based on Lamb wave tomographic imaging techniques. An experimental procedure with a cross-hole layout using 16 piezoelectric transducers (PZTs was designed. The A0 mode of the Lamb wave was selected, which is sensitive to thickness-loss damage. The iterative algebraic reconstruction technique (ART method was used to locate and quantify the corrosion damage at the edge of the hole. Hydrofluoric acid with a concentration of 20% was used to corrode the specimen artificially. To estimate the effectiveness of the proposed method, the real corrosion damage was compared with the predicted corrosion damage based on the tomographic method. The results show that the Lamb-wave-based tomographic method can be used to monitor the hole-edge corrosion damage accurately.

  20. Response functions of imaging plates to photons, electrons and 4He particles.

    Science.gov (United States)

    Bonnet, T; Comet, M; Denis-Petit, D; Gobet, F; Hannachi, F; Tarisien, M; Versteegen, M; Aléonard, M M

    2013-10-01

    Imaging plates from Fuji (BAS-SR, MS, and TR types) are phosphor films routinely used in ultra high intensity laser experiments. However, few data are available on the absolute IP response functions to ionizing particles. We have previously measured and modeled the IP response functions to protons. We focus here on the determination of the responses to photons, electrons, and (4)He particles. The response functions are obtained on an energy range going from a few tens of keV to a few tens of MeV and are compared to available data. The IP sensitivities to the different ionizing particles demonstrate a quenching effect depending on the particle stopping power.

  1. Calibration of imaging plates to electrons between 40 and 180 MeV.

    Science.gov (United States)

    Rabhi, N; Bohacek, K; Batani, D; Boutoux, G; Ducret, J-E; Guillaume, E; Jakubowska, K; Thaury, C; Thfoin, I

    2016-05-01

    This paper presents the response calibration of Imaging Plates (IPs) for electrons in the 40-180 MeV range using laser-accelerated electrons at Laboratoire d'Optique Appliquée (LOA), Palaiseau, France. In the calibration process, the energy spectrum and charge of electron beams are measured by an independent system composed of a magnetic spectrometer and a Lanex scintillator screen used as a calibrated reference detector. It is possible to insert IPs of different types or stacks of IPs in this spectrometer in order to detect dispersed electrons simultaneously. The response values are inferred from the signal on the IPs, due to an appropriate charge calibration of the reference detector. The effect of thin layers of tungsten in front and/or behind IPs is studied in detail. GEANT4 simulations are used in order to analyze our measurements.

  2. Comparison of discrimination methods for alpha radiation signals using imaging plates.

    Science.gov (United States)

    Chen, B; Zhuo, W

    2012-11-01

    The discrimination of different radiation signals is important for quantitative measurements of naturally occurring radionulides by using the technique of imaging plates (IPs). In this study, four discrimination algorithms previously proposed for discriminating and counting the incident alpha signals were experimentally compared from the view points of linearity response, the discrimination capability of alpha signals from beta signals and the detection uncertainty. The results showed that all the methods had a good linearity response and could discriminate alpha signals from beta signals. In general, a larger region of interest (ROI) has a higher detection efficiency, but the discrimination capability of alpha signals from beta signals is worse. By taking into account both the detection efficiency and the uncertainty of detection, the algorithm using an ROI of 5 × 100 μm × 100 μm was considered to be the most appropriate method for quantitative measurements of alpha radiation.

  3. A compensating method of an imaging plate response to clinical proton beams

    CERN Document Server

    Kohno, R; Takada, Y; Terunuma, T; Sakae, T; Matsumoto, K

    2002-01-01

    For charged particle irradiations, the response of an imaging plate (IP) changes around the Bragg peak. Therefore, an appropriate compensation is necessary for the evaluation of dose distribution formed by charged particles such as protons. In this paper, the response of IPs to clinical proton beams is investigated. An experimentally-obtained depth-dose distribution (an ordinary Bragg curve) by a silicon semiconductor detector (SSD) is employed to evaluate the compensation factors as a function of proton penetrating depth, i.e. residual range. A typical dose distribution in a water phantom formed by an L-shaped bolus is measured by IPs and corrected by using the information of those compensation factors; the residual proton range is successfully calculated by the pencil beam algorithm at an arbitrary point. The results show a good agreement with the measurements by the SSD within the rms error of 3.0%.

  4. Design and performance of an imaging plate system for X-ray diffraction study

    Science.gov (United States)

    Amemiya, Yoshiyuki; Matsushita, Tadashi; Nakagawa, Atsushi; Satow, Yoshinori; Miyahara, Junji; Chikawa, Jun-ichi

    1988-04-01

    A new readout system for a BaFBr: Eu 2+ photostimulable phosphor screen (imaging plate) was constructed by modifying a drum scanner, with a design optimized for X-ray diffraction and scattering applications. An effort was made to achieve a high detective quantum efficiency below 20 keV, a small pixel size (25 μm × 25 μm), a low quantization noise (0.22%) using 12-bit A/D converters, and the capability to cover an inherent dynamic range (1:10 5) of the photostimulated luminescence by using two photomultiplier tubes. This system is being used in several synchrotron radiation experiments: Laue diffraction of protein crystals, small angle diffraction from a single muscle fiber, powder diffraction from crystals in a diamond anvil cell, and time-resolved small-angle X-ray scattering from a synthetic polymer during stretching.

  5. Design study of multi-imaging plate system for BNCT irradiation field at Kyoto university reactor.

    Science.gov (United States)

    Tanaka, Kenichi; Sakurai, Yoshinori; Kajimoto, Tsuyoshi; Tanaka, Hiroki; Takata, Takushi; Endo, Satoru

    2016-09-01

    The converter configuration for a multi-imaging plate system was investigated for the application of quality assurance in the irradiation field profile for boron neutron capture therapy. This was performed by the simulation calculation using the PHITS code in the fields at the Heavy Water Neutron Irradiation Facility of Kyoto University Reactor. The converter constituents investigated were carbon for gamma rays, and polyethylene with and without LiF at varied (6)Li concentration for thermal, epithermal, and fast neutrons. Consequently, potential combinations of the converters were found for two components, gamma rays and thermal neutrons, for the standard thermal neutron mode and three components of gamma rays, epithermal neutrons, and thermal or fast neutrons, for the standard mixed or epithermal neutron modes, respectively.

  6. Resonant X-ray diffraction using high-resolution image-plate data

    Energy Technology Data Exchange (ETDEWEB)

    Ehrenberg, H.; Knapp, M.; Hartmann, T.; Fuess, H. [Technische Hochschule Darmstadt (Germany). Fachbereich Materialwissenschaften; Wroblewski, T. [Hamburger Synchrotron Lab., Hamburg (Germany)

    2000-06-01

    The experimental setup for the collection of synchrotron X-ray powder diffraction data from samples with high absorption ({mu}R > 10) is described. It consists of a combination of a vacuum chamber with an image-plate system. A numerical absorption correction for the applied geometry has been derived and the data were corrected accordingly. Values for f'(Er) and f{sup ''}(Er) were refined from eight measurements on Er{sub 5}Re{sub 2}O{sub 12} above and below the Er L{sub III} absorption edge. Successful refinement of the crystallographic data has verified the high quality of the collected intensities. (orig.)

  7. Hierarchical and successive approximate registration of the non-rigid medical image based on thin-plate splines

    Science.gov (United States)

    Hu, Jinyan; Li, Li; Yang, Yunfeng

    2017-06-01

    The hierarchical and successive approximate registration method of non-rigid medical image based on the thin-plate splines is proposed in the paper. There are two major novelties in the proposed method. First, the hierarchical registration based on Wavelet transform is used. The approximate image of Wavelet transform is selected as the registered object. Second, the successive approximation registration method is used to accomplish the non-rigid medical images registration, i.e. the local regions of the couple images are registered roughly based on the thin-plate splines, then, the current rough registration result is selected as the object to be registered in the following registration procedure. Experiments show that the proposed method is effective in the registration process of the non-rigid medical images.

  8. High Spatial Resolution Investigations of Microchannel Plate Imaging Properties for UV Detectors

    Science.gov (United States)

    Siegmund, Oswald

    1996-01-01

    Microchannel plate (MCP) photon counting detectors are currently being used with great success on many of the recent NASA/ESA ultraviolet (UV) astrophysics missions that make observations in the 1OO A - 1600 A range. These include HUT, the Wide Field Camera on ROSAT, EUVE, ALEXIS, ORFEUS, and SOHO. These devices have also been chosen to fly on future UV astrophysics missions such as FUSE, FUVITA, IMAGE, and both the HST STIS and Advanced Camera instruments. During the period of this award we have fabricated a dual-chamber vacuum test facility to carry out laboratory testing of detector resolution, image stability and linearity, and flat field performance to enable us to characterize the performance of MCPs and their associated read-out architectures. We have also fabricated and tested a laboratory 'test-bed' delay line detector, which can accommodate MCP's with a wide range of formats and run at high data rates, to continue our studies of MCP image fixed pattern noise, and particularly for new small pore MCP's which have recently come onto the market. These tests were mainly focussed on the assessment of cross delay-line (XDL) and double delay line (DDL) anode read-out schemes, with particular attention being focussed on flat-field and spatial resolution performance.

  9. Dependence of fading patterns of photo-stimulated luminescence from imaging plates on radiation, energy, and image reader

    CERN Document Server

    Ohuchi, H

    2002-01-01

    We have been investigating the fading characteristics of imaging plates (IPs) as integral type detectors. The dependence on alpha, beta, and gamma ray radiation and their energies of the fading effect was measured using three types of IPs (BAS-UR, BAS-TR, and BAS-MS). The functions to correct the fading were determined by using the method reported in a previous paper. In all types of IPs, we confirmed that the fading effect is independent of the energy of the incident particles of beta and gamma rays and also independent of radiation except for the first component, which fades out in a very short time after irradiation with alpha rays. These results are very useful in the utilization of IPs as integral detectors in practical radiation fields. Empirically, the fading pattern is known to change when the IP is scanned by different types of image readers. The differences in the fading patterns obtained with two types of image readers, the BAS-1000 and the BAS-5000 (Fuji Film Co.), is discussed. Development of an ...

  10. Imaging of Lamb Waves in Plates for Quantitative Determination of Anisotropy using Photorefractive Dynamic Holography

    Energy Technology Data Exchange (ETDEWEB)

    Telschow, Kenneth Louis; Deason, Vance Albert; Schley, Robert Scott; Watson, Scott Marshall

    1998-06-01

    Anisotropic properties of sheet materials can be determined by measuring the propagation of Lamb waves in different directions. Electromagnetic acoustic transduction and laser ultrasonic methods provide noncontacting approaches that are often desired for application to industrial and processing environments. This paper describes a laser imaging approach utilizing the adaptive property of photorefractive materials to produce a real-time measurement of the antisymmetric Lamb wave mode in all directions simultaneously. Continuous excitation is employed enabling the data to be recorded and displayed by a CCD camera. Analysis of the image produces a direct quantitative determination of the phase velocity in all directions showing plate anisotropy in the plane. Many optical techniques for measuring ultrasonic motion at surfaces have been developed for use in applications such as vibration measurement and laser ultrasonics. Most of these methods have similar sensitivities and are based on time domain processing using homodyne, Fabry-Perot [1], and, more recently, photorefractive interferometry [2]. Generally, the methods described above do not allow measurement at more than one surface point simultaneously, requiring multiple beam movements and scanning in order to produce images of surface ultrasonic motion over a large area. Electronic speckle interferometry, including shearography, does provide images directly of vibrations over large surface areas. This method has proven very durable in the field for large displacement amplitudes of several wavelengths. In addition, a sensitivity of ë/3000 has been demonstrated under laboratory conditions [3]. Full-field imaging of traveling ultrasonic waves using digital shearography has been recently reported with sensitivity in the nanometer range [4]. With this method, optical interference occurs at the photodetector

  11. Polarized light imaging specifies the anisotropy of light scattering in the superficial layer of a tissue

    Science.gov (United States)

    Jacques, Steven L.; Roussel, Stéphane; Samatham, Ravikant

    2016-01-01

    Abstract. This report describes how optical images acquired using linearly polarized light can specify the anisotropy of scattering (g) and the ratio of reduced scattering [μs′=μs(1−g)] to absorption (μa), i.e., N′=μs′/μa. A camera acquired copolarized (HH) and crosspolarized (HV) reflectance images of a tissue (skin), which yielded images based on the intensity (I=HH+HV) and difference (Q=HH−HV) of reflectance images. Monte Carlo simulations generated an analysis grid (or lookup table), which mapped Q and I into a grid of g versus N′, i.e., g(Q,I) and N′(Q,I). The anisotropy g is interesting because it is sensitive to the submicrometer structure of biological tissues. Hence, polarized light imaging can monitor shifts in the submicrometer (50 to 1000 nm) structure of tissues. The Q values for forearm skin on two subjects (one Caucasian, one pigmented) were in the range of 0.046±0.007 (24), which is the mean±SD for 24 measurements on 8 skin sites×3 visible wavelengths, 470, 524, and 625 nm, which indicated g values of 0.67±0.07 (24). PMID:27165546

  12. Photostimulated phosphor based image plate detection system for HRVUV beamline at Indus-1 synchrotron radiation source

    Energy Technology Data Exchange (ETDEWEB)

    Haris, K. [Department of Physics, Aligarh Muslim University, Aligarh 202002 (India); Singh, Param Jeet [Atomic and Molecular Physics Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Shastri, Aparna, E-mail: ashastri@barc.gov.in [Atomic and Molecular Physics Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Sunanda, K.; Babita, K.; Rao, S.V.N. Bhaskara [Atomic and Molecular Physics Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Ahmad, Shabbir; Tauheed, A. [Department of Physics, Aligarh Muslim University, Aligarh 202002 (India)

    2014-12-11

    A high resolution vacuum ultraviolet (HRVUV) beamline based on a 6.65 m off-plane Eagle spectrometer is in operation at the Indus-1 synchrotron radiation source, RRCAT, Indore, India. To facilitate position sensitive detection and fast spectral recording, a new BaFBr:Eu{sup 2+} phosphor based image plate (IP) detection system interchangeable with the existing photomultiplier (PMT) scanning system has been installed on this beamline. VUV photoabsorption studies on Xe, O{sub 2}, N{sub 2}O and SO{sub 2} are carried out to evaluate the performance of the IP detection system. An FWHM of ∼0.5 Å is achieved for the Xe atomic line at 1469.6 Å. Reproducibility of spectra is found to be within the experimental resolution. Compared to the PMT scanning system, the IP shows several advantages in terms of sensitivity, recording time and S/N ratio, which are highlighted in the paper. This is the first report of incorporation of an IP detection system in a VUV beamline using synchrotron radiation. Commissioning of the new detection system is expected to greatly enhance the utilization of the HRVUV beamline as a number of spectroscopic experiments which require fast recording times combined with a good signal to noise ratio are now feasible. - Highlights: • Incorporation of an image plate detection system on HRVUV beamline at Indus-1. • Design and fabrication of mounting mechanisms, performance evaluation of new system. • Photoabsorption spectra of Xe, O{sub 2}, SO{sub 2} and N{sub 2}O recorded in the region 1150–2300 Å. • Sensitivity, wavelength coverage, reproducibility and resolution of IP demonstrated. • First report of IP detector for VUV photoabsorption using synchrotron radiation.

  13. A noiseless kilohertz frame rate imaging detector based on microchannel plates read out with the Medipix2 CMOS pixel chip

    CERN Document Server

    Mikulec, Bettina; Ferrère, Didier; La Marra, Daniel; McPhate, J B; Tremsin, A S; Siegmund, O H W; Vallerga, J V; Clement, J; Ponchut, C; Rigal, J M; CERN. Geneva

    2006-01-01

    A new hybrid optical imaging detector is described that is being developed for the next generation adaptive optics (AO) wavefront sensors (WFS) for ground-based telescopes. The detector consists of a photocathode and proximity focused microchannel plates (MCPs) read out by the Medipix2 CMOS pixel ASIC. Each pixel of the Medipix2 device measures 55x55 um2 and comprises pre-amplifier, a window discriminator and a 14-bit counter. The 256x256 Medipix2 array can be read out noiselessly in 287 us. The readout can be electronically shuttered down to a temporal window of a few us. The Medipix2 is buttable on 3 sides to produce 512x(n*256) pixel devices. Measurements with ultraviolet light yield a spatial resolution of the detector at the Nyquist limit. Sub-pixel resolution can be achieved using centroiding algorithms. For the AO application, very high continuous frame rates of the order of 1 kHz are required for a matrix of 512x512 pixels. The design concepts of a parallel readout board are presented that will allow ...

  14. High-content imaging with micropatterned multiwell plates reveals influence of cell geometry and cytoskeleton on chromatin dynamics.

    Science.gov (United States)

    Harkness, Ty; McNulty, Jason D; Prestil, Ryan; Seymour, Stephanie K; Klann, Tyler; Murrell, Michael; Ashton, Randolph S; Saha, Krishanu

    2015-10-01

    Understanding the mechanisms underpinning cellular responses to microenvironmental cues requires tight control not only of the complex milieu of soluble signaling factors, extracellular matrix (ECM) connections and cell-cell contacts within cell culture, but also of the biophysics of human cells. Advances in biomaterial fabrication technologies have recently facilitated detailed examination of cellular biophysics and revealed that constraints on cell geometry arising from the cellular microenvironment influence a wide variety of human cell behaviors. Here, we create an in vitro platform capable of precise and independent control of biochemical and biophysical microenvironmental cues by adapting microcontact printing technology into the format of standard six- to 96-well plates to create MicroContact Printed Well Plates (μCP Well Plates). Automated high-content imaging of human cells seeded on μCP Well Plates revealed tight, highly consistent control of single-cell geometry, cytoskeletal organization, and nuclear elongation. Detailed subcellular imaging of the actin cytoskeleton and chromatin within live human fibroblasts on μCP Well Plates was then used to describe a new relationship between cellular geometry and chromatin dynamics. In summary, the μCP Well Plate platform is an enabling high-content screening technology for human cell biology and cellular engineering efforts that seek to identify key biochemical and biophysical cues in the cellular microenvironment.

  15. Imaging spectroscopic analysis at the Advanced Light Source

    Energy Technology Data Exchange (ETDEWEB)

    MacDowell, A. A.; Warwick, T.; Anders, S.; Lamble, G.M.; Martin, M.C.; McKinney, W.R.; Padmore, H.A.

    1999-05-12

    One of the major advances at the high brightness third generation synchrotrons is the dramatic improvement of imaging capability. There is a large multi-disciplinary effort underway at the ALS to develop imaging X-ray, UV and Infra-red spectroscopic analysis on a spatial scale from. a few microns to 10nm. These developments make use of light that varies in energy from 6meV to 15KeV. Imaging and spectroscopy are finding applications in surface science, bulk materials analysis, semiconductor structures, particulate contaminants, magnetic thin films, biology and environmental science. This article is an overview and status report from the developers of some of these techniques at the ALS. The following table lists all the currently available microscopes at the. ALS. This article will describe some of the microscopes and some of the early applications.

  16. Light and sound - emerging imaging techniques for inflammatory bowel disease

    Science.gov (United States)

    Knieling, Ferdinand; Waldner, Maximilian J

    2016-01-01

    Patients with inflammatory bowel disease are known to have a high demand of recurrent evaluation for therapy and disease activity. Further, the risk of developing cancer during the disease progression is increasing from year to year. New, mostly non-radiant, quick to perform and quantitative methods are challenging, conventional endoscopy with biopsy as gold standard. Especially, new physical imaging approaches utilizing light and sound waves have facilitated the development of advanced functional and molecular modalities. Besides these advantages they hold the promise to predict personalized therapeutic responses and to spare frequent invasive procedures. Within this article we highlight their potential for initial diagnosis, assessment of disease activity and surveillance of cancer development in established techniques and recent advances such as wide-view full-spectrum endoscopy, chromoendoscopy, autofluorescence endoscopy, endocytoscopy, confocal laser endoscopy, multiphoton endoscopy, molecular imaging endoscopy, B-mode and Doppler ultrasound, contrast-enhanced ultrasound, ultrasound molecular imaging, and elastography. PMID:27433080

  17. Compression and Processing of Space Image Sequences of Northern Lights and Sprites

    DEFF Research Database (Denmark)

    Forchhammer, Søren Otto; Martins, Bo; Jensen, Ole Riis

    1999-01-01

    Compression of image sequences of auroral activity as northern lights and thunderstorms with sprites is investigated.......Compression of image sequences of auroral activity as northern lights and thunderstorms with sprites is investigated....

  18. Comparative evaluation of image quality in computed radiology systems using imaging plates with different usage time; Avaliacao comparativa da qualidade da imagem em sistemas de radiologia computadorizada utilizando Imaging Plates com diferentes tempos de uso

    Energy Technology Data Exchange (ETDEWEB)

    Lazzaro, M.V.; Luz, R.M. da; Capaverde, A.S., E-mail: marcos.lazzaro@acad.pucrs.br [Hospital Sao Lucas (PUC-RS), Porto Alegre, RS (Brazil); Silva, A.M. Marques da [Pontificia Universidade Catolica do Rio Grande do Sul (PUC-RS), Porto Alegre, RS (Brazil). Faculdade de Fisica

    2015-04-15

    Computed Radiology (CR) systems use imaging plates (IPs) for latent image acquisition. Taking into account the quality control (QC) of these systems, imaging plates usage time is undetermined. Different recommendations and publications on the subject suggest tests to evaluate these systems. The objective of this study is to compare the image quality of IPs of a CR system, in a mammography service, considering the usage time and consistency of assessments. 8 IPs were used divided into two groups: the first group included 4 IPs with 3 years of use (Group A); the second group consisted of 4 new IPs with no previous exposure (Group B). The tests used to assess the IP's quality were: Uniformity, Differential Signal to Noise Ratio (SDNR), Ghost Effect and Figure of Merit (FOM). Statistical results show that the proposed tests are shown efficient in assessing the conditions of image quality obtained in CR systems in mammography and can be used as determining factors for the replacement of IP's. Moreover, comparing the two sets of IP, results led to the replacement of all the set of IP’s with 3 years of use. This work demonstrates the importance of an efficient quality control, not only with regard to the quality of IP's used, but in the acquisition system as a whole. From this work, these tests will be conducted on an annual basis, already targeting as future work, monitoring the wear of IP's Group B and the creation of a baseline for analysis and future replacements. (author)

  19. Fully Noncontact Wave Propagation Imaging in an Immersed Metallic Plate with a Crack

    Directory of Open Access Journals (Sweden)

    Jung-Ryul Lee

    2014-01-01

    Full Text Available This study presents a noncontact sensing technique with ultrasonic wave propagation imaging algorithm, for damage visualization of liquid-immersed structures. An aluminum plate specimen (400 mm × 400 mm × 3 mm with a 12 mm slit was immersed in water and in glycerin. A 532 nm Q-switched continuous wave laser is used at an energy level of 1.2 mJ to scan an area of 100 mm × 100 mm. A laser Doppler vibrometer is used as a noncontact ultrasonic sensor, which measures guided wave displacement at a fixed point. The tests are performed with two different cases of specimen: without water and filled with water and with glycerin. Lamb wave dispersion curves for the respective cases are calculated, to investigate the velocity-frequency relationship of each wave mode. Experimental propagation velocities of Lamb waves for different cases are compared with the theoretical dispersion curves. This study shows that the dispersion and attenuation of the Lamb wave is affected by the surrounding liquid, and the comparative experimental results are presented to verify it. In addition, it is demonstrated that the developed fully noncontact ultrasonic propagation imaging system is capable of damage sizing in submerged structures.

  20. Quantification of dispersed phase concentration using light sheet imaging methods

    Science.gov (United States)

    Knowles, Philip L.; Kiger, Ken T.

    2012-03-01

    With the prevalence of particle image velocimetry (PIV) as a quantitative tool for fluid mechanics diagnostics, its application for analyzing complicated multiphase flows has been steadily increasing over the last several decades. While the primary issue in using PIV for multiphase flows is in separating the information of the phases for independent analysis with a minimum of spurious "cross-talk," an equally crucial but often overlooked point is in the accurate quantitative measurement of the dispersed phase concentration. Accurate concentration measurement is important due to the fact that the dispersed phase is often heterogeneously distributed in both space and time, either due to a non-uniformity of the source of particulates (such as a spray nozzle or sediment boundary) or due to inertial migration of the particles even from originally homogeneous spatial distributions. In the current work, we examine the effects of light sheet profile distortion and attenuation by tracer seeding particles, as well as reflected light from local wall boundaries on the effective light sheet thickness. The effective thickness is critical for concentration measurements, as it dictates the dispersed phase detection volume. A direct calibration method is demonstrated to measure the effective light sheet thickness in a water/glass bead system, which shows that systematic bias errors on the order of 30% can result if the reflective bed condition is not accounted for, and the errors can be as high as 50% or more if a single-point measure of the sheet width is used.

  1. Backscattered light confocal imaging of intracellular MTT-formazan crystals.

    Science.gov (United States)

    Bernas, Tytus; Dobrucki, Jurek W

    2004-06-01

    Metabolically active animal and plant cells reduce MTT tetrazolium salt to a corresponding nonfluorescent formazan. Reduction of MTT by viable cells is exploited in a number of tests widely used in biological research. The aim of this study was to optimize a microscopy method of detecting small crystals of MTT-formazan formed in intact cells maintained in in vitro cultures. We examined scattering properties of small intracellular crystals of MTT formazan and found that the efficiency of light scattering was dependent on wavelength. Small (formazan, formed in viable cells, scattered red, but not blue, light. Large crystals, which are formed later at a stage when cells begin to lose viability, scattered both red and blue light. We conclude that optimal detection of early stages of crystallization of MTT-formazan in living cells is possible using confocal microscopy of red, but not blue, scattered light. High contrast and resolution of images can be achieved by filtering out interference effects in the frequency domain.

  2. Hexabundles: imaging fiber arrays for low-light astronomical applications.

    Science.gov (United States)

    Bland-Hawthorn, Joss; Bryant, Julia; Robertson, Gordon; Gillingham, Peter; O'Byrne, John; Cecil, Gerald; Haynes, Roger; Croom, Scott; Ellis, Simon; Maack, Martin; Skovgaard, Peter; Noordegraaf, Danny

    2011-01-31

    We demonstrate a novel imaging fiber bundle ("hexabundle") that is suitable for low-light applications in astronomy. The most successful survey instruments at optical-infrared wavelengths use hundreds to thousands of multimode fibers fed to one or more spectrographs. Since most celestial sources are spatially extended on the celestial sphere, a hexabundle provides spectroscopic information at many distinct locations across the source. We discuss two varieties of hexabundles: (i) lightly fused, closely packed, circular cores; (ii) heavily fused non-circular cores with higher fill fractions. In both cases, we find the important result that the cladding can be reduced to ~2 μm over the short fuse length, well below the conventional ~10λ thickness employed more generally, with a consequent gain in fill factor. Over the coming decade, it is to be expected that fiber-based instruments will be upgraded with hexabundles in order to increase the spatial multiplex capability by two or more orders of magnitude.

  3. Detection of light images by simple tissues as visualized by photosensitized magnetic resonance imaging.

    Directory of Open Access Journals (Sweden)

    Catherine Tempel-Brami

    Full Text Available In this study, we show how light can be absorbed by the body of a living rat due to an injected pigment circulating in the blood stream. This process is then physiologically translated in the tissue into a chemical signature that can be perceived as an image by magnetic resonance imaging (MRI. We previously reported that illumination of an injected photosynthetic bacteriochlorophyll-derived pigment leads to a generation of reactive oxygen species, upon oxygen consumption in the blood stream. Consequently, paramagnetic deoxyhemoglobin accumulating in the illuminated area induces changes in image contrast, detectable by a Blood Oxygen Level Dependent (BOLD-MRI protocol, termed photosensitized (psMRI. Here, we show that laser beam pulses synchronously trigger BOLD-contrast transients in the tissue, allowing representation of the luminous spatiotemporal profile, as a contrast map, on the MR monitor. Regions with enhanced BOLD-contrast (7-61 fold were deduced as illuminated, and were found to overlap with the anatomical location of the incident light. Thus, we conclude that luminous information can be captured and translated by typical oxygen exchange processes in the blood of ordinary tissues, and made visible by psMRI (Fig. 1. This process represents a new channel for communicating environmental light into the body in certain analogy to light absorption by visual pigments in the retina where image perception takes place in the central nervous system. Potential applications of this finding may include: non-invasive intra-operative light guidance and follow-up of photodynamic interventions, determination of light diffusion in opaque tissues for optical imaging and possible assistance to the blind.

  4. Hyperspectral Image-Based Night-Time Vehicle Light Detection Using Spectral Normalization and Distance Mapper for Intelligent Headlight Control

    Directory of Open Access Journals (Sweden)

    Heekang Kim

    2016-07-01

    Full Text Available This paper proposes a vehicle light detection method using a hyperspectral camera instead of a Charge-Coupled Device (CCD or Complementary metal-Oxide-Semiconductor (CMOS camera for adaptive car headlamp control. To apply Intelligent Headlight Control (IHC, the vehicle headlights need to be detected. Headlights are comprised from a variety of lighting sources, such as Light Emitting Diodes (LEDs, High-intensity discharge (HID, and halogen lamps. In addition, rear lamps are made of LED and halogen lamp. This paper refers to the recent research in IHC. Some problems exist in the detection of headlights, such as erroneous detection of street lights or sign lights and the reflection plate of ego-car from CCD or CMOS images. To solve these problems, this study uses hyperspectral images because they have hundreds of bands and provide more information than a CCD or CMOS camera. Recent methods to detect headlights used the Spectral Angle Mapper (SAM, Spectral Correlation Mapper (SCM, and Euclidean Distance Mapper (EDM. The experimental results highlight the feasibility of the proposed method in three types of lights (LED, HID, and halogen.

  5. MICADO: first light imager for the E-ELT

    CERN Document Server

    Davies, R; Hartl, M; Alves, J; Clénet, Y; Lang-Bardl, F; Nicklas, H; Pott, J -U; Ragazzoni, R; Tolstoy, E; Agocs, T; Anwand-Heerwart, H; Barboza, S; Baudoz, P; Bender, R; Bizenberger, P; Boccaletti, A; Boland, W; Bonifacio, P; Briegel, F; Buey, T; Chapron, F; Cohen, M; Czoske, O; Dreizler, S; Falomo, R; Feautrier, P; Schreiber, N Förster; Gendron, E; Genzel, R; Glück, M; Gratadour, D; Greimel, R; Grupp, F; Häuser, M; Haug, M; Hennawi, J; Hess, H -J; Hörmann, V; Hofferbert, R; Hopp, U; Hubert, Z; Ives, D; Kausch, W; Kerber, F; Kravcar, H; Kuijken, K; Lang-Bardl, F; Leitzinger, M; Leschinski, K; Massari, D; Mei, S; Merlin, F; Mohr, L; Monna, A; Müller, F; Navarro, R; Plattner, M; Przybilla, N; Ramlau, R; Ramsay, S; Ratzka, T; Rhode, P; Richter, J; Rix, H -W; Rodeghiero, G; Rohloff, R -R; Rousset, G; Ruddenklau, R; Schaffenroth, V; Schlichter, J; Sevin, A; Stuik, R; Sturm, E; Thomas, J; Tromp, N; Turatto, M; Verdoes-Kleijn, G; Vidal, F; Wagner, R; Wegner, M; Zeilinger, W; Ziegler, B; Zins, G

    2016-01-01

    MICADO will equip the E-ELT with a first light capability for diffraction limited imaging at near-infrared wavelengths. The instrument's observing modes focus on various flavours of imaging, including astrometric, high contrast, and time resolved. There is also a single object spectroscopic mode optimised for wavelength coverage at moderately high resolution. This contribution provides an overview of the key functionality of the instrument, outlining the scientific rationale for its observing modes. The interface between MICADO and the adaptive optics system MAORY that feeds it is summarised. The design of the instrument is discussed, focussing on the optics and mechanisms inside the cryostat, together with a brief overview of the other key sub-systems.

  6. Three-dimensional microscopic light field particle image velocimetry

    Science.gov (United States)

    Truscott, Tadd T.; Belden, Jesse; Ni, Rui; Pendlebury, Jonathon; McEwen, Bryce

    2017-03-01

    A microscopic particle image velocimetry (μ {PIV}) technique is developed based on light field microscopy and is applied to flow through a microchannel containing a backward-facing step. The only hardware difference from a conventional μPIV setup is the placement of a microlens array at the intermediate image plane of the microscope. The method combines this optical hardware alteration with post-capture computation to enable 3D reconstruction of particle fields. From these particle fields, we measure three-component velocity fields, but find that accurate velocity measurements are limited to the two in-plane components at discrete depths through the volume (i.e., 2C-3D). Results are compared with a computational fluid dynamics simulation.

  7. General theory of light propagation and imaging through the atmosphere

    CERN Document Server

    McKechnie, T Stewart

    2016-01-01

    This book lays out a new, general theory of light propagation and imaging through Earth’s turbulent atmosphere. Current theory is based on the – now widely doubted – assumption of Kolmogorov turbulence. The new theory is based on a generalized atmosphere, the turbulence characteristics of which can be established, as needed, from readily measurable properties of point-object, or star, images. The pessimistic resolution predictions of Kolmogorov theory led to lax optical tolerance prescriptions for large ground-based astronomical telescopes which were widely adhered to in the 1970s and 1980s. Around 1990, however, it became clear that much better resolution was actually possible, and Kolmogorov tolerance prescriptions were promptly abandoned. Most large telescopes built before 1990 have had their optics upgraded (e.g., the UKIRT instrument) and now achieve, without adaptive optics (AO), almost an order of magnitude better resolution than before. As well as providing a more comprehensive and precise under...

  8. Phase imaging from defocus information in a light field

    CERN Document Server

    Davis, Quintin Tyrell

    2012-01-01

    Optical microscopy is without a doubt an essential component of life science research, but many objects of interest in biology are transparent. Chemical or immunological dyes, which can often be toxic, fluorescent transgenes, which require a protocol for transformation of exogenous DNA, and phase contrast, which inextricably combines phase information with amplitude, all serve to increase the contrast of transparent objects. Transparent objects of non-uniform refractive index and/or thickness are phase objects and phase can be extracted from defocus information above and below the object. The light microscopist will recognize this in that object contrast can vary as the stage is moved around an object's focal plane. This phase information can be quantitatively retrieved from a set of defocused images, but this has the disadvantage of decreasing temporal resolution, as the microscope stage has to be moved between image captures. By incorporating additional optics in the form of an array of pinholes or microlen...

  9. Spatio-Temporal Imaging of Light Transport in Highly Scattering Media under White Light Illumination

    CERN Document Server

    Badon, Amaury; Lerosey, Geoffroy; Boccara, Albert C; Fink, Mathias; Aubry, Alexandre

    2016-01-01

    Imaging the propagation of light in time and space is crucial in optics, notably for the study of complex media. We here demonstrate the passive measurement of time-dependent Green's functions between every point at the surface of a strongly scattering medium by means of low coherence interferometry. The experimental access to this Green's matrix is essential since it contains all the information about the complex trajectories of light within the medium. In particular, the spatio-temporal spreading of the diffusive halo can be locally investigated in the vicinity of each point then acting as a virtual source. On the one hand, this approach allows a quantitative imaging of the diffusion constant in the scattering medium with a spatial resolution of the order of a few transport mean free paths. On the other hand, our approach is able to reveal and quantify the anisotropy of light diffusion, which can be of great interest for optical characterization purposes. This study opens important perspectives both in opti...

  10. Incident Light Frequency-Based Image Defogging Algorithm

    Directory of Open Access Journals (Sweden)

    Wenbo Zhang

    2017-01-01

    Full Text Available To solve the color distortion problem produced by the dark channel prior algorithm, an improved method for calculating transmittance of all channels, respectively, was proposed in this paper. Based on the Beer-Lambert Law, the influence between the frequency of the incident light and the transmittance was analyzed, and the ratios between each channel’s transmittance were derived. Then, in order to increase efficiency, the input image was resized to a smaller size before acquiring the refined transmittance which will be resized to the same size of original image. Finally, all the transmittances were obtained with the help of the proportion between each color channel, and then they were used to restore the defogging image. Experiments suggest that the improved algorithm can produce a much more natural result image in comparison with original algorithm, which means the problem of high color saturation was eliminated. What is more, the improved algorithm speeds up by four to nine times compared to the original algorithm.

  11. Axial light emission and Ar metastable densities in a parallel plate dc micro discharge in steady state and transient regimes

    CERN Document Server

    Kuschel, T; Stefanović, I; Böke, M; Skoro, N; Marić, D; Petrović, Z Lj; Winter, J

    2011-01-01

    Axial emission profiles in a parallel plate dc micro discharge (feedgas: argon; discharge gap d=1mm; pressure p=10Torr) were studied by means of time resolved imaging with a fast ICCD camera. Additionally, volt-ampere (V-A) characteristics were recorded and Ar* metastable densities were measured by tunable diode laser absorption spectroscopy (TDLAS). Axial emission profiles in the steady state regime are similar to corresponding profiles in standard size discharges (d=1cm, p=1Torr). For some discharge conditions relaxation oscillations are present when the micro discharge switches periodically between low current Townsend-like mode and normal glow. At the same time the axial emission profile shows transient behavior, starting with peak distribution at the anode, which gradually moves towards the cathode during the normal glow. The development of argon metastable densities highly correlates with the oscillating discharge current. Gas temperatures in the low current Townsend-like mode (T= 320-400K) and the high...

  12. Photocatalytic degradation of three azo dyes using immobilized TiO{sub 2} nanoparticles on glass plates activated by UV light irradiation: Influence of dye molecular structure

    Energy Technology Data Exchange (ETDEWEB)

    Khataee, A.R., E-mail: a_khataee@tabrizu.ac.ir [Department of Applied Chemistry, Faculty of Chemistry, University of Tabriz, Tabriz (Iran, Islamic Republic of); Laboratoire des Sciences du Genie Chimique, CNRS, Nancy Universite, ENSIC, 1, rue Grandville, BP 20451, F-54001 Nancy Cedex (France); Pons, M.N., E-mail: Marie-Noelle.Pons@ensic.inpl-nancy.fr [Laboratoire des Sciences du Genie Chimique, CNRS, Nancy Universite, ENSIC, 1, rue Grandville, BP 20451, F-54001 Nancy Cedex (France); Zahraa, O., E-mail: Orfan.Zahraa@ensic.inpl-nancy.fr [Departement de Chimie-Physique des Reactions, INPL, Nancy Universite, ENSIC, 1, rue Grandville, BP 451, F-54001 Nancy Cedex (France)

    2009-08-30

    In order to discuss the effect of chemical structure on photocatalysis efficiency, the photocatalytic degradation of three commercial textile dyes (C.I. Acid Orange 10 (AO10), C.I. Acid Orange 12 (AO12) and C.I. Acid Orange 8 (AO8)) with different structure and different substitute groups has been investigated using supported TiO{sub 2} photocatalyst under UV light irradiation. All the experiments were performed in a circulation photochemical reactor equipped with a 15-W UV lamp emitted around 365 nm. The investigated photocatalyst was industrial Millennium PC-500 (crystallites mean size 5-10 nm) immobilized on glass plates by a heat attachment method. SEM images of the immobilized TiO{sub 2} nanoparticles showed the good coating on the plates, after repeating the deposition procedure three times. Our results indicated that the photocatalytic decolorization kinetics of the dyes were in the order of AO10 > AO12 > AO8. Photocatalytic mineralization of the dyes was monitored by total organic carbon (TOC) decrease, changes in UV-vis spectra and ammonium ion formation. The dye solutions could be completely decolorized and effectively mineralized, with an average overall TOC removal larger than 94% for a photocatalytic reaction time of 6 h. The nitrogen-to-nitrogen double bond of the azo dyes was transformed predominantly into NH{sub 4}{sup +} ion. The kinetic of photocatalytic decolorization of the dyes was found to follow a first-order rate law. The photocatalysis efficiency was evaluated by figure-of-merit electrical energy per order (E{sub EO}).

  13. Multi-Mode Electromagnetic Ultrasonic Lamb Wave Tomography Imaging for Variable-Depth Defects in Metal Plates

    Directory of Open Access Journals (Sweden)

    Songling Huang

    2016-05-01

    Full Text Available This paper proposes a new cross-hole tomography imaging (CTI method for variable-depth defects in metal plates based on multi-mode electromagnetic ultrasonic Lamb waves (LWs. The dispersion characteristics determine that different modes of LWs are sensitive to different thicknesses of metal plates. In this work, the sensitivities to thickness variation of A0- and S0-mode LWs are theoretically studied. The principles and procedures for the cooperation of A0- and S0-mode LW CTI are proposed. Moreover, the experimental LW imaging system on an aluminum plate with a variable-depth defect is set up, based on A0- and S0-mode EMAT (electromagnetic acoustic transducer arrays. For comparison, the traditional single-mode LW CTI method is used in the same experimental platform. The imaging results show that the computed thickness distribution by the proposed multi-mode method more accurately reflects the actual thickness variation of the defect, while neither the S0 nor the A0 single-mode method was able to distinguish thickness variation in the defect region. Moreover, the quantification of the defect’s thickness variation is more accurate with the multi-mode method. Therefore, theoretical and practical results prove that the variable-depth defect in metal plates can be successfully quantified and visualized by the proposed multi-mode electromagnetic ultrasonic LW CTI method.

  14. Multi-Mode Electromagnetic Ultrasonic Lamb Wave Tomography Imaging for Variable-Depth Defects in Metal Plates.

    Science.gov (United States)

    Huang, Songling; Zhang, Yu; Wang, Shen; Zhao, Wei

    2016-05-02

    This paper proposes a new cross-hole tomography imaging (CTI) method for variable-depth defects in metal plates based on multi-mode electromagnetic ultrasonic Lamb waves (LWs). The dispersion characteristics determine that different modes of LWs are sensitive to different thicknesses of metal plates. In this work, the sensitivities to thickness variation of A0- and S0-mode LWs are theoretically studied. The principles and procedures for the cooperation of A0- and S0-mode LW CTI are proposed. Moreover, the experimental LW imaging system on an aluminum plate with a variable-depth defect is set up, based on A0- and S0-mode EMAT (electromagnetic acoustic transducer) arrays. For comparison, the traditional single-mode LW CTI method is used in the same experimental platform. The imaging results show that the computed thickness distribution by the proposed multi-mode method more accurately reflects the actual thickness variation of the defect, while neither the S0 nor the A0 single-mode method was able to distinguish thickness variation in the defect region. Moreover, the quantification of the defect's thickness variation is more accurate with the multi-mode method. Therefore, theoretical and practical results prove that the variable-depth defect in metal plates can be successfully quantified and visualized by the proposed multi-mode electromagnetic ultrasonic LW CTI method.

  15. 90Sr in mammal teeth from contaminated areas in the former Soviet Union measured by imaging plates.

    Science.gov (United States)

    Toyoda, Shin; Hino, Yoshitsugu; Romanyukha, Alexander A; Tarasov, Oleg; Pivovarov, Sergey P; Hoshi, Masaharu

    2010-02-01

    Imaging plates sensitive to beta rays were used to obtain the images of 90Sr in tooth samples taken from mammals collected in contaminated areas of the former Soviet Union. The average concentrations of 90Sr in the samples were determined by comparing the intensities of the luminescence using a single crystal of KCl. The results showed that the determined 90Sr concentration has a positive correlation with the soil contamination levels in the South Ural region. Tooth samples from both inside of the Semipalatinsk nuclear test site and the villages nearby have detectable amounts of 90Sr, indicating the possible presence of residual soil contamination. The present study demonstrates that using imaging plates is a very sensitive method to detect 90Sr in teeth as well as to estimate low-level 90Sr contamination in soil.

  16. Light, Wind and Fire - Beautiful Image of a Cosmic Sculpture

    Science.gov (United States)

    2010-02-01

    Today ESO has released a dramatic new image of NGC 346, the brightest star-forming region in our neighbouring galaxy, the Small Magellanic Cloud, 210 000 light-years away towards the constellation of Tucana (the Toucan). The light, wind and heat given off by massive stars have dispersed the glowing gas within and around this star cluster, forming a surrounding wispy nebular structure that looks like a cobweb. NGC 346, like other beautiful astronomical scenes, is a work in progress, and changes as the aeons pass. As yet more stars form from loose matter in the area, they will ignite, scattering leftover dust and gas, carving out great ripples and altering the face of this lustrous object. NGC 346 spans approximately 200 light-years, a region of space about fifty times the distance between the Sun and its nearest stellar neighbours. Astronomers classify NGC 346 as an open cluster of stars, indicating that this stellar brood all originated from the same collapsed cloud of matter. The associated nebula containing this clutch of bright stars is known as an emission nebula, meaning that gas within it has been heated up by stars until the gas emits its own light, just like the neon gas used in electric store signs. Many stars in NGC 346 are relatively young in cosmic terms with their births dating back only a few million years or so (eso0834). Powerful winds thrown off by a massive star set off this recent round of star birth by compressing large amounts of matter, the first critical step towards igniting new stars. This cloud of material then collapses under its own gravity, until some regions become dense and hot enough to roar forth as a brilliantly shining, nuclear fusion-powered furnace - a star, illuminating the residual debris of gas and dust. In sufficiently congested regions like NGC 346, with high levels of recent star birth, the result is a glorious, glowing vista for our telescopes to capture. NGC 346 is in the Small Magellanic Cloud, a dwarf galaxy some 210

  17. Study on kinetics of hydrogen dissolution and hydrogen solubility in oxides using imaging plate technique

    Energy Technology Data Exchange (ETDEWEB)

    Hashizume, K., E-mail: hashi@nucl.kyushu-u.ac.jp [Interdisciplinary Graduate School of Engineering Science, Kyushu Univ., Fukuoka (Japan); Ogata, K.; Nishikawa, M.; Tanabe, T. [Interdisciplinary Graduate School of Engineering Science, Kyushu Univ., Fukuoka (Japan); Abe, S.; Akamaru, S.; Hatano, Y. [Hydrogen Isotope Research Center, Univ. of Toyama, Toyama (Japan)

    2013-11-15

    Using a tritium imaging plate technique, kinetics of tritium dissolution and its solubility in several oxides were examined. Mirror-polished single crystals of alumina, spinel and zirconia were used as specimens, which were exposed to 133 Pa of a tritium(T)–deuterium(D) gas mixture (T/(T + D) ∼ 0.17) at temperatures ranging from 673 to 973 K for 1–5 h. The T surface activity on the specimens increased with increasing temperature and exposure time, it almost saturated at 873 K and reached 2 × 10{sup 5} Bq/cm{sup 2} (1 × 10{sup 14} T/cm{sup 2}), and no clear difference appeared among the types of specimens. The T activity in the oxide bulk also increased with temperature, in which there was a trend for the oxides: spinel ≧ zirconia ≧ alumina. In the T dissolution process for all oxides, the concentration gradient due to its diffusion was not observed even for short exposure times: the T density was almost uniform over the specimens in transition states and increased with exposure time up to the saturated value. These experimental results suggested that the rate-controlling process of T dissolution in the temperature region should be not its diffusion in the oxides but dissociation of hydrogen molecules (T–D mixture in this case) into atoms, its adsorption on the surface and/or T penetration from the surface into the bulk.

  18. Photostimulated phosphor based image plate detection system for HRVUV beamline at Indus-1 synchrotron radiation source

    Science.gov (United States)

    Haris, K.; Singh, Param Jeet; Shastri, Aparna; Sunanda, K.; Babita, K.; Rao, S. V. N. Bhaskara; Ahmad, Shabbir; Tauheed, A.

    2014-12-01

    A high resolution vacuum ultraviolet (HRVUV) beamline based on a 6.65 m off-plane Eagle spectrometer is in operation at the Indus-1 synchrotron radiation source, RRCAT, Indore, India. To facilitate position sensitive detection and fast spectral recording, a new BaFBr:Eu2+ phosphor based image plate (IP) detection system interchangeable with the existing photomultiplier (PMT) scanning system has been installed on this beamline. VUV photoabsorption studies on Xe, O2, N2O and SO2 are carried out to evaluate the performance of the IP detection system. An FWHM of ~0.5 Å is achieved for the Xe atomic line at 1469.6 Å. Reproducibility of spectra is found to be within the experimental resolution. Compared to the PMT scanning system, the IP shows several advantages in terms of sensitivity, recording time and S/N ratio, which are highlighted in the paper. This is the first report of incorporation of an IP detection system in a VUV beamline using synchrotron radiation. Commissioning of the new detection system is expected to greatly enhance the utilization of the HRVUV beamline as a number of spectroscopic experiments which require fast recording times combined with a good signal to noise ratio are now feasible.

  19. Photostimulated phosphor based image plate detection system for HRVUV beamline at Indus-1 synchrotron radiation source

    CERN Document Server

    Haris, K; Shastri, Aparna; K., Sunanda; K., Babita; Rao, S V N Bhaskara; Ahmad, Shabbir; Tauheed, A

    2014-01-01

    A high resolution vacuum ultraviolet (HRVUV) beamline based on a 6.65 meter off-plane Eagle spectrometer is in operation at the Indus-1 synchrotron radiation source, RRCAT, Indore, India. To facilitate position sensitive detection and fast spectral recording, a new BaFBr:Eu2+ phosphor based image plate (IP) detection system interchangeable with the existing photomultiplier (PMT) scanning system has been installed on this beamline. VUV photoabsorption studies on Xe, O2, N2O and SO2 are carried out to evaluate the performance of the IP detection system. An FWHM of ~ 0.5 {\\AA} is achieved for the Xe atomic line at 1469.6 {\\AA}. Reproducibility of spectra is found to be within the experimental resolution. Compared to the PMT scanning system, the IP shows several advantages in terms of sensitivity, recording time and S/N ratio, which are highlighted in the paper. This is the first report of incorporation of an IP detection system in a VUV beamline using synchrotron radiation. Commissioning of the new detection sys...

  20. Sharpest Ever VLT Images at NAOS-CONICA "First Light"

    Science.gov (United States)

    2001-12-01

    Very Promising Start-Up of New Adaptive Optics Instrument at Paranal Summary A team of astronomers and engineers from French and German research institutes and ESO at the Paranal Observatory is celebrating the successful accomplishment of "First Light" for the NAOS-CONICA Adaptive Optics facility . With this event, another important milestone for the Very Large Telescope (VLT) project has been passed. Normally, the achievable image sharpness of a ground-based telescope is limited by the effect of atmospheric turbulence. However, with the Adaptive Optics (AO) technique, this drawback can be overcome and the telescope produces images that are at the theoretical limit, i.e., as sharp as if it were in space . Adaptive Optics works by means of a computer-controlled, flexible mirror that counteracts the image distortion induced by atmospheric turbulence in real time. The larger the main mirror of the telescope is, and the shorter the wavelength of the observed light, the sharper will be the images recorded. During a preceding four-week period of hard and concentrated work, the expert team assembled and installed this major astronomical instrument at the 8.2-m VLT YEPUN Unit Telescope (UT4). On November 25, 2001, following careful adjustments of this complex apparatus, a steady stream of photons from a southern star bounced off the computer-controlled deformable mirror inside NAOS and proceeded to form in CONICA the sharpest image produced so far by one of the VLT telescopes. With a core angular diameter of only 0.07 arcsec, this image is near the theoretical limit possible for a telescope of this size and at the infrared wavelength used for this demonstration (the K-band at 2.2 µm). Subsequent tests reached the spectacular performance of 0.04 arcsec in the J-band (wavelength 1.2 µm). "I am proud of this impressive achievement", says ESO Director General Catherine Cesarsky. "It shows the true potential of European science and technology and it provides a fine

  1. Optical-thermal light-tissue interactions during photoacoustic imaging

    Science.gov (United States)

    Gould, Taylor; Wang, Quanzeng; Pfefer, T. Joshua

    2014-03-01

    Photoacoustic imaging (PAI) has grown rapidly as a biomedical imaging technique in recent years, with key applications in cancer diagnosis and oximetry. In spite of these advances, the literature provides little insight into thermal tissue interactions involved in PAI. To elucidate these basic phenomena, we have developed, validated, and implemented a three-dimensional numerical model of tissue photothermal (PT) response to repetitive laser pulses. The model calculates energy deposition, fluence distributions, transient temperature and damage profiles in breast tissue with blood vessels and generalized perfusion. A parametric evaluation of these outputs vs. vessel diameter and depth, optical beam diameter, wavelength, and irradiance, was performed. For a constant radiant exposure level, increasing beam diameter led to a significant increase in subsurface heat generation rate. Increasing vessel diameter resulted in two competing effects - reduced mean energy deposition in the vessel due to light attenuation and greater thermal superpositioning due to reduced thermal relaxation. Maximum temperatures occurred either at the surface or in subsurface regions of the dermis, depending on vessel geometry and position. Results are discussed in terms of established exposure limits and levels used in prior studies. While additional experimental and numerical study is needed, numerical modeling represents a powerful tool for elucidating the effect of PA imaging devices on biological tissue.

  2. Morphometric Evaluation of Preeclamptic Placenta Using Light Microscopic Images

    Directory of Open Access Journals (Sweden)

    Rashmi Mukherjee

    2014-01-01

    Full Text Available Deficient trophoblast invasion and anomalies in placental development generally lead to preeclampsia (PE but the inter-relationship between placental function and morphology in PE still remains unknown. The aim of this study was to evaluate the morphometric features of placental villi and capillaries in preeclamptic and normal placentae. The study included light microscopic images of placental tissue sections of 40 preeclamptic and 35 normotensive pregnant women. Preprocessing and segmentation of these images were performed to characterize the villi and capillaries. Fisher’s linear discriminant analysis (FLDA, hierarchical cluster analysis (HCA, and principal component analysis (PCA were applied to identify the most significant placental (morphometric features from microscopic images. A total of 10 morphometric features were extracted, of which the villous parameters were significantly altered in PE. FLDA identified 5 highly significant morphometric features (>90% overall discrimination accuracy. Two large subclusters were clearly visible in HCA based dendrogram. PCA returned three most significant principal components cumulatively explaining 98.4% of the total variance based on these 5 significant features. Hence, quantitative microscopic evaluation revealed that placental morphometry plays an important role in characterizing PE, where the villous is the major component that is affected.

  3. Infrared imaging of LED lighting tubes and fluorescent tubes

    Science.gov (United States)

    Siikanen, Sami; Kivi, Sini; Kauppinen, Timo; Juuti, Mikko

    2011-05-01

    The low energy efficiency of conventional light sources is mainly caused by generation of waste heat. We used infrared (IR) imaging in order to monitor the heating of both LED tube luminaires and ordinary T8 fluorescent tubes. The IR images showed clearly how the surface temperatures of the fluorescent tube ends quickly rose up to about +50...+70°C, whereas the highest surface temperatures seen on the LED tubes were only about +30...+40°C. The IR images demonstrated how the heat produced by the individual LED chips can be efficiently guided to the supporting structure in order to keep the LED emitters cool and hence maintain efficient operation. The consumed electrical power and produced illuminance were also recorded during 24 hour measurements. In order to assess the total luminous efficacy of the luminaires, separate luminous flux measurements were made in a large integrating sphere. The currently available LED tubes showed efficacies of up to 88 lm/W, whereas a standard "cool white" T8 fluorescent tube produced ca. 75 lm/W. Both lamp types gave ca. 110 - 130 lx right below the ceiling-mounted luminaire, but the LED tubes consume only 40 - 55% of the electric power compared to fluorescent tubes.

  4. A fast image registration approach of neural activities in light-sheet fluorescence microscopy images

    Science.gov (United States)

    Meng, Hui; Hui, Hui; Hu, Chaoen; Yang, Xin; Tian, Jie

    2017-03-01

    The ability of fast and single-neuron resolution imaging of neural activities enables light-sheet fluorescence microscopy (LSFM) as a powerful imaging technique in functional neural connection applications. The state-of-art LSFM imaging system can record the neuronal activities of entire brain for small animal, such as zebrafish or C. elegans at single-neuron resolution. However, the stimulated and spontaneous movements in animal brain result in inconsistent neuron positions during recording process. It is time consuming to register the acquired large-scale images with conventional method. In this work, we address the problem of fast registration of neural positions in stacks of LSFM images. This is necessary to register brain structures and activities. To achieve fast registration of neural activities, we present a rigid registration architecture by implementation of Graphics Processing Unit (GPU). In this approach, the image stacks were preprocessed on GPU by mean stretching to reduce the computation effort. The present image was registered to the previous image stack that considered as reference. A fast Fourier transform (FFT) algorithm was used for calculating the shift of the image stack. The calculations for image registration were performed in different threads while the preparation functionality was refactored and called only once by the master thread. We implemented our registration algorithm on NVIDIA Quadro K4200 GPU under Compute Unified Device Architecture (CUDA) programming environment. The experimental results showed that the registration computation can speed-up to 550ms for a full high-resolution brain image. Our approach also has potential to be used for other dynamic image registrations in biomedical applications.

  5. 图像处理在车牌识别技术中的应用%Application of image processing in license plate recognition technique

    Institute of Scientific and Technical Information of China (English)

    刘萌

    2014-01-01

    该课题论述了在车牌识别中运用到的各种数字图像处理技术,经过图像摄取、车牌图像预处理、VLP检测、字符分割、OCR、车牌识别几个过程构成了车牌牌照自动识别系统。图像处理在车牌识别技术中的应用方便了人们的生活。%This paper discusses all kinds of digital image processing technology to use in vehicle license plate recognition,image after ingestion,the license plate image preprocessing,VLP detection,character segmentation,OCR,license plate recognition process consists of automatic recognition system of vehicle license plate.Application of image processing in license plate recognition technique to facilitate people's life.

  6. Imaging of Lesser Metatarsophalangeal Joint Plantar Plate Degeneration, Tear, and Repair.

    Science.gov (United States)

    Linklater, James M; Bird, Stephen J

    2016-04-01

    Plantar plate degeneration and tear is a common cause of forefoot pain, typically involving the second metatarsophalangeal joint at the proximal phalangeal insertion laterally, frequently confused with the second web space Morton neuroma. The condition has received increased attention with the development of surgical techniques that can result in successful repair of the plantar plate and substantial improvement in patient symptoms. High-resolution MRI or ultrasound can confirm a diagnosis of plantar plate degeneration and tear and exclude other pathologies, particularly Morton neuroma. The normal plantar plate is a mildly hyperechoic structure on ultrasound and is hypointense on all conventional MR sequences. Plantar plate degeneration manifests on ultrasound as hypoechoic echotextural change and on MRI as mild signal hyperintensity on short TE sequences, becoming less conspicuous on long TE sequences. Adjacent entheseal bony irregularity is commonly present. Plantar plate tears on ultrasound may be seen as an anechoic cleft defect or area of heterogeneous echotexture, sometimes more conspicuous with dorsiflexion stress. Plantar plate tears demonstrate greater signal hyperintensity on proton-density sequences, becoming more conspicuous on fat-suppressed proton density and T2-weighted sequences. Edema and fibrotic change in the pericapsular fat plane is commonly seen in the setting of an adjacent plantar plate tear and should not be misinterpreted as reflecting a Morton neuroma.

  7. Quantitative Evaluation of Growth Plates around the Knees of Adolescent Soccer Players by Diffusion-Weighted Magnetic Resonance Imaging

    Directory of Open Access Journals (Sweden)

    Zmago Krajnc

    2015-01-01

    Full Text Available Purpose. To quantitatively evaluate growth plates around the knees in adolescent soccer players utilizing the diffusion-weighted MR imaging (DWI. Methods. The knees and adjacent growth plates of eleven 14-year-old male soccer players were evaluated by MRI before (end of season’s summer break and after two months of intense soccer training. MRI evaluation was conducted in coronal plane by PD-FSE and DWI. All images were screened for any major pathological changes. Later, central growth plate surface area (CGPSA was measured and the apparent diffusion coefficient (ADC values were calculated in two most central coronal slices divided into four regions: distal femur medial (DFM, distal femur lateral (DFL, proximal tibia medial (PTM, and proximal tibia lateral (PTL. Results. No gross pathology was diagnosed on MRI. CGPSA was not significantly reduced: DFM 278 versus 272, DFL 265 versus 261, PTM 193 versus 192, and PTL 214 versus 210. ADC decrease was statistically significant only for PTM: DFM 1.27 versus 1.22, DFL 1.37 versus 1.34, PTM 1.13 versus 1.03 (p=0.003, and PTL 1.28 versus 1.22. Conclusions. DWI measurements indicate increased cellularity in growth plates around knees in footballers most prominent in PTM after intense training. No detectable differences on a standard PD-FSE sequence were observed.

  8. Hexabundles: imaging fibre arrays for low-light astronomical applications

    DEFF Research Database (Denmark)

    Bland-Hawthorn, Joss; Bryant, Julie; Robertson, Gordon

    2010-01-01

    We demonstrate for the first time an imaging fibre bundle (“hexabundle”) that is suitable for low-light applications in astronomy. The most successful survey instruments at optical-infrared wavelengths today have obtained data on up to a million celestial sources using hundreds of multimode fibres...... at a time fed to multiple spectrographs. But a large fraction of these sources are spatially extended on the celestial sphere such that a hexabundle would be able to provide spectroscopic information at many distinct locations across the source. Our goal is to upgrade single-fibre survey instruments...... with multimode hexabundles in place of the multimode fibres. We discuss two varieties of hexabundles: (i) closely packed circular cores allowing the covering fraction to approach the theoretical maximum of 91%; (ii) fused noncircular cores where the interstitial holes have been removed and the covering fraction...

  9. Biomass estimator for NIR image with a few additional spectral band images taken from light UAS

    Science.gov (United States)

    Pölönen, Ilkka; Salo, Heikki; Saari, Heikki; Kaivosoja, Jere; Pesonen, Liisa; Honkavaara, Eija

    2012-05-01

    A novel way to produce biomass estimation will offer possibilities for precision farming. Fertilizer prediction maps can be made based on accurate biomass estimation generated by a novel biomass estimator. By using this knowledge, a variable rate amount of fertilizers can be applied during the growing season. The innovation consists of light UAS, a high spatial resolution camera, and VTT's novel spectral camera. A few properly selected spectral wavelengths with NIR images and point clouds extracted by automatic image matching have been used in the estimation. The spectral wavelengths were chosen from green, red, and NIR channels.

  10. High resolution image of the Lithosphere-Asthenosphere Boundary of the subducting Nazca plate beneath northern Chile

    Science.gov (United States)

    Sodoudi, F.; Yuan, X.; Asch, G.; Kind, R.

    2010-12-01

    Results obtained from S and P receiver functions produced a clear image of the top and bottom of the subducting Nazca lithosphere beneath northern Chile. Using data from the teleseismic events recorded at 15 permanent IPOC (Integrated Plate boundary Observatory Chile) stations, we were able to obtain new constraints on the shape and thickness of the descending Nazca lithosphere. We observed the subducted crust of the Nazca plate at depths ranging from 40 km beneath the Coastal Cordillera down to 110 km beneath the Western Cordillera. We found significant along-strike variations in the geometry of the Nazca plate beneath northern Chile. On closer inspection, it appears that the oceanic Nazca plate is divided into two distinct segments as it descends beneath the continental South American plate. The transition from the relatively steeper and deeper slab to the north of 21° S to the flatter southern segment is shown reasonably clearly by our data. This feature could well be associated with variations in the curvature of the plate margin and the geometry of the Chile trench, which is mainly curved to the north of 21° S. We have also mapped the continental Moho of the South American plate at depths ranging between 60-70 km to the east of the Longitudinal Valley. Beneath the Coastal Cordillera, this boundary becomes invisible, probably due to the serpentinization of the forearc mantle wedge. The Lithosphere-Astheonsphere Boundary (LAB) of the subducted Nazca plate was clearly identified as a sharp boundary in the results obtained from the P and S receiver functions. The LAB lies at a depth of 80 km beneath the coastal area and dips from a depth of 100 km beneath the Coastal Cordillera to about 150 km underneath the Western Cordillera. High frequency PRF data enabled us to make confident estimates of the top and bottom of the Nazca lithosphere, which results in a lithospheric thickness of 57-60 km. In relation to the age of the Nazca plate, which is assumed to be ~ 50

  11. Determining the fibrillar orientation of bast fibres with polarized light microscopy: the modified Herzog test (red plate test) explained.

    Science.gov (United States)

    Haugan, E; Holst, B

    2013-11-01

    The identification of bast fibre samples, in particular, bast fibres used in textiles, is an important issue in archaeology, criminology and other scientific fields. One of the characteristic features of bast fibres is their fibrillar orientation, referred to as Z- or S twist (or alternatively right- and left-handed fibres). An empirical test for determining the fibrillar orientation using polarized light microscopy has been known in the community for many years. It is referred to as the modified Herzog test or red plate test. The test has the reputation for never producing false results, but also for occasionally not working. However, so far, no proper justification has been provided in the literature that the 'no false results' assumption is really correct and it has also not been clear up till now, why the method sometimes does not work. In this paper, we present an analytical model for the modified Herzog test, which explains why the test never gives a false result. We also provide an explanation for why the Herzog test sometimes does not work: According to our model, the Herzog test will not work if none of the three distinct layers in the secondary cell wall is significantly thicker than the others.

  12. Determining the fibrillar orientation of bast fibres with polarized light microscopy: the modified Herzog test (red plate test) explained

    Science.gov (United States)

    HAUGAN, E; HOLST, B

    2013-01-01

    The identification of bast fibre samples, in particular, bast fibres used in textiles, is an important issue in archaeology, criminology and other scientific fields. One of the characteristic features of bast fibres is their fibrillar orientation, referred to as Z- or S twist (or alternatively right- and left-handed fibres). An empirical test for determining the fibrillar orientation using polarized light microscopy has been known in the community for many years. It is referred to as the modified Herzog test or red plate test. The test has the reputation for never producing false results, but also for occasionally not working. However, so far, no proper justification has been provided in the literature that the ‘no false results’ assumption is really correct and it has also not been clear up till now, why the method sometimes does not work. In this paper, we present an analytical model for the modified Herzog test, which explains why the test never gives a false result. We also provide an explanation for why the Herzog test sometimes does not work: According to our model, the Herzog test will not work if none of the three distinct layers in the secondary cell wall is significantly thicker than the others. PMID:24020614

  13. Mapping cardiac surface mechanics with structured light imaging.

    Science.gov (United States)

    Laughner, Jacob I; Zhang, Song; Li, Hao; Shao, Connie C; Efimov, Igor R

    2012-09-15

    Cardiovascular disease often manifests as a combination of pathological electrical and structural heart remodeling. The relationship between mechanics and electrophysiology is crucial to our understanding of mechanisms of cardiac arrhythmias and the treatment of cardiac disease. While several technologies exist for describing whole heart electrophysiology, studies of cardiac mechanics are often limited to rhythmic patterns or small sections of tissue. Here, we present a comprehensive system based on ultrafast three-dimensional (3-D) structured light imaging to map surface dynamics of whole heart cardiac motion. Additionally, we introduce a novel nonrigid motion-tracking algorithm based on an isometry-maximizing optimization framework that forms correspondences between consecutive 3-D frames without the use of any fiducial markers. By combining our 3-D imaging system with nonrigid surface registration, we are able to measure cardiac surface mechanics at unprecedented spatial and temporal resolution. In conclusion, we demonstrate accurate cardiac deformation at over 200,000 surface points of a rabbit heart recorded at 200 frames/s and validate our results on highly contrasting heart motions during normal sinus rhythm, ventricular pacing, and ventricular fibrillation.

  14. Imaging and dynamics of light atoms and molecules on graphene.

    Science.gov (United States)

    Meyer, Jannik C; Girit, C O; Crommie, M F; Zettl, A

    2008-07-17

    Observing the individual building blocks of matter is one of the primary goals of microscopy. The invention of the scanning tunnelling microscope revolutionized experimental surface science in that atomic-scale features on a solid-state surface could finally be readily imaged. However, scanning tunnelling microscopy has limited applicability due to restrictions in, for example, sample conductivity, cleanliness, and data acquisition rate. An older microscopy technique, that of transmission electron microscopy (TEM), has benefited tremendously in recent years from subtle instrumentation advances, and individual heavy (high-atomic-number) atoms can now be detected by TEM even when embedded within a semiconductor material. But detecting an individual low-atomic-number atom, for example carbon or even hydrogen, is still extremely challenging, if not impossible, via conventional TEM owing to the very low contrast of light elements. Here we demonstrate a means to observe, by conventional TEM, even the smallest atoms and molecules: on a clean single-layer graphene membrane, adsorbates such as atomic hydrogen and carbon can be seen as if they were suspended in free space. We directly image such individual adatoms, along with carbon chains and vacancies, and investigate their dynamics in real time. These techniques open a way to reveal dynamics of more complex chemical reactions or identify the atomic-scale structure of unknown adsorbates. In addition, the study of atomic-scale defects in graphene may provide insights for nanoelectronic applications of this interesting material.

  15. Trabecular bone characterization on the continuum of plates and rods using in vivo MR imaging and volumetric topological analysis.

    Science.gov (United States)

    Chen, Cheng; Jin, Dakai; Liu, Yinxiao; Wehrli, Felix W; Chang, Gregory; Snyder, Peter J; Regatte, Ravinder R; Saha, Punam K

    2016-09-21

    Osteoporosis is associated with increased risk of fractures, which is clinically defined by low bone mineral density. Increasing evidence suggests that trabecular bone (TB) micro-architecture is an important determinant of bone strength and fracture risk. We present an improved volumetric topological analysis algorithm based on fuzzy skeletonization, results of its application on in vivo MR imaging, and compare its performance with digital topological analysis. The new VTA method eliminates data loss in the binarization step and yields accurate and robust measures of local plate-width for individual trabeculae, which allows classification of TB structures on the continuum between perfect plates and rods. The repeat-scan reproducibility of the method was evaluated on in vivo MRI of distal femur and distal radius, and high intra-class correlation coefficients between 0.93 and 0.97 were observed. The method's ability to detect treatment effects on TB micro-architecture was examined in a 2 years testosterone study on hypogonadal men. It was observed from experimental results that average plate-width and plate-to-rod ratio significantly improved after 6 months and the improvement was found to continue at 12 and 24 months. The bone density of plate-like trabeculae was found to increase by 6.5% (p  =  0.06), 7.2% (p  =  0.07) and 16.2% (p  =  0.003) at 6, 12, 24 months, respectively. While the density of rod-like trabeculae did not change significantly, even at 24 months. A comparative study showed that VTA has enhanced ability to detect treatment effects in TB micro-architecture as compared to conventional method of digital topological analysis for plate/rod characterization in terms of both percent change and effect-size.

  16. Image quality improvement by the structured light illumination method in an optical readout cantilever array infrared imaging system.

    Science.gov (United States)

    Feng, Yun; Zhao, Yuejin; Liu, Ming; Dong, Liquan; Yu, Xiaomei; Kong, Lingqin; Ma, Wei; Liu, Xiaohua

    2015-04-01

    The structured light illumination method is applied in an optical readout uncooled infrared imaging system to improve the IR image quality. The unavoidable nonuniform distribution of the initial bending angles of the bimaterial cantilever pixels in the focal plane array (FPA) can be well compensated by this method. An ordinary projector is used to generate structured lights of different intensity distribution. The projected light is divided into patches of rectangular regions, and the brightness of each region can be set automatically according to the deflection angles of the FPA and the light intensity focused on the imaging plane. By this method, the FPA image on the CCD plane can be much more uniform and the image quality of the IR target improved significantly. A comparative experiment is designed to verify the effectiveness. The theoretical analysis and experimental results show that the proposed structured light illumination method outperforms the conventional one, especially when it is difficult to perfect the FPA fabrication.

  17. Radiation imaging system

    Energy Technology Data Exchange (ETDEWEB)

    Bobbitt, III, John T.; Immel, David M.; Folsom, Matthew D.; Plummer, Jean R.; Serrato, Michael G.

    2016-06-28

    A radiation imaging system includes a casing and a camera disposed inside the casing. A first field of view through the casing exposes the camera to light from outside of the casing. An image plate is disposed inside the casing, and a second field of view through the casing to the image plate exposes the image plate to high-energy particles produced by a radioisotope outside of the casing. An optical reflector that is substantially transparent to the high-energy particles produced by the radioisotope is disposed with respect to the camera and the image plate to reflect light to the camera and to allow the high-energy particles produced by the radioisotope to pass through the optical reflector to the image plate.

  18. Radiation imaging system

    Energy Technology Data Exchange (ETDEWEB)

    Immel, David M.; Bobbit, III, John T.; Plummer, Jean R.; Folsom, Matthew D.; Serrato, Michael G.

    2016-03-22

    A radiation imaging system includes a casing and a camera disposed inside the casing. A first field of view through the casing exposes the camera to light from outside of the casing. An image plate is disposed inside the casing, and a second field of view through the casing to the image plate exposes the image plate to high-energy particles produced by a radioisotope outside of the casing. An optical reflector that is substantially transparent to the high-energy particles produced by the radioisotope is disposed with respect to the camera and the image plate to reflect light to the camera and to allow the high-energy particles produced by the radioisotope to pass through the optical reflector to the image plate.

  19. Ultra-high resolution of radiocesium distribution detection based on Cherenkov light imaging

    Energy Technology Data Exchange (ETDEWEB)

    Yamamoto, Seiichi, E-mail: s-yama@met.nagoya-u.ac.jp [Department of Radiological and Medical Laboratory Sciences, Nagoya University Graduate School of Medicine (Japan); Ogata, Yoshimune [Department of Radiological and Medical Laboratory Sciences, Nagoya University Graduate School of Medicine (Japan); Kawachi, Naoki; Suzui, Nobuo; Yin, Yong-Gen; Fujimaki, Shu [Radiotracer Imaging Group, Japan Atomic Energy Agency (Japan)

    2015-03-21

    After the nuclear disaster in Fukushima, radiocesium contamination became a serious scientific concern and research of its effects on plants increased. In such plant studies, high resolution images of radiocesium are required without contacting the subjects. Cherenkov light imaging of beta radionuclides has inherently high resolution and is promising for plant research. Since {sup 137}Cs and {sup 134}Cs emit beta particles, Cherenkov light imaging will be useful for the imaging of radiocesium distribution. Consequently, we developed and tested a Cherenkov light imaging system. We used a high sensitivity cooled charge coupled device (CCD) camera (Hamamatsu Photonics, ORCA2-ER) for imaging Cherenkov light from {sup 137}Cs. A bright lens (Xenon, F-number: 0.95, lens diameter: 25 mm) was mounted on the camera and placed in a black box. With a 100-μm {sup 137}Cs point source, we obtained 220-μm spatial resolution in the Cherenkov light image. With a 1-mm diameter, 320-kBq {sup 137}Cs point source, the source was distinguished within 2-s. We successfully obtained Cherenkov light images of a plant whose root was dipped in a {sup 137}Cs solution, radiocesium-containing samples as well as line and character phantom images with our imaging system. Cherenkov light imaging is promising for the high resolution imaging of radiocesium distribution without contacting the subject.

  20. Correcting incompatible DN values and geometric errors in nighttime lights time series images

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Naizhuo [Texas Tech Univ., Lubbock, TX (United States); Zhou, Yuyu [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Samson, Eric L. [Mayan Esteem Project, Farmington, CT (United States)

    2014-09-19

    The Defense Meteorological Satellite Program’s Operational Linescan System (DMSP-OLS) nighttime lights imagery has proven to be a powerful remote sensing tool to monitor urbanization and assess socioeconomic activities at large scales. However, the existence of incompatible digital number (DN) values and geometric errors severely limit application of nighttime light image data on multi-year quantitative research. In this study we extend and improve previous studies on inter-calibrating nighttime lights image data to obtain more compatible and reliable nighttime lights time series (NLT) image data for China and the United States (US) through four steps: inter-calibration, geometric correction, steady increase adjustment, and population data correction. We then use gross domestic product (GDP) data to test the processed NLT image data indirectly and find that sum light (summed DN value of pixels in a nighttime light image) maintains apparent increase trends with relatively large GDP growth rates but does not increase or decrease with relatively small GDP growth rates. As nighttime light is a sensitive indicator for economic activity, the temporally consistent trends between sum light and GDP growth rate imply that brightness of nighttime lights on the ground is correctly represented by the processed NLT image data. Finally, through analyzing the corrected NLT image data from 1992 to 2008, we find that China experienced apparent nighttime lights development in 1992-1997 and 2001-2008 respectively and the US suffered from nighttime lights decay in large areas after 2001.

  1. Image fusion based on nonsubsampled contourlet transform for infrared and visible light image

    Science.gov (United States)

    Adu, Jianhua; Gan, Jianhong; Wang, Yan; Huang, Jian

    2013-11-01

    In this paper, a new method based on nonsubsampled contourlet transform (NSCT) is proposed to fuse the infrared image and the visible light image, which will produce a new fused image by which the target can be identified more easily. Firstly, two original images were decomposed into low frequency subband coefficients and the bandpass direction subband coefficients by using NSCT. Secondly, the selection of the low frequency subband coefficient and the bandpass direction subband coefficient is discussed in detail. The low frequency subband coefficients are selected based on the regional visual characteristics. For the selection of bandpass direction subband coefficients, this paper proposes a minimum regional cross-gradient method, and the cross-gradient is gained by calculating the gradient between the pixel of bandpass subbands and the adjacent pixel in the fused image of the low-frequency components. Comparison experiments have been performed on different image sets, and experimental results demonstrate that the proposed method performs better in both subjective and objective qualities.

  2. Establishing a Customized Guide Plate for Osteotomy in Total Knee Arthroplasty Using Lower-extremity X-ray and Knee Computed Tomography Images

    Directory of Open Access Journals (Sweden)

    Jin Zhang

    2016-01-01

    Conclusions: A customized guide plate to create an accurate osteotomy in TKAs may be created using lower-extremity X-ray and knee CT images. This allows for shorter operative times and better postoperative alignment than the traditional surgery. Application of the digital guide plate may also result in better short-term outcomes.

  3. High-Power, Computer-Controlled, Light-Emitting Diode–Based Light Sources for Fluorescence Imaging and Image-Guided Surgery

    Directory of Open Access Journals (Sweden)

    Sylvain Gioux

    2009-05-01

    Full Text Available Optical imaging requires appropriate light sources. For image-guided surgery, in particular fluorescence-guided surgery, a high fluence rate, a long working distance, computer control, and precise control of wavelength are required. In this article, we describe the development of light-emitting diode (LED-based light sources that meet these criteria. These light sources are enabled by a compact LED module that includes an integrated linear driver, heat dissipation technology, and real-time temperature monitoring. Measuring only 27 mm wide by 29 mm high and weighing only 14.7 g, each module provides up to 6,500 lx of white (400–650 nm light and up to 157 mW of filtered fluorescence excitation light while maintaining an operating temperature ≤ 50°C. We also describe software that can be used to design multimodule light housings and an embedded processor that permits computer control and temperature monitoring. With these tools, we constructed a 76-module, sterilizable, three-wavelength surgical light source capable of providing up to 40,000 lx of white light, 4.0 mW/cm2 of 670 nm near-infrared (NIR fluorescence excitation light, and 14.0 mW/cm2 of 760 nm NIR fluorescence excitation light over a 15 cm diameter field of view. Using this light source, we demonstrated NIR fluorescence–guided surgery in a large-animal model.

  4. Retinal vascular calibre and response to light exposure and serial imaging

    DEFF Research Database (Denmark)

    von Hanno, T.; Sjølie, Anne K.; Mathiesen, E. B.

    2014-01-01

    and vein equivalents (CRAE and CRVE). Outcome measures were difference in calibres after prior light versus prior dark exposure and difference in calibre during each of the two imaging sequences. Results: CRVE was wider with prior light exposure (2.7%, p = 0.0001), comparing the first image in each image......Purpose: To investigate whether retinal vessel calibre measurements on optical retinal photography are affected by light and dark exposure prior to photography and whether the vessel calibre changes during an imaging sequence of several images. Methods: Digital optical retinal photographs were...... obtained from 32 healthy adults in two separate image sequences of six images during 1 min; one sequence with 10 min of dark exposure and one with 10 min of light exposure prior to imaging. Retinal arteriolar and venular calibres were measured computer-assisted and summarized as central retinal artery...

  5. Alaska Megathrust 2: Imaging the megathrust zone and Yakutat/Pacific plate interface in the Alaska subduction zone

    Science.gov (United States)

    Kim, YoungHee; Abers, Geoffrey A.; Li, Jiyao; Christensen, Douglas; Calkins, Josh; Rondenay, Stéphane

    2014-03-01

    We image the slab underneath a 450 km long transect of the Alaska subduction zone to investigate (1) the geometry and velocity structure of the downgoing plate and their relationship to slab seismicity and (2) the interplate coupled zone where the great 1964 earthquake (Mw 9.2) exhibited the largest amount of rupture. The joint teleseismic migration of two array data sets based on receiver functions (RFs) reveals a prominent, shallow-dipping low-velocity layer at ~25-30 km depth in southern Alaska. Modeling of RF amplitudes suggests the existence of a thin layer (Vs of ~2.1-2.6 km/s) that is ~20-40% slower than underlying oceanic crustal velocities, and is sandwiched between the subducted slab and the overriding plate. The observed megathrust layer (with Vp/Vs of 1.9-2.3) may be due to a thick sediment input from the trench in combination with elevated pore fluid pressure in the channel. Our image also includes an unusually thick low-velocity crust subducting with a ~20° dip down to 130 km depth at ~200 km inland beneath central Alaska. The unusual nature of this subducted segment results from the subduction of the Yakutat terrane crust. Our imaged western edge of the Yakutat terrane aligns with the western end of a geodetically locked patch with high slip deficit, and coincides with the boundary of aftershock events from the 1964 earthquake. It appears that this sharp change in the nature of the downgoing plate could control the slip distribution of great earthquakes on this plate interface.

  6. Single Photon Counting Detectors for Low Light Level Imaging Applications

    Science.gov (United States)

    Kolb, Kimberly

    2015-10-01

    moderate to high flux rates where dark noise and CIC are insignificant noise sources. Research into decreasing the dark count rate of GM-APDs will lead to development of imaging arrays that are competitive for low light level imaging and spectroscopy applications in the near future.

  7. Automatic Boat Identification System for VIIRS Low Light Imaging Data

    Directory of Open Access Journals (Sweden)

    Christopher D. Elvidge

    2015-03-01

    Full Text Available The ability for satellite sensors to detect lit fishing boats has been known since the 1970s. However, the use of the observations has been limited by the lack of an automatic algorithm for reporting the location and brightness of offshore lighting features arising from boats. An examination of lit fishing boat features in Visible Infrared Imaging Radiometer Suite (VIIRS day/night band (DNB data indicates that the features are essentially spikes. We have developed a set of algorithms for automatic detection of spikes and characterization of the sharpness of spike features. A spike detection algorithm generates a list of candidate boat detections. A second algorithm measures the height of the spikes for the discard of ionospheric energetic particle detections and to rate boat detections as either strong or weak. A sharpness index is used to label boat detections that appear blurry due to the scattering of light by clouds. The candidate spikes are then filtered to remove features on land and gas flares. A validation study conducted using analyst selected boat detections found the automatic algorithm detected 99.3% of the reference pixel set. VIIRS boat detection data can provide fishery agencies with up-to-date information of fishing boat activity and changes in this activity in response to new regulations and enforcement regimes. The data can provide indications of illegal fishing activity in restricted areas and incursions across Exclusive Economic Zone (EEZ boundaries. VIIRS boat detections occur widely offshore from East and Southeast Asia, South America and several other regions.

  8. Coding/decoding two-dimensional images with orbital angular momentum of light.

    Science.gov (United States)

    Chu, Jiaqi; Li, Xuefeng; Smithwick, Quinn; Chu, Daping

    2016-04-01

    We investigate encoding and decoding of two-dimensional information using the orbital angular momentum (OAM) of light. Spiral phase plates and phase-only spatial light modulators are used in encoding and decoding of OAM states, respectively. We show that off-axis points and spatial variables encoded with a given OAM state can be recovered through decoding with the corresponding complimentary OAM state.

  9. Three-contrast, metal test pattern (Snellen E-plate) in evaluation of imaging techniques in clinical chest radiography

    Energy Technology Data Exchange (ETDEWEB)

    Manninen, H.

    A metal test pattern based on a minified Snellen-type E-plate was evaluated in testing six imaging techniques for chest radiography. The device consisted of three contrast zones and it was attached to the patient's back over the right lung during chest radiography. The values for visual detectability of the E-figures were compared with the film scores obtained by grading the radiographs with respect to visibility of diagnostically important anatomic details. The test plate proved to be a simple, quick and reproducible tool for testing several imaging techniques at the same time. The E-plate results were similar to those of the visual grading analysis in most respects. A few discrepancies existed, which were probably due to the inability of the test pattern to fully consider the effect of motion unsharpness and varying scattering conditions within the human thorax, as well as to great differences in roentgen ray absorption properties between Au and tissues. (orig.).

  10. High-resolution Imaging of the Philippine Sea Plate subducting beneath Central Japan

    Science.gov (United States)

    Padhy, S.; Furumura, T.

    2016-12-01

    Thermal models predict that the oceanic crust of the young (PHP) is more prone to melting. Deriving a high-resolution image of the PHP, including slab melting and other features of the subduction zone, is a key to understand the basics of earthquake occurrence and origin of magma in complex subduction zone like central Japan, where both the PHP and Pacific (PAC) Plates subduct. To this purpose, we analyzed high-resolution waveforms of moderate sized (M 4-6), intermediate-to-deep (>150 km) PAC earthquakes occurring in central Japan and conducted numerical simulation to derive a fine-scale PHP model, which is not constrained in earlier studies. Observations show spindle-shaped seismograms with strong converted phases and extended coda with very slow decay from a group of PAC events occurring in northern part of central Japan and recorded by high-sensitivity seismograph network (Hi-net) stations in the region. We investigate the mechanism of propagation of these anomalous waveforms using the finite difference method (FDM) simulation of wave propagation through the subduction zone. We examine the effects on waveform changes of major subduction zone features, such as the melting of oceanic crust in PHP, serpentinized mantle wedge, hydrated layer on the PAC due to slab dehydration, and anomaly in upper mantle between the PAC and PHP. Simulation results show that the waveform anomaly is primarily explained by strong scattering and absorption of high-frequency energy by the low-velocity anomalous mantle structure, with a strong coda excitation yielding spindle-shaped waveforms. The data are secondarily explained by melting of PHP in the basaltic crust. The location of the mantle anomaly is tightly constrained by the observation and evidence of PAC thinning in the region; these localized low-velocity structures aid in ascending the slab-derived fluids around the slab thinning. We expect that the results of this study will enhance our present understanding on the mechanism

  11. High energy muon induced radioactive nuclides in nickel plate and its use for 2-D muon-beam image profile

    Energy Technology Data Exchange (ETDEWEB)

    Kurebayashi, Y. [Graduate School of Science and Engineering, Yamagata University, Yamagata 990-8560 (Japan); Sakurai, H., E-mail: sakurail@sci.kj.yamagata-u.ac.jp [Department of Physics, Yamagata University, 1-4-12 Kojirakawa, Yamagata 990-8560 (Japan); Takahashi, Y. [Graduate School of Science and Engineering, Yamagata University, Yamagata 990-8560 (Japan); Doshita, N. [Department of Physics, Yamagata University, 1-4-12 Kojirakawa, Yamagata 990-8560 (Japan); Kikuchi, S. [Graduate School of Science and Engineering, Yamagata University, Yamagata 990-8560 (Japan); Tokanai, F. [Department of Physics, Yamagata University, 1-4-12 Kojirakawa, Yamagata 990-8560 (Japan); Horiuchi, K. [Graduate School of Science and Technology, Hirosaki University, 3, Bunkyo-chou, Hirosaki 036-8561, Aomori (Japan); Tajima, Y. [Institute of Arts and Sciences, Yamagata University, 1-4-12 Kojirakawa, Yamagata 990-8560 (Japan); Oe, T. [Department of Physics, Yamagata University, 1-4-12 Kojirakawa, Yamagata 990-8560 (Japan); Sato, T. [Graduate School of Science and Engineering, Yamagata University, Yamagata 990-8560 (Japan); Gunji, S. [Department of Physics, Yamagata University, 1-4-12 Kojirakawa, Yamagata 990-8560 (Japan); Inui, E. [Faculty of Science, Yamagata University, 1-4-12 Kojirakawa, Yamagata 990-8560 (Japan); Kondo, K. [Department of Physics, Yamagata University, 1-4-12 Kojirakawa, Yamagata 990-8560 (Japan); Iwata, N. [Dept. of Earth and Environmental Science, Yamagata University, 1-4-12 Kojirakawa, Yamagata 990-8560 (Japan); Sasaki, N. [Graduate School of Science and Technology, Hirosaki University, 3, Bunkyo-chou, Hirosaki 036-8561, Aomori (Japan); Matsuzaki, H. [Micro Analysis Laboratory, Tandem accelerator (MALT), The University Museum, The University of Tokyo, 2-11-16, Yayoi, Bunkyo-ku, Tokyo 113-0032 (Japan); Kunieda, S. [Nuclear Data Center, Japan Atomic Energy Agency, Tokai-mura, Naka-gun 319-1195, Ibaraki (Japan)

    2015-11-01

    Target materials were exposed to a muon beam with an energy of 160 GeV/c at the COMPASS experiment line in CERN-SPS to measure the production cross-sections for muon-induced radionuclides. A muon imager containing four nickel plates, each measuring 100 mm×100 mm, exposed to the IP plate successfully detected the muon beam image during an irradiation period of 33 days. The contrasting density rate of the nickel plate was (5.2±0.7)×10{sup –9} PSL/muon per one-day exposure to IP. The image measured 122 mm and 174 mm in horizontal and vertical lengths, respectively, in relation to the surface of the base, indicating that 50±6% of the muon beam flux is confined to an area of 18% of the whole muon beam. The number of muons estimated from the PSL value in the total beam image area (0.81±0.1)×10{sup 13} was comparable to the total muon counts of the ion-chamber at the M2 beam line in the CERN-SPS. The production cross-sections of Cr-51, Mn-54, Co-56, Co-57, and Co-58 in nickel were 0.19±0.08, 0.34±0.06, 0.5±0.05, 3.44±0.07, 0.4±0.03 in the unit of mb, respectively, reducing muon associated particles effects. They are approximately 10 times smaller than that a proceeding study by Heisinger et al.

  12. Image-based ELISA on an activated polypropylene microtest plate--a spectrophotometer-free low cost assay technique.

    Science.gov (United States)

    Parween, Shahila; Nahar, Pradip

    2013-10-15

    In this communication, we report ELISA technique on an activated polypropylene microtest plate (APPµTP) as an illustrative example of a low cost diagnostic assay. Activated test zone in APPµTP binds a capture biomolecule through covalent linkage thereby, eliminating non-specific binding often prevalent in absorption based techniques. Efficacy of APPµTP is demonstrated by detecting human immunoglobulin G (IgG), human immunoglobulin E (IgE) and Aspergillus fumigatus antibody in patient's sera. Detection is done by taking the image of the assay solution by a desktop scanner and analyzing the color of the image. Human IgE quantification by color saturation in the image-based assay shows excellent correlation with absorbance-based assay (Pearson correlation coefficient, r=0.992). Significance of the relationship is seen from its p value which is 4.087e-11. Performance of APPµTP is also checked with respect to microtiter plate and paper-based ELISA. APPµTP can quantify an analyte as precisely as in microtiter plate with insignificant non-specific binding, a necessary prerequisite for ELISA assay. In contrast, paper-ELISA shows high non-specific binding in control sera (false positive). Finally, we have carried out ELISA steps on APPµTP by ultrasound waves on a sonicator bath and the results show that even in 8 min, it can convincingly differentiate a test sample from a control sample. In short, spectrophotometer-free image-based miniaturized ELISA on APPµTP is precise, reliable, rapid, and sensitive and could be a good substitute for conventional immunoassay procedures widely used in clinical and research laboratories.

  13. Experience of the Indirect Neutron Radiography Method Based on the X-ray Imaging Plate at CARR

    Science.gov (United States)

    Wei, Guohai; Han, Songbai; Wang, Hongli; He, Linfeng; Wang, Yu; Wu, Meimei; Liu, Yuntao; Chen, Dongfeng

    Indirect neutron radiography (INR) experiments by X-ray imaging plate were carried out at the China Advanced Research Reactor (CARR). The key experiment parameters were optimized, especially the exposure time of the neutron converter andimaging plate. The optimized total exposure time is 37.25 min, it is two-fifths of the timebased on the film method under the same experimental conditions. The qualitative and quantitativeinspections were tested with dummy nuclear fuel rods and a water temperaturesensor ofa motor vehicle. The spring in the sensor and the defects of the dummy fuel rod's pellets can be qualitatively detected. The thickness of the tape at one position on the cladding of the dummy nuclear fuel rodwas quantitatively calculated to be 9.57 layers with the relative error of ±4.3%.

  14. Comparing Saddle, Slotted-tube and Parallel-plate Coils for Magnetic Resonance Imaging

    Directory of Open Access Journals (Sweden)

    Nespor D.

    2014-06-01

    Full Text Available The paper is concerned with a comparison of the properties of RF coils of three configurations for MRI measurements on small animals. In comparison with the classical saddle coil the proposed modification of slotted-tube coil exhibits identical homogeneity of B1 field in a larger space. The parallel-plate coil has a satisfactory homogeneity of B1 field over the whole internal space. The signal-to-noise ratio measured for all three coils is roughly the same and is given by the magnitude of RF pre-amplifier noise. As the slotted-tube and parallel-plate coils have a lower inductance compared with the saddle coil, they can be tuned to resonance on the 200 MHz frequency even at larger dimensions. The results show that the parallel-plate coil has very good properties for the measurement of small animals.

  15. Application of Image Processing in License Plate Identification%图像处理在车牌识别中的运用

    Institute of Scientific and Technical Information of China (English)

    姚兆楠

    2014-01-01

    License plate identification is to point to license plate characters extracted from vehicle image information by computer vision, image processing and pattern identification method. License plate identification can be divided into three parts:license plate location,character division and character identification. Realizing each part by using MATLAB software program and finally identify the license plate.%车牌识别是指通过计算机视觉、图像处理与模式识别能方法从车辆图像中提取车牌字符信息,从而确定车辆的身份。车牌识别分为车牌定位、字符分割、字符识别三大部分。采用MATLAB软件编程来实现每一个部分,最后识别出汽车牌照。

  16. Multi-pass light amplification for tomographic particle image velocimetry applications

    NARCIS (Netherlands)

    Ghaemi, S.; Scarano, F.

    2010-01-01

    The light source budget is a critical issue for tomographic particle image velocimetry (Tomo-PIV) systems due to its requirement for large illuminated volume and imaging at small apertures. In this work, a light amplification system based on the multi-pass concept is investigated for Tomo-PIV applic

  17. Magnetic field distribution in the presence of paramagnetic plates in magnetic resonance imaging: a combined numerical and experimental study.

    Science.gov (United States)

    Mertens, Philipp; Machann, Juergen; Mueller-Bierl, Bernd; Steidle, Guenter; Bellemann, Matthias E; Schick, Fritz

    2008-05-01

    The amount and geometric distribution of paramagnetic components in tissue is considered as the basis of T2*-weighted magnetic resonance imaging (MRI). Such techniques are routinely applied for assessment of iron in parenchymal organs such as the liver (hemosiderosis). Furthermore, susceptibility sensitive MRI is discussed as an alternative method to x-ray techniques for quantitative assessment of paramagnetic spongy bone components in patients with osteoporosis. The presented work is dedicated to systematically examining the possible influences of macroscopic arrangements of paramagnetic plates on the magnetic field. In a theoretical approach magnetic field distribution was simulated applying decomposition of the plates in single dipoles. Plate size and distances between parallel plates, as well as plate orientation with respect to the static field, were varied for these numerical simulations. Experiments on corresponding plate arrangements were carried out on a 3 T whole body MR scanner using the field-sensitive MR sequence technique for B0 field mapping. Further examinations were carried out on a bone preparation of the femur, where T2* maps were measured and analyzed on a pixel-by-pixel basis at two orientations with respect to the static field. A series of experiments were performed using isotropic and anisotropic volume elements in three-dimensional gradient echo sequences. Resulting magnetic field distributions in the experimentally recorded B0 field maps were in good agreement with the numerical simulations. Field distortions dominated in areas close to the plates and especially near the edges. Those areas showed strong local field gradients, leading to pronounced signal dephasing effects. The examination of the bone preparations revealed different T2* values for identical regions in the bone when the orientation of the bone or the pixel geometry was changed with respect to the magnetic field. Those effects amounted to nearly 70% (22.9 ms versus 13.6 ms in

  18. Direct Imaging of Single Plasmonic Metal Nanoparticles in Capillary with Laser Light-Sheet Scattering Imaging.

    Science.gov (United States)

    Cao, Xuan; Feng, Jingjing; Pan, Qi; Xiong, Bin; He, Yan; Yeung, Edward S

    2017-03-07

    Understanding the heterogeneous distribution of the physical and chemical properties of plasmonic metal nanoparticles is fundamentally important to their basic and applied research. Traditionally, they are obtained either indirectly via bulk spectroscopic measurements plus electron microscopic characterizations or through single molecule/particle imaging of nanoparticles immobilized on planar substrates. In this study, by using light-sheet scattering microscopy with a supercontinuum white laser, highly sensitive imaging of individual metal nanoparticles (MNPs) flowing inside a capillary, driven by either pressure or electric field, was achieved for the first time. We demonstrate that single plasmonic nanoparticles with different size or chemical modification could be differentiated through their electrophoretic mobility in a few minutes. This technique could potentially be applied to high throughput characterization and evaluation of single metal nanoparticles as well as their dynamic interactions with various local environments.

  19. Multiple damage identification and imaging in an aluminum plate using effective Lamb wave response automatic extraction technology

    Science.gov (United States)

    Ouyang, Qinghua; Zhou, Li; Liu, Xiaotong

    2016-04-01

    In order to identify multiple damage in the structure, a method of multiple damage identification and imaging based on the effective Lamb wave response automatic extraction algorithm is proposed. In this method, the detected key area in the structure is divided into a number of subregions, and then, the effective response signals including the structural damage information are automatically extracted from the entire Lamb wave responses which are received by the piezoelectric sensors. Further, the damage index values of every subregion based on the correlation coefficient are calculated using the effective response signals. Finally, the damage identification and imaging are performed using the reconstruction algorithm for probabilistic inspection of damage (RAPID) technique. The experimental research was conducted using an aluminum plate. The experimental results show that the method proposed in this research can quickly and effectively identify the single damage or multiple damage and image the damages clearly in detected area.

  20. Subcellular in vivo time-lapse imaging and optical manipulation of Caenorhabditis elegans in standard multiwell plates.

    Science.gov (United States)

    Rohde, Christopher B; Yanik, Mehmet Fatih

    2011-01-01

    High-resolution in vivo time-lapse assays require repeated immobilization and imaging of whole animals. Here we report a technology for screening Caenorhabditis elegans at cellular resolution over its entire lifespan inside standard multiwell plates using repeated immobilization, imaging and optical manipulation. Our system does not use any fluidic or mechanical components, and can operate for tens of thousands of cycles without failure. It is also compatible with industrial high-throughput screening platforms and robotics, and it allows both chemical, and forward and reverse genetic screens. We used this technology to perform subcellular-resolution femtosecond laser microsurgery of single neurons in vivo, and to image the subsequent regeneration dynamics at subcellular resolution. Our single-neuron in vivo time-lapse analysis shows that neurite regrowth occurring over short time windows is significantly greater than that predicted by ensemble averaging over many animals.

  1. Angular shear plate

    Science.gov (United States)

    Ruda, Mitchell C [Tucson, AZ; Greynolds, Alan W [Tucson, AZ; Stuhlinger, Tilman W [Tucson, AZ

    2009-07-14

    One or more disc-shaped angular shear plates each include a region thereon having a thickness that varies with a nonlinear function. For the case of two such shear plates, they are positioned in a facing relationship and rotated relative to each other. Light passing through the variable thickness regions in the angular plates is refracted. By properly timing the relative rotation of the plates and by the use of an appropriate polynomial function for the thickness of the shear plate, light passing therethrough can be focused at variable positions.

  2. Photonic crystals, light manipulation, and imaging in complex nematic structures

    Science.gov (United States)

    Ravnik, Miha; Å timulak, Mitja; Mur, Urban; Čančula, Miha; Čopar, Simon; Žumer, Slobodan

    2016-03-01

    Three selected approaches for manipulation of light by complex nematic colloidal and non-colloidal structures are presented using different own custom developed theoretical and modelling approaches. Photonic crystals bands of distorted cholesteric liquid crystal helix and of nematic colloidal opals are presented, also revealing distinct photonic modes and density of states. Light propagation along half-integer nematic disclinations is shown with changes in the light polarization of various winding numbers. As third, simulated light transmission polarization micrographs of nematic torons are shown, offering a new insight into the complex structure characterization. Finally, this work is a contribution towards using complex soft matter in optics and photonics for advanced light manipulation.

  3. Multimodal sparse reconstruction in guided wave imaging of defects in plates

    Science.gov (United States)

    Golato, Andrew; Santhanam, Sridhar; Ahmad, Fauzia; Amin, Moeness G.

    2016-07-01

    A multimodal sparse reconstruction approach is proposed for localizing defects in thin plates in Lamb wave-based structural health monitoring. The proposed approach exploits both the sparsity of the defects and the multimodal nature of Lamb wave propagation in plates. It takes into account the variation of the defects' aspect angles across the various transducer pairs. At low operating frequencies, only the fundamental symmetric and antisymmetric Lamb modes emanate from a transmitting transducer. Asymmetric defects scatter these modes and spawn additional converted fundamental modes. Propagation models are developed for each of these scattered and spawned modes arriving at the various receiving transducers. This enables the construction of modal dictionary matrices spanning a two-dimensional array of pixels representing potential defect locations in the region of interest. Reconstruction of the region of interest is achieved by inverting the resulting linear model using the group sparsity constraint, where the groups extend across the various transducer pairs and the different modes. The effectiveness of the proposed approach is established with finite-element scattering simulations of the fundamental Lamb wave modes by crack-like defects in a plate. The approach is subsequently validated with experimental results obtained from an aluminum plate with asymmetric defects.

  4. A novel method for detecting light source for digital images forensic

    Science.gov (United States)

    Roy, A. K.; Mitra, S. K.; Agrawal, R.

    2011-06-01

    Manipulation in image has been in practice since centuries. These manipulated images are intended to alter facts — facts of ethics, morality, politics, sex, celebrity or chaos. Image forensic science is used to detect these manipulations in a digital image. There are several standard ways to analyze an image for manipulation. Each one has some limitation. Also very rarely any method tried to capitalize on the way image was taken by the camera. We propose a new method that is based on light and its shade as light and shade are the fundamental input resources that may carry all the information of the image. The proposed method measures the direction of light source and uses the light based technique for identification of any intentional partial manipulation in the said digital image. The method is tested for known manipulated images to correctly identify the light sources. The light source of an image is measured in terms of angle. The experimental results show the robustness of the methodology.

  5. Displacement tracking in single human trabecula with metal-plated micro-spheres using X-ray radiography imaging

    Science.gov (United States)

    Jiroušek, O.; Kytýř, D.; Doktor, T.; Dammer, J.; Krejčí, F.

    2013-02-01

    This study presents an improved radiographic method for strain measurement in very small samples of a single trabeculae. X-ray micro-radiography was used to track the deformation behaviour of individual trabecula during mechanical loading. As the X-ray micro-radiography images of a single trabecula show no significant features applicable for digital image correlation (DIC) a random pattern of markers was created on the surfaces of the samples to improve the accuracy of tracking. Metal plated borosilicate glassmicro-spheres (mean diameter 10 μm) were used as the markers for trabecular displacement tracking. Two different X-ray imaging setups were used for this purpose. The specimens of isolated trabeculae were loaded by a micro-mechanical testing device developed with respect to radiographical observation. This compact device enables a high precision three-point bending measurement. The specimen was continuously irradiated during the loading procedure by a micro-focus X-ray source. The radiographs were acquired by a single-photon counting silicon pixel detector and s flat panel sensor with CsI flipped scintillator plate. Circular Hough transform was used to locate positions of the spherical markers in the sequence of acquired radiographs and to calculate the strain in the loaded sample. The gold-coated micro-spheres provide clearly visible features in the sequence of radiographs after beam hardening correction, which in conjunction with pattern recognition algorithm enables to substantially improve the accuracy of strain measurements.

  6. Collection of reciprocal space maps using imaging plates at the Australian National Beamline Facility at the Photon Factory.

    Science.gov (United States)

    Mudie, S T; Pavlov, K M; Morgan, M J; Hester, J R; Tabuchi, M; Takeda, Y

    2004-09-01

    Weissenberg screens and a translating cassette have been employed to allow an imaging plate to collect 30 scans per readout. In this configuration the imaging plate functions as a curved one-dimensional position-sensitive detector and, by changing the sample angle for each of the scans, two-dimensional images were produced in reciprocal space. This method of data collection leads to a reduction in scan time compared with methods based on a scintillation detector, particularly for asymmetric reflections. The data-collection method was tested using InGaN/GaN/AlN multilayers on sapphire substrates, since these exhibit broad features in reciprocal space. The geometry of the scans in reciprocal space required the data to be interpolated onto a Cartesian grid. Several interpolation schemes were investigated, with the results compared with the reciprocal space maps collected using a triple-axis scheme with a point detector. The quality of the interpolated reciprocal space maps depends upon the size and shape of the feature in reciprocal space, the interpolation method used, and the step size of the sample rotation. The method can be extended to three dimensions without an increase in data-collection time.

  7. Multichannel Seismic Imaging of the Rivera Plate Subduction at the Seismogenic Jalisco Block Area (Western Mexican Margin)

    Science.gov (United States)

    Bartolome, Rafael; Górriz, Estefanía; Dañobeitia, Juanjo; Cordoba, Diego; Martí, David; Cameselle, Alejandra L.; Núñez-Cornú, Francisco; Bandy, William L.; Mortera-Gutiérrez, Carlos A.; Nuñez, Diana; Castellón, Arturo; Alonso, Jose Luis

    2016-10-01

    During the TSUJAL marine geophysical survey, conducted in February and March 2014, Spanish, Mexican and British scientists and technicians explored the western margin of Mexico, considered one of the most active seismic zones in America. This work aims to characterize the internal structure of the subduction zone of the Rivera plate beneath the North American plate in the offshore part of the Jalisco Block, to link the geodynamic and the recent tectonic deformation occurring there with the possible generation of tsunamis and earthquakes. For this purpose, it has been carried out acquisition, processing and geological interpretation of a multichannel seismic reflection profile running perpendicular to the margin. Crustal images show an oceanic domain, dominated by subduction-accretion along the lower slope of the margin with a subparallel sediment thickness of up to 1.6 s two-way travel time (approx. 2 km) in the Middle American Trench. Further, from these data the region appears to be prone to giant earthquake production. The top of the oceanic crust (intraplate reflector) is very well imaged. It is almost continuous along the profile with a gentle dip (continental crust presents a well-developed accretionary prism consisting of highly deformed sediments with prominent slumping towards the trench that may be the result of past tsunamis. Also, a bottom simulating reflector (BSR) is identified in the first half a second (twtt) of the section. High amplitude reflections at around 7-8 s twtt clearly image a discontinuous Moho, defining a very gentle dipping subduction plane.

  8. Processless offset printing plates

    Directory of Open Access Journals (Sweden)

    Sanja Mahović Poljaček

    2015-06-01

    Full Text Available With the implementation of platesetters in the offset printing plate making process, imaging of the printing plate became more stable and ensured increase of the printing plate quality. But as the chemical processing of the printing plates still highly influences the plate making process and the graphic reproduction workflow, development of printing plates that do not require chemical processing for offset printing technique has been one of the top interests in graphic technology in the last few years. The main reason for that came from the user experience, where majority of the problems with plate making process could be connected with the chemical processing of the printing plate. Furthermore, increased environmental standards lead to reducing of the chemicals used in the industrial processes. Considering these facts, different types of offset printing plates have been introduced to the market today. This paper presents some of the processless printing plates.

  9. Multichannel Seismic Imaging of the Rivera Plate Subduction at the Seismogenic Jalisco Block Area (Western Mexican Margin)

    Science.gov (United States)

    Bartolome, R.; Gorriz, E.; Danobeitia, J.; Barba, D. C., Sr.; Martí, D.; L Cameselle, A.; Nuñez-Cornu, F. J.; Bandy, W. L.; Mortera, C.; Nunez, D.; Alonso, J. L.; Castellon, A.; Prada, M.

    2016-12-01

    During the TSUJAL marine geophysical survey, conducted in February and March 2014 Spanish, Mexican and British scientists and technicians explored the western margin of Mexico, considered one of the most active seismic zones in America. This work aims to characterize the internal structure of the subduction zone of the Rivera plate beneath the North American plate in the offshore part of the Jalisco Block, to link the geodynamic and the recent tectonic deformation occurring there with the possible generation of tsunamis and earthquakes. For this purpose, it has been carried out acquisition, processing and geological interpretation of a multichannel seismic reflection profile running perpendicular to the margin. Crustal images show an oceanic domain, dominated by subduction-accretion along the lower slope of the margin with a subparallel sediment thickness of up to 1.6 s two way travel time (approx. 2 km) in the Middle American Trench. Further, from these data the region appears to be prone to giant earthquake production. The top of the oceanic crust (intraplate reflector) is very well imaged. It is almost continuous along the profile with a gentle dip (<10°); however, it is disrupted by normal faulting resulting from the bending of the plate during subduction. The continental crust presents a well-developed accretionary prism consisting of highly deformed sediments with prominent slumping towards the trench that may be the result of past tsunamis. Also, a Bottom Simulating Reflector (BSR) is identified in the first half a second (twtt) of the section. High amplitude reflections at around 7-8 s twtt clearly image a discontinuous Moho, defining a very gentle dipping subduction plane.

  10. Multichannel Seismic Imaging of the Rivera Plate Subduction at the Seismogenic Jalisco Block Area (Western Mexican Margin)

    Science.gov (United States)

    Bartolome, Rafael; Górriz, Estefanía; Dañobeitia, Juanjo; Cordoba, Diego; Martí, David; Cameselle, Alejandra L.; Núñez-Cornú, Francisco; Bandy, William L.; Mortera-Gutiérrez, Carlos A.; Nuñez, Diana; Castellón, Arturo; Alonso, Jose Luis

    2016-06-01

    During the TSUJAL marine geophysical survey, conducted in February and March 2014, Spanish, Mexican and British scientists and technicians explored the western margin of Mexico, considered one of the most active seismic zones in America. This work aims to characterize the internal structure of the subduction zone of the Rivera plate beneath the North American plate in the offshore part of the Jalisco Block, to link the geodynamic and the recent tectonic deformation occurring there with the possible generation of tsunamis and earthquakes. For this purpose, it has been carried out acquisition, processing and geological interpretation of a multichannel seismic reflection profile running perpendicular to the margin. Crustal images show an oceanic domain, dominated by subduction-accretion along the lower slope of the margin with a subparallel sediment thickness of up to 1.6 s two-way travel time (approx. 2 km) in the Middle American Trench. Further, from these data the region appears to be prone to giant earthquake production. The top of the oceanic crust (intraplate reflector) is very well imaged. It is almost continuous along the profile with a gentle dip (<10°); however, it is disrupted by normal faulting resulting from the bending of the plate during subduction. The continental crust presents a well-developed accretionary prism consisting of highly deformed sediments with prominent slumping towards the trench that may be the result of past tsunamis. Also, a bottom simulating reflector (BSR) is identified in the first half a second (twtt) of the section. High amplitude reflections at around 7-8 s twtt clearly image a discontinuous Moho, defining a very gentle dipping subduction plane.

  11. Real-time image difference detection using a polarization rotation spacial light modulator

    Science.gov (United States)

    Chao, Tien-Hsin (Inventor); Liu, Hua-Kuang (Inventor)

    1990-01-01

    An image difference detection system is described, of the type wherein two created image representations such as transparencies representing the images to be compared lie coplanar, while light passes through the two transparencies and is formed into coincident images at the image plane for comparison. The two transparencies are formed by portions of a polarization rotation spacial light modulator display such as a multi-pixel liquid crystal display or a magneto optical rotation type. In a system where light passing through the two transparencies is polarized in transverse directions to enable the use of a Wollaston prism to bring the images into coincidence, a liquid crystal display can be used which is devoid of polarizing sheets that would interfere with transverse polarizing of the light passing through the two transparencies.

  12. RGB Color Calibration for Quantitative Image Analysis: The “3D Thin-Plate Spline” Warping Approach

    Directory of Open Access Journals (Sweden)

    Corrado Costa

    2012-05-01

    Full Text Available In the last years the need to numerically define color by its coordinates in n-dimensional space has increased strongly. Colorimetric calibration is fundamental in food processing and other biological disciplines to quantitatively compare samples’ color during workflow with many devices. Several software programmes are available to perform standardized colorimetric procedures, but they are often too imprecise for scientific purposes. In this study, we applied the Thin-Plate Spline interpolation algorithm to calibrate colours in sRGB space (the corresponding Matlab code is reported in the Appendix. This was compared with other two approaches. The first is based on a commercial calibration system (ProfileMaker and the second on a Partial Least Square analysis. Moreover, to explore device variability and resolution two different cameras were adopted and for each sensor, three consecutive pictures were acquired under four different light conditions. According to our results, the Thin-Plate Spline approach reported a very high efficiency of calibration allowing the possibility to create a revolution in the in-field applicative context of colour quantification not only in food sciences, but also in other biological disciplines. These results are of great importance for scientific color evaluation when lighting conditions are not controlled. Moreover, it allows the use of low cost instruments while still returning scientifically sound quantitative data.

  13. Rapid small-angle X-ray diffraction of a tonically contracting molluscan smooth muscle recorded with imaging plates

    Energy Technology Data Exchange (ETDEWEB)

    Tajima, Y.; Okada, K.; Yoshida, O.; Seto, T.; Amemiya, Y.

    1989-02-01

    Small-angle X-ray diffraction patterns from the anterior byssus retractor muscles of Mytilus edulis contracting tonically in response to stimulation with acetylcholine were recorded in a 30 s exposure with synchrotron radiation and a high-sensitivity X-ray area detector called an imaging plate. The 190 A layer line from the thin filaments increased in intensity with increase in tonic tension up to 6x10/sup 4/ kg m/sup -2/. Above this value, the layer-line intensity remained almost constant and comparable to that for a contracting skeletal muscle, indicating that the same structural changes of the thin filaments occur in both muscles.

  14. Foetal and postnatal equine articular cartilage development: magnetic resonance imaging and polarised light microscopy

    Directory of Open Access Journals (Sweden)

    C Cluzel

    2013-08-01

    Full Text Available Adult articular cartilage (AC has a well described multizonal collagen structure. Knowledge of foetal AC organisation and development may provide a prototype for cartilage repair strategies, and improve understanding of structural changes in developmental diseases such as osteochondrosis (OC. The objective of this study was to describe normal development of the spatial architecture of the collagen network of equine AC using 1.5 T magnetic resonance imaging (MRI and polarised light microscopy (PLM, at sites employed for cartilage repair studies or susceptible to OC. T2-weighted fast-spin echo (FSE sequences and PLM assessment were performed on distal femoral epiphyses of equine foetuses, foals and adults. Both MRI and PLM revealed an early progressive collagen network zonal organisation of the femoral epiphyses, beginning at 4 months of gestation. PLM revealed that the collagen network of equine foetal AC prior to birth was already organised into an evident anisotropic layered structure that included the appearance of a dense tangential zone in the superficial AC in the youngest specimens, with the progressive development of an underlying transitional zone. A third, increasingly birefringent, radial layer developed in the AC from 6 months of gestation. Four laminae were observed on the MR images in the last third of gestation. These included not only the AC but also the superficial growth plate of the epiphysis. These findings provide novel data on normal equine foetal cartilage collagen development, and may serve as a template for cartilage repair studies in this species or a model for developmental studies of OC.

  15. High-power, computer-controlled, light-emitting diode-based light sources for fluorescence imaging and image-guided surgery.

    Science.gov (United States)

    Gioux, Sylvain; Kianzad, Vida; Ciocan, Razvan; Gupta, Sunil; Oketokoun, Rafiou; Frangioni, John V

    2009-01-01

    Optical imaging requires appropriate light sources. For image-guided surgery, in particular fluorescence-guided surgery, a high fluence rate, a long working distance, computer control, and precise control of wavelength are required. In this article, we describe the development of light-emitting diode (LED)-based light sources that meet these criteria. These light sources are enabled by a compact LED module that includes an integrated linear driver, heat dissipation technology, and real-time temperature monitoring. Measuring only 27 mm wide by 29 mm high and weighing only 14.7 g, each module provides up to 6,500 lx of white (400-650 nm) light and up to 157 mW of filtered fluorescence excitation light while maintaining an operating temperature mW/cm2 of 670 nm near-infrared (NIR) fluorescence excitation light, and 14.0 mW/cm2 of 760 nm NIR fluorescence excitation light over a 15 cm diameter field of view. Using this light source, we demonstrated NIR fluorescence-guided surgery in a large-animal model.

  16. LED 扩散板光扩散的性能评价的研究%Study on the Light Diffusion Performance Evaluation of LED Diffusion Plate

    Institute of Scientific and Technical Information of China (English)

    彭文利

    2013-01-01

      LED 扩散板光扩散的性能评价是根据环境要求和不同场所照度标准要求,利用 LED 扩散板光扩散的性能(如照度均匀度、眩光限制、光源颜色、显色性、反射比等),生产出具备一定柔和舒适度的 LED 照明灯具,制造出符合室内照明要求的气氛照明、情景照明、情调照明,满足用户的各种照明要求,其造型也要符合用户的审美观,最主要的是符合能源高效的利用。这项技术的成功研制将会使我国 LED 灯具在 LED 国际市场的竞争中处于优势地位,打开国际市场。这项技术的成功研制也填补了行业内无 LED 扩散板光扩散的性能评价体系的一个空白。%The light diffusion performance evaluation of LED diffusion plate is based on the environmental requirements and standards requirements in different places. The use of the light diffusion properties (e.g., uniformity of illumination, glare limitation, the light source color, the color, reflectance, etc.) of LED diffusion plate can product the LED light with soft comfort. It can create the mood lighting, scene lighting and mood lighting meeting the indoor lighting requirements and the user's requirements, and its shape is also in line with the aesthetics of the user, the most important is compliance with the energy efficient use. The success of this technology will make China's LED lamps in a dominant position in the LED international market competition, and open the international market. And it also will fill a blank of the light diffusion performance evaluation system of LED diffuser plate.

  17. Images of Light - Is phasing out the solution?

    DEFF Research Database (Denmark)

    Jensen, Charlotte Louise; Remmen, Arne

    2012-01-01

    the incandescent bulb[1], which seem to imply that some people oppose this move. However, some people are reaching out for the new lighting technologies, especially the light emitting diodes (LED), and it is interesting to analyze why these people, the so-called front runners, have chosen to incorporate...... approximately 20% of the world’s total energy consumption was consumed by lighting (Brown, 2010) which calls for attention to how energy consumption from lighting may be reduced. A strategy for phasing out the worst-performing light bulbs for domestic use is included in the European Ecodesign directive (2005....../32/EC), constantly raising the performance standards. Various lighting technologies are now on the market, however with fluctuating quality, which, among other things, affect the rate households adopting new technologies (Krantz and Bladh, 2008) (Wall and Crosbie, 2009). However, aspects such as culture...

  18. Programmable aperture microscopy: A computational method for multi-modal phase contrast and light field imaging

    Science.gov (United States)

    Zuo, Chao; Sun, Jiasong; Feng, Shijie; Zhang, Minliang; Chen, Qian

    2016-05-01

    We demonstrate a simple and cost-effective programmable aperture microscope to realize multi-modal computational imaging by integrating a programmable liquid crystal display (LCD) into a conventional wide-field microscope. The LCD selectively modulates the light distribution at the rear aperture of the microscope objective, allowing numerous imaging modalities, such as bright field, dark field, differential phase contrast, quantitative phase imaging, multi-perspective imaging, and full resolution light field imaging to be achieved and switched rapidly in the same setup, without requiring specialized hardwares and any moving parts. We experimentally demonstrate the success of our method by imaging unstained cheek cells, profiling microlens array, and changing perspective views of thick biological specimens. The post-exposure refocusing of a butterfly mouthpart and RFP-labeled dicot stem cross-section is also presented to demonstrate the full resolution light field imaging capability of our system for both translucent and fluorescent specimens.

  19. Imaging in scattering media via the second-order correlation of light field

    CERN Document Server

    Gong, Wenlin; Shen, Xia; Han, Shensheng

    2009-01-01

    Imaging with the second-order correlation of two light fields is a method to image an object by two-photon interference involving a joint detection of two photons at distant space-time points. We demonstrate for the first time that an image with high quality can still be obtained in the scattering media by applying the second-order correlation of illuminating light field. The scattering effect on the visibility of images is analyzed both theoretically and experimentally. Potential applications and the methods to further improve the visibility of the images in scattering media are also discussed.

  20. Improvement of visualization efficiency for the nondestructive inspection image of internal defects in plate type nuclear fuel

    Energy Technology Data Exchange (ETDEWEB)

    Park, Seung Kyu; Park, Nak Kyu; Baik, Sung Hoon; Lee, Yoon Sang; Cheong, Yong Moo [KAERI, Daejeon (Korea, Republic of); Kang, Young June [Chonbuk National Univ., Chonju (Korea, Republic of)

    2012-10-15

    Plate type nuclear fuel has been adopted in most research reactors. The production quality of the fuel is a key part for an efficient and stable generation of thermal energy in research reactors. Thus, a nondestructive quality inspection for the internal defects of plate type nuclear fuel is a key process during the production of nuclear fuel for safety insurance. Nondestructive quality inspections based on X rays and ultrasounds have been widely used for the defect detection of plate type nuclear fuel. X ray testing is a simple and fast inspection method, and provides an image in real time as the inspection results. Thus, the testing can be carried out by a non expert field worker. However, it is hard to detect closed type defects that should be detected during the production of plate type nuclear fuel. Ultrasonic testing is a powerful tool to detect internal defects including open type and closed type defects in plate type nuclear fuel. However, the inspection process is complicated because an immersion test should be carried out in a water tank. It is also a time consuming inspection method because area testing to acquire image is based on the scanning of the point by point inspections. Among nondestructive inspection techniques, the techniques based on laser interferometry and infrared thermography have been widely used in the detection of internal defects of plate type composite materials, such as aircraft, automotive etc. While infrared thermography technique (IRT) analyses the thermal behavior of the specimen surface, laser interferometry technique (LIT) analyses the deformation field. Both techniques are useful tools for detection and evaluation of internal defects in composite materials. Especially, the laser interferometry technique can provide the depth information of internal defects. Laser interferometry technique (LIT) is a non contact inspection method faster than thermography. Also, this technique requires less energy than thermography and the

  1. Antiproton, positron, and electron imaging with a microchannel plate/phosphor detector

    Science.gov (United States)

    Andresen, G. B.; Bertsche, W.; Bowe, P. D.; Bray, C. C.; Butler, E.; Cesar, C. L.; Chapman, S.; Charlton, M.; El Nasr, S. Seif; Fajans, J.; Fujiwara, M. C.; Gill, D. R.; Hangst, J. S.; Hardy, W. N.; Hayano, R. S.; Hayden, M. E.; Humphries, A. J.; Hydomako, R.; Jørgensen, L. V.; Kerrigan, S. J.; Kurchaninov, L.; Lambo, R.; Madsen, N.; Nolan, P.; Olchanski, K.; Olin, A.; Povilus, A. P.; Pusa, P.; Sarid, E.; Silveira, D. M.; Storey, J. W.; Thompson, R. I.; van der Werf, D. P.; Yamazaki, Y.; Alpha Collaboration

    2009-12-01

    A microchannel plate (MCP)/phosphor screen assembly has been used to destructively measure the radial profile of cold, confined antiprotons, electrons, and positrons in the ALPHA experiment, with the goal of using these trapped particles for antihydrogen creation and confinement. The response of the MCP to low energy (10-200 eV, <1 eV spread) antiproton extractions is compared to that of electrons and positrons.

  2. Antiproton, positron, and electron imaging with a microchannel plate/phosphor detector

    CERN Document Server

    Andresen, G B; Bowe, P D; Bray, C; Butler, E; Cesar, C L; Chapman, S; Charlton, M; Fajans, J; Fujiwara, M C; Gill, D R; Hangst, J S; Hardy, W N; Hayano, R S; Hayden, M E; Humphries, A J; Hydomako, R; Jørgensen, L V; Kerrigan, S J; Kurchaninov, L; Lambo, R; Madsen, N; Nolan, P; Olchanski, K; Olin, A; Povilus, A; Pusa, P; Sarid, E; Seif El Nasr, S; Silveira, D M; Storey, J W; Thompson, R I; van der Werf, D P; Yamazaki, Y

    2009-01-01

    A microchannel plate (MCP)/phosphor screen assembly has been used to destructively measure the radial profile of cold, confined antiprotons, electrons, and positrons in the ALPHA experiment, with the goal of using these trapped particles for antihydrogen creation and confinement. The response of the MCP to low energy (10-200 eV, <1 eV spread) antiproton extractions is compared to that of electrons and positrons.

  3. Imaging the Southeast Caribbean Plate Margin with Teleseismic P-wave Tomography

    Science.gov (United States)

    Bravo, T. K.; Pavlis, G. L.

    2007-12-01

    As part of the Bolivar Project, the Passive Array Group (authors plus Funvisis; University of the West Indies; University of California, San Diego; and Rice University) operated a 113 station, broadband array in Venezuela and the southern Antilles. The combined array ran from December 2003 to May 2005 with stations running from the craton south of the Orinoco River to OBS instruments located on oceanic crust of the Caribbean plate. This collaborative geological and geophysical study of the Caribbean-South American Plate boundary was designed to investigate the large scale structure and tectonic framework of this northern boundary of South America. We measured P wave residuals from 382 teleseismic events with a two-step procedure. First, we used a new array processing method to cross-correlate vertical component data with an array beam computed through a robust, nonlinear stacking method. Second, we reviewed the cross-correlation results adding picks manually for stations that did not correlate reliably with the array beam. We used these P wave residuals to construct a series of P- wave tomographic models of this region. Robust features seen in these models include: (1) a high velocity upper mantle under the craton grading to lower velocities under the Orinoco basin; (2) higher velocities are seen in western Venezuela that correlate with the subducting Nazca plate; and (3) the subduction of the Atlantic at the Antilles Arc is marginally resolved in the northwest corner of the study area.

  4. 结构光在集装箱顶角加强板焊缝定位中的应用%Weld seam positioning method of container reinforced plate based on structured light

    Institute of Scientific and Technical Information of China (English)

    王海霞; 林青; 许琳

    2011-01-01

    According to the welding characteristic of container reinforced plate, an automation positioning method based on the structured light of the welding seam is developed.Two traits are included in the method: The camera is located on a right-angled framework, and its optical axis is normal to the working plane,then depth information can be obtained by comparing the size of area, accordingly three-dimensional information extraction can be transformed into two-dimensional and space point can be transformed image point by affine transform.This system consists of two lasers and one camera.lt will be much easier to process image because of the significant characteristic of laser light in welding environment when laser is used as an aide to help camera to locate much reliably.The particular implementation procedure is as follows: Transition emerged on the welding between the reinforced plate and the roof plate when two laser beans are projected to an angel of the reinforced plate.Four couple of image coordinates of transition points are attained by processing tripe effectively which are used to gain the reinforced plate's welding initial characteristic point and orientation by fitting a straight line,finally the other characteristic points can be attained one by one referring to the image template which is made beforehand.This system takes advantage of the laser efficiently, resolves the automatic positioning problems on reinforced plate welding beam reliably.%针对集装箱顶角加强板的焊接特点,设计了一种基于结构光的自动焊缝定位方法.该方法主要有两个特点:一是将摄像机安装在机器人上,使光轴垂直工作平面,通过比较面积大小来获得深度信息,从而将三维信息的获取问题转化为二维信息的提取,并利用仿射变换获得空间信息;二是利用激光器与摄像机相配合的方式进行定位,由于激光束在焊接环境中的特征明显,可降低图像处理的难度.具体实现过程是

  5. SEGMENTATION ALGORITHM BASED ON EDGE-SEARCHING FOR MUlTI-LINEAR STRUCTURED LIGHT IMAGES

    Institute of Scientific and Technical Information of China (English)

    LIU Baohua; LI Bing; JIANG Zhuangde

    2006-01-01

    Aiming at the problem that the existence of disturbances on the edges of light-stripe makes the segmentation of the light-stripes images difficult, a new segmentation algorithm based on edge-searching is presented. It firstly calculates every edge pixel's horizontal coordinate grads to produce the corresponding grads-edge, then uses a designed length-variable 1D template to scan the light-stripes' grads-edges. The template is able to fmd the disturbances with different width utilizing the distributing character of the edge disturbances. The found disturbances are eliminated finally. The algorithm not only can smoothly segment the light-stripes images, but also eliminate most disturbances on the light-stripes' edges without damaging the light-stripes images' 3D information. A practical example of using the proposed algorithm is given in the end. It is proved that the efficiency of the algorithm has been improved obviously by comparison.

  6. License Plate Recognition Based on Image Processing%基于图像处理的车牌识别研究

    Institute of Scientific and Technical Information of China (English)

    郑雪

    2014-01-01

    The application of image processing technique was put forward to identify the license plate aiming at solving the prob-lem of license plate recognition in the intelligent traffic management system. License plate location, character segmentation, and li-cense plate recognition are the most important three parts, which constitute the license plate recognition system. First, using HSV model and RGB model to identify and segment the color image, and preliminary positioning for the license plate image. Then li-cense plate tilt correction was processed by Radon transform, and using the projection method for license plate location and seg-mentation. At last, read the result of license information recognized. Simulation by MATLAB programming and experiment, the results show that using image processing technology can quickly identify the license plate, and is an effective method to study the license plate recognition.%针对智能交通管理系统中的车牌识别问题,提出应用图像处理技术对汽车的牌照进行识别。车牌定位(LPL, License Plate Location)、车牌分割(LPS, License Plate Segmentation)、车牌识别(LPR, License Plate Recognition)是实现车牌识别系统的最主要的三个部分。先采用HSV模型和RGB模型识别与分割彩色图像,并初步定位车牌图像;再采用radon变换实现车牌的倾斜校正,用投影法对车牌进行定位和分割;最后通过语音读出识别到的车牌信息。通过MATLAB编程进行实验仿真,结果表明利用图像处理技术能够快速地识别出汽车牌照,是一种研究车牌识别的有效方法。

  7. Post-processing for statistical image analysis in light microscopy.

    Science.gov (United States)

    Cardullo, Richard A; Hinchcliffe, Edward H

    2013-01-01

    Image processing of images serves a number of important functions including noise reduction, contrast enhancement, and feature extraction. Whatever the final goal, an understanding of the nature of image acquisition and digitization and subsequent mathematical manipulations of that digitized image is essential. Here we discuss the basic mathematical and statistical processes that are routinely used by microscopists to routinely produce high quality digital images and to extract key features of interest using a variety of extraction and thresholding tools. Copyright © 2013 Elsevier Inc. All rights reserved.

  8. Rapid and simultaneous in situ assessment of aflatoxins and stilbenes using silica plate imprinting mass spectrometry imaging.

    Directory of Open Access Journals (Sweden)

    Diogo N de Oliveira

    Full Text Available A fast and direct combination of techniques for simultaneous mycotoxin and phytoalexin identification in peanut skin and kernel is described. Silica Plate Imprinting Laser Desorption/Ionization Mass Spectrometry Imaging (SPILDI-MSI is a powerful technique that exhibits great advantages, such as solvent-free and matrix-free characteristics, as well as no sample preparation or separation steps. It also permits accurate identification of mycotoxins and phytoalexins with unique fingerprint profiles in just a few seconds. Results are expressed as chemical images of the 4 identified types of aflatoxins (B1, B2, G1 and G2 and a stilbenoid (resveratrol. Also, SPILDI-MSI allows the comparison between the spatial distribution of aflatoxins and resveratrol found in kernel and skin. This novel application has proven to be useful for instantaneous qualitative assessment of aflatoxins and stilbenoids both in the peanut skin and kernel and offers precise tracking of fungal contamination in nuts and other foodstuffs.

  9. Rapid and simultaneous in situ assessment of aflatoxins and stilbenes using silica plate imprinting mass spectrometry imaging.

    Science.gov (United States)

    de Oliveira, Diogo N; Ferreira, Mônica S; Catharino, Rodrigo R

    2014-01-01

    A fast and direct combination of techniques for simultaneous mycotoxin and phytoalexin identification in peanut skin and kernel is described. Silica Plate Imprinting Laser Desorption/Ionization Mass Spectrometry Imaging (SPILDI-MSI) is a powerful technique that exhibits great advantages, such as solvent-free and matrix-free characteristics, as well as no sample preparation or separation steps. It also permits accurate identification of mycotoxins and phytoalexins with unique fingerprint profiles in just a few seconds. Results are expressed as chemical images of the 4 identified types of aflatoxins (B1, B2, G1 and G2) and a stilbenoid (resveratrol). Also, SPILDI-MSI allows the comparison between the spatial distribution of aflatoxins and resveratrol found in kernel and skin. This novel application has proven to be useful for instantaneous qualitative assessment of aflatoxins and stilbenoids both in the peanut skin and kernel and offers precise tracking of fungal contamination in nuts and other foodstuffs.

  10. Sparsity based sub-wavelength imaging with partially incoherent light via quadratic compressed sensing

    CERN Document Server

    Shechtman, Yoav; Szameit, Alexander; Segev, Mordechai

    2011-01-01

    We demonstrate that sub-wavelength optical images borne on partially-spatially-incoherent light can be recovered, from their far-field or from the blurred image, given the prior knowledge that the image is sparse, and only that. The reconstruction method relies on the recently demonstrated sparsity-based sub-wavelength imaging. However, for partially-spatially-incoherent light, the relation between the measurements and the image is quadratic, yielding non-convex measurement equations that do not conform to previously used techniques. Consequently, we demonstrate new algorithmic methodology, referred to as quadratic compressed sensing, which can be applied to a range of other problems involving information recovery from partial correlation measurements, including when the correlation function has local dependencies. Specifically for microscopy, this method can be readily extended to white light microscopes with the additional knowledge of the light source spectrum.

  11. Avaliação por imagem das lesões da placa de crescimento Imaging of growth plate injuries

    Directory of Open Access Journals (Sweden)

    Matiko Yanaguizawa

    2008-06-01

    Full Text Available As estruturas responsáveis pelo crescimento do osso incluem a fise (também chamada placa de crescimento e as epífises. Afecções que acometem pacientes com o esqueleto imaturo, ou seja, com a placa de crescimento ainda aberta, podem interferir no crescimento ósseo, resultando em complicações como parada do crescimento, encurtamento dos membros ou deformidades angulares. Condições traumáticas que resultam muitas vezes em fraturas epifisárias são a causa mais comum das lesões da placa de crescimento. A avaliação cuidadosa desses pacientes pelos métodos de diagnóstico por imagem atualmente disponíveis, sobretudo a radiografia, a tomografia computadorizada e a ressonância magnética, permite o reconhecimento precoce do comprometimento das estruturas relacionadas ao crescimento ósseo, além de tratamento adequado, diminuindo a possibilidade do desenvolvimento de tais complicações.The structures responsible for the growth of bones include the physis (also called growth plate and the epiphysis. Affections involving patients with immature skeletons, i.e., with a still open growth plate, may affect the bone growth, resulting in complications such as growth arrest, limb shortening and angular deformities. Traumatic conditions, many times resulting in epiphyseal fractures, are the most frequent cause of growth plate injuries. A careful evaluation of these patients by means of currently available imaging methods, especially radiography, computed tomography and magnetic resonance imaging, allows an early diagnosis of the involvement of structures related to the bone growth, besides an appropriate management, reducing the probability of secondary complications.

  12. Crystal structure analysis of a hexatungstate by a high-energy X-ray diffraction experiment using an imaging plate Weissenberg camera at the BL04B2 beamline of SPring-8

    Energy Technology Data Exchange (ETDEWEB)

    Ozeki, Tomoji; Honma, Noritaka [Department of Chemistry and Materials Science, Tokyo Institute of Technology, Tokyo (Japan); Kusaka, Katsuhiro [Core Research for Evolutional Science and Technology (CREST), Japan Science and Technology Corporation (JST), Tokyo (Japan)

    2001-08-01

    An imaging plate Weissenberg camera was installed in the BL04B2 beamline of SPring-8 aiming at automated crystal structure determinations of small molecules. Since this beamline is designed to provide X-rays with the energies higher than 37 keV ({lambda}<0.33 A), this camera is advantageous in crystal structure analyses of heavily X-ray absorbing materials. The title crystal structure analysis led to precise positional parameters and well-behaved displacement parameters not only for heavy atoms but also for light atoms. (author)

  13. Seismotectonics at the junction of the Philippine Sea plate and the Eurasian plate, in light of the 1990 Hualien earthquake and the near-field waveform inversion

    Science.gov (United States)

    Cheng, Hou-Sheng; Mozziconacci, Laetitia; Chang, Emmy T. Y.; Huang, Bor-Shouh

    2016-04-01

    In eastern Taiwan, the Longitudinal Valley (LV) is the suture zone separating the Eurasian plate (EUP) to the West from the Philippine Sea plate (PSP) to the East. The northern tip of the LV (near Hualien city) is the junction point where the collision evolve northward to a subduction of the PSP under the EUP. As a result, a high seismic activity is observed. Based on the CWB (Central Weather Bureau, Taiwan) earthquake catalog, four distinct seismic clusters can be observed in this area since 1990. We restrict our effort to the cluster caused by a doublet events of 1990 with two moderate-large earthquakes. The first shock of these doublet occurred on 13rd December with ML 6.5. Seventeen hours later and 15 km to the southeast occurred the second shock of ML 6.7. A campaign seismic network of 15 short-period stations - the Hualien Temporary Seismic Network (HTSN) was deployed during 2 months to detect the aftershocks of the doublet. By applying the near-field waveform inversion to the HTSN records, we can retrieve the focal mechanism solutions (FMS) from 50 aftershocks of local magnitude ranging from 2.5 to 5.0. A modified version of the program "FMNEAR" is adopted in this study, which has been proven to be efficient to retrieve FMS for small-to-moderate earthquakes with a limited number of stations. In practice, the near-field waveforms, were processed by band-pass filter between 0.52 and 1.2 Hz. Synthetic waveforms are built from the discrete wave number method of Bouchon (1981). The inversion is done by grid searches on the FMS parameters while the rake is inverted, the best result gives the lowest waveform misfit. The waveform adjustment are improved by depth optimization and a specific 1D velocity model for each station. Focal depths of events are in average 10km deeper than the depth determined by the island-wide seismic stations that suffered from the lack of stations to the east due to the ocean. The FMS of the 50 aftershocks can be classified into three

  14. Depth profiling of hydrogen in ferritic/martensitic steels by means of a tritium imaging plate technique

    Energy Technology Data Exchange (ETDEWEB)

    Otsuka, Teppei, E-mail: t-otsuka@nucl.kyushu-u.ac.jp [Interdisciplinary Graduate School of Engineering Sciences, Kyushu University, Hakozaki 6-10-1, Higashi-ku, Fukuoka 812-8581 (Japan); Tanabe, Tetsuo [Interdisciplinary Graduate School of Engineering Sciences, Kyushu University, Hakozaki 6-10-1, Higashi-ku, Fukuoka 812-8581 (Japan)

    2013-12-15

    Highlights: ► We applied a tritium imaging plate technique to depth profiling of hydrogen in bulk. ► Changes of hydrogen depth profiles in the steel by thermal annealing were examined. ► We proposed a release model of plasma-loaded hydrogen in the steel. ► Hydrogen is trapped at trapping sites newly developed by plasma loading. ► Hydrogen is also trapped at surface oxides and hardly desorbed by thermal annealing. -- Abstract: In order to understand how hydrogen loaded by plasma in F82H is removed by annealing at elevated temperatures in vacuum, depth profiles of plasma-loaded hydrogen were examined by means of a tritium imaging plate technique. Owing to large hydrogen diffusion coefficients in F82H, the plasma-loaded hydrogen easily penetrates into a deeper region becoming solute hydrogen and desorbs by thermal annealing in vacuum. However the plasma-loading creates new hydrogen trapping sites having larger trapping energy than that for the intrinsic sites beyond the projected range of the loaded hydrogen. Some surface oxides also trap an appreciable amount of hydrogen which is more difficult to remove by the thermal annealing.

  15. Imaging of a Defect in Thin Plates Using the Time Reversal of Single Mode Lamb Wave: Simulation

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Hyun Jo; Lee, Jung Sik; Bae, Sung Min; Lee, Hyun Ki [Wonkwang University, Iksan (Korea, Republic of)

    2010-06-15

    This paper presents an analytical investigation for a baseline-free imaging of a defect in plate-like structures using the time-reversal of Lamb waves. We first consider the flexural wave (A0 mode) propagation in a plate containing a defect, and reception and time reversal process of the output signal at the receiver. The received output signal is then composed of two parts: a directly propagated wave and a scattered wave from the defect. The time reversal of these waves recovers the original input signal, and produces two additional side bands that contain the time-of-flight information on the defect location. One of the side band signals is then extracted as a pure defect signal. A defect localization image is then constructed from a beamforming technique based on the time-frequency analysis of the side band signal for each transducer pair in a network of sensors. The simulation results show that the proposed scheme enables the accurate, baseline-free detection of a defect, so that experimental studies are needed to verify the proposed method and to be applied to real structure

  16. Mössbauer spectroscopy of europium-containing glasses: optical activator study for x-ray image plates

    Science.gov (United States)

    Johnson, C. E.; Vu, M.; Johnson, J. A.; Brown, D. E.; Weber, J. K. R.; Paßlick, C.; Schweizer, S.

    2014-04-01

    A fluorozirconate glass (ZBLAN) containing BaCl 2 nanocrystals doped with divalent Eu is a promising material for x-ray image plates for medical diagnosis. Since it is known that Eu 2+ readily oxidizes to Eu 3+, which reduces fluorescence efficiency of the image plates, 151Eu Mössbauer spectroscopy was used in this work to monitor the Eu oxidation state of the samples during degradation over time in the presence of ambient humidity. In addition, Mössbauer spectroscopic experiments show that the oxidation state has already changed during the glass melt: The sample made from 5 mol% EuCl 2 contained 78 % EuCl 2 + 22 % EuCl 3 deduced from the relative areas of the absorption lines. The sample made from 2.5 mol% EuCl2 + 2.5 mol% EuCl2 contained 37 % EuCl2 + 63 % EuCl3, i.e. 26 % of the original EuCl 2 was oxidized to EuCl 3.

  17. Strain Library Imaging Protocol for high-throughput, automated single-cell microscopy of large bacterial collections arrayed on multiwell plates.

    Science.gov (United States)

    Shi, Handuo; Colavin, Alexandre; Lee, Timothy K; Huang, Kerwyn Casey

    2017-02-01

    Single-cell microscopy is a powerful tool for studying gene functions using strain libraries, but it suffers from throughput limitations. Here we describe the Strain Library Imaging Protocol (SLIP), which is a high-throughput, automated microscopy workflow for large strain collections that requires minimal user involvement. SLIP involves transferring arrayed bacterial cultures from multiwell plates onto large agar pads using inexpensive replicator pins and automatically imaging the resulting single cells. The acquired images are subsequently reviewed and analyzed by custom MATLAB scripts that segment single-cell contours and extract quantitative metrics. SLIP yields rich data sets on cell morphology and gene expression that illustrate the function of certain genes and the connections among strains in a library. For a library arrayed on 96-well plates, image acquisition can be completed within 4 min per plate.

  18. Illumination Effect of Laser Light in Foggy Objects Using an Active Imaging System

    Energy Technology Data Exchange (ETDEWEB)

    Kwon, Seong-Ouk; Park, Seung-Kyu; Ahn, Yong-Jin; Baik, Sung-Hoon; Choi, Young-Soo; Jeong, Kyung-Min [KAERI, Daejeon (Korea, Republic of)

    2015-05-15

    Active imaging techniques usually provide improved image information when compared to passive imaging techniques. Active vision is a direct visualization technique using an artificial illuminant. Range-gated imaging (RGI) technique is one of active vision technologies. The RGI technique extracts vision information by summing time sliced vision images. In the RGI system, objects are illuminated for ultra-short time by a high intensity illuminant and then the light reflected from objects is captured by a highly sensitive image sensor with the exposure of ultra-short time. The Range-gated imaging is an emerging technology in the field of surveillance for security application, especially in the visualization of darken night or foggy environment. Although RGI viewing was discovered in the 1960's, this technology is currently more applicable by virtue of the rapid development of optical and sensor technologies, such as highly sensitive imaging sensor and ultra-short pulse laser light. Especially, this system can be adopted in robot-vision system by virtue of the compact system configuration. During the past decades, several applications of this technology have been applied in target recognition and in harsh environments, such as fog, underwater vision. Also, this technology has been demonstrated range imaging based on range-gated imaging. Laser light having a short pulse width is usually used for the range-gated imaging system. In this paper, an illumination effect of laser light in foggy objects is studied using a range-gated imaging system. The used imaging system consists of an ultra-short pulse (0.35 ns) laser light and a gated imaging sensor. The experiment is carried out to monitor objects in a box filled by fog. In this paper, the effects by fog particles in range-gated imaging technique are studied. Edge blurring and range distortion are the generated by fog particles.

  19. Development of gamma-photon/Cerenkov-light hybrid system for simultaneous imaging of I-131 radionuclide

    Energy Technology Data Exchange (ETDEWEB)

    Yamamoto, Seiichi; Suzuki, Mayumi; Kato, Katsuhiko [Radiological and Medical Laboratory Sciences, Nagoya University Graduate School of Medicine (Japan); Watabe, Tadashi; Ikeda, Hayato; Kanai, Yasukazu [Department of Molecular Imaging in Medicine, Osaka University Graduate School of Medicine (Japan); Ogata, Yoshimune [Radiological and Medical Laboratory Sciences, Nagoya University Graduate School of Medicine (Japan); Hatazawa, Jun [Department of Molecular Imaging in Medicine, Osaka University Graduate School of Medicine (Japan)

    2016-09-11

    Although iodine 131 (I-131) is used for radionuclide therapy, high resolution images are difficult to obtain with conventional gamma cameras because of the high energy of I-131 gamma photons (364 keV). Cerenkov-light imaging is a possible method for beta emitting radionuclides, and I-131 (606 MeV maximum beta energy) is a candidate to obtain high resolution images. We developed a high energy gamma camera system for I-131 radionuclide and combined it with a Cerenkov-light imaging system to form a gamma-photon/Cerenkov-light hybrid imaging system to compare the simultaneously measured images of these two modalities. The high energy gamma imaging detector used 0.85-mm×0.85-mm×10-mm thick GAGG scintillator pixels arranged in a 44×44 matrix with a 0.1-mm thick reflector and optical coupled to a Hamamatsu 2 in. square position sensitive photomultiplier tube (PSPMT: H12700 MOD). The gamma imaging detector was encased in a 2 cm thick tungsten shield, and a pinhole collimator was mounted on its top to form a gamma camera system. The Cerenkov-light imaging system was made of a high sensitivity cooled CCD camera. The Cerenkov-light imaging system was combined with the gamma camera using optical mirrors to image the same area of the subject. With this configuration, we simultaneously imaged the gamma photons and the Cerenkov-light from I-131 in the subjects. The spatial resolution and sensitivity of the gamma camera system for I-131 were respectively ~3 mm FWHM and ~10 cps/MBq for the high sensitivity collimator at 10 cm from the collimator surface. The spatial resolution of the Cerenkov-light imaging system was 0.64 mm FWHM at 10 cm from the system surface. Thyroid phantom and rat images were successfully obtained with the developed gamma-photon/Cerenkov-light hybrid imaging system, allowing direct comparison of these two modalities. Our developed gamma-photon/Cerenkov-light hybrid imaging system will be useful to evaluate the advantages and disadvantages of these two

  20. Development of gamma-photon/Cerenkov-light hybrid system for simultaneous imaging of I-131 radionuclide

    Science.gov (United States)

    Yamamoto, Seiichi; Suzuki, Mayumi; Kato, Katsuhiko; Watabe, Tadashi; Ikeda, Hayato; Kanai, Yasukazu; Ogata, Yoshimune; Hatazawa, Jun

    2016-09-01

    Although iodine 131 (I-131) is used for radionuclide therapy, high resolution images are difficult to obtain with conventional gamma cameras because of the high energy of I-131 gamma photons (364 keV). Cerenkov-light imaging is a possible method for beta emitting radionuclides, and I-131 (606 MeV maximum beta energy) is a candidate to obtain high resolution images. We developed a high energy gamma camera system for I-131 radionuclide and combined it with a Cerenkov-light imaging system to form a gamma-photon/Cerenkov-light hybrid imaging system to compare the simultaneously measured images of these two modalities. The high energy gamma imaging detector used 0.85-mm×0.85-mm×10-mm thick GAGG scintillator pixels arranged in a 44×44 matrix with a 0.1-mm thick reflector and optical coupled to a Hamamatsu 2 in. square position sensitive photomultiplier tube (PSPMT: H12700 MOD). The gamma imaging detector was encased in a 2 cm thick tungsten shield, and a pinhole collimator was mounted on its top to form a gamma camera system. The Cerenkov-light imaging system was made of a high sensitivity cooled CCD camera. The Cerenkov-light imaging system was combined with the gamma camera using optical mirrors to image the same area of the subject. With this configuration, we simultaneously imaged the gamma photons and the Cerenkov-light from I-131 in the subjects. The spatial resolution and sensitivity of the gamma camera system for I-131 were respectively ~3 mm FWHM and ~10 cps/MBq for the high sensitivity collimator at 10 cm from the collimator surface. The spatial resolution of the Cerenkov-light imaging system was 0.64 mm FWHM at 10 cm from the system surface. Thyroid phantom and rat images were successfully obtained with the developed gamma-photon/Cerenkov-light hybrid imaging system, allowing direct comparison of these two modalities. Our developed gamma-photon/Cerenkov-light hybrid imaging system will be useful to evaluate the advantages and disadvantages of these two

  1. Enhanced image reconstruction of three-dimensional fluorescent assays by subtractive structured-light illumination microscopy.

    Science.gov (United States)

    Choi, Jong-ryul; Kim, Donghyun

    2012-10-01

    We investigate improved image reconstruction of structured light illumination for high-resolution imaging of three-dimensional (3D) cell-based assays. For proof of concept, an in situ fluorescence optical detection system was built with a digital micromirror device as a spatial light modulator, for which phase and tilting angle in a grid pattern were varied to implement specific image reconstruction schemes. Subtractive reconstruction algorithms based on structured light illumination were used to acquire images of fluorescent microbeads deposited as a two-dimensional monolayer or in 3D alginate matrix. We have confirmed that an optical subtraction algorithm improves axial and lateral resolution by effectively removing out-of-focus fluorescence. The results suggest that subtractive image reconstruction can be useful for structured illumination microscopy of broad types of cell-based assays with high image resolution.

  2. Non-imaging Optics of multi-LED light source for hyperspectral imaging

    Science.gov (United States)

    Islam, Kashif; Gosnell, Martin E.; Ploschner, Martin; Anwer, Ayad G.; Goldys, Ewa M.

    2016-12-01

    The main objective of our work was to design a light source which should be capable to collect and illuminate light of LEDs at the smaller aperture of cone (9mm) which could be either coupled with secondary optics of a microscope or utilized independently for hyperspectral studies. Optimized performance of cone was assessed for different substrates (diffused glass silica, Alumina, Zerodur glass, acrylic plastic) and coating surfaces (white diffused, flat white paint, standard mirror) using a simulation software. The parameters optimized for truncated cone include slanting length and Top Major R (Larger diameter of cone) which were also varied from 10 to 350 mm and 10 to 80 mm respectively. In order to see affect of LED positions on cone efficiency, the positions of LED were varied from central axis to off-axis. Similarly, interLED distance was varied from 2 mm to 6 mm to reckon its effect on the performance of cone. The optimized Slant length (80 mm) and Top Major R (50 mm) were determined for substrates (glass zerodur or acrylic plastic) and coating surface (standard mirror). The output profile of truncated source was found non uniform, which is a typical presentation of non imaging optics problem. The maximum efficiency of cone has been found for LED at the centre and it was found decreasing as LED moves away from the central axis. Moreover, shorter the interLED distance, better is the performance of cone. The primary optics of cone shaped light source is capable to lit visible and UV LEDs in practical design. The optimum parameters obtained through simulations could be implemented in the fabrication procedure if the reflectance of source would have been maintained upto finish level of a standard mirror.

  3. Evaluation of relative speed of latent images in relation to changes in fading time and storage temperature of imaging plates in computed radiography systems.

    Science.gov (United States)

    Seoung, Youl-Hun

    2014-01-01

    This study aimed to evaluate the relative speed (RS) of latent images in relation to changes in the fading time and storage temperature of imaging plates (IPs) in computed radiography systems. The storage temperatures adopted were 20, 30, and 40°C, while the fading times employed were 0, 4, 8, 12, and 24 hours. The X-ray exposure factors were 50 kVp, 10 mAs, and a 150 cm distance from an IP to an X-ray source. In the processing of each image, the parameters used for multi-scale image contrast amplification were multiscale image contrast, noise reduction, edge enhancement, and latitude reduction, all assigned a value of 0. Image sensitivity was used to convert linear properties. The RS used for the characteristic curve was evaluated using a uniform aluminum 11-step wedge. Results show that the RS values of IPs with changing fading time were 17.8 ± 0.9 at 20°C, 13.9 ± 1.1 at 30°C, and 13.4 ± 0.9 at 40°C. On the basis of these findings, we conclude that IPs should be stored in the long term at temperatures as low as 20°C.

  4. Development of Multi-gap Resistive Plate Chamber (MRPC) for medical imaging

    Energy Technology Data Exchange (ETDEWEB)

    Banerjee, A.; Roy, A. [Variable Energy Cyclotron Centre, 1/AF Bidhan Nagar, Kolkata 700 064 (India); Biswas, S., E-mail: saikat.ino@gmail.com [Variable Energy Cyclotron Centre, 1/AF Bidhan Nagar, Kolkata 700 064 (India); GSI Helmholtzzentrum für Schwerionenforschung GmbH, Darmstadt 64291 (Germany); Chattopadhyay, S.; Das, G.; Pal, S. [Variable Energy Cyclotron Centre, 1/AF Bidhan Nagar, Kolkata 700 064 (India)

    2013-08-01

    The low cost and high resolution Multi-gap Resistive Plate Chamber (MRPC) opens up a new possibility to find an efficient alternative detector for the Time of Flight (TOF) based Positron Emission Tomography, where the sensitivity of the system depends largely on the time resolution of the detector. In a layered structure, suitable converters can be used to increase the photon detection efficiency. In this paper results of the cosmic ray test of a four-gap bakelite-based prototype MRPC operated in streamer mode and six-gap glass-based MRPC operated in avalanche mode are discussed.

  5. New seismic images of the crust across the Rivera Plate and Jalisco Block (Mexico)

    Science.gov (United States)

    Cordoba, Diego; Núñez-Cornú, Francisco Javier; Bartolomé, Rafael; José Dañobeitia, Juan; Bandy, William Lee; Núñez, Diana; Prada, Manel; Escudero-Ayala, Christian; Espíndola, Juan Manuel; Zamora, Araceli; Gómez, Adán; Ortiz, Modesto; Tsujal Working Group

    2015-04-01

    During the spring and summer of 2014, we achieved an extensive offshore geophysical experiment at West Coast of México entitled "Crustal characterization of the Rivera Plate-Jalisco Block boundary and its implications for seismic and tsunami hazard assessment (TSUJAL)". The project is the result of continuous scientific collaboration between institutions in Mexico and Spain, whose main objective is to study the lithospheric structure at the collision zone between Rivera, North America Plates and the Jalisco Block, and identifying submarine structures which can potentially be tsunamigenic sources The active phase of this project carried out in February and March of 2014, we acquired around 5200 km of Multichannel Seismic Reflection (MCS) together with multibeam bathymetry and potential fields (gravity and magnetism) data. Moreover, a wide angle experiment was performed, deploying 16 OBS in 32 locations in Jalisco and Nayarit offshore regions, also recorded on a terrestrial network of 100 portable seismic stations in 240 locations across 5 seismic profiles of 200-300 km in length combined with the Seismological Network of the State of Jalisco (SisVOc). In addition, 8 land seismic stations were installed in Marías Islands and Isabel Island. These instruments registered, in continuous mode, the airgun shots generated by airgun array of 5800 ci, shooting every 120 s. The UK vessel RRS James Cook participated in this project as a part of the exchange program between Spanish and English scientific vessels, she was responsible of marine seismic experiment (MCS & WA) using a 6 km length streamer and a high capacity airgun array. Furthermore, the ARM Holzinger and RV El Puma participated in this project and were provided by the Mexican Navy and UNAM, respectively. The second phase of this project was achieved in June 2014, where 100 short period seismic stations were installed along a 200 km seismic profile from La Caldera de la Primavera (Guadalajara) to Barra de Navidad

  6. Holographic and light-field imaging for augmented reality

    Science.gov (United States)

    Lee, Byoungho; Hong, Jong-Young; Jang, Changwon; Jeong, Jinsoo; Lee, Chang-Kun

    2017-02-01

    We discuss on the recent state of the augmented reality (AR) display technology. In order to realize AR, various seethrough three-dimensional (3D) display techniques have been reported. We describe the AR display with 3D functionality such as light-field display and holography. See-through light-field display can be categorized by the optical elements which are used for see-through property: optical elements controlling path of the light-fields and those generating see-through light-field. Holographic display can be also a good candidate for AR display because it can reconstruct wavefront information and provide realistic virtual information. We introduce the see-through holographic display using various optical techniques.

  7. Simultaneous two-photon imaging and photo-stimulation with structured light illumination.

    Science.gov (United States)

    Dal Maschio, Marco; Difato, Francesco; Beltramo, Riccardo; Blau, Axel; Benfenati, Fabio; Fellin, Tommaso

    2010-08-30

    Holographic microscopy is increasingly recognized as a promising tool for the study of the central nervous system. Here we present a "holographic module", a simple optical path that can be combined with commercial scanheads for simultaneous imaging and uncaging with structured two-photon light. The present microscope is coupled to two independently tunable lasers and has two principal configurations: holographic imaging combined with galvo-steered uncaging and holographic uncaging combined with conventional scanning imaging. We applied this flexible system for simultaneous two-photon imaging and photostimulation of neuronal cells with complex light patterns, opening new perspectives for the study of brain function in situ and in vivo.

  8. Plate-like structure damage location identification based on Lamb wave baseline-free probability imaging method

    Directory of Open Access Journals (Sweden)

    Dongsheng Li

    2017-01-01

    Full Text Available Damage-scattering signal extraction using conventional ultrasonic guided wave–based damage detection techniques requires the measurement of baseline data under pristine condition. This study proposes a baseline-free ultrasonic guided wave damage localization and imaging method based on Lamb wave baseline-free probability imaging method. Although traditional Lamb wave probability imaging can monitor damage location in plate-like structures, the absolute time of arrival and magnitude of the signal are affected by several factors and are therefore difficult to obtain. This study also proposes a probability-based hyperbola diagnostic imaging method that is based on different times of arrival and has no magnitude information. A distributed active sensor network conforming to a pulse-echo configuration and time window functions is developed to separate damage-scattering signals from structural response signals. Continuous wavelet transform is used to calculate the time of flight of damage signal waves. The numerical simulation and experiments validate the effectiveness of the proposed method in identifying damage.

  9. Light on Body Image Treatment: Acceptance Through Mindfulness

    Science.gov (United States)

    Stewart, Tiffany M.

    2004-01-01

    The treatment of body image has to be multifaceted and should be directed toward the treatment of the whole individual - body, mind, and spirit - with an ultimate culmination of acceptance and compassion for the self. This article presents information on a mindful approach to the treatment of body image as it pertains to concerns with body size…

  10. Sensing and reconstruction of arbitrary light-in-flight paths by a relativistic imaging approach

    Science.gov (United States)

    Laurenzis, Martin; Klein, Jonathan; Bacher, Emmanuel; Metzger, Nicolas; Christnacher, Frank

    2016-10-01

    Transient light imaging is an emerging technology and interesting sensing approach for fundamental multidisciplinary research ranging from computer science to remote sensing. Recent developments in sensor technologies and computational imaging has made this emerging sensing approach a candidate for next generation sensor systems with rapidly increasing maturity but still relay on laboratory technology demonstrations. At ISL, transient light sensing is investigated by time correlated single photon counting (TCSPC). An eye-safe shortwave infrared (SWIR) TCSPC setup, consisting of an avalanche photodiode array and a pulsed fiber laser source, is used to investigate sparsely scattered light while propagating through air. Fundamental investigation of light in light are carried out with the aim to reconstruct the propagation path of arbitrary light paths. Light pulses are observed in light at various propagation angles and distances. As demonstrated, arbitrary light paths can be distinguished due to a relativistic effect leading to a distortion of temporal signatures. A novel method analyzing the time difference of arrival (TDOA) is carried out to determine the propagation angle and distance with respect to this relativistic effect. Based on our results, the performance of future laser warning receivers can be improved by the use of single photon counting imaging devices. They can detect laser light even when the laser does not directly hit the sensor or is passing at a certain distance.

  11. Method for low-light-level image compression based on wavelet transform

    Science.gov (United States)

    Sun, Shaoyuan; Zhang, Baomin; Wang, Liping; Bai, Lianfa

    2001-10-01

    Low light level (LLL) image communication has received more and more attentions in the night vision field along with the advance of the importance of image communication. LLL image compression technique is the key of LLL image wireless transmission. LLL image, which is different from the common visible light image, has its special characteristics. As still image compression, we propose in this paper a wavelet-based image compression algorithm suitable for LLL image. Because the information in the LLL image is significant, near lossless data compression is required. The LLL image is compressed based on improved EZW (Embedded Zerotree Wavelet) algorithm. We encode the lowest frequency subband data using DPCM (Differential Pulse Code Modulation). All the information in the lowest frequency is kept. Considering the HVS (Human Visual System) characteristics and the LLL image characteristics, we detect the edge contour in the high frequency subband image first using templet and then encode the high frequency subband data using EZW algorithm. And two guiding matrix is set to avoid redundant scanning and replicate encoding of significant wavelet coefficients in the above coding. The experiment results show that the decoded image quality is good and the encoding time is shorter than that of the original EZW algorithm.

  12. Optical Imaging of Cells with Gold Nanoparticle Clusters as Light Scattering Contrast Agents

    DEFF Research Database (Denmark)

    Tanev, Stoyan

    2011-01-01

    developments in advanced cytometry research by pointing out potential new research directions. A brief description of the FDTD method focusing on the features associated with its application to modeling of light scattering and OPCM cell imaging experiments is provided. The examples include light scattering...... from OPCM imaging of single biological cells in conditions of controlled refractive index matching (RIM) and labeling by diffused and clustered gold NPs. The chapter concludes with a discussion and suggestions for future research....

  13. Pulsed operation of high-power light emitting diodes for imaging flow velocimetry

    OpenAIRE

    Willert, Christian; Stasicki, Boleslaw; Klinner, Joachim; Moessner, S.

    2010-01-01

    High-powered light emitting diodes (LED) are investigated for possible uses as light sources in flow diagnostics, in particular, as an alternative to laser-based illumination in particle imaging flow velocimetry in side-scatter imaging arrangements. Recent developments in solid state illumination resulted in mass-produced LEDs that provide average radiant power in excess of 10 W. By operating these LEDs with short duration, pulsed currents that are considerably beyond their continuous c...

  14. Light, sound, chemistry… action: state of the art optical methods for animal imaging.

    Science.gov (United States)

    Ripoll, Jorge; Ntziachristos, Vasilis

    2011-01-01

    During recent years, macroscopic optical methods have been promoted from backstage to main actors in biological imaging. Many possible forms of energy conservation have been explored that involve light, including fluorescence emission, sound generated through absorption and bioluminescence, that is light generated through a chemical reaction. These physicochemical approaches for contrast generation have resulted in optical imaging methods that come with potent performance characteristics over simple epi-illumination optical imaging approaches of the past, and can play a central role in imaging applications in vivo as it pertains to modern biological and drug discovery, pre-clinical imaging and clinical applications. This review focuses on state of the art optical and opto-acoustic (photo-acoustic) imaging methods and discusses key performance characteristics that convert optical imaging from a qualitative modality to a powerful high-resolution and quantitative volumetric interrogation tool for operation through several millimeters of tissue depth.: © 2011 Elsevier Ltd . All rights reserved.

  15. HEIDI: An Automated Process for the Identification and Extraction of Photometric Light Curves from Astronomical Images

    CERN Document Server

    Todd, M; Tanga, P; Coward, D M; Zadnik, M G

    2014-01-01

    The production of photometric light curves from astronomical images is a very time-consuming task. Larger data sets improve the resolution of the light curve, however, the time requirement scales with data volume. The data analysis is often made more difficult by factors such as a lack of suitable calibration sources and the need to correct for variations in observing conditions from one image to another. Often these variations are unpredictable and corrections are based on experience and intuition. The High Efficiency Image Detection & Identification (HEIDI) pipeline software rapidly processes sets of astronomical images. HEIDI automatically selects multiple sources for calibrating the images using an algorithm that provides a reliable means of correcting for variations between images in a time series. The algorithm takes into account that some sources may intrinsically vary on short time scales and excludes these from being used as calibration sources. HEIDI processes a set of images from an entire nigh...

  16. Analytic parallel-polarized light imaging technique using various light-emitting diodes: a comparison with skin conductance values.

    Science.gov (United States)

    Kim, D H; Choi, J E; Ryu, H J; Seo, S H; Kye, Y C; Ahn, H H

    2015-05-01

    The quantitative difference of the light reflected from a skin surface can be analyzed using parallel-polarized light (PPL) photography when combined with an analytic technique similar to colorimetric photography. To improve the PPL photography technique as an assessment tool for the evaluation of skin condition using light-emitting diodes (LED) of different colors. Parallel-polarized light images were taken using white and green LED illuminators. The acquired images were transformed to CIELAB coordinates. An in-house skin conductance meter was constructed to assess skin hydration level. A dermatologist evaluated the clinical grading of dryness and glossiness. These clinical severities were also compared statistically with the CIELAB values. As with the green illuminator, the correlation analysis of whole sites showed that the L* value positively correlated with age (r = 0.18677, P light was applied. In addition, coherent relationships between the grade of dryness and skin conductance values showed that visual assessment could be appropriate for the study as with objective measurement. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  17. Locomotion of microspheres for imaging and light focusing applications

    CERN Document Server

    Krivitsky, Leonid A; Wang, Zengbo; Lukiyanchuk, Boris

    2013-01-01

    Super-resolution imaging using sub-diffraction field localization by micron sized transparent beads (microspheres) was recently demonstrated [1]. Practical applications in microscopy require control over the positioning of the microspheres. We present a simple method of positioning and controllable movement of a microsphere by using a glass micropipette. This allows sub-diffraction imaging at arbitrary points in three dimensions, as well as the ability to track moving objects. The results are relevant to a broad scope of applications, including sample inspection, and bio-imaging.

  18. Fresh meat color evaluation using a structured light imaging system

    DEFF Research Database (Denmark)

    Trinderup, Camilla Himmelstrup; Kim, Yuan H. Brad

    2015-01-01

    The objective of this study was to investigate the efficacy of a computer vision system (CVS) with structured light for meat color assessment. Three muscles (longissimus dorsi (LD), semimembranosus (SM), and psoas major (PM)) from eight beef carcasses were obtained at 1 day postmortem, vacuum...... packaged and assigned to three aging periods (9, 16, and 23 days). After aging, steaks were cut and displayed for 7 days at 3 °C under light. The surface colors were evaluated by using a Minolta, the CVS and trained color panel. In general, the CVS was highly correlated to the sensory scores, and showed...... an equivalent meat color assessment compared to the colorimeter. The CVS had a significantly higher correlation with the panel scores for the lighter and more color stable samples compared to the colorimeter. These results indicate that the CVS with structured light could be an appropriate alternative...

  19. High-resolution light field reconstruction using a hybrid imaging system.

    Science.gov (United States)

    Wang, Xiang; Li, Lin; Hou, GuangQi

    2016-04-01

    Recently, light field cameras have drawn much attraction for their innovative performance in photographic and scientific applications. However, narrow baselines and constrained spatial resolution of current light field cameras impose restrictions on their usability. Therefore, we design a hybrid imaging system containing a light field camera and a high-resolution digital single lens reflex camera, and these two kinds of cameras share the same optical path with a beam splitter so as to achieve the reconstruction of high-resolution light fields. The high-resolution 4D light fields are reconstructed with a phase-based perspective variation strategy. First, we apply complex steerable pyramid decomposition on the high-resolution image from the digital single lens reflex camera. Then, we perform phase-based perspective-shift processing with the disparity value, which is extracted from the upsampled light field depth map, to create high-resolution synthetic light field images. High-resolution digital refocused images and high-resolution depth maps can be generated in this way. Furthermore, controlling the magnitude of the perspective shift enables us to change the depth of field rendering in the digital refocused images. We show several experimental results to demonstrate the effectiveness of our approach.

  20. Reducing dose in urography while maintaining image quality-a comparison of storage phosphor plates and a flat-panel detector.

    Science.gov (United States)

    Jansson, Margareta; Geijer, Håkan; Persliden, Jan; Andersson, Torbjörn

    2006-01-01

    The introduction of new flat-panel detector technology often forces us to accept too high dose levels as proposed by the manufacturers. We need a tool to compare the image quality of a new system with the accepted standard. The aim of this study was to obtain a comparable image quality for two systems-storage phosphor plates and a flat-panel system using intravenous urography (IVU) as a clinical model. The image quality figure was calculated using a contrast-detail phantom (CDRAD) for the two evaluated systems. This allowed us to set a dose for the flat-panel system that gave equivalent image quality to the storage phosphor plates. This reduced detector dose was used in an evaluation of clinical images to find out if the dose reduction from the phantom study indeed resulted in images of equal clinical image quality. The image quality was assessed using image criteria of the European guidelines for IVU with visual grading analysis. Equivalent image quality in image pairs was achieved at 30% of the dose. The CDRAD contrast-detail phantom makes it possible to find dose levels that give equal image quality using different imaging systems.

  1. Novel Frame Shift and Integral Technique for Enhancing Low-Light-Level Moving Images

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    A novel frame shift and integral technique for the enhancement of low light level moving image sequence is introduced. According to the technique, motion parameters of target are measured by algorithm based on difference processing. To obtain spatial relativity, images are shifted according to the motion parameters. As a result, the processing of integral and average can be applied to images that have been shifted. The technique of frame shift and integral that includes the algorithm of motion parameter determination is discussed, experiments with low light level moving image sequences are also described. The experiment results show the effectiveness and the robustness of the parameter determination algorithm, and the improvement in the signal-to-noise ratio (SNR) of low light level moving images.

  2. A Comparison of Techniques for Approximating Full Image-Based Lighting

    DEFF Research Database (Denmark)

    Madsen, Claus B.; Laursen, Rune Elmgaard

    2006-01-01

    Light probes, or environment maps, are used extensively in computer graphics for visual effects involving rendering virtual objects into real scenes (Augment Reality). A light probe is a High Dynamic Range omni-directional image covering all directions on a sphere at some location. Each pixel...

  3. Radiation monitoring using imaging plate technology: A case study of leaves affected by the Chernobyl nuclear power plant and JCO criticality accidents

    Directory of Open Access Journals (Sweden)

    Kimura Shinzo

    2006-01-01

    Full Text Available This paper describes the use of a photostimulable phosphor screen imaging technique to detect radioactive contamination in the leaves of wormwood (Artemisia vulgaris L and fern (Dryopteris filix-max CL. Schoff plants affected by the Chernobyl nuclear power plant accident. The imaging plate technology is well known for many striking performances in two-dimensional radiation detection. Since imaging plate comprises an integrated detection system, it has been extensively applied to surface contamination distribution studies. In this study, plant samples were collected from high- and low-contaminated areas of Ukraine and Belarus, which were affected due to the Chernobyl accident and exposed to imaging technique. Samples from the highly contaminated areas revealed the highest photo-stimulated luminescence on the imaging plate. Moreover, the radio nuclides detected in the leaves by gamma and beta ray spectroscopy were 137Cs and 90Sr, respectively. Additionally, in order to assess contamination, a comparison was also made with leaves of plants affected during the JCO criticality accident in Japan. Based on the results obtained, the importance of imaging plate technology in environmental radiation monitoring has been suggested.

  4. Large-area, flexible imaging arrays constructed by light-charge organic memories

    OpenAIRE

    Lei Zhang; Ti Wu; Yunlong Guo; Yan Zhao; Xiangnan Sun; Yugeng Wen; Gui Yu; Yunqi Liu

    2013-01-01

    Existing organic imaging circuits, which offer attractive benefits of light weight, low cost and flexibility, are exclusively based on phototransistor or photodiode arrays. One shortcoming of these photo-sensors is that the light signal should keep invariant throughout the whole pixel-addressing and reading process. As a feasible solution, we synthesized a new charge storage molecule and embedded it into a device, which we call light-charge organic memory (LCOM). In LCOM, the functionalities ...

  5. Analysis of phenolics in wine by high performance thin-layer chromatography with gradient elution and high resolution plate imaging.

    Science.gov (United States)

    Agatonovic-Kustrin, Snezana; Hettiarachchi, Chandima G; Morton, David W; Razic, Slavica

    2015-01-01

    Health benefits of wine, especially with red wine, have been linked to the presence of a wide range of phenolic antioxidants. Thus, the aim of this study was to develop a simple, high performance thin layer chromatographic (HPTLC) method combined with high resolution digital plate images to visually compare multiple wine samples simultaneously on a single chromatographic plate and to quantify levels of gallic acid, caffeic acid, resveratrol and rutin, as representatives of the four different classes of phenolics found in wines. We also wanted to investigate the contribution of the investigated phenolic compounds to the total polyphenolic content (TPC) and total antioxidant capacity (TAC) of the wine samples. The average concentrations of caffeic acid, gallic acid, resveratrol, and rutin in the red wines were 2.15, 30.17, 0.59 and 2.47 mg/L respectively with their concentration below limit of quantification in the white wine samples. The highest concentration of resveratrol and rutin is found in the Cabernet and Shiraz wine samples. The amounts of gallic acid are correlated with TPC (r=0.58). Italian wines have the highest correlation between TPC and TAC (r=0.99) although they do not contain detectable amounts of resveratrol, they contain significant amount of rutin. Therefore, antioxidant properties might be associated with the presence of flavanols in these wines.

  6. Cherenkov light imaging in astro-particle physics

    Science.gov (United States)

    Mirzoyan, Razmik

    2014-12-01

    Cherenkov light emission plays a key role in contemporary science; it is widely used in high energy, nuclear, and numerous astro-particle physics experiments. Most astro-particle physics experiments are based on the detection of light, and a vast majority of them on the measurement of Cherenkov light. Cherenkov light emission is measured in gases (used in air-Cherenkov technique), in water (for example, neutrino experiments BAIKAL, Super-Kamiokande, NESTOR, ANTARES, future KM3NeT; cosmic and γ-ray experiments Milagro, HAWC, AUGER) and in ice (IceCube). In this report our goal is not limited to simply listing the multitude of experiments that are based on using Cherenkov emission, but we will clarify the reasons making this emission so important and so frequently used. For completeness we will first give a short historical overview on the discovery and evolution of Cherenkov emission and then we will dwell on its main features and numerous applications in astro-particle physics experiments.

  7. Using high-power light emitting diodes for photoacoustic imaging

    DEFF Research Database (Denmark)

    Hansen, René Skov

    for the experiment consists of a 3mm high x 5mm wide slice of green colored gelatine overlaid by a 3cm layer of colorless gelatine. The light pulses from the LED is focused on the green gelatine. The photoacoustic response from the green gelatine is detected by a single transducer on the opposite (top) surface...... of the colorless gelatine layer....

  8. Images of Light - Is phasing out the solution?

    DEFF Research Database (Denmark)

    Jensen, Charlotte Louise; Remmen, Arne

    2012-01-01

    this technology in their homes. This paper will present the initial studies of how front-runners have incorporated the technology, why they have, and how/whether it has influenced their everyday life practices of which lighting engage with. The study is done through semi-structured interviews inspired by social...

  9. Degradation of some typical pharmaceuticals and personal care products with copper-plating iron doped Cu2O under visible light irradiation

    Institute of Scientific and Technical Information of China (English)

    Jing An; Qixing Zhou

    2012-01-01

    A mixture of five commonly used pharmaceuticals and personal care products (PPCPs) was degraded using a new combined catalyst under visible light irradiation.Scanning electron microscopy and X-ray diffraction analysis revealed that the combined catalyst was composed of copper-plating iron doped Cu2O (FeCu/Cu2O).Compared with the Fe/C inner micro-circuit,the electric currents flowing between Cu and Fe increase the speed of anodic Fe dissolution.Moreover,due to the photochemical properties,Cu2O can accelerate the PPCPs degradation processes under the irradiation of visible light.In addition,shaking increased the dissolved oxygen concentration in the solution,which not only preconditioned the photo-catalysis reaction,but also set the stage for Fe reduction.Aocording to the experimental results,we propose the possible reaction mechanism of the reaction.

  10. The direct measurement using an imaging plate for coincidence of radiation centre and laser position in external radiation therapy.

    Science.gov (United States)

    Terunuma, Toshiyuki; Sakae, Takeji; Nohtomi, Akihiro; Tsunashima, Yoshikazu

    2003-02-21

    A new method of quality assurance has been studied to measure coincidence of the radiation centre and a patient-setup laser position on a transverse plane to the beam at the isocentre. This measurement is achieved by using an imaging plate (IP). When radiation is applied to an IP, the energy is stored as trapped electrons. The number of electrons is decreased by local laser exposure. As a result, the radiation field produced by external beam irradiation is recorded as 'positive' information and the position of the patient-setup laser is recorded as 'negative' on an IP. The advantages of this method are the direct measurement, short time and high resolution. These are required for daily and monthly quality checks. We confirmed the advantage of this method by an experiment using a proton beam.

  11. First results of KALI-30 GW with 1 MV flash X-rays generation and characterization by Imaging plate

    Science.gov (United States)

    Sharma, A.; Shaikh, A. M.; Senthil, K.; Mitra, S.; Chandra, R.; Vishnu, S.; Sandeep, S.; Roy, A.; Rakhee, M.; Sharma, V.; Danish, M. B.; Kolge, T. S.; Ranjeet, K.; Agrawal, R.; Saroj, P. C.; Tewari, S. V.; Mittal, K. C.

    2014-07-01

    The design, development and commissioning of 1 MV pulsed electron accelerator producing Flash X-Rays is described in this paper. This pulsed power system is based on bipolar MARX generator and Blumlein followed by Explosive electron emission diode assembly. The peak pulsed power is ~ 30 GW. The electron energies in the range of 400 keV to 1030 keV are produced and delivered to experimental load of Industrial diode. Electrons are emitted from a stainless steel ring at ground potential by explosive field emission and bombard the anode tungsten pin for flash X-rays generation. The relativistic electron beam has been simulated within the diode chamber and pattern shows the beam propagation. Imaging plates are used to characterize the source size and optimization has been reported.

  12. LCD and CRT display of storage phosphor plate and limited cone beam computed tomography images for the evaluation of root canal fillings.

    Science.gov (United States)

    Baksi, B Güniz; Soğur, Elif; Gröndahl, Hans-Göran

    2009-03-01

    The aim was to compare quality of liquid crystal display (LCD) and high resolution cathode ray tube (CRT) screens for the evaluation of length and homogeneity of root canal fillings in storage phosphor plate (SPP) and limited cone beam computed tomography (LCBCT) images. Endodontic treatment was performed to 17 extracted permanent lower incisor teeth. Images of each tooth positioned in a dried mandible were obtained with Digora SPP and Accu-I-Tomo LCBCT systems. Six observers scored the quality of all images on CRT and LCD screens. Results were compared using McNemar's and Cochran's Q tests (p LCD displays (p > 0.05). Agreement among observers' scores was higher with CRT display. Within the limits of this ex vivo study, differences between LCD and CRT monitors for the evaluation of root canal fillings are clinically insignificant independent on whether conventional radiographs, captured by means of image plates, or cone beam images are being displayed.

  13. Image translational shifts in microchannel plate detectors due to the presence of MCP channel bias

    CERN Document Server

    Tremsin, A S; Siegmund, O H W

    2002-01-01

    A detailed study of possible image displacements in MCP detectors due to the presence of MCP pore bias is presented. We show that fluctuations of the rear accelerating field, characteristic to some MCP detector configurations, result in translational shifts of the entire image, which degrade the detector spatial resolution. It was experimentally observed that a 10% increase in the rear voltage of 400 V for a detector with 13 deg. -biased MCPs and 8.5 mm MCP-to-anode distance results in a 32 mu m shift of the image in the direction opposite to the pore bias. Increasing the voltage to 800 V induced a 200 mu m image displacement. No displacement was observed for a detector with a 0 deg. -biased output MCP. We also present a model for calculation of the charge footprint centroid in MCP detectors based on the output distribution function of the charge cloud. The results of our computer simulation of the image displacements prove to be in a very good agreement with the experimental data, thus providing the basis fo...

  14. Person Recognition System Based on a Combination of Body Images from Visible Light and Thermal Cameras.

    Science.gov (United States)

    Nguyen, Dat Tien; Hong, Hyung Gil; Kim, Ki Wan; Park, Kang Ryoung

    2017-03-16

    The human body contains identity information that can be used for the person recognition (verification/recognition) problem. In this paper, we propose a person recognition method using the information extracted from body images. Our research is novel in the following three ways compared to previous studies. First, we use the images of human body for recognizing individuals. To overcome the limitations of previous studies on body-based person recognition that use only visible light images for recognition, we use human body images captured by two different kinds of camera, including a visible light camera and a thermal camera. The use of two different kinds of body image helps us to reduce the effects of noise, background, and variation in the appearance of a human body. Second, we apply a state-of-the art method, called convolutional neural network (CNN) among various available methods, for image features extraction in order to overcome the limitations of traditional hand-designed image feature extraction methods. Finally, with the extracted image features from body images, the recognition task is performed by measuring the distance between the input and enrolled samples. The experimental results show that the proposed method is efficient for enhancing recognition accuracy compared to systems that use only visible light or thermal images of the human body.

  15. Multispectral endoscopy and microscopy imaging system using a spectrally programmable light engine

    Science.gov (United States)

    MacKinnon, N.; Stange, Ulrich; Lane, Pierre M.; MacAulay, Calum E.

    2005-03-01

    We report a spectrally and temporally programmable light engine based on a spatial light modulator that can dynamically create any narrow or broadband spectral profile for hyperspectral, fluorescence, or principal component imaging. Most hyperspectral or multispectral imaging systems use wavelength selection devices such as acousto-optic tunable filters (AOTFs), tunable grating or prism-based monochromators, or filter wheels. While these devices can select wavelengths they cannot create arbitrary spectral profiles. This simple and economical system can be controlled at high speed (up to 5000 illumination profiles per second). Digitally controlled illumination is bit additive with image data providing high dynamic range imaging with monochrome or color imaging devices. This is especially advantageous for endoscopes employing small well CCD or CMOS sensors since the dynamic range now can extend beyond the limits of the sensor itself. In this report we show multispectral images of in vivo tissue and in vitro tissue samples using endoscopes, surgical microscopes and conventional microscopes.

  16. Live imaging of Tribolium castaneum embryonic development using light-sheet-based fluorescence microscopy.

    Science.gov (United States)

    Strobl, Frederic; Schmitz, Alexander; Stelzer, Ernst H K

    2015-10-01

    Tribolium castaneum has become an important insect model organism for evolutionary developmental biology, genetics and biotechnology. However, few protocols for live fluorescence imaging of Tribolium have been reported, and little image data is available. Here we provide a protocol for recording the development of Tribolium embryos with light-sheet-based fluorescence microscopy. The protocol can be completed in 4-7 d and provides procedural details for: embryo collection, microscope configuration, embryo preparation and mounting, noninvasive live imaging for up to 120 h along multiple directions, retrieval of the live embryo once imaging is completed, and image data processing, for which exemplary data is provided. Stringent quality control criteria for developmental biology studies are also discussed. Light-sheet-based fluorescence microscopy complements existing toolkits used to study Tribolium development, can be adapted to other insect species, and requires no advanced imaging or sample preparation skills.

  17. Measuring urban sprawl in China by night time light images

    Science.gov (United States)

    Liu, Lu; Tang, Lin

    2017-01-01

    In the process of urbanization, a phenomenon called “urban sprawl” usually occurs. This phenomenon may exaggerated the negative effects of urbanization on environment, public and social health, energy efficiency, and maintenance of farmland. Therefore, the understanding of this phenomenon is urgently required for us to achieve sustainable development. This study proposed a group of night time lights (NTL) indicators of urban sprawl, which intend to use the distribution of lightness to quantify urban sprawl. These measures are proved to be efficient in describing urban sprawl. In addition, they are consistent and easy calculating, making comparison analysis easy to be done. These indicators are used to study urban sprawl in China during the year 2000 to 2010, the results show that in the last ten years, metropolitan areas in the northern part of China have undergone a more sprawl-like urban growth compared with other parts of China.

  18. Parametric based morphological transformation for contrast enhancement of color images in poor-lighting

    Indian Academy of Sciences (India)

    Atluri Srikrishna; M Pompapathi; G Srinivasa Rao

    2015-04-01

    The objective of contrast operators consists in normalizing the gray levels of the input image for the purpose of avoiding abrupt changes in intensity among different regions. In this paper morphological transformations are used to detect the background in color images characterized by poor lighting. The disadvantage of contrast enhancement as studied in previous contrast enhancement algorithms is over illumination. An efficient algorithm is introduced to tackle the problem of over illumination by controlling the intensities at dark and bright regions of an image and preserve the geometry of the object. Finally the performance of the proposed algorithm is illustrated through the processing of gray scale images and color images with different backgrounds.

  19. The Research of License Plate Image Preprocessing Method Base on VC++%基于VC++车牌图像预处理方法研究

    Institute of Scientific and Technical Information of China (English)

    李德峰; 丁玉飞; 邱细亚

    2011-01-01

    车牌图像识别的预处理是车牌图像识别系统的重要环节之一。该文简要地介绍车牌图像受环境因素影响所呈现的特征后,系统地阐述了车牌识别系统中图像预处理的各个步骤,包括图像的灰度化、中值滤波、灰度拉伸、sobel算子梯度锐化、二值化等。提出了一种图像预处理方案.并运用VC++编程开发的软件验证了各阶段的实验结果,证实了这种方案对图像的预处理可以达到较好的处理效果,%The license plate image preprocessing is one component of the license Plate recognition system. This paper systematically describes each step of the image preprocessing in the license plate recognition system after describing briefly the characteristics of the license plate images affected by environmental factors,including gray-scale image,median filtering,gray stretch,sobel operator image sharpening,license plate title correction and so on.Proposing an image preprocessing program and developing the Software using VC++ program,which verified the experimental results of the various stages that confirmed the image preprocessing program can achieve better processing results.

  20. Ultrahigh resolution optical coherence tomography imaging with a broadband superluminescent diode light source.

    Science.gov (United States)

    Ko, Tony; Adler, Desmond; Fujimoto, James; Mamedov, Dmitry; Prokhorov, Viatcheslav; Shidlovski, Vladimir; Yakubovich, Sergei

    2004-05-17

    Ultrahigh resolution optical coherence tomography imaging is performed with a compact broadband superluminescent diode light source. The source consists of two multiplexed broadband superluminescent diodes and has a power output of 4 mW with a spectral bandwidth of 155 nm, centered at a wavelength of 890 nm. In vivo imaging was performed with approximately 2.3 microm axial resolution in scattering tissue and approximately 3.2 microm axial resolution in the retina. These results demonstrate that it is possible to perform in vivo ultrahigh resolution optical coherence tomography imaging using a superluminescent diode light source that is inexpensive, compact, and easy to operate.

  1. Determination of Rate of Degradation of Iron Plates Due To Rust Using Image Processing -A Review

    Directory of Open Access Journals (Sweden)

    Priyanka Choudhary

    2014-03-01

    Full Text Available Abstract: most of industries and bridges around us make use of iron for manufacturing their products. On the other hand corrosion is a natural process that deteriorates the integrity of iron surface. Therefore, rusting of iron takes place. To avoid unwanted accidents in industries and bridges, it is necessary to detect rusting in earlier stage, so that it can be prevented. Digital image processing for the detection of the rusting provides fast, accurate and objectives results. In this research paper, we have done a systematic review of algorithms that help us to detect the rust area from a metal (iron.it has been found that most of researches are bring their images, processing series in usage for this purpose due to its simplicity in implementing and due to fact the images help capturing the visual inspection process easily and due to the ground teeth. The image processing techniques explored by other peoples based on in-depth analysis, we have also proposed a novel technique to overcome the limitation.

  2. Determination of Rate of Degradation of Iron Plates due to Rust using Image Processing

    Directory of Open Access Journals (Sweden)

    Priyanka Choudhary

    2015-02-01

    Full Text Available Most of industries and bridges around us make use of iron for manufacturing their products. On the other hand corrosion is a natural process that deteriorates the integrity of iron surface. Therefore, rusting of iron takes place. To avoid unwanted accidents in industries and bridges, it is necessary to detect rusting in earlier stage, so that it can be prevented. Digital image processing for the detection of the rusting provides fast, accurate and objectives results. In this research paper, we have done a systematic review of algorithms that help us to detect the rust area from a metal (iron.it has been found that most of researches are bring their images, processing series in usage for this purpose due to its simplicity in implementing and due to fact the images help capturing the visual inspection process easily and due to the ground teeth. The image processing techniques explored by other peoples based on in-depth analysis, we have also proposed a novel technique to overcome the limitation.

  3. Adaptive light-sheet microscopy for long-term, high-resolution imaging in living organisms.

    Science.gov (United States)

    Royer, Loïc A; Lemon, William C; Chhetri, Raghav K; Wan, Yinan; Coleman, Michael; Myers, Eugene W; Keller, Philipp J

    2016-12-01

    Optimal image quality in light-sheet microscopy requires a perfect overlap between the illuminating light sheet and the focal plane of the detection objective. However, mismatches between the light-sheet and detection planes are common owing to the spatiotemporally varying optical properties of living specimens. Here we present the AutoPilot framework, an automated method for spatiotemporally adaptive imaging that integrates (i) a multi-view light-sheet microscope capable of digitally translating and rotating light-sheet and detection planes in three dimensions and (ii) a computational method that continuously optimizes spatial resolution across the specimen volume in real time. We demonstrate long-term adaptive imaging of entire developing zebrafish (Danio rerio) and Drosophila melanogaster embryos and perform adaptive whole-brain functional imaging in larval zebrafish. Our method improves spatial resolution and signal strength two to five-fold, recovers cellular and sub-cellular structures in many regions that are not resolved by non-adaptive imaging, adapts to spatiotemporal dynamics of genetically encoded fluorescent markers and robustly optimizes imaging performance during large-scale morphogenetic changes in living organisms.

  4. Visible-Light Tomography Using an Optical Imaging-System

    NARCIS (Netherlands)

    Ingesson, L. C.; Koning, J. J.; Donne, A. J. H.; D.C. Schram,

    1992-01-01

    A system for tomography in the wavelength range 200-1 100 nm has been designed for the Rijnhuizen Tokamak Project (RTP). The plasma is viewed from five directions in one poloidal plane with a total of 80 detectors. An optical imaging system consisting of two spherical mirrors for each viewing direct

  5. Coherent imaging with pseudo-thermal incoherent light

    DEFF Research Database (Denmark)

    Gatti, A.; Bache, Morten; Magatti, D.

    2006-01-01

    We investigate experimentally fundamental properties of coherent ghost imaging using spatially incoherent beams generated from a pseudo-thermal source. A complementarity between the coher- ence of the beams and the correlation between them is demonstrated by showing a complementarity between ghos...

  6. Saturation and Dynamic Range of Microchannel Plate-Based X-Ray Imagers

    Energy Technology Data Exchange (ETDEWEB)

    ,

    2012-05-04

    This paper describes recent advances in Monte Carlo simulations of microchannel plate (MCP)–based x-ray detectors, a continuation of ongoing work in this area. A Monte Carlo simulation model has been developed over the past several years by National Security Technologies, LLC (NSTec). The model simulates the secondary electron emission process in an MCP pore and includes the effects of gain saturation. In this work we focus on MCP gain saturation and dynamic range. We have performed modeling and experimental characterizations of L/D = 46, 10-micron diameter, MCP-based detectors. The detectors are typically operated by applying a subnanosecond voltage pulse, which gates the detector on. Agreement between the simulations and experiment is very good for a variety of voltage pulse waveforms ranging in width from 150 to 300 ps. The results indicate that such an MCP begins to show nonlinear gain around 5 × 10^4 electrons per pore and hard saturation around 105 electrons per pore. The simulations show a difference in MCP sensitivity vs voltage for high flux of photons producing large numbers of photoelectrons on a subpicosecond timescale. Simulations and experiments both indicate an MCP dynamic range of 1 to 10,000, and the dynamic range depends on how the voltage is applied.

  7. Visible Light Image-Based Method for Sugar Content Classification of Citrus.

    Science.gov (United States)

    Wang, Xuefeng; Wu, Chunyan; Hirafuji, Masayuki

    2016-01-01

    Visible light imaging of citrus fruit from Mie Prefecture of Japan was performed to determine whether an algorithm could be developed to predict the sugar content. This nondestructive classification showed that the accurate segmentation of different images can be realized by a correlation analysis based on the threshold value of the coefficient of determination. There is an obvious correlation between the sugar content of citrus fruit and certain parameters of the color images. The selected image parameters were connected by addition algorithm. The sugar content of citrus fruit can be predicted by the dummy variable method. The results showed that the small but orange citrus fruits often have a high sugar content. The study shows that it is possible to predict the sugar content of citrus fruit and to perform a classification of the sugar content using light in the visible spectrum and without the need for an additional light source.

  8. A Novel Light Source Design for Spectral Tuning in Biomedical Imaging

    CERN Document Server

    Basu, Chandrajit; Meinhardt-Wollweber, Merve; Roth, Bernhard

    2014-01-01

    We propose a novel architecture with a remote phosphor based modular and compact light source in a non-contact dermoscope prototype for skin cancer screening. The spectrum and color temperature of the output light can easily and significantly be changed depending on spectral absorption characteristics of the tissues being imaged. The new system has several advantages compared to state-of-the-art phosphor converted ultra-bright white LEDs, used in a wide range of medical imaging devices, which have a fixed spectrum and color temperature at a given operating point. In particular, the system can more easily be adapted to the requirements originating from different tissues in the human body which have wavelength dependent absorption and reflectivity. This leads to improved contrast for different kinds of imaged tissue components. The concept of such a lighting architecture can be vastly utilized in many other medical imaging devices including endoscopic systems.

  9. High-resolution Fourier hologram synthesis from photographic images through computing the light field.

    Science.gov (United States)

    Chen, Ni; Ren, Zhenbo; Lam, Edmund Y

    2016-03-01

    We present a technique for synthesizing the Fourier hologram of a three-dimensional scene from its light field. The light field captures the volumetric information of an object, and an important advantage is that it does not require coherent illumination, as in conventional holography. In this work, we show how to obtain a high-resolution digital hologram with the light field obtained from a series of photographic images captured along the optical axis. The method is verified both by simulations and experimentally captured light field.

  10. Adaptive imaging system with spatial light modulator for robust shape measurement of partially specular objects.

    Science.gov (United States)

    Jeong, Joongki; Kim, Min Young

    2010-12-20

    In imaging systems, when specular surfaces responding sensitively to varying illumination conditions are imaged on groups of CCD pixels using imaging optics, the obtained image usually suffers from pixel saturation, resulting in smearing or blooming phenomena. These problems are then serious obstacles when applying structured light-based optical profiling methods to the shape measurement of general objects with partially specular surfaces. Therefore, this paper combines a phase-based profiling system with an with an adaptive spatial light modulator in the imaging part for measuring the three-dimensional shapes of objects with an advanced dynamic range. The use of a spatial light modulator in front of a CCD camera prevents the image sensor from being saturated, as the pixel transmittance is controlled by monitoring the input images and providing modulator feedback signals over time and space. When using the proposed system, since the projected fringes are effectively imaged on the CCD without any pixel saturation, phase information according to the object's shape can be correctly extracted from non-saturated images. The configuration of the proposed system and transmittance control scheme are explained in detail, plus the performance is verified through a series of experiments, in which phase information was successfully extracted from areas that are not normally measurable due to saturation. Based on the results, the proposed shape measurement system showed a more advanced adaptive dynamic range when compared with a conventional system.

  11. On the effect of the fiber orientation on the flexural stiffness of injection molded short fiber reinforced polycarbonate plates

    NARCIS (Netherlands)

    Neves, N.M.; Isdell, G.; Pouzada, A.S.; Powell, P.C.

    1998-01-01

    The through-thickness fiber orientation distribution of injection molded polycarbonate plates was experimentally determined by light reflection microscopy and manual digitization of polished cross sections. Fiber length distribution was determined by pyrolysis tests followed by image analysis. A sta

  12. Image quality of a novel light-emitting diode (LED)-illuminated colonoscope.

    Science.gov (United States)

    Sasaki, Sho; Nishikawa, Jun; Yanai, Hideo; Nakamura, Munetaka; Nishimura, Junichi; Goto, Atsushi; Kiyotoki, Shu; Saito, Mari; Hamabe, Kouichi; Tanabe, Ryo; Nakamura, Yohei; Tokiyama, Hiroshi; Hashimoto, Shinichi; Okamoto, Takeshi; Higaki, Shingo; Kurai, Satoshi; Ogihara, Hiroyuki; Hamamoto, Yoshihiko; Sakaida, Isao

    2016-10-01

    Light-emitting diodes (LEDs) are used widely for their high luminous efficiency and durability. We developed a novel prototype high definition endoscope with white LEDs and evaluated the image quality it produced against a commercial endoscope with conventional light source. The specifications of both colonoscopes were identical, except for the LED light source at the tip of the prototype. We examined 20 patients with rectal or sigmoid colon lesions and the image quality was evaluated in 40 images (one image from the LED colonoscope and one from the conventional colonoscope for each lesion) by three endoscopists. We additionally evaluated the 17 videos recorded with the LED colonoscope that were available. Image quality, mucosal and vascular color, and luminous distribution and intensity were scored on a 5-point scale. The mean score for vascular color given by one evaluator was significantly higher using the LED colonoscope than using the conventional colonoscope. The mean scores for mucosal color and luminous intensity from another evaluator were significantly lower with the LED colonoscope than with the conventional colonoscope. There were no significant differences in the luminous distribution scores for any of the evaluators. The image quality of the videos was evaluated as being similar with both colonoscopes. Image quality from the LED and conventional colonoscopes were similar, although the luminous intensity of the LEDs is inferior to that of the conventional light source at the present time. © Georg Thieme Verlag KG Stuttgart · New York.

  13. Enhanced light element imaging in atomic resolution scanning transmission electron microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Findlay, S.D., E-mail: scott.findlay@monash.edu [School of Physics, Monash University, Victoria 3800 (Australia); Kohno, Y. [JEOL Ltd., Tokyo 196-8558 (Japan); Cardamone, L.A. [School of Physics, Monash University, Victoria 3800 (Australia); Ikuhara, Y. [Institute of Engineering Innovation, School of Engineering, University of Tokyo, Tokyo 113-8656 (Japan); Nanostructures Research Laboratory, Japan Fine Ceramics Center, Nagoya 456-8587 (Japan); WPI Advanced Institute for Materials Research, Tohoku University, Sendai 980-8577 (Japan); Shibata, N. [Institute of Engineering Innovation, School of Engineering, University of Tokyo, Tokyo 113-8656 (Japan); PRESTO, Japan Science and Technology Agency, Saitama 332-0012 (Japan)

    2014-01-15

    We show that an imaging mode based on taking the difference between signals recorded from the bright field (forward scattering region) in atomic resolution scanning transmission electron microscopy provides an enhancement of the detectability of light elements over existing techniques. In some instances this is an enhancement of the visibility of the light element columns relative to heavy element columns. In all cases explored it is an enhancement in the signal-to-noise ratio of the image at the light column site. The image formation mechanisms are explained and the technique is compared with earlier approaches. Experimental data, supported by simulation, are presented for imaging the oxygen columns in LaAlO{sub 3}. Case studies looking at imaging hydrogen columns in YH{sub 2} and lithium columns in Al{sub 3}Li are also explored through simulation, particularly with respect to the dependence on defocus, probe-forming aperture angle and detector collection aperture angles. - Author-Highlights: • We present a method for enhancing the visibility and reliability of imaging light elements in STEM. • The method involves taking the difference between signals on separate bright field detectors. • Experimental data for LaAlO{sub 3} are presented, and are shown to compare favourably with simulation. • Optimum imaging parameters are explored through simulation.

  14. Determination of Absolute Plate Spacing for the Fabry-Perot Subassembly of the Thermosphere Imager for Global Observations Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Task 1: rad test AD7746 component for failure dosage for use in GEO Task 2: Algorithm for determining absolute plate spacing of the TIGO Fabry-Perot plates,...

  15. 基于车辆牌照图像的识别技术研究%Research on Image Recognition Technology Based on Vehicle License Plate

    Institute of Scientific and Technical Information of China (English)

    石昊苏

    2015-01-01

    This paper,the whole process of vehicle license plate image recognition is discussed in four aspects:preprocessing,vehicle license plate location,character segmentation and character recognition.Through the analysis of the part of the algorithm,the problem of image quality is solved effectively,and the related problems of batch and automatic vehicle license plate recognition are identiifed.%文章讨论了车辆牌照图像识别整个过程的四个环节:预处理、车辆牌照定位、字符分割、字符识别。通过优化改进Canny算法有效地解决了图像质量不足,批量、自动识别车辆牌照的相关问题。

  16. A study of a photoelectrooptical light modulator for image processing

    Energy Technology Data Exchange (ETDEWEB)

    Bun, A.Z.; Feldvush, V.I.; Merkin, S.U.; Mezhevenko, E.S.; Oparin, A.N.; Potaturkin, O.P.; Sherbakov, G.N.

    1982-01-01

    The operation of a photoelectrooptical spatial modulator as one element in an optoelectronic system is studied during the on-line introduction and initial processing of perceptible images. Possible contouring variations for use with this scheme are analyzed. The use of such a modulator in conjunction with a holographic intensity correlator, upon which the system is based, makes it possible to produce quasioptimal recognition algorithms. Experimental results are given.

  17. Determining 3D flow fields via multi-camera light field imaging.

    Science.gov (United States)

    Truscott, Tadd T; Belden, Jesse; Nielson, Joseph R; Daily, David J; Thomson, Scott L

    2013-03-06

    In the field of fluid mechanics, the resolution of computational schemes has outpaced experimental methods and widened the gap between predicted and observed phenomena in fluid flows. Thus, a need exists for an accessible method capable of resolving three-dimensional (3D) data sets for a range of problems. We present a novel technique for performing quantitative 3D imaging of many types of flow fields. The 3D technique enables investigation of complicated velocity fields and bubbly flows. Measurements of these types present a variety of challenges to the instrument. For instance, optically dense bubbly multiphase flows cannot be readily imaged by traditional, non-invasive flow measurement techniques due to the bubbles occluding optical access to the interior regions of the volume of interest. By using Light Field Imaging we are able to reparameterize images captured by an array of cameras to reconstruct a 3D volumetric map for every time instance, despite partial occlusions in the volume. The technique makes use of an algorithm known as synthetic aperture (SA) refocusing, whereby a 3D focal stack is generated by combining images from several cameras post-capture (1). Light Field Imaging allows for the capture of angular as well as spatial information about the light rays, and hence enables 3D scene reconstruction. Quantitative information can then be extracted from the 3D reconstructions using a variety of processing algorithms. In particular, we have developed measurement methods based on Light Field Imaging for performing 3D particle image velocimetry (PIV), extracting bubbles in a 3D field and tracking the boundary of a flickering flame. We present the fundamentals of the Light Field Imaging methodology in the context of our setup for performing 3DPIV of the airflow passing over a set of synthetic vocal folds, and show representative results from application of the technique to a bubble-entraining plunging jet.

  18. Imaging plates applied to gamma-ray image measurement%成像板伽马图像测量研究

    Institute of Scientific and Technical Information of China (English)

    付澜; 张建华; 祁建敏; 章法强; 谢红卫; 陈进川

    2012-01-01

    研究了成像板辐射图像测量的基本原理及其物理机制,并将其应用于伽马图像测量.建立了MS,SR和TR三种类型成像板数值模拟模型,分别使用MCNPX程序和基于GEANT4开发的NPE程序计算了三种成像板对不同能量伽马射线的能量沉积,计算结果表明:SR和MS成像板比TR成像板能量沉积在低能部分大3~5倍,高能部分大7~9倍.实验测量了MS成像板γ灵敏度随铜膜厚度的变化关系,测量结果与理论计算结果有较好的一致性.理论与实验结果表明:成像板伽马图像测量的空间分辨力优于50 μm.%Basic principles and physical mechanism of image measurement by using imaging plates (IPs) are studied in this paper, and fundamental problems about applications of the IPs in gamma-ray image measurement are also analyzed. Monte Carlo models of imaging plates in common use are built, involving three types of IPs, i. e. MS, SR, TR. And the energy deposition of gamma rays of different energies in the IPs are calculated through the MCNPX code and the NPE code based on a Geant4 platform. As a result, the energy deposition of SR-type and MS-type IPs is 3-5 times larger than that of TR-type IPs in the low energy part, and 7-9 times larger in the high energy part. The theoretical and experimental results of the relation between gamma-ray sensitivity of MS-type IPs and copper foil thickness agree well with each other. The spatial resolution of IPs in gamma-ray imaging is better than 50 μm.

  19. Highly stable polymer coated nano-clustered silver plates: a multimodal optical contrast agent for biomedical imaging.

    Science.gov (United States)

    Ray, Aniruddha; Mukundan, Ananya; Xie, Zhixing; Karamchand, Leshern; Wang, Xueding; Kopelman, Raoul

    2014-11-07

    Here, we present a new optical contrast agent based on silver nanoplate clusters embedded inside of a polymer nano matrix. Unlike nanosphere clusters, which have been well studied, nanoplate clusters have unique properties due to the different possible orientations of interaction between the individual plates, resulting in a significant broadening of the absorption spectra. These nanoclusters were immobilized inside of a polymer cladding so as to maintain their stability and optical properties under in vivo conditions. The polymer-coated silver nanoplate clusters show a lower toxicity compared to the uncoated nanoparticles. At high nanoparticle concentrations, cell death occurs mostly due to apoptosis. These nanoparticles were used for targeted fluorescence imaging in a rat glioma cell line by incorporating a fluorescent dye into the matrix, followed by conjugation of a tumor targeting an F3 peptide. We further used these nanoparticles as photoacoustic contrast agents in vivo to enhance the contrast of the vasculature structures in a rat ear model. We observed a contrast enhancement of over 90% following the nanoparticle injection. It is also shown that these NPs can serve as efficient contrast agents, with specific targeting abilities for broadband multimodal imaging that are usable for diagnostic applications and that extend into use as therapeutic agents as well.

  20. Application of the laser generated focused-Lamb wave for non-contact imaging of defects in plate.

    Science.gov (United States)

    Jhang, Kyung-Young; Shin, Min Jae; Lim, Byoung Ok

    2006-12-22

    The laser generation method of focused-Lamb wave is expected to have high defect-detection ability with advantages of non-contact testing. In this method, the laser beam is illuminated on the surface of the object through an arrayed-arc slit, and then the energy of the generated Lamb wave is concentrated on the focus point of arc. This focusing effect enables the concentration of higher wave intensity on the focus with better S/N ratio of signal, and has better spatial resolution compared to the conventional line arrayed method. This paper describes a 2-D imaging system using this laser generated, focused-Lamb wave combined with its detection by the air-coupled transducer. This technique is fully non-contact so it can be easily applied for the automatic inspection. The effectiveness of the proposed method was verified by experiments on a 1-mm thick aluminum plate with artificial drill-hole defect with diameters of 1mm. The 2-D image of was constructed by scanning and the result showed that the location and size of defects were clearly detected.

  1. Highly stable polymer coated nano-clustered silver plates: a multimodal optical contrast agent for biomedical imaging

    Science.gov (United States)

    Ray, Aniruddha; Mukundan, Ananya; Xie, Zhixing; Karamchand, Leshern; Wang, Xueding; Kopelman, Raoul

    2014-11-01

    Here, we present a new optical contrast agent based on silver nanoplate clusters embedded inside of a polymer nano matrix. Unlike nanosphere clusters, which have been well studied, nanoplate clusters have unique properties due to the different possible orientations of interaction between the individual plates, resulting in a significant broadening of the absorption spectra. These nanoclusters were immobilized inside of a polymer cladding so as to maintain their stability and optical properties under in vivo conditions. The polymer-coated silver nanoplate clusters show a lower toxicity compared to the uncoated nanoparticles. At high nanoparticle concentrations, cell death occurs mostly due to apoptosis. These nanoparticles were used for targeted fluorescence imaging in a rat glioma cell line by incorporating a fluorescent dye into the matrix, followed by conjugation of a tumor targeting an F3 peptide. We further used these nanoparticles as photoacoustic contrast agents in vivo to enhance the contrast of the vasculature structures in a rat ear model. We observed a contrast enhancement of over 90% following the nanoparticle injection. It is also shown that these NPs can serve as efficient contrast agents, with specific targeting abilities for broadband multimodal imaging that are usable for diagnostic applications and that extend into use as therapeutic agents as well.

  2. Image Shutters: Gated Proximity-Focused Microchannel-Plate (MCP) Wafer Tubes Versus Gated Silicon Intensified Target (SIT) Vidicons

    Science.gov (United States)

    Yates, G. J.; King, N. S. P.; Jaramillo, S. A.; Ogle, J. W.; Noel, B. W.; Thayer, N. N.

    1983-03-01

    The imaging characteristics of two fast image shutters used for recording the spatial and temporal evolution of transient optical events in the nanosecond range have been studied. Emphasis is on the comparative performances of each shutter type under similar conditions. Response data, including gating speed, gain, dynamic range, shuttering efficiency, and resolution for 18 and 25-mm-diam proximity-focused microchannel-plate (MCP) intensifiers are com-pared with similar data for a prototype electrostatically-focused 25-mm-diam gated silicon-intensified-target (SIT) vidicon currently under development for Los Alamos National Laboratory. Several key parameters critical to optical gating speed have been varied in both tube types in order to determine the optimum performance attainable from each design. These include conductive substrate material and thickness used to reduce photocathode resistivity, spacing between gating electrodes to minimize interelectrode capacitance, the use of con-ductive grids on the photocathode substrate to permit rapid propagation of the electrical gate pulse to all areas of the photocathode, and different package geometries to provide a more effective interface with external biasing and gating circuitry. For comparable spatial resolution, most 18-mm-diam MCPs require gate times > 2.5 ns while the fastest SIT has demonstrated sub-nanosecond optical gates as short as r 400 ± 50 ps for full shuttering of the 25-mm-diam input window.

  3. Real-time depth controllable integral imaging pickup and reconstruction method with a light field camera.

    Science.gov (United States)

    Jeong, Youngmo; Kim, Jonghyun; Yeom, Jiwoon; Lee, Chang-Kun; Lee, Byoungho

    2015-12-10

    In this paper, we develop a real-time depth controllable integral imaging system. With a high-frame-rate camera and a focus controllable lens, light fields from various depth ranges can be captured. According to the image plane of the light field camera, the objects in virtual and real space are recorded simultaneously. The captured light field information is converted to the elemental image in real time without pseudoscopic problems. In addition, we derive characteristics and limitations of the light field camera as a 3D broadcasting capturing device with precise geometry optics. With further analysis, the implemented system provides more accurate light fields than existing devices without depth distortion. We adapt an f-number matching method at the capture and display stage to record a more exact light field and solve depth distortion, respectively. The algorithm allows the users to adjust the pixel mapping structure of the reconstructed 3D image in real time. The proposed method presents a possibility of a handheld real-time 3D broadcasting system in a cheaper and more applicable way as compared to the previous methods.

  4. VLC-based indoor location awareness using LED light and image sensors

    Science.gov (United States)

    Lee, Seok-Ju; Yoo, Jong-Ho; Jung, Sung-Yoon

    2012-11-01

    Recently, indoor LED lighting can be considered for constructing green infra with energy saving and additionally providing LED-IT convergence services such as visible light communication (VLC) based location awareness and navigation services. For example, in case of large complex shopping mall, location awareness to navigate the destination is very important issue. However, the conventional navigation using GPS is not working indoors. Alternative location service based on WLAN has a problem that the position accuracy is low. For example, it is difficult to estimate the height exactly. If the position error of the height is greater than the height between floors, it may cause big problem. Therefore, conventional navigation is inappropriate for indoor navigation. Alternative possible solution for indoor navigation is VLC based location awareness scheme. Because indoor LED infra will be definitely equipped for providing lighting functionality, indoor LED lighting has a possibility to provide relatively high accuracy of position estimation combined with VLC technology. In this paper, we provide a new VLC based positioning system using visible LED lights and image sensors. Our system uses location of image sensor lens and location of reception plane. By using more than two image sensor, we can determine transmitter position less than 1m position error. Through simulation, we verify the validity of the proposed VLC based new positioning system using visible LED light and image sensors.

  5. Generation of keys for image optical encryption in spatially incoherent light aimed at reduction of image decryption error

    Science.gov (United States)

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

    2014-05-01

    At present time methods of optical encryption are actively developed. The majority of existing methods of optical encryption use not only light intensity distribution, easily registered with photosensors, but also its phase distribution which require application of complex holographic schemes in conjunction with spatially coherent light. This leads to complex optical schemes and low decryption quality. To eliminate these disadvantages it is possible to implement optical encryption using spatially incoherent illumination which requires registration of light intensity distribution only. However this applies new restrictions on encryption keys: Fourier spectrum amplitude distribution of encryption key should overlap Fourier spectrum amplitude distribution of image to be encrypted otherwise loss of information is unavoidable. Therefore it seems that best key should have white spectrum. On the other hand due to fact that only light intensity distribution is registered, spectra of image to be encrypted and encryption key always have peaks at zero frequency and their heights depend on corresponding total energy. Since encrypted image contains noise, ratio of its average spectrum energy to noise average energy determines signal to noise ratio of decrypted image. Therefore ratio of amplitude at zero frequency to average spectrum amplitude (RZA) of encryption key defines decrypted images quality. For generation of encryption keys with low RZA method of direct search with random trajectory (DSRT) was used. To estimate impact of key RZA on decrypted images error numerical experiments were conducted. For experiments keys with different RZA values but with same energy value were generated and used. Numerically simulated optical encryption and decryption of set of test images was conducted. Results of experiment demonstrate that application of keys with low RZA generated by DSRT method leads to up to 20% lower error in comparison to keys generated by means of uniform random

  6. Light Emission Requires Exposure to the Atmosphere in Ex Vivo Bioluminescence Imaging

    Directory of Open Access Journals (Sweden)

    Yusuke Inoue

    2006-04-01

    Full Text Available The identification of organs bearing luciferase activity by in vivo bioluminescence imaging (BLI is often difficult, and ex vivo imaging of excised organs plays a complementary role. This study investigated the importance of exposure to the atmosphere in ex vivo BLI. Mice were inoculated with murine pro-B cell line Ba/F3 transduced with firefly luciferase and p190 BCR-ABL. They were killed following in vivo BLI, and whole-body imaging was done after death and then after intraperitoneal air injection. In addition, the right knee was exposed and imaged before and after the adjacent bones were cut. Extensive light signals were seen on in vivo imaging. The luminescence disappeared after the animal was killed, and air injection restored the light emission from the abdomen only, suggesting a critical role of atmospheric oxygen in luminescence after death. Although no substantial light signal at the right knee was seen before bone cutting, light emission was evident after cutting. In conclusion, in ex vivo BLI, light emission requires exposure to the atmosphere. Bone destruction is required to demonstrate luciferase activity in the bone marrow after death.

  7. PC-based car license plate reader

    Science.gov (United States)

    Hwang, Chung-Mu; Shu, Shyh-Yeong; Chen, Wen-Yu; Chen, Yie-Wern; Wen, Kuang-Pu

    1992-11-01

    A car license plate reader (CLPR) using fuzzy inference and neural network algorithm has been developed in Industrial Technology Research Institute (ITRI) and installed in highway toll stations to identify stolen cars. It takes an average of 0.7 seconds to recognize a car license plate by using a PC with 80486-50 CPU. The recognition rate of the system is about 97%. The techniques of CLPR include vehicle sensing, image grab control, optic pre- processing, lighting, and optic character recognition (OCR). The CLPR can be used in vehicle flow statistics, the checking of stolen vehicles, automatic charging systems in parking lots or garage management, and so on.

  8. Dual encryption scheme of images using polarized light.

    Science.gov (United States)

    Alfalou, A; Brosseau, C

    2010-07-01

    We propose and analyze a dual encryption/decryption scheme, motivated by recent interest in polarization encoding. Compared to standard optical encryption methods, which are based on phase and amplitude manipulation, this encryption procedure relying on Mueller-Stokes formalism provides large flexibility in the key encryption design. The effectiveness of our algorithm is discussed, thanks to a numerical simulation of the polarization encryption/decryption procedure of a 256 gray-level image. Of additional special interest is the immunity of this encryption algorithm to brute force attacks.

  9. A Novel Approach of Low-Light Image Denoising for Face Recognition

    Directory of Open Access Journals (Sweden)

    Yimei Kang

    2014-04-01

    Full Text Available Illumination variation makes automatic face recognition a challenging task, especially in low light environments. A very simple and efficient novel low-light image denoising of low frequency noise (DeLFN is proposed. The noise frequency distribution of low-light images is presented based on massive experimental results. The low and very low frequency noise are dominant in low light conditions. DeLFN is a three-level image denoising method. The first level denoises mixed noises by histogram equalization (HE to improve overall contrast. The second level denoises low frequency noise by logarithmic transformation (LOG to enhance the image detail. The third level denoises residual very low frequency noise by high-pass filtering to recover more features of the true images. The PCA (Principal Component Analysis recognition method is applied to test recognition rate of the preprocessed face images with DeLFN. DeLFN are compared with several representative illumination preprocessing methods on the Yale Face Database B, the Extended Yale face database B, and the CMU PIE face database, respectively. DeLFN not only outperformed other algorithms in improving visual quality and face recognition rate, but also is simpler and computationally efficient for real time applications.

  10. A multi-plate velocity-map imaging design for high-resolution photoelectron spectroscopy

    Science.gov (United States)

    Kregel, Steven J.; Thurston, Glen K.; Zhou, Jia; Garand, Etienne

    2017-09-01

    A velocity map imaging (VMI) setup consisting of multiple electrodes with three adjustable voltage parameters, designed for slow electron velocity map imaging applications, is presented. The motivations for this design are discussed in terms of parameters that influence the VMI resolution and functionality. Particularly, this VMI has two tunable potentials used to adjust for optimal focus, yielding good VMI focus across a relatively large energy range. It also allows for larger interaction volumes without significant sacrifice to the resolution via a smaller electric gradient at the interaction region. All the electrodes in this VMI have the same dimensions for practicality and flexibility, allowing for relatively easy modifications to suit different experimental needs. We have coupled this VMI to a cryogenic ion trap mass spectrometer that has a flexible source design. The performance is demonstrated with the photoelectron spectra of S- and CS2 -. The latter has a long vibrational progression in the ground state, and the temperature dependence of the vibronic features is probed by changing the temperature of the ion trap.

  11. Imaging at soft X-ray wavelengths with high-gain microchannel plate detector systems

    Science.gov (United States)

    Timothy, J. Gethyn

    1986-01-01

    Multianode microchannel array (MAMA) detector systems with formats of 256 x 1024 pixels and active areas of 6 x 26 mm are now under evaluation at visible, UV and soft X-ray wavelengths. Very-large-format versions of the MAMA detectors with formats of 2048 x 2048 pixels and active areas of 52 x 52 mm are under development for use in the NASA Goddard Space Telescope Imaging Spectrograph (STIS). Open-structure versions of these detectors with Cs I photocathodes can provide a high-resolution imaging capability at EUV and soft X-ray wavelengths and can deliver a maximum count rate from each array in excess of 10 to the 6th counts/s. In addition, these detector systems have the unique capability to determine the arrival time of a detected photon to an accuracy of 100 ns or better. The construction, mode of operation, and performance characteristics of the MAMA detectors are described, and the program for the development of the very-large-format detectors is outlined.

  12. Lighting

    Data.gov (United States)

    Federal Laboratory Consortium — Lighting Systems Test Facilities aid research that improves the energy efficiency of lighting systems. • Gonio-Photometer: Measures illuminance from each portion of...

  13. Shedding light on filovirus infection with high-content imaging.

    Science.gov (United States)

    Pegoraro, Gianluca; Bavari, Sina; Panchal, Rekha G

    2012-08-01

    Microscopy has been instrumental in the discovery and characterization of microorganisms. Major advances in high-throughput fluorescence microscopy and automated, high-content image analysis tools are paving the way to the systematic and quantitative study of the molecular properties of cellular systems, both at the population and at the single-cell level. High-Content Imaging (HCI) has been used to characterize host-virus interactions in genome-wide reverse genetic screens and to identify novel cellular factors implicated in the binding, entry, replication and egress of several pathogenic viruses. Here we present an overview of the most significant applications of HCI in the context of the cell biology of filovirus infection. HCI assays have been recently implemented to quantitatively study filoviruses in cell culture, employing either infectious viruses in a BSL-4 environment or surrogate genetic systems in a BSL-2 environment. These assays are becoming instrumental for small molecule and siRNA screens aimed at the discovery of both cellular therapeutic targets and of compounds with anti-viral properties. We discuss the current practical constraints limiting the implementation of high-throughput biology in a BSL-4 environment, and propose possible solutions to safely perform high-content, high-throughput filovirus infection assays. Finally, we discuss possible novel applications of HCI in the context of filovirus research with particular emphasis on the identification of possible cellular biomarkers of virus infection.

  14. Shedding Light on Filovirus Infection with High-Content Imaging

    Directory of Open Access Journals (Sweden)

    Rekha G. Panchal

    2012-08-01

    Full Text Available Microscopy has been instrumental in the discovery and characterization of microorganisms. Major advances in high-throughput fluorescence microscopy and automated, high-content image analysis tools are paving the way to the systematic and quantitative study of the molecular properties of cellular systems, both at the population and at the single-cell level. High-Content Imaging (HCI has been used to characterize host-virus interactions in genome-wide reverse genetic screens and to identify novel cellular factors implicated in the binding, entry, replication and egress of several pathogenic viruses. Here we present an overview of the most significant applications of HCI in the context of the cell biology of filovirus infection. HCI assays have been recently implemented to quantitatively study filoviruses in cell culture, employing either infectious viruses in a BSL-4 environment or surrogate genetic systems in a BSL-2 environment. These assays are becoming instrumental for small molecule and siRNA screens aimed at the discovery of both cellular therapeutic targets and of compounds with anti-viral properties. We discuss the current practical constraints limiting the implementation of high-throughput biology in a BSL-4 environment, and propose possible solutions to safely perform high-content, high-throughput filovirus infection assays. Finally, we discuss possible novel applications of HCI in the context of filovirus research with particular emphasis on the identification of possible cellular biomarkers of virus infection.

  15. Simultaneous whole-animal 3D-imaging of neuronal activity using light field microscopy

    CERN Document Server

    Prevedel, R; Hoffmann, M; Pak, N; Wetzstein, G; Kato, S; Schrödel, T; Raskar, R; Zimmer, M; Boyden, E S; Vaziri, A

    2014-01-01

    3D functional imaging of neuronal activity in entire organisms at single cell level and physiologically relevant time scales faces major obstacles due to trade-offs between the size of the imaged volumes, and spatial and temporal resolution. Here, using light-field microscopy in combination with 3D deconvolution, we demonstrate intrinsically simultaneous volumetric functional imaging of neuronal population activity at single neuron resolution for an entire organism, the nematode Caenorhabditis elegans. The simplicity of our technique and possibility of the integration into epi-fluoresence microscopes makes it an attractive tool for high-speed volumetric calcium imaging.

  16. A novel semiconductor-based, fully incoherent amplified spontaneous emission light source for ghost imaging

    Science.gov (United States)

    Hartmann, Sébastien; Elsäßer, Wolfgang

    2017-01-01

    Initially, ghost imaging (GI) was demonstrated with entangled light from parametric down conversion. Later, classical light sources were introduced with the development of thermal light GI concepts. State-of-the-art classical GI light sources rely either on complex combinations of coherent light with spatially randomizing optical elements or on incoherent lamps with monochromating optics, however suffering strong losses of efficiency and directionality. Here, a broad-area superluminescent diode is proposed as a new light source for classical ghost imaging. The coherence behavior of this spectrally broadband emitting opto-electronic light source is investigated in detail. An interferometric two-photon detection technique is exploited in order to resolve the ultra-short correlation timescales. We thereby quantify the coherence time, the photon statistics as well as the number of spatial modes unveiling a complete incoherent light behavior. With a one-dimensional proof-of-principle GI experiment, we introduce these compact emitters to the field which could be beneficial for high-speed GI systems as well as for long range GI sensing in future applications. PMID:28150737

  17. A novel semiconductor-based, fully incoherent amplified spontaneous emission light source for ghost imaging

    Science.gov (United States)

    Hartmann, Sébastien; Elsäßer, Wolfgang

    2017-02-01

    Initially, ghost imaging (GI) was demonstrated with entangled light from parametric down conversion. Later, classical light sources were introduced with the development of thermal light GI concepts. State-of-the-art classical GI light sources rely either on complex combinations of coherent light with spatially randomizing optical elements or on incoherent lamps with monochromating optics, however suffering strong losses of efficiency and directionality. Here, a broad-area superluminescent diode is proposed as a new light source for classical ghost imaging. The coherence behavior of this spectrally broadband emitting opto-electronic light source is investigated in detail. An interferometric two-photon detection technique is exploited in order to resolve the ultra-short correlation timescales. We thereby quantify the coherence time, the photon statistics as well as the number of spatial modes unveiling a complete incoherent light behavior. With a one-dimensional proof-of-principle GI experiment, we introduce these compact emitters to the field which could be beneficial for high-speed GI systems as well as for long range GI sensing in future applications.

  18. IP(Image Plate)板的使用与保养

    Institute of Scientific and Technical Information of China (English)

    吴珊红

    2009-01-01

    计算机X线摄影(Computer Radiography CR)目前应用临床已逐渐成熟与完善。IP(Image Plate)板作为记录影像的媒介已全面取代传统屏/胶组合暗盒,成为CR成像系统的关键元件。IP性能优劣直接影响CR成像质量。因此,对IP板进行正确使用与合理保养是延长IP使用期限,保证CR图像质量及CR系统正常运转的首要条件,结合我们实际使用情况做如下探讨。

  19. Retrieval of the polarized submarine light field from above surface measurements using polarimetric imaging

    Science.gov (United States)

    Foster, Robert; McGilloway, Anna; Ottaviani, Matteo; Carrizo, Carlos; Gilerson, Alex; El-Habashi, Ahmed; Ahmed, Sam

    2016-05-01

    Knowledge of the underwater light field is fundamental to determining the health of the world's oceans and coastal regions. For decades, traditional remote sensing retrieval methods that rely solely on the spectral intensity of the water-leaving light have provided indicators of marine ecosystem health. As the demand for retrieval accuracy rises, use of the polarized nature of light as an additional remote sensing tool is becoming necessary. For two weeks in December 2015, the NOAA NPP-VIIRS Calibration/Validation cruise continuously observed the polarized radiance of the ocean and the sky using a HyperSAS-POL system. Additionally, a full Stokes imaging polarimetric camera was used to acquire images and videos of the sea surface and sky during stations at coincident angles with HyperSAS-POL. Polarized remote sensing reflectance is computed for all viewing elevations present in the polarization images, and the results are compared to vector radiative transfer calculations.

  20. Pulsed operation of high-power light emitting diodes for imaging flow velocimetry

    Science.gov (United States)

    Willert, C.; Stasicki, B.; Klinner, J.; Moessner, S.

    2010-07-01

    High-powered light emitting diodes (LED) are investigated for possible uses as light sources in flow diagnostics, in particular, as an alternative to laser-based illumination in particle imaging flow velocimetry in side-scatter imaging arrangements. Recent developments in solid state illumination resulted in mass-produced LEDs that provide average radiant power in excess of 10 W. By operating these LEDs with short duration, pulsed currents that are considerably beyond their continuous current damage threshold, light pulses can be generated that are sufficient to illuminate and image micron-sized particles in flow velocimetry. Time-resolved PIV measurements in water at a framing rate of 2kHz are presented. The feasibility of LED-based PIV measurements in air is also demonstrated.

  1. Enhanced two-photon excited fluorescence from imaging agents using true thermal light

    Science.gov (United States)

    Jechow, Andreas; Seefeldt, Michael; Kurzke, Henning; Heuer, Axel; Menzel, Ralf

    2013-12-01

    Two-photon excited fluorescence (TPEF) is a standard technique in modern microscopy, but is still affected by photodamage to the probe. It has been proposed that TPEF can be enhanced using entangled photons, but this has proven challenging. Recently, it was shown that some features of entangled photons can be mimicked with thermal light, which finds application in ghost imaging, subwavelength lithography and metrology. Here, we use true thermal light from a superluminescent diode to demonstrate TPEF that is enhanced compared to coherent light, using two common fluorophores and luminescent quantum dots, which suit applications in imaging and microscopy. We find that the TPEF rate is directly proportional to the measured degree of second-order coherence, as predicted by theory. Our results show that photon bunching in thermal light can be exploited in two-photon microscopy, with the photon statistic providing a new degree of freedom.

  2. Optimizing and extending light-sculpting microscopy for fast functional imaging in neuroscience

    CERN Document Server

    Rupprecht, Peter; Groessl, Florian; Haubensak, Wulf E; Vaziri, Alipasha

    2015-01-01

    A number of questions in systems biology such as understanding how dynamics of neuronal networks are related to brain function require the ability to capture the functional dynamics of large cellular populations at high speed. Recently, this has driven the development of a number of parallel and high speed imaging techniques such as light-sculpting microscopy, which has been used to capture neuronal dynamics at the whole brain and single cell level in small model organism. However, the broader applicability of light-sculpting microscopy is limited by the size of volumes for which high speed imaging can be obtained and scattering in brain tissue. Here, we present strategies for optimizing the present tradeoffs in light-sculpting microscopy. Various scanning modalities in light-sculpting microscopy are theoretically and experimentally evaluated, and strategies to maximize the obtainable volume speeds, and depth penetration in brain tissue using different laser systems are provided. Design-choices, important par...

  3. TECHNICAL DESIGN NOTE Multi-pass light amplification for tomographic particle image velocimetry applications

    Science.gov (United States)

    Ghaemi, Sina; Scarano, Fulvio

    2010-12-01

    The light source budget is a critical issue for tomographic particle image velocimetry (Tomo-PIV) systems due to its requirement for large illuminated volume and imaging at small apertures. In this work, a light amplification system based on the multi-pass concept is investigated for Tomo-PIV applications. The system design is performed on the basis of a theoretical model providing an estimation of the most important system parameters and above all the amplification gain. The multi-pass light amplification concept is verified experimentally by measuring the scattered light intensity across the illuminated volume. The results demonstrate a gain factor of 7 and 5 times in comparison with the single-pass and double-pass illumination approaches, respectively.

  4. Multiphoton microscopy and image guided light activated therapy using nanomaterials (Conference Presentation)

    Science.gov (United States)

    Prasad, Paras N.

    2017-02-01

    This talk will focus on design and applications of nanomaterials exhibiting strong multiphoton upconversion for multiphoton microscopy as well as for image-guided and light activated therapy .1-3 Such processes can occur by truly nonlinear optical interactions proceeding through virtual intermediate states or by stepwise coupled linear excitations through real intermediate states. Multiphoton processes in biocompatible multifunctional nanoparticles allow for 3D deep tissue imaging. In addition, they can produce in-situ photon conversion of deep tissue penetrating near IR light into a needed shorter wavelength light for photo-activated therapy at a targeted site, thus overcoming the limited penetration of UV or visible light into biological media. We are using near IR emitters such as silicon quantum dots which also exhibit strong multiphoton excitation for multiphoton microscopy. Another approach involves nonlinear nanocrystals such as ZnO which can produce four wave mixing, sum frequency generation as well as second harmonic generation to convert a deep tissue penetrating Near IR light at the targeted biological site to a desired shorter wavelength light suitable for bio imaging or activation of a therapy. We have utilized this approach to activate a photosensitizer for photodynamic therapy. Yet another type of upconversion materials is rare-earth ion doped optical nanotransformers which transform a Near IR (NIR) light from an external source by sequential single photon absorption, in situ and on demand, to a needed wavelength. Applications of these nanotransformers in multiphoton photoacoustic imaging will also be presented. An exciting direction pursued by us using these multiphoton nanoparticles, is functional imaging of brain. Simultaneously, they can effect optogenetics for regioselective stimulation of neurons for providing an effective intervention/augmentation strategy to enhance the cognitive state and lead to a foundation for futuristic vision of super

  5. Multispectral imaging of the ocular fundus using light emitting diode illumination.

    Science.gov (United States)

    Everdell, N L; Styles, I B; Calcagni, A; Gibson, J; Hebden, J; Claridge, E

    2010-09-01

    We present an imaging system based on light emitting diode (LED) illumination that produces multispectral optical images of the human ocular fundus. It uses a conventional fundus camera equipped with a high power LED light source and a highly sensitive electron-multiplying charge coupled device camera. It is able to take pictures at a series of wavelengths in rapid succession at short exposure times, thereby eliminating the image shift introduced by natural eye movements (saccades). In contrast with snapshot systems the images retain full spatial resolution. The system is not suitable for applications where the full spectral resolution is required as it uses discrete wavebands for illumination. This is not a problem in retinal imaging where the use of selected wavelengths is common. The modular nature of the light source allows new wavelengths to be introduced easily and at low cost. The use of wavelength-specific LEDs as a source is preferable to white light illumination and subsequent filtering of the remitted light as it minimizes the total light exposure of the subject. The system is controlled via a graphical user interface that enables flexible control of intensity, duration, and sequencing of sources in synchrony with the camera. Our initial experiments indicate that the system can acquire multispectral image sequences of the human retina at exposure times of 0.05 s in the range of 500-620 nm with mean signal to noise ratio of 17 dB (min 11, std 4.5), making it suitable for quantitative analysis with application to the diagnosis and screening of eye diseases such as diabetic retinopathy and age-related macular degeneration.

  6. Fast two-photon neuronal imaging and control using a spatial light modulator and ruthenium compounds

    Science.gov (United States)

    Peterka, Darcy S.; Nikolenko, Volodymyr; Fino, Elodie; Araya, Roberto; Etchenique, Roberto; Yuste, Rafael

    2010-02-01

    We have developed a spatial light modulator (SLM) based microscope that uses diffraction to shape the incoming two-photon laser source to any arbitrary light pattern. This allows the simultaneous imaging or photostimulation of different regions of a sample with three-dimensional precision at high frame rates. Additionally, we have combined this microscope with a new class of two photon active neuromodulators with Ruthenium BiPyridine (RuBi) based cages that offer great flexibility for neuronal control.

  7. Deep focus; a digital image processing technique to produce improved focal depth in light microscopy:

    OpenAIRE

    Goldsmith, Noel T.

    2000-01-01

    In light microscopy, the spatial transverse resolution is a function of the wavelength and numerical aperture. The depth resolution is another function of these parameters. The factors that enable the detection of fine detail, make the sharp focusing of more than a thin slice of the depth in an object impossible. When the examination of fracture surfaces is attempted using light reflection microscopy, the roughness will often restrict the in-focus parts of an image to a small portion of the f...

  8. ON GEOMETRIC PROCESSING OF MULTI-TEMPORAL IMAGE DATA COLLECTED BY LIGHT UAV SYSTEMS

    Directory of Open Access Journals (Sweden)

    T. Rosnell

    2012-09-01

    Full Text Available Data collection under highly variable weather and illumination conditions around the year will be necessary in many applications of UAV imaging systems. This is a new feature in rigorous photogrammetric and remote sensing processing. We studied performance of two georeferencing and point cloud generation approaches using image data sets collected in four seasons (winter, spring, summer and autumn and under different imaging conditions (sunny, cloudy, different solar elevations. We used light, quadrocopter UAVs equipped with consumer cameras. In general, matching of image blocks collected with high overlaps provided high quality point clouds. All of the before mentioned factors influenced the point cloud quality. In winter time, the point cloud generation failed on uniform snow surfaces in many situations, and during leaf-off season the point cloud generation was not successful over deciduous trees. The images collected under cloudy conditions provided better point clouds than the images collected in sunny weather in shadowed regions and of tree surfaces. On homogeneous surfaces (e.g. asphalt the images collected under sunny conditions outperformed cloudy data. The tested factors did not influence the general block adjustment results. The radiometric sensor performance (especially signal-to-noise ratio is a critical factor in all weather data collection and point cloud generation; at the moment, high quality, light weight imaging sensors are still largely missing; sensitivity to wind is another potential limitation. There lies a great potential in low flying, low cost UAVs especially in applications requiring rapid aerial imaging for frequent monitoring.

  9. Light

    DEFF Research Database (Denmark)

    Prescott, N.B.; Kristensen, Helle Halkjær; Wathes, C.M.

    2004-01-01

    This chapter presents the effect of artificial light environments (light levels, colour, photoperiod and flicker) on the welfare of broilers in terms of vision, behaviour, lameness and mortality......This chapter presents the effect of artificial light environments (light levels, colour, photoperiod and flicker) on the welfare of broilers in terms of vision, behaviour, lameness and mortality...

  10. Face relighting from a single image under arbitrary unknown lighting conditions.

    Science.gov (United States)

    Wang, Yang; Zhang, Lei; Liu, Zicheng; Hua, Gang; Wen, Zhen; Zhang, Zhengyou; Samaras, Dimitris

    2009-11-01

    In this paper, we present a new method to modify the appearance of a face image by manipulating the illumination condition, when the face geometry and albedo information is unknown. This problem is particularly difficult when there is only a single image of the subject available. Recent research demonstrates that the set of images of a convex Lambertian object obtained under a wide variety of lighting conditions can be approximated accurately by a low-dimensional linear subspace using a spherical harmonic representation. Moreover, morphable models are statistical ensembles of facial properties such as shape and texture. In this paper, we integrate spherical harmonics into the morphable model framework by proposing a 3D spherical harmonic basis morphable model (SHBMM). The proposed method can represent a face under arbitrary unknown lighting and pose simply by three low-dimensional vectors, i.e., shape parameters, spherical harmonic basis parameters, and illumination coefficients, which are called the SHBMM parameters. However, when the image was taken under an extreme lighting condition, the approximation error can be large, thus making it difficult to recover albedo information. In order to address this problem, we propose a subregion-based framework that uses a Markov random field to model the statistical distribution and spatial coherence of face texture, which makes our approach not only robust to extreme lighting conditions, but also insensitive to partial occlusions. The performance of our framework is demonstrated through various experimental results, including the improved rates for face recognition under extreme lighting conditions.

  11. Real-time intravascular ultrasound/photoacoustic imaging system with omni-directional light excitation

    Science.gov (United States)

    Hsieh, Bao-Yu; Li, Pai-Chi

    2012-02-01

    Photoacoustic (PA) imaging has been investigated for intravascular applications. One of the main challenges is that the imaging frame rate is limited by the pulse repetition frequency (PRF), thus making real-time imaging difficult with most high-power solid-state pulse lasers. The goal of this study is to combine omni-directional optical excitation with a ring array transducer for high-frame-rate imaging, so that the image frame rate is the same as the laser PRF. In the preliminary study, we developed a real-time integrated IVUS/IVPA imaging system by modifying an IVUS system in combination with a high-speed Nd:YLF pulsed laser. In addition, an optical fiber with axicon-like distal tip is designed for omni-directional excitation. In this design, a PA image is acquired without rotating the laser light. The imaging frame rate of this integrated imaging system is 19 fps. Both US and PA images are recorded at the same time and co-registered in the fusion image. The US/PA images of tungsten wire, black tube and rabbit's atherosclerotic aorta were acquired with this integrated system to evaluate its imaging performance. The lateral/axial -6 dB resolution of US image is 2.56°/62.4μm. Resolution of PA imaging is 3.76°/91.5μm. The imaging system was also utilized to acquire IVUS/IVPA images of atherosclerotic rabbit's aorta in ex vivo study.

  12. Advances in detection of diffuse seafloor venting using structured light imaging.

    Science.gov (United States)

    Smart, C.; Roman, C.; Carey, S.

    2016-12-01

    Systematic, remote detection and high resolution mapping of low temperature diffuse hydrothermal venting is inefficient and not currently tractable using traditional remotely operated vehicle (ROV) mounted sensors. Preliminary results for hydrothermal vent detection using a structured light laser sensor were presented in 2011 and published in 2013 (Smart) with continual advancements occurring in the interim. As the structured light laser passes over active venting, the projected laser line effectively blurs due to the associated turbulence and density anomalies in the vent fluid. The degree laser disturbance is captured by a camera collecting images of the laser line at 20 Hz. Advancements in the detection of the laser and fluid interaction have included extensive normalization of the collected laser data and the implementation of a support vector machine algorithm to develop a classification routine. The image data collected over a hydrothermal vent field is then labeled as seafloor, bacteria or a location of venting. The results can then be correlated with stereo images, bathymetry and backscatter data. This sensor is a component of an ROV mounted imaging suite which also includes stereo cameras and a multibeam sonar system. Originally developed for bathymetric mapping, the structured light laser sensor, and other imaging suite components, are capable of creating visual and bathymetric maps with centimeter level resolution. Surveys are completed in a standard mowing the lawn pattern completing a 30m x 30m survey with centimeter level resolution in under an hour. Resulting co-registered data includes, multibeam and structured light laser bathymetry and backscatter, stereo images and vent detection. This system allows for efficient exploration of areas with diffuse and small point source hydrothermal venting increasing the effectiveness of scientific sampling and observation. Recent vent detection results collected during the 2013-2015 E/V Nautilus seasons will be

  13. Anatomy of the Java plate interface from depth-migrated seismic images: Implications for sediment transfer

    Science.gov (United States)

    Kopp, H.; Hindle, D.; Klaeschen, D.; Oncken, O.; Reichert, C.; Scholl, D.

    2008-12-01

    We present seismic data from the western Java margin off Indonesia. The newly pre-stack depth migrated seismic images resolve the structural details of the western Java forearc and the fate of sediment subducted at the trench. Approximately 2/3 of the trench sediment fill is detached and incorporated into frontal prism imbricates, while the floor sequence is transported down a subduction channel. Basal mass transfer occurs by episodic accretion of sediment beneath the submerged forearc as the active detachment stepwise descends to a deeper level below the outer wedge. Fluctuations in subduction channel dimensions are enhanced by deep-reaching thrust faults that are traced from a velocity singularity marking the top of the oceanic basement towards the seafloor. These thrust faults breach the subduction channel and inhibit recycling of material to mantle depth, while serving as an incremental ramp along which the active detachment is transferred to a lower position. The high ratio of accreted/subducted sediment is associated with the evolution of a large bivergent wedge (>100 km) despite the comparatively low sediment input to the trench (member type of subduction zone where near-complete accretion of the trench sediment fill by frontal and basal accretion is supported by the lack of evidence for subducted sediment in the geochemical signature of Mt. Guntur and Mt. Gallunggung, two volcanoes positioned in the prolongation of our seismic line on Java.

  14. Study on the backscattered light intensity to airborne laser range-gated imaging

    Science.gov (United States)

    Wang, Ling; Yu, Lei; Kou, Tian; Wu, Xueming

    2016-10-01

    Based on the range-gated technology in the application of airborne laser detection imaging system, sequence relations of the parameters in the model of range gating in detail was analyzed. The effective scope of atmospheric backscatter and the moment before or after pulsing of the unit section was obtained. Horizontal range-gated imaging model was established and the calculation method of backscattered light intensity was given. Then slant distance detection of airborne laser active imaging was revised. By the object-image relation of points on the scattering section, the light path diagram of imaging detection system was built and the corresponding relation of light intensity between scattering points and receiving points was given. The variation regularity and distribution of light intensity on the detector under horizontal and slant detection were gained. Under the idea, the outfield testing platform was set up, and the relative error of data between measured and simulated results was controlled within 5%. The two kinds of data achieved a good coincident, which demonstrated the effectiveness of the built model. The two kinds of data achieved a good coincident, which demonstrated the effectiveness of the built model.

  15. Improved Excitation Light Rejection Enhances Small-Animal Fluorescent Optical Imaging

    Directory of Open Access Journals (Sweden)

    Kildong Hwang

    2005-07-01

    Full Text Available Small-animal fluorescence-enhanced imaging involves the detection of weak fluorescent signals emanating from nanomolar to picomolar concentrations of exogenous or endogenously produced fluorophore concurrent with the rejection of an overwhelmingly large component of backscattered excitation light. The elimination of the back-reflected excitation light of the collected signal remains a major and often unrecognized challenge for further reducing the noise floor and increasing sensitivity of small-animal fluorescence imaging. Herein, we show that the combination of three-cavity interference and holographic super notch filters with appropriate imaging lenses to collimate light improves rejection of excitation light, enabling more accurate imaging. To assess excitation leakage, the “out-of-band (S(Λx” to “in-band (S(Λm–S(Λx” signal ratio from phantom studies and the target-to-background ratio (TBR from in vivo animal imaging was acquired with and without collimating optics. The addition of collimating optics resulted in a 51% to 75% reduction in the ratio of (S(Λx/(S(Λm–S(Λx for the phantom studies and an improvement of TBR from 11% to 31% and of signal-to-noise ratio from 11% to 142% for an integrin-targeting conjugate in human glioma xenografts.

  16. High-Contrast Color-Stripe Pattern for Rapid Structured-Light Range Imaging

    CERN Document Server

    Je, Changsoo; Park, Rae-Hong

    2015-01-01

    For structured-light range imaging, color stripes can be used for increasing the number of distinguishable light patterns compared to binary BW stripes. Therefore, an appropriate use of color patterns can reduce the number of light projections and range imaging is achievable in single video frame or in "one shot". On the other hand, the reliability and range resolution attainable from color stripes is generally lower than those from multiply projected binary BW patterns since color contrast is affected by object color reflectance and ambient light. This paper presents new methods for selecting stripe colors and designing multiple-stripe patterns for "one-shot" and "two-shot" imaging. We show that maximizing color contrast between the stripes in one-shot imaging reduces the ambiguities resulting from colored object surfaces and limitations in sensor/projector resolution. Two-shot imaging adds an extra video frame and maximizes the color contrast between the first and second video frames to diminish the ambigui...

  17. Calcium imaging of neural circuits with extended depth-of-field light-sheet microscopy.

    Science.gov (United States)

    Quirin, Sean; Vladimirov, Nikita; Yang, Chao-Tsung; Peterka, Darcy S; Yuste, Rafael; Ahrens, Misha B

    2016-03-01

    Increasing the volumetric imaging speed of light-sheet microscopy will improve its ability to detect fast changes in neural activity. Here, a system is introduced for brain-wide imaging of neural activity in the larval zebrafish by coupling structured illumination with cubic phase extended depth-of-field (EDoF) pupil encoding. This microscope enables faster light-sheet imaging and facilitates arbitrary plane scanning-removing constraints on acquisition speed, alignment tolerances, and physical motion near the sample. The usefulness of this method is demonstrated by performing multi-plane calcium imaging in the fish brain with a 416×832×160  μm field of view at 33 Hz. The optomotor response behavior of the zebrafish is monitored at high speeds, and time-locked correlations of neuronal activity are resolved across its brain.

  18. In situ image segmentation using the convexity of illumination distribution of the light sources.

    Science.gov (United States)

    Zhang, Li

    2008-10-01

    When separating objects from a background in an image, we often meet difficulties in obtaining the precise output due to the unclear edges of the objects, as well as the poor or nonuniform illumination. In order to solve this problem, this paper presents an in situ segmentation method which takes advantages of the distribution feature of illumination of light sources, rather than analyzing the image pixels themselves. After analyzing the convexity of illumination distribution (CID) of point and linear light sources, the paper makes use of the CID features to find pixels belonging to the background. Then some background pixels are selected as control points to reconstruct the image background by means of B-spline; finally, by subtracting the reconstructed background from the original image, global thresholding can be employed to make the final segmentation. Quantitative evaluation experiments are made to test the performance of the method.

  19. Discovery of a new class of coronal structures in white light eclipse images

    Energy Technology Data Exchange (ETDEWEB)

    Druckmüller, Miloslav [Faculty of Mechanical Engineering, Brno University of Technology, 616 69 Brno (Czech Republic); Habbal, Shadia Rifai; Morgan, Huw, E-mail: shadia@ifa.hawaii.edu [Institute for Astronomy, University of Hawaii, 2680 Woodlawn Drive, Honolulu, HI 96822 (United States)

    2014-04-10

    White light images of the solar corona, taken during total solar eclipses, capture the complex dynamic relationship between the coronal plasma and the magnetic field. This relationship can be recorded on timescales of seconds to minutes, within a few solar radii above the solar surface. Rays, large-scale loops, and streamers, which are the brightest structures in these images, have shaped current models of the coronal magnetic field and solar wind flow. We show in this work how the application of novel image processing techniques to unique high-resolution white light eclipse images reveals the presence of a new class of structures, reminiscent of smoke rings, faint nested expanding loops, expanding bubbles, and twisted helical structures. These features are interpreted as snapshots of the dynamical evolution of instabilities developing at prominence-corona interfaces and propagating outward with the solar wind.

  20. Imaging of human differentiated 3D neural aggregates using light sheet fluorescence microscopy

    Directory of Open Access Journals (Sweden)

    Emilio J Gualda

    2014-08-01

    Full Text Available The development of three dimensional cell cultures represents a big step for the better understanding of cell behavior and disease in a more natural like environment, providing not only single but multiple cell type interactions in a complex three dimensional matrix, highly resembling physiological conditions. Light sheet fluorescence microscopy is becoming an excellent tool for fast imaging of such three-dimensional biological structures. We demonstrate the potential of this technique for the imaging of human differentiated 3D neural aggregates in fixed and live samples, namely calcium imaging and cell death processes, showing the power of imaging modality compared with traditional microscopy. The combination of light sheet microscopy and 3D neural cultures will open the door to more challenging experiments involving drug testing at large scale as well as a better understanding of relevant biological processes in a more realistic environment.

  1. Morphological background detection and illumination normalization of text image with poor lighting.

    Directory of Open Access Journals (Sweden)

    Guocheng Wang

    Full Text Available In this paper, some morphological transformations are used to detect the unevenly illuminated background of text images characterized by poor lighting, and to acquire illumination normalized result. Based on morphologic Top-Hat transform, the uneven illumination normalization algorithm has been carried out, and typically verified by three procedures. The first procedure employs the information from opening based Top-Hat operator, which is a classical method. In order to optimize and perfect the classical Top-Hat transform, the second procedure, featuring the definition of multi direction illumination notion, utilizes opening by reconstruction and closing by reconstruction based on multi direction structuring elements. Finally, multi direction images are merged to the final even illumination image. The performance of the proposed algorithm is illustrated and verified through the processing of different ideal synthetic and camera collected images, with backgrounds characterized by poor lighting conditions.

  2. Rapid imaging of mammalian brain slices with a compact light sheet fluorescent microscope

    Science.gov (United States)

    Yang, Zhengyi; Haslehurst, Peter; Scott, Suzanne; Emptage, Nigel; Dholakia, Kishan

    2017-02-01

    Light sheet fluorescent microscopy is able to provide high acquisition speed and high contrast images, as well as the low photo-bleaching and photo-damage brought to the sample. Here we describe a compact setup design optimized for applications in neuroscience, in particular fast imaging of sub-neuronal structures in mammalian brain slices. We report this prototype instrument is capable of rapid imaging wide area of the dendritic or axonal arbor of a dye-filled neuron in hippocampal slice. We also show several applications of this compact light sheet fluorescent microscope, to demonstrate that our approach offers a powerful functionality to the neuroscience community that is not achievable with traditional imaging methods.

  3. Hypomelanosis of Ito. Wood's light and magnetic resonance imaging as diagnostic measures

    Energy Technology Data Exchange (ETDEWEB)

    Ardinger, H.H.; Bell, W.E.

    1986-08-01

    Hypomelanosis of Ito is an uncommonly reported neurocutaneous syndrome with a peculiar pattern of swirling hypopigmentation. The skin markings in the lightly pigmented individual are not easily visualized in regular light but can be readily seen with the use of Wood's light. We describe a 7-month-old female infant with this disorder who presented with intractable convulsions. Computed tomography showed enlargement of the left cerebral hemisphere but was otherwise not definitive. Abnormalities of neuronal migration were demonstrated with magnetic resonance imaging that could not be shown by computed tomography.

  4. 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.

  5. Position and time resolution measurements with a microchannel plate image intensifier: A comparison of monolithic and pixelated CeBr{sub 3} scintillators

    Energy Technology Data Exchange (ETDEWEB)

    Ackermann, Ulrich, E-mail: ulrich.ackermann@unibw.de [Universität der Bundeswehr München, Institut für angewandte Physik und Messtechnik (LRT2), Werner-Heisenberg-Weg 39, 85577 Neubiberg (Germany); Eschbaumer, Stephan, E-mail: stephan.eschbaumer@unibw.de [Universität der Bundeswehr München, Institut für angewandte Physik und Messtechnik (LRT2), Werner-Heisenberg-Weg 39, 85577 Neubiberg (Germany); Bergmaier, Andreas, E-mail: andreas.bergmaier@unibw.de [Universität der Bundeswehr München, Institut für angewandte Physik und Messtechnik (LRT2), Werner-Heisenberg-Weg 39, 85577 Neubiberg (Germany); Egger, Werner, E-mail: werner.egger@unibw.de [Universität der Bundeswehr München, Institut für angewandte Physik und Messtechnik (LRT2), Werner-Heisenberg-Weg 39, 85577 Neubiberg (Germany); Sperr, Peter, E-mail: peter.sperr@unibw.de [Universität der Bundeswehr München, Institut für angewandte Physik und Messtechnik (LRT2), Werner-Heisenberg-Weg 39, 85577 Neubiberg (Germany); Greubel, Christoph, E-mail: christoph.greubel@unibw.de [Universität der Bundeswehr München, Institut für angewandte Physik und Messtechnik (LRT2), Werner-Heisenberg-Weg 39, 85577 Neubiberg (Germany); and others

    2016-07-01

    To perform Four Dimensional Age Momentum Correlation measurements in the near future, where one obtains the positron lifetime in coincidence with the three dimensional momentum of the electron annihilating with the positron, we have investigated the time and position resolution of two CeBr{sub 3} scintillators (monolithic and an array of pixels) using a Photek IPD340/Q/BI/RS microchannel plate image intensifier. The microchannel plate image intensifier has an active diameter of 40 mm and a stack of two microchannel plates in chevron configuration. The monolithic CeBr{sub 3} scintillator was cylindrically shaped with a diameter of 40 mm and a height of 5 mm. The pixelated scintillator array covered the whole active area of the microchannel plate image intensifier and the shape of each pixel was 2.5·2.5·8 mm{sup 3} with a pixel pitch of 3.3 mm. For the monolithic setup the measured mean single time resolution was 330 ps (FWHM) at a gamma energy of 511 keV. No significant dependence on the position was detected. The position resolution at the center of the monolithic scintillator was about 2.5 mm (FWHM) at a gamma energy of 662 keV. The single time resolution of the pixelated crystal setup reached 320 ps (FWHM) in the region of the center of the active area of the microchannel plate image intensifier. The position resolution was limited by the cross-section of the pixels. The gamma energy for the pixel setup measurements was 511 keV.

  6. Use of image analysis tool for the development of light distribution pattern inside the photobioreactor for the algal cultivation.

    Science.gov (United States)

    Kumar, Kanhaiya; Sirasale, Anusha; Das, Debabrata

    2013-09-01

    Light is one of the important parameters for the growth of photosynthetic microorganisms. In algal photobioreactors, pigmentation of algal cells has additional shading effect which reduces light penetration. Information on the local light intensity inside the photobioreactor is helpful for its efficient designs. Image analysis is based on trichromatic theory and it is used as a tool in studying the light distribution. Digital images of the top view of the photobioreactor were taken and processed using image processing tool in the MATLAB software. This was used to estimate the light intensity distribution in the externally radiating stirred tank photobioreactor across the radial path length. In addition, the effect of light tubes arrangement was studied. This was to find out the effect of light distribution along the periphery of culture suspension. Modified Beer-Lambert's law was found to fit the generated light intensity profile at various cell concentrations and light intensity.

  7. Polarized light imaging of birefringence and diattenuation at highresolution and high sensitivity

    CERN Document Server

    Mehta, Shalin B; Oldenbourg, Rudolf

    2013-01-01

    Polarized light microscopy provides unique opportunities for analyzing the molecular order in man-made and natural materials, including biological structures inside living cells, tissues, and whole organisms. 20 years ago, the LC-PolScope was introduced as a modern version of the traditional polarizing microscope enhanced by liquid crystal devices for the control of polarization, and by electronic imaging and digital image processing for fast and comprehensive image acquisition and analysis. The LC- PolScope is commonly used for birefringence imaging, analyzing the spatial and temporal variations of the differential phase delay in ordered and transparent materials. Here we describe an alternative use of the LC-PolScope for imaging the polarization dependent transmittance of dichroic materials. We explain the minor changes needed to convert the instrument between the two imaging modes, discuss the relationship between the quantities measured with either instrument, and touch on the physical connection between ...

  8. Polarized light imaging of birefringence and diattenuation at high resolution and high sensitivity

    Science.gov (United States)

    Mehta, Shalin B.; Shribak, Michael; Oldenbourg, Rudolf

    2013-01-01

    Polarized light microscopy provides unique opportunities for analyzing the molecular order in man-made and natural materials, including biological structures inside living cells, tissues, and whole organisms. 20 years ago, the LC-PolScope was introduced as a modern version of the traditional polarizing microscope enhanced by liquid crystal devices for the control of polarization, and by electronic imaging and digital image processing for fast and comprehensive image acquisition and analysis. The LCPolScope is commonly used for birefringence imaging, analyzing the spatial and temporal variations of the differential phase delay in ordered and transparent materials. Here we describe an alternative use of the LC-PolScope for imaging the polarization dependent transmittance of dichroic materials. We explain the minor changes needed to convert the instrument between the two imaging modes, discuss the relationship between the quantities measured with either instrument, and touch on the physical connection between refractive index, birefringence, transmittance, diattenuation, and dichroism. PMID:24273640

  9. Determination of hydrogen diffusion coefficients in F82H by hydrogen depth profiling with a tritium imaging plate technique

    Energy Technology Data Exchange (ETDEWEB)

    Higaki, M.; Otsuka, T.; Hashizume, K. [Interdisciplinary Graduate School of Engineering and Sciences, Kyushu University, Kasuga, Fukuoka (Japan); Tokunaga, K. [Research Institute of Applied Mechanics, Kyushu University, Kasuga, Fukuoka (Japan); Ezato, K.; Suzuki, S.; Enoeda, M.; Akiba, M. [Japan Atomic Energy Agency - JAEA, Naka, Ibaraki (Japan)

    2015-03-15

    Hydrogen diffusion coefficients in a reduced activation ferritic/martensitic steel (F82H) and an oxide dispersion strengthened F82H (ODS-F82H) have been determined from depth profiles of plasma-loaded hydrogen with a tritium imaging plate technique (TIPT) in the temperature range from 298 K to 523 K. Data on hydrogen diffusion coefficients, D, in F82H, are summarized as D [m{sup 2}*s{sup -1}] =1.1*10{sup -7}exp(-16[kJ mol{sup -1}]/RT). The present data indicate almost no trapping effect on hydrogen diffusion due to an excess entry of energetic hydrogen by the plasma loading, which results in saturation of the trapping sites at the surface and even in the bulk. In the case of ODS-F82H, data of hydrogen diffusion coefficients are summarized as D [m{sup 2}*s{sup -1}] =2.2*10{sup -7}exp(-30[kJ mol{sup -1}]/RT) indicating a remarkable trapping effect on hydrogen diffusion caused by tiny oxide particles (Y{sub 2}O{sub 3}) in the bulk of F82H. Such oxide particles introduced in the bulk may play an effective role not only on enhancement of mechanical strength but also on suppression of hydrogen penetration by plasma loading.

  10. Calibration of a Thomson parabola ion spectrometer and Fujifilm imaging plate detectors for protons, deuterons, and alpha particles

    Energy Technology Data Exchange (ETDEWEB)

    Freeman, C. G.; Canfield, M. J.; Graeper, G. B.; Lombardo, A. T.; Stillman, C. R.; Padalino, S. J. [Physics Department, SUNY Geneseo, Geneseo, New York 14454 (United States); Fiksel, G.; Stoeckl, C.; Mileham, C.; Sangster, T. C. [Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623 (United States); Sinenian, N.; Frenje, J. A. [Plasma Science and Fusion Center, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States)

    2011-07-15

    A Thomson parabola ion spectrometer has been designed for use at the Multiterawatt (MTW) laser facility at the Laboratory for Laser Energetics (LLE) at University of Rochester. This device uses parallel electric and magnetic fields to deflect particles of a given mass-to-charge ratio onto parabolic curves on the detector plane. Once calibrated, the position of the ions on the detector plane can be used to determine the particle energy. The position dispersion of both the electric and magnetic fields of the Thomson parabola was measured using monoenergetic proton and alpha particle beams from the SUNY Geneseo 1.7 MV tandem Pelletron accelerator. The sensitivity of Fujifilm BAS-TR imaging plates, used as a detector in the Thomson parabola, was also measured as a function of the incident particle energy over the range from 0.6 MeV to 3.4 MeV for protons and deuterons and from 0.9 MeV to 5.4 MeV for alpha particles. The device was used to measure the energy spectrum of laser-produced protons at MTW.

  11. Calibration of a Thomson parabola ion spectrometer and Fujifilm imaging plate detectors for protons, deuterons, and alpha particles.

    Science.gov (United States)

    Freeman, C G; Fiksel, G; Stoeckl, C; Sinenian, N; Canfield, M J; Graeper, G B; Lombardo, A T; Stillman, C R; Padalino, S J; Mileham, C; Sangster, T C; Frenje, J A

    2011-07-01

    A Thomson parabola ion spectrometer has been designed for use at the Multiterawatt (MTW) laser facility at the Laboratory for Laser Energetics (LLE) at the University of Rochester. This device uses parallel electric and magnetic fields to deflect particles of a given mass-to-charge ratio onto parabolic curves on the detector plane. Once calibrated, the position of the ions on the detector plane can be used to determine the particle energy. The position dispersion of both the electric and magnetic fields of the Thomson parabola was measured using monoenergetic proton and alpha particle beams from the SUNY Geneseo 1.7 MV tandem Pelletron accelerator. The sensitivity of Fujifilm BAS-TR imaging plates, used as a detector in the Thomson parabola, was also measured as a function of the incident particle energy over the range from 0.6 MeV to 3.4 MeV for protons and deuterons and from 0.9 MeV to 5.4 MeV for alpha particles. The device was used to measure the energy spectrum of laser-produced protons at MTW.

  12. Implementation of an X ray image plate camera in characterisation and crystallisation studies of iron based alloys

    CERN Document Server

    Steer, W A

    2001-01-01

    Developed in the early 1980s, versatile X-ray storage phosphor screens have opened up new possibilities in diffraction instruments for crystallography. Originally adopted by high-pressure researchers using diamond-anvil cells and very small sample volumes, flat phosphor screens give great advantage because of their high intrinsic sensitivity. But less demanding applications still stand to benefit from increased throughput and enhanced count rates made possible by this technology. With this in mind the Curved Image Plate camera, a large radius (350mm and 185mm) Debye-Scherrer instrument primarily designed for use with capillary-contained powder samples had been devised. As a substantial part of this work, new software to pre-process the data, calibration procedures and modes of operation were developed to enable the full potential of the system to be realised. One particular application of the CIP camera is the comparative study of a large number of samples, for example as a function of heat treatment. Amorpho...

  13. Three-dimensional display based on integral imaging using light shaping diffusor

    Science.gov (United States)

    Jiang, Xiaoyu; Yan, Zhiqiang; Yan, Xingpeng; Su, Jian; Gao, Hui

    2016-10-01

    Integral imaging is known as a promising 3D display method for its ability to reconstruct the light field of the scene. However, integral imaging suffers from low spatial resolution and narrow viewing angle due to the limited spatial bandwidth product of LCD, which prevents its commercial application. In conventional integral imaging display, spatial resolution and viewing angle are two vital factors that should be considered, and many previous research focuses on the two factors. A novel integral imaging 3D display system with large viewing angle about 35° and high spatial resolution for HVS is presented. The method is composed of a high definition 5K LCD panel, a macro lens array and a light shaping diffusor. One point of the method different from conventional integral imaging in which micro lens array is used, a macro lens array with elemental lens diameter 1cm is employed in our method to ensure a large viewing angle, however, this may result in low spatial resolution for HVS. And the other point is a light shaping diffusor is placed in front of the lens array with proper distance, and lifelike 3D reconstruction is obtained. Experimental results with full parallax, large viewing angle and high resolution 3D images are shown to verify the validity of the proposed system.

  14. Imaging of occlusal dental caries (decay) with near-IR light at 1310-nm

    Science.gov (United States)

    Bühler, Christopher M.; Ngaotheppitak, Patara; Fried, Daniel

    2005-01-01

    Dental enamel manifests high transparency in the near-IR. Previous work demonstrated that near-IR light at 1310-nm is ideally suited for the transillumination of interproximal dental caries (dental decay in between teeth) [1]. However, most new dental decay occurs in the pits and fissures of the occlusal (biting) surfaces of posterior teeth. These caries lesions cannot be detected by x-rays during the early stages of decay due to the overlapping topography of the crown of the tooth. In this study, a near- IR imaging system operating at 1310-nm was used to acquire occlusal images by launching the near-IR light into the buccal surface of the tooth just above the gingival margin (gum-line). The near-IR light diffuses through the highly scattering dentin providing uniform back illumination of the enamel of the crowns allowing imaging of the occlusal surfaces. The near-IR images show high contrast between sound and demineralized areas. Demineralization (decay) can be easily differentiated from stains, pigmentation, and hypomineralization (fluorosis). Moreover, the high transparency of the enamel enables imaging at greater depth for the detection of subsurface decay hidden under the enamel. These early images suggest that the near-IR offers significant advantages over conventional visual, tactile and radiographic caries detection methods.

  15. Ionic matrices pre-spotted matrix-assisted laser desorption/ionization plates for patient maker following in course of treatment, drug titration, and MALDI mass spectrometry imaging.

    Science.gov (United States)

    Bonnel, David; Franck, Julien; Mériaux, Céline; Salzet, Michel; Fournier, Isabelle

    2013-03-01

    In the current study, we compared plastic matrix-assisted laser desorption/ionization (MALDI) plates pre-spotted with different solid ionic matrices. Data reflect that after 3 months of storage, the standards were oxidized in α-cyano-4-hydroxycinnamic acid (HCCA) whether or not in HCCA/3-acetylpyridine (3APY) and HCCA/aniline, and certain peptides, such as ubiquitin, were not detected using the HCCA matrix, whereas they were detected in pre-spotted ionic matrices. Application in peptidomics of these MALDI matrices pre-spotted plates (after 3 months of storage) with ovarian cyst fluid showed less intense signals with HCCA than with solid ionic matrices. We show that these pre-spotted ionic matrices plates can be used for relative drug quantification, high mass protein detection, and MALDI mass spectrometry imaging.

  16. Bioabsorbable bone fixation plates for X-ray imaging diagnosis by a radiopaque layer of barium sulfate and poly(lactic-co-glycolic acid).

    Science.gov (United States)

    Choi, Sung Yoon; Hur, Woojune; Kim, Byeung Kyu; Shasteen, Catherine; Kim, Myung Hun; Choi, La Mee; Lee, Seung Ho; Park, Chun Gwon; Park, Min; Min, Hye Sook; Kim, Sukwha; Choi, Tae Hyun; Choy, Young Bin

    2015-04-01

    Bone fixation systems made of biodegradable polymers are radiolucent, making post-operative diagnosis with X-ray imaging a challenge. In this study, to allow X-ray visibility, we separately prepared a radiopaque layer and attached it to a bioabsorbable bone plate approved for clinical use (Inion, Finland). We employed barium sulfate as a radiopaque material due to the high X-ray attenuation coefficient of barium (2.196 cm(2) /g). The radiopaque layer was composed of a fine powder of barium sulfate bound to a biodegradable material, poly(lactic-co-glycolic acid) (PLGA), to allow layer degradation similar to the original Inion bone plate. In this study, we varied the mass ratio of barium sulfate and PLGA in the layer between 3:1 w/w and 10:1 w/w to modulate the degree and longevity of X-ray visibility. All radiopaque plates herein were visible via X-ray, both in vitro and in vivo, for up to 40 days. For all layer types, the radio-opacity decreased with time due to the swelling and degradation of PLGA, and the change in the layer shape was more apparent for layers with a higher PLGA content. The radiopaque plates released, at most, 0.5 mg of barium sulfate every 2 days in a simulated in vitro environment, which did not appear to affect the cytotoxicity. The radiopaque plates also exhibited good biocompatibility, similar to that of the Inion plate. Therefore, we concluded that the barium sulfate-based, biodegradable plate prepared in this work has the potential to be used as a fixation device with both X-ray visibility and biocompatibility.

  17. Magneto-optical color imaging of magnetic field distribution

    Directory of Open Access Journals (Sweden)

    Yosuke Nagakubo

    2017-05-01

    Full Text Available The magneto-optical (MO imaging technique allows magnetic field distributions to be observed in real-time. In this paper, we demonstrate a MO color imaging technique that allows quantitative values of magnetic fields to be determined by the naked eye. MO color imaging is realized using a MO imaging plate, which contains a bismuth-substituted iron garnet film. The imaging plate was prepared by the metal organic decomposition method, and a light source consisting of green and yellow light-emitting diodes or a white light-emitting diode. MO color imaging of the magnetic field distribution of a commercial ferrite magnet is demonstrated.

  18. High-resolution two-dimensional image upconversion of incoherent light

    DEFF Research Database (Denmark)

    Dam, Jeppe Seidelin; Pedersen, Christian; Tidemand-Lichtenberg, Peter

    2010-01-01

    We consider a technique for high-resolution image upconversion of thermal light. Experimentally, we demonstrate cw upconversion with a resolution of more than 200 × 1000 pixels of thermally illuminated objects. This is the first demonstration (to our knowledge) of high-resolution cw image...... upconversion. The upconversion method promises an alternative route to high-quantum-efficiency all-optical imaging in the mid-IR wavelength region and beyond using standard CCD cameras. A particular advantage of CCD cameras compared to state-of-the-art thermal cameras is the possibility to tailor and tune...

  19. Geometrical Reasoning in Wave Situations: The Case of Light Diffraction and Coherent Illumination Optical Imaging

    Science.gov (United States)

    Maurines, Laurence

    2010-01-01

    This particular study is part of a research programme on the difficulties encountered by students when learning about wave phenomena in a three-dimensional medium in the absence or presence of obstacles. It focuses on how students reason in situations in which wave optics need to be used: diffraction of light by an aperture, imaging in the…

  20. A light sheet confocal microscope for image cytometry with a variable linear slit detector

    Science.gov (United States)

    Hutcheson, Joshua A.; Khan, Foysal Z.; Powless, Amy J.; Benson, Devin; Hunter, Courtney; Fritsch, Ingrid; Muldoon, Timothy J.

    2016-03-01

    We present a light sheet confocal microscope (LSCM) capable of high-resolution imaging of cell suspensions in a microfluidic environment. In lieu of conventional pressure-driven flow or mechanical translation of the samples, we have employed a novel method of fluid transport, redox-magnetohydrodynamics (redox-MHD). This method achieves fluid motion by inducing a small current into the suspension in the presence of a magnetic field via electrodes patterned onto a silicon chip. This on-chip transportation requires no moving parts, and is coupled to the remainder of the imaging system. The microscopy system comprises a 450 nm diode 20 mW laser coupled to a single mode fiber and a cylindrical lens that converges the light sheet into the back aperture of a 10x, 0.3 NA objective lens in an epi-illumination configuration. The emission pathway contains a 150 mm tube lens that focuses the light onto the linear sensor at the conjugate image plane. The linear sensor (ELiiXA+ 8k/4k) has three lateral binning modes which enables variable detection aperture widths between 5, 10, or 20 μm, which can be used to vary axial resolution. We have demonstrated redox-MHD-enabled light sheet microscopy in suspension of fluorescent polystyrene beads. This approach has potential as a high-throughput image cytometer with myriad cellular diagnostic applications.

  1. A Jones matrix formalism for simulating three-dimensional polarized light imaging of brain tissue

    NARCIS (Netherlands)

    Menzel, M.; Michielsen, K.; De Raedt, H.; Reckfort, J.; Amunts, K.; Axer, M.

    2015-01-01

    The neuroimaging technique three-dimensional polarized light imaging (3D-PLI) provides a high-resolution reconstruction of nerve fibres in human post-mortem brains. The orientations of the fibres are derived from birefringence measurements of histological brain sections assuming that the nerve

  2. Live imaging of nervous system development and function using light-sheet microscopy.

    Science.gov (United States)

    Lemon, William C; Keller, Philipp J

    2015-01-01

    In vivo imaging applications typically require carefully balancing conflicting parameters. Often it is necessary to achieve high imaging speed, low photo-bleaching, and photo-toxicity, good three-dimensional resolution, high signal-to-noise ratio, and excellent physical coverage at the same time. Light-sheet microscopy provides good performance in all of these categories, and is thus emerging as a particularly powerful live imaging method for the life sciences. We see an outstanding potential for applying light-sheet microscopy to the study of development and function of the early nervous system in vertebrates and higher invertebrates. Here, we review state-of-the-art approaches to live imaging of early development, and show how the unique capabilities of light-sheet microscopy can further advance our understanding of the development and function of the nervous system. We discuss key considerations in the design of light-sheet microscopy experiments, including sample preparation and fluorescent marker strategies, and provide an outlook for future directions in the field.

  3. Near-field imaging of out-of-plane light scattering in photonic crystal slabs

    DEFF Research Database (Denmark)

    Volkov, Valentyn; Bozhevolnyi, Sergey; Taillaert, Dirk

    2003-01-01

    A collection scanning near-field optical microscope (SNOM) is used to image the propagating of light at telecommunication wavelengths (1520-1570 nm) along photonic crystal (PC) slabs, which combine slab waveguides with in-plane PCs consisting of one- and two-dimensional gratings. The efficient out...

  4. Structured light 3D depth map enhancement and gesture recognition using image content adaptive filtering

    Science.gov (United States)

    Ramachandra, Vikas; Nash, James; Atanassov, Kalin; Goma, Sergio

    2013-03-01

    A structured-light system for depth estimation is a type of 3D active sensor that consists of a structured-light projector that projects an illumination pattern on the scene (e.g. mask with vertical stripes) and a camera which captures the illuminated scene. Based on the received patterns, depths of different regions in the scene can be inferred. In this paper, we use side information in the form of image structure to enhance the depth map. This side information is obtained from the received light pattern image reflected by the scene itself. The processing steps run real time. This post-processing stage in the form of depth map enhancement can be used for better hand gesture recognition, as is illustrated in this paper.

  5. Polarized light imaging in biomedicine: emerging Mueller matrix methodologies for bulk tissue assessment.

    Science.gov (United States)

    Alali, Sanaz; Vitkin, Alex

    2015-06-01

    Polarized light point measurements and wide-field imaging have been studied for many years in an effort to develop accurate and information-rich tissue diagnostic methods. However, the extensive depolarization of polarized light in thick biological tissues has limited the success of these investigations. Recently, advances in technology and conceptual understanding have led to a significant resurgence of research activity in the promising field of bulk tissue polarimetry. In particular, with the advent of improved measurement, analysis, and interpretation methods, including Mueller matrix decomposition, new diagnostic avenues, such as quantification of microstructural anisotropy in bulk tissues, have been enabled. Further, novel technologies have improved the speed and the accuracy of polarimetric instruments for ex vivo and in vivo diagnostics. In this paper, we review some of the recent progress in tissue polarimetry, provide illustrative application examples, and offer an outlook to the future of polarized light imaging in bulk biological tissues.

  6. [Influence of human body target's spectral characteristics on visual range of low light level image intensifiers].

    Science.gov (United States)

    Zhang, Jun-Ju; Yang, Wen-Bin; Xu, Hui; Liu, Lei; Tao, Yuan-Yaun

    2013-11-01

    To study the effect of different human target's spectral reflective characteristic on low light level (LLL) image intensifier's distance, based on the spectral characteristics of the night-sky radiation and the spectral reflective coefficients of common clothes, we established a equation of human body target's spectral reflective distribution, and analyzed the spectral reflective characteristics of different human targets wearing the clothes of different color and different material, and from the actual detection equation of LLL image intensifier distance, discussed the detection capability of LLL image intensifier for different human target. The study shows that the effect of different human target's spectral reflective characteristic on LLL image intensifier distance is mainly reflected in the average reflectivity rho(-) and the initial contrast of the target and the background C0. Reflective coefficient and spectral reflection intensity of cotton clothes are higher than polyester clothes, and detection capability of LLL image intensifier is stronger for the human target wearing cotton clothes. Experimental results show that the LLL image intensifiers have longer visual ranges for targets who wear cotton clothes than targets who wear same color but polyester clothes, and have longer visual ranges for targets who wear light-colored clothes than targets who wear dark-colored clothes. And in the full moon illumination conditions, LLL image intensifiers are more sensitive to the clothes' material.

  7. Cerebral vessels segmentation for light-sheet microscopy image using convolutional neural networks

    Science.gov (United States)

    Hu, Chaoen; Hui, Hui; Wang, Shuo; Dong, Di; Liu, Xia; Yang, Xin; Tian, Jie

    2017-03-01

    Cerebral vessel segmentation is an important step in image analysis for brain function and brain disease studies. To extract all the cerebrovascular patterns, including arteries and capillaries, some filter-based methods are used to segment vessels. However, the design of accurate and robust vessel segmentation algorithms is still challenging, due to the variety and complexity of images, especially in cerebral blood vessel segmentation. In this work, we addressed a problem of automatic and robust segmentation of cerebral micro-vessels structures in cerebrovascular images acquired by light-sheet microscope for mouse. To segment micro-vessels in large-scale image data, we proposed a convolutional neural networks (CNNs) architecture trained by 1.58 million pixels with manual label. Three convolutional layers and one fully connected layer were used in the CNNs model. We extracted a patch of size 32x32 pixels in each acquired brain vessel image as training data set to feed into CNNs for classification. This network was trained to output the probability that the center pixel of input patch belongs to vessel structures. To build the CNNs architecture, a series of mouse brain vascular images acquired from a commercial light sheet fluorescence microscopy (LSFM) system were used for training the model. The experimental results demonstrated that our approach is a promising method for effectively segmenting micro-vessels structures in cerebrovascular images with vessel-dense, nonuniform gray-level and long-scale contrast regions.

  8. First Scattered-Light Image of the Debris Disk around HD 131835 with the Gemini Planet Imager

    CERN Document Server

    Hung, Li-Wei; Arriaga, Pauline; Fitzgerald, Michael P; Maire, Jérôme; Marois, Christian; Millar-Blanchaer, Maxwell A; Bruzzone, Sebastian; Rajan, Abhijith; Pueyo, Laurent; Kalas, Paul G; De Rosa, Robert J; Graham, James R; Konopacky, Quinn; Wolff, Schuyler G; Ammons, S Mark; Chen, Christine; Chilcote, Jeffrey K; Draper, Zachary H; Esposito, Thomas M; Gerard, Benjamin; Goodsell, Stephen; Greenbaum, Alexandra; Hibon, Pascale; Hinkley, Sasha; Macintosh, Bruce; Marchis, Franck; Metchev, Stanimir; Nielsen, Eric L; Oppenheimer, Rebecca; Patience, Jenny; Perrin, Marshall; Rantakyrö, Fredrik T; Sivaramakrishnan, Anand; Wang, Jason J; Ward-Duong, Kimberly; Wiktorowicz, Sloane J

    2015-01-01

    We present the first scattered-light image of the debris disk around HD 131835 in $H$ band using the Gemini Planet Imager. HD 131835 is a $\\sim$15 Myr old A2IV star at a distance of $\\sim$120 pc in the Sco-Cen OB association. We detect the disk only in polarized light and place an upper limit on the peak total intensity. No point sources resembling exoplanets were identified. Compared to its mid-infrared thermal emission, the disk in scattered light shows similar orientation but different morphology. The scattered-light disk extends from $\\sim$75 to $\\sim$210 AU in the disk plane with roughly flat surface density. Our Monte Carlo radiative transfer model can well describe the observations with a model disk composed of a mixture of silicates and amorphous carbon. In addition to the obvious brightness asymmetry due to stronger forward scattering, we discover a weak brightness asymmetry along the major axis with the northeast side being 1.3 times brighter than the southwest side at a 3-{\\sigma} level.

  9. FIRST SCATTERED-LIGHT IMAGE OF THE DEBRIS DISK AROUND HD 131835 WITH THE GEMINI PLANET IMAGER

    Energy Technology Data Exchange (ETDEWEB)

    Hung, Li-Wei; Arriaga, Pauline; Fitzgerald, Michael P.; Esposito, Thomas M. [Department of Physics and Astronomy, University of California, Los Angeles, CA 90095 (United States); Duchêne, Gaspard; Kalas, Paul G.; De Rosa, Robert J.; Graham, James R. [Astronomy Department, University of California, Berkeley CA 94720-3411 (United States); Maire, Jérôme; Chilcote, Jeffrey K. [Dunlap Institute for Astronomy and Astrophysics, University of Toronto, 50 St. George Street, Toronto, ON M5S 3H4 (Canada); Marois, Christian [National Research Council of Canada Herzberg, 5071 West Saanich Road, Victoria, BC V9E 2E7 (Canada); Millar-Blanchaer, Maxwell A. [Department of Astronomy and Astrophysics, University of Toronto, Toronto ON M5S 3H4 (Canada); Bruzzone, Sebastian [Department of Physics and Astronomy, Centre for Planetary and Space Exploration, University of Western Ontario, London, ON N6A 3K7 (Canada); Rajan, Abhijith [School of Earth and Space Exploration, Arizona State University, P.O. Box 871404, Tempe, AZ 85287 (United States); Pueyo, Laurent; Wolff, Schuyler G.; Chen, Christine H. [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Konopacky, Quinn [Center for Astrophysics and Space Sciences, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093 (United States); Ammons, S. Mark [Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, CA 94040 (United States); Draper, Zachary H. [University of Victoria, 3800 Finnerty Road, Victoria, BC V8P 5C2 (Canada); and others

    2015-12-10

    We present the first scattered-light image of the debris disk around HD 131835 in the H band using the Gemini Planet Imager. HD 131835 is a ∼15 Myr old A2IV star at a distance of ∼120 pc in the Sco-Cen OB association. We detect the disk only in polarized light and place an upper limit on the peak total intensity. No point sources resembling exoplanets were identified. Compared to its mid-infrared thermal emission,  in scattered light the disk shows similar orientation but different morphology. The scattered-light disk extends from ∼75 to ∼210 AU in the disk plane with roughly flat surface density. Our Monte Carlo radiative transfer model can describe the observations with a model disk composed of a mixture of silicates and amorphous carbon. In addition to the obvious brightness asymmetry due to stronger forward scattering, we discover a weak brightness asymmetry along the major axis, with the northeast side being 1.3 times brighter than the southwest side at a 3σ level.

  10. Soft X-ray Tomography and Cryogenic Light Microscopy: The Cool Combination in Cellular Imaging

    Science.gov (United States)

    McDermott, Gerry; Le Gros, Mark A.; Knoechel, Christian G.; Uchida, Maho; Larabell, Carolyn A.

    2012-01-01

    Soft x-ray tomography (SXT) is ideally suited to imaging sub-cellular architecture and organization, particularly in eukaryotic cells. SXT is similar in concept to the well-established medical diagnostic technique computed axial tomography (CAT), except SXT is capable of imaging with a spatial resolution of 50 nm, or better. In soft x-ray tomography (SXT) cells are imaged using photons from a region of the spectrum known as the ‘water window’. This results in quantitative, high-contrast images of intact, fully hydrated cells without the need to use contrast-enhancing agents. Cells are therefore visualized very close to their native, fully functional state. The utility of SXT has recently been enhanced by the development of high numerical aperture cryogenic light microscopy for correlated imaging. Taking this multi-modal approach now allows labeled molecules to be localized in the context of a high-resolution 3-dimensional tomographic reconstruction of the cell. PMID:19818625

  11. Active imaging systems to see through adverse conditions: Light-scattering based models and experimental validation

    Science.gov (United States)

    Riviere, Nicolas; Ceolato, Romain; Hespel, Laurent

    2014-10-01

    Onera, the French aerospace lab, develops and models active imaging systems to understand the relevant physical phenomena affecting these systems performance. As a consequence, efforts have been done on the propagation of a pulse through the atmosphere and on target geometries and surface properties. These imaging systems must operate at night in all ambient illumination and weather conditions in order to perform strategic surveillance for various worldwide operations. We have implemented codes for 2D and 3D laser imaging systems. As we aim to image a scene in the presence of rain, snow, fog or haze, we introduce such light-scattering effects in our numerical models and compare simulated images with measurements provided by commercial laser scanners.

  12. Fast compressive measurements acquisition using optimized binary sensing matrices for low-light-level imaging.

    Science.gov (United States)

    Ke, Jun; Lam, Edmund Y

    2016-05-02

    Compressive measurements benefit low-light-level imaging (L3-imaging) due to the significantly improved measurement signal-to-noise ratio (SNR). However, as with other compressive imaging (CI) systems, compressive L3-imaging is slow. To accelerate the data acquisition, we develop an algorithm to compute the optimal binary sensing matrix that can minimize the image reconstruction error. First, we make use of the measurement SNR and the reconstruction mean square error (MSE) to define the optimal gray-value sensing matrix. Then, we construct an equality-constrained optimization problem to solve for a binary sensing matrix. From several experimental results, we show that the latter delivers a similar reconstruction performance as the former, while having a smaller dynamic range requirement to system sensors.

  13. Depth resolved hyperspectral imaging spectrometer based on structured light illumination and Fourier transform interferometry.

    Science.gov (United States)

    Choi, Heejin; Wadduwage, Dushan; Matsudaira, Paul T; So, Peter T C

    2014-10-01

    A depth resolved hyperspectral imaging spectrometer can provide depth resolved imaging both in the spatial and the spectral domain. Images acquired through a standard imaging Fourier transform spectrometer do not have the depth-resolution. By post processing the spectral cubes (x, y, λ) obtained through a Sagnac interferometer under uniform illumination and structured illumination, spectrally resolved images with depth resolution can be recovered using structured light illumination algorithms such as the HiLo method. The proposed scheme is validated with in vitro specimens including fluorescent solution and fluorescent beads with known spectra. The system is further demonstrated in quantifying spectra from 3D resolved features in biological specimens. The system has demonstrated depth resolution of 1.8 μm and spectral resolution of 7 nm respectively.

  14. An assessment of high-power light-emitting diodes for high frame rate schlieren imaging

    Science.gov (United States)

    Willert, Christian E.; Mitchell, Daniel M.; Soria, Julio

    2012-08-01

    The feasibility of using high-power light-emitting diodes (LED) as a light source for high frame rate schlieren imaging is investigated. Continuous sequences of high-intensity light pulses are achieved by overdriving the LED with current pulses up to a factor of ten beyond its specifications. In comparison to commonly used pulsed light sources such as gas discharge lamps and pulsed lasers, the pulsed LED has several attractive advantages: the pulse-to-pulse intensity variation is on the same order of magnitude as the detector (camera) noise permitting quantitative intensity measurements. The LED's narrow emission bandwidth reduces chromatic abberations, yet it is spectrally wide enough to prevent the appearance of speckle and diffraction effects in the images. Most importantly, the essentially lag-free light emission within tens of nanoseconds of the applied current pulse allows the LED to be operated at varying frequencies (i.e., asynchronously), which generally is not possible with neither lasers nor discharge lamps. The pulsed LED source, driven by a simple driver circuit, is demonstrated on two schlieren imaging setups. The first configuration visualizes the temporal evolution of shock structures and sound waves of an under-expanded jet that is impinging on a rigid surface at frame rates of 500 kHz to 1 MHz. In a second application, long sequences of several thousand high-resolution images are acquired on a free jet at a frame rate of 1 kHz. The low-intensity fluctuation and large sample number allow a reliable computation of two-point correlation data from the image sequences.

  15. Single particle imaging with soft x-rays at the Linac Coherent Light Source

    Science.gov (United States)

    Martin, Andrew V.; Andreasson, Jakob; Aquila, Andrew; Bajt, Saša; Barends, Thomas R. M.; Barthelmess, Miriam; Barty, Anton; Benner, W. Henry; Bostedt, Christoph; Bozek, John D.; Bucksbaum, Phillip; Caleman, Carl; Coppola, Nicola; DePonte, Daniel P.; Ekeberg, Tomas; Epp, Sascha W.; Erk, Benjamin; Farquar, George R.; Fleckenstein, Holger; Foucar, Lutz; Frank, Matthias; Gumprecht, Lars; Hampton, Christina Y.; Hantke, Max; Hartmann, Andreas; Hartmann, Elisabeth; Hartmann, Robert; Hau-Riege, Stephan P.; Hauser, Günther; Holl, Peter; Hoemke, André; Jönsson, Olof; Kassemeyer, Stephan; Kimmel, Nils; Kiskinova, Maya; Krasniqi, Faton; Krzywinski, Jacek; Liang, Mengning; Loh, Ne-Te Duane; Lomb, Lukas; Maia, Filipe R. N. C.; Marchesini, Stefano; Messerschmidt, Marc; Nass, Karol; Odic, Duško; Pedersoli, Emanuele; Reich, Christian; Rolles, Daniel; Rudek, Benedikt; Rudenko, Artem; Schmidt, Carlo; Schultz, Joachim; Seibert, M. Marvin; Shoeman, Robert L.; Sierra, Raymond G.; Soltau, Heike; Starodub, Dmitri; Steinbrener, Jan; Stellato, Francesco; Strüder, Lothar; Svenda, Martin; Tobias, Herbert; Ullrich, Joachim; Weidenspointner, Georg; Westphal, Daniel; White, Thomas A.; Williams, Garth; Hajdu, Janos; Schlichting, Ilme; Bogan, Michael J.; Chapman, Henry N.

    2011-06-01

    Results of coherent diffractive imaging experiments performed with soft X-rays (1-2 keV) at the Linac Coherent Light Source are presented. Both organic and inorganic nano-sized objects were injected into the XFEL beam as an aerosol focused with an aerodynamic lens. The high intensity and femtosecond duration of X-ray pulses produced by the Linac Coherent Light Source allow structural information to be recorded by X-ray diffraction before the particle is destroyed. Images were formed by using iterative methods to phase single shot diffraction patterns. Strategies for improving the reconstruction methods have been developed. This technique opens up exciting opportunities for biological imaging, allowing structure determination without freezing, staining or crystallization.

  16. Zodiacal light dynamics experiment: A wideband imaging Fabry-Perot interferometer

    Science.gov (United States)

    Torr, D. G.; Young, E.; Torr, M. R.; Nagy, A. F.

    1978-01-01

    The Solar Probe will provide an ideal platform from which to study dynamics of dust particles near the sun by measuring the detailed character of the Fraunhofer structure of the zodiacal light. The suggested instrument is a wideband imaging Fabry-Perot interferometer with state of the art technology in both the optics and the detector. The instrument would function as a high-resolution imaging device providing wavelength resolution of 0.03 A over about a 20 A range. The wideband imaging capability would provide sky maps of the zodiacal light on a despun spacecraft without mechanical scanning. The Solar Probe mission would allow the velocity distribution of the dust to be mapped along most of the trajectory of the spacecraft.

  17. Optical coherence tomography imaging of telangiectasias during intense pulsed light treatment

    DEFF Research Database (Denmark)

    Ring, Hans Christian; Mogensen, Mette; Banzhaf, Christina

    2013-01-01

    Vascular malformations commonly occur in the facial region, and can be associated with significant stigma and embarrassment. Studies have shown that even recommended light-based treatments do not always result in complete clearance. This indicates the need for more accurate pre-treatment assessment...... and minutes after IPL treatment. OCT images of the telangiectasias before treatment were displayed as hyporeflective/signal poor bands clearly demarcated from the surrounding tissue. Minutes after treatment, OCT images demonstrated two different reactions. (1) Narrow hyperreflective bands surrounding...... the vessels, which may indicate edema or insufficient coagulation. (2) Hyperreflective signals within the lumen of the vessels, compatible with the expected irreversible microthrombus formation in the vessels. OCT imaging is capable of real-time assessment of tissue damage during light and laser treatment...

  18. Supplemental Blue LED Lighting Array to Improve the Signal Quality in Hyperspectral Imaging of Plants

    Directory of Open Access Journals (Sweden)

    Anne-Katrin Mahlein

    2015-06-01

    Full Text Available Hyperspectral imaging systems used in plant science or agriculture often have suboptimal signal-to-noise ratio in the blue region (400–500 nm of the electromagnetic spectrum. Typically there are two principal reasons for this effect, the low sensitivity of the imaging sensor and the low amount of light available from the illuminating source. In plant science, the blue region contains relevant information about the physiology and the health status of a plant. We report on the improvement in sensitivity of a hyperspectral imaging system in the blue region of the spectrum by using supplemental illumination provided by an array of high brightness light emitting diodes (LEDs with an emission peak at 470 nm.

  19. Image encryption using polarized light encoding and amplitude and phase truncation in the Fresnel domain.

    Science.gov (United States)

    Rajput, Sudheesh K; Nishchal, Naveen K

    2013-06-20

    In this paper, an image encryption scheme based on polarized light encoding and a phase-truncation approach in the Fresnel transform domain is proposed. The phase-truncated data obtained by an asymmetric cryptosystem is encrypted and decrypted by using the concept of the Stokes-Mueller formalism. Image encryption based on polarization of light using Stokes-Mueller formalism has the main advantage over Jones vector formalism that it manipulates only intensity information, which is measurable. Thus any intensity information can be encrypted and decrypted using this scheme. The proposed method offers several advantages: (1) a lens-free setup, (2) flexibility in the encryption key design, (3) use of asymmetric keys, and (4) immunity against special attack. We present numerical simulation results for gray-scale and color images in support of the proposed security scheme. The performance measurement parameters relative error and correlation coefficient have been calculated to check the effectiveness of the scheme.

  20. The reduction of the National Aeronautics and Space Administration plates at the New Mexico University

    Science.gov (United States)

    Haas, W. H.

    1971-01-01

    A method of reducing GEOS satellite plates is described. The catalog positions of stars, whose images were measured, are updated to the time of the photographic observation. The plate constants are used to compute the positions of the seven (or fewer) flashing light images which were measured. There are corrected for refraction, parallax, and radial and decentering lens distortions. With sidereally tracking cameras, the exterior orientation is further corrected to the time of the particular flash, and the change of refraction with time is allowed for. First and second differences and standard deviations and covariances for the flashing light images are developed as a measure of accuracy.